Science.gov

Sample records for growth biomass allocation

  1. Effects of carbofuran on growth, biomass allocation, and intraspecific competition in Bouteloua gracilis.

    PubMed

    Ingham, R E; Detling, J K

    1982-01-01

    Growth, biomass allocation and competition between blue grama plants were examined with and without application of carbofuran, a pesticide which has been used to study insect and nematode effects on primary production. Carbofuran had no apparent effect on total plant growth, biomass allocation, or competition between neighboring plants.

  2. Biomass allocation and long-term growth patterns of temperate lianas in comparison with trees.

    PubMed

    Ichihashi, Ryuji; Tateno, Masaki

    2015-08-01

    The host-dependent support habit of lianas is generally interpreted as a strategy designed to reduce resource investment in mechanical tissues; this allows preferential allocation to leaf and stem extension, thereby enhancing productivity and competitive abilities. However, this hypothesis has not been rigorously tested. We examined the aboveground allometries regarding biomass allocation (leaf mass and current-year stem mass (approximated as biomass allocated to extension growth) vs total aboveground mass) and long-term apparent growth patterns (height and aboveground mass vs age, i.e. numbers of growth rings) for nine deciduous liana species in Japan. Lianas had, on average, three- and five-fold greater leaf and current-year stem mass, respectively, than trees for a given aboveground mass, whereas the time course to reach the forest canopy was comparable and biomass accumulation during that period was only one-tenth that of co-occurring canopy trees. The balance between the lengths of yearly stem extension and existing older stems indicated that lianas lost c. 75% of stem length during growth to the canopy, which is probably a consequence of the host-dependent growth. Our observations suggest that, although lianas rely on hosts mechanically, allowing for short-term vigorous growth, this habit requires a large cost and could limit plant growth over protracted periods.

  3. Sapling biomass allocation and growth in the understory of a deciduous hardwood forest.

    PubMed

    Delucia, E; Sipe, T; Herrick, J; Maherali, H

    1998-07-01

    Above- and belowground tissues of co-occurring saplings (0.1-1 m height) of Acer saccharum Marsh. (very shade tolerant), Acer rubrum L. (shade tolerant), Fraxinus americana L. (intermediate shade tolerant), and Prunus serotina Ehrh. (shade intolerant) were harvested from a forest understory to test the hypothesis that the pattern of biomass allocation varied predictably with shade-tolerance rank. The placement and length of branches along the main axis were consistent with the formation of a monolayer of foliage for the tolerant and intermediate species. Other morphological characteristics did not vary predictably with shade-tolerance rank. The maintenance of high specific leaf area (SLA; leaf area/leaf mass) and leaf area ratio (LAR; leaf area/sapling mass) is considered important for growth under extreme shade, yet these traits were not clearly related to the shade-tolerance rank of these species. Fraxinus americana, an intermediate species, had the highest LAR and growth rate in the understory, and with the exception of P. serotina, the very shade-tolerant A. saccharum had the lowest LAR. Prunus serotina maintained a large starch-rich tap root and shoot dieback was common, yielding the largest root/shoot ratio for these species. The observed allocation patterns were not similar to the long-standing expectation for the phenotypic response of juvenile trees to shade, but were consistent with three hypothetical "growth strategies" in the understory: (1) the low SLA and LAR of A. saccharum may provide a measure of defense against herbivores and pathogens and thus promote persistence in the understory, (2) the high SLA for F. americana and high LAR for F. americana and A. rubrum may enable these species to achieve high growth rates in shade, and (3) the large carbohydrate stores of P. serotina may poise this species for opportunistic growth following disturbance. The relative importance of resistance to herbivores and pathogens vs. the maintenance of high growth

  4. Sapling biomass allocation and growth in the understory of a deciduous hardwood forest.

    PubMed

    Delucia, E; Sipe, T; Herrick, J; Maherali, H

    1998-07-01

    Above- and belowground tissues of co-occurring saplings (0.1-1 m height) of Acer saccharum Marsh. (very shade tolerant), Acer rubrum L. (shade tolerant), Fraxinus americana L. (intermediate shade tolerant), and Prunus serotina Ehrh. (shade intolerant) were harvested from a forest understory to test the hypothesis that the pattern of biomass allocation varied predictably with shade-tolerance rank. The placement and length of branches along the main axis were consistent with the formation of a monolayer of foliage for the tolerant and intermediate species. Other morphological characteristics did not vary predictably with shade-tolerance rank. The maintenance of high specific leaf area (SLA; leaf area/leaf mass) and leaf area ratio (LAR; leaf area/sapling mass) is considered important for growth under extreme shade, yet these traits were not clearly related to the shade-tolerance rank of these species. Fraxinus americana, an intermediate species, had the highest LAR and growth rate in the understory, and with the exception of P. serotina, the very shade-tolerant A. saccharum had the lowest LAR. Prunus serotina maintained a large starch-rich tap root and shoot dieback was common, yielding the largest root/shoot ratio for these species. The observed allocation patterns were not similar to the long-standing expectation for the phenotypic response of juvenile trees to shade, but were consistent with three hypothetical "growth strategies" in the understory: (1) the low SLA and LAR of A. saccharum may provide a measure of defense against herbivores and pathogens and thus promote persistence in the understory, (2) the high SLA for F. americana and high LAR for F. americana and A. rubrum may enable these species to achieve high growth rates in shade, and (3) the large carbohydrate stores of P. serotina may poise this species for opportunistic growth following disturbance. The relative importance of resistance to herbivores and pathogens vs. the maintenance of high growth

  5. Seedling growth and biomass allocation in relation to leaf habit and shade tolerance among 10 temperate tree species.

    PubMed

    Modrzyński, Jerzy; Chmura, Daniel J; Tjoelker, Mark G

    2015-08-01

    Initial growth of germinated seeds is an important life history stage, critical for establishment and succession in forests. Important questions remain regarding the differences among species in early growth potential arising from shade tolerance. In addition, the role of leaf habit in shaping relationships underlying shade tolerance-related differences in seedling growth remains unresolved. In this study we examined variation in morphological and physiological traits among seedlings of 10 forest tree species of the European temperate zone varying in shade tolerance and leaf habit (broadleaved winter-deciduous species vs needle-leaved conifers) during a 10-week period. Seeds were germinated and grown in a controlled environment simulating an intermediate forest understory light environment to resolve species differences in initial growth and biomass allocation. In the high-resource experimental conditions during the study, seedlings increased biomass allocation to roots at the cost of leaf biomass independent of shade tolerance and leaf habit. Strong correlations between relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA) and leaf mass fraction (LMF) indicate that physiology and biomass allocation were equally important determinants of RGR as plant structure and leaf morphology among these species. Our findings highlight the importance of seed mass- and seed size-related root morphology (specific root length-SRL) for shade tolerance during early ontogeny. Leaf and plant morphology (SLA, LAR) were more successful in explaining variation among species due to leaf habit than shade tolerance. In both broadleaves and conifers, shade-tolerant species had lower SRL and greater allocation of biomass to stems (stem mass fraction). Light-seeded shade-intolerant species with greater SRL had greater RGR in both leaf habit groups. However, the greatest plant mass was accumulated in the group of heavy-seeded shade

  6. Seedling growth and biomass allocation in relation to leaf habit and shade tolerance among 10 temperate tree species.

    PubMed

    Modrzyński, Jerzy; Chmura, Daniel J; Tjoelker, Mark G

    2015-08-01

    Initial growth of germinated seeds is an important life history stage, critical for establishment and succession in forests. Important questions remain regarding the differences among species in early growth potential arising from shade tolerance. In addition, the role of leaf habit in shaping relationships underlying shade tolerance-related differences in seedling growth remains unresolved. In this study we examined variation in morphological and physiological traits among seedlings of 10 forest tree species of the European temperate zone varying in shade tolerance and leaf habit (broadleaved winter-deciduous species vs needle-leaved conifers) during a 10-week period. Seeds were germinated and grown in a controlled environment simulating an intermediate forest understory light environment to resolve species differences in initial growth and biomass allocation. In the high-resource experimental conditions during the study, seedlings increased biomass allocation to roots at the cost of leaf biomass independent of shade tolerance and leaf habit. Strong correlations between relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA) and leaf mass fraction (LMF) indicate that physiology and biomass allocation were equally important determinants of RGR as plant structure and leaf morphology among these species. Our findings highlight the importance of seed mass- and seed size-related root morphology (specific root length-SRL) for shade tolerance during early ontogeny. Leaf and plant morphology (SLA, LAR) were more successful in explaining variation among species due to leaf habit than shade tolerance. In both broadleaves and conifers, shade-tolerant species had lower SRL and greater allocation of biomass to stems (stem mass fraction). Light-seeded shade-intolerant species with greater SRL had greater RGR in both leaf habit groups. However, the greatest plant mass was accumulated in the group of heavy-seeded shade

  7. Relative importance of photosynthetic physiology and biomass allocation for tree seedling growth across a broad light gradient.

    PubMed

    Montgomery, Rebecca

    2004-02-01

    Studies of tree seedling physiology and growth under field conditions provide information on the mechanisms underlying inter- and intraspecific differences in growth and survival at a critical period during forest regeneration. I compared photosynthetic physiology, growth and biomass allocation in seedlings of three shade-tolerant tree species, Virola koschynii Warb., Dipteryx panamensis (Pittier) Record & Mell and Brosimum alicastrum Swartz., growing across a light gradient created by a forest-pasture edge (0.5 to 67% diffuse transmittance (%T)). Most growth and physiological traits showed nonlinear responses to light availability, with the greatest changes occurring between 0.5 and 20 %T. Specific leaf area (SLA) and nitrogen per unit leaf mass (N mass) decreased, maximum assimilation per unit leaf area (A area) and area-based leaf N concentration (N area) increased, and maximum assimilation per unit leaf mass (A mass) did not change with increasing irradiance. Plastic responses in SLA were important determinants of leaf N and A area across the gradient. Species differed in magnitude and plasticity of growth; B. alicastrum had the lowest relative growth rates (RGR) and low plasticity. Its final biomass varied only 10-fold across the light gradient. In contrast, the final biomass of D. panamensis and V. koschynii varied by 100- and 50-fold, respectively, and both had higher RGR than B. alicastrum. As light availability increased, all species decreased biomass allocation to leaf tissue (mass and area) and showed a trade-off between allocation to leaf area at a given plant mass (LAR) and net gain in mass per unit leaf area (net assimilation rate, NAR). This trade-off largely reflected declines in SLA with increasing light. Finally, A area was correlated with NAR and both were major determinants of intraspecific variation in RGR. These data indicate the importance of plasticity in photosynthetic physiology and allocation for variation in tree seedling growth among

  8. EFFECTS OF CARBON DIOXIDE AND OZONE ON GROWTH AND BIOMASS ALLOCATION IN PINUS PONDEROSA

    EPA Science Inventory

    The future productivity of forests will be affected by combinations of elevated atmospheric CO2 and O3. Because productivity of forests will, in part, be determined by growth of young trees, we evaluated shoot growth and biomass responses of Pinus ponderosa seedlings exposed to ...

  9. Nitrogen, phosphorus and light effects on growth and allocation of biomass and nutrients in wild rice.

    PubMed

    Sims, Lee; Pastor, John; Lee, Tali; Dewey, Brad

    2012-09-01

    Separating plastic from ontogenetic and growth-limiting responses of plants to changes in resource availability can be challenging because there are a total of eight combinations of these three types of responses. These can, however, be uniquely distinguished on plots of root:shoot ratios against total biomass through time. We used this approach to separate ontogenetic, plastic, and growth-limiting responses of wild rice (Zizania palustris L.) to changes in nitrogen, phosphorus, and light availabilities. Relative growth rate was limited primarily by nitrogen but responded to increased light and phosphorus after nitrogen limitations were alleviated. Nitrogen addition increased relative growth rate because it simultaneously increased unit leaf rate, specific leaf area, and leaf weight ratio. Increased light did not change relative growth rate because decreased specific leaf area and leaf weight ratio compensated the increased unit leaf rate. Phosphorus did not change either relative growth rate or its underlying components. Plants responded ontogenetically to increased nitrogen and light availabilities by accelerating their developmental rate, and plastically by decreasing or increasing their root:shoot ratios, respectively. Plants did not respond either ontogenetically or plastically to increased phosphorus availability. Ontogenetic changes in growth can be separated from plastic and growth-limiting responses by plotting root:shoot ratio against total biomass in the context of the eight possible responses identified above, and also by examining how the underlying components of relative growth rate respond.

  10. Growth, biomass allocation and nutrient use efficiency in Cladium jamaicense and Typha domingensis as affected by phosphorus and oxygen availability

    USGS Publications Warehouse

    Lorenzen, B.; Brix, H.; Mendelssohn, I.A.; McKee, K.L.; Miao, S.L.

    2001-01-01

    The effects of phosphorus (P) and oxygen availability on growth, biomass allocation and nutrient use efficiency in Cladium jamaicense Crantz and Typha domingensis Pers. were studied in a growth facility equipped with steady-state hydroponic rhizotrons. The treatments included four P concentrations (10, 40, 80 and 500 ??g I-1) and two oxygen concentration (8.0 and <0.5 mg O2 I-1) in the culture solutions. In Cladium, no clear relationship was found between P availability and growth rate (19-37 mg g-1 d-1), the above to below ground biomass ratio (A/B) (mean = 4.6), or nitrogen use efficiency (NUE) (mean = 72 g dry weight g-1 N). However, the ratio between root supported tissue (leaves, rhizomes and ramets) and root biomass (S/R) (5.6-8) increased with P availability. In contrast, the growth rate (48-89 mg g-1 d-1) and the biomass ratios A/B (2.4-6.1) and S/R (5.4-10.3) of Typha increased with P availability, while NUE (71-30 g dry weight g-1 N) decreased. The proportion of root laterals was similar in the two species, but Typha had thinner root laterals (diameter = 186 ??m) than Cladium (diameter = 438 ??m) indicating a larger root surface area in Typha. The two species had a similar P use efficiency (PUE) at 10 ??g PI-1 (mean = 1134 g dry weight g-1 P) and at 40 and 80 ??g PI-1 (mean = 482 dry weight g-1 P) but the N/P ratio indicated imbalances in nutrient uptake at a higher P concentration (40 ??g PI-1) in Typha than in Cladium (10 ??g PI-1). The two species had similar root specific P accumulation rate at the two lowest P levels, whereas Typha had 3-13-fold higher P uptake rates at the two highest P levels, indicating a higher nutrient uptake capacity in Typha. The experimental oxygen concentration in the rhizosphere had only limited effect on the growth of the two species and had little effect on biomass partitioning and nutrient use efficiency. The aerenchyma in these species was probably sufficient to maintain adequate root oxygenation under partially oxygen

  11. Sensitivity of growth and biomass allocation patterns to increasing nitrogen: a comparison between ephemerals and annuals in the Gurbantunggut Desert, north-western China

    PubMed Central

    Zhou, Xiaobing; Zhang, Yuanming; Niklas, Karl J.

    2014-01-01

    Background and Aims Biomass accumulation and allocation patterns are critical to quantifying ecosystem dynamics. However, these patterns differ among species, and they can change in response to nutrient availability even among genetically related individuals. In order to understand this complexity further, this study examined three ephemeral species (with very short vegetative growth periods) and three annual species (with significantly longer vegetative growth periods) in the Gurbantunggut Desert, north-western China, to determine their responses to different nitrogen (N) supplements under natural conditions. Methods Nitrogen was added to the soil at rates of 0, 0·5, 1·0, 3·0, 6·0 and 24·0 g N m−2 year−1. Plants were sampled at various intervals to measure relative growth rate and shoot and root dry mass. Key Results Compared with annuals, ephemerals grew more rapidly, increased shoot and root biomass with increasing N application rates and significantly decreased root/shoot ratios. Nevertheless, changes in the biomass allocation of some species (i.e. Erodium oxyrrhynchum) in response to the N treatment were largely a consequence of changes in overall plant size, which was inconsistent with an optimal partitioning model. An isometric log shoot vs. log root scaling relationship for the final biomass harvest was observed for each species and all annuals, while pooled data of three ephemerals showed an allometric scaling relationship. Conclusions These results indicate that ephemerals and annuals differ observably in their biomass allocation patterns in response to soil N supplements, although an isometric log shoot vs. log root scaling relationship was maintained across all species. These findings highlight that different life history strategies behave differently in response to N application even when interspecific scaling relationships remain nearly isometric. PMID:24287812

  12. Heterogeneous light supply affects growth and biomass allocation of the understory fern Diplopterygium glaucum at high patch contrast.

    PubMed

    Guo, Wei; Song, Yao-Bin; Yu, Fei-Hai

    2011-01-01

    Spatial heterogeneity in resource supply is common and responses to heterogeneous resource supply have been extensively documented in clonal angiosperms but not in pteridophytes. To test the hypotheses that clonal integration can modify responses of pteridophytes to heterogeneous resource supply and the integration effect is larger at higher patch contrast, we conducted a field experiment with three homogeneous and two heterogeneous light treatments on the rhizomatous, understory fern Diplopterygium glaucum in an evergreen broad-leaved forest in East China. In homogeneous treatments, all D. glaucum ramets in 1.5 m×1.5 m units were subjected to 10, 40 and 100% natural light, respectively. In the heterogeneous treatment of low patch contrast, ramets in the central 0.5 m×0.5 m plots of the units were subjected to 40% natural light and their interconnected ramets in the surrounding area of the units to 100%; in the heterogeneous treatment of high patch contrast, ramets in the central plots were subjected to 10% natural light and those in the surrounding area to 100%. In the homogeneous treatments, biomass and number of living ramets in the central plots decreased and number of dead ramets increased with decreasing light supply. At low contrast heterogeneous light supply did not affect performance or biomass allocation of D. glaucum in the central plots, but at high contrast it increased lamina biomass and number of living ramets older than annual and modified biomass allocation to lamina and rhizome. Thus, clonal integration can affect responses of understory ferns to heterogeneous light supply and ramets in low light patches can be supported by those in high light. The results also suggest that effects of clonal integration depend on the degree of patch contrast and a significant integration effect may be found only under a relatively high patch contrast.

  13. Biomass Resource Allocation among Competing End Uses

    SciTech Connect

    Newes, E.; Bush, B.; Inman, D.; Lin, Y.; Mai, T.; Martinez, A.; Mulcahy, D.; Short, W.; Simpkins, T.; Uriarte, C.; Peck, C.

    2012-05-01

    The Biomass Scenario Model (BSM) is a system dynamics model developed by the U.S. Department of Energy as a tool to better understand the interaction of complex policies and their potential effects on the biofuels industry in the United States. However, it does not currently have the capability to account for allocation of biomass resources among the various end uses, which limits its utilization in analysis of policies that target biomass uses outside the biofuels industry. This report provides a more holistic understanding of the dynamics surrounding the allocation of biomass among uses that include traditional use, wood pellet exports, bio-based products and bioproducts, biopower, and biofuels by (1) highlighting the methods used in existing models' treatments of competition for biomass resources; (2) identifying coverage and gaps in industry data regarding the competing end uses; and (3) exploring options for developing models of biomass allocation that could be integrated with the BSM to actively exchange and incorporate relevant information.

  14. High yielding biomass genotypes of willow (Salix spp.) show differences in below ground biomass allocation

    PubMed Central

    Cunniff, Jennifer; Purdy, Sarah J.; Barraclough, Tim J.P.; Castle, March; Maddison, Anne L.; Jones, Laurence E.; Shield, Ian F.; Gregory, Andrew S.; Karp, Angela

    2015-01-01

    Willows (Salix spp.) grown as short rotation coppice (SRC) are viewed as a sustainable source of biomass with a positive greenhouse gas (GHG) balance due to their potential to fix and accumulate carbon (C) below ground. However, exploiting this potential has been limited by the paucity of data available on below ground biomass allocation and the extent to which it varies between genotypes. Furthermore, it is likely that allocation can be altered considerably by environment. To investigate the role of genotype and environment on allocation, four willow genotypes were grown at two replicated field sites in southeast England and west Wales, UK. Above and below ground biomass was intensively measured over two two-year rotations. Significant genotypic differences in biomass allocation were identified, with below ground allocation differing by up to 10% between genotypes. Importantly, the genotype with the highest below ground biomass also had the highest above ground yield. Furthermore, leaf area was found to be a good predictor of below ground biomass. Growth environment significantly impacted allocation; the willow genotypes grown in west Wales had up to 94% more biomass below ground by the end of the second rotation. A single investigation into fine roots showed the same pattern with double the volume of fine roots present. This greater below ground allocation may be attributed primarily to higher wind speeds, plus differences in humidity and soil characteristics. These results demonstrate that the capacity exists to breed plants with both high yields and high potential for C accumulation. PMID:26339128

  15. Biomass allocation patterns across China's terrestrial biomes.

    PubMed

    Wang, Limei; Li, Longhui; Chen, Xi; Tian, Xin; Wang, Xiaoke; Luo, Geping

    2014-01-01

    Root to shoot ratio (RS) is commonly used to describe the biomass allocation between below- and aboveground parts of plants. Determining the key factors influencing RS and interpreting the relationship between RS and environmental factors is important for biological and ecological research. In this study, we compiled 2088 pairs of root and shoot biomass data across China's terrestrial biomes to examine variations in the RS and its responses to biotic and abiotic factors including vegetation type, soil texture, climatic variables, and stand age. The median value of RS (RSm) for grasslands, shrublands, and forests was 6.0, 0.73, and 0.23, respectively. The range of RS was considerably wide for each vegetation type. RS values for all three major vegetation types were found to be significantly correlated to mean annual precipitation (MAP) and potential water deficit index (PWDI). Mean annual temperature (MAT) also significantly affect the RS for forests and grasslands. Soil texture and forest origin altered the response of RS to climatic factors as well. An allometric formula could be used to well quantify the relationship between aboveground and belowground biomass, although each vegetation type had its own inherent allometric relationship.

  16. Biomass for biorefining: Resources, allocation, utilization, and policies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The importance of biomass in the development of renewable energy, the availability and allocation of biomass, its preparation for use in biorefineries, and the policies affecting biomass are discussed in this chapter. Bioenergy development will depend on maximizing the amount of biomass obtained fro...

  17. Do plants modulate biomass allocation in response to petroleum pollution?

    PubMed

    Nie, Ming; Yang, Qiang; Jiang, Li-Fen; Fang, Chang-Ming; Chen, Jia-Kuan; Li, Bo

    2010-12-23

    Biomass allocation is an important plant trait that responds plastically to environmental heterogeneities. However, the effects on this trait of pollutants owing to human activities remain largely unknown. In this study, we investigated the response of biomass allocation of Phragmites australis to petroleum pollution by a ¹³CO₂ pulse-labelling technique. Our data show that plant biomass significantly decreased under petroleum pollution, but the root-shoot ratio for both plant biomass and ¹³C increased with increasing petroleum concentration, suggesting that plants could increase biomass allocation to roots in petroleum-polluted soil. Furthermore, assimilated ¹³C was found to be significantly higher in soil, microbial biomass and soil respiration after soils were polluted by petroleum. These results suggested that the carbon released from roots is rapidly turned over by soil microbes under petroleum pollution. This study found that plants can modulate biomass allocation in response to petroleum pollution.

  18. Biomass Allocation of Stoloniferous and Rhizomatous Plant in Response to Resource Availability: A Phylogenetic Meta-Analysis.

    PubMed

    Xie, Xiu-Fang; Hu, Yu-Kun; Pan, Xu; Liu, Feng-Hong; Song, Yao-Bin; Dong, Ming

    2016-01-01

    Resource allocation to different functions is central in life-history theory. Plasticity of functional traits allows clonal plants to regulate their resource allocation to meet changing environments. In this study, biomass allocation traits of clonal plants were categorized into absolute biomass for vegetative growth vs. for reproduction, and their relative ratios based on a data set including 115 species and derived from 139 published literatures. We examined general pattern of biomass allocation of clonal plants in response to availabilities of resource (e.g., light, nutrients, and water) using phylogenetic meta-analysis. We also tested whether the pattern differed among clonal organ types (stolon vs. rhizome). Overall, we found that stoloniferous plants were more sensitive to light intensity than rhizomatous plants, preferentially allocating biomass to vegetative growth, aboveground part and clonal reproduction under shaded conditions. Under nutrient- and water-poor condition, rhizomatous plants were constrained more by ontogeny than by resource availability, preferentially allocating biomass to belowground part. Biomass allocation between belowground and aboveground part of clonal plants generally supported the optimal allocation theory. No general pattern of trade-off was found between growth and reproduction, and neither between sexual and clonal reproduction. Using phylogenetic meta-analysis can avoid possible confounding effects of phylogeny on the results. Our results shown the optimal allocation theory explained a general trend, which the clonal plants are able to plastically regulate their biomass allocation, to cope with changing resource availability, at least in stoloniferous and rhizomatous plants. PMID:27200071

  19. Biomass Allocation of Stoloniferous and Rhizomatous Plant in Response to Resource Availability: A Phylogenetic Meta-Analysis.

    PubMed

    Xie, Xiu-Fang; Hu, Yu-Kun; Pan, Xu; Liu, Feng-Hong; Song, Yao-Bin; Dong, Ming

    2016-01-01

    Resource allocation to different functions is central in life-history theory. Plasticity of functional traits allows clonal plants to regulate their resource allocation to meet changing environments. In this study, biomass allocation traits of clonal plants were categorized into absolute biomass for vegetative growth vs. for reproduction, and their relative ratios based on a data set including 115 species and derived from 139 published literatures. We examined general pattern of biomass allocation of clonal plants in response to availabilities of resource (e.g., light, nutrients, and water) using phylogenetic meta-analysis. We also tested whether the pattern differed among clonal organ types (stolon vs. rhizome). Overall, we found that stoloniferous plants were more sensitive to light intensity than rhizomatous plants, preferentially allocating biomass to vegetative growth, aboveground part and clonal reproduction under shaded conditions. Under nutrient- and water-poor condition, rhizomatous plants were constrained more by ontogeny than by resource availability, preferentially allocating biomass to belowground part. Biomass allocation between belowground and aboveground part of clonal plants generally supported the optimal allocation theory. No general pattern of trade-off was found between growth and reproduction, and neither between sexual and clonal reproduction. Using phylogenetic meta-analysis can avoid possible confounding effects of phylogeny on the results. Our results shown the optimal allocation theory explained a general trend, which the clonal plants are able to plastically regulate their biomass allocation, to cope with changing resource availability, at least in stoloniferous and rhizomatous plants.

  20. Biomass Allocation of Stoloniferous and Rhizomatous Plant in Response to Resource Availability: A Phylogenetic Meta-Analysis

    PubMed Central

    Xie, Xiu-Fang; Hu, Yu-Kun; Pan, Xu; Liu, Feng-Hong; Song, Yao-Bin; Dong, Ming

    2016-01-01

    Resource allocation to different functions is central in life-history theory. Plasticity of functional traits allows clonal plants to regulate their resource allocation to meet changing environments. In this study, biomass allocation traits of clonal plants were categorized into absolute biomass for vegetative growth vs. for reproduction, and their relative ratios based on a data set including 115 species and derived from 139 published literatures. We examined general pattern of biomass allocation of clonal plants in response to availabilities of resource (e.g., light, nutrients, and water) using phylogenetic meta-analysis. We also tested whether the pattern differed among clonal organ types (stolon vs. rhizome). Overall, we found that stoloniferous plants were more sensitive to light intensity than rhizomatous plants, preferentially allocating biomass to vegetative growth, aboveground part and clonal reproduction under shaded conditions. Under nutrient- and water-poor condition, rhizomatous plants were constrained more by ontogeny than by resource availability, preferentially allocating biomass to belowground part. Biomass allocation between belowground and aboveground part of clonal plants generally supported the optimal allocation theory. No general pattern of trade-off was found between growth and reproduction, and neither between sexual and clonal reproduction. Using phylogenetic meta-analysis can avoid possible confounding effects of phylogeny on the results. Our results shown the optimal allocation theory explained a general trend, which the clonal plants are able to plastically regulate their biomass allocation, to cope with changing resource availability, at least in stoloniferous and rhizomatous plants. PMID:27200071

  1. Photoreceptor effects on plant biomass, resource allocation, and metabolic state.

    PubMed

    Yang, Deyue; Seaton, Daniel D; Krahmer, Johanna; Halliday, Karen J

    2016-07-01

    Plants sense the light environment through an ensemble of photoreceptors. Members of the phytochrome class of light receptors are known to play a critical role in seedling establishment, and are among the best-characterized plant signaling components. Phytochromes also regulate adult plant growth; however, our knowledge of this process is rather fragmented. This study demonstrates that phytochrome controls carbon allocation and biomass production in the developing plant. Phytochrome mutants have a reduced CO2 uptake, yet overaccumulate daytime sucrose and starch. This finding suggests that even though carbon fixation is impeded, the available carbon resources are not fully used for growth during the day. Supporting this notion, phytochrome depletion alters the proportion of day:night growth. In addition, phytochrome loss leads to sizeable reductions in overall growth, dry weight, total protein levels, and the expression of CELLULOSE SYNTHASE-LIKE genes. Because cellulose and protein are major constituents of plant biomass, our data point to an important role for phytochrome in regulating these fundamental components of plant productivity. We show that phytochrome loss impacts core metabolism, leading to elevated levels of tricarboxylic acid cycle intermediates, amino acids, sugar derivatives, and notably the stress metabolites proline and raffinose. Furthermore, the already growth-retarded phytochrome mutants are less responsive to growth-inhibiting abiotic stresses and have elevated expression of stress marker genes. This coordinated response appears to divert resources from energetically costly biomass production to improve resilience. In nature, this strategy may be activated in phytochrome-disabling, vegetation-dense habitats to enhance survival in potentially resource-limiting conditions. PMID:27330114

  2. Growth, biomass allocation and photosynthetic responses are related to intensity of root severance and soil moisture conditions in the plantation tree Cunninghamia lanceolata.

    PubMed

    Dong, Tingfa; Duan, Baoli; Zhang, Sheng; Korpelainen, Helena; Niinemets, Ülo; Li, Chunyang

    2016-07-01

    We employed the warm temperate conifer Cunninghamia lanceolata (Lamb.) Hook. as a model of plantation forest species to investigate ecophysiological responses to root treatments (control (0%), and ∼25, 50 or 75% of the initial root mass) under well-watered and water-limited conditions. Our results indicated that total root dry mass accumulation was negatively associated with the severity of root pruning, but there was evidence of multiple compensatory responses. The plants exhibited higher instantaneous and long-term (assessed by carbon isotope composition, δ(13)C) water-use efficiency in pruning treatments, especially under low water availability. Root pruning also increased the fine root/total root mass ratio, specific root length and fine root vitality in both water availability treatments. As a result of the compensatory responses, under well-watered conditions, height, stem dry mass accumulation, leaf/fine root biomass ratio (L/FR), transpiration rate, photosynthetic capacity and photosynthetic nitrogen-use efficiency (EN) were the highest under 25% pruning. Yet, all these traits except L/FR and foliage nitrogen content were severely reduced under 75% pruning. Drought negatively affected growth and leaf gas exchange rates, and there was a greater negative effect on growth, water potential, gas exchange and EN when >25% of total root biomass was removed. The stem/aboveground mass ratio was the highest under 25% pruning in both watering conditions. These results indicate that the responses to root severance are related to the excision intensity and soil moisture content. A moderate root pruning proved to be an effective means to improve stem dry mass accumulation. PMID:27122365

  3. Biomass allocation of montane and desert Pondersoa Pine: An analog for response to climate change

    SciTech Connect

    Callaway, R.M.; DeLucia, E.H. ); Schlesinger, W.H. )

    1994-07-01

    Aboveground biomass allocation of Pinus ponderosa on hydrothermally altered andesite in montane and desert climates was measured. Trees from montane climates had higher leaf mass per unit cross-sectional area of sapwood than trees from desert climates, suggesting a function response to differences in climate. Results also indicate that sapwood mass:leaf mass ratios of P. ponderosa may increase [approx]50% with a 5[degrees]C change in mean growing-season temperature. High proportional allocation of biomass to sapwood may improve water relations of P. ponderosa, but because sapwood contains living parenchyma, respiratory costs may be high. Simulated montane trees were 46-52% taller than desert trees, and montane trees 10 cm in dbh had twice the total aboveground mass of desert counterparts. Simulated 50-cm montane and desert trees were almost identical in total mass, even though the montane tree was 46% taller. The predicted proportion of biomass allocated to bole sapwood increased with size for both montane and desert models; however, the 50-cm desert model contained 8% more total sapwood mass than the taller montane model. Biomass of primary and secondary branches differed considerably. The 50-cm desert model had twice as much biomass in primary branches, whereas the montane model had 3 times more biomass in secondary branches than the desert model. For 10-cm trees of the desert and montane models 29 and 33% of the biomass were leaves, respectively. In larger trees, leaf allocation decreased to 5 and 7% for desert and montane models, respectively. The effects of climate on biomass allocation such as reported here, and corresponding changes in whole-plant assimilation rates must be incorporated into growth-response models used to predict future fluctuations in forest productivity due to global climate change. 35 refs., 3 figs., 3 tabs.

  4. Remotely-sensed indicators of N-related biomass allocation in Schoenoplectus acutus

    USGS Publications Warehouse

    O’Connell, Jessica L.; Byrd, Kristin B.; Kelly, Maggi

    2014-01-01

    Coastal marshes depend on belowground biomass of roots and rhizomes to contribute to peat and soil organic carbon, accrete soil and alleviate flooding as sea level rises. For nutrient-limited plants, eutrophication has either reduced or stimulated belowground biomass depending on plant biomass allocation response to fertilization. Within a freshwater wetland impoundment receiving minimal sediments, we used experimental plots to explore growth models for a common freshwater macrophyte, Schoenoplectus acutus. We used N-addition and control plots (4 each) to test whether remotely sensed vegetation indices could predict leaf N concentration, root:shoot ratios and belowground biomass of S. acutus. Following 5 months of summer growth, we harvested whole plants, measured leaf N and total plant biomass of all above and belowground vegetation. Prior to harvest, we simulated measurement of plant spectral reflectance over 164 hyperspectral Hyperion satellite bands (350–2500 nm) with a portable spectroradiometer. N-addition did not alter whole plant, but reduced belowground biomass 36% and increased aboveground biomass 71%. We correlated leaf N concentration with known N-related spectral regions using all possible normalized difference (ND), simple band ratio (SR) and first order derivative ND (FDN) and SR (FDS) vegetation indices. FDN1235, 549 was most strongly correlated with leaf N concentration and also was related to belowground biomass, the first demonstration of spectral indices and belowground biomass relationships. While S. acutus exhibited balanced growth (reduced root:shoot ratio with respect to nutrient addition), our methods also might relate N-enrichment to biomass point estimates for plants with isometric root growth. For isometric growth, foliar N indices will scale equivalently with above and belowground biomass. Leaf N vegetation indices should aid in scaling-up field estimates of biomass and assist regional monitoring.

  5. Remotely-Sensed Indicators of N-Related Biomass Allocation in Schoenoplectus acutus

    PubMed Central

    O’Connell, Jessica L.; Byrd, Kristin B.; Kelly, Maggi

    2014-01-01

    Coastal marshes depend on belowground biomass of roots and rhizomes to contribute to peat and soil organic carbon, accrete soil and alleviate flooding as sea level rises. For nutrient-limited plants, eutrophication has either reduced or stimulated belowground biomass depending on plant biomass allocation response to fertilization. Within a freshwater wetland impoundment receiving minimal sediments, we used experimental plots to explore growth models for a common freshwater macrophyte, Schoenoplectus acutus. We used N-addition and control plots (4 each) to test whether remotely sensed vegetation indices could predict leaf N concentration, root:shoot ratios and belowground biomass of S. acutus. Following 5 months of summer growth, we harvested whole plants, measured leaf N and total plant biomass of all above and belowground vegetation. Prior to harvest, we simulated measurement of plant spectral reflectance over 164 hyperspectral Hyperion satellite bands (350–2500 nm) with a portable spectroradiometer. N-addition did not alter whole plant, but reduced belowground biomass 36% and increased aboveground biomass 71%. We correlated leaf N concentration with known N-related spectral regions using all possible normalized difference (ND), simple band ratio (SR) and first order derivative ND (FDN) and SR (FDS) vegetation indices. FDN1235, 549 was most strongly correlated with leaf N concentration and also was related to belowground biomass, the first demonstration of spectral indices and belowground biomass relationships. While S. acutus exhibited balanced growth (reduced root:shoot ratio with respect to nutrient addition), our methods also might relate N-enrichment to biomass point estimates for plants with isometric root growth. For isometric growth, foliar N indices will scale equivalently with above and belowground biomass. Leaf N vegetation indices should aid in scaling-up field estimates of biomass and assist regional monitoring. PMID:24614037

  6. Seasonal evolution of carbon allocation to biomass in a French beech forest.

    NASA Astrophysics Data System (ADS)

    Heid, Laura; Calvaruso, Christophe; Conil, Sébastien; Turpault, Marie-Pierre; Longdoz, Bernard

    2015-04-01

    The objective of this study is to get a better understanding of ecosystem behavior in term of assimilated carbon (C) use. In the global climate change context, this C allocation could play a critical role in predicting ecosystems long terms emissions (Trumbore 2006) and has become a major goal of several emergent studies The monthly C allocation has been determined for a 50-year old beech forest located in north-east of France through the quantification of Gross Primary Production (GPP), biomass production and some of its components (holocelluloses, lignin). In a second phase, the potential factors influencing those productions and allocations throughout a year have been assessed. The temporal evolution of GPP was obtained from the partitioning of eddy-covariance flux measurements and monitored for one year. It was connected to tree aboveground C biomass growth at a monthly step. To achieve the latter, site specific allometric equations were used with trees diameter at breast height (DBH) measured monthly during the growing season on one hand and, on the other hand, C concentrations were deduced from analyses on trunk cores (sampled monthly) and on leaves and bulk branches cores (sampled at the beginning and at the end of the growing season). The C allocated to the aboveground biomass was then estimated, along with the portion allocated to structural C. The results show the delay existing between the end of the tree growth and carbon assimilation. We analyze the possibility to explain this divergence by a compensation coming from the C concentration evolution. Keywords: Carbon allocation, Forest, Biomass production, Carbon concentration, Eddy Covariance Trumbore S. 2006. Carbon Respired by Terrestrial Ecosystems - Recent Progress and Challenges. Global Change Biology 12 (2): 141-53.

  7. Conditioning biomass for microbial growth

    DOEpatents

    Bodie, Elizabeth A; England, George

    2015-03-31

    The present invention relates to methods for improving the yield of microbial processes that use lignocellulose biomass as a nutrient source. The methods comprise conditioning a composition comprising lignocellulose biomass with an enzyme composition that comprises a phenol oxidizing enzyme. The conditioned composition can support a higher rate of growth of microorganisms in a process. In one embodiment, a laccase composition is used to condition lignocellulose biomass derived from non-woody plants, such as corn and sugar cane. The invention also encompasses methods for culturing microorganisms that are sensitive to inhibitory compounds in lignocellulose biomass. The invention further provides methods of making a product by culturing the production microorganisms in conditioned lignocellulose biomass.

  8. Effects of nutrient treatment and previous stem galling on biomass allocation in tall goldenrod, Solidago altissima

    SciTech Connect

    Anderson, S.S.; Abrahamson, W.G.; McCrea, K.D.

    1987-07-01

    Ramets from six goldenrod clones of known resistance to the gallmaker (Eurosta solidaginis) were grown with and without nutrient treatment. Mated female Eurosta oviposited in ramets which were grown through flowering and harvested to determine biomass allocation. Nutrient treatment increased biomass but did not affect resistance. Gall mass was increased by nutrient treatment and was correlated with larval mass. Additional ramets from two of the susceptible clones were grown from rhizomes of ramets galled and ungalled the previous year. Galls reduced ramet growth in both years. A gall in the previous year reduced total ramet biomass as well as biomass of all component organs in the current year but a gall in the current season had no effect. The detrimental effects of a gall are carried into the next growing season.

  9. Patterns of plant biomass allocation in temperate grasslands across a 2500-km transect in northern China.

    PubMed

    Luo, Wentao; Jiang, Yong; Lü, Xiaotao; Wang, Xue; Li, Mai-He; Bai, Edith; Han, Xingguo; Xu, Zhuwen

    2013-01-01

    Plant biomass allocation between below- and above-ground parts can actively adapt to the ambient growth conditions and is a key parameter for estimating terrestrial ecosystem carbon (C) stocks. To investigate how climatic variations affect patterns of plant biomass allocation, we sampled 548 plants belonging to four dominant genera (Stipa spp., Cleistogenes spp., Agropyron spp., and Leymus spp.) along a large-scale (2500 km) climatic gradient across the temperate grasslands from west to east in northern China. Our results showed that Leymus spp. had the lowest root/shoot ratios among the each genus. Root/shoot ratios of each genera were positively correlated with mean annual temperature (MAT), and negatively correlated with mean annual precipitation (MAP) across the transect. Temperature contributed more to the variation of root/shoot ratios than precipitation for Cleistogenes spp. (C4 plants), whereas precipitation exerted a stronger influence than temperature on their variations for the other three genera (C3 plants). From east to west, investment of C into the belowground parts increased as precipitation decreased while temperature increased. Such changes in biomass allocation patterns in response to climatic factors may alter the competition regimes among co-existing plants, resulting in changes in community composition, structure and ecosystem functions. Our results suggested that future climate change would have great impact on C allocation and storage, as well as C turnover in the grassland ecosystems in northern China. PMID:23977135

  10. Effects of aspect on clonal reproduction and biomass allocation of layering modules of Nitraria tangutorum in nebkha dunes.

    PubMed

    Li, Qinghe; Xu, Jun; Li, Huiqing; Wang, Saixiao; Yan, Xiu; Xin, Zhiming; Jiang, Zeping; Wang, Linlong; Jia, Zhiqing

    2013-01-01

    The formation of many nebkha dunes relies on the layering of clonal plants. The microenvironmental conditions of such phytogenic nebkha are heterogeneous depending on the aspect and slope. Exploring the effects of aspect on clonal reproduction and biomass allocation can be useful in understanding the ecological adaptation of species. We hypothesized that on the windward side layering propagation would be promoted, that biomass allocation to leaves and stems of ramets would increase, and that the effects of aspect would be greater in the layering with larger biomass. To test these hypotheses, we surveyed the depth of germination points of axillary buds, the rate of ramet sprouting, the density of adventitious root formation points, and the biomass of modules sprouting from layering located on the NE, SE, SW and NW, aspects of Nitraria tangutorum nebkhas. The windward side was located on the NW and SW aspects. The results indicated that conditions of the NW aspect were more conducive to clonal reproduction and had the highest rate of ramet sprouting and the highest density of adventitious formation points. For the modules sprouting from layering on the SW aspect, biomass allocation to leaves and stems was greatest with biomass allocation to adventitious roots being lowest. This result supported our hypothesis. Contrary to our hypothesis, the effects of aspect were greater in layering of smaller biomass. These results support the hypothesis that aspect does affect layering propagation capacity and biomass allocation in this species. Additionally, clonal reproduction and biomass allocation of modules sprouting from layering with smaller biomass was more affected by aspect. These results suggest that the clonal growth of N. tangutorum responses to the microenvironmental heterogeneity that results from aspect of the nebkha.

  11. Effects of Aspect on Clonal Reproduction and Biomass Allocation of Layering Modules of Nitraria tangutorum in Nebkha Dunes

    PubMed Central

    Li, Qinghe; Xu, Jun; Li, Huiqing; Wang, Saixiao; Yan, Xiu; Xin, Zhiming; Jiang, Zeping; Wang, Linlong; Jia, Zhiqing

    2013-01-01

    The formation of many nebkha dunes relies on the layering of clonal plants. The microenvironmental conditions of such phytogenic nebkha are heterogeneous depending on the aspect and slope. Exploring the effects of aspect on clonal reproduction and biomass allocation can be useful in understanding the ecological adaptation of species. We hypothesized that on the windward side layering propagation would be promoted, that biomass allocation to leaves and stems of ramets would increase, and that the effects of aspect would be greater in the layering with larger biomass. To test these hypotheses, we surveyed the depth of germination points of axillary buds, the rate of ramet sprouting, the density of adventitious root formation points, and the biomass of modules sprouting from layering located on the NE, SE, SW and NW, aspects of Nitraria tangutorum nebkhas. The windward side was located on the NW and SW aspects. The results indicated that conditions of the NW aspect were more conducive to clonal reproduction and had the highest rate of ramet sprouting and the highest density of adventitious formation points. For the modules sprouting from layering on the SW aspect, biomass allocation to leaves and stems was greatest with biomass allocation to adventitious roots being lowest. This result supported our hypothesis. Contrary to our hypothesis, the effects of aspect were greater in layering of smaller biomass. These results support the hypothesis that aspect does affect layering propagation capacity and biomass allocation in this species. Additionally, clonal reproduction and biomass allocation of modules sprouting from layering with smaller biomass was more affected by aspect. These results suggest that the clonal growth of N. tangutorum responses to the microenvironmental heterogeneity that results from aspect of the nebkha. PMID:24205391

  12. The effect of a rosette-crown fly, Botanophila turcica, on growth,biomass allocation and reproduction of the thistle Carthamus lanatus

    NASA Astrophysics Data System (ADS)

    Sheppard, Andrew W.; Vitou, Janine

    2000-12-01

    Plant growth and reproductive output of the winter annual invasive thistle, Carthamus lanatus was characterised in relation to plant size in three native populations in southern France. The effects of the rosette-crown feeding fly Botanophila turcica on these plant characteristics were assessed by comparing unattacked with naturally attacked plants at each site and by a field experiment. Indirect effects of B. turcica on plant seed production were also compared with direct seed loss caused by a guild of capitulum-feeding insects that incidentally attacked the marked plants at these sites. C. lanatus showed no size or weight requirement for flowering, but larger flowering plants produced less total receptacle surface and less seed production (female reproductive potential) in proportion to plant weight than smaller flowering plants. B. turcica did not select hosts on the basis of size or density. B. turcica reduced plant relative growth rate (RGR) in all situations, but attacked plants compensated fully at two of three sites as attack failed to halt rosette growth. Attacked plants suffered 12 % mortality, and 71 % lower seed production than unattacked plants at the site with the lowest RGR. This corresponded to 9 % lower seed production for the whole thistle population compared to 8.6-19.5 % direct seed loss to capitulum insects across all sites.

  13. Effect of temperature on biomass allocation in seedlings of two contrasting genotypes of the oilseed crop Ricinus communis.

    PubMed

    Ribeiro, Paulo R; Zanotti, Rafael F; Deflers, Carole; Fernandez, Luzimar G; Castro, Renato D de; Ligterink, Wilco; Hilhorst, Henk W M

    2015-08-01

    Ricinus communis is becoming an important crop for oil production, and studying the physiological and biochemical aspects of seedling development may aid in the improvement of crop quality and yield. The objective of this study was to assess the effect of temperature on biomass allocation in two R. communis genotypes. Biomass allocation was assessed by measuring dry weight of roots, stems, and cotyledons of seedlings grown at three different temperatures. Root length of each seedling was measured. Biomass allocation was strongly affected by temperature. Seedlings grown at 25°C and 35°C showed greater biomass than seedlings grown at 20°C. Cotyledon and stem dry weight increased for both genotypes with increasing temperature, whereas root biomass allocation showed a genotype-dependent behavior. Genotype MPA11 showed a continuous increase in root dry weight with increasing temperature, while genotype IAC80 was not able to sustain further root growth at higher temperatures. Based on metabolite and gene expression profiles, genotype MPA11 increases its level of osmoprotectant molecules and transcripts of genes encoding for antioxidant enzymes and heat shock proteins to a higher extent than genotype IAC80. This might be causal for the ability to maintain homeostasis and support root growth at elevated temperatures in genotype MPA11.

  14. Aboveground Tree Growth Varies with Belowground Carbon Allocation in a Tropical Rainforest Environment

    PubMed Central

    Raich, James W.; Clark, Deborah A.; Schwendenmann, Luitgard; Wood, Tana E.

    2014-01-01

    Young secondary forests and plantations in the moist tropics often have rapid rates of biomass accumulation and thus sequester large amounts of carbon. Here, we compare results from mature forest and nearby 15–20 year old tree plantations in lowland Costa Rica to evaluate differences in allocation of carbon to aboveground production and root systems. We found that the tree plantations, which had fully developed, closed canopies, allocated more carbon belowground - to their root systems - than did mature forest. This increase in belowground carbon allocation correlated significantly with aboveground tree growth but not with canopy production (i.e., leaf fall or fine litter production). In contrast, there were no correlations between canopy production and either tree growth or belowground carbon allocation. Enhanced allocation of carbon to root systems can enhance plant nutrient uptake, providing nutrients beyond those required for the production of short-lived tissues such as leaves and fine roots, and thus enabling biomass accumulation. Our analyses support this deduction at our site, showing that enhanced allocation of carbon to root systems can be an important mechanism promoting biomass accumulation during forest growth in the moist tropics. Identifying factors that control when, where and for how long this occurs would help us to improve models of forest growth and nutrient cycling, and to ascertain the role that young forests play in mitigating increased atmospheric carbon dioxide. PMID:24945351

  15. Aboveground tree growth varies with belowground carbon allocation in a tropical rainforest environment.

    PubMed

    Raich, James W; Clark, Deborah A; Schwendenmann, Luitgard; Wood, Tana E

    2014-01-01

    Young secondary forests and plantations in the moist tropics often have rapid rates of biomass accumulation and thus sequester large amounts of carbon. Here, we compare results from mature forest and nearby 15-20 year old tree plantations in lowland Costa Rica to evaluate differences in allocation of carbon to aboveground production and root systems. We found that the tree plantations, which had fully developed, closed canopies, allocated more carbon belowground - to their root systems - than did mature forest. This increase in belowground carbon allocation correlated significantly with aboveground tree growth but not with canopy production (i.e., leaf fall or fine litter production). In contrast, there were no correlations between canopy production and either tree growth or belowground carbon allocation. Enhanced allocation of carbon to root systems can enhance plant nutrient uptake, providing nutrients beyond those required for the production of short-lived tissues such as leaves and fine roots, and thus enabling biomass accumulation. Our analyses support this deduction at our site, showing that enhanced allocation of carbon to root systems can be an important mechanism promoting biomass accumulation during forest growth in the moist tropics. Identifying factors that control when, where and for how long this occurs would help us to improve models of forest growth and nutrient cycling, and to ascertain the role that young forests play in mitigating increased atmospheric carbon dioxide.

  16. Aboveground biomass allocation of ponderosa pine along an elevational gradient: An analog for response to climate change

    SciTech Connect

    Callaway, R.M.; DeLucia, E.H.; Schlesinger, W.H. Duke Univ., Durham, NC )

    1993-06-01

    Predictions of CO[sub 2]-enhanced growth for adult trees are primarily based on leaf-level assimilation responses and improved growth rates of seedlings and saplings. Plant growth may be more dependent on biomass allocation than on rates of assimilation, but predictions have not incorporated the effects of temperature on biomass reallocation among autotrophic and heterotrophic tissues and whole-plant carbon balance. We measured biomass allocation of Pinus ponderosa on hydrothermally altered andesite in montane and desert climates, thus substrate was held constant while climate varied. Trees from montane climates supported higher leaf mass per cross-sectional sapwood area (functional conducting xylem) than trees from desert climates, suggesting that a functional response to climate had occurred. Our results also indicate that sapwood mass:leaf mass ratios of P. ponderosa may increase [approx] 50% with a 5[degrees]C change. in mean growing season temperature, approximately the difference between our montane and desert sites. Such an increase in sapwood:leaf ratio may partially offset predicted CO[sub 2]-enhancement effects and substantially reduce whole-plant carbon balance. Biomass allocation responses must be incorporated into growth-response models used to predict fluctuations in forest productivity with changes in climate and atmospheric CO[sub 2] concentration.

  17. Shifts in Aboveground Biomass Allocation Patterns of Dominant Shrub Species across a Strong Environmental Gradient

    PubMed Central

    Kumordzi, Bright B.; Gundale, Michael J.; Nilsson, Marie-Charlotte; Wardle, David A.

    2016-01-01

    Most plant biomass allocation studies have focused on allocation to shoots versus roots, and little is known about drivers of allocation for aboveground plant organs. We explored the drivers of within-and between-species variation of aboveground biomass allocation across a strong environmental resource gradient, i.e., a long-term chronosequence of 30 forested islands in northern Sweden across which soil fertility and plant productivity declines while light availability increases. For each of the three coexisting dominant understory dwarf shrub species on each island, we estimated the fraction of the total aboveground biomass produced year of sampling that was allocated to sexual reproduction (i.e., fruits), leaves and stems for each of two growing seasons, to determine how biomass allocation responded to the chronosequence at both the within-species and whole community levels. Against expectations, within-species allocation to fruits was least on less fertile islands, and allocation to leaves at the whole community level was greatest on intermediate islands. Consistent with expectations, different coexisting species showed contrasting allocation patterns, with the species that was best adapted for more fertile conditions allocating the most to vegetative organs, and with its allocation pattern showing the strongest response to the gradient. Our study suggests that co-existing dominant plant species can display highly contrasting biomass allocations to different aboveground organs within and across species in response to limiting environmental resources within the same plant community. Such knowledge is important for understanding how community assembly, trait spectra, and ecological processes driven by the plant community vary across environmental gradients and among contrasting ecosystems. PMID:27270445

  18. Shifts in Aboveground Biomass Allocation Patterns of Dominant Shrub Species across a Strong Environmental Gradient.

    PubMed

    Kumordzi, Bright B; Gundale, Michael J; Nilsson, Marie-Charlotte; Wardle, David A

    2016-01-01

    Most plant biomass allocation studies have focused on allocation to shoots versus roots, and little is known about drivers of allocation for aboveground plant organs. We explored the drivers of within-and between-species variation of aboveground biomass allocation across a strong environmental resource gradient, i.e., a long-term chronosequence of 30 forested islands in northern Sweden across which soil fertility and plant productivity declines while light availability increases. For each of the three coexisting dominant understory dwarf shrub species on each island, we estimated the fraction of the total aboveground biomass produced year of sampling that was allocated to sexual reproduction (i.e., fruits), leaves and stems for each of two growing seasons, to determine how biomass allocation responded to the chronosequence at both the within-species and whole community levels. Against expectations, within-species allocation to fruits was least on less fertile islands, and allocation to leaves at the whole community level was greatest on intermediate islands. Consistent with expectations, different coexisting species showed contrasting allocation patterns, with the species that was best adapted for more fertile conditions allocating the most to vegetative organs, and with its allocation pattern showing the strongest response to the gradient. Our study suggests that co-existing dominant plant species can display highly contrasting biomass allocations to different aboveground organs within and across species in response to limiting environmental resources within the same plant community. Such knowledge is important for understanding how community assembly, trait spectra, and ecological processes driven by the plant community vary across environmental gradients and among contrasting ecosystems. PMID:27270445

  19. Genotypic effects of fertilization on seedling sweetgum biomass allocation, N uptake, and N use efficiency.

    PubMed

    Chang, S X; Robison, D J

    2001-10-23

    Screening and selecting tree genotypes that are responsive to N additions and that have high nutrient use efficiencies can provide better genetic material for short-rotation plantation establishment. A pot experiment was conducted to test the hypotheses that (1) sweetgum ( Liquidambar styraciflua L.) families have different patterns in biomass production and allocation, N uptake, and N use efficiency (NUE), because of their differences in growth strategies, and (2) sweetgum families that are more responsive to N additions will also have greater nutrient use efficiencies. Seedlings from two half-sib families (F10022 and F10023) that were known to have contrasting responses to fertility and other stress treatments were used for an experiment with two levels of N (0 vs. 100 kg N/ha equivalent) and two levels of P (0 vs. 50 kg P/ha equivalent) in a split-plot design. Sweetgum seedlings responded to N and P treatments rapidly, with increases in both size and biomass production, and those responses were greater with F10023 than with F10022. Growth response to N application was particularly strong. N and P application increased the proportional allocation of biomass to leaves. Under increased N supply, P application increased foliar N concentration and content, as well as total N uptake by the seedlings. However, NUE was decreased by N addition and was higher in F10023 than in F10022 when P was not limiting. A better understanding of genotype by fertility interactions is important in selecting genotypes for specific site conditions and for optimizing nutrient use in forestry production.

  20. ROOT BIOMASS ALLOCATION IN THE WORLD'S UPLAND FORESTS

    EPA Science Inventory

    Because the world's forests play a major role in regulating nutrient and carbon cycles, there is much interest in estimating their biomass. Estimates of aboveground biomass based on well-established methods are relatively abundant; estimates of root biomass based on standard meth...

  1. Phytohormonal Regulation of Biomass Allocation and Morphological and Physiological Traits of Leaves in Response to Environmental Changes in Polygonum cuspidatum.

    PubMed

    Sugiura, Daisuke; Kojima, Mikiko; Sakakibara, Hitoshi

    2016-01-01

    Plants plastically change their morphological and physiological traits in response to environmental changes, which are accompanied by changes in endogenous levels of phytohormones. Although roles of phytohormones in various aspects of plant growth and development were elucidated, their importance in the regulation of biomass allocation was not fully investigated. This study aimed to determine causal relationships among changes in biomass allocation, morphological and physiological traits, and endogenous levels of phytohormones such as gibberellins (GAs) and cytokinins (CKs) in response to environmental changes in Polygonum cuspidatum. Seedlings of P. cuspidatum were grown under two light intensities, each at three nitrogen availabilities. The seedlings grown in high light intensity and high nitrogen availability (HH) were subjected to three additional treatments: Defoliating half of the leaves (Def), transferral to low nitrogen availability (LowN), or low light intensity (LowL). Biomass allocation at the whole-plant level, morphological and physiological traits of each leaf, and endogenous levels of phytohormones in each leaf and shoot apex were measured. Age-dependent changes in leaf traits were also investigated. After the treatments, endogenous levels of GAs in the shoot apex and leaves significantly increased in Def, decreased in LowN, and did not change in LowL compared with HH seedlings. Among all of the seedlings, the levels of GAs in the shoot apex and leaves were strongly correlated with biomass allocation ratio between leaves and roots. The levels of GAs in the youngest leaves were highest, while the levels of CKs were almost consistent in each leaf. The levels of CKs were positively correlated with leaf nitrogen content in each leaf, whereas the levels of GAs were negatively correlated with the total non-structural carbohydrate content in each leaf. These results support our hypothesis that GAs and CKs are key regulatory factors that control biomass

  2. Phytohormonal Regulation of Biomass Allocation and Morphological and Physiological Traits of Leaves in Response to Environmental Changes in Polygonum cuspidatum

    PubMed Central

    Sugiura, Daisuke; Kojima, Mikiko; Sakakibara, Hitoshi

    2016-01-01

    Plants plastically change their morphological and physiological traits in response to environmental changes, which are accompanied by changes in endogenous levels of phytohormones. Although roles of phytohormones in various aspects of plant growth and development were elucidated, their importance in the regulation of biomass allocation was not fully investigated. This study aimed to determine causal relationships among changes in biomass allocation, morphological and physiological traits, and endogenous levels of phytohormones such as gibberellins (GAs) and cytokinins (CKs) in response to environmental changes in Polygonum cuspidatum. Seedlings of P. cuspidatum were grown under two light intensities, each at three nitrogen availabilities. The seedlings grown in high light intensity and high nitrogen availability (HH) were subjected to three additional treatments: Defoliating half of the leaves (Def), transferral to low nitrogen availability (LowN), or low light intensity (LowL). Biomass allocation at the whole-plant level, morphological and physiological traits of each leaf, and endogenous levels of phytohormones in each leaf and shoot apex were measured. Age-dependent changes in leaf traits were also investigated. After the treatments, endogenous levels of GAs in the shoot apex and leaves significantly increased in Def, decreased in LowN, and did not change in LowL compared with HH seedlings. Among all of the seedlings, the levels of GAs in the shoot apex and leaves were strongly correlated with biomass allocation ratio between leaves and roots. The levels of GAs in the youngest leaves were highest, while the levels of CKs were almost consistent in each leaf. The levels of CKs were positively correlated with leaf nitrogen content in each leaf, whereas the levels of GAs were negatively correlated with the total non-structural carbohydrate content in each leaf. These results support our hypothesis that GAs and CKs are key regulatory factors that control biomass

  3. Global allocation rules for patterns of biomass partitioning in seed plants.

    PubMed

    Enquist, Brian J; Niklas, Karl J

    2002-02-22

    A general allometric model has been derived to predict intraspecific and interspecific scaling relationships among seed plant leaf, stem, and root biomass. Analysis of a large compendium of standing organ biomass sampled across a broad sampling of taxa inhabiting diverse ecological habitats supports the relations predicted by the model and defines the boundary conditions for above- and below-ground biomass partitioning. These canonical biomass relations are insensitive to phyletic affiliation (conifers versus angiosperms) and variation in averaged local environmental conditions. The model thus identifies and defines the limits that have guided the diversification of seed plant biomass allocation strategies.

  4. Reproductive Allocation of Biomass and Nitrogen in Annual and Perennial Lesquerella Crops

    PubMed Central

    PLOSCHUK, E. L.; SLAFER, G. A.; RAVETTA, D. A.

    2005-01-01

    • Background and Aims The use of perennial crops could contribute to increase agricultural sustainability. However, almost all of the major grain crops are herbaceous annuals and opportunities to replace them with more long-lived perennials have been poorly explored. This follows the presumption that the perennial life cycle is associated with a lower potential yield, due to a reduced allocation of biomass to grains. The hypothesis was tested that allocation to perpetuation organs in the perennial L. mendocina would not be directly related to a lower allocation to seeds. • Methods Two field experiments were carried on with the annual Lesquerella fendleri and the iteroparous perennial L. mendocina, two promising oil-seed crops for low-productivity environments, subjected to different water and nitrogen availability. • Key Results Seed biomass allocation was similar for both species, and unresponsive to water and nitrogen availability. Greater root and vegetative shoot allocation in the perennial was counterbalanced by a lower allocation to other reproductive structures compared with the annual Lesquerella. Allometric relationships revealed that allocation differences between the annual and the perennial increased linearly with plant size. The general allocation patterns for nitrogen did not differ from those of biomass. However, nitrogen concentrations were higher in the vegetative shoot and root of L. mendocina than of L. fendleri but remained stable in seeds of both species. • Conclusions It is concluded that vegetative organs are more hierarchically important sinks in L. mendocina than in the annual L. fendleri, but without disadvantages in seed hierarchy. PMID:15863469

  5. Biogeographical patterns of biomass allocation in leaves, stems, and roots in China's forests.

    PubMed

    Zhang, Hao; Wang, Kelin; Xu, Xianli; Song, Tongqing; Xu, Yanfang; Zeng, Fuping

    2015-11-03

    To test whether there are general patterns in biomass partitioning in relation to environmental variation when stand biomass is considered, we investigated biomass allocation in leaves, stems, and roots in China's forests using both the national forest inventory data (2004-2008) and our field measurements (2011-2012). Distribution patterns of leaf, stem, and root biomass showed significantly different trends according to latitude, longitude, and altitude, and were positively and significantly correlated with stand age and mean annual precipitation. Trade-offs among leaves, stems, and roots varied with forest type and origin and were mainly explained by stand biomass. Based on the constraints of stand biomass, biomass allocation was also influenced by forest type, origin, stand age, stand density, mean annual temperature, precipitation, and maximum temperature in the growing season. Therefore, after stand biomass was accounted for, the residual variation in biomass allocation could be partially explained by stand characteristics and environmental factors, which may aid in quantifying carbon cycling in forest ecosystems and assessing the impacts of climate change on forest carbon dynamics in China.

  6. Biogeographical patterns of biomass allocation in leaves, stems, and roots in China's forests.

    PubMed

    Zhang, Hao; Wang, Kelin; Xu, Xianli; Song, Tongqing; Xu, Yanfang; Zeng, Fuping

    2015-01-01

    To test whether there are general patterns in biomass partitioning in relation to environmental variation when stand biomass is considered, we investigated biomass allocation in leaves, stems, and roots in China's forests using both the national forest inventory data (2004-2008) and our field measurements (2011-2012). Distribution patterns of leaf, stem, and root biomass showed significantly different trends according to latitude, longitude, and altitude, and were positively and significantly correlated with stand age and mean annual precipitation. Trade-offs among leaves, stems, and roots varied with forest type and origin and were mainly explained by stand biomass. Based on the constraints of stand biomass, biomass allocation was also influenced by forest type, origin, stand age, stand density, mean annual temperature, precipitation, and maximum temperature in the growing season. Therefore, after stand biomass was accounted for, the residual variation in biomass allocation could be partially explained by stand characteristics and environmental factors, which may aid in quantifying carbon cycling in forest ecosystems and assessing the impacts of climate change on forest carbon dynamics in China. PMID:26525117

  7. Biogeographical patterns of biomass allocation in leaves, stems, and roots in China’s forests

    PubMed Central

    Zhang, Hao; Wang, Kelin; Xu, Xianli; Song, Tongqing; Xu, Yanfang; Zeng, Fuping

    2015-01-01

    To test whether there are general patterns in biomass partitioning in relation to environmental variation when stand biomass is considered, we investigated biomass allocation in leaves, stems, and roots in China’s forests using both the national forest inventory data (2004–2008) and our field measurements (2011–2012). Distribution patterns of leaf, stem, and root biomass showed significantly different trends according to latitude, longitude, and altitude, and were positively and significantly correlated with stand age and mean annual precipitation. Trade-offs among leaves, stems, and roots varied with forest type and origin and were mainly explained by stand biomass. Based on the constraints of stand biomass, biomass allocation was also influenced by forest type, origin, stand age, stand density, mean annual temperature, precipitation, and maximum temperature in the growing season. Therefore, after stand biomass was accounted for, the residual variation in biomass allocation could be partially explained by stand characteristics and environmental factors, which may aid in quantifying carbon cycling in forest ecosystems and assessing the impacts of climate change on forest carbon dynamics in China. PMID:26525117

  8. Above- and Belowground Biomass Allocation in Shrub Biomes across the Northeast Tibetan Plateau

    PubMed Central

    Yang, Yuanhe; Yang, Lucun; Zhou, Guoying

    2016-01-01

    Biomass partitioning has been explored across various biomes. However, the strategies of allocation in plants still remain contentious. This study investigated allocation patterns of above- and belowground biomass at the community level, using biomass survey from the Tibetan Plateau. We explored above- and belowground biomass by conducting three consecutive sampling campaigns across shrub biomes on the northeast Tibetan Plateau during 2011–2013. We then documented the above-ground biomass (AGB), below-ground biomass (BGB) and root: shoot ratio (R/S) and the relationships between R/S and environment factors using data from 201 plots surveyed from 67 sites. We further examined relationships between above-ground and below-ground biomass across various shrub types. Our results indicated that the median values of AGB, BGB, and R/S in Tibetan shrub were 1102.55, 874.91 g m-2, and 0.85, respectively. R/S showed significant trend with mean annual precipitation (MAP), while decreased with mean annual temperature (MAT). Reduced major axis analysis indicated that the slope of the log-log relationship between above- and belowground biomass revealed a significant difference from 1.0 over space, supporting the optimal hypothesis. Interestingly, the slopes of the allometric relationship between log AGB and log BGB differed significantly between alpine and desert shrub. Our findings supported the optimal theory of above- and belowground biomass partitioning in Tibetan shrub, while the isometric hypothesis for alpine shrub at the community level. PMID:27119379

  9. Macrophyte growth in shallow streams: biomass model

    SciTech Connect

    Wright, R.M.; Mc Donnell, A.J.

    1986-10-01

    An assessment was made of the water quality and the magnitude of growth of rooted aquatic macrophytes in a nutrient-enriched, shallow stream system in order to provide a basis for evaluating the recovery of the ecosystem following the implementation of a program of phosphorus removal. Field investigations defined the temporal and spatial changes of plant biomass in selected study sections. A model to predict changes in macrophyte biomass as a function of varying environmental factors including nutrient flux was developed, calibrated and validated. The potential of the biomass model as a management tool to assess the impact of nutrient reductions on stream oxygen budgets was demonstrated.

  10. Food restriction alters energy allocation strategy during growth in tobacco hornworms (Manduca sexta larvae).

    PubMed

    Jiao, Lihong; Amunugama, Kaushalya; Hayes, Matthew B; Jennings, Michael; Domingo, Azriel; Hou, Chen

    2015-08-01

    Growing animals must alter their energy budget in the face of environmental changes and prioritize the energy allocation to metabolism for life-sustaining requirements and energy deposition in new biomass growth. We hypothesize that when food availability is low, larvae of holometabolic insects with a short development stage (relative to the low food availability period) prioritize biomass growth at the expense of metabolism. Driven by this hypothesis, we develop a simple theoretical model, based on conservation of energy and allometric scaling laws, for understanding the dynamic energy budget of growing larvae under food restriction. We test the hypothesis by manipulative experiments on fifth instar hornworms at three temperatures. At each temperature, food restriction increases the scaling power of growth rate but decreases that of metabolic rate, as predicted by the hypothesis. During the fifth instar, the energy budgets of larvae change dynamically. The free-feeding larvae slightly decrease the energy allocated to growth as body mass increases and increase the energy allocated to life sustaining. The opposite trends were observed in food restricted larvae, indicating the predicted prioritization in the energy budget under food restriction. We compare the energy budgets of a few endothermic and ectothermic species and discuss how different life histories lead to the differences in the energy budgets under food restriction. PMID:26105046

  11. Food restriction alters energy allocation strategy during growth in tobacco hornworms ( Manduca sexta larvae)

    NASA Astrophysics Data System (ADS)

    Jiao, Lihong; Amunugama, Kaushalya; Hayes, Matthew B.; Jennings, Michael; Domingo, Azriel; Hou, Chen

    2015-08-01

    Growing animals must alter their energy budget in the face of environmental changes and prioritize the energy allocation to metabolism for life-sustaining requirements and energy deposition in new biomass growth. We hypothesize that when food availability is low, larvae of holometabolic insects with a short development stage (relative to the low food availability period) prioritize biomass growth at the expense of metabolism. Driven by this hypothesis, we develop a simple theoretical model, based on conservation of energy and allometric scaling laws, for understanding the dynamic energy budget of growing larvae under food restriction. We test the hypothesis by manipulative experiments on fifth instar hornworms at three temperatures. At each temperature, food restriction increases the scaling power of growth rate but decreases that of metabolic rate, as predicted by the hypothesis. During the fifth instar, the energy budgets of larvae change dynamically. The free-feeding larvae slightly decrease the energy allocated to growth as body mass increases and increase the energy allocated to life sustaining. The opposite trends were observed in food restricted larvae, indicating the predicted prioritization in the energy budget under food restriction. We compare the energy budgets of a few endothermic and ectothermic species and discuss how different life histories lead to the differences in the energy budgets under food restriction.

  12. Food restriction alters energy allocation strategy during growth in tobacco hornworms (Manduca sexta larvae).

    PubMed

    Jiao, Lihong; Amunugama, Kaushalya; Hayes, Matthew B; Jennings, Michael; Domingo, Azriel; Hou, Chen

    2015-08-01

    Growing animals must alter their energy budget in the face of environmental changes and prioritize the energy allocation to metabolism for life-sustaining requirements and energy deposition in new biomass growth. We hypothesize that when food availability is low, larvae of holometabolic insects with a short development stage (relative to the low food availability period) prioritize biomass growth at the expense of metabolism. Driven by this hypothesis, we develop a simple theoretical model, based on conservation of energy and allometric scaling laws, for understanding the dynamic energy budget of growing larvae under food restriction. We test the hypothesis by manipulative experiments on fifth instar hornworms at three temperatures. At each temperature, food restriction increases the scaling power of growth rate but decreases that of metabolic rate, as predicted by the hypothesis. During the fifth instar, the energy budgets of larvae change dynamically. The free-feeding larvae slightly decrease the energy allocated to growth as body mass increases and increase the energy allocated to life sustaining. The opposite trends were observed in food restricted larvae, indicating the predicted prioritization in the energy budget under food restriction. We compare the energy budgets of a few endothermic and ectothermic species and discuss how different life histories lead to the differences in the energy budgets under food restriction.

  13. Regional allocation of biomass to U.S. energy demands under a portfolio of policy scenarios.

    PubMed

    Mullins, Kimberley A; Venkatesh, Aranya; Nagengast, Amy L; Kocoloski, Matt

    2014-01-01

    The potential for widespread use of domestically available energy resources, in conjunction with climate change concerns, suggest that biomass may be an essential component of U.S. energy systems in the near future. Cellulosic biomass in particular is anticipated to be used in increasing quantities because of policy efforts, such as federal renewable fuel standards and state renewable portfolio standards. Unfortunately, these independently designed biomass policies do not account for the fact that cellulosic biomass can equally be used for different, competing energy demands. An integrated assessment of multiple feedstocks, energy demands, and system costs is critical for making optimal decisions about a unified biomass energy strategy. This study develops a spatially explicit, best-use framework to optimally allocate cellulosic biomass feedstocks to energy demands in transportation, electricity, and residential heating sectors, while minimizing total system costs and tracking greenhouse gas emissions. Comparing biomass usage across three climate policy scenarios suggests that biomass used for space heating is a low cost emissions reduction option, while biomass for liquid fuel or for electricity becomes attractive only as emissions reduction targets or carbon prices increase. Regardless of the policy approach, study results make a strong case for national and regional coordination in policy design and compliance pathways.

  14. Regional allocation of biomass to U.S. energy demands under a portfolio of policy scenarios.

    PubMed

    Mullins, Kimberley A; Venkatesh, Aranya; Nagengast, Amy L; Kocoloski, Matt

    2014-01-01

    The potential for widespread use of domestically available energy resources, in conjunction with climate change concerns, suggest that biomass may be an essential component of U.S. energy systems in the near future. Cellulosic biomass in particular is anticipated to be used in increasing quantities because of policy efforts, such as federal renewable fuel standards and state renewable portfolio standards. Unfortunately, these independently designed biomass policies do not account for the fact that cellulosic biomass can equally be used for different, competing energy demands. An integrated assessment of multiple feedstocks, energy demands, and system costs is critical for making optimal decisions about a unified biomass energy strategy. This study develops a spatially explicit, best-use framework to optimally allocate cellulosic biomass feedstocks to energy demands in transportation, electricity, and residential heating sectors, while minimizing total system costs and tracking greenhouse gas emissions. Comparing biomass usage across three climate policy scenarios suggests that biomass used for space heating is a low cost emissions reduction option, while biomass for liquid fuel or for electricity becomes attractive only as emissions reduction targets or carbon prices increase. Regardless of the policy approach, study results make a strong case for national and regional coordination in policy design and compliance pathways. PMID:24512511

  15. [Biomass- and energy allocation in Eucalyptus urophylla x Eucalyptus tereticornis plantations at different stand ages].

    PubMed

    Zhou, Qun-Ying; Chen, Shao-Xiong; Han, Fei-Yang; Chen, Wen-Ping; Wu, Zhi-Hua

    2010-01-01

    An investigation was made on the biomass- and energy allocation in 1-4-year-old Eucalyptus urophylla x Eucalyptus tereticornis plantations at Beipo Forest Farm of Suixi County in Guangdong Province. Stand age had significant effects on the retained biomass of the plantations (P < 0.01). The biomass was in the range of 10.61-147.28 t x hm(-2). Both the total biomass and the biomass of above- and belowground components increased with increasing stand age. The proportions of leaf-, branch- and bark biomass to total biomass decreased with year, while that of stem biomass was in reverse. The biomass allocation of the components in 1- and 2-year-old plantations decreased in order of stem > branch > bark > root > leaf, and that in 3- and 4 -year-old plantations was in order of stem > root > branch > bark > leaf. The mean ash content (AC) of the five components at different stand ages ranged from 0.47% to 5.91%, being the highest in bark and the lowest in stem. The mean gross caloric value (GCV) and ash free caloric value (AFCV) of different components ranged from 17.33 to 20. 60 kJ x g(-1) and from 18.42 to 21.59 kJ x g(-1) respectively. Of all the components, leaf had the highest GVC and AFCV, while bark had the lowest ones. Stand age had significant effects on the GVC of branch, stem, and bark, and on the AFCV of leaf, stem, and bark (P < 0.05), but the effects on the GVC of leaf and root, the AFCV of branch and root, and the GVC and AFCV of individual trees were not significant (P > 0.05). The retained energy of 1-4-year-old plantations ranged from 199.98 to 2837.20 GJ x hm(-2), with significant differences among the stand ages (P < 0.01). The retained energy of various components and plantations increased with stand age, and the energy allocation of various components had the same trend as biomass allocation.

  16. Does ozone exposure alter growth and carbon allocation of mycorrhizal plants

    SciTech Connect

    Yoshida, L.C.; Gamon, J.A. ); Andersen, C.P. )

    1994-06-01

    Ozone is known to adversely affect plant growth. However, it is less clear how ozone affects belowground processes. This study tests the hypothesis that ozone alters growth and carbon allocation of vesicular arbuscular mycorrhizal (VAM) plants. Two ecotypes of Elymus glaucus (blue wild rye) were exposed to mycorrhizal inoculation and episodic ozone exposures simulating atmospheric conditions in the Los Angeles Basin. Preliminary results show that effects of ozone on growth were subtle. In both ecotypes, growth of aboveground biomass was not affected by ozone while root growth was decreased. In most treatments, mycorrhizal inoculation decreased growth of leaves and stems, but had no significant effect on root growth. Three-way ANOVA tests indicated interactive effects between ecotype, mycorrhiza and ozone. Further experimental work is needed to reveal the biological processes governing these responses.

  17. Growth, allocation and tissue chemistry of Picea abies seedlings affected by nutrient supply during the second growing season.

    PubMed

    Kaakinen, Seija; Jolkkonen, Annika; Iivonen, Sari; Vapaavuori, Elina

    2004-06-01

    One-year-old Norway spruce (Picea abies (L.) Karst.) seedlings were grown hydroponically in a growth chamber to investigate the effects of low and high nutrient availability (LN; 0.25 mM N and HN; 2.50 mM N) on growth, biomass allocation and chemical composition of needles, stem and roots during the second growing season. Climatic conditions in the growth chamber simulated the mean growing season from May to early October in Flakaliden, northern Sweden. In the latter half of the growing season, biomass allocation changed in response to nutrient availability: increased root growth and decreased shoot growth led to higher root/shoot ratios in LN seedlings than in HN seedlings. At high nutrient availability, total biomass, especially stem biomass, increased, as did total nonstructural carbohydrate and nitrogen contents per seedling. Responses of stem chemistry to nutrient addition differed from those of adult trees of the same provenance. In HN seedlings, concentrations of alpha-cellulose, hemicellulose and lignin decreased in the secondary xylem. Our results illustrate the significance of retranslocation of stored nutrients to support new growth early in the season when root growth and nutrient uptake are still low. We conclude that nutrient availability alters allocation patterns, thereby influencing the success of 2-year-old Norway spruce seedlings at forest planting sites. PMID:15059771

  18. High water level impedes the adaptation of Polygonum hydropiper to deep burial: responses of biomass allocation and root morphology.

    PubMed

    Pan, Ying; Xie, Yong H; Deng, Zheng M; Tang, Yue; Pan, Dong D

    2014-07-08

    Many studies have investigated the individual effects of sedimentation or inundation on the performance of wetland plants, but few have examined the combined influence of these processes. Wetland plants might show greater morphological plasticity in response to inundation than to sedimentation when these processes occur simultaneously since inundation can negate the negative effects of burial on plant growth. Here, we evaluate this hypothesis by assessing growth of the emergent macrophyte Polygonum hydropiper under flooding (0 and 40 cm) and sedimentation (0, 5, and 10 cm), separately and in combination. Deep burial and high water level each led to low oxidation-reduction potential, biomass (except for 5-cm burial), and growth of thick, short roots. These characteristics were generally more significant under high water level than under deep burial conditions. More biomass was allocated to stems in the deep burial treatments, but more to leaves in the high water level treatments. Additionally, biomass accumulation was lower and leaf mass ratio was higher in the 40-cm water level + 10-cm burial depth treatment than both separate effects. Our data indicate that inundation plays a more important role than sedimentation in determining plant morphology, suggesting hierarchical effects of environmental stressors on plant growth.

  19. High water level impedes the adaptation of Polygonum hydropiper to deep burial: Responses of biomass allocation and root morphology

    PubMed Central

    Pan, Ying; Xie, Yong H.; Deng, Zheng M.; Tang, Yue; Pan, Dong D.

    2014-01-01

    Many studies have investigated the individual effects of sedimentation or inundation on the performance of wetland plants, but few have examined the combined influence of these processes. Wetland plants might show greater morphological plasticity in response to inundation than to sedimentation when these processes occur simultaneously since inundation can negate the negative effects of burial on plant growth. Here, we evaluate this hypothesis by assessing growth of the emergent macrophyte Polygonum hydropiper under flooding (0 and 40 cm) and sedimentation (0, 5, and 10 cm), separately and in combination. Deep burial and high water level each led to low oxidation-reduction potential, biomass (except for 5-cm burial), and growth of thick, short roots. These characteristics were generally more significant under high water level than under deep burial conditions. More biomass was allocated to stems in the deep burial treatments, but more to leaves in the high water level treatments. Additionally, biomass accumulation was lower and leaf mass ratio was higher in the 40-cm water level + 10-cm burial depth treatment than both separate effects. Our data indicate that inundation plays a more important role than sedimentation in determining plant morphology, suggesting hierarchical effects of environmental stressors on plant growth. PMID:25002329

  20. Carbon budget for Scots pine trees: effects of size, competition and site fertility on growth allocation and production.

    PubMed

    Vanninen, Petteri; Mäkelä, Annikki

    2005-01-01

    Time series of carbon fluxes in individual Scots pine (Pinus sylvestris L.) trees were constructed based on biomass measurements and information about component-specific turnover and respiration rates. Foliage, branch, stem sapwood, heartwood and bark components of aboveground biomass were measured in 117 trees sampled from 17 stands varying in age, density and site fertility. A subsample of 32 trees was measured for belowground biomass excluding fine roots. Biomass of fine roots was estimated from the results of an earlier study. Statistical models were constructed to predict dry mass (DW) of components from tree height and basal area, and time derivatives of these models were used to estimate biomass increments from height growth and basal area growth. Biomass growth (G) was estimated by adding estimated biomass turnover rates to increments, and gross photosynthetic production (P) was estimated by adding estimated component respiration rates to growth. The method, which predicts the time course of G, P and biomass increment in individual trees as functions of height growth and basal area growth, was applied to eight example trees representing different dominance positions and site fertilities. Estimated G and P of the example trees varied with competition, site fertility and tree height, reaching maximum values of 22 and 43 kg(DW) year(-1), respectively. The site types did not show marked differences in productivity of trees of the same height, although height growth was greater on the fertile site. The G:P ratio decreased with tree height from 65 to 45%. Growth allocation to needles and branches increased with increasing dominance, whereas growth allocation to the stem decreased. Growth allocation to branches decreased and growth allocation to coarse roots increased with increasing tree size. Trees at the poor site allocated 49% more to fine roots than trees at the fertile site. The belowground parts accounted for 25 to 55% of annual G, increasing with tree size

  1. C3 and C4 biomass allocation responses to elevated CO2 and nitrogen: contrasting resource capture strategies

    USGS Publications Warehouse

    White, K.P.; Langley, J.A.; Cahoon, D.R.; Megonigal, J.P.

    2012-01-01

    Plants alter biomass allocation to optimize resource capture. Plant strategy for resource capture may have important implications in intertidal marshes, where soil nitrogen (N) levels and atmospheric carbon dioxide (CO2) are changing. We conducted a factorial manipulation of atmospheric CO2 (ambient and ambient + 340 ppm) and soil N (ambient and ambient + 25 g m-2 year-1) in an intertidal marsh composed of common North Atlantic C3 and C4 species. Estimation of C3 stem turnover was used to adjust aboveground C3 productivity, and fine root productivity was partitioned into C3-C4 functional groups by isotopic analysis. The results suggest that the plants follow resource capture theory. The C3 species increased aboveground productivity under the added N and elevated CO2 treatment (P 2 alone. C3 fine root production decreased with added N (P 2 (P = 0.0481). The C4 species increased growth under high N availability both above- and belowground, but that stimulation was diminished under elevated CO2. The results suggest that the marsh vegetation allocates biomass according to resource capture at the individual plant level rather than for optimal ecosystem viability in regards to biomass influence over the processes that maintain soil surface elevation in equilibrium with sea level.

  2. Belowground plant biomass allocation in tundra ecosystems and its relationship with temperature

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Heijmans, Monique M. P. D.; Mommer, Liesje; van Ruijven, Jasper; Maximov, Trofim C.; Berendse, Frank

    2016-05-01

    Climate warming is known to increase the aboveground productivity of tundra ecosystems. Recently, belowground biomass is receiving more attention, but the effects of climate warming on belowground productivity remain unclear. Enhanced understanding of the belowground component of the tundra is important in the context of climate warming, since most carbon is sequestered belowground in these ecosystems. In this study we synthesized published tundra belowground biomass data from 36 field studies spanning a mean annual temperature (MAT) gradient from -20 °C to 0 °C across the tundra biome, and determined the relationships between different plant biomass pools and MAT. Our results show that the plant community biomass-temperature relationships are significantly different between above and belowground. Aboveground biomass clearly increased with MAT, whereas total belowground biomass and fine root biomass did not show a significant increase over the broad MAT gradient. Our results suggest that biomass allocation of tundra vegetation shifts towards aboveground in warmer conditions, which could impact on the carbon cycling in tundra ecosystems through altered litter input and distribution in the soil, as well as possible changes in root turnover.

  3. Belowground plant biomass allocation in tundra ecosystems and its relationship with temperature

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Heijmans, Monique M. P. D.; Mommer, Liesje; van Ruijven, Jasper; Maximov, Trofim C.; Berendse, Frank

    2016-05-01

    Climate warming is known to increase the aboveground productivity of tundra ecosystems. Recently, belowground biomass is receiving more attention, but the effects of climate warming on belowground productivity remain unclear. Enhanced understanding of the belowground component of the tundra is important in the context of climate warming, since most carbon is sequestered belowground in these ecosystems. In this study we synthesized published tundra belowground biomass data from 36 field studies spanning a mean annual temperature (MAT) gradient from ‑20 °C to 0 °C across the tundra biome, and determined the relationships between different plant biomass pools and MAT. Our results show that the plant community biomass–temperature relationships are significantly different between above and belowground. Aboveground biomass clearly increased with MAT, whereas total belowground biomass and fine root biomass did not show a significant increase over the broad MAT gradient. Our results suggest that biomass allocation of tundra vegetation shifts towards aboveground in warmer conditions, which could impact on the carbon cycling in tundra ecosystems through altered litter input and distribution in the soil, as well as possible changes in root turnover.

  4. Soil water content and patterns of allocation to below- and above-ground biomass in the sexes of the subdioecious plant Honckenya peploides

    PubMed Central

    Sánchez-Vilas, Julia; Bermúdez, Raimundo; Retuerto, Rubén

    2012-01-01

    Background and aims Dioecious plants often show sex-specific differences in growth and biomass allocation. These differences have been explained as a consequence of the different reproductive functions performed by the sexes. Empirical evidence strongly supports a greater reproductive investment in females. Sex differences in allocation may determine the performance of each sex in different habitats and therefore might explain the spatial segregation of the sexes described in many dimorphic plants. Here, an investigation was made of the sexual dimorphism in seasonal patterns of biomass allocation in the subdioecious perennial herb Honckenya peploides, a species that grows in embryo dunes (i.e. the youngest coastal dune formation) and displays spatial segregation of the sexes at the studied site. The water content in the soil of the male- and female-plant habitats at different times throughout the season was also examined. Methods The seasonal patterns of soil-water availability and biomass allocation were compared in two consecutive years in male and female H. peploides plants by collecting soil and plant samples in natural populations. Vertical profiles of below-ground biomass and water content were studied by sampling soil in male- and female-plant habitats at different soil depths. Key Results The sexes of H. peploides differed in their seasonal patterns of biomass allocation to reproduction. Males invested twice as much in reproduction than females early in the season, but sexual differences became reversed as the season progressed. No differences were found in above-ground biomass between the sexes, but the allocation of biomass to below-ground structures varied differently in depth for males and females, with females usually having greater below-ground biomass than males. In addition, male and female plants of H. peploides had different water-content profiles in the soil where they were growing and, when differences existed (usually in the upper layers of the

  5. Floral bud damage compensation by branching and biomass allocation in genotypes of Brassica napus with different architecture and branching potential

    PubMed Central

    Pinet, Amélie; Mathieu, Amélie; Jullien, Alexandra

    2015-01-01

    Plant branching is a key process in the yield elaboration of winter oilseed rape (WOSR). It is also involved in plant tolerance to flower damage because it allows the setting of new fertile inflorescences. Here we characterize the changes in the branching and distribution of the number of pods between primary and secondary inflorescences in response to floral bud clippings. Then we investigate the impacts of the modifications in branching on the biomass allocation and its consequence on the crop productivity (harvest index). These issues were addressed on plants with contrasted architecture and branching potential, using three genotypes (Exocet, Pollen, and Gamin) grown under two levels of nitrogen fertilization. Clipping treatments of increasing intensities were applied to either inflorescences or flower buds. We were able to show that restoration of the number of pods after clipping is the main lever for the compensation. Genotypes presented different behaviors in branching and biomass allocation as a function of clipping treatments. The number of fertile ramifications increased for the high intensities of clipping. In particular, the growth of secondary ramifications carried by branches developed before clipping has been observed. The proportions of yield and of number of pods carried by these secondary axes increased and became almost equivalent to the proportion carried by primary inflorescences. In terms of biomass allocation, variations have also been evidenced in the relationship between pod dry mass on a given axis and the number of pods set, while the shoot/root ratio was not modified. The harvest index presented different responses: it decreased after flower buds clipping, while it was maintained after the clipping of the whole inflorescences. The results are discussed relative to their implications regarding the identification of interesting traits to be target in breeding programs in order to improve WOSR tolerance. PMID:25759703

  6. Elevated air humidity affects hydraulic traits and tree size but not biomass allocation in young silver birches (Betula pendula).

    PubMed

    Sellin, Arne; Rosenvald, Katrin; Õunapuu-Pikas, Eele; Tullus, Arvo; Ostonen, Ivika; Lõhmus, Krista

    2015-01-01

    As changes in air temperature, precipitation, and air humidity are expected in the coming decades, studies on the impact of these environmental shifts on plant growth and functioning are of major importance. Greatly understudied aspects of climate change include consequences of increasing air humidity on forest ecosystems, predicted for high latitudes. The main objective of this study was to find a link between hydraulic acclimation and shifts in trees' resource allocation in silver birch (Betula pendula Roth) in response to elevated air relative humidity (RH). A second question was whether the changes in hydraulic architecture depend on tree size. Two years of application of increased RH decreased the biomass accumulation in birch saplings, but the biomass partitioning among aboveground parts (leaves, branches, and stems) remained unaffected. Increased stem Huber values (xylem cross-sectional area to leaf area ratio) observed in trees under elevated RH did not entail changes in the ratio of non-photosynthetic to photosynthetic tissues. The reduction of stem-wood density is attributable to diminished mechanical load imposed on the stem, since humidified trees had relatively shorter crowns. Growing under higher RH caused hydraulic conductance of the root system (K R) to increase, while K R (expressed per unit leaf area) decreased and leaf hydraulic conductance increased with tree size. Saplings of silver birch acclimate to increasing air humidity by adjusting plant morphology (live crown length, slenderness, specific leaf area, and fine-root traits) and wood density rather than biomass distribution among aboveground organs. The treatment had a significant effect on several hydraulic properties of the trees, while the shifts were largely associated with changes in tree size but not in biomass allocation.

  7. Elevated air humidity affects hydraulic traits and tree size but not biomass allocation in young silver birches (Betula pendula)

    PubMed Central

    Sellin, Arne; Rosenvald, Katrin; Õunapuu-Pikas, Eele; Tullus, Arvo; Ostonen, Ivika; Lõhmus, Krista

    2015-01-01

    As changes in air temperature, precipitation, and air humidity are expected in the coming decades, studies on the impact of these environmental shifts on plant growth and functioning are of major importance. Greatly understudied aspects of climate change include consequences of increasing air humidity on forest ecosystems, predicted for high latitudes. The main objective of this study was to find a link between hydraulic acclimation and shifts in trees’ resource allocation in silver birch (Betula pendula Roth) in response to elevated air relative humidity (RH). A second question was whether the changes in hydraulic architecture depend on tree size. Two years of application of increased RH decreased the biomass accumulation in birch saplings, but the biomass partitioning among aboveground parts (leaves, branches, and stems) remained unaffected. Increased stem Huber values (xylem cross-sectional area to leaf area ratio) observed in trees under elevated RH did not entail changes in the ratio of non-photosynthetic to photosynthetic tissues. The reduction of stem–wood density is attributable to diminished mechanical load imposed on the stem, since humidified trees had relatively shorter crowns. Growing under higher RH caused hydraulic conductance of the root system (KR) to increase, while KR (expressed per unit leaf area) decreased and leaf hydraulic conductance increased with tree size. Saplings of silver birch acclimate to increasing air humidity by adjusting plant morphology (live crown length, slenderness, specific leaf area, and fine-root traits) and wood density rather than biomass distribution among aboveground organs. The treatment had a significant effect on several hydraulic properties of the trees, while the shifts were largely associated with changes in tree size but not in biomass allocation. PMID:26528318

  8. Plant competition and slug herbivory: Effects on the yield and biomass allocation pattern of Poa annua L

    NASA Astrophysics Data System (ADS)

    Rodríguez, Miguel A.; Brown, Valerie K.

    1998-02-01

    A factorial greenhouse experiment was conducted to examine the overall impact of slug herbivory, plant density and neighbour identity on the yield and allocation pattern of the short-lived grass Poa annua. The effects of slug herbivory were compared in experimental plants at two densities in two types of culture: pure and mixed with Arabidopsis thaliana. All the plant parts of P. annua showed significantly greater biomass in mixed than in pure stands, and in low compared to high density stands. Slug herbivory consistently reduced the biomass of reproductive organs and the percentage of total biomass allocated to reproduction, whereas density had no effect on allocation. In mixed stands, the proportion of biomass allocated to reproductive organs and leaves was greater and lesser, respectively, than in pure stands. There were significant interactions between herbivory and culture for root biomass and for the percentage of biomass allocated to root and shoots, and between herbivory, culture and density for shoot, stem, leaf and total biomass. Slug herbivory reduced root biomass in pure stands, whereas it did the opposite in mixed stands. The root:shoot ratio did not vary between mixed and pure stands in the absence of slugs, while when slugs were present pure stands had lower root/shoot ratio than mixed stands. Except for reproductive structures, all the plant parts showed greater biomass in grazed than in ungrazed low density mixed stands, whereas the general trend in high and low density pure stands, and in high density mixed stands was that herbivory decreased biomass. The study indicates that the competitive ability of plants is conditioned by a variety of factors. Plant density, the identity of competitors, and occurrence of herbivory are all relevant factors, the particular combination of which will alter competitive interactions.

  9. Life history implications of allocation to growth versus reproduction in dynamic energy budgets.

    PubMed

    Lika, Konstadia; Kooijman, Sebastiaan A L M

    2003-09-01

    We compare the implications of determinate vs. indeterminate growth of a parthenogenetic iteroparous ectotherm at constant food density in the context of the dynamic energy budget theory, which specifies the tight links between life history traits, such as feeding, aging, growth and reproduction. We do a comparative analysis using, as measure of fitness, the life span reproduction, the population growth rate, and the conversion efficiency of food to biomass. When extrinsic mortality is constant, indeterminate growth cannot maximize fitness if measured by the population growth rate or the conversion efficiency, except when mortality is low, in which case both types of animals are similar. If the fitness measure is life span reproduction, indeterminate growth maximizes fitness even with constant mortality, provided it is not very high. When mortality decreases with size, indeterminate growth maximizes fitness for almost all measures of fitness. Finally, we suggest an evolutionary link between allocation strategies and expected life span. In populations of long living species, each type of animal can establish in the population of the other. In populations of short living species, determinate growers can invade, and displace, a population of indeterminate ones. However, when the mortality risk of organisms with small size is much higher than those of large size, indeterminate growers can be superior.

  10. [Vegetation biomass allocation and its spatial distribution after 20 years ecological restoration in a dry-hot valley in Yuanmou, Yunnan Province of Southwest China].

    PubMed

    Li, Bin; Tang, Guo-Yong; Li, Kun; Gao, Cheng-Jie; Liu, Fang-Yan; Wang, Xiao-Fei

    2013-06-01

    By using layering harvest method, a comparative study was conducted on the biomass allocation and its spatial distribution of 20-year-old Eucalyptus camaldulensis plantation, Leucaena leucocephala plantation, and E. camaldulensis-L. leucocephala plantation in Yuanmou dry-hot valley of Yunnan Province, Southwest China. The stand biomass in the mixed E. camaldulensis-L. leucocephala plantation (82.99 t x hm(-2)) was between that of monoculture E. camaldulensis plantation (60.64 t x hm(-2)) and L. leucocephala plantation (127.79 t x hm(-2)). The individual tree biomass of E. camaldulensis in the mixed plantation (44.32 kg) was 49.8% higher than that in monoculture plantation (29.58 kg). The branch and leaf biomass of L. leucocephala (25.4%) in monoculture plantation was larger than that of E. camaldulensis (8.9%) in monoculture plantation, and the aboveground biomass distribution ratio (78.0%) of L. leucocephala (25.4%) was also higher than that of E. camaldulensis (73.4%). The roots of L. leucocephala in both monoculture and mixed plantations were mainly distributed in 0-40 cm soil layer, while those of E. camaldulensis in monoculture and mixed plantations were mainly found in 0-80 cm and 0-60 cm, respectively. The proportion of biomass allocated to roots including medium roots, small roots, and fine roots of L. leucocephala in mixed plantation was higher than that in monoculture plantation, but it was contrary for E. camaldulensis. It was suggested that introducing L. leucocephala in E. camaldulensis plantation promoted the growth of E. camaldulensis, especially for its aboveground biomass, and increased the amount of lateral roots in 0-20 cm soil layer, which had significance in soil and water conservation in the study area.

  11. [Vegetation biomass allocation and its spatial distribution after 20 years ecological restoration in a dry-hot valley in Yuanmou, Yunnan Province of Southwest China].

    PubMed

    Li, Bin; Tang, Guo-Yong; Li, Kun; Gao, Cheng-Jie; Liu, Fang-Yan; Wang, Xiao-Fei

    2013-06-01

    By using layering harvest method, a comparative study was conducted on the biomass allocation and its spatial distribution of 20-year-old Eucalyptus camaldulensis plantation, Leucaena leucocephala plantation, and E. camaldulensis-L. leucocephala plantation in Yuanmou dry-hot valley of Yunnan Province, Southwest China. The stand biomass in the mixed E. camaldulensis-L. leucocephala plantation (82.99 t x hm(-2)) was between that of monoculture E. camaldulensis plantation (60.64 t x hm(-2)) and L. leucocephala plantation (127.79 t x hm(-2)). The individual tree biomass of E. camaldulensis in the mixed plantation (44.32 kg) was 49.8% higher than that in monoculture plantation (29.58 kg). The branch and leaf biomass of L. leucocephala (25.4%) in monoculture plantation was larger than that of E. camaldulensis (8.9%) in monoculture plantation, and the aboveground biomass distribution ratio (78.0%) of L. leucocephala (25.4%) was also higher than that of E. camaldulensis (73.4%). The roots of L. leucocephala in both monoculture and mixed plantations were mainly distributed in 0-40 cm soil layer, while those of E. camaldulensis in monoculture and mixed plantations were mainly found in 0-80 cm and 0-60 cm, respectively. The proportion of biomass allocated to roots including medium roots, small roots, and fine roots of L. leucocephala in mixed plantation was higher than that in monoculture plantation, but it was contrary for E. camaldulensis. It was suggested that introducing L. leucocephala in E. camaldulensis plantation promoted the growth of E. camaldulensis, especially for its aboveground biomass, and increased the amount of lateral roots in 0-20 cm soil layer, which had significance in soil and water conservation in the study area. PMID:24066529

  12. Biomass Production System (BPS) Plant Growth Unit

    NASA Astrophysics Data System (ADS)

    Morrow, R. C.; Crabb, T. M.

    The Biomass Production System (BPS) was developed under the Small Business Innovative Research (SBIR) program to meet science, biotechnology and commercial plant growth needs in the Space Station era. The BPS is equivalent in size to a double middeck locker, but uses it's own custom enclosure with a slide out structure to which internal components mount. The BPS contains four internal growth chambers, each with a growing volume of more than 4 liters. Each of the growth chambers has active nutrient delivery, and independent control of temperature, humidity, lighting, and CO2 set-points. Temperature control is achieved using a thermoelectric heat exchanger system. Humidity control is achieved using a heat exchanger with a porous interface which can both humidify and dehumidify. The control software utilizes fuzzy logic for nonlinear, coupled temperature and humidity control. The fluorescent lighting system can be dimmed to provide a range of light levels. CO2 levels are controlled by injecting pure CO2 to the system based on input from an infrared gas analyzer. The unit currently does not scrub CO2, but has been designed to accept scrubber cartridges. In addition to providing environmental control, a number of features are included to facilitate science. The BPS chambers are sealed to allow CO2 and water vapor exchange measurements. The plant chambers can be removed to allow manipulation or sampling of specimens, and each chamber has gas/fluid sample ports. A video camera is provided for each chamber, and frame-grabs and complete environmental data for all science and hardware system sensors are stored on an internal hard drive. Data files can also be transferred to 3.5-inch disks using the front panel disk drive

  13. Biomass Production System (BPS) plant growth unit.

    PubMed

    Morrow, R C; Crabb, T M

    2000-01-01

    The Biomass Production System (BPS) was developed under the Small Business Innovative Research (SBIR) program to meet science, biotechnology and commercial plant growth needs in the Space Station era. The BPS is equivalent in size to a double middeck locker, but uses its own custom enclosure with a slide out structure to which internal components mount. The BPS contains four internal growth chambers, each with a growing volume of more than 4 liters. Each of the growth chambers has active nutrient delivery, and independent control of temperature, humidity, lighting, and CO2 set-points. Temperature control is achieved using a thermoelectric heat exchanger system. Humidity control is achieved using a heat exchanger with a porous interface which can both humidify and dehumidify. The control software utilizes fuzzy logic for nonlinear, coupled temperature and humidity control. The fluorescent lighting system can be dimmed to provide a range of light levels. CO2 levels are controlled by injecting pure CO2 to the system based on input from an infrared gas analyzer. The unit currently does not scrub CO2, but has been designed to accept scrubber cartridges. In addition to providing environmental control, a number of features are included to facilitate science. The BPS chambers are sealed to allow CO2 and water vapor exchange measurements. The plant chambers can be removed to allow manipulation or sampling of specimens, and each chamber has gas/fluid sample ports. A video camera is provided for each chamber, and frame-grabs and complete environmental data for all science and hardware system sensors are stored on an internal hard drive. Data files can also be transferred to 3.5-inch disks using the front panel disk drive. PMID:11543164

  14. The effects of defoliation on carbon allocation: can carbon limitation reduce growth in favour of storage?

    PubMed

    Wiley, Erin; Huepenbecker, Sarah; Casper, Brenda B; Helliker, Brent R

    2013-11-01

    There is no consensus about how stresses such as low water availability and temperature limit tree growth. Sink limitation to growth and survival is often inferred if a given stress does not cause non-structural carbohydrate (NSC) concentrations or levels to decline along with growth. However, trees may actively maintain or increase NSC levels under moderate carbon stress, making the pattern of reduced growth and increased NSCs compatible with carbon limitation. To test this possibility, we used full and half defoliation to impose severe and moderate carbon limitation on 2-year-old Quercus velutina Lam. saplings grown in a common garden. Saplings were harvested at either 3 weeks or 4 months after treatments were applied, representing short- and longer-term effects on woody growth and NSC levels. Both defoliation treatments maintained a lower total leaf area than controls throughout the experiment with no evidence of photosynthetic up-regulation, and resulted in a similar total biomass reduction. While fully defoliated saplings had lower starch levels than controls in the short term, half defoliated saplings maintained control starch levels in both the short and longer term. In the longer term, fully defoliated saplings had the greatest starch concentration increment, allowing them to recover to near-control starch levels. Furthermore, between the two harvest dates, fully and half defoliated saplings allocated a greater proportion of new biomass to starch than did controls. The maintenance of control starch levels in half defoliated saplings indicates that these trees actively store a substantial amount of carbon before growth is carbon saturated. In addition, the allocation shift favouring storage in defoliated saplings is consistent with the hypothesis that, as an adaptation to increasing carbon stress, trees can prioritize carbon reserve formation at the expense of growth. Our results suggest that as carbon limitation increases, reduced growth is not necessarily

  15. Biomass allocation and C-N-P stoichiometry in C3 and C4 crops under abiotic stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biomass allocation to structural, metabolic and reproductive organs as well as their carbon, nitrogen and phosphorus (C-N-P) profiles and ratios (C:N, C:P, and N:P) were estimated in C3 and C4 crop plants subjected to multiple abiotic stresses (i.e., combination of temperature and water stress level...

  16. Flexible C, N and P allocation in maize plants and soil microbial biomass under recurrent and long-term drought

    NASA Astrophysics Data System (ADS)

    Larionova, Alla; Semenov, Vyacheslav; Yevdokimov, Ilya; Blagodatskaya, Evgenia

    2016-04-01

    One of the negative effects of the global warming is increasing aridity worldwide. Alterations in plant and microbial C, N and P in response to drought events can differ considerably in magnitude and direction. Therefore, synchronization between C, N and P in plants, dissolved forms and microbial biomass in soil is of great interest. Our objective was to evaluate C:N:P stoichiometry relations in plants and soil as affected by moderate water shortage and severe drought with subsequent rewetting. We tested the sensitivity of stoichiometry ratios in plants, dissolved compounds and soil microbial biomass in greenhouse experiment with maize. Three treatments were used: i) control with constant soil moisture (CTL); ii) soil with constantly low wetness of 25% WHC (DRY) and iii) soil exposed to drying-rewetting events (DRW). N dynamics was the most sensitive to water stress in maize plants and soil, while P dynamics was almost unaffected by drought and rewetting. As a result, C:N and N:P ratios were also sensitive to water treatment indicating that C, N and P cycles were decoupled by the water stresses. High C:N ratios in CTL and low C:N ratios in DRY and DRW treatments indicate stoichiometric flexibility in plants and soil microbes. N allocation was found to respond to N shortage in CTL and increased salt concentrations in soil solution in DRY and DRW treatments. C:N:P stoichiometry in soil microbes was found flexible during active plant growth, while that at the end of growth season turned to almost homeostatic ratio. The research was supported by Russian Science Foundation (project 14-14-00625)

  17. Leaf physiology and biomass allocation of backcross hybrid American chestnut (Castanea dentata) seedlings in response to light and water availability.

    PubMed

    Brown, Caleb E; Mickelbart, Michael V; Jacobs, Douglass F

    2014-12-01

    Partial canopy cover promotes regeneration of many temperate forest trees, but the consequences of shading on seedling drought resistance are unclear. Reintroduction of blight-resistant American chestnut (Castanea dentata (Marsh.) Borkh.) into eastern North American forests will often occur on water-limited sites and under partial canopy cover. We measured leaf pre-dawn water potential (Ψpd), leaf gas exchange, and growth and biomass allocation of backcross hybrid American chestnut seedlings from three orchard sources grown under different light intensities (76, 26 and 8% full photosynthetically active radiation (PAR)) and subjected to well-watered or mid-season water-stressed conditions. Seedlings in the water-stress treatment were returned to well-watered conditions after wilting to examine recovery. Seedlings growing under medium- and high-light conditions wilted at lower leaf Ψpd than low-light seedlings. Recovery of net photosynthesis (Anet) and stomatal conductance (gs) was greater in low and medium light than in high light. Seed source did not affect the response to water stress or light level in most cases. Between 26 and 8% full PAR, light became limiting to the extent that the effects of water stress had no impact on some growth and morphological traits. We conclude that positive and negative aspects of shading on seedling drought tolerance and recovery are not mutually exclusive. Partial shade may help American chestnut tolerate drought during early establishment through effects on physiological conditioning.

  18. Biomass allocation, morphology and photosynthesis of invasive and noninvasive exotic species grown at four irradiance levels

    NASA Astrophysics Data System (ADS)

    Feng, Yulong; Wang, Junfeng; Sang, Weiguo

    2007-01-01

    We tested the hypotheses that invasive species had higher irradiance plasticity, capture ability and efficiency than noninvasive species using two invasive aliens - Ageratina adenophora and Chromolaena odorata, and one noninvasive alien - Gynura sp. The three aliens were grown at 4.5%, 12.5%, 36%, 50% and 100% irradiances for 64 days before harvesting. The plastic response of specific leaf area (SLA) contributed to improved light interception at low irradiance, carbon gain and water balance at high irradiance. It was a good predictor for intraspecific irradiance responses of leaf area ratio (LAR), leaf area:root mass ratio, maximum photosynthetic rate ( Pmax) and net assimilation rate (NAR). Biomass allocation-related traits were species specific and their plasticity to irradiance was low. The high root mass fraction, leaf mass fraction and LAR distinguished the two invaders from Gynura. However, other resource capture-related traits, such as SLA, NAR and Pmax, were not always higher for the invaders than for Gynura. Furthermore, plasticity to irradiance was not different between the invasive and noninvasive aliens. With increasing irradiance, Gynura decreased biomass investment to roots and leaves but increased the investment to support structures adversely affecting both low and high irradiance acclimation. Ageratina might invade new habitat successfully through tolerating shading at low irradiance and outshading competitors by forming dense stands when irradiance is increased. The results suggested that both resource capture-related traits and irradiance acclimation conferred competitive advantage to the two invaders and some traits were common for invasive and noninvasive aliens but others were specific for invaders.

  19. Experimental sand burial affects seedling survivorship, morphological traits, and biomass allocation of Ulmus pumila var. sabulosa in the Horqin Sandy Land, China

    NASA Astrophysics Data System (ADS)

    Tang, Jiao; Busso, Carlos Alberto; Jiang, Deming; Musa, Ala; Wu, Dafu; Wang, Yongcui; Miao, Chunping

    2016-07-01

    As a native tree species, Ulmus pumila var. sabulosa (sandy elm) is widely distributed in the Horqin Sandy Land, China. However, seedlings of this species have to withstand various depths of sand burial after emergence because of increasing soil degradation, which is mainly caused by overgrazing, climate change, and wind erosion. An experiment was conducted to evaluate the changes in its survivorship, morphological traits, and biomass allocation when seedlings were buried at different burial depths: unburied controls and seedlings buried vertically up to 33, 67, 100, or 133 % of their initial mean seedling height. The results showed that partial sand burial treatments (i.e., less than 67 % burial) did not reduce seedling survivorship, which still reached 100 %. However, seedling mortality increased when sand burial was equal to or greater than 100 %. In comparison with the control treatment, seedling height and stem diameter increased at least by 6 and 14 % with partial burial, respectively. In the meantime, seedling taproot length, total biomass, and relative mass growth rates were at least enhanced by 10, 15.6, and 27.6 %, respectively, with the partial sand burial treatment. Furthermore, sand burial decreased total leaf area and changed biomass allocation in seedlings, partitioning more biomass to aboveground organs (e.g., leaves) and less to belowground parts (roots). Complete sand burial after seedling emergence inhibited its re-emergence and growth, even leading to death. Our findings indicated that seedlings of sandy elm showed some resistance to partial sand burial and were adapted to sandy environments from an evolutionary perspective. The negative effect of excessive sand burial after seedling emergence might help in understanding failures in recruitments of sparse elm in the study region.

  20. Artificial defoliation effect on Populus growth, biomass production, and total nonstructural carbohydrate concentration

    SciTech Connect

    Reichenbacker, R.R.; Hart, E.R.; Schultz, R.C.

    1996-06-01

    The impact of artificial defoliation on Populus growth, biomass production, and total nonstructural carbohydrate concentration was examined. Four Populus clones were field planted and artificially defoliated. Assigned defoliation levels (0, 25, 50, or 75%) were applied to leaves of leaf plastochron index 0 through 8 during a 6-d period in a 3-step incremental manner to simulate cottonwood leaf beetle, Chrysomela scripta F., larval feeding patterns. Artificial defoliations were timed to coincide with the outbreaks of natural beetle populations in adjacent areas. After 2 growing seasons, trees were measured for height, diameter, and biomass accumulation. Root samples were collected from 0 and 75% defoliation treatments for each clone. Biomass was reduced an average of 33% as defoliation level increased from 0 to 75%. As defoliation level increased from 0 to 75%, a consistent allocation ratio of biomass to 2/3 above and 1/3 below ground components continued in all clones. An overcompensation response occurred in above ground biomass when a defoliation level of 25% was applied. Between 25 and 75% a strong linear trend of decreasing biomass as defoliation increased was indicated. Vitality of the tree, as indicated by total nonstructural carbohydrate content, was affected only slightly by increasing defoliation. 26 refs., 1 fig., 6 tabs.

  1. The linkages between photosynthesis, productivity, growth and biomass in lowland Amazonian forests.

    PubMed

    Malhi, Yadvinder; Doughty, Christopher E; Goldsmith, Gregory R; Metcalfe, Daniel B; Girardin, Cécile A J; Marthews, Toby R; Del Aguila-Pasquel, Jhon; Aragão, Luiz E O C; Araujo-Murakami, Alejandro; Brando, Paulo; da Costa, Antonio C L; Silva-Espejo, Javier E; Farfán Amézquita, Filio; Galbraith, David R; Quesada, Carlos A; Rocha, Wanderley; Salinas-Revilla, Norma; Silvério, Divino; Meir, Patrick; Phillips, Oliver L

    2015-06-01

    Understanding the relationship between photosynthesis, net primary productivity and growth in forest ecosystems is key to understanding how these ecosystems will respond to global anthropogenic change, yet the linkages among these components are rarely explored in detail. We provide the first comprehensive description of the productivity, respiration and carbon allocation of contrasting lowland Amazonian forests spanning gradients in seasonal water deficit and soil fertility. Using the largest data set assembled to date, ten sites in three countries all studied with a standardized methodology, we find that (i) gross primary productivity (GPP) has a simple relationship with seasonal water deficit, but that (ii) site-to-site variations in GPP have little power in explaining site-to-site spatial variations in net primary productivity (NPP) or growth because of concomitant changes in carbon use efficiency (CUE), and conversely, the woody growth rate of a tropical forest is a very poor proxy for its productivity. Moreover, (iii) spatial patterns of biomass are much more driven by patterns of residence times (i.e. tree mortality rates) than by spatial variation in productivity or tree growth. Current theory and models of tropical forest carbon cycling under projected scenarios of global atmospheric change can benefit from advancing beyond a focus on GPP. By improving our understanding of poorly understood processes such as CUE, NPP allocation and biomass turnover times, we can provide more complete and mechanistic approaches to linking climate and tropical forest carbon cycling.

  2. Effects of Grazing on Above- vs. Below-Ground Biomass Allocation of Alpine Grasslands on the Northern Tibetan Plateau.

    PubMed

    Zeng, Chaoxu; Wu, Jianshuang; Zhang, Xianzhou

    2015-01-01

    Biomass allocation is an essential concept for understanding above- vs. below-ground functions and for predicting the dynamics of community structure and ecosystem service under ongoing climate change. There is rare available knowledge of grazing effects on biomass allocation in multiple zonal alpine grassland types along climatic gradients across the Northern Tibetan Plateau. We collected the peak above- and below-ground biomass (AGB and BGB) values at 106 pairs of well-matched grazed vs. fenced sites during summers of 2010-2013, of which 33 pairs were subject to meadow, 52 to steppe and 21 to desert-steppe. The aboveground net primary productivity (ANPP) was represented by the peak AGB while the belowground net primary productivity (BNPP) was estimated from ANPP, the ratio of living vs. dead BGB, and the root turnover rate. Two-ways analyses of variance (ANOVA) and paired samples comparisons with t-test were applied to examine the effects of pasture managements (PMS, i.e., grazed vs. fenced) and zonal grassland types on both ANPP and BNPP. Allometric and isometric allocation hypotheses were also tested between logarithmically transformed ANPP and BNPP using standardized major axis (SMA) analyses across grazed, fenced and overall sites. In our study, a high community-dependency was observed to support the allometric biomass allocation hypothesis, in association with decreased ANPP and a decreasing-to-increasing BNPP proportions with increasing aridity across the Northern Tibetan Plateau. Grazing vs. fencing seemed to have a trivial effect on ANPP compared to the overwhelming influence of different zonal grassland types. Vegetation links above- and below-ground ecological functions through integrated meta-population adaptive strategies to the increasing severity of habitat conditions. Therefore, more detailed studies on functional diversity are essentially to achieve conservation and sustainability goals under ongoing climatic warming and intensifying human

  3. Effects of Grazing on Above- vs. Below-Ground Biomass Allocation of Alpine Grasslands on the Northern Tibetan Plateau

    PubMed Central

    Zeng, Chaoxu; Wu, Jianshuang; Zhang, Xianzhou

    2015-01-01

    Biomass allocation is an essential concept for understanding above- vs. below-ground functions and for predicting the dynamics of community structure and ecosystem service under ongoing climate change. There is rare available knowledge of grazing effects on biomass allocation in multiple zonal alpine grassland types along climatic gradients across the Northern Tibetan Plateau. We collected the peak above- and below-ground biomass (AGB and BGB) values at 106 pairs of well-matched grazed vs. fenced sites during summers of 2010–2013, of which 33 pairs were subject to meadow, 52 to steppe and 21 to desert-steppe. The aboveground net primary productivity (ANPP) was represented by the peak AGB while the belowground net primary productivity (BNPP) was estimated from ANPP, the ratio of living vs. dead BGB, and the root turnover rate. Two-ways analyses of variance (ANOVA) and paired samples comparisons with t-test were applied to examine the effects of pasture managements (PMS, i.e., grazed vs. fenced) and zonal grassland types on both ANPP and BNPP. Allometric and isometric allocation hypotheses were also tested between logarithmically transformed ANPP and BNPP using standardized major axis (SMA) analyses across grazed, fenced and overall sites. In our study, a high community-dependency was observed to support the allometric biomass allocation hypothesis, in association with decreased ANPP and a decreasing-to-increasing BNPP proportions with increasing aridity across the Northern Tibetan Plateau. Grazing vs. fencing seemed to have a trivial effect on ANPP compared to the overwhelming influence of different zonal grassland types. Vegetation links above- and below-ground ecological functions through integrated meta-population adaptive strategies to the increasing severity of habitat conditions. Therefore, more detailed studies on functional diversity are essentially to achieve conservation and sustainability goals under ongoing climatic warming and intensifying human

  4. Effects of Grazing on Above- vs. Below-Ground Biomass Allocation of Alpine Grasslands on the Northern Tibetan Plateau.

    PubMed

    Zeng, Chaoxu; Wu, Jianshuang; Zhang, Xianzhou

    2015-01-01

    Biomass allocation is an essential concept for understanding above- vs. below-ground functions and for predicting the dynamics of community structure and ecosystem service under ongoing climate change. There is rare available knowledge of grazing effects on biomass allocation in multiple zonal alpine grassland types along climatic gradients across the Northern Tibetan Plateau. We collected the peak above- and below-ground biomass (AGB and BGB) values at 106 pairs of well-matched grazed vs. fenced sites during summers of 2010-2013, of which 33 pairs were subject to meadow, 52 to steppe and 21 to desert-steppe. The aboveground net primary productivity (ANPP) was represented by the peak AGB while the belowground net primary productivity (BNPP) was estimated from ANPP, the ratio of living vs. dead BGB, and the root turnover rate. Two-ways analyses of variance (ANOVA) and paired samples comparisons with t-test were applied to examine the effects of pasture managements (PMS, i.e., grazed vs. fenced) and zonal grassland types on both ANPP and BNPP. Allometric and isometric allocation hypotheses were also tested between logarithmically transformed ANPP and BNPP using standardized major axis (SMA) analyses across grazed, fenced and overall sites. In our study, a high community-dependency was observed to support the allometric biomass allocation hypothesis, in association with decreased ANPP and a decreasing-to-increasing BNPP proportions with increasing aridity across the Northern Tibetan Plateau. Grazing vs. fencing seemed to have a trivial effect on ANPP compared to the overwhelming influence of different zonal grassland types. Vegetation links above- and below-ground ecological functions through integrated meta-population adaptive strategies to the increasing severity of habitat conditions. Therefore, more detailed studies on functional diversity are essentially to achieve conservation and sustainability goals under ongoing climatic warming and intensifying human

  5. Does chronic nitrogen deposition during biomass growth affect atmospheric emissions from biomass burning?

    NASA Astrophysics Data System (ADS)

    Giordano, Michael R.; Chong, Joey; Weise, David R.; Asa-Awuku, Akua A.

    2016-03-01

    Chronic nitrogen deposition has measureable impacts on soil and plant health. We investigate burning emissions from biomass grown in areas of high and low NO x deposition. Gas and aerosol-phase emissions were measured as a function of photochemical aging in an environmental chamber at UC-Riverside. Though aerosol chemical speciation was not available, results indicate a systemic compositional difference between biomass grown in high and low deposition areas. Aerosol emissions from biomass grown in areas of high NO x deposition exhibit a lower volatility than biomass grown in a low deposition area. Furthermore, fuel elemental analysis, NO x emission rates, and aerosol particle number distributions differed significantly between the two sites. Despite the limited scale of fuels explored, there is strong evidence that the atmospheric emissions community must pay attention to the regional air quality of biomass fuels growth areas.

  6. Optimization of biomass composition explains microbial growth-stoichiometry relationships

    USGS Publications Warehouse

    Franklin, O.; Hall, E.K.; Kaiser, C.; Battin, T.J.; Richter, A.

    2011-01-01

    Integrating microbial physiology and biomass stoichiometry opens far-reaching possibilities for linking microbial dynamics to ecosystem processes. For example, the growth-rate hypothesis (GRH) predicts positive correlations among growth rate, RNA content, and biomass phosphorus (P) content. Such relationships have been used to infer patterns of microbial activity, resource availability, and nutrient recycling in ecosystems. However, for microorganisms it is unclear under which resource conditions the GRH applies. We developed a model to test whether the response of microbial biomass stoichiometry to variable resource stoichiometry can be explained by a trade-off among cellular components that maximizes growth. The results show mechanistically why the GRH is valid under P limitation but not under N limitation. We also show why variability of growth rate-biomass stoichiometry relationships is lower under P limitation than under N or C limitation. These theoretical results are supported by experimental data on macromolecular composition (RNA, DNA, and protein) and biomass stoichiometry from two different bacteria. In addition, compared to a model with strictly homeostatic biomass, the optimization mechanism we suggest results in increased microbial N and P mineralization during organic-matter decomposition. Therefore, this mechanism may also have important implications for our understanding of nutrient cycling in ecosystems.

  7. [Effects of elevated CO2 concentration and nitrogen deposition on the biomass accumulation and allocation in south subtropical main native tree species and their mixed communities].

    PubMed

    Zhao, Liang; Zhou, Guo-yi; Zhang, De-qiang; Duan, Hong-lang; Liu, Ju-xiu

    2011-08-01

    A 5-year experiment was conducted to study the effects of simulated elevated CO2 concentration, nitrogen deposition, and their combination on the biomass accumulation and allocation in five south subtropical native tree species Schima superba, Ormosia pinnata, Acmena acuminatissima, Syzygium hancei, and Castanopsis hystrix and their mixed communities. The test tree species had different responses in their biomass accumulation and allocation to the elevated CO2 concentration and nitrogen deposition. Elevated CO2 concentration and nitrogen deposition increased the biomass of legume species by 49.3% and 71.0%, respectively, and promoted the biomass accumulation in sun species. Nitrogen deposition increased the biomass of shade-preference species significantly, but elevated CO2 concentration was in adverse. Elevated CO2 concentration inhibited the biomass allocation in the belowground part of sun species but promoted the biomass allocation in the belowground part of shade-preference species. Elevated CO2 concentration, nitrogen deposition, and their interaction all promoted the biomass accumulation in mixed communities. Elevated CO2 concentration increased the biomass accumulation in the belowground part of the communities, while nitrogen deposition increased the biomass accumulation in the aboveground part. Under the background of global climate change, Ormosia pinnata and Castanopsis hystrix tended to be the appropriate species for carbon fixation in south subtropical area.

  8. Growth and carbon allocation of tropical and temperate N-fixing trees grown in elevated CO{sub 2}

    SciTech Connect

    Tissue, D.T.; Megonigal, J.P.; Thomas, R.B.

    1995-09-01

    Seeds of two tree species, Gliricidia seplum (tropical) and Robinia pseudoacacia (temperate), were inoculated with N-fixing Rhizobium bacteria and grown in environmentally controlled glasshouses for 75 days to determine the effects of atmospheric CO{sub 2} on seedling growth and carbon allocation. Seedlings were grown in ambient CO{sub 2}(35 Pa) and elevated CO{sub 22}(70 Pa) and watered with a N-deficient nutrient solution such that bacterial N-fixation was the only source of N. Elevated CO{sub 2} increased leaf, stem, root and total biomass in Gliricidia, but did not affect nodule mass; Robinia biomass was unchanged by CO{sub 2}. Leaf photosynthetic rates at 70 Pa CO{sub 2} were increased 49% in Gliricidia, but were unchanged in Robinia, and there was no change in respiration rate in either species. A {sup 14}CO{sub 2} labelling experiment demonstrated that elevated CO{sub 2} did not affect the kinetics or allocation patterns of photosynthetically fixed carbon to nodules or other plant parts in either species. Our results demonstrate that Gliricidia, but not Robinia, will show an early, positive growth and photosynthetic response to elevated CO{sub 2} in N-poor soils, suggesting that tropical N-fixing trees may be more responsive than temperate N-fixing trees to future atmospheric CO{sub 2} conditions.

  9. Effects of light acclimation on shoot morphology, structure, and biomass allocation of two Taxus species in southwestern China

    NASA Astrophysics Data System (ADS)

    Liu, Wande; Su, Jianrong

    2016-10-01

    Acclimation to changing light conditions plays a crucial role in determining the competitive capability of tree species. There is currently limited information about acclimation to natural light gradient and its effect on shoot structure and biomass in Taxus species. We examined the acclimation of the leaf and shoot axis morphology, structure and biomass allocation of Taxus yunnanensis and T. chinensis var. mairei under three different natural light environments, full daylight, 40–60% full daylight and <10% full daylight. The leaf biomass, nitrogen content per unit area, leaf carbon content per dry mass and leaf dry mass to fresh mass ratio increased with light in both species, demonstrating an enhanced investment of photosynthetic biomass and structural investment under high light. The number of leaves per unit shoot axis length and the leaf dry mass per unit shoot axis length increased with light in both species. However, the light increase did not result in the increase of the total shoot mass. T. yunnanensis produced larger leaves under low light and a higher shoot axis length per unit dry mass under high light, whereas the leaf size and biomass yield of T. chinensis var. mairei were not sensitive to light.

  10. Effects of light acclimation on shoot morphology, structure, and biomass allocation of two Taxus species in southwestern China

    PubMed Central

    Liu, Wande; Su, Jianrong

    2016-01-01

    Acclimation to changing light conditions plays a crucial role in determining the competitive capability of tree species. There is currently limited information about acclimation to natural light gradient and its effect on shoot structure and biomass in Taxus species. We examined the acclimation of the leaf and shoot axis morphology, structure and biomass allocation of Taxus yunnanensis and T. chinensis var. mairei under three different natural light environments, full daylight, 40–60% full daylight and <10% full daylight. The leaf biomass, nitrogen content per unit area, leaf carbon content per dry mass and leaf dry mass to fresh mass ratio increased with light in both species, demonstrating an enhanced investment of photosynthetic biomass and structural investment under high light. The number of leaves per unit shoot axis length and the leaf dry mass per unit shoot axis length increased with light in both species. However, the light increase did not result in the increase of the total shoot mass. T. yunnanensis produced larger leaves under low light and a higher shoot axis length per unit dry mass under high light, whereas the leaf size and biomass yield of T. chinensis var. mairei were not sensitive to light. PMID:27734944

  11. Biomass of algae growth on natural water medium.

    PubMed

    Ramaraj, Rameshprabu; Tsai, David Dah-Wei; Chen, Paris Honglay

    2015-01-01

    Algae are the dominant primary producers in aquatic ecosystems. Since algae are highly varied group organisms, which have important functions in ecosystem, and their biomass is an essential biological resource. Currently, algae have been applied increasingly to diverse range of biomass applications. Therefore, this study was aimed to investigate the ecological algae features of microalgal production by natural medium, ecological function by lab scale of the symbiotic reactor which is imitated nature ecosystem, and atmospheric CO2 absorption that was related the algal growth of biomass to understand algae in natural water body better. Consequently, this study took advantages of using the unsupplemented freshwater natural medium to produce microalgae. Algal biomass by direct measurement of total suspended solids (TSS) and volatile suspended solids (VSS) resulted as 0.14g/L and 0.08g/L respectively. The biomass measurements of TSS and VSS are the sensible biomass index for algae production. The laboratory results obtained in the present study proved the production of algae by the natural water medium is potentially feasible.

  12. The dynamic of annual carbon allocation to wood in European forests is consistent with a combined source-sink limitation of growth: implications for modelling

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrêne, E.; François, C.; Soudani, K.; Ourcival, J. M.; Delpierre, N.

    2015-02-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will condition the response of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study is to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in five tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex, Quercus robur and Picea abies). Combining field measurements and process-based simulations at 49 sites (931 site-years), we assessed the stand biomass growth dependences at both inter-site and inter-annual scales. Specifically, the relative influence of forest C balance (source control), direct environmental control (water and temperature controls of sink activity) and allocation adjustments related to age, past climate conditions, competition intensity and soil nutrient availability on growth were quantified. The inter-site variability in stand C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual stand woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. We provide an evaluation of the spatio-temporal dynamics of annual carbon allocation to wood in European forests. Our study supports the premise that European forest growth is under a complex control including both source and sink limitations. The relative influences of the different growth drivers strongly vary across years and spatial ecological gradients. We suggest a

  13. A modeling framework for inferring tree growth and allocation from physiological, morphological and allometric traits.

    PubMed

    Ogle, Kiona; Pacala, Stephen W

    2009-04-01

    Predictions of forest succession, diversity and function require an understanding of how species differ in their growth, allocation patterns and susceptibility to mortality. These processes in turn are affected by allometric constraints and the physiological state of the tree, both of which are coupled to the tree's labile carbon status. Ultimately, insight into the hidden labile pools and the processes affecting the allocation of labile carbon to storage, maintenance and growth will improve our ability to predict tree growth, mortality and forest dynamics. We developed the 'Allometrically Constrained Growth and Carbon Allocation' (ACGCA) model that explicitly couples tree growth, mortality, allometries and labile carbon. This coupling results in (1) a semi-mechanistic basis for predicting tree death, (2) an allocation scheme that simultaneously satisfies allometric relationships and physiology-based carbon dynamics and (3) a range of physiological states that are consistent with tree behavior (e.g., healthy, static, shrinking, recovering, recovered and dead). We present the ACGCA model and illustrate aspects of its behavior by conducting simulations under different forest gap dynamics scenarios and with parameter values obtained for two ecologically dissimilar species: loblolly pine (Pinus taeda L.) and red maple (Acer rubrum L.). The model reproduces growth and mortality patterns of these species that are consistent with their shade-tolerance and succession status. The ACGCA framework provides an alternative, and potentially improved, approach for predicting tree growth, mortality and forest dynamics. PMID:19203984

  14. Overexpression of GA20-OXIDASE1 impacts plant height, biomass allocation and saccharification efficiency in maize.

    PubMed

    Voorend, Wannes; Nelissen, Hilde; Vanholme, Ruben; De Vliegher, Alex; Van Breusegem, Frank; Boerjan, Wout; Roldán-Ruiz, Isabel; Muylle, Hilde; Inzé, Dirk

    2016-03-01

    Increased biomass yield and quality are of great importance for the improvement of feedstock for the biorefinery. For the production of bioethanol, both stem biomass yield and the conversion efficiency of the polysaccharides in the cell wall to fermentable sugars are of relevance. Increasing the endogenous levels of gibberellic acid (GA) by ectopic expression of GA20-OXIDASE1 (GA20-OX1), the rate-limiting step in GA biosynthesis, is known to affect cell division and cell expansion, resulting in larger plants and organs in several plant species. In this study, we examined biomass yield and quality traits of maize plants overexpressing GA20-OX1 (GA20-OX1). GA20-OX1 plants accumulated more vegetative biomass than control plants in greenhouse experiments, but not consistently over two years of field trials. The stems of these plants were longer but also more slender. Investigation of GA20-OX1 biomass quality using biochemical analyses showed the presence of more cellulose, lignin and cell wall residue. Cell wall analysis as well as expression analysis of lignin biosynthetic genes in developing stems revealed that cellulose and lignin were deposited earlier in development. Pretreatment of GA20-OX1 biomass with NaOH resulted in a higher saccharification efficiency per unit of dry weight, in agreement with the higher cellulose content. On the other hand, the cellulose-to-glucose conversion was slower upon HCl or hot-water pretreatment, presumably due to the higher lignin content. This study showed that biomass yield and quality traits can be interconnected, which is important for the development of future breeding strategies to improve lignocellulosic feedstock for bioethanol production. PMID:26903034

  15. Factors modulating cottongrass seedling growth stimulation to enhanced nitrogen and carbon dioxide: compensatory tradeoffs in leaf dynamics and allocation to meet potassium-limited growth.

    PubMed

    Siegenthaler, Andy; Buttler, Alexandre; Grosvernier, Philippe; Gobat, Jean-Michel; Nilsson, Mats B; Mitchell, Edward A D

    2013-02-01

    Eriophorum vaginatum is a characteristic species of northern peatlands and a keystone plant for cutover bog restoration. Understanding the factors affecting E. vaginatum seedling establishment (i.e. growth dynamics and allocation) under global change has practical implications for the management of abandoned mined bogs and restoration of their C-sequestration function. We studied the responses of leaf dynamics, above- and belowground biomass production of establishing seedlings to elevated CO(2) and N. We hypothesised that nutrient factors such as limitation shifts or dilutions would modulate growth stimulation. Elevated CO(2) did not affect biomass, but increased the number of young leaves in spring (+400 %), and the plant vitality (i.e. number of green leaves/total number of leaves) (+3 %), both of which were negatively correlated to [K(+)] in surface porewater, suggesting a K-limited production of young leaves. Nutrient ratios in green leaves indicated either N and K co-limitation or K limitation. N addition enhanced the number of tillers (+38 %), green leaves (+18 %), aboveground and belowground biomass (+99, +61 %), leaf mass-to-length ratio (+28 %), and reduced the leaf turnover (-32 %). N addition enhanced N availability and decreased [K(+)] in spring surface porewater. Increased tiller and leaf production in July were associated with a doubling in [K(+)] in surface porewater suggesting that under enhanced N production is K driven. Both experiments illustrate the importance of tradeoffs in E. vaginatum growth between: (1) producing tillers and generating new leaves, (2) maintaining adult leaves and initiating new ones, and (3) investing in basal parts (corms) for storage or in root growth for greater K uptake. The K concentration in surface porewater is thus the single most important factor controlling the growth of E. vaginatum seedlings in the regeneration of selected cutover bogs.

  16. Influence of atmospheric [CO2] on growth, carbon allocation and cost of plant tissues on leaf nitrogen concentration maintenance in nodulated Medicago sativa

    NASA Astrophysics Data System (ADS)

    Pereyra, Gabriela; Hartmann, Henrik; Ziegler, Waldemar; Michalzik, Beate; Gonzalez-Meler, Miquel; Trumbore, Susan

    2015-04-01

    Plant carbon (C) allocation and plant metabolic processes (i.e. photosynthesis and respiration) can be affected by changes in C availability, for example from changing atmospheric [CO2]. In nodulated plants, C availability may also influence nitrogen (N) fixation by bacteriods. But C allocation and N fixation are often studied independently and hence do not allow elucidating interactive effects. We investigated how different atmospheric [CO2] (Pleistocene: 170 ppm, ambient: 400 ppm and projected future: 700 ppm) influence plant growth, allocation to nodules, and the ratio of photosynthesis-to-respiration (R:A) as an indicator of C cost in Medicago sativa inoculated with Ensifer meliloti. M. sativa grew c. 38% more nodules at 400 ppm and 700 ppm than at 170 ppm. However, ratios of above- and belowground plant biomass to nodule biomass were constant over time and independent of atmospheric [CO2]. Total non-structural carbohydrate concentrations were not significantly different between plants grown at 400 and 700 ppm, but were four to five-fold higher than in 170 ppm plants. Leaf level N concentration was similar across treatments, but N-based photosynthetic rates were 82% and 93% higher in leaves of plants grown at 400 and 700 ppm, respectively, than plants grown at 170 ppm. In addition, leaf R:A was greater (48% or 55%) in plants grown at 170 ppm than plants grown at 400 and 700 ppm. Similarly, the greatest proportion of assimilated CO2 released by root respiration occurred in rhizobial plants growing at 170 ppm. Our results suggest that C limitation in nodulated Medicago sativa plants did not influence C allocation to nodule biomass but caused a proportionally greater allocation of C to belowground respiration, most likely to bacteriods. This suggests that N tissue concentration was maintained at low [CO2] by revving up bacteriod metabolism and at the expense of non-structural carbohydrate reserves.

  17. Carbon allocation during defoliation: testing a defense-growth trade-off in balsam fir

    PubMed Central

    Deslauriers, Annie; Caron, Laurie; Rossi, Sergio

    2015-01-01

    During repetitive defoliation events, carbon can become limiting for trees. To maintain growth and survival, the resources have to be shared more efficiently, which could result in a trade-off between the different physiological processes of a plant. The objective of this study was to assess the effect of defoliation in carbon allocation of balsam fir [Abies balsamea (L.) Mill.] to test the presence of a trade-off between allocation to growth, carbon storage, and defense. Three defoliation intensities [control (C-trees, 0% defoliation), moderately (M-trees, 41–60%), and heavily (H-trees, 61–80%) defoliated] were selected in order to monitor several variables related to stem growth (wood formation in xylem), carbon storage in stem and needle (non-structural soluble sugars and starch), and defense components in needles (terpenoids compound) from May to October 2011. The concentration of starch was drastically reduced in both wood and leaves of H-trees with a quasi-absence of carbon partitioning to storage in early summer. Fewer kinds of monoterpenes and sesquiterpenes were formed with an increasing level of defoliation indicating a lower carbon allocation for the production of defense. The carbon allocation to wood formation gradually reduced at increasing defoliation intensities, with a lower growth rate and fewer tracheids resulting in a reduced carbon sequestration in cell walls. The hypothesis of a trade-off between the allocations to defense components and to non-structural (NCS) and structural (growth) carbon was rejected as most of the measured variables decreased with increasing defoliation. The starch amount was highly indicative of the tree carbon status at different defoliation intensity and future research should focus on the mechanism of starch utilization for survival and growth following an outbreak. PMID:26029235

  18. 13C and 15N allocations of two alpine species from early and late snowmelt locations reflect their different growth strategies.

    PubMed

    Baptist, Florence; Tcherkez, Guillaume; Aubert, Serge; Pontailler, Jean-Yves; Choler, Philippe; Nogués, Salvador

    2009-01-01

    Intense efforts are currently devoted to disentangling the relationships between plant carbon (C) allocation patterns and soil nitrogen (N) availability because of their consequences for growth and more generally for C sequestration. In cold ecosystems, only a few studies have addressed whole-plant C and/or N allocation along natural elevational or topographical gradients. (12)C/(13)C and (14)N/(15)N isotope techniques have been used to elucidate C and N partitioning in two alpine graminoids characterized by contrasted nutrient economies: a slow-growing species, Kobresia myosuroides (KM), and a fast-growing species, Carex foetida (CF), located in early and late snowmelt habitats, respectively, within the alpine tundra (French Alps). CF allocated higher labelling-related (13)C content belowground and produced more root biomass. Furthermore, assimilates transferred to the roots were preferentially used for growth rather than respiration and tended to favour N reduction in this compartment. Accordingly, this species had higher (15)N uptake efficiency than KM and a higher translocation of reduced (15)N to aboveground organs. These results suggest that at the whole-plant level, there is a compromise between N acquisition/reduction and C allocation patterns for optimized growth.

  19. Allocation changes buffer CO2 effect on tree growth since the last ice age

    NASA Astrophysics Data System (ADS)

    Li, G.; Harrison, S. P.; Prentice, I. C. C.; Gerhart, L. M.; Ward, J. K.

    2015-12-01

    Isotopic measurements on junipers growing in southern California during the last glacial, when the ambient atmospheric [CO2] (ca) was ~180 ppm, show the leaf- internal [CO2] (ci) was close to the modern CO2 compensation point for C3 plants. Despite this, stem growth rates were similar to today. Using a coupled light-use efficiency and tree growth model, we show that the ci/ca ratio was stable because both vapor pressure deficit and temperature were decreased with compensating effects. Reduced photorespiration at lower temperatures partly mitigated the effect of low ci on gross primary production, but maintenance of present-day radial growth also required changes in carbon allocation, including a ~25% reduction in below-ground carbon allocation and a ~7% in allocation to leaves. Such a shift was possible due to reduced drought stress. Our findings are consistent with the observed increase in below-ground allocation in FACE experiments and the apparent homoeostasis of measured radial growth as ca increases today; results which our model can also reproduce.

  20. Mortality affects adaptive allocation to growth and reproduction: field evidence from a guild of body snatchers

    PubMed Central

    2010-01-01

    Background The probability of being killed by external factors (extrinsic mortality) should influence how individuals allocate limited resources to the competing processes of growth and reproduction. Increased extrinsic mortality should select for decreased allocation to growth and for increased reproductive effort. This study presents perhaps the first clear cross-species test of this hypothesis, capitalizing on the unique properties offered by a diverse guild of parasitic castrators (body snatchers). I quantify growth, reproductive effort, and expected extrinsic mortality for several species that, despite being different species, use the same species' phenotype for growth and survival. These are eight trematode parasitic castrators—the individuals of which infect and take over the bodies of the same host species—and their uninfected host, the California horn snail. Results As predicted, across species, growth decreased with increased extrinsic mortality, while reproductive effort increased with increased extrinsic mortality. The trematode parasitic castrator species (operating stolen host bodies) that were more likely to be killed by dominant species allocated less to growth and relatively more to current reproduction than did species with greater life expectancies. Both genders of uninfected snails fit into the patterns observed for the parasitic castrator species, allocating as much to growth and to current reproduction as expected given their probability of reproductive death (castration by trematode parasites). Additionally, species differences appeared to represent species-specific adaptations, not general plastic responses to local mortality risk. Conclusions Broadly, this research illustrates that parasitic castrator guilds can allow unique comparative tests discerning the forces promoting adaptive evolution. The specific findings of this study support the hypothesis that extrinsic mortality influences species differences in growth and reproduction

  1. Metabolic efficiency in yeast Saccharomyces cerevisiae in relation to temperature dependent growth and biomass yield.

    PubMed

    Zakhartsev, Maksim; Yang, Xuelian; Reuss, Matthias; Pörtner, Hans Otto

    2015-08-01

    Canonized view on temperature effects on growth rate of microorganisms is based on assumption of protein denaturation, which is not confirmed experimentally so far. We develop an alternative concept, which is based on view that limits of thermal tolerance are based on imbalance of cellular energy allocation. Therefore, we investigated growth suppression of yeast Saccharomyces cerevisiae in the supraoptimal temperature range (30-40°C), i.e. above optimal temperature (Topt). The maximal specific growth rate (μmax) of biomass, its concentration and yield on glucose (Yx/glc) were measured across the whole thermal window (5-40°C) of the yeast in batch anaerobic growth on glucose. Specific rate of glucose consumption, specific rate of glucose consumption for maintenance (mglc), true biomass yield on glucose (Yx/glc(true)), fractional conservation of substrate carbon in product and ATP yield on glucose (Yatp/glc) were estimated from the experimental data. There was a negative linear relationship between ATP, ADP and AMP concentrations and specific growth rate at any growth conditions, whilst the energy charge was always high (~0.83). There were two temperature regions where mglc differed 12-fold, which points to the existence of a 'low' (within 5-31°C) and a 'high' (within 33-40°C) metabolic mode regarding maintenance requirements. The rise from the low to high mode occurred at 31-32°C in step-wise manner and it was accompanied with onset of suppression of μmax. High mglc at supraoptimal temperatures indicates a significant reduction of scope for growth, due to high maintenance cost. Analysis of temperature dependencies of product formation efficiency and Yatp/glc revealed that the efficiency of energy metabolism approaches its lower limit at 26-31°C. This limit is reflected in the predetermined combination of Yx/glc(true), elemental biomass composition and degree of reduction of the growth substrate. Approaching the limit implies a reduction of the safety margin

  2. Metabolic efficiency in yeast Saccharomyces cerevisiae in relation to temperature dependent growth and biomass yield.

    PubMed

    Zakhartsev, Maksim; Yang, Xuelian; Reuss, Matthias; Pörtner, Hans Otto

    2015-08-01

    Canonized view on temperature effects on growth rate of microorganisms is based on assumption of protein denaturation, which is not confirmed experimentally so far. We develop an alternative concept, which is based on view that limits of thermal tolerance are based on imbalance of cellular energy allocation. Therefore, we investigated growth suppression of yeast Saccharomyces cerevisiae in the supraoptimal temperature range (30-40°C), i.e. above optimal temperature (Topt). The maximal specific growth rate (μmax) of biomass, its concentration and yield on glucose (Yx/glc) were measured across the whole thermal window (5-40°C) of the yeast in batch anaerobic growth on glucose. Specific rate of glucose consumption, specific rate of glucose consumption for maintenance (mglc), true biomass yield on glucose (Yx/glc(true)), fractional conservation of substrate carbon in product and ATP yield on glucose (Yatp/glc) were estimated from the experimental data. There was a negative linear relationship between ATP, ADP and AMP concentrations and specific growth rate at any growth conditions, whilst the energy charge was always high (~0.83). There were two temperature regions where mglc differed 12-fold, which points to the existence of a 'low' (within 5-31°C) and a 'high' (within 33-40°C) metabolic mode regarding maintenance requirements. The rise from the low to high mode occurred at 31-32°C in step-wise manner and it was accompanied with onset of suppression of μmax. High mglc at supraoptimal temperatures indicates a significant reduction of scope for growth, due to high maintenance cost. Analysis of temperature dependencies of product formation efficiency and Yatp/glc revealed that the efficiency of energy metabolism approaches its lower limit at 26-31°C. This limit is reflected in the predetermined combination of Yx/glc(true), elemental biomass composition and degree of reduction of the growth substrate. Approaching the limit implies a reduction of the safety margin

  3. WHOLE-SEEDLING BIOMASS ALLOCATION, LEAF AREA, AND TISSUE CHEMISTRY FOR DOUGLAS-FIR EXPOSED TO ELEVATED CO2 AND TEMPERATURE FOR 4 YEARS

    EPA Science Inventory

    Changes in the global climate may impact forests, but data are lacking for climate change effects on whole tree productivity over multiple seasons and conditions representative of the field. To address this critical need, we measured biomass allocation for whole Pseudotsuga menzi...

  4. Cation Uptake and Allocation by Red Pine Seedlings under Cation-Nutrient Stress in a Column Growth Experiment

    SciTech Connect

    Shi, Zhenqing; Balogh-Brunstad, Zsuzsanna; Grant, Michael R.; Harsh, James B.; Gill, Richard; Thomashow, Linda; Dohnalkova, Alice; Stacks, Daryl; Letourneau, Melissa; Keller, Chester K.

    2014-01-10

    Background and Aims Plant nutrient uptake is affected by environmental stress, but how plants respond to cation-nutrient stress is poorly understood. We assessed the impact of varying degrees of cation-nutrient limitation on cation uptake in an experimental plant-mineral system. Methods Column experiments, with red pine (Pinus resinosa Ait.) seedlings growing in sand/mineral mixtures, were conducted for up to nine months under a range of Ca- and K-limited conditions. The Ca and K were supplied from both minerals and nutrient solutions with varying Ca and K concentrations. Results Cation nutrient stress had little impact on carbon allocation after nine months of plant growth and K was the limiting nutrient for biomass production. The Ca/Sr and K/Rb ratio results allowed independent estimation of dissolution incongruency and discrimination against Sr and Rb during cation uptake processes. The fraction of K in biomass from biotite increased with decreasing K supply from nutrient solutions. The mineral anorthite was consistently the major source of Ca, regardless of nutrient treatment. Conclusions Red pine seedlings exploited more mineral K in response to more severe K deficiency. This did not occur for Ca. Plant discrimination factors must be carefully considered to accurately identify nutrient sources using cation tracers.

  5. Watching sexy displays improves hatching success and offspring growth through maternal allocation.

    PubMed

    Loyau, Adeline; Lacroix, Frédéric

    2010-11-22

    Male attractiveness can have tremendous effects on the fitness of his offspring via good genes, but also via enhanced maternal allocation of resources. Yet the proximate mechanisms influencing differential maternal allocation in relation to male sexiness are poorly known. Here, we studied the importance of visual stimulation for maternal allocation in the Houbara bustard, a vulnerable bird species bred in captivity to support wild populations. Artificial insemination allowed controlling for potential confounding factors, such as a male's territory quality, social interactions or sperm quality/quantity, probably linked to mate attractiveness. We show that artificially inseminated females stimulated by highly displaying males increased their hatching success, owing to increased fertilization success. The females also increased the allocation of maternal androgens in their eggs, leading to an increase of circulating testosterone and growth rate in chicks. Hence, visual stimulation of the females can promote differential maternal allocation and favour offspring fitness. Our results further suggest that using artificial insemination for species conservation without appropriate stimulation of the breeding females probably has negative impacts on their breeding performance and therefore on population viability.

  6. Watching sexy displays improves hatching success and offspring growth through maternal allocation.

    PubMed

    Loyau, Adeline; Lacroix, Frédéric

    2010-11-22

    Male attractiveness can have tremendous effects on the fitness of his offspring via good genes, but also via enhanced maternal allocation of resources. Yet the proximate mechanisms influencing differential maternal allocation in relation to male sexiness are poorly known. Here, we studied the importance of visual stimulation for maternal allocation in the Houbara bustard, a vulnerable bird species bred in captivity to support wild populations. Artificial insemination allowed controlling for potential confounding factors, such as a male's territory quality, social interactions or sperm quality/quantity, probably linked to mate attractiveness. We show that artificially inseminated females stimulated by highly displaying males increased their hatching success, owing to increased fertilization success. The females also increased the allocation of maternal androgens in their eggs, leading to an increase of circulating testosterone and growth rate in chicks. Hence, visual stimulation of the females can promote differential maternal allocation and favour offspring fitness. Our results further suggest that using artificial insemination for species conservation without appropriate stimulation of the breeding females probably has negative impacts on their breeding performance and therefore on population viability. PMID:20538650

  7. Acclimation dynamics and sub-optimality in carbon allocation for C3 and C4 plants subject to growth under elevated CO2

    NASA Astrophysics Data System (ADS)

    Srinivasan, V.; Kumar, P.

    2012-12-01

    -optimally with respect to maximizing end of season seed biomass. Furthermore, when comparing observed carbon allocation patterns with the optimality results under elevated CO2 growing conditions, the extent of sub-optimality is amplified in C3 plant species. Experimental manipulations of plant carbon allocation patterns guided by model results confirm this sub-optimal effect. Our results demonstrate that allometric relationships cannot be used to model carbon allocation and growth of C3 plants under acclimation due to elevated CO2. The observed sub-optimality in ambient CO2 conditions and the increased sub-optimality under elevated CO2 conditions indicate that a teleonomic approach might be incomplete in capturing acclimation aspects of plant growth. We hypothesize that the observed sub-optimality is caused by a resilience constraint whereby plants device a carbon allocation strategy that maximizes end of season seed yield subject to variability in climate forcing. Since, the teleonomic approach provides the necessary degrees of freedom to capture changes in allometric relationships we suggest that incorporating a suitable resilience constraint within the optimality framework can explain the observed sub-optimal behavior.

  8. Spatial allocation of future landscape patterns for biomass and alleviation of hydrologic impacts of climate change

    NASA Astrophysics Data System (ADS)

    Ssegane, H.; Negri, M. C.

    2015-12-01

    Current and future demand for food, feed, fiber, and energy require novel approaches to land management, which demands that multifunctional landscapes are created to integrate various ecosystem functions into a sustainable land use. Concurrently, the Intergovernmental Panel on Climate Change (IPCC) predicts an increase of 2 to 4°C over the next 100 years above the preindustrial baseline, beginning as early as 2016 to 2035 over all seasons in the North America. This climate change is projected to further strain water resources currently stressed by anthropogenic activities. Therefore, placement of bioenergy crops on strategically selected sub-field areas in an agricultural landscape has the potential to increase the environmental and economic sustainability if location and choice of the crops result in minimal disruption of current food production systems and therefore cause minimal indirect land use change. This study identified sub-field marginal areas in an agricultural watershed using soil-based environmental sustainability criteria and a crop productivity index. Future landscape patterns (FLPs) were developed by allocating bioenergy crops (switchgrass: Panicum virgatum or shrub willows: Salix spp.) to these marginal areas (20% of the watershed). SWAT hydrologic model and dynamically downscaled climatic projection were used to asses impact of climate change on extreme flow conditions, total annual production of commodity and bioenergy crops, and water quality under current and future landscape patterns for the mid-21st century (2045-2055) and late 21st century (2085-2095) climatic projections. The frequency of flood and drought conditions was projected to increase while the corresponding durations to decrease. Sediment yields were projected to increase by 85% to 170% while FLPs would mitigate this increase by 26% to 32%.

  9. Effects of externally supplied protein on root morphology and biomass allocation in Arabidopsis.

    PubMed

    Lonhienne, Thierry G A; Trusov, Yuri; Young, Anthony; Rentsch, Doris; Näsholm, Torgny; Schmidt, Susanne; Paungfoo-Lonhienne, Chanyarat

    2014-01-01

    Growth, morphogenesis and function of roots are influenced by the concentration and form of nutrients present in soils, including low molecular mass inorganic N (IN, ammonium, nitrate) and organic N (ON, e.g. amino acids). Proteins, ON of high molecular mass, are prevalent in soils but their possible effects on roots have received little attention. Here, we investigated how externally supplied protein of a size typical of soluble soil proteins influences root development of axenically grown Arabidopsis. Addition of low to intermediate concentrations of protein (bovine serum albumen, BSA) to IN-replete growth medium increased root dry weight, root length and thickness, and root hair length. Supply of higher BSA concentrations inhibited root development. These effects were independent of total N concentrations in the growth medium. The possible involvement of phytohormones was investigated using Arabidopsis with defective auxin (tir1-1 and axr2-1) and ethylene (ein2-1) responses. That no phenotype was observed suggests a signalling pathway is operating independent of auxin and ethylene responses. This study expands the knowledge on N form-explicit responses to demonstrate that ON of high molecular mass elicits specific responses. PMID:24852366

  10. Effects of externally supplied protein on root morphology and biomass allocation in Arabidopsis

    PubMed Central

    Lonhienne, Thierry G. A.; Trusov, Yuri; Young, Anthony; Rentsch, Doris; Näsholm, Torgny; Schmidt, Susanne; Paungfoo-Lonhienne, Chanyarat

    2014-01-01

    Growth, morphogenesis and function of roots are influenced by the concentration and form of nutrients present in soils, including low molecular mass inorganic N (IN, ammonium, nitrate) and organic N (ON, e.g. amino acids). Proteins, ON of high molecular mass, are prevalent in soils but their possible effects on roots have received little attention. Here, we investigated how externally supplied protein of a size typical of soluble soil proteins influences root development of axenically grown Arabidopsis. Addition of low to intermediate concentrations of protein (bovine serum albumen, BSA) to IN-replete growth medium increased root dry weight, root length and thickness, and root hair length. Supply of higher BSA concentrations inhibited root development. These effects were independent of total N concentrations in the growth medium. The possible involvement of phytohormones was investigated using Arabidopsis with defective auxin (tir1-1 and axr2-1) and ethylene (ein2-1) responses. That no phenotype was observed suggests a signalling pathway is operating independent of auxin and ethylene responses. This study expands the knowledge on N form-explicit responses to demonstrate that ON of high molecular mass elicits specific responses. PMID:24852366

  11. Concentrative nitrogen allocation to sun-lit branches and the effects on whole-plant growth under heterogeneous light environments.

    PubMed

    Sugiura, D; Tateno, M

    2013-08-01

    We investigated the nitrogen and carbohydrate allocation patterns of trees under heterogeneous light environments using saplings of the devil maple tree (Acer diabolicum) with Y-shaped branches. Different branch groups were created: all branches of a sapling exposed to full light (L-branches), all branches exposed to full shade (S-branches), and half of the branches of a sapling exposed to light (HL-branches) and the other half exposed to shade (HS-branches). Throughout the growth period, nitrogen was preferentially allocated to HL-branches, whereas nitrogen allocation to HS-branches was suppressed compared to L- and S-branches. HL-branches with the highest leaf nitrogen content (N(area)) also had the highest rates of growth, and HS-branches with the lowest N(area) had the lowest observed growth rates. In addition, net nitrogen assimilation, estimated using a photosynthesis model, was strongly correlated with branch growth and whole-plant growth. In contrast, patterns of photosynthate allocation to branches and roots were not affected by the light conditions of the other branch. These observations suggest that tree canopies develop as a result of resource allocation patterns, where the growth of sun-lit branches is favoured over shaded branches, which leads to enhanced whole-plant growth in heterogeneous light environments. Our results indicate that whole-plant growth is enhanced by the resource allocation patterns created for saplings in heterogeneous light environments.

  12. The dynamic of the annual carbon allocation to wood in European tree species is consistent with a combined source-sink limitation of growth: implications for modelling

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrene, E.; Francois, C.; Soudani, K.; Ourcival, J. M.; Delpierre, N.

    2015-05-01

    The extent to which wood growth is limited by carbon (C) supply (i.e. source control) or by cambial activity (i.e. sink control) will strongly determine the responses of trees to global changes. Nevertheless, the physiological processes that are responsible for limiting forest growth are still a matter of debate. The aim of this study was to evaluate the key determinants of the annual C allocation to wood along large soil and climate regional gradients over France. The study was conducted for five tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex, Quercus robur and Picea abies). The drivers of stand biomass growth were assessed on both inter-site and inter-annual scales. Our data set comprised field measurements performed at 49 sites (931 site-years) that included biometric measurements and a variety of stand characteristics (e.g. soil water holding capacity, leaf area index). It was complemented with process-based simulations when possible explanatory variables could not be directly measured (e.g. annual and seasonal tree C balance, bioclimatic water stress indices). Specifically, the relative influences of tree C balance (source control), direct environmental control (water and temperature controls of sink activity) and allocation adjustments related to age, past climate conditions, competition intensity and soil nutrient availability on growth were quantified. The inter-site variability in the stand C allocation to wood was predominantly driven by age-related decline. The direct effects of temperature and water stress on sink activity (i.e. effects independent from their effects on the C supply) exerted a strong influence on the annual stand wood growth in all of the species considered, including deciduous temperate species. The lagged effect of the past environmental conditions (e.g. the previous year's water stress and low C uptake) significantly affected the annual C allocation to wood. The C supply

  13. Dynamical Allocation of Cellular Resources as an Optimal Control Problem: Novel Insights into Microbial Growth Strategies.

    PubMed

    Giordano, Nils; Mairet, Francis; Gouzé, Jean-Luc; Geiselmann, Johannes; de Jong, Hidde

    2016-03-01

    Microbial physiology exhibits growth laws that relate the macromolecular composition of the cell to the growth rate. Recent work has shown that these empirical regularities can be derived from coarse-grained models of resource allocation. While these studies focus on steady-state growth, such conditions are rarely found in natural habitats, where microorganisms are continually challenged by environmental fluctuations. The aim of this paper is to extend the study of microbial growth strategies to dynamical environments, using a self-replicator model. We formulate dynamical growth maximization as an optimal control problem that can be solved using Pontryagin's Maximum Principle. We compare this theoretical gold standard with different possible implementations of growth control in bacterial cells. We find that simple control strategies enabling growth-rate maximization at steady state are suboptimal for transitions from one growth regime to another, for example when shifting bacterial cells to a medium supporting a higher growth rate. A near-optimal control strategy in dynamical conditions is shown to require information on several, rather than a single physiological variable. Interestingly, this strategy has structural analogies with the regulation of ribosomal protein synthesis by ppGpp in the enterobacterium Escherichia coli. It involves sensing a mismatch between precursor and ribosome concentrations, as well as the adjustment of ribosome synthesis in a switch-like manner. Our results show how the capability of regulatory systems to integrate information about several physiological variables is critical for optimizing growth in a changing environment.

  14. Dynamical Allocation of Cellular Resources as an Optimal Control Problem: Novel Insights into Microbial Growth Strategies

    PubMed Central

    Giordano, Nils; Mairet, Francis; Gouzé, Jean-Luc

    2016-01-01

    Microbial physiology exhibits growth laws that relate the macromolecular composition of the cell to the growth rate. Recent work has shown that these empirical regularities can be derived from coarse-grained models of resource allocation. While these studies focus on steady-state growth, such conditions are rarely found in natural habitats, where microorganisms are continually challenged by environmental fluctuations. The aim of this paper is to extend the study of microbial growth strategies to dynamical environments, using a self-replicator model. We formulate dynamical growth maximization as an optimal control problem that can be solved using Pontryagin’s Maximum Principle. We compare this theoretical gold standard with different possible implementations of growth control in bacterial cells. We find that simple control strategies enabling growth-rate maximization at steady state are suboptimal for transitions from one growth regime to another, for example when shifting bacterial cells to a medium supporting a higher growth rate. A near-optimal control strategy in dynamical conditions is shown to require information on several, rather than a single physiological variable. Interestingly, this strategy has structural analogies with the regulation of ribosomal protein synthesis by ppGpp in the enterobacterium Escherichia coli. It involves sensing a mismatch between precursor and ribosome concentrations, as well as the adjustment of ribosome synthesis in a switch-like manner. Our results show how the capability of regulatory systems to integrate information about several physiological variables is critical for optimizing growth in a changing environment. PMID:26958858

  15. Sex-related differences in growth and carbon allocation to defence in Populus tremula as explained by current plant defence theories.

    PubMed

    Randriamanana, Tendry R; Nybakken, Line; Lavola, Anu; Aphalo, Pedro J; Nissinen, Katri; Julkunen-Tiitto, Riitta

    2014-05-01

    Plant defence theories have recently evolved in such a way that not only the quantity but also the quality of mineral nutrients is expected to influence plant constitutive defence. Recently, an extended prediction derived from the protein competition model (PCM) suggested that nitrogen (N) limitation is more important for the production of phenolic compounds than phosphorus (P). We aimed at studying sexual differences in the patterns of carbon allocation to growth and constitutive defence in relation to N and P availability in Populus tremula L. seedlings. We compared the gender responses in photosynthesis, growth and whole-plant allocation to phenolic compounds at different combination levels of N and P, and studied how they are explained by the main plant defence theories. We found no sexual differences in phenolic concentrations, but interestingly, slow-growing females had higher leaf N concentration than did males, and genders differed in their allocation priority. There was a trade-off between growth and the production of flavonoid-derived phenylpropanoids on one hand, and between the production of salicylates and flavonoid-derived phenylpropanoids on the other. Under limited nutrient conditions, females prioritized mineral nutrient acquisition, flavonoid and condensed tannin (CT) production, while males invested more in above-ground biomass. Salicylate accumulation followed the growth differentiation balance hypothesis as low N mainly decreased the production of leaf and stem salicylate content while the combination of both low N and low P increased the amount of flavonoids and CTs allocated to leaves and to a lesser extent stems, which agrees with the PCM. We suggest that such a discrepancy in the responses of salicylates and flavonoid-derived CTs is linked to their clearly distinct biosynthetic origins and/or their metabolic costs.

  16. Uav-Based Automatic Tree Growth Measurement for Biomass Estimation

    NASA Astrophysics Data System (ADS)

    Karpina, M.; Jarząbek-Rychard, M.; Tymków, P.; Borkowski, A.

    2016-06-01

    Manual in-situ measurements of geometric tree parameters for the biomass volume estimation are time-consuming and economically non-effective. Photogrammetric techniques can be deployed in order to automate the measurement procedure. The purpose of the presented work is an automatic tree growth estimation based on Unmanned Aircraft Vehicle (UAV) imagery. The experiment was conducted in an agriculture test field with scots pine canopies. The data was collected using a Leica Aibotix X6V2 platform equipped with a Nikon D800 camera. Reference geometric parameters of selected sample plants were measured manually each week. In situ measurements were correlated with the UAV data acquisition. The correlation aimed at the investigation of optimal conditions for a flight and parameter settings for image acquisition. The collected images are processed in a state of the art tool resulting in a generation of dense 3D point clouds. The algorithm is developed in order to estimate geometric tree parameters from 3D points. Stem positions and tree tops are identified automatically in a cross section, followed by the calculation of tree heights. The automatically derived height values are compared to the reference measurements performed manually. The comparison allows for the evaluation of automatic growth estimation process. The accuracy achieved using UAV photogrammetry for tree heights estimation is about 5cm.

  17. Modelling Growth and Partitioning of Annual Above-Ground Vegetative and Reproductive Biomass of Grapevine

    NASA Astrophysics Data System (ADS)

    Meggio, Franco; Vendrame, Nadia; Maniero, Giovanni; Pitacco, Andrea

    2014-05-01

    In the current climate change scenarios, both agriculture and forestry inherently may act as carbon sinks and consequently can play a key role in limiting global warming. An urgent need exists to understand which land uses and land resource types have the greatest potential to mitigate greenhouse gas (GHG) emissions contributing to global change. A common believe is that agricultural fields cannot be net carbon sinks due to many technical inputs and repeated disturbances of upper soil layers that all contribute to a substantial loss both of the old and newly-synthesized organic matter. Perennial tree crops (vineyards and orchards), however, can behave differently: they grow a permanent woody structure, stand undisturbed in the same field for decades, originate a woody pruning debris, and are often grass-covered. In this context, reliable methods for quantifying and modelling emissions and carbon sequestration are required. Carbon stock changes are calculated by multiplying the difference in oven dry weight of biomass increments and losses with the appropriate carbon fraction. These data are relatively scant, and more information is needed on vineyard management practices and how they impact vineyard C sequestration and GHG emissions in order to generate an accurate vineyard GHG footprint. During the last decades, research efforts have been made for estimating the vineyard carbon budget and its allocation pattern since it is crucial to better understand how grapevines control the distribution of acquired resources in response to variation in environmental growth conditions and agronomic practices. The objective of the present study was to model and compare the dynamics of current year's above-ground biomass among four grapevine varieties. Trials were carried out over three growing seasons in field conditions. The non-linear extra-sums-of-squares method demonstrated to be a feasible way of growth models comparison to statistically assess significant differences among

  18. Development of a rotating algal biofilm growth system for attached microalgae growth with in situ biomass harvest.

    PubMed

    Gross, Martin; Henry, Wesley; Michael, Clayton; Wen, Zhiyou

    2013-12-01

    This work aimed to develop a rotating algal biofilm (RAB) cultivation system that can be widely adopted by microalgae producers for easy biomass harvest. Algal cells were grown on the surface of a material rotating between nutrient-rich liquid and CO2-rich gaseous phase. Scrapping biomass from the attached surface avoided the expensive harvest operations such as centrifugation. Among various attachment materials, cotton sheet resulted in best algal growth, durability, and cost effectiveness. A lab-scale RAB system was further optimized with harvest frequency, rotation speed, and CO2 levels. The algal biomass from the RAB system had a similar water content as that in centrifuged biomass. An open pond raceway retrofitted with a pilot-scale RAB system resulted in a much higher biomass productivity when compared to a control open pond. Collectively, the research shows that the RAB system is an efficient algal culture system for easy biomass harvest with enhanced biomass productivity.

  19. Incorrect representation of uncertainty in the modeling of growth leads to biased estimates of future biomass.

    PubMed

    Valle, Denis

    2011-06-01

    Biomass is a fundamental measure in the natural sciences, and numerous models have been developed to forecast timber and fishery yields, forest carbon content, and other environmental services that depend on biomass estimates. We derive general results that reveal how dynamic models that simulate growth as an increase in a linear measure of size (e.g., diameter, length, height) result in biased estimates of future mean biomass when uncertainty in growth is misrepresented. Our case study shows how models of tree growth that predict the same mean diameter increment, but with alternative representations of growth uncertainty, result in almost a threefold difference in the projections of future mean tree biomass after a 20-yr simulation. These results have important implications concerning our ability to accurately predict future biomass and all the related environmental services (e.g., forest carbon content, timber and fishery yields). If the objective is to predict future biomass, we strongly recommend that: (1) ecological modelers should choose a growth model based on a variable more linearly related to biomass (e.g., tree basal area instead of tree diameter for forest models); (2) if field measurements preclude the use of variables other than the linear measure of size, both the mean and other statistical moments (e.g., covariances) should be carefully modeled; (3) careful assessment be done on models that aggregate similar individuals (i.e., cohort models) to see if neglecting autocorrelated growth from individuals leads to biased estimates of future mean biomass.

  20. Red:far-red light conditions affect the emission of volatile organic compounds from barley (Hordeum vulgare), leading to altered biomass allocation in neighbouring plants

    PubMed Central

    Kegge, Wouter; Ninkovic, Velemir; Glinwood, Robert; Welschen, Rob A. M.; Voesenek, Laurentius A. C. J.; Pierik, Ronald

    2015-01-01

    Background and Aims Volatile organic compounds (VOCs) play various roles in plant–plant interactions, and constitutively produced VOCs might act as a cue to sense neighbouring plants. Previous studies have shown that VOCs emitted from the barley (Hordeum vulgare) cultivar ‘Alva’ cause changes in biomass allocation in plants of the cultivar ‘Kara’. Other studies have shown that shading and the low red:far-red (R:FR) conditions that prevail at high plant densities can reduce the quantity and alter the composition of the VOCs emitted by Arabidopsis thaliana, but whether this affects plant–plant signalling remains unknown. This study therefore examines the effects of far-red light enrichment on VOC emissions and plant–plant signalling between ‘Alva’ and ‘Kara’. Methods The proximity of neighbouring plants was mimicked by supplemental far-red light treatment of VOC emitter plants of barley grown in growth chambers. Volatiles emitted by ‘Alva’ under control and far-red light-enriched conditions were analysed using gas chromatography–mass spectrometry (GC-MS). ‘Kara’ plants were exposed to the VOC blend emitted by the ‘Alva’ plants that were subjected to either of the light treatments. Dry matter partitioning, leaf area, stem and total root length were determined for ‘Kara’ plants exposed to ‘Alva’ VOCs, and also for ‘Alva’ plants exposed to either control or far-red-enriched light treatments. Key Results Total VOC emissions by ‘Alva’ were reduced under low R:FR conditions compared with control light conditions, although individual volatile compounds were found to be either suppressed, induced or not affected by R:FR. The altered composition of the VOC blend emitted by ‘Alva’ plants exposed to low R:FR was found to affect carbon allocation in receiver plants of ‘Kara’. Conclusions The results indicate that changes in R:FR light conditions influence the emissions of VOCs in barley, and that these altered emissions

  1. Simulation of wheat growth and development based on organ-level photosynthesis and assimilate allocation.

    PubMed

    Evers, J B; Vos, J; Yin, X; Romero, P; van der Putten, P E L; Struik, P C

    2010-05-01

    Intimate relationships exist between form and function of plants, determining many processes governing their growth and development. However, in most crop simulation models that have been created to simulate plant growth and, for example, predict biomass production, plant structure has been neglected. In this study, a detailed simulation model of growth and development of spring wheat (Triticum aestivum) is presented, which integrates degree of tillering and canopy architecture with organ-level light interception, photosynthesis, and dry-matter partitioning. An existing spatially explicit 3D architectural model of wheat development was extended with routines for organ-level microclimate, photosynthesis, assimilate distribution within the plant structure according to organ demands, and organ growth and development. Outgrowth of tiller buds was made dependent on the ratio between assimilate supply and demand of the plants. Organ-level photosynthesis, biomass production, and bud outgrowth were simulated satisfactorily. However, to improve crop simulation results more efforts are needed mechanistically to model other major plant physiological processes such as nitrogen uptake and distribution, tiller death, and leaf senescence. Nevertheless, the work presented here is a significant step forwards towards a mechanistic functional-structural plant model, which integrates plant architecture with key plant processes.

  2. Simulation of wheat growth and development based on organ-level photosynthesis and assimilate allocation.

    PubMed

    Evers, J B; Vos, J; Yin, X; Romero, P; van der Putten, P E L; Struik, P C

    2010-05-01

    Intimate relationships exist between form and function of plants, determining many processes governing their growth and development. However, in most crop simulation models that have been created to simulate plant growth and, for example, predict biomass production, plant structure has been neglected. In this study, a detailed simulation model of growth and development of spring wheat (Triticum aestivum) is presented, which integrates degree of tillering and canopy architecture with organ-level light interception, photosynthesis, and dry-matter partitioning. An existing spatially explicit 3D architectural model of wheat development was extended with routines for organ-level microclimate, photosynthesis, assimilate distribution within the plant structure according to organ demands, and organ growth and development. Outgrowth of tiller buds was made dependent on the ratio between assimilate supply and demand of the plants. Organ-level photosynthesis, biomass production, and bud outgrowth were simulated satisfactorily. However, to improve crop simulation results more efforts are needed mechanistically to model other major plant physiological processes such as nitrogen uptake and distribution, tiller death, and leaf senescence. Nevertheless, the work presented here is a significant step forwards towards a mechanistic functional-structural plant model, which integrates plant architecture with key plant processes. PMID:20231326

  3. Is growth reduction in defoliated trees a consequence of prioritized carbon allocation to reserves?

    NASA Astrophysics Data System (ADS)

    Hoch, Guenter; Schmid, Sandra; Palacio, Sara

    2015-04-01

    Tissue concentrations of carbon reserve compounds are frequently used as proxies for the carbon balance of trees, but the mechanisms regulating the formation of carbon reserves are still under debate. It is often assumed that carbon storage in trees is largely a consequence of surplus carbon supply (reserve accumulation). In contrast, carbon storage might also occur against prevailing carbon demand from other sink activities, like growth (reserve formation), in which case carbon reserve pools might increase even at carbon limitation, and thus, cannot be used as indicators for a tree's carbon supply status. Such a situation might be severe defoliation by herbivores. Especially in evergreen tree species, it has been shown that natural and experimental defoliation leads to a reduction of growth that is proportional to the lost leaf area. Compared to this strong effect on growth, carbon reserve pools (i.e. sugars, starch and storage lipids) of defoliated trees often exert only a temporary decrease immediately after defoliation, while tissue concentrations of carbon reserves return to those of undefoliated trees by the end of the growing season. Within a recent experiment, we investigated, if the growth decline in trees following early season defoliation is the consequence of prioritized carbon allocation to carbon reserves over growth. To test this hypothesis we grew seedlings of evergreen Quecus ilex and deciduous Quercus petraea trees under low (140 ppm), medium (280 ppm) and high (560 ppm) CO2 concentrations and completely defoliated half of the seedlings in each CO2 treatment at the beginning of the growing season. In undefoliated control trees, CO2 had a significant positive effect on the seasonal growth in both species. Defoliation had a strong negative impact on growth in the evergreen Q. illex, but less in the deciduous Q. petraea. In both species, the growth reduction after defoliation relative to undefoliated controls was very similar at all three CO2

  4. Tree Biomass Allocation and Its Model Additivity for Casuarina equisetifolia in a Tropical Forest of Hainan Island, China

    PubMed Central

    Xue, Yang; Yang, Zhongyang; Wang, Xiaoyan; Lin, Zhipan; Li, Dunxi; Su, Shaofeng

    2016-01-01

    Casuarina equisetifolia is commonly planted and used in the construction of coastal shelterbelt protection in Hainan Island. Thus, it is critical to accurately estimate the tree biomass of Casuarina equisetifolia L. for forest managers to evaluate the biomass stock in Hainan. The data for this work consisted of 72 trees, which were divided into three age groups: young forest, middle-aged forest, and mature forest. The proportion of biomass from the trunk significantly increased with age (P<0.05). However, the biomass of the branch and leaf decreased, and the biomass of the root did not change. To test whether the crown radius (CR) can improve biomass estimates of C. equisetifolia, we introduced CR into the biomass models. Here, six models were used to estimate the biomass of each component, including the trunk, the branch, the leaf, and the root. In each group, we selected one model among these six models for each component. The results showed that including the CR greatly improved the model performance and reduced the error, especially for the young and mature forests. In addition, to ensure biomass additivity, the selected equation for each component was fitted as a system of equations using seemingly unrelated regression (SUR). The SUR method not only gave efficient and accurate estimates but also achieved the logical additivity. The results in this study provide a robust estimation of tree biomass components and total biomass over three groups of C. equisetifolia. PMID:27002822

  5. Tree Biomass Allocation and Its Model Additivity for Casuarina equisetifolia in a Tropical Forest of Hainan Island, China.

    PubMed

    Xue, Yang; Yang, Zhongyang; Wang, Xiaoyan; Lin, Zhipan; Li, Dunxi; Su, Shaofeng

    2016-01-01

    Casuarina equisetifolia is commonly planted and used in the construction of coastal shelterbelt protection in Hainan Island. Thus, it is critical to accurately estimate the tree biomass of Casuarina equisetifolia L. for forest managers to evaluate the biomass stock in Hainan. The data for this work consisted of 72 trees, which were divided into three age groups: young forest, middle-aged forest, and mature forest. The proportion of biomass from the trunk significantly increased with age (P<0.05). However, the biomass of the branch and leaf decreased, and the biomass of the root did not change. To test whether the crown radius (CR) can improve biomass estimates of C. equisetifolia, we introduced CR into the biomass models. Here, six models were used to estimate the biomass of each component, including the trunk, the branch, the leaf, and the root. In each group, we selected one model among these six models for each component. The results showed that including the CR greatly improved the model performance and reduced the error, especially for the young and mature forests. In addition, to ensure biomass additivity, the selected equation for each component was fitted as a system of equations using seemingly unrelated regression (SUR). The SUR method not only gave efficient and accurate estimates but also achieved the logical additivity. The results in this study provide a robust estimation of tree biomass components and total biomass over three groups of C. equisetifolia.

  6. Arabidopsis coordinates the diurnal regulation of carbon allocation and growth across a wide range of photoperiods.

    PubMed

    Sulpice, Ronan; Flis, Anna; Ivakov, Alexander A; Apelt, Federico; Krohn, Nicole; Encke, Beatrice; Abel, Christin; Feil, Regina; Lunn, John E; Stitt, Mark

    2014-01-01

    In short photoperiods, plants accumulate starch more rapidly in the light and degrade it more slowly at night, ensuring that their starch reserves last until dawn. To investigate the accompanying changes in the timing of growth, Arabidopsis was grown in a range of photoperiods and analyzed for rosette biomass, photosynthesis, respiration, ribosome abundance, polysome loading, starch, and over 40 metabolites at dawn and dusk. The data set was used to model growth rates in the daytime and night, and to identify metabolites that correlate with growth. Modeled growth rates and polysome loading were high in the daytime and at night in long photoperiods, but decreased at night in short photoperiods. Ribosome abundance was similar in all photoperiods. It is discussed how the amount of starch accumulated in the light period, the length of the night, and maintenance costs interact to constrain growth at night in short photoperiods, and alter the strategy for optimizing ribosome use. Significant correlations were found in the daytime and the night between growth rates and the levels of the sugar-signal trehalose 6-phosphate and the amino acid biosynthesis intermediate shikimate, identifying these metabolites as hubs in a network that coordinates growth with diurnal changes in the carbon supply.

  7. Biomass and lipid production of a local isolate Chlorella sorokiniana under mixotrophic growth conditions.

    PubMed

    Juntila, D J; Bautista, M A; Monotilla, W

    2015-09-01

    A local Chlorella sp. isolate with 97% rbcL sequence identity to Chlorella sorokiniana was evaluated in terms of its biomass and lipid production under mixotrophic growth conditions. Glucose-supplemented cultures exhibited increasing growth rate and biomass yield with increasing glucose concentration. Highest growth rate and biomass yield of 1.602 day(-1) and 687.5 mg L(-1), respectively, were achieved under 2 g L(-1) glucose. Nitrogen starvation up to 75% in the 1.0 g L(-1) glucose-supplemented culture was done to induce lipid accumulation and did not significantly affect the growth. Lipid content ranges from 20% to 27% dry weight. Nile Red staining showed more prominent neutral lipid bodies in starved mixotrophic cultures. C. sorokiniana exhibited enhanced biomass production under mixotrophy and more prominent neutral lipid accumulation under nitrogen starvation with no significant decrease in growth; hence, this isolate could be further studied to establish its potential for biodiesel production. PMID:25847795

  8. Biomass and lipid production of a local isolate Chlorella sorokiniana under mixotrophic growth conditions.

    PubMed

    Juntila, D J; Bautista, M A; Monotilla, W

    2015-09-01

    A local Chlorella sp. isolate with 97% rbcL sequence identity to Chlorella sorokiniana was evaluated in terms of its biomass and lipid production under mixotrophic growth conditions. Glucose-supplemented cultures exhibited increasing growth rate and biomass yield with increasing glucose concentration. Highest growth rate and biomass yield of 1.602 day(-1) and 687.5 mg L(-1), respectively, were achieved under 2 g L(-1) glucose. Nitrogen starvation up to 75% in the 1.0 g L(-1) glucose-supplemented culture was done to induce lipid accumulation and did not significantly affect the growth. Lipid content ranges from 20% to 27% dry weight. Nile Red staining showed more prominent neutral lipid bodies in starved mixotrophic cultures. C. sorokiniana exhibited enhanced biomass production under mixotrophy and more prominent neutral lipid accumulation under nitrogen starvation with no significant decrease in growth; hence, this isolate could be further studied to establish its potential for biodiesel production.

  9. Growth, aboveground biomass, and nutrient concentration of young Scots pine and lodgepole pine in oil shale post-mining landscapes in Estonia.

    PubMed

    Kuznetsova, Tatjana; Tilk, Mari; Pärn, Henn; Lukjanova, Aljona; Mandre, Malle

    2011-12-01

    The investigation was carried out in 8-year-old Scots pine (Pinus sylvestris L.) and lodgepole pine (Pinus contorta var. latifolia Engelm.) plantations on post-mining area, Northeast Estonia. The aim of the study was to assess the suitability of lodgepole pine for restoration of degraded lands by comparing the growth, biomass, and nutrient concentration of studied species. The height growth of trees was greater in the Scots pine stand, but the tree aboveground biomass was slightly larger in the lodgepole pine stand. The aboveground biomass allocation to the compartments did not differ significantly between species. The vertical distribution of compartments showed that 43.2% of the Scots pine needles were located in the middle layer of the crown, while 58.5% of the lodgepole pine needles were in the lowest layer of the crown. The largest share of the shoots and stem of both species was allocated to the lowest layer of the crown. For both species, the highest NPK concentrations were found in the needles and the lowest in the stems. On the basis of the present study results, it can be concluded that the early growth of Scots pine and lodgepole pine on oil shale post-mining landscapes is similar. PMID:21374054

  10. Characteristic time scales of mixing, mass transfer and biomass growth in a Taylor vortex algal photobioreactor.

    PubMed

    Gao, Xi; Kong, Bo; Vigil, R Dennis

    2015-12-01

    Recently it has been demonstrated that algal biomass yield can be enhanced using fluid flow patterns known as Taylor vortices. It has been suggested that these growth rate improvements can be attributed to improved light delivery as a result of rapid transport of microorganisms between light and dark regions of the reactor. However, Taylor vortices also strongly impact fluid mixing and interphase (gas-liquid) mass transport, and these in turn may also explain improvements in biomass productivity. To identify the growth-limiting factor in a Taylor vortex algal photobioreactor, experiments were performed to determine characteristic time scales for mixing and mass transfer. By comparing these results with the characteristic time scale for biomass growth, it is shown that algal growth rate in Taylor vortex reactors is not limited by fluid mixing or interphase mass transfer, and therefore the observed biomass productivity improvements are likely attributable to improved light utilization efficiency.

  11. The potential impacts of increasing temperatures on old-growth forest biomass density

    NASA Astrophysics Data System (ADS)

    Larjavaara, M.; Muller-Landau, H. C.

    2012-04-01

    Global atmospheric and climate change could alter forest carbon stores, potentially causing important positive or negative feedbacks on global change. For example, rising temperatures are likely to influence old-growth forest biomass density (biomass per unit area), and thereby could make old growth forests sources or sinks of carbon to the atmosphere, but the magnitude and direction of likely change continue to be debated. It is difficult if not impossible to run experiments on sufficiently large spatial and temporal scale to capture global change impacts on old-growth biomass in different forest types. Thus, models that capture the key physiological impacts of global change on forest carbon budgets are a critical tool for assessing impacts of climate and atmospheric change. The expected changes in temperatures are similar to spatial temperature variation observed currently and, therefore, models explaining current variation in old¬-growth forest biomass can be directly applied to predict expected equilibrium biomass after a transitional period lasting decades or centuries. In a recent paper (Larjavaara and Muller-Landau 2012. Temperature explains global variation in biomass among humid old-growth forests. Global Ecology and Biogeography), we developed a physiologically motivated model for global variation in old-growth forest biomass. We modelled annual GPP as a function of monthly average temperatures (minimum and maximum) and sun angle, and modelled plant biomass "maintenance cost" (including autotrophic respiration and construction required to maintain biomass) as a function of temperatures alone. We then used fitted models for GPP and maintenance cost to predict old-growth forest biomass density under different climates. We found that highest old-growth biomass is expected in maritime temperate climates in which temperatures remain between 5˚C and 25˚C for most of the year, and in which the ratio of GPP to maintenance cost is thus the highest. In tropical

  12. Stand density, tree social status and water stress influence allocation in height and diameter growth of Quercus petraea (Liebl.).

    PubMed

    Trouvé, Raphaël; Bontemps, Jean-Daniel; Seynave, Ingrid; Collet, Catherine; Lebourgeois, François

    2015-10-01

    Even-aged forest stands are competitive communities where competition for light gives advantages to tall individuals, thereby inducing a race for height. These same individuals must however balance this competitive advantage with height-related mechanical and hydraulic risks. These phenomena may induce variations in height-diameter growth relationships, with primary dependences on stand density and tree social status as proxies for competition pressure and access to light, and on availability of local environmental resources, including water. We aimed to investigate the effects of stand density, tree social status and water stress on the individual height-circumference growth allocation (Δh-Δc), in even-aged stands of Quercus petraea Liebl. (sessile oak). Within-stand Δc was used as surrogate for tree social status. We used an original long-term experimental plot network, set up in the species production area in France, and designed to explore stand dynamics on a maximum density gradient. Growth allocation was modelled statistically by relating the shape of the Δh-Δc relationship to stand density, stand age and water deficit. The shape of the Δh-Δc relationship shifted from linear with a moderate slope in open-grown stands to concave saturating with an initial steep slope in closed stands. Maximum height growth was found to follow a typical mono-modal response to stand age. In open-grown stands, increasing summer soil water deficit was found to decrease height growth relative to radial growth, suggesting hydraulic constraints on height growth. A similar pattern was found in closed stands, the magnitude of the effect however lowering from suppressed to dominant trees. We highlight the high phenotypic plasticity of growth in sessile oak trees that further adapt their allocation scheme to their environment. Stand density and tree social status were major drivers of growth allocation variations, while water stress had a detrimental effect on height in the

  13. Systems Level Regulation of Rhythmic Growth Rate and Biomass Accumulation in Grasses

    SciTech Connect

    Kay, Steve A.

    2013-05-02

    Several breakthroughs have been recently made in our understanding of plant growth and biomass accumulation. It was found that plant growth is rhythmically controlled throughout the day by the circadian clock through a complex interplay of light and phytohormone signaling pathways. While plants such as the C4 energy crop sorghum (Sorghum bicolor (L.) Moench) and possibly the C3 grass (Brachypodium distachyon) also exhibit daily rhythms in growth rate, the molecular details of its regulation remain to be explored. A better understanding of diurnally regulated growth behavior in grasses may lead to species-specific mechanisms highly relevant to future strategies to optimize energy crop biomass yield. Here we propose to devise a systems approach to identify, in parallel, regulatory hubs associated with rhythmic growth in C3 and C4 plants. We propose to use rhythmicity in daily growth patterns to drive the discovery of regulatory network modules controlling biomass accumulation.

  14. A PCR-based method to quantify fungal growth during pretreatment of lignocellulosic biomass.

    PubMed

    Simeng, Zhou; Sacha, Grisel; Isabelle, Herpoël-Gimbert; Marie-Noëlle, Rosso

    2015-08-01

    Filamentous fungi have shown great potential in the pretreatment of lignocellulosic biomass and their use in bio-processes based on Solid State Fermentation (SSF) opens promising perspectives for plant biomass valorization. Obviously, quantification of the fungal biomass throughout the fermentation is a crucial parameter for SSF evaluation and control, both at the laboratory and industrial scale. Here we provide a qPCR-based method as a reliable alternative to conventional methods to estimate mycelial growth during plant biomass treatment. For the three strains analyzed, the lowest detection limit ranged from 58 to 272 μg mycelium dry weight per gram biomass (dry weight). We show that the qPCR-based method allows fungal growth monitoring during fermentation and provides relevant information for selection of the most appropriate fungal strains in specific SSF/reactor conditions. PMID:26031470

  15. A PCR-based method to quantify fungal growth during pretreatment of lignocellulosic biomass.

    PubMed

    Simeng, Zhou; Sacha, Grisel; Isabelle, Herpoël-Gimbert; Marie-Noëlle, Rosso

    2015-08-01

    Filamentous fungi have shown great potential in the pretreatment of lignocellulosic biomass and their use in bio-processes based on Solid State Fermentation (SSF) opens promising perspectives for plant biomass valorization. Obviously, quantification of the fungal biomass throughout the fermentation is a crucial parameter for SSF evaluation and control, both at the laboratory and industrial scale. Here we provide a qPCR-based method as a reliable alternative to conventional methods to estimate mycelial growth during plant biomass treatment. For the three strains analyzed, the lowest detection limit ranged from 58 to 272 μg mycelium dry weight per gram biomass (dry weight). We show that the qPCR-based method allows fungal growth monitoring during fermentation and provides relevant information for selection of the most appropriate fungal strains in specific SSF/reactor conditions.

  16. Extraction of solubles from plant biomass for use as microbial growth stimulant and methods related thereto

    DOEpatents

    Lau, Ming Woei

    2015-12-08

    A method for producing a microbial growth stimulant (MGS) from a plant biomass is described. In one embodiment, an ammonium hydroxide solution is used to extract a solution of proteins and ammonia from the biomass. Some of the proteins and ammonia are separated from the extracted solution to provide the MGS solution. The removed ammonia can be recycled and the proteins are useful as animal feeds. In one embodiment, the method comprises extracting solubles from pretreated lignocellulosic biomass with a cellulase enzyme-producing growth medium (such T. reesei) in the presence of water and an aqueous extract.

  17. Research and evaluation of biomass resources/conversion/utilization systems (market/experimental analysis for development of a data base for a fuels from biomass model. Volume I. Biomass allocation model. Technical progress report for the period ending September 30, 1980

    SciTech Connect

    Ahn, Y.K.; Chen, H.T.; Helm, R.W.; Nelson, E.T.; Shields K.J.

    1980-01-01

    A biomass allocation model has been developed to show the most profitable combination of biomass feedstocks thermochemical conversion processes, and fuel products to serve the seasonal conditions in a regional market. This optimization model provides a tool for quickly calculating the most profitable biomass missions from a large number of potential biomass missions. Other components of the system serve as a convenient storage and retrieval mechanism for biomass marketing and thermochemical conversion processing data. The system can be accessed through the use of a computer terminal, or it could be adapted to a portable micro-processor. A User's Manual for the system has been included in Appendix A of the report. The validity of any biomass allocation solution provided by the allocation model is dependent on the accuracy of the data base. The initial data base was constructed from values obtained from the literature, and, consequently, as more current thermochemical conversion processing and manufacturing costs and efficiencies become available, the data base should be revised. Biomass derived fuels included in the data base are the following: medium Btu gas low Btu gas, substitute natural gas, ammonia, methanol, electricity, gasoline, and fuel oil. The market sectors served by the fuels include: residential, electric utility, chemical (industrial), and transportation. Regional/seasonal costs and availabilities and heating values for 61 woody and non-woody biomass species are included. The study has included four regions in the United States which were selected because there was both an availability of biomass and a commercial demand for the derived fuels: Region I: NY, WV, PA; Region II: GA, AL, MS; Region III: IN, IL, IA; and Region IV: OR, WA.

  18. Biomass Accumulation Rates of Amazonian Secondary Forest and Biomass of Old-Growth Forests from Landsat Time Series and GLAS

    NASA Astrophysics Data System (ADS)

    Helmer, E.; Lefsky, M. A.; Roberts, D.

    2009-12-01

    We estimate the age of humid lowland tropical forests in Rondônia, Brazil, from a somewhat densely spaced time series of Landsat images (1975-2003) with an automated procedure, the Threshold Age Mapping Algorithm (TAMA), first described here. We then estimate a landscape-level rate of aboveground woody biomass accumulation of secondary forest by combining forest age mapping with biomass estimates from the Geoscience Laser Altimeter System (GLAS). Though highly variable, the estimated average biomass accumulation rate of 8.4 Mg ha-1 yr-1 agrees well with ground-based studies for young secondary forests in the region. In isolating the lowland forests, we map land cover and general types of old-growth forests with decision tree classification of Landsat imagery and elevation data. We then estimate aboveground live biomass for seven classes of old-growth forest. TAMA is simple, fast, and self-calibrating. By not using between-date band or index differences or trends, it requires neither image normalization nor atmospheric correction. In addition, it uses an approach to map forest cover for the self-calibrations that is novel to forest mapping with satellite imagery; it maps humid secondary forest that is difficult to distinguish from old-growth forest in single-date imagery; it does not assume that forest age equals time since disturbance; and it incorporates Landsat Multispectral Scanner (MSS) imagery. Variations on the work that we present here can be applied to other forested landscapes. Applications that use image time series will be helped by the free distribution of coregistered Landsat imagery, which began in December 2008, and of the Ice Cloud and land Elevation Satellite (ICESat) Vegetation Product, which simplifies the use of GLAS data. Finally, we demonstrate here for the first time how the optical imagery of fine spatial resolution that is viewable on Google Earth provides a new source of reference data for remote sensing applications related to land cover

  19. Biomass and nutrient distributions in central Oregon second-growth ponderosa pine ecosystems. Forest Service research paper

    SciTech Connect

    Little, S.N.; Shainsky, L.J.

    1995-03-01

    We investigated the distributioin of biomass and nurtrients in second-growth ponderosa pine (Pinus ponderosa Dougl. ex Laws.) ecosystems in central Oregon. Destructive sampling of aboveground and belowground tree biomass was carried out at six sites in the Deschutes National Forest; three of these sites also were intensively sampled for biomass and nutrient concentrations of the soil, forest floor, residue, and shrub components. Tree biomass equations were developed that related component biomass to diameter at breast height and total tree height.

  20. A Screening Model to Predict Microalgae Biomass Growth in Photobioreactors and Raceway Ponds

    SciTech Connect

    Huesemann, Michael H.; Van Wagenen, Jonathan M.; Miller, Tyler W.; Chavis, Aaron R.; Hobbs, Watts B.; Crowe, Braden J.

    2013-06-01

    A microalgae biomass growth model was developed for screening novel strains for their potential to exhibit high biomass productivities under nutrient-replete conditions in photobioreactors or outdoor ponds. Growth is modeled by first estimating the light attenuation by biomass according to Beer-Lambert’s law, and then calculating the specific growth rate in discretized culture volume slices that receive declining light intensities due to attenuation. The model requires only two physical and two species-specific biological input parameters, all of which are relatively easy to determine: incident light intensity, culture depth, as well as the biomass light absorption coefficient and the specific growth rate as a function of light intensity. Roux bottle culture experiments were performed with Nannochloropsis salina at constant temperature (23 °C) at six different incident light intensities (5, 10, 25, 50, 100, 250, and 850 μmol/m2∙ sec) to determine both the specific growth rate under non-shading conditions and the biomass light absorption coefficient as a function of light intensity. The model was successful in predicting the biomass growth rate in these Roux bottle cultures during the light-limited linear phase at different incident light intensities. Model predictions were moderately sensitive to minor variations in the values of input parameters. The model was also successful in predicting the growth performance of Chlorella sp. cultured in LED-lighted 800 L raceway ponds operated at constant temperature (30 °C) and constant light intensity (1650 μmol/m2∙ sec). Measurements of oxygen concentrations as a function of time demonstrated that following exposure to darkness, it takes at least 5 seconds for cells to initiate dark respiration. As a result, biomass loss due to dark respiration in the aphotic zone of a culture is unlikely to occur in highly mixed small-scale photobioreactors where cells move rapidly in and out of the light. By contrast, as

  1. Genotypic Tannin Levels in Populus tremula Impact the Way Nitrogen Enrichment Affects Growth and Allocation Responses for Some Traits and Not for Others

    PubMed Central

    Bandau, Franziska; Decker, Vicki Huizu Guo; Gundale, Michael J.; Albrectsen, Benedicte Riber

    2015-01-01

    Plant intraspecific variability has been proposed as a key mechanism by which plants adapt to environmental change. In boreal forests where nitrogen availability is strongly limited, nitrogen addition happens indirectly through atmospheric N deposition and directly through industrial forest fertilization. These anthropogenic inputs of N have numerous environmental consequences, including shifts in plant species composition and reductions in plant species diversity. However, we know less about how genetic differences within plant populations determine how species respond to eutrophication in boreal forests. According to plant defense theories, nitrogen addition will cause plants to shift carbon allocation more towards growth and less to chemical defense, potentially enhancing vulnerability to antagonists. Aspens are keystone species in boreal forests that produce condensed tannins to serve as chemical defense. We conducted an experiment using ten Populus tremula genotypes from the Swedish Aspen Collection that express extreme levels of baseline investment into foliar condensed tannins. We investigated whether investment into growth and phenolic defense compounds in young plants varied in response to two nitrogen addition levels, corresponding to atmospheric N deposition and industrial forest fertilization. Nitrogen addition generally caused growth to increase, and tannin levels to decrease; however, individualistic responses among genotypes were found for height growth, biomass of specific tissues, root:shoot ratios, and tissue lignin and N concentrations. A genotype’s baseline ability to produce and store condensed tannins also influenced plant responses to N, although this effect was relatively minor. High-tannin genotypes tended to grow less biomass under low nitrogen levels and more at the highest fertilization level. Thus, the ability in aspen to produce foliar tannins is likely associated with a steeper reaction norm of growth responses, which suggests a

  2. Genotypic Tannin Levels in Populus tremula Impact the Way Nitrogen Enrichment Affects Growth and Allocation Responses for Some Traits and Not for Others.

    PubMed

    Bandau, Franziska; Decker, Vicki Huizu Guo; Gundale, Michael J; Albrectsen, Benedicte Riber

    2015-01-01

    Plant intraspecific variability has been proposed as a key mechanism by which plants adapt to environmental change. In boreal forests where nitrogen availability is strongly limited, nitrogen addition happens indirectly through atmospheric N deposition and directly through industrial forest fertilization. These anthropogenic inputs of N have numerous environmental consequences, including shifts in plant species composition and reductions in plant species diversity. However, we know less about how genetic differences within plant populations determine how species respond to eutrophication in boreal forests. According to plant defense theories, nitrogen addition will cause plants to shift carbon allocation more towards growth and less to chemical defense, potentially enhancing vulnerability to antagonists. Aspens are keystone species in boreal forests that produce condensed tannins to serve as chemical defense. We conducted an experiment using ten Populus tremula genotypes from the Swedish Aspen Collection that express extreme levels of baseline investment into foliar condensed tannins. We investigated whether investment into growth and phenolic defense compounds in young plants varied in response to two nitrogen addition levels, corresponding to atmospheric N deposition and industrial forest fertilization. Nitrogen addition generally caused growth to increase, and tannin levels to decrease; however, individualistic responses among genotypes were found for height growth, biomass of specific tissues, root:shoot ratios, and tissue lignin and N concentrations. A genotype's baseline ability to produce and store condensed tannins also influenced plant responses to N, although this effect was relatively minor. High-tannin genotypes tended to grow less biomass under low nitrogen levels and more at the highest fertilization level. Thus, the ability in aspen to produce foliar tannins is likely associated with a steeper reaction norm of growth responses, which suggests a

  3. Genotypic Tannin Levels in Populus tremula Impact the Way Nitrogen Enrichment Affects Growth and Allocation Responses for Some Traits and Not for Others.

    PubMed

    Bandau, Franziska; Decker, Vicki Huizu Guo; Gundale, Michael J; Albrectsen, Benedicte Riber

    2015-01-01

    Plant intraspecific variability has been proposed as a key mechanism by which plants adapt to environmental change. In boreal forests where nitrogen availability is strongly limited, nitrogen addition happens indirectly through atmospheric N deposition and directly through industrial forest fertilization. These anthropogenic inputs of N have numerous environmental consequences, including shifts in plant species composition and reductions in plant species diversity. However, we know less about how genetic differences within plant populations determine how species respond to eutrophication in boreal forests. According to plant defense theories, nitrogen addition will cause plants to shift carbon allocation more towards growth and less to chemical defense, potentially enhancing vulnerability to antagonists. Aspens are keystone species in boreal forests that produce condensed tannins to serve as chemical defense. We conducted an experiment using ten Populus tremula genotypes from the Swedish Aspen Collection that express extreme levels of baseline investment into foliar condensed tannins. We investigated whether investment into growth and phenolic defense compounds in young plants varied in response to two nitrogen addition levels, corresponding to atmospheric N deposition and industrial forest fertilization. Nitrogen addition generally caused growth to increase, and tannin levels to decrease; however, individualistic responses among genotypes were found for height growth, biomass of specific tissues, root:shoot ratios, and tissue lignin and N concentrations. A genotype's baseline ability to produce and store condensed tannins also influenced plant responses to N, although this effect was relatively minor. High-tannin genotypes tended to grow less biomass under low nitrogen levels and more at the highest fertilization level. Thus, the ability in aspen to produce foliar tannins is likely associated with a steeper reaction norm of growth responses, which suggests a

  4. Pretreatment of fibrous biomass and growth of biosurfactant-producing Bacillus subtilis on biomass-derived fermentable sugars.

    PubMed

    Sharma, Rajat; Lamsal, Buddhi P; Colonna, William J

    2016-01-01

    Pretreatment of six fibrous biomasses (switchgrass, alfalfa, soy hulls, soy fiber, DDGS and Baggase) and subsequent hydrolysis using cellulolytic enzymes at a 2.5% (v/v) and 5% (v/v) loading 2.5 (v/v) and 5% (v/v) loading was compared for higher amounts of sugars released. Soaking of biomasses of switchgrass, alfalfa, soy hulls and bagasse in 15% w/w ammonia was optimal at 60 °C for 12 h, followed by enzymatic hydrolysis, yielding 72, 70, 80 and 75% carbohydrate conversions, respectively. However, soaking in ammonia was not needed for soy fiber and DDGS as these contained very little lignin. Ultrasonication for 3 min @ 100% amplitude (170 µM) was found to be optimal for soy fiber and DDGS from which 77 and 83% carbohydrate conversion, respectively, was obtained following enzyme treatment at 5% (w/v) enzyme. The sugars released by enzymatic hydrolysis of pretreated biomass were utilized as an energy source by Bacillus subtilis in fermentation media at 2% (w/v) of concentration. In shake flask trials, cell growth was 15-20% higher on hydrolysates of ammonia-treated switchgrass and alfalfa vs. glucose-based control media due to the presence of a wider range of monomeric sugars (glucose, xylose, arabinose, mannose and galactose). In contrast, growth was less on soy hull hydrolysates prepared with ammonia pretreatment.

  5. Response of woody swamp seedlings to flooding and increased water temperatures. I. Growth, biomass, and survivorship

    SciTech Connect

    Donovan, L.A.; McLeod, K.W.; Sherrod, K.C.; Stumpff, N.J. )

    1988-08-01

    Growth, biomass, and survival of bald cypress (Taxodium distichum (L.) Richard), water tupelo (Nyssa aquatica L.), black willow (Salix nigra Marshall), and button bush (Cephalanthus occidentalis L.) were examined in a 3 {times} 3 factorial experiment varying water temperatures (Ambient, mid, and high ({approximately} 40 C)) and water levels (drained, saturated, and flooded). Stem diameter and height, biomass, and survivorship for water tupelo and bald cypress were all reduced by the high/flooded treatment. Black willow growth had the greatest variability among nonlethal flooding and temperature treatments, and achieved the greatest biomass of the four species. In the high/flooded treatment, however, only 47% of the black willow seedlings survived and stem diameter, height, and biomass of survivors were greatly reduced. Button bush had intermediate variability of growth to the nonlethal treatments as compared to the other study species. Survival of button bush seedlings in the high/flooded treatment was high (87%), but root biomass of the survivors was reduced. Interspecific differences in growth, biomass, survivorship, and morphological characteristics existed among these swamp species to experimental conditions. These responses may help explain vegetation patterns in a thermally impacted swamp.

  6. Hormonal changes in relation to biomass partitioning and shoot growth impairment in salinized tomato (Solanum lycopersicum L.) plants

    PubMed Central

    Albacete, Alfonso; Ghanem, Michel Edmond; Martínez-Andújar, Cristina; Acosta, Manuel; Sánchez-Bravo, José; Martínez, Vicente; Lutts, Stanley; Dodd, Ian C.; Pérez-Alfocea, Francisco

    2008-01-01

    Following exposure to salinity, the root/shoot ratio is increased (an important adaptive response) due to the rapid inhibition of shoot growth (which limits plant productivity) while root growth is maintained. Both processes may be regulated by changes in plant hormone concentrations. Tomato plants (Solanum lycopersicum L. cv Moneymaker) were cultivated hydroponically for 3 weeks under high salinity (100 mM NaCl) and five major plant hormones (abscisic acid, ABA; the cytokinins zeatin, Z, and zeatin-riboside, ZR; the auxin indole-3-acetic acid, IAA; and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid, ACC) were determined weekly in roots, xylem sap, and leaves. Salinity reduced shoot biomass by 50–60% and photosynthetic area by 20–25% both by decreasing leaf expansion and delaying leaf appearance, while root growth was less affected, thus increasing the root/shoot ratio. ABA and ACC concentrations strongly increased in roots, xylem sap, and leaves after 1 d (ABA) and 15 d (ACC) of salinization. By contrast, cytokinins and IAA were differentially affected in roots and shoots. Salinity dramatically decreased the Z+ZR content of the plant, and induced the conversion of ZR into Z, especially in the roots, which accounted for the relative increase of cytokinins in the roots compared to the leaf. IAA concentration was also strongly decreased in the leaves while it accumulated in the roots. Decreased cytokinin content and its transport from the root to the shoot were probably induced by the basipetal transport of auxin from the shoot to the root. The auxin/cytokinin ratio in the leaves and roots may explain both the salinity-induced decrease in shoot vigour (leaf growth and leaf number) and the shift in biomass allocation to the roots, in agreement with changes in the activity of the sink-related enzyme cell wall invertase. PMID:19036841

  7. Maximum photosynthetic efficiency of biomass growth: a criticism of some measurements

    SciTech Connect

    Lee, Y.K.; Pirt, S.J.

    1982-02-01

    The yield of biomass produced in a photosynthetic culture is an expression of the photosynthetic efficiency. Microbial cells consume energy for both growth and for maintenance. The bioenergetics of Chlorella cultures and the maximum growth yields obtained by various researchers are examined in this paper.

  8. Differentiation in growth and biomass allocation among three native Alternathera philoxeroides varieties from Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge about the life-history traits of native conspecifics of exotic invasive plants can be of fundamental importance in exploring their origin of invasiveness and disentangling distinct invasion mechanisms. We conducted a common garden experiment to examine genetically based differentiation in ...

  9. Sowing Density: A Neglected Factor Fundamentally Affecting Root Distribution and Biomass Allocation of Field Grown Spring Barley (Hordeum Vulgare L.)

    PubMed Central

    Hecht, Vera L.; Temperton, Vicky M.; Nagel, Kerstin A.; Rascher, Uwe; Postma, Johannes A.

    2016-01-01

    Studies on the function of root traits and the genetic variation in these traits are often conducted under controlled conditions using individual potted plants. Little is known about root growth under field conditions and how root traits are affected by agronomic practices in particular sowing density. We hypothesized that with increasing sowing density, root length density (root length per soil volume, cm cm−3) increases in the topsoil as well as specific root length (root length per root dry weight, cm g−1) due to greater investment in fine roots. Therefore, we studied two spring barley cultivars at ten different sowing densities (24–340 seeds m−2) in 2 consecutive years in a clay loam field in Germany and established sowing density dose-response curves for several root and shoot traits. We took soil cores for measuring roots up to a depth of 60 cm in and between plant rows (inter-row distance 21 cm). Root length density increased with increasing sowing density and was greatest in the plant row in the topsoil (0–10 cm). Greater sowing density increased specific root length partly through greater production of fine roots in the topsoil. Rooting depth (D50) of the major root axes (root diameter class 0.4–1.0 mm) was not affected. Root mass fraction decreased, while stem mass fraction increased with sowing density and over time. Leaf mass fraction was constant over sowing density but greater leaf area was realized through increased specific leaf area. Considering fertilization, we assume that light competition caused plants to grow more shoot mass at the cost of investment into roots, which is partly compensated by increased specific root length and shallow rooting. Increased biomass per area with greater densities suggest that density increases the efficiency of the cropping system, however, declines in harvest index at densities over 230 plants m−2 suggest that this efficiency did not translate into greater yield. We conclude that plant density is a

  10. Sowing Density: A Neglected Factor Fundamentally Affecting Root Distribution and Biomass Allocation of Field Grown Spring Barley (Hordeum Vulgare L.).

    PubMed

    Hecht, Vera L; Temperton, Vicky M; Nagel, Kerstin A; Rascher, Uwe; Postma, Johannes A

    2016-01-01

    Studies on the function of root traits and the genetic variation in these traits are often conducted under controlled conditions using individual potted plants. Little is known about root growth under field conditions and how root traits are affected by agronomic practices in particular sowing density. We hypothesized that with increasing sowing density, root length density (root length per soil volume, cm cm(-3)) increases in the topsoil as well as specific root length (root length per root dry weight, cm g(-1)) due to greater investment in fine roots. Therefore, we studied two spring barley cultivars at ten different sowing densities (24-340 seeds m(-2)) in 2 consecutive years in a clay loam field in Germany and established sowing density dose-response curves for several root and shoot traits. We took soil cores for measuring roots up to a depth of 60 cm in and between plant rows (inter-row distance 21 cm). Root length density increased with increasing sowing density and was greatest in the plant row in the topsoil (0-10 cm). Greater sowing density increased specific root length partly through greater production of fine roots in the topsoil. Rooting depth (D50) of the major root axes (root diameter class 0.4-1.0 mm) was not affected. Root mass fraction decreased, while stem mass fraction increased with sowing density and over time. Leaf mass fraction was constant over sowing density but greater leaf area was realized through increased specific leaf area. Considering fertilization, we assume that light competition caused plants to grow more shoot mass at the cost of investment into roots, which is partly compensated by increased specific root length and shallow rooting. Increased biomass per area with greater densities suggest that density increases the efficiency of the cropping system, however, declines in harvest index at densities over 230 plants m(-2) suggest that this efficiency did not translate into greater yield. We conclude that plant density is a

  11. Sowing Density: A Neglected Factor Fundamentally Affecting Root Distribution and Biomass Allocation of Field Grown Spring Barley (Hordeum Vulgare L.).

    PubMed

    Hecht, Vera L; Temperton, Vicky M; Nagel, Kerstin A; Rascher, Uwe; Postma, Johannes A

    2016-01-01

    Studies on the function of root traits and the genetic variation in these traits are often conducted under controlled conditions using individual potted plants. Little is known about root growth under field conditions and how root traits are affected by agronomic practices in particular sowing density. We hypothesized that with increasing sowing density, root length density (root length per soil volume, cm cm(-3)) increases in the topsoil as well as specific root length (root length per root dry weight, cm g(-1)) due to greater investment in fine roots. Therefore, we studied two spring barley cultivars at ten different sowing densities (24-340 seeds m(-2)) in 2 consecutive years in a clay loam field in Germany and established sowing density dose-response curves for several root and shoot traits. We took soil cores for measuring roots up to a depth of 60 cm in and between plant rows (inter-row distance 21 cm). Root length density increased with increasing sowing density and was greatest in the plant row in the topsoil (0-10 cm). Greater sowing density increased specific root length partly through greater production of fine roots in the topsoil. Rooting depth (D50) of the major root axes (root diameter class 0.4-1.0 mm) was not affected. Root mass fraction decreased, while stem mass fraction increased with sowing density and over time. Leaf mass fraction was constant over sowing density but greater leaf area was realized through increased specific leaf area. Considering fertilization, we assume that light competition caused plants to grow more shoot mass at the cost of investment into roots, which is partly compensated by increased specific root length and shallow rooting. Increased biomass per area with greater densities suggest that density increases the efficiency of the cropping system, however, declines in harvest index at densities over 230 plants m(-2) suggest that this efficiency did not translate into greater yield. We conclude that plant density is a

  12. Distributed Generators Allocation in Radial Distribution Systems with Load Growth using Loss Sensitivity Approach

    NASA Astrophysics Data System (ADS)

    Kumar, Ashwani; Vijay Babu, P.; Murty, V. V. S. N.

    2016-07-01

    Rapidly increasing electricity demands and capacity shortage of transmission and distribution facilities are the main driving forces for the growth of distributed generation (DG) integration in power grids. One of the reasons for choosing a DG is its ability to support voltage in a distribution system. Selection of effective DG characteristics and DG parameters is a significant concern of distribution system planners to obtain maximum potential benefits from the DG unit. The objective of the paper is to reduce the power losses and improve the voltage profile of the radial distribution system with optimal allocation of the multiple DG in the system. The main contribution in this paper is (i) combined power loss sensitivity (CPLS) based method for multiple DG locations, (ii) determination of optimal sizes for multiple DG units at unity and lagging power factor, (iii) impact of DG installed at optimal, that is, combined load power factor on the system performance, (iv) impact of load growth on optimal DG planning, (v) Impact of DG integration in distribution systems on voltage stability index, (vi) Economic and technical Impact of DG integration in the distribution systems. The load growth factor has been considered in the study which is essential for planning and expansion of the existing systems. The technical and economic aspects are investigated in terms of improvement in voltage profile, reduction in total power losses, cost of energy loss, cost of power obtained from DG, cost of power intake from the substation, and savings in cost of energy loss. The results are obtained on IEEE 69-bus radial distribution systems and also compared with other existing methods.

  13. Clonal Patch Size and Ramet Position of Leymus chinensis Affected Reproductive Allocation

    PubMed Central

    Zhang, Zhuo; Yang, Yunfei

    2015-01-01

    Reproductive allocation is critically important for population maintenance and usually varies with not only environmental factors but also biotic ones. As a typical rhizome clonal plant in China's northern grasslands, Leymus chinensis usually dominates the steppe communities and grows in clonal patches. In order to clarify the sexual reproductive allocation of L. chinensis in the process of the growth and expansion, we selected L. chinensis clonal patches of a range of sizes to examine the reproductive allocation and allometric growth of the plants. Moreover, the effects of position of L. chinensis ramets within the patch on their reproductive allocation were also examined. Clonal patch size and position both significantly affected spike biomass, reproductive tiller biomass and SPIKE/TILLER biomass ratio. From the central to the marginal zone, both the spike biomass and reproductive tiller biomass displayed an increasing trend in all the five patch size categories except for reproductive tiller biomass in 15–40m2 category. L. chinensis had significantly larger SPIKE/TILLER biomass ratio in marginal zone than in central zone of clonal patches that are larger than 15 m2 in area. Regression analysis showed that the spike biomass and SPIKE/TILLER biomass ratio were negatively correlated with clonal patch size while patch size showed significantly positive effect on SEED/SPIKE biomass ratio, but the reproductive tiller biomass and SEED/TILLER biomass ratio were not dependent on clonal patch size. The relationships between biomass of spike and reproductive tiller, between mature seed biomass and spike biomass and between mature seed biomass and reproductive tiller biomass were significant allometric for all or some of patch size categories, respectively. The slopes of all these allometric relationships were significantly different from 1. The allometric growth of L. chinensis is patch size-dependent. This finding will be helpful for developing appropriate practices for

  14. Biomass, growth, and development of populations of herbivorous zooplankton in the southeastern Bering Sea during spring

    SciTech Connect

    Vidal, J.; Smith, S.L.

    1985-09-01

    Two distinct communities of herbivorous zooplankton, separated by an oceanographic front, inhabit the continental shelf and slope of the southeastern Bering Sea during spring. The community over the outer shelf and slope is dominated by populations of large-sized oceanic copepods (mainly Neocalanus ssp.) that develop early in spring and attain maximum biomass and growth rates by mid- to late spring. Total biomass and growth rates of herbivores follow the spring outburst of phytoplankton; during April and May biomass increases from less than or equal to1 to approx.14 g C m/sup -2/ on the slope and to approx.10 g C m/sup -2/ on the outer shelf, and maximum growth rates >500 and approx.300 mg C m/sup -2/ day/sup -1/ occure on the slope and outer shelf, respectively in May. The dominant species, N. plumchrus, grows from copepodid I and V between late March and early May, and after attaining maximum body weight in late May and early June it begins its downward migration. The inshore community on the middle shelf is dominated by the euphausiid Thysanoessa raschi in April and May and by the copepod Calanus marshallae in late May and early June. Total biomass (less than or equal to g C m/sup -2/) and growth rates (less than or equal to50 mg C m/sup -2/) of the inshore community are substantially lower than those of the offshore community and show a delayed response to the spring bloom of phytoplankton; both biomass and growth rates increase about one month after the bloom. Small herbivorous copepods contributed little to the total biomass and growth rates of either community and the cumulative community growth rates during April and May decreases from 18.3 g C m/sup -2/ on the slope to 2.5 g C m/sup -2/ on the middle shelf. 79 refs., 15 figs., 7 tabs.

  15. Storage of atmospheric carbon in global litter and soil pools in response to vegetation change and biomass allocation

    SciTech Connect

    Klooster, S.A.; Potter, C.S.

    1995-06-01

    Changes in the distribution of vegetation types under altered climate regimes could have important consequences for the storage of stems. Because there are relatively few definitive field studies of changes in whole ecosystem carbon process-level models driven by gridded global databases may provide reasonable indicators of to changes in vegetation cover. We have used plant litter quality (lignin content) and carbon allocation to woody tissues as surrogates for testing the hypothetical effects of future vegetation change using the CASA (Carnegie-Ames-Stanford Approach) Biosphere model. The model is driven by global gridded (1{degree}) satellite imagery on a monthly time interval to simulate seasonal patterns in net ecosystem carbon balance and steady-state carbon storage in detritus arid soils. Sensitivity tests treated litter quality and allocation effects independently from other direct effects of changes in climate, atmospheric CO{sub 2} levels, and primary production. Results support the hypothesis that soil C storage in today`s temperate and boreal forest life zones are those most sensitive to changes in litter lignin content which may accompany increased climate stress. For these systems, the model predicts that a 50% increase in litter lignin concentration would result in a long-term net gain of about 10% C from the atmosphere into surface litter and soil organic matter pools. A 50% decrease in C allocation to woody tissues would invoke a net loss of 10% C from litter and soil organic matter pools.

  16. Simulation of tree-ring widths with a model for primary production, carbon allocation, and growth

    NASA Astrophysics Data System (ADS)

    Li, G.; Harrison, S. P.; Prentice, I. C.; Falster, D.

    2014-12-01

    We present a simple, generic model of annual tree growth, called "T". This model accepts input from a first-principles light-use efficiency model (the "P" model). The P model provides values for gross primary production (GPP) per unit of absorbed photosynthetically active radiation (PAR). Absorbed PAR is estimated from the current leaf area. GPP is allocated to foliage, transport tissue, and fine-root production and respiration in such a way as to satisfy well-understood dimensional and functional relationships. Our approach thereby integrates two modelling approaches separately developed in the global carbon-cycle and forest-science literature. The T model can represent both ontogenetic effects (the impact of ageing) and the effects of environmental variations and trends (climate and CO2) on growth. Driven by local climate records, the model was applied to simulate ring widths during the period 1958-2006 for multiple trees of Pinus koraiensis from the Changbai Mountains in northeastern China. Each tree was initialised at its actual diameter at the time when local climate records started. The model produces realistic simulations of the interannual variability in ring width for different age cohorts (young, mature, and old). Both the simulations and observations show a significant positive response of tree-ring width to growing-season total photosynthetically active radiation (PAR0) and the ratio of actual to potential evapotranspiration (α), and a significant negative response to mean annual temperature (MAT). The slopes of the simulated and observed relationships with PAR0 and α are similar; the negative response to MAT is underestimated by the model. Comparison of simulations with fixed and changing atmospheric CO2 concentration shows that CO2 fertilisation over the past 50 years is too small to be distinguished in the ring-width data, given ontogenetic trends and interannual variability in climate.

  17. Explaining biomass growth of tropical canopy trees: the importance of sapwood.

    PubMed

    van der Sande, Masha T; Zuidema, Pieter A; Sterck, Frank

    2015-04-01

    Tropical forests are important in worldwide carbon (C) storage and sequestration. C sequestration of these forests may especially be determined by the growth of canopy trees. However, the factors driving variation in growth among such large individuals remain largely unclear. We evaluate how crown traits [total leaf area, specific leaf area and leaf nitrogen (N) concentration] and stem traits [sapwood area (SA) and sapwood N concentration] measured for individual trees affect absolute biomass growth for 43 tropical canopy trees belonging to four species, in a moist forest in Bolivia. Biomass growth varied strongly among trees, between 17.3 and 367.3 kg year(-1), with an average of 105.4 kg year(-1). We found that variation in biomass growth was chiefly explained by a positive effect of SA, and not by tree size or other traits examined. SA itself was positively associated with sapwood growth, sapwood lifespan and basal area. We speculate that SA positively affects the growth of individual trees mainly by increasing water storage, thus securing water supply to the crown. These positive roles of sapwood on growth apparently offset the increased respiration costs incurred by more sapwood. This is one of the first individual-based studies to show that variation in sapwood traits-and not crown traits-explains variation in growth among tropical canopy trees. Accurate predictions of C dynamics in tropical forests require similar studies on biomass growth of individual trees as well as studies evaluating the dual effect of sapwood (water provision vs. respiratory costs) on tropical tree growth.

  18. The relative contributions of forest growth and areal expansion to forest biomass carbon

    NASA Astrophysics Data System (ADS)

    Li, P.; Zhu, J.; Hu, H.; Guo, Z.; Pan, Y.; Birdsey, R.; Fang, J.

    2016-01-01

    Forests play a leading role in regional and global terrestrial carbon (C) cycles. Changes in C sequestration within forests can be attributed to areal expansion (increase in forest area) and forest growth (increase in biomass density). Detailed assessment of the relative contributions of areal expansion and forest growth to C sinks is crucial to reveal the mechanisms that control forest C sinks and it is helpful for developing sustainable forest management policies in the face of climate change. Using the Forest Identity concept and forest inventory data, this study quantified the spatial and temporal changes in the relative contributions of forest areal expansion and increased biomass growth to China's forest biomass C sinks from 1977 to 2008. Over the last 30 years, the areal expansion of forests has been a larger contributor to C sinks than forest growth for planted forests in China (62.2 % vs. 37.8 %). However, for natural forests, forest growth has made a larger contribution than areal expansion (60.4 % vs. 39.6 %). For all forests (planted and natural forests), growth in area and density has contributed equally to the total C sinks of forest biomass in China (50.4 % vs. 49.6 %).The relative contribution of forest growth of planted forests showed an increasing trend from an initial 25.3 % to 61.0 % in the later period of 1998 to 2003, but for natural forests, the relative contributions were variable without clear trends, owing to the drastic changes in forest area and biomass density over the last 30 years. Our findings suggest that afforestation will continue to increase the C sink of China's forests in the future, subject to sustainable forest growth after the establishment of plantations.

  19. Storage of atmospheric carbon in global litter and soil pools in response to vegetation change and biomass allocation

    SciTech Connect

    Klooster, S.A.; Potter, C.S.

    1995-09-01

    Changes in the distribution of vegetation types under altered climate regimes could have important consequences for the storage of atmospheric carbon in terrestrial ecosystems. Because there are relatively few definitive field studies of changes in whole ecosystem carbon balance under modified climate stress, process-level models driven by gridded global databases may provide reasonable indicators of biome-specific sensitivity of C storage to changes in vegetation cover. We have used plant litter quality (lignin content) and carbon allocation to woody tissues as surrogates for testing the hypothetical effects of future vegetation change using the CASA (Carnegie-Ames-Stanford Approach) Biosphere model. The model is driven by global gridded (1{degrees}) satellite imagery on a monthly time interval to simulate seasonal patterns in net ecosystem carbon balance and steady-state carbon storage in detritus and soils. Sensitivity tests treated litter quality and allocation effects independently from other direct effects of changes in climate, atmospheric CO{sub 2} levels, and primary production. Results support the hypothesis that soil C storage in today`s temperate and boreal forest life zones are those most sensitive to changes in litter lignin content which may accompany increased climate stress. For these systems, the model predicts that a 50% increase in litter lignin concentrations would result in a long-term net gain of about 10% C from the atmosphere into surface litter and soil organic matter pools. A 50% decrease in C allocation to woody tissues would invoke a net loss of 10% C from litter and soil organic matter pools.

  20. Fungal growth and biomass development is boosted by plants in snow-covered soil.

    PubMed

    Kuhnert, Regina; Oberkofler, Irmgard; Peintner, Ursula

    2012-07-01

    Soil microbial communities follow distinct seasonal cycles which result in drastic changes in processes involving soil nutrient availability. The biomass of fungi has been reported to be highest during winter, but is fungal growth really occurring in frozen soil? And what is the effect of plant cover on biomass formation and on the composition of fungal communities? To answer these questions, we monitored microbial biomass N, ergosterol, and the amount of fungal hyphae during summer and winter in vegetated and unvegetated soils of an alpine primary successional habitat. The winter fungal communities were identified by rDNA ITS clone libraries. Winter soil temperatures ranged between -0.6°C and -0.1°C in snow-covered soil. We found distinct seasonal patterns for all biomass parameters, with highest biomass concentrations during winter in snow-covered soil. The presence of plant cover had a significant positive effect on the amount of biomass in the soil, but the type of plant cover (plant species) was not a significant factor. A mean hyphal ingrowth of 5.6 m g(-1) soil was detected in snow-covered soil during winter, thus clearly proving fungal growth during winter in snow-covered soil. Winter fungal communities had a typical species composition: saprobial fungi were dominating, among them many basidiomycete yeasts. Plant cover had no influence on the composition of winter fungal communities.

  1. The hemicellulolytic enzyme arsenal of Thermobacillus xylanilyticus depends on the composition of biomass used for growth

    PubMed Central

    2012-01-01

    Background Thermobacillus xylanilyticus is a thermophilic and highly xylanolytic bacterium. It produces robust and stable enzymes, including glycoside hydrolases and esterases, which are of special interest for the development of integrated biorefineries. To investigate the strategies used by T. xylanilyticus to fractionate plant cell walls, two agricultural by-products, wheat bran and straw (which differ in their chemical composition and tissue organization), were used in this study and compared with glucose and xylans. The ability of T. xylanilyticus to grow on these substrates was studied. When the bacteria used lignocellulosic biomass, the production of enzymes was evaluated and correlated with the initial composition of the biomass, as well as with the evolution of any residues during growth. Results Our results showed that T. xylanilyticus is not only able to use glucose and xylans as primary carbon sources but can also use wheat bran and straw. The chemical compositions of both lignocellulosic substrates were modified by T. xylanilyticus after growth. The bacteria were able to consume 49% and 20% of the total carbohydrates in bran and straw, respectively, after 24 h of growth. The phenolic and acetyl ester contents of these substrates were also altered. Bacterial growth on both lignocellulosic biomasses induced hemicellulolytic enzyme production, and xylanase was the primary enzyme secreted. Debranching activities were differentially produced, as esterase activities were more important to bacterial cultures grown on wheat straw; arabinofuranosidase production was significantly higher in bacterial cultures grown on wheat bran. Conclusion This study provides insight into the ability of T. xylanilyticus to grow on abundant agricultural by-products, which are inexpensive carbon sources for enzyme production. The composition of the biomass upon which the bacteria grew influenced their growth, and differences in the biomass provided resulted in dissimilar enzyme

  2. Biomass growth restriction in a packed bed reactor

    DOEpatents

    Griffith, William L.; Compere, Alicia L.

    1978-01-01

    When carrying out continuous biologically catalyzed reactions with anaerobic microorganisms attached to a support in an upflow packed bed column, growth of the microorganisms is restricted to prevent the microorganisms from plugging the column by limiting the availability of an essential nutrient and/or by the presence of predatory protozoa which consume the anaerobic microorganisms. A membrane disruptive detergent may be provided in the column to lyse dead microorganisms to make them available as nutrients for live microorganisms.

  3. Larval growth rate and sex determine resource allocation and stress responsiveness across life stages in juvenile frogs.

    PubMed

    Warne, Robin W; Crespi, Erica J

    2015-03-01

    The extent to which interactions between environmental stressors and phenotypic variation during larval life stages impose carry-over effects on adult phenotypes in wildlife are not clear. Using semi-natural mesocosms, we examined how chronically low food availability and size-specific phenotypes in larval amphibians interact and carry over to influence frog growth, resource allocation, endocrine activity and survival. We tagged three cohorts of larvae that differed in body size and developmental stage at 3 weeks after hatching, and tracked them through 10 weeks after metamorphosis in high and low food conditions. We found that growth and development rates during the early tadpole stage not only affected metamorphic rates, but also shaped resource allocation and stress responsiveness in frogs: the slowest growing larvae from low-food mesocosms exhibited a suppressed glucocorticoid response to a handling stressor; reduced growth rate and fat storage as frogs. We also show for the first time that larval developmental trajectories varied with sex, where females developed faster than males especially in food-restricted conditions. Last, while larval food restriction profoundly affected body size in larvae and frogs, time to metamorphosis was highly constrained, which suggests that the physiology and development of this ephemeral pond-breeding amphibian is adapted for rapid metamorphosis despite large potential variation in nutrient availability. Taken together, these results suggest that larval phenotypic variation significantly influences multiple dimensions of post-metamorphic physiology and resource allocation, which likely affect overall performance.

  4. Growth and allocation of Douglas-fir seedlings in response to CO[sub 2], temperature, and nitrogen

    SciTech Connect

    Gillham, M.L.; Perry, D.A.; Grulke, N.E.; Winner, W.E. )

    1994-06-01

    Douglas-fir seedlings were grown, from cold-stratified seed, for 32 weeks in controlled-environment chambers. This factorial experiment had two levels each of atmospheric CO[sub 2] (350 an 700 ppm), soil temperature (13 and 17[degrees]C), and soil nitrogen (soils from 1200-m-elevation in the western Cascade Mountains of Oregon contained roughly two times as much carbon and nitrogen than soils from 900-m-elevation). Each whole plot (chamber) treatment (CO[sub 2] [times] temperature) was replicated three times. Photosynthetic photon flux density and soil temperature (at 15-cm-depth) were determined for each seedling/pot, and were analyzed as covariates. Doubled atmospheric CO[sub 2] resulted in greater biomass of seedlings grown in higher N-content soils, and +4[degrees]C soil temperature increased biomass of seedlings grown in both soils, at both levels of CO[sub 2]. Root-to-shoot ratios were greatest for seedlings grown in lower N-content soils for all treatments except +CO[sub 2] [times] +T, where they were equal. Doubled CO[sub 2] increased c-allocation belowground for trees grown in both soil types and at both temperatures. Corresponding data include seedling height and basal caliper, mass of structural compartments, and C, N, and total nonstructural carbohydrate contents of biomass compartments.

  5. Sudden cold temperature delays plant carbon transport and shifts allocation from growth to respiratory demand

    NASA Astrophysics Data System (ADS)

    Barthel, M.; Cieraad, E.; Zakharova, A.; Hunt, J. E.

    2014-03-01

    Since substrates for respiration are supplied mainly by recent photo-assimilates, there is a strong but time-lagged link between short-term above- and belowground carbon (C) cycling. However, regulation of this coupling by environmental variables is poorly understood. Whereas recent studies focussed on the effect of drought and shading on the link between above- and belowground short-term C cycling, the effect of temperature remains unclear. We used a 13CO2 pulse-chase labelling experiment to investigate the effect of a sudden temperature change from 25 to 10 °C on the short-term coupling between assimilatory C uptake and respiratory loss. The study was done in the laboratory using two-month-old perennial rye-grass plants (Lolium perenne L.). After label application, the δ13C signal of respired shoot and root samples was analysed at regular time intervals using laser spectroscopy. In addition, δ13C was analysed in bulk root and shoot samples. Cold temperature (10 °C) reduced the short-term coupling between shoot and roots by delaying belowground transfer of recent assimilates and its subsequent respiratory use, as indicated by the δ13C signal of root respiration (δ13CRR). That is, the time lag from the actual shoot labelling to the first appearance of the label in 13CRR was about 1.5 times longer under cold temperature. Moreover, analysis of bulk shoot and root material revealed that plants at cold temperature invest relatively more carbon into respiration compared to growth or storage. While the whole plant C turnover increased under cold temperature, the turnover time of the labile C pool decreased, probably because less 13C is used for growth and/or storage. That is, (almost) all recent C remained in the labile pool serving respiration under these conditions. Overall, our results highlight the importance of temperature as a driver of C transport and relative C allocation within the plant-soil system.

  6. Interactive effects of soil temperature, atmospheric carbon dioxide and soil N on root development, biomass and nutrient uptake of winter wheat during vegetative growth.

    PubMed

    Gavito, M E; Curtis, P S; Mikkelsen, T N; Jakobsen, I

    2001-09-01

    Nutrient requirements for plant growth are expected to rise in response to the predicted changes in CO(2) and temperature. In this context, little attention has been paid to the effects of soil temperature, which limits plant growth at early stages in temperate regions. A factorial growth-room experiment was conducted with winter wheat, varying soil temperature (10 degrees C and 15 degrees C), atmospheric CO(2) concentration (360 and 700 ppm), and N supply (low and high). The hypothesis was that soil temperature would modify root development, biomass allocation and nutrient uptake during vegetative growth and that its effects would interact with atmospheric CO(2) and N availability. Soil temperature effects were confirmed for most of the variables measured and 3-factor interactions were observed for root development, plant biomass components, N-use efficiency, and shoot P content. Importantly, the soil temperature effects were manifest in the absence of any change in air temperature. Changes in root development, nutrient uptake and nutrient-use efficiencies were interpreted as counterbalancing mechanisms for meeting nutrient requirements for plant growth in each situation. Most variables responded to an increase in resource availability in the order: N supply >soil temperature >CO(2).

  7. Growth kinetics of Chlorococcum humicola - A potential feedstock for biomass with biofuel properties.

    PubMed

    Thomas, Jibu; Jayachithra, E V

    2015-11-01

    Economically viable production facilities for microalgae depend on the optimization of growth parameters with regard to nutrient requirements. Using microalgae to treat industrial effluents containing heavy metals presents an alternative to the current practice of using physical and chemical methods. Present work focuses on the statistical optimization of growth of Chlorococcum humicola to ascertain the maximum production of biomass. Plackett Burman design was carried out to screen the significant variables influencing biomass production. Further, Response Surface Methodology was employed to optimize the effect of inoculum, light intensity and pH on net biomass yield. Optimum conditions for maximum biomass yield were identified to be inoculum at 15%, light intensity to be 1500lx and pH 8.5. Theoretical and predicted values were in agreement and thus the model was found to be significant. Gas chromatography analyses of the FAME derivatives showed a high percentage of saturated fatty acids thereby confirming the biofuel properties of the oil derived from algal biomass.

  8. Comparison of growth, biomass and nutrient distribution in five promising clones of Populus deltoides under an agrisilviculture system.

    PubMed

    Swamy, S L; Mishra, Alka; Puri, S

    2006-01-01

    Variations in growth, above- and below-ground biomass and nutrient distribution were examined in five clones (G3, G48, 65/27, D121 and S7C1) of Populus deltoides grown under agrisilviculture system in sub-humid tropics of Central India. The monoclonal blocks were planted at 4x5 m in a randomized block design with three replications. Diameter at breast height (dbh) and tree height were consistently higher in clone 65/27 and lowest in clone S7C1. Mean annual increments (MAI) in dbh and height were 1.6 and 1.3 times higher in clone 65/27 compared to clone S7C1. Total biomass varied from 48.5 to 62.2 Mg ha(-1) in six-year-old clones. In rank order, the total biomass of clones was: 65/27>D121>G48>G3>S7C1. Stem wood accounted 60.4-68.9% to total biomass followed by coarse roots (12.2-18.9%), branches (12.3-15%), leaves (3.02-6.9%) and fine roots (1.5-2.7%). Root-shoot ratio ranged from 0.2 to 0.35. It was highest in clone G48 and lowest in clone S7C1. In six-year-old clones, total N ranged from 184.3 to 266.3 kg ha(-1), P from 16.8 to 31.1 kg ha(-1) and K from 81.9 to 128.7 kg ha(-1). Total N and P were highest in clone 65/27, while K in clone G48. Nutrients were lowest in clone S7C1. In general, maximum nutrients (N, P and K) were allocated to above-ground components (leaves>stem>branches) than below-ground components. Available N, P and K in the soil improved significantly after six years of planting. It was higher in 0-20 cm and decreased with soil depth. At 0-20 cm soil depth, N increased from 14.9% to 24.1%, P from 17.2% to 23.3% and K from 3.1% to 5.1% under different clones. The yield of both soybean and wheat reduced under poplar clones. Yield losses in soybean ranged from 10.1% to 33% and wheat from 15% to 30.3% under different clones. The management strategies for reducing tree-crop competition and nutrient export from the site under P. deltoides based agrisilviculture system for achieving sustainable production are discussed.

  9. Microalgae cultivation using an aquaculture wastewater as growth medium for biomass and biofuel production.

    PubMed

    Guo, Zhen; Liu, Yuan; Guo, Haiyan; Yan, Song; Mu, Jun

    2013-12-01

    Microalgae as a main feedstock has attracted much attention in recent years but is still not economically feasible due to high algal culture cost. The objective of this study was to develop a comprehensive eco-friendly technology for cultivating microalgae Platymonas subcordiformis using aquaculture wastewater as growth medium for biomass and biofuel production. Platymonas subcordiformis was grown in pretreated flounder aquaculture wastewaters taken from different stages. Each of wastewater contained different levels of nutrients. The biomass yield of microalgae and associated nitrogen and phosphorous removal were investigated. The results showed that algal cell density increased 8.9 times than the initial level. Platymonas subcordiformis removed nitrogen and phosphorus from wastewater with an average removal efficiency of 87%-95% for nitrogen and 98%-99% for phosphorus. It was feasible to couple the removal of nitrogen and phosphorus from wastewater to algal biomass and biofuel production. However, further studies are required to make this technologies economically viable for algae biofuel production.

  10. Cell growth kinetics of Chlorella sorokiniana and nutritional values of its biomass.

    PubMed

    Kumar, Kanhaiya; Dasgupta, Chitralekha Nag; Das, Debabrata

    2014-09-01

    The present study investigates the effects of different physico-chemical parameters for the growth of Chlorella sorokiniana and subsequently determination of nutritional values of its biomass. Most suitable temperature, light intensity, pH, and acetic acid concentration were 30°C, 100 μmol m(-2)s(-1), pH 7.5, and 34.8mM, respectively for the growth of this microorganism. Arrhenius growth activation energy, Ea was calculated as 7.08 kJ mol(-1). Monod kinetics constants: maximum specific growth rate (μ max) and substrate (acetic acid) affinity coefficient (Ks) were determined as 0.1 ± 0.01 h(-1) and 76 ± 8 mg L(-1), respectively. Stoichiometric analysis revealed the capture of 1.83 g CO2 and release of 1.9 g O2 for 1g algal biomass synthesis. Algal biomass of C. sorokiniana was found rich in protein and several important minerals such as Mg, Ca, and Fe. Astaxanthin and β-carotene were extracted and quantified using high performance liquid chromatography.

  11. Accumulation of biomass and mineral elements with calendar time by cotton: application of the expanded growth model.

    PubMed

    Overman, Allen R; Scholtz, Richard V

    2013-01-01

    Accumulation of plant biomass (Mg ha(-1)) with calendar time (wk) occurs as a result of photosynthesis for green land-based plants. A corresponding accumulation of mineral elements (kg ha(-1)) such as nitrogen, phosphorus, and potassium occurs from the soil through plant roots. Field data from literature for the warm-season annual cotton (Gossypium hirsutum L.) are used in this analysis. The expanded growth model is used to describe accumulation of biomass and mineral elements with calendar time. The growth model predicts a simple linear relationship between biomass yield and the growth quantifier, which is confirmed with the data. The growth quantifier incorporates the unit processes of distribution of solar energy which drives biomass accumulation by photosynthesis, partitioning of biomass between light-gathering and structural components of the plants, and an aging function. A hyperbolic relationship between plant nutrient uptake and biomass yield is assumed, and is confirmed for the mineral elements nitrogen, phosphorus, and potassium. It is concluded that the rate limiting process in the system is biomass accumulation by photosynthesis and that nutrient accumulation occurs in virtual equilibrium with biomass accumulation. The expanded growth model describes field data from California and Alabama rather well. Furthermore, all model parameters were common for the two sites with the exception of the yield factor A which accounts for differences in soil types, environmental conditions, fertilizer levels, and plant population.

  12. Effect of population density on growth, biomass and nickel accumulation capacity of Lemna gibba (Lemnaceae).

    PubMed

    Demirezen, Dilek; Aksoy, Ahmet; Uruç, Kadiriye

    2007-01-01

    The effect of population densities on the growth rate and metal (nickel) accumulation capacity of Lemna gibba (Lemnaceae) was studied under laboratory conditions. At high population densities (800 or 1600 seedling per pot), we observed decreasing growth rate with increasing L. gibba density. Especially, at a density of 1600 seedling a pot the net growth rate became negative. This lower growth rate may relate to lower local temperatures and nutrients within L. gibba mats. Biomass production was inhibited by an increase in plant density. Additionally, high population densities caused decreasing nickel accumulation by L. gibba. In this study, a simple model was created according to data obtained from this study. The model has suggested that crowding is an important factor in limitation of growth of L. gibba. PMID:16828144

  13. Growth, biomass, and fecundity of Bothriocephalus acheilognathi in a North Carolina cooling reservoir

    SciTech Connect

    Riggs, M.R.; Lemly, A.D.; Esch, G.W.

    1987-10-01

    An investigation of differences in growth, maturation, biomass, and fecundity of Bothriocephalus acheilognathi in 3 host species was conducted on metapopulations from 3 distinct communities in Belews Lake, North Carolina. The results indicated that host-specific differences in growth and biomass were additive among metapopulations from different localities. However, species-specific differences in maturation and fecundity exhibited differential variation between the sites. These site X host interactions were related to host-specific differences in bioaccumulation of selenium at sites that were exposed to effluent from a coal-fired power plant. Significant (alpha = 0.001) statistical associations were observed between selenium concentration in tapeworm tissue and fecundity measures. The results of this study demonstrate that host suitability is determined by morphological, physiological, and behavioral differences in the host species which affect transmission dynamics and the quality and stability of the enteric environment.

  14. Allocation of new growth between shoot, root and mycorrhiza in relation to carbon, nitrogen and phosphate supply: teleonomy with maximum growth rate.

    PubMed

    Thornley, John H M; Parsons, Anthony J

    2014-02-01

    Treating resource allocation within plants, and between plants and associated organisms, is essential for plant, crop and ecosystem modelling. However, it is still an unresolved issue. It is also important to consider quantitatively when it is efficient and to what extent a plant can invest profitably in a mycorrhizal association. A teleonomic model is used to address these issues. A six state-variable model giving exponential growth is constructed. This represents carbon (C), nitrogen (N) and phosphorus (P) substrates with structure in shoot, root and mycorrhiza. The shoot is responsible for uptake of substrate C, the root for substrates N and P, and the mycorrhiza also for substrates N and P. A teleonomic goal, maximizing proportional growth rate, is solved analytically for the allocation fractions. Expressions allocating new dry matter to shoot, root and mycorrhiza are derived which maximize growth rate. These demonstrate several key intuitive phenomena concerning resource sharing between plant components and associated mycorrhizae. For instance, if root uptake rate for phosphorus is equal to that achievable by mycorrhiza and without detriment to root uptake rate for nitrogen, then this gives a faster growing mycorrhizal-free plant. However, if root phosphorus uptake is below that achievable by mycorrhiza, then a mycorrhizal association may be a preferred strategy. The approach offers a methodology for introducing resource sharing between species into ecosystem models. Applying teleonomy may provide a valuable short-term means of modelling allocation, avoiding the circularity of empirical models, and circumventing the complexities and uncertainties inherent in mechanistic approaches. However it is subjective and brings certain irreducible difficulties with it.

  15. Looking for age-related growth decline in natural forests: unexpected biomass patterns from tree rings and simulated mortality

    USGS Publications Warehouse

    Foster, Jane R.; D'Amato, Anthony W.; Bradford, John B.

    2014-01-01

    Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with a census tree-ring data set from eight temperate forest types to reconstruct stand-level biomass increments (in Minnesota, USA). We compared growth patterns among mortality models, forest types and stands. Timing of peak biomass growth varied significantly among mortality models, peaking 20–30 years earlier when mortality was random with respect to tree growth and size, than when mortality favored slow-growing individuals. Random or u-shaped mortality (highest in small or large trees) produced peak growth 25–30 % higher than the surviving tree sample alone. Growth trends for even-aged, monospecific Pinus banksiana or Acer saccharum forests were similar to the early peak and decline expectation. However, we observed continually increasing biomass growth in older, low-productivity forests of Quercus rubra, Fraxinus nigra, and Thuja occidentalis. Tree-ring reconstructions estimated annual changes in live biomass growth and identified more diverse development patterns than previous methods. These detailed, long-term patterns of biomass development are crucial for detecting recent growth responses to global change and modeling future forest dynamics.

  16. Looking for age-related growth decline in natural forests: unexpected biomass patterns from tree rings and simulated mortality.

    PubMed

    Foster, Jane R; D'Amato, Anthony W; Bradford, John B

    2014-05-01

    Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with a census tree-ring data set from eight temperate forest types to reconstruct stand-level biomass increments (in Minnesota, USA). We compared growth patterns among mortality models, forest types and stands. Timing of peak biomass growth varied significantly among mortality models, peaking 20-30 years earlier when mortality was random with respect to tree growth and size, than when mortality favored slow-growing individuals. Random or u-shaped mortality (highest in small or large trees) produced peak growth 25-30% higher than the surviving tree sample alone. Growth trends for even-aged, monospecific Pinus banksiana or Acer saccharum forests were similar to the early peak and decline expectation. However, we observed continually increasing biomass growth in older, low-productivity forests of Quercus rubra, Fraxinus nigra, and Thuja occidentalis. Tree-ring reconstructions estimated annual changes in live biomass growth and identified more diverse development patterns than previous methods. These detailed, long-term patterns of biomass development are crucial for detecting recent growth responses to global change and modeling future forest dynamics. PMID:24442595

  17. Willow growth in response to nutrients and moisture on a clay landfill cap soil. I. Growth and biomass production.

    PubMed

    Martin, Peter J; Stephens, William

    2006-02-01

    The growth and biomass production by willow (Salix viminalis L.) was studied in lysimeters containing Oxford clay landfill cap soil with different amendments, bulk densities and watering regimes. Three years from planting, stem biomass in well-watered plants was least (0.28 kg plant(-1)) with high bulk density soil (1480 kg m(-3)) and no nutritional amendment but was increased 10-fold (2.53 kg plant(-1)) by reducing soil bulk density (1200 kg m3) and adding amendments. In comparison, on a sandy loam soil it was 6.23 kg plant(-1). There were similar differences in number of stems plant(-1), stem basal area plant(-1) and plant leaf area which can be attributed to low nitrogen and phosphorus levels in Oxford clay. Water stress reduced stem biomass production by 26-37% and caused higher root:stem ratios. These were also higher on Oxford clay than on the sandy loam. Successful biomass production from willow on Oxford clay landfill caps will therefore require nutritional amendment.

  18. Growth, yield and compositional characteristics of Jerusalem artichoke as it relates to biomass production

    SciTech Connect

    Stauffer, M.D.; Chubey, B.B.; Dorrell, D.G.

    1980-01-01

    Jerusalem artichoke (Helianthus tuberosus L.) has shown excellent potential as a carbohydrate-rich crop. Initial investigations determined inulin and tuber yields; however, when additional studies showed that good quality pulp remained after inulin extraction and high forage yields per hectare were obtainable, the scope of investigation was broadened to assess utilization of the total plant. Plant growth, yield and compositional characteristics of Jerusalem artichoke as they relate to biomass production will be reported.

  19. Effects of propagation phenomena and frequency allocation on the growth of satellite communications

    NASA Technical Reports Server (NTRS)

    Freibaum, J.

    1976-01-01

    The development of new allocations and new frequency and orbit sharing criteria for satellite communications below 10 GHz is discussed. These criteria are dependent on the outcome of current spectrum and orbit utilization and propagation studies addressing such problems as intersystem interference, satellite spacing, positioning, and repositioning, spillover of radio signals across geographic boundaries, and the adverse effects of propagation phenomena. These problems are discussed in relation to preparations for the 1979 General World Administrative Radio Conference.

  20. Energy allocation strategy modifies growth-survival trade-offs in juvenile fish across ecological and environmental gradients.

    PubMed

    Mogensen, Stephanie; Post, John R

    2012-04-01

    In young temperate zone fishes, conflicting energy demands lead to variability in growing season and winter survival. Growing season survival is driven by size-dependent predation risk whereas winter survival is constrained by autumn body size, energy storage and winter duration. We developed a model of the seasonality of energetics coupled to empirical measures of resource availability, size-dependent predation and temperature seasonality for rainbow trout (Oncorhynchus mykiss) in two sets of lakes in British Columbia, Canada, representing endpoints of a gradient of temperature, growing season duration and winter duration. This model was used to determine the energy allocation strategy which maximized first-year survival across these gradients. Survival was sensitive to the timing of the switch from somatic to storage strategies in cold, short growing season, low resource environments. A broader range of energy allocation strategies were viable in warmer, longer growing season and higher resource lakes. We used empirical observations of autumn energy storage and our modeled values for size-dependent minimal lipid levels needed to survive winter in each system to estimate winter survival for juvenile rainbow trout. Winter survival estimates were 6% in cold lakes with low resources, 82% in warm, lakes with low resources and 100% in warm lakes with high resources. Fish in warm lakes with ample resources allocated substantially more to storage than the minimum required to survive winter generated from our model, suggesting additional selection pressures for increased storage when there was ample surplus energy. We concluded that growth-survival trade-offs, modified by seasonality of the environment, influenced the growing season energy allocation strategies for young-of-the-year fish, and suggested this may be important for understanding population viability across environmental gradients.

  1. Selecting and optimizing eco-physiological parameters of Biome-BGC to reproduce observed woody and leaf biomass growth of Eucommia ulmoides plantation in China using Dakota optimizer

    NASA Astrophysics Data System (ADS)

    Miyauchi, T.; Machimura, T.

    2013-12-01

    In the simulation using an ecosystem process model, the adjustment of parameters is indispensable for improving the accuracy of prediction. This procedure, however, requires much time and effort for approaching the simulation results to the measurements on models consisting of various ecosystem processes. In this study, we tried to apply a general purpose optimization tool in the parameter optimization of an ecosystem model, and examined its validity by comparing the simulated and measured biomass growth of a woody plantation. A biometric survey of tree biomass growth was performed in 2009 in an 11-year old Eucommia ulmoides plantation in Henan Province, China. Climate of the site was dry temperate. Leaf, above- and below-ground woody biomass were measured from three cut trees and converted into carbon mass per area by measured carbon contents and stem density. Yearly woody biomass growth of the plantation was calculated according to allometric relationships determined by tree ring analysis of seven cut trees. We used Biome-BGC (Thornton, 2002) to reproduce biomass growth of the plantation. Air temperature and humidity from 1981 to 2010 was used as input climate condition. The plant functional type was deciduous broadleaf, and non-optimizing parameters were left default. 11-year long normal simulations were performed following a spin-up run. In order to select optimizing parameters, we analyzed the sensitivity of leaf, above- and below-ground woody biomass to eco-physiological parameters. Following the selection, optimization of parameters was performed by using the Dakota optimizer. Dakota is an optimizer developed by Sandia National Laboratories for providing a systematic and rapid means to obtain optimal designs using simulation based models. As the object function, we calculated the sum of relative errors between simulated and measured leaf, above- and below-ground woody carbon at each of eleven years. In an alternative run, errors at the last year (at the

  2. Density-dependent reproductive and vegetative allocation in the aquatic plant Pistia stratiotes (Araceae).

    PubMed

    Coelho, Flávia Freitas; Deboni, Liene; Lopes, Frederico Santos

    2005-01-01

    Pistia stratiotes is an aquatic macrophyte that grows in temporary-ponds in the southern Pantanal, Brazil. It reproduces both sexually and asexually and is usually observed forming dense mats on the water surface, a condition favored by the plant's vegetative reproduction coupled with an ability for rapid growth. In this study we examined the effect of densely crowded conditions on the production of reproductive and vegetative structures. In addition, we verified whether there is a trade-off between clonal growth and investment in sexual reproductive structures, and whether there is an allocation pattern with plant size. Individual plant biomass and the number of the rosettes producing sexual reproductive structures and vegetative growth structures both increased with density. Increase in plant size resulted in increased proportional allocation to sexual reproductive structures and vegetative growth structures. Allocation of biomass to reproduction did not occur at the expense of clonal growth. Thus, the density response appears as a increase of rosettes producing sexual reproductive structures and vegetative growth structures. Therefore, long leaves and stolons may be adaptive under densely crowded conditions where competition for light is intense. An important aspect in the study of trade-offs is the size-dependency of the allocation patterns .Usually, larger plants produce more biomass. Therefore, larger plants can allocate more biomass to both vegetative and sexual reproduction than smaller plants and thus show a positive correlation between both traits rather than the expected negative one. PMID:17354448

  3. Effect of Tris-(hydroxymethyl)-amino methane on microalgae biomass growth in a photobioreactor.

    PubMed

    Nguyen, Thanh Tin; Bui, Xuan Thanh; Pham, Minh Duyen; Guo, Wenshan; Ngo, Huu Hao

    2016-05-01

    One of the buffers namely Tris (Tris-(hydroxymethyl)-amino methane) was used to increase the growth of microalgae by stabilizing the pH value in microalgae cultures. The objective of this research is to determine the growth rate and biomass productivity of Chlorella sp. with and without Tris addition. Both conditions function at various N:P ratios cultured in photobioreactors (carbon dioxide of 5%(v/v), light intensity of 3.3 Klux). Daily variations in nutrient removal (nitrogen and phosphorus), cell concentration, DO, temperature and pH were measured for data analysis. The results show that the largest yield of biomass was achieved at the N:P ratio of 15:1 with and without Tris. After cultivation lasting 92 h, the algae concentration at this ratio was 1250 mg L(-1) and 3568 mg L(-1) with and without Tris, respectively. This indicates that adding Tris to the photobioreactor greatly reduces algae biomass due to bacterial competition. PMID:26913641

  4. Winter wheat optimizes allocation in response to carbon limitation

    NASA Astrophysics Data System (ADS)

    Huang, Jianbei; Hammerbacher, Almuth; Trumbore, Susan; Hartmann, Henrik

    2016-04-01

    • Plant photosynthesis is not carbon-saturated at current atmospheric CO2 concentration ([CO2]) thus carbon allocation priority is of critical importance in determining plant response to environmental changes, including increasing [CO2]. • We quantified the percentage of daytime net assimilation (A) allocated to whole-plant nighttime respiration (R) and structural growth (SG), nonstructural carbohydrates (NSC) and secondary metabolites (SMs) during winter wheat (Triticum aestivum) vegetative growth (over 4 weeks) at glacial, ambient, and elevated [CO2] (170, 390 and 680 ppm). • We found that R/A remained relatively constant (11-14%) across [CO2] treatments, whereas plants allocated less C to growth and more C to export at low [CO2] than elevated [CO2]; low [CO2] grown plants tended to invest overall less C into NSC and SMs than to SG due to reduced NSC availability; while leaf SMs/NSC was greater at 170 ppm than at 680 ppm [CO2] this was the opposite for root SMs/NSC; biomass, especially NSC, were preferentially allocated to leaves instead of stems and roots, likely to relieve C limitation induced by low [CO2]. • We conclude that C limitation may force plants to reduce C allocation to long-term survival in order to secure short-term survival. Furthermore, they optimized allocation of the available resource by concentrating biomass and storage to those tissues responsible for assimilation.

  5. A Minimalistic Resource Allocation Model to Explain Ubiquitous Increase in Protein Expression with Growth Rate

    PubMed Central

    Keren, Leeat; Segal, Eran; Milo, Ron

    2016-01-01

    Most proteins show changes in level across growth conditions. Many of these changes seem to be coordinated with the specific growth rate rather than the growth environment or the protein function. Although cellular growth rates, gene expression levels and gene regulation have been at the center of biological research for decades, there are only a few models giving a base line prediction of the dependence of the proteome fraction occupied by a gene with the specific growth rate. We present a simple model that predicts a widely coordinated increase in the fraction of many proteins out of the proteome, proportionally with the growth rate. The model reveals how passive redistribution of resources, due to active regulation of only a few proteins, can have proteome wide effects that are quantitatively predictable. Our model provides a potential explanation for why and how such a coordinated response of a large fraction of the proteome to the specific growth rate arises under different environmental conditions. The simplicity of our model can also be useful by serving as a baseline null hypothesis in the search for active regulation. We exemplify the usage of the model by analyzing the relationship between growth rate and proteome composition for the model microorganism E.coli as reflected in recent proteomics data sets spanning various growth conditions. We find that the fraction out of the proteome of a large number of proteins, and from different cellular processes, increases proportionally with the growth rate. Notably, ribosomal proteins, which have been previously reported to increase in fraction with growth rate, are only a small part of this group of proteins. We suggest that, although the fractions of many proteins change with the growth rate, such changes may be partially driven by a global effect, not necessarily requiring specific cellular control mechanisms. PMID:27073913

  6. Placental phenotype and resource allocation to fetal growth are modified by the timing and degree of hypoxia during mouse pregnancy

    PubMed Central

    Higgins, J. S.; Vaughan, O. R.; Fernandez de Liger, E.; Fowden, A. L.

    2015-01-01

    Key points Hypoxia is a major cause of fetal growth restriction, particularly at high altitude, although little is known about its effects on placental phenotype and resource allocation to fetal growth.In the present study, maternal hypoxia induced morphological and functional changes in the mouse placenta, which depended on the timing and severity of hypoxia, as well as the degree of maternal hypophagia.Hypoxia at 13% inspired oxygen induced beneficial changes in placental morphology, nutrient transport and metabolic signalling pathways associated with little or no change in fetal growth, irrespective of gestational age.Hypoxia at 10% inspired oxygen adversely affected placental phenotype and resulted in severe fetal growth restriction, which was due partly to maternal hypophagia.There is a threshold between 13% and 10% inspired oxygen, corresponding to altitudes of ∼3700 m and 5800 m, respectively, at which the mouse placenta no longer adapts to support fetal resource allocation. This has implications for high altitude human pregnancies. Abstract The placenta adapts its transport capacity to nutritional cues developmentally, although relatively little is known about placental transport phenotype in response to hypoxia, a major cause of fetal growth restriction. The present study determined the effects of both moderate hypoxia (13% inspired O2) between days (D)11 and D16 or D14 and D19 of pregnancy and severe hypoxia (10% inspired O2) from D14 to D19 on placental morphology, transport capacity and fetal growth on D16 and D19 (term∼D20.5), relative to normoxic mice in 21% O2. Placental morphology adapted beneficially to 13% O2; fetal capillary volume increased at both ages, exchange area increased at D16 and exchange barrier thickness reduced at D19. Exposure to 13% O2 had no effect on placental nutrient transport on D16 but increased placental uptake and clearance of 3H‐methyl‐d‐glucose at D19. By contrast, 10% O2 impaired fetal vascularity

  7. Controlled expression of pectic enzymes in Arabidopsis thaliana enhances biomass conversion without adverse effects on growth.

    PubMed

    Tomassetti, Susanna; Pontiggia, Daniela; Verrascina, Ilaria; Reca, Ida Barbara; Francocci, Fedra; Salvi, Gianni; Cervone, Felice; Ferrari, Simone

    2015-04-01

    Lignocellulosic biomass from agriculture wastes is a potential source of biofuel, but its use is currently limited by the recalcitrance of the plant cell wall to enzymatic digestion. Modification of the wall structural components can be a viable strategy to overcome this bottleneck. We have previously shown that the expression of a fungal polygalacturonase (pga2 from Aspergillus niger) in Arabidopsis and tobacco plants reduces the levels of de-esterified homogalacturonan in the cell wall and significantly increases saccharification efficiency. However, plants expressing pga2 show stunted growth and reduced biomass production, likely as a consequence of an extensive loss of pectin integrity during the whole plant life cycle. We report here that the expression in Arabidopsis of another pectic enzyme, the pectate lyase 1 (PL1) of Pectobacterium carotovorum, under the control of a chemically inducible promoter, results, after induction of the transgene, in a saccharification efficiency similar to that of plants expressing pga2. However, lines with high levels of transgene induction show reduced growth even in the absence of the inducer. To overcome the problem of plant fitness, we have generated Arabidopsis plants that express pga2 under the control of the promoter of SAG12, a gene expressed only during senescence. These plants expressed pga2 only at late stages of development, and their growth was comparable to that of WT plants. Notably, leaves and stems of transgenic plants were more easily digested by cellulase, compared to WT plants, only during senescence. Expression of cell wall-degrading enzymes at the end of the plant life cycle may be therefore a useful strategy to engineer crops unimpaired in biomass yield but improved for bioconversion.

  8. Effects of nitrogen form on growth, CO₂ assimilation, chlorophyll fluorescence, and photosynthetic electron allocation in cucumber and rice plants.

    PubMed

    Zhou, Yan-hong; Zhang, Yi-li; Wang, Xue-min; Cui, Jin-xia; Xia, Xiao-jian; Shi, Kai; Yu, Jing-quan

    2011-02-01

    Cucumber and rice plants with varying ammonium (NH(4)(+)) sensitivities were used to examine the effects of different nitrogen (N) sources on gas exchange, chlorophyll (Chl) fluorescence quenching, and photosynthetic electron allocation. Compared to nitrate (NO(3)(-))-grown plants, cucumber plants grown under NH(4)(+)-nutrition showed decreased plant growth, net photosynthetic rate, stomatal conductance, intercellular carbon dioxide (CO(2)) level, transpiration rate, maximum photochemical efficiency of photosystem II, and O(2)-independent alternative electron flux, and increased O(2)-dependent alternative electron flux. However, the N source had little effect on gas exchange, Chl a fluorescence parameters, and photosynthetic electron allocation in rice plants, except that NH(4)(+)-grown plants had a higher O(2)-independent alternative electron flux than NO(3)(-)-grown plants. NO(3)(-) reduction activity was rarely detected in leaves of NH(4)(+)-grown cucumber plants, but was high in NH(4)(+)-grown rice plants. These results demonstrate that significant amounts of photosynthetic electron transport were coupled to NO(3)(-) assimilation, an effect more significant in NO(3)(-)-grown plants than in NH(4)(+)-grown plants. Meanwhile, NH(4)(+)-tolerant plants exhibited a higher demand for the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) for NO(3)(-) reduction, regardless of the N form supplied, while NH(4)(+)-sensitive plants had a high water-water cycle activity when NH(4)(+) was supplied as the sole N source.

  9. Soil microbial biomass and root growth in Bt and non-Bt cotton

    NASA Astrophysics Data System (ADS)

    Tan, D. K. Y.; Broughton, K.; Knox, O. G.; Hulugalle, N. R.

    2012-04-01

    The introduction of transgenic Bacillus thuringiensis (Bt) cotton (Gossypium hirsutum L.) has had a substantial impact on pest management in the cotton industry. While there has been substantial research done on the impact of Bt on the above-ground parts of the cotton plant, less is known about the effect of Bt genes on below ground growth of cotton and soil microbial biomass. The aim of this research was to test the hypothesis that Bt [Sicot 80 BRF (Bollgard II Roundup Ready Flex®)] and non-Bt [Sicot 80 RRF (Roundup Ready Flex®)] transgenic cotton varieties differ in root growth and root turnover, carbon indices and microbial biomass. A field experiment was conducted in Narrabri, north-western NSW. The experimental layout was a randomised block design and used minirhizotron and core break and root washing methods to measure cotton root growth and turnover during the 2008/09 season. Root growth in the surface 0-0.1 m of the soil was measured using the core break and root washing methods, and that in the 0.1 to 1 m depth was measured with a minirhizotron and an I-CAP image capture system. These measurements were used to calculate root length per unit area, root carbon added to the soil through intra-seasonal root death, carbon in roots remaining at the end of the season and root carbon potentially added to the soil. Microbial biomass was also measured using the ninhydrin reactive N method. Root length densities and length per unit area of non-Bt cotton were greater than Bt cotton. There were no differences in root turnover between Bt and non-Bt cotton at 0-1 m soil depth, indicating that soil organic carbon stocks may not be affected by cotton variety. Cotton variety did not have an effect on soil microbial biomass. The results indicate that while there are differences in root morphology between Bt and non-Bt cotton, these do not change the carbon turnover dynamics in the soil.

  10. The relationship between leaf area growth and biomass accumulation in Arabidopsis thaliana

    PubMed Central

    Weraduwage, Sarathi M.; Chen, Jin; Anozie, Fransisca C.; Morales, Alejandro; Weise, Sean E.; Sharkey, Thomas D.

    2015-01-01

    Leaf area growth determines the light interception capacity of a crop and is often used as a surrogate for plant growth in high-throughput phenotyping systems. The relationship between leaf area growth and growth in terms of mass will depend on how carbon is partitioned among new leaf area, leaf mass, root mass, reproduction, and respiration. A model of leaf area growth in terms of photosynthetic rate and carbon partitioning to different plant organs was developed and tested with Arabidopsis thaliana L. Heynh. ecotype Columbia (Col-0) and a mutant line, gigantea-2 (gi-2), which develops very large rosettes. Data obtained from growth analysis and gas exchange measurements was used to train a genetic programming algorithm to parameterize and test the above model. The relationship between leaf area and plant biomass was found to be non-linear and variable depending on carbon partitioning. The model output was sensitive to the rate of photosynthesis but more sensitive to the amount of carbon partitioned to growing thicker leaves. The large rosette size of gi-2 relative to that of Col-0 resulted from relatively small differences in partitioning to new leaf area vs. leaf thickness. PMID:25914696

  11. The relationship between leaf area growth and biomass accumulation in Arabidopsis thaliana

    SciTech Connect

    Weraduwage, Sarathi M.; Chen, Jin; Anozie, Fransisca C.; Morales, Alejandro; Weise, Sean E.; Sharkey, Thomas D.

    2015-04-09

    Leaf area growth determines the light interception capacity of a crop and is often used as a surrogate for plant growth in high-throughput phenotyping systems. The relationship between leaf area growth and growth in terms of mass will depend on how carbon is partitioned among new leaf area, leaf mass, root mass, reproduction, and respiration. A model of leaf area growth in terms of photosynthetic rate and carbon partitioning to different plant organs was developed and tested with Arabidopsis thaliana L. Heynh. ecotype Columbia (Col-0) and a mutant line, gigantea-2 (gi-2), which develops very large rosettes. Data obtained from growth analysis and gas exchange measurements was used to train a genetic programming algorithm to parameterize and test the above model. The relationship between leaf area and plant biomass was found to be non-linear and variable depending on carbon partitioning. The model output was sensitive to the rate of photosynthesis but more sensitive to the amount of carbon partitioned to growing thicker leaves. The large rosette size of gi-2 relative to that of Col-0 resulted from relatively small differences in partitioning to new leaf area vs. leaf thickness.

  12. Microalgae cultivation using an aquaculture wastewater as growth medium for biomass and biofuel production.

    PubMed

    Guo, Zhen; Liu, Yuan; Guo, Haiyan; Yan, Song; Mu, Jun

    2013-12-01

    Microalgae as a main feedstock has attracted much attention in recent years but is still not economically feasible due to high algal culture cost. The objective of this study was to develop a comprehensive eco-friendly technology for cultivating microalgae Platymonas subcordiformis using aquaculture wastewater as growth medium for biomass and biofuel production. Platymonas subcordiformis was grown in pretreated flounder aquaculture wastewaters taken from different stages. Each of wastewater contained different levels of nutrients. The biomass yield of microalgae and associated nitrogen and phosphorous removal were investigated. The results showed that algal cell density increased 8.9 times than the initial level. Platymonas subcordiformis removed nitrogen and phosphorus from wastewater with an average removal efficiency of 87%-95% for nitrogen and 98%-99% for phosphorus. It was feasible to couple the removal of nitrogen and phosphorus from wastewater to algal biomass and biofuel production. However, further studies are required to make this technologies economically viable for algae biofuel production. PMID:25078847

  13. C4 photosynthesis boosts growth by altering physiology, allocation and size.

    PubMed

    Atkinson, Rebecca R L; Mockford, Emily J; Bennett, Christopher; Christin, Pascal-Antoine; Spriggs, Elizabeth L; Freckleton, Robert P; Thompson, Ken; Rees, Mark; Osborne, Colin P

    2016-01-01

    C4 photosynthesis is a complex set of leaf anatomical and biochemical adaptations that have evolved more than 60 times to boost carbon uptake compared with the ancestral C3 photosynthetic type(1-3). Although C4 photosynthesis has the potential to drive faster growth rates(4,5), experiments directly comparing C3 and C4 plants have not shown consistent effects(1,6,7). This is problematic because differential growth is a crucial element of ecological theory(8,9) explaining C4 savannah responses to global change(10,11), and research to increase C3 crop productivity by introducing C4 photosynthesis(12). Here, we resolve this long-standing issue by comparing growth across 382 grass species, accounting for ecological diversity and evolutionary history. C4 photosynthesis causes a 19-88% daily growth enhancement. Unexpectedly, during the critical seedling establishment stage, this enhancement is driven largely by a high ratio of leaf area to mass, rather than fast growth per unit leaf area. C4 leaves have less dense tissues, allowing more leaves to be produced for the same carbon cost. Consequently, C4 plants invest more in roots than C3 species. Our data demonstrate a general suite of functional trait divergences between C3 and C4 species, which simultaneously drive faster growth and greater investment in water and nutrient acquisition, with important ecological and agronomic implications. PMID:27243645

  14. Risks and benefits of marginal biomass-derived biochars for plant growth.

    PubMed

    Buss, Wolfram; Graham, Margaret C; Shepherd, Jessica G; Mašek, Ondřej

    2016-11-01

    In this study, 19 biochars from marginal biomass, representing all major biomass groups (woody materials, grass, an aquatic plant, anthropogenic wastes) were investigated regarding their content of available potentially toxic elements (PTEs) and nutrients (determined by NH4NO3-extractions) and their effects on cress (Lepidium sativum) seedling growth. The objective was to assess the potential and actual effects of biochar with increased PTE content on plant growth in the context of use in soil amendments and growing media. It showed that the percentage of available PTEs was highest for biochars produced at the highest treatment temperature (HTT) of 750°C. On average, however, for all 19 biochars, the percentage availability of Cu, Cr, Ni and Zn (<1.5% for all) was similar to the percentage availability reported in the literature for the same elements in soils at similar pH values which is a highly important finding. Most biochars exceeded German soil threshold values for NH4NO3-extractable PTEs, such as Zn (by up to 25-fold), As and Cd. Despite this, cress seedling growth tests with 5% biochar in sand did not show any correlations between inhibitory effects (observed in 5 of the 19 biochars) and the available PTE concentrations. Instead, the available K concentration and biochar pH were highly significantly, negatively correlated with seedling growth (K: p<0.001, pH: p=0.004). K had the highest available concentration of all elements and the highest percentage availability (47.7±19.7% of the total K was available). Consequently, available K contributed most to the osmotic pressure and high pH which negatively affected the seedlings. Although a potential risk if some of these marginal biomass-derived biochar were applied at high concentrations, e.g. 5% (>100tha(-1)), when applied at agriculturally realistic application rates (1-10tha(-1)), the resulting smaller increases in pH and available K concentration may actually be beneficial for plant growth. PMID:27362631

  15. Importance of algal biomass to growth and development of Anopheles gambiae larvae.

    PubMed

    Kaufman, Michael G; Wanja, Elizabeth; Maknojia, Shahnaz; Bayoh, M Nabie; Vulule, John M; Walker, Edward D

    2006-07-01

    We conducted experiments to investigate the importance of algal food resources for larval growth and adult emergence of Anopheles gambiae Giles s.s. in simulated larval habitats in Kenya, and in greenhouse and laboratory microcosms in the United States. In the first experiment, we used shading to reduce algal biomass, and because algal production and larval development might be a function of underlying soil nutrients, we crossed sun-shade treatments with soils of two distinct types collected near larval habitats. Shading reduced pupation rates and total adult biomass of An. gambiae by approximately 50%. Soil type had no significant effect on mosquito production, but it did significantly affect concentrations of phosphorus and chlorophyll a in the surface microlayer. In a subsequent experiment conducted in the greenhouse to reduce temperature differences found between the shaded and sunlit treatments, <1% of larvae in the shaded treatments reached the pupal stage. There was a marked reduction of chlorophyll a levels as a function of shading and larval density. In a third experiment, larvae receiving material harvested from sunlit surface microlayers performed as well as those receiving liver powder, whereas those receiving surface microlayer from shaded habitats suffered >90% mortality and failed to pupate. In a fourth experiment, glucose was added to shaded microcosms to stimulate bacterial activity in the absence of algae. Bacterial growth rates were 2 to 3 times higher, and larval development was enhanced in glucose-amended treatments. However, pupation rates and adult weights in glucose-amended shaded microcosms were still poor compared with those in nonamended sunlit microcosms. Overall, these results demonstrate the importance of algal biomass in the surface microlayers of larval habitats to development and adult production of An. gambiae.

  16. Increased biomass yield of Lactococcus lactis during energetically limited growth and respiratory conditions.

    PubMed

    Koebmann, Brian; Blank, Lars Mathias; Solem, Christian; Petranovic, Dina; Nielsen, Lars K; Jensen, Peter Ruhdal

    2008-05-01

    Lactococcus lactis is known to be capable of respiration under aerobic conditions in the presence of haemin. In the present study the effect of respiration on ATP production during growth on different sugars was examined. With glucose as the sole carbon source, respiratory conditions in L. lactis MG1363 resulted in only a minor increase, 21%, in biomass yield. Since ATP production through substrate-level phosphorylation was essentially identical with and without respiration, the increased biomass yield was a result of energy-saving under respiratory conditions estimated to be 0.4 mol of ATP/mol of glucose. With maltose as the energy source, the increase in biomass yield amounted to 51% compared with an aerobic culture that lacked haemin. This higher ATP yield was obtained by redirecting pyruvate metabolism from lactate to acetate production, and from savings through respiration. However, even after subtracting these contributions, approx. 0.3 mol of ATP/mol of glucose remained unaccounted for. A similar response to respiratory conditions (0.2 mol of ATP/mol of glucose) was observed in a mutant that had a decreased glucose uptake rate during growth on glucose caused by disruption of the PTS(mannose) (glucose/mannose-specific phosphotransferase system). Amino acid catabolism could be excluded as the source of the additional ATP. Since mutants without a functional H+-ATPase produced less ATP under sugar starvation and respiratory conditions, the additional ATP yield appears to come partly from energy saved on proton pumping through the H+-ATPase due to respiration and partly from a reversed function of the H+-ATPase towards oxidative phosphorylation. These results may contribute to the design and implementation of carbon-efficient high-cell-density cultures of this industrially important species of bacterium.

  17. The relationship between leaf area growth and biomass accumulation in Arabidopsis thaliana

    DOE PAGES

    Weraduwage, Sarathi M.; Chen, Jin; Anozie, Fransisca C.; Morales, Alejandro; Weise, Sean E.; Sharkey, Thomas D.

    2015-04-09

    Leaf area growth determines the light interception capacity of a crop and is often used as a surrogate for plant growth in high-throughput phenotyping systems. The relationship between leaf area growth and growth in terms of mass will depend on how carbon is partitioned among new leaf area, leaf mass, root mass, reproduction, and respiration. A model of leaf area growth in terms of photosynthetic rate and carbon partitioning to different plant organs was developed and tested with Arabidopsis thaliana L. Heynh. ecotype Columbia (Col-0) and a mutant line, gigantea-2 (gi-2), which develops very large rosettes. Data obtained from growthmore » analysis and gas exchange measurements was used to train a genetic programming algorithm to parameterize and test the above model. The relationship between leaf area and plant biomass was found to be non-linear and variable depending on carbon partitioning. The model output was sensitive to the rate of photosynthesis but more sensitive to the amount of carbon partitioned to growing thicker leaves. The large rosette size of gi-2 relative to that of Col-0 resulted from relatively small differences in partitioning to new leaf area vs. leaf thickness.« less

  18. Physiological, morphological and allocational plasticity in understory deciduous trees: importance of plant size and light availability.

    PubMed

    Delagrange, Sylvain; Messier, Christian; Lechowicz, Martin J; Dizengremel, Pierre

    2004-07-01

    In a 4-year study, we investigated changes in leaf physiology, crown morphology and whole-tree biomass allocation in seedlings and saplings of shade-tolerant sugar maple (Acer saccharum Marsh.) and intermediate shade-tolerant yellow birch (Betula alleghaniensis Britt.) growing in natural understory light (0.5 to 35% of full sunlight) or in understory light reduced by 50% with shade nets to simulate the effect of gap closure. Leaf physiological parameters were mainly influenced by the light gradient, whereas crown morphological and whole-tree allocational parameters were mainly influenced by tree size. No single physiological, morphological or allocational trait was identified that could explain the difference in shade tolerance between the species. Yellow birch had higher growth rates, biomass allocation to branches and leaf physiological plasticity and lower crown morphological plasticity in unmodified understory light than sugar maple. Sugar maple did not display significant physiological plasticity, but showed variation with tree size in both crown morphology and whole-tree biomass allocation. When sugar maple was small, a greater proportion of whole-tree biomass was allocated to roots. However, physiological differences between the species decreased with decreasing light and most morphological and allocational differences tended to disappear with increasing tree size, suggesting that many species differences in shade-tolerance are expressed mainly during the seedling stage. Understory trees of both species survived for 4 years under shade nets, possibly because of higher plasticity when small and the use of stored reserves when taller.

  19. Abundance, biomass and growth rates of Synechococcus sp. in a tropical coastal ecosystem (Philippines, South China Sea)

    NASA Astrophysics Data System (ADS)

    Agawin, N. S. R.; Duarte, C. M.; Agustí, S.; McManus, L.

    2003-03-01

    The abundance, biomass and growth rates of Synechococcus sp. were estimated in a tropical coastal ecosystem (Philippines, South China Sea). The patterns of change of these parameters were further examined in relation to human-derived disturbance such as siltation, and by short-term episodic disturbances such as the typhoons, which are frequent in the region. The average abundance and biomass of Synechococcus sp. in the coastal ecosystem ranged from 0.13 to 21×10 6 cells l -1, and from 0.01 to l.6 mg C m -3, respectively, with higher biomass occurring near river sources rich in inorganic nutrients. There was, however, a significant decline of specific growth rates and maximum frequency of cells in division with increasing siltation, which suggests a deterioration of the environmental conditions to support picocyanobacterial populations. The low biomass of Synechococcus sp. in more pristine sites, in spite of relatively high growth rates there suggests that loss factors (i.e. grazing) are important in controlling the biomass in the area. The temporal pattern of picocyanobacterial abundance in the tropical ecosystem studied was tightly coupled with their temporal patterns of growth indicating that changes in abundance may result from changes in growth rate. There was not, however, a clear annual pattern of Synechococcus sp. abundance in the study site but there was some evidence for effects of storms on Synechococcus sp. abundance.

  20. Carbon allocation, source-sink relations and plant growth: do we need to revise our carbon centric concepts?

    NASA Astrophysics Data System (ADS)

    Körner, Christian

    2014-05-01

    Since the discovery that plants 'eat air' 215 years ago, carbon supply was considered the largely unquestioned top driver of plant growth. The ease at which CO2 uptake (C source activity) can be measured, and the elegant algorithms that describe the responses of photosynthesis to light, temperature and CO2 concentration, explain why carbon driven growth and productivity became the starting point of all process based vegetation models. Most of these models, nowadays adopt other environmental drivers, such as nutrient availability, as modulating co-controls, but the carbon priority is retained. Yet, if we believe in the basic rules of stoichometry of all life, there is an inevitable need of 25-30 elements other then carbon, oxygen and hydrogen to build a healthy plant body. Plants compete for most of these elements, and their availability (except for N) is finite per unit land area. Hence, by pure plausibility, it is a highly unlikely situation that carbon plays the rate limiting role of growth under natural conditions, except in deep shade or on exceptionally fertile soils. Furthermore, water shortage and low temperature, both act directly upon tissue formation (meristems) long before photosynthetic limitations come into play. Hence, plants will incorporate C only to the extent other environmental drivers permit. In the case of nutrients and mature ecosystems, this sink control of plant growth may be masked in the short term by a tight, almost closed nutrient cycle or by widening the C to other element ratio. Because source and sink activity must match in the long term, it is not possible to identify the hierarchy of growth controls without manipulating the environment. Dry matter allocation to C rich structures and reserves may provide some stoichimetric leeway or periodic escapes from the more fundamental, long-term environmental controls of growth and productivity. I will explain why carbon centric explanations of growth are limited or arrive at plausible answers

  1. Estimates of bacterial growth from changes in uptake rates and biomass.

    PubMed Central

    Kirchman, D; Ducklow, H; Mitchell, R

    1982-01-01

    Rates of nucleic acid synthesis have been used to examine microbiol growth in natural waters. These rates are calculated from the incorporation of [3H]adenine and [3H]thymidine for RNA and DNA syntheses, respectively. Several additional biochemical parameters must be measured or taken from the literature to estimate growth rates from the incorporation of the tritiated compounds. We propose a simple method of estimating a conversion factor which obviates measuring these biochemical parameters. The change in bacterial abundance and incorporation rates of [3H]thymidine was measured in samples from three environments. The incorporation of exogenous [3H]thymidine was closely coupled with growth and cell division as estimated from the increase in bacterial biomass. Analysis of the changes in incorporation rates and initial bacterial abundance yielded a conversion factor for calculating bacterial production rates from incorporation rates. Furthermore, the growth rate of only those bacteria incorporating the compound can be estimated. The data analysis and experimental design can be used to estimate the proportion of nondividing cells and to examine changes in cell volumes. PMID:6760812

  2. Prediction of microbial growth rate versus biomass yield by a metabolic network with kinetic parameters.

    PubMed

    Adadi, Roi; Volkmer, Benjamin; Milo, Ron; Heinemann, Matthias; Shlomi, Tomer

    2012-01-01

    Identifying the factors that determine microbial growth rate under various environmental and genetic conditions is a major challenge of systems biology. While current genome-scale metabolic modeling approaches enable us to successfully predict a variety of metabolic phenotypes, including maximal biomass yield, the prediction of actual growth rate is a long standing goal. This gap stems from strictly relying on data regarding reaction stoichiometry and directionality, without accounting for enzyme kinetic considerations. Here we present a novel metabolic network-based approach, MetabOlic Modeling with ENzyme kineTics (MOMENT), which predicts metabolic flux rate and growth rate by utilizing prior data on enzyme turnover rates and enzyme molecular weights, without requiring measurements of nutrient uptake rates. The method is based on an identified design principle of metabolism in which enzymes catalyzing high flux reactions across different media tend to be more efficient in terms of having higher turnover numbers. Extending upon previous attempts to utilize kinetic data in genome-scale metabolic modeling, our approach takes into account the requirement for specific enzyme concentrations for catalyzing predicted metabolic flux rates, considering isozymes, protein complexes, and multi-functional enzymes. MOMENT is shown to significantly improve the prediction accuracy of various metabolic phenotypes in E. coli, including intracellular flux rates and changes in gene expression levels under different growth rates. Most importantly, MOMENT is shown to predict growth rates of E. coli under a diverse set of media that are correlated with experimental measurements, markedly improving upon existing state-of-the art stoichiometric modeling approaches. These results support the view that a physiological bound on cellular enzyme concentrations is a key factor that determines microbial growth rate. PMID:22792053

  3. Prediction of microbial growth rate versus biomass yield by a metabolic network with kinetic parameters.

    PubMed

    Adadi, Roi; Volkmer, Benjamin; Milo, Ron; Heinemann, Matthias; Shlomi, Tomer

    2012-01-01

    Identifying the factors that determine microbial growth rate under various environmental and genetic conditions is a major challenge of systems biology. While current genome-scale metabolic modeling approaches enable us to successfully predict a variety of metabolic phenotypes, including maximal biomass yield, the prediction of actual growth rate is a long standing goal. This gap stems from strictly relying on data regarding reaction stoichiometry and directionality, without accounting for enzyme kinetic considerations. Here we present a novel metabolic network-based approach, MetabOlic Modeling with ENzyme kineTics (MOMENT), which predicts metabolic flux rate and growth rate by utilizing prior data on enzyme turnover rates and enzyme molecular weights, without requiring measurements of nutrient uptake rates. The method is based on an identified design principle of metabolism in which enzymes catalyzing high flux reactions across different media tend to be more efficient in terms of having higher turnover numbers. Extending upon previous attempts to utilize kinetic data in genome-scale metabolic modeling, our approach takes into account the requirement for specific enzyme concentrations for catalyzing predicted metabolic flux rates, considering isozymes, protein complexes, and multi-functional enzymes. MOMENT is shown to significantly improve the prediction accuracy of various metabolic phenotypes in E. coli, including intracellular flux rates and changes in gene expression levels under different growth rates. Most importantly, MOMENT is shown to predict growth rates of E. coli under a diverse set of media that are correlated with experimental measurements, markedly improving upon existing state-of-the art stoichiometric modeling approaches. These results support the view that a physiological bound on cellular enzyme concentrations is a key factor that determines microbial growth rate.

  4. Direct Image-Based Enumeration of Clostridium phytofermentans Cells on Insoluble Plant Biomass Growth Substrates

    PubMed Central

    Alvelo-Maurosa, Jesús G.; Lee, Scott J.; Hazen, Samuel P.

    2015-01-01

    A dual-fluorescent-dye protocol to visualize and quantify Clostridium phytofermentans ISDg (ATCC 700394) cells growing on insoluble cellulosic substrates was developed by combining calcofluor white staining of the growth substrate with cell staining using the nucleic acid dye Syto 9. Cell growth, cell substrate attachment, and fermentation product formation were investigated in cultures containing either Whatman no. 1 filter paper, wild-type Sorghum bicolor, or a reduced-lignin S. bicolor double mutant (bmr-6 bmr-12 double mutant) as the growth substrate. After 3 days of growth, cell numbers in cultures grown on filter paper as the substrate were 6.0- and 2.2-fold higher than cell numbers in cultures with wild-type sorghum and double mutant sorghum, respectively. However, cells produced more ethanol per cell when grown with either sorghum substrate than with filter paper as the substrate. Ethanol yields of cultures were significantly higher with double mutant sorghum than with wild-type sorghum or filter paper as the substrate. Moreover, ethanol production correlated with cell attachment in sorghum cultures: 90% of cells were directly attached to the double mutant sorghum substrate, while only 76% of cells were attached to wild-type sorghum substrate. With filter paper as the growth substrate, ethanol production was correlated with cell number; however, with either wild-type or mutant sorghum, ethanol production did not correlate with cell number, suggesting that only a portion of the microbial cell population was active during growth on sorghum. The dual-staining procedure described here may be used to visualize and enumerate cells directly on insoluble cellulosic substrates, enabling in-depth studies of interactions of microbes with plant biomass. PMID:26637592

  5. Biomass or growth rate endpoint for algae and aquatic plants: relevance for the aquatic risk assessment of herbicides.

    PubMed

    Bergtold, Matthias; Dohmen, Gerhard Peter

    2011-04-01

    Ecotoxicological studies with algae and aquatic plants are essential parts of the aquatic risk assessment for crop protection products (CPP). Growth rate is used as a response variable and in addition the effects on biomass and/or yield (in the following biomass) can be measured. The parameter biomass generally provides a lower numerical value compared with the growth rate for systematic and mathematical reasons. Therefore, some regulators prefer to use the EbC50 value (i.e., the concentration at which 50% reduction of biomass is observed) rather than ErC50 (the concentration at which a 50% inhibition of growth rate is observed) as the endpoint for ecotoxicological risk assessment. However, the parameter growth rate is scientifically more appropriate and robust against deviations in test conditions, permitting better interpretation of, and comparison between, studies. The aim of the present work is to evaluate the growth rate and biomass parameters with regard to their protectiveness and suitability for environmental risk assessment of CPP. It has been shown for a number of herbicides that the use of the EC50 value (without distinction between growth rate and biomass endpoints) from laboratory studies in combination with an assessment factor of 10 is sufficiently protective for aquatic plants (except for the herbicide 2,4-D). In this paper we evaluated EbC50 and ErC50 values separately. Data on 19 different herbicides were compiled from the literature or GLP reports. The EbC50 and ErC50 values obtained in laboratory studies were compared with effect concentrations in ecosystem studies (mainly mesocosm). This comparison of laboratory and field data shows that the overall aquatic risk assessment using ErC50 values in combination with the currently applied assessment factor of 10 is sufficient to exclude significant risk to aquatic plants in the environment. PMID:20836059

  6. Biomass accumulation rates of Amazonian secondary forest and biomass of old-growth forests from Landsat time series and the Geoscience Laser Altimeter System

    NASA Astrophysics Data System (ADS)

    Helmer, Eileen H.; Lefsky, Michael A.; Roberts, Dar A.

    2009-01-01

    We estimate the age of humid lowland tropical forests in Rondônia, Brazil, from a somewhat densely spaced time series of Landsat images (1975-2003) with an automated procedure, the Threshold Age Mapping Algorithm (TAMA), first described here. We then estimate a landscape-level rate of aboveground woody biomass accumulation of secondary forest by combining forest age mapping with biomass estimates from the Geoscience Laser Altimeter System (GLAS). Though highly variable, the estimated average biomass accumulation rate of 8.4 Mg ha-1 yr-1 agrees well with ground-based studies for young secondary forests in the region. In isolating the lowland forests, we map land cover and general types of old-growth forests with decision tree classification of Landsat imagery and elevation data. We then estimate aboveground live biomass for seven classes of old-growth forest. TAMA is simple, fast, and self-calibrating. By not using between-date band or index differences or trends, it requires neither image normalization nor atmospheric correction. In addition, it uses an approach to map forest cover for the self-calibrations that is novel to forest mapping with satellite imagery; it maps humid secondary forest that is difficult to distinguish from old-growth forest in single-date imagery; it does not assume that forest age equals time since disturbance; and it incorporates Landsat Multispectral Scanner imagery. Variations on the work that we present here can be applied to other forested landscapes. Applications that use image time series will be helped by the free distribution of coregistered Landsat imagery, which began in December 2008, and of the Ice Cloud and land Elevation Satellite Vegetation Product, which simplifies the use of GLAS data. Finally, we demonstrate here for the first time how the optical imagery of fine spatial resolution that is viewable on Google Earth provides a new source of reference data for remote sensing applications related to land cover.

  7. [Effects of NaCl stress on the seedling growth and K(+)- and Na(+) -allocation of four leguminous tree species].

    PubMed

    Mo, Hai-Bo; Yin, Yun-Long; Lu, Zhi-Guo; Wei, Xiu-Jun; Xu, Jian-Hua

    2011-05-01

    Taking the pot-cultured seedlings of four leguminous tree species (Albizia julibrissin, Robinia pseudoacacia, Sophora japonica, and Gleditsia sinensis) as test materials, this paper studied their growth indices, critical salt concentration (C50), and K+ and Na+ allocation under different levels of NaCl stress, aimed to understand the difference of test tree species in salt tolerance. NaCl stress inhibited the seedling growth of the tree species. Under NaCl stress, the dry matter accumulation decreased, while the root/shoot ratio increased, especially for A. julibrissin and G. sinensis. Quadratic regression analysis showed that the C50 of A. julibrissin, R. pseudoacacia, S. japonica, and G. sinensis was 3.0 per thousand, 5.0 per thousand, 4.5 per thousand, and 3.9 per thousand, respectively, i.e., the salt tolerance of the four tree species was in the order of R. pseudoacacia > S. japonica > G. sinensis > A. julibrissin. In the root, stem, and leaf of the four tree species seedlings, the Na+ content increased with the increase of NaCl stress, while the K+ content (except in the root of A. julibrissin) decreased after an initial increase, resulting in a larger difference in the K+/Na+ ratio in the organs. Under the same NaCl stress, the allocation of Na+ in different organs of the four tree species seedlings decreased in the order of root>stem>leaf, while that of K+ differed with tree species and NaCl stress, and leaf was the main storage organ for K+. The K+/Na+ ratio in different organs decreased in the sequence of leaf>stem>root. R. pseudoacacia under NaCl stress accumulated more K+ and less Na+ in stem and leaf, and had higher K+/Na+ ratio in all organs and higher dry mass, being assessed to be more salt-tolerant. In contrast, A. julibrissin under high NaCl stress accumulated more Na+ in stem and leaf, and had a lower K+/Na+ ratio in all organs and lower dry mass, being evaluated to be lesser salt-tolerant. The K+ accumulation in seedling stem and leaf and the Na

  8. Treatment of agro based industrial wastewater in sequencing batch reactor: performance evaluation and growth kinetics of aerobic biomass.

    PubMed

    Lim, J X; Vadivelu, V M

    2014-12-15

    A sequencing batch reactor (SBR) with a working volume of 8 L and an exchange ratio of 25% was used to enrich biomass for the treatment of the anaerobically treated low pH palm oil mill effluent (POME). The influent concentration was stepwise increased from 5000 ± 500 mg COD/L to 11,500 ± 500 mg COD/L. The performance of the reactor was monitored at different organic loading rates (OLRs). It was found that approximately 90% of the COD content of the POME wastewater was successfully removed regardless of the OLR applied to the SBR. Cycle studies of the SBR show that the oxygen uptake by the biomass while there is no COD reduction may be due to the oxidation of the storage product by the biomass. Further, the growth kinetic parameters of the biomass were determined in batch experiments using respirometer. The maximum specific growth rate (μmax) was estimated to be 1.143 day(-1) while the half saturation constant (Ks) with respect to COD was determined to be 0.429 g COD/L. The decay coefficient (bD) and biomass yield (Y) were found to be 0.131 day(-1) and 0.272 mg biomass/mg COD consumed, respectively.

  9. Effects of industrial wastewater on growth and biomass production in commonly grown vegetables.

    PubMed

    Uzma, Syeda; Azizullah, Azizullah; Bibi, Roqaia; Nabeela, Farhat; Muhammad, Uzair; Ali, Imran; Rehman, Zia Ur; Häder, Donat-Peter

    2016-06-01

    In developing countries like Pakistan, irrigation of crops with industrial and municipal wastewater is a common practice. However, the impact of wastewater irrigation on vegetables growth has rarely been studied. Therefore, the present study was conducted to determine the effect of industrial wastewater on the germination and seedling growth of some commonly grown vegetables in Pakistan. Wastewater samples were collected from two different industries (marble industry and match alam factory) at Hayatabad Industrial Estate (HIE) in Peshawar, Pakistan, and their effect on different growth parameters of four vegetables including Hibiscus esculentus, Lactuca sativa, Cucumis sativus, and Cucumis melo was investigated. The obtained results revealed that wastewater from marble industry did not affect seed germination except a minor inhibition in H. esculentus. Effluents from match alam factory stimulated seed germination in C. melo and C. sativus but had no effect on seed germination in the other two vegetables. Wastewater increased root and shoot length in H. esculentus, L. sativa and C. melo, but decreased it in C. sativus. Similarly, differential effects of wastewater were observed on fresh and dry biomass of seedlings in all vegetables. It can be concluded that wastewater may have different effects on different crops, depending upon the nature of wastewater and sensitivity of a plant species to wastewater. PMID:27149970

  10. The use of flue gas for the growth of microalgal biomass

    SciTech Connect

    Zeiler, K.G.; Kadam, K.L.; Heacox, D.A.

    1995-11-01

    Capture and utilization of carbon dioxide (CO{sub 2}) by microalgae is a promising technology to help reduce emissions from fossil fuel-fired power plants. Microalgae are of particular interest because of their rapid growth rates and tolerance to varying environmental conditions. Laboratory work is directed toward investigating the effects of simulated flue gas on microalgae, while engineering studies have focused on the economics of the technology. One strain of a green algae, Monoraphidium minutum, has shown excellent tolerance and growth when exposed to simulated flue gas which meets the requirements of the 1990 Clean Air Act Amendments (1990 CAAA). Biomass concentrations of {similar_to}2g/L have been measured in batch culture. Several other microalgae have also shown tolerance to simulated flue gas; however, the growth of these strains is not equivalent to that observed for M. minutum. Coupling the production of biodiesel or other microalgae-derived commodity chemicals with the use of flue gas carbon dioxide is potentially a zero-cost method of reducing the amount of carbon dioxide contributed to the atmosphere by fossil fuel-fired power plants. We have identified two major biological performance parameters which can provide sufficient improvement in this technology to render it cost-competitive with other existing CO{sub x} mitigation technologies. These are algal growth rate and lipid content. An updated economic analysis shows that growth rate is the more important of the two, and should be the focus of near term research activities. The long term goal of achieving zero cost will require other, non-biological, improvements in the process.

  11. Genomics Mechanisms of Carbon Allocation and Partitioning in Poplar

    SciTech Connect

    Kirst, Matias; Peter, Gary; Martin, Timothy

    2009-07-30

    The genetic control of carbon allocation and partitioning in woody perennial plants is poorly understood despite its importance for carbon sequestration. It is also unclear how environmental cues such as nitrogen availability impact the genes that regulate growth, and biomass allocation and wood composition in trees. To address these questions we phenotyped 396 clonally replicated genotypes of an interspecific pseudo-backcross pedigree of Populus for wood composition and biomass traits in above and below ground organs. The loci that regulate growth, carbon allocation and partitioning under two nitrogen conditions were identified, defining the contribution of environmental cues to their genetic control. Fifty-seven quantitative trait loci (QTL) were identified for twenty traits analyzed. The majority of QTL are specific to one of the two nitrogen treatments, demonstrating significant nitrogen-dependent genetic control. A highly significant genetic correlation was observed between plant growth and lignin/cellulose composition, and QTL co-localization identified the genomic position of potential pleiotropic regulators. Gene expression analysis of all poplar genes was also characterized in differentiating xylem, whole-roots and developing leaves of 192 of the segregating population. By integrating the QTL and gene expression information we identified genes that regulate carbon partitioning and several biomass growth related properties. The work developed in this project resulted in the publication of three book chapters, four scientific articles (three others currently in preparation), 17 presentations in international conferences and two provisional patent applications.

  12. Pattern and dynamics of biomass stock in old growth forests: The role of habitat and tree size

    NASA Astrophysics Data System (ADS)

    Yuan, Zuoqiang; Gazol, Antonio; Wang, Xugao; Lin, Fei; Ye, Ji; Zhang, Zhaochen; Suo, YanYan; Kuang, Xu; Wang, Yunyun; Jia, Shihong; Hao, Zhanqing

    2016-08-01

    Forest ecosystems play a fundamental role in the global carbon cycle. However, how stand-level changes in tree age and structure influence biomass stock and dynamics in old-growth forests is a question that remains unclear. In this study, we quantified the aboveground biomass (AGB) standing stock, the coarse woody productivity (CWP), and the change in biomass over ten years (2004-2014) in a 25 ha unmanaged broad-leaved Korean pine mixed forest in northeastern China. In addition, we quantified how AGB stock and change (tree growth, recruitment and mortality) estimations are influenced by the variation in habitat heterogeneity, tree size structure and subplot size. Our analysis indicated that Changbai forest had AGB of 265.4 Mg ha-1 in 2004, and gained1.36 Mg ha-1 y-1 between 2004 and 2014. Despite recruitment having better performance in nutrient rich habitat, we found that there is a directional tree growth trend independent of habitat heterogeneity for available nutrients in this old growth forest. The observed increases in AGB stock (∼70%) are mainly attributed to the growth of intermediate size trees (30-70 cm DBH), indicating that this forest is still reaching its mature stage. Meanwhile, we indicated that biomass loss due to mortality reduces living biomass, not increment, may be the primary factor to affect forest biomass dynamics in this area. Also, spatial variation in forest dynamics is large for small sizes (i.e. coefficient of variation in 20 × 20 m subplots is 53.2%), and more than 90 percent of the inherent variability of these coefficients was predicted by a simple model including plot size. Our result provides a mean by which to estimate within-plot variability at a local scale before inferring any directional change in forest dynamics at a regional scale, and information about the variability of forest structure and dynamics are fundamental to design effective sampling strategies in future study.

  13. Applying Central Composite Design and Response Surface Methodology to Optimize Growth and Biomass Production of Haemophilus influenzae Type b

    PubMed Central

    Momen, Seyed Bahman; Siadat, Seyed Davar; Akbari, Neda; Ranjbar, Bijan; Khajeh, Khosro

    2016-01-01

    Background Haemophilus influenzae type b (Hib) is the leading cause of bacterial meningitis, otitis media, pneumonia, cellulitis, bacteremia, and septic arthritis in infants and young children. The Hib capsule contains the major virulence factor, and is composed of polyribosyl ribitol phosphate (PRP) that can induce immune system response. Vaccines consisting of Hib capsular polysaccharide (PRP) conjugated to a carrier protein are effective in the prevention of the infections. However, due to costly processes in PRP production, these vaccines are too expensive. Objectives To enhance biomass, in this research we focused on optimizing Hib growth with respect to physical factors such as pH, temperature, and agitation by using a response surface methodology (RSM). Materials and Methods We employed a central composite design (CCD) and a response surface methodology to determine the optimum cultivation conditions for growth and biomass production of H. influenzae type b. The treatment factors investigated were initial pH, agitation, and temperature, using shaking flasks. After Hib cultivation and determination of dry biomass, analysis of experimental data was performed by the RSM-CCD. Results The model showed that temperature and pH had an interactive effect on Hib biomass production. The dry biomass produced in shaking flasks was about 5470 mg/L, which was under an initial pH of 8.5, at 250 rpm and 35° C. Conclusions We found CCD and RSM very effective in optimizing Hib culture conditions, and Hib biomass production was greatly influenced by pH and incubation temperature. Therefore, optimization of the growth factors to maximize Hib production can lead to 1) an increase in bacterial biomass and PRP productions, 2) lower vaccine prices, 3) vaccination of more susceptible populations, and 4) lower risk of Hib infections.

  14. Applying Central Composite Design and Response Surface Methodology to Optimize Growth and Biomass Production of Haemophilus influenzae Type b

    PubMed Central

    Momen, Seyed Bahman; Siadat, Seyed Davar; Akbari, Neda; Ranjbar, Bijan; Khajeh, Khosro

    2016-01-01

    Background Haemophilus influenzae type b (Hib) is the leading cause of bacterial meningitis, otitis media, pneumonia, cellulitis, bacteremia, and septic arthritis in infants and young children. The Hib capsule contains the major virulence factor, and is composed of polyribosyl ribitol phosphate (PRP) that can induce immune system response. Vaccines consisting of Hib capsular polysaccharide (PRP) conjugated to a carrier protein are effective in the prevention of the infections. However, due to costly processes in PRP production, these vaccines are too expensive. Objectives To enhance biomass, in this research we focused on optimizing Hib growth with respect to physical factors such as pH, temperature, and agitation by using a response surface methodology (RSM). Materials and Methods We employed a central composite design (CCD) and a response surface methodology to determine the optimum cultivation conditions for growth and biomass production of H. influenzae type b. The treatment factors investigated were initial pH, agitation, and temperature, using shaking flasks. After Hib cultivation and determination of dry biomass, analysis of experimental data was performed by the RSM-CCD. Results The model showed that temperature and pH had an interactive effect on Hib biomass production. The dry biomass produced in shaking flasks was about 5470 mg/L, which was under an initial pH of 8.5, at 250 rpm and 35° C. Conclusions We found CCD and RSM very effective in optimizing Hib culture conditions, and Hib biomass production was greatly influenced by pH and incubation temperature. Therefore, optimization of the growth factors to maximize Hib production can lead to 1) an increase in bacterial biomass and PRP productions, 2) lower vaccine prices, 3) vaccination of more susceptible populations, and 4) lower risk of Hib infections. PMID:27630761

  15. Fibroblast growth factor receptor-3 regulates Paneth cell lineage allocation and accrual of epithelial stem cells during murine intestinal development.

    PubMed

    Vidrich, Alda; Buzan, Jenny M; Brodrick, Brooks; Ilo, Chibuzo; Bradley, Leigh; Fendig, Kirstin Skaar; Sturgill, Thomas; Cohn, Steven M

    2009-07-01

    Fibroblast growth factor receptor 3 (FGFR-3) is expressed in the lower crypt epithelium, where stem cells of the intestine reside. The role of FGFR-3 signaling in regulating features of intestinal morphogenesis was examined in FGFR-3-null (FGFR-3(-/-)) mice. FGFR-3(-/-) mice had only about half the number of intestinal crypts and a marked decrease in the number of functional clonogenic stem cells, as assessed by an in vivo microcolony-forming assay, compared with wild-type littermates. A marked deficit in allocation of progenitor cells to Paneth cell differentiation was noted, although all the principal epithelial lineages were represented in FGFR-3(-/-) mice. The total cellular content and nuclear localization of beta-catenin protein were reduced in FGFR-3(-/-) mice, as was expression of cyclin D1 and matrix metalloproteinase-7, major downstream targets of beta-catenin/T cell factor-4 (Tcf-4) signaling. Activation of FGFR-3 in Caco-2 cells, an intestinal epithelial cell line, abrogated the fall in beta-catenin/Tcf-4 signaling activity that is normally observed in these cells as cultures become progressively more confluent. These findings are consistent with the hypothesis that, during intestinal development, FGFR-3 signaling regulates crypt epithelial stem cell expansion and crypt morphogenesis, as well as Paneth cell lineage specification, through beta-catenin/Tcf-4-dependent and -independent pathways. PMID:19407216

  16. Effects of space allocation within a deep-bedded finishing system on pig growth performance, fatty acid composition and pork quality.

    PubMed

    Patton, B S; Huff-Lonergan, E; Honeyman, M S; Kerr, B J; Lonergan, S M

    2008-03-01

    The objectives of the current study were to determine the degree to which space allocation in a deep-bedded system influences swine performance and pork quality. The deep-bedded method employed was hoop structures, which are large, tent-like shelters with cornstalks or straw for bedding. One hundred gilts ranging in weight from 59 to 71 kg were randomly assigned to treatments of low (0.70 m2 per pig, n = 50) or high (1.13 m2 per pig, n = 50) space allocation. During the 45-day experimental period, gilts were ad libitum fed a two-phase diet. Six gilts per treatment were used for carcass composition and pork quality evaluation for each replication. Five replications were conducted over a period of 4 months. Pigs finished with greater space allocation had smaller longissimus muscle area and produced pork that appeared to be darker. Variations in fatty acid composition and lipid percentage of subcutaneous adipose and longissimus dorsi muscle were observed when space allocation was changed within hoop structures. Less space resulted in greater proportion of lipid present as polyunsaturated fatty acids. Greater space allocation resulted in lower total lipid in subcutaneous pork adipose tissue. Space allocation did not affect fat firmness. Replications spanned the months of August to November, with temperatures ranging from 32°C to -2°C within the hoop structure. As environmental temperature declined, the proportion of monounsaturated fatty acids increased. Providing more space during finishing in these systems had only a small affect on pig growth and pork quality. Variations observed from replication to replication at fluctuating temperatures provide insight to seasonal differences in growth and adipose tissue composition and firmness. Therefore, finishing pigs in these systems may lead to seasonal variation in lipid composition.

  17. Non-structural carbon dynamics and allocation relate to growth rate and leaf habit in California oaks.

    PubMed

    Trumbore, Susan; Czimczik, Claudia I; Sierra, Carlos A; Muhr, Jan; Xu, Xiaomei

    2015-11-01

    Trees contain non-structural carbon (NSC), but it is unclear for how long these reserves are stored and to what degree they are used to support plant activity. We used radiocarbon ((14)C) to show that the carbon (C) in stemwood NSC can achieve ages of several decades in California oaks. We separated NSC into two fractions: soluble (∼50% sugars) and insoluble (mostly starch) NSC. Soluble NSC contained more C than insoluble NSC, but we found no consistent trend in the amount of either pool with depth in the stem. There was no systematic difference in C age between the two fractions, although ages increased with stem depth. The C in both NSC fractions was consistently younger than the structural C from which they were extracted. Together, these results indicate considerable inward mixing of NSC within the stem and rapid exchange between soluble and insoluble pools, compared with the timescale of inward mixing. We observed similar patterns in sympatric evergreen and deciduous oaks and the largest differences among tree stems with different growth rates. The (14)C signature of carbon dioxide (CO2) emitted from tree stems was higher than expected from very recent photoassimilates, indicating that the mean age of C in respiration substrates included a contribution from C fixed years previously. A simple model that tracks NSC produced each year, followed by loss (through conversion to CO2) in subsequent years, matches our observations of inward mixing of NSC in the stem and higher (14)C signature of stem CO2 efflux. Together, these data support the idea of continuous accumulation of NSC in stemwood and that 'vigor' (growth rate) and leaf habit (deciduous vs evergreen) control NSC pool size and allocation.

  18. Non-structural carbon dynamics and allocation relate to growth rate and leaf habit in California oaks.

    PubMed

    Trumbore, Susan; Czimczik, Claudia I; Sierra, Carlos A; Muhr, Jan; Xu, Xiaomei

    2015-11-01

    Trees contain non-structural carbon (NSC), but it is unclear for how long these reserves are stored and to what degree they are used to support plant activity. We used radiocarbon ((14)C) to show that the carbon (C) in stemwood NSC can achieve ages of several decades in California oaks. We separated NSC into two fractions: soluble (∼50% sugars) and insoluble (mostly starch) NSC. Soluble NSC contained more C than insoluble NSC, but we found no consistent trend in the amount of either pool with depth in the stem. There was no systematic difference in C age between the two fractions, although ages increased with stem depth. The C in both NSC fractions was consistently younger than the structural C from which they were extracted. Together, these results indicate considerable inward mixing of NSC within the stem and rapid exchange between soluble and insoluble pools, compared with the timescale of inward mixing. We observed similar patterns in sympatric evergreen and deciduous oaks and the largest differences among tree stems with different growth rates. The (14)C signature of carbon dioxide (CO2) emitted from tree stems was higher than expected from very recent photoassimilates, indicating that the mean age of C in respiration substrates included a contribution from C fixed years previously. A simple model that tracks NSC produced each year, followed by loss (through conversion to CO2) in subsequent years, matches our observations of inward mixing of NSC in the stem and higher (14)C signature of stem CO2 efflux. Together, these data support the idea of continuous accumulation of NSC in stemwood and that 'vigor' (growth rate) and leaf habit (deciduous vs evergreen) control NSC pool size and allocation. PMID:26452766

  19. Running Title: C and N Allocation in Pine

    SciTech Connect

    Ball, J. Timothy

    1996-12-01

    uptake, and the dynamics of nutrient use were all seen to be influenced by the interplay between previous N supply, previous C supply, and the concentration of CO{sub 2} in the atmosphere. The data suggest that in an elevated CO{sub 2} atmosphere ponderosa pine seedlings will have higher root biomass and be likely to capture more N compared to seedlings today. Further, the combined growth and allocation responses of Ponderosa pine at elevated CO{sub 2} resulted in higher growth per unit N (nitrogen productivity) and lower N per gram of tissue (all tissues not just leaves) when nitrogen was not in abundant supply.

  20. Production of biomass by Spirulina maxima using sugar beet vinasse in growth media.

    PubMed

    Barrocal, Víctor M; García-Cubero, M Teresa; González-Benito, Gerardo; Coca, Mónica

    2010-12-31

    Cultivation of Spirulina maxima in media containing vinasse from beet molasses fermentation has been studied in both batch cultures and a photobioreactor. The results obtained in batch tests showed that S. maxima was able to grow in Schlösser media containing up to 5 g/L of vinasse or alkaline diluted vinasse (5 g/L). Biomass concentrations ranging from 3.5 and 4.8 g/L, productivities from 0.15 to 0.24 (g/L d) and specific growth rates about 0.1 d⁻¹ were found. Betaine, an organic nitrogenous compound present in vinasse, was completely consumed. The continuous operation in a tubular photobioreactor with Schlösser medium supplemented with 2g/L of vinasse led to S. maxima concentrations about 8 g/L and productivities of 0.7 g/L d for an hydraulic retention time of 11 d using a light intensity of 3000 lux, slightly higher than those achieved with Schlösser medium, showing that the addition of vinasse presents a positive effect on the growth of the microalgae.

  1. The dynamics of annual carbon allocation to wood in European forests is consistent with a combined source-sink limitation of growth.

    NASA Astrophysics Data System (ADS)

    Guillemot, Joannès; Martin-StPaul, Nicolas K.; Dufrêne, Eric; François, Christophe; Soudani, Kamel; Ourcival, Jean-Marc; Leadley, Paul; Delpierre, Nicolas

    2015-04-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will strongly determines the responses of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study was i) to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in four tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex and Picea abies) ii) to implement the identified key drivers in a new C allocation scheme within the CASTANEA terrestrial biosphere model (TBM). Combining field measurements and process-based simulations at 49 sites (931 site-years), our analyses revealed that the inter-site variability in C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. Our study supports the premise that European forest growth is under a complex panel of source- and sink- limitations, contradicting the simple source control implemented in most TBMs. The implementation of these combined forest growth limitations in the CASTANEA model significantly improved its performance when evaluated against independent stand growth data at the regional scale (mainland France, >10000 plots). We finally discuss how the sink imitation affects the CASTANEA simulated projections of forest productivity along the 21th century, especially with respect to the expected fertilizing effect of increasing atmospheric

  2. Microalgae biomass growth using primary treated wastewater as nutrient source and their potential use for lipids production

    NASA Astrophysics Data System (ADS)

    Frementiti, Anastacia; Aravantinou, Andriana F.; Manariotis, Ioannis D.

    2015-04-01

    The great demand for energy, the rising price of the crude oil and the rapid decrease of the supply of fossil fuels are the main reasons that have increased the interest for the production of fuels from renewable resources. Microalgae are considered to be the most promising new source of biomass and biofuels, since their lipid content in some cases is up to 70%. The microalgal growth and its metabolism processes are essential in wastewater treatment with many economical prospects. The aim of this work was to evaluate the algal production in a laboratory scale open pond. The pond had a working volume of 30 L and was fed with sterilized primary treated wastewater. Chlorococcum sp. was used as a model microalgal. Experiments were conducted under controlled environmental conditions in order to investigate the removal of nutrients, biomass growth, and lipids accumulation in microalgae. Chlorococcum sp. cultures behavior was investigated under batch, fill and draw, and continuous operation mode, at two different radiation intensities (100 and 200 μmol/m2s). The maximum biomass concentration of 630 mg/L was observed with the fill and draw mode. Moreover, the growth rates of microalgal biomass were depended on the influent nutrients concentration. Specifically, the phosphates were the limiting factor for biomass growth in continuous condition; the phosphates removal in this condition, reached a 100%. Chemical demand oxygen (COD) was not removed efficiently by Chlorococcum sp. since it was an autotrophic microalgal with no organic carbon demands for its growth. The lipids content in the dry weight of Chlorococcum sp. ranged from 1 to 9% depending on the concentration of nutrients and the operating conditions.

  3. Competition between macroalgae and corals: effects of herbivore exclusion and increased algal biomass on coral survivorship and growth

    NASA Astrophysics Data System (ADS)

    Lirman, D.

    2001-05-01

    Recent declines in coral abundance accompanied by increases in macroalgal cover on Florida reefs highlight the importance of competition for space between these groups. This paper documents the frequency of coral-algal interactions on the Northern Florida Reef Tract and evaluates the effects of grazer exclusions and experimental algal addition on growth and tissue mortality of three coral species, Siderastrea siderea, Porites astreoides, and Montastraea faveolata. The frequency of interactions between corals and macroalgae was high as more than 50% of the basal perimeter of colonies was in contact with macroalgae; turf forms, Halimeda spp., and Dictyota spp. were the most common groups in contact with corals. Decreased grazing pressure resulted in significant increases in algal biomass within cages, and caged corals showed species-specific susceptibility to increased algal biomass. While no effects were detected for S. siderea, significant decreases in growth rates were documented for caged P. astreoides which had growth rates three to four times lower than uncaged colonies. When an algal addition treatment was included to duplicate maximum algal biomass levels documented for reefs in the area, colonies of P. astreoides in the algal addition treatment had growth rates up to ten times lower than uncaged colonies. High susceptibility to algal overgrowth was also found for the reef-building coral M. faveolata, which experienced significant tissue mortality under both uncaged (5.2% decrease in live tissue area per month) and caged (10.2% per month) conditions. The documented effects of increased algal biomass on coral growth and tissue mortality suggest a potential threat for the long-term survivorship and growth of corals in the Florida Reef Tract if present rates of algal growth and space utilization are maintained.

  4. Microbial maximal specific growth rate as a square-root function of biomass yield and two kinetic parameters.

    PubMed

    Wong, Wilson W; Liao, James C

    2009-11-01

    Understanding how growth rates changes under different perturbations is fundamental to many aspect of microbial physiology. In this work, we experimentally showed that maximal specific growth rate is a square-root function of the biomass yield, the substrate turnover number, and the maximum synthesis rate of the substrate transporter under that condition. We used Escherichia coli cultures in lactose minimal medium as a model system by introducing genetic modifications, in vitro evolution, and ethanol stress to the cell. Deletion of crr affected all three parameters in different directions while deletion of ptsG decreased only the biomass yield. Ethanol stress negatively impacted all three parameters, while anaerobicity decreased biomass yield and transporter synthesis rate. In addition, laboratory evolution increased the growth rate in lactose mostly through enhancing the expression rate of the lac operon. Despite all these changes, the growth rate of the perturbed strain was successfully related to the three parameters by the square-root equation. Thus, this square-root relationship provides insight into how growth rate is altered by different physiological parameters. PMID:19712746

  5. Growth, reproduction, mortality, distribution, and biomass of freshwater drum in Lake Erie

    USGS Publications Warehouse

    Bur, Michael T.

    1984-01-01

    Predominant age-groups in the Lake Erie freshwater drum Aplodinotus grunnienspopulation were 3, 4, and 5 as determined from gill net, trap net, bottom trawl, and midwater trawl samples. Age and growth calculations indicated that females grew faster than males. However, the length-weight relation did not differ between sexes and was described by the equation: log W = −5.4383 + 3.1987 log L. Some males became sexually mature at age 2 and all were mature by age 6. Females matured 1 year later than males. Three sizes of eggs were present in ovaries; the average total number was 127,000 per female for 20 females over a length range of 270 to 478 mm. Seasonal analysis of the ovary-body weight ratio indicated that spawning extended from June to August. A total annual mortality rate of 49% for drum aged 4 through 11 was derived from catch-curve analysis. Freshwater drum were widely distributed throughout Lake Erie in 1977–1979, the greatest concentration being in the western basin. They moved into warm, shallow water (less than 10 m deep) during summer, and returned to deeper water in late fall. Summer biomass estimates for the western basin, based on systematic surveys with bottom trawls, were 9,545 t in 1977 and 2,333 t in 1978.

  6. 'Carolina' session growth, reproduction, and biomass of hydrilla in North Carolina

    SciTech Connect

    Harlan, S.M.; Davis, G.J.; Pesacreta, G.

    1984-06-01

    Certain morphological and physiological characteristics are associated with the phenomenal ability of hydrilla to invade an aquatic system, overtop more desirable native rooted aquatic species, and form very dense monospecific mats. One of these adaptations is the formation of tubers which are vegetative propagules formed at the ends of positively geotropic rhizomes (Van, Haller, and Garrard 1978). Tubers develop in the hydrosoil and thus are very resistant to all control methods. Also, hydrilla's ability to become established and photosynthesize under low light intensities is unequaled by any other submersed rooted aquatic macrophyte (Van, Haller, and Bowes 1976). Hydrilla growing in lakes in Umstead State Park in North Carolina was first identified by William Haller in 1981 and had apparently been established in the area for several years. Since its initial identification, hydrilla has been found in 18 other water bodies, all in Wake Country. Hydrilla has the potential to become a very serious problem as there are presently no effective means of halting its spreading or eradicating it after infestation occurs. For effective management in North Carolina, knowledge of the growth, reproduction, and biomass of hydrilla in North Carolina is needed. This research addresses these questions.

  7. Lipase Production in Solid-State Fermentation Monitoring Biomass Growth of Aspergillus niger Using Digital Image Processing

    NASA Astrophysics Data System (ADS)

    Dutra, Julio C. V.; da Terzi, Selma C.; Bevilaqua, Juliana Vaz; Damaso, Mônica C. T.; Couri, Sônia; Langone, Marta A. P.; Senna, Lilian F.

    The aim of this study was to monitor the biomass growth of Aspergillus niger in solid-state fermentation (SSF) for lipase production using digital image processing technique. The strain A. niger 11T53A14 was cultivated in SSF using wheat bran as support, which was enriched with 0.91% (m/v) of ammonium sulfate. The addition of several vegetable oils (castor, soybean, olive, corn, and palm oils) was investigated to enhance lipase production. The maximum lipase activity was obtained using 2% (m/m) castor oil. In these conditions, the growth was evaluated each 24 h for 5 days by the glycosamine content analysis and digital image processing. Lipase activity was also determined. The results indicated that the digital image process technique can be used to monitor biomass growth in a SSF process and to correlate biomass growth and enzyme activity. In addition, the immobilized esterification lipase activity was determined for the butyl oleate synthesis, with and without 50% v/v hexane, resulting in 650 and 120 U/g, respectively. The enzyme was also used for transesterification of soybean oil and ethanol with maximum yield of 2.4%, after 30 min of reaction.

  8. Estimation of the relationship between growth, consumption, and energy allocation in juvenile pacific cod (Gadus macrocephalus) as a function of temperature and ration

    NASA Astrophysics Data System (ADS)

    Sreenivasan, Ashwin; Heintz, Ron

    2016-10-01

    Pacific cod (Gadus macrocephalus) are generalist predators in the Gulf of Alaska (GOA), and are an important predator on other commercially important species. Efficient management of this species can benefit by knowing how these fish adapt to changing environmental conditions, with a focus on how growth and condition are affected by changes in temperature and diet. We conducted a feeding study to understand the relationship between growth, ration, and temperature, and how these factors interact to affect energy allocation strategies. Since growth and condition of juveniles can determine recruitment into the population, this study focused on growth and consumption of age 1+Pacific cod held over 4 temperature treatments (4 °C, 8 °C, 12 °C, and 16 °C) and 3 ration levels (unlimited ration, medium ration, and low ration). We also compared cellular nucleic acid (RNA/DNA) ratios, an instantaneous growth index, total-body lipid, and proximate composition between fish. At 4 °C, 8 °C, and 12 °C, fish at medium and low rations had higher growth rates relative to fish at high rations. Higher food consumption appears to negatively affect digestive ability, assimilation efficiency, and nutrient utilization. RNA/DNA was clearly correlated with growth rates at 4 °C and 8 °C, but this relationship did not hold at higher temperatures. A secondary growth study was conducted to test the reliability of the growth/consumption models derived from the main growth study. Temperature influenced energy reserves (lipid) while tissue growth (protein) was influenced by ration level. Average lipid values were higher at 4 °C than at 8 °C or 12 °C, suggesting a predisposition to heightened lipid synthesis at colder temperatures. Longer durations of warmer water temperature in the GOA could consequently affect energy allocation strategies, with dietary changes in the field potentially amplifying this effect in cold and warm years. This energy allocation strategy could be detrimental

  9. A growth inhibitory model with SO(x) influenced effective growth rate for estimation of algal biomass concentration under flue gas atmosphere.

    PubMed

    Ronda, Srinivasa Reddy; Kethineni, Chandrika; Parupudi, Lakshmi Chandrika Pavani; Thunuguntla, Venkata Bala Sai Chaitanya; Vemula, Sandeep; Settaluri, Vijaya Saradhi; Allu, Prasada Rao; Grande, Suresh Kumar; Sharma, Suraj; Kandala, Chari Venkatakrishna

    2014-01-01

    A theoretical model for the prediction of biomass concentration under rice husk flue gas emission has been developed. The growth inhibitory model (GIM) considers the CO2 mass transfer rate, the critical SOx concentration and its role in pH-based inter-conversion of bicarbonate. The calibration and subsequent validation of the growth profile of Nannochloropsis limnetica at 2% and 10% (v/v) CO2 showed that the predicted values were consistent with the measured values, with r(2) being 0.96 and 0.98, respectively, and p<0.001 in both cases. The constants used in the GIM for the prediction of biomass have been justified using sensitivity analysis. GIM applicability was defined as ±30% of the calibrated flow rate (3.0 L min(-1)). This growth model can be applied to predict algal growth in photo-bioreactors treated with flue gas in the generation of biomass feed stock for biofuel production. PMID:24300846

  10. Global model estimates of carbon and nitrogen storage in litter and soil pools: response to changes in vegetation quality and biomass allocation

    NASA Astrophysics Data System (ADS)

    Potter, Christopher S.; Klooster, Steven A.

    1997-02-01

    Changes in plant production, structure, and tissue composition are primary drivers for terrestrial biogeochemistry under future environmental conditions. Consequently, there is a need for process-oriented assessment of the potential global importance of vegetation controls over extended periods of C and N sequestration in terrestrial ecosystems. In this study, plant litter quality (lignin content) and carbon allocation to woody tissues are used as surrogates for testing the hypothetical effects of vegetation change on C and N cycles. We tested the CASA (Carnegie-Ames-Stanford approach) biosphere model, which uses global gridded (1°) satellite imagery on a monthly time interval to simulate seasonal patterns in net ecosystem carbon balance and near steady-state C/N storage in detritus and soils. Under contemporary "reference" settings, combined organic matter storage (litter plus surface soil to c. 30cm depth) for C and N is estimated highest in tropical and boreal forest ecosystem zones, and in cultivated ecosystems. The worldwide C:N ratio (by weight) for standing litter plus surface soil organic matter (SOM) is estimated at 23. About 14% of the projected global pool of 1327Pg (1015 g) soil C resides in "modern" form, in the sense that this proportion is in near-steady state exchange with plant production and decomposition on time scales of several decades. Likewise, about 12% of the projected global pool of 104Pg soil N is in modern form. Sensitivity tests treated litter quality and allocation effects independently from other direct effects of changes in climate, atmospheric CO2 levels, and primary production. For forested ecosystems, the model predicts that a hypothetical 50% decrease in litter lignin concentration would result in a long-term net loss of about 10% C from surface litter and soil organic matter pools. A 50% decrease in C allocation to woody tissues would invoke approximately the same net loss of C as a 50% decrease in litter lignin. With respect

  11. Resource Allocation.

    ERIC Educational Resources Information Center

    Stennett, R. G.

    A research allocation formula employed in London, Ontario elementary schools, as well as supporting data on the method, are provided in this report. Attempts to improve on the traditional methods of resource allocation in London's schools were based on two principles: (1) that need for a particular service could and should be determined…

  12. Optimizing reproductive phenology in a two-resource world: a dynamic allocation model of plant growth predicts later reproduction in phosphorus-limited plants

    PubMed Central

    Nord, Eric A.; Shea, Katriona; Lynch, Jonathan P.

    2011-01-01

    Background and Aims Timing of reproduction is a key life-history trait that is regulated by resource availability. Delayed reproduction in soils with low phosphorus availability is common among annuals, in contrast to the accelerated reproduction typical of other low-nutrient environments. It is hypothesized that this anomalous response arises from the high marginal value of additional allocation to root growth caused by the low mobility of phosphorus in soils. Methods To better understand the benefits and costs of such delayed reproduction, a two-resource dynamic allocation model of plant growth and reproduction is presented. The model incorporates growth, respiration, and carbon and phosphorus acquisition of both root and shoot tissue, and considers the reallocation of resources from senescent leaves. The model is parameterized with data from Arabidopsis and the optimal reproductive phenology is explored in a range of environments. Key Results The model predicts delayed reproduction in low-phosphorus environments. Reproductive timing in low-phosphorus environments is quite sensitive to phosphorus mobility, but is less sensitive to the temporal distribution of mortality risks. In low-phosphorus environments, the relative metabolic cost of roots was greater, and reproductive allocation reduced, compared with high-phosphorus conditions. The model suggests that delayed reproduction in response to low phosphorus availability may be reduced in plants adapted to environments where phosphorus mobility is greater. Conclusions Delayed reproduction in low-phosphorus soils can be a beneficial response allowing for increased acquisition and utilization of phosphorus. This finding has implications both for efforts to breed crops for low-phosphorus soils, and for efforts to understand how climate change may impact plant growth and productivity in low-phosphorus environments. PMID:21712299

  13. Atmospheric phenanthrene pollution modulates carbon allocation in red clover (Trifolium pratense L.).

    PubMed

    Desalme, Dorine; Binet, Philippe; Epron, Daniel; Bernard, Nadine; Gilbert, Daniel; Toussaint, Marie-Laure; Plain, Caroline; Chiapusio, Geneviève

    2011-10-01

    The influence of atmospheric phenanthrene (PHE) exposure (160 μg m(-3)) during one month on carbon allocation in clover was investigated by integrative (plant growth analysis) and instantaneous (13)CO(2) pulse-labelling approaches. PHE exposure diminished plant growth parameters (relative growth rate and net assimilation rate) and disturbed photosynthesis (carbon assimilation rate and chlorophyll content), leading to a 25% decrease in clover biomass. The root-shoot ratio was significantly enhanced (from 0.32 to 0.44). Photosynthates were identically allocated to leaves while less allocated to stems and roots. PHE exposure had a significant overall effect on the (13)C partitioning among clover organs as more carbon was retained in leaves at the expense of roots and stems. The findings indicate that PHE decreases root exudation or transfer to symbionts and in leaves, retains carbon in a non-structural form diverting photosynthates away from growth and respiration (emergence of an additional C loss process).

  14. Custom fabrication of biomass containment devices using 3-D printing enables bacterial growth analyses with complex insoluble substrates

    DOE PAGES

    Nelson, Cassandra E.; Beri, Nina R.; Gardner, Jeffrey G.

    2016-09-21

    Physiological studies of recalcitrant polysaccharide degradation are challenging for several reasons, one of which is the difficulty in obtaining a reproducibly accurate real-time measurement of bacterial growth using insoluble substrates. Current methods suffer from several problems including (i) high background noise due to the insoluble material interspersed with cells, (ii) high consumable and reagent cost and (iii) significant time delay between sampling and data acquisition. A customizable substrate and cell separation device would provide an option to study bacterial growth using optical density measurements. To test this hypothesis we used 3-D printing to create biomass containment devices that allow interactionmore » between insoluble substrates and microbial cells but do not interfere with spectrophotometer measurements. Evaluation of materials available for 3-D printing indicated that UV-cured acrylic plastic was the best material, being superior to nylon or stainless steel when examined for heat tolerance, reactivity, and ability to be sterilized. Cost analysis of the 3-D printed devices indicated they are a competitive way to quantitate bacterial growth compared to viable cell counting or protein measurements, and experimental conditions were scalable over a 100-fold range. The presence of the devices did not alter growth phenotypes when using either soluble substrates or insoluble substrates. Furthermore, we applied biomass containment to characterize growth of Cellvibrio japonicus on authentic lignocellulose (non-pretreated corn stover), and found physiological evidence that xylan is a significant nutritional source despite an abundance of cellulose present.« less

  15. Multiscale Modeling for Biomass Growth Associated with Bioremediation and Its Impact on Permeability Change and Distribution of Contaminants

    NASA Astrophysics Data System (ADS)

    Oka, G. K.; Pinder, G.

    2009-12-01

    Bioremediation involves using bacteria present in the soil or injected into the soil to degrade contaminants dissolved in groundwater. The degrading bacteria grow attached to the soil particles using the contaminants as substrate for growth. In the process, the pore spaces between soil particles get partially or totally blocked. This blocking, called bioclogging, affects an important parameter, the permeability of soil, which governs the distribution of contaminants in groundwater. The distribution of contaminants in turn affects the growth of bacteria through its changed availability pattern. We attempt to model the complex relationship between the growth of bacteria and biodegradation of the contaminants by coupling a 'Cellular Automata' (CA) model for biomass growth with a multiphase transport model for contaminants in groundwater. The growth in biomass of bacteria at the microscopic spatial scale is translated into a change in permeability at the macroscopic scale by using averaging techniques on CA grids regarding them as 'Representative Elementary Volume' (REV) elements. The results of simulation are presented and compared with a laboratory column experiment.

  16. Multi-decade biomass dynamics in an old-growth hemlock-northern hardwood forest, Michigan, USA.

    PubMed

    Woods, Kerry D

    2014-01-01

    Trends in living aboveground biomass and inputs to the pool of coarse woody debris (CWD) in an undisturbed, old-growth hemlock-northern hardwood forest in northern MI were estimated from multi-decade observations of permanent plots. Growth and demographic data from seven plot censuses over 47 years (1962-2009), combined with one-time measurement of CWD pools, help assess biomass/carbon status of this landscape. Are trends consistent with traditional notions of late-successional forests as equilibrial ecosystems? Specifically, do biomass pools and CWD inputs show consistent long-term trends and relationships, and can living and dead biomass pools and trends be related to forest composition and history? Aboveground living biomass densities, estimated using standard allometric relationships, range from 360-450 Mg/ha among sampled stands and types; these values are among the highest recorded for northeastern North American forests. Biomass densities showed significant decade-scale variation, but no consistent trends over the full study period (one stand, originating following an 1830 fire, showed an aggrading trend during the first 25 years of the study). Even though total above-ground biomass pools are neither increasing nor decreasing, they have been increasingly dominated, over the full study period, by very large (>70 cm dbh) stems and by the most shade-tolerant species (Acer saccharum and Tsuga canadensis). CWD pools measured in 2007 averaged 151 m(3)/ha, with highest values in Acer-dominated stands. Snag densities averaged 27/ha, but varied nearly ten-fold with canopy composition (highest in Tsuga-dominated stands, lowest in Acer-dominated); snags constituted 10-50% of CWD biomass. Annualized CWD inputs from tree mortality over the full study period averaged 1.9-3.2 Mg/ha/yr, depending on stand and species composition. CWD input rates tended to increase over the course of the study. Input rates may be expected to increase over longer-term observations because, (a

  17. The Dynamic of Annual Carbon Allocation to Wood in European Forests Is Consistent with a Combined Source-Sink Limitation of Growth: Implications on Growth Simulations in a Terrestrial Biosphere Model

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrêne, E.; François, C.; Soudani, K.; Ourcival, J. M.; Leadley, P.; Delpierre, N.

    2014-12-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will strongly determines the responses of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study was i) to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in four tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex and Picea abies) ii) to implement the identified key drivers in a new C allocation scheme within the CASTANEA terrestrial biosphere model (TBM). Combining field measurements and process-based simulations at 49 sites (931 site-years), our analyses revealed that the inter-site variability in C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. Our study supports the premise that European forest growth is under a complex panel of source- and sink- limitations, contradicting the simple source control implemented in most TBMs. The implementation of these combined forest growth limitations in the CASTANEA model significantly improved its performance when evaluated against independent stand growth data at the regional scale (mainland France, >103 plots). We finally discuss how the sink imitation affects the CASTANEA simulated projections of forest productivity along the 21th century, especially with respect to the expected fertilizing effect of increasing atmospheric

  18. Seasonal trends in growth and biomass accumulation of selected nutrients and metals in six species of emergent aquatic macrophytes

    SciTech Connect

    Behrends, L.L.; Bailey, E.; Bulls, M.J.; Coonrod, H.S.; Sikora, F.J.

    1996-05-01

    Growth and biomass accumulation of selected nutrients and trace metals were monitored for six species of aquatic macrophytes during June, August and November, 1993. Plant species were cultivated in two polyculture treatments, each replicated three times. Polyculture I consisted of Scirpus acutus (hardstem bullrush), Phragmites communes (common reed), and Phalaris arundinacea (canary grass). Polyculture H consisted of Typha spp. (cattail), Scirpus atrovirens (green bullrush), and Scirpus cyperinus (wool grass). Each of the six cells (6 x 9 x 0.6 m), was operated as a gravel-substrate, subsurface-flow wetlands in a continuous recirculating mode. At six week intervals, macro, micro and trace elements were dissolved and added to the sump of the recirculating system. On each of three sampling dates, replicate shoot and root samples were collected, segregated by species and tissue type (roots, rhizomes, stems and leaves), and prepared for gravimetric biomass estimates and chemical analysis. Tissue specific concentrations of N, P, K, Ca, Mg, Fe, Mn, Zn and Cu, were determined on each date for each species and tissue type. Results will be discussed with respect to species specific growth rates, biomass accumulation, and seasonal uptake and translocation of plant nutrients.

  19. A growth inhibitory model with SOx influenced effective growth rate for estimation of algal biomass concentration under flue gas atmosphere

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A theoretical model for the prediction of biomass concentration under real flue gas emission has been developed. The model considers the CO2 mass transfer rate, the critical SOx concentration and its role on pH based inter-conversion of bicarbonate in model building. The calibration and subsequent v...

  20. Phylogenetic constraints on elemental stoichiometry and resource allocation in heterotrophic marine bacteria.

    PubMed

    Zimmerman, Amy E; Allison, Steven D; Martiny, Adam C

    2014-05-01

    The objective of this study was to evaluate the contribution of evolutionary history to variation in the biomass stoichiometry and underlying biochemical allocation patterns of heterotrophic marine bacteria. We hypothesized that phylogeny significantly constrains biochemical allocation strategy and elemental composition among taxa of heterotrophic marine bacteria. Using a 'common-garden' experimental design, we detected significant interspecific variation in stoichiometry, macromolecule allocation and growth rate among 13 strains of marine Proteobacteria. However, this variation was not well explained by 16S rRNA phylogenetic relationships or differences in growth rate. Heterotrophic bacteria likely experience C-limitation when consuming resources in Redfield proportions, which consequently decouples growth rate from allocation to rRNA and biomass P content. Accordingly, overall bacterial C : nutrient ratios (C : P = 77, C : N = 4.9) were lower than Redfield proportions, whereas the average N : P ratio of 17 was consistent with the Redfield ratio. Our results suggest that strain-level diversity is an important driver of variation in the C : N : P ratios of heterotrophic bacterial biomass and that the potential importance of non-nucleic acid pools of P warrants further investigation. Continued work clarifying the range and controls on the stoichiometry of heterotrophic marine bacteria will help improve understanding and predictions of global ocean C, N and P dynamics.

  1. Coordination between water transport capacity, biomass growth, metabolic scaling and species stature in co-occurring shrub and tree species.

    PubMed

    Smith, Duncan D; Sperry, John S

    2014-12-01

    The significance of xylem function and metabolic scaling theory begins from the idea that water transport is strongly coupled to growth rate. At the same time, coordination of water transport and growth seemingly should differ between plant functional types. We evaluated the relationships between water transport, growth and species stature in six species of co-occurring trees and shrubs. Within species, a strong proportionality between plant hydraulic conductance (K), sap flow (Q) and shoot biomass growth (G) was generally supported. Across species, however, trees grew more for a given K or Q than shrubs, indicating greater growth-based water-use efficiency (WUE) in trees. Trees also showed slower decline in relative growth rate (RGR) than shrubs, equivalent to a steeper G by mass (M) scaling exponent in trees (0.77-0.98). The K and Q by M scaling exponents were common across all species (0.80, 0.82), suggesting that the steeper G scaling in trees reflects a size-dependent increase in their growth-based WUE. The common K and Q by M exponents were statistically consistent with the 0.75 of ideal scaling theory. A model based upon xylem anatomy and branching architecture consistently predicted the observed K by M scaling exponents but only when deviations from ideal symmetric branching were incorporated. PMID:25041417

  2. Coordination between water transport capacity, biomass growth, metabolic scaling and species stature in co-occurring shrub and tree species.

    PubMed

    Smith, Duncan D; Sperry, John S

    2014-12-01

    The significance of xylem function and metabolic scaling theory begins from the idea that water transport is strongly coupled to growth rate. At the same time, coordination of water transport and growth seemingly should differ between plant functional types. We evaluated the relationships between water transport, growth and species stature in six species of co-occurring trees and shrubs. Within species, a strong proportionality between plant hydraulic conductance (K), sap flow (Q) and shoot biomass growth (G) was generally supported. Across species, however, trees grew more for a given K or Q than shrubs, indicating greater growth-based water-use efficiency (WUE) in trees. Trees also showed slower decline in relative growth rate (RGR) than shrubs, equivalent to a steeper G by mass (M) scaling exponent in trees (0.77-0.98). The K and Q by M scaling exponents were common across all species (0.80, 0.82), suggesting that the steeper G scaling in trees reflects a size-dependent increase in their growth-based WUE. The common K and Q by M exponents were statistically consistent with the 0.75 of ideal scaling theory. A model based upon xylem anatomy and branching architecture consistently predicted the observed K by M scaling exponents but only when deviations from ideal symmetric branching were incorporated.

  3. Disparities between in situ and optically derived carbon biomass and growth rates of the prymnesiophyte Phaeocystis globosa

    NASA Astrophysics Data System (ADS)

    Peperzak, L.; van der Woerd, H. J.; Timmermans, K. R.

    2015-03-01

    The oceans play a pivotal role in the global carbon cycle. It is not practical to measure the global daily production of organic carbon, the product of phytoplankton standing stock and its growth rate using discrete oceanographic methods. Instead, optical proxies from Earth-orbiting satellites must be used. To test the accuracy of optically derived proxies of phytoplankton physiology and growth rate, hyperspectral reflectance data from the wax and wane of a Phaeocystis bloom in laboratory mesocosms were compared with standard ex situ data. Chlorophyll biomass could be estimated accurately from reflectance using specific chlorophyll absorption algorithms. However, the conversion of chlorophyll (Chl) to carbon (C) was obscured by the non-linear increase in C : Chl under nutrient-limited growth. Although C : Chl was inversely correlated (r2 = 0.88) with the in situ fluorometric growth rate indicator Fv / Fm (Photosystem II quantum efficiency), none of them was linearly correlated to growth rate, constraining the accurate calculation of Phaeocystis growth or production rates. Unfortunately, the optical proxy ϕph (quantum efficiency of fluorescence: the ratio of the number of fluoresced photons to the number of photons absorbed by the phytoplankton) did not show any correlation with Phaeocystis growth rate, and therefore it is concluded that ϕph cannot be applied in the remotely sensed measurement of this species' carbon production rate.

  4. Physiological, biomass elemental composition and proteomic analyses of Escherichia coli ammonium-limited chemostat growth, and comparison with iron- and glucose-limited chemostat growth

    PubMed Central

    Folsom, James Patrick

    2015-01-01

    Escherichia coli physiological, biomass elemental composition and proteome acclimations to ammonium-limited chemostat growth were measured at four levels of nutrient scarcity controlled via chemostat dilution rate. These data were compared with published iron- and glucose-limited growth data collected from the same strain and at the same dilution rates to quantify general and nutrient-specific responses. Severe nutrient scarcity resulted in an overflow metabolism with differing organic byproduct profiles based on limiting nutrient and dilution rate. Ammonium-limited cultures secreted up to 35  % of the metabolized glucose carbon as organic byproducts with acetate representing the largest fraction; in comparison, iron-limited cultures secreted up to 70  % of the metabolized glucose carbon as lactate, and glucose-limited cultures secreted up to 4  % of the metabolized glucose carbon as formate. Biomass elemental composition differed with nutrient limitation; biomass from ammonium-limited cultures had a lower nitrogen content than biomass from either iron- or glucose-limited cultures. Proteomic analysis of central metabolism enzymes revealed that ammonium- and iron-limited cultures had a lower abundance of key tricarboxylic acid (TCA) cycle enzymes and higher abundance of key glycolysis enzymes compared with glucose-limited cultures. The overall results are largely consistent with cellular economics concepts, including metabolic tradeoff theory where the limiting nutrient is invested into essential pathways such as glycolysis instead of higher ATP-yielding, but non-essential, pathways such as the TCA cycle. The data provide a detailed insight into ecologically competitive metabolic strategies selected by evolution, templates for controlling metabolism for bioprocesses and a comprehensive dataset for validating in silico representations of metabolism. PMID:26018546

  5. A new generic plant growth model framework (PMF): Simulating distributed dynamic interaction of biomass production and its interaction with water and nutrients fluxes

    NASA Astrophysics Data System (ADS)

    Multsch, Sebastian; Kraft, Philipp; Frede, Hans-Georg; Breuer, Lutz

    2010-05-01

    about changing boundary conditions. The crop model concept refers to two main elements. A plant model, which represents an abstract network of plant organs and processes and a process library, which holds mathematical solutions for the growth processes. Growth processes were mainly taken from existing, well known crop models such as SUCROS and CERES. The crop specific properties of root architecture are described based on a maximum rooting depth and a vertical growth rate. The biomass distribution depends on an interactive allocation process due to the soil layers with a daily time step. In order to show the performance and capabilities of PMF, the model is coupled with the Catchment Modeling Framework (CMF) and the simple nitrogen mineralization model DeComp. The main feature of the integrated model set up is the interaction between root growth, water uptake and nitrogen supply of the soil. We show a virtual case study on the hillslope scale and spatially dependence of water and nitrogen stress based on topographic position and seasonal development.

  6. Modeling temperature responses of leaf growth, development, and biomass in maize with MAIZSIM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changing climate, growing costs of agricultural inputs, and social and environmental demands are challenges facing agriculture in the 21st century. There is a need for decision support and assessment tools including crop simulation models for estimation of yield and biomass, and management of nutrie...

  7. Intercropping of two Leucaena spp. with sweet potato: yield, growth rate and biomass

    SciTech Connect

    Swift, J.F.

    1982-01-01

    Results of trials with Leucaena leucocephala and Leucaena diversifolia at Wau, Papua New Guinea, showed potential benefits of the agroforestry cropping system. The total biomass yield (sweet potato plus firewood and green manure) was considerably greater than the yield per unit area of sweet potato alone. 3 references.

  8. Predicting tree biomass growth in the temperate-boreal ecotone: Is tree size, age, competition, or climate response most important?

    PubMed

    Foster, Jane R; Finley, Andrew O; D'Amato, Anthony W; Bradford, John B; Banerjee, Sudipto

    2016-06-01

    As global temperatures rise, variation in annual climate is also changing, with unknown consequences for forest biomes. Growing forests have the ability to capture atmospheric CO2 and thereby slow rising CO2 concentrations. Forests' ongoing ability to sequester C depends on how tree communities respond to changes in climate variation. Much of what we know about tree and forest response to climate variation comes from tree-ring records. Yet typical tree-ring datasets and models do not capture the diversity of climate responses that exist within and among trees and species. We address this issue using a model that estimates individual tree response to climate variables while accounting for variation in individuals' size, age, competitive status, and spatially structured latent covariates. Our model allows for inference about variance within and among species. We quantify how variables influence aboveground biomass growth of individual trees from a representative sample of 15 northern or southern tree species growing in a transition zone between boreal and temperate biomes. Individual trees varied in their growth response to fluctuating mean annual temperature and summer moisture stress. The variation among individuals within a species was wider than mean differences among species. The effects of mean temperature and summer moisture stress interacted, such that warm years produced positive responses to summer moisture availability and cool years produced negative responses. As climate models project significant increases in annual temperatures, growth of species like Acer saccharum, Quercus rubra, and Picea glauca will vary more in response to summer moisture stress than in the past. The magnitude of biomass growth variation in response to annual climate was 92-95% smaller than responses to tree size and age. This means that measuring or predicting the physical structure of current and future forests could tell us more about future C dynamics than growth responses

  9. Effects of Artificial Defoliation on Growth and Biomass Accumulation in Short-Rotation Sweetgum (Liquidambar styraciflua) in North Carolina

    PubMed Central

    Jetton, Robert M.; Robison, Daniel J.

    2014-01-01

    Sweetgum, Liquidambar styraciflua L. (Hamamelidales: Hamamelidaceae), is a species of interest for short-rotation plantation forestry in the southeastern United States. Despite its high levels of resistance to many native insects and pathogens, the species is susceptible to generalist defoliators during outbreak epidemics. The objective of this field study was to evaluate the potential impact of defoliation on sweetgum growth and productivity within the context of an operational plantation. Over three growing seasons, trees were subjected to artificial defoliation treatments of various intensity (control = 0% defoliation; low intensity = 33% defoliation; moderate intensity = 67% defoliation; high intensity = 99% defoliation) and frequency (not defoliated; defoliated once in April of the first growing season; defoliated twice, once in April of the first growing season and again in April of the second growing season). The responses of stem height, stem diameter, stem volume, crown volume, total biomass accumulation, and branch growth were measured in November of each growing season. At the end of the first growing season, when trees had received single defoliations, significant reductions in all growth traits followed the most severe (99%) defoliation treatment only. After the second and third growing seasons, when trees had received one or two defoliations of varying intensity, stem diameter and volume and total tree biomass were reduced significantly by 67 and 99% defoliation, while reductions in stem height and crown volume followed the 99% treatment only. All growth traits other than crown volume were reduced significantly by two defoliations but not one defoliation. Results indicate that sweetgum is highly resilient to single defoliations of low, moderate, and high intensity. However, during the three-year period of the study, repeated high-intensity defoliation caused significant reductions in growth and productivity that could have lasting impacts on yield

  10. Effects of artificial defoliation on growth and biomass accumulation in short-rotation sweetgum (Liquidambar styraciflua) in North Carolina.

    PubMed

    Jetton, Robert M; Robison, Daniel J

    2014-01-01

    Sweetgum, Liquidambar styraciflua L. (Hamamelidales: Hamamelidaceae), is a species of interest for short-rotation plantation forestry in the southeastern United States. Despite its high levels of resistance to many native insects and pathogens, the species is susceptible to generalist defoliators during outbreak epidemics. The objective of this field study was to evaluate the potential impact of defoliation on sweetgum growth and productivity within the context of an operational plantation. Over three growing seasons, trees were subjected to artificial defoliation treatments of various intensity (control = 0% defoliation; low intensity = 33% defoliation; moderate intensity = 67% defoliation; high intensity = 99% defoliation) and frequency (not defoliated; defoliated once in April of the first growing season; defoliated twice, once in April of the first growing season and again in April of the second growing season). The responses of stem height, stem diameter, stem volume, crown volume, total biomass accumulation, and branch growth were measured in November of each growing season. At the end of the first growing season, when trees had received single defoliations, significant reductions in all growth traits followed the most severe (99%) defoliation treatment only. After the second and third growing seasons, when trees had received one or two defoliations of varying intensity, stem diameter and volume and total tree biomass were reduced significantly by 67 and 99% defoliation, while reductions in stem height and crown volume followed the 99% treatment only. All growth traits other than crown volume were reduced significantly by two defoliations but not one defoliation. Results indicate that sweetgum is highly resilient to single defoliations of low, moderate, and high intensity. However, during the three-year period of the study, repeated high-intensity defoliation caused significant reductions in growth and productivity that could have lasting impacts on yield

  11. Predicting tree biomass growth in the temperate-boreal ecotone: is tree size, age, competition or climate response most important?

    USGS Publications Warehouse

    Foster, Jane R.; Finley, Andrew O.; D'Amato, Anthony W.; Bradford, John B.; Banerjee, Sudipto

    2016-01-01

    As global temperatures rise, variation in annual climate is also changing, with unknown consequences for forest biomes. Growing forests have the ability to capture atmospheric CO2and thereby slow rising CO2 concentrations. Forests’ ongoing ability to sequester C depends on how tree communities respond to changes in climate variation. Much of what we know about tree and forest response to climate variation comes from tree-ring records. Yet typical tree-ring datasets and models do not capture the diversity of climate responses that exist within and among trees and species. We address this issue using a model that estimates individual tree response to climate variables while accounting for variation in individuals’ size, age, competitive status, and spatially structured latent covariates. Our model allows for inference about variance within and among species. We quantify how variables influence aboveground biomass growth of individual trees from a representative sample of 15 northern or southern tree species growing in a transition zone between boreal and temperate biomes. Individual trees varied in their growth response to fluctuating mean annual temperature and summer moisture stress. The variation among individuals within a species was wider than mean differences among species. The effects of mean temperature and summer moisture stress interacted, such that warm years produced positive responses to summer moisture availability and cool years produced negative responses. As climate models project significant increases in annual temperatures, growth of species likeAcer saccharum, Quercus rubra, and Picea glauca will vary more in response to summer moisture stress than in the past. The magnitude of biomass growth variation in response to annual climate was 92–95% smaller than responses to tree size and age. This means that measuring or predicting the physical structure of current and future forests could tell us more about future C dynamics than growth

  12. Forest biomass carbon sinks in East Asia, with special reference to the relative contributions of forest expansion and forest growth.

    PubMed

    Fang, Jingyun; Guo, Zhaodi; Hu, Huifeng; Kato, Tomomichi; Muraoka, Hiroyuki; Son, Yowhan

    2014-06-01

    Forests play an important role in regional and global carbon (C) cycles. With extensive afforestation and reforestation efforts over the last several decades, forests in East Asia have largely expanded, but the dynamics of their C stocks have not been fully assessed. We estimated biomass C stocks of the forests in all five East Asian countries (China, Japan, North Korea, South Korea, and Mongolia) between the 1970s and the 2000s, using the biomass expansion factor method and forest inventory data. Forest area and biomass C density in the whole region increased from 179.78 × 10(6) ha and 38.6 Mg C ha(-1) in the 1970s to 196.65 × 10(6) ha and 45.5 Mg C ha(-1) in the 2000s, respectively. The C stock increased from 6.9 Pg C to 8.9 Pg C, with an averaged sequestration rate of 66.9 Tg C yr(-1). Among the five countries, China and Japan were two major contributors to the total region's forest C sink, with respective contributions of 71.1% and 32.9%. In China, the areal expansion of forest land was a larger contributor to C sinks than increased biomass density for all forests (60.0% vs. 40.0%) and for planted forests (58.1% vs. 41.9%), while the latter contributed more than the former for natural forests (87.0% vs. 13.0%). In Japan, increased biomass density dominated the C sink for all (101.5%), planted (91.1%), and natural (123.8%) forests. Forests in South Korea also acted as a C sink, contributing 9.4% of the total region's sink because of increased forest growth (98.6%). Compared to these countries, the reduction in forest land in both North Korea and Mongolia caused a C loss at an average rate of 9.0 Tg C yr(-1), equal to 13.4% of the total region's C sink. Over the last four decades, the biomass C sequestration by East Asia's forests offset 5.8% of its contemporary fossil-fuel CO2 emissions.

  13. Comparative Secretome Analysis of Trichoderma reesei and Aspergillus niger during Growth on Sugarcane Biomass

    PubMed Central

    Borin, Gustavo Pagotto; Sanchez, Camila Cristina; de Souza, Amanda Pereira; de Santana, Eliane Silva; de Souza, Aline Tieppo; Leme, Adriana Franco Paes; Squina, Fabio Marcio; Buckeridge, Marcos; Goldman, Gustavo Henrique; Oliveira, Juliana Velasco de Castro

    2015-01-01

    Background Our dependence on fossil fuel sources and concern about the environment has generated a worldwide interest in establishing new sources of fuel and energy. Thus, the use of ethanol as a fuel is advantageous because it is an inexhaustible energy source and has minimal environmental impact. Currently, Brazil is the world's second largest producer of ethanol, which is produced from sugarcane juice fermentation. However, several studies suggest that Brazil could double its production per hectare by using sugarcane bagasse and straw, known as second-generation (2G) bioethanol. Nevertheless, the use of this biomass presents a challenge because the plant cell wall structure, which is composed of complex sugars (cellulose and hemicelluloses), must be broken down into fermentable sugar, such as glucose and xylose. To achieve this goal, several types of hydrolytic enzymes are necessary, and these enzymes represent the majority of the cost associated with 2G bioethanol processing. Reducing the cost of the saccharification process can be achieved via a comprehensive understanding of the hydrolytic mechanisms and enzyme secretion of polysaccharide-hydrolyzing microorganisms. In many natural habitats, several microorganisms degrade lignocellulosic biomass through a set of enzymes that act synergistically. In this study, two fungal species, Aspergillus niger and Trichoderma reesei, were grown on sugarcane biomass with two levels of cell wall complexity, culm in natura and pretreated bagasse. The production of enzymes related to biomass degradation was monitored using secretome analyses after 6, 12 and 24 hours. Concurrently, we analyzed the sugars in the supernatant. Results Analyzing the concentration of monosaccharides in the supernatant, we observed that both species are able to disassemble the polysaccharides of sugarcane cell walls since 6 hours post-inoculation. The sugars from the polysaccharides such as arabinoxylan and β-glucan (that compose the most external

  14. SuMoToRI, an Ecophysiological Model to Predict Growth and Sulfur Allocation and Partitioning in Oilseed Rape (Brassica napus L.) Until the Onset of Pod Formation.

    PubMed

    Brunel-Muguet, Sophie; Mollier, Alain; Kauffmann, François; Avice, Jean-Christophe; Goudier, Damien; Sénécal, Emmanuelle; Etienne, Philippe

    2015-01-01

    Sulfur (S) nutrition in rapeseed (Brassica napus L.) is a major concern for this high S-demanding crop, especially in the context of soil S oligotrophy. Therefore, predicting plant growth, S plant allocation (between the plant's compartments) and S pool partitioning (repartition of the mobile-S vs. non-mobile-S fractions) until the onset of reproductive phase could help in the diagnosis of S deficiencies during the early stages. For this purpose, a process-based model, SuMoToRI (Sulfur Model Toward Rapeseed Improvement), was developed up to the onset of pod formation. The key features rely on (i) the determination of the S requirements used for growth (structural and metabolic functions) through critical S dilution curves and (ii) the estimation of a mobile pool of S that is regenerated by daily S uptake and remobilization from senescing leaves. This study describes the functioning of the model and presents the model's calibration and evaluation. SuMoToRI was calibrated and evaluated with independent datasets from greenhouse experiments under contrasting S supply conditions. It is run with a small number of parameters with generic values, except in the case of the radiation use efficiency, which was shown to be modulated by S supply. The model gave satisfying predictions of the dynamics of growth, S allocation between compartments and S partitioning, such as the mobile-S fraction in the leaves, which is an indicator of the remobilization potential toward growing sinks. The mechanistic features of SuMoToRI provide a process-based framework that has enabled the description of the S remobilizing process in a species characterized by senescence during the vegetative phase. We believe that this model structure could be useful for modeling S dynamics in other arable crops that have similar senescence-related characteristics. PMID:26635825

  15. SuMoToRI, an Ecophysiological Model to Predict Growth and Sulfur Allocation and Partitioning in Oilseed Rape (Brassica napus L.) Until the Onset of Pod Formation

    PubMed Central

    Brunel-Muguet, Sophie; Mollier, Alain; Kauffmann, François; Avice, Jean-Christophe; Goudier, Damien; Sénécal, Emmanuelle; Etienne, Philippe

    2015-01-01

    Sulfur (S) nutrition in rapeseed (Brassica napus L.) is a major concern for this high S-demanding crop, especially in the context of soil S oligotrophy. Therefore, predicting plant growth, S plant allocation (between the plant’s compartments) and S pool partitioning (repartition of the mobile-S vs. non-mobile-S fractions) until the onset of reproductive phase could help in the diagnosis of S deficiencies during the early stages. For this purpose, a process-based model, SuMoToRI (Sulfur Model Toward Rapeseed Improvement), was developed up to the onset of pod formation. The key features rely on (i) the determination of the S requirements used for growth (structural and metabolic functions) through critical S dilution curves and (ii) the estimation of a mobile pool of S that is regenerated by daily S uptake and remobilization from senescing leaves. This study describes the functioning of the model and presents the model’s calibration and evaluation. SuMoToRI was calibrated and evaluated with independent datasets from greenhouse experiments under contrasting S supply conditions. It is run with a small number of parameters with generic values, except in the case of the radiation use efficiency, which was shown to be modulated by S supply. The model gave satisfying predictions of the dynamics of growth, S allocation between compartments and S partitioning, such as the mobile-S fraction in the leaves, which is an indicator of the remobilization potential toward growing sinks. The mechanistic features of SuMoToRI provide a process-based framework that has enabled the description of the S remobilizing process in a species characterized by senescence during the vegetative phase. We believe that this model structure could be useful for modeling S dynamics in other arable crops that have similar senescence-related characteristics. PMID:26635825

  16. Screening and kinetic studies of catharanthine and ajmalicine accumulation and their correlation with growth biomass in Catharanthus roseus hairy roots.

    PubMed

    Benyammi, Roukia; Paris, Cédric; Khelifi-Slaoui, Majda; Zaoui, Djamila; Belabbassi, Ouarda; Bakiri, Nouara; Meriem Aci, Myassa; Harfi, Boualem; Malik, Sonia; Makhzoum, Abdullah; Desobry, Stéphane; Khelifi, Lakhdar

    2016-10-01

    Context Catharanthus roseus (L.) G. Don (Apocynaceae) is still one of the most important sources of terpene indole alkaloids including anticancer and hypertensive drugs as vincristine and vinblastine. These final compounds have complex pathway and many enzymes are involved in their biosynthesis. Indeed, ajmalicine and catharanthine are important precursors their increase can lead to enhance levels of molecules of interest. Objective This study aims at selecting the highest yield of hairy root line(s) and at identifying best times for further treatments. We study kinetics growth and alkaloids (ajmalicine and catharanthine) accumulation of three selected hairy root lines during the culture cycle in order to determine the relationship between biomass production and alkaloids accumulation. Materials and methods Comparative analysis has been carried out on three selected lines of Catharanthus roseus hairy roots (LP10, LP21 and L54) for their kinetics of growth and the accumulation of ajamalicine and catharanthine, throughout a 35-day culture cycle. The methanolic extract for each line in different times during culture cycle is analyzed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Results Maximum accumulation of the alkaloids is recorded for LP10 line in which the peak of ajmalicine and catharanthine accumulation reached to 3.8 and 4.3 mg/g dry weight (DW), respectively. This increase coincides with an exponential growth phase. Discussion and conclusion Our results suggest that the evolution of accumulation of ajmalicine and catharanthine are positively correlated with the development of the biomass growth. Significantly, for LP10 line the most promising line to continue optimizing the production of TIAs. Additionally, the end of exponential phase remains the best period for elicitor stimuli. PMID:26983347

  17. Xylose Isomerase Improves Growth and Ethanol Production Rates from Biomass Sugars for Both Saccharomyces Pastorianus and Saccharomyces Cerevisiae

    PubMed Central

    Miller, Kristen P.; Gowtham, Yogender Kumar; Henson, J. Michael; Harcum, Sarah W.

    2013-01-01

    The demand for biofuel ethanol made from clean, renewable nonfood sources is growing. Cellulosic biomass, such as switch grass (Panicum virgatum L.), is an alternative feedstock for ethanol production; however, cellulosic feedstock hydrolysates contain high levels of xylose, which needs to be converted to ethanol to meet economic feasibility. In this study, the effects of xylose isomerase on cell growth and ethanol production from biomass sugars representative of switch grass were investigated using low cell density cultures. The lager yeast species Saccharomyces pastorianus was grown with immobilized xylose isomerase in the fermentation step to determine the impact of the glucose and xylose concentrations on the ethanol production rates. Ethanol production rates were improved due to xylose isomerase; however, the positive effect was not due solely to the conversion of xylose to xylulose. Xylose isomerase also has glucose isomerase activity, so to better understand the impact of the xylose isomerase on S. pastorianus, growth and ethanol production were examined in cultures provided fructose as the sole carbon. It was observed that growth and ethanol production rates were higher for the fructose cultures with xylose isomerase even in the absence of xylose. To determine whether the positive effects of xylose isomerase extended to other yeast species, a side-by-side comparison of S. pastorianus and Saccharomyces cerevisiae was conducted. These comparisons demonstrated that the xylose isomerase increased ethanol productivity for both the yeast species by increasing the glucose consumption rate. These results suggest that xylose isomerase can contribute to improved ethanol productivity, even without significant xylose conversion. PMID:22866331

  18. Salinity Reduction and Biomass Accumulation in Hydroponic Growth of Purslane (Portulaca oleracea).

    PubMed

    de Lacerda, Laís Pessôa; Lange, Liséte Celina; Costa França, Marcel Giovanni; Zonta, Everaldo

    2015-01-01

    In many of the world's semi-arid and arid regions, the increase in demand for good quality water associated with the gradual and irreversible salinisation of the soil and water have raised the development of techniques that facilitate the safe use of brackish and saline waters for agronomic purposes. This study aimed to evaluate the salinity reduction of experimental saline solutions through the ions uptake capability of purslane (Portulaca oleracea), as well as its biomass accumulation. The hydroponic system used contained three different nutrient solutions composed of fixed concentrations of macro and micronutrients to which three different concentrations of sodium chloride had been added. Two conditions were tested, clipped and intact plants. It was observed that despite there being a notable removal of magnesium and elevated biomass accumulation, especially in the intact plants, purslane did not present the expected removal quantity of sodium and chloride. We confirmed that in the research conditions of the present study, purslane is a saline-tolerant species but accumulation of sodium and chloride was not shown as previously described in the literature.

  19. Salinity Reduction and Biomass Accumulation in Hydroponic Growth of Purslane (Portulaca oleracea).

    PubMed

    de Lacerda, Laís Pessôa; Lange, Liséte Celina; Costa França, Marcel Giovanni; Zonta, Everaldo

    2015-01-01

    In many of the world's semi-arid and arid regions, the increase in demand for good quality water associated with the gradual and irreversible salinisation of the soil and water have raised the development of techniques that facilitate the safe use of brackish and saline waters for agronomic purposes. This study aimed to evaluate the salinity reduction of experimental saline solutions through the ions uptake capability of purslane (Portulaca oleracea), as well as its biomass accumulation. The hydroponic system used contained three different nutrient solutions composed of fixed concentrations of macro and micronutrients to which three different concentrations of sodium chloride had been added. Two conditions were tested, clipped and intact plants. It was observed that despite there being a notable removal of magnesium and elevated biomass accumulation, especially in the intact plants, purslane did not present the expected removal quantity of sodium and chloride. We confirmed that in the research conditions of the present study, purslane is a saline-tolerant species but accumulation of sodium and chloride was not shown as previously described in the literature. PMID:25397981

  20. Modelling C allocation in response to nutrient availability

    NASA Astrophysics Data System (ADS)

    Stocker, Benjamin; Prentice, Colin

    2015-04-01

    Carbon (C) allocation in ecosystems is a key variable of the global terrestrial C cycle. While photosynthesis governs the amount of C that enters ecosystems, its subsequent allocation to compartments with different life times determines its over-all residence time and variations in allocation patterns drive changes in ecosystem C balance and its response to environmental change. A better understanding of the controls on allocation is thus key to improving global vegetation models that commonly rely on using fixed partitioning factors. Observational data suggests variations of ecosystem structure and functioning along large-scale gradients of resource availability. Below-ground C allocation, inferred as gross primary production minus above-ground biomass production increases along gradients of decreasing nutrient availability. This is not only due to more root growth, but also due to enhanced production of exudates and stimulation of root symbionts and has been interpreted to reflect optimal plant allocation decisions under a varying soil fertility status. Here, we propose a model that accounts for trade-offs between (i) growth in above-ground and (ii) below-ground plant compartments, (iii) exudation to the rhizosphere and root symbionts and (iv) temporary storage in non-structural pools. By postulating the maximization of long-term growth under a given (seasonal regime) of soil nitrogen (N) availability, we attempt to reproduce observed large-scale gradients. The model is formulated based on a C cost for different N uptake decisions, where the cost is a function of N availability, root mass, and soil temperature (for biological N fixation). On a daily time scale, ecosystem N uptake may be realized by C exudation to the rhizosphere and/or symbiotic fixation of atmospheric N2. On an annual time scale, allocation to roots versus leaves is adjusted to soil inorganic N availability and modeled to yield maximum total growth. Exudation versus temporary storage of C is

  1. Difference in C3–C4 metabolism underlies tradeoff between growth rate and biomass yield in Methylobacterium extorquens AM1

    DOE PAGES

    Fu, Yanfen; Beck, David A. C.; Lidstrom, Mary E.

    2016-07-19

    In this study, two variants of Methylobacterium extorquens AM1 demonstrated a trade-off between growth rate and biomass yield. In addition, growth rate and biomass yield were also affected by supplementation of growth medium with different amounts of cobalt. The metabolism changes relating to these growth phenomena as well as the trade-off were investigated in this study. 13C metabolic flux analysis was used to generate a detailed central carbon metabolic flux map with both absolute and normalized flux values. As a result, the major differences between the two variants occurred at the formate node as well as within C3-C4 inter-conversion pathways.more » Higher relative fluxes through formyltetrahydrofolate ligase, phosphoenolpyruvate carboxylase, and malic enzyme led to higher biomass yield, while higher relative fluxes through pyruvate kinase and pyruvate dehydrogenase led to higher growth rate. These results were then tested by phenotypic studies on three mutants (null pyk, null pck mutant and null dme mutant) in both variants, which agreed with the model prediction. In this study, 13C metabolic flux analysis for two strain variants of M. extorquens AM1 successfully identified metabolic pathways contributing to the trade-off between cell growth and biomass yield. Phenotypic analysis of mutants deficient in corresponding genes supported the conclusion that C3-C4 inter-conversion strategies were the major response to the trade-off.« less

  2. Assessing the fate of nutrients and carbon in the bioenergy chain through the modeling of biomass growth and conversion.

    PubMed

    François, Jessica; Fortin, Mathieu; Patisson, Fabrice; Dufour, Anthony

    2014-12-01

    A forest growth model was coupled to a model of combined heat and power (CHP) production in a gasification plant developed in Aspen Plus. For a given production, this integrated forest-to-energy model made it possible to predict the annual flows in wood biomass, carbon, and nutrients, including N, S, P, and K, from the forest to the air emissions (NOx, SOx, PAH, etc.) and ash flows. We simulated the bioenergy potential of pure even-aged high-forest stands of European beech, an abundant forest type in Northeastern France. Two forest management practices were studied, a standard-rotation and a shorter-rotation scenario, along with two wood utilizations: with or without fine woody debris (FWD) harvesting. FWD harvesting tended to reduce the forested area required to supply the CHP by 15–22% since larger amounts of energy wood were available for the CHP process, especially in the short-rotation scenario. Because less biomass was harvested, the short-rotation scenario with FWD decreased the nutrient exports per hectare and year by 4–21% compared to standard practices but increased the amount of N, S, and P in the CHP process by 2–9%. This increase in the input nutrient flows had direct consequences on the inorganic air emissions, thus leading to additional NOx and SO2 emissions. This model is a valuable tool for assessing the life cycle inventories of the entire bioenergy chain.

  3. Anaerobic digestion of waste biomass from the production of L-cystine in suspended-growth bioreactors.

    PubMed

    Chávez-Fuentes, Juan José; Hutňan, Miroslav; Bodík, Igor; Zakhar, Ronald; Czölderová, Marianna

    2015-01-01

    Waste biomass from the industrial production of the amino acid L-cystine contains above-average concentrations of organic pollutants and significant concentrations of nitrogen and sulfur. The specific biogas production (SBP) of waste biomass was monitored in parallel suspended-growth laboratory anaerobic bioreactors. After severe inhibition was observed, three different procedures were applied to inhibited reactor sludge to counter-attack the inhibitory effects of sulfides, respectively hydrogen sulfide: micro-aeration, dilution with water and precipitation by ferrous iron cations. The performance of bioreactors was weekly monitored. Organic loading rates (as chemical oxygen demand, COD) ranged from 1.07 to 1.97 g L(-1) d(-1). At the end of the experimentation, SBP averaged 217, 300 and 320 l kg(-1) COD with a methane content of 21%, 52% and 54%; specific sludge production averaged 133, 111 and 400 g total solids kg(-1) COD, and inhibition was 49%, 27% and 25%; for the applied procedures of micro-aeration, dilution and precipitation respectively.

  4. Assessing the fate of nutrients and carbon in the bioenergy chain through the modeling of biomass growth and conversion.

    PubMed

    François, Jessica; Fortin, Mathieu; Patisson, Fabrice; Dufour, Anthony

    2014-12-01

    A forest growth model was coupled to a model of combined heat and power (CHP) production in a gasification plant developed in Aspen Plus. For a given production, this integrated forest-to-energy model made it possible to predict the annual flows in wood biomass, carbon, and nutrients, including N, S, P, and K, from the forest to the air emissions (NOx, SOx, PAH, etc.) and ash flows. We simulated the bioenergy potential of pure even-aged high-forest stands of European beech, an abundant forest type in Northeastern France. Two forest management practices were studied, a standard-rotation and a shorter-rotation scenario, along with two wood utilizations: with or without fine woody debris (FWD) harvesting. FWD harvesting tended to reduce the forested area required to supply the CHP by 15–22% since larger amounts of energy wood were available for the CHP process, especially in the short-rotation scenario. Because less biomass was harvested, the short-rotation scenario with FWD decreased the nutrient exports per hectare and year by 4–21% compared to standard practices but increased the amount of N, S, and P in the CHP process by 2–9%. This increase in the input nutrient flows had direct consequences on the inorganic air emissions, thus leading to additional NOx and SO2 emissions. This model is a valuable tool for assessing the life cycle inventories of the entire bioenergy chain. PMID:25372499

  5. Anaerobic digestion of waste biomass from the production of L-cystine in suspended-growth bioreactors.

    PubMed

    Chávez-Fuentes, Juan José; Hutňan, Miroslav; Bodík, Igor; Zakhar, Ronald; Czölderová, Marianna

    2015-01-01

    Waste biomass from the industrial production of the amino acid L-cystine contains above-average concentrations of organic pollutants and significant concentrations of nitrogen and sulfur. The specific biogas production (SBP) of waste biomass was monitored in parallel suspended-growth laboratory anaerobic bioreactors. After severe inhibition was observed, three different procedures were applied to inhibited reactor sludge to counter-attack the inhibitory effects of sulfides, respectively hydrogen sulfide: micro-aeration, dilution with water and precipitation by ferrous iron cations. The performance of bioreactors was weekly monitored. Organic loading rates (as chemical oxygen demand, COD) ranged from 1.07 to 1.97 g L(-1) d(-1). At the end of the experimentation, SBP averaged 217, 300 and 320 l kg(-1) COD with a methane content of 21%, 52% and 54%; specific sludge production averaged 133, 111 and 400 g total solids kg(-1) COD, and inhibition was 49%, 27% and 25%; for the applied procedures of micro-aeration, dilution and precipitation respectively. PMID:26247757

  6. Influence of specific growth rate on biomass yield, productivity, and compostion of Candida utilis in batch and continuous culture.

    PubMed Central

    Paredes-López, O; Camargo-Rubio, E; Ornelas-Vale, A

    1976-01-01

    Candida utilis was grown in batch and continuous culture on prickly pear juice as sole carbon and energy source. In batch culture the maximum specific growth rate (mum) and the substrate yield coefficient (Yps) varied according to sugar concentration. When the fermentation was carried out with 1% sugar, mum and Ys were 0.47/h and 42.6%, respectively. The best yields occurred in a chemostat at the pH range of 3.5 to 4.5 and temperature of 30 C. A beneficial effect on Ys was observed when the dilution rate (D) was increased. At a D of 0.55/h, the productivity was 2.38 g/liter per h. The maintenance coefficient attained a value of 0.09 g of sugar/g of biomass per h. Increases of D produced higher protein contents of the biomass. The information obtained indicates that protein production with Candida utilis, using prickly pear juice, should be carried out a high dilution rates where the Ys and protein content of the cell mass are also higher. PMID:5055

  7. Influence of specific growth rate on biomass yield, productivity, and compostion of Candida utilis in batch and continuous culture.

    PubMed

    Paredes-López, O; Camargo-Rubio, E; Ornelas-Vale, A

    1976-04-01

    Candida utilis was grown in batch and continuous culture on prickly pear juice as sole carbon and energy source. In batch culture the maximum specific growth rate (mum) and the substrate yield coefficient (Yps) varied according to sugar concentration. When the fermentation was carried out with 1% sugar, mum and Ys were 0.47/h and 42.6%, respectively. The best yields occurred in a chemostat at the pH range of 3.5 to 4.5 and temperature of 30 C. A beneficial effect on Ys was observed when the dilution rate (D) was increased. At a D of 0.55/h, the productivity was 2.38 g/liter per h. The maintenance coefficient attained a value of 0.09 g of sugar/g of biomass per h. Increases of D produced higher protein contents of the biomass. The information obtained indicates that protein production with Candida utilis, using prickly pear juice, should be carried out a high dilution rates where the Ys and protein content of the cell mass are also higher.

  8. Cytokinin-dependent secondary growth determines root biomass in radish (Raphanus sativus L.).

    PubMed

    Jang, Geupil; Lee, Jung-Hun; Rastogi, Khushboo; Park, Suhyoung; Oh, Sang-Hun; Lee, Ji-Young

    2015-08-01

    The root serves as an essential organ in plant growth by taking up nutrients and water from the soil and supporting the rest of the plant body. Some plant species utilize roots as storage organs. Sweet potatoes (Ipomoea batatas), cassava (Manihot esculenta), and radish (Raphanus sativus), for example, are important root crops. However, how their root growth is regulated remains unknown. In this study, we characterized the relationship between cambium and radial root growth in radish. Through a comparative analysis with Arabidopsis root expression data, we identified putative cambium-enriched transcription factors in radish and analysed their expression in representative inbred lines featuring distinctive radial growth. We found that cell proliferation activities in the cambium positively correlated with radial growth and final yields of radish roots. Expression analysis of candidate transcription factor genes revealed that some genes are differentially expressed between inbred lines and that the difference is due to the distinct cytokinin response. Taken together, we have demonstrated for the first time, to the best of our knowledge, that cytokinin-dependent radial growth plays a key role in the yields of root crops. PMID:25979997

  9. Cytokinin-dependent secondary growth determines root biomass in radish (Raphanus sativus L.).

    PubMed

    Jang, Geupil; Lee, Jung-Hun; Rastogi, Khushboo; Park, Suhyoung; Oh, Sang-Hun; Lee, Ji-Young

    2015-08-01

    The root serves as an essential organ in plant growth by taking up nutrients and water from the soil and supporting the rest of the plant body. Some plant species utilize roots as storage organs. Sweet potatoes (Ipomoea batatas), cassava (Manihot esculenta), and radish (Raphanus sativus), for example, are important root crops. However, how their root growth is regulated remains unknown. In this study, we characterized the relationship between cambium and radial root growth in radish. Through a comparative analysis with Arabidopsis root expression data, we identified putative cambium-enriched transcription factors in radish and analysed their expression in representative inbred lines featuring distinctive radial growth. We found that cell proliferation activities in the cambium positively correlated with radial growth and final yields of radish roots. Expression analysis of candidate transcription factor genes revealed that some genes are differentially expressed between inbred lines and that the difference is due to the distinct cytokinin response. Taken together, we have demonstrated for the first time, to the best of our knowledge, that cytokinin-dependent radial growth plays a key role in the yields of root crops.

  10. Dynamics of biomass composition and growth during recovery of nitrogen-starved Chromochloris zofingiensis.

    PubMed

    Mulders, Kim J M; Lamers, Packo P; Wijffels, René H; Martens, Dirk E

    2015-02-01

    The effect of nitrogen replenishment on the kinetics of secondary carotenoids, triacylglycerol (TAG) and primary cell components was studied in nitrogen-starved Chromochloris zofingiensis (Chlorophyta), an oleaginous and carotenogenic microalga. Nitrogen resupplied after a period of starvation was initially consumed at a more than four times higher rate than in an equivalent nitrogen-replete culture. Simultaneously, chlorophylls, primary carotenoids, polar (membrane) lipids and proteins were rapidly produced. After 2 days, the contents of these primary metabolites, as well as the nitrogen consumption rate and the overall biomass production rate, had returned to values equivalent to those of cells grown under nitrogen-replete conditions, indicating that culture recovery required 2 days. Nitrogen resupply was immediately followed by rapid degradation of TAG and starch, suggesting that these metabolites served as carbon and energy source for the recovery process. Also, the secondary carotenoids canthaxanthin and ketolutein were rapidly degraded upon nitrogen resupply, whereas degradation of astaxanthin, the main secondary carotenoid, started only when the cells were fully recovered 2 days after nitrogen resupply. This is the first time that such culture recovery has been described in detail and, moreover, that astaxanthin was found to be not immediately degraded after nitrogen resupply. The observed rapid recovery of C. zofingiensis and the delay in astaxanthin degradation suggest that a repeated batch cultivation may result in a higher secondary carotenoid productivity than a series of classical single batch cultivations.

  11. Substudies on Allocation and Targeting of Funds and Services, Assessment of Student Growth, and Effects of Attrition. Technical Report #13 from the Study of the Sustaining Effects of Compensatory Education on Basic Skills.

    ERIC Educational Resources Information Center

    Hoepfner, Ralph, Ed.

    This study of Compensatory Education is divided into four parts: allocation of Title I funds and services, achievement and Compensatory Education, measurement of student growth, and the effects of attrition. Part one examines poverty concentrations to determine which schools and districts are eligible for Title I or for concentration grants. The…

  12. Impact of mine waste dumps on growth and biomass of economically important crops.

    PubMed

    Mathiyazhagan, Narayanan; Natarajan, Devarajan

    2012-11-01

    The present study aimed to investigate the effect of magnesite and bauxite waste dumps on growth and biochemical parameters of some edible and economically important plants such as Vigna radiata, V. mungo, V. unguiculata, Eleusine coracana, Cajanus cajan, Pennisetum glaucum, Macrotyloma uniflorum, Oryza sativa, Sorghum bicolour, Sesamum indicum, Ricinus communis, Brassica juncea, Gossypium hirsutum and Jatropha curcas. The growth rate of all the crops was observed in the range of 75 to 100% in magnesite and 15 to 100% in bauxite mine soil. The moisture content of roots and shoots of all the crops were in the range of 24 to 77, 20 to 88% and 42 to 87, 59 to 88% respectively. The height of the crops was in the range of 2.6 to 48 cm in magnesite soil and 3 to 33 cm in bauxite soil. Thus the study shows that both mine soils reflects some physical and biomolecule impact on selected crops. PMID:23741803

  13. Influence of mechanical disintegration on the microbial growth of aerobic sludge biomass: A comparative study of ultrasonic and shear gap homogenizers by oxygen uptake measurements.

    PubMed

    Divyalakshmi, P; Murugan, D; Sivarajan, M; Saravanan, P; Lajapathi Rai, C

    2015-11-01

    Wastewater treatment plant incorporates physical, chemical and biological processes to treat and remove the contaminants. The main drawback of conventional activated sludge process is the huge production of excess sludge, which is an unavoidable byproduct. The treatment and disposal of excess sludge costs about 60% of the total operating cost. The ideal way to reduce excess sludge production during wastewater treatment is by preventing biomass formation within the aerobic treatment train rather than post treatment of the generated sludge. In the present investigation two different mechanical devices namely, Ultrasonic and Shear Gap homogenizers have been employed to disintegrate the aerobic biomass. This study is intended to restrict the multiplication of microbial biomass and at the same time degrade the organics present in wastewater by increasing the oxidative capacity of microorganisms. The disintegrability on biomass was determined by biochemical methods. Degree of inactivation provides the information on inability of microorganisms to consume oxygen upon disruption. The soluble COD quantifies the extent of release of intra cellular compounds. The participation of disintegrated microorganism in wastewater treatment process was carried out in two identical respirometeric reactors. The results show that Ultrasonic homogenizer is very effective in the disruption of microorganisms leading to a maximum microbial growth reduction of 27%. On the other hand, Shear gap homogenizer does not favor the sludge growth reduction rather it facilitates the growth. This study also shows that for better microbial growth reduction, floc size reduction alone is not sufficient but also microbial disruption is essential.

  14. Effect of environmental forcing on the biomass, production and growth rate of size-fractionated phytoplankton in the central Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Huete-Ortega, María; Calvo-Díaz, Alejandra; Graña, Rocío; Mouriño-Carballido, Beatriz; Marañón, Emilio

    2011-11-01

    To ascertain the response of phytoplankton size classes to changes in environmental forcing, we determined size-fractionated biomass, carbon fixation and growth (production/biomass) rates in surface waters along the central Atlantic Ocean (26°N-5°S). As a result of the enhanced input of nutrients into the euphotic layer and the higher water column stability found at the equatorial upwelling, we observed increases not only in phytoplankton biomass and primary production, but also in turnover rates, suggesting nutrient limitation of phytoplankton physiology in the oligotrophic central Atlantic. The phytoplankton groups analysed (pico-, small nano-, large nano- and micro-phytoplankton) showed different responses to the equatorial environmental forcing, in terms of carbon biomass, primary production and growth rate. Large nano- and micro-phytoplankton consistently showed higher growth rates and carbon fixation to chl a ratios than smaller phytoplankton. We observed a higher stimulating effect of increased nitrate supply on the small phytoplankton growth rates. This observation can be explained by the dynamics of the equatorial upwelling, where the continuous but small nutrient input into the euphotic layer provide a competitive advantage for smaller cells adapted to oligotrophic conditions. The size-fractionated approach shown here reveals important group-specific differences in the response to environmental forcing, which cannot be appreciated in bulk measurements of the whole community.

  15. A systems biology, whole-genome association analysis of the molecular regulation of biomass growth and composition in Populus deltoides

    SciTech Connect

    Kirst, Matias

    2014-04-14

    Poplars trees are well suited for biofuel production due to their fast growing habit, favorable wood composition and adaptation to a broad range of environments. The availability of a reference genome sequence, ease of vegetative propagation and availability of transformation methods also make poplar an ideal model for the study of wood formation and biomass growth in woody, perennial plants. The objective of this project was to conduct a genome-wide association genetics study to identify genes that regulate bioenergy traits in Populus deltoides (eastern cottonwood). Populus deltoides is a genetically diverse keystone forest species in North America and an important short rotation woody crop for the bioenergy industry. We searched for associations between eight growth and wood composition traits and common and low-frequency single-nucleotide polymorphisms (SNPs) detected by targeted resequencing of 18,153 genes in a population of 391 unrelated individuals. To increase power to detect associations with low-frequency variants, multiple-marker association tests were used in combination with single-marker association tests. Significant associations were discovered for all phenotypes and are indicative that low-frequency polymorphisms contribute to phenotypic variance of several bioenergy traits. These polymorphism are critical tools for the development of specialized plant feedstocks for bioenergy.

  16. A systems biology, whole-genome association analysis of the molecular regulation of biomass growth and composition in Populus deltoides

    SciTech Connect

    Kirst, Matias

    2015-04-15

    Poplars trees are well suited for biofuel production due to their fast growing habit, favorable wood composition and adaptation to a broad range of environments. The availability of a reference genome sequence, ease of vegetative propagation and availability of transformation methods also make poplar an ideal model for the study of wood formation and biomass growth in woody, perennial plants. The objective of this project was to conduct a genome-wide association genetics study to identify genes that regulate bioenergy traits in Populus deltoides (eastern cottonwood). Populus deltoides is a genetically diverse keystone forest species in North America and an important short rotation woody crop for the bioenergy industry. We searched for associations between eight growth and wood composition traits and common and low-frequency single-nucleotide polymorphisms (SNPs) detected by targeted resequencing of 18,153 genes in a population of 391 unrelated individuals. To increase power to detect associations with low-frequency variants, multiple-marker association tests were used in combination with single-marker association tests. Significant associations were discovered for all phenotypes and are indicative that low-frequency polymorphisms contribute to phenotypic variance of several bioenergy traits. These polymorphism are critical tools for the development of specialized plant feedstocks for bioenergy.

  17. Phenotypic and genotypic components of growth and reproduction in Typha latifolia: experimental studies in three contrasting marshes

    SciTech Connect

    Grace, J.B.

    1980-01-01

    The magnitude and causes of intraspecific variation in biomass production and allocation, and morphology for Typha latifolia L. from three marshes which can be distinguished by their successional maturity were investigated. The first stage of investigation was to determine the environmental characteristics of the three marshes and the characteristics of the T. latifolia populations. Second, in situ studies of /sup 14/C fixation and allocation were used to determine the phenotypic variation in biomass production and allocation. Third, populations were sampled for genotypic variation in biomass allocation patterns by comparing growth in controlled garden experiments. Fourth, the growth of different biotypes was compared by transplantation into natural stands of T. latifolia. And fifth, the intraspecific variations were considered in terms of their consequences for the persistence of T. latifolia in habitats over successional time.

  18. Divergence in plant and microbial allocation strategies explains continental patterns in microbial allocation and biogeochemical fluxes.

    PubMed

    Averill, Colin

    2014-10-01

    Allocation trade-offs shape ecological and biogeochemical phenomena at local to global scale. Plant allocation strategies drive major changes in ecosystem carbon cycling. Microbial allocation to enzymes that decompose carbon vs. organic nutrients may similarly affect ecosystem carbon cycling. Current solutions to this allocation problem prioritise stoichiometric tradeoffs implemented in plant ecology. These solutions may not maximise microbial growth and fitness under all conditions, because organic nutrients are also a significant carbon resource for microbes. I created multiple allocation frameworks and simulated microbial growth using a microbial explicit biogeochemical model. I demonstrate that prioritising stoichiometric trade-offs does not optimise microbial allocation, while exploiting organic nutrients as carbon resources does. Analysis of continental-scale enzyme data supports the allocation patterns predicted by this framework, and modelling suggests large deviations in soil C loss based on which strategy is implemented. Therefore, understanding microbial allocation strategies will likely improve our understanding of carbon cycling and climate.

  19. Unravelling carbon allocation dynamics in an evergreen temperate forest

    NASA Astrophysics Data System (ADS)

    Griebel, Anne; Bennett, Lauren T.; Arndt, Stefan K.

    2015-04-01

    Eucalypt trees have the potential to sequester carbon from the atmosphere year-round by maintaining evergreen leaves with a prolonged multi-year lifetime. Unlike deciduous trees, eucalypts are generally known to grow opportunistic resulting in a lack of defined growth rings and no distinct seasonal crown turnover events. Stem expansion has been successfully measured with micro-dendrometers, however, it remains challenging to monitor crown dynamics at a similarly high temporal resolution. Hence, carbon allocation dynamics and seasonal variations of carbon distribution between stem and crown biomass remain largely unknown for evergreen species. Ecosystem scale observations of net ecosystem exchange (NEE) from a flux tower located in a predominantly temperature and moisture regulated environment in south-eastern Australia have demonstrated that the ecosystem is a constant terrestrial sink for carbon. Intra-annual variations in temperature and moisture and prolonged heat waves and dry spells result in a wide range of annual sums (e.g. 2013: NEE~4 t C ha-1yr-1, 2012: NEE~12 t C ha-1yr-1). Newly developed low-cost terrestrial lidar sensors (VEGNET) now allow for automated daily monitoring of crown dynamics, enabling more detailed observations on the duration of crown biomass changes. In addition to leaf area index (LAI), VEGNET sensors define the location within the crown strata of the gains and losses in plant volume across the vertical forest structure. With the development of VEGNET sensors, combined with ecosystem carbon fluxes from eddy covariance measurements and with micro-dendrometers, we are able to quantify the dynamics of carbon allocation to above ground biomass pools. Our results demonstrate that stem growth dominates in spring and in autumn, and is strongly associated with water availability. Leaf turnover predominantly takes place in summer and is initiated by prolonged heat stress and isolated storm events, yet crown biomass remains stable throughout the

  20. Growth, biomass, carbon storage and nutrient distribution in Gmelina arborea Roxb. stands on red lateritic soils in central India.

    PubMed

    Swamy, S L; Puri, S; Singh, A K

    2003-11-01

    Growth, biomass, carbon storage and nutrient (N, P and K) variations in 1 to 6-year-old chronosequence plantations of Gmelina arborea were studied in three degraded red lateritic sites in central India. Growth parameters (dbh, total height and number of branches) varied significantly due to difference in age and site quality, but tree density showed non-significant variation. Stand biomass ranged from 3.94 (1-year-old) to 53.67 Mgha(-1) (6-year-old) and stand carbon in 6-year-old plantations ranged from 24.12 to 31.12 Mgha(-1) at different sites. Among the tree components, the stem wood accounted for maximum C (56.25% at site 1) followed by branches (19.8% at site 3), roots (18.51% at site 2) and foliage (7.01% at site 3). Mean annual C accretion at 6 years age of plantation was highest in site 3 and it was 0.35, 2.66, 0.965 and 0.87 Mgha(-1) for leaf, stem, branches and roots, respectively. Quantity of nutrients increased with age. Total nitrogen accumulation in 6-year-old stands at the three sites ranged from 212.9 to 279.5 kgha(-1) with a mean annual storage of 238.43 kgha(-1) and total K ranged from 170.8 to 220.5 kgha(-1) with a mean annual storage of 189.93 kgha(-1). Phosphorous accumulation was lowest with a mean storage of 16.75 kgha(-1). The organic carbon and nutrients in the soils improved significantly after 6 years of G. arborea planting. Soil organic carbon increased from 8.46 to 14.02 Mgha(-1) within 6 years. At soil depths 0-20 cm, 21-40 cm and 41-60 cm, available N enhanced by 14.85%, 11.98% and 11.25%, K by 10%, 9.13% and 10.63%, whereas phosphorous declined by 26%, 23% and 20%, respectively. At 6 years, G. arborea stands sequestered 31.37 Mgha(-1) carbon. The nutrient management strategies in relation to carbon accretion in G. arborea stands on degraded lateritic sites are discussed. PMID:12895553

  1. Effect of arbuscular mycorrhizal fungi on growth and on micronutrient and macronutrient uptake and allocation in olive plantlets growing under high total Mn levels.

    PubMed

    Briccoli Bati, Caterina; Santilli, Elena; Lombardo, Luca

    2015-02-01

    The reported work was designed to increase knowledge about the role of arbuscular mycorrhizal fungi (AMF) on the phytoavailability and allocation of some of the principal macroelements and microelements in young potted olive plants growing in a soil presenting high levels of manganese (Mn), taken from an experimental olive field. A greenhouse trial was performed using self-rooted cuttings of Ascolana tenera, Nocellara del Belice and Carolea cultivars inoculated or not with two mycorrhizal inocula (commercial vs native). Molecular characterization of the indigenous AMF indicated that the species found in the experimental soil were different from those present in the commercial inoculum. The important incidence of AMF on P uptake was confirmed with generally double the concentration in mycorrhizal olive plants as compared to non-mycorrhizal controls, irrespective of genotype and inocula. Furthermore, apart from promoting plant growth (from 1.7- to 5-fold), the symbiosis reduced Mn concentrations from 43 to 83%. The observed differences depended on the cultivar and the inoculum, with native AMF being more effective probably as a result of their adaptation to the experimental soil. No clear direct relationship was found between AMF inoculation and other elements analysed.

  2. The dynamics of resource allocation and costs of reproduction in a sexually dimorphic, wind-pollinated dioecious plant.

    PubMed

    Teitel, Z; Pickup, M; Field, D L; Barrett, S C H

    2016-01-01

    Sexual dimorphism in resource allocation is expected to change during the life cycle of dioecious plants because of temporal differences between the sexes in reproductive investment. Given the potential for sex-specific differences in reproductive costs, resource availability may contribute to variation in reproductive allocation in females and males. Here, we used Rumex hastatulus, a dioecious, wind-pollinated annual plant, to investigate whether sexual dimorphism varies with life-history stage and nutrient availability, and determine whether allocation patterns differ depending on reproductive commitment. To examine if the costs of reproduction varied between the sexes, reproduction was either allowed or prevented through bud removal, and biomass allocation was measured at maturity. In a second experiment to assess variation in sexual dimorphism across the life cycle, and whether this varied with resource availability, plants were grown in high and low nutrients and allocation to roots, aboveground vegetative growth and reproduction were measured at three developmental stages. Males prevented from reproducing compensated with increased above- and belowground allocation to a much larger degree than females, suggesting that male reproductive costs reduce vegetative growth. The proportional allocation to roots, reproductive structures and aboveground vegetative growth varied between the sexes and among life-cycle stages, but not with nutrient treatment. Females allocated proportionally more resources to roots than males at peak flowering, but this pattern was reversed at reproductive maturity under low-nutrient conditions. Our study illustrates the importance of temporal dynamics in sex-specific resource allocation and provides support for high male reproductive costs in wind-pollinated plants.

  3. Photosynthate allocations patterns and mode of postfire reproduction in two shrub species from the California chaparral

    SciTech Connect

    Sparks, S.R.

    1989-01-01

    Age-specific patterns of photosynthate allocation in leaves were investigated for two chaparral shrubs, Adenostoma fasciculatum and Ceanothus greggii, in five stands of various ages. Branches of shrubs were labeled with {sup 14}CO{sub 2}, and seasonal allocation of {sup 14}C-labeled photosynthate to storage, defense, metabolic, and structural compounds was followed. Age-specific allocation patterns were found only in the spring, when older shrubs showed a reduced allocation of photosynthate within leaves to storage compounds. Older shrubs may be less able than younger shrubs to allocate photosynthate to storage compounds when demands on photosynthate for growth are high. The influence of senescence on postfire sprouting was investigated by quantifying the proportion of standing dead biomass in A. fasciculatum, as well as other shrub structural characteristics, before an experimental burn. After the burn, sprout production during the first postfire season was determined and correlated with prefire structural characteristics. Photosynthate allocation to shoots and roots was investigated for seedlings of both species.

  4. Effect of carbon source on biomass growth and nutrients removal of Scenedesmus obliquus for wastewater advanced treatment and lipid production.

    PubMed

    Shen, Qiao-Hui; Jiang, Jia-Wei; Chen, Li-Ping; Cheng, Li-Hua; Xu, Xin-Hua; Chen, Huan-Lin

    2015-08-01

    The combination of tertiary wastewater treatment and microalgal lipid production is considered to be a promising approach to water eutrophication as well as energy crisis. To intensify wastewater treatment and microalgal biofuel production, the effect of organic and inorganic carbon on algal growth and nutrient removal of Scenedesmus obliquus were examined by varying TOC (total organic carbon) concentrations of 20-120mgL(-1) in wastewater and feeding CO2 concentrations in the range of 0.03-15%, respectively. The results showed that the maximal biomass and average lipid productivity were 577.6 and 16.7mgL(-1)d(-1) with 5% CO2 aeration. The total nitrogen, total phosphorus and TOC removal efficiencies were 97.8%, 95.6% and 59.1% respectively within 6days when cultured with real secondary municipal wastewater. This work further showed that S. obliquus could be utilized for simultaneous organic pollutants reduction, N, P removal and lipid accumulation.

  5. Biomass effects on stalagmite growth and isotope ratios: A 20th century analogue from Wiltshire, England [rapid communication

    NASA Astrophysics Data System (ADS)

    Baldini, J. U. L.; McDermott, F.; Baker, A.; Baldini, L. M.; Mattey, D. P.; Railsback, L. Bruce

    2005-12-01

    Increases in calcite deposition rates combined with decreases in δ 13C and δ 18O in three modern stalagmites from Brown's Folly Mine, Wiltshire, England, are correlative with a well-documented re-vegetation above the mine. Increased soil PCO 2 resulted in greater amounts of dissolved CaCO 3 in the drip waters, which consequently increased annual calcite deposition rates. The absence of deposition prior to 1916 (28 years after the mine was closed) indicates that vegetation had not yet sufficiently developed to allow higher PCO 2 values to form in the soil. Lower δ 13C values through time may reflect the increased input of isotopically light biogenic carbon to the total dissolved inorganic carbon (DIC). δ 18O decreased synchronously with δ 13C, reflecting the increased importance of isotopically light winter recharge due to greater biomass-induced summer evapotranspiration. This is the first empirical demonstration that vegetation density can control stalagmite growth rates, δ 13C, and δ 18O, contributing critical insights into the interpretation of these climate proxies in ancient stalagmites.

  6. Nutrients and light limit biomass growth of N2-fixing but not non-fixing trees in tropical forests after 15 years of fertilization

    NASA Astrophysics Data System (ADS)

    Trierweiler, Annette; Wright, Joseph; Winter, Klaus; Hedin, Lars

    2015-04-01

    Tropical forests contribute a major fraction to the land C sink but the role of soil nutrients in limiting tree biomass growth in response to rising atmospheric CO2 is poorly known. Recent findings suggest that, following disturbance, successionally young forests may be deficient in nitrogen (N) and/or phosphorus (P), however nutrient manipulations of mature forests have revealed surprisingly weak effects of nutrients on the stem growth of mature individual trees. It is unclear how such weak experimental nutrient effects are reconciled with the existence of broad geographical correlations between soil nutrients and forest biomass growth. While tree growth is a complex function of nutrients, light, and canopy status, it is plausible that responses differ across different plant functional types. Here we use data from the longest running tropical fertilization experiment to ask first whether different functional groups have different nutrient needs, second, whether a differential nutrient limitation response will affect biomass accretion, and third, whether there is an interactive light-nutrient effect. Finally we examined how nutrient responses changed over time. We show that, in an intact and biodiverse mature tropical forest in Panama, N2-fixing trees more than double their basal area growth rate when exposed to increased soil P and N in the first 11 years of fertilization, for an overall 60% increase over 15 years. In contrast, there was no effect of nutrient treatment on the growth of non-fixing trees. We found a strong interactive effect of soil nutrients and light on fixer tree growth as the greatest growth response was in mature canopy-level trees with full access to light and potentially new nitrogen through fixation. In addition, the positive nutrient effect declined over the 15 years, rather than the expected increase. Our findings suggest that N2-fixing tree species may play a disproportionately important role in governing tropical forest response to

  7. Maternal backfat depth in gestating sows has a greater influence on offspring growth and carcass lean yield than maternal feed allocation during gestation.

    PubMed

    Amdi, Charlotte; Giblin, Linda; Ryan, Tomas; Stickland, Neil C; Lawlor, Peadar G

    2014-02-01

    A commercial pig spends nearly half of its life in utero and its nutrition during this time can influence birth weight and postnatal growth. We hypothesised that postnatal growth is increased in pigs raised by sows with a high backfat depth and high level of energy intake during gestation compared with sows with a low backfat depth and low level of energy intake during gestation. This was tested in a 2 × 3 factorial design experiment with 2 factors for gilt backfat depth (Thin and Fat) and 3 factors for gestation feed allowance (Restricted, Control and High). Between d 25 and d 90 of gestation, Thin gilts (n=68; 12 ± 0.6 mm P2 backfat) and Fat gilts (n=72; 19 ± 0.6 mm P2 backfat) were randomly allocated, as individuals, to a gestation diet (6.19 g/kg lysine, 13.0 MJ DE/kg) at the following feed allowances: 1.8 kg/day (Restricted); 2.5 kg/day (Control) and 3.5 kg/day (High). For the remainder of gestation and during lactation all gilts were treated similarly. At weaning (day 28), 155 piglets were sacrificed and 272 were individually housed and followed through to slaughter (day 158). At day 80 of gestation, fasted Thin Restricted gilts had lower serum IGF-1 concentrations than Thin High or Thin Control fed gilts (P<0.001). Pigs born from Fat gilts had greater backfat depths (P<0.05), a lower lean meat yield (P<0.05) and were heavier (P<0.05) at slaughter than pigs born from Thin gilts. Gilt gestation feed allowance had only transitory effects on average daily gain and feed conversion efficiency and had no effect on pig weight at slaughter (P>0.05) or lean meat yield (P>0.05). In conclusion, gilts with a backfat depth of ~19 mm at insemination produced pigs that were heavier and fatter at ~158 days of age than those born from gilts with ~12 mm backfat depth at insemination. Maternal body condition during gestation had a more predominant influence on growth parameters of the offspring, such as weight at slaughter and backfat depth, than did feed level during

  8. Polyhydroxyalkanoate (PHA) storage within a mixed-culture biomass with simultaneous growth as a function of accumulation substrate nitrogen and phosphorus levels.

    PubMed

    Valentino, Francesco; Karabegovic, Lamija; Majone, Mauro; Morgan-Sagastume, Fernando; Werker, Alan

    2015-06-15

    The response of a mixed-microbial-culture (MMC) biomass for PHA accumulation was evaluated over a range of relative nitrogen (N) and phosphorus (P) availabilities with respect to the supply of either complex (fermented whey permeate - FWP) or simpler (acetic acid) organic feedstocks. Fed-batch feed-on-demand PHA accumulation experiments were conducted where the feed N/COD and P/COD ratios were varied ranging from conditions of nutrient starvation to excess. A feast-famine enrichment (activated sludge) biomass, produced in a pilot-scale aerobic sequencing batch reactor on FWP and with a long history of stable PHA accumulation performance, was used for all the experiments as reference material. FWP with N/COD ratios of (2, 5, 15, 70 mg/g all with P/COD = 8 mg/g) as well as simulated FWP with nutrient starvation (N/COD = P/COD = 0) conditions were applied. For the acetic acid accumulations, nutrient starvation as well as N/COD variations (2.5, 5, 50 mg/g all with P/COD = 9 mg/g) and P/COD variations (0.5, 2, 9, 15 mg/g all with N/COD = 10 mg/g) were evaluated. An optimal range of combined N and P limitation with N/COD from 2 to 15 mg/g and P/COD from 0.5 to 3 mg/g was considered to offer consistent improvement of productivity over the case of nutrient starvation. Productivity increased due to active biomass growth of the PHA storing biomass without observed risk for a growth response overtaking PHA storage activity. PHA production with respect to the initial active biomass was significantly higher even in cases of excess nutrient additions when compared to the cases of nutrient starvation. The 24-h PHA productivities were enhanced as much as 4-fold from a base value of 1.35 g-PHA per gram initial active biomass with respect nutrient starvation feedstock. With or without nutrient loading the biomass consistently accumulated similar and significant PHA (nominally 60% g-PHA/g-VSS). Based on results from replicate experiments some variability in the extant biomass maximum

  9. Polyhydroxyalkanoate (PHA) storage within a mixed-culture biomass with simultaneous growth as a function of accumulation substrate nitrogen and phosphorus levels.

    PubMed

    Valentino, Francesco; Karabegovic, Lamija; Majone, Mauro; Morgan-Sagastume, Fernando; Werker, Alan

    2015-06-15

    The response of a mixed-microbial-culture (MMC) biomass for PHA accumulation was evaluated over a range of relative nitrogen (N) and phosphorus (P) availabilities with respect to the supply of either complex (fermented whey permeate - FWP) or simpler (acetic acid) organic feedstocks. Fed-batch feed-on-demand PHA accumulation experiments were conducted where the feed N/COD and P/COD ratios were varied ranging from conditions of nutrient starvation to excess. A feast-famine enrichment (activated sludge) biomass, produced in a pilot-scale aerobic sequencing batch reactor on FWP and with a long history of stable PHA accumulation performance, was used for all the experiments as reference material. FWP with N/COD ratios of (2, 5, 15, 70 mg/g all with P/COD = 8 mg/g) as well as simulated FWP with nutrient starvation (N/COD = P/COD = 0) conditions were applied. For the acetic acid accumulations, nutrient starvation as well as N/COD variations (2.5, 5, 50 mg/g all with P/COD = 9 mg/g) and P/COD variations (0.5, 2, 9, 15 mg/g all with N/COD = 10 mg/g) were evaluated. An optimal range of combined N and P limitation with N/COD from 2 to 15 mg/g and P/COD from 0.5 to 3 mg/g was considered to offer consistent improvement of productivity over the case of nutrient starvation. Productivity increased due to active biomass growth of the PHA storing biomass without observed risk for a growth response overtaking PHA storage activity. PHA production with respect to the initial active biomass was significantly higher even in cases of excess nutrient additions when compared to the cases of nutrient starvation. The 24-h PHA productivities were enhanced as much as 4-fold from a base value of 1.35 g-PHA per gram initial active biomass with respect nutrient starvation feedstock. With or without nutrient loading the biomass consistently accumulated similar and significant PHA (nominally 60% g-PHA/g-VSS). Based on results from replicate experiments some variability in the extant biomass maximum

  10. Phosphate supply explains variation in nucleic acid allocation but not C : P stoichiometry in the Western North Atlantic

    NASA Astrophysics Data System (ADS)

    Zimmerman, A. E.; Martiny, A. C.; Lomas, M. W.; Allison, S. D.

    2013-10-01

    Marine microbial communities mediate many biogeochemical transformations in the ocean. Consequently, processes such as primary production and carbon (C) export are linked to nutrient regeneration and are influenced by the resource demand and elemental composition of marine microbial biomass. Laboratory studies have demonstrated that differential partitioning of element resources to various cellular components can directly influence overall cellular elemental ratios, especially with respect to growth machinery (i.e., ribosomal RNA) and phosphorus (P) allocation. To investigate whether allocation to RNA is related to biomass P content and overall C : P biomass composition in the open ocean, we characterized patterns of P allocation and C : P elemental ratios along an environmental gradient of P-supply in the North Atlantic subtropical gyre (NASG) from 35.67° N 64.17° W to 22.67° N 65.52° W. Because the NASG is characterized as a P-stressed ecosystem, we hypothesized that biochemical allocation would reflect sensitivity to bioavailable P, such that greater P supply would result in increased allocation toward P-rich RNA for growth. We expected these changes in allocation to also result in lower C : P ratios with increased P supply. In contrast to our predictions however, bulk C : P ratios were decoupled from allocation to nucleic acids and did not vary systematically across a P supply gradient of 2.2-14.7 μmol m-2 d-1. Overall, we found that C : P ratios ranged from 188-306 along the transect, and RNA represented only 6-12% of total particulate P, whereas DNA represented 11-19%. However, we did find that allocation to RNA was positively correlated with SRP supply rate, suggesting a consistent physiological response in biochemical allocation to resource supply within the whole community. These results suggest that community composition or non-nucleic acid P pools may influence ecosystem scale variation in C : P stoichiometry more than nucleic acid allocation or

  11. Phosphate supply explains variation in nucleic acid allocation but not C : P stoichiometry in the western North Atlantic

    NASA Astrophysics Data System (ADS)

    Zimmerman, A. E.; Martiny, A. C.; Lomas, M. W.; Allison, S. D.

    2014-03-01

    Marine microbial communities mediate many biogeochemical transformations in the ocean. Consequently, processes such as primary production and carbon (C) export are linked to nutrient regeneration and are influenced by the resource demand and elemental composition of marine microbial biomass. Laboratory studies have demonstrated that differential partitioning of element resources to various cellular components can directly influence overall cellular elemental ratios, especially with respect to growth machinery (i.e., ribosomal RNA) and phosphorus (P) allocation. To investigate whether allocation to RNA is related to biomass P content and overall C : P biomass composition in the open ocean, we characterized patterns of P allocation and C : P elemental ratios along an environmental gradient of phosphate supply in the North Atlantic subtropical gyre (NASG) from 35.67° N, 64.17° W to 22.676° N, 65.526° W. Because the NASG is characterized as a P-stressed ecosystem, we hypothesized that biochemical allocation would reflect sensitivity to bioavailable phosphate, such that greater phosphate supply would result in increased allocation toward P-rich RNA for growth. We predicted these changes in allocation would also result in lower C : P ratios with increased phosphate supply. However, bulk C : P ratios were decoupled from allocation to nucleic acids and did not appear to vary systematically across a phosphate supply gradient of 2.2-14.7 μmol m-2 d-1. Overall, we found that C : P ratios ranged from 188 to 306 along the transect, and RNA represented only 6-12% of total particulate P, whereas DNA represented 11-19%. We did find that allocation to RNA was positively correlated with phosphate supply rate, suggesting a consistent physiological response in biochemical allocation to resource supply within the whole community. These results suggest that community composition and/or nonnucleic acid P pools may influence ecosystem-scale variation in C : P stoichiometry more than

  12. Consumer-Resource Dynamics: Quantity, Quality, and Allocation

    PubMed Central

    Getz, Wayne M.; Owen-Smith, Norman

    2011-01-01

    Background The dominant paradigm for modeling the complexities of interacting populations and food webs is a system of coupled ordinary differential equations in which the state of each species, population, or functional trophic group is represented by an aggregated numbers-density or biomass-density variable. Here, using the metaphysiological approach to model consumer-resource interactions, we formulate a two-state paradigm that represents each population or group in a food web in terms of both its quantity and quality. Methodology and Principal Findings The formulation includes an allocation function controlling the relative proportion of extracted resources to increasing quantity versus elevating quality. Since lower quality individuals senesce more rapidly than higher quality individuals, an optimal allocation proportion exists and we derive an expression for how this proportion depends on population parameters that determine the senescence rate, the per-capita mortality rate, and the effects of these rates on the dynamics of the quality variable. We demonstrate that oscillations do not arise in our model from quantity-quality interactions alone, but require consumer-resource interactions across trophic levels that can be stabilized through judicious resource allocation strategies. Analysis and simulations provide compelling arguments for the necessity of populations to evolve quality-related dynamics in the form of maternal effects, storage or other appropriate structures. They also indicate that resource allocation switching between investments in abundance versus quality provide a powerful mechanism for promoting the stability of consumer-resource interactions in seasonally forcing environments. Conclusions/Significance Our simulations show that physiological inefficiencies associated with this switching can be favored by selection due to the diminished exposure of inefficient consumers to strong oscillations associated with the well-known paradox of

  13. Overflow metabolism in E. coli results from efficient proteome allocation

    PubMed Central

    Okano, Hiroyuki; Zhang, Zhongge; Shen, Yang; Williamson, James R.; Hwa, Terence

    2015-01-01

    Overflow metabolism refers to the seemingly wasteful strategy in which cells use fermentation instead of the more efficient respiration to generate energy, despite the availability of oxygen. Known as Warburg effect in the context of cancer growth, this phenomenon occurs ubiquitously for fast growing cells, including bacteria, fungi, and mammalian cells, but its origin has remained mysterious despite decades of research. Here we study metabolic overflow in E. coli and show that it is a global physiological response used to cope with changing proteomic demands of energy biogenesis and biomass synthesis under different growth conditions. A simple model of proteomic resource allocation can quantitatively account for all of the observed behaviors and accurately predict responses to novel perturbations. The key hypothesis of the model, that the proteome cost of energy biogenesis by respiration exceeds that by fermentation, is quantitatively confirmed by direct measurement of protein abundances via quantitative mass spectrometry. PMID:26632588

  14. Overflow metabolism in Escherichia coli results from efficient proteome allocation.

    PubMed

    Basan, Markus; Hui, Sheng; Okano, Hiroyuki; Zhang, Zhongge; Shen, Yang; Williamson, James R; Hwa, Terence

    2015-12-01

    Overflow metabolism refers to the seemingly wasteful strategy in which cells use fermentation instead of the more efficient respiration to generate energy, despite the availability of oxygen. Known as the Warburg effect in the context of cancer growth, this phenomenon occurs ubiquitously for fast-growing cells, including bacteria, fungi and mammalian cells, but its origin has remained unclear despite decades of research. Here we study metabolic overflow in Escherichia coli, and show that it is a global physiological response used to cope with changing proteomic demands of energy biogenesis and biomass synthesis under different growth conditions. A simple model of proteomic resource allocation can quantitatively account for all of the observed behaviours, and accurately predict responses to new perturbations. The key hypothesis of the model, that the proteome cost of energy biogenesis by respiration exceeds that by fermentation, is quantitatively confirmed by direct measurement of protein abundances via quantitative mass spectrometry.

  15. Formation of ozone and growth of aerosols in young smoke plumes from biomass burning: 1. Lagrangian parcel studies

    NASA Astrophysics Data System (ADS)

    Alvarado, Matthew James; Prinn, Ronald G.

    2009-05-01

    We have developed a new model of the gas- and aerosol-phase chemistry of biomass burning smoke plumes called Aerosol Simulation Program (ASP). Here we use ASP combined with a Lagrangian parcel model to simulate the chemistry in smoke plumes from three fires: the Otavi savannah fire in Namibia, an Alaska boreal forest fire, and the Timbavati savannah fire. Our model explained the observations of ozone in the Otavi and Alaska plumes fairly well, but our initial model simulation of the Timbavati plume underestimated the concentrations of ozone, OH, and secondary aerosol matter. The Timbavati simulation agrees with observations if we increase OH to equal its observed levels. Heterogeneous reactions of NO2 and SO2 could explain the needed higher concentrations of OH and the rapid formation of ozone, nitrate, and sulfate in the smoke plume if the uptake coefficients on smoke aerosols are large (O(10-3) and O(10-4), respectively). Uncharacterized organic species in the smoke plume were likely responsible for the rapid formation of aerosol organic carbon. The changes in the aerosol size distribution were dominated by plume dilution and condensational growth. The single scattering albedo of the modeled smoke increases from 0.866 to 0.902 over 1 h of aging. The change in aerosol scattering with relative humidity for the modeled fresh smoke matches observations up to 66% RH, but the model greatly overestimates the humidification factor at 80% RH (2.88 versus an observed value of 1.70-1.79). For the aged smoke, the modeled humidification factor is 1.22, slightly below the observed value of 1.40.

  16. Gradient domestication of Haematococcus pluvialis mutant with 15% CO2 to promote biomass growth and astaxanthin yield.

    PubMed

    Cheng, Jun; Li, Ke; Yang, Zongbo; Lu, Hongxiang; Zhou, Junhu; Cen, Kefa

    2016-09-01

    In order to increase biomass yield and reduce culture cost of Haematococcus pluvialis with flue gas from coal-fired power plants, a screened mutant by nuclear irradiation was gradually domesticated with 15% CO2 to promote biomass dry weight and astaxanthin yield. The biomass yield of mutant after 10 generations of 15% CO2 domestication increased to 1.3 times as that with air. With the optimization of nitrogen and phosphorus concentration, the biomass dry weight was further increased by 62%. The astaxanthin yield induced with 15% CO2 and high light of 135 μmol photons m(-2) s(-1) increased to 87.4mg/L, which was 6 times higher than that induced with high light in air.

  17. Gradient domestication of Haematococcus pluvialis mutant with 15% CO2 to promote biomass growth and astaxanthin yield.

    PubMed

    Cheng, Jun; Li, Ke; Yang, Zongbo; Lu, Hongxiang; Zhou, Junhu; Cen, Kefa

    2016-09-01

    In order to increase biomass yield and reduce culture cost of Haematococcus pluvialis with flue gas from coal-fired power plants, a screened mutant by nuclear irradiation was gradually domesticated with 15% CO2 to promote biomass dry weight and astaxanthin yield. The biomass yield of mutant after 10 generations of 15% CO2 domestication increased to 1.3 times as that with air. With the optimization of nitrogen and phosphorus concentration, the biomass dry weight was further increased by 62%. The astaxanthin yield induced with 15% CO2 and high light of 135 μmol photons m(-2) s(-1) increased to 87.4mg/L, which was 6 times higher than that induced with high light in air. PMID:27259189

  18. Age-related variation in carbon allocation at tree and stand scales in beech (Fagus sylvatica L.) and sessile oak (Quercus petraea (Matt.) Liebl.) using a chronosequence approach.

    PubMed

    Genet, H; Bréda, N; Dufrêne, E

    2010-02-01

    Two types of physiological mechanisms can contribute to growth decline with age: (i) the mechanisms leading to the reduction of carbon assimilation (input) and (ii) those leading to modification of the resource economy. Surprisingly, the processes relating to carbon allocation have been little investigated as compared to research on the processes governing carbon assimilation. The objective of this paper was thus to test the hypothesis that growth decrease related to age is accompanied by changes in carbon allocation to the benefit of storage and reproductive functions in two contrasting broad-leaved species: beech (Fagus sylvatica L.) and sessile oak (Quercus petraea (Matt.) Liebl.). Age-related changes in carbon allocation were studied using a chronosequence approach. Chronosequences, each consisting of several even-aged stands ranging from 14 to 175 years old for beech and from 30 to 134 years old for sessile oak, were divided into five or six age classes. In this study, carbon allocations to growth, storage and reproduction were defined as the relative amount of carbon invested in biomass increment, carbohydrate increment and seed production, respectively. Tree-ring width and allometric relationships were used to assess biomass increment at the tree and stand scales. Below-ground biomass was assessed using a specific allometric relationship between root:shoot ratio and age, established from the literature review. Seasonal variations of carbohydrate concentrations were used to assess carbon allocation to storage. Reproduction effort was quantified for beech stands by collecting seed and cupule production. Age-related flagging of biomass productivity was assessed at the tree and stand scales, and carbohydrate quantities in trees increased with age for both species. Seed and cupule production increased with stand age in beech from 56 gC m(-)(2) year(-1) at 30 years old to 129 gC m(-2) year(-1) at 138 years old. In beech, carbon allocation to storage and

  19. Effects of chlorimuron-ethyl and cadimum on biomass growth and cadimum accumulation of wheat in the phaiozem area, Northeast China.

    PubMed

    Jin, Caixia; Zhou, Qixing; Zhou, Qingxiang; Fan, Jing

    2010-04-01

    The joint effect of chlorimuron-ethyl and cadmium (Cd) on biomass growth and cadmium accumulation in wheat (Triticum aestivum L.) was investigated and compared with single-factor effect of soil cadmium pollution. The results showed that dry biomass of wheat had significantly (p < 0.01) negative relationships with increasing concentrations of chlorimuron-ethyl and cadmium in phaiozem. The highest inhibition rates observed were 76.2%, 62.7% and 55.6% for roots, shoots and glumes, respectively, when the concentration of cadmium in soil was up to 100 mg kg(-1). There were synergistically inhibitory interactions between chlorimuron-ethyl and cadmium on biomass growth of wheat. The SPT values of cadmium for wheat decreased with an increase in the concentration of cadmium added to the tested soil. The accumulation of cadmium in wheat shoots, roots and glumes could be inhibited by chlorimuron-ethyl to some extent. There was an antagonistic interaction between chlorimuron-ethyl and cadmium on accumulation of cadmium in wheat.

  20. Constrained Allocation Flux Balance Analysis.

    PubMed

    Mori, Matteo; Hwa, Terence; Martin, Olivier C; De Martino, Andrea; Marinari, Enzo

    2016-06-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an "ensemble averaging" procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws.

  1. Constrained Allocation Flux Balance Analysis.

    PubMed

    Mori, Matteo; Hwa, Terence; Martin, Olivier C; De Martino, Andrea; Marinari, Enzo

    2016-06-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an "ensemble averaging" procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws. PMID:27355325

  2. Constrained Allocation Flux Balance Analysis

    PubMed Central

    Mori, Matteo; Hwa, Terence; Martin, Olivier C.

    2016-01-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an “ensemble averaging” procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws. PMID:27355325

  3. High-EPA Biomass from Nannochloropsis salina Cultivated in a Flat-Panel Photo-Bioreactor on a Process Water-Enriched Growth Medium.

    PubMed

    Safafar, Hamed; Hass, Michael Z; Møller, Per; Holdt, Susan L; Jacobsen, Charlotte

    2016-01-01

    Nannochloropsis salina was grown on a mixture of standard growth media and pre-gasified industrial process water representing effluent from a local biogas plant. The study aimed to investigate the effects of enriched growth media and cultivation time on nutritional composition of Nannochloropsis salina biomass, with a focus on eicosapentaenoic acid (EPA). Variations in fatty acid composition, lipids, protein, amino acids, tocopherols and pigments were studied and results compared to algae cultivated on F/2 media as reference. Mixed growth media and process water enhanced the nutritional quality of Nannochloropsis salina in laboratory scale when compared to algae cultivated in standard F/2 medium. Data from laboratory scale translated to the large scale using a 4000 L flat panel photo-bioreactor system. The algae growth rate in winter conditions in Denmark was slow, but results revealed that large-scale cultivation of Nannochloropsis salina at these conditions could improve the nutritional properties such as EPA, tocopherol, protein and carotenoids compared to laboratory-scale cultivated microalgae. EPA reached 44.2% ± 2.30% of total fatty acids, and α-tocopherol reached 431 ± 28 µg/g of biomass dry weight after 21 days of cultivation. Variations in chemical compositions of Nannochloropsis salina were studied during the course of cultivation. Nannochloropsis salina can be presented as a good candidate for winter time cultivation in Denmark. The resulting biomass is a rich source of EPA and also a good source of protein (amino acids), tocopherols and carotenoids for potential use in aquaculture feed industry. PMID:27483291

  4. High-EPA Biomass from Nannochloropsis salina Cultivated in a Flat-Panel Photo-Bioreactor on a Process Water-Enriched Growth Medium

    PubMed Central

    Safafar, Hamed; Hass, Michael Z.; Møller, Per; Holdt, Susan L.; Jacobsen, Charlotte

    2016-01-01

    Nannochloropsis salina was grown on a mixture of standard growth media and pre-gasified industrial process water representing effluent from a local biogas plant. The study aimed to investigate the effects of enriched growth media and cultivation time on nutritional composition of Nannochloropsis salina biomass, with a focus on eicosapentaenoic acid (EPA). Variations in fatty acid composition, lipids, protein, amino acids, tocopherols and pigments were studied and results compared to algae cultivated on F/2 media as reference. Mixed growth media and process water enhanced the nutritional quality of Nannochloropsis salina in laboratory scale when compared to algae cultivated in standard F/2 medium. Data from laboratory scale translated to the large scale using a 4000 L flat panel photo-bioreactor system. The algae growth rate in winter conditions in Denmark was slow, but results revealed that large-scale cultivation of Nannochloropsis salina at these conditions could improve the nutritional properties such as EPA, tocopherol, protein and carotenoids compared to laboratory-scale cultivated microalgae. EPA reached 44.2% ± 2.30% of total fatty acids, and α-tocopherol reached 431 ± 28 µg/g of biomass dry weight after 21 days of cultivation. Variations in chemical compositions of Nannochloropsis salina were studied during the course of cultivation. Nannochloropsis salina can be presented as a good candidate for winter time cultivation in Denmark. The resulting biomass is a rich source of EPA and also a good source of protein (amino acids), tocopherols and carotenoids for potential use in aquaculture feed industry. PMID:27483291

  5. Interactive effects of CO2 enrichment and temperature on the growth of dioecious Hydrilla verticillata

    USGS Publications Warehouse

    Chen, De-Xing; Coughenour, M. B.; Eberts, Debra; Thullen, Joan S.

    1994-01-01

    Experiments of plant growth responses to different CO2 concentrations and temperatures were conducted in growth chambers to explore the interactive effects of atmospheric CO2 enrichment and temperature on the growth and dry matter allocation of dioecious Hydrilla [Hydrilla verticillata (L.f.) Royle]. Hydrilla plants were exposed to two atmospheric CO2 concentrations (350 and 700 ppm) and three temperatures (15, 25 and 32°C) under a 12-hr photoperiod for about 2 months. The plant growth analysis showed that elevated CO2 appeared to enhance the growth of Hydrilla, and that the percentage of the enhancement is strongly temperature-dependent. Maximum biomass production was achieved at 700 ppm CO2 and 32°C. At 15°C, the total dry matter production was increased about 27% by doubling CO2, due to a 26% enhancement of leaf biomass, a 34% enhancement of stem biomass and 16% enhancement of root biomass. At 25°C, the dry matter production was increased about 46% by doubling CO2, due to a 29% enhancement of leaf biomass, a 27% enhancement of stem biomass and 40% enhancement of root biomass. At 32°C, however, the percentage of the enhancement of total dry matter production by doubling CO2 was only about 7%. The dry matter allocation among different plant parts was influenced by temperature but not by elevated CO2 concentration.

  6. Insights into nitrogen allocation and recycling from nitrogen elemental analysis and 15N isotope labelling in 14 genotypes of willow.

    PubMed

    Brereton, Nicholas J B; Pitre, Frederic E; Shield, Ian; Hanley, Steven J; Ray, Michael J; Murphy, Richard J; Karp, Angela

    2014-11-01

    Minimizing nitrogen (N) fertilization inputs during cultivation is essential for sustainable production of bioenergy and biofuels. The biomass crop willow (Salix spp.) is considered to have low N fertilizer requirements due to efficient recycling of nutrients during the perennial cycle. To investigate how successfully different willow genotypes assimilate and allocate N during growth, and remobilize and consequently recycle N before the onset of winter dormancy, N allocation and N remobilization (to and between different organs) were examined in 14 genotypes of a genetic family using elemental analysis and (15)N as a label. Cuttings were established in pots in April and sampled in June, August and at onset of senescence in October. Biomass yield of the trees correlated well with yields recorded in the field. Genotype-specific variation was observed for all traits measured and general trends spanning these sampling points were identified when trees were grouped by biomass yield. Nitrogen reserves in the cutting fuelled the entirety of the canopy establishment, yet earlier cessation of this dependency was linked to higher biomass yields. The stem was found to be the major N reserve by autumn, which constitutes a major source of N loss at harvest, typically every 2-3 years. These data contribute to understanding N remobilization in short rotation coppice willow and to the identification of traits that could potentially be selected for in breeding programmes to further improve the sustainability of biomass production.

  7. Optimal allocation in annual plants and its implications for drought response

    NASA Astrophysics Data System (ADS)

    Caldararu, Silvia; Smith, Matthew; Purves, Drew

    2015-04-01

    The concept of plant optimality refers to the plastic behaviour of plants that results in lifetime and offspring fitness. Optimality concepts have been used in vegetation models for a variety of processes, including stomatal conductance, leaf phenology and biomass allocation. Including optimality in vegetation models has the advantages of creating process based models with a relatively low complexity in terms of parameter numbers but which are capable of reproducing complex plant behaviour. We present a general model of plant growth for annual plants based on the hypothesis that plants allocate biomass to aboveground and belowground vegetative organs in order to maintain an optimal C:N ratio. The model also represents reproductive growth through a second optimality criteria, which states that plants flower when they reach peak nitrogen uptake. We apply this model to wheat and maize crops at 15 locations corresponding to FLUXNET cropland sites. The model parameters are data constrained using a Bayesian fitting algorithm to eddy covariance data, satellite derived vegetation indices, specifically the MODIS fAPAR product and field level crop yield data. We use the model to simulate the plant drought response under the assumption of plant optimality and show that the plants maintain unstressed total biomass levels under drought for a reduction in precipitation of up to 40%. Beyond that level plant response stops being plastic and growth decreases sharply. This behaviour results simply from the optimal allocation criteria as the model includes no explicit drought sensitivity component. Models that use plant optimality concepts are a useful tool for simulation plant response to stress without the addition of artificial thresholds and parameters.

  8. Allocation Games: Addressing the Ill-Posed Nature of Allocation in Life-Cycle Inventories.

    PubMed

    Hanes, Rebecca J; Cruze, Nathan B; Goel, Prem K; Bakshi, Bhavik R

    2015-07-01

    Allocation is required when a life cycle contains multi-functional processes. One approach to allocation is to partition the embodied resources in proportion to a criterion, such as product mass or cost. Many practitioners apply multiple partitioning criteria to avoid choosing one arbitrarily. However, life cycle results from different allocation methods frequently contradict each other, making it difficult or impossible for the practitioner to draw any meaningful conclusions from the study. Using the matrix notation for life-cycle inventory data, we show that an inventory that requires allocation leads to an ill-posed problem: an inventory based on allocation is one of an infinite number of inventories that are highly dependent upon allocation methods. This insight is applied to comparative life-cycle assessment (LCA), in which products with the same function but different life cycles are compared. Recently, there have been several studies that applied multiple allocation methods and found that different products were preferred under different methods. We develop the Comprehensive Allocation Investigation Strategy (CAIS) to examine any given inventory under all possible allocation decisions, enabling us to detect comparisons that are not robust to allocation, even when the comparison appears robust under conventional partitioning methods. While CAIS does not solve the ill-posed problem, it provides a systematic way to parametrize and examine the effects of partitioning allocation. The practical usefulness of this approach is demonstrated with two case studies. The first compares ethanol produced from corn stover hydrolysis, corn stover gasification, and corn grain fermentation. This comparison was not robust to allocation. The second case study compares 1,3-propanediol (PDO) produced from fossil fuels and from biomass, which was found to be a robust comparison. PMID:26061700

  9. Allocation Games: Addressing the Ill-Posed Nature of Allocation in Life-Cycle Inventories.

    PubMed

    Hanes, Rebecca J; Cruze, Nathan B; Goel, Prem K; Bakshi, Bhavik R

    2015-07-01

    Allocation is required when a life cycle contains multi-functional processes. One approach to allocation is to partition the embodied resources in proportion to a criterion, such as product mass or cost. Many practitioners apply multiple partitioning criteria to avoid choosing one arbitrarily. However, life cycle results from different allocation methods frequently contradict each other, making it difficult or impossible for the practitioner to draw any meaningful conclusions from the study. Using the matrix notation for life-cycle inventory data, we show that an inventory that requires allocation leads to an ill-posed problem: an inventory based on allocation is one of an infinite number of inventories that are highly dependent upon allocation methods. This insight is applied to comparative life-cycle assessment (LCA), in which products with the same function but different life cycles are compared. Recently, there have been several studies that applied multiple allocation methods and found that different products were preferred under different methods. We develop the Comprehensive Allocation Investigation Strategy (CAIS) to examine any given inventory under all possible allocation decisions, enabling us to detect comparisons that are not robust to allocation, even when the comparison appears robust under conventional partitioning methods. While CAIS does not solve the ill-posed problem, it provides a systematic way to parametrize and examine the effects of partitioning allocation. The practical usefulness of this approach is demonstrated with two case studies. The first compares ethanol produced from corn stover hydrolysis, corn stover gasification, and corn grain fermentation. This comparison was not robust to allocation. The second case study compares 1,3-propanediol (PDO) produced from fossil fuels and from biomass, which was found to be a robust comparison.

  10. Carbon and Nitrogen Storage in Aboveground Biomass and Organic Layer in Natural Larix Stands in Eastern Siberia

    NASA Astrophysics Data System (ADS)

    Shibuya, M.; Saito, H.; Sawamoto, T.; Hatano, R.; Yajima, T.; Takahashi, K.; Cha, J.; Isaev, A.; Maximov, T.

    2002-12-01

    To evaluate the carbon storage capacity of natural Larix stands in eastern Siberia, aboveground biomass, carbon and nitrogen storage in the biomass and organic layer of soil, and net primary production (NPP) were estimated in relation to stand age. Stands studied were from young to mature growth stage. The aboveground biomass and carbon storage in the biomass increased sigmoidally with stand age. The asymptotes of the biomass and carbon storage were 104 t\\ha-1 and 52 tC\\ha-1, respectively. The carbon storage capacity of the aboveground biomass was considered not to be small depending on the long period during which a large biomass close to the asymptote is retained, while the annual increment of the biomass is small. Also, carbon sink efficiency of the biomass changed with stand age. NPP of the stands was small comparing with those of temperate and boreal stands. Estimated net ecosystem production was positive even in a mature stand. Siberian Larix stands studied were carbon sink irrespective of stand age. The carbon storage in organic layer of soil accounted for 80-100 % of that in the aboveground biomass and was a significant carbon sink. Nitrogen was considered as a limited nutrient for the production of the stands from its allocation pattern to aboveground tree organs and storage pattern in soil. Furthermore, the decomposition rate of litter was small and affects the accumulation of organic materials.

  11. Allocation to carbon storage pools in Norway spruce saplings under drought and low CO2.

    PubMed

    Hartmann, Henrik; McDowell, Nate G; Trumbore, Susan

    2015-03-01

    Non-structural carbohydrates (NSCs) are critical to maintain plant metabolism under stressful environmental conditions, but we do not fully understand how NSC allocation and utilization from storage varies with stress. While it has become established that storage allocation is unlikely to be a mere overflow process, very little empirical evidence has been produced to support this view, at least not for trees. Here we present the results of an intensively monitored experimental manipulation of whole-tree carbon (C) balance (young Picea abies (L.) H Karst.) using reduced atmospheric [CO2] and drought to reduce C sources. We measured specific C storage pools (glucose, fructose, sucrose, starch) over 21 weeks and converted concentration measurement into fluxes into and out of the storage pool. Continuous labeling ((13)C) allowed us to track C allocation to biomass and non-structural C pools. Net C fluxes into the storage pool occurred mainly when the C balance was positive. Storage pools increased during periods of positive C gain and were reduced under negative C gain. (13)C data showed that C was allocated to storage pools independent of the net flux and even under severe C limitation. Allocation to below-ground tissues was strongest in control trees followed by trees experiencing drought followed by those grown under low [CO2]. Our data suggest that NSC storage has, under the conditions of our experimental manipulation (e.g., strong progressive drought, no above-ground growth), a high allocation priority and cannot be considered an overflow process. While these results also suggest active storage allocation, definitive proof of active plant control of storage in woody plants requires studies involving molecular tools.

  12. Computer Processor Allocator

    2004-03-01

    The Compute Processor Allocator (CPA) provides an efficient and reliable mechanism for managing and allotting processors in a massively parallel (MP) computer. It maintains information in a database on the health. configuration and allocation of each processor. This persistent information is factored in to each allocation decision. The CPA runs in a distributed fashion to avoid a single point of failure.

  13. [Effects of leaf damage and sediment type on compensatory growth of submerged macrophyte Vallisneria spiralis].

    PubMed

    Li, Kuan-yi; Li, Yan-min; Liu, Zheng-wen

    2008-11-01

    Through a 2 x 2 factorial outdoor experiment, the effects of leaf damage and sediment type on the compensatory growth of submerged macrophyte Vallisneria spiralis were examined. The results showed that leaf damage and sediment type had significant effects on the cumulative biomass, biomass allocation, and ramet number of V. spiralis. Compared with undamaged plant, the strongly damaged one had a decrease of cumulative biomass and ramet number and an increase of biomass allocation, but no evident difference was observed between weakly damaged and undamaged plants. The cumulative biomass of undamaged and strongly damaged plants was lower in infertile sediments (bank sediment) than in fertile sediments (lake sediment), but that of weakly damaged plant was almost the same in the two sediments. The biomass allocation and ramet number of V. spiralis were higher in bank sediment than in lake sediment. Leaf damage and sediment type also affected the relative growth rate (RGR) of V. spiralis. Leaf damage resulted in an increase of RGR, but the difference of RGR between weak damage and strong damage was not evident. The RGR of undamaged and strongly damaged plants was significantly higher in lake sediment than in bank sediment, but that of weakly damaged plant was almost the same in the two sediments. The mechanisms of the compensatory growth of V. spiralis were discussed. PMID:19238834

  14. Growth and Content of Spirulina Platensis Biomass Chlorophyll Cultivated at Different Values of Light Intensity and Temperature Using Different Nitrogen Sources

    PubMed Central

    Godoy Danesi, Eliane Dalva; Oliveira Rangel-Yagui, Carlota; Sato, Sunao; Monteiro de Carvalho, João Carlos

    2011-01-01

    The effects of light intensity and temperature in S. platensis cultivation with potassium nitrate or urea as nitrogen source were investigated, as well as the biomass chlorophyll contents of this cyanobacteria, through the Response Surface Methodology. Experiments were performed at temperatures from 25 to 34.5ºC and light intensities from 15 to 69 µmol photons m−2 s−1, in mineral medium. In cultivations with both sources of nitrogen, KNO3 and urea, statistic evaluation through multiple regression, no interactions of such independent variables were detected in the results of the dependent variables maximum cell concentration, chlorophyll biomass contents, cell and chlorophyll productivities, as well as in the nitrogen-cell conversion factor. In cultivation performed with both sources of nitrogen, it was possible to obtain satisfactory adjustments to relate the dependent variables to the independent variables. The best results were achieved at temperature of 30ºC, at light intensity of 60 µmol photons m−2s−1, for cell growth, with cell productivity of approximately 95 mg L−1 d−1 in cultivations with urea. For the chlorophyll biomass content, the most adequate light intensity was 24 µmol photons m−2 s−1. PMID:24031643

  15. Growth, biomass production and photosynthesis of Cenchrus ciliaris L. under Acacia tortilis (Forssk.) Hayne based silvopastoral systems in semi arid tropics.

    PubMed

    Mishra, A K; Tiwari, H S; Bhatt, R K

    2010-11-01

    The growth, biomass production and photosynthesis of Cenchrus ciliaris was studied under the canopies of 17 yr old Acacia tortilis trees in semi arid tropical environment. On an average the full grown canopy of A. tortilis at the spacing of 4 x 4 m allowed 55% of total Photosynthetically Active Radiation (PAR) which in turn increased Relative Humidity (RH) and reduced under canopy temperature to -1.75 degrees C over the open air temperature. C. ciliaris attained higher height under the shade of A. tortilis. The tiller production and leaf area index decreased marginally under the shade of tree canopies as compared to the open grown grasses. C. ciliaris accumulated higher chlorophyll a and b under the shade of tree canopies indicating its shade adaptation potential. The assimilatory functions such as rate of photosynthesis, transpiration, stomatal conductance, photosynthetic water use efficiency (PN/TR) and carboxylation efficiency (PN/CINT) decreased under the tree canopies due to low availability of PAR. The total biomass production in term of fresh and dry weight decreased under the tree canopies. On average of 2 yr C. ciliaris had produced 12.78 t ha(-1) green and 3.72 -t ha(-1) dry biomass under the tree canopies of A. tortilis. The dry matter yield reduced to 38% under the tree canopies over the open grown grasses. The A. tortilis + C. ciliaris maintained higher soil moisture, organic carbon content and available N P K for sustainable biomass production for the longer period. The higher accumulation of crude protein, starch, sugar and nitrogen in leaves and stem of C. ciliaris indicates that this grass species also maintained its quality under A. tortilis based silvopastoral system. The photosynthesis and dry matter accumulation are closely associated with available PAR indicating that for sustainable production of this grass species in the silvopasture systems for longer period about 55% or more PAR is required. PMID:21506487

  16. Growth, biomass production and photosynthesis of Cenchrus ciliaris L. under Acacia tortilis (Forssk.) Hayne based silvopastoral systems in semi arid tropics.

    PubMed

    Mishra, A K; Tiwari, H S; Bhatt, R K

    2010-11-01

    The growth, biomass production and photosynthesis of Cenchrus ciliaris was studied under the canopies of 17 yr old Acacia tortilis trees in semi arid tropical environment. On an average the full grown canopy of A. tortilis at the spacing of 4 x 4 m allowed 55% of total Photosynthetically Active Radiation (PAR) which in turn increased Relative Humidity (RH) and reduced under canopy temperature to -1.75 degrees C over the open air temperature. C. ciliaris attained higher height under the shade of A. tortilis. The tiller production and leaf area index decreased marginally under the shade of tree canopies as compared to the open grown grasses. C. ciliaris accumulated higher chlorophyll a and b under the shade of tree canopies indicating its shade adaptation potential. The assimilatory functions such as rate of photosynthesis, transpiration, stomatal conductance, photosynthetic water use efficiency (PN/TR) and carboxylation efficiency (PN/CINT) decreased under the tree canopies due to low availability of PAR. The total biomass production in term of fresh and dry weight decreased under the tree canopies. On average of 2 yr C. ciliaris had produced 12.78 t ha(-1) green and 3.72 -t ha(-1) dry biomass under the tree canopies of A. tortilis. The dry matter yield reduced to 38% under the tree canopies over the open grown grasses. The A. tortilis + C. ciliaris maintained higher soil moisture, organic carbon content and available N P K for sustainable biomass production for the longer period. The higher accumulation of crude protein, starch, sugar and nitrogen in leaves and stem of C. ciliaris indicates that this grass species also maintained its quality under A. tortilis based silvopastoral system. The photosynthesis and dry matter accumulation are closely associated with available PAR indicating that for sustainable production of this grass species in the silvopasture systems for longer period about 55% or more PAR is required.

  17. Quantitative Genetic Analysis of Biomass and Wood Chemistry of Populus under Different Nitrogen Levels

    SciTech Connect

    Novaes, E.; Osorio, L.; Drost, D. R.; Miles, B. L.; Boaventura-Novaes, C. R. D.; Benedict, C.; Dervinis, C.; Yu, Q.; Sykes, R.; Davis, M.; Martin, T. A.; Peter, G. F.; Kirst, M.

    2009-01-01

    The genetic control of carbon allocation and partitioning in woody perennial plants is poorly understood despite its importance for carbon sequestration, biofuels and other wood-based industries. It is also unclear how environmental cues, such as nitrogen availability, impact the genes that regulate growth, biomass allocation and wood composition in trees. We phenotyped 396 clonally replicated genotypes of an interspecific pseudo-backcross pedigree of Populus for wood composition and biomass traits in above- and below-ground organs. The loci that regulate growth, carbon allocation and partitioning under two nitrogen conditions were identified, defining the contribution of environmental cues to their genetic control. Sixty-three quantitative trait loci were identified for the 20 traits analyzed. The majority of quantitative trait loci are specific to one of the two nitrogen treatments, demonstrating significant nitrogen-dependent genetic control. A highly significant genetic correlation was observed between plant growth and lignin/cellulose composition, and quantitative trait loci co-localization identified the genomic position of potential pleiotropic regulators. Pleiotropic loci linking higher growth rates to wood with less lignin are excellent targets to engineer tree germplasm improved for pulp, paper and cellulosic ethanol production. The causative genes are being identified with a genetical genomics approach.

  18. Effects of elevated CO2 concentration on growth, photosynthetic characteristics and biomass of wheat (Triticum aestivum L.) in Lunar Palace 1

    NASA Astrophysics Data System (ADS)

    Dong, Chen; Liu, Hui; Liu, Hong; Wang, Minjuan; Fu, Yuming; Shao, Lingzhi; Liu, Guanghui; Yu, Juan

    Short- and long-term effects of elevated CO2 concentration on growth, photosynthetic characteristics and biomass of wheat (Triticum aestivum L.) are examined during 90 days in Lunar Palace 1. While a short-term exposure to elevated CO2 induces a large increase in photosynthesis in wheat plants, long-term growth in elevated CO2 often results in a smaller increase due to reduced photosynthetic capacity. In this study, it was also shown that, net photosynthesis per unit leaf area was raised at an increased CO2 concentration partly due to a decrease in photorespiration, partly due to an increased substrate supply. Transpiration was reduced due to a lower stomatal conductance. The growth response of whole plants to a high CO2 concentration will be the main subject of this paper. Firstly, an estimation is made to what extent a doubling in CO2 concentration affects wheat plant growth in Lunar Palace 1. Secondly, the mechanisms behind this growth stimulation will be assessed. Finally, in those cases where wheat plants are grown over a range of environmental conditions, we select that condition where control plants are growing fastest. Thus, this study may be a matter of interest for researchers in both space and unban agriculture fields.

  19. Responses of Gmelina arborea, a tropical deciduous tree species, to elevated atmospheric CO2: growth, biomass productivity and carbon sequestration efficacy.

    PubMed

    Rasineni, Girish K; Guha, Anirban; Reddy, Attipalli R

    2011-10-01

    The photosynthetic response of trees to rising CO(2) concentrations largely depends on source-sink relations, in addition to differences in responsiveness by species, genotype, and functional group. Previous studies on elevated CO(2) responses in trees have either doubled the gas concentration (>700 μmol mol(-1)) or used single large addition of CO(2) (500-600 μmol mol(-1)). In this study, Gmelina arborea, a fast growing tropical deciduous tree species, was selected to determine the photosynthetic efficiency, growth response and overall source-sink relations under near elevated atmospheric CO(2) concentration (460 μmol mol(-1)). Net photosynthetic rate of Gmelina was ~30% higher in plants grown in elevated CO(2) compared with ambient CO(2)-grown plants. The elevated CO(2) concentration also had significant effect on photochemical and biochemical capacities evidenced by changes in F(V)/F(M), ABS/CSm, ET(0)/CSm and RuBPcase activity. The study also revealed that elevated CO(2) conditions significantly increased absolute growth rate, above ground biomass and carbon sequestration potential in Gmelina which sequestered ~2100 g tree(-1) carbon after 120 days of treatment when compared to ambient CO(2)-grown plants. Our data indicate that young Gmelina could accumulate significant biomass and escape acclimatory down-regulation of photosynthesis due to high source-sink capacity even with an increase of 100 μmo lmol(-1) CO(2). PMID:21889049

  20. Elucidating temporal resource allocation and diurnal dynamics in phototrophic metabolism using conditional FBA.

    PubMed

    Rügen, Marco; Bockmayr, Alexander; Steuer, Ralf

    2015-01-01

    The computational analysis of phototrophic growth using constraint-based optimization requires to go beyond current time-invariant implementations of flux-balance analysis (FBA). Phototrophic organisms, such as cyanobacteria, rely on harvesting the sun's energy for the conversion of atmospheric CO2 into organic carbon, hence their metabolism follows a strongly diurnal lifestyle. We describe the growth of cyanobacteria in a periodic environment using a new method called conditional FBA. Our approach enables us to incorporate the temporal organization and conditional dependencies into a constraint-based description of phototrophic metabolism. Specifically, we take into account that cellular processes require resources that are themselves products of metabolism. Phototrophic growth can therefore be formulated as a time-dependent linear optimization problem, such that optimal growth requires a differential allocation of resources during different times of the day. Conditional FBA then allows us to simulate phototrophic growth of an average cell in an environment with varying light intensity, resulting in dynamic time-courses for all involved reaction fluxes, as well as changes in biomass composition over a diurnal cycle. Our results are in good agreement with several known facts about the temporal organization of phototrophic growth and have implications for further analysis of resource allocation problems in phototrophic metabolism. PMID:26496972

  1. Interactive effects of pollination and heavy metals on resource allocation in Potentilla anserina L.

    SciTech Connect

    Saikkonen, K. |; Koivunen, S.; Vuorisalo, T.; Mutikainen, P. |

    1998-07-01

    The authors studied resource allocation between sexual reproduction and clonal propagation in a perennial stoloniferous clonal plant, Potentilla anserina, an obligate outcrosser. They manipulated reproductive effort of Potentilla anserina either by hand-pollinating all flowers or by preventing pollination. To test the effect of resource-limiting conditions on resource allocation and reproductive output, the authors used a control and two levels of heavy metals (copper and nickel) to limit plant growth. The experiment was conducted as a 2 {times} 3 factorial design to reveal possible interactions between reproductive manipulation and resource limitation. Heavy metals decreased the total biomass of the plants and number of flowers and ramets produced. Only 50% of the plants grown with the higher level of heavy metals produced flowers. Pollination treatment interacted significantly with the heavy-metal treatment. In the metal control and lower heavy-metal treatment, there were no significant differences in total vegetative biomass between the two pollination treatments. Costs of reproduction in terms of subsequent flowering in the later season appeared to be clear, because the number of flowers per whole plant was lower if the plants were hand-pollinated and because the proportion of flowering ramets decreased due to hand-pollination. However, flowering may also be partly hormonally controlled. In contrast, hand-pollinated plants exposed to high concentrations of heavy metals tended to have greater biomass of vegetative plant structures and higher number of flowers compared to nonpollinated plants.

  2. The allocation of ecosystem net primary productivity in tropical forests

    PubMed Central

    Malhi, Yadvinder; Doughty, Christopher; Galbraith, David

    2011-01-01

    The allocation of the net primary productivity (NPP) of an ecosystem between canopy, woody tissue and fine roots is an important descriptor of the functioning of that ecosystem, and an important feature to correctly represent in terrestrial ecosystem models. Here, we collate and analyse a global dataset of NPP allocation in tropical forests, and compare this with the representation of NPP allocation in 13 terrestrial ecosystem models. On average, the data suggest an equal partitioning of allocation between all three main components (mean 34 ± 6% canopy, 39 ± 10% wood, 27 ± 11% fine roots), but there is substantial site-to-site variation in allocation to woody tissue versus allocation to fine roots. Allocation to canopy (leaves, flowers and fruit) shows much less variance. The mean allocation of the ecosystem models is close to the mean of the data, but the spread is much greater, with several models reporting allocation partitioning outside of the spread of the data. Where all main components of NPP cannot be measured, litterfall is a good predictor of overall NPP (r2 = 0.83 for linear fit forced through origin), stem growth is a moderate predictor and fine root production a poor predictor. Across sites the major component of variation of allocation is a shifting allocation between wood and fine roots, with allocation to the canopy being a relatively invariant component of total NPP. This suggests the dominant allocation trade-off is a ‘fine root versus wood’ trade-off, as opposed to the expected ‘root–shoot’ trade-off; such a trade-off has recently been posited on theoretical grounds for old-growth forest stands. We conclude by discussing the systematic biases in estimates of allocation introduced by missing NPP components, including herbivory, large leaf litter and root exudates production. These biases have a moderate effect on overall carbon allocation estimates, but are smaller than the observed range in allocation values across sites. PMID

  3. Overexpression of a novel Arabidopsis PP2C isoform, AtPP2CF1, enhances plant biomass production by increasing inflorescence stem growth.

    PubMed

    Sugimoto, Hiroki; Kondo, Satoshi; Tanaka, Tomoko; Imamura, Chie; Muramoto, Nobuhiko; Hattori, Etsuko; Ogawa, Ken'ichi; Mitsukawa, Norihiro; Ohto, Chikara

    2014-10-01

    In contrast to mammals, higher plants have evolved to express diverse protein phosphatase 2Cs (PP2Cs). Of all Arabidopsis thaliana PP2Cs, members of PP2C subfamily A, including ABI1, have been shown to be key negative regulators of abscisic acid (ABA) signalling pathways, which regulate plant growth and development as well as tolerance to adverse environmental conditions. However, little is known about the enzymatic and signalling roles of other PP2C subfamilies. Here, we report a novel Arabidopsis subfamily E PP2C gene, At3g05640, designated AtPP2CF1. AtPP2CF1 was dramatically expressed in response to exogenous ABA and was expressed in vascular tissues and guard cells, similar to most subfamily A PP2C genes. In vitro enzymatic activity assays showed that AtPP2CF1 possessed functional PP2C activity. However, yeast two-hybrid analysis revealed that AtPP2CF1 did not interact with PYR/PYL/RCAR receptors or three SnRK2 kinases, which are ABI1-interacting proteins. This was supported by homology-based structural modelling demonstrating that the putative active- and substrate-binding site of AtPP2CF1 differed from that of ABI1. Furthermore, while overexpression of ABI1 in plants induced an ABA-insensitive phenotype, Arabidopsis plants overexpressing AtPP2CF1 (AtPP2CF1oe) were weakly hypersensitive to ABA during seed germination and drought stress. Unexpectedly, AtPP2CF1oe plants also exhibited increased biomass yield, mainly due to accelerated growth of inflorescence stems through the activation of cell proliferation and expansion. Our results provide new insights into the physiological significance of AtPP2CF1 as a candidate gene for plant growth production and for potential application in the sustainable supply of plant biomass.

  4. Overexpression of a novel Arabidopsis PP2C isoform, AtPP2CF1, enhances plant biomass production by increasing inflorescence stem growth.

    PubMed

    Sugimoto, Hiroki; Kondo, Satoshi; Tanaka, Tomoko; Imamura, Chie; Muramoto, Nobuhiko; Hattori, Etsuko; Ogawa, Ken'ichi; Mitsukawa, Norihiro; Ohto, Chikara

    2014-10-01

    In contrast to mammals, higher plants have evolved to express diverse protein phosphatase 2Cs (PP2Cs). Of all Arabidopsis thaliana PP2Cs, members of PP2C subfamily A, including ABI1, have been shown to be key negative regulators of abscisic acid (ABA) signalling pathways, which regulate plant growth and development as well as tolerance to adverse environmental conditions. However, little is known about the enzymatic and signalling roles of other PP2C subfamilies. Here, we report a novel Arabidopsis subfamily E PP2C gene, At3g05640, designated AtPP2CF1. AtPP2CF1 was dramatically expressed in response to exogenous ABA and was expressed in vascular tissues and guard cells, similar to most subfamily A PP2C genes. In vitro enzymatic activity assays showed that AtPP2CF1 possessed functional PP2C activity. However, yeast two-hybrid analysis revealed that AtPP2CF1 did not interact with PYR/PYL/RCAR receptors or three SnRK2 kinases, which are ABI1-interacting proteins. This was supported by homology-based structural modelling demonstrating that the putative active- and substrate-binding site of AtPP2CF1 differed from that of ABI1. Furthermore, while overexpression of ABI1 in plants induced an ABA-insensitive phenotype, Arabidopsis plants overexpressing AtPP2CF1 (AtPP2CF1oe) were weakly hypersensitive to ABA during seed germination and drought stress. Unexpectedly, AtPP2CF1oe plants also exhibited increased biomass yield, mainly due to accelerated growth of inflorescence stems through the activation of cell proliferation and expansion. Our results provide new insights into the physiological significance of AtPP2CF1 as a candidate gene for plant growth production and for potential application in the sustainable supply of plant biomass. PMID:25038254

  5. Biomass pretreatment

    DOEpatents

    Hennessey, Susan Marie; Friend, Julie; Elander, Richard T; Tucker, III, Melvin P

    2013-05-21

    A method is provided for producing an improved pretreated biomass product for use in saccharification followed by fermentation to produce a target chemical that includes removal of saccharification and or fermentation inhibitors from the pretreated biomass product. Specifically, the pretreated biomass product derived from using the present method has fewer inhibitors of saccharification and/or fermentation without a loss in sugar content.

  6. Carbon allocation to ectomycorrhizal fungi correlates with belowground allocation in culture studies.

    PubMed

    Hobbie, Erik A

    2006-03-01

    Ectomycorrhizal fungi form symbioses with most temperate and boreal tree species, but difficulties in measuring carbon allocation to these symbionts have prevented the assessment of their importance in forest ecosystems. Here, I surveyed allocation patterns in 14 culture studies and five field studies of ectomycorrhizal plants. In culture studies, allocation to ectomycorrhizal fungi (NPPf) was linearly related to total belowground net primary production (NPPb) by the equation NPPf = 41.5% x NPPb - 11.3% (r2 = 0.55, P < 0.001) and ranged from 1% to 21% of total net primary production. As a percentage of NPP, allocation to ectomycorrhizal fungi was highest at lowest plant growth rates and lowest nutrient availabilities. Because total belowground allocation can be estimated using carbon balance techniques, these relationships should allow ecologists to incorporate mycorrhizal fungi into existing ecosystem models. In field studies, allocation to ectomycorrhizal fungi ranged from 0% to 22% of total allocation, but wide differences in measurement techniques made intercomparisons difficult. Techniques such as fungal in-growth cores, root branching-order studies, and isotopic analyses could refine our estimates of turnover rates of fine roots, mycorrhizae, and extraradical hyphae. Together with ecosystem modeling, such techniques could soon provide good estimates of the relative importance of root vs. fungal allocation in belowground carbon budgets.

  7. [Effects of UV-B radiation on the growth and reproduction of Vicia angustifolia].

    PubMed

    Wang, Ying; Wang, Xing-An; Wang, Ren-Jun; Qiu, Nian-Wei; Ma, Zong-Qi; Du, Guo-Zhen

    2012-05-01

    A simulation experiment with supplementation and exclusion of solar ultraviolet-B (UV-B) radiation was conducted to study the effects of enhanced and near ambient UV-B radiation on the growth and reproduction of alpine annual pasture Vicia angustifolia on Qinghai-Tibet Plateau. Enhanced UV-B decreased the plant height and biomass, biomass allocation to fruit, flower number, and 100-seed mass significantly, delayed flowering stage, increased the concentration degree of flowering and success rate of reproduction, but had little effect on seed yield. Near ambient UV-B radiation made the plant height increased after an initial decrease, decreased biomass allocation to fruit and 100-seed mass, but little affected flowering duration, flower number, and seed yield. Both enhanced and near ambient UV-B radiation could inhibit the growth and production of V. angustifolia, and the effect of enhanced UV-B radiation was even larger.

  8. Biomass Logistics

    SciTech Connect

    J. Richard Hess; Kevin L. Kenney; William A. Smith; Ian Bonner; David J. Muth

    2015-04-01

    Equipment manufacturers have made rapid improvements in biomass harvesting and handling equipment. These improvements have increased transportation and handling efficiencies due to higher biomass densities and reduced losses. Improvements in grinder efficiencies and capacity have reduced biomass grinding costs. Biomass collection efficiencies (the ratio of biomass collected to the amount available in the field) as high as 75% for crop residues and greater than 90% for perennial energy crops have also been demonstrated. However, as collection rates increase, the fraction of entrained soil in the biomass increases, and high biomass residue removal rates can violate agronomic sustainability limits. Advancements in quantifying multi-factor sustainability limits to increase removal rate as guided by sustainable residue removal plans, and mitigating soil contamination through targeted removal rates based on soil type and residue type/fraction is allowing the use of new high efficiency harvesting equipment and methods. As another consideration, single pass harvesting and other technologies that improve harvesting costs cause biomass storage moisture management challenges, which challenges are further perturbed by annual variability in biomass moisture content. Monitoring, sampling, simulation, and analysis provide basis for moisture, time, and quality relationships in storage, which has allowed the development of moisture tolerant storage systems and best management processes that combine moisture content and time to accommodate baled storage of wet material based upon “shelf-life.” The key to improving biomass supply logistics costs has been developing the associated agronomic sustainability and biomass quality technologies and processes that allow the implementation of equipment engineering solutions.

  9. Evaluation of wheat growth, morphological characteristics, biomass yield and quality in Lunar Palace-1, plant factory, green house and field systems

    NASA Astrophysics Data System (ADS)

    Dong, Chen; Shao, Lingzhi; Fu, Yuming; Wang, Minjuan; Xie, Beizhen; Yu, Juan; Liu, Hong

    2015-06-01

    Wheat (Triticum aestivum L.) is one of the most important agricultural crops in both space such as Bioregenerative Life Support Systems (BLSS) and urban agriculture fields, and its cultivation is affected by several environmental factors. The objective of this study was to investigate the influences of different environmental conditions (BLSS, plant factory, green house and field) on the wheat growth, thousand kernel weight (TKW), harvest index (HI), biomass yield and quality during their life cycle. The results showed that plant height partially influenced by the interaction effects with environment, and this influence decreased gradually with the plant development. It was found that there was no significant difference between the BLSS and plant factory treatments on yields per square, but the yield of green house and field treatments were both lower. TKW and HI in BLSS and plant factory were larger than those in the green house and field. However, grain protein concentration can be inversely correlated with grain yield. Grain protein concentrations decreased under elevate CO2 condition and the magnitude of the reductions depended on the prevailing environmental condition. Conditional interaction effects with environment also influenced the components of straw during the mature stage. It indicated that CO2 enriched environment to some extent was better for inedible biomass degradation and had a significant effect on "source-sink flow" at grain filling stage, which was more beneficial to recycle substances in the processes of the environment regeneration.

  10. Interspecific Competition and Trade-offs in Resource Allocation are the Key to Successful Growth of Seedlings of White Spruce (Picea glauca (Moench) Voss) at Subarctic Treelines in Warming Alaska.

    NASA Astrophysics Data System (ADS)

    Okano, K.; Bret-Harte, M. S.

    2015-12-01

    Alpine treelines in Alaska have advanced for the past 50 years in response to the recent climate warming. However, further increases in temperatures may cause treeline species drought stress and increase susceptibility to insect outbreaks and fire. Complex factors such as soil conditions and plant species composition also impact the growth of seedlings, which are essential to sustain boreal forests. Our goals were to assess 1) the current optimal elevation for the treeline species Picea glauca (white spruce) seedlings and how it is altered by climate change, and 2) their growth/survival strategies at each environmental site. We studied the growth response of spruce seedlings along an altitudinal gradient at 6 sites, consisting of tundra, forest, or transitional ecotone in Denali National Park and one forest site in Fairbanks, AK. In May 2012, four-month old seedlings were planted with or without naturally occurring plants to compare the presence or absence of the interspecific interaction. Summer temperatures were increased by one small greenhouse per site. Over 2 growing seasons, growth was measured non-destructively, and then the seedlings were harvested. Relative growth rate (RGR) in height was increased significantly as the altitude was increased. Elevated temperature increased height only in seedlings at a high-altitude forest. Seedlings with neighboring plants had a higher RGR in height than seedlings that had neighbors removed, while significantly wider diameters were measured from the seedlings without neighbors. A weak trend of declining diameter width with increasing altitudes was seen. Seedlings that grew taller did not grow their stems wider, indicating trade-offs in resource allocation. None of the altitudinal sites had a clear advantage for the growth of the seedlings. Habitat microclimate and the interaction with other species could be more important than the altitude or temperatures and hence, key to the survival and growth of spruce seedlings in

  11. No cumulative effect of 10 years of elevated [CO2 ] on perennial plant biomass components in the Mojave Desert.

    PubMed

    Newingham, Beth A; Vanier, Cheryl H; Charlet, Therese N; Ogle, Kiona; Smith, Stanley D; Nowak, Robert S

    2013-07-01

    Elevated atmospheric CO2 concentrations ([CO2 ]) generally increase primary production of terrestrial ecosystems. Production responses to elevated [CO2 ] may be particularly large in deserts, but information on their long-term response is unknown. We evaluated the cumulative effects of elevated [CO2 ] on primary production at the Nevada Desert FACE (free-air carbon dioxide enrichment) Facility. Aboveground and belowground perennial plant biomass was harvested in an intact Mojave Desert ecosystem at the end of a 10-year elevated [CO2 ] experiment. We measured community standing biomass, biomass allocation, canopy cover, leaf area index (LAI), carbon and nitrogen content, and isotopic composition of plant tissues for five to eight dominant species. We provide the first long-term results of elevated [CO2 ] on biomass components of a desert ecosystem and offer information on understudied Mojave Desert species. In contrast to initial expectations, 10 years of elevated [CO2 ] had no significant effect on standing biomass, biomass allocation, canopy cover, and C : N ratios of above- and belowground components. However, elevated [CO2 ] increased short-term responses, including leaf water-use efficiency (WUE) as measured by carbon isotope discrimination and increased plot-level LAI. Standing biomass, biomass allocation, canopy cover, and C : N ratios of above- and belowground pools significantly differed among dominant species, but responses to elevated [CO2 ] did not vary among species, photosynthetic pathway (C3 vs. C4 ), or growth form (drought-deciduous shrub vs. evergreen shrub vs. grass). Thus, even though previous and current results occasionally show increased leaf-level photosynthetic rates, WUE, LAI, and plant growth under elevated [CO2 ] during the 10-year experiment, most responses were in wet years and did not lead to sustained increases in community biomass. We presume that the lack of sustained biomass responses to elevated [CO2 ] is explained by inter

  12. Climate warming shifts carbon allocation from stemwood to roots in calcium-depleted spruce forests

    NASA Astrophysics Data System (ADS)

    Lapenis, Andrei; Lawrence, Gregory; Buyantuev, Alexander

    2015-04-01

    Increased greening of northern forests, measured by the Normalized Difference Vegetation Index (NDVI), has been presented as evidence that a warmer climate has increased both net primary productivity (NPP) and the carbon sink in boreal forests. However, higher production and greener canopies may accompany changes in carbon allocation that favor foliage or fine roots over less decomposable woody biomass. Furthermore, tree core data throughout mid- and northern latitudes have revealed a divergence problem (DP), a weakening in tree ring responses to warming over the past half century that is receiving increasing attention, but remains poorly understood. Often, the same sites exhibit trend inconsistency phenomenon (TIP), namely positive, or no trends in growing season NDVI where negative trends in tree ring indexes are observed. Here we studied growth of two Norway spruce (Picea abies) stands in western Russia that exhibited both the DP and TIP but were subject to soil acidification and calcium depletion of differing timing and severity. Our results link the decline in radial growth starting in 1980 to a shift in carbon allocation from wood to roots driven by a combination of two factors: (a) soil acidification that depleted calcium and impaired root function and (b) earlier onset of the growing season that further taxed the root system. The latter change in phenology appears to act as a trigger at both sites to push trees into nutrient limitation as the demand for Ca increased with the longer growing season, thereby causing the shift in carbon allocation.

  13. Climate warming shifts carbon allocation from stemwood to roots in calcium-depleted spruce forests

    USGS Publications Warehouse

    Lapenis, Andrei Gennady; Lawrence, Gregory B.; Heim, Alexander; Zheng, Chengyang; Shortle, Walter

    2013-01-01

    Increased greening of northern forests, measured by the Normalized Difference Vegetation Index (NDVI), has been presented as evidence that a warmer climate has increased both net primary productivity (NPP) and the carbon sink in boreal forests. However, higher production and greener canopies may accompany changes in carbon allocation that favor foliage or fine roots over less decomposable woody biomass. Furthermore, tree core data throughout mid- and northern latitudes have revealed a divergence problem (DP), a weakening in tree ring responses to warming over the past half century that is receiving increasing attention, but remains poorly understood. Often, the same sites exhibit trend inconsistency phenomenon (TIP), namely positive, or no trends in growing season NDVI where negative trends in tree ring indexes are observed. Here we studied growth of two Norway spruce (Picea abies) stands in western Russia that exhibited both the DP and TIP but were subject to soil acidification and calcium depletion of differing timing and severity. Our results link the decline in radial growth starting in 1980 to a shift in carbon allocation from wood to roots driven by a combination of two factors: (a) soil acidification that depleted calcium and impaired root function and (b) earlier onset of the growing season that further taxed the root system. The latter change in phenology appears to act as a trigger at both sites to push trees into nutrient limitation as the demand for Ca increased with the longer growing season, thereby causing the shift in carbon allocation.

  14. Phenotypic correlates of the lianescent growth form: a review

    PubMed Central

    Wyka, Tomasz P.; Oleksyn, Jacek; Karolewski, Piotr; Schnitzer, Stefan A.

    2013-01-01

    Background As proposed by Darwin, climbers have been assumed to allocate a smaller fraction of biomass to support organs in comparison with self-supporting plants. They have also been hypothesized to possess a set of traits associated with fast growth, resource uptake and high productivity. Scope In this review, these hypotheses are evaluated by assembling and synthesizing published and unpublished data sets from across the globe concerning resource allocation, growth rates and traits of leaves, stems and roots of climbers and self-supporting species. Conclusions The majority of studies offer little support for the smaller allocation of biomass to stems or greater relative growth rates in climbers; however, these results are based on small sized (<1 kg) plants. Simulations based on allometric biomass equations demonstrate, however, that larger lianas allocate a greater fraction of above-ground biomass to leaves (and therefore less biomass to stems) compared with similar sized trees. A survey of leaf traits of lianas revealed their lower average leaf mass per area (LMA), higher N and P concentration and a slightly higher mass-based photosynthetic rate, as well as a lower concentration of phenolic-based compounds than in woody self-supporting species, consistent with the specialization of lianas towards the fast metabolism/rapid turnover end of the global trait spectra. Liana stems have an efficient hydraulic design and unique mechanical features, while roots appear to penetrate deeper soil levels than in trees and are often able to generate hydraulic pressure. Much remains to be learned, however, about these and other functional specializations of their axial organs and the associated trade-offs. Developmental switches between self-supporting, searcher and climbing shoots within the same individual are a promising field of comparative studies on trait association in lianas. Finally, some of the vast trait variability within lianas may be reduced when species with

  15. Contrasting patterns of diameter and biomass increment across tree functional groups in Amazonian forests.

    PubMed

    Keeling, Helen C; Baker, Timothy R; Martinez, Rodolfo Vasquez; Monteagudo, Abel; Phillips, Oliver L

    2008-12-01

    Species' functional traits may help determine rates of carbon gain, with physiological and morphological trade-offs relating to shade tolerance affecting photosynthetic capacity and carbon allocation strategies. However, few studies have examined these trade-offs from the perspective of whole-plant biomass gain of adult trees. We compared tree-level annual diameter increments and annual above-ground biomass (AGB) increments in eight long-term plots in hyper-diverse northwest Amazonia to wood density (rho; a proxy for shade tolerance), whilst also controlling for resource supply (light and soil fertility). rho and annual diameter increment were negatively related, confirming expected differences in allocation associated with shade tolerance, such that light-demanding species allocate a greater proportion of carbon to diameter gain at the expense of woody tissue density. However, contrary to expectations, we found a positive relationship between rho and annual AGB increment in more fertile sites, although AGB gain did not differ significantly with rho class on low-fertility sites. Whole-plant carbon gain may be greater in shade-tolerant species due to higher total leaf area, despite lower leaf-level carbon assimilation rates. Alternatively, rates of carbon loss may be higher in more light-demanding species: higher rates of litterfall, respiration or allocation to roots, are all plausible mechanisms. However, the relationships between rho and AGB and diameter increments were weak; resource availability always exerted a stronger influence on tree growth rates. PMID:18853192

  16. Contrasting patterns of diameter and biomass increment across tree functional groups in Amazonian forests.

    PubMed

    Keeling, Helen C; Baker, Timothy R; Martinez, Rodolfo Vasquez; Monteagudo, Abel; Phillips, Oliver L

    2008-12-01

    Species' functional traits may help determine rates of carbon gain, with physiological and morphological trade-offs relating to shade tolerance affecting photosynthetic capacity and carbon allocation strategies. However, few studies have examined these trade-offs from the perspective of whole-plant biomass gain of adult trees. We compared tree-level annual diameter increments and annual above-ground biomass (AGB) increments in eight long-term plots in hyper-diverse northwest Amazonia to wood density (rho; a proxy for shade tolerance), whilst also controlling for resource supply (light and soil fertility). rho and annual diameter increment were negatively related, confirming expected differences in allocation associated with shade tolerance, such that light-demanding species allocate a greater proportion of carbon to diameter gain at the expense of woody tissue density. However, contrary to expectations, we found a positive relationship between rho and annual AGB increment in more fertile sites, although AGB gain did not differ significantly with rho class on low-fertility sites. Whole-plant carbon gain may be greater in shade-tolerant species due to higher total leaf area, despite lower leaf-level carbon assimilation rates. Alternatively, rates of carbon loss may be higher in more light-demanding species: higher rates of litterfall, respiration or allocation to roots, are all plausible mechanisms. However, the relationships between rho and AGB and diameter increments were weak; resource availability always exerted a stronger influence on tree growth rates.

  17. Trichoderma virens, a plant beneficial fungus, enhances biomass production and promotes lateral root growth through an auxin-dependent mechanism in Arabidopsis.

    PubMed

    Contreras-Cornejo, Hexon Angel; Macías-Rodríguez, Lourdes; Cortés-Penagos, Carlos; López-Bucio, José

    2009-03-01

    Trichoderma species belong to a class of free-living fungi beneficial to plants that are common in the rhizosphere. We investigated the role of auxin in regulating the growth and development of Arabidopsis (Arabidopsis thaliana) seedlings in response to inoculation with Trichoderma virens and Trichoderma atroviride by developing a plant-fungus interaction system. Wild-type Arabidopsis seedlings inoculated with either T. virens or T. atroviride showed characteristic auxin-related phenotypes, including increased biomass production and stimulated lateral root development. Mutations in genes involved in auxin transport or signaling, AUX1, BIG, EIR1, and AXR1, were found to reduce the growth-promoting and root developmental effects of T. virens inoculation. When grown under axenic conditions, T. virens produced the auxin-related compounds indole-3-acetic acid, indole-3-acetaldehyde, and indole-3-ethanol. A comparative analysis of all three indolic compounds provided detailed information about the structure-activity relationship based on their efficacy at modulating root system architecture, activation of auxin-regulated gene expression, and rescue of the root hair-defective phenotype of the rhd6 auxin response Arabidopsis mutant. Our results highlight the important role of auxin signaling for plant growth promotion by T. virens.

  18. Growth of Quailbush in Acidic, Metalliferous Desert Mine Tailings: Effect of Azospirillum brasilense Sp6 on Biomass Production and Rhizosphere Community Structure

    PubMed Central

    de-Bashan, Luz E.; Hernandez, Juan-Pablo; Nelson, Karis N.; Bashan, Yoav

    2010-01-01

    Mine tailing deposits in semiarid and arid environments frequently remain devoid of vegetation due to the toxicity of the substrate and the absence of a diverse soil microbial community capable of supporting seed germination and plant growth. The contribution of the plant growth promoting bacterium (PGPB) Azospirillum brasilense Sp6 to the growth of quailbush in compost-amended, moderately acidic, high-metal content mine tailings using an irrigation-based reclamation strategy was examined along with its influence on the rhizosphere bacterial community. Sp6 inoculation resulted in a significant (2.2-fold) increase in plant biomass production. The data suggest that the inoculum successfully colonized the root surface and persisted throughout the 60-day experiment in both the rhizosphere, as demonstrated by excision and sequencing of the appropriate denaturing gradient gel electrophoresis (DGGE) band, and the rhizoplane, as indicated by fluorescent in situ hybridization of root surfaces. Changes in rhizosphere community structure in response to Sp6 inoculation were evaluated after 15, 30, and 60 days using DGGE analysis of 16S rRNA polymerase chain reaction amplicons. A comparison of DGGE profiles using canonical correspondence analysis revealed a significant treatment effect (Sp6-inoculated vs. uninoculated plants vs. unplanted) on bacterial community structure at 15, 30, and 60 days (p<0.05). These data indicate that in an extremely stressed environment such as acid mine tailings, an inoculated plant growth promoting bacterium not only can persist and stimulate plant growth but also can directly or indirectly influence rhizobacterial community development. PMID:20632001

  19. Growth of quailbush in acidic, metalliferous desert mine tailings: effect of Azospirillum brasilense Sp6 on biomass production and rhizosphere community structure.

    PubMed

    de-Bashan, Luz E; Hernandez, Juan-Pablo; Nelson, Karis N; Bashan, Yoav; Maier, Raina M

    2010-11-01

    Mine tailing deposits in semiarid and arid environments frequently remain devoid of vegetation due to the toxicity of the substrate and the absence of a diverse soil microbial community capable of supporting seed germination and plant growth. The contribution of the plant growth promoting bacterium (PGPB) Azospirillum brasilense Sp6 to the growth of quailbush in compost-amended, moderately acidic, high-metal content mine tailings using an irrigation-based reclamation strategy was examined along with its influence on the rhizosphere bacterial community. Sp6 inoculation resulted in a significant (2.2-fold) increase in plant biomass production. The data suggest that the inoculum successfully colonized the root surface and persisted throughout the 60-day experiment in both the rhizosphere, as demonstrated by excision and sequencing of the appropriate denaturing gradient gel electrophoresis (DGGE) band, and the rhizoplane, as indicated by fluorescent in situ hybridization of root surfaces. Changes in rhizosphere community structure in response to Sp6 inoculation were evaluated after 15, 30, and 60 days using DGGE analysis of 16S rRNA polymerase chain reaction amplicons. A comparison of DGGE profiles using canonical correspondence analysis revealed a significant treatment effect (Sp6-inoculated vs. uninoculated plants vs. unplanted) on bacterial community structure at 15, 30, and 60 days (p < 0.05). These data indicate that in an extremely stressed environment such as acid mine tailings, an inoculated plant growth promoting bacterium not only can persist and stimulate plant growth but also can directly or indirectly influence rhizobacterial community development.

  20. Effect of nutrients and salinity pulses on biomass and growth of Vallisneria americana in lower St Johns River, FL, USA

    PubMed Central

    Boustany, Ronald G.; Michot, Thomas C.; Moss, Rebecca F.

    2015-01-01

    We determined the interactive effects of nutrient loading and salinity pulsing on Vallisneria americana Michx., the dominant submerged aquatic vegetation species in the lower St Johns River (LSJR), FL, USA, and its associated algal community. Five hundred and ninety 6-inch diameter intact plant plugs of Vallisneria were collected from the LSJR in March 2003 and transported to US Geological Survey mesocosm facilities in Lafayette, LA, USA. A 3×3 experimental design consisting of three nutrient levels (control, 1/3 control and 3× control) and three salinity pulsing regimes (no pulse, 1-pulse at 18 ppt and 2-pulse at 12 and 18 ppt) was implemented with three replicates per treatment for a total of 27 experimental tanks. Salinity pulsing significantly reduced all measured Vallisneria growth parameters including above- and below-ground biomass, areal productivity and leaf area index. Nutrient levels had little effect on plants subjected to salinity pulses, but in non-salinity pulse treatments we observed higher mean macrophyte biomass in the low-nutrient loading treatments. Macroalgal components (epiphytes and surface algal mats) were not significantly different ( p=0.2998 and p=0.2444, respectively), but water column chlorophyll a (phytoplankton) was significantly higher ( p<0.0001) in all salinity pulse treatments except for the 1-pulse, low-nutrient treatment. A single salinity pulse at 18 ppt resulted in 22% pot mortality and two consecutive pulses of 18 and 12 ppt resulted in an additional 14% mortality. Individual leaves and ramets lost 59.7% and 67.8%, respectively, in the combined salinity pulse treatments. Nutrient loading tends to have a long-term effect on Vallisneria through complex community interactions while salinity pulsing frequency and intensity has an immediate and direct influence on growth and distribution. PMID:26064592

  1. Effect of nutrients and salinity pulses on biomass and growth of Vallisneria americana in lower St Johns River, FL, USA.

    PubMed

    Boustany, Ronald G; Michot, Thomas C; Moss, Rebecca F

    2015-02-01

    We determined the interactive effects of nutrient loading and salinity pulsing on Vallisneria americana Michx., the dominant submerged aquatic vegetation species in the lower St Johns River (LSJR), FL, USA, and its associated algal community. Five hundred and ninety 6-inch diameter intact plant plugs of Vallisneria were collected from the LSJR in March 2003 and transported to US Geological Survey mesocosm facilities in Lafayette, LA, USA. A 3×3 experimental design consisting of three nutrient levels (control, 1/3 control and 3× control) and three salinity pulsing regimes (no pulse, 1-pulse at 18 ppt and 2-pulse at 12 and 18 ppt) was implemented with three replicates per treatment for a total of 27 experimental tanks. Salinity pulsing significantly reduced all measured Vallisneria growth parameters including above- and below-ground biomass, areal productivity and leaf area index. Nutrient levels had little effect on plants subjected to salinity pulses, but in non-salinity pulse treatments we observed higher mean macrophyte biomass in the low-nutrient loading treatments. Macroalgal components (epiphytes and surface algal mats) were not significantly different ( p=0.2998 and p=0.2444, respectively), but water column chlorophyll a (phytoplankton) was significantly higher ( p<0.0001) in all salinity pulse treatments except for the 1-pulse, low-nutrient treatment. A single salinity pulse at 18 ppt resulted in 22% pot mortality and two consecutive pulses of 18 and 12 ppt resulted in an additional 14% mortality. Individual leaves and ramets lost 59.7% and 67.8%, respectively, in the combined salinity pulse treatments. Nutrient loading tends to have a long-term effect on Vallisneria through complex community interactions while salinity pulsing frequency and intensity has an immediate and direct influence on growth and distribution. PMID:26064592

  2. Effect of nutrients and salinity pulses on biomass and growth of Vallisneria americana in lower St Johns River, FL, USA.

    PubMed

    Boustany, Ronald G; Michot, Thomas C; Moss, Rebecca F

    2015-02-01

    We determined the interactive effects of nutrient loading and salinity pulsing on Vallisneria americana Michx., the dominant submerged aquatic vegetation species in the lower St Johns River (LSJR), FL, USA, and its associated algal community. Five hundred and ninety 6-inch diameter intact plant plugs of Vallisneria were collected from the LSJR in March 2003 and transported to US Geological Survey mesocosm facilities in Lafayette, LA, USA. A 3×3 experimental design consisting of three nutrient levels (control, 1/3 control and 3× control) and three salinity pulsing regimes (no pulse, 1-pulse at 18 ppt and 2-pulse at 12 and 18 ppt) was implemented with three replicates per treatment for a total of 27 experimental tanks. Salinity pulsing significantly reduced all measured Vallisneria growth parameters including above- and below-ground biomass, areal productivity and leaf area index. Nutrient levels had little effect on plants subjected to salinity pulses, but in non-salinity pulse treatments we observed higher mean macrophyte biomass in the low-nutrient loading treatments. Macroalgal components (epiphytes and surface algal mats) were not significantly different ( p=0.2998 and p=0.2444, respectively), but water column chlorophyll a (phytoplankton) was significantly higher ( p<0.0001) in all salinity pulse treatments except for the 1-pulse, low-nutrient treatment. A single salinity pulse at 18 ppt resulted in 22% pot mortality and two consecutive pulses of 18 and 12 ppt resulted in an additional 14% mortality. Individual leaves and ramets lost 59.7% and 67.8%, respectively, in the combined salinity pulse treatments. Nutrient loading tends to have a long-term effect on Vallisneria through complex community interactions while salinity pulsing frequency and intensity has an immediate and direct influence on growth and distribution.

  3. A strain of Saccharomyces cerevisiae evolved for fermentation of lignocellulosic biomass displays improved growth and fermentative ability in high solids concentrations and in the presence of inhibitory compounds

    PubMed Central

    2011-01-01

    Background Softwoods are the dominant source of lignocellulosic biomass in the northern hemisphere, and have been investigated worldwide as a renewable substrate for cellulosic ethanol production. One challenge to using softwoods, which is particularly acute with pine, is that the pretreatment process produces inhibitory compounds detrimental to the growth and metabolic activity of fermenting organisms. To overcome the challenge of bioconversion in the presence of inhibitory compounds, especially at high solids loading, a strain of Saccharomyces cerevisiae was subjected to evolutionary engineering and adaptation for fermentation of pretreated pine wood (Pinus taeda). Results An industrial strain of Saccharomyces, XR122N, was evolved using pretreated pine; the resulting daughter strain, AJP50, produced ethanol much more rapidly than its parent in fermentations of pretreated pine. Adaptation, by preculturing of the industrial yeast XR122N and the evolved strains in 7% dry weight per volume (w/v) pretreated pine solids prior to inoculation into higher solids concentrations, improved fermentation performance of all strains compared with direct inoculation into high solids. Growth comparisons between XR122N and AJP50 in model hydrolysate media containing inhibitory compounds found in pretreated biomass showed that AJP50 exited lag phase faster under all conditions tested. This was due, in part, to the ability of AJP50 to rapidly convert furfural and hydroxymethylfurfural to their less toxic alcohol derivatives, and to recover from reactive oxygen species damage more quickly than XR122N. Under industrially relevant conditions of 17.5% w/v pretreated pine solids loading, additional evolutionary engineering was required to decrease the pronounced lag phase. Using a combination of adaptation by inoculation first into a solids loading of 7% w/v for 24 hours, followed by a 10% v/v inoculum (approximately equivalent to 1 g/L dry cell weight) into 17.5% w/v solids, the final

  4. Growth temperature-induced changes in biomass accumulation, photosynthesis and glutathione redox homeostasis as influenced by hydrogen peroxide in cucumber.

    PubMed

    Li, Hao; Wang, Xue Min; Chen, Li; Ahammed, Golam Jalal; Xia, Xiao Jian; Shi, Kai; Considine, Michael J; Yu, Jing Quan; Zhou, Yan Hong

    2013-10-01

    Hydrogen peroxide (H2O2) and glutathione (GSH) are involved in the stress response in plants. To elucidate the role of H2O2 in the acclimation of CO2 assimilation under sub- or supra-optimal growth temperatures, we examined the effect and interaction of H2O2 manipulation on the photosynthetic metabolism of cucumber plants (Cucumis sativus L.) grown under five temperature regimes spanning above and below the optimal growth temperature; 11/9, 18/15, 25/20, 32/27, and 39/33 °C (day/night), with or without dimethylthiourea (DMTU) or H2O2 treatment. As expected, exposure to sub- or supra-optimal growth temperatures resulted in decreased plant growth, associated with a decline in CO2 assimilation (Asat), Rubisco content, and activities of enzymes involved in the CO2 assimilation, as well as a decrease in the ratio of reduced (GSH) to oxidized (GSSG) glutathione (GSH/GSSG). Foliar application of H2O2 promoted, whilst DMTU retarded the capacity of plants to acclimate to non-optimal growth temperatures; this was consistently shown in altered activity of redox-sensitive enzymes involved in CO2 assimilation. These results strongly suggest that the influence of growth temperature on CO2 assimilation was primarily targeted at the activities of the redox-sensitive enzymes of CO2 assimilation. Meanwhile, the data suggest that the cellular H2O2 level is an important signal for the glutathione-dependent regulation of redox-sensitive enzymes of CO2 assimilation in cucumber plants.

  5. An integrated microalgal growth model and its application to optimize the biomass production of Scenedesmus sp. LX1 in open pond under the nutrient level of domestic secondary effluent.

    PubMed

    Wu, Yin-Hu; Li, Xin; Yu, Yin; Hu, Hong-Ying; Zhang, Tian-Yuan; Li, Feng-Min

    2013-09-01

    Microalgal growth is the key to the coupled system of wastewater treatment and microalgal biomass production. In this study, Monod model, Droop model and Steele model were incorporated to obtain an integrated growth model describing the combined effects of nitrogen, phosphorus and light intensity on the growth rate of Scenedesmus sp. LX1. The model parameters were obtained via fitting experimental data to these classical models. Furthermore, the biomass production of Scenedesmus sp. LX1 in open pond under nutrient level of secondary effluent was analyzed based on the integrated model, predicting a maximal microalgal biomass production rate about 20 g m(-2) d(-1). In order to optimize the biomass production of open pond the microalgal biomass concentration, light intensity on the surface of open pond, total depth of culture medium and hydraulic retention time should be 500 g m(-3), 16,000 lx, 0.2 m and 5.2 d in the conditions of this study, respectively. PMID:23891148

  6. Dynamic allocation and transfer of non-structural carbohydrates, a possible mechanism for the explosive growth of Moso bamboo (Phyllostachys heterocycla).

    PubMed

    Song, Xinzhang; Peng, Changhui; Zhou, Guomo; Gu, Honghao; Li, Quan; Zhang, Chao

    2016-05-16

    Moso bamboo can rapidly complete its growth in both height and diameter within only 35-40 days after shoot emergence. However, the underlying mechanism for this "explosive growth" remains poorly understood. We investigated the dynamics of non-structural carbohydrates (NSCs) in shoots and attached mature bamboos over a 20-month period. The results showed that Moso bamboos rapidly completed their height and diameter growth within 38 days. At the same time, attached mature bamboos transferred almost all the NSCs of their leaves, branches, and especially trunks and rhizomes to the "explosively growing" shoots via underground rhizomes for the structural growth and metabolism of shoots. Approximately 4 months after shoot emergence, this transfer stopped when the leaves of the young bamboos could independently provide enough photoassimilates to meet the carbon demands of the young bamboos. During this period, the NSC content of the leaves, branches, trunks and rhizomes of mature bamboos declined by 1.5, 23, 28 and 5 fold, respectively. The trunk contributed the most NSCs to the shoots. Our findings provide new insight and a possible rational mechanism explaining the "explosive growth" of Moso bamboo and shed new light on understanding the role of NSCs in the rapid growth of Moso bamboo.

  7. Formation of ozone and growth of aerosols in young smoke plumes from biomass burning: 2. Three-dimensional Eulerian studies

    NASA Astrophysics Data System (ADS)

    Alvarado, Matthew James; Wang, Chien; Prinn, Ronald G.

    2009-05-01

    Global-scale models of atmospheric chemistry (GACMs) "mix" biomass burning emissions into grid boxes with horizontal scales of 10-200 km. This ignores the complex nonlinear transformations that take place in the young smoke plumes. Here we use a new gas- and aerosol-phase chemistry model called Aerosol Simulation Program (ASP) and a 3-D Eulerian smoke plume model to simulate the fluid dynamics, radiative transfer, gas-phase chemistry, and aerosol-phase chemistry of the Timbavati smoke plume observed during SAFARI 2000. We then compare the results of the 3-D plume model with those of an Eulerian box model, which is used as an analog for the large grid boxes of GACMs. The 3-D plume model matched the observed plume injection height but required a large minimum horizontal diffusion coefficient to match the observed horizontal dispersion of the plume. Absorption and scattering by smoke aerosols reduced the modeled photolysis rates in the plume by 10-20%. Increasing the heterogeneous production of HONO and H2SO4 in the model and including uncharacterized organic species using monoterpenes as a proxy compound improves the model-observation match. Direct measurements of OH in the smoke plumes would be an excellent way to determine if heterogeneous production of HONO is taking place. The automatic dilution of smoke plume emissions into the large grid boxes of global models can result in large errors in predicted concentrations of O3, NOx and aerosol species downwind. We discuss several potential approaches that could reduce these errors.

  8. Density and composition of microorganisms during long-term (418 day) growth of potato using biologically reclaimed nutrients from inedible plant biomass

    NASA Astrophysics Data System (ADS)

    Garland, J. L.; Cook, K. L.; Johnson, M.; Sumner, R.; Fields, N.

    1997-01-01

    A study evaluating alternative methods for long term operation of biomass production systems was recently completed at the Kennedy Space Center (KSC). The 418-day study evaluated repeated batch versus mixed-aged production of potato grown on either standard 1/2-strength Hoagland's nutrient solution or solutions including nutrients recycled from inedible plant material. The long term effects of closure and recycling on microbial dynamics were evaluated by monitoring the microbial communities associated with various habitats within the plant growth system (i.e., plant roots, nutrient solution, biofilms within the hydroponic systems, atmosphere, and atmospheric condensate). Plate count methods were used to enumerate and characterize microorganisms. Microscopic staining methods were used to estimate total cell densities. The primary finding was that the density and composition of microbial communities associated with controlled environmental plant growth systems are stable during long term operation. Continuous production resulted in slightly greater stability. Nutrient recycling, despite the addition of soluble organic material from the waste processing system, did not significantly increase microbial density in any of the habitats.

  9. Density and composition of microorganisms during long-term (418 day) growth of potato using biologically reclaimed nutrients from inedible plant biomass

    NASA Astrophysics Data System (ADS)

    1997-01-01

    A study evaluating alternative methods for long term operation of biomass production systems was recently completed at the Kennedy Space Center (KSC). The 418-day study evaluated repeated batch versus mixed-aged production of potato grown on either standard 12-strength Hoagland's nutrient solution or solutions including nutrients recycled from inedible plant material. The long term effects of closure and recycling on microbial dynamics were evaluated by monitoring the microbial communities associated with various habitats within the plant growth system (i.e., plant roots, nutrient solution, biofilms within the hydroponic systems, atmosphere, and atmospheric condensate). Plate count methods were used to enumerate and characterize microorganisms. Microscopic staining methods were used to estimate total cell densities. The primary finding was that the density and composition of microbial communities associated with controlled environmental plant growth systems are stable during long term operation. Continuous production resulted in slightly greater stability. Nutrient recycling, despite the addition of soluble organic material from the waste processing system, did not significantly increase microbial density in any of the habitats.

  10. Effects of an acute dose of gamma radiation exposure on stem diameter growth, carbon gain, and biomass partitioning in Helianthus annuus

    SciTech Connect

    Thiede, M.E.

    1988-05-25

    Nineteen-day-old dwarf sunflower plants (Helianthus annuus, variety NK894) received a variable dose (0-40 Gy) from a cobalt-60 gamma source. A very sensitive stem monitoring device, developed at Battelle's Pacific Northwest Laboratories, Richland, Washington was used to measure real-time changes in stem diameter. Exposure of plants caused a significant reduction in stem growth and root biomass. Doses as low as 5 Gy resulted in a significant increase in leaf density, suggesting that nonreversible morphological growth changes could be induced by very low doses of radiation. Carbohydrate analysis of 40-Gy irradiated plants demonstrated significantly more starch content in leaves and significantly less starch content in stems 18 days after exposure than did control plants. In contrast, the carbohydrate content in roots of 40-Gy irradiated plants were not significantly different from unirradiated plants 18 days after exposure. These results indicate that radiation either decreased phloem transport or reduced the availability of sugar reducing enzymes in irradiated plants. 44 refs., 12 figs.

  11. Evaluation of nutrient uptake and physical parameters on cell biomass growth and production of spilanthol in suspension cultures of Spilanthes acmella Murr.

    PubMed

    Singh, Mithilesh; Chaturvedi, Rakhi

    2012-08-01

    Spilanthes acmella Murr. has a plethora of highly valuable biologically active compounds and has been listed as one of the important medicinal plants of the world. However, no perceptible biotechnological advances have been made for this genus to exploit or enhance its utility. To nullify the effect of seasonal variations, the present report is the first attempt to establish in vitro cell suspension cultures and to evaluate the production of spilanthol from them, a key component of the plant responsible for most of its pharmaceutical activities. The study examined the biomass growth in relation to the consumption of major nutrients and sucrose, agitation speed and dynamic change in pH. Results indicated that the consumption of phosphate resulted in the onset of decline phase in cultures. Spilanthol production was observed to be growth associated and maximum production occurred on the 15th day. Among the carbon sources, the highest production of spilanthol as 91.4 µg g(-1) DW was recorded in the medium supplemented with sucrose, followed by glucose which produced 56.8 µg g(-1) DW of spilanthol. Spilanthol could not be detected in fructose containing medium. Maximum viable cultures were obtained at a rotation speed of cells at 120 rpm. This study signifies the utility of Spilanthes suspension cultures for biosynthesis and constant production of spilanthol, throughout the year. The results of present study are useful for further scale-up process. PMID:22237684

  12. Density and composition of microorganisms during long-term (418 day) growth of potato using biologically reclaimed nutrients from inedible plant biomass.

    PubMed

    Garland, J L; Cook, K L; Johnson, M; Sumner, R; Fields, N

    1997-01-01

    A study evaluating alternative methods for long term operation of biomass production systems was recently completed at the Kennedy Space Center (KSC). The 418-day study evaluated repeated batch versus mixed-aged production of potato grown on either standard 1/2-strength Hoagland's nutrient solution or solutions including nutrients recycled from inedible plant material. The long term effects of closure and recycling on microbial dynamics were evaluated by monitoring the microbial communities associated with various habitats within the plant growth system (i.e., plant roots, nutrient solution, biofilms within the hydroponic systems, atmosphere, and atmospheric condensate). Plate count methods were used to enumerate and characterize microorganisms. Microscopic staining methods were used to estunate total cell densities. The primary finding was that the density and composition of microbial communities associated with controlled environmental plant growth systems are stable during long term operation. Continuous production resulted in slightly greater stability. Nutrient recycling, despite the addition of soluble organic material from the waste processing system, did not significantly increase microbial density in any of the habitats. PMID:11542572

  13. Density and composition of microorganisms during long-term (418 day) growth of potato using biologically reclaimed nutrients from inedible plant biomass

    NASA Technical Reports Server (NTRS)

    Garland, J. L.; Cook, K. L.; Johnson, M.; Sumner, R.; Fields, N.; Sager, J. C. (Principal Investigator)

    1997-01-01

    A study evaluating alternative methods for long term operation of biomass production systems was recently completed at the Kennedy Space Center (KSC). The 418-day study evaluated repeated batch versus mixed-aged production of potato grown on either standard 1/2-strength Hoagland's nutrient solution or solutions including nutrients recycled from inedible plant material. The long term effects of closure and recycling on microbial dynamics were evaluated by monitoring the microbial communities associated with various habitats within the plant growth system (i.e., plant roots, nutrient solution, biofilms within the hydroponic systems, atmosphere, and atmospheric condensate). Plate count methods were used to enumerate and characterize microorganisms. Microscopic staining methods were used to estunate total cell densities. The primary finding was that the density and composition of microbial communities associated with controlled environmental plant growth systems are stable during long term operation. Continuous production resulted in slightly greater stability. Nutrient recycling, despite the addition of soluble organic material from the waste processing system, did not significantly increase microbial density in any of the habitats.

  14. An energy balance from absorbed photons to new biomass for Chlamydomonas reinhardtii and Chlamydomonas acidophila under neutral and extremely acidic growth conditions.

    PubMed

    Langner, Uwe; Jakob, Torsten; Stehfest, Katja; Wilhelm, Christian

    2009-03-01

    Chlamydomonas is one of the most well-studied photosynthetic organisms that had important biotechnological potential for future bioproductions of biofuels. However, an energy balance from incident photons to the energy stored in the new biomass is still lacking. In this study, we applied a recently developed system to measure the energy balance for steady state growth of Chlamydomonas reinhardtii grown at pH 6.5, and C. acidophila that was grown at pH 6.5 and 2.6. Energy use efficiency was quantified on the basis of light absorption, photosynthetic quantum yield, photosynthetic and respiratory quotient, and electron partitioning into proteins, carbohydrates and lipids. The results showed that lower growth rates of C. acidophila under both pH conditions were not caused by the differences in the photosynthetic quantum yield or in alternative electron cycling, but rather by differences in the efficiency of light absorption and increased dark respiration. Analysis of the macromolecular composition of the cells during the light phase showed that C. acidophila uses biosynthetic electrons preferentially for carbohydrate synthesis but not for synthesis of lipids. This led to a strong diurnal cycle of the C/N ratio and could explain the higher dark respiration of C. acidophila compared with C. reinhardtii. PMID:19054351

  15. The Unobtrusive Memory Allocator

    2003-03-31

    This library implements a memory allocator/manager which ask its host program or library for memory refions to manage rather than requesting them from the operating system. This allocator supports multiple distinct heaps within a single executable, each of which may grow either upward or downward in memory. The GNU mmalloc library has been modified in such a way that its allocation algorithms have been preserved, but the manner in which it obtains regions to managemore » has been changed to request memory from the host program or library. Additional modifications allow the allocator to manage each heap as either upward or downward-growing. By allowing the hosting program or library to determine what memory is managed, this package allows a greater degree of control than other memory allocation/management libraries. Additional distinguishing features include the ability to manage multiple distinct heaps with in a single executable, each of which may grow either upward or downward in memory. The most common use of this library is in conjunction with the Berkeley Unified Parallel C (UPC) Runtime Library. This package is a modified version of the LGPL-licensed "mmalloc" allocator from release 5.2 of the "gdb" debugger's source code.« less

  16. Dynamic allocation and transfer of non-structural carbohydrates, a possible mechanism for the explosive growth of Moso bamboo (Phyllostachys heterocycla)

    PubMed Central

    Song, Xinzhang; Peng, Changhui; Zhou, Guomo; Gu, Honghao; Li, Quan; Zhang, Chao

    2016-01-01

    Moso bamboo can rapidly complete its growth in both height and diameter within only 35–40 days after shoot emergence. However, the underlying mechanism for this “explosive growth” remains poorly understood. We investigated the dynamics of non-structural carbohydrates (NSCs) in shoots and attached mature bamboos over a 20-month period. The results showed that Moso bamboos rapidly completed their height and diameter growth within 38 days. At the same time, attached mature bamboos transferred almost all the NSCs of their leaves, branches, and especially trunks and rhizomes to the “explosively growing” shoots via underground rhizomes for the structural growth and metabolism of shoots. Approximately 4 months after shoot emergence, this transfer stopped when the leaves of the young bamboos could independently provide enough photoassimilates to meet the carbon demands of the young bamboos. During this period, the NSC content of the leaves, branches, trunks and rhizomes of mature bamboos declined by 1.5, 23, 28 and 5 fold, respectively. The trunk contributed the most NSCs to the shoots. Our findings provide new insight and a possible rational mechanism explaining the “explosive growth” of Moso bamboo and shed new light on understanding the role of NSCs in the rapid growth of Moso bamboo. PMID:27181522

  17. Mechanisms driving carbon allocation in tropical rainforests: allometric constraints and environmental responses

    NASA Astrophysics Data System (ADS)

    Hofhansl, Florian; Schnecker, Jörg; Singer, Gabriel; Wanek, Wolfgang

    2014-05-01

    Tropical forest ecosystems play a major role in global water and carbon cycles. However, mechanisms of C allocation in tropical forests and their response to environmental variation are largely unresolved as, due to the scarcity of data, they are underrepresented in global syntheses of forest C allocation. Allocation of gross primary production to wood production exerts a key control on forest C residence time and biomass C turnover, and therefore is of special interest for terrestrial ecosystem research and earth system science. Here, we synthesize pantropical data from 105 old-growth rainforests to investigate relationships between climate (mean annual precipitation, mean annual temperature, dry season length and cloud cover), soil nutrient relations (soil N:P) and the partitioning of aboveground net primary production (ANPP) to wood production (WPart) using structural equation modelling. Our results show a strong increase of WPart with ANPP, pointing towards allometric scaling controls on WPart, with increasing light competition in more productive forests triggering greater ANPP allocation to wood production. ANPP itself was positively affected by mean annual temperature and soil N:P. Beyond these allometric controls on WPart we found direct environmental controls. WPart increased with dry season length in tropical montane rainforests and with mean annual precipitation in lowland tropical rainforests. We discuss different trade-offs between plant traits, such as community-wide changes along the wood economics spectrum, the leaf economics spectrum and the plant resource economics spectrum, as underlying mechanisms for direct climatic controls on WPart. We thereby provide new insights into mechanisms driving carbon allocation to WPart in tropical rainforests and show that low and high productive tropical rainforests may respond differently to projected global changes.

  18. Single-Domain Peptidyl-Prolyl cis/trans Isomerase FkpA from Corynebacterium glutamicum Improves the Biomass Yield at Increased Growth Temperatures.

    PubMed

    Kallscheuer, Nicolai; Bott, Michael; van Ooyen, Jan; Polen, Tino

    2015-11-01

    Peptidyl-prolyl cis/trans isomerases (PPIases) catalyze the rate-limiting protein folding step at peptidyl bonds preceding proline residues and were found to be involved in several biological processes, including gene expression, signal transduction, and protein secretion. Representative enzymes were found in almost all sequenced genomes, including Corynebacterium glutamicum, a facultative anaerobic Gram-positive and industrial workhorse for the production of amino acids. In C. glutamicum, a predicted single-domain FK-506 (tacrolimus) binding protein (FKBP)-type PPIase (FkpA) is encoded directly downstream of gltA, which encodes citrate synthase (CS). This gene cluster is also present in other Actinobacteria. Here we carried out in vitro and in vivo experiments to study the function and influence of predicted FkpA in C. glutamicum. In vitro, FkpA indeed shows typical PPIase activity with artificial substrates and is inhibited by FK-506. Furthermore, FkpA delays the aggregation of CS, which is also inhibited by FK-506. Surprisingly, FkpA has a positive effect on the activity and temperature range of CS in vitro. Deletion of fkpA causes a 50% reduced biomass yield compared to that of the wild type when grown at 37°C, whereas there is only a 10% reduced biomass yield at the optimal growth temperature of 30°C accompanied by accumulation of 7 mM l-glutamate and 22 mM 2-oxoglutarate. Thus, FkpA may be exploited for improved product formation in biotechnical processes. Comparative transcriptome analysis revealed 69 genes which exhibit ≥2-fold mRNA level changes in C. glutamicum ΔfkpA, giving insight into the transcriptional response upon mild heat stress when FkpA is absent. PMID:26341203

  19. Single-Domain Peptidyl-Prolyl cis/trans Isomerase FkpA from Corynebacterium glutamicum Improves the Biomass Yield at Increased Growth Temperatures.

    PubMed

    Kallscheuer, Nicolai; Bott, Michael; van Ooyen, Jan; Polen, Tino

    2015-11-01

    Peptidyl-prolyl cis/trans isomerases (PPIases) catalyze the rate-limiting protein folding step at peptidyl bonds preceding proline residues and were found to be involved in several biological processes, including gene expression, signal transduction, and protein secretion. Representative enzymes were found in almost all sequenced genomes, including Corynebacterium glutamicum, a facultative anaerobic Gram-positive and industrial workhorse for the production of amino acids. In C. glutamicum, a predicted single-domain FK-506 (tacrolimus) binding protein (FKBP)-type PPIase (FkpA) is encoded directly downstream of gltA, which encodes citrate synthase (CS). This gene cluster is also present in other Actinobacteria. Here we carried out in vitro and in vivo experiments to study the function and influence of predicted FkpA in C. glutamicum. In vitro, FkpA indeed shows typical PPIase activity with artificial substrates and is inhibited by FK-506. Furthermore, FkpA delays the aggregation of CS, which is also inhibited by FK-506. Surprisingly, FkpA has a positive effect on the activity and temperature range of CS in vitro. Deletion of fkpA causes a 50% reduced biomass yield compared to that of the wild type when grown at 37°C, whereas there is only a 10% reduced biomass yield at the optimal growth temperature of 30°C accompanied by accumulation of 7 mM l-glutamate and 22 mM 2-oxoglutarate. Thus, FkpA may be exploited for improved product formation in biotechnical processes. Comparative transcriptome analysis revealed 69 genes which exhibit ≥2-fold mRNA level changes in C. glutamicum ΔfkpA, giving insight into the transcriptional response upon mild heat stress when FkpA is absent.

  20. Effects of heavy metals contained in soil irrigated with a mixture of sewage sludge and effluent for thirty years on soil microbial biomass and plant growth

    NASA Astrophysics Data System (ADS)

    Katanda, Y.; Mushonga, C.; Banganayi, F.; Nyamangara, J.

    The use of sewage effluent as a source of nutrients and water in peri-urban crop production is widespread in developing countries. A study was conducted in 2005 at Crowborough and Firle farms (near Harare) to assess effect of Cd on microbial biomass and activity, effect of sewage sludge and effluent on soybean (Glycine max L (Merr)) nodulation, and uptake of Zn and Cu by lettuce ( Lactuca sativa L.), mustard rape ( Brassica juncea L.), covo ( Brassica napus) and star grass ( Cynodon nlemfuensis). The soil that was used had been irrigated with sewage sludge and effluent for 30 years. Soil collected from Crowborough farm was enriched with Cd to different concentrations (0.4-5 mg Cd kg -1 soil) using Cd(NO 3) 2 and microbial biomass C and N (chloroform-incubation extraction) and respiration rates (CO 2 evolution) determined. A similar experiment to determine the effect of repeated addition of small amounts of Cd to soil over time on the same parameters was conducted. Three vegetables and star grass were grown in a pot experiment and harvested at six weeks after transplanting for the determination of above ground dry matter yield, and Zn and Cu, uptake. In another pot experiment, two soybean varieties, Magoye and Solitaire, were harvested after eight weeks and nodule number and effectiveness, and above ground dry matter yield were then determined. Cd significantly decreased biomass C (68%) and N (73%). Microbial respiration also significantly decreased. It was concluded that long-term application of sewage sludge and effluent to soil has negative effects on soil micro organisms, including Rhizobia. These micro organisms are essential for N-fixation. The damage to Rhizobia, caused diminished nodulation of soybean. Mustard rape and lettuce can accumulate Zn and Cu beyond toxic limits without apparent reduction in growth thereby posing a serious concern to the food chain. The consumption of mustard rape and lettuce grown on soil amended with sewage sludge and effluent at

  1. Biomass Program Factsheet

    SciTech Connect

    2010-03-01

    The emerging U.S. bioindustry is using a range of biomass resources to provide a secure and growing supply of transportation fuels and electric power. Displacing an increasing portion of our imported oil with renewable, domestic bioenergy will provide clear benefits:Reduced greenhouse gas (GHG) emissions; A cleaner, more secure energy future; Sustainable transportation fuels; Opportunities for economic growth

  2. Effect of microbial enzyme allocation strategies on stoichiometry of soil organic matter (SOM) decomposition

    NASA Astrophysics Data System (ADS)

    Wutzler, Thomas

    2014-05-01

    We explored different strategies of soil microbial community to invest resources into extracellular enzymes by conceptual modelling. Similar to the EEZY model by Moorhead et al. (2012), microbial community can invest into two separate pools of enzymes that depolymerize two different SOM pools. We show that with assuming that a fixed fraction of substrate uptake is allocated to enzymes, the microbial dynamics decouples from decomposition dynamics. We propose an alternative formulation where investment into enzymes is proportional to microbial biomass. Next, we show that the strategy of optimizing stoichiometry of decomposition flux according to microbial biomass stoichiometry yield less microbial growth than the strategy of optimizing revenue of the currently limiting element. However, both strategies result in better usage of the resources, i.e. less C overflow or N mineralization, than the strategy of equal allocation to both enzymes. Further, we discuss effects of those strategies on decomposition of SOM and priming at different time scales and discuss several abstractions from the detailed model dynamics for usage in larger scale models.

  3. Final Harvest of Above-Ground Biomass and Allometric Analysis of the Aspen FACE Experiment

    SciTech Connect

    Mark E. Kubiske

    2013-04-15

    The Aspen FACE experiment, located at the US Forest Service Harshaw Research Facility in Oneida County, Wisconsin, exposes the intact canopies of model trembling aspen forests to increased concentrations of atmospheric CO2 and O3. The first full year of treatments was 1998 and final year of elevated CO2 and O3 treatments is scheduled for 2009. This proposal is to conduct an intensive, analytical harvest of the above-ground parts of 24 trees from each of the 12, 30 m diameter treatment plots (total of 288 trees) during June, July & August 2009. This above-ground harvest will be carefully coordinated with the below-ground harvest proposed by D.F. Karnosky et al. (2008 proposal to DOE). We propose to dissect harvested trees according to annual height growth increment and organ (main stem, branch orders, and leaves) for calculation of above-ground biomass production and allometric comparisons among aspen clones, species, and treatments. Additionally, we will collect fine root samples for DNA fingerprinting to quantify biomass production of individual aspen clones. This work will produce a thorough characterization of above-ground tree and stand growth and allocation above ground, and, in conjunction with the below ground harvest, total tree and stand biomass production, allocation, and allometry.

  4. Biomass power for rural development

    SciTech Connect

    Shepherd, P.

    2000-06-02

    Biomass is a proven option for electricity generation. A diverse range of biopower producers includes electric utilities, independent power producers, and the pulp and paper industry. To help expand opportunities for biomass power production, the U.S. Department of Energy established the Biopower Program and is sponsoring efforts to increase the productivity of dedicated energy crops. The Program aims to double biomass conversion efficiencies, thus reducing biomass power generation costs. These efforts will promote industrial and agricultural growth, improve the environment, create jobs, increase U.S. energy security, and provide new export markets.

  5. Reproductive efficiency and metabolism of female broiler breeders as affected by genotype, feed allocation, and age at photostimulation. 1. Pullet growth and development.

    PubMed

    Robinson, F E; Zuidhof, M J; Renema, R A

    2007-10-01

    A 3 x 4 x 2 factorial design was carried out to determine the effect of 3 broiler breeder strains, 4 target BW profiles, and 2 photostimulation ages on pullet growth and development. A total of 560 pullets from each strain (Hubbard Hi-Y, Ross 508, and Ross 708) were reared on BW profiles that separated at 4 wk and converged at 32 wk of age as follows: standard (mean target BW profile of the 3 strains used), low (12-wk BW target = 25% lower than standard followed by rapid gain to 32 wk), moderate (12-wk BW target = 150% of standard followed by lower rate of gain to 32 wk), and high (12-wk BW target = 200% of standard followed by minimal growth to 32 wk). Birds were photostimulated at 18 (18WK) or 22 wk (22WK). During the prephotostimulation phase (2 to 18 wk of age), 4 birds were killed for each of the 12 interactions at 14-d intervals to characterize changes in carcass traits. After 18 wk (wk 20, 22, and 24), 4 birds from each of the 24 interactions were killed and dissected (n = 768). Growth rate restricted frame size (e.g., 18-wk shank length: low = 101.8; standard = 105.6; moderate = 109.5; and high = 112.3 mm). At 24 wk of age, the 22WK birds had similar amounts of breast muscle compared with 18WK birds, whereas the later photostimulated hens had heavier abdominal fat pads. Early photo-stimulation resulted in increased 24-wk liver weights in all strains, but the difference was greatest in Ross 708 birds. The 22-wk ovary weight was influenced by age at photostimulation in high (18WK = 17.3; 22WK = 1.6 g) and moderate (18WK = 14.1; 22WK = 1.1 g) birds. The more extensive feed restriction of LOW birds before 12 wk of age appeared to limit breast muscle and fat pad growth and slow reproductive tract development following photostimulation. Pullets on heavier BW profiles respond to early PS by developing the reproductive system at the expense of breast muscle and fat pad growth. Genetic strain modulates some of the effect of very different target BW profiles.

  6. Can observed ecosystem responses to elevated CO2 and N fertilisation be explained by optimal plant C allocation?

    NASA Astrophysics Data System (ADS)

    Stocker, Benjamin; Prentice, I. Colin

    2016-04-01

    The degree to which nitrogen availability limits the terrestrial C sink under rising CO2 is a key uncertainty in carbon cycle and climate change projections. Results from ecosystem manipulation studies and meta-analyses suggest that plant C allocation to roots adjusts dynamically under varying degrees of nitrogen availability and other soil fertility parameters. In addition, the ratio of biomass production to GPP appears to decline under nutrient scarcity. This reflects increasing plant C export into the soil and to symbionts (Cex) with decreasing nutrient availability. Cex is consumed by an array of soil organisms and may imply an improvement of nutrient availability to the plant. These concepts are left unaccounted for in Earth system models. We present a model for the coupled cycles of C and N in grassland ecosystems to explore optimal plant C allocation under rising CO2 and its implications for the ecosystem C balance. The model follows a balanced growth approach, accounting for the trade-offs between leaf versus root growth and Cex in balancing C fixation and N uptake. We further model a plant-controlled rate of biological N fixation (BNF) by assuming that Cex is consumed by N2-fixing processes if the ratio of Nup:Cex falls below the inverse of the C cost of N2-fixation. The model is applied at two temperate grassland sites (SwissFACE and BioCON), subjected to factorial treatments of elevated CO2 (FACE) and N fertilization. Preliminary simulation results indicate initially increased N limitation, evident by increased relative allocation to roots and Cex. Depending on the initial state of N availability, this implies a varying degree of aboveground growth enhancement, generally consistent with observed responses. On a longer time scale, ecosystems are progressively released from N limitation due tighter N cycling. Allowing for plant-controlled BNF implies a quicker release from N limitation and an adjustment to more open N cycling. In both cases, optimal plant

  7. Arabidopsis has a cytosolic fumarase required for the massive allocation of photosynthate into fumaric acid and for rapid plant growth on high nitrogen.

    PubMed

    Pracharoenwattana, Itsara; Zhou, Wenxu; Keech, Olivier; Francisco, Perigio B; Udomchalothorn, Thanikan; Tschoep, Hendrik; Stitt, Mark; Gibon, Yves; Smith, Steven M

    2010-06-01

    The Arabidopsis genome has two fumarase genes, one of which encodes a protein with mitochondrial targeting information (FUM1) while the other (FUM2) does not. We show that a FUM1-green fluorescent protein fusion is directed to mitochondria while FUM2-red fluorescent protein remains in the cytosol. While mitochondrial FUM1 is an essential gene, cytosolic FUM2 is not required for plant growth. However FUM2 is required for the massive accumulation of carbon into fumarate that occurs in Arabidopsis leaves during the day. In fum2 knock-out mutants, fumarate levels remain low while malate increases, and these changes can be reversed with a FUM2 transgene. The fum2 mutant has lower levels of many amino acids in leaves during the day compared with the wild type, but higher levels at night, consistent with a link between fumarate and amino acid metabolism. To further test this relationship we grew plants in the absence or presence of nitrogen fertilizer. The amount of fumarate in leaves increased several fold in response to nitrogen in wild-type plants, but not in fum2. Malate increased to a small extent in the wild type but to a greater extent in fum2. Growth of fum2 plants was similar to that of the wild type in low nitrogen but much slower in the presence of high nitrogen. Activities of key enzymes of nitrogen assimilation were similar in both genotypes. We conclude that FUM2 is required for the accumulation of fumarate in leaves, which is in turn required for rapid nitrogen assimilation and growth on high nitrogen.

  8. Genotype and environment determine allocation to and costs of resistance in quaking aspen.

    PubMed

    Osier, Tod L; Lindroth, Richard L

    2006-06-01

    Although genetic variability and resource availability both influence plant chemical composition, little is known about how these factors interact to modulate costs of resistance, expressed as negative correlations between growth and defense. We evaluated genotype x environment effects on foliar chemistry and growth of quaking aspen (Populus tremuloides) by growing multiple aspen genotypes under variable conditions of light and soil nutrient availability in a common garden. Foliage was analyzed for levels of nitrogen, phenolic glycosides and condensed tannins. Bioassays of leaf quality were conducted with fourth-stadium gypsy moth (Lymantria dispar) larvae. Results revealed strong effects of plant genotype, light availability and nutrient availability; the importance of each factor depended upon compound type. For example, tannin concentrations differed little among genotypes and across nutrient regimes under low light conditions, but markedly so under high light conditions. Phenolic glycoside concentrations, in contrast, were largely determined by genotype. Variation in phenolic glycoside concentrations among genotypes was the most important factor affecting gypsy moth performance. Gypsy moth biomass and development time were negatively and positively correlated, respectively, with phenolic glycoside levels. Allocation to phenolic glycosides appeared to be costly in terms of growth, but only under resource-limiting conditions. Context-dependent trade-offs help to explain why costs of allocation to resistance are often difficult to demonstrate.

  9. Fuels from biomass and wastes

    NASA Astrophysics Data System (ADS)

    Klass, D. L.; Emert, G. H.

    The production, use, and effects of fuels from biomass and waste energy sources are discussed. Biomass procurement from silviculture, including hybrid poplar and sycamore farms, in addition to the growth of mass algal culture and Jerusalem artichokes for fuels are considered. The conversion of biomass and solid waste materials through biological and thermal gasification, hydrolysis and extraction, and fermentation to produce ethanol, along with natural and thermal liquefaction processes involving euphorbia lathyris and cellulosic materials are elaborated. Environmental and health aspects of biomass and waste conversion systems are outlined, noting the large land surface areas needed for significant contributions to total demands from biomass, specific instances and case studies are reviewed for biomass use in Indiana, the Dominican Republic, the southeast U.S., and in small wood stoves.

  10. Microbial activity balance in size fractionated suspended growth biomass from full-scale sidestream combined nitritation-anammox reactors.

    PubMed

    Shi, Yijing; Wells, George; Morgenroth, Eberhard

    2016-10-01

    The purpose of this study was to determine the abundance, distribution and activity of aerobic ammonia-oxidizing bacteria (AOB) and anammox in size fractionated aggregates from full-scale suspended growth combined nitritation-anammox sidestream reactors. Plants with or without a cyclone device were also studied to assess a purported enrichment of anammox granules. Specific aerobic ammonium oxidation rates (p=0.01) and specific oxygen uptake rates (p=0.02) were significantly greater in flocs than in granules. AOB abundance measured using quantitative FISH was significantly higher in flocs than in granules (p=0.01). Conversely, anammox abundance was significantly greater in granules (p=0.03). The average ratio of anammox/AOB in systems employing hydrocyclone separation devices was 2.4, significantly higher (p=0.02) than the average ratio (0.5) in a system without a hydrocyclone. Our results demonstrate substantial functional and population-level segregation between floccular and granular fractions, and provide a key corroboration that cyclone separation devices can increase anammox levels in such systems.

  11. Microbial activity balance in size fractionated suspended growth biomass from full-scale sidestream combined nitritation-anammox reactors.

    PubMed

    Shi, Yijing; Wells, George; Morgenroth, Eberhard

    2016-10-01

    The purpose of this study was to determine the abundance, distribution and activity of aerobic ammonia-oxidizing bacteria (AOB) and anammox in size fractionated aggregates from full-scale suspended growth combined nitritation-anammox sidestream reactors. Plants with or without a cyclone device were also studied to assess a purported enrichment of anammox granules. Specific aerobic ammonium oxidation rates (p=0.01) and specific oxygen uptake rates (p=0.02) were significantly greater in flocs than in granules. AOB abundance measured using quantitative FISH was significantly higher in flocs than in granules (p=0.01). Conversely, anammox abundance was significantly greater in granules (p=0.03). The average ratio of anammox/AOB in systems employing hydrocyclone separation devices was 2.4, significantly higher (p=0.02) than the average ratio (0.5) in a system without a hydrocyclone. Our results demonstrate substantial functional and population-level segregation between floccular and granular fractions, and provide a key corroboration that cyclone separation devices can increase anammox levels in such systems. PMID:27347796

  12. High intraspecific ability to adjust both carbon uptake and allocation under light and nutrient reduction in Halimium halimifolium L.

    PubMed Central

    Wegener, Frederik; Beyschlag, Wolfram; Werner, Christiane

    2015-01-01

    The allocation of recently assimilated carbon (C) by plants depends on developmental stage and on environmental factors, but the underlying mechanisms are still a matter of debate. In the present study, we investigated the regulation of C uptake and allocation and their adjustments during plant growth. We induced different allocation strategies in the Mediterranean shrub Halimium halimifolium L. by a reduction of light (Low L treatment) and nutrient availability (Low N treatment) and analyzed allocation parameters as well as morphological and physiological traits for 15 months. Further, we conducted a 13CO2 pulse-labeling and followed the way of recently assimilated carbon to eight different tissue classes and respiration for 13 days. The plant responses were remarkably distinct in our study, with mainly morphological/physiological adaptions in case of light reduction and adjustment of C allocation in case of nutrient reduction. The transport of recently assimilated C to the root system was enhanced in amount (c. 200%) and velocity under nutrient limited conditions compared to control plants. Despite the 57% light reduction the total biomass production was not affected in the Low L treatment. The plants probably compensated light reduction by an improvement of their ability to fix C. Thus, our results support the concept that photosynthesis is, at least in a medium term perspective, influenced by the C demand of the plant and not exclusively by environmental factors. Finally, our results indicate that growing heterotrophic tissues strongly reduce the C reflux from storage and structural C pools and therefore enhance the fraction of recent assimilates allocated to respiration. We propose that this interruption of the C reflux from storage and structural C pools could be a regulation mechanism for C translocation in plants. PMID:26300906

  13. Biomass Conversion

    NASA Astrophysics Data System (ADS)

    Decker, Stephen R.; Sheehan, John; Dayton, David C.; Bozell, Joseph J.; Adney, William S.; Hames, Bonnie; Thomas, Steven R.; Bain, Richard L.; Czernik, Stefan; Zhang, Min; Himmel, Michael E.

    In its simplest terms, biomass is all the plant matter found on our planet. Biomass is produced directly by photosynthesis, the fundamental engine of life on earth. Plant photosynthesis uses energy from the sun to combine carbon dioxide from the atmosphere with water to produce organic plant matter. More inclusive definitions are possible. For example, animal products and waste can be included in the definition of biomass. Animals, like plants, are renewable; but animals clearly are one step removed from the direct use of sunlight. Using animal rather than plant material thus leads to substantially less efficient use of our planet's ultimate renewable resource, the sun. So, we emphasize plant matter in our definition of biomass. It is the photosynthetic capability of plants to utlize carbon dioxide from the atmosphere that leads to its designation as a "carbon neutral" fuel, meaning that it does not introduce new carbon into the atmosphere.

  14. Biomass [updated

    SciTech Connect

    Turhollow Jr, Anthony F

    2016-01-01

    Biomass resources and conversion technologies are diverse. Substantial biomass resources exist including woody crops, herbaceous perennials and annuals, forest resources, agricultural residues, and algae. Conversion processes available include fermentation, gasification, pyrolysis, anaerobic digestion, combustion, and transesterification. Bioderived products include liquid fuels (e.g. ethanol, biodiesel, and gasoline and diesel substitutes), gases, electricity, biochemical, and wood pellets. At present the major sources of biomass-derived liquid fuels are from first generation biofuels; ethanol from maize and sugar cane (89 billion L in 2013) and biodiesel from vegetable oils and fats (24 billion liters in 2011). For other than traditional uses, policy in the forms of mandates, targets, subsidies, and greenhouse gas emission targets has largely been driving biomass utilization. Second generation biofuels have been slow to take off.

  15. Growth of oleaginous Rhodotorula glutinis in an internal-loop airlift bioreactor by using lignocellulosic biomass hydrolysate as the carbon source.

    PubMed

    Yen, Hong-Wei; Chang, Jung-Tzu

    2015-05-01

    The conversion of abundant lignocellulosic biomass (LCB) to valuable compounds has become a very attractive idea recently. This study successfully used LCB (rice straw) hydrolysate as a carbon source for the cultivation of oleaginous yeast-Rhodotorula glutinis in an airlift bioreactor. The lipid content of 34.3 ± 0.6% was obtained in an airlift batch with 60 g reducing sugars/L of LCB hydrolysate at a 2 vvm aeration rate. While using LCB hydrolysate as the carbon source, oleic acid (C18:1) and linoleic acid (C18:2) were the predominant fatty acids of the microbial lipids. Using LCB hydrolysate in the airlift bioreactor at 2 vvm achieved the highest cell mass growth as compared to the agitation tank. Despite the low lipid content of the batch using LCB hydrolysate, this low cost feedstock has the potential of being adopted for the production of β-carotene instead of lipid accumulation in the airlift bioreactor for the cultivation of R. glutinis.

  16. Growth of oleaginous Rhodotorula glutinis in an internal-loop airlift bioreactor by using lignocellulosic biomass hydrolysate as the carbon source.

    PubMed

    Yen, Hong-Wei; Chang, Jung-Tzu

    2015-05-01

    The conversion of abundant lignocellulosic biomass (LCB) to valuable compounds has become a very attractive idea recently. This study successfully used LCB (rice straw) hydrolysate as a carbon source for the cultivation of oleaginous yeast-Rhodotorula glutinis in an airlift bioreactor. The lipid content of 34.3 ± 0.6% was obtained in an airlift batch with 60 g reducing sugars/L of LCB hydrolysate at a 2 vvm aeration rate. While using LCB hydrolysate as the carbon source, oleic acid (C18:1) and linoleic acid (C18:2) were the predominant fatty acids of the microbial lipids. Using LCB hydrolysate in the airlift bioreactor at 2 vvm achieved the highest cell mass growth as compared to the agitation tank. Despite the low lipid content of the batch using LCB hydrolysate, this low cost feedstock has the potential of being adopted for the production of β-carotene instead of lipid accumulation in the airlift bioreactor for the cultivation of R. glutinis. PMID:25454603

  17. Biomass Burning

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.; Cofer, Wesley R., III; Pinto, Joseph P.

    1993-01-01

    Biomass burning may be the overwhelming regional or continental-scale source of methane (CH4) as in tropical Africa and a significant global source of CH4. Our best estimate of present methane emissions from biomass burning is about 51.9 Tg/yr, or 10% of the annual methane emissions to the atmosphere. Increased frequency of fires that may result as the Earth warms up may result in increases in this source of atmospheric methane.

  18. Effects of SO(2) and O(3) on Allocation of C-Labeled Photosynthate in Phaseolus vulgaris.

    PubMed

    McLaughlin, S B; McConathy, R K

    1983-11-01

    A series of laboratory exposures of two varieties of bush bean (Phaseolus vulgaris L., var 274 and var 290) was conducted to determine the sensitivity of [(14)C]photosynthate allocation patterns to alteration by SO(2) and O(3). Experiments with the pollution-resistant 274 variety demonstrated short-term changes in both (14)C and biomass allocation to roots of (14)CO(2)-labeled plants but no significant effect on yield by up to 40 hours of exposure to SO(2) at 0.50 microliters per liter or 4 hours of O(3) at 0.40 microliters per liter. Subsequent experiments with the more sensitive 290 variety demonstrated significant alteration of photosynthesis, translocation, and partitioning of photosynthate between plant parts including developing pods. Significant increases in foliar retention of photosynthate (+40%) occurred after 8 hours of exposure to SO(2) at 0.75 microliters per liter (6.0 microliters per liter-hour) and 11 hours of exposure to O(3) at 0.30 microliters per liter-hour (3.3 microliters-hours). Time series sampling of labeled tissues after (14)CO(2) uptake showed that the disruption of translocation patterns was persistent for at least 1 week after exposures ceased. Subsequent longer-term exposures at lower concentrations of both O(3) (0.0, 0.10, 0.15, and 0.20 microliters per liter) and SO(2) (0.0, 0.20, and 0.40 microliters per liter) demonstrated that O(3) more effectively altered allocation than SO(2), that primary leaves were generally more sensitive than trifoliates, and that responses of trifoliate leaves varied with plant growth stage. Altered rates of allocation of photosynthate by leaves were generally associated with alterations of similar magnitude and opposite direction in developing pods. Collectively, these experiments suggest that allocation patterns can provide sensitive indices of incipient growth responses of pollution-stressed vegetation.

  19. Roots, shoots and reproduction: sexual dimorphism in size and costs of reproductive allocation in an annual herb.

    PubMed

    Harris, Mark S; Pannell, John R

    2008-11-22

    Females tend to be smaller than males in woody dioecious plant species, but they tend to be larger in herbs. The smaller size of females in woody species has been attributed to higher reproductive costs, yet no satisfactory explanation has been provided for their larger size in herbs. Because herbs have higher nitrogen concentrations in their tissues than woody plants, and because pollen is particularly rich in nitrogen, we predicted that male growth would be more compromised by reproduction than female growth. To test this hypothesis, we conducted three experiments on the annual dioecious herb Mercurialis annua. First, we compared the timing of reproduction between males and females and found that males started flowering earlier than females; early flowering is expected to compromise growth more than later flowering. Second, we compared plants allowed to flower with those prevented from flowering by experimental debudding and found that males incurred a higher reproductive cost than females in terms of both biomass and, particularly, nitrogen. Third, we grew plants under varying levels of nitrogen availability and found that although sexual size dimorphism was unaffected by nitrogen, females, but not males, decreased their relative allocation to both roots and reproduction under high nitrogen availability. We propose that males deal with the high cost of pollen production in terms of nitrogen by allocating biomass to nitrogen-harvesting roots, whereas females pay for carbon-rich seeds and fruits by investing in photosynthetic organs. Sexual dimorphism would thus seem to be the outcome of allocation to above- versus below-ground sinks that supply resources (carbon versus nitrogen) limiting the female and male reproduction differentially.

  20. Approaches to Resource Allocation

    ERIC Educational Resources Information Center

    Dressel, Paul; Simon, Lou Anna Kimsey

    1976-01-01

    Various budgeting patterns and strategies are currently in use, each with its own particular strengths and weaknesses. Neither cost-benefit analysis nor cost-effectiveness analysis offers any better solution to the allocation problem than do the unsupported contentions of departments or the historical unit costs. An operable model that performs…

  1. Coal + Biomass → Liquids + Electricity (with CCS)

    EPA Science Inventory

    In this presentation, Matt Aitken applies the MARKet ALlocation energy system model to evaluate the market potential for a class of technologies that convert coal and biomass to liquid fuels and electricity (CBtLE), paired with carbon capture and storage (CCS). The technology is ...

  2. Clean energy for development and economic growth: Biomass and other renewable options to meet energy and development needs in poor nations

    SciTech Connect

    Lilley, Art; Pandey, Bikash; Karstad, Elsen; Owen, Matthew; Bailis, Robert; Ribot, Jesse; Masera, Omar; Diaz, Rodolpho; Benallou, Abdelahanine; Lahbabi, Abdelmourhit

    2012-10-01

    The document explores the linkages between renewable energy, poverty alleviation, sustainable development, and climate change in developing countries. In particular, the paper places emphasis on biomass-based energy systems. Biomass energy has a number of unique attributes that make it particularly suitable to climate change mitigation and community development applications.

  3. Habitat stress initiates changes in composition, CO2 gas exchange and C-allocation as life traits in biological soil crusts.

    PubMed

    Colesie, Claudia; Green, T G Allan; Haferkamp, Ilka; Büdel, Burkhard

    2014-10-01

    Biological soil crusts (BSC) are the dominant functional vegetation unit in some of the harshest habitats in the world. We assessed BSC response to stress through changes in biotic composition, CO2 gas exchange and carbon allocation in three lichen-dominated BSC from habitats with different stress levels, two more extreme sites in Antarctica and one moderate site in Germany. Maximal net photosynthesis (NP) was identical, whereas the water content to achieve maximal NP was substantially lower in the Antarctic sites, this apparently being achieved by changes in biomass allocation. Optimal NP temperatures reflected local climate. The Antarctic BSC allocated fixed carbon (tracked using (14)CO2) mostly to the alcohol soluble pool (low-molecular weight sugars, sugar alcohols), which has an important role in desiccation and freezing resistance and antioxidant protection. In contrast, BSC at the moderate site showed greater carbon allocation into the polysaccharide pool, indicating a tendency towards growth. The results indicate that the BSC of the more stressed Antarctic sites emphasise survival rather than growth. Changes in BSC are adaptive and at multiple levels and we identify benefits and risks attached to changing life traits, as well as describing the ecophysiological mechanisms that underlie them.

  4. Habitat stress initiates changes in composition, CO2 gas exchange and C-allocation as life traits in biological soil crusts.

    PubMed

    Colesie, Claudia; Green, T G Allan; Haferkamp, Ilka; Büdel, Burkhard

    2014-10-01

    Biological soil crusts (BSC) are the dominant functional vegetation unit in some of the harshest habitats in the world. We assessed BSC response to stress through changes in biotic composition, CO2 gas exchange and carbon allocation in three lichen-dominated BSC from habitats with different stress levels, two more extreme sites in Antarctica and one moderate site in Germany. Maximal net photosynthesis (NP) was identical, whereas the water content to achieve maximal NP was substantially lower in the Antarctic sites, this apparently being achieved by changes in biomass allocation. Optimal NP temperatures reflected local climate. The Antarctic BSC allocated fixed carbon (tracked using (14)CO2) mostly to the alcohol soluble pool (low-molecular weight sugars, sugar alcohols), which has an important role in desiccation and freezing resistance and antioxidant protection. In contrast, BSC at the moderate site showed greater carbon allocation into the polysaccharide pool, indicating a tendency towards growth. The results indicate that the BSC of the more stressed Antarctic sites emphasise survival rather than growth. Changes in BSC are adaptive and at multiple levels and we identify benefits and risks attached to changing life traits, as well as describing the ecophysiological mechanisms that underlie them. PMID:24694713

  5. Habitat stress initiates changes in composition, CO2 gas exchange and C-allocation as life traits in biological soil crusts

    PubMed Central

    Colesie, Claudia; Allan Green, T G; Haferkamp, Ilka; Büdel, Burkhard

    2014-01-01

    Biological soil crusts (BSC) are the dominant functional vegetation unit in some of the harshest habitats in the world. We assessed BSC response to stress through changes in biotic composition, CO2 gas exchange and carbon allocation in three lichen-dominated BSC from habitats with different stress levels, two more extreme sites in Antarctica and one moderate site in Germany. Maximal net photosynthesis (NP) was identical, whereas the water content to achieve maximal NP was substantially lower in the Antarctic sites, this apparently being achieved by changes in biomass allocation. Optimal NP temperatures reflected local climate. The Antarctic BSC allocated fixed carbon (tracked using 14CO2) mostly to the alcohol soluble pool (low-molecular weight sugars, sugar alcohols), which has an important role in desiccation and freezing resistance and antioxidant protection. In contrast, BSC at the moderate site showed greater carbon allocation into the polysaccharide pool, indicating a tendency towards growth. The results indicate that the BSC of the more stressed Antarctic sites emphasise survival rather than growth. Changes in BSC are adaptive and at multiple levels and we identify benefits and risks attached to changing life traits, as well as describing the ecophysiological mechanisms that underlie them. PMID:24694713

  6. Growth and physiological responses of tree seedlings to experimental manipulation of light and water

    SciTech Connect

    Huston, M.A.; Holmgren, M.

    1995-06-01

    Seedlings of two tree species with similar tolerance to soil water and nutrient levels, but contrasting tolerance to shade (Acer saccharum and Liriodendron tulipifera) were grown in shade houses under 5 light levels (27%, 17%, 12%, 5%, and 1%) and three soil water regimes (5-9%, 11-15%, and >20%). Soil, light, and water conditions were representative of those in the Walker Branch Throughfall Displacement Experiment, where the same species are being monitored under field conditions. Treatments were maintained from mid-June through October, when all plants were harvested for determination of biomass allocation patterns. The only mortality occurred among the tulip poplars, but there was a significant interaction effect of the treatments on leaf area, total biomass, and allocation patterns. Highest growth rates in both species occurred at 17% light in the highest water treatment, with the 27% treatment showing reduced growth, perhaps due to photoinhibition. Gas exchange measurements indicated that the light compensation point increased under dry conditions.

  7. Evaluation of zinc accumulation, allocation, and tolerance in Zea mays L. seedlings: implication for zinc phytoextraction.

    PubMed

    Bashmakov, Dmitry I; Lukatkin, Alexander S; Anjum, Naser A; Ahmad, Iqbal; Pereira, Eduarda

    2015-10-01

    This work investigated the accumulation, allocation, and impact of zinc (Zn; 1.0 μM-10 mM) in maize (Zea mays L.) seedlings under simulated laboratory conditions. Z. mays exhibited no significant change in its habitus (the physical characteristics of plants) up to 10-1000 μM of Zn (vs 5-10 mM Zn). Zn tolerance evaluation, based on the root test, indicated a high tolerance of Z. mays to both low and intermediate (or relatively high) concentrations of Zn, whereas this plant failed to tolerate 10 mM Zn and exhibited a 5-fold decrease in its Zn tolerance. Contingent to Zn treatment levels, Zn hampered the growth of axial organs and brought decreases in the leaf area, water regime, and biomass accumulation. Nevertheless, at elevated levels of Zn (10 mM), Zn(2+) was stored in the root cytoplasm and inhibited both axial organ growth and water regime. However, accumulation and allocation of Zn in Z. mays roots, studied herein employing X-ray fluorimeter and histochemical methods, were close to Zn accumulator plants. Overall, the study outcomes revealed Zn tolerance of Z. mays, and also implicate its potential role in Zn phytoextraction.

  8. Eco-hydrologic Modeling of Rangelands: Evaluating a New Carbon Allocation Approach and Simulating Ecosystem Response to Changing Climate and Management Conditions

    NASA Astrophysics Data System (ADS)

    Reyes, J. J.; Tague, C.; Choate, J. S.; Adam, J. C.

    2014-12-01

    More than one-third of the United States' land cover is comprised of rangelands, which support both forage production and livestock grazing. For grasses in both semi-arid and humid environments, small changes in precipitation and temperature, as well as grazing, can have disproportionately larger impacts on ecosystem processes. For example, these areas may experience large response pulses under highly variable precipitation and other potential future changes. The ultimate goal of this study is to provide information on the interactions between management activities, climate and ecosystem processes to inform sustainable rangeland management. The specific objectives of this paper are to (1) evaluate a new carbon allocation strategy for grasses and (2) test the sensitivity of this improved strategy to changes in climate and grazing strategies. The Regional Hydro-ecologic Simulation System (RHESSys) is a process-based, watershed-scale model that simulates hydrology and biogeochemical cycling with dynamic soil and vegetation modules. We developed a new carbon allocation algorithm for partitioning net primary productivity (NPP) between roots and leaves for grasses. The 'hybrid' approach represents a balance between preferential partitioning due to environmental conditions and age-related growth. We evaluated this new allocation scheme at the point-scale at a variety of rangeland sites in the U.S. using observed biomass measurements and against existing allocation schemes used in RHESSys. Additionally, changes in the magnitude, frequency, and intensity of precipitation and temperature were used to assess ecosystem responses using our new allocation scheme. We found that changes in biomass and NPP were generally more sensitive to changes in precipitation than changes in temperature. At more arid sites, larger percent reductions in historic baseline precipitation affected biomass and NPP more negatively. We incorporated grazing impacts through biomass removal. We found that

  9. Biomass energy

    SciTech Connect

    Smil, V.

    1983-01-01

    This book offers a broad, interdisciplinary approach to assessing the factors that are key determinants to the use of biomass energies, stressing their limitations, complexities, uncertainties, links, and consequences. Considers photosynthesis, energy costs of nutrients, problems with monoculture, and the energy analysis of intensive tree plantations. Subjects are examined in terms of environmental and economic impact. Emphasizes the use and abuse of biomass energies in China, India, and Brazil. Topics include forests, trees for energy, crop residues, fuel crops, aquatic plants, and animal and human wastes. Recommended for environmental engineers and planners, and those involved in ecology, systematics, and forestry.

  10. Seasonal evolution of Biomass Production Efficiency (BPE) of a French beech forest.

    NASA Astrophysics Data System (ADS)

    Heid, L.; Calvaruso, C.; Conil, S.; Turpault, M. P.; Longdoz, B.

    2015-12-01

    With the evolution of ecosystem management and the actual climate change we are facing, there is a need to improve our knowledge of carbon (C) balance and more specifically of C allocation in the plants. In our study, we quantified the seasonal variation of gross primary production (GPP, obtained through eddy covariance measurements) and biomass production (BP, the C fixed into the biomass obtained thanks to inventory campaign) for a 60-year-old even-aged beech stand located in North East of France. We also assessed the seasonal evolution of the BP efficiency (BPE=BP/GPP; Vicca et al., 2012) and its potential determining factors for our site. For 2014, we found a net ecosystem exchange (NEE) of -549 gC m-2, corresponding to a C sequestration. This value breaks down between 1089 gC m-2 for the respiration of the ecosystem and -1639 gC m-2 for the GPP. On the same year, our stand built up 461.6 gC m-2 of tree biomass (leaves, trunk, branches, fine roots), leading to an annual BPE of 0.28, which is within the range of value found on other similar sites. There was a large temporal variation of C allocation to the different parts of the tree biomass during the growth season. Our results show that the growth first happened in the trunk and branches -with a peak value of 74.5 gC m-2 month-1 in May - whereas the fine roots biomass production started later (end of July) and reached a maximum at the end of the growth season (28.49 gC m-2 month-1 for September). The BPE varied also during the year from 0.13 in April to 0.31 in August, where the BP was the same than in July but the cumulated GPP was already decreasing. The seasonal variation may be mainly explained by climatic variations, whereas the shift between woody above-ground biomass and fine roots biomass could be explained by the phenology (linked to physiological mechanisms).

  11. Myrmics Memory Allocator

    SciTech Connect

    Lymperis, S.

    2011-09-23

    MMA is a stand-alone memory management system for MPI clusters. It implements a shared Partitioned Global Address Space, where multiple MPI processes request objects from the allocator and the latter provides them with system-wide unique memory addresses for each object. It provides applications with an intuitive way of managing the memory system in a unified way, thus enabling easier writing of irregular application code.

  12. Global biomass production potentials exceed expected future demand without the need for cropland expansion.

    PubMed

    Mauser, Wolfram; Klepper, Gernot; Zabel, Florian; Delzeit, Ruth; Hank, Tobias; Putzenlechner, Birgitta; Calzadilla, Alvaro

    2015-01-01

    Global biomass demand is expected to roughly double between 2005 and 2050. Current studies suggest that agricultural intensification through optimally managed crops on today's cropland alone is insufficient to satisfy future demand. In practice though, improving crop growth management through better technology and knowledge almost inevitably goes along with (1) improving farm management with increased cropping intensity and more annual harvests where feasible and (2) an economically more efficient spatial allocation of crops which maximizes farmers' profit. By explicitly considering these two factors we show that, without expansion of cropland, today's global biomass potentials substantially exceed previous estimates and even 2050s' demands. We attribute 39% increase in estimated global production potentials to increasing cropping intensities and 30% to the spatial reallocation of crops to their profit-maximizing locations. The additional potentials would make cropland expansion redundant. Their geographic distribution points at possible hotspots for future intensification. PMID:26558436

  13. Global biomass production potentials exceed expected future demand without the need for cropland expansion.

    PubMed

    Mauser, Wolfram; Klepper, Gernot; Zabel, Florian; Delzeit, Ruth; Hank, Tobias; Putzenlechner, Birgitta; Calzadilla, Alvaro

    2015-11-12

    Global biomass demand is expected to roughly double between 2005 and 2050. Current studies suggest that agricultural intensification through optimally managed crops on today's cropland alone is insufficient to satisfy future demand. In practice though, improving crop growth management through better technology and knowledge almost inevitably goes along with (1) improving farm management with increased cropping intensity and more annual harvests where feasible and (2) an economically more efficient spatial allocation of crops which maximizes farmers' profit. By explicitly considering these two factors we show that, without expansion of cropland, today's global biomass potentials substantially exceed previous estimates and even 2050s' demands. We attribute 39% increase in estimated global production potentials to increasing cropping intensities and 30% to the spatial reallocation of crops to their profit-maximizing locations. The additional potentials would make cropland expansion redundant. Their geographic distribution points at possible hotspots for future intensification.

  14. Global biomass production potentials exceed expected future demand without the need for cropland expansion

    PubMed Central

    Mauser, Wolfram; Klepper, Gernot; Zabel, Florian; Delzeit, Ruth; Hank, Tobias; Putzenlechner, Birgitta; Calzadilla, Alvaro

    2015-01-01

    Global biomass demand is expected to roughly double between 2005 and 2050. Current studies suggest that agricultural intensification through optimally managed crops on today's cropland alone is insufficient to satisfy future demand. In practice though, improving crop growth management through better technology and knowledge almost inevitably goes along with (1) improving farm management with increased cropping intensity and more annual harvests where feasible and (2) an economically more efficient spatial allocation of crops which maximizes farmers' profit. By explicitly considering these two factors we show that, without expansion of cropland, today's global biomass potentials substantially exceed previous estimates and even 2050s' demands. We attribute 39% increase in estimated global production potentials to increasing cropping intensities and 30% to the spatial reallocation of crops to their profit-maximizing locations. The additional potentials would make cropland expansion redundant. Their geographic distribution points at possible hotspots for future intensification. PMID:26558436

  15. [Effects of Cuscuta australis parasitism on the growth, reproduction and defense of Solidago canadensis].

    PubMed

    Yang, Bei-fen; Du, Le-shan; Li, Jun-min

    2015-11-01

    In order to find out how parasitic Cuscuta australis influences the growth and reproduction of Solidago canadensis, the effects of the parasitism of C. australis on the morphological, growth and reproductive traits of S. canadensis were examined and the relationships between the biomass and the contents of the secondary metabolites were analyzed. The results showed that the parasitism significantly reduced the plant height, basal diameter, root length, root diameter, root biomass, stem biomass, leaf biomass, total biomass, number of inflorescences branches, axis length of inflorescence, and number of inflorescence. In particular, plant height, number of inflorescence and the stem biomass of parasitized S. canadensis were only 1/2, 1/5 and 1/8 of non-parasitized plants, respectively. There was no significant difference of plant height, root length, stem biomass and total biomass between plants parasitized with high and low intensities. But the basal diameter, root volume, leaf biomass, root biomass, the number of inflorescences branches, axis length of inflorescence and number of inflorescence of S. canadensis parasitized with high intensity were significantly lower than those of plants parasitized with low intensity. The parasitism of C. australis significantly increased the tannins content in the root and the flavonoids content in the stem of S. canadensis. The biomass of S. canadensis was significantly negatively correlated with the tannin content in the root and the flavonoids content in the stem. These results indicated that the parasitism of C. australis could inhibit the growth of S. canadensis by changing the resources allocation patterns as well as reducing the resources obtained by S. canadensis. PMID:26915184

  16. [Effects of Cuscuta australis parasitism on the growth, reproduction and defense of Solidago canadensis].

    PubMed

    Yang, Bei-fen; Du, Le-shan; Li, Jun-min

    2015-11-01

    In order to find out how parasitic Cuscuta australis influences the growth and reproduction of Solidago canadensis, the effects of the parasitism of C. australis on the morphological, growth and reproductive traits of S. canadensis were examined and the relationships between the biomass and the contents of the secondary metabolites were analyzed. The results showed that the parasitism significantly reduced the plant height, basal diameter, root length, root diameter, root biomass, stem biomass, leaf biomass, total biomass, number of inflorescences branches, axis length of inflorescence, and number of inflorescence. In particular, plant height, number of inflorescence and the stem biomass of parasitized S. canadensis were only 1/2, 1/5 and 1/8 of non-parasitized plants, respectively. There was no significant difference of plant height, root length, stem biomass and total biomass between plants parasitized with high and low intensities. But the basal diameter, root volume, leaf biomass, root biomass, the number of inflorescences branches, axis length of inflorescence and number of inflorescence of S. canadensis parasitized with high intensity were significantly lower than those of plants parasitized with low intensity. The parasitism of C. australis significantly increased the tannins content in the root and the flavonoids content in the stem of S. canadensis. The biomass of S. canadensis was significantly negatively correlated with the tannin content in the root and the flavonoids content in the stem. These results indicated that the parasitism of C. australis could inhibit the growth of S. canadensis by changing the resources allocation patterns as well as reducing the resources obtained by S. canadensis.

  17. Chronic nitrogen deposition alters tree allometric relationships: implications for biomass production and carbon storage.

    PubMed

    Ibáñez, Inés; Zak, Donald R; Burton, Andrew J; Pregitzer, Kurt S

    2016-04-01

    As increasing levels of nitrogen (N) deposition impact many terrestrial ecosystems, understanding the potential effects of higher N availability is critical for forecasting tree carbon allocation patterns and thus future forest productivity. Most regional estimates of forest biomass apply allometric equations, with parameters estimated from a limited number of studies, to forest inventory data (i.e., tree diameter). However most of these allometric equations cannot account for potential effects of increased N availability on biomass allocation patterns. Using 18 yr of tree diameter, height, and mortality data collected for a dominant tree species (Acer saccharum) in an atmospheric N deposition experiment, we evaluated how greater N availability affects allometric relationships in this species. After taking into account site and individual variability, our results reveal significant differences in allometric parameters between ambient and experimental N deposition treatments. Large trees under experimental N deposition reached greater heights at a given diameter; moreover, their estimated maximum height (mean ± standard deviation: 33.7 ± 0.38 m) was significantly higher than that estimated under the ambient condition (31.3 ± 0.31 m). Within small tree sizes (5-10 cm diameter) there was greater mortality under experimental N deposition, whereas the relative growth rates of small trees were greater under experimental N deposition. Calculations of stemwood biomass using our parameter estimates for the diameter-height relationship indicated the potential for significant biases in these estimates (~2.5%), with under predictions of stemwood biomass averaging 4 Mg/ha lower if ambient parameters were to be used to estimate stem biomass of trees in the experimental N deposition treatment. As atmospheric N deposition continues to increase into the future, ignoring changes in tree allometry will contribute to the uncertainty associated with aboveground carbon storage

  18. Chronic nitrogen deposition alters tree allometric relationships: implications for biomass production and carbon storage.

    PubMed

    Ibáñez, Inés; Zak, Donald R; Burton, Andrew J; Pregitzer, Kurt S

    2016-04-01

    As increasing levels of nitrogen (N) deposition impact many terrestrial ecosystems, understanding the potential effects of higher N availability is critical for forecasting tree carbon allocation patterns and thus future forest productivity. Most regional estimates of forest biomass apply allometric equations, with parameters estimated from a limited number of studies, to forest inventory data (i.e., tree diameter). However most of these allometric equations cannot account for potential effects of increased N availability on biomass allocation patterns. Using 18 yr of tree diameter, height, and mortality data collected for a dominant tree species (Acer saccharum) in an atmospheric N deposition experiment, we evaluated how greater N availability affects allometric relationships in this species. After taking into account site and individual variability, our results reveal significant differences in allometric parameters between ambient and experimental N deposition treatments. Large trees under experimental N deposition reached greater heights at a given diameter; moreover, their estimated maximum height (mean ± standard deviation: 33.7 ± 0.38 m) was significantly higher than that estimated under the ambient condition (31.3 ± 0.31 m). Within small tree sizes (5-10 cm diameter) there was greater mortality under experimental N deposition, whereas the relative growth rates of small trees were greater under experimental N deposition. Calculations of stemwood biomass using our parameter estimates for the diameter-height relationship indicated the potential for significant biases in these estimates (~2.5%), with under predictions of stemwood biomass averaging 4 Mg/ha lower if ambient parameters were to be used to estimate stem biomass of trees in the experimental N deposition treatment. As atmospheric N deposition continues to increase into the future, ignoring changes in tree allometry will contribute to the uncertainty associated with aboveground carbon storage

  19. Synaptic Tagging During Memory Allocation

    PubMed Central

    Rogerson, Thomas; Cai, Denise; Frank, Adam; Sano, Yoshitake; Shobe, Justin; Aranda, Manuel L.; Silva, Alcino J.

    2014-01-01

    There is now compelling evidence that the allocation of memory to specific neurons (neuronal allocation) and synapses (synaptic allocation) in a neurocircuit is not random and that instead specific mechanisms, such as increases in neuronal excitability and synaptic tagging and capture, determine the exact sites where memories are stored. We propose an integrated view of these processes, such that neuronal allocation, synaptic tagging and capture, spine clustering and metaplasticity reflect related aspects of memory allocation mechanisms. Importantly, the properties of these mechanisms suggest a set of rules that profoundly affect how memories are stored and recalled. PMID:24496410

  20. Biomass energy systems program summary

    NASA Astrophysics Data System (ADS)

    1980-07-01

    Research and development in appropriate conversion technologies is reported. The technologies include direct combustion, biochemical conversion, and thermochemical conversion techniques. Biomass sources were reviewed. Estimates indicate that the conversion of unused agricultural residues, forestry residues, and noncommercial timber growth can provide 6 to 10% of the national energy needs. The use of biomass energy conversion in fuel production, chemical production, residential space heating, and electricity supplies is discussed.

  1. 50 CFR 660.323 - Pacific whiting allocations, allocation attainment, and inseason allocation reapportionment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Pacific whiting allocations, allocation attainment, and inseason allocation reapportionment. 660.323 Section 660.323 Wildlife and Fisheries FISHERY...) FISHERIES OFF WEST COAST STATES West Coast Groundfish Fisheries § 660.323 Pacific whiting...

  2. The estimation of microbial biomass.

    PubMed

    Harris, C M; Kell, D B

    1985-01-01

    Methods that have been used to estimate the content, and in some cases the nature, of the microbial biomass in a sample are reviewed. The methods may be categorised in terms of their principle (physical, chemical, biological or mathematical/computational), their speed (real-time or otherwise) and the amount of automation/expense involved. For sparse populations, where the output signal is to be enhanced by growth of the organisms, physical, chemical and biological approaches may be of equal merit, whilst in systems, such as laboratory and industrial fermentations, in which the microbial biomass content is high, physical methods (alone) can permit the real-time estimation of microbial biomass.

  3. Growth and nutrient responses of Eloecharis cellulosa (Cyperaceae) to phosphate level and redox intensity.

    PubMed

    Chen, Hongjun; Mendelssohn, Irving A; Lorenzen, Bent; Brix, Hans; Miao, Shili

    2005-09-01

    Phosphorus (P) availability limits plant growth in many ecosystems. The ability of plants to explore for soil P is often impaired by nonresource stressors. Understanding the effects of these stressors on P acquisition in oligotrophic environments is critical in predicting species dominance. Growth and nutrient responses of Eleocharis cellulosa to redox intensity and phosphate level were evaluated under three redox potentials (Eh) and three phosphate (PO(4)) levels (P). Although low Eh (-150 mV) decreased root length at low P, Eh did not affect shoot height, relative growth rate (RGR), shoot elongation, photosynthesis, or biomass of E. cellulosa. Low PO(4) (10 μg P · L(-1)) strongly inhibited growth. Shoot height, RGR, elongation, photosynthesis, and biomass were lower at 10 μg P · L(-1) than at 80 or 500 μg P · L(-1). None of the growth variables, except the ratio of root-supported biomass to root biomass, significantly differed between the 80 and 500 μg P · L(-1) treatments. At low P, plants allocated relatively more biomass to roots than to shoots, compared to the medium and high P levels. Eleocharis cellulosa is well adapted to flooded conditions that lower soil Eh, and elevated PO(4) levels further promote its growth potential.

  4. Arabidopsis growth under prolonged high temperature and water deficit: independent or interactive effects?

    PubMed

    Vile, Denis; Pervent, Marjorie; Belluau, Michaël; Vasseur, François; Bresson, Justine; Muller, Bertrand; Granier, Christine; Simonneau, Thierry

    2012-04-01

    High temperature (HT) and water deficit (WD) are frequent environmental constraints restricting plant growth and productivity. These stresses often occur simultaneously in the field, but little is known about their combined impacts on plant growth, development and physiology. We evaluated the responses of 10 Arabidopsis thaliana natural accessions to prolonged elevated air temperature (30 °C) and soil WD applied separately or in combination. Plant growth was significantly reduced under both stresses and their combination was even more detrimental to plant performance. The effects of the two stresses were globally additive, but some traits responded specifically to one but not the other stress. Root allocation increased in response to WD, while reproductive allocation, hyponasty and specific leaf area increased under HT. All the traits that varied in response to combined stresses also responded to at least one of them. Tolerance to WD was higher in small-sized accessions under control temperature and HT and in accessions with high biomass allocation to root under control conditions. Accessions that originate from sites with higher temperature have less stomatal density and allocate less biomass to the roots when cultivated under HT. Independence and interaction between stresses as well as the relationships between traits and stress responses are discussed.

  5. Biotechnology of biomass conversion

    SciTech Connect

    Wayman, M.; Parekh, S.R.

    1990-01-01

    This book covers: An introduction to biomass crops; The microbiology of fermentation processes; The production of ethanol from biomass crops, such as sugar cane and rubbers; The energy of biomass conversion; and The economics of biomass conversion.

  6. Pilot-scale continuous recycling of growth medium for the mass culture of a halotolerant Tetraselmis sp. in raceway ponds under increasing salinity: a novel protocol for commercial microalgal biomass production.

    PubMed

    Fon Sing, S; Isdepsky, A; Borowitzka, M A; Lewis, D M

    2014-06-01

    The opportunity to recycle microalgal culture medium for further cultivation is often hampered by salinity increases from evaporation and fouling by dissolved and particulate matter. In this study, the impact of culture re-use after electro-flocculation of seawater-based medium on growth and biomass productivity of the halotolerant green algal strain Tetraselmis sp., MUR 233, was investigated in pilot-scale open raceway ponds over 5months. Despite a salinity increase from 5.5% to 12% (w/v) NaCl, Tetraselmis MUR 233 grown on naturally DOC-enriched recycled medium produced 48-160% more ash free dry weight (AFDW) biomass daily per unit pond area than when grown on non-recycled medium. A peak productivity of 37.5±3.1gAFDWm(-2)d(-1) was reached in the recycled medium upon transition from ∼14% to ∼7% NaCl. The combination of high biomass-yielding mixotrophic growth under high salinity has been proven to be a successful sustainable cultivation strategy. PMID:24681683

  7. Biomass shock pretreatment

    DOEpatents

    Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

    2014-07-01

    Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

  8. [Organ allocation. Ethical issues].

    PubMed

    Cattorini, P

    2010-01-01

    The criteria for allocating organs are one of the most debated ethical issue in the transplantation programs. The article examines some rules and principles followed by "Nord Italia Transplant program", summarized in its Principles' Charter and explained in a recent interdisciplinary book. General theories of justice and their application to individual clinical cases are commented and evaluated, in order to foster a public, democratic, transparent debate among professionals and citizens, scientific associations and customers' organizations. Some specific moral dilemmas are focused regarding the concepts of proportionate treatment, unselfish donation by living persons, promotion of local institutions efficiency. PMID:20677677

  9. The ontogeny of postmaturation resource allocation in turtles.

    PubMed

    Bowden, R M; Paitz, Ryan T; Janzen, Fredric J

    2011-01-01

    Resource-allocation decisions vary with life-history strategy, and growing evidence suggests that long-lived endothermic vertebrates direct resources toward growth and self-maintenance when young, increasing allocation toward reproductive effort over time. Few studies have tracked the ontogeny of resource allocation (energy, steroid hormones, etc.) in long-lived ectothermic vertebrates, limiting our understanding of the generality of life-history strategies among vertebrates. We investigated how reproductively mature female painted turtles (Chrysemys picta) from two distinct age classes allocated resources over a 4-yr period and whether resource-allocation patterns varied with nesting experience. We examined age-related variation in body size, egg mass, reproductive frequency, and yolk steroids and report that younger females were smaller and allocated fewer resources to reproduction than did older females. Testosterone levels were higher in eggs from younger females, whereas eggs from second (seasonal) clutches contained higher concentrations of progesterone and estradiol. These allocation patterns resulted in older, larger females laying larger eggs and producing second clutches more frequently than their younger counterparts. We conclude that resource-allocation patterns do vary with age in a long-lived ectotherm.

  10. Computationally efficient control allocation

    NASA Technical Reports Server (NTRS)

    Durham, Wayne (Inventor)

    2001-01-01

    A computationally efficient method for calculating near-optimal solutions to the three-objective, linear control allocation problem is disclosed. The control allocation problem is that of distributing the effort of redundant control effectors to achieve some desired set of objectives. The problem is deemed linear if control effectiveness is affine with respect to the individual control effectors. The optimal solution is that which exploits the collective maximum capability of the effectors within their individual physical limits. Computational efficiency is measured by the number of floating-point operations required for solution. The method presented returned optimal solutions in more than 90% of the cases examined; non-optimal solutions returned by the method were typically much less than 1% different from optimal and the errors tended to become smaller than 0.01% as the number of controls was increased. The magnitude of the errors returned by the present method was much smaller than those that resulted from either pseudo inverse or cascaded generalized inverse solutions. The computational complexity of the method presented varied linearly with increasing numbers of controls; the number of required floating point operations increased from 5.5 i, to seven times faster than did the minimum-norm solution (the pseudoinverse), and at about the same rate as did the cascaded generalized inverse solution. The computational requirements of the method presented were much better than that of previously described facet-searching methods which increase in proportion to the square of the number of controls.

  11. Generalized multidimensional dynamic allocation method.

    PubMed

    Lebowitsch, Jonathan; Ge, Yan; Young, Benjamin; Hu, Feifang

    2012-12-10

    Dynamic allocation has received considerable attention since it was first proposed in the 1970s as an alternative means of allocating treatments in clinical trials which helps to secure the balance of prognostic factors across treatment groups. The purpose of this paper is to present a generalized multidimensional dynamic allocation method that simultaneously balances treatment assignments at three key levels: within the overall study, within each level of each prognostic factor, and within each stratum, that is, combination of levels of different factors Further it offers capabilities for unbalanced and adaptive designs for trials. The treatment balancing performance of the proposed method is investigated through simulations which compare multidimensional dynamic allocation with traditional stratified block randomization and the Pocock-Simon method. On the basis of these results, we conclude that this generalized multidimensional dynamic allocation method is an improvement over conventional dynamic allocation methods and is flexible enough to be applied for most trial settings including Phases I, II and III trials.

  12. Slow Growth Rates of Amazonian Trees: Consequences for Carbon Sequestration and Forest Management.

    NASA Astrophysics Data System (ADS)

    Vieira, S. A.; Camargo, P. B.; Selhorst, D.; Chambers, J.; Higuchi, N.; Martinelli, L. A.; Trumbore, S.

    2004-12-01

    Growth rates for tropical forest trees estimated from radiocarbon ages and dendrometer measurements illustrate differences in forest age and structure among three sites located in the eastern, central and western Amazon basin. Although growth rates vary dramatically among individual trees overall the slowest growing trees (averaging \\sim0.1mm yr-1 as opposed to 0.3mm yr-1 diameter increment) are found in the central Amazon. Small individuals (DBH \\<30cm) have slower growth rates than larger diameter trees, and trees in this size class with radiocarbon ages >500 yr are encountered at all sites. Only \\sim2MgC ha-1 year-1, or \\SIM7% of annual photosynthesis, is allocated to growth of living wood at the eastern and central Amazon sites. Rates of C allocation to stem growth are similar across the three sites we studied because slowest growth occurs at the central Amazon site that has highest stem density and greatest biomass. Extrapolating our growth increment data to forest stand, we estimate the mean age of individual trees is \\SIM350 years in the central Amazon but \\SIM200\\-250 years in the other two areas. The mean age of C making up the trees has a smaller range of \\SIM250\\-310 years, because of the greater fraction of biomass in larger individuals in the eastern and western Amazon sites. These residence times for C are longer than those of 100\\-180 years obtained by simply dividing the total biomass C by the rate of C allocation to new wood for the same reason. We estimate that >20% of trees at all sites should have ages >300 years, and that maximum tree ages of >1000 years, though not common, are in accord with the growth rates we find. The fact that many Amazon trees attain ages greater than several centuries should be accounted for in management practices in these forests.

  13. Simulation of Biomass Accumulation Pattern in Vapor-Phase Biofilters.

    PubMed

    Xi, Jin-Ying; Hu, Hong-Ying; Zhang, Xian

    2012-06-01

    Existence of inert biomass and its impact on biomass accumulation patterns and biofilter performance were investigated. Four biofilters were set up in parallel to treat gaseous toluene. Each biofilter operated under different inlet toluene loadings for 100 days. Two microbial growth models, one with an inert biomass assumption and the other without, were established and compared. Results from the model with the inert biomass assumption showed better agreement with the experimental data than those based on the model without the inert biomass assumption thus verifying that inert biomass accumulation cannot be ignored in the long-term operation of biofilters. According to the model with an inert biomass assumption, the ratio of active biomass to total biomass will decrease and the inert biomass will become dominant in total biomass after a period of time. Filter bed structure simulation results showed that the void fraction is more sensitive to biomass accumulation than the specific surface area. The final void fraction of the biofilters with the highest inlet toluene loading is only 67% of its initial level while the final specific surface area is 82%. Identification and quantification of inert biomass will give a better understanding of biomass accumulation in biofilters and will result in a more exact simulation of biomass change during long-term operations. Results also indicate that an ideal biomass control technique should be able to remove most inert biomass while simultaneously preserving as much active biomass as possible.

  14. Seedling Growth Strategies in Bauhinia Species: Comparing Lianas and Trees

    PubMed Central

    Cai, Zhi-Quan; Poorter, Lourens; Cao, Kun-Fang; Bongers, Frans

    2007-01-01

    Background and Aims Lianas are expected to differ from trees in their growth strategies. As a result these two groups of woody species will have different spatial distributions: lianas are more common in high light environments. This study determines the differences in growth patterns, biomass allocation and leaf traits in five closely related liana and tree species of the genus Bauhinia. Methods Seedlings of two light-demanding lianas (Bauhinia tenuiflora and B. claviflora), one shade-tolerant liana (B. aurea), and two light-demanding trees (B. purpurea and B. monandra) were grown in a shadehouse at 25 % of full sunlight. A range of physiological, morphological and biomass parameters at the leaf and whole plant level were compared among these five species. Key Results The two light-demanding liana species had higher relative growth rate (RGR), allocated more biomass to leaf production [higher leaf mass fraction (LMF) and higher leaf area ratio (LAR)] and stem mass fraction (SMF), and less biomass to the roots [root mass fraction (RMF)] than the two tree species. The shade-tolerant liana had the lowest RGR of all five species, and had a higher RMF, lower SMF and similar LMF than the two light-demanding liana species. The two light-demanding lianas had lower photosynthetic rates per unit area (Aarea) and similar photosynthetic rates per unit mass (Amass) than the trees. Across species, RGR was positively related to SLA, but not to LAR and Aarea. Conclusions It is concluded that the faster growth of light-demanding lianas compared with light-demanding trees is based on morphological parameters (SLA, LMF and LAR), and cannot be attributed to higher photosynthetic rates at the leaf level. The shade-tolerant liana exhibited a slow-growth strategy, compared with the light-demanding species. PMID:17720978

  15. [Aboveground architecture and biomass distribution of Quercus variabilis].

    PubMed

    Yu, Bi-yun; Zhang, Wen-hui; Hu, Xiao-jing; Shen, Jia-peng; Zhen, Xue-yuan; Yang, Xiao-zhou

    2015-08-01

    The aboveground architecture, biomass and its allocation, and the relationship between architecture and biomass of Quercus variabilis of different diameter classes in Shangluo, south slope of Qinling Mountains were researched. The results showed that differences existed in the aboveground architecture and biomass allocation of Q. variabilis of different diameter classes. With the increase of diameter class, tree height, DBH, and crown width increased gradually. The average decline rate of each diameter class increased firstly then decreased. Q. variabilis overall bifurcation ratio and stepwise bifurcation ratio increased then declined. The specific leaf areas of Q. variabilis of all different diameter classes at vertical direction were 0.02-0.03, and the larger values of leaf mass ratio, LAI and leaf area ratio at vertical direction in diameter level I , II, III appeared in the middle and upper trunk, while in diameter level IV, V, VI, they appeared in the central trunk, with the increase of diameter class, there appeared two peaks in vertical direction, which located in the lower and upper trunk. The trunk biomass accounted for 71.8%-88.4% of Q. variabilis aboveground biomass, while the branch biomass accounted for 5.8%-19.6%, and the leaf biomass accounted for 4.2%-8.6%. With the increase of diameter class, stem biomass proportion of Q. variabilis decreased firstly then increased, while the branch and leaf biomass proportion showed a trend that increased at first then decreased, and then increased again. The aboveground biomass of Q. variabilis was significantly positively correlated to tree height, DBH, crown width and stepwise bifurcation ratio (R2:1), and positively related to the overall bifurcation ratio and stepwise bifurcation ratio (R3:2), but there was no significant correlation. Trunk biomass and total biomass aboveground were negatively related to the trunk decline rate, while branch biomass and leaf biomass were positively related to trunk decline

  16. [Aboveground architecture and biomass distribution of Quercus variabilis].

    PubMed

    Yu, Bi-yun; Zhang, Wen-hui; Hu, Xiao-jing; Shen, Jia-peng; Zhen, Xue-yuan; Yang, Xiao-zhou

    2015-08-01

    The aboveground architecture, biomass and its allocation, and the relationship between architecture and biomass of Quercus variabilis of different diameter classes in Shangluo, south slope of Qinling Mountains were researched. The results showed that differences existed in the aboveground architecture and biomass allocation of Q. variabilis of different diameter classes. With the increase of diameter class, tree height, DBH, and crown width increased gradually. The average decline rate of each diameter class increased firstly then decreased. Q. variabilis overall bifurcation ratio and stepwise bifurcation ratio increased then declined. The specific leaf areas of Q. variabilis of all different diameter classes at vertical direction were 0.02-0.03, and the larger values of leaf mass ratio, LAI and leaf area ratio at vertical direction in diameter level I , II, III appeared in the middle and upper trunk, while in diameter level IV, V, VI, they appeared in the central trunk, with the increase of diameter class, there appeared two peaks in vertical direction, which located in the lower and upper trunk. The trunk biomass accounted for 71.8%-88.4% of Q. variabilis aboveground biomass, while the branch biomass accounted for 5.8%-19.6%, and the leaf biomass accounted for 4.2%-8.6%. With the increase of diameter class, stem biomass proportion of Q. variabilis decreased firstly then increased, while the branch and leaf biomass proportion showed a trend that increased at first then decreased, and then increased again. The aboveground biomass of Q. variabilis was significantly positively correlated to tree height, DBH, crown width and stepwise bifurcation ratio (R2:1), and positively related to the overall bifurcation ratio and stepwise bifurcation ratio (R3:2), but there was no significant correlation. Trunk biomass and total biomass aboveground were negatively related to the trunk decline rate, while branch biomass and leaf biomass were positively related to trunk decline

  17. Slow growth rates of Amazonian trees: consequences for carbon cycling.

    PubMed

    Vieira, Simone; Trumbore, Susan; Camargo, Plinio B; Selhorst, Diogo; Chambers, Jeffrey Q; Higuchi, Niro; Martinelli, Luiz Antonio

    2005-12-20

    Quantifying age structure and tree growth rate of Amazonian forests is essential for understanding their role in the carbon cycle. Here, we use radiocarbon dating and direct measurement of diameter increment to document unexpectedly slow growth rates for trees from three locations spanning the Brazilian Amazon basin. Central Amazon trees, averaging only approximately 1 mm/year diameter increment, grow half as fast as those from areas with more seasonal rainfall to the east and west. Slow growth rates mean that trees can attain great ages; across our sites we estimate 17-50% of trees with diameter >10 cm have ages exceeding 300 years. Whereas a few emergent trees that make up a large portion of the biomass grow faster, small trees that are more abundant grow slowly and attain ages of hundreds of years. The mean age of carbon in living trees (60-110 years) is within the range of or slightly longer than the mean residence time calculated from C inventory divided by annual C allocation to wood growth (40-100 years). Faster C turnover is observed in stands with overall higher rates of diameter increment and a larger fraction of the biomass in large, fast-growing trees. As a consequence, forests can recover biomass relatively quickly after disturbance, whereas recovering species composition may take many centuries. Carbon cycle models that apply a single turnover time for carbon in forest biomass do not account for variations in life strategy and therefore may overestimate the carbon sequestration potential of Amazon forests.

  18. Research on allocation efficiency of the daisy chain allocation algorithm

    NASA Astrophysics Data System (ADS)

    Shi, Jingping; Zhang, Weiguo

    2013-03-01

    With the improvement of the aircraft performance in reliability, maneuverability and survivability, the number of the control effectors increases a lot. How to distribute the three-axis moments into the control surfaces reasonably becomes an important problem. Daisy chain method is simple and easy to be carried out in the design of the allocation system. But it can not solve the allocation problem for entire attainable moment subset. For the lateral-directional allocation problem, the allocation efficiency of the daisy chain can be directly measured by the area of its subset of attainable moments. Because of the non-linear allocation characteristic, the subset of attainable moments of daisy-chain method is a complex non-convex polygon, and it is difficult to solve directly. By analyzing the two-dimensional allocation problems with a "micro-element" idea, a numerical calculation algorithm is proposed to compute the area of the non-convex polygon. In order to improve the allocation efficiency of the algorithm, a genetic algorithm with the allocation efficiency chosen as the fitness function is proposed to find the best pseudo-inverse matrix.

  19. Growing up with stress - carbon sequestration and allocation dynamics of a broadleaf evergreen forest

    NASA Astrophysics Data System (ADS)

    Griebel, Anne; Bennett, Lauren T.; Arndt, Stefan K.

    2016-04-01

    Evergreen forests have the potential to sequester carbon year-round due to the presence of leaves with a multi-year lifespan. Eucalypt forests occur in warmer climates where temperature and radiation are not imposing a strong seasonality. Thus, unlike deciduous or many coniferous trees, many eucalypts grow opportunistically as conditions allow. As such, many eucalypts do not produce distinct growth rings, which present challenges to the implementation of standard methods and data interpretation approaches for monitoring and explaining carbon allocation dynamics in response to climatic stress. As a consequence, there is a lack of detailed understanding of seasonal growth dynamics of evergreen forests as a whole, and, in particular, of the influence of climatic drivers on carbon allocation to the various biomass pools. We used a multi-instrument approach in a mixed species eucalypt forest to investigate the influence of climatic drivers on the seasonal growth dynamics of a predominantly temperate and moisture-regulated environment in south-eastern Australia. Ecosystem scale observations of net ecosystem exchange (NEE) from a flux tower in the Wombat forest near Melbourne indicated that the ecosystem is a year-round carbon sink, but that intra-annual variations in temperature and moisture along with prolonged heat waves and dry spells resulted in a wide range of annual sums over the past three years (NEE ranging from ~4 to 12 t C ha-1 yr-1). Dendrometers were used to monitor stem increments of the three dominant eucalypt species. Stem expansion was generally opportunistic with the greatest increments under warm but moist conditions (often in spring and autumn), and the strongest indicators of stem growth dynamics being radiation, vapour pressure deficit and a combined heat-moisture index. Differences in the seasonality of stem increments between species were largely due to differences in the canopy position of sampled individuals. The greatest stem increments were

  20. Light quanta modulated characteristics of Ni uptake by Brassica juncea seedlings: the interdependence of plant metal concentration and biomass.

    PubMed

    Dasgupta-Schubert, N; Whelan, T; Reyes, M A; Lloren, C; Brandt, T T; Persans, M W

    2007-01-01

    The relationships between the concentration of metal in the growth medium, Cs, the concentration of metal absorbed by the plant, Cp, and the total biomass achieved, M, all of which are factors relevant to the efficiency of metal uptake and tolerance by the plant, have been investigated via the physiological response of Brassica juncea seedlings to Ni stress. The factorial growth experiments treated the Ni concentration in agar medium and the diurnal light quanta as independently variable parameters. Observations included the evidence of light enhancement of Ni toxicity in the root, as well as at the whole-plant level. The shoot mass index possibly is an indicator of the amount of shoot metal sequestration in B. juncea, as are the logarithmic variation of Cp with Cs and the power-law dependence of M on Cp. The sum total of these observations indicates that, for the Ni accumulating plant B. juncea, the overall metabolic allocation to either growth or metal tolerance of the plant is important. Neither a rapid biomass increase nor a high metal absorbed concentration favored the removal of high metal mass from the medium. Rather, the plants with a moderate rate of biomass growth and a moderate absorbed metal concentration demonstrated the ability to remove the maximum mass of metal from the medium. The implication of these results as related to the extant model of phyoextraction efficiency is discussed.

  1. Allocation of freshly assimilated carbon into primary and secondary metabolites after in situ ¹³C pulse labelling of Norway spruce (Picea abies).

    PubMed

    Heinrich, Steffen; Dippold, Michaela A; Werner, Christiane; Wiesenberg, Guido L B; Kuzyakov, Yakov; Glaser, Bruno

    2015-11-01

    Plants allocate carbon (C) to sink tissues depending on phenological, physiological or environmental factors. We still have little knowledge on C partitioning into various cellular compounds and metabolic pathways at various ecophysiological stages. We used compound-specific stable isotope analysis to investigate C partitioning of freshly assimilated C into tree compartments (needles, branches and stem) as well as into needle water-soluble organic C (WSOC), non-hydrolysable structural organic C (stOC) and individual chemical compound classes (amino acids, hemicellulose sugars, fatty acids and alkanes) of Norway spruce (Picea abies) following in situ (13)C pulse labelling 15 days after bud break. The (13)C allocation within the above-ground tree biomass demonstrated needles as a major C sink, accounting for 86% of the freshly assimilated C 6 h after labelling. In needles, the highest allocation occurred not only into the WSOC pool (44.1% of recovered needle (13)C) but also into stOC (33.9%). Needle growth, however, also caused high (13)C allocation into pathways not involved in the formation of structural compounds: (i) pathways in secondary metabolism, (ii) C-1 metabolism and (iii) amino acid synthesis from photorespiration. These pathways could be identified by a high (13)C enrichment of their key amino acids. In addition, (13)C was strongly allocated into the n-alkyl lipid fraction (0.3% of recovered (13)C), whereby (13)C allocation into cellular and cuticular exceeded that of epicuticular fatty acids. (13)C allocation decreased along the lipid transformation and translocation pathways: the allocation was highest for precursor fatty acids, lower for elongated fatty acids and lowest for the decarbonylated n-alkanes. The combination of (13)C pulse labelling with compound-specific (13)C analysis of key metabolites enabled tracing relevant C allocation pathways under field conditions. Besides the primary metabolism synthesizing structural cell compounds, a complex

  2. The effects of soil and air temperature on CO2 exchange and net biomass accumulation in Norway spruce, Scots pine and silver birch seedlings.

    PubMed

    Pumpanen, Jukka; Heinonsalo, Jussi; Rasilo, Terhi; Villemot, Julie; Ilvesniemi, Hannu

    2012-06-01

    Soil temperature is proposed to affect the photosynthetic rate and carbon allocation in boreal trees through sink limitation. The aim of this study was to investigate the effect of temperature on CO(2) exchange, biomass partitioning and ectomycorrhizal (ECM) fungi of boreal tree species. We measured carbon allocation, above- and below-ground CO(2) exchange and the species composition of associated ECM fungi in the rhizosphere of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies K.) and silver birch (Betula pendula Roth) seedlings grown in soil maintained at 7-12, 12-15 and 16-22 °C. We found increased root biomass and photosynthetic rate at higher soil temperatures, but simultaneously with photosynthesis rate, higher temperature generally increased soil respiration as well as shoot, and root and rhizosphere respiration. The net CO(2) exchange and seedling biomass did not increase significantly with increasing temperature due to a concomitant increase in carbon assimilation and respiration rates. The 2-month-long growth period in different soil temperatures did not alter the ECM fungi species composition and the below-ground carbon sink strength did not seem to be directly related to ECM biomass and species composition in any of the tree species. Ectomycorrhizal species composition and number of mycorrhiza did not explain the CO(2) exchange results at different temperatures.

  3. The Principal as Resource Allocator.

    ERIC Educational Resources Information Center

    Peterson, Kent D.

    The effect of political influences on the allocation of personnel, money, facilities, and equipment by elementary school principals is discussed in this paper. The use of Zald's political economy framework as a tool for understanding the principal's role in allocating resources is described by the author. He suggests that the principal occupies a…

  4. Growth patterns of Chromolaena odorata in varied ecosystems at Kodayar in the Western Ghats, India

    NASA Astrophysics Data System (ADS)

    Chandrasekaran, Sivagnanam; Swamy, P. S.

    2010-07-01

    The growth and allocation patterns of biomass and nutrients (nitrogen, phosphorus and potassium) were studied in Chromolaena odorata populations grown in different human modified ecosystems including an Albizia plantation, a rubber plantation, community land and a naturally regenerating forest. The greater shoot length of C. odorata in the regenerating forest could be attributed to the competitive and shady environment created by the mature vegetation here. High relative growth rate, net assimilation rate and reproductive potential of C. odorata populations growing on the community land and in the rubber plantation may be due to the open habitat and frequent disturbances to these sites. In general, allocation of biomass and nutrients to the leaf and reproductive components was low in the regenerating forest. On the other hand, greater allocation to the root component in the regenerating forest may be a strategy for survival and regeneration after the disturbance. Low nutrient uptake and greater resource use efficiency in the regenerating forest could be a response to limited resource availability under the competitive micro-environment created by the fast growing tree species. C. odorata has an exploitative growth strategy and will persist in regenerating open habitats whereas it showed suppressed growth in the light - limited shaded environment.

  5. Research and evaluation of biomass resources/conversion/utilization systems (market/experimental analysis for development of a data base for a fuels from biomass model). Quarterly technical progress report, November 1, 1979-January 31, 1980

    SciTech Connect

    Ahn, Y.K.; Chen, Y.C.; Chen, H.T.; Helm, R.W.; Nelson, E.T.; Shields, K.J.; Stringer, R.P.; Bailie, R.C.

    1980-01-01

    The biomass allocation model has been developed and is undergoing testing. Data bases for biomass feedstock and thermochemical products are complete. Simulated data on process efficiency and product costs are being used while more accurate data are being developed. Market analyses data are stored for the biomass allocation model. The modeling activity will assist in providing process efficiency information required for the allocation model. Process models for entrained bed and fixed bed gasifiers based on coal have been adapted to biomass. Fuel product manufacturing costs will be used as inputs for the data banks of the biomass allocations model. Conceptual economics have been generated for seven of the fourteen process configurations via a biomass economic computer program. The PDU studies are designed to demonstrate steady state thermochemical conversions of biomass to fuels in fluidized, moving and entrained bed reactor configurations. Pulse tests in a fluidized bed to determine the effect of particle size on reaction rates and product gas composition have been completed. Two hour shakedown tests using peanut hulls and wood as the biomass feedstock and the fluidized bed reactor mode have been carried out. A comparison was made of the gas composition using air and steam - O/sub 2/. Biomass thermal profiles and biomass composition information shall be provided. To date approximately 70 biomass types have been collected. Chemical characterization of this material has begun. Thermal gravimetric, pyrogaschromatographic and effluent gas analysis has begun on pelletized samples of these biomass species.

  6. Soil warming and CO2 enrichment induce biomass shifts in alpine tree line vegetation.

    PubMed

    Dawes, Melissa A; Philipson, Christopher D; Fonti, Patrick; Bebi, Peter; Hättenschwiler, Stephan; Hagedorn, Frank; Rixen, Christian

    2015-05-01

    Responses of alpine tree line ecosystems to increasing atmospheric CO2 concentrations and global warming are poorly understood. We used an experiment at the Swiss tree line to investigate changes in vegetation biomass after 9 years of free air CO2 enrichment (+200 ppm; 2001-2009) and 6 years of soil warming (+4 °C; 2007-2012). The study contained two key tree line species, Larix decidua and Pinus uncinata, both approximately 40 years old, growing in heath vegetation dominated by dwarf shrubs. In 2012, we harvested and measured biomass of all trees (including root systems), above-ground understorey vegetation and fine roots. Overall, soil warming had clearer effects on plant biomass than CO2 enrichment, and there were no interactive effects between treatments. Total plant biomass increased in warmed plots containing Pinus but not in those with Larix. This response was driven by changes in tree mass (+50%), which contributed an average of 84% (5.7 kg m(-2) ) of total plant mass. Pinus coarse root mass was especially enhanced by warming (+100%), yielding an increased root mass fraction. Elevated CO2 led to an increased relative growth rate of Larix stem basal area but no change in the final biomass of either tree species. Total understorey above-ground mass was not altered by soil warming or elevated CO2 . However, Vaccinium myrtillus mass increased with both treatments, graminoid mass declined with warming, and forb and nonvascular plant (moss and lichen) mass decreased with both treatments. Fine roots showed a substantial reduction under soil warming (-40% for all roots <2 mm in diameter at 0-20 cm soil depth) but no change with CO2 enrichment. Our findings suggest that enhanced overall productivity and shifts in biomass allocation will occur at the tree line, particularly with global warming. However, individual species and functional groups will respond differently to these environmental changes, with consequences for ecosystem structure and functioning. PMID

  7. Soil warming and CO2 enrichment induce biomass shifts in alpine tree line vegetation.

    PubMed

    Dawes, Melissa A; Philipson, Christopher D; Fonti, Patrick; Bebi, Peter; Hättenschwiler, Stephan; Hagedorn, Frank; Rixen, Christian

    2015-05-01

    Responses of alpine tree line ecosystems to increasing atmospheric CO2 concentrations and global warming are poorly understood. We used an experiment at the Swiss tree line to investigate changes in vegetation biomass after 9 years of free air CO2 enrichment (+200 ppm; 2001-2009) and 6 years of soil warming (+4 °C; 2007-2012). The study contained two key tree line species, Larix decidua and Pinus uncinata, both approximately 40 years old, growing in heath vegetation dominated by dwarf shrubs. In 2012, we harvested and measured biomass of all trees (including root systems), above-ground understorey vegetation and fine roots. Overall, soil warming had clearer effects on plant biomass than CO2 enrichment, and there were no interactive effects between treatments. Total plant biomass increased in warmed plots containing Pinus but not in those with Larix. This response was driven by changes in tree mass (+50%), which contributed an average of 84% (5.7 kg m(-2) ) of total plant mass. Pinus coarse root mass was especially enhanced by warming (+100%), yielding an increased root mass fraction. Elevated CO2 led to an increased relative growth rate of Larix stem basal area but no change in the final biomass of either tree species. Total understorey above-ground mass was not altered by soil warming or elevated CO2 . However, Vaccinium myrtillus mass increased with both treatments, graminoid mass declined with warming, and forb and nonvascular plant (moss and lichen) mass decreased with both treatments. Fine roots showed a substantial reduction under soil warming (-40% for all roots <2 mm in diameter at 0-20 cm soil depth) but no change with CO2 enrichment. Our findings suggest that enhanced overall productivity and shifts in biomass allocation will occur at the tree line, particularly with global warming. However, individual species and functional groups will respond differently to these environmental changes, with consequences for ecosystem structure and functioning.

  8. 24 CFR 92.50 - Formula allocation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Formula allocation. 92.50 Section... Development HOME INVESTMENT PARTNERSHIPS PROGRAM Allocation Formula § 92.50 Formula allocation. (a) Jurisdictions eligible for a formula allocation. HUD will provide allocations of funds in amounts determined...

  9. 23 CFR 1240.15 - Allocations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Allocations. 1240.15 Section 1240.15 Highways NATIONAL... GUIDELINES SAFETY INCENTIVE GRANTS FOR USE OF SEAT BELTS-ALLOCATIONS BASED ON SEAT BELT USE RATES Determination of Allocations § 1240.15 Allocations. (a) Funds allocated under this part shall be available...

  10. Greater carbon allocation to mycorrhizal fungi reduces tree nitrogen uptake in a boreal forest.

    PubMed

    Hasselquist, Niles J; Metcalfe, Daniel B; Inselsbacher, Erich; Stangl, Zsofia; Oren, Ram; Näsholm, Torgny; Högberg, Peter

    2016-04-01

    The central role that ectomycorrhizal (EM) symbioses play in the structure and function of boreal forests pivots around the common assumption that carbon (C) and nitrogen (N) are exchanged at rates favorable for plant growth. However, this may not always be the case. It has been hypothesized that the benefits mycorrhizal fungi convey to their host plants strongly depends upon the availability of C and N, both of which are rapidly changing as a result of intensified human land use and climate change. Using large-scale shading and N addition treatments, we assessed the independent and interactive effects of changes in C and N supply on the transfer of N in intact EM associations with -15 yr. old Scots pine trees. To assess the dynamics of N transfer in EM symbioses, we added trace amounts of highly enriched 5NO3(-) label to the EM-dominated mor-layer and followed the fate of the 15N label in tree foliage, fungal chitin on EM root tips, and EM sporocarps. Despite no change in leaf biomass, shading resulted in reduced tree C uptake, ca. 40% lower fungal biomass on EM root tips, and greater 15N label in tree foliage compared to unshaded control plots, where more 15N label was found in fungal biomass on EM colonized root tips. Short-term addition of N shifted the incorporation of 15N label from EM fungi to tree foliage, despite no significant changes in below-ground tree C allocation to EM fungi. Contrary to the common assumption that C and N are exchanged at rates favorable for plant growth, our results show for the first time that under N-limited conditions greater C allocation to EM fungi in the field results in reduced, not increased, N transfer to host trees. Moreover, given the ubiquitous nature of mycorrhizal symbioses, our results stress the need to incorporate mycorrhizal dynamics into process-based ecosystem models to better predict forest C and N cycles in light of global climate change. PMID:27220217

  11. Resource Balancing Control Allocation

    NASA Technical Reports Server (NTRS)

    Frost, Susan A.; Bodson, Marc

    2010-01-01

    Next generation aircraft with a large number of actuators will require advanced control allocation methods to compute the actuator commands needed to follow desired trajectories while respecting system constraints. Previously, algorithms were proposed to minimize the l1 or l2 norms of the tracking error and of the control effort. The paper discusses the alternative choice of using the l1 norm for minimization of the tracking error and a normalized l(infinity) norm, or sup norm, for minimization of the control effort. The algorithm computes the norm of the actuator deflections scaled by the actuator limits. Minimization of the control effort then translates into the minimization of the maximum actuator deflection as a percentage of its range of motion. The paper shows how the problem can be solved effectively by converting it into a linear program and solving it using a simplex algorithm. Properties of the algorithm are investigated through examples. In particular, the min-max criterion results in a type of resource balancing, where the resources are the control surfaces and the algorithm balances these resources to achieve the desired command. A study of the sensitivity of the algorithms to the data is presented, which shows that the normalized l(infinity) algorithm has the lowest sensitivity, although high sensitivities are observed whenever the limits of performance are reached.

  12. No allocation trade-offs between flowering and sproutingin the lignotuberous, Mediterranean shrub Erica australis

    NASA Astrophysics Data System (ADS)

    Cruz, Alberto; Moreno, José M.

    2001-04-01

    Trade-offs between allocation to sexual or vegetative regeneration capacity are well established as a driving force in the life history patterns of plants in fire-prone environments. However, it is not known whether such trade-offs exist in plants which after aboveground removing disturbances, such as fire, may regenerate by sexual (seeding) or asexual (sprouting) mechanisms. We evaluated whether in the fire-recruiting resprouter Erica australis, which after fire can regenerate by seedling establishment or resprouting, a larger investment in flowers and seeds prior to being disturbed by clipping its aboveground parts would decrease subsequent sprouting, that is, its vegetative regeneration capacity. We analysed the relationships between flower and seed production and the ensuing production and growth of sprouts of six plants from thirteen different sites in central-western Spain. We found no significant relationships between measures of sexual reproductive effort and resprout production and growth 6 months after clipping the aboveground parts of the plants. No evidence of trade-offs between sexual and asexual efforts was found. Furthermore, no significant relationship was found between lignotuber total non-structural carbohydrates and sexual reproductive effort. In addition, 2 years after the disturbance, resprout biomass was positively and significantly correlated with sexual reproductive effort prior to the disturbance. This indicates that growth of resprouts was higher at the sites where plants made a greater reproductive effort. The sites that were more favourable to producing flowers and seeds could also be more favourable to resprouting.

  13. Tree allometry, leaf size and adult tree size in old-growth forests of western Oregon.

    PubMed

    King, D A

    1991-10-01

    Relationships between tree height and crown dimensions and trunk diameter were determined for shade-tolerant species of old-growth forests of western Oregon. The study included both understory and overstory species, deciduous and evergreen angiosperms and evergreen conifers. A comparison of adult understory species with sapling overstory species of similar height showed greater crown width and trunk diameter in the former, whether the comparison is made among conifers or deciduous trees. Conifer saplings had wider crowns than deciduous saplings, but the crown widths of the two groups converged with increase in tree height. Conifer saplings had thicker trunks than deciduous saplings of similar crown width, possibly because of selection for resistance to stem bending under snow loads. The results suggest that understory species have morphologies that increase light interception and persistence in the understory, whereas overstory species allocate their biomass for efficient height growth, thereby attaining the high-light environment of the canopy. The greater crown widths and the additional strength requirements imposed by snow loads on conifer saplings result in less height growth per biomass increment in conifer saplings than in deciduous saplings. However, the convergence in crown width of the two groups at heights greater than 20 m, and the proportionately smaller effect of snow loads on large trees, may result in older conifers equalling or surpassing deciduous trees in biomass allocation to height growth.

  14. Revisiting a model of ontogenetic growth: estimating model parameters from theory and data.

    PubMed

    Moses, Melanie E; Hou, Chen; Woodruff, William H; West, Geoffrey B; Nekola, Jeffery C; Zuo, Wenyun; Brown, James H

    2008-05-01

    The ontogenetic growth model (OGM) of West et al. provides a general description of how metabolic energy is allocated between production of new biomass and maintenance of existing biomass during ontogeny. Here, we reexamine the OGM, make some minor modifications and corrections, and further evaluate its ability to account for empirical variation on rates of metabolism and biomass in vertebrates both during ontogeny and across species of varying adult body size. We show that the updated version of the model is internally consistent and is consistent with other predictions of metabolic scaling theory and empirical data. The OGM predicts not only the near universal sigmoidal form of growth curves but also the M(1/4) scaling of the characteristic times of ontogenetic stages in addition to the curvilinear decline in growth efficiency described by Brody. Additionally, the OGM relates the M(3/4) scaling across adults of different species to the scaling of metabolic rate across ontogeny within species. In providing a simple, quantitative description of how energy is allocated to growth, the OGM calls attention to unexplained variation, unanswered questions, and opportunities for future research.

  15. Biomass torrefaction mill

    DOEpatents

    Sprouse, Kenneth M.

    2016-05-17

    A biomass torrefaction system includes a mill which receives a raw biomass feedstock and operates at temperatures above 400 F (204 C) to generate a dusty flue gas which contains a milled biomass product.

  16. Biomass Energy Research

    SciTech Connect

    Traylor, T.D.; Pitsenbarger, J.

    1996-03-01

    Biomass Energy Research announces on a bimonthly basis the current worldwide research and development (R&D) information available on biomass power systems, alternate feedstocks from biomass, and biofuels supply options.

  17. Energy from Biomass for Conversion of Biomass

    NASA Astrophysics Data System (ADS)

    Abolins, J.; Gravitis, J.

    2009-01-01

    Along with estimates of minimum energy required by steam explosion pre-treatment of biomass some general problems concerning biomass conversion into chemicals, materials, and fuels are discussed. The energy necessary for processing biomass by steam explosion auto-hydrolysis is compared with the heat content of wood and calculated in terms of the amount of saturated steam consumed per unit mass of the dry content of wood biomass. The fraction of processed biomass available for conversion after steam explosion pre-treatment is presented as function of the amount of steam consumed per unit mass of the dry content of wood. The estimates based on a simple model of energy flows show the energy required by steam explosion pre-treatment of biomass being within 10% of the heat content of biomass - a realistic amount demonstrating that energy for the process can be supplied from a reasonable proportion of biomass used as the source of energy for steam explosion pre-treatment.

  18. The effect of salinity on the allocation of carbon to energy-rich compounds in Euphorbia lathyris

    SciTech Connect

    Taylor, S.E.; Skrukrud, C.L.; Calvin, M.

    1987-01-01

    Hydroponically-grown Euphorbia lathyris plants were exposed to increasing levels of NaCl to study the effect of salinity on carbon allocation within the plant. Salinization caused a decrease in overall growth and an increase in the percentage of both hydrocarbons and sugars. The hydrocarbon fraction, containing mostly triterpenoids, increased by 50% and the sugar fraction, containing mostly sucrose, was increased by 88%. This resulted in a shift of available biomass from lignocellulose to the more usable sugars and hydrocarbons. A two-fold increase in the activity (per leaf area) of the enzyme ..beta..-Hydroxymethylglutaryl-Coenzyme A Reductase was also observed with increased salinity. This enzyme is involved in the biosynthesis of the triterpenoids, and its response to increased salinity indicates a role for this enzyme in the regulation of plant hydrocarbon productivity. 10 refs., 4 figs., 3 tabs.

  19. Carbon limitation reveals allocation priority to defense compounds in peppermint

    NASA Astrophysics Data System (ADS)

    Forkelova, Lenka; Unsicker, Sybille; Forkel, Matthias; Huang, Jianbei; Trumbore, Susan; Hartmann, Henrik

    2016-04-01

    Studies of carbon partitioning during insect or pathogen infestation reveal high carbon investment into induced chemical defenses to deter the biotic agent (Baldwin, 1998). However, little is known how carbon investment into chemical defenses changes under abiotic stress such as drought. Drought forces plants to close their stomata to prevent water loss through transpiration while decreasing the amount of assimilated carbon. Furthermore drought hampers carbohydrates translocation due to declining plant hydration and reduced phloem functioning (McDowell, 2011; Hartmann et al., 2013; Sevanto, 2014). Hence long lasting drought can force plants into carbon starvation. The aim of our study was to disentangle carbon allocation priorities between growth, maintenance metabolism, storage and production of defense compounds under carbon limiting conditions using peppermint as our model plant. Drought is not the only method how to manipulate plant carbon metabolism and photosynthetic yield. Exposing plants to reduced [CO2] air is a promising tool simulating drought induced carbon limitation without affecting phloem functioning and so carbohydrate translocation (Hartmann et al., 2015). We exposed peppermint plants to drought (50% of the control irrigation) and to low [CO2] (progressive decrease from 350 ppm to 20 ppm) to disentangle hydraulic failure from carbon starvation effects on carbon allocation. Drought was applied as a cross-treatment yielding four treatments: watered and high [CO2] (W+CO2), drought and high [CO2] (D+CO2), water and low [CO2] (W-CO2), drought and low [CO2] (D-CO2). We analyzed the most abundant terpenoid defense compounds (α-Pinene, sabinene, myrcene, limonene, menthone, menthol and pulegone) and used continuous 13CO2 labelling to trace allocation pattern of new and old assimilated carbon in the four carbon sinks (structural biomass, water soluble sugars, starch and terpenoid defense compounds) in young expanding leaf tissue. This leaf tissue grew

  20. Collaborative Resource Allocation

    NASA Technical Reports Server (NTRS)

    Wang, Yeou-Fang; Wax, Allan; Lam, Raymond; Baldwin, J