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Sample records for growth biomass allocation

  1. 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

  2. [Interactive effects of light intensity and nitrogen supply on fraxinus mandshurica seedlings growth, biomass, and nitrogen allocation].

    PubMed

    Huo, Chang-fu; Wang, Zheng-quan; Sun, Hai-long; Fan, Zhi-qiang; Zhao, Xiao-min

    2008-08-01

    With sand culture in greenhouse, the responses of Fraxinus mandshurica seedlings growth, biomass, and N allocation to 2 levels of light intensity and 4 levels of N supply were studied. The results showed that under low light intensity, the seedlings shoot/root ratio (S/R) and net N uptake rate (NNUR) increased significantly (P < 0.01), but their relative growth rate (RGR) and net assimilation rate (NAR) had a significant decrease (P < 0.01). The biomass of root, stem, leaf, and total plant under low light was decreased by 36.8% (P < 0.01), 1.7%, 12.7% (P < 0.05) , and 24.3% (P < 0.01), respectively, and the N allocation to leaf increased but that to root was in adverse. At the two light levels, N supply had an obvious promotion effect on the seedlings growth, and the S/R and the N allocation to leaf were increased obviously with increasing N supply. Significant interactive effects of light and N supply were observed on the seedlings diameter, S/R, RGR, and biomass allocation. PMID:18975738

  3. 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 ...

  4. 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

  5. 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

  6. Heterogeneous Light Supply Affects Growth and Biomass Allocation of the Understory Fern Diplopterygium glaucum at High Patch Contrast

    PubMed Central

    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. PMID:22132189

  7. 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.

  8. 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

  9. 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...

  10. 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

  11. 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

  12. 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

  13. 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

  14. Biomass allocation and nutrients balance related to the concentration of Nitrogen and Phosphorus in Salvinia auriculata (Salviniaceae).

    PubMed

    Medeiros, J C C; Coelho, F F; Teixeira, E

    2016-06-01

    Aquatic plants can use differential allocation (trade-off) of carbon among their structures depending on the nutrition concentration. Given that N and P are limiting in the growth of plants, our questions were: Are the N and P concentrations in S. auriculata related to the biomass allocation to its structures? Is a differential allocation of N and P between floating and submerged leaves? We evaluated the relation between the nutrients and the biomass allocation, and the trade-off among the leaves using the Spearman correlation. Our results showed that N and P concentrations in S. auriculata are related to the biomass allocation to its structures, and that there is no trade-off of these nutrients between "shoot and root". Thus, we can see the importance of N and P concentration in the biomass of S. auriculata, and why this plant is capable to development in different environments as a weedy. PMID:26959946

  15. 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.

  16. 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

  17. 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.

  18. Management and fertility control ecosystem carbon allocation to biomass production

    NASA Astrophysics Data System (ADS)

    Campioli, Matteo; Vicca, Sara; Janssens, Ivan

    2015-04-01

    Carbon (C) allocation within the ecosystem is one of the least understood processes in plant- and geo-sciences. The proportion of the C assimilated through photosynthesis (gross primary production, GPP) that is used for biomass production (BP) is a key variable of the C allocation process and it has been termed as biomass production efficiency (BPE). We investigated the potential drivers of BPE using a global dataset of BP, GPP, BPE and ancillary ecosystem characteristics (vegetation properties, climatic and environmental variables, anthropogenic impacts) for 131 sites comprising six major ecosystem types: forests, grasslands, croplands, tundra, boreal peatlands and marshes. We obtained two major findings. First, site fertility is the key driver of BPE across forests, with nutrient-rich forests allocating 58% of their photosynthates to BP, whereas this fraction is only 42% for nutrient-poor forests. Second, by disentangling the effect of management from the effect of fertility and by integrating all ecosystem types, we observed that BPE is globally not driven by the 'natural' site fertility, but by the positive effect brought by management on the nutrient availability. This resulted in managed ecosystems having substantially larger BPE than natural ecosystems. These findings will crucially improve our elucidation of the human impact on ecosystem functioning and our predictions of the global C cycle.

  19. Conditioning biomass for microbial growth

    SciTech Connect

    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.

  20. 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

  1. 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.

  2. Distinguishing the Biomass Allocation Variance Resulting from Ontogenetic Drift or Acclimation to Soil Texture

    PubMed Central

    Xie, Jiangbo; Tang, Lisong; Wang, Zhongyuan; Xu, Guiqing; Li, Yan

    2012-01-01

    In resource-poor environments, adjustment in plant biomass allocation implies a complex interplay between environmental signals and plant development rather than a delay in plant development alone. To understand how environmental factors influence biomass allocation or the developing phenotype, it is necessary to distinguish the biomass allocations resulting from environmental gradients or ontogenetic drift. Here, we compared the development trajectories of cotton plants (Gossypium herbaceum L.), which were grown in two contrasting soil textures during a 60-d period. Those results distinguished the biomass allocation pattern resulting from ontogenetic drift and the response to soil texture. The soil texture significantly changed the biomass allocation to leaves and roots, but not to stems. Soil texture also significantly changed the development trajectories of leaf and root traits, but did not change the scaling relationship between basal stem diameter and plant height. Results of nested ANOVAs of consecutive plant-size categories in both soil textures showed that soil gradients explained an average of 63.64–70.49% of the variation of biomass allocation to leaves and roots. Ontogenetic drift explained 77.47% of the variation in biomass allocation to stems. The results suggested that the environmental factors governed the biomass allocation to roots and leaves, and ontogenetic drift governed the biomass allocation to stems. The results demonstrated that biomass allocation to metabolically active organs (e.g., roots and leaves) was mainly governed by environmental factors, and that biomass allocation to metabolically non-active organs (e.g., stems) was mainly governed by ontogenetic drift. We concluded that differentiating the causes of development trajectories of plant traits was important to the understanding of plant response to environmental gradients. PMID:22911802

  3. Biomass allocation in an agropyron Smithii-glomus symbiosis

    SciTech Connect

    Miller, R.M.; Jarstfer, A.G.; Pillai, J.K. )

    1987-01-01

    The type of response the steppe grass Agropyron smithii Rydb. exhibits to mycorrhizal fungi is dependent upon where along the resource gradient the experiment is conducted. At the lower end of a soil-phosphorus (P) gradient (2 {mu}g P g{sup {minus}1} soil) mycorrhizal A. smithii biomass was 35% greater than its nonmycorrhizal counterpart; while at the high end of the gradient (20 {mu}g P g{sup {minus}1} soil) no difference in host biomass production was evident. Mycorrhizal plants were shorter in stature and produced more tillers than nonmycorrhizal plants. The stature and tiller response was more pronounced at the high end of the soil-P gradient. The partitioning of the mycorrhizal fungus was influenced by the soil-P gradient. At the lower end of the gradient the majority of the fungus was produced extramatrically, where over 5,000 cm of hyphae per plant were encountered after 10 wk growth. While at the high end of the gradient, the majority of fungus was produced internally. The highest mycorrhizal dependency values were measured at the lower end of the soil-P gradient where cost to the host (as measured by fungus biomass expressed as a percentage of the root system) was also highest. Increasing shoot and root-P concentrations were correlated with decreasing external fungus biomass. A positive association between tiler production and internal fungus biomass also existed.

  4. 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. PMID:26276402

  5. 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

  6. Plants adapted to nutrient limitation allocate less biomass into stems in an arid-hot grassland.

    PubMed

    Yan, Bangguo; Ji, Zhonghua; Fan, Bo; Wang, Xuemei; He, Guangxiong; Shi, Liangtao; Liu, Gangcai

    2016-09-01

    Biomass allocation can exert a great influence on plant resource acquisition and nutrient use. However, the role of biomass allocation strategies in shaping plant community composition under nutrient limitations remains poorly addressed. We hypothesized that species-specific allocation strategies can affect plant adaptation to nutrient limitations, resulting in species turnover and changes in community-level biomass allocations across nutrient gradients. In this study, we measured species abundance and the concentrations of nitrogen and phosphorus in leaves and soil nutrients in an arid-hot grassland. We quantified species-specific allocation parameters for stems vs leaves based on allometric scaling relationships. Species-specific stem vs leaf allocation parameters were weighted with species abundances to calculate the community-weighted means driven by species turnover. We found that the community-weighted means of biomass allocation parameters were significantly related to the soil nutrient gradient as well as to leaf stoichiometry, indicating that species-specific allocation strategies can affect plant adaptation to nutrient limitations in the studied grassland. Species that allocate less to stems than leaves tend to dominate nutrient-limited environments. The results support the hypothesis that species-specific allocations affect plant adaptation to nutrient limitations. The allocation trade-off between stems and leaves has the potential to greatly affect plant distribution across nutrient gradients. PMID:27101947

  7. 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.

  8. Biomass allocation and photosynthetic responses of lianas and pioneer tree seedlings to light

    NASA Astrophysics Data System (ADS)

    Toledo-Aceves, Tarin; Swaine, Michael D.

    2008-07-01

    Lianas are frequently considered as light demanding plants due to their proliferation in gaps and forest edges. Since lianas are exposed to a very heterogeneous light environment, they could be expected to express morphological and physiological plasticity in response to changes in the light environment, as high as that found in pioneer trees. We compared the biomass allocation and photosynthetic responses of seedlings of three species of lianas and two species of pioneer trees to increased light availability. Seedlings were transferred from medium (4-5 mol m -2 d -1) to high irradiance (12-15 mol m -2 d -1) in a controlled environment. In general the three liana species allocated fewer resources to the stem in comparison with the trees. The difference in the response between irradiance regimes was similar among the species, with no strong differences between trees and lianas probably due the early stage of the plants. With increase in irradiance plants accumulated more biomass, allocated more resources to the roots and less to the leaves, reduced the leaf area ratio (LAR) and specific leaf area (SLA). The photosynthetic rates recorded were not related to the rates of growth as measured by the increase in dry biomass (RGRm). Regardless of the life form, plants under higher irradiance increased their light compensation point (Lcp) and attained light saturation (Lsp) at higher levels of irradiance, while the saturated photosynthetic rate (A max) did not show a clear pattern, and dark respiration (R d) and quantum yield (Q) were not affected by the transference. The understanding of liana and tree seedlings responses to the light environment may have important implications in the dynamics of tropical forest regeneration.

  9. 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

  10. 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

  11. 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...

  12. 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

  13. 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

  14. 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

  15. 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

  16. The interplay between shifts in biomass allocation and costs of reproduction in four grassland perennials under simulated successional change.

    PubMed

    Jongejans, Eelke; de Kroon, Hans; Berendse, Frank

    2006-03-01

    When perennial herbs face the risk of being outcompeted in the course of succession, they are hypothesized to either increase their biomass allocation to flowers and seeds or to invest more in vegetative growth. We tested these hypotheses in a 3-year garden experiment with four perennials (Hypochaeris radicata, Cirsium dissectum, Succisa pratensis and Centaurea jacea) by growing them in the midst of a tall tussock-forming grass (Molinia caerulea) that may successionally replace them in their natural habitat. In all species except for the short-lived H. radicata, costs of sexual reproduction were significant over the 3 years, since continuous bud removal enhanced total biomass or rosette number. To mimic succession we added nutrients, which resulted in a tripled grass biomass and higher death rates in the shorter-lived species. The simulated succession resulted also in a number of coupled growth responses in the survivors: enhanced plant size as well as elevated seed production. The latter was partly due to larger plant sizes, but mostly due to higher reproductive allocation, which in turn could be partly explained by lower relative somatic costs and by lower root-shoot ratios in the high-nutrient plots. Our results suggest that perennial plants can increase both their persistence and their colonization ability by simultaneously increasing their vegetative size and reproductive allocation in response to enhanced competition and nutrient influxes. These responses can be very important for the survival of a species in a metapopulation context. PMID:16400509

  17. Research and evaluation of biomass resources/conversion/utilization systems. Biomass allocation model. Volume 1: Test and appendices A & B

    NASA Astrophysics Data System (ADS)

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

    1981-08-01

    A biomass allocation model was 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 which of a large number of potential biomass missions is the most profitable mission. 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 microprocessor. A User's Manual for the system is included. 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.

  18. Adventitious Root Production and Plastic Resource Allocation to Biomass Determine Burial Tolerance in Woody Plants from Central Canadian Coastal Dunes

    PubMed Central

    DECH, JEFFERY P.; MAUN, M. ANWAR

    2006-01-01

    • Background and Aims Burial is a recurrent stress imposed upon plants of coastal dunes. Woody plants are buried on open coastal dunes and in forested areas behind active blowouts; however, little is known about the burial responses and adaptive traits of these species. The objectives of this study were: (a) to determine the growth and morphological responses to burial in sand of seven woody plant species native to central Canadian coastal dunes; and (b) to identify traits that determine burial tolerance in these species. • Methods Field experiments were conducted to determine the responses of each species to burial. Saplings were exposed to burial treatments of 0, 10, 25, 50 and 75 % of their height. Burial responses were evaluated based on regressions of total biomass, height, adventitious root production and percentage allocation to shoot, root and adventitious root biomass on percentage burial. • Key Results Pinus strobus and Picea glauca lacked burial tolerance. In response to the burial gradient, these species showed a strong linear decline in total biomass, minimal adventitious root production that peaked at moderate levels (25–50 % burial) and no change in allocation to shoots vs. roots. The tolerant species Juniperus virginiana, Thuja occidentalis and Picea mariana showed a quadratic response to burial, with little change in biomass up to 50 % burial, but a large decline at 75 %. These species produced abundant adventitious roots up to 50 % burial, but did not alter allocation patterns over the range of burial levels. Populus balsamifera and Salix cordata were stimulated by burial. These species showed linear increases in biomass with increasing burial, produced copious adventitious roots across the gradient and showed a clear shift in allocation to vertical shoot growth and adventitious root production at the expense of the original roots under high burial conditions. • Conclusions Adventitious root production and plastic resource

  19. 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

  20. Biomass Allocation is an Important Determinant of the Tannin Concentration in Growing Plants

    PubMed Central

    Häring, D. A.; Suter, D.; Amrhein, N.; Lüscher, A.

    2007-01-01

    Background and aims Condensed tannins (CTs) in the diet affect consumers in a concentration-dependent manner. Because of their importance in plant defence against herbivores and pathogens as well as their potential application against gastrointestinal parasites of ruminants in agronomy, an understanding of the seasonal dynamics of CT concentrations during plant growth is essential. Methods Over a vegetation period, CT concentrations in leaves, stems and roots and the biomass proportions between these organs were investigated in Onobrychis viciifolia, Lotus corniculatus and Cichorium intybus. Based on the experimental data, a model has been suggested to predict CT concentrations in harvestable biomass of these species. Key Results During the experiment, leaf mass fractions of plants decreased from 85, 64, 85 to 30, 18, 39 % d. wt in Onobrychis, Lotus and Cichorium, respectively, and proportions of stems and roots increased accordingly. While CT concentrations almost doubled in leaves in Onobrychis (from 52 to 86 mg g−1 d. wt, P<0·001) and Lotus (from 25 to 54 mg g−1 d. wt, P<0·001), they were stable at low levels in expanding leaves of Cichorium (5 mg g−1 d. wt) and in stems and roots of all investigated species. Due to an inverse effect of the increasing CT concentrations in leaves and simultaneous dilution from increasing proportions of ‘CT-poor’ stems, CT concentrations in harvestable biomass were stable over time in all investigated species: 62, 26 and 5 mg g−1 d. wt for Onobrychis, Lotus and Cichorium, respectively. Conclusions As a consequence of the unequal distribution of tannins in different plant parts and due to the changing biomass proportions between them, various herbivores (e.g. a leaf-eating insect and a grazing ruminant) may find not only different concentrations of CT in their diets but also different CT dynamics during the season. For the prediction of seasonal variations of CT concentrations, biomass allocation and accumulation

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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

  12. Visibility vs. biomass in flowers: exploring corolla allocation in Mediterranean entomophilous plants

    PubMed Central

    Herrera, Javier

    2009-01-01

    Background and Aims While pollinators may in general select for large, morphologically uniform floral phenotypes, drought stress has been proposed as a destabilizing force that may favour small flowers and/or promote floral variation within species. Methods The general validity of this concept was checked by surveying a taxonomically diverse array of 38 insect-pollinated Mediterranean species. The interplay between fresh biomass investment, linear size and percentage corolla allocation was studied. Allometric relationships between traits were investigated by reduced major-axis regression, and qualitative correlates of floral variation explored using general linear-model MANOVA. Key Results Across species, flowers were perfectly isometrical with regard to corolla allocation (i.e. larger flowers were just scaled-up versions of smaller ones and vice versa). In contrast, linear size and biomass varied allometrically (i.e. there were shape variations, in addition to variations in size). Most floral variables correlated positively and significantly across species, except corolla allocation, which was largely determined by family membership and floral symmetry. On average, species with bilateral flowers allocated more to the corolla than those with radial flowers. Plant life-form was immaterial to all of the studied traits. Flower linear size variation was in general low among conspecifics (coefficients of variation around 10 %), whereas biomass was in general less uniform (e.g. 200–400 mg in Cistus salvifolius). Significant among-population differences were detected for all major quantitative floral traits. Conclusions Flower miniaturization can allow an improved use of reproductive resources under prevailingly stressful conditions. The hypothesis that flower size reflects a compromise between pollinator attraction, water requirements and allometric constraints among floral parts is discussed. PMID:19258340

  13. Optimal Resource Allocation in Steel Making Using Torrefied Biomass as Auxiliary Reductant

    NASA Astrophysics Data System (ADS)

    Wiklund, Carl-Mikael; Saxén, Henrik; Helle, Mikko

    Steelmaking is an energy intensive industrial sector and being largely coal-based it gives rise to 5-6 % of the global CO2 emissions. Energy use for producing 1 ton of crude steel has been reduced by 50 % since 1975, but the annual production rate of crude steel has been increasing more strongly. Since 2002, the production rate has increased by almost 80 % amounting to 1,510 Mt in 2012, and this trend seems to continue in the future. Therefore, making the iron production itself more efficient is not enough to reduce carbon dioxide emissions. A possible remedy is to replace part of the fossil reductants by renewables and to optimize the entire production chain from ores to steel, allowing more beneficial resource allocation in the processes involved. The present study focuses on the use of biomass as auxiliary reductant in the blast furnace, also paying attention to the effect of the introduction on the material and energy flows of the whole steel plant using a simulation model. Substituting part of the fossil coke or injected hydrocarbon by biomass may result in reduced fossil carbon dioxide emissions, as long as the biomass is harvested, transported and pre-processed in a sustainable way. As the biomass may need upgrading before it is used, a torrefaction model is included in the steel plant model. Results are presented from studies where the entire system is optimized with respect to costs, considering a penalty for CO2 emissions.

  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 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

  16. 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...

  17. 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)

  18. 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. PMID:25428828

  19. Deciduous and evergreen trees differ in juvenile biomass allometries because of differences in allocation to root storage

    PubMed Central

    Tomlinson, Kyle W.; van Langevelde, Frank; Ward, David; Bongers, Frans; da Silva, Dulce Alves; Prins, Herbert H. T.; de Bie, Steven; Sterck, Frank J.

    2013-01-01

    Background and Aims Biomass partitioning for resource conservation might affect plant allometry, accounting for a substantial amount of unexplained variation in existing plant allometry models. One means of resource conservation is through direct allocation to storage in particular organs. In this study, storage allocation and biomass allometry of deciduous and evergreen tree species from seasonal environments were considered. It was expected that deciduous species would have greater allocation to storage in roots to support leaf regrowth in subsequent growing seasons, and consequently have lower scaling exponents for leaf to root and stem to root partitioning, than evergreen species. It was further expected that changes to root carbohydrate storage and biomass allometry under different soil nutrient supply conditions would be greater for deciduous species than for evergreen species. Methods Root carbohydrate storage and organ biomass allometries were compared for juveniles of 20 savanna tree species of different leaf habit (nine evergreen, 11 deciduous) grown in two nutrient treatments for periods of 5 and 20 weeks (total dry mass of individual plants ranged from 0·003 to 258·724 g). Key Results Deciduous species had greater root non-structural carbohydrate than evergreen species, and lower scaling exponents for leaf to root and stem to root partitioning than evergreen species. Across species, leaf to stem scaling was positively related, and stem to root scaling was negatively related to root carbohydrate concentration. Under lower nutrient supply, trees displayed increased partitioning to non-structural carbohydrate, and to roots and leaves over stems with increasing plant size, but this change did not differ between leaf habits. Conclusions Substantial unexplained variation in biomass allometry of woody species may be related to selection for resource conservation against environmental stresses, such as resource seasonality. Further differences in plant

  20. 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.

  1. 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.

  2. 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.

  3. 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. PMID:25640987

  4. 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

  5. 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

  6. 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.

  7. 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.

  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. 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

  10. Vegetation in karst terrain of southwestern China allocates more biomass to roots

    NASA Astrophysics Data System (ADS)

    Ni, J.; Luo, D. H.; Xia, J.; Zhang, Z. H.; Hu, G.

    2015-07-01

    In mountainous areas of southwestern China, especially Guizhou province, continuous, broadly distributed karst landscapes with harsh and fragile habitats often lead to land degradation. Research indicates that vegetation located in karst terrains has low aboveground biomass and land degradation that reduces vegetation biomass, but belowground biomass measurements are rarely reported. Using the soil pit method, we investigated the root biomass of karst vegetation in five land cover types: grassland, grass-scrub tussock, thorn-scrub shrubland, scrub-tree forest, and mixed evergreen and deciduous forest in Maolan, southern Guizhou province, growing in two different soil-rich and rock-dominated habitats. The results show that roots in karst vegetation, especially the coarse roots, and roots in rocky habitats are mostly distributed in the topsoil layers (89 % on the surface up to 20 cm depth). The total root biomass in all habitats of all vegetation degradation periods is 18.77 Mg ha-1, in which roots in rocky habitat have higher biomass than in earthy habitat, and coarse root biomass is larger than medium and fine root biomass. The root biomass of mixed evergreen and deciduous forest in karst habitat (35.83 Mg ha-1) is not greater than that of most typical, non-karst evergreen broad-leaved forests in subtropical regions of China, but the ratio of root to aboveground biomass in karst forest (0.37) is significantly greater than the mean ratio (0.26 ± 0.07) of subtropical evergreen forests. Vegetation restoration in degraded karst terrain will significantly increase the belowground carbon stock, forming a potential regional carbon sink.

  11. Vegetation in karst terrain of southwestern China allocates more biomass to roots

    NASA Astrophysics Data System (ADS)

    Ni, J.; Luo, D. H.; Xia, J.; Zhang, Z. H.; Hu, G.

    2015-03-01

    In mountainous areas of southwestern China, especially Guizhou Province, continuous, broadly distributed karst landscapes with harsh and fragile habitats often lead to land degradation. Research indicates that vegetation located in karst terrains has low aboveground biomass, and land degradation reduces vegetation biomass, but belowground biomass measurements are rarely reported. Using the soil pit method, we investigated the root biomass of karst vegetation in five degraded (successional) stages: grassland, grass-scrub tussock, thorn-scrub shrubland, scrub-tree forest, and mixed evergreen and deciduous forest in Maolan, southern Guizhou Province, growing in two different soil-rich and rock-dominated habitats. The results show that roots in karst vegetation, especially the coarse roots, and roots in rocky habitats, are mostly distributed in the topsoil layers (89% on the surface up to 20 cm depth). The total root biomass in all habitats of all vegetation degradation periods is 18.77 Mg ha-1, in which roots in rocky habitat have higher biomass than in earthy habitat, and coarse root biomass is larger than medium and fine root biomass. The root biomass of mixed evergreen and deciduous forest in karst habitat (35.83 Mg ha-1) is not greater than that of most typical, non-karst evergreen broad-leaved forests in subtropical regions of China, but the ratio of root to aboveground biomass in karst forest (0.37) is significantly greater than the mean ratio (0.26±0.07) of subtropical evergreen forests. Vegetation restoration in degraded karst terrain will significantly increase the belowground carbon stock, forming a potential regional carbon sink.

  12. 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

  13. Response of highbush blueberry to nitrogen fertilizer during field establishment. I. Accumulation and allocation of fertilizer nitrogen and biomass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of N fertilizer rate on plant growth, N uptake, and biomass and N partitioning was studied in highbush blueberry during the first 2 years after planting. Plants were grown without N fertilizer or with either 50, 100, or 150 kg/ha N applied each year using 15N-depleted ammonium sulfate t...

  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. 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.

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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...

  1. Physiological responses of biomass allocation, root architecture, and invertase activity to copper stress in young seedlings from two populations of Kummerowia stipulacea (maxim.) Makino.

    PubMed

    Zhang, Luan; Pan, Yuxue; Lv, Wei; Xiong, Zhi-ting

    2014-06-01

    In the current study, we hypothesize that mine (metallicolous) populations of metallophytes form a trade-off between the roots and shoots when under copper (Cu) stress to adapt themselves to heavy metal contaminated habitats, and thus, differ from normal (non-metallicolous) populations in biomass allocation. To test the hypothesis, two populations of the metallophyte Kummerowia stipulacea, one from an ancient Cu mine (MP) and the other from a non-contaminated site (NMP), were treated with Cu(2+) in hydroponic conditions. The results showed that MP plants had higher root/shoot biomass allocation and more complicated root system architecture compared to those of the NMP plants when under Cu stress. The net photosynthetic capacity was more inhibited in the NMP plants than in the MP plants when under Cu stress. The sugar (sucrose and hexose) contents and acid invertase activities of MP plants were elevated while those in NMP plants were inhibited after Cu treatment. The neutral/alkaline invertase activities and sucrose synthase level showed no significant differences between the two populations when under Cu stress. The results showed that acid invertase played an important role in biomass allocation and that the physiological responses were beneficial for the high root/shoot biomass allocation, which were advantageous during adaptive evolution to Cu-enriched mine soils. PMID:24726940

  2. 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.

  3. 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

  4. Observed allocations of productivity and biomass, and turnover times in tropical forests are not accurately represented in CMIP5 Earth system models

    NASA Astrophysics Data System (ADS)

    Negrón-Juárez, Robinson I.; Koven, Charles D.; Riley, William J.; Knox, Ryan G.; Chambers, Jeffrey Q.

    2015-06-01

    A significant fraction of anthropogenic CO2 emissions is assimilated by tropical forests and stored as biomass, slowing the accumulation of CO2 in the atmosphere. Because different plant tissues have different functional roles and turnover times, predictions of carbon balance of tropical forests depend on how earth system models (ESMs) represent the dynamic allocation of productivity to different tree compartments. This study shows that observed allocation of productivity, biomass, and turnover times of main tree compartments (leaves, wood, and roots) are not accurately represented in Coupled Model Intercomparison Project Phase 5 ESMs. In particular, observations indicate that biomass saturates with increasing productivity. In contrast, most models predict continuous increases in biomass with increases in productivity. This bias may lead to an over-prediction of carbon uptake in response to CO2 or climate-driven changes in productivity. Compartment-specific productivity and biomass are useful benchmarks to assess terrestrial ecosystem model performance. Improvements in the predicted allocation patterns and turnover times by ESMs will reduce uncertainties in climate predictions.

  5. 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.

  6. 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%.

  7. Allometry in global models: an important reality check on the growth and biomass of forests

    NASA Astrophysics Data System (ADS)

    Wolf, A.; Berry, J. A.

    2009-12-01

    Data assimilation incorporates information into a model of nature, and regardless of the algorithm employed the success of DA rests heavily on the quality of both the data and the model. Here we ask the question: if would could assimilate biomass from remote sensing or direct observation, could the models accommodate this information? We find that the state variables that are simulated by land surface models, such as biomass per unit area, are not amenable to developing an "observation operator" necessary for comparison with data. That is, lidar, radar, and multi-angle observations are sensitive to the size and shape of individual trees, whereas most land surface models have no representation of an individual. In addition, most land surface models make no distinction between aboveground and belowground woody biomass. We used the Cannell (1982) forest inventory database to individuate the biomass simulated in land surface models and found that the scaling of biomass pools - leaves, stem, coarse and fine roots - do not obey widely observed empirical and theoretical allometric constraints that are observed for individual trees (Enquist and Niklas, 2002), suggesting that the fractional allocation to these pools and their characteristic turnover times are in error. This discrepancy represents a gap in the translation of research on individual-based allocation to the stand level, where self-pruning and competition are manifest in the observed fluxes and biomass pools per unit area. We develop an approach to synthesize individual-based allocation with area-based flux models using a recent database of component flux and biomass compiled from Fluxnet sites (Luyssaert et al., 2008). We present the size-dependent pattern of allocation and turnover time for forest biomass pools at the spatial scale appropriate for land surface models. We discuss the implications of these results at the global scale for forests with changing size and age structure.

  8. Sensitivity of ring growth and carbon allocation to climatic variation vary within ponderosa pine trees.

    PubMed

    Kerhoulas, Lucy P; Kane, Jeffrey M

    2012-01-01

    Most dendrochronological studies focus on cores sampled from standard positions (main stem, breast height), yet vertical gradients in hydraulic constraints and priorities for carbon allocation may contribute to different growth sensitivities with position. Using cores taken from five positions (coarse roots, breast height, base of live crown, mid-crown branch and treetop), we investigated how radial growth sensitivity to climate over the period of 1895-2008 varies by position within 36 large ponderosa pines (Pinus ponderosa Dougl.) in northern Arizona. The climate parameters investigated were Palmer Drought Severity Index, water year and monsoon precipitation, maximum annual temperature, minimum annual temperature and average annual temperature. For each study tree, we generated Pearson correlation coefficients between ring width indices from each position and six climate parameters. We also investigated whether the number of missing rings differed among positions and bole heights. We found that tree density did not significantly influence climatic sensitivity to any of the climate parameters investigated at any of the sample positions. Results from three types of analyses suggest that climatic sensitivity of tree growth varied with position height: (i) correlations of radial growth and climate variables consistently increased with height; (ii) model strength based on Akaike's information criterion increased with height, where treetop growth consistently had the highest sensitivity and coarse roots the lowest sensitivity to each climatic parameter; and (iii) the correlation between bole ring width indices decreased with distance between positions. We speculate that increased sensitivity to climate at higher positions is related to hydraulic limitation because higher positions experience greater xylem tensions due to gravitational effects that render these positions more sensitive to climatic stresses. The low sensitivity of root growth to all climatic variables

  9. 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

  10. 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

  11. 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. PMID:24852570

  12. 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

  13. Transgenic plants changed in carbon allocation pattern display a shift in diurnal growth pattern.

    PubMed

    Kehr, J; Hustiak, F; Walz, C; Willmitzer, L; Fisahn, J

    1998-11-01

    Photosynthesis, partitioning of carbohydrates and growth have to be highly orchestrated to enable an efficient performance of plants. To study the diurnal relationships between carbon distribution and growth, we analysed transgenic potato plants with altered carbon allocation patterns. To modify carbohydrate supply of growing sinks, we used plants that accumulated starch as a consequence of inhibition in triose-phosphate export from chloroplasts and plants that were genetically inhibited in starch production. Carbon assimilation was analysed by gas exchange and single cell analysis of source leaves. Export was determined by microanalysis of phloem exudates and internodal growth rates were measured by displacement transducers. Gas exchange measurements showed similar assimilation rates in the wild-type and transgenic plants during the light period. Sugar analysis of phloem exudates and epidermal cells revealed a severe shift of sucrose concentrations in the individual plant lines. Moreover, epidermal cells turned out to be a potential storage site for carbohydrates in potato. Finally, we could demonstrate that changing the diurnal rhythm of carbon allocation results in a change in the diurnal growth pattern. PMID:9881169

  14. 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.

  15. 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

  16. 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. PMID:24161650

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. Effect of Continuous Cropping Generations on Each Component Biomass of Poplar Seedlings during Different Growth Periods

    PubMed Central

    Xia, Jiangbao; Zhang, Shuyong; Li, Tian; Liu, Xia; Zhang, Ronghua; Zhang, Guangcan

    2014-01-01

    In order to investigate the change rules and response characteristics of growth status on each component of poplar seedling followed by continuous cropping generations and growth period, we clear the biomass distribution pattern of poplar seedling, adapt continuous cropping, and provide theoretical foundation and technical reference on cultivation management of poplar seedling, the first generation, second generation, and third generation continuous cropping poplar seedlings were taken as study objects, and the whole poplar seedling was harvested to measure and analyze the change of each component biomass on different growth period poplar leaves, newly emerging branches, trunks and root system, and so forth. The results showed that the whole biomass of poplar seedling decreased significantly with the leaf area and its ratio increased, and the growth was inhibited obviously. The biomass aboveground was more than that underground. The ratios of leaf biomass and newly emerging branches biomass of first continuous cropping poplar seedling were relatively high. With the continuous cropping generations and growth cycle increasing, poplar seedling had a growth strategy to improve the ratio of root-shoot and root-leaf to adapt the limited soil nutrient of continuous cropping. PMID:25401150

  4. [Effects of plant species combination and water body nutrient level on the biomass accumulation and allocation of three kinds functional plants].

    PubMed

    Sun, Li-Fang; Sun, Yi-Xiang; Zhou, Chang-Fang; An, Shu-Qing

    2009-10-01

    Four nutrient levels, i.e., 0.5 mg N x L(-1) and 0.1 mg P x L(-1) (I), 1.5 mg N x L(-1) and 0.3 mg P x L(-1) (II), 4.5 mg N x L(-1) and 0.9 mg P x L(-1) (III), and 13.5 mg N x L(-1) and 2.7 mg P x L(-1) (IV), were installed to study the effects of water body's nutrient level, plant species combination, and their interactions on the biomass accumulation and allocation of invasive floating species Eichhornia crassipes, native rooted leaf-floating species Jussiaea stipulacea, and submerged plant Vallisneria spiralis. The total, root, stem, and leaf biomass of E. crassipes and J. stipulacea, either in monoculture or in mixed-culture, increased with increasing water body's nutrient level, their total biomass in treatments III and IV being averagely 54.47% and 102.63% higher than that in treatments I and II, respectively. Under different plant species combination, the total, root, stem, and leaf biomass of V. spiralis showed a declining trend with the increase of nutrient level, and the total biomass of V. spiralis in treatments III and IV was averagely 45.88% lower than that in treatments I and II. The results of two-way ANOVA showed that water body's nutrient level had significant positive effects on the biomass of E. crassipes and J. stipulacea but negative effects on that of V. spiralis, and the effects of plant species combination varied with target plant species. PMID:20077692

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

    SciTech Connect

    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.

  6. 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.

  7. 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

  8. 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

  9. 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

  10. Interpretation of tree-ring data with a model for primary production, carbon allocation and growth

    NASA Astrophysics Data System (ADS)

    Li, G.; Wang, H.; Harrison, S. P.; Prentice, I. C.

    2013-12-01

    We present a simple, generic model of annual tree growth, called ';T'. This model accepts input from a generic light-use efficiency model which is known to provide good simulations of terrestrial carbon exchange. The light-use efficiency 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 relationships. The result is a model that can represent both ontogenetic effects and the effects of environmental variations and trends on growth. The model has been applied to simulate ring-width series from multiple individual trees in temperature- and drought-limited contexts. Each tree is initialized at its actual diameter at the time when local climate records started. These records are used to drive the trees' subsequent growth. Realistic simulations of the pattern of interannual variability of ring-width are generated, and shown to relate statistically to climate. An upward trend in ring-width during 1958-2007 is shown to be present in the primary observations, and in the simulations; but not in the standard, detrended ring-width series. This approach combines two modelling approaches previously developed in the global carbon cycle and forest science literature respectively. Neither has been widely applied in the context of tree-ring based climate reconstruction. This combination of methods offers promise, however, because it could provide a way to sidestep several known problems. These include: reliance on correlations for the interpretation of ring-width variations in terms of climate; the necessity of detrending using empirical functions (which can remove trends caused by variations in the environment as well as those that are ontogenetic); and the difficulty of assessing effects of extrinsic, non

  11. 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.

  12. 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

  13. Microalgal growth with intracellular phosphorus for achieving high biomass growth rate and high lipid/triacylglycerol content simultaneously.

    PubMed

    Wu, Yin-Hu; Yu, Yin; Hu, Hong-Ying

    2015-09-01

    Nutrient deprivation is a commonly-used trigger for microalgal lipid accumulation, but its adverse impact on microalgal growth seems to be inevitable. In this study, Scenedesmus sp. LX1 was found to show similar physiological and biochemical variation under oligotrophic and eutrophic conditions during growth with intracellular phosphorus. Under both conditions microalgal chlorophyll content and photosynthesis activity was stable during this growth process, leading to significant increase of single cell weight and size. Therefore, while algal density growth rate dropped significantly to below 1.0 × 10(5)cells mL(-1) d(-1) under oligotrophic condition, the biomass dry weight growth rate still maintained about 40 mg L(-1) d(-1). Meanwhile, the lipid content in biomass and triacylglycerols (TAGs) content in lipids increased significantly to about 35% and 65%, respectively. Thus, high biomass growth rate and high lipid/TAG content were achieved simultaneously at the late growth phase with intracellular phosphorus. Besides, microalgal biomass produced was rich in carbohydrate with low protein content. PMID:26056779

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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 ...

  19. 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

  20. 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

  1. 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.

  2. 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.

    2014-07-01

    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 (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 1958-2006 for multiple trees of Pinus koraiensis from the Changbai Mountain, 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, 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 fertilization over the past 50 years is too small to be distinguished in the ring-width data given ontogenetic trends and interannual variability in climate.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. Testing the Growth Rate Hypothesis in Vascular Plants with Above- and Below-Ground Biomass

    PubMed Central

    Yu, Qiang; Wu, Honghui; He, Nianpeng; Lü, Xiaotao; Wang, Zhiping; Elser, James J.; Wu, Jianguo; Han, Xingguo

    2012-01-01

    The growth rate hypothesis (GRH) proposes that higher growth rate (the rate of change in biomass per unit biomass, μ) is associated with higher P concentration and lower C∶P and N∶P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done on belowground biomass. Here we showed that, for aboveground, belowground and total biomass of three study species, μ was positively correlated with N∶C under N limitation and positively correlated with P∶C under P limitation. However, the N∶P ratio was a unimodal function of μ, increasing for small values of μ, reaching a maximum, and then decreasing. The range of variations in μ was positively correlated with variation in C∶N∶P stoichiometry. Furthermore, μ and C∶N∶P ranges for aboveground biomass were negatively correlated with those for belowground. Our results confirm the well-known association of growth rate with tissue concentration of the limiting nutrient and provide empirical support for recent theoretical formulations. PMID:22427823

  10. Long-term exposure to twice-ambient ozone (O3) affects carbon sink strength, allocation and stem growth in adult central European forest trees

    NASA Astrophysics Data System (ADS)

    Grams, T. E.; Matyssek, R.

    2009-12-01

    Amongst air pollutants, ground-level ozone (O3) is potentially the most detrimental to vegetation. Spreading globally, enhanced O3 levels are predicted to increase, in particular, in rapidly developing countries and, thus, O3 must now be considered in climate change scenarios and post-Kyoto policies. Here, we present an appraisal of a unique 8-year free-air O3 fumigation experiment on adult European beech (Fagus sylvatica) and Noway spruce (Picea abies), ecologically and economically important, late-succession tree species in Central Europe. For the first time, whole-plant canopies of naturally grown, 60 to 70 years old forest trees were exposed to twice-ambient O3 levels for a total of eight years. Throughout the study period, enhanced O3 uptake in the elevated O3 treatment affected net C fixation and distinctly weakened the whole-stem growth in beech. In contrast, adult spruce at the same site did not display decline in stem biomass development. Those findings corroborate species-specific sensitivities to O3 reported from previous chamber studies on juvenile beech and spruce trees. Carbon allocation of adult trees, as a mechanistical basis of growth processes, was investigated through stable isotope tracer experiments using 13C depleted CO2 at the canopy level. To this end, a novel free-air CO2 exposure system, named tubeFACE, was developed, which employed micro-porous PVC tubes hanging through the canopy of adult trees. In a 19-day 13CO2/12CO2 labeling experiment, CO2 with a δ13C of -46.9 ‰ was continuously released into the canopy to increase [CO2] by 100 µmol mol-1, resulting in a reduction in δ13C of about 8 ‰. Subsequently, C allocation to respiratory pools of various tree organs was studied. Similar to the reduced stem growth in beech, elevated O3 significantly reduced allocation of labeled C to stem respiration, whereas in spruce such a reduction was not found. Hence, our study underlines the need to understand O3 risks by species, so that modeling

  11. 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.

  12. 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.

  13. Hydrolysate of lipid extracted microalgal biomass residue: An algal growth promoter and enhancer.

    PubMed

    Maurya, Rahulkumar; Paliwal, Chetan; Chokshi, Kaumeel; Pancha, Imran; Ghosh, Tonmoy; Satpati, Gour Gopal; Pal, Ruma; Ghosh, Arup; Mishra, Sandhya

    2016-05-01

    The present study demonstrates the utilization of the algal hydrolysate (AH) prepared from lipid extracted residual harmful bloom-forming cyanobacteria Lyngbya majuscula biomass, as a growth supplement for the cultivation of green microalgae Chlorella vulgaris. BG-11 replacements with AH in different proportions significantly affects the cell count, dry cell weight (DCW), biomass productivity (BP) and pigments concentration. Among all, 25% AH substitution in BG11 media was found to be optimum which enhanced DCW, BP and pigments content by 39.13%, 40.81% and 129.47%, respectively, compared to control. The lipid content (31.95%) was also significantly higher in the 25% AH replacement. The volumetric productivity of neutral lipids (ideal for biodiesel) and total protein content of the cells significantly increased in all AH substitutions. Thus, lipid extracted microalgal biomass residue (LMBR) hydrolysate can be a potential growth stimulating supplement for oleaginous microalgae C. vulgaris. PMID:26890794

  14. 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.

  15. 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. PMID:25791468

  16. Toward detection of CO2 fertilization of tree growth and biomass accumulation in Amazon forests

    NASA Astrophysics Data System (ADS)

    Chambers, J. Q.; Negron Juarez, R. I.; Di Vittorio, A. V.; Marra, D.; Rifai, S. W.; Ribeiro, G.; Higuchi, N.

    2012-12-01

    Synthesis studies of old-growth tropical forest plot networks indicate a pantropical net carbon sink of more than 1 Pg C/yr. However a number of confounding factors limit our ability to attribute these changes to direct CO2 fertilization of tree growth and forest productivity. Of primary importance is determining if the plots adequately sample natural disturbance and recovery gradients, and the larger landscape successional mosaic. In addition, forest biomass dynamics which include tree growth, recruitment and mortality can interact in complex ways with changes in forest productivity and biomass accumulation. This study represents a novel approach to determine the sensitivity of different sampling strategies for detecting tropical forest CO2 fertilization while accounting for these confounding factors. Our approach, developed for Amazon forests in Brazil and Peru, combines extensive field plot data on biomass dynamics, remote sensing analyses to generate disturbance probability distribution functions, and individual-based simulation modeling for placing plot-level results into a landscape context. Results indicate that forest plots significantly larger than 10 ha are required to maximize the signal-to-noise ratio for detecting CO2 fertilization. We also present a field sampling strategy for quantifying site-to-site differences in forest biomass accumulation rates, which is useful for detecting regional differences in tropical forest sensitivity to rising atmospheric CO2 concentration. Overall, this approach is useful in developing field campaigns that explicitly account for landscape heterogeneity in testing key predictions of Earth system models.

  17. Growth periodicity, biomass and nutrient content of fine roots in a northern hardwood forest

    SciTech Connect

    Burke, M.K.; Raynal, D.J.

    1987-07-01

    Seasonal periodicity of growth, biomass and nutrient content of fine roots were estimated in a beech-birch-maple forest in the Adirondack Mountains. Root elongation rate was measured at regular intervals for one calendar using rhizotrons. Root growth was minimal from January to April and from September to December. Initiation of fine root growth occurred in mid-April, remained high throughout the summer months and declined sharply during August. Fine root biomass, necromass, length, and nutrient content (Ca, Mg, K, N, P and S) were estimated from soil core samples. Estimates for each parameter generally declined with depth in the profile. Fine root production is strongly seasonal, decreases with depth, and accounts for a significant portion of the soil nutrient capital.

  18. Loss of growth homeostasis by genetic decoupling of cell division from biomass growth: implication for size control mechanisms

    PubMed Central

    Schmidt-Glenewinkel, Hannah; Barkai, Naama

    2014-01-01

    Growing cells adjust their division time with biomass accumulation to maintain growth homeostasis. Size control mechanisms, such as the size checkpoint, provide an inherent coupling of growth and division by gating certain cell cycle transitions based on cell size. We describe genetic manipulations that decouple cell division from cell size, leading to the loss of growth homeostasis, with cells becoming progressively smaller or progressively larger until arresting. This was achieved by modulating glucose influx independently of external glucose. Division rate followed glucose influx, while volume growth was largely defined by external glucose. Therefore, the coordination of size and division observed in wild-type cells reflects tuning of two parallel processes, which is only refined by an inherent feedback-dependent coupling. We present a class of size control models explaining the observed breakdowns of growth homeostasis. PMID:25538138

  19. Halimeda biomass, growth rates and sediment generation on reefs in the central great barrier reef province

    NASA Astrophysics Data System (ADS)

    Drew, Edward A.

    1983-06-01

    The average biomass of Halimeda per m2 of solid substratum increased progressively on a series of reefs situated at increasing distances from the shore in the central Great Barrier Reef. There was none on a reef close inshore, increasing to nearly 500 g m-2 total biomass (≃90% calcium carbonate) on an oceanic atoll system in the Coral Sea. The biomass measured contained 13 species of Halimeda but was dominated by only two species, H. copiosa and H. opuntia, except on the atoll where H. minima was dominant. Three sand-dwelling species were also present but did not occur anywhere in substantial quantities. Growth rates of the dominant species were measured bv tagging individual branch tips. A mean value of 0.16 segments d-1 was recorded but 41% of the branch tips did not grow any new segments whilst only 1% grew more than one per day. The number of branch tips per unit biomass was very constant and has been used in conjunction with growth rates and biomass to calculate productivity rates, and thence sedimentation, in the lagoon of one of the reefs. Biomass doubling time of 15 d and production of 6.9 g dry wt m-2 d-1 are considerably higher than previously reported values for Halimeda vegetation and there was little seasonal change detected over a whole year. Those values indicate annual accretion of 184.9 g m-2 year-1 of Halimeda segment debris over the entire lagoon floor (5.9 km2) of Davies Reef, equivalent to 0.13 mm year-1 due to Halimeda alone, or 1 m every 1,892 years when other contributions to that sediment are taken into account.

  20. 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. PMID:24997380

  1. The relative contributions of forest growth and areal expansion to forest biomass carbon sinks in China

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

    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 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 C sinks from 1977 to 2008. Over the last 30 years, the areal expansion of forests was a larger contributor to C sinks than forest growth for all forests and planted forests in China (74.6 vs. 25.4 % for all forests, and 62.4 vs. 37.8 % for plantations). However, for natural forests, forest growth made a larger contribution than areal expansion (60.4 vs. 39.6 %). 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 can continue to increase the C sink of China's forests in the future subject to persistently-increasing forest growth after establishment of plantation.

  2. 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.

  3. 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.

  4. [Effects of phosphorus fertilization on leaf area index, biomass accumulation and allocation, and phosphorus use efficiency of intercropped maize].

    PubMed

    Chen, Yuan-Xue; Li, Han-Han; Zhou, Tao; Chen, Xin-Ping; Huang, Wei; Liu, Jing; Zhang, Chao-Chun; Xu, Kai-Wei

    2013-10-01

    A 2-year field experiment was conducted in 2011 and 2012 to investigate the effects of phosphorus (P) fertilization on the leaf area index (LAI), dry matter accumulation (DMA), and P use efficiency (PUE) of maize in wheat/maize/soybean intercropping system. Five P fertilization rates were installed, i.e., 0, 45, 90, 135, and 180 kg P2O5 x hm(-2) for wheat, marked as WP0, WP1, WP2, WP3, and WP4, respectively, and 0, 37.5, 75, 112.5, and 150 kg P2O5 x hm(-2) for maize, marked as MP0, MP1, MP2, MP3, and MP4, respectively. During the coexisted growth periods of wheat and maize, P fertilization increased the LAI, leaf area duration (LAD), and stem and leaf DMA of maize significantly. After the jointing stage of maize, the maize LAI, LAD, DMA, and crop growth rate (CGR) all decreased after an initial increase with the increasing P rate, with the maximum growth in treatment MP2 or MP3. During the reproductive stage of maize, the maize dry mass translocation from vegetative to reproductive organ increased with increasing P fertilization rate, and the grain yield of both maize and whole cropping system increased firstly and decreased then, with the maximum grain yield of maize and whole cropping system being 6588 and 11955 kg x hm(-2) in treatment P3, respectively. The P apparent recovery efficiency of maize was the highest (26.3%) in treatment MP2, being 82.6%, 38.4%, and 152.9% higher than that in MP1 (14.4%), MP3 (19.0%), and MP4 (10.4%), respectively. In sum, for the wheat/maize/soybean intercropping system, applying appropriate amount of P fertilizer could promote maize growth, alleviate the impact of wheat on maize, and consequently, increase the P apparent recovery efficiency of maize. In this study, the appropriate P fertilization rate was 75-112.5 kg P2O5 x hm(-2). PMID:24483073

  5. Growth Properties and Biomass Production in the Hybrid C4 Crop Sorghum bicolor.

    PubMed

    Tazoe, Youshi; Sazuka, Takashi; Yamaguchi, Miki; Saito, Chieko; Ikeuchi, Masahiro; Kanno, Keiichi; Kojima, Soichi; Hirano, Ko; Kitano, Hideki; Kasuga, Shigemitsu; Endo, Tsuyoshi; Fukuda, Hiroo; Makino, Amane

    2016-05-01

    Hybrid vigor (heterosis) has been used as a breeding technique for crop improvement to achieve enhanced biomass production, but the physiological mechanisms underlying heterosis remain poorly understood. In this study, to find a clue to the enhancement of biomass production by heterosis, we systemically evaluated the effect of heterosis on the growth rate and photosynthetic efficiency in sorghum hybrid [Sorghum bicolor (L.) Moench cv. Tentaka] and its parental lines (restorer line and maintainer line). The final biomass of Tentaka was 10-14 times greater than that of the parental lines grown in an experimental field, but the relative growth rate during the vegetative growth stage did not differ. Tentaka exhibited a relatively enlarged leaf area with lower leaf nitrogen content per leaf area (Narea). When the plants were grown hydroponically at different N levels, daily CO2 assimilation per leaf area (A) increased with Narea, and the ratio of A to Narea (N-use efficiency) was higher in the plants grown at low N levels but not different between Tentaka and the parental lines. The relationships between the CO2 assimilation rate, the amounts of photosynthetic enzymes, including ribulose-1,5-bisphosphate carboxylase/oxygenase, phosphoenolpyruvate carboxylase and pyruvate phosphate dikinase, Chl and Narea did not differ between Tentaka and the parental lines. Thus, Tentaka tended to exhibit enlargement of leaf area with lower N content, leading to a higher N-use efficiency for CO2 assimilation, but the photosynthetic properties did not differ. The greater biomass in Tentaka was mainly due to the prolonged vegetative growth period. PMID:26508521

  6. 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.

  7. 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

  8. 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

  9. Comparative performance of air-lift partial nitritation processes with attached growth and suspended growth without biomass retention.

    PubMed

    Choi, Jeongdong; Ahn, Youngho

    2014-01-01

    Partial nitritation is an essential first step in anaerobic ammonium oxidation. This study compared the performance of air-lift partial nitritation reactors with attached growth (AG) and suspended growth (SG) without biomass retention using ammonium-rich recirculated liquor produced from the dewatering of anaerobically digested sludge. The steady-state results showed that the AG can effectively retain ammonium-oxidizing bacteria (AOB) with high activity and allow minimizing biomass discharge (approximately 10 mg volatile suspended solids/L) in the effluent. The nitrogen loading (based on the total reactor volume) satisfying the effluent characteristics could be suggested to be 0.42 g N/L/d for the SG, and 0.76 g N/L/d for the AG, respectively. Compared with the SG, the AG achieved a higher ammonium loading rate (approximately 1.8 times), maximal ammonium oxidation activity (48 mg N/L-h based on liquid-phase volume) under a short hydraulic retention time (HRT) and a long solids retention time (SRT > 80 d). The overall performance confirmed that AG is a promising configuration for partial nitritation in terms of the process stability, maximization of the AOB activity and minimization of the effluent biomass under a short HRT and high nitrogen loading rate. PMID:24701930

  10. 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.

  11. Effect of growth factors on oocyte maturation and allocations of inner cell mass and trophectoderm cells of cloned bovine embryos.

    PubMed

    Arat, Sezen; Caputcu, Arzu Tas; Cevik, Mesut; Akkoc, Tolga; Cetinkaya, Gaye; Bagis, Haydar

    2016-08-01

    This study was conducted to determine the additive effects of exogenous growth factors during in vitro oocyte maturation (IVM) and the sequential culture of nuclear transfer (NT) embryos. Oocyte maturation and culture of reconstructed embryos derived from bovine granulosa cells were performed in culture medium supplemented with either epidermal growth factor (EGF) alone or a combination of EGF with insulin-like growth factor-I (IGF-I). The maturation rates of oocytes matured in the presence of EGF or the EGF + IGF-I combination were significantly higher than those of oocytes matured in the presence of only fetal calf serum (FCS) (P 0.05). IGF-I alone or in combination with EGF in sequential embryo culture medium significantly increased the ratio of inner cell mass (ICM) to total blastocyst cells (P < 0.05). Our results showed that the addition of growth factors to IVM and sequential culture media of cloned bovine embryos increased the ICM without changing the total cell number. These unknown and uncontrolled effects of growth factors can alter the allocation of ICM and trophectoderm cells (TE) in NT embryos. A decrease in TE cell numbers could be a reason for developmental abnormalities in embryos in the cloning system. PMID:26444069

  12. 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

  13. 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

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

    PubMed

    Barenholz, Uri; 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

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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.

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

    PubMed

    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

  1. Simulation of individual leaf size and canopy development: Approaches to carbon allocation and growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Simulation of individual leaf growth in potato offers many potential benefits as compared to simulation of one ‘big leaf’. These advantages include better simulation of assimilate partitioning, light interception, and nitrogen response and dynamics. In previous research we developed algorithms for s...

  2. 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

  3. Dynamic carbon allocation significantly changed land carbon sink and carbon pool sizes

    NASA Astrophysics Data System (ADS)

    Xia, J.; Yuan, W.

    2015-12-01

    The allocation of photosynthate among the plant components (e.g., leaves, stems, and roots) plays an important role in regulating plant growth, competition, and terrestrial carbon cycle. However, the carbon allocation process is still a weak part in the earth system models (ESMs). In this study, the Integrated BIosphere Simulator (IBIS) model coupled with a dynamic carbon allocation model (IBISAL) is used to explore the impact of carbon allocation on the terrestrial carbon cycle. This dynamic carbon allocation model suggests that plants should allocate the largest part of carbon to the plant components which need to capture the most limiting resources, such as light, water and nitrogen. In comparison to the results of original IBIS model using fixed allocation ratios, the net ecosystem productivity, global biomass and soil organic carbon simulated by IBISAL model decreased by13.4% , 9.9% and 20.8%, respectively . The dynamic allocation scheme tends to benefit roots allocation. Because roots had short turnover times, high roots allocation led to the decreases of global carbon sink and carbon pool sizes. The observations showed that the carbon allocation ratios changed with temperature and precipitation. The dynamic carbon allocation model could reproduce this phenomenon correctly. The results show that the dynamic carbon allocation ratios of boreal evergreen forests and C3 grasses are consistent well with the observations. However, the IBISAL, and another three ESMs (i.e., CESM1-BGC, IPSL-CM5A-MR and NorESM1-ME models) adopting dynamic allocation scheme overestimated the stems allocation of tropical forests. This study shows the substantial influences of carbon allocation on the carbon sink and carbon pool sizes. Therefore, improving estimations of carbon allocation by ESMs are an important and effective path to reduce uncertainties in the global carbon cycle simulation and climate change prediction.

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

    DOE PAGESBeta

    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

  5. 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

  6. 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.

  7. 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.

  8. 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

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

    PubMed

    Alvelo-Maurosa, Jesús G; Lee, Scott J; Hazen, Samuel P; Leschine, Susan B

    2016-02-01

    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

  10. 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.

  11. 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

  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. Phytoplankton biomass, production and growth limitations on the Huanghe (Yellow River) continental shelf

    NASA Astrophysics Data System (ADS)

    Turner, R. Eugene; Rabalais, Nancy N.; Zhang, Zhi Nan

    1990-06-01

    We examined phytoplankton populations in coastal waters of the Huanghe (Yellow River) estuary during two cruises in the annual high and normal discharge periods: August 1986 and October 1987, respectively. Strong salinity, nutrient, and phytoplankton pigment concentration gradients occur along the 5 m isobath. Landward of these gradients the phytoplankton growth potential (PGP) appears strongly phosphorus-limited and light limitation of PGP, paradoxically, appears less significant than it does further offshore where the euphotic zone depth is greater. Phytoplankton pigments are sparse both in the river and far offshore, and the peak accumulation (9 μg l -1 chlorophyll a) is centered broadly between 20 and 25 ppt, thus straddling the region of the hypopycnal plume from the hyperpycnal plunge point to where Secchi disk depth exceeds 1 m. As the suspended matter falls out (sharply) near the 25 ppt isohaline, light conditions improve, the N:P ratio drops to below 100, and nitrate concentrations continue to decrease in an offshore direction. Phytoplankton production rates reach a maximum and large algal cells accumulate where the suspended particulate matter concentration drops to less than 10 mg l -1. Both phytoplankton biomass and production declines beyond approximately 32 ppt. Sedimentary pigment accumulations also increase going from land to sea. Phosphorus and nitrogen dominate the suite of nutrients tested to determine which nutrients limit PGP. Phosphorus is probably the major nutrient limiting phytoplankton growth (not necessarily biomass accumulation) in most of the Huanghe estuary. This conclusion is based on the very high N:P ratios of dissolved nutrients, the results of an extensive array of addition and deletion bioassay experiments, and the results of P addition experiments. Where trace metals and EDTA limit PGP, they are usually limiting in concert with other nutrients and do not act alone. Comparison with other large river plumes are made.

  14. 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.

  15. 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.

  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. PMID:22445050

  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. PMID:26452766

  18. 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.

  19. Selective consumption and metabolic allocation of terrestrial and algal carbon determine allochthony in lake bacteria.

    PubMed

    Guillemette, François; Leigh McCallister, S; Del Giorgio, Paul A

    2016-06-01

    Here we explore strategies of resource utilization and allocation of algal versus terrestrially derived carbon (C) by lake bacterioplankton. We quantified the consumption of terrestrial and algal dissolved organic carbon, and the subsequent allocation of these pools to bacterial growth and respiration, based on the δ(13)C isotopic signatures of bacterial biomass and respiratory carbon dioxide (CO2). Our results confirm that bacterial communities preferentially remove algal C from the terrestrially dominated organic C pool of lakes, but contrary to current assumptions, selectively allocate this autochthonous substrate to respiration, whereas terrestrial C was preferentially allocated to biosynthesis. The results provide further evidence of a mechanism whereby inputs of labile, algal-derived organic C may stimulate the incorporation of a more recalcitrant, terrestrial C pool. This mechanism resulted in a counterintuitive pattern of high and relatively constant levels of allochthony (~76%) in bacterial biomass across lakes that otherwise differ greatly in productivity and external inputs. PMID:26623544

  20. 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

  1. Mulch and fertilizer management practices for organic production of highbush blueberry. I. Plant growth and allocation of biomass during establishment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A systems trial was established to evaluate management practices for organic production of highbush blueberry. The practices included two bed types (flat and raised), two sources and rates of fertilizer (feather meal and fish emulsion applied at 29 and 57 kg/ha N), three mulches [sawdust, compost to...

  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. Effects of environmental variables on between-year variation of Ulva growth and biomass in a eutrophic brackish lake

    NASA Astrophysics Data System (ADS)

    Malta, Erik-jan; Verschuure, Jacobus M.

    1997-12-01

    Biomass development, growth rate, tissue composition and habitat characteristics of macroalgal blooms were monitored in the eutrophic Veerse Meer (the Netherlands) in 1992 and in 1994 to determine seasonal and between-year variabilities and their relation with environmental factors. In both years, the blooms were dominated by Ulva species (more than 95% of total macroalgal biomass). In 1992, the maximum biomass was 602 g DW m -2, in 1994 the maximum biomass was only 282 g DW m -2. Growth rates (μ), measured in cages, were high at the beginning of May 1992, but quickly dropped to values between 0.05 and 0.10 day -1. In 1994, high growth rates were observed for 1 week in early May only. Water nitrogen concentrations (DIN) and tissue nitrogen levels in Ulva spp. were higher in 1994 than in 1992. No overall difference was found in irradiance between 1992 and 1994 at the beginning of the growing season, but irradiance levels were much higher in 1992. The results of a stepwise multiple regression analysis indicate that in 1992 the part of variation in growth rate that could be explained by regression was due to water DIN. In 1994, water phosphorus concentration and light were the variables explaining this part of the variation in growth rate. It is concluded that macroalgal biomass development in the Veerse Meer shows high variability, both within one season and between years. Although positive correlations were shown between tissue nitrogen levels and DIN, differences in DIN could not explain between-year variability. In a eutrophic lagoon, incident irradiance levels are probably more important in regulating maximum macroalgal yield than DIN.

  4. Maximal sum of metabolic exchange fluxes outperforms biomass yield as a predictor of growth rate of microorganisms.

    PubMed

    Zarecki, Raphy; Oberhardt, Matthew A; Yizhak, Keren; Wagner, Allon; Shtifman Segal, Ella; Freilich, Shiri; Henry, Christopher S; Gophna, Uri; Ruppin, Eytan

    2014-01-01

    Growth rate has long been considered one of the most valuable phenotypes that can be measured in cells. Aside from being highly accessible and informative in laboratory cultures, maximal growth rate is often a prime determinant of cellular fitness, and predicting phenotypes that underlie fitness is key to both understanding and manipulating life. Despite this, current methods for predicting microbial fitness typically focus on yields [e.g., predictions of biomass yield using GEnome-scale metabolic Models (GEMs)] or notably require many empirical kinetic constants or substrate uptake rates, which render these methods ineffective in cases where fitness derives most directly from growth rate. Here we present a new method for predicting cellular growth rate, termed SUMEX, which does not require any empirical variables apart from a metabolic network (i.e., a GEM) and the growth medium. SUMEX is calculated by maximizing the SUM of molar EXchange fluxes (hence SUMEX) in a genome-scale metabolic model. SUMEX successfully predicts relative microbial growth rates across species, environments, and genetic conditions, outperforming traditional cellular objectives (most notably, the convention assuming biomass maximization). The success of SUMEX suggests that the ability of a cell to catabolize substrates and produce a strong proton gradient enables fast cell growth. Easily applicable heuristics for predicting growth rate, such as what we demonstrate with SUMEX, may contribute to numerous medical and biotechnological goals, ranging from the engineering of faster-growing industrial strains, modeling of mixed ecological communities, and the inhibition of cancer growth. PMID:24866123

  5. 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.

  6. Microalgae cultivation in air-lift reactors: modeling biomass yield and growth rate as a function of mixing frequency.

    PubMed

    Barbosa, Maria J; Janssen, Marcel; Ham, Nienke; Tramper, Johannes; Wijffels, René H

    2003-04-20

    The slow development of microalgal biotechnology stems from the failure in the design of large-scale photobioreactors where light energy is efficiently utilized. Due to the light gradient inside the reactor and depending on the mixing properties, algae are subjected to certain light/dark cycles where the light period is characterized by a light gradient. These light/dark cycles will determine productivity and biomass yield on light energy. Air-lift reactors can be used for microalgae cultivation and medium-frequency light/dark cycles will be found in these systems. Light/dark cycles are associated with two basic parameters: first, the light fraction, i.e., the ratio between the light period and the cycle time and second, the frequency of the light/dark cycle. In the present work, light/dark cycles found in air-lift reactors were simulated taking into account the light gradient during the light period. The effect of medium-frequency cycle time (10-100 s) and light fraction (0.1-1) on growth rate and biomass yield on light energy of the microalgae Dunaliella tertiolecta was studied. The biomass yield and growth rates were mainly affected by the light fraction, while cycle time had little influence. Response surface methodology was used and a statistical model describing the effect of light fraction and cycle time on growth rate and biomass yield on light energy was developed. The use of the model as a reactor design criterion is discussed. PMID:12584758

  7. 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

  8. Models of knot and stem development in black spruce trees indicate a shift in allocation priority to branches when growth is limited

    PubMed Central

    Duchateau, Emmanuel; Auty, David; Mothe, Frédéric; Longuetaud, Fleur; Ung, Chhun Huor

    2015-01-01

    The branch autonomy principle, which states that the growth of individual branches can be predicted from their morphology and position in the forest canopy irrespective of the characteristics of the tree, has been used to simplify models of branch growth in trees. However, observed changes in allocation priority within trees towards branches growing in light-favoured conditions, referred to as ‘Milton’s Law of resource availability and allocation,’ have raised questions about the applicability of the branch autonomy principle. We present models linking knot ontogeny to the secondary growth of the main stem in black spruce (Picea mariana (Mill.) B.S.P.), which were used to assess the patterns of assimilate allocation over time, both within and between trees. Data describing the annual radial growth of 445 stem rings and the three-dimensional shape of 5,377 knots were extracted from optical scans and X-ray computed tomography images taken along the stems of 10 trees. Total knot to stem area increment ratios (KSR) were calculated for each year of growth, and statistical models were developed to describe the annual development of knot diameter and curvature as a function of stem radial increment, total tree height, stem diameter, and the position of knots along an annual growth unit. KSR varied as a function of tree age and of the height to diameter ratio of the stem, a variable indicative of the competitive status of the tree. Simulations of the development of an individual knot showed that an increase in the stem radial growth rate was associated with an increase in the initial growth of the knot, but also with a shorter lifespan. Our results provide support for ‘Milton’s Law,’ since they indicate that allocation priority is given to locations where the potential return is the highest. The developed models provided realistic simulations of knot morphology within trees, which could be integrated into a functional-structural model of tree growth and above

  9. Improved growth media and culture techniques for genetic analysis and assessment of biomass utilization by Caldicellulosiruptor bescii.

    PubMed

    Farkas, Joel; Chung, Daehwan; Cha, Minseok; Copeland, Jennifer; Grayeski, Philip; Westpheling, Janet

    2013-01-01

    Methods for efficient growth and manipulation of relatively uncharacterized bacteria facilitate their study and are essential for genetic manipulation. We report new growth media and culture techniques for Caldicellulosiruptor bescii, the most thermophilic cellulolytic bacterium known. A low osmolarity defined growth medium (LOD) was developed that avoids problems associated with precipitates that form in previously reported media allowing the monitoring of culture density by optical density at 680 nm (OD(680)) and more efficient DNA transformation by electroporation. This is a defined minimal medium and does not support growth when a carbon source is omitted, making it suitable for selection of nutritional markers as well as the study of biomass utilization by C. bescii. A low osmolarity complex growth medium (LOC) was developed that dramatically improves growth and culture viability during storage, making it a better medium for routine growth and passaging of C. bescii. Both media contain significantly lower solute concentration than previously published media, allowing for flexibility in developing more specialized media types while avoiding the issues of growth inhibition and cell lysis due to osmotic stress. Plating on LOD medium solidified by agar results in ~1,000-fold greater plating efficiency than previously reported and allows the isolation of discrete colonies. These new media represent a significant advance for both genetic manipulation and the study of biomass utilization in C. bescii, and may be applied broadly across the Caldicellulosiruptor genus. PMID:23149625

  10. Improved growth media and culture techniques for genetic analysis and assessment of biomass utilization by Caldicellulosiruptor bescii

    PubMed Central

    Farkas, Joel; Chung, Daehwan; Cha, Minseok; Copeland, Jennifer; Grayeski, Philip

    2014-01-01

    Methods for efficient growth and manipulation of relatively uncharacterized bacteria facilitate their study and are essential for genetic manipulation. We report new growth media and culture techniques for Caldicellulosiruptor bescii, the most thermophilic cellulolytic bacterium known. A low osmolarity defined growth medium (LOD) was developed that avoids problems associated with precipitates that form in previously reported media allowing the monitoring of culture density by optical density at 680 nm (OD680) and more efficient DNA transformation by electroporation. This is a defined minimal medium and does not support growth when a carbon source is omitted, making it suitable for selection of nutritional markers as well as the study of biomass utilization by C. bescii. A low osmolarity complex growth medium (LOC) was developed that dramatically improves growth and culture viability during storage, making it a better medium for routine growth and passaging of C. bescii. Both media contain significantly lower solute concentration than previously published media, allowing for flexibility in developing more specialized media types while avoiding the issues of growth inhibition and cell lysis due to osmotic stress. Plating on LOD medium solidified by agar results in ~ 1,000-fold greater plating efficiency than previously reported and allows the isolation of discrete colonies. These new media represent a significant advance for both genetic manipulation and the study of biomass utilization in C. bescii, and may be applied broadly across the Caldicellulosiruptor genus. PMID:23149625

  11. Activity and growth of anammox biomass on aerobically pre-treated municipal wastewater.

    PubMed

    Laureni, Michele; Weissbrodt, David G; Szivák, Ilona; Robin, Orlane; Nielsen, Jeppe Lund; Morgenroth, Eberhard; Joss, Adriano

    2015-09-01

    Direct treatment of municipal wastewater (MWW) based on anaerobic ammonium oxidizing (anammox) bacteria holds promise to turn the energy balance of wastewater treatment neutral or even positive. Currently, anammox processes are successfully implemented at full scale for the treatment of high-strength wastewaters, whereas the possibility of their mainstream application still needs to be confirmed. In this study, the growth of anammox organisms on aerobically pre-treated municipal wastewater (MWW(pre-treated)), amended with nitrite, was proven in three parallel reactors. The reactors were operated at total N concentrations in the range 5-20 mg(N)∙L(-1), as expected for MWW. Anammox activities up to 465 mg(N)∙L(-1)∙d(-1) were reached at 29 °C, with minimum doubling times of 18 d. Lowering the temperature to 12.5 °C resulted in a marked decrease in activity to 46 mg(N)∙L(-1)∙d(-1) (79 days doubling time), still in a reasonable range for autotrophic nitrogen removal from MWW. During the experiment, the biomass evolved from a suspended growth inoculum to a hybrid system with suspended flocs and wall-attached biofilm. At the same time, MWW(pre-treated) had a direct impact on process performance. Changing the influent from synthetic medium to MWW(pre-treated) resulted in a two-month delay in net anammox growth and a two to three-fold increase in the estimated doubling times of the anammox organisms. Interestingly, anammox remained the primary nitrogen consumption route, and high-throughput 16S rRNA gene-targeted amplicon sequencing analyses revealed that the shift in performance was not associated with a shift in dominant anammox bacteria ("Candidatus Brocadia fulgida"). Furthermore, only limited heterotrophic denitrification was observed in the presence of easily biodegradable organics (acetate, glucose). The observed delays in net anammox growth were thus ascribed to the acclimatization of the initial anammox population or/and the development of a side

  12. '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.

  13. 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.

  14. 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.

  15. Lipase production in solid-state fermentation monitoring biomass growth of aspergillus niger using digital image processing.

    PubMed

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

    2008-03-01

    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. PMID:18401753

  16. 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.

  17. 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

  18. 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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  20. 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

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

    PubMed Central

    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 m3/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

  2. 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

  3. Effect of different growth conditions on biomass increase in kefir grains.

    PubMed

    Guzel-Seydim, Z; Kok-Tas, T; Ertekin-Filiz, B; Seydim, A C

    2011-03-01

    Kefir is a functional dairy product and the effects of kefir consumption on health have been well documented. Kefir grains have naturally high numbers of lactic acid bacteria and yeasts and are used in manufacturing kefir. The biomass of kefir grains slowly increases after successive fermentations. The effects of adding whey protein isolate, modified whey protein (MWP, fat replacer; Carbery Inc., Cork, Ireland), or inulin to milk and different atmospheric conditions (ambient or 6% CO(2)) during fermentation on the increase in biomass of kefir grains were investigated. Reconstituted milks (10% milk powder) enriched with whey protein isolate (2%), MWP (2%), and inulin (2%) were inoculated with kefir grains and fermented in ambient and 6% CO(2) incubators at 25°C until a final pH of 4.6 was reached. Biomass increments of kefir grains were determined weekly over 30 d. Lactic acid bacteria and yeast contents of kefir grains were also determined. The highest biomass increase (392%) was found in kefir grains grown in milk supplemented with whey protein isolate under ambient atmospheric conditions. Application of CO(2) did not provide a significant supporting effect on the biomass of kefir grains. Addition of MWP significantly accelerated the formation of kefir grain biomass (223%). The use of whey protein isolate, MWP, or inulin in milk did not cause any adverse effects on the microbial flora of kefir grains. PMID:21338789

  4. Influence of abscisic acid on growth, biomass and lipid yield of Scenedesmus quadricauda under nitrogen starved condition.

    PubMed

    Sulochana, Sujitha Balakrishnan; Arumugam, Muthu

    2016-08-01

    Scenedesmus quadricauda, accumulated more lipid but with a drastic reduction in biomass yield during nitrogen starvation. Abscisic acid (ABA) being a stress responsible hormone, its effect on growth and biomass with sustainable lipid yield during nitrogen depletion was studied. The result revealed that the ABA level shoots up at 24h (27.21pmol/L) during the onset of nitrogen starvation followed by a sharp decline. The external supplemented ABA showed a positive effect on growth pattern (38×10(6)cells/ml) at a lower concentration. The dry biomass yield is also increasing up to 2.1 fold compared to nitrogen deficient S. quadricauda. The lipid content sustains in 1 and 2μM concentration of ABA under nitrogen-deficient condition. The fatty acid composition of ABA treated S. quadricauda cultures with respect to nitrogen-starved cells showed 11.17% increment in saturated fatty acid content, the desired lipid composition for biofuel application. PMID:26949054

  5. 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.

  6. 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...

  7. 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

  8. The evaluation of mixtures of yeast and potato extracts in growth media for biomass production of lactic cultures.

    PubMed

    Gaudreau, H; Renard, N; Champagne, C P; Van Horn, D

    2002-07-01

    The effectiveness of yeast extracts (YE) and potato extracts (PE) to promote growth of seven lactic cultures was evaluated by automated spectrophotometry (AS). Two aspects of the growth curve were analysed: (1) maximum biomass obtained (using ODmax) and (2) highest specific growth rate mu(max)) Eleven lots from the same PE-manufacturing process were examined for lot-to-lot variability. The ODmax values of three of the seven strains were significantly affected by lot source, but mu(max) was not significantly affected. The growth of bacteria was systematically lower in base medium containing 100% PE than in base medium containing 100% YE for both ODmax or mu(max) data, which could be related to the lower content in nitrogen-based compounds in PE. In AS assays, highest OD values for Lactobacillus casei EQ28, Lactobacillus rhamnosus R-011, Lactobacillus plantarum EQ12, and Streptococcus thermophilus R-083 were obtained with a mixture of PE and YE. Fermentations (2 L) were also carried out to determine the accuracy of AS to predict biomass levels obtained under fermentation trials. In these fermentations, replacement of 50% YE with PE was shown to enable good growth of S. thermophilus. With L. rhamnosus R-011, a high correlation (R2 = 0.95) was found between ODmax data obtained in the AS assays and that of the 2-L bioreactor when the same growth medium was used for both series of fermentations. However, AS was not as efficient when industrial media were used for the bioreactor assays. The relationship was still good for ODmax between AS data and that of the bioreactor data with L. rhamnosus R-011 in industrial LBS medium (R2 = 0.87), but was very poor with the S. thermophilus R-083 on Rosell #43 industrial medium (R2 = 0.33). Since PE cost 40% less than YE, there are strong economic advantages in considering such a partial replacement of YE by PE. PMID:12224561

  9. 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.

  10. 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

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

    PubMed

    Folsom, James Patrick; Carlson, Ross P

    2015-08-01

    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

  12. Charting the Impacts of Disturbance on Biomass Accumulation in Old-Growth Amazon Forests

    NASA Astrophysics Data System (ADS)

    Chambers, J.; Fisher, J.; Hurtt, G.; Baker, T.; Camargo, P.; Campanella, R.; Dos Santos, J.; Higuchi, N.; Malhi, Y.; Phillips, O.; Plourde, L.; Smith, M.; Trumbore, S.

    2006-12-01

    Observed increases in intact Amazon forest biomass, averaging ~0.6 Mg C ha-1 yr-1, have led to suggestions that a forest sink may be of a magnitude large enough to substantially offset Amazonian land- use sources. The mechanism which explains the biomass increase remains unclear. Here we use a synthetic approach, combining remote sensing, intensive field observations, and simulation modeling to elucidate the impact of disturbance on forest structure and changes in biomass. EO-1 Hyperion data and existing field data will be analyzed to generate broad scale disturbance maps. These maps will integrate information from field and remote sensing investigations, spanning a gradient from individual trees to landscape-scale events. Intensive field work will quantify the mortality from these disturbance events. Mapped data will be used to parameterize the height-structured Ecosystem Demography model (ED). ED offers a general method of scaling stochastic individual-based models of ecosystem dynamics to regional scales. Model runs of ED with synthetic mortality rates brackets the range of potential carbon flux attributable to disturbance, mortality, and recovery. The parameterization of the model with generated disturbance maps will provide a best estimate biomass gain due to disturbance patterns across the Amazon.

  13. 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...

  14. VARIED GROWTH, BIOMASS AND CELLULOSE CONTENT IN TOBACCO EXPRESSING YEAST-DERIVED INVERTASES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of the expression of yeast-derived apoplastic (AI) and cytosolic (CI) invertases on biomass and structural carbohydrate accumulation in tobacco (Nicotiana tabacum cv. Xanthi) were evaluated. Transgenic tobacco plants expressing AI or CI under the control of either a tandem repeat of the...

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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. PMID:24464906

  20. 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

  1. 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

  2. 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

  3. Seasonal Variation in Growth, Nitrogen Uptake and Allocation by Container-Grown Evergreen and Deciduos Rhododendron Cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growth, nitrogen (N) uptake, and storage were assessed in deciduous and evergreen cultivars of 1-year-old Rhododendron (Rhododendron ‘P. J. Mezitt Compact’ (PJM), ‘English Roseum’ (ER), and ‘Gibraltar’ (AZ)). Increased N availability increased growth after July (ER, PJM) or August (AZ), and resulted...

  4. 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

  5. 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

  6. 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

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

    DOE PAGESBeta

    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

  8. 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

  9. 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

  10. 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

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

    PubMed Central

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

    2015-01-01

    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

  12. Atmospheric CO2 enrichment alters energy assimilation, investment and allocation in Xanthium strumarium.

    PubMed

    Nagel, Jennifer M; Wang, Xianzhong; Lewis, James D; Fung, Howard A; Tissue, David T; Griffin, Kevin L

    2005-05-01

    Energy-use efficiency and energy assimilation, investment and allocation patterns are likely to influence plant growth responses to increasing atmospheric CO2 concentration ([CO2]). Here, we describe the influence of elevated [CO2] on energetic properties as a mechanism of growth responses in Xanthium strumarium. Individuals of X. strumarium were grown at ambient or elevated [CO2] and harvested. Total biomass and energetic construction costs (CC) of leaves, stems, roots and fruits and percentage of total biomass and energy allocated to these components were determined. Photosynthetic energy-use efficiency (PEUE) was calculated as the ratio of total energy gained via photosynthetic activity (Atotal) to leaf CC. Elevated [CO2] increased leaf Atotal, but decreased CC per unit mass of leaves and roots. Consequently, X. strumarium individuals produced more leaf and root biomass at elevated [CO2] without increasing total energy investment in these structures (CCtotal). Whole-plant biomass was associated positively with PEUE. Whole-plant construction required 16.1% less energy than modeled whole-plant energy investment had CC not responded to increased [CO2]. As a physiological mechanism affecting growth, altered energetic properties could positively influence productivity of X. strumarium, and potentially other species, at elevated [CO2]. PMID:15819914

  13. 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.

  14. 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

  15. 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. PMID:25866205

  16. Plant biomass and stem juice of the C4 sugarcane at elevated growth CO2 and temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant biomass, stem juice and stem sugar were determined for four sugarcane cultivars grown for three months at daytime [CO2] of 360 (ambient) and 720 (doubled) ppm and temperatures (T) of 1.5 (near-ambient) and 6.0C higher than outside ambient T. Leaf area and biomass, stem biomass, stem juice and ...

  17. Effect of indigo dye effluent on the growth, biomass production and phenotypic plasticity of Scenedesmus quadricauda (Chlorococcales).

    PubMed

    Chia, Mathias A; Musa, Rilwan I

    2014-03-01

    The effect of indigo dye effluent on the freshwater microalga Scenedesmus quadricauda ABU12 was investigated under controlled laboratory conditions. The microalga was exposed to different concentrations of the effluent obtained by diluting the dye effluent from 100 to 175 times in bold basal medium (BBM). The growth rate of the microalga decreased as indigo dye effluent concentration increased (p <0.05). The EC50 was found to be 166 dilution factor of the effluent. Chlorophyll a, cell density and dry weight production as biomarkers were negatively affected by high indigo dye effluent concentration, their levels were higher at low effluent concentrations (p <0.05). Changes in coenobia size significantly correlated with the dye effluent concentration. A shift from large to small coenobia with increasing indigo dye effluent concentration was obtained. We conclude that even at low concentrations; effluents from textile industrial processes that use indigo dye are capable of significantly reducing the growth and biomass production, in addition to altering the morphological characteristics of the freshwater microalga S. quadricauda. The systematic reduction in the number of cells per coenobium observed in this study further confirms that environmental stress affects coenobium structure in the genus Scenedesmus, which means it can be considered an important biomarker for toxicity testing. PMID:24676177

  18. A revised mineral nutrient supplement increases biomass and growth rate in Chlamydomonas reinhardtii.

    PubMed

    Kropat, Janette; Hong-Hermesdorf, Anne; Casero, David; Ent, Petr; Castruita, Madeli; Pellegrini, Matteo; Merchant, Sabeeha S; Malasarn, Davin

    2011-06-01

    Interest in exploiting algae as a biofuel source and the role of inorganic nutrient deficiency in inducing triacylglyceride (TAG) accumulation in cells necessitates a strategy to efficiently formulate species-specific culture media that can easily be manipulated. Using the reference organism Chlamydomonas reinhardtii, we tested the hypothesis that modeling trace element supplements after the cellular ionome would result in optimized cell growth. We determined the trace metal content of several commonly used Chlamydomonas strains in various culture conditions and developed a revised trace element solution to parallel these measurements. Comparison of cells growing in the revised supplement versus a traditional trace element solution revealed faster growth rates and higher maximum cell densities with the revised recipe. RNA-seq analysis of cultures growing in the traditional versus revised medium suggest that the variation in transcriptomes was smaller than that found between different wild-type strains grown in traditional Hutner's supplement. Visual observation did not reveal defects in cell motility or mating efficiency in the new supplement. Ni²⁺-inducible expression from the CYC6 promoter remained a useful tool, albeit with an increased requirement for Ni²⁺ because of the introduction of an EDTA buffer system in the revised medium. Other advantages include more facile preparation of trace element stock solutions, a reduction in total chemical use, a more consistent batch-to-batch formulation and long-term stability (tested up to 5 years). Under the new growth regime, we analyzed cells growing under different macro- and micronutrient deficiencies. TAG accumulation in N deficiency is comparable in the new medium. Fe and Zn deficiency also induced TAG accumulation, as suggested by Nile Red staining. This approach can be used to efficiently optimize culture conditions for other algal species to improve growth and to assay cell physiology. PMID:21309872

  19. 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. PMID:25865555

  20. Trade-offs between biomass growth and inducible biosynthesis of polyhydroxybutyrate in transgenic poplar.

    PubMed

    Dalton, David A; Ma, Cathleen; Shrestha, Shreya; Kitin, Peter; Strauss, Steven H

    2011-09-01

    Polyhydroxybutyrate (PHB) is a bioplastic that can be produced in transgenic plants by the coexpression of three bacterial genes for its biosynthesis. PHB yields from plants have been constrained by the negative impacts on plant health that result from diversion of resources into PHB production; thus, we employed an ecdysone analogue-based system for induced gene expression. We characterized 49 insertion events in hybrid transgenic poplar (Populus tremula x alba) that were produced using Agrobacterium transformation and studied two high-producing events in detail. Regenerated plants contained up to 1-2% PHB (dry weight) in leaves after 6-8 weeks of induction. Strong induction was observed with 1-10 mm Intrepid and limited direct toxicity observed. Confocal fluorescence microscopy was used to visualize PHB granules in chloroplasts after chemical treatment to reduce autofluorescence. A greenhouse study indicated that there were no negative consequences of PHB production on growth unless the PHB content exceeded 1% of leaf weight; at PHB levels above 1%, growth (height, diameter and total mass) decreased by 10%-34%. PMID:21265995

  1. Carbon allocation, osmotic adjustment, antioxidant capacity and growth in cotton under long-term soil drought during flowering and boll-forming period.

    PubMed

    Wang, Rui; Gao, Min; Ji, Shu; Wang, Shanshan; Meng, Yali; Zhou, Zhiguo

    2016-10-01

    Responses of plant to drought largely depend on the intensity, duration and developmental stage at which water stress occurs. The purpose of this study was to analyze the dynamic of cotton physiology response to different levels sustained soil water deficit during reproductive growth stage at leaf basis. Three levels of steady-state water regimes [soil relative water content (SRWC) maintained at (75 ± 5)%, (60 ± 5)% and (45 ± 5)%] were imposed when the white flowers had opened on the first fruiting position of the 6-7th fruiting branches (FB6-7), which was the first day post anthesis (i.e. 1 DPA) and lasted to 50 DPA. Results showed decreasing SRWC slowed cotton growth on the base of biomass and leaf area. However, carbon metabolites levels were globally increased under drought despite of notably inhibited photosynthesis throughout the treatment period. Clear diurnal pattern of sucrose and starch concentrations was obtained and sucrose levels were evaluated while starch concentration was reduced with decreasing soil water content during a 24-h cycle. Osmotic adjustment (OA) was observed at most of the sampling dates throughout the drought period. K(+) was the main contributor to osmotic adjustment (OA) at 10 and 24 DPA then turned out to be amino acid at 38 and 50 DPA. The stressed cotton gradually failed to scavenge reactive oxygen species (ROS) with increasing days post anthesis, primarily due to the permanent decrease in SOD activity. Elevated carbohydrates levels suggest cotton growth was more inhibited by other factors than carbon assimilation. OA and antioxidant could be important protective mechanisms against soil water deficit in this species, and transition of these mechanisms was observed with drought intensity and duration increased. PMID:27288990

  2. Soil type affects Pinus ponderosa var. scopulorum (Pinaceae) seedling growth in simulated drought experiments1

    PubMed Central

    Lindsey, Alexander J.; Kilgore, Jason S.

    2013-01-01

    • Premise of the study: Effects of drought stress and media type interactions on growth of Pinus ponderosa var. scopulorum germinants were investigated. • Methods and Results: Soil properties and growth responses under drought were compared across four growth media types: two native soils (dolomitic limestone and granite), a soil-less industry standard conifer medium, and a custom-mixed conifer medium. After 35 d of growth, the seedlings under drought stress (reduced watering) produced less shoot and root biomass than watered control seedlings. Organic media led to decreased root biomass, but increased root length and shoot biomass relative to the mineral soils. • Conclusions: Media type affected root-to-shoot biomass partitioning of P. ponderosa var. scopulorum, which may influence net photosynthetic rates, growth, and long-term seedling survival. Further work should examine how specific soil properties like bulk density and organic matter influence biomass allocation in greenhouse studies. PMID:25202578

  3. 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

  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. PMID:25958150

  5. 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

  6. 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

  7. 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

  8. Effects of anaerobic growth conditions on biomass accumulation, root morphology, and efficiencies of nutrient uptake and utilization in seedlings of some southern coastal plain

    SciTech Connect

    Topa, M.A.

    1984-01-01

    Seedlings of pond, and loblolly pines were grown in a non-circulating, continuously-flowing solution culture under anaerobic (0.75 mg/1 O/sub 2/) conditions to determine the effects of anaerobiosis on overall growth, root morphology and efficiencies of nutrient uptake and utilization. Although shoot growth of the 11-week old loblolly and pond was not affected by anaerobic treatment, it did significantly reduce root biomass. Sand pine suffered the largest biomass reduction. Flooding tolerance was positively correlated with morphological changes which enhanced root internal aeration. Oxygen transport from shoot to the root was demonstrated via rhizosphere oxidation experiments using indigo-carmine dye solutions and polarography. Stem and root collar lenticels were found to be the major sites of atmospheric O/sub 2/ entry for submerged roots. Longitudinal and radial pathways for gas diffusion via intercellular spaces in the pericycle and ray parenchyma, respectively, were elucidated histologically. Lenticel and aerenchyma development, and rhizosphere oxidation in roots of anaerobically-grown sand pine seedlings were minimal. Elemental analyses showed that anaerobic conditions interfered with nutrient absorption and utilization. Short-term /sup 32/P uptake experiments with intact seedlings indicated that net absorption decreased because of the reduction in root biomass. Phosphorus absorption rates were negatively correlated with internal tissue phosphorus concentrations, and root and shoot biomass. 315 refs., 25 figs., 14 tabs.

  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. 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

  11. Higher growth temperatures decreased net carbon assimilation and biomass accumulation of northern red oak seedlings near the southern limit of the species range.

    PubMed

    Wertin, Timothy M; McGuire, Mary Anne; Teskey, Robert O

    2011-12-01

    If an increase in temperature will limit the growth of a species, it will be in the warmest portion of the species distribution. Therefore, in this study we examined the effects of elevated temperature on net carbon assimilation and biomass production of northern red oak (Quercus rubra L.) seedlings grown near the southern limit of the species distribution. Seedlings were grown in chambers in elevated CO(2) (700 µmol mol(-1)) at three temperature conditions, ambient (tracking diurnal and seasonal variation in outdoor temperature), ambient +3 °C and ambient +6 °C, which produced mean growing season temperatures of 23, 26 and 29 °C, respectively. A group of seedlings was also grown in ambient [CO(2)] and ambient temperature as a check of the growth response to elevated [CO(2)]. Net photosynthesis and leaf respiration, photosynthetic capacity (V(cmax), J(max) and triose phosphate utilization (TPU)) and chlorophyll fluorescence, as well as seedling height, diameter and biomass, were measured during one growing season. Higher growth temperatures reduced net photosynthesis, increased respiration and reduced height, diameter and biomass production. Maximum net photosynthesis at saturating [CO(2)] and maximum rate of electron transport (J(max)) were lowest throughout the growing season in seedlings grown in the highest temperature regime. These parameters were also lower in June, but not in July or September, in seedlings grown at +3 °C above ambient, compared with those grown in ambient temperature, indicating no impairment of photosynthetic capacity with a moderate increase in air temperature. An unusual and potentially important observation was that foliar respiration did not acclimate to growth temperature, resulting in substantially higher leaf respiration at the higher growth temperatures. Lower net carbon assimilation was correlated with lower growth at higher temperatures. Total biomass at the end of the growing season decreased in direct proportion to the

  12. 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

  13. 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

  14. 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.

  15. 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. PMID:24186940

  16. Carbon allocation and accumulation in conifers

    SciTech Connect

    Gower, S.T.; Isebrands, J.G.; Sheriff, D.W.

    1995-07-01

    Forests cover approximately 33% of the land surface of the earth, yet they are responsible for 65% of the annual carbon (C) accumulated by all terrestrial biomes. In general, total C content and net primary production rates are greater for forests than for other biomes, but C budgets differ greatly among forests. Despite several decades of research on forest C budgets, there is still an incomplete understanding of the factors controlling C allocation. Yet, if we are to understand how changing global events such as land use, climate change, atmospheric N deposition, ozone, and elevated atmospheric CO{sub 2} affect the global C budget, a mechanistic understanding of C assimilation, partitioning, and allocation is necessary. The objective of this chapter is to review the major factors that influence C allocation and accumulation in conifer trees and forests. In keeping with the theme of this book, we will focus primarily on evergreen conifers. However, even among evergreen conifers, leaf, canopy, and stand-level C and nutrient allocation patterns differ, often as a function of leaf development and longevity. The terminology related to C allocation literature is often inconsistent, confusing and inadequate for understanding and integrating past and current research. For example, terms often used synonymously to describe C flow or movement include translocation, transport, distribution, allocation, partitioning, apportionment, and biomass allocation. A common terminology is needed because different terms have different meanings to readers. In this paper we use C allocation, partitioning, and accumulation according to the definitions of Dickson and Isebrands (1993). Partitioning is the process of C flow into and among different chemical, storage, and transport pools. Allocation is the distribution of C to different plant parts within the plant (i.e., source to sink). Accumulation is the end product of the process of C allocation.

  17. 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.

  18. 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

  19. Biomass Burning

    Atmospheric Science Data Center

    2015-07-27

    Projects:  Biomass Burning Definition/Description:  Biomass Burning: This data set represents the geographical and temporal distribution of total amount of biomass burned. These data may be used in general circulation models (GCMs) and ...

  20. 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

  1. 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

  2. NO removal in continuous BioDeNOx reactors: Fe(II)EDTA2- regeneration, biomass growth, and EDTA degradation.

    PubMed

    van der Maas, Peter; van den Brink, Paula; Utomo, Sudarno; Klapwijk, Bram; Lens, Piet

    2006-06-20

    BioDeNOx is a novel technique for NOx removal from industrial flue gases. In principle, BioDeNOx is based on NO absorption into an aqueous Fe(II)EDTA2- solution combined with biological regeneration of that scrubber liquor in a bioreactor. The technical and economical feasibility of the BioDeNOx concept is strongly determined by high rate biological regeneration of the aqueous Fe(II)EDTA2- scrubber liquor and by EDTA degradation. This investigation deals with the Fe(II)EDTA2- regeneration capacity and EDTA degradation in a lab-scale BioDeNOx reactor (10-20 mM Fe(II)EDTA2-, pH 7.2 +/- 0.2, 55 degrees C), treating an artificial flue gas (1.5 m3/h) containing 60-155 ppm NO and 3.5-3.9% O2. The results obtained show a contradiction between the optimal redox state of the aqueous FeEDTA solution for NO absorption and the biological regeneration. A low redox potential (below -150 mV vs. Ag/AgCl) is needed to obtain a maximal NO removal efficiency from the gas phase via Fe(II)EDTA2- absorption. Fe(III)EDTA- reduction was found to be too slow to keep all FeEDTA in the reduced state. Stimulation of Fe(III)EDTA- reduction via periodical sulfide additions (2 mM spikes twice a week for the conditions applied in this study) was found to be necessary to regenerate the Fe(II)EDTA2- scrubber liquor and to achieve stable operation at redox potentials below -150 mV (pH 7.2 +/- 0.2). However, redox potentials of below -200 mV should be avoided since sulfide accumulation is unwanted because it is toxic for NO reduction. Very low values for biomass growth rate and yield, respectively, 0.043/d and 0.009 mg protein per mg ethanol, were observed. This might be due to substrate limitations, that is the electron acceptors NO and presumably polysulfide, or to physiological stress conditions induced by the EDTA rich medium or by radicals formed in the scrubber upon the oxidation of Fe(II)EDTA2- by oxygen present in the flue gas. Radicals possibly also induce EDTA degradation, which occurs at a

  3. 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. PMID:25769339

  4. Carbon accumulation and allocation in a primary Bornean tropical rainforest

    NASA Astrophysics Data System (ADS)

    Katayama, A.; Komatsu, H.; Kume, T.; Ohashi, M.; Nakagawa, M.; Otsuki, K.; Kumagai, T.

    2010-12-01

    To develop our knowledge of global carbon cycling, it is important to know all components of allocated carbon in tropical rainforests because of their enormous accumulation and elimination. Our goals in this study are to estimate carbon allocation (i.e. carbon flux to aboveground biomass increment, litterfall, aboveground plant respiration and belowground) and compare GPP based on biometric and flux measurement in a primary Bornean tropical rainforest. GPP estimated by biometric method (35.39 tCha-2yr-1) was similar to that measured by flux measurement (31.56 tCha-2yr-1). Mean annual aboveground biomass increment (2.77 tCha-2yr-1) was reasonable compared to former literatures in spite of larger aboveground biomass (272 tCha-2yr-1). Ratio of TBCF to GPP (0.55) was extremely high. These results suggested that considerable carbon is allocated to belowground, causing low productivity of aboveground biomass.

  5. Growth of the oleaginous microalga Aurantiochytrium sp. KRS101 on cellulosic biomass and the production of lipids containing high levels of docosahexaenoic acid.

    PubMed

    Hong, Won-Kyung; Kim, Chul Ho; Rairakhwada, Dina; Kim, Seonghun; Hur, Byung-Ki; Kondo, Akihiko; Seo, Jeong-Woo

    2012-01-01

    We examined the growth of a novel oleaginous microalga, Aurantiochytrium sp. KRS101, using cellulosic materials as nutrients, and the resultant production of lipids containing high levels of docosahexaenoic acid (DHA). The microalgal strain could grow using either carboxymethylcellulose or cellobiose as a carbon source, and produced lipids containing high levels of DHA (49-58% of total fatty acids). In line with this growth behavior, carboxymethylcellulase and cellobiohydrolase activities were evident in both cell-free lysates and culture broths. Additionally, an industrial cellulosic biomass, palm oil empty fruit bunches (POEFB), a by-product of the palm oil industry, were utilized by the microalgal strain for cell growth and lipid production. PMID:21959581

  6. Computer Processor Allocator

    Energy Science and Technology Software Center (ESTSC)

    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.

  7. Effect of landscape positions and their associated soil and terrain attributes on biomass crop yield and growth rates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to advance the use of biomass crops as a feedstock for a wide range of bioindustrial applications, it is essential that we optimize the placement of crops at the field scale in a way that will maximize overall productivity and profitability while addressing critical environmental and ecolog...

  8. 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

  9. Modeling biomass competition and invasion in a schematic wetland

    NASA Astrophysics Data System (ADS)

    Ursino, N.

    2010-08-01

    Plants growing along hydrologic gradients adjust their biomass allocation and distribution in response to interspecific competition. Furthermore, susceptibility of a community to invasion is to some extent mediated by differences in growth habit, including root architecture and canopy hight. With reference to the study of a schematic wetland, the aim of this paper is (1) to test, via numerical modeling, the capacity of native plants to counteract an alien dominant species and cause eco-hydrological shifts of the ecosystem by changing their growth habit (e.g. allocating biomass below ground and by so doing changing the evapotranspiration locally) and (2) to test the impact on biodiversity of management practices that alter nutrient supply. The results demonstrated that unique combinations of vegetation types characterized by different growth habits may lead to different vegetation patterns under the same hydrologic forcing, and additionally, the vegetation patterns may change in response to major hydrological shifts, which could be related to diverse wetland management and restoration practices.

  10. C allocation among fine roots, above-, and belowground wood in a deciduous forest and its implication to ecosystem C cycling: a modelling analysis

    NASA Astrophysics Data System (ADS)

    Campioli, M.; Verbeeck, H.; Lemeur, R.; Samson, R.

    2008-09-01

    Knowledge about allocation of carbohydrates among tree organs with different life times and decomposition rates is crucial in determining the residence time of carbon (C) in forests and the overall ecosystem C cycling rate. A new model (named CAF) able to simulate C allocation among fine roots, above-, and belowground wood in deciduous forests was developed and integrated into the net ecosystem exchange model FORUG. CAF draws on growth rules and source-sink relationships. Maintenance and growth of the modelled sinks i.e. fine roots, coarse roots, stems, and branches, are controlled by phenology, environment, and by the reserve of non-structural carbohydrates. CAF was parameterized for 2-y and tested against 6-y observations from a beech (Fagus sylvatica L.) stand in North-East France, experiencing summer droughts of different intensities. The model reproduced well (i) the C fluxes allocated annually to assimilation, respiration and biomass production, and (ii) the interannual pattern of wood biomass accumulation. Seasonality of C reserve and wood growth was captured, but some discrepancies were detected at the onset of the growing season. The allocation pattern differed among years, although the overall net primary production decreased only in case of severe drought. During a year with severe drought, the fraction of C allocated to production of fast-decomposing C pools (e.g. fine roots, C reserve) increased by +13% than years without drought, whereas the same fraction increased on average by +18% in case of low to moderate drought. Carbon invested in biomass during a year with summer drought has therefore a shorter residence time in the ecosystem than the C stored during a year without summer drought.

  11. 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.

  12. 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

  13. Biomass Growth and Clogging in Porous Media: From Microscale and Mesoscale Observations in Silicon Pore Imaging Elements to the Modeling of Aggregates in Network Models Using Material Mechanics

    NASA Astrophysics Data System (ADS)

    Dupin, H. J.; Mccarty, P. L.; Kitanidis, P. K.

    2002-05-01

    An apparatus for non-destructive continuous visualization of biological growth and clogging in porous media has been constructed. Silicon Pore Imaging Elements (micromodels featuring two-dimensional pore networks) were seeded with mixed cultures. A feed solution was then continuously forced through the SPIEs. Subsequently, several forms of biomass developped simultaneously: aggregates, biofilms and filaments ressembling mycellia. Clogging appeared mostly related to the presence of aggregates along preferential flow paths. Due to clogging, mesocale flow paths were modified, and flow was reversed in channels. A novel numerical model was then developped to investigate bioclogging of two-dimensional pore networks by aggregates. Each pore (channel) is seeded with initial biomass that consumes an electron donor and an electron acceptor according to dual Monod kinetics. Biomass is modeled as a continuous uniform isotropic hyperelastic material, whose expansion and deformation are governed by material mechanics stress-strain relations, unlike traditional approaches that use ad hoc empirical schemes. The Stokes flow, the advection-diffusion- reaction mass transport, and the biomass deformation partial differential equations are solved using finite elements. Simple networks are investigated to identify phenomena of interest: four channels of different width operating in parallel to study the effect of local heterogeneity; a periodic network to quantify the effects of distance from the injection point on clogging and substrate utilization; and square lattice 5 x 5 random width networks. Although square-lattice random-width networks are deemed better approximations of porous media, the simpler networks exhibit all the phenomena of interest, with the added advantage of these phenomena being decoupled. Results of numerical simulations for different network types under various boundary conditions show that aggregates have a far greater potential than biofilms to clog a porous

  14. Elucidating temporal resource allocation and diurnal dynamics in phototrophic metabolism using conditional FBA

    PubMed Central

    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

  15. 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.

  16. The secretion of the bacterial phytase PHY-US417 by Arabidopsis roots reveals its potential for increasing phosphate acquisition and biomass production during co-growth.

    PubMed

    Belgaroui, Nibras; Berthomieu, Pierre; Rouached, Hatem; Hanin, Moez

    2016-09-01

    Phytic acid (PA) is a major source of inorganic phosphate (Pi) in the soil; however, the plant lacks the capacity to utilize it for Pi nutrition and growth. Microbial phytases constitute a group of enzymes that are able to remobilize Pi from PA. Thus, the use of these phytases to increase the capacity of higher plants to remobilize Pi from PA is of agronomical interest. In the current study, we generate transgenic Arabidopsis lines (ePHY) overexpressing an extracellular form of the phytase PHY-US417 of Bacillus subtilis, which are characterized by high levels of secreted phytase activity. In the presence of PA as sole source of Pi, while the wild-type plants show hallmark of Pi deficiency phenotypes, including the induction of the expression of Pi starvation-induced genes (PSI, e.g. PHT1;4) and the inhibition of growth capacity, the ePHY overexpressing lines show a higher biomass production and no PSI induction. Interestingly, when co-cultured with ePHY overexpressors, wild-type Arabidopsis plants (or tobacco) show repression of the PSI genes, improvement of Pi content and increases in biomass production. In line with these results, mutants in the high-affinity Pi transporters, namely pht1;1 and pht1;1-1;4, both fail to accumulate Pi and to grow when co-cultured with ePHY overexpressors. Taken together, these data demonstrate the potential of secreted phytases in improving the Pi content and enhancing growth of not only the transgenic lines but also the neighbouring plants. PMID:26914451

  17. Biofilm growth and hydrodynamic behaviour in the biological plate tower (BPT) with and without hanging biomass (BPT-HB).

    PubMed

    Peixoto, João Monteiro; Pinto, João Carlos Ribeiro

    2012-01-01

    Deodorization and volatile organic compound abatement from polluted air streams can be accomplished with the biological plate tower (BPT), which has proved to be a reliable alternative to biofilters and biotrickling filters. Unlike those, the BPT is a non-clogging device, with constant active surface, and steady performance, making it ideal for scale-up and modelling. The initial BPT design needed improvement for better performance. The cylindrical body (circular plates) was replaced by a rectangular cuboid (rectangular plates). Holes in the plates did augment the amount of active biomass (hanging from the holes and under the plates), without reducing the transfer of toluene from the gaseous to the liquid phase. The diminished distance between plates was well tolerated in co-current flow, allowing much higher quantities of biomass in the same reactor volume. With 18 and 14 mm spacing between adjacent plates, the BPT, with and without holes, was tested for flooding, holdup and pressure drop. Several gas and liquid flows were tested, both in co-current and counter-current. In hydrodynamic terms, the BPT-HB with co-current flow was clearly the best option. Higher stability with higher flow rates, and lower pressure drops were observed. The inoculum was obtained from wastewater plant activated sludge (petrochemical industry). PMID:22907451

  18. 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

  19. BIOMASS UTILIZATION

    EPA Science Inventory

    The biomass utilization task consists of the evaluation of a biomass conversion technology including research and development initiatives. The project is expected to provide information on co-control of pollutants, as well as, to prove the feasibility of biomass conversion techn...

  20. Biomass pretreatment

    SciTech Connect

    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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. Allocation without locking

    SciTech Connect

    Appel, A.W.

    1988-01-01

    In a programming environment with both concurrency and automatic garbage collection, the allocation and initialization of a new record is a sensitive matter: if it is interrupted halfway through, the allocating process may be in a state that the garbage collector can't understand. In particular, the collector won't know which words of the new record have been initialized and which are meaningless (and unsafe to transverse). For this reason, parallel implementations usually use a locking or semaphore mechanism to ensure that allocation is an atomic operation. The locking significantly adds to the cost of allocation. This paper shows that allocation can run extremely quickly even in a multi-thread environment: open-coded, without locking.

  6. 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

  7. 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.

  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. Manipulation of light wavelength at appropriate growth stage to enhance biomass productivity and fatty acid methyl ester yield using Chlorella vulgaris.

    PubMed

    Kim, Dae Geun; Lee, Changsu; Park, Seung-Moon; Choi, Yoon-E

    2014-05-01

    LEDs light offer several advantages over the conventional lamps, thereby being considered as the optimal light sources for microalgal cultivation. In this study, various light-emitting diodes (LEDs) especially red and blue color with different light wavelengths were employed to explore the effects of light source on phototrophic cultivation of Chlorella vulgaris. Blue light illumination led to significantly increased cell size, whereas red light resulted in small-sized cell with active divisions. Based on the discovery of the effect of light wavelengths on microalgal biology, we then applied appropriate wavelength at different growth stages; blue light was illuminated first and then shifted to red light. By doing so, biomass and lipid productivity of C. vulgaris could be significantly increased, compared to that in the control. These results will shed light on a novel approach using LED light for microalgal biotechnology. PMID:24657754

  10. 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

  11. 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

  12. 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

    2016-01-01

    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

  13. 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

  14. The Unobtrusive Memory Allocator

    Energy Science and Technology Software Center (ESTSC)

    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

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Single-Domain Peptidyl-Prolyl cis/trans Isomerase FkpA from Corynebacterium glutamicum Improves the Biomass Yield at Increased Growth Temperatures

    PubMed Central

    Bott, Michael; van Ooyen, Jan

    2015-01-01

    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

  4. 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

  5. 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

  6. 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

  7. 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

  8. Early Root Herbivory Impairs Arbuscular Mycorrhizal Fungal Colonization and Shifts Defence Allocation in Establishing Plantago lanceolata

    PubMed Central

    Bennett, Alison E.; Macrae, Anna M.; Moore, Ben D.; Caul, Sandra; Johnson, Scott N.

    2013-01-01

    Research into plant-mediated indirect interactions between arbuscular mycorrhizal (AM) fungi and insect herbivores has focussed on those between plant shoots and above-ground herbivores, despite the fact that only below-ground herbivores share the same part of the host plant as AM fungi. Using Plantago lanceolata L., we aimed to characterise how early root herbivory by the vine weevil (Otiorhynchus sulcatus F.) affected subsequent colonization by AM fungi (Glomus spp.) and determine how the two affected plant growth and defensive chemistry. We exposed four week old P. lanceolata to root herbivory and AM fungi using a 2×2 factorial design (and quantified subsequent effects on plant biomass and iridoid glycosides (IGs) concentrations. Otiorhynchus sulcatus reduced root growth by c. 64%, whereas plant growth was unaffected by AM fungi. Root herbivory reduced extent of AM fungal colonization (by c. 61%). O. sulcatus did not influence overall IG concentrations, but caused qualitative shifts in root and shoot IGs, specifically increasing the proportion of the more toxic catalpol. These changes may reflect defensive allocation in the plant against further attack. This study demonstrates that very early root herbivory during plant development can shape future patterns of AM fungal colonization and influence defensive allocation in the plant. PMID:23840398

  9. 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.

  10. Slow pyrolysis of poultry litter and pine woody biomass: impact of chars and bio-oils on microbial growth.

    PubMed

    Das, K C; Garcia-Perez, M; Bibens, B; Melear, N

    2008-06-01

    Accidental or prescribed fires in forests and in cultivated fields, as well as primitive charcoal production practices, are responsible for the release of large amounts of gases, char and condensable organic molecules into the environment. This paper describes the impact of condensable organic molecules and chars resulting from the slow pyrolysis of poultry litter, pine chips and pine pellets on the growth of microbial populations in soil and water. The proximate and elemental analyses as well as the content of proteins, cellulose, hemicellulose, lignin, and ash for each of these bio-materials are reported. The yields and some properties of char and condensable liquids are also documented. The behavior of microbial populations in soil and water is followed through respiration studies. It was found that biological activity was highest when aqueous fractions from poultry litter were applied in water. Cumulative oxygen consumption over a 120-h period was highest in the aqueous phases from poultry litter coarse fraction (1.82 mg/g). On average the oxygen consumption when oily fractions from poultry litter were applied represented 44 to 62% of that when aqueous fractions were applied. Pine chip and pine pellet derived liquids and chars produced respiration activity that were an order of magnitude lower than that of poultry litter liquid fractions. These results suggest that the growth observed is due to the effect of protein-derived molecules. PMID:18444073

  11. 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

  12. 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.

  13. Sucrose phosphate synthase and sucrose phosphate phosphatase interact in planta and promote plant growth and biomass accumulation

    PubMed Central

    Maloney, Victoria J.; Park, Ji-Young; Unda, Faride; Mansfield, Shawn D.

    2015-01-01

    Bioinformatic analysis indicates that sucrose phosphate synthase (SPS) contains a putative C-terminal sucrose phosphate phosphatase (SPP)-like domain that may facilitates the binding of SPP. If an SPS–SPP enzyme complex exists, it may provide sucrose biosynthesis with an additional level of regulation, forming a direct metabolic channel for sucrose-6-phosphate between these two enzymes. Herein, the formation of an enzyme complex between SPS and SPP was examined, and the results from yeast two-hybrid experiments suggest that there is indeed an association between these proteins. In addition, in planta bioluminescence resonance energy transfer (BRET) was observed in Arabidopsis seedlings, providing physical evidence for a protein interaction in live cells and in real time. Finally, bimolecular fluorescence complementation (BiFC) was employed in an attempt to detect SPS–SPP interactions visually. The findings clearly demonstrated that SPS interacts with SPP and that this interaction impacts soluble carbohydrate pools and affects carbon partitioning to starch. Moreover, a fusion construct between the two genes promotes plant growth in both transgenic Arabidopsis and hybrid poplar. PMID:25873678

  14. 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

  15. Seasonal and spatial variability in phytoplankton biomass, productivity and growth in the northwestern Indian Ocean: the southwest and northeast monsoon, 1992 1993

    NASA Astrophysics Data System (ADS)

    Veldhuis, Marcel J. W.; Kraay, Gijsbert W.; Van Bleijswijk, Judith D. L.; Baars, Martien A.

    1997-03-01

    and surface water replete with nutrients. Chlorophyll a values varied between 0.5 and 1.0 mg.m -3, with the highest values in diatom blooms in the Red Sea. Mean primary production was 1.2 g C.m -2.day -1 (range 0.5-2.2 g C.m -2.day -1). A detailed study, applying flow-cytometry, of the daily net growth rates of individual phytoplankton species/groups during the NE monsoon showed a large spatial variation indicative of active dynamics in the algal composition even on a daily basis. For picophytoplankton the highest growth rates exceeded 1.5 day -1, but larger phytoplankton showed lower maxima for growth rates ( ca 1 day -1). Net growth rates decreased often to negative values at the bottom of the euphotic zone, implying a high grazing pressure. Net growth rates were converted to daily variations in plant carbon and compared with 14C-based primary production data (only during the NE monsoon). In nutrient replete regions, the two methods showed comparable values for carbon production, indicating that all newly fixed carbon resulted in an increase in plant biomass. Higher nutrient levels in particular favoured growth of larger phytoplankton (> 3 μm). In more oligotrophic (low surface nitrate) areas, < 35% of the primary production resulted in a net increase in plant carbon. At some stations grazing pressure balanced phytoplankton growth, as plant carbon did not change over a full day incubation period.

  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. 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

  19. 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

  20. 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 ...

  1. 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.

  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. 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

  4. Spectrum allocations above 40 GHz

    NASA Technical Reports Server (NTRS)

    Katzenstein, W. E.; Moore, R. P.; Kimball, H. G.

    1981-01-01

    The 1979 World Administrative Radio Conference (WARC-79) revised the International Table of Frequency Allocations to reflect increased interest and activity in the region of the EM spectrum above 40 GHz. The total width of the spectrum allocated (235 GHz) in the region above 40 GHz indicates the extent of this new spectrum resource, made accessible by advances in the state-of-the-art of telecommunications equipment. There are some striking differences between the approach to allocation above and below 40 GHz. For example, there are not bands allocated exclusively. This reflects the characteristics of propagation and the small antenna beamwidths achievable at these frequencies. Attention is given to atmospheric window and absorption band limits, allocations to satellite services, allocations to scientific services, allocations to terrestrial services, the future refinement of the radio regulations above 40 GHz, and allocations of WARC-79 and frequency management.

  5. Testing the sensitivity of terrestrial carbon models using remotely sensed biomass estimates

    NASA Astrophysics Data System (ADS)

    Hashimoto, H.; Saatchi, S. S.; Meyer, V.; Milesi, C.; Wang, W.; Ganguly, S.; Zhang, G.; Nemani, R. R.

    2010-12-01

    There is a large uncertainty in carbon allocation and biomass accumulation in forest ecosystems. With the recent availability of remotely sensed biomass estimates, we now can test some of the hypotheses commonly implemented in various ecosystem models. We used biomass estimates derived by integrating MODIS, GLAS and PALSAR data to verify above-ground biomass estimates simulated by a number of ecosystem models (CASA, BIOME-BGC, BEAMS, LPJ). This study extends the hierarchical framework (Wang et al., 2010) for diagnosing ecosystem models by incorporating independent estimates of biomass for testing and calibrating respiration, carbon allocation, turn-over algorithms or parameters.

  6. [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

  7. 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).

  8. Economics of spectrum allocation

    NASA Astrophysics Data System (ADS)

    Melody, W. H.

    The effective and efficient allocation and use of the spectrum can be ensured only by a set of sharing rules that will reflect the interests, values, and power of all affected parties. What is now happening is that the new interests and different values of the developing countries are pressing to change the international sharing rules established by a small group of high-technology nations. It is noted that the latter have established a massive telecommunications infrastructure on the basis of inherited sharing rules that reflect only their interests and a much simplified scarcity problem. Once long-term goals and underlying principles of allocation are established, communication technologies and markets can be directed, through a series of adjustment policies, to achieve them. A crucial first step in the creation of an international information environment in which 'free' flows will be balanced flows is the establishment of a balanced and equitable set of sharing rules for the radio spectrum.

  9. Myrmics Memory Allocator

    Energy Science and Technology Software Center (ESTSC)

    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.

  10. Attention allocation before antisaccades.

    PubMed

    Klapetek, Anna; Jonikaitis, Donatas; Deubel, Heiner

    2016-01-01

    In the present study, we investigated the distribution of attention before antisaccades. We used a dual task paradigm, in which participants made prosaccades or antisaccades and discriminated the orientation of a visual probe shown at the saccade goal, the visual cue location (antisaccade condition), or a neutral location. Moreover, participants indicated whether they had made a correct antisaccade or an erroneous prosaccade. We observed that, while spatial attention in the prosaccade task was allocated only to the saccade goal, attention in the antisaccade task was allocated both to the cued location and to the antisaccade goal. This suggests parallel attentional selection of the cued and antisaccade locations. We further observed that in error trials--in which participants made an incorrect prosaccade instead of an antisaccade--spatial attention was biased towards the prosaccade goal. These erroneous prosaccades were mostly unnoticed and were often followed by corrective antisaccades with very short latencies (<100 ms). Data from error trials therefore provide further evidence for the parallel programming of the reflexive prosaccade to the cue and the antisaccade to the intended location. Taken together, our results suggest that attention allocation and saccade goal selection in the antisaccade task are mediated by a common competitive process. PMID:26790843

  11. 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

  12. 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

  13. 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.

  14. 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

  15. 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...) FISHERIES OFF WEST COAST STATES West Coast Groundfish Fisheries § 660.323 Pacific whiting allocations... amounts that will be harvested, or a combination of the two. Estimates of the amount of Pacific...

  16. Telescope Time Allocation Tool

    NASA Astrophysics Data System (ADS)

    Alves, J.

    2005-03-01

    TaToo is ESO's new Time Allocation Tool. This software scheduler is a combination of a user-friendly graphical user interface and an intelligent constraint-programming engine fine-tuned to ESO's scheduling problem. TaToo is able to produce a high quality and reliable schedule taking into consideration all constraints of the recommended programs for all telescopes in about 15 minutes. This performance allows schedulers at ESO-VISAS to simulate and evaluate different scenarios, optimize the scheduling of engineering activities at the observatories, and in the end construct the most science efficient schedule possible.

  17. [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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. [Physiological and growth responses of Sabina vulgaris to disturbance of leaf removal].

    PubMed

    He, W

    2001-04-01

    To examine the physiological and growth responses to Sabina vulgaris to natural disturbance, a field experiment to simulate the grazing and pest disturbance was conducted in Maowusu sandy land through artificially removing leaves. The disturbance of leaf removal could modify the species' diurnal physiological dynamics through changing the timing of extreme values, and moreover, change the average daily values of physiological indexes significantly. Leaf removal could affect the growth traits, but not biomass allocation significantly. The consequences of the disturbance were confined by its means and intensity, and there existed significant differences in sensitivity of different physiological and growth characteristics e.g., net photosynthesis rate and transpiration rate to leaf removal. The disturbance of leaf removal, especially that of old leaf removal, had compensation effects. Therefore, moderately removing the leaves on the shoots with less than 2 years old could enhance the growth and the biomass accumulation of current-year shoots. PMID:11757356

  4. 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.

  5. [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

  6. 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

  7. Above- and Below-ground Biomass, Net Ecosystem Carbon Exchange, and Soil Respiration in a Poplar Populus deltoides Bartr.) stand : Changes after 3 years of Growth under Elevated CO2

    NASA Astrophysics Data System (ADS)

    Barron-Gafford, G. A.; Grieve, K.; Bil, K.; Kudeyarov, V.; Handley, L.; Murthy, R.

    2003-12-01

    Stands of cottonwood (Populus deltoides Bartr.) trees were grown as a coppiced system under ambient (40 Pa), twice ambient (80 Pa), and three times ambient (120 Pa) partial pressure CO2 for the past three years in the Intensively-managed Forest Mesocosm (IFM) of the Biosphere 2 Center. Over three years Net Ecosystem CO2 exchange (NECE) was measured continuously and in the third year, nine whole trees were harvested from each CO2 treatment over the growing season. Both above- and below-ground parameters were measured. Three years of growth under elevated CO2 showed the expected stimulation in foliar biomass (8.7, 11.9, and 13.1 kg for the 40, 80, and 120 Pa treatments, respectively). Rates of NECE also followed an expected increase with elevated atmospheric CO2 concentrations, with maximum CO2 uptake rates reaching 10.5, 15.6, and 19.6 μ moles m-2 s-1 in the 40, 80, and 120 Pa treatments, respectively. However, above ground woody biomass and root biomass were not much stimulated beyond 80 Pa CO2. Wood/foliage and above/below ground biomass ratios reflect this decline. Under conditions of non-limiting nutrients and water, we found consistent increases in the above/below ground biomass ratio and wood to foliage biomass ratios in the 80 compared to the 40 Pa pCO2. Woody biomass production and the above/below ground biomass ratio were lower under the 120 Pa than any other treatment. Although biomass production did not change appreciably between 80 and 120 Pa CO2 treatments, both substrate induced and in-situ soil respiration values are also significantly higher in the 120Pa treatment, though no differences were present prior to CO2 treatments (Murthy et al. 2003). The unique closed-system operation of the IFM allowed for measures of soil CO2 efflux to be measured at both the soil collar and stand scales using a box model that takes into account all inputs and outputs from the stand. In-situ soil respiration rates increased significantly with increased atmospheric CO2

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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. PMID:18419571

  14. 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.

  15. Introduction of the rice CYP714D1 gene into Populus inhibits expression of its homologous genes and promotes growth, biomass production and xylem fibre length in transgenic trees

    PubMed Central

    Wang, Cuiting; Bao, Yan; Wang, Qiuqing; Zhang, Hongxia

    2013-01-01

    The rice (Oryza sativa) OsCYP714D1 gene (also known as EUI) encodes a cytochrome P450 monooxygenase which functions as a gibberellin (GA)-deactivating enzyme, catalysing 16α, 17-epoxidation of non-13-hydroxylated GAs. To understand whether it would also reduce the production of active GAs and depress the growth rate in transgenic trees, we constitutively expressed OsCYP714D1 in the aspen hybrid clone Populus alba×P. berolinensis. Unexpectedly, ectopic expression of OsCYP714D1 in aspen positively regulated the biosynthesis of GAs, including the active GA1 and GA4, leading to promotion of the growth rate and biomass production in transgenic plants. Transgenic lines which showed significant expression of the introduced OsCYP714D1 gene accumulated a higher GA level and produced more numerous and longer xylem fibres than did the wild-type plants. Quantitative real-time PCR indicated that transcription of most homologous PtCYP714 genes was suppressed in these transgenic lines. Therefore, the promoted GA and biomass production in transgenic trees constitutively expressing OsCYP714D1 is probably attributed to the down-regulated expression of the native PtCYP714 homologues involved in the GA biosynthesis pathway, although their precise functions are yet to be further elucidated. PMID:23667043

  16. GIGANTUS1 (GTS1), a member of Transducin/WD40 protein superfamily, controls seed germination, growth and biomass accumulation through ribosome-biogenesis protein interactions in Arabidopsis thaliana

    PubMed Central

    2014-01-01

    Background WD40 domains have been found in a plethora of eukaryotic proteins, acting as scaffolding molecules assisting proper activity of other proteins, and are involved in multi-cellular processes. They comprise several stretches of 44-60 amino acid residues often terminating with a WD di-peptide. They act as a site of protein-protein interactions or multi-interacting platforms, driving the assembly of protein complexes or as mediators of transient interplay among other proteins. In Arabidopsis, members of WD40 protein superfamily are known as key regulators of plant-specific events, biologically playing important roles in development and also during stress signaling. Results Using reverse genetic and protein modeling approaches, we characterize GIGANTUS1 (GTS1), a new member of WD40 repeat protein in Arabidopsis thaliana and provide evidence of its role in controlling plant growth development. GTS1 is highly expressed during embryo development and negatively regulates seed germination, biomass yield and growth improvement in plants. Structural modeling analysis suggests that GTS1 folds into a β-propeller with seven pseudo symmetrically arranged blades around a central axis. Molecular docking analysis shows that GTS1 physically interacts with two ribosomal protein partners, a component of ribosome Nop16, and a ribosome-biogenesis factor L19e through β-propeller blade 4 to regulate cell growth development. Conclusions Our results indicate that GTS1 might function in plant developmental processes by regulating ribosomal structural features, activities and biogenesis in plant cells. Our results suggest that GIGANTUS1 might be a promising target to engineer transgenic plants with higher biomass and improved growth development for plant-based bioenergy production. PMID:24467952

  17. 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

  18. 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.

  19. 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.

  20. Collaborative Resource Allocation

    NASA Technical Reports Server (NTRS)

    Wang, Yeou-Fang; Wax, Allan; Lam, Raymond; Baldwin, John; Borden, Chester

    2007-01-01

    Collaborative Resource Allocation Networking Environment (CRANE) Version 0.5 is a prototype created to prove the newest concept of using a distributed environment to schedule Deep Space Network (DSN) antenna times in a collaborative fashion. This program is for all space-flight and terrestrial science project users and DSN schedulers to perform scheduling activities and conflict resolution, both synchronously and asynchronously. Project schedulers can, for the first time, participate directly in scheduling their tracking times into the official DSN schedule, and negotiate directly with other projects in an integrated scheduling system. A master schedule covers long-range, mid-range, near-real-time, and real-time scheduling time frames all in one, rather than the current method of separate functions that are supported by different processes and tools. CRANE also provides private workspaces (both dynamic and static), data sharing, scenario management, user control, rapid messaging (based on Java Message Service), data/time synchronization, workflow management, notification (including emails), conflict checking, and a linkage to a schedule generation engine. The data structure with corresponding database design combines object trees with multiple associated mortal instances and relational database to provide unprecedented traceability and simplify the existing DSN XML schedule representation. These technologies are used to provide traceability, schedule negotiation, conflict resolution, and load forecasting from real-time operations to long-range loading analysis up to 20 years in the future. CRANE includes a database, a stored procedure layer, an agent-based middle tier, a Web service wrapper, a Windows Integrated Analysis Environment (IAE), a Java application, and a Web page interface.

  1. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

    SciTech Connect

    Dr. Kalyan Annamalai; Dr. John Sweeten; Dr. Sayeed Mukhtar

    2000-10-24

    The following are proposed activities for quarter 1 (6/15/00-9/14/00): (1) Finalize the allocation of funds within TAMU to co-principal investigators and the final task lists; (2) Acquire 3 D computer code for coal combustion and modify for cofiring Coal:Feedlot biomass and Coal:Litter biomass fuels; (3) Develop a simple one dimensional model for fixed bed gasifier cofired with coal:biomass fuels; and (4) Prepare the boiler burner for reburn tests with feedlot biomass fuels. The following were achieved During Quarter 5 (6/15/00-9/14/00): (1) Funds are being allocated to co-principal investigators; task list from Prof. Mukhtar has been received (Appendix A); (2) Order has been placed to acquire Pulverized Coal gasification and Combustion 3 D (PCGC-3) computer code for coal combustion and modify for cofiring Coal: Feedlot biomass and Coal: Litter biomass fuels. Reason for selecting this code is the availability of source code for modification to include biomass fuels; (3) A simplified one-dimensional model has been developed; however convergence had not yet been achieved; and (4) The length of the boiler burner has been increased to increase the residence time. A premixed propane burner has been installed to simulate coal combustion gases. First coal, as a reburn fuel will be used to generate base line data followed by methane, feedlot and litter biomass fuels.

  2. My Biomass, Your Biomass, Our Solution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The US is pursuing an array of renewable energy sources to reduce reliance on imported fossil fuels and reduce greenhouse gas emissions. Biomass energy and biomass ethanol are key components in the pursuit. The need for biomass feedstock to produce sufficient ethanol to meet any of the numerous stat...

  3. Host shoot clipping depresses the growth of weedy hemiparasitic Pedicularis kansuensis.

    PubMed

    Sui, Xiao-Lin; Huang, Wei; Li, Yun-Ju; Guan, Kai-Yun; Li, Ai-Rong

    2015-07-01

    Root hemiparasitic plants show optimal growth when attached to a suitable host by abstracting water and nutrients. Despite the fact that damage to host plants in the wild occurs frequently in various forms (e.g. grazing), effects of host damage on growth and physiological performance of root hemiparasites remain unclear. In this study, host shoot clipping was conducted to determine the influence of host damage on photosynthetic and growth performance of a weedy root hemiparasite, Pedicularis kansuensis, and its interaction with a host, Elymus nutans. Photosynthetic capacity, tissue mineral nutrient content and plant biomass of P. kansuensis were significantly improved when attached to a host plant. Host clipping had no effect on quantum efficiency (ΦPSII), but significantly reduced the growth rate and biomass of P. kansuensis. In contrast, clipping significantly improved photosynthetic capacity and accumulation of potassium in E. nutans. No significant decrease in biomass was observed in clipped host plants. By changing nutrient absorption and allocation, clipping affected the interaction between P. kansuensis and its host. Our results showed that host clipping significantly suppressed the growth of weedy P. kansuensis, but did not affect biomass accumulation in E. nutans. We propose that grazing (a dominant way of causing host damage in the field) may have a potential in the control against the weedy hemiparasite. PMID:25956077

  4. Demographic drivers of tree biomass change during secondary succession in northeastern Costa Rica.

    PubMed

    Rozendaal, Danae M A; Chazdon, Robin L

    2015-03-01

    Second-growth tropical forests are an important global carbon sink. As current knowledge on biomass accumulation during secondary succession is heavily based on chronosequence studies, direct estimates of annual rates of biomass accumulation in monitored stands are largely unavailable. We evaluated the contributions of tree diameter increment, recruitment, and mortality to annual tree biomass change during succession for three groups of tree species: second-growth (SG) specialists, generalists, and old-growth (OG) specialists. We monitored six second-growth tropical forests that varied in stand age and two old-growth forests in northeastern Costa Rica. We monitored these over a period of 8 to 16 years. To assess rates of biomass change during secondary succession, we compared standing biomass and biomass dynamics between second-growth forest stages and old-growth forest, and evaluated the effect of stand age on standing biomass and biomass dynamics in second-growth forests. Standing tree biomass increased with stand age during succession, whereas the rate of biomass change decreased. Biomass change was largely driven by tree diameter increment and mortality, with a minor contribution from recruitment. The relative importance of these demographic drivers shifted over succession. Biomass gain due to tree diameter increment decreased with stand age, whereas biomass loss due to mortality increased. In the age range of our second-growth forests, 10-41 years, SG specialists dominated tree biomass in second-growth forests. SG specialists, and to a lesser extent generalists, also dominated stand-level biomass increase due to tree diameter increment, whereas SG specialists largely accounted for decreases in biomass due to mortality. Our results indicate that tree growth is largely driving biomass dynamics early in succession, whereas both growth and mortality are important later in succession. Biomass dynamics are largely accounted for by a few SG specialists and one

  5. Engineering verification of the biomass production chamber

    NASA Technical Reports Server (NTRS)

    Prince, R. P.; Knott, W. M., III; Sager, J. C.; Jones, J. D.

    1992-01-01

    The requirements for life support systems, both biological and physical-chemical, for long-term human attended space missions are under serious study throughout NASA. The KSC 'breadboard' project has focused on biomass production using higher plants for atmospheric regeneration and food production in a special biomass production chamber. This chamber is designed to provide information on food crop growth rate, contaminants in the chamber that alter plant growth requirements for atmospheric regeneration, carbon dioxide consumption, oxygen production, and water utilization. The shape and size, mass, and energy requirements in relation to the overall integrity of the biomass production chamber are under constant study.

  6. Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy-covariance, biometric and continuous soil chamber measurements

    NASA Astrophysics Data System (ADS)

    Zanotelli, D.; Montagnani, L.; Manca, G.; Tagliavini, M.

    2012-10-01

    Carbon use efficiency (CUE) is a functional parameter that could possibly link the current increasingly accurate global estimates of gross primary production with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, net primary production (NPP) and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a~measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross-check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard both net ecosystem production and gross primary production on yearly basis, 380 ± 30 g C m-2 and 1263 ± 189 g C m-2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruits: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.09, was higher than the previously suggested

  7. Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy covariance, biometric and continuous soil chamber measurements

    NASA Astrophysics Data System (ADS)

    Zanotelli, D.; Montagnani, L.; Manca, G.; Tagliavini, M.

    2013-05-01

    Carbon use efficiency (CUE), the ratio of net primary production (NPP) over gross primary production (GPP), is a functional parameter that could possibly link the current increasingly accurate global GPP estimates with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, NPP and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard, both net ecosystem production and gross primary production on a yearly basis, 380 ± 30 g C m-2 and 1263 ± 189 g C m-2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruit: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.12, was higher

  8. Adaptation of carbon allocation under light and nutrient reduction

    NASA Astrophysics Data System (ADS)

    Wegener, Frederik; Werner, Christiane

    2015-04-01

    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. Whereas shifts in the allocation of photosynthates induced by reduced water availability, enhanced temperature and CO2 concentration were recently investigated in various studies, less is known about the response to light and nutrient reduction. We induced different allocation patterns in the Mediterranean shrub Halimium halimifolium L. by a reduction of light (Low L treatment) and nutrient availability (Low N treatment) and analysed allocation parameters as well as morphological and physiological traits for 15 months. Finally, we conducted a 13CO2 pulse-labelling and followed the fate of recently assimilated carbon to eight different classes of plant tissues and respiration for 13 days. The results revealed a high intraspecific variability in C distribution to tissues and in respiration. Allocation changes even varied within leaf and stem tissue classes (e.g. more C in main stems, less in lateral stems). These results show that the common separation of plant tissues in only three classes, i.e. root, shoot and leaf tissues, can result in missing information about allocation changes. The nutrient reduction enhanced the transport of recently assimilated C from leaves to roots in terms of quantity (c. 200%) and velocity compared to control plants. Interestingly, a 57% light reduction enhanced photosynthetic capacity and caused no change in final biomass after 15 months. Therefore, our results support the recently discussed sink regulation of photosynthesis. Finally, our results indicate that growing heterotrophic tissues strongly reduce the C loss from storage and structural C pools and therefore enhance the fraction of recent assimilates used for respiration. We propose that this interruption of the C reflux from storage and structural C pools could be a control mechanism for C

  9. Growth and Physiological Responses to Water Depths in Carex schmidtii Meinsh

    PubMed Central

    Yan, Hong; Liu, Ruiquan; Liu, Zinan; Wang, Xue; Luo, Wenbo; Sheng, Lianxi

    2015-01-01

    A greenhouse experiment was performed to investigate growth and physiological responses to water depth in completely submerged condition of a wetland plant Carex schmidtii Meinsh., one of the dominant species in the Longwan Crater Lake wetlands (China). Growth and physiological responses of C. schmidtii were investigated by growing under control (non-submerged) and three submerged conditions (5 cm, 15 cm and 25 cm water level). Total biomass was highest in control, intermediate in 5 cm treatment and lowest in the other two submerged treatments. Water depth prominently affected the first-order lateral root to main root mass ratio. Alcohol dehydrogenase (ADH) activity decreased but malondialdehyde (MDA) content increased as water depth increased. The starch contents showed no differences among the various treatments at the end of the experiment. However, soluble sugar contents were highest in control, intermediate in 5 cm and 15 cm treatments and lowest in 25 cm treatment. Our data suggest that submergence depth affected some aspects of growth and physiology of C. schmidtii, which can reduce anoxia damage not only through maintaining the non-elongation strategy in shoot part but also by adjusting biomass allocation to different root orders rather than adjusting root-shoot biomass allocation. PMID:26009895

  10. Fixed allocation patterns, rather than plasticity, benefit recruitment and recovery from drought in seedlings of a desert shrub

    PubMed Central

    Zhang, Yao; Li, Yan; Xie, Jiang-Bo

    2016-01-01

    The response of plants to drought is controlled by the interaction between physiological regulation and morphological adjustment. Although recent studies have highlighted the long-term morphological acclimatization of plants to drought, there is still debate on how plant biomass allocation patterns respond to drought. In this study, we performed a greenhouse experiment with first-year seedlings of a desert shrub in control, drought and re-water treatments, to examine their physiological and morphological traits during drought and subsequent recovery. We found that (i) biomass was preferentially allocated to roots along a fixed allometric trajectory throughout the first year of development, irrespective of the variation in water availability; and (ii) this fixed biomass allocation pattern benefited the post-drought recovery. These results suggest that, in a stressful environment, natural selection has favoured a fixed biomass allocation pattern rather than plastic responses to environmental variation. The fixed ‘preferential allocation to root’ biomass suggests that roots may play a critical role in determining the fate of this desert shrub during prolonged drought. As the major organ for resource acquisition and storage, how the root system functions during drought requires further investigation. PMID:27073036

  11. Fixed allocation patterns, rather than plasticity, benefit recruitment and recovery from drought in seedlings of a desert shrub.

    PubMed

    Zhang, Yao; Li, Yan; Xie, Jiang-Bo

    2016-01-01

    The response of plants to drought is controlled by the interaction between physiological regulation and morphological adjustment. Although recent studies have highlighted the long-term morphological acclimatization of plants to drought, there is still debate on how plant biomass allocation patterns respond to drought. In this study, we performed a greenhouse experiment with first-year seedlings of a desert shrub in control, drought and re-water treatments, to examine their physiological and morphological traits during drought and subsequent recovery. We found that (i) biomass was preferentially allocated to roots along a fixed allometric trajectory throughout the first year of development, irrespective of the variation in water availability; and (ii) this fixed biomass allocation pattern benefited the post-drought recovery. These results suggest that, in a stressful environment, natural selection has favoured a fixed biomass allocation pattern rather than plastic responses to environmental variation. The fixed 'preferential allocation to root' biomass suggests that roots may play a critical role in determining the fate of this desert shrub during prolonged drought. As the major organ for resource acquisition and storage, how the root system functions during drought requires further investigation. PMID:27073036

  12. Algal biofuels from urban wastewaters: maximizing biomass yield using nutrients recycled from hydrothermal processing of biomass.

    PubMed

    Selvaratnam, T; Pegallapati, A K; Reddy, H; Kanapathipillai, N; Nirmalakhandan, N; Deng, S; Lammers, P J

    2015-04-01

    Recent studies have proposed algal cultivation in urban wastewaters for the dual purpose of waste treatment and bioenergy production from the resulting biomass. This study proposes an enhancement to this approach that integrates cultivation of an acidophilic strain, Galdieria sulphuraria 5587.1, in a closed photobioreactor (PBR); hydrothermal liquefaction (HTL) of the wet algal biomass; and recirculation of the nutrient-rich aqueous product (AP) of HTL to the PBR to achieve higher biomass productivity than that could be achieved with raw wastewater. The premise is that recycling nutrients in the AP can maintain optimal C, N and P levels in the PBR to maximize biomass growth to increase energy returns. Growth studies on the test species validated growth on AP derived from HTL at temperatures from 180 to 300°C. Doubling N and P concentrations over normal levels in wastewater resulted in biomass productivity gains of 20-25% while N and P removal rates also doubled. PMID:25704095

  13. Analysis of integrated animal-fish production system under subtropical hill agro ecosystem in India: growth performance of animals, total biomass production and monetary benefit.

    PubMed

    Kumaresan, A; Pathak, K A; Bujarbaruah, K M; Vinod, K

    2009-03-01

    The present study assessed the benefits of integration of animals with fish production in optimizing the bio mass production from unit land in subtropical hill agro ecosystem. Hampshire pigs and Khaki Campbell ducks were integrated with composite fish culture. The pig and duck excreta were directly allowed into the pond and no supplementary feed was given to fish during the period of study. The average levels of N, P and K in dried pig and duck manure were 0.9, 0.7 and 0.6 per cent and 1.3, 0.6 and 0.5 per cent, respectively. The average body weight of pig and duck at 11 months age was 90 and 1.74 kg with an average daily weight gain of 333.33 and 6.44 g, respectively. The fish production in pig-fish and duck-fish systems were 2209 and 2964 kg/ha, respectively while the fish productivity in control pond was only 820 kg/ha. The total biomass (animal and fish) production was higher (p<0.05) in commercial feeding system compared to the traditional system, however the input/output ratio was 1:1.2 and 1:1.55 for commercial and traditional systems, respectively. It was inferred that the total biomass production per unit land was high (p<0.05) when animal and fish were integrated together. PMID:18622714

  14. Can Canopy Uptake Influence Nitrogen Acquisition and Allocation by Trees?

    NASA Astrophysics Data System (ADS)

    Nair, Richard; Perks, Mike; Mencuccini, Maurizio

    2015-04-01

    field conditions, and if this extra N supplies growth in woody tissues such as the stem, as well as the canopy. To test these ideas, we applied a low (~ 2.5 % above ambient NDEP) 15N treatment to Picea sitchensis saplings, targeting the soil or the canopy in monthly fertilizations for 16 months, and investigating 15N return in different age classes of biomass and over time. While soil-targeted deposition treatments agreed well with existing knowledge of N partitioning from this source, we could infer 2-3 times more 15N was retained above-ground in canopy-targeted treatments, including a relative increase in 15N allocation to stem and woody biomass when compared to the soil treatment. These results suggest that existing forest 15N-fertilization experiments could under-estimate the overall ΔCΔN effect of atmospheric deposition.

  15. Ecophysiological differences in tree carbon gain and water use for two fast growing loblolly pine ideotypes that differ in carbon allocation

    NASA Astrophysics Data System (ADS)

    Maier, C. A.; Johnsen, K. H.; Dougherty, P.; Albaugh, T.; Patterson, S.

    2013-12-01

    We examined the ecophysiological basis for differences in growth efficiency and water-use for two contrasting Pinus taeda (L.) ideotypes: a ';broad-crown' (BC) and a ';narrow crown' (NC) clone, which allocate more growth to leaves and wood, respectively. Tree growth, above and belowground biomass production, fine root turnover, light use efficiency (LUE), and transpiration on a ground (Et) and leaf (EL) basis were measured periodically over eight years. Silviculture treatments were a control consisting of shearing and bedding following local commercial operations and a mulch treatment where chipped logging residue (C/N≈700) was incorporated into the soil during bedding at a rate of 25 Mg ha-1. We hypothesized that: 1) the NC and BC clone would display similar aboveground productivity in the control treatment, but because of lower leaf area and thus lower nitrogen demand, the NC would display higher productivity than BC on the mulch treatment, 2) the NC would have higher LUE, and 3) the NC clone would have lower Et and EL. There were no treatment, clone, or interaction effects on stemwood production. At age eight, standing stem biomass was 80.7 and 86.0 Mg ha-1 (p=0.33), for the NC and BC, respectively. However, there were significant clone effects on carbon allocation. The BC had greater foliage (BC: 8.1, NC: 6.6 Mg ha-1, se=0.2, p=0.01) and branch (BC: 15.0, NC: 12.4 Mg ha-1, se=0.4, p<0.001) biomass, while the NC clone had greater taproot (BC: 14.8, NC: 17.1, Mg ha-1, se=0.4, p=0.003) and coarse root (>2mm) (BC: 9.7, NC: 11.23 Mg ha-1, se=0.2, P<0.001) biomass. In addition, the NC clone averaged on a monthly basis 30% more fine root biomass (<2mm) (BC: 42.4, NC: 61.0 g m-2, se=4.0, p=0.011). The BC clone had 16% more LAI (BC: 3.52×0.12, NC: 2.94×0.14 m2 m-2) at peak foliage biomass and had more leaf area to conducting sapwood area (AL/AS) (BC: 0.175 m2 cm-2, NC: 0.150 m2 cm-2) than the NC clone. Growth efficiency, defined as annual stem increment per unit

  16. 24 CFR 92.50 - Formula allocation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Formula allocation. 92.50 Section 92.50 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development HOME INVESTMENT PARTNERSHIPS PROGRAM Allocation Formula § 92.50 Formula allocation. (a) Jurisdictions eligible for a formula allocation. HUD...

  17. Biomass treatment method

    DOEpatents

    Friend, Julie; Elander, Richard T.; Tucker, III; Melvin P.; Lyons, Robert C.

    2010-10-26

    A method for treating biomass was developed that uses an apparatus which moves a biomass and dilute aqueous ammonia mixture through reaction chambers without compaction. The apparatus moves the biomass using a non-compressing piston. The resulting treated biomass is saccharified to produce fermentable sugars.

  18. Biomass resilience of Neotropical secondary forests

    NASA Astrophysics Data System (ADS)

    Poorter, Lourens; Bongers, Frans; Aide, T. Mitchell; Almeyda Zambrano, Angélica M.; Balvanera, Patricia; Becknell, Justin M.; Boukili, Vanessa; Brancalion, Pedro H. S.; Broadbent, Eben N.; Chazdon, Robin L.; Craven, Dylan; de Almeida-Cortez, Jarcilene S.; Cabral, George A. L.; de Jong, Ben H. J.; Denslow, Julie S.; Dent, Daisy H.; Dewalt, Saara J.; Dupuy, Juan M.; Durán, Sandra M.; Espírito-Santo, Mario M.; Fandino, María C.; César, Ricardo G.; Hall, Jefferson S.; Hernandez-Stefanoni, José Luis; Jakovac, Catarina C.; Junqueira, André B.; Kennard, Deborah; Letcher, Susan G.; Licona, Juan-Carlos; Lohbeck, Madelon; Marín-Spiotta, Erika; Martínez-Ramos, Miguel; Massoca, Paulo; Meave, Jorge A.; Mesquita, Rita; Mora, Francisco; Muñoz, Rodrigo; Muscarella, Robert; Nunes, Yule R. F.; Ochoa-Gaona, Susana; de Oliveira, Alexandre A.; Orihuela-Belmonte, Edith; Peña-Claros, Marielos; Pérez-García, Eduardo A.; Piotto, Daniel; Powers, Jennifer S.; Rodríguez-Velázquez, Jorge; Romero-Pérez, I. Eunice; Ruíz, Jorge; Saldarriaga, Juan G.; Sanchez-Azofeifa, Arturo; Schwartz, Naomi B.; Steininger, Marc K.; Swenson, Nathan G.; Toledo, Marisol; Uriarte, Maria; van Breugel, Michiel; van der Wal, Hans; Veloso, Maria D. M.; Vester, Hans F. M.; Vicentini, Alberto; Vieira, Ima C. G.; Bentos, Tony Vizcarra; Williamson, G. Bruce; Rozendaal, Danaë M. A.

    2016-02-01

    Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha-1), corresponding to a net carbon uptake of 3.05 Mg C ha-1 yr-1, 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha-1) across sites, and this recovery increased with water availability (higher local rainfall and lower climatic water deficit). We present a biomass recovery map of Latin America, which illustrates geographical and climatic variation in carbon sequestration potential during forest regrowth. The map will support policies to minimize forest loss in areas where biomass resilience is naturally low (such as seasonally dry forest regions) and promote forest regeneration and restoration in humid tropical lowland areas with high biomass resilience.

  19. Collective credit allocation in science

    PubMed Central

    Shen, Hua-Wei; Barabási, Albert-László

    2014-01-01

    Collaboration among researchers is an essential component of the modern scientific enterprise, playing a particularly important role in multidisciplinary research. However, we continue to wrestle with allocating credit to the coauthors of publications with multiple authors, because the relative contribution of each author is difficult to determine. At the same time, the scientific community runs an informal field-dependent credit allocation process that assigns credit in a collective fashion to each work. Here we develop a credit allocation algorithm that captures the coauthors’ contribution to a publication as perceived by the scientific community, reproducing the informal collective credit allocation of science. We validate the method by identifying the authors of Nobel-winning papers that are credited for the discovery, independent of their positions in the author list. The method can also compare the relative impact of researchers working in the same field, even if they did not publish together. The ability to accurately measure the relative credit of researchers could affect many aspects of credit allocation in science, potentially impacting hiring, funding, and promotion decisions. PMID:25114238

  20. Endophyte-Mediated Effects on the Growth and Physiology of Achnatherum sibiricum Are Conditional on Both N and P Availability

    PubMed Central

    Li, Xia; Ren, Anzhi; Han, Rong; Yin, Lijia; Wei, Maoying; Gao, Yubao

    2012-01-01

    The interaction of endophyte–grass associations are conditional on nitrogen (N) availability, but the reported responses of these associations to N are inconsistent. We hypothesized that this inconsistency is caused, at least in part, by phosphorus (P) availability. In this experiment, we compared the performance of endophyte-infected (EI) and endophyte-free (EF) Achnatherum sibiricum subjected to four treatments comprising a factorial combination of two levels of N (N+ vs. N−, i.e. N supply vs. N deficiency) and two levels of P (P+ vs. P−, i.e. P supply vs. P deficiency) availability. The results showed that A. sibiricum–Neotyphodium associations were conditional on both N and P availability, but more conditional on N than P. Under N+P− conditions, endophyte infection significantly improved acid phosphatase activity of EI plants, such that the biomass of EI plants was not affected by P deficiency (i.e. similar growth to N+P+ conditions), and resulted in more biomass in EI than EF plants. Under N−P+ conditions, biomass of both EI and EF decreased compared with N+P+; however, EI biomass decreased slowly by decreasing leaf N concentration more rapidly but allocating higher fractions of N to photosynthetic machinery compared with EF plants. This change of N allocation not only improved photosynthetic ability of EI plants but also significantly increased their biomass. Under N−P− conditions, EI plants allocated higher fractions of N to photosynthesis and had greater P concentrations in roots, but there was no significant difference in biomass between EI and EF plants. Our results support the hypothesis that endophyte–grass interactions are dependent on both N and P availability. However, we did not find a clear cost of endophyte infection in A. sibiricum. PMID:23185245

  1. [Adaptive adjustment of rhizome and root system on morphology, biomass and nutrient in Phyllostachys rivalis under long-term waterlogged condition].

    PubMed

    Liu, Yu-fang; Chen, Shuang-lin; Li Ying-chun; Guo, Zi-wu; Li, Ying-chun; Yang, Qing-ping

    2015-12-01

    The research was to approach the growth strategy of rhizome and roots based on the morphology, biomass and nutrient in Phyllostachys rivalis under long-term waterlogged conditions, and provided a theoretical basis for its application for vegetation restoration in wetland and water-level fluctuation belts. The morphological characteristics, physiological and biochemical indexes of annual bamboo rhizome and roots were investigated with an experiment using individually potted P. rivalis which was treated by artificial water-logging for 3, 6, and 12 months. Accordingly the morphological characteristics, biomass allocation, nutrient absorption and balance in rhizome and roots of P. rivalis were analyzed. The results showed that there was no obvious impact of long-term water-logging on the length and diameter of rhizomes, diameter of roots in P. rivalis. The morphological characteristics of rhizome had been less affected generally under water-logging for 3 months. And less rhizomes were submerged, while the growth of roots was inhibited to some extent. Furthermore, with waterlogging time extended, submerged roots and rhizomes grew abundantly, and the roots and rhizomes in soil were promoted. Moreover for ratios of rhizome biomass in soil and water, there were no obvious variations, the same for the root biomass in soil to total biomass. The ratio of root biomass in water to total biomass and the ratio of root biomass in water to root biomass in soil both increased significantly. The results indicated that P. rivalis could adapt to waterlogged conditions gradually through growth regulation and reasonable biomass distribution. However, the activity of rhizome roots in soil decreased and the nutrient absorption was inhibited by long-term water-logging, although it had no effect on stoichiometric ratios of root nutrient in soil. The activity of rhizome root in water increased and the stoichiometric ratios adjusted adaptively to waterlogged conditions, the ratio of N

  2. Biomass in a petrochemical world.

    PubMed

    Roddy, Dermot J

    2013-02-01

    The world's increasingly voracious appetite for fossil fuels is driven by fast-growing populations and ever-rising aspirations for the lifestyles and standard of living exemplified in the developed world. Forecasts for higher electricity consumption, more comfortable living environments (via heating or cooling) and greater demand for transport fuels are well known. Similar growth in demand is projected for petrochemical-based products in the form of man-made fibres for clothing, ubiquitous plastic artefacts, cosmetics, etc. All drawing upon the same finite oil, gas and coal feedstocks. Biomass can, in principle, substitute for all of these feedstocks. Although ultimately finite, biomass resources can be expanded and renewed if this is a societal priority. This paper examines the projected growth of an energy-intensive international petrochemicals industry, considers its demand for both utilities and feedstocks, and considers the extent to which biomass can substitute for fossil fuels. The scope of this study includes biomass component extraction, direct chemical conversion, thermochemical conversion and biochemical conversion. Noting that the petrochemicals industry consumes around 10 per cent of the world's fossil fuels as feedstocks and almost as much again in utilities, various strategies for addressing future demand are considered. The need for long-term infrastructure and logistics planning is highlighted. PMID:24427511

  3. Biomass in a petrochemical world

    PubMed Central

    Roddy, Dermot J.

    2013-01-01

    The world's increasingly voracious appetite for fossil fuels is driven by fast-growing populations and ever-rising aspirations for the lifestyles and standard of living exemplified in the developed world. Forecasts for higher electricity consumption, more comfortable living environments (via heating or cooling) and greater demand for transport fuels are well known. Similar growth in demand is projected for petrochemical-based products in the form of man-made fibres for clothing, ubiquitous plastic artefacts, cosmetics, etc. All drawing upon the same finite oil, gas and coal feedstocks. Biomass can, in principle, substitute for all of these feedstocks. Although ultimately finite, biomass resources can be expanded and renewed if this is a societal priority. This paper examines the projected growth of an energy-intensive international petrochemicals industry, considers its demand for both utilities and feedstocks, and considers the extent to which biomass can substitute for fossil fuels. The scope of this study includes biomass component extraction, direct chemical conversion, thermochemical conversion and biochemical conversion. Noting that the petrochemicals industry consumes around 10 per cent of the world's fossil fuels as feedstocks and almost as much again in utilities, various strategies for addressing future demand are considered. The need for long-term infrastructure and logistics planning is highlighted. PMID:24427511

  4. Productivity and carbon allocation in pure and mixed-species plantations of Eucalyptus grandis and Acacia mangium in Brazil

    NASA Astrophysics Data System (ADS)

    Nouvellon, Y.; Laclau, J.; Epron, D.; Le Maire, G.; Gonçalves, J.; Bouillet, J.

    2010-12-01

    Nitrogen fertilizer inputs are required in fast growing eucalypt plantations to meet tree requirements, and to compensate for the large nitrogen outputs associated with wood exportation at the end of the short rotations. Due to the economic and potential environmental cost of fertilizers, mixed-species plantations (MSP) with N-fixing species (NFS) such as Acacia sp. might be an attractive option to improve the long-term soil N (and possibly soil carbon) status. In such MSP, increases in N availability may influence the productivity and C partitioning of the non-N fixing species. To investigate the effects of NFS on nutrient cycling, wood production, C sequestration, and soil fertility, a randomized block design including monocultures of Eucalyptus grandis (100%E) and Acacia mangium (100%A), and mixtures of these species (50%E:50%A) was set up in southern Brazil. Our specific goals in the present study were to compare the production and C allocation patterns of these plantations, during the two last years of the 6-yr rotation. We hypothesized that 1) a large part of the differences in wood production between monospecific stands would be explained by differences in C allocation; and 2) the C allocation patterns of each species would be strongly modified in mixed- species plantations compared to mono-specific plantations due to inter-specific interactions and shifts in soil N status. Biomass increase (growth, G) in the different plant compartments was assessed by means of inventories and allometric relationships. Total aboveground net primary productivity (ANPP), and the productivity of each aboveground plant compartment were estimated from measurements of G and litterfall (L) (ANPP=G+L). Total belowground C allocations (TBCA) were estimated using a mass-balance approach as soil CO2 efflux C minus the C input from aboveground litter plus changes in the C stored in roots, in the forest floor litter layer, and in soil. Over this first rotation, mixing NFS with eucalypt

  5. The Oldest, Slowest Rainforests in the World? Massive Biomass and Slow Carbon Dynamics of Fitzroya cupressoides Temperate Forests in Southern Chile.

    PubMed

    Urrutia-Jalabert, Rocio; Malhi, Yadvinder; Lara, Antonio

    2015-01-01

    Old-growth temperate rainforests are, per unit area, the largest and most long-lived stores of carbon in the terrestrial biosphere, but their carbon dynamics have rarely been described. The endangered Fitzroya cupressoides forests of southern South America include stands that are probably the oldest dense forest stands in the world, with long-lived trees and high standing biomass. We assess and compare aboveground biomass, and provide the first estimates of net primary productivity (NPP), carbon allocation and mean wood residence time in medium-age stands in the Alerce Costero National Park (AC) in the Coastal Range and in old-growth forests in the Alerce Andino National Park (AA) in the Andean Cordillera. Aboveground live biomass was 113-114 Mg C ha(-1) and 448-517 Mg C ha(-1) in AC and AA, respectively. Aboveground productivity was 3.35-3.36 Mg C ha(-1) year(-1) in AC and 2.22-2.54 Mg C ha(-1) year(-1) in AA, values generally lower than others reported for temperate wet forests worldwide, mainly due to the low woody growth of Fitzroya. NPP was 4.21-4.24 and 3.78-4.10 Mg C ha(-1) year(-1) in AC and AA, respectively. Estimated mean wood residence time was a minimum of 539-640 years for the whole forest in the Andes and 1368-1393 years for only Fitzroya in this site. Our biomass estimates for the Andes place these ecosystems among the most massive forests in the world. Differences in biomass production between sites seem mostly apparent as differences in allocation rather than productivity. Residence time estimates for Fitzroya are the highest reported for any species and carbon dynamics in these forests are the slowest reported for wet forests worldwide. Although primary productivity is low in Fitzroya forests, they probably act as ongoing biomass carbon sinks on long-term timescales due to their low mortality rates and exceptionally long residence times that allow biomass to be accumulated for millennia. PMID:26353111

  6. The Oldest, Slowest Rainforests in the World? Massive Biomass and Slow Carbon Dynamics of Fitzroya cupressoides Temperate Forests in Southern Chile

    PubMed Central

    Urrutia-Jalabert, Rocio; Malhi, Yadvinder; Lara, Antonio

    2015-01-01

    Old-growth temperate rainforests are, per unit area, the largest and most long-lived stores of carbon in the terrestrial biosphere, but their carbon dynamics have rarely been described. The endangered Fitzroya cupressoides forests of southern South America include stands that are probably the oldest dense forest stands in the world, with long-lived trees and high standing biomass. We assess and compare aboveground biomass, and provide the first estimates of net primary productivity (NPP), carbon allocation and mean wood residence time in medium-age stands in the Alerce Costero National Park (AC) in the Coastal Range and in old-growth forests in the Alerce Andino National Park (AA) in the Andean Cordillera. Aboveground live biomass was 113–114 Mg C ha-1 and 448–517 Mg C ha-1 in AC and AA, respectively. Aboveground productivity was 3.35–3.36 Mg C ha-1 year-1 in AC and 2.22–2.54 Mg C ha-1 year-1 in AA, values generally lower than others reported for temperate wet forests worldwide, mainly due to the low woody growth of Fitzroya. NPP was 4.21–4.24 and 3.78–4.10 Mg C ha-1 year-1 in AC and AA, respectively. Estimated mean wood residence time was a minimum of 539–640 years for the whole forest in the Andes and 1368–1393 years for only Fitzroya in this site. Our biomass estimates for the Andes place these ecosystems among the most massive forests in the world. Differences in biomass production between sites seem mostly apparent as differences in allocation rather than productivity. Residence time estimates for Fitzroya are the highest reported for any species and carbon dynamics in these forests are the slowest reported for wet forests worldwide. Although primary productivity is low in Fitzroya forests, they probably act as ongoing biomass carbon sinks on long-term timescales due to their low mortality rates and exceptionally long residence times that allow biomass to be accumulated for millennia. PMID:26353111

  7. Growth

    NASA Astrophysics Data System (ADS)

    Waag, Andreas

    This chapter is devoted to the growth of ZnO. It starts with various techniques to grow bulk samples and presents in some detail the growth of epitaxial layers by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and pulsed laser deposition (PLD). The last section is devoted to the growth of nanorods. Some properties of the resulting samples are also presented. If a comparison between GaN and ZnO is made, very often the huge variety of different growth techniques available to fabricate ZnO is said to be an advantage of this material system. Indeed, growth techniques range from low cost wet chemical growth at almost room temperature to high quality MOCVD growth at temperatures above 1, 000∘C. In most cases, there is a very strong tendency of c-axis oriented growth, with a much higher growth rate in c-direction as compared to other crystal directions. This often leads to columnar structures, even at relatively low temperatures. However, it is, in general, not straight forward to fabricate smooth ZnO thin films with flat surfaces. Another advantage of a potential ZnO technology is said to be the possibility to grow thin films homoepitaxially on ZnO substrates. ZnO substrates are mostly fabricated by vapor phase transport (VPT) or hydrothermal growth. These techniques are enabling high volume manufacturing at reasonable cost, at least in principle. The availability of homoepitaxial substrates should be beneficial to the development of ZnO technology and devices and is in contrast to the situation of GaN. However, even though a number of companies are developing ZnO substrates, only recently good quality substrates have been demonstrated. However, these substrates are not yet widely available. Still, the situation concerning ZnO substrates seems to be far from low-cost, high-volume production. The fabrication of dense, single crystal thin films is, in general, surprisingly difficult, even when ZnO is grown on a ZnO substrate. However

  8. A Functional and Structural Mongolian Scots Pine (Pinus sylvestris var. mongolica) Model Integrating Architecture, Biomass and Effects of Precipitation

    PubMed Central

    Wang, Feng; Letort, Véronique; Lu, Qi; Bai, Xuefeng; Guo, Yan; de Reffye, Philippe; Li, Baoguo

    2012-01-01

    Mongolian Scots pine (Pinus sylvestris var. mongolica) is one of the principal tree species in the network of Three-North Shelterbelt for windbreak and sand stabilisation in China. The functions of shelterbelts are highly correlated with the architecture and eco-physiological processes of individual tree. Thus, model-assisted analysis of canopy architecture and function dynamic in Mongolian Scots pine is of value for better understanding its role and behaviour within shelterbelt ecosystems in these arid and semiarid regions. We present here a single-tree functional and structural model, derived from the GreenLab model, which is adapted for young Mongolian Scots pines by incorporation of plant biomass production, allocation, allometric rules and soil water dynamics. The model is calibrated and validated based on experimental measurements taken on Mongolian Scots pines in 2007 and 2006 under local meteorological conditions. Measurements include plant biomass, topology and geometry, as well as soil attributes and standard meteorological data. After calibration, the model allows reconstruction of three-dimensional (3D) canopy architecture and biomass dynamics for trees from one- to six-year-old at the same site using meteorological data for the six years from 2001 to 2006. Sensitivity analysis indicates that rainfall variation has more influence on biomass increment than on architecture, and the internode and needle compartments and the aboveground biomass respond linearly to increases in precipitation. Sensitivity analysis also shows that the balance between internode and needle growth varies only slightly within the range of precipitations considered here. The model is expected to be used to investigate the growth of Mongolian Scots pines in other regions with different soils and climates. PMID:22927982

  9. A functional and structural Mongolian Scots pine (Pinus sylvestris var. mongolica) model integrating architecture, biomass and effects of precipitation.

    PubMed

    Wang, Feng; Letort, Véronique; Lu, Qi; Bai, Xuefeng; Guo, Yan; de Reffye, Philippe; Li, Baoguo

    2012-01-01

    Mongolian Scots pine (Pinus sylvestris var. mongolica) is one of the principal tree species in the network of Three-North Shelterbelt for windbreak and sand stabilisation in China. The functions of shelterbelts are highly correlated with the architecture and eco-physiological processes of individual tree. Thus, model-assisted analysis of canopy architecture and function dynamic in Mongolian Scots pine is of value for better understanding its role and behaviour within shelterbelt ecosystems in these arid and semiarid regions. We present here a single-tree functional and structural model, derived from the GreenLab model, which is adapted for young Mongolian Scots pines by incorporation of plant biomass production, allocation, allometric rules and soil water dynamics. The model is calibrated and validated based on experimental measurements taken on Mongolian Scots pines in 2007 and 2006 under local meteorological conditions. Measurements include plant biomass, topology and geometry, as well as soil attributes and standard meteorological data. After calibration, the model allows reconstruction of three-dimensional (3D) canopy architecture and biomass dynamics for trees from one- to six-year-old at the same site using meteorological data for the six years from 2001 to 2006. Sensitivity analysis indicates that rainfall variation has more influence on biomass increment than on architecture, and the internode and needle compartments and the aboveground biomass respond linearly to increases in precipitation. Sensitivity analysis also shows that the balance between internode and needle growth varies only slightly within the range of precipitations considered here. The model is expected to be used to investigate the growth of Mongolian Scots pines in other regions with different soils and climates. PMID:22927982

  10. A sustainable woody biomass biorefinery.

    PubMed

    Liu, Shijie; Lu, Houfang; Hu, Ruofei; Shupe, Alan; Lin, Lu; Liang, Bin

    2012-01-01

    Woody biomass is renewable only if sustainable production is imposed. An optimum and sustainable biomass stand production rate is found to be one with the incremental growth rate at harvest equal to the average overall growth rate. Utilization of woody biomass leads to a sustainable economy. Woody biomass is comprised of at least four components: extractives, hemicellulose, lignin and cellulose. While extractives and hemicellulose are least resistant to chemical and thermal degradation, cellulose is most resistant to chemical, thermal, and biological attack. The difference or heterogeneity in reactivity leads to the recalcitrance of woody biomass at conversion. A selection of processes is presented together as a biorefinery based on incremental sequential deconstruction, fractionation/conversion of woody biomass to achieve efficient separation of major components. A preference is given to a biorefinery absent of pretreatment and detoxification process that produce waste byproducts. While numerous biorefinery approaches are known, a focused review on the integrated studies of water-based biorefinery processes is presented. Hot-water extraction is the first process step to extract value from woody biomass while improving the quality of the remaining solid material. This first step removes extractives and hemicellulose fractions from woody biomass. While extractives and hemicellulose are largely removed in the extraction liquor, cellulose and lignin largely remain in the residual woody structure. Xylo-oligomers, aromatics and acetic acid in the hardwood extract are the major components having the greatest potential value for development. Higher temperature and longer residence time lead to higher mass removal. While high temperature (>200°C) can lead to nearly total dissolution, the amount of sugars present in the extraction liquor decreases rapidly with temperature. Dilute acid hydrolysis of concentrated wood extracts renders the wood extract with monomeric sugars

  11. Task allocation among multiple intelligent robots

    NASA Technical Reports Server (NTRS)

    Gasser, L.; Bekey, G.

    1987-01-01

    Researchers describe the design of a decentralized mechanism for allocating assembly tasks in a multiple robot assembly workstation. Currently, the approach focuses on distributed allocation to explore its feasibility and its potential for adaptability to changing circumstances, rather than for optimizing throughput. Individual greedy robots make their own local allocation decisions using both dynamic allocation policies which propagate through a network of allocation goals, and local static and dynamic constraints describing which robots are elibible for which assembly tasks. Global coherence is achieved by proper weighting of allocation pressures propagating through the assembly plan. Deadlock avoidance and synchronization is achieved using periodic reassessments of local allocation decisions, ageing of allocation goals, and short-term allocation locks on goals.

  12. Different biomechanical design and ecophysiological strategies in juveniles of two liana species with contrasting growth habit.

    PubMed

    Chen, Ya-Jun; Bongers, Frans; Zhang, Jiao-Lin; Liu, Jin-Yu; Cao, Kun-Fang

    2014-06-01

    • Premise of the study: Lianas constitute a major functional type in tropical zones. While some liana species start climbing immediately after germination (shade-avoidance), others have a long self-supporting phase (shade-tolerance). The morphophysiological characteristics of these two growth habits are unknown.• Methods: We quantified growth traits, biomass allocation, mechanics, anatomy, and hydraulics for saplings of Ventilago calyculata (an immediate obligate climber) and Ziziphus attopensis (having a long self-supporting phase), both in the family Rhamnaceae. The mechanics, anatomy, and hydraulics for the mature individuals of the two species were also evaluated.• Key results: In the juvenile stage, V. calyculata had a higher slenderness ratio, height growth rate, and photosynthetic rate but similar biomass growth rate compared with Z. attopensis. In contrast, Z. attopensis had a higher leaf area growth rate, specific leaf area, and leaf mass fraction. Ziziphus attopensis had stiffer, but less conductive stems than V. calyculata. Stem rigidity of saplings decreased from base to apex in Z. attopensis, but increased in V. calyculata. Both species had similar resistance to xylem embolism. However, the leaves of V. calyculata were able to resist greater water deficits. At the mature stage, wider and longer vessels emerged in the xylem, and both species increased stem specific conductivity and drought resistance in stems and leaves. Ventilago calyculata had significantly higher specific conductivity and was more drought tolerant than Z. attopensis.• Conclusions: The two lianas differed significantly in growth, biomass allocation, anatomy, mechanics, ecophysiology, and hydraulic properties in line with their growth habits and shade adaptation strategies. PMID:24907257

  13. Allometric scaling relationship between above- and below-ground biomass within and across five woody seedlings

    PubMed Central

    Cheng, Dongliang; Ma, Yuzhu; Zhong, Quanling; Xu, Weifeng

    2014-01-01

    Allometric biomass allocation theory predicts that leaf biomass (ML) scaled isometrically with stem (MS) and root (MR) biomass, and thus above-ground biomass (leaf and stem) (MA) and root (MR) scaled nearly isometrically with below-ground biomass (root) for tree seedlings across a wide diversity of taxa. Furthermore, prior studies also imply that scaling constant should vary with species. However, litter is known about whether such invariant isometric scaling exponents hold for intraspecific biomass allocation, and how variation in scaling constants influences the interspecific scaling relationship between above- and below-ground biomass. Biomass data of seedlings from five evergreen species were examined to test scaling relationships among biomass components across and within species. Model Type II regression was used to compare the numerical values of scaling exponents and constants among leaf, stem, root, and above- to below-ground biomass. The results indicated that ML and MS scaled in an isometric or a nearly isometric manner with MR, as well as MA to MR for five woody species. Significant variation was observed in the Y-intercepts of the biomass scaling curves, resulting in the divergence for intraspecific scaling and interspecific scaling relationships for ML versus MS and ML versus MR, but not for MS versus MR and MA versus MR. We conclude, therefore, that a nearly isometric scaling relationship of MA versus MR holds true within each of the studied woody species and across them irrespective the negative scaling relationship between leaf and stem. PMID:25505524

  14. Automated UV-C mutagenesis of Kluyveromyces marxianus NRRL Y-1109 and selection for microaerophilic growth and ethanol production at elevated temperature on biomass sugars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The yeast Kluyveromyces marxianus is a potential microbial catalyst for producing ethanol from lignocellulosic substrates at elevated temperatures. To improve its growth and ethanol yield under anaerobic conditions, K. marxianus NRRL Y-1109 was irradiated with UV-C, and surviving cells were grown a...

  15. SHOOT BIOMASS AND ZINC/CADMIUM UPTAKE FOR HYPERACCUMULATOR AND NON-ACCUMULATOR THLASPI SPECIES IN RESPONSE TO GROWTH ON A ZINC-DEFICIENT CALCAREOUS SOIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, the Zn/Cd hyperaccumulator, Thlaspi caerulescens and a related non-accumulator, Thlaspi arvense, were used to study shoot growth (dry matter production) and Zn and Cd uptake from a severely Zn-deficient calcareous soil supplemented with increasing amounts of Zn and Cd. Shoot dry matte...

  16. Quantitative prediction of genome-wide resource allocation in bacteria.

    PubMed

    Goelzer, Anne; Muntel, Jan; Chubukov, Victor; Jules, Matthieu; Prestel, Eric; Nölker, Rolf; Mariadassou, Mahendra; Aymerich, Stéphane; Hecker, Michael; Noirot, Philippe; Becher, Dörte; Fromion, Vincent

    2015-11-01

    Predicting resource allocation between cell processes is the primary step towards decoding the evolutionary constraints governing bacterial growth under various conditions. Quantitative prediction at genome-scale remains a computational challenge as current methods are limited by the tractability of the problem or by simplifying hypotheses. Here, we show that the constraint-based modeling method Resource Balance Analysis (RBA), calibrated using genome-wide absolute protein quantification data, accurately predicts resource allocation in the model bacterium Bacillus subtilis for a wide range of growth conditions. The regulation of most cellular processes is consistent with the objective of growth rate maximization except for a few suboptimal processes which likely integrate more complex objectives such as coping with stressful conditions and survival. As a proof of principle by using simulations, we illustrated how calibrated RBA could aid rational design of strains for maximizing protein production, offering new opportunities to investigate design principles in prokaryotes and to exploit them for biotechnological applications. PMID:26498510

  17. Increased growth and root Cu accumulation of Sorghum sudanense by endophytic Enterobacter sp. K3-2: Implications for Sorghum sudanense biomass production and phytostabilization.

    PubMed

    Li, Ya; Wang, Qi; Wang, Lu; He, Lin-Yan; Sheng, Xia-Fang

    2016-02-01

    Endophytic bacterial strain K3-2 was isolated from the roots of Sorghum sudanense (an bioenergy plant) grown in a Cu mine wasteland soils and characterized. Strain K3-2 was identified as Enterobacter sp. based on 16S rRNA gene sequence analysis. Strain K3-2 exhibited Cu resistance and produced 1-aminocyclopropane-1-carboxylate (ACC) deaminase, indole-3-acetic acid (IAA), siderophores, and arginine decarboxylase. Pot experiments showed that strain K3-2 significantly increased the dry weight and root Cu accumulation of Sorghum sudanense grown in the Cu mine wasteland soils. Furthermore, increase in total Cu uptake (ranging from 49% to 95%) of the bacterial inoculated-Sorghum sudanense was observed compared to the control. Notably, most of Cu (83-86%) was accumulated in the roots of Sorghum sudanense. Furthermore, inoculation with strain K3-2 was found to significantly increase Cu bioconcentration factors and the proportions of IAA- and siderophore-producing bacteria in the root interiors and rhizosphere soils of Sorghum sudanense compared with the control. Significant decrease in the available Cu content was also observed in the rhizosphere soils of the bacterial-inoculated Sorghum sudanense. The results suggest that the endophytic bacterial strain K3-2 may be exploited for promoting Sorghum sudanense biomass production and Cu phytostabilization in the Cu mining wasteland soils. PMID:26517728

  18. Belowground carbon allocation in a temperate beech forest: new insight into carbon residence time using whole tree 13C labelling

    NASA Astrophysics Data System (ADS)

    Epron, D.; Ngao, J.; Plain, C.; Longdoz, B.; Granier, A.

    2011-12-01

    Belowground carbon allocation is an important component of forest carbon budget, affecting tree growth (competition between aboveground and belowground carbon sinks), acquisition of belowground resources (nutrients and water) that are often limiting forest ecosystems and soil carbon sequestration. Total belowground carbon flow can be estimated using a mass-balance approach as cumulative soil CO2 efflux minus the carbon input from aboveground litter plus the changes in the C stored in roots, in the forest floor, and in the soil, and further compared to gross annual production. While this approach is useful for understanding the whole ecosystem carbon budget, uncertainties remain about the contribution of the different belowground pools of carbon to ecosystem respiration and carbon sequestration. New insights into transfer rate and residence time of carbon in belowground compartments can be gained from in situ whole-crown 13C labelling experiments. We combined both approaches in a young temperate beech forest in north-eastern France where ecosystem carbon fluxes are recorded since a decade. Carbon allocated belowground represented less than 40% of gross primary production in this young beech forest. Autotrophic respiration assessed by comparing soil CO2 efflux measured on normal and on root exclusion plots, accounted for 60% of the total belowground carbon flow. This indicated a rather short mean residence time of carbon allocated belowground in the soil compartments. The recovery of 13C in soil CO2 efflux after pulse-labelling entire crowns of tree with 13CO2 at several occasions during the growing season was observed a few couple of hours after the labelling. That indicates a rapid transfer of 13C belowground with a maximum occurring within 2 to 4 days after labelling. Label was recovered at the same time in the respiration and in the biomass of both fine roots and soil microbes. Allocation of recently assimilated carbon to soil microbial respiration was greater in

  19. Resource Allocation: A Participatory Process.

    ERIC Educational Resources Information Center

    Reid, Alban E.

    Whether a participatory process for resource allocation in a public community college setting occurs depends upon several key factors: (1) the leadership style of the institutional chief executive officer; (2) the administrative organizational structure of the institution; (3) the relationship which exists between and among members of the various…

  20. Report on Tribal Priority Allocations.

    ERIC Educational Resources Information Center

    Bureau of Indian Affairs (Dept. of Interior), Washington, DC.

    As part of Bureau of Indian Affairs (BIA) funding, Tribal Priority Allocations (TPA) are the principal source of funds for tribal governments and agency offices at the reservation level. According to their unique needs and circumstances, tribes may prioritize funding among eight general categories: government, human services, education, public…

  1. Regulating nutrient allocation in plants

    DOEpatents

    Udvardi, Michael; Yang, Jiading; Worley, Eric

    2014-12-09

    The invention provides coding and promoter sequences for a VS-1 and AP-2 gene, which affects the developmental process of senescence in plants. Vectors, transgenic plants, seeds, and host cells comprising heterologous VS-1 and AP-2 genes are also provided. Additionally provided are methods of altering nutrient allocation and composition in a plant using the VS-1 and AP-2 genes.

  2. Administrators' Decisions about Resource Allocation

    ERIC Educational Resources Information Center

    Knight, William E.; Folkins, John W.; Hakel, Milton D.; Kennell, Richard P.

    2011-01-01

    Do academic administrators make decisions about resource allocation differently depending on the discipline receiving the funding? Does an administrator's academic identity influence these decisions? This study explored those questions with a sample of 1,690 academic administrators at doctoral-research universities. Participants used fictional…

  3. Influence of natural ultraviolet radiation on lotic periphytic diatom community growth, biomass accrual, and species composition: Short-term versus long-term effects

    SciTech Connect

    Bothwell, M.L.; Sherbot, D. ); Roberge, A.C. ); Daley, R.J. )

    1993-02-01

    Growth rates, accumulation dynamics, and species succession of periphytic diatom communities were examined in the presence and absence of natural ultraviolet (UV) radiation using outdoor, continuous-flow experimental flumes located on the South Thompson River, British Columbia. In a short-term experiment (2-3 wk), log-phase growth rates of naturally seeded diatom communities comprised of Tabellaria fenestrata (Lyngb.) Kuetz., T. flocculosa (Rtoh) Kuetz., Fragilaria crotonesis Kitton, and F. vaucheriae (Ehr.) Peter. exposed to 90% ambient photosynthetically active radiation (PAR) + UV were 30-40% lower than growth rates under 90% PAR alone. UV inhibition of growth rates was independent of the degree of P limitation within the range of relative specific growth rates ([mu]:[mu]max[minus]P) of 0.5-1.0. In a long-term trial, inhibition of attached diatom accumulation under 90% PAR + UV during the first 2-3 wk was corroborated. Reduction of full sunlight to 50% PAR + UV prevented the initial inhibition phase. The initial inhibitory effect of 90% PAR + UV on algal accumulation was reversed after 3-4 wk, and by 5 wk total diatom abundance (chlorophyll a, cell numbers and cell biovolumes) in communities exposed to PAR + UV were 2-4-fold greater than in communities protected from UV. Under 90% PAR + UN and 50% PAR + UV, a succession to stalked diatom general (Cymbella and Gomphoneis) occurred. Species succession under UV radiation doubled the mean cell size of the diatom communities. The shift from inhibition to a long-term increase in the autotrophic community under PAR + UV compared ot PAR alone provides further evidence against the use of short-term incubation experiments to define the long-term implications of increases in UVS. These results suggest that the ecological effects of present-day levels of UBS and UBS:UVA ratios on autotrophic communities are not well understood and might be mediated through complex trophic level interactions. 69 refs., 10 figs., 3 tabs.

  4. Optimality Versus Resilience In Patterns Of Carbon Allocation Within Plants Under Climate Change

    NASA Astrophysics Data System (ADS)

    Srinivasan, V.; Kumar, P.; Sivapalan, M.

    2010-12-01

    Predicting the allocation of assimilated carbon among different parts within a plant under current and future climates is a challenging task that is of significant interest. Several empirical and mechanistic models have been developed over the years to solve for the carbon allocation within a plant and these have demonstrated limited success. This challenge is further exacerbated when we need to consider the issue of plant acclimation due to climate change. Optimality based carbon allocation models have the ability to provide a general framework and have been proposed to be a strong alternative to empirical and mechanistic models. While several optimality functions have been proposed, more recently the idea of optimizing end of life cycle reproductive biomass has been demonstrated to have significant success (Iwasa 2000). This optimality function unlike others is more fundamental as it is directly based on the concept of evolutionary fitness of each individual. We apply an optimality based carbon allocation model to the soybean ecosystem and other ecosystems and analyze the predictions. Our analysis demonstrates that plants have the capability to achieve a given end state using different allocation strategies during a growing season. More importantly, the soybean ecosystem exhibits significant suboptimal behavior, where the end of life cycle reproductive biomass realized through field measurements, is lower than the model predicted optimum. From these one can infer that in reality, plants allocate a relatively larger fraction of its carbon to leaf and root biomass and a relatively smaller fraction to reproductive biomass when compared to the model predicted optimal allocation pathway. This trend is also obtained while simulating acclimation behavior under elevated CO2 conditions simulating future climate scenarios. We hypothesize that plants in nature exhibit a significant degree of resilience that prevents them from following an optimal pathway resulting in a

  5. Biomass resources for energy in Ohio: The OH-MARKAL modeling framework

    NASA Astrophysics Data System (ADS)

    Shakya, Bibhakar

    The latest reports from the Intergovernmental Panel on Climate Change have indicated that human activities are directly responsible for a significant portion of global warming trends. In response to the growing concerns regarding climate change and efforts to create a sustainable energy future, biomass energy has come to the forefront as a clean and sustainable energy resource. Biomass energy resources are environmentally clean and carbon neutral with net-zero carbon dioxide (CO2) emissions, since CO2 is absorbed or sequestered from the atmosphere during the plant growth. Hence, biomass energy mitigates greenhouse gases (GHG) emissions that would otherwise be added to the environment by conventional fossil fuels, such as coal. The use of biomass resources for energy is even more relevant in Ohio, as the power industry is heavily based on coal, providing about 90 percent of the state's total electricity while only 50 percent of electricity comes from coal at the national level. The burning of coal for electricity generation results in substantial GHG emissions and environmental pollution, which are responsible for global warming and acid rain. Ohio is currently one of the top emitters of GHG in the nation. This dissertation research examines the potential use of biomass resources by analyzing key economic, environmental, and policy issues related to the energy needs of Ohio over a long term future (2001-2030). Specifically, the study develops a dynamic linear programming model (OH-MARKAL) to evaluate biomass cofiring as an option in select coal power plants (both existing and new) to generate commercial electricity in Ohio. The OH-MARKAL model is based on the MARKAL (MARKet ALlocation) framework. Using extensive data on the power industry and biomass resources of Ohio, the study has developed the first comprehensive power sector model for Ohio. Hence, the model can serve as an effective tool for Ohio's energy planning, since it evaluates economic and environmental

  6. Root-to-shoot signalling when soil moisture is heterogeneous: increasing the proportion of root biomass in drying soil inhibits leaf growth and increases leaf abscisic acid concentration.

    PubMed

    Martin-Vertedor, Ana Isabel; Dodd, Ian C

    2011-07-01

    To determine whether root-to-shoot signalling of soil moisture heterogeneity depended on root distribution, wild-type (WT) and abscisic acid (ABA)-deficient (Az34) barley (Hordeum vulgare) plants were grown in split pots into which different numbers of seminal roots were inserted. After establishment, all plants received the same irrigation volumes, with one pot watered (w) and the other allowed to dry the soil (d), imposing three treatments (1 d: 3 w, 2 d: 2 w, 3 d: 1 w) that differed in the number of seminal roots exposed to drying soil. Root distribution did not affect leaf water relations and had no sustained effect on plant evapotranspiration (ET). In both genotypes, leaf elongation was less and leaf ABA concentrations were higher in plants with more roots in drying soil, with leaf ABA concentrations and water potentials 30% and 0.2 MPa higher, respectively, in WT plants. Whole-pot soil drying increased xylem ABA concentrations, but maximum values obtained when leaf growth had virtually ceased (100 nm in Az34, 330 nm in WT) had minimal effects (<40% leaf growth inhibition) when xylem supplied to detached shoots. Although ABA may not regulate leaf growth in vivo, genetic variation in foliar ABA concentration in the field may indicate different root distributions between upper (drier) and lower (wetter) soil layers. PMID:21410712

  7. Biomass for Electricity Generation

    EIA Publications

    2002-01-01

    This paper examines issues affecting the uses of biomass for electricity generation. The methodology used in the National Energy Modeling System to account for various types of biomass is discussed, and the underlying assumptions are explained.

  8. Energy from Biomass.

    ERIC Educational Resources Information Center

    Carioca, J. O. B.; And Others

    1987-01-01

    Discusses how biomass in the form of fuelwood, crop residues, and animal dung can be converted into fuels such as biogas and ethanol to replace or supplement fossil fuels. Argues for future decentralized, integrated biomass energy development. (TW)

  9. The effect of steepness of temporal resource gradients on spatial root allocation

    PubMed Central

    Novoplansky, Ariel; Ovadia, Ofer

    2011-01-01

    Plants are able to discriminately allocate greater biomass to organs that grow under higher resource levels. Recent evidence demonstrates that split-root plants also discriminately allocate more resources to roots that grow under dynamically improving nutrient levels, even when their other roots grow in richer patches. Here, we further tested whether, besides their responsiveness to the direction of resource gradients, plants are also sensitive to the steepness of environmental trajectories. Split-root Pisum sativum plants were grown so that one of their roots developed under constantly-high nutrient levels and the other root was subjected to dynamically improving nutrient levels of variable steepness. As expected, plants usually allocated a greater proportion of their biomass to roots that developed under constantly high resource availability; however, when given a choice, they allocated greater biomass to roots that initially experienced relatively low but steeply improving nutrient availabilities than to roots that developed under continuously-high nutrient availability. Such discrimination was not observed when the roots in the poor patch experienced only gentler improvements in nutrient availability. The results are compatible with the notion that responsiveness to the direction and steepness of environmental gradients could assist annual plants to increase their performance by anticipating resource availabilities foreseeable before the end of the growing season. The results exemplify the ability of plants to integrate and utilize environmental information and execute adaptive behaviors which, until recently, were attributed only to animals with central nervous systems. PMID:22019637

  10. Optimizing rice plant photosynthate allocation reduces N2O emissions from paddy fields.

    PubMed

    Jiang, Yu; Huang, Xiaomin; Zhang, Xin; Zhang, Xingyue; Zhang, Yi; Zheng, Chengyan; Deng, Aixing; Zhang, Jun; Wu, Lianhai; Hu, Shuijin; Zhang, Weijian

    2016-01-01

    Rice paddies are a major source of anthropogenic nitrous oxide (N2O) emissions, especially under alternate wetting-drying irrigation and high N input. Increasing photosynthate allocation to the grain in rice (Oryza sativa L.) has been identified as an effective strategy of genetic and agronomic innovation for yield enhancement; however, its impacts on N2O emissions are still unknown. We conducted three independent but complementary experiments (variety, mutant study, and spikelet clipping) to examine the impacts of rice plant photosynthate allocation on paddy N2O emissions. The three experiments showed that N2O fluxes were significantly and negatively correlated with the ratio of grain yield to total aboveground biomass, known as the harvest index (HI) in agronomy (P < 0.01). Biomass accumulation and N uptake after anthesis were significantly and positively correlated with HI (P < 0.05). Reducing photosynthate allocation to the grain by spikelet clipping significantly increased white root biomass and soil dissolved organic C and reduced plant N uptake, resulting in high soil denitrification potential (P < 0.05). Our findings demonstrate that optimizing photosynthate allocation to the grain can reduce paddy N2O emissions through decreasing belowground C input and increasing plant N uptake, suggesting the potential for genetic and agronomic efforts to produce more rice with less N2O emissions. PMID:27378420

  11. Optimizing rice plant photosynthate allocation reduces N2O emissions from paddy fields

    PubMed Central

    Jiang, Yu; Huang, Xiaomin; Zhang, Xin; Zhang, Xingyue; Zhang, Yi; Zheng, Chengyan; Deng, Aixing; Zhang, Jun; Wu, Lianhai; Hu, Shuijin; Zhang, Weijian

    2016-01-01

    Rice paddies are a major source of anthropogenic nitrous oxide (N2O) emissions, especially under alternate wetting-drying irrigation and high N input. Increasing photosynthate allocation to the grain in rice (Oryza sativa L.) has been identified as an effective strategy of genetic and agronomic innovation for yield enhancement; however, its impacts on N2O emissions are still unknown. We conducted three independent but complementary experiments (variety, mutant study, and spikelet clipping) to examine the impacts of rice plant photosynthate allocation on paddy N2O emissions. The three experiments showed that N2O fluxes were significantly and negatively correlated with the ratio of grain yield to total aboveground biomass, known as the harvest index (HI) in agronomy (P < 0.01). Biomass accumulation and N uptake after anthesis were significantly and positively correlated with HI (P < 0.05). Reducing photosynthate allocation to the grain by spikelet clipping significantly increased white root biomass and soil dissolved organic C and reduced plant N uptake, resulting in high soil denitrification potential (P < 0.05). Our findings demonstrate that optimizing photosynthate allocation to the grain can reduce paddy N2O emissions through decreasing belowground C input and increasing plant N uptake, suggesting the potential for genetic and agronomic efforts to produce more rice with less N2O emissions. PMID:27378420

  12. Optimizing rice plant photosynthate allocation reduces N2O emissions from paddy fields

    NASA Astrophysics Data System (ADS)

    Jiang, Yu; Huang, Xiaomin; Zhang, Xin; Zhang, Xingyue; Zhang, Yi; Zheng, Chengyan; Deng, Aixing; Zhang, Jun; Wu, Lianhai; Hu, Shuijin; Zhang, Weijian

    2016-07-01

    Rice paddies are a major source of anthropogenic nitrous oxide (N2O) emissions, especially under alternate wetting-drying irrigation and high N input. Increasing photosynthate allocation to the grain in rice (Oryza sativa L.) has been identified as an effective strategy of genetic and agronomic innovation for yield enhancement; however, its impacts on N2O emissions are still unknown. We conducted three independent but complementary experiments (variety, mutant study, and spikelet clipping) to examine the impacts of rice plant photosynthate allocation on paddy N2O emissions. The three experiments showed that N2O fluxes were significantly and negatively correlated with the ratio of grain yield to total aboveground biomass, known as the harvest index (HI) in agronomy (P < 0.01). Biomass accumulation and N uptake after anthesis were significantly and positively correlated with HI (P < 0.05). Reducing photosynthate allocation to the grain by spikelet clipping significantly increased white root biomass and soil dissolved organic C and reduced plant N uptake, resulting in high soil denitrification potential (P < 0.05). Our findings demonstrate that optimizing photosynthate allocation to the grain can reduce paddy N2O emissions through decreasing belowground C input and increasing plant N uptake, suggesting the potential for genetic and agronomic efforts to produce more rice with less N2O emissions.

  13. Assessing soybean leaf area and leaf biomass by spectral measurements

    NASA Technical Reports Server (NTRS)

    Holben, B. N.; Tucker, C. J.; Fan, C. J.

    1979-01-01

    Red and photographic infrared spectral radiances were correlated with soybean total leaf area index, green leaf area index, chlorotic leaf area index, green leaf biomass, chlorotic leaf biomass, and total biomass. The most significant correlations were found to exist between the IR/red radiance ratio data and green leaf area index and/or green leaf biomass (r squared equals 0.85 and 0.86, respectively). These findings demonstrate that remote sensing data can supply information basic to soybean canopy growth, development, and status by nondestructive determination of the green leaf area or green leaf biomass.

  14. Ectomycorrhizal colonization and diversity in relation to tree biomass and nutrition in a plantation of transgenic poplars with modified lignin biosynthesis.

    PubMed

    Danielsen, Lara; Lohaus, Gertrud; Sirrenberg, Anke; Karlovsky, Petr; Bastien, Catherine; Pilate, Gilles; Polle, Andrea

    2013-01-01

    Wood from biomass plantations with fast growing tree species such as poplars can be used as an alternative feedstock for production of biofuels. To facilitate utilization of lignocellulose for saccharification, transgenic poplars with modified or reduced lignin contents may be useful. However, the potential impact of poplars modified in the lignification pathway on ectomycorrhizal (EM) fungi, which play important roles for plant nutrition, is not known. The goal of this study was to investigate EM colonization and community composition in relation to biomass and nutrient status in wildtype (WT, Populus tremula × Populus alba) and transgenic poplar lines with suppressed activities of cinnamyl alcohol dehydrogenase, caffeate/5-hydroxyferulate O-methyltransferase, and cinnamoyl-CoA reductase in a biomass plantation. In different one-year-old poplar lines EM colonization varied from 58% to 86%, but the EM community composition of WT and transgenic poplars were indistinguishable. After two years, the colonization rate of all lines was increased to about 100%, but separation of EM communities between distinct transgenic poplar genotypes was observed. The differentiation of the EM assemblages was similar to that found between different genotypes of commercial clones of Populus × euramericana. The transgenic poplars exhibited significant growth and nutrient element differences in wood, with generally higher nutrient accumulation in stems of genotypes with lower than in those with higher biomass. A general linear mixed model simulated biomass of one-year-old poplar stems with high accuracy (adjusted R(2) = 97%) by two factors: EM colonization and inverse wood N concentration. These results imply a link between N allocation and EM colonization, which may be crucial for wood production in the establishment phase of poplar biomass plantations. Our data further support that multiple poplar genotypes regardless whether generated by transgenic approaches or conventional

  15. Ectomycorrhizal Colonization and Diversity in Relation to Tree Biomass and Nutrition in a Plantation of Transgenic Poplars with Modified Lignin Biosynthesis

    PubMed Central

    Danielsen, Lara; Lohaus, Gertrud; Sirrenberg, Anke; Karlovsky, Petr; Bastien, Catherine; Pilate, Gilles; Polle, Andrea

    2013-01-01

    Wood from biomass plantations with fast growing tree species such as poplars can be used as an alternative feedstock for production of biofuels. To facilitate utilization of lignocellulose for saccharification, transgenic poplars with modified or reduced lignin contents may be useful. However, the potential impact of poplars modified in the lignification pathway on ectomycorrhizal (EM) fungi, which play important roles for plant nutrition, is not known. The goal of this study was to investigate EM colonization and community composition in relation to biomass and nutrient status in wildtype (WT, Populus tremula × Populus alba) and transgenic poplar lines with suppressed activities of cinnamyl alcohol dehydrogenase, caffeate/5-hydroxyferulate O-methyltransferase, and cinnamoyl-CoA reductase in a biomass plantation. In different one-year-old poplar lines EM colonization varied from 58% to 86%, but the EM community composition of WT and transgenic poplars were indistinguishable. After two years, the colonization rate of all lines was increased to about 100%, but separation of EM communities between distinct transgenic poplar genotypes was observed. The differentiation of the EM assemblages was similar to that found between different genotypes of commercial clones of Populus × euramericana. The transgenic poplars exhibited significant growth and nutrient element differences in wood, with generally higher nutrient accumulation in stems of genotypes with lower than in those with higher biomass. A general linear mixed model simulated biomass of one-year-old poplar stems with high accuracy (adjusted R2 = 97%) by two factors: EM colonization and inverse wood N concentration. These results imply a link between N allocation and EM colonization, which may be crucial for wood production in the establishment phase of poplar biomass plantations. Our data further support that multiple poplar genotypes regardless whether generated by transgenic approaches or conventional

  16. Pretreated densified biomass products

    SciTech Connect

    Dale, Bruce E; Ritchie, Bryan; Marshall, Derek

    2014-03-18

    A product comprising at least one densified biomass particulate of a given mass having no added binder and comprised of a plurality of lignin-coated plant biomass fibers is provided, wherein the at least one densified biomass particulate has an intrinsic density substantially equivalent to a binder-containing densified biomass particulate of the same given mass and h a substantially smooth, non-flakey outer surface. Methods for using and making the product are also described.

  17. [Spatial distribution pattern and allometric growth of three common species on moving sand dunes in Horqin Sandy Land, China].

    PubMed

    Jia, Mei-yu; Li, Xue-hua; Oh, Choong-hyeon; Park, Hong-chul; Miao, Chun-ping; Han, Xu

    2015-10-01

    Research on fine scale pattern and characteristics of allometric growth could contribute to better understanding plants' adaptation in moving sandy dunes. The abundance, height and biomass of 3 species Agriophilum aquarrosum, Corispermum candelabrum and Setaria viridis in twenty-eight 1 m x 1 m quadrats of Horqin Sandy Land were identified, mapped and described. The nearest neighbor method and O-ring O(r) function analysis were applied to analyze the spatial patterns. The results showed that the individual spatial pattern was mainly aggregated in 1 m x 1 m quadrat at community level but mainly random at population level. At 0-50 cm individual distance scale, both intraspecific and interspecific relationship were facilitation and aggregated distribution occurred at some scales and varied with increasing plant abundance in 1 m x 1 m quadrat. In 0-40 cm, the aggregated distribution of S. viridis and A. aquarrosum increased obviously; in 10-20 cm, both intraspecific and interspecific aggregation increased; in 10-30 cm, the occurrence possibility of positive correlations between S. viridis and A. aquarrosum, S. viridis and C. candelabrum all increased; in 40-50 cm, the possibility of positive correlations between A. squarrosum and S. viridis, A. squarrosum and C. candelabrum all increased. Research on the three species components indicated that the growth rate of above-ground was faster than that of underground. S. viridis had the highest ratio of under-ground biomass to above-ground biomass but its nutritional organs' biomass ratio was medium. C. candelabrum allocated more biomass to propagative organs and stem, but A. squarrosum allocated more biomass to nutritional organs. Based on the spatial distribution and allometric characteristics, the three common species in moving sand dunes preferred r strategy in their life history. PMID:26995902

  18. Allocation of recent photoassimilates in mature European beech and Norway spruce - seasonal variability and responses to experimentally increased tropospheric O3 concentration and long-term drought

    NASA Astrophysics Data System (ADS)

    Grams, Thorsten

    2016-04-01

    This contribution summarizes a series of C allocation studies in maturing European beech and Norway spruce trees at Kranzberg Forest, located in southern Germany. Study objects are 60 to 70 year old trees, readily accessible via scaffoldings and canopy crane. Allocation of recently fixed photoassimilates is assessed either by conventional branch-bag labelling with 99 atom% 13CO2 or whole-tree labeling using 13C-depleted CO2 (isoFACE system). While labeling in branch bags, employed for few hours only, focused on phloem functionality in particular under long-term drought, C labeling of whole tree canopies was employed for up to 20 days, studying allocation of recent photoassimilates from the canopy along branches and stems to roots and soils below ground. In all experiments, dynamics of C allocation were mostly pursued assessing carbon isotopic composition of CO2 efflux from woody tissues which typically reflected isotopic composition of phloem sugars. Effects of severe and long-term summer drought are assessed in an ongoing experiment with roughly 100 trees assigned to a total of 12 plots (kroof.wzw.tum.de). Precipitation throughfall was completely excluded since early spring, resulting in pre-dawn leaf water potentials of both beech and spruce up to -2.2 MPa. The hypothesis was tested that long-term drought affects allocation of recently fixed C to branches and phloem functionality. In the annual course under unstressed conditions, phloem transport speed from the canopy to the stem (breast height) was double in beech compared to spruce, with highest transport velocities in early summer (about 0.51 and 0.26 m/h) and lowest in spring (0.26 and 0.12 m/h for beech and spruce, respectively). After leaf flush in spring, growth respiration of beech trunks was largely supplied by C stores. Recent photoassimilates supplied beech stem growth in early summer and refilled C stores in late summer, whereas seasonality was less pronounced in spruce. The hypothesis that growth

  19. Where does the carbon go? A model–data intercomparison of vegetation carbon allocation and turnover processes at two temperate forest free-air CO2 enrichment sites

    PubMed Central

    De Kauwe, Martin G; Medlyn, Belinda E; Zaehle, Sönke; Walker, Anthony P; Dietze, Michael C; Wang, Ying-Ping; Luo, Yiqi; Jain, Atul K; El-Masri, Bassil; Hickler, Thomas; Wårlind, David; Weng, Ensheng; Parton, William J; Thornton, Peter E; Wang, Shusen; Prentice, I Colin; Asao, Shinichi; Smith, Benjamin; McCarthy, Heather R; Iversen, Colleen M; Hanson, Paul J; Warren, Jeffrey M; Oren, Ram; Norby, Richard J

    2014-01-01

    Elevated atmospheric CO2 concentration (eCO2) has the potential to increase vegetation carbon storage if increased net primary production causes increased long-lived biomass. Model predictions of eCO2 effects on vegetation carbon storage depend on how allocation and turnover processes are represented. We used data from two temperate forest free-air CO2 enrichment (FACE) experiments to evaluate representations of allocation and turnover in 11 ecosystem models. Observed eCO2 effects on allocation were dynamic. Allocation schemes based on functional relationships among biomass fractions that vary with resource availability were best able to capture the general features of the observations. Allocation schemes based on constant fractions or resource limitations performed less well, with some models having unintended outcomes. Few models represent turnover processes mechanistically and there was wide variation in predictions of tissue lifespan. Consequently, models did not perform well at predicting eCO2 effects on vegetation carbon storage. Our recommendations to reduce uncertainty include: use of allocation schemes constrained by biomass fractions; careful testing of allocation schemes; and synthesis of allocation and turnover data in terms of model parameters. Data from intensively studied ecosystem manipulation experiments are invaluable for constraining models and we recommend that such experiments should attempt to fully quantify carbon, water and nutrient budgets. PMID:24844873

  20. Where does the carbon go? A model-data intercomparison of vegetation carbon allocation and turnover processes at two temperate forest free-air CO2 enrichment sites.

    PubMed

    De Kauwe, Martin G; Medlyn, Belinda E; Zaehle, Sönke; Walker, Anthony P; Dietze, Michael C; Wang, Ying-Ping; Luo, Yiqi; Jain, Atul K; El-Masri, Bassil; Hickler, Thomas; Wårlind, David; Weng, Ensheng; Parton, William J; Thornton, Peter E; Wang, Shusen; Prentice, I Colin; Asao, Shinichi; Smith, Benjamin; McCarthy, Heather R; Iversen, Colleen M; Hanson, Paul J; Warren, Jeffrey M; Oren, Ram; Norby, Richard J

    2014-08-01

    Elevated atmospheric CO2 concentration (eCO2) has the potential to increase vegetation carbon storage if increased net primary production causes increased long-lived biomass. Model predictions of eCO2 effects on vegetation carbon storage depend on how allocation and turnover processes are represented. We used data from two temperate forest free-air CO2 enrichment (FACE) experiments to evaluate representations of allocation and turnover in 11 ecosystem models. Observed eCO2 effects on allocation were dynamic. Allocation schemes based on functional relationships among biomass fractions that vary with resource availability were best able to capture the general features of the observations. Allocation schemes based on constant fractions or resource limitations performed less well, with some models having unintended outcomes. Few models represent turnover processes mechanistically and there was wide variation in predictions of tissue lifespan. Consequently, models did not perform well at predicting eCO2 effects on vegetation carbon storage. Our recommendations to reduce uncertainty include: use of allocation schemes constrained by biomass fractions; careful testing of allocation schemes; and synthesis of allocation and turnover data in terms of model parameters. Data from intensively studied ecosystem manipulation experiments are invaluable for constraining models and we recommend that such experiments should attempt to fully quantify carbon, water and nutrient budgets. PMID:24844873

  1. BIOMASS DRYING TECHNOLOGIES

    EPA Science Inventory

    The report examines the technologies used for drying of biomass and the energy requirements of biomass dryers. Biomass drying processes, drying methods, and the conventional types of dryers are surveyed generally. Drying methods and dryer studies using superheated steam as the d...

  2. Small Modular Biomass Systems

    SciTech Connect

    2002-12-01

    This fact sheet provides information about modular biomass systems. Small modular biomass systems can help supply electricity to rural areas, businesses, and the billions of people who live without power worldwide. These systems use locally available biomass fuels such as wood, crop waste, animal manures, and landfill gas.

  3. Biomass Program Biopower Factsheet

    SciTech Connect

    2010-03-01

    Generating electricity and thermal energy from biomass has the potential to help meet national goals for renewable energy. The forest products industry has used biomass for power and heat for many decades, yet widespread use of biomass to supply electricity to the U.S. power grid and other applications is relatively recent.

  4. On System Engineering a Barter-Based Re-allocation of Space System Key Development Resources

    NASA Astrophysics Data System (ADS)

    Kosmann, William J.

    NASA has had a decades-long problem with cost growth during the development of space science missions. Numerous agency-sponsored studies have produced average mission level development cost growths ranging from 23 to 77%. A new study of 26 historical NASA science instrument set developments using expert judgment to re-allocate key development resources has an average cost growth of 73.77%. Twice in history, during the Cassini and EOS-Terra science instrument developments, a barter-based mechanism has been used to re-allocate key development resources. The mean instrument set development cost growth was -1.55%. Performing a bivariate inference on the means of these two distributions, there is statistical evidence to support the claim that using a barter-based mechanism to re-allocate key instrument development resources will result in a lower expected cost growth than using the expert judgment approach. Agent-based discrete event simulation is the natural way to model a trade environment. A NetLogo agent-based barter-based simulation of science instrument development was created. The agent-based model was validated against the Cassini historical example, as the starting and ending instrument development conditions are available. The resulting validated agent-based barter-based science instrument resource re-allocation simulation was used to perform 300 instrument development simulations, using barter to re-allocate development resources. The mean cost growth was -3.365%. A bivariate inference on the means was performed to determine that additional significant statistical evidence exists to support a claim that using barter-based resource re-allocation will result in lower expected cost growth, with respect to the historical expert judgment approach. Barter-based key development resource re-allocation should work on science spacecraft development as well as it has worked on science instrument development. A new study of 28 historical NASA science spacecraft

  5. Physiological and developmental effects of O3 on cottonwood growth in urban and rural sites.

    PubMed

    Gregg, Jillian W; Jones, Clive G; Dawson, Todd E

    2006-12-01

    Previously we found that cloned cottonwood saplings (Populus deltoides) grew twice as large in New York, New York, USA, compared to surrounding rural environments and that soils, temperature, CO2, nutrient deposition, and microclimatic variables could not account for the greater urban plant biomass. Correlations between final season biomass and cumulative O3 exposures, combined with twofold growth reductions in an open-top chamber experiment provided strong evidence that higher cumulative O3 exposures in rural sites reduced growth in the country. Here, we assess the field gas exchange, growth and development, and allocation responses underlying the observed growth differences and compare them with isolated O3 responses documented in the open-top chamber experiment. Cottonwoods showed no visible foliar injury, reduced photosynthesis of recently expanded foliage, early leaf senescence, protective reduction in stomatal conductance, or compensatory allocation to shoot relative to root biomass for either the chamber or field experiment. Instead, O3-impacted chamber plants had significantly higher conductance and reduced photosynthesis of older foliage that led to reduced leaf area production and a twofold biomass reduction in the absence of visible injury. Rural-grown field plants showed the same pattern of significantly higher conductance in the absence of concomitant increases in photosynthesis that was indicative of a loss of stomatal control. Incremental changes in foliar production were also significantly inversely related to fluctuations in ambient O3 exposures. The similarity in biomass, gas exchange, phenological, and allocation responses between chamber and field experiments indicate that mechanisms accounting for reduced growth at rural sites were consistent with those in the open-top chamber O3 experiment. This study shows the limitation of visible symptoms as a sole diagnostic factor for documenting detrimental O3 impacts and points toward a new approach to

  6. Complex Genetic Effects on Early Vegetative Development Shape Resource Allocation Differences Between Arabidopsis lyrata Populations

    PubMed Central

    Remington, David L.; Leinonen, Päivi H.; Leppälä, Johanna; Savolainen, Outi

    2013-01-01

    Costs of reproduction due to resource allocation trade-offs have long been recognized as key forces in life history evolution, but little is known about their functional or genetic basis. Arabidopsis lyrata, a perennial relative of the annual model plant A. thaliana with a wide climatic distribution, has populations that are strongly diverged in resource allocation. In this study, we evaluated the genetic and functional basis for variation in resource allocation in a reciprocal transplant experiment, using four A. lyrata populations and F2 progeny from a cross between North Carolina (NC) and Norway parents, which had the most divergent resource allocation patterns. Local alleles at quantitative trait loci (QTL) at a North Carolina field site increased reproductive output while reducing vegetative growth. These QTL had little overlap with flowering date QTL. Structural equation models incorporating QTL genotypes and traits indicated that resource allocation differences result primarily from QTL effects on early vegetative growth patterns, with cascading effects on later vegetative and reproductive development. At a Norway field site, North Carolina alleles at some of the same QTL regions reduced survival and reproductive output components, but these effects were not associated with resource allocation trade-offs in the Norway environment. Our results indicate that resource allocation in perennial plants may involve important adaptive mechanisms largely independent of flowering time. Moreover, the contributions of resource allocation QTL to local adaptation appear to result from their effects on developmental timing and its interaction with environmental constraints, and not from simple models of reproductive costs. PMID:23979581

  7. Carbon allocation belowground in Pinus pinaster using stable carbon isotope pulse labeling technique

    NASA Astrophysics Data System (ADS)

    Dannoura, M.; Bosc, A.; Chipeaux, C.; Sartore, M.; Lambrot, C.; Trichet, P.; Bakker, M.; Loustau, D.; Epron, D.

    2010-12-01

    Carbon allocation belowground competes with aboveground growth and biomass production. In the other hand, it contributes to resource acquisition such as nutrient, water and carbon sequestration in soil. Thus, a better characterization of carbon flow from plant to soil and its residence time within each compartment is an important issue for understanding and modeling forest ecosystem carbon budget. 13C pulse labeling of whole crown was conducted at 4 seasons to study the fate of assimilated carbon by photosynthesis into the root on 12 year old Pinus pinaster planted in the INRA domain of Pierroton. Maritime pine is the most widely planted species in South-West Europe. Stem, root and soil CO2 effluxes and their isotope composition were measured continuously by tunable diode laser absorption spectroscopy with a trace gas analyzer (TGA 100A; Campbell Scientific) coupled to flow-through chambers. 13CO2 recovery and peak were observed in respiration of each compartment after labeling. It appeared sequentially from top of stem to bottom, and to coarse root. The maximum velocity of carbon transfer was calculated as the difference in time lag of recovery between two positions on the trunk or on the root. It ranged between 0.08-0.2 m h-1 in stem and between 0.04-0.12 m h-1 in coarse root. This velocity was higher in warmer season, and the difference between time lag of recovery and peak increased after first frost. Photosynthates arrived underground 1.5 to 5 days after labeling, at similar time in soil CO2 effluxes and coarse root respiration. 0.08-1.4 g of carbon was respired per tree during first 20 days following labeling. It presented 0.6 -10% of 13C used for labeling and it is strongly related to seasons. The isotope signal was detected in fine root organs and microbial biomass by periodical core sampling. The peak was observed 6 days after labeling in early summer while it was delayed more than 10 days in autumn and winter with less amount of carbon allocated

  8. 23 CFR 660.107 - Allocations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Allocations. 660.107 Section 660.107 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS SPECIAL PROGRAMS (DIRECT FEDERAL) Forest Highways § 660.107 Allocations. On October 1 of each fiscal year, the FHWA will allocate 66 percent of Public Lands...

  9. 15 CFR 923.110 - Allocation formula.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Allocation formula. 923.110 Section... Grants § 923.110 Allocation formula. (a) As required by subsection 306(a), the Secretary may make grants...) Allocation formula factors and weighting. Each State eligible to receive a financial assistance award...

  10. 10 CFR 455.31 - Allocation formulas.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Allocation formulas. 455.31 Section 455.31 Energy... § 455.31 Allocation formulas. (a) Financial assistance for conducting technical assistance programs for... this section. (c) The allocation factor (K) shall be determined by the formula: EC14NO91.086 where,...

  11. 24 CFR 574.130 - Formula allocations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Formula allocations. 574.130... URBAN DEVELOPMENT COMMUNITY FACILITIES HOUSING OPPORTUNITIES FOR PERSONS WITH AIDS Formula Entitlements § 574.130 Formula allocations. (a) Data sources. HUD will allocate funds based on the number of cases...

  12. 45 CFR 1355.57 - Cost allocation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Cost allocation. 1355.57 Section 1355.57 Public... MAINTENANCE PAYMENTS, ADOPTION ASSISTANCE, AND CHILD AND FAMILY SERVICES GENERAL § 1355.57 Cost allocation. (a... maintenance payments or adoption assistance payments may be made under the State plan. (b) Cost allocation...

  13. 45 CFR 400.13 - Cost allocation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Cost allocation. 400.13 Section 400.13 Public... for Refugee Resettlement Award of Grants to States § 400.13 Cost allocation. (a) A State must allocate... management of the State's refugee program (e.g., development of the State plan, overall program...

  14. 45 CFR 400.13 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false Cost allocation. 400.13 Section 400.13 Public... for Refugee Resettlement Award of Grants to States § 400.13 Cost allocation. (a) A State must allocate... management of the State's refugee program (e.g., development of the State plan, overall program...

  15. 45 CFR 1355.57 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Cost allocation. 1355.57 Section 1355.57 Public... MAINTENANCE PAYMENTS, ADOPTION ASSISTANCE, AND CHILD AND FAMILY SERVICES GENERAL § 1355.57 Cost allocation. (a... maintenance payments or adoption assistance payments may be made under the State plan. (b) Cost allocation...

  16. 24 CFR 92.50 - Formula allocation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Formula allocation. 92.50 Section 92.50 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development HOME INVESTMENT PARTNERSHIPS PROGRAM Allocation Formula § 92.50 Formula allocation....

  17. 24 CFR 92.50 - Formula allocation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Formula allocation. 92.50 Section 92.50 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development HOME INVESTMENT PARTNERSHIPS PROGRAM Allocation Formula § 92.50 Formula allocation....

  18. 24 CFR 92.50 - Formula allocation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Formula allocation. 92.50 Section 92.50 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development HOME INVESTMENT PARTNERSHIPS PROGRAM Allocation Formula § 92.50 Formula allocation....

  19. 45 CFR 98.55 - Cost allocation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Cost allocation. 98.55 Section 98.55 Public... of Child Care and Development Funds § 98.55 Cost allocation. (a) The Lead Agency and subgrantees shall keep on file cost allocation plans or indirect cost agreements, as appropriate, that have...

  20. 45 CFR 98.55 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Cost allocation. 98.55 Section 98.55 Public... of Child Care and Development Funds § 98.55 Cost allocation. (a) The Lead Agency and subgrantees shall keep on file cost allocation plans or indirect cost agreements, as appropriate, that have...

  1. 45 CFR 1355.57 - Cost allocation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 4 2012-10-01 2012-10-01 false Cost allocation. 1355.57 Section 1355.57 Public... MAINTENANCE PAYMENTS, ADOPTION ASSISTANCE, AND CHILD AND FAMILY SERVICES GENERAL § 1355.57 Cost allocation. (a...) Cost allocation and distribution for the planning, design, development, installation and operation...

  2. 45 CFR 400.13 - Cost allocation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 2 2013-10-01 2012-10-01 true Cost allocation. 400.13 Section 400.13 Public... for Refugee Resettlement Award of Grants to States § 400.13 Cost allocation. (a) A State must allocate... management of the State's refugee program (e.g., development of the State plan, overall program...

  3. 45 CFR 400.13 - Cost allocation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 2 2012-10-01 2012-10-01 false Cost allocation. 400.13 Section 400.13 Public... for Refugee Resettlement Award of Grants to States § 400.13 Cost allocation. (a) A State must allocate... management of the State's refugee program (e.g., development of the State plan, overall program...

  4. Communication patterns and allocation strategies.

    SciTech Connect

    Leung, Vitus Joseph; Mache, Jens Wolfgang; Bunde, David P.

    2004-01-01

    Motivated by observations about job runtimes on the CPlant system, we use a trace-driven microsimulator to begin characterizing the performance of different classes of allocation algorithms on jobs with different communication patterns in space-shared parallel systems with mesh topology. We show that relative performance varies considerably with communication pattern. The Paging strategy using the Hilbert space-filling curve and the Best Fit heuristic performed best across several communication patterns.

  5. Minority Transportation Expenditure Allocation Model

    Energy Science and Technology Software Center (ESTSC)

    1993-04-12

    MITRAM (Minority TRansportation expenditure Allocation Model) can project various transportation related attributes of minority (Black and Hispanic) and majority (white) populations. The model projects vehicle ownership, vehicle miles of travel, workers, new car and on-road fleet fuel economy, amount and share of household income spent on gasoline, and household expenditures on public transportation and taxis. MITRAM predicts reactions to sustained fuel price changes for up to 10 years after the change.

  6. The effect of limited availability of N or water on C allocation to fine roots and annual fine root turnover in Alnus incana and Salix viminalis.

    PubMed

    Rytter, Rose-Marie

    2013-09-01

    The effect of limited nitrogen (N) or water availability on fine root growth and turnover was examined in two deciduous species, Alnus incana L. and Salix viminalis L., grown under three different regimes: (i) supply of N and water in amounts which would not hamper growth, (ii) limited N supply and (iii) limited water supply. Plants were grown outdoors during three seasons in covered and buried lysimeters placed in a stand structure and filled with quartz sand. Computer-controlled irrigation and fertilization were supplied through drip tubes. Production and turnover of fine roots were estimated by combining minirhizotron observations and core sampling, or by sequential core sampling. Annual turnover rates of fine roots <1 mm (5-6 year(-1)) and 1-2 mm (0.9-2.8 year(-1)) were not affected by changes in N or water availability. Fine root production (<1 mm) differed between Alnus and Salix, and between treatments in Salix; i.e., absolute length and biomass production increased in the order: water limited < unlimited < N limited. Few treatment effects were detected for fine roots 1-2 mm. Proportionally more C was allocated to fine roots (≤2 mm) in N or water-limited Salix; 2.7 and 2.3 times the allocation to fine roots in the unlimited regime, respectively. Estimated input to soil organic carbon increased by ca. 20% at N limitation in Salix. However, future studies on fine root decomposition under various environmental conditions are required. Fine root growth responses to N or water limitation were less pronounced in Alnus, thus indicating species differences caused by N-fixing capacity and slower initial growth in Alnus, or higher fine root plasticity in Salix. A similar seasonal growth pattern across species and treatments suggested the influence of outer stimuli, such as temperature and light. PMID:23963409

  7. Understanding Biomass Feedstock Variability

    SciTech Connect

    Kevin L. Kenney; Garold L. Gresham; William A. Smith; Tyler L. Westover

    2013-01-01

    If the singular goal of biomass logistics and the design of biomass feedstock supply systems is to reduce the per-ton supply cost of biomass, these systems may very well develop with ultimate unintended consequences of highly variable and reduced quality biomass feedstocks. This paper demonstrates that, due to inherent species variabilities, production conditions and differing harvest, collection and storage practices, this is a very real scenario that biomass producers and suppliers as well as conversion developers should be aware of. Biomass feedstock attributes of ash, carbohydrates, moisture and particle morphology will be discussed. We will also discuss specifications for these attributes, inherent variability of these attributes in biomass feedstocks, and approaches and solutions for reducing variability for improving feedstock quality.

  8. Understanding Biomass Feedstock Variability

    SciTech Connect

    Kevin L. Kenney; William A. Smith; Garold L. Gresham; Tyler L. Westover

    2013-01-01

    If the singular goal of biomass logistics and the design of biomass feedstock supply systems is to reduce the per ton supply cost of biomass, these systems may very well develop with ultimate unintended consequences of highly variable and reduced quality biomass feedstocks. This paper demonstrates that due to inherent species variabilities, production conditions, and differing harvest, collection, and storage practices, this is a very real scenario that biomass producers and suppliers as well as conversion developers should be aware of. Biomass feedstock attributes of ash, carbohydrates, moisture, and particle morphology will be discussed. We will also discuss specifications for these attributes, inherent variability of these attributes in biomass feedstocks, and approaches and solutions for reducing variability for improving feedstock quality.

  9. Slow growth rates of Amazonian trees: Consequences for carbon cycling

    PubMed Central

    Vieira, Simone; Trumbore, Susan; Camargo, Plinio B.; Selhorst, Diogo; Chambers, Jeffrey Q.; Higuchi, Niro; Martinelli, Luiz Antonio

    2005-01-01

    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 ≈1mm/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. PMID:16339903

  10. Allocating Variability and Reserve Requirements (Presentation)

    SciTech Connect

    Kirby, B.; King, J.; Milligan, M.

    2011-10-01

    This presentation describes how you could conceivably allocate variability and reserve requirements, including how to allocate aggregation benefits. Conclusions of this presentation are: (1) Aggregation provides benefits because individual requirements are not 100% correlated; (2) Method needed to allocate reduced requirement among participants; (3) Differences between allocation results are subtle - (a) Not immediately obvious which method is 'better'; (b) Many are numerically 'correct', they sum to the physical requirement; (c) Many are not 'fair', Results depend on sub-aggregation and/or the order individuals are included; and (4) Vector allocation method is simple and fair.

  11. 45 CFR 402.31 - Determination of allocations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ASSISTANCE GRANTS State Allocations § 402.31 Determination of allocations. (a) Allocation formula. Allocations will be computed according to a formula using the following factors and weights: (1) 50...

  12. 45 CFR 402.31 - Determination of allocations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... State Allocations § 402.31 Determination of allocations. (a) Allocation formula. Allocations will be computed according to a formula using the following factors and weights: (1) 50 percent based on the...

  13. Effects of road dust on the growth characteristics of Sophora japonica L. seedlings.

    PubMed

    Bao, Le; Qu, Laiye; Ma, Keming; Lin, Lin

    2016-08-01

    Road dust is one of the most common pollutants and causes a series of negative effects on plant physiology. Dust's impacts on plants can be regarded as a combination of load, composition and grain size impacts on plants; however, there is a lack of integrated dust effect studies involving these three aspects. In our study, Sophora japonica seedlings were artificially dusted with road dust collected from the road surface of Beijing so that we could study the impacts of this dust on nitrogen/carbon allocation, biomass allocation and photosynthetic pigments from the three aspects of composition, load and grain size. The results showed that the growth characteristics of S. japonica seedlings were mostly influenced by dust composition and load. Leaf N, root-shoot ratio and chlorophyll a/b were significantly affected by dust composition and load; leaf C/N, shoot biomass, total chlorophyll and carotenoid were significantly affected by dust load; stem N and stem C/N were significantly affected by dust composition; while the dust grain size alone did not affect any of the growth characteristics. Road dust did influence the growth characteristics more extensively than loam. Therefore, a higher dust load could increase the differences between road dust and loam treatments. The elements in dust are well correlated to the shoot N, shoot C/N, and root-shoot ratio of S. japonica seedlings. This knowledge could benefit the management of urban green spaces. PMID:27521946

  14. Tree species richness affecting fine root biomass in European forests

    NASA Astrophysics Data System (ADS)

    Finér, Leena; Domisch, Timo; Vesterdal, Lars; Dawud, Seid M.; Raulund-Rasmussen, Karsten

    2016-04-01

    Fine roots are an important factor in the forest carbon cycle, contributing significantly to below-ground biomass and soil carbon storage. Therefore it is essential to understand the role of the forest structure, indicated by tree species diversity in controlling below-ground biomass and managing the carbon pools of forest soils. We studied how tree species richness would affect fine root biomass and its distribution in the soil profile and biomass above- and below-ground allocation patterns of different tree species. Our main hypothesis was that increasing tree species richness would lead to below-ground niche differentiation and more efficient soil exploitation by the roots, resulting in a higher fine root biomass in the soil. We sampled fine roots of trees and understorey vegetation in six European forest types in Finland, Poland, Germany, Romania, Italy and Spain, representing boreal, temperate and Mediterranean forests, established within the FunDivEUROPE project for study