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Sample records for litter environment affects

  1. Litter Environment Affects Behavior and Brain Metabolic Activity of Adult Knockout Mice

    PubMed Central

    Crews, David; Rushworth, David; Gonzalez-Lima, Francisco; Ogawa, Sonoko

    2009-01-01

    In mammals, the formative environment for social and anxiety-related behaviors is the family unit; in the case of rodents, this is the litter and the mother-young bond. A deciding factor in this environment is the sex ratio of the litter and, in the case of mice lacking functional copies of gene(s), the ratio of the various genotypes in the litter. Both Sex and Genotype ratios of the litter affect the nature and quality of the individual's behavior later in adulthood, as well as metabolic activity in brain nuclei that underlie these behaviors. Mice were raised in litters reconstituted shortly after to birth to control for sex ratio and genotype ratio (wild type pups versus pups lacking a functional estrogen receptor α). In both males and females, the Sex and Genotype of siblings in the litter affected aggressive behaviors as well as patterns of metabolic activity in limbic nuclei in the social behavior network later in adulthood. Further, this pattern in males varied depending upon the Genotype of their brothers and sisters. Principal Components Analysis revealed two components comprised of several amygdalar and hypothalamic nuclei; the VMH showed strong correlations in both clusters, suggesting its pivotal nature in the organization of two neural networks. PMID:19707539

  2. Factors affecting arsenic and copper runoff from fields fertilized with poultry litter.

    PubMed

    DeLaune, P B; Moore, P A

    2014-07-01

    Arsenic (As) and copper (Cu) runoff from fields fertilized with poultry litter has received increasing attention in recent years, although it is not known if heavy metal runoff from poultry litter poses a significant threat to the environment. The objective of this study was to determine the main factors affecting As and Cu concentrations in runoff water from pastures receiving poultry litter applications. Rainfall simulation studies were conducted to determine the effects of the following treatments on metal runoff: (i) aluminum sulfate (alum) additions, (ii) diet modification using phytase or high available phosphorus corn, (iii) fertilizer type, (iv) poultry litter application rate, and (v) time until the first runoff event occurs after poultry litter application. Results showed that alum additions to poultry litter significantly decreased As and Cu concentrations in runoff water. Copper concentrations were highest in runoff from poultry litter from birds fed phytase diets compared with other diets; however, this effect may have been a result of wet storage conditions rather than diet. Triple superphosphate applications resulted in the lowest heavy metal concentrations in runoff water among all fertilizer treatments, while normal poultry litter resulted in the highest concentrations. Arsenic and Cu concentrations increased in runoff water as poultry litter application rates increased and decreased with increasing time until the first runoff event. These data indicate that adding alum to poultry litter, a cost-effective best management practice, which also results in lower P runoff and ammonia emissions, may also be an effective tool in reducing metal runoff. PMID:25603088

  3. [Litter decomposition and its main affecting factors in tidal marshes of Minjiang River Estuary, East China].

    PubMed

    Zhang, Lin-Hai; Zeng, Cong-Sheng; Zhang, Wen-Juan; Wang, Tian-E; Tong, Chuan

    2012-09-01

    By using litterbag method, this paper studied the decomposition of the leaf- and flower litters of two emergent macrophytes, native species Phragmites australis and invasive species Spartina alterniflora, and related affecting factors in the Minjiang River estuary of East China. In the decomposition process of the litters, the decay of standing litter (0-90 days) was an important period, and the loss rate of the flower- and leaf litters dry mass of P. australis and S. alterniflora was 15.0 +/- 3.5% and 13.3 +/- 1.1%, and 31.9 +/- 1.1% and 20.8 +/- 1.4%, respectively. During lodging decay period (91-210 days), the loss rate of the flower- and leaf litters dry mass of P. australis and S. alterniflora was 69.5 +/- 0.6% and 71.5 +/- 2.5%, and 76.8 +/- 1.9% and 67.5 +/- 2.1%, respectively. In standing decay period, the decomposition rate of the two plants litters was positively correlated with the litters C/N but negatively correlated to the litters N/P, and the litters P was an important factor limiting the litters decay. In lodging decay period, the effects of the litters C/N, C/P, and N/P decreased, while the environment factors (climate, soil moisture, soil acidity and salinity, and sediment properties) acted more important roles. The differences in the factors affecting the decay of the litters in different decomposition periods were mainly related to the micro-environment and tidal process for the two plant communities. PMID:23285995

  4. Increasing shrub abundance and N addition in Arctic tundra affect leaf and root litter decomposition differently

    NASA Astrophysics Data System (ADS)

    McLaren, J.; van de Weg, M. J.; Shaver, G. R.; Gough, L.

    2013-12-01

    Changes in global climate have resulted in a ';greening' of the Arctic as the abundance of deciduous shrub species increases. Consequently, not only the living plant community, but also the litter composition changes, which in turn can affect carbon turnover patterns in the Arctic. We examined effects of changing litter composition (both root and leaf litter) on decomposition rates with a litter bag study, and specifically focused on the impact of deciduous shrub Betula nana litter on litter decomposition from two evergreen shrubs (Ledum palustre, and Vaccinium vitis-idaea) and one graminoid (Eriophorum vaginatum) species. Additionally, we investigated how decomposition was affected by nutrient availability by placing the litterbags in an ambient and a fertilized moist acidic tundra environment. Measurements were carried out seasonally over 2 years (after snow melt, mid-growing season, end growing season). We measured litter mass loss over time, as well as the respiration rates (standardized for temperature and moisture) and temperature sensitivity of litter respiration at the time of harvesting the litter bags. For leaves, Betula litter decomposed faster than the other three species, with Eriophorum leaves decomposing the slowest. This pattern was observed for both mass loss and litter respiration rates, although the differences in respiration became smaller over time. Surprisingly, combining Betula with any other species resulted in slower overall weight loss rates than would be predicted based on monoculture weight loss rates. This contrasted with litter respiration at the time of sampling, which showed a positive mixing effect of adding Betula leaf liter to the other species. Apparently, during the first winter months (September - May) Betula litter decomposition is negatively affected by mixing the species and this legacy can still be observed in the total mass loss results later in the year. For root litter there were fewer effects of species identity on root

  5. Impacts of Poultry House Environment on Poultry Litter Bacterial Community Composition

    PubMed Central

    Dumas, Michael D.; Polson, Shawn W.; Ritter, Don; Ravel, Jacques; Gelb, Jack; Morgan, Robin; Wommack, K. Eric

    2011-01-01

    Viral and bacterial pathogens are a significant economic concern to the US broiler industry and the ecological epicenter for poultry pathogens is the mixture of bedding material, chicken excrement and feathers that comprises the litter of a poultry house. This study used high-throughput sequencing to assess the richness and diversity of poultry litter bacterial communities, and to look for connections between these communities and the environmental characteristics of a poultry house including its history of gangrenous dermatitis (GD). Cluster analysis of 16S rRNA gene sequences revealed differences in the distribution of bacterial phylotypes between Wet and Dry litter samples and between houses. Wet litter contained greater diversity with 90% of total bacterial abundance occurring within the top 214 OTU clusters. In contrast, only 50 clusters accounted for 90% of Dry litter bacterial abundance. The sixth largest OTU cluster across all samples classified as an Arcobacter sp., an emerging human pathogen, occurring in only the Wet litter samples of a house with a modern evaporative cooling system. Ironically, the primary pathogenic clostridial and staphylococcal species associated with GD were not found in any house; however, there were thirteen 16S rRNA gene phylotypes of mostly Gram-positive phyla that were unique to GD-affected houses and primarily occurred in Wet litter samples. Overall, the poultry house environment appeared to substantially impact the composition of litter bacterial communities and may play a key role in the emergence of food-borne pathogens. PMID:21949751

  6. The Effects of Litter on Littering Behavior in a Forest Environment

    ERIC Educational Resources Information Center

    Crump, S. Larry; And Others

    1977-01-01

    The effects of littered and nonlittered areas on littering behavior were determined in picnic areas in the Uinta National Forest, Utah. Littered and nonlittered conditions were controlled by spreading or removing litter from specified areas. Observations revealed that in the nonlittered areas there was more litter than in the littered areas. (CS)

  7. Alum affects ammonia-producing microorganisms in poultry litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scientists at the USDA-ARS in Bowling Green, KY and in Fayetteville, AR are working to uncover the microbiology of ammonia production in poultry litter. Poultry litter is a valuable nutrient source for plants and microorganisms that contains high levels of protein, nitrogen, and other minerals. Howe...

  8. Poultry litter and the environment: Physiochemical properties of litter and soil during successive flock rotations and after remote site deposition.

    PubMed

    Crippen, Tawni L; Sheffield, Cynthia L; Byrd, J Allen; Esquivel, Jesus F; Beier, Ross C; Yeater, Kathleen

    2016-05-15

    The U.S. broiler meat market has grown over the past 16 years and destinations for U.S. broiler meat exports expanded to over 150 countries. This market opportunity has spurred a corresponding increase in industrialized poultry production, which due to the confined space in which high numbers of animals are housed, risks accumulating nutrients and pollutants. The purpose of this research was to determine the level of pollutants within poultry litter and the underlying soil within a production facility; and to explore the impact of spent litter deposition into the environment. The study follows a production facility for the first 2.5 years of production. It monitors the effects of successive flocks and management practices on 15 physiochemical parameters: Ca, Cu, electrical conductivity, Fe, K, Mg, Mn, moisture, Na, NO3(-)/N, organic matter, P, pH, S, and Zn. Litter samples were collected in-house, after clean-outs and during stockpiling. The soil before house placement, after the clean-outs and following litter stockpiling was monitored. Management practices markedly altered the physiochemical profiles of the litter in-house. A canonical discriminant analysis was used to describe the relationship between the parameters and sampling times. The litter profiles grouped into five clusters corresponding to time and management practices. The soil in-house exhibited mean increases in all physiochemical parameters (2-297 fold) except Fe, Mg, %M, and pH. The spent litter was followed after deposition onto a field for use as fertilizer. After 20 weeks, the soil beneath the litter exhibited increases in EC, Cu, K, Na, NO3(-)/N, %OM, P, S and Zn; while %M decreased. Understanding the impacts of industrialized poultry farms on the environment is vital as the cumulative ecological impact of this land usage could be substantial if not properly managed to reduce the risk of potential pollutant infiltration into the environment. PMID:26990075

  9. How does litter cover, litter diversity and fauna affect sediment discharge and runoff?

    NASA Astrophysics Data System (ADS)

    Goebes, Philipp; Seitz, Steffen; Kühn, Peter; Scholten, Thomas

    2013-04-01

    Litter cover plays a major role in soil erosion processes. It is known that litter cover reduces erosivity of raindrops, decreases sediment discharge and lowers runoff volume compared to bare ground. However, in the context of biodiversity, the composition of litter cover, its effect on sediment discharge and runoff volume and their influence on soil erosion have not yet been analyzed in detail. Focusing on initial soil erosion (splash), our experimental design is designated to get a better understanding of these mechanisms. The experiments were carried out within the DFG research unit "Biodiversity and Ecosystem Functioning (BEF)-China" in subtropical China. The "New Integrated Litter Experiment (NILEx)" used as platform combining different subprojects of BEF-China dealing with "decomposition and nutrient cycling", "mechanisms of soil erosion" and "functional effects of herbivores, predators and saproxylics" in one experiment. In NILEx, 96 40cm x 40cm runoff plots on two hill slopes inside a castanea molissima forest plantation have been installed and filled with seven different types of litter cover. 16 one-species plots, 24 two-species plots, 4 four-species plots and 4 bare ground plots have been set up, each replicated once. We prepared 48 Plots with traps (Renner solution) for soil macrofauna (diplopods and collembola), so half of the plots were kept free from fauna while the other half was accessible for fauna. Rainfall was generated artificially by using a rainfall simulator with a continuous and stable intensity of 60 mm/h. Our experiments included two runs of 20 minutes duration each, both conducted at two different time steps (summer 2012 and autumn 2012). Runoff volume and sediment discharge were measured every 5 minutes during one rainfall run. Litter coverage and litter mass were recorded at the beginning (summer 2012) and at the end of the experiment (autumn 2012). Our results show that sediment discharge as well as runoff volume decreases

  10. Intestinal Microbiota of Broiler Chickens As Affected by Litter Management Regimens.

    PubMed

    Wang, Lingling; Lilburn, Mike; Yu, Zhongtang

    2016-01-01

    Poultry litter is a mixture of bedding materials and enteric bacteria excreted by chickens, and it is typically reused for multiple growth cycles in commercial broiler production. Thus, bacteria can be transmitted from one growth cycle to the next via litter. However, it remains poorly understood how litter reuse affects development and composition of chicken gut microbiota. In this study, the effect of litter reuse on the microbiota in litter and in chicken gut was investigated using 2 litter management regimens: fresh vs. reused litter. Samples of ileal mucosa and cecal digesta were collected from young chicks (10 days of age) and mature birds (35 days of age). Based on analysis using DGGE and pyrosequencing of bacterial 16S rRNA gene amplicons, the microbiota of both the ileal mucosa and the cecal contents was affected by both litter management regimen and age of birds. Faecalibacterium, Oscillospira, Butyricicoccus, and one unclassified candidate genus closely related to Ruminococcus were most predominant in the cecal samples, while Lactobacillus was predominant in the ileal samples at both ages and in the cecal samples collected at day 10. At days 10 and 35, 8 and 3 genera, respectively, in the cecal luminal microbiota differed significantly in relative abundance between the 2 litter management regimens. Compared to the fresh litter, reused litter increased predominance of halotolerant/alkaliphilic bacteria and Faecalibacterium prausnitzii, a butyrate-producing gut bacterium. This study suggests that litter management regimens affect the chicken GI microbiota, which may impact the host nutritional status and intestinal health. PMID:27242676

  11. Intestinal Microbiota of Broiler Chickens As Affected by Litter Management Regimens

    PubMed Central

    Wang, Lingling; Lilburn, Mike; Yu, Zhongtang

    2016-01-01

    Poultry litter is a mixture of bedding materials and enteric bacteria excreted by chickens, and it is typically reused for multiple growth cycles in commercial broiler production. Thus, bacteria can be transmitted from one growth cycle to the next via litter. However, it remains poorly understood how litter reuse affects development and composition of chicken gut microbiota. In this study, the effect of litter reuse on the microbiota in litter and in chicken gut was investigated using 2 litter management regimens: fresh vs. reused litter. Samples of ileal mucosa and cecal digesta were collected from young chicks (10 days of age) and mature birds (35 days of age). Based on analysis using DGGE and pyrosequencing of bacterial 16S rRNA gene amplicons, the microbiota of both the ileal mucosa and the cecal contents was affected by both litter management regimen and age of birds. Faecalibacterium, Oscillospira, Butyricicoccus, and one unclassified candidate genus closely related to Ruminococcus were most predominant in the cecal samples, while Lactobacillus was predominant in the ileal samples at both ages and in the cecal samples collected at day 10. At days 10 and 35, 8 and 3 genera, respectively, in the cecal luminal microbiota differed significantly in relative abundance between the 2 litter management regimens. Compared to the fresh litter, reused litter increased predominance of halotolerant/alkaliphilic bacteria and Faecalibacterium prausnitzii, a butyrate-producing gut bacterium. This study suggests that litter management regimens affect the chicken GI microbiota, which may impact the host nutritional status and intestinal health. PMID:27242676

  12. Factors affecting arsenic and copper runoff from pastures fertilized with poultry litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heavy metal runoff from soils fertilized with poultry litter has received increasing attention in recent years, although it is not really known if heavy runoff from poultry litter poses a significant threat to the environment. The objective of this study was to evaluate arsenic (As) and copper (Cu)...

  13. The Evaluation of Litter Behavior Modification in a River Environment.

    ERIC Educational Resources Information Center

    Wagstaff, Mark C.; Wilson, Beth E.

    1988-01-01

    Behavior modification techniques were evaluated by observing litter collection behavior of commercial rafting groups. The number of litter pieces retrieved by treatment and control groups was significantly different. Results support the idea that verbal appeal and role modeling can be effective litter control techniques. (Author/CW)

  14. Habitat, food, and climate affecting leaf litter anuran assemblages in an Atlantic Forest remnant

    NASA Astrophysics Data System (ADS)

    Rievers, Camila Rabelo; Pires, Maria Rita Silvério; Eterovick, Paula Cabral

    2014-07-01

    Leaf litter anuran assemblages include both species that have terrestrial development and species that, during the breeding season, aggregate around bodies of water where their tadpoles develop. The resources used by these two groups in the leaf litter are likely to differ, as well as their sampled species richness, abundance and biomass as resource availability changes. We conducted a 12-month survey of leaf litter anuran assemblages at three forest areas in the largest Atlantic Forest remnant in the state of Minas Gerais in southeastern Brazil. Each month we estimated, based on capture rates, anuran species richness, abundance, and biomass as assemblage descriptors. We also measured variables that could potentially affect these descriptors in space and time: invertebrate litter fauna (abundance and richness of taxa), leaf litter biomass, and microclimatic conditions (air humidity, air and soil temperature, soil water content, and rainfall). We tested for differences in these variables among areas. We used general linear models to search for the variables that best explained variation in anuran abundance (based on capture rates) throughout the year. We analyzed species with terrestrial development (TD) and with aquatic larvae (AL) separately. We recorded 326 anurans of 15 species. Sampled anuran abundance (correlated to species richness and biomass) was explained by air humidity and/or invertebrate abundance for species with TD, and by soil water content or air humidity and leaf litter biomass for species with AL. The variability in the results of studies on leaf litter frogs that try to find variables to explain changes in community descriptors may be due to spatial variation of resources among areas and also to the fact that TD and AL species are frequently analyzed together, when in fact they are likely to show different responses to resources present in the leaf litter habitat, reflected on capture rates.

  15. SOIL COMPACTION AND POULTRY LITTER EFFECTS ON FACTORS AFFECTING NITROGEN AVAILABILITY IN A CLAYPAN SOIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil compaction may affect N mineralization and the subsequent fate of N in agroecosystems. Laboratory incubation and field experiments were conducted to determine the effects of surface soil compaction on soil N mineralization in a claypan soil amended with poultry litter (i.e., turkey excrement mi...

  16. Evidence for mild sediment Pb contamination affecting leaf-litter decomposition in a lake.

    PubMed

    Oguma, Andrew Y; Klerks, Paul L

    2015-08-01

    Much work has focused on the effects of metal-contaminated sediment on benthic community structure, but effects on ecosystem functions have received far less attention. Decomposition has been widely used as an integrating metric of ecosystem function in lotic systems, but not for lentic ones. We assessed the relationship between low-level sediment lead (Pb) contamination and leaf-litter decomposition in a lentic system. We measured 30-day weight loss in 30 litter-bags that were deployed along a Pb-contamination gradient in a cypress-forested lake. At each deployment site we also quantified macrobenthos abundance, dissolved oxygen, water depth, sediment organic content, sediment silt/clay content, and both total sediment and porewater concentrations of Cd, Cu, Ni, Pb and Zn. Principal components (PC) analysis revealed a negative relationship between Pb concentration and benthic macroinvertebrate abundance, and this covariation dominated the first PC axis (PC1). Subsequent correlation analyses revealed a negative relationship between PC1 and percent leaf-litter loss. Our results indicate that leaf-litter decomposition was related to sediment Pb and benthic macroinvertebrate abundance. They also showed that ecosystem function may be affected even where sediment Pb concentrations are mostly below threshold-effects sediment quality guidelines--a finding with potential implications for sediment risk assessment. Additionally, the litter-bag technique used in this study showed promise as a tool in risk assessments of metal-contaminated sediments in lentic systems. PMID:26115904

  17. Prior Hydrologic Disturbance Affects Competition between Aedes Mosquitoes via Changes in Leaf Litter.

    PubMed

    Smith, Cassandra D; Freed, T Zachary; Leisnham, Paul T

    2015-01-01

    Allochthonous leaf litter is often the main resource base for invertebrate communities in ephemeral water-filled containers, and detritus quality can be affected by hydrologic conditions. The invasive mosquito Aedes albopictus utilizes container habitats for its development where it competes as larvae for detritus and associated microorganisms with the native Aedes triseriatus. Different hydrologic conditions that containers are exposed to prior to mosquito utilization affect litter decay and associated water quality. We tested the hypothesis that larval competition between A. albopictus and A. triseriatus would be differentially affected by prior hydrologic conditions. Experimental microcosms provisioned with Quercus alba L. litter were subjected to one of three different hydrologic treatments prior to the addition of water and mosquito larvae: dry, flooded, and a wet/dry cycle. Interspecific competition between A. albopictus and A. triseriatus was mediated by hydrologic treatment, and was strongest in the dry treatment vs. the flooded or wet/dry treatments. Aedes triseriatus estimated rate of population change (λ') was lowest in the dry treatment. Aedes albopictus λ' was unaffected by hydrologic treatment, and was on average always increasing (i.e., > 1). Aedes triseriatus λ' was affected by the interaction of hydrologic treatment with interspecific competition, and was on average declining (i.e., < 1.0), at the highest interspecific densities in the dry treatment. Dry treatment litter had the slowest decay rate and leached the highest concentration of tannin-lignin, but supported more total bacteria than the other treatments. These results suggest that dry conditions negatively impact A. triseriatus population performance and may result in the competitive exclusion of A. triseriatus by A. albopictus, possibly by reducing microbial taxa that Aedes species browse. Changing rainfall patterns with climate change are likely to affect competition between A

  18. Prior Hydrologic Disturbance Affects Competition between Aedes Mosquitoes via Changes in Leaf Litter

    PubMed Central

    Smith, Cassandra D.; Freed, T. Zachary; Leisnham, Paul T.

    2015-01-01

    Allochthonous leaf litter is often the main resource base for invertebrate communities in ephemeral water-filled containers, and detritus quality can be affected by hydrologic conditions. The invasive mosquito Aedes albopictus utilizes container habitats for its development where it competes as larvae for detritus and associated microorganisms with the native Aedes triseriatus. Different hydrologic conditions that containers are exposed to prior to mosquito utilization affect litter decay and associated water quality. We tested the hypothesis that larval competition between A. albopictus and A. triseriatus would be differentially affected by prior hydrologic conditions. Experimental microcosms provisioned with Quercus alba L. litter were subjected to one of three different hydrologic treatments prior to the addition of water and mosquito larvae: dry, flooded, and a wet/dry cycle. Interspecific competition between A. albopictus and A. triseriatus was mediated by hydrologic treatment, and was strongest in the dry treatment vs. the flooded or wet/dry treatments. Aedes triseriatus estimated rate of population change (λ') was lowest in the dry treatment. Aedes albopictus λ' was unaffected by hydrologic treatment, and was on average always increasing (i.e., > 1). Aedes triseriatus λ' was affected by the interaction of hydrologic treatment with interspecific competition, and was on average declining (i.e., < 1.0), at the highest interspecific densities in the dry treatment. Dry treatment litter had the slowest decay rate and leached the highest concentration of tannin-lignin, but supported more total bacteria than the other treatments. These results suggest that dry conditions negatively impact A. triseriatus population performance and may result in the competitive exclusion of A. triseriatus by A. albopictus, possibly by reducing microbial taxa that Aedes species browse. Changing rainfall patterns with climate change are likely to affect competition between A

  19. Infant Affect and Home Environment.

    ERIC Educational Resources Information Center

    Luster, Tom; And Others

    1993-01-01

    Examined data from National Longitudinal Survey of Youth to investigate relationship between infant affect and quality of home environment. Found that infant irritability was negatively correlated with quality of home environment in both low-risk and high-risk families. Infant positive affect was more strongly related to quality of care in…

  20. Tadpoles of Early Breeding Amphibians are Negatively Affected by Leaf Litter From Invasive Chinese Tallow Trees

    NASA Astrophysics Data System (ADS)

    Leonard, N. E.

    2005-05-01

    As wetlands are invaded by Chinese tallow trees (Triadica sebifera), native trees are displaced and detrital inputs to amphibian breeding ponds are altered. I used a mesocosm experiment to examine the effect of Chinese tallow leaf litter on the survival to, size at, and time to metamorphosis of amphibian larvae. Fifty 1000-L cattle watering tanks were treated with 1500 g dry weight of one of five leaf litter treatments: Chinese tallow, laurel oak (Quercus laurifolia), water tupelo (Nyssa aquatica), slash pine (Pinus elliottii), or a 3:1:1:1 mixture. Each tank received 45 tadpoles of Pseudacris feriarum, Bufo terrestris, and Hyla cinerea in sequence according to their natural breeding phonologies. Every Pseudacris feriarum and Bufo terrestris tadpole exposed to Chinese tallow died prior to metamorphosis. Hyla cinerea survival in tanks with tallow-only was significantly lower than that observed for all other leaf treatments. Hyla cinerea tadpoles from tallow-only and mixed-leaf treatments were larger at metamorphosis and transformed faster than those in tanks with native leaves only. These results suggest that Chinese tallow leaf litter may negatively affect tadpoles of early breeding frogs and that Chinese tallow invasion may change the structure of amphibian communities in temporary ponds.

  1. Does Proximity to Subsurface Poultry Litter Affect Corn Seedling Survival and Growth?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poultry litter provides a rich nutrient source for crops, but the usual practice of surface broadcasting litter can degrade water quality by allowing storm runoff to transport nutrients into streams and lakes, while much of the ammonia N escapes into the atmosphere. Subsurface application of litter...

  2. Genetic by environment interactions affect plant–soil linkages

    PubMed Central

    Pregitzer, Clara C; Bailey, Joseph K; Schweitzer, Jennifer A

    2013-01-01

    The role of plant intraspecific variation in plant–soil linkages is poorly understood, especially in the context of natural environmental variation, but has important implications in evolutionary ecology. We utilized three 18- to 21-year-old common gardens across an elevational gradient, planted with replicates of five Populus angustifolia genotypes each, to address the hypothesis that tree genotype (G), environment (E), and G × E interactions would affect soil carbon and nitrogen dynamics beneath individual trees. We found that soil nitrogen and carbon varied by over 50% and 62%, respectively, across all common garden environments. We found that plant leaf litter (but not root) traits vary by genotype and environment while soil nutrient pools demonstrated genotype, environment, and sometimes G × E interactions, while process rates (net N mineralization and net nitrification) demonstrated G × E interactions. Plasticity in tree growth and litter chemistry was significantly related to the variation in soil nutrient pools and processes across environments, reflecting tight plant–soil linkages. These data overall suggest that plant genetic variation can have differential affects on carbon storage and nitrogen cycling, with implications for understanding the role of genetic variation in plant–soil feedback as well as management plans for conservation and restoration of forest habitats with a changing climate. PMID:23919173

  3. Soil Fauna Affects Dissolved Carbon and Nitrogen in Foliar Litter in Alpine Forest and Alpine Meadow.

    PubMed

    Liao, Shu; Yang, Wanqin; Tan, Yu; Peng, Yan; Li, Jun; Tan, Bo; Wu, Fuzhong

    2015-01-01

    Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) are generally considered important active biogeochemical pools of total carbon and nitrogen. Many studies have documented the contributions of soil fauna to litter decomposition, but the effects of the soil fauna on labile substances (i.e., DOC and TDN) in litter during early decomposition are not completely clear. Therefore, a field litterbag experiment was carried out from 13th November 2013 to 23rd October 2014 in an alpine forest and an alpine meadow located on the eastern Tibetan Plateau. Litterbags with different mesh sizes were used to provide access to or prohibit the access of the soil fauna, and the concentrations of DOC and TDN in the foliar litter were measured during the winter (the onset of freezing, deep freezing and thawing stage) and the growing season (early and late). After one year of field incubation, the concentration of DOC in the litter significantly decreased, whereas the TDN concentration in the litter increased. Similar dynamic patterns were detected under the effects of the soil fauna on both DOC and TDN in the litter between the alpine forest and the alpine meadow. The soil fauna showed greater positive effects on decreasing DOC concentration in the litter in the winter than in the growing season. In contrast, the dynamics of TND in the litter were related to seasonal changes in environmental factors, rather than the soil fauna. In addition, the soil fauna promoted a decrease in litter DOC/TDN ratio in both the alpine forest and the alpine meadow throughout the first year of decomposition, except for in the late growing season. These results suggest that the soil fauna can promote decreases in DOC and TDN concentrations in litter, contributing to early litter decomposition in these cold biomes. PMID:26406249

  4. Soil Fauna Affects Dissolved Carbon and Nitrogen in Foliar Litter in Alpine Forest and Alpine Meadow

    PubMed Central

    Liao, Shu; Yang, Wanqin; Tan, Yu; Peng, Yan; Li, Jun; Tan, Bo; Wu, Fuzhong

    2015-01-01

    Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) are generally considered important active biogeochemical pools of total carbon and nitrogen. Many studies have documented the contributions of soil fauna to litter decomposition, but the effects of the soil fauna on labile substances (i.e., DOC and TDN) in litter during early decomposition are not completely clear. Therefore, a field litterbag experiment was carried out from 13th November 2013 to 23rd October 2014 in an alpine forest and an alpine meadow located on the eastern Tibetan Plateau. Litterbags with different mesh sizes were used to provide access to or prohibit the access of the soil fauna, and the concentrations of DOC and TDN in the foliar litter were measured during the winter (the onset of freezing, deep freezing and thawing stage) and the growing season (early and late). After one year of field incubation, the concentration of DOC in the litter significantly decreased, whereas the TDN concentration in the litter increased. Similar dynamic patterns were detected under the effects of the soil fauna on both DOC and TDN in the litter between the alpine forest and the alpine meadow. The soil fauna showed greater positive effects on decreasing DOC concentration in the litter in the winter than in the growing season. In contrast, the dynamics of TND in the litter were related to seasonal changes in environmental factors, rather than the soil fauna. In addition, the soil fauna promoted a decrease in litter DOC/TDN ratio in both the alpine forest and the alpine meadow throughout the first year of decomposition, except for in the late growing season. These results suggest that the soil fauna can promote decreases in DOC and TDN concentrations in litter, contributing to early litter decomposition in these cold biomes. PMID:26406249

  5. Differences in the sensitivity of fungi and bacteria to season and invertebrates affect leaf litter decomposition in a Mediterranean stream.

    PubMed

    Mora-Gómez, Juanita; Elosegi, Arturo; Duarte, Sofia; Cássio, Fernanda; Pascoal, Cláudia; Romaní, Anna M

    2016-08-01

    Microorganisms are key drivers of leaf litter decomposition; however, the mechanisms underlying the dynamics of different microbial groups are poorly understood. We investigated the effects of seasonal variation and invertebrates on fungal and bacterial dynamics, and on leaf litter decomposition. We followed the decomposition of Populus nigra litter in a Mediterranean stream through an annual cycle, using fine and coarse mesh bags. Irrespective of the season, microbial decomposition followed two stages. Initially, bacterial contribution to total microbial biomass was higher compared to later stages, and it was related to disaccharide and lignin degradation; in a later stage, bacteria were less important and were associated with hemicellulose and cellulose degradation, while fungi were related to lignin decomposition. The relevance of microbial groups in decomposition differed among seasons: fungi were more important in spring, whereas in summer, water quality changes seemed to favour bacteria and slowed down lignin and hemicellulose degradation. Invertebrates influenced litter-associated microbial assemblages (especially bacteria), stimulated enzyme efficiencies and reduced fungal biomass. We conclude that bacterial and fungal assemblages play distinctive roles in microbial decomposition and differ in their sensitivity to environmental changes, ultimately affecting litter decomposition, which might be particularly relevant in highly seasonal ecosystems, such as intermittent streams. PMID:27288197

  6. Initial phylogenetic relatedness of saprotrophic fungal communities affects subsequent litter decomposition rates.

    PubMed

    Kivlin, Stephanie N; Treseder, Kathleen K

    2015-05-01

    Ecosystem-level consequences of biodiversity loss of macroorganisms are well understood, while the repercussions of species extirpation in microbial systems are not. We manipulated species richness and phylogenetic relatedness of saprotrophic fungi in situ in a boreal forest to address this issue. Litter decomposition rates (as total mass loss) after 2 months were significantly higher in the least phylogenetically related fungal assemblages. Likewise, cellulose loss was also highest in the most distantly related treatments after 1 year. There were marginal effects of species richness on mass loss that only affected decomposition after 2 months. At the end of 1 year of decomposition, most fungal communities had collapsed from their original diversity to two species, mainly in the Penicillium or Hypocrea clades. Two concurrent processes may explain these results: competition between closely related fungal taxa and phylogenetic conservation in cellulose decomposition. Our results suggest that phylogenetic relatedness of fungal communities may be a more appropriate metric than species richness or community composition to predict functional responses of fungal communities to global change. PMID:25331109

  7. Does Litter Size Variation Affect Models of Terrestrial Carnivore Extinction Risk and Management?

    PubMed Central

    Devenish-Nelson, Eleanor S.; Stephens, Philip A.; Harris, Stephen; Soulsbury, Carl; Richards, Shane A.

    2013-01-01

    Background Individual variation in both survival and reproduction has the potential to influence extinction risk. Especially for rare or threatened species, reliable population models should adequately incorporate demographic uncertainty. Here, we focus on an important form of demographic stochasticity: variation in litter sizes. We use terrestrial carnivores as an example taxon, as they are frequently threatened or of economic importance. Since data on intraspecific litter size variation are often sparse, it is unclear what probability distribution should be used to describe the pattern of litter size variation for multiparous carnivores. Methodology/Principal Findings We used litter size data on 32 terrestrial carnivore species to test the fit of 12 probability distributions. The influence of these distributions on quasi-extinction probabilities and the probability of successful disease control was then examined for three canid species – the island fox Urocyon littoralis, the red fox Vulpes vulpes, and the African wild dog Lycaon pictus. Best fitting probability distributions differed among the carnivores examined. However, the discretised normal distribution provided the best fit for the majority of species, because variation among litter-sizes was often small. Importantly, however, the outcomes of demographic models were generally robust to the distribution used. Conclusion/Significance These results provide reassurance for those using demographic modelling for the management of less studied carnivores in which litter size variation is estimated using data from species with similar reproductive attributes. PMID:23469140

  8. 40 CFR 1502.15 - Affected environment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Affected environment. 1502.15 Section 1502.15 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY ENVIRONMENTAL IMPACT STATEMENT § 1502.15 Affected environment. The environmental impact statement shall succinctly describe...

  9. 40 CFR 1502.15 - Affected environment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Affected environment. 1502.15 Section 1502.15 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY ENVIRONMENTAL IMPACT STATEMENT § 1502.15 Affected environment. The environmental impact statement shall succinctly describe...

  10. 40 CFR 1502.15 - Affected environment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Affected environment. 1502.15 Section 1502.15 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY ENVIRONMENTAL IMPACT STATEMENT § 1502.15 Affected environment. The environmental impact statement shall succinctly describe...

  11. 40 CFR 1502.15 - Affected environment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Affected environment. 1502.15 Section 1502.15 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY ENVIRONMENTAL IMPACT STATEMENT § 1502.15 Affected environment. The environmental impact statement shall succinctly describe...

  12. 40 CFR 1502.15 - Affected environment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Affected environment. 1502.15 Section 1502.15 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY ENVIRONMENTAL IMPACT STATEMENT § 1502.15 Affected environment. The environmental impact statement shall succinctly describe...

  13. Maternal immune activation affects litter success, size and neuroendocrine responses related to behavior in adult offspring.

    PubMed

    French, Susannah S; Chester, Emily M; Demas, Gregory E

    2013-07-01

    It is increasingly evident that influences other than genetics can contribute to offspring phenotype. In particular, maternal influences are an important contributing factor to offspring survival, development, physiology and behavior. Common environmental pathogens such as viral or bacterial microorganisms can induce maternal immune responses, which have the potential to alter the prenatal environment via multiple independent pathways. The effects of maternal immune activation on endocrine responses and behavior are less well studied and provide the basis for the current study. Our approach in the current study was two-pronged: 1) quantify sickness responses during pregnancy in adult female hamsters experiencing varying severity of immune responsiveness (i.e., differing doses of lipopolysaccharide [LPS]), and 2) assess the effects of maternal immune activation on offspring development, immunocompetence, hormone profiles, and social behavior during adulthood. Pregnancy success decreased with increasing doses of LPS, and litter size was reduced in LPS dams that managed to successfully reproduce. Unexpectedly, pregnant females treated with LPS showed a hypothermic response in addition to the more typical anorexic and body mass changes associated with sickness. Significant endocrine changes related to behavior were observed in the offspring of LPS-treated dams; these effects were apparent in adulthood. Specifically, offspring from LPS treated dams showed significantly greater cortisol responses to stressful resident-intruder encounters compared with offspring from control dams. Post-behavior cortisol was elevated in male LPS offspring relative to the offspring of control dams, and was positively correlated with the frequency of bites during agonistic interactions, and cortisol levels in both sexes were related to defensive behaviors, suggesting that changes in hypothalamo-pituitary-adrenal axis responsiveness may play a regulatory role in the observed behavioral

  14. MINERALIZATION OF NITROGEN FROM BROILER LITTER AS AFFECTED BY SOIL TEXTURE IN THE SOUTHEASTERN COASTAL PLAIN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field study was conducted during 2004-2005 to determine nitrogen (N) mineralization of broiler litter (BL) in two Coastal Plain soils of differing texture, sandy or clayey. The soils were a Tifton loamy sand (fine-loamy, siliceous, thermic, Plinthic Kandiudults) and a Greenville sandy clay loam (...

  15. Leaf litter quality affects aquatic insect emergence: contrasting patterns from two foundation trees.

    PubMed

    Compson, Zacchaeus G; Adams, Kenneth J; Edwards, Joeseph A; Maestas, Jesse M; Whitham, Thomas G; Marks, Jane C

    2013-10-01

    Reciprocal subsidies between rivers and terrestrial habitats are common where terrestrial leaf litter provides energy to aquatic invertebrates while emerging aquatic insects provide energy to terrestrial predators (e.g., birds, lizards, spiders). We examined how aquatic insect emergence changed seasonally with litter from two foundation riparian trees, whose litter often dominates riparian streams of the southwestern United States: Fremont (Populus fremontii) and narrowleaf (Populus angustifolia) cottonwood. P. fremontii litter is fast-decomposing and lower in defensive phytochemicals (i.e., condensed tannins, lignin) relative to P. angustifolia. We experimentally manipulated leaf litter from these two species by placing them in leaf enclosures with emergence traps attached in order to determine how leaf type influenced insect emergence. Contrary to our initial predictions, we found that packs with slow-decomposing leaves tended to support more emergent insects relative to packs with fast-decomposing leaves. Three findings emerged. Firstly, abundance (number of emerging insects m(-2) day(-1)) was 25% higher on narrowleaf compared to Fremont leaves for the spring but did not differ in the fall, demonstrating that leaf quality from two dominant trees of the same genus yielded different emergence patterns and that these patterns changed seasonally. Secondly, functional feeding groups of emerging insects differed between treatments and seasons. Specifically, in the spring collector-gatherer abundance and biomass were higher on narrowleaf leaves, whereas collector-filterer abundance and biomass were higher on Fremont leaves. Shredder abundance and biomass were higher on narrowleaf leaves in the fall. Thirdly, diversity (Shannon's H') was higher on Fremont leaves in the spring, but no differences were found in the fall, showing that fast-decomposing leaves can support a more diverse, complex emergent insect assemblage during certain times of the year. Collectively, these

  16. Field Experiments in Litter Control

    ERIC Educational Resources Information Center

    Finnie, William C.

    1973-01-01

    A series of urban and highway litter experiments in Richmond (Virginia), St. Louis, and Philadelphia indicated well-designed litter cans reduced littering about 15 percent along city streets and nearly 30 percent along highways. Also, the propensity to litter is critically affected by the characteristics of the individual and environmental…

  17. Factors affecting the abundance of leaf-litter arthropods in unburned and thrice-burned seasonally-dry Amazonian forests.

    PubMed

    Silveira, Juliana M; Barlow, Jos; Louzada, Julio; Moutinho, Paulo

    2010-01-01

    Fire is frequently used as a land management tool for cattle ranching and annual crops in the Amazon. However, these maintenance fires often escape into surrounding forests, with potentially severe impacts for forest biodiversity. We examined the effect of experimental fires on leaf-litter arthropod abundance in a seasonally-dry forest in the Brazilian Amazon. The study plots (50 ha each) included a thrice-burned forest and an unburned control forest. Pitfall-trap samples were collected at 160 randomly selected points in both plots, with sampling stratified across four intra-annual replicates across the dry and wet seasons, corresponding to 6, 8, 10 and 12 months after the most recent fire. Arthropods were identified to the level of order (separating Formicidae). In order to better understand the processes that determine arthropod abundance in thrice-burned forests, we measured canopy openness, understory density and litter depth. All arthropod taxa were significantly affected by fire and season. In addition, the interactions between burn treatment and season were highly significant for all taxa but Isoptera. The burned plot was characterized by a more open canopy, lower understory density and shallower litter depth. Hierarchical partitioning revealed that canopy openness was the most important factor explaining arthropod order abundances in the thrice-burned plot, whereas all three environmental variables were significant in the unburned control plot. These results reveal the marked impact of recurrent wildfires and seasonality on litter arthropods in this transitional forest, and demonstrate the overwhelming importance of canopy-openness in driving post-fire arthropod abundance. PMID:20877720

  18. Factors Affecting the Abundance of Leaf-Litter Arthropods in Unburned and Thrice-Burned Seasonally-Dry Amazonian Forests

    PubMed Central

    Silveira, Juliana M.; Barlow, Jos; Louzada, Julio; Moutinho, Paulo

    2010-01-01

    Fire is frequently used as a land management tool for cattle ranching and annual crops in the Amazon. However, these maintenance fires often escape into surrounding forests, with potentially severe impacts for forest biodiversity. We examined the effect of experimental fires on leaf-litter arthropod abundance in a seasonally-dry forest in the Brazilian Amazon. The study plots (50 ha each) included a thrice-burned forest and an unburned control forest. Pitfall-trap samples were collected at 160 randomly selected points in both plots, with sampling stratified across four intra-annual replicates across the dry and wet seasons, corresponding to 6, 8, 10 and 12 months after the most recent fire. Arthropods were identified to the level of order (separating Formicidae). In order to better understand the processes that determine arthropod abundance in thrice-burned forests, we measured canopy openness, understory density and litter depth. All arthropod taxa were significantly affected by fire and season. In addition, the interactions between burn treatment and season were highly significant for all taxa but Isoptera. The burned plot was characterized by a more open canopy, lower understory density and shallower litter depth. Hierarchical partitioning revealed that canopy openness was the most important factor explaining arthropod order abundances in the thrice-burned plot, whereas all three environmental variables were significant in the unburned control plot. These results reveal the marked impact of recurrent wildfires and seasonality on litter arthropods in this transitional forest, and demonstrate the overwhelming importance of canopy-openness in driving post-fire arthropod abundance. PMID:20877720

  19. Enrichment of uranium in particulate matter during litter decomposition affected by Gammarus pulex L.

    PubMed

    Schaller, Jörg; Weiske, Arndt; Mkandawire, Martin; Dudel, E Gert

    2008-12-01

    Plant litter and organic matter of aquatic sediments provide a significant sink of soluble inorganic uranium species in contaminated ecosystems. The uranium content in detritus has been observed to increase significantly during decomposition. However, the influence of the decomposer community on uranium fixation remains unclear. In view of this, we investigated the influence of a shredder (the freshwater shrimp Gammarus pulex L) on uranium fixation and mobilization during the degradation of plant litter. Leaf litter from Alnus glutinosa (L.) Gaertn. with 1152 mg kg(-1) U of dry biomass (DM) and without uranium was used in a 14-day laboratory experiment. The uranium concentration in the particulate organic material (POM) at the end of experiment was 1427 mg kg(-1) DM. After 14 days of decay, the residues of the leaves show a uranium concentration of 644 mg kg(-1) DM. Uranium concentrations in the media initially increased reaching up to 63.9 microg L(-1) but finally decreased to an average value of 34.3 microg L(-1). Atthe same time, DOC levels increased from 2.43 mg L(-1) up to 11.4 mg L(-1) in the course of the experiment Hence, inorganic uranium fixation onto particulate organic matter was enhanced by the activity of G. pulex. PMID:19192788

  20. Metaproteomics to unravel major microbial players in leaf litter and soil environments: challenges and perspectives.

    PubMed

    Becher, Dörte; Bernhardt, Jörg; Fuchs, Stephan; Riedel, Katharina

    2013-10-01

    Soil- and litter-borne microorganisms vitally contribute to biogeochemical cycles. However, changes in environmental parameters but also human interferences may alter species composition and elicit alterations in microbial activities. Soil and litter metaproteomics, implying the assignment of soil and litter proteins to specific phylogenetic and functional groups, has a great potential to provide essential new insights into the impact of microbial diversity on soil ecosystem functioning. This article will illuminate challenges and perspectives of current soil and litter metaproteomics research, starting with an introduction to an appropriate experimental design and state-of-the-art proteomics methodologies. This will be followed by a summary of important studies aimed at (i) the discovery of the major biotic drivers of leaf litter decomposition, (ii) metaproteomics analyses of rhizosphere-inhabiting microbes, and (iii) global approaches to study bioremediation processes. The review will be closed by a brief outlook on future developments and some concluding remarks, which should assist the reader to develop successful concepts for soil and litter metaproteomics studies. PMID:23894095

  1. Succession of Phylogeny and Function During Plant Litter Decomposition (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect

    Brodie, Eoin

    2013-03-01

    Eoin Brodie of Berkeley Lab on "Succession of phylogeny and function during plant litter decomposition" at the 8th Annual Genomics of Energy & Environment Meeting on March 27, 2013 in Walnut Creek, Calif.

  2. Fungal diversity of saprotrophic litter fungi in a Mediterranean maquis environment.

    PubMed

    Lunghini, D; Granito, V M; Di Lonardo, D P; Maggi, O; Persiani, A M

    2013-01-01

    Monospecific and mixed-leaf litters from plant species of Mediterranean maquis (Quercus ilex, Phillyrea angustifolia, Pistacia lentiscus, Cistus spp.) in an undisturbed area in southern Italy were studied with respect to the structure and composition of their decomposer fungal community over an incubation period of 403 d. The data matrix structure was analyzed by means of detrended correspondence analysis (DCA), while indicator species analysis (ISA) was used to determine the preferential association of species with a substrate, a succession phase and monospecific/mixed experimental conditions. The ecological nature of the gradient expressed by the DCA axes was investigated by means of experimental and main chemical leaf-litter variables. The litter mixture had non-additive effects on the decomposition process even though the fungal species richness of the mixed litter was considerably higher than that of the monospecific litter. Our findings highlight the occurrence of shifts in the fungal community during decomposition in response to changes in the substrate, such as those related to the cellulose content and lignin/N ratio. PMID:23921238

  3. A Fungal Endosymbiont Affects Host Plant Recruitment Through Seed- and Litter-mediated Mechanisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. Many grass species are associated with maternally transmitted fungal endophytes. Increasing evidence shows that endophytes enhance host plant success under varied conditions, yet studies have rarely considered alternative mechanisms whereby these mutualistic symbionts may affect regeneration from...

  4. Early environment affects neuroendocrine regulation in adulthood

    PubMed Central

    Karlamangla, Arun S.; Friedman, Esther M.; Seeman, Teresa E.

    2011-01-01

    Animal and human research indicates that the early environment can exert effects on hypothalamic pituitary adrenal (HPA) axis functioning across the lifespan. Using data from the National Study of Midlife Development in the United States and the National Study of Daily Experience substudy, we identified curvilinear relations between adult reports of parental affection in childhood and adult diurnal cortisol rhythms. Reports of both very affectionate and very unaffectionate parental relations in childhood were associated with flatter diurnal rhythms, suggesting potential dysregulation of the HPA axis at both extremes of family environment. Participants in the bottom tertile showed more signs of HPA axis dysregulation than those in the top tertile. We discuss processes that may underlie these effects, with reference to the theory of allostatic load. PMID:20400490

  5. Controls on mass loss and nitrogen dynamics of oak leaf litter along an urban-rural land-use gradient.

    PubMed

    Pouyat, Richard V; Carreiro, Margaret M

    2003-04-01

    Using reciprocal leaf litter transplants, we investigated the effects of contrasting environments (urban vs. rural) and intraspecific variations in oak leaf litter quality on mass loss rates and nitrogen (N) dynamics along an urban-rural gradient in the New York City metropolitan area. Differences in earthworm abundances and temperature had previously been documented in the stands along this gradient. Red oak leaf litter was collected and returned to its original source stand as native litter to measure decay rates along the gradient. To separate site effects from litter quality effects on decay, reciprocal transplants of litter were also made between stands at the extremes of the environmental gradient (urban and rural stands). Land-use had no effect on mass loss and N dynamics of native litter by the end of the 22-month incubation period. The lack of differences in native litter suggests the factors affecting decay were similar across the stands in this study. However, in the transplant study both environment and litter type strongly affected decay of oak leaf litter. On average urban and rural litter decomposed faster over the incubation period in urban than in rural stands (P=0.016 and P=0.001, respectively, repeated measures ANOVA). Differences in mass loss between urban and rural stands resulted in rural environments having less mass remaining than urban environments at the end of the incubation period (25.6 and 46.2% for urban and rural sites, respectively). Likewise, less N remained in leaf residue in urban sites (71.3%) compared to that in rural sites (115.1%). Litter type also affected mass loss rates during the 22-month incubation period. On average rural litter mass loss rates were faster than urban litter rates in both urban and rural stands (P=0.030 and P=0.026, respectively, repeated measures ANOVA). By the end of the incubation period, rural litter exhibited 43 and 20% greater mass loss and retained 44 and 5% less N than urban litter decomposing in

  6. Suberin-derived aliphatic monomers as biomarkers for SOM affected by root litter contribution

    NASA Astrophysics Data System (ADS)

    Kogel-Knabner, I.; Spielvogel, S.-; Prietzel, J.-

    2012-12-01

    belowground carbon input among the tree species and that (iii) forest conversion may substantially alter SOC stocks and spatial distribution. Suberin biomarkers can thus be used as indicators for the presence of root influence on SOM composition and for identifying root-affected soil compartments.

  7. Arsenic species in broiler (Gallus gallus domesticus) litter, soils, maize (Zea mays L.), and groundwater from litter-amended fields.

    PubMed

    D'Angelo, Elisa; Zeigler, Georgia; Beck, E Glenn; Grove, John; Sikora, Frank

    2012-11-01

    Manure and bedding material (litter) generated by the broiler industry (Gallus gallus domesticus) often contain high levels of arsenic (As) when organoarsenical roxarsone and p-arsanilic acid are included in feed to combat disease and improve weight gain of the birds. This study was conducted to determine As levels and species in litter from three major broiler producing companies, and As levels in soils, corn tissue (Zea mays L.), and groundwater in fields where litter was applied. Total As in litter from the three different integrators ranged between <1 and 44 mg kg(-1). Between 15 and 20% of total As in litter consisted of mostly of arsenate, with smaller amounts of roxarsone and several transformation products that were extractable with phosphate buffer. Soils amended with litter had higher levels of bioavailable As (extractable with Mehlich 3 solution and taken up by corn leaves). Arsenic concentrations in plant tissue and groundwater, however, were below the World Health Organization thresholds, which was attributed to strong sorption/precipitation of arsenate in Fe- and Al-rich soils. Ecological impacts of amending soils with As-laden litter depend on the As species in the litter, and chemical and physical properties of soil that strongly affect As mobility and bioavailability in the environment. PMID:23010102

  8. Microbial mineralization of organic nitrogen forms in poultry litters.

    PubMed

    Rothrock, Michael J; Cook, Kimberly L; Warren, Jason G; Eiteman, Mark A; Sistani, Karamat

    2010-01-01

    Ammonia volatilization from the mineralization of uric acid and urea has a major impact on the poultry industry and the environment. Dry acids are commonly used to reduce ammonia emissions from poultry houses; however, little is known about how acidification affects the litter biologically. The goal of this laboratory incubation was to compare the microbiological and physiochemical effects of dry acid amendments (Al+Clear, Poultry Litter Treatment, Poultry Guard) on poultry litter to an untreated control litter and to specifically correlate uric acid and urea contents of these litters to the microbes responsible for their mineralization. Although all three acidifiers eventually produced similar effects within the litter, there was at least a 2-wk delay in the microbiological responses using Poultry Litter Treatment. Acidification of the poultry litter resulted in >3 log increases in total fungal concentrations, with both uricolytic (uric acid degrading) and ureolytic (urea degrading) fungi increasing by >2 logs within the first 2 to 4 wk of the incubation. Conversely, total, uricolytic, and ureolytic bacterial populations all significantly declined during this same time period. While uric acid and urea mineralization occurred within the first 2 wk in the untreated control litter, acidification resulted in delayed mineralization events for both uric acid and urea (2 and 4 wk delay, respectively) once fungal cell concentrations exceeded a threshold level. Therefore, fungi, and especially uricolytic fungi, appear to have a vital role in the mineralization of organic N in low-pH, high-N environments, and the activity of these fungi should be considered in best management practices to reduce ammonia volatilization from acidified poultry litter. PMID:21043291

  9. Litter quality and decomposability of species from a Mediterranean succession depend on leaf traits but not on nitrogen supply

    PubMed Central

    Kazakou, Elena; Violle, Cyrille; Roumet, Catherine; Pintor, Cristina; Gimenez, Olivier; Garnier, Eric

    2009-01-01

    Background and Aims The rate of plant decomposition depends on both the decomposition environment and the functional traits of the individual species (e.g. leaf and litter quality), but their relative importance in determining interspecific differences in litter decomposition remains unclear. The aims of this study were to: (a) determine if species from different successional stages grown on soils with low and high nitrogen levels produce leaf and litter traits that decompose differently under identical conditions; and (b) assess which trait of living leaves best relates to litter quality and litter decomposability Methods The study was conducted on 17 herbaceous species representative of three stages of a Mediterranean successional sere of Southern France. Plants were grown in monocultures in a common garden under two nitrogen levels. To elucidate how different leaf traits affected litter decomposition a microcosm experiment was conducted to determine decomposability under standard conditions. Tests were also carried out to determine how successional stage and nitrogen supply affected functional traits of living leaves and how these traits then modified litter quality and subsequent litter decomposability. Key Results The results demonstrated that leaf traits and litter decomposability varied according to species and successional stage. It was also demonstrated that while nitrogen addition affected leaf and litter traits, it had no effect on decomposition rates. Finally, leaf dry matter content stood out as the leaf trait best related to litter quality and litter decomposability Conclusions In this study, species litter decomposability was affected by some leaf and litter traits but not by soil nitrogen supply. The results demonstrated the strength of a trait-based approach to predict changes in ecosystem processes as a result of species shifts in ecosystems. PMID:19710073

  10. Photodegradation of roxarsone in poultry litter leachates

    USGS Publications Warehouse

    Bednar, A.J.; Garbarino, J.R.; Ferrer, I.; Rutherford, D.W.; Wershaw, R. L.; Ranville, J.F.; Wildeman, T.R.

    2003-01-01

    Arsenic compounds have been used extensively in agriculture in the US for applications ranging from cotton herbicides to animal feed supplements. Roxarsone (3-nitro-4-hydroxyphenylarsonic acid), in particular, is used widely in poultry production to control coccidial intestinal parasites. It is excreted unchanged in the manure and introduced into the environment when litter is applied to farmland as fertilizer. Although the toxicity of roxarsone is less than that of inorganic arsenic, roxarsone can degrade, biotically and abiotically, to produce more toxic inorganic forms of arsenic, such as arsenite and arsenate. Experiments were conducted on aqueous litter leachates to test the stability of roxarsone under different conditions. Laboratory experiments have shown that arsenite can be cleaved photolytically from the roxarsone moiety at pH 4-8 and that the degradation rate increases with increasing pH. Furthermore, the rate of photodegradation increases with nitrate and natural organic matter concentration, reactants that are commonly found in poultry-litter-water leachates. Additional photochemical reactions rapidly oxidize the cleaved arsenite to arsenate. The formation of arsenate is not entirely undesirable, because it is less mobile in soil systems and less toxic than arsenite. A possible mechanism for the degradation of roxarsone in poultry litter leachates is proposed. The results suggest that poultry litter storage and field application practices could affect the degradation of roxarsone and subsequent mobilization of inorganic arsenic species. ?? 2002 Elsevier Science B.V. All rights reserved.

  11. Transcriptomic Analysis of Ovaries from Pigs with High And Low Litter Size

    PubMed Central

    Feng, Yifang; Ding, Yueyun; Ye, Pengfei; Yin, Zongjun

    2015-01-01

    Litter size is one of the most important economic traits for pig production as it is directly related to the production efficiency. Litter size is affected by interactions between multiple genes and the environment. While recent studies have identified some genes associated with prolificacy in pigs, transcriptomic studies of specific genes affecting litter size in porcine ovaries are rare. In order to identify candidate genes associated with litter size in swine, we assessed gene expression differences between the ovaries of Yorkshire pigs with extremely high and low litter sizes using the RNA-Seq method. A total of 1 243 differentially expressed genes were identified: 897 genes were upregulated and 346 genes were downregulated in high litter size ovary samples compared with low litter size ovary samples. A large number of these genes related to steroid hormone regulation in animal ovaries, including 59 Gene Ontology terms and 27 Kyoto Encyclopedia of Genes and Genomes pathways involved in steroid biosynthesis and ovarian steroidogenesis. From these differentially expressed genes, we identified a total of 11 genes using a bioinformatics screen that may be associated with high litter size in Yorkshire pigs. These results provide a list of new candidate genes for porcine litter size and prolificacy to be further investigated. PMID:26426260

  12. Design Matters: How School Environment Affects Children.

    ERIC Educational Resources Information Center

    Hebert, Elizabeth A.

    1998-01-01

    The organization of space profoundly affects learning. Students feel better connected to a building that anticipates their needs and respects them as individuals. Built in 1971, Crow Island School, in Winnetka, Illinois, is a prize-winning facility that has provided generations of children with windowed classrooms, skylights, adjacent workrooms,…

  13. Effects of litter manipulation on litter decomposition in a successional gradients of tropical forests in southern China.

    PubMed

    Chen, Hao; Gurmesa, Geshere A; Liu, Lei; Zhang, Tao; Fu, Shenglei; Liu, Zhanfeng; Dong, Shaofeng; Ma, Chuan; Mo, Jiangming

    2014-01-01

    Global changes such as increasing CO2, rising temperature, and land-use change are likely to drive shifts in litter inputs to forest floors, but the effects of such changes on litter decomposition remain largely unknown. We initiated a litter manipulation experiment to test the response of litter decomposition to litter removal/addition in three successional forests in southern China, namely masson pine forest (MPF), mixed coniferous and broadleaved forest (MF) and monsoon evergreen broadleaved forest (MEBF). Results showed that litter removal decreased litter decomposition rates by 27%, 10% and 8% and litter addition increased litter decomposition rates by 55%, 36% and 14% in MEBF, MF and MPF, respectively. The magnitudes of changes in litter decomposition were more significant in MEBF forest and less significant in MF, but not significant in MPF. Our results suggest that change in litter quantity can affect litter decomposition, and this impact may become stronger with forest succession in tropical forest ecosystem. PMID:24901698

  14. Litter chemistry prevails over litter consumers in mediating effects of past steel industry activities on leaf litter decomposition.

    PubMed

    Lucisine, Pierre; Lecerf, Antoine; Danger, Michaël; Felten, Vincent; Aran, Delphine; Auclerc, Apolline; Gross, Elisabeth M; Huot, Hermine; Morel, Jean-Louis; Muller, Serge; Nahmani, Johanne; Maunoury-Danger, Florence

    2015-12-15

    Soil pollution has adverse effects on the performance and life history traits of microorganisms, plants, and animals, yet evidence indicates that even the most polluted sites can support structurally-complex and dynamic ecosystems. The present study aims at determining whether and how litter decomposition, one of the most important soil ecological processes leaf, is affected in a highly trace-metal polluted site. We postulated that past steel mill activities resulting in soil pollution and associated changes in soil characteristics would influence the rate of litter decomposition through two non-exclusive pathways: altered litter chemistry and responses of decomposers to lethal and sub-lethal toxic stress. We carried out a litter-bag experiment using Populus tremula L. leaf litter collected at, and allowed to decompose in, a trace metal polluted site and in three unpolluted sites used as controls. We designed a fully-factorial transplant experimental design to assess effects of litter origin and exposure site on the rate of litter decomposition. We further determined initial litter chemistry, fungal biomass, mesofauna abundance in litter bags, and the soil macrofauna community. Irrespective of the site of litter exposure, litter originating from the polluted site had a two-fold faster decomposition than litter from the unpolluted sites. Litter chemistry, notably the lignin content, seemed most important in explaining the degradation rate of the leaf litter. Abundance of meso and macro-detritivores was higher at the polluted site than at the unpolluted sites. However, litter decomposition proceeded at similar rates in polluted and unpolluted sites. Our results show that trace metal pollution and associated soil and litter changes do not necessarily weaken consumer control on litter decomposition through lethal and sub-lethal toxic stress. PMID:26282755

  15. Microbial mineralization of organic nitrogen forms in poultry litters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia volatilization from the mineralization of uric acid and urea has a major impact on the poultry industry and the environment. Dry acids are a common management practice to reduce ammonia emissions from poultry houses, however little is known about how acidification affects the litter biologic...

  16. Litter-of-origin trait effects on gilt development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The preweaning litter environment of gilts can affect subsequent development. In a recent experiment designed to test the effects of diet on gilt development, individual birth weights, immunocrits, sow parity, number weaned, and individual weaning weights were collected for gilts during the preweani...

  17. Experimental evidence that litter size imposes an oxidative challenge to offspring.

    PubMed

    Gibson, Alyssa B; Garratt, Michael; Brooks, Robert C

    2015-12-01

    The post-natal environment in which young develop can substantially impact development, adult phenotype and fitness. In wild mice, competition among litter-mates affects development rate and adult behaviour. We manipulated post-natal litter size in a cross-fostering design to investigate the effects of enlarged and reduced litter sizes on sexual signalling, oxidative stress and the links between them. Oxidative stress causes somatic damage that can limit reproductive success and lifespan, and is predicted to mediate investment in life-history traits, including sexual signals. We predicted that litter enlargement would cause an increase in potential oxidative stress, inhibit growth and reduce sexual signalling in male mice. Males reared in enlarged litters were smaller at weaning and, despite rapid growth immediately after weaning, remained smaller at 10 weeks of age than those reared in smaller litters. Females from enlarged litters were consistently smaller throughout post-weaning development and showed no increase in growth rate compared with females from reduced litters. In enlarged litters, protein thiol concentration was lower at weaning in the liver and kidneys, with this trend continuing at 10 weeks of age in the kidneys only. Aconitase enzyme activity was also lower in mice from enlarged litters at weaning and 10 weeks of age in the kidneys. Male mice from enlarged litters scent marked more frequently and had larger preputial glands than those from reduced litters, indicating greater sexual signalling investment irrespective of this increased oxidative challenge. The results of this study are the first to reveal oxidative costs of developmental stress in small mammals. PMID:26519509

  18. Decreased Toxicity of Bacillus thuringiensis subsp. israelensis to Mosquito Larvae after Contact with Leaf Litter

    PubMed Central

    Stalinski, Renaud; Kersusan, Dylann; Veyrenc, Sylvie; David, Jean-Philippe; Reynaud, Stéphane; Després, Laurence

    2012-01-01

    Bacillus thuringiensis subsp. israelensis is a bacterium producing crystals containing Cry and Cyt proteins, which are toxic for mosquito larvae. Nothing is known about the interaction between crystal toxins and decaying leaf litter, which is a major component of several mosquito breeding sites and represents an important food source. In the present work, we investigated the behavior of B. thuringiensis subsp. israelensis toxic crystals sprayed on leaf litter. In the presence of leaf litter, a 60% decrease in the amount of Cyt toxin detectable by immunology (enzyme-linked immunosorbent assays [ELISAs]) was observed, while the respective proportions of Cry toxins were not affected. The toxicity of Cry toxins toward Aedes aegypti larvae was not affected by leaf litter, while the synergistic effect of Cyt toxins on all B. thuringiensis subsp. israelensis Cry toxins was decreased by about 20% when mixed with leaf litter. The toxicity of two commercial B. thuringiensis subsp. israelensis strains (VectoBac WG and VectoBac 12AS) and a laboratory-produced B. thuringiensis subsp. israelensis strain decreased by about 70% when mixed with leaf litter. Taken together, these results suggest that Cyt toxins interact with leaf litter, resulting in a decreased toxicity of B. thuringiensis subsp. israelensis in litter-rich environments and thereby dramatically reducing the efficiency of mosquitocidal treatments. PMID:22610426

  19. Evidence for extraintestinal growth of bacteroidales originating from poultry litter.

    PubMed

    Weidhaas, Jennifer; Mantha, Sirisha; Hair, Elliott; Nayak, Bina; Harwood, Valerie J

    2015-01-01

    Water quality monitoring techniques that target microorganisms in the order Bacteroidales are potential alternatives to conventional methods for detection of fecal indicator bacteria. Bacteroidales and members of the genus Bacteroides have been the focus of microbial source tracking (MST) investigations for discriminating sources of fecal pollution (e.g., human or cattle feces) in environmental waters. For accurate source apportionment to occur, one needs to understand both the abundance of Bacteroides in host feces and the survival of these host-associated microbial markers after deposition in the environment. Studies were undertaken to evaluate the abundance, persistence, and potential for growth of Bacteroidales originating from poultry litter under oxic and anoxic environmental conditions. Bacteroidales abundance, as determined by quantitative PCR (qPCR) with GenBac primers and probe, increased 2 to 5 log gene copies ml(-1) and 2 log gene copies g litter(-1) under most conditions during incubation of poultry litter in a variety of laboratory microcosm and field mesocosm studies. DNA sequencing of the Bacteroidales organisms in the litter identified taxa with sequences corresponding exactly to the GenBac primer and probe sequences and that were closely related to Bacteroides uniformis, B. ovatus, and B. vulgatus. These results suggest that MST studies using qPCR methods targeting Bacteroidales in watersheds that are affected by poultry litter should be interpreted cautiously. Growth of Bacteroidales originating from poultry litter in environmental waters may occur while Bacteroidales growth from other fecal sources declines, thus confounding the interpretation of MST results. PMID:25326306

  20. Litter composition effects on decomposition across the litter-soil interface

    EPA Science Inventory

    Background/Question/Methods Many studies have investigated the influence of plant litter species composition on decomposition dynamics, but given the variety of communities and environments around the world, a variety of consequences of litter-mixing have been reported. Litter ...

  1. Considering Affective Responses towards Environments for Enhancing Location Based Services

    NASA Astrophysics Data System (ADS)

    Huang, H.; Gartner, G.; Klettner, S.; Schmidt, M.

    2014-04-01

    A number of studies in the field of environmental psychology show that humans perceive and evaluate their surroundings affectively. Some places are experienced as unsafe, while some others as attractive and interesting. Experiences from daily life show that many of our daily behaviours and decision-making are often influenced by this kind of affective responses towards environments. Location based services (LBS) are often designed to assist and support people's behaviours and decision-making in space. In order to provide services with high usefulness (usability and utility), LBS should consider these kinds of affective responses towards environments. This paper reports on the results of a research project, which studies how people's affective responses towards environments can be modelled and acquired, as well as how LBS can benefit by considering these affective responses. As one of the most popular LBS applications, mobile pedestrian navigation systems are used as an example for illustration.

  2. Litter ammonia generation: moisture content and organic versus inorganic bedding materials.

    PubMed

    Miles, D M; Rowe, D E; Cathcart, T C

    2011-06-01

    Negative impacts on the environment, bird well-being, and farm worker health indicate the need for abatement strategies for poultry litter NH(3) generation. Type of bedding affects many parameters related to poultry production including NH(3) losses. In a randomized complete block design, 3 trials compared the cumulative NH(3) volatilization for laboratory-prepared litter (4 bedding types mixed with excreta) and commercial litter (sampled from a broiler house during the second flock on reused pine wood chips). Litters were assessed at the original moisture content and 2 higher moisture contents. Broiler excrement was mixed with pine wood shavings, rice hulls, sand, and vermiculite to create litter samples. Volumetrically uniform litter samples were placed in chambers receiving humidified air where the exhaust passed through H(3)BO(3) solution, trapping litter-emitted NH(3). At the original moisture content, sand and vermiculite litters generated the most NH(3) (5.3 and 9.1 mg of N, respectively) whereas wood shavings, commercial, and rice hull litters emitted the least NH(3) (0.9-2.6 mg of N). For reducing NH(3) emissions, the results support recommendations for using wood shavings and rice hulls, already popular bedding choices in the United States and worldwide. In this research, the organic bedding materials generated the least NH(3) at the original moisture content when compared with the inorganic materials. For each bedding type, incremental increases in litter moisture content increased NH(3) volatilization. However, the effects of bedding material on NH(3) volatilization at the increased moisture levels were not clearly differentiated across the treatments. Vermiculite generated the most NH(3) (26.3 mg of N) at the highest moisture content. Vermiculite was a novel bedding choice that has a high water absorption capacity, but because of high NH(3) generation, it is not recommended for further study as broiler bedding material. Controlling unnecessary moisture

  3. Responses of litter invertebrate communities to litter manipulation in a Japanese conifer plantation

    NASA Astrophysics Data System (ADS)

    Yoshida, Tomohiro; Takito, Yuki; Soga, Masashi; Hijii, Naoki

    2013-08-01

    We examined how the litter invertebrate communities were affected by the temporal changes in the mass and structural complexity of the litter resources by adding and removing litter on the forest floor of a temperate conifer plantation (Cryptomeria japonica) in Japan. We showed that litter mass and depth in the litter-addition (L+) plots changed rapidly into a steady-state condition similar to those in the control plots, mainly due to accelerated decomposition processes during the rainy season. Higher area-based densities of litter invertebrates in the L+ plots, similar mass-based densities between the L+ and control plots, and significant positive correlations between litter mass and the number of individuals implied that the abundance of litter invertebrates would be governed by litter mass rather than by the litter depth. Many litter invertebrates including detritivores were collected even in the litter-removal (L-) area. The relative abundances of invertebrate predators collecting pitfall traps were higher in the L- plots and lower in the L+ plots compared to those in the control plots, whereas those collecting Tullgren funnels were higher in the L+ plots than in the control plots. In the L+ plots, the range of variation in the community compositions among the samples decreased significantly over time in response to a drastic decrease in litter mass, in contrast to the control plots, which showed a relatively constant community composition during the study period. Our litter manipulation experiment reveals some of the mechanisms responsible for maintaining an equilibrium state of forest-floor litter mass and for the responses of litter invertebrate communities to temporal changes in the litter.

  4. Litter sex composition influences dominance status of Alpine marmots (Marmota marmota).

    PubMed

    Dupont, Pierre; Pradel, Roger; Lardy, Sophie; Allainé, Dominique; Cohas, Aurélie

    2015-11-01

    In social species, the hierarchical status of an individual has important consequences for its fitness. While many studies have focused on individual condition to explain access to dominance, very few have investigated the influence of the social environment, especially during early life. Yet it is known that environmental conditions early in life may influence several traits at adulthood. Here, we examine the influence of early social environment on accession to dominance by investigating the influence of litter size and sex composition on survival and the probability of ascending to dominance later in life using a 20-year dataset from a wild population of Alpine marmots (Marmota marmota). Although litter size had no effect on the fate of individuals, litter sex composition affected male juvenile survival and both male and female probabilities of reaching dominant status when adult. Male juveniles incur lower survival when the number of male juveniles in the litter increases, and individuals of both sexes from male-biased litters are more likely to become dominant than individuals from female-biased litters. However, the absolute number of sisters in the litter, rather than the sex ratio, seems to be an important predictor of the probability of acquiring dominant status: pups having more sisters are less likely to become dominant. Several potential mechanisms to explain these results are discussed. PMID:26169393

  5. Microbial Environment Affects Innate Immunity in Two Closely Related Earthworm Species Eisenia andrei and Eisenia fetida

    PubMed Central

    Dvořák, Jiří; Mančíková, Veronika; Pižl, Václav; Elhottová, Dana; Šilerová, Marcela; Roubalová, Radka; Škanta, František; Procházková, Petra; Bilej, Martin

    2013-01-01

    Survival of earthworms in the environment depends on their ability to recognize and eliminate potential pathogens. This work is aimed to compare the innate defense mechanisms of two closely related earthworm species, Eisenia andrei and Eisenia fetida, that inhabit substantially different ecological niches. While E. andrei lives in a compost and manure, E. fetida can be found in the litter layer in forests. Therefore, the influence of environment-specific microbiota on the immune response of both species was followed. Firstly, a reliable method to discern between E. andrei and E. fetida based on species-specific primers for cytochrome c oxidase I (COI) and stringent PCR conditions was developed. Secondly, to analyze the immunological profile in both earthworm species, the activity and expression of lysozyme, pattern recognition protein CCF, and antimicrobial proteins with hemolytic function, fetidin and lysenins, have been assessed. Whereas, CCF and lysozyme showed only slight differences in the expression and activity, fetidin/lysenins expression as well as the hemolytic activity was considerably higher in E. andrei as compared to E. fetida. The expression of fetidin/lysenins in E. fetida was not affected upon the challenge with compost microbiota, suggesting more substantial changes in the regulation of the gene expression. Genomic DNA analyses revealed significantly higher level of fetidin/lysenins (determined using universal primer pairs) in E. andrei compared to E. fetida. It can be hypothesized that E. andrei colonizing compost as a new habitat acquired an evolutionary selection advantage resulting in a higher expression of antimicrobial proteins. PMID:24223917

  6. Microbial environment affects innate immunity in two closely related earthworm species Eisenia andrei and Eisenia fetida.

    PubMed

    Dvořák, Jiří; Mančíková, Veronika; Pižl, Václav; Elhottová, Dana; Silerová, Marcela; Roubalová, Radka; Skanta, František; Procházková, Petra; Bilej, Martin

    2013-01-01

    Survival of earthworms in the environment depends on their ability to recognize and eliminate potential pathogens. This work is aimed to compare the innate defense mechanisms of two closely related earthworm species, Eisenia andrei and Eisenia fetida, that inhabit substantially different ecological niches. While E. andrei lives in a compost and manure, E. fetida can be found in the litter layer in forests. Therefore, the influence of environment-specific microbiota on the immune response of both species was followed. Firstly, a reliable method to discern between E. andrei and E. fetida based on species-specific primers for cytochrome c oxidase I (COI) and stringent PCR conditions was developed. Secondly, to analyze the immunological profile in both earthworm species, the activity and expression of lysozyme, pattern recognition protein CCF, and antimicrobial proteins with hemolytic function, fetidin and lysenins, have been assessed. Whereas, CCF and lysozyme showed only slight differences in the expression and activity, fetidin/lysenins expression as well as the hemolytic activity was considerably higher in E. andrei as compared to E. fetida. The expression of fetidin/lysenins in E. fetida was not affected upon the challenge with compost microbiota, suggesting more substantial changes in the regulation of the gene expression. Genomic DNA analyses revealed significantly higher level of fetidin/lysenins (determined using universal primer pairs) in E. andrei compared to E. fetida. It can be hypothesized that E. andrei colonizing compost as a new habitat acquired an evolutionary selection advantage resulting in a higher expression of antimicrobial proteins. PMID:24223917

  7. Birth order, family environments, academic and affective outcomes.

    PubMed

    Marjoribanks, Kevin

    2003-06-01

    Relations were examined among birth order, family social status, family learning environments, and a set of affective and academic outcomes. Data were collected as part of an Australian longitudinal study (4,171 females and 3,718 males). Analysis suggested that birth order continued to have small but significant associations with adolescents' self-concept and educational aspirations and with young adults' educational attainment, after taking into account differences in family social status and family learning environments. PMID:12931949

  8. Water addition, evaporation and water holding capacity of poultry litter.

    PubMed

    Dunlop, Mark W; Blackall, Patrick J; Stuetz, Richard M

    2015-12-15

    Litter moisture content has been related to ammonia, dust and odour emissions as well as bird health and welfare. Improved understanding of the water holding properties of poultry litter as well as water additions to litter and evaporation from litter will contribute to improved litter moisture management during the meat chicken grow-out. The purpose of this paper is to demonstrate how management and environmental conditions over the course of a grow-out affect the volume of water A) applied to litter, B) able to be stored in litter, and C) evaporated from litter on a daily basis. The same unit of measurement has been used to enable direct comparison-litres of water per square metre of poultry shed floor area, L/m(2), assuming a litter depth of 5cm. An equation was developed to estimate the amount of water added to litter from bird excretion and drinking spillage, which are sources of regular water application to the litter. Using this equation showed that water applied to litter from these sources changes over the course of a grow-out, and can be as much as 3.2L/m(2)/day. Over a 56day grow-out, the total quantity of water added to the litter was estimated to be 104L/m(2). Litter porosity, water holding capacity and water evaporation rates from litter were measured experimentally. Litter porosity decreased and water holding capacity increased over the course of a grow-out due to manure addition. Water evaporation rates at 25°C and 50% relative humidity ranged from 0.5 to 10L/m(2)/day. Evaporation rates increased with litter moisture content and air speed. Maintaining dry litter at the peak of a grow-out is likely to be challenging because evaporation rates from dry litter may be insufficient to remove the quantity of water added to the litter on a daily basis. PMID:26367067

  9. Evidence for Extraintestinal Growth of Bacteroidales Originating from Poultry Litter

    PubMed Central

    Mantha, Sirisha; Hair, Elliott; Nayak, Bina; Harwood, Valerie J.

    2014-01-01

    Water quality monitoring techniques that target microorganisms in the order Bacteroidales are potential alternatives to conventional methods for detection of fecal indicator bacteria. Bacteroidales and members of the genus Bacteroides have been the focus of microbial source tracking (MST) investigations for discriminating sources of fecal pollution (e.g., human or cattle feces) in environmental waters. For accurate source apportionment to occur, one needs to understand both the abundance of Bacteroides in host feces and the survival of these host-associated microbial markers after deposition in the environment. Studies were undertaken to evaluate the abundance, persistence, and potential for growth of Bacteroidales originating from poultry litter under oxic and anoxic environmental conditions. Bacteroidales abundance, as determined by quantitative PCR (qPCR) with GenBac primers and probe, increased 2 to 5 log gene copies ml−1 and 2 log gene copies g litter−1 under most conditions during incubation of poultry litter in a variety of laboratory microcosm and field mesocosm studies. DNA sequencing of the Bacteroidales organisms in the litter identified taxa with sequences corresponding exactly to the GenBac primer and probe sequences and that were closely related to Bacteroides uniformis, B. ovatus, and B. vulgatus. These results suggest that MST studies using qPCR methods targeting Bacteroidales in watersheds that are affected by poultry litter should be interpreted cautiously. Growth of Bacteroidales originating from poultry litter in environmental waters may occur while Bacteroidales growth from other fecal sources declines, thus confounding the interpretation of MST results. PMID:25326306

  10. Soil moisture regime and soil type affect the decomposition of graminoid litter grown under three levels of atmospheric CO2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increases in atmospheric CO2 can augment the quantity and change the quality of plant carbon (C) inputs into grassland soils. Soil moisture interacts with substrate characteristics and soil properties to affect decomposition and transfer of plant-derived C into soil organic matter (SOM). Thus, pre...

  11. Sibsize, Family Environment, Cognitive Performance, and Affective Characteristics

    ERIC Educational Resources Information Center

    Marjoribanks, Kevin

    1976-01-01

    Incorporates measures of family environment (parent-child interaction) into research methodology to study the effects of sibsize (family size and birth order) on a child's cognitive performance and affective behavior. Provides tentative support for the confluence model of sibsize influences on children's behaviors. (RL)

  12. Litter-Spinning Retarders

    NASA Technical Reports Server (NTRS)

    Wilson, John C.

    1995-01-01

    Aerodynamic plates stop litter from spinning during hoisting by helicopter. Features of proposed litter-spinning retarders include convenience of deployment and independence from ground restraint. Retarder plate(s) folded flat against bottom of litter during storage or while litter is loaded. Plate(s) held in storage position by latch that releases manually or automatically as litter is hoisted. Upon release, springs move plates into deployed position.

  13. Evaluation of broiler litter transportation in northern Alabama, USA.

    PubMed

    Paudel, Krishna P; Adhikari, Murali; Martin, Neil R

    2004-10-01

    The profitability of using broiler litter as a source of crop nutrients was calculated using a phosphorus-consistent litter application rule. A ton of litter can cost effectively be transported up to 164 miles from the production facility. A cost-minimizing phosphorus-consistent transportation model developed to meet the nutrient needs of 29 counties in northern Alabama revealed that not all of the litter can be utilized in the region. The total cost increased when transportation of the litter out of the heavily surplus counties was prioritized. Total litter use was minimally affected by changes in chemical fertilizer prices. Shadow prices indicated the robustness of the model. PMID:15327843

  14. High litter moisture content suppresses litter ammonia volatilization.

    PubMed

    Miles, D M; Rowe, D E; Cathcart, T C

    2011-07-01

    With global food demand expected to increase by 100% in the next 50 yr, urgency to combine comprehensive strategies for sustainable, efficacious, and environmentally sensible agronomic practices has never been greater. One effort for US meat bird management is to reduce NH(3) volatilization from litter to create a better growing environment for the birds, improve production efficiency, retain N in litter for fertilizer value, and negate the detrimental environmental impacts of NH(3) loss to the air. To derive the fundamental effects of temperature and moisture on litter NH(3) volatilization over the range of conditions found in commercial houses, experiments were conducted using commercial broiler litter that had moisture contents of approximately 20 to 55% while controlling temperatures ranging from 18.3 to 40.6°C. Litter samples (100 g) were placed in 1-L containers that received humidified air at approximately 113 mL/min. Volatilized NH(3) in exhaust air was captured in H(3)BO(3) traps. Ammonia loss (log(10) transformation) was modeled via an equation using linear coefficients for temperature and moisture, an interaction term for temperature × moisture, and a quadratic term for moisture. The surface responses resembled parabolic cylinders, indicating a critical moisture level at which NH(3) no longer increases but is diminished as moisture continues to increase. The critical moisture level lies between 37.4 and 51.1% litter moisture, depending on the temperature. An increase in temperature consistently increased NH(3) generation. When the temperature extremes were compared, the maximum NH(3) was up to 7 times greater at 40.6 vs. 18.3°C. The upper moisture limit at which NH(3) release is maximized and subsequently arrested as moisture continues to increase had not been defined previously for commercial broiler litter. The poultry industry and researchers can use these results as a decision tool to enable management strategies that limit NH(3) production. PMID

  15. Analysis of candidate genes underlying two epistatic quantitative trait loci on SSC12 affecting litter size in pig.

    PubMed

    Fernández-Rodríguez, A; Rodríguez, C; Varona, L; Balcells, I; Noguera, J L; Ovilo, C; Fernández, A I

    2010-02-01

    The previous results from a genome scan for total number of piglets born and number of piglets born alive in a F(2) Iberian by Meishan intercross showed several single and epistatic QTL. One of the most interesting results was obtained for SSC12, where two QTL affecting both traits showed epistatic interaction. In this study, we proposed two genes (SLC9A3R1 and NOS2) as biological and potentially positional candidates underlying these QTL. Both cDNAs were characterized and 23 polymorphisms were detected. A chromosome scan was conducted with 12 markers, plus one SNP in SLC9A3R1 and one in NOS2, covering 110 cM of SSC12. The epistatic QTL (QTL1 at 15 cM and QTL2 at 97 cM) were confirmed, and SLC9A3R1 and NOS2 were mapped around the QTL1 and QTL2 regions respectively. Several SNPs in both genes were tested with standard animal model and marker assisted association tests. The most significant results were obtained with the NOS2 haplotype defined by one missense SNP c.2192C > T (Val to Ala) and a 15 bp duplication at the 3'UTR. This duplication seems to include AU-rich elements, and could be a target site for miRNA, therefore there are statistical and biological indications to consider this haplotype as the potential causal mutation underlying QTL2. SLC9A3R1 results were not conclusive. Although the interaction between the SNPs was not significant, we cannot reject the possibility of interaction of the NOS2 haplotype with other polymorphisms closely linked to the SL9A3R1 SNPs analysed. PMID:19793269

  16. Effects of prescribed burning and litter type on litter decomposition and nutrient release in mixed-grass prairie in Eastern Montana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fire can affect litter decomposition and carbon (C) and nitrogen (N) dynamics. Here, we examined the effect of summer fire and three litter types on litter decomposition and litter C and N dynamics in a northern mixed-grass prairie over a 24 month period starting ca. 14 months after fire. Over all...

  17. Chinese herbal medicine for miscarriage affects decidual micro-environment and fetal growth

    PubMed Central

    Piao, L.; Chen, C.-P.; Yeh, C.-C.; Basar, M.; Masch, R.; Cheng, Y.-C.; Lockwood, C. J.; Schatz, F.; Huang, S. J.

    2015-01-01

    Introduction Intrauterine growth restriction complicates 5 - 10% of pregnancies. This study aims to test the hypothesis that Chinese herbal formula, JLFC01, affects pregnancy and fetal development by modulating the pro-inflammatory decidual micro-environment. Methods Human decidua from gestational age-matched elective terminations or incomplete/missed abortion was immunostained using anti-CD68 + anti-CD86 or anti-CD163 antibodies. qRT-PCR and Luminex assay measured the effects of JLFC01 on IL-1β- or TNF-α-induced cytokine expression in first trimester decidual cells and on an established spontaneous abortion/intrauterine growth restriction (SA/IUGR)-prone mouse placentae. The effect of JLFC01 on human endometrial endothelial cell angiogenesis was evaluated by average area, length and numbers of branching points of tube formation. Food intake, litter size, fetal weight, placental weight and resorption rate were recorded in SA/IUGR-prone mouse treated with JLFC01. qRT-PCR, Western blot and immunohistochemistry assessed the expression of mouse placental IGF-I and IGF-IR. Results In spontaneous abortion, numbers of decidual macrophages expressing CD86 and CD163 are increased and decreased, respectively. JLFC01 reduces IL-1β- or TNF-α-induced GM-CSF, M-CSF, C-C motif ligand 2 (CCL2), interferon-γ-inducible protein-10 (IP-10), CCL5 and IL-8 production in first trimester decidual cells. JLFC01 suppresses the activity of IL-1β- or TNF-α-treated first trimester decidual cells in enhancing macrophage-inhibited angiogenesis. In SA/IUGR-prone mice, JLFC01 increases maternal food intake, litter size, fetal and placental weight, and reduces fetal resorption rate. JLFC01 induces IGF-I and IGF-IR expression and inhibits M-CSF, CCL2, CCL5, CCL11, CCL3 and G-CSF expression in the placentae. Discussion JLFC01 improves gestation by inhibiting decidual inflammation, enhancing angiogenesis and promoting fetal growth. PMID:25771406

  18. Microarthropods accelerate litter decomposition and alter the fate of litter carbon and nitrogen in the soil

    NASA Astrophysics Data System (ADS)

    Soong, Jennifer; Horton, Andrew; Wall, Diana; Cotrufo, Francesca

    2015-04-01

    Soil fauna have been found to accelerate litter decomposition in some ecosystems, with calls for the need to include them in global models of C and N cycling. However, their influence on the fate of decomposing litter C and N is not clear. Does the acceleration of mass loss affect how much litter C and N end up stored as soil organic matter (SOM), or how much C and N are lost to the atmosphere during decomposition? We will present the results from our three-year, 100% mass loss, tracking of 13C and 15N labeled Andropogon gerardii leaf litter decomposing at a tallgrass prairie site, where we used a naphthalene treatment to suppress microarthropods and examine their effects on the fate of decomposing litter C and N. Initially, leaching was the main pathway of litter inputs to the mineral associated SOM. We found that microarthropods accelerated the first 18 months of litter mass loss, but after 24 months mass loss rates converged. This early acceleration of mass loss was associated with an increase of litter fragment inputs to the soil. This increase in litter inputs to the soil caused by microarthropods resulted in an increase in microbial uptake of litter C (measured by tracing 13C into phospholipid fatty acids), and a shift in the microbial community. The C:N ratio of litter inputs to the soil was significantly increased by the presence of microarthropods. Together these results demonstrate how microarthropods accelerate shredding, mass loss, and litter fragment inputs to the soil during the early stages of decomposition but they do not affect the total amount of litter contribution to SOM over the entire course of decomposition. However, microarthropods do alter the C:N composition of litter inputs to the soil through their top-down influence on the microbial community responsible for decomposing and transforming litter inputs to the soil. Our results reveal the complex interactions between microarthropods, litter mass loss, soil microbes and C:N dynamics, and

  19. Cigarette litter: smokers' attitudes and behaviors.

    PubMed

    Rath, Jessica M; Rubenstein, Rebecca A; Curry, Laurel E; Shank, Sarah E; Cartwright, Julia C

    2012-06-01

    Cigarette butts are consistently the most collected items in litter clean-up efforts, which are a costly burden to local economies. In addition, tobacco waste may be detrimental to our natural environment. The tobacco industry has conducted or funded numerous studies on smokers' littering knowledge and behavior, however, non-industry sponsored research is rare. We sought to examine whether demographics and smokers' knowledge and beliefs toward cigarette waste as litter predicts littering behavior. Smokers aged 18 and older (n = 1,000) were interviewed about their knowledge and beliefs towards cigarette waste as litter. Respondents were members of the Research Now panel, an online panel of over three million respondents in the United States. Multivariate logistic regressions were conducted to determine factors significantly predictive of ever having littered cigarette butts or having littered cigarette butts within the past month (p-value < 0.05). The majority (74.1%) of smokers reported having littered cigarette butts at least once in their life, by disposing of them on the ground or throwing them out of a car window. Over half (55.7%) reported disposing of cigarette butts on the ground, in a sewer/gutter, or down a drain in the past month. Those who did not consider cigarette butts to be litter were over three and half times as likely to report having ever littered cigarette butts (OR = 3.68, 95%CI = 2.04, 6.66) and four times as likely to have littered cigarette butts in the past month (OR = 4.00, 95%CI = 2.53, 6.32). Males were significantly more likely to have littered cigarette butts in the past month compared to females (OR = 1.49, 95%CI = 1.14, 1.94). Holding the belief that cigarette butts are not litter was the only belief in this study that predicted ever or past-month littering of cigarette waste. Messages in anti-cigarette-litter campaigns should emphasize that cigarette butts are not just litter but are toxic waste and are harmful when disposed of

  20. Cigarette Litter: Smokers’ Attitudes and Behaviors

    PubMed Central

    Rath, Jessica M.; Rubenstein, Rebecca A.; Curry, Laurel E.; Shank, Sarah E.; Cartwright, Julia C.

    2012-01-01

    Cigarette butts are consistently the most collected items in litter clean-up efforts, which are a costly burden to local economies. In addition, tobacco waste may be detrimental to our natural environment. The tobacco industry has conducted or funded numerous studies on smokers’ littering knowledge and behavior, however, non-industry sponsored research is rare. We sought to examine whether demographics and smokers’ knowledge and beliefs toward cigarette waste as litter predicts littering behavior. Smokers aged 18 and older (n = 1,000) were interviewed about their knowledge and beliefs towards cigarette waste as litter. Respondents were members of the Research Now panel, an online panel of over three million respondents in the United States. Multivariate logistic regressions were conducted to determine factors significantly predictive of ever having littered cigarette butts or having littered cigarette butts within the past month (p-value < 0.05). The majority (74.1%) of smokers reported having littered cigarette butts at least once in their life, by disposing of them on the ground or throwing them out of a car window. Over half (55.7%) reported disposing of cigarette butts on the ground, in a sewer/gutter, or down a drain in the past month. Those who did not consider cigarette butts to be litter were over three and half times as likely to report having ever littered cigarette butts (OR = 3.68, 95%CI = 2.04, 6.66) and four times as likely to have littered cigarette butts in the past month (OR = 4.00, 95%CI = 2.53, 6.32). Males were significantly more likely to have littered cigarette butts in the past month compared to females (OR = 1.49, 95%CI = 1.14, 1.94). Holding the belief that cigarette butts are not litter was the only belief in this study that predicted ever or past-month littering of cigarette waste. Messages in anti-cigarette-litter campaigns should emphasize that cigarette butts are not just litter but are toxic waste and are harmful when disposed of

  1. How Environment Affects Galaxy Metallicity: Lessons from the Illustris Simulation

    NASA Astrophysics Data System (ADS)

    Genel, S.

    2016-06-01

    Recent studies have found higher galaxy metallicities in richer environments. It is not yet clear, however, whether metallicity-environment dependencies are merely an indirect consequence of environmentally dependent formation histories, or of environment related processes directly affecting metallicity. Here, we present a detailed study of metallicity-environment correlations in a cosmological hydrodynamical simulation, in particular the Illustris simulation. Illustris galaxies display similar relations to those observed. Utilizing our knowledge of simulated formation histories, and leveraging the large simulation volume, we construct galaxy samples of satellites and centrals that are matched in formation histories. This allows us to find that ˜1/3 of the metallicity-environment correlation is due to different formation histories in different environments. This is a combined effect of satellites (in particular, in denser environments) having on average lower z=0 star formation rates (SFRs), and of their older stellar ages, even at a given z=0 SFR. Most of the difference, ˜2/3, however, is caused by the higher concentration of star-forming disks of satellite galaxies, as this biases their SFR-weighted metallicities toward their inner, more metal-rich parts. With a newly defined quantity, the `radially averaged' metallicity, which captures the metallicity profile but is independent of the SFR profile, the metallicities of satellites and centrals become environmentally independent once they are matched in formation history. This effect may also explain most of the differences between metallicities of galaxies in different large-scale environmental densities. A prediction for observations is that those differences become smaller as smaller apertures are considered.

  2. Litter of origin effects on gilt development in a commercial setting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The preweaning litter environment of gilts can affect subsequent development. In a recent experiment designed to test the effects of dietary ME and lysine on gilt development, individual birth weights, immunocrits (related to colostrum intake), sow parity, number weaned, individual weaning weights, ...

  3. Natural zeolites in diet or litter of broilers.

    PubMed

    Schneider, A F; Almeida, D S De; Yuri, F M; Zimmermann, O F; Gerber, M W; Gewehr, C E

    2016-04-01

    This study aims to analyse the influence of adding natural zeolites (clinoptilolite) to the diet or litter of broilers and their effects on growth performance, carcass yield and litter quality. Three consecutive flocks of broilers were raised on the same sawdust litter, from d 1 to d 42 of age, and distributed in three treatments (control with no added zeolites, addition of 5 g/kg zeolite to diet and addition of 100 g/kg zeolites to litter). The addition of zeolites to the diet or litter did not affect growth performance or carcass yield. The addition of zeolites to the diet did not influence moisture content of the litter, ammonia volatilisation was reduced only in the first flock and pH of litter was reduced in the second and third flock. However, the addition of zeolites to the litter reduced moisture content, litter pH and ammonia volatilisation in all flocks analysed. The addition of 5 g/kg zeolite to the diet in three consecutive flocks was not effective in maintaining litter quality, whereas the addition of 100 g/kg natural zeolites to sawdust litter reduced litter moisture and ammonia volatilisation in three consecutive flocks raised on the same litter. PMID:26879673

  4. Litter quality versus soil microbial community controls over decomposition: a quantitative analysis

    USGS Publications Warehouse

    Cleveland, Cory C.; Reed, Sasha C.; Keller, Adrienne B.; Nemergut, Diana R.; O'Neill, Sean P.; Ostertag, Rebecca; Vitousek, Peter M.

    2014-01-01

    The possible effects of soil microbial community structure on organic matter decomposition rates have been widely acknowledged, but are poorly understood. Understanding these relationships is complicated by the fact that microbial community structure and function are likely to both affect and be affected by organic matter quality and chemistry, thus it is difficult to draw mechanistic conclusions from field studies. We conducted a reciprocal soil inoculum × litter transplant laboratory incubation experiment using samples collected from a set of sites that have similar climate and plant species composition but vary significantly in bacterial community structure and litter quality. The results showed that litter quality explained the majority of variation in decomposition rates under controlled laboratory conditions: over the course of the 162-day incubation, litter quality explained nearly two-thirds (64 %) of variation in decomposition rates, and a smaller proportion (25 %) was explained by variation in the inoculum type. In addition, the relative importance of inoculum type on soil respiration increased over the course of the experiment, and was significantly higher in microcosms with lower litter quality relative to those with higher quality litter. We also used molecular phylogenetics to examine the relationships between bacterial community composition and soil respiration in samples through time. Pyrosequencing revealed that bacterial community composition explained 32 % of the variation in respiration rates. However, equal portions (i.e., 16 %) of the variation in bacterial community composition were explained by inoculum type and litter quality, reflecting the importance of both the meta-community and the environment in bacterial assembly. Taken together, these results indicate that the effects of changing microbial community composition on decomposition are likely to be smaller than the potential effects of climate change and/or litter quality changes in

  5. Non-native plant litter enhances soil carbon dioxide emissions in an invaded annual grassland.

    PubMed

    Zhang, Ling; Wang, Hong; Zou, Jianwen; Rogers, William E; Siemann, Evan

    2014-01-01

    Litter decomposition is a fundamental ecosystem process in which breakdown and decay of plant detritus releases carbon and nutrients. Invasive exotic plants may produce litter that differs from native plant litter in quality and quantity. Such differences may impact litter decomposition and soil respiration in ways that depend on whether exotic and native plant litters decompose in mixtures. However, few field experiments have examined how exotic plants affect soil respiration via litter decomposition. Here, we conducted an in situ study of litter decomposition of an annual native grass (Eragrostis pilosa), a perennial exotic forb (Alternanthera philoxeroides), and their mixtures in an annual grassland in China to examine potential invasion effects on soil respiration. Alternanthera litter decomposed faster than Eragrostis litter when each was incubated separately. Mass loss in litter mixes was more rapid than predicted from rates in single species bags (only 35% of predicted mass remained at 8 months) showing synergistic effects. Notably, exotic plant litter decomposition rate was unchanged but native plant litter decomposition rate was accelerated in mixtures (decay constant k = 0.20 month(-1)) compared to in isolation (k = 0.10 month(-1)). On average, every litter type increased soil respiration compared to bare soil from which litter was removed. However, the increases were larger for mixed litter (1.82 times) than for Alternanthera litter (1.58 times) or Eragrostis litter (1.30 times). Carbon released as CO2 relative to litter carbon input was also higher for mixed litter (3.34) than for Alternathera litter (2.29) or Eragrostis litter (1.19). Our results indicated that exotic Alternanthera produces rapidly decomposing litter which also accelerates the decomposition of native plant litter in litter mixtures and enhances soil respiration rates. Thus, this exotic invasive plant species will likely accelerate carbon cycling and increase soil respiration

  6. Nitrogen and Phosphorus Loads in an Agricultural Watershed Affected by Poultry Litter Application and Wastewater Effluent, Northeastern Oklahoma and Northwestern Arkansas, 2002-2009

    NASA Astrophysics Data System (ADS)

    Esralew, R.; Tortorelli, R. L.

    2010-12-01

    The Eucha-Spavinaw Basin in Northeastern Oklahoma and Northwestern Arkansas is the source of water for Lake Eucha and Spavinaw Lake, which are part of the water supply for the city of Tulsa, Oklahoma. Lake Eucha and Spavinaw Lakes have experienced deteriorating water quality largely due to growth of algae, notably cyanobacteria, from the excess input of nutrients. As a result, the city of Tulsa has spent millions of dollars to eliminate taste and odor problems resulting from production of algal and bacterial byproducts. To evaluate changes in nutrient loading resulting from a reduction in land application of poultry litter, installation of best management practices, and reductions in the phosphorus concentrations in wastewater effluent, the U.S. Geological Survey investigated nitrogen and phosphorus concentrations from samples collected during baseflow and runoff and used regression models to estimate nitrogen and phosphorus loads, yields, and flow-weighted concentrations in two major tributaries to Lake Eucha, Spavinaw and Beaty Creeks, for the period 2002-2009. Estimated mean flow-weighted total unfiltered nitrogen and phosphorus concentrations in the basin were about 5 to 10 times greater than the 75th percentile of flow-weighted nutrient concentrations in other mostly undeveloped basins of the United States. Spavinaw and Beaty Creeks contributed an estimated mean annual total load of about 762,500 kilograms of nitrogen and 49,200 kilograms of phosphorus per year, 76 to 91 percent of which was transported to Lake Eucha by runoff. Thirty-four percent of the nitrogen load and 48 percent of the phosphorus load to Lake Eucha occurred during the year 2008 which was the wettest year on record for the Eucha-Spavinaw Basin. The results of this analysis indicate that although efforts were made to control nutrient loading, nutrient concentrations, especially phosphorus, were substantially augmented by non-point sources and that most loading occurs during runoff events

  7. Carbon redistribution during interrill erosion in subtropical forests: Effects of leaf litter diversity and soil fauna

    NASA Astrophysics Data System (ADS)

    Goebes, Philipp; Seitz, Steffen; Kühn, Peter; Scholten, Thomas

    2016-04-01

    Soil erosion is crucial for degradation of carbon (C) from their pools in the soil. If C of the eroded sediment and runoff are not only related to soil pools but also resulting additively from decomposition of litter cover, the system gets more complex. The role of these amounts for C cycling in a forest environment is not yet known properly and thus, the aim of this study was to investigate the role of leaf litter diversity, litter cover and soil fauna on C redistribution during interrill erosion. We established 96 runoff plots that were deployed with seven domestic leaf litter species resulting in none species (bare ground), 1-species, 2-species and 4-species mixtures. Every second runoff plot was equipped with a fauna extinction feature to investigate the role of soil meso- and macrofauna. Erosion processes were initiated using a rainfall simulator at two time steps (summer 2012 and autumn 2012) to investigate the role of leaf litter decomposition on C redistribution. C fluxes during 20 min rainfall simulation were 99.13 ± 94.98 g/m². C fluxes and C contents both were affected by soil fauna. C fluxes were higher with presence of soil fauna due to loosening and slackening of the soil surface rather than due to faster decomposition of leaves. In contrast, C contents were higher in the absence of soil fauna possibly resulting from a missing dilution effect in the top soil layer. Leaf litter diversity did not affect C fluxes, but indirectly affected C contents as it increased the soil fauna effect with higher leaf litter diversity due to superior food supply. Initial C contents in the soil mainly determined those of the eroded sediment. For future research, it will be essential to introduce a long-term decomposition experiment to get further insights into the processes of C redistribution.

  8. A sea anemone's environment affects discharge of its isolated nematocysts.

    PubMed

    Greenwood, Paul G; Balboni, Imelda M; Lohmann, Cynthia

    2003-02-01

    Nematocysts were isolated from individuals of Calliactis tricolor maintained under different feeding schedules or in different salinities in an attempt to determine how these culture conditions influence the discharge of isolated nematocysts. In addition, the discharge frequencies of nematocysts isolated from two different populations of sea anemones found in two different environments were also compared. Undischarged acontial nematocysts were isolated by extrusion into 1 M sodium citrate and were then treated with 5 mM EGTA to initiate discharge. Nematocysts isolated from anemones maintained under three different feeding schedules showed significantly different responses to the test solution. Nematocysts isolated from anemones maintained in two different salinities did not differ significantly in discharge frequency. Nematocysts isolated from individuals from two separate populations of C. tricolor responded significantly differently to 5 mM EGTA and to deionized water, and these responses also depended upon the isolation solution used. Environmental conditions are known to have an impact on the physiological state of most organisms, but this is the first study providing evidence that the environment or feeding state of an anemone affects discharge of isolated nematocysts. Inherent differences in ionic and osmotic characteristics among nematocysts could explain some of the ambiguities when comparing past studies of isolated nematocyst discharge. PMID:12547257

  9. Mixing effects on litter decomposition rates in a young tree diversity experiment

    NASA Astrophysics Data System (ADS)

    Setiawan, Nuri Nurlaila; Vanhellemont, Margot; De Schrijver, An; Schelfhout, Stephanie; Baeten, Lander; Verheyen, Kris

    2016-01-01

    Litter decomposition is an essential process for biogeochemical cycling and for the formation of new soil organic matter. Mixing litter from different tree species has been reported to increase litter decomposition rates through synergistic effects. We assessed the decomposition rates of leaf litter from five tree species in a recently established tree diversity experiment on a post-agriculture site in Belgium. We used 20 different leaf litter compositions with diversity levels ranging from 1 up to 4 species. Litter mass loss in litterbags was assessed 10, 20, 25, 35, and 60 weeks after installation in the field. We found that litter decomposition rates were higher for high-quality litters, i.e., with high nitrogen content and low lignin content. The decomposition rates of mixed litter were more affected by the identity of the litter species within the mixture than by the diversity of the litter per se, but the variability in litter decomposition rates decreased as the litter diversity increased. Among the 15 different mixed litter compositions in our study, only three litter combinations showed synergistic effects. Our study suggests that admixing tree species with high-quality litter in post-agricultural plantations helps in increasing the mixture's early-stage litter decomposition rate.

  10. Effect of Fresh Poultry Litter and Compost on Soil Physical and Chemical Properties

    NASA Technical Reports Server (NTRS)

    Carr, Stacy; Tsegaye, Teferi; Coleman, Tommy

    1998-01-01

    Application of poultry litter and compost as a substitute for fertilizer not only uses unwanted waste and decreases expenditures for commercial fertilizer, it adds nutrients to soil for plant uptake. The properties of soil affected by poultry litter were analyzed to determine the positive and negative aspects of using this substitute fertilizer. This study focused on changes associated with saturated hydraulic conductivity, bulk density, nitrate concentrations, and pH after application of varying concentrations of poultry litter and compost. Soil samples from Tennessee Valley Substation in Alabama were analyzed in a laboratory at Alabama A&M University. As a result of the application of fresh poultry litter and compost, we found that the saturated hydraulic conductivity increased and the bulk density decreased, while the pH was generally not affected. Using poultry litter and compost as an alternative commercial fertilizers could be adapted by the farming community to protect the sustainability of our environment. Unwanted waste is used productively and soil is enriched for farming.

  11. The impact of alum addition on organic P transformations in poultry litter and litter-amended soil.

    PubMed

    Warren, Jason G; Penn, Chad J; McGrath, Joshua M; Sistani, Karamat

    2008-01-01

    Poultry litter treatment with alum (Al(2)(SO(4))(3) . 18H(2)O) lowers litter phosphorus (P) solubility and therefore can lower litter P release to runoff after land application. Lower P solubility in litter is generally attributed to aluminum-phosphate complex formation. However, recent studies suggest that alum additions to poultry litter may influence organic P mineralization. Therefore, alum-treated and untreated litters were incubated for 93 d to assess organic P transformations during simulated storage. A 62-d soil incubation was also conducted to determine the fate of incorporated litter organic P, which included alum-treated litter, untreated litter, KH(2)PO(4) applied at 60 mg P kg(-1) of soil, and an unamended control. Liquid-state (31)P nuclear magnetic resonance indicated that phytic acid was the only organic P compound present, accounting for 50 and 45% of the total P in untreated and alum-treated litters, respectively, before incubation and declined to 9 and 37% after 93 d of storage-simulating incubation. Sequential fractionation of litters showed that alum addition to litter transformed 30% of the organic P from the 1.0 mol L(-1) HCl to the 0.1 mol L(-1) NaOH extractable fraction and that both organic P fractions were more persistent in alum-treated litter compared with untreated litter. The soil incubation revealed that 0.1 mol L(-1) NaOH-extractable organic P was more recalcitrant after mixing than was the 1.0 mol L(-1) HCl-extractable organic P. Thus, adding alum to litter inhibits organic P mineralization during storage and promotes the formation of alkaline extractable organic P that sustains lower P solubility in the soil environment. PMID:18268310

  12. Video-Based Affect Detection in Noninteractive Learning Environments

    ERIC Educational Resources Information Center

    Chen, Yuxuan; Bosch, Nigel; D'Mello, Sidney

    2015-01-01

    The current paper explores possible solutions to the problem of detecting affective states from facial expressions during text/diagram comprehension, a context devoid of interactive events that can be used to infer affect. These data present an interesting challenge for face-based affect detection because likely locations of affective facial…

  13. Watching eyes on potential litter can reduce littering: evidence from two field experiments.

    PubMed

    Bateson, Melissa; Robinson, Rebecca; Abayomi-Cole, Tim; Greenlees, Josh; O'Connor, Abby; Nettle, Daniel

    2015-01-01

    Littering constitutes a major societal problem, and any simple intervention that reduces its prevalence would be widely beneficial. In previous research, we have found that displaying images of watching eyes in the environment makes people less likely to litter. Here, we investigate whether the watching eyes images can be transferred onto the potential items of litter themselves. In two field experiments on a university campus, we created an opportunity to litter by attaching leaflets that either did or did not feature an image of watching eyes to parked bicycles. In both experiments, the watching eyes leaflets were substantially less likely to be littered than control leaflets (odds ratios 0.22-0.32). We also found that people were less likely to litter when there other people in the immediate vicinity than when there were not (odds ratios 0.04-0.25) and, in one experiment but not the other, that eye leaflets only reduced littering when there no other people in the immediate vicinity. We suggest that designing cues of observation into packaging could be a simple but fruitful strategy for reducing littering. PMID:26644979

  14. Watching eyes on potential litter can reduce littering: evidence from two field experiments

    PubMed Central

    Bateson, Melissa; Robinson, Rebecca; Abayomi-Cole, Tim; Greenlees, Josh; O’Connor, Abby

    2015-01-01

    Littering constitutes a major societal problem, and any simple intervention that reduces its prevalence would be widely beneficial. In previous research, we have found that displaying images of watching eyes in the environment makes people less likely to litter. Here, we investigate whether the watching eyes images can be transferred onto the potential items of litter themselves. In two field experiments on a university campus, we created an opportunity to litter by attaching leaflets that either did or did not feature an image of watching eyes to parked bicycles. In both experiments, the watching eyes leaflets were substantially less likely to be littered than control leaflets (odds ratios 0.22–0.32). We also found that people were less likely to litter when there other people in the immediate vicinity than when there were not (odds ratios 0.04–0.25) and, in one experiment but not the other, that eye leaflets only reduced littering when there no other people in the immediate vicinity. We suggest that designing cues of observation into packaging could be a simple but fruitful strategy for reducing littering. PMID:26644979

  15. Environmental fate of roxarsone in poultry litter. Part II. Mobility of arsenic in soils amended with poultry litter

    USGS Publications Warehouse

    Rutherford, D.W.; Bednar, A.J.; Garbarino, J.R.; Needham, R.; Staver, K.W.; Wershaw, R. L.

    2003-01-01

    Poultry litter often contains arsenic as a result of organo-arsenical feed additives. When the poultry litter is applied to agricultural fields, the arsenic is released to the environment and may result in increased arsenic in surface and groundwater and increased uptake by plants. The release of arsenic from poultry litter, litter-amended soils, and soils without litter amendment was examined by extraction with water and strong acids (HCI and HN03). The extracts were analyzed for As, C, P, Cu, Zn, and Fe. Copper, zinc, and iron are also poultry feed additives. Soils with a known history of litter application and controlled application rate of arsenic-containing poultry litter were obtained from the University of Maryland Agricultural Experiment Station. Soils from fields with long-term application of poultry litter were obtained from a tilled field on the Delmarva Peninsula (MD) and an untilled Oklahoma pasture. Samples from an adjacent forest or nearby pasture that had no history of litter application were used as controls. Depth profiles were sampled for the Oklahoma pasture soils. Analysis of the poultry litter showed that 75% of the arsenic was readily soluble in water. Extraction of soils shows that weakly bound arsenic mobilized by water correlates positively with C, P, Cu, and Zn in amended fields and appears to come primarily from the litter. Strongly bound arsenic correlates positively with Fe in amended fields and suggests sorption or coprecipitation of As and Fe in the soil column.

  16. Influence of waste management policy on the characteristics of beach litter in Kaohsiung, Taiwan.

    PubMed

    Liu, Ta-Kang; Wang, Meng-Wei; Chen, Ping

    2013-07-15

    Marine debris is a ubiquitous problem that poses a serious threat to the global oceans; it has motivated public participation in clean-up campaigns, as well as governmental involvement in developing mitigation strategies. While it is known that the problem of marine litter may be affected by waste management practices on land, beach survey results have seldom been compared with them. In this study, marine litter surveys on four beaches of Cijin Island were conducted to explore the effects of waste management and policy implications. Indirect evidence shows that chances for land-based litter, such as plastic bags and bottles, entering the marine environment can be greatly decreased if they can be properly reduced, reused and recycled. We suggest that mitigation measures should focus on source reduction, waste recycling and management, utilizing effective economic instruments, and pursuing a long-term public education campaign to raise the public awareness of this problem. PMID:23673204

  17. Parents and Early Life Environment Affect Behavioral Development of Laying Hen Chickens

    PubMed Central

    de Haas, Elske N.; Bolhuis, J. Elizabeth; Kemp, Bas; Groothuis, Ton G. G.; Rodenburg, T. Bas

    2014-01-01

    Severe feather pecking (SFP) in commercial laying hens is a maladaptive behavior which is associated with anxiety traits. Many experimental studies have shown that stress in the parents can affect anxiety in the offspring, but until now these effects have been neglected in addressing the problem of SFP in commercially kept laying hens. We therefore studied whether parental stock (PS) affected the development of SFP and anxiety in their offspring. We used flocks from a brown and white genetic hybrid because genetic background can affect SFP and anxiety. As SFP can also be influenced by housing conditions on the rearing farm, we included effects of housing system and litter availability in the analysis. Forty-seven rearing flocks, originating from ten PS flocks were followed. Behavioral and physiological parameters related to anxiety and SFP were studied in the PS at 40 weeks of age and in the rearing flocks at one, five, ten and fifteen weeks of age. We found that PS had an effect on SFP at one week of age and on anxiety at one and five weeks of age. In the white hybrid, but not in the brown hybrid, high levels of maternal corticosterone, maternal feather damage and maternal whole-blood serotonin levels showed positive relations with offsprings’ SFP at one week and offsprings’ anxiety at one and five weeks of age. Disruption and limitation of litter supply at an early age on the rearing farms increased SFP, feather damage and fearfulness. These effects were most prominent in the brown hybrid. It appeared that hens from a brown hybrid are more affected by environmental conditions, while hens from a white hybrid were more strongly affected by parental effects. These results are important for designing measures to prevent the development of SFP, which may require a different approach in brown and white flocks. PMID:24603500

  18. UVB Exposure Does Not Accelerate Rates of Litter Decomposition in a Semiarid Riparian Ecosystem

    NASA Astrophysics Data System (ADS)

    Uselman, S. M.; Snyder, K. A.; Blank, R. R.; Jones, T. J.

    2010-12-01

    Aboveground litter decomposition is controlled mainly by substrate quality and climate factors across terrestrial ecosystems, but photodegradation from exposure to high-intensity ultraviolet-B (UVB) radiation may also be important in arid and semi-arid environments. We investigated the interactive effects of UVB exposure and litter quality on decomposition in a Tamarix-invaded riparian ecosystem during the establishment of an insect biological control agent in northern Nevada. Feeding by the northern tamarisk beetle (Diorhabda carinulata) on Tamarix spp. trees leads to altered leaf litter quality and increased exposure to solar UVB radiation from canopy opening. In addition, we examined the dynamics of litter decomposition of the invasive exotic Lepidium latifolium, because it is well-situated to invade beetle-infested Tamarix sites. Three leaf litter types (natural Tamarix, beetle-affected Tamarix, and L. latifolium) differing in substrate quality were decomposed in litterbags for one year in the field. Litterbags were subjected to one of three treatments: (1) Ambient UVB or (2) Reduced UVB (where UVB was manipulated by using clear plastic films that transmit or block UVB), and (3) No Cover (a control used to test for the effect of using the plastic films, i.e. a cover effect). Results showed a large cover effect on rates of decomposition and nutrient release, and our findings suggested that frequent cycles of freeze-thaw, and possibly rainfall intensity, influenced decomposition at this site. Contrary to our expectations, greater UVB exposure did not result in faster rates of decomposition. Greater UVB exposure resulted in decreased rates of decomposition and P release for the lower quality litter and no change in rates of decomposition and nutrient release for the two higher quality litter types, possibly due to a negative effect of UVB on soil microbes. Among litter types, rates of decomposition and net release of N and P followed this ranking: L. latifolium

  19. Toxicity evaluation of diazinon contaminated leaf litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diazinon is an organophosphate pesticide with widespread use on a variety of agricultural crops. Because of its use, diazinon is a potential contributor to non-point source contamination of aquatic environments. A prominent feature within these aquatic environments includes leaf litter, especially...

  20. Impacts of Photodegradation on Surface Litter Decomposition and Organic Matter Cycling in Semi-Arid Grasslands

    NASA Astrophysics Data System (ADS)

    King, J. Y.; Brandt, L. A.; Milchunas, D. G.

    2006-12-01

    Litter decomposition is typically modeled as a biological process controlled primarily by moisture and temperature effects on faunal decomposers. The role of ultraviolet (UV) radiation in surface plant litter decomposition via the abiotic process of photodegradation is not well understood or quantified. We hypothesized that photodegradation by UV radiation may significantly influence decomposition rates and organic matter cycling in the semi-arid environment of the Colorado shortgrass steppe. We conducted a 3-year field litterbag experiment to investigate the effects of UV radiation on litter decomposition under high and low precipitation conditions for litter of differing tissue chemistry. The experimental treatments included UV (10% and 90% of ambient), precipitation (wet and dry), and litter chemistry (high and low carbon to nitrogen ratio (C:N)) in a factorial design. UV radiation can suppress biotic decomposition by inhibiting faunal activity; UV radiation can also enhance abiotic decomposition via photodegradation. We therefore imposed the precipitation and litter chemistry treatments in order to examine responses to UV radiation with different levels of biotic decomposition. Our results demonstrate that UV radiation plays an important role in litter decomposition. Under dry conditions, decomposition rates were significantly higher (18-30%) for litter exposed to higher UV compared to lower UV radiation. Under wet conditions, decomposition rates were not significantly affected by level of UV radiation. Under dry conditions, high C:N litter showed a greater increase in decomposition rates with UV radiation than low C:N litter. Nitrogen immobilization did not increase with higher decomposition rates under higher UV radiation. These observations are consistent with our hypothesis that UV radiation is an important abiotic mechanism of decomposition. Our results indicate that photodegradation is responsible for as much as 23% of mass loss under dry conditions

  1. Abundance of litter on Condor seamount (Azores, Portugal, Northeast Atlantic)

    NASA Astrophysics Data System (ADS)

    Pham, C. K.; Gomes-Pereira, J. N.; Isidro, E. J.; Santos, R. S.; Morato, T.

    2013-12-01

    Marine litter is an emerging problem for the world's ocean health but little is known on its distribution and abundance on seamounts and how it affects deep-sea ecosystems. The scientific underwater laboratory set up on Condor seamount offered an ideal case study for the first documentation of litter distribution on a shallow seamount with historical fishing. A total of 48 video transects deployed on the summit (n=45) and the northern flank (n=3) covered an area of 0.031 and 0.025km2, respectively, revealing 55 litter items. Litter density on the summit was 1439 litter items km-2, whilst on the deeper northern flank, estimates indicate densities of 397 litter items km-2. Lost fishing line was the dominant litter item encountered on both areas (73% of total litter on the summit and 50% on northern flank), all being entirely or partly entangled in the locally abundant gorgonians Dentomuricea cf. meteor and Viminella flagellum. Other items included lost weights, anchors and glass bottles. The predominance of lost fishing gear identifies the source of litter on Condor seamount as exclusively ocean-based and related to fishing activities. Abundance of litter on the Condor seamount was much lower than that reported from other locations closer to populated areas.

  2. Environmentally friendly animal litter

    DOEpatents

    Chett, Boxley; McKelvie, Jessica

    2013-08-20

    A method of making an animal litter that includes geopolymerized ash, wherein, the animal litter is made from a quantity of a pozzolanic ash mixed with a sufficient quantity of water and an alkaline activator to initiate a geopolymerization reaction that forms geopolymerized ash. After the geopolymerized ash is formed, it is dried, broken into particulates, and sieved to a desired size. These geopolymerized ash particulates are used to make a non-clumping or clumping animal litter. Odor control may be accomplished with the addition of a urease inhibitor, pH buffer, an odor eliminating agent, and/or fragrance.

  3. Littering Behavior in Public Places

    ERIC Educational Resources Information Center

    Robinson, Stuart N.

    1976-01-01

    This review summarizes the present state of knowledge concerning littering behavior. Available studies are categorized according to the variables that influence littering--individual and environmental. Theoretical issues of attitude-behavior consistency and incentive effectiveness are analyzed with respect to littering and litter control. Results…

  4. Odour emissions from poultry litter - A review litter properties, odour formation and odorant emissions from porous materials.

    PubMed

    Dunlop, Mark W; Blackall, Patrick J; Stuetz, Richard M

    2016-07-15

    Odour emissions from meat chicken sheds can at times cause odour impacts on surrounding communities. Litter is seen as the primary source of this odour. Formation and emission of odour from meat chicken litter during the grow-out period are influenced by various factors such as litter conditions, the environment, microbial activity, properties of the odorous gases and management practices. Odour emissions vary spatially and temporally. This variability has made it challenging to understand how specific litter conditions contribute to odour emissions from the litter and production sheds. Existing knowledge on odorants, odour formation mechanisms and emission processes that contribute to odour emissions from litter are reviewed. Litter moisture content and water thermodynamics (i.e. water activity, Aw) are also examined as factors that contribute to microbial odour formation, physical litter conditions and the exchange of individual odorant gases at the air-water interface. Substantial opportunities exist for future research on litter conditions and litter formation mechanisms and how these contribute to odour emissions. Closing this knowledge gap will improve management strategies that intercept and interfere with odour formation and emission processes leading to an overall reduction in the potential to cause community impacts. PMID:27111649

  5. LIGHT-INDUCED PROCESSES AFFECTING ENTEROCOCCI IN AQUATIC ENVIRONMENTS

    EPA Science Inventory

    Fecal indicator bacteria such as enterococci have been used to assess contamination of freshwater and marine environments by pathogenic microorganisms. Various past studies have shown that sunlight plays an important role in reducing concentrations of culturable enterococci and ...

  6. Ingestion of marine litter by loggerhead sea turtles, Caretta caretta, in Portuguese continental waters.

    PubMed

    Nicolau, Lídia; Marçalo, Ana; Ferreira, Marisa; Sá, Sara; Vingada, José; Eira, Catarina

    2016-02-15

    The accumulation of litter in marine and coastal environments is a major threat to marine life. Data on marine litter in the gastrointestinal tract of stranded loggerhead turtles, Caretta caretta, found along the Portuguese continental coast was presented. Out of the 95 analysed loggerheads, litter was present in 56 individuals (59.0%) and most had less than 10 litter items (76.8%) and less than 5 g (dm) (96.8%). Plastic was the main litter category (frequency of occurrence=56.8%), while sheet (45.3%) was the most relevant plastic sub-category. There was no influence of loggerhead stranding season, cause of stranding or size on the amount of litter ingested (mean number and dry mass of litter items per turtle). The high ingested litter occurrence frequency in this study supports the use of the loggerhead turtle as a suitable tool to monitor marine litter trends, as required by the European Marine Strategy Framework Directive. PMID:26763321

  7. Control of climate and litter quality on leaf litter decomposition in different climatic zones.

    PubMed

    Zhang, Xinyue; Wang, Wei

    2015-09-01

    Climate and initial litter quality are the major factors influencing decomposition rates on large scales. We established a comprehensive database of terrestrial leaf litter decomposition, including 785 datasets, to examine the relationship between climate and litter quality and evaluate the factors controlling decomposition on a global scale, the arid and semi-arid (AS) zone, the humid middle and humid low (HL) latitude zones. Initial litter nitrogen (N) and phosphorus (P) concentration only increased with mean annual temperature (MAT) in the AS zone and decreased with mean annual precipitation (MAP) in the HL zone. Compared with nutrient content, MAT imposed less effect on initial litter lignin content than MAP. MAT were the most important decomposition driving factors on a global scale as well as in different climatic zones. MAP only significantly affected decomposition constants in AS zone. Although litter quality parameters also showed significant influence on decomposition, their importance was less than the climatic factors. Besides, different litter quality parameters exerted significant influence on decomposition in different climatic zones. Our results emphasized that climate consistently exerted important effects on decomposition constants across different climatic zones. PMID:26135888

  8. Anti-Litter Curriculum Packet, Interdisciplinary, K-12.

    ERIC Educational Resources Information Center

    Tillis, Richard

    This curriculum packet consists of 20 illustrated cards with 15 activities designed to create "positive feelings" about a clean environment. Activities range from picture coloring for younger students, to lessons such as the economic and health problems litter creates for older students. Objectives include encouraging anti-litter and…

  9. Canine dysautonomia in a litter of Havanese puppies.

    PubMed

    Hull, Noah C; O'Toole, Donal; Miller, Myrna M; Shoults, Hannah; Deck, Robin; Jones, Warren; Johnson, Gayle C; Shaw, Daniel P; Schumaker, Brant A

    2015-09-01

    Canine dysautonomia is a sporadic, generally fatal disease that rarely affects groups of related animals. Four 10-week-old Havanese puppies from a litter of 5 developed clinical signs of canine dysautonomia. The 4 affected dogs were exposed to an outdoor environment, whereas the fifth littermate was not exposed to the outdoors and remained clinically healthy. Clinical signs of dysautonomia developed 10-16 days after going outside the house. An unrelated dog also developed dysautonomia after exposure to 1 of the affected Havanese littermates. All 5 dogs had morphological changes consistent with dysautonomia (widespread neuronal degeneration in autonomic ganglia, select brainstem nuclei, and ventral horn motor neurons). Differential diagnoses were excluded through negative toxicological evaluation, fecal parasite screening, negative Canine distemper virus reverse transcription polymerase chain reaction, fluorescent antibody testing, attempted virus isolation, and electron microscopy. The 5 affected dogs were in the Kansas City, Missouri area, where there is a high incidence of dysautonomia. PMID:26179098

  10. Trans-generational exposure to low levels of rhodamine B does not adversely affect litter size or liver function in murine mucopolysaccharidosis type IIIA.

    PubMed

    Roberts, Ainslie L K; Fletcher, Janice M; Moore, Lynette; Byers, Sharon

    2010-01-01

    MPS IIIA is a lysosomal storage disorder caused by mutations in the sulphamidase gene, resulting in the accumulation of heparan sulphate glycosaminoglycans (HS GAGs). Symptoms predominantly manifest in the CNS and there is no current therapy that effectively addresses neuropathology in MPS IIIA patients. Recent studies in MPS IIIA mice have shown that rhodamine B substrate deprivation therapy (SDT) (also termed substrate reduction therapy/SRT) inhibits GAG biosynthesis and, improves both somatic and CNS disease pathology. Acute overexposure to high doses of rhodamine B results in liver toxicity and is detrimental to reproductive ability. However, the long-term effects of decreasing GAG synthesis, at the low dose sufficient to alter neurological function are unknown. A trans-generational study was therefore initiated to evaluate the continuous exposure of rhodamine B treatment in MPS IIIA mice over 4 generations, including treatment during pregnancy. No alterations in litter size, liver histology or liver function were observed. Overall, there are no long-term issues with the administration of rhodamine B at the low dose tested and no adverse effects were noted during pregnancy in mice. PMID:20650670

  11. Office Space: How Will Technology Affect the Education Office Environment?

    ERIC Educational Resources Information Center

    Day, C. William

    2009-01-01

    The office environment 10 years from now will be different from the one today. More office personnel will be organized around processes rather than functions. More work activities will be done by teams rather than individuals, and those teams will change over time, as will the nature of the work projects and the people who constitute the team. The…

  12. Designing for Automatic Affect Inference in Learning Environments

    ERIC Educational Resources Information Center

    Afzal, Shazia; Robinson, Peter

    2011-01-01

    Emotions play a significant role in healthy cognitive functioning; they impact memory, attention, decision-making and attitude; and are therefore influential in learning and achievement. Consequently, affective diagnoses constitute an important aspect of human teacher-learner interactions motivating efforts to incorporate skills of affect…

  13. Affective Behavior and Nonverbal Interaction in Collaborative Virtual Environments

    ERIC Educational Resources Information Center

    Peña, Adriana; Rangel, Nora; Muñoz, Mirna; Mejia, Jezreel; Lara, Graciela

    2016-01-01

    While a person's internal state might not be easily inferred through an automatic computer system, within a group, people express themselves through their interaction with others. The group members' interaction can be then helpful to understand, to certain extent, its members' affective behavior in any case toward the task at hand. In this…

  14. Critical processes affecting Cryptosporidium oocyst survival in the environment.

    PubMed

    King, B J; Monis, P T

    2007-03-01

    Cryptosporidium are parasitic protozoans that cause gastrointestinal disease and represent a significant risk to public health. Cryptosporidium oocysts are prevalent in surface waters as a result of human, livestock and native animal faecal contamination. The resistance of oocysts to the concentrations of chlorine and monochloramine used to disinfect potable water increases the risk of waterborne transmission via drinking water. In addition to being resistant to commonly used disinfectants, it is thought that oocysts can persist in the environment and be readily mobilized by precipitation events. This paper will review the critical processes involved in the inactivation or removal of oocysts in the terrestrial and aquatic environments and consider how these processes will respond in the context of climate change. PMID:17096874

  15. Physical processes affecting the sedimentary environments of Long Island Sound

    USGS Publications Warehouse

    Signell, R.P.; Knebel, H. J.; List, J.H.; Farris, A.S.

    1997-01-01

    A modeling study was undertaken to simulate the bottom tidal-, wave-, and wind-driven currents in Long Island Sound in order to provide a general physical oceanographic framework for understanding the characteristics and distribution of seafloor sedimentary environments. Tidal currents are important in the funnel-shaped eastern part of the Sound, where a strong gradient of tidal-current speed was found. This current gradient parallels the general westward progression of sedimentary environments from erosion or non-deposition, through bedload transport and sediment sorting, to fine-grained deposition. Wave-driven currents, meanwhile, appear to be important along the shallow margins of the basin, explaining the occurrence of relatively coarse sediments in regions where tidal currents alone are not strong enough to move sediment. Finally, westerly wind events are shown to locally enhance bottom currents along the axial depression of the sound, providing a possible explanation for the relatively coarse sediments found in the depression despite tide- and wave-induced currents below the threshold of sediment movement. The strong correlation between the near-bottom current intensity based on the model results and the sediment response as indicated by the distribution of sedimentary environments provides a framework for predicting the long-term effects of anthropogenic activities.

  16. Developmental and Evolutionary History Affect Survival in Stressful Environments

    PubMed Central

    Hopkins, Gareth R.; Brodie, Edmund D.; French, Susannah S.

    2014-01-01

    The world is increasingly impacted by a variety of stressors that have the potential to differentially influence life history stages of organisms. Organisms have evolved to cope with some stressors, while with others they have little capacity. It is thus important to understand the effects of both developmental and evolutionary history on survival in stressful environments. We present evidence of the effects of both developmental and evolutionary history on survival of a freshwater vertebrate, the rough-skinned newt (Taricha granulosa) in an osmotically stressful environment. We compared the survival of larvae in either NaCl or MgCl2 that were exposed to salinity either as larvae only or as embryos as well. Embryonic exposure to salinity led to greater mortality of newt larvae than larval exposure alone, and this reduced survival probability was strongly linked to the carry-over effect of stunted embryonic growth in salts. Larval survival was also dependent on the type of salt (NaCl or MgCl2) the larvae were exposed to, and was lowest in MgCl2, a widely-used chemical deicer that, unlike NaCl, amphibian larvae do not have an evolutionary history of regulating at high levels. Both developmental and evolutionary history are critical factors in determining survival in this stressful environment, a pattern that may have widespread implications for the survival of animals increasingly impacted by substances with which they have little evolutionary history. PMID:24748021

  17. The Effect of Litter Position on Ultraviolet Photodegradation of Standing Dead Litter

    NASA Astrophysics Data System (ADS)

    Lin, Y.; King, J. Y.

    2012-12-01

    In dryland ecosystems, models incorporating only biotic mechanisms usually underestimate the decay rate of plant litter. Photodegradation, an abiotic process through which solar radiation breaks down organic matter, has recently been proposed as an important pathway of litter decomposition in dryland ecosystems, accounting for as much as 25 to 60% of mass loss. However, it remains unclear what factors control the relative importance of photodegradation and biotic decomposition. It is hypothesized that this balance is affected by the location of litter within the litter layer (or thatch): in upper layers of thatch, photodegradation is significant because litter is exposed to sunlight; in lower layers where litter is strongly shaded, photodegradation is negligible compared to biotic decomposition. In August 2011, a field experiment was initiated at the University of California's Sedgwick Reserve, Santa Ynez, CA, in order to understand how ultraviolet (UV) radiation and litter position within the thatch affect litter decomposition. Two levels of UV radiation (280-400 nm) are achieved by screens: "UV-Pass" (transmitting > 81% of UV radiation) and "UV-Block" (transmitting < 8% of UV radiation). Litterbags were placed either at the top or at the bottom of the thatch. Results after 9 months of field exposure show that at the top of the thatch, litter mass loss was 13% higher in UV-Pass than in UV-Block, suggesting the occurrence of UV photodegradation. Surprisingly, litter mass loss was 52% higher in UV-Pass at the bottom of the thatch, even though very limited UV radiation penetrated through the thatch (at least 10 cm thick). The relative humidity in the thatch was higher in UV-Pass than in UV-Block treatments, especially at night; thus it is speculated that the UV manipulation not only alters the incoming radiation spectrum but also affects microclimate, consequently changing biotic decomposition. At the bottom of the thatch, lignin concentration of plant litter was 19

  18. Effects of neonatal litter size and age on ovarian gene expression and follicular development in gilts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gilts raised in small litters have greater ovulation rate, stay in the herd longer and produce more pigs. The objective was to understand how neonatal litter size affects gilt development. The hypothesis is that gilts reared in smaller litters have greater ovarian follicular development. Within 24 h...

  19. The Unintended Effects of a Posted Sign on Littering Attitudes and Stated Intentions.

    ERIC Educational Resources Information Center

    Horsley, A. Doyne

    1988-01-01

    Compares the effect of two different anti-littering signs. Results suggest that the ambiguously worded litterbug sign was interpreted differently by individuals and that it did not encourage an anti-littering attitude or affect stated intention to litter. (CW)

  20. Highly reduced mass loss rates and increased litter layer in radioactively contaminated areas.

    PubMed

    Mousseau, Timothy A; Milinevsky, Gennadi; Kenney-Hunt, Jane; Møller, Anders Pape

    2014-05-01

    The effects of radioactive contamination from Chernobyl on decomposition of plant material still remain unknown. We predicted that decomposition rate would be reduced in the most contaminated sites due to an absence or reduced densities of soil invertebrates. If microorganisms were the main agents responsible for decomposition, exclusion of large soil invertebrates should not affect decomposition. In September 2007 we deposited 572 bags with uncontaminated dry leaf litter from four species of trees in the leaf litter layer at 20 forest sites around Chernobyl that varied in background radiation by more than a factor 2,600. Approximately one quarter of these bags were made of a fine mesh that prevented access to litter by soil invertebrates. These bags were retrieved in June 2008, dried and weighed to estimate litter mass loss. Litter mass loss was 40% lower in the most contaminated sites relative to sites with a normal background radiation level for Ukraine. Similar reductions in litter mass loss were estimated for individual litter bags, litter bags at different sites, and differences between litter bags at pairs of neighboring sites differing in level of radioactive contamination. Litter mass loss was slightly greater in the presence of large soil invertebrates than in their absence. The thickness of the forest floor increased with the level of radiation and decreased with proportional loss of mass from all litter bags. These findings suggest that radioactive contamination has reduced the rate of litter mass loss, increased accumulation of litter, and affected growth conditions for plants. PMID:24590204

  1. Habitat structure alters top-down control in litter communities.

    PubMed

    Kalinkat, Gregor; Brose, Ulrich; Rall, Björn Christian

    2013-07-01

    The question whether top-down or bottom-up forces dominate trophic relationships, energy flow, and abundances within food webs has fuelled much ecological research with particular focus on soil litter ecosystems. Because litter simultaneously provides habitat structure and a basal resource, disentangling direct trophic and indirect non-trophic effects on different trophic levels remains challenging. Here, we focussed on short-term per capita interaction strengths of generalist predators (centipedes) on their microbi-detritivore prey (springtails) and addressed how the habitat structuring effects of the leaf litter modifies this interaction. We performed a series of laboratory functional response experiments where four levels of habitat structure were constructed by adding different amounts of leaf litter to the experimental arenas. We found that increased leaf litter reduced the consumption rate of the predator. We interpreted this as a dilution effect of the augmented habitat size provided by the increasing leaf litter surface available to the species. Dilution of the prey population decreased encounter rates, whereas the capture success was not affected. Interestingly, our results imply that top-down control by centipedes decreased with increasing resource supply for the microbi-detritivore prey (i.e. the leaf litter that simultaneously provides habitat structure). Therefore, effective top-down control of predators on microbi-detritvore populations seems unlikely in litter-rich ecosystems due to the non-trophic, habitat-structuring effect of the basal litter resource. PMID:23188055

  2. Occurrence and sorption of fluoroquinolones in poultry litters and soils from São Paulo State, Brazil.

    PubMed

    Leal, Rafael Marques Pereira; Figueira, Rafael Fernandes; Tornisielo, Valdemar Luiz; Regitano, Jussara Borges

    2012-08-15

    Animal production is one of the most expressive sectors of Brazilian agro-economy. Although antibiotics are routinely used in this activity, their occurrence, fate, and potential impacts to the local environment are largely unknown. This research evaluated sorption-desorption and occurrence of four commonly used fluoroquinolones (norfloxacin, ciprofloxacin, danofloxacin, and enrofloxacin) in poultry litter and soil samples from São Paulo State, Brazil. The sorption-desorption studies involved batch equilibration technique and followed the OECD guideline for pesticides. All compounds were analyzed by HPLC, using fluorescence detector. Fluoroquinolones' sorption potential to the poultry litters (K(d) ≤65 L kg(-1)) was lower than to the soil (K(d) ~40,000 L kg(-1)), but was always high (≥69% of applied amount) indicating a higher specificity of fluoroquinolones interaction with soils. The addition of poultry litter (5%) to the soil had not affected sorption or desorption of these compounds. Desorption was negligible in the soil (≤0.5% of sorbed amount), but not in the poultry litters (up to 42% of sorbed amount). Fluoroquinolones' mean concentrations found in the poultry litters (1.37 to 6.68 mg kg(-1)) and soils (22.93 μg kg(-1)) were compatible to those found elsewhere (Austria, China, and Turkey). Enrofloxacin was the most often detected compound (30% of poultry litters and 27% of soils) at the highest mean concentrations (6.68 mg kg(-1) for poultry litters and 22.93 μg kg(-1) for soils). These results show that antibiotics are routinely used in poultry production and might represent one potential source of pollution to the environment that has been largely ignored and should be further investigated in Brazil. PMID:22750180

  3. Poultry litter as a source of gastrointestinal helminth infections.

    PubMed

    Maurer, V; Amsler, Z; Perler, E; Heckendorn, F

    2009-05-12

    worm burdens in tracer animals were low compared to a similar study with tracers kept in poultry runs. The reasons for this may be that poultry litter negatively affects viability and infectiousness of helminth eggs. However, underlying mechanisms need to be clarified. PMID:19251370

  4. Understanding processes affecting mineral deposits in humid environments

    USGS Publications Warehouse

    Seal, Robert R., II; Ayuso, Robert A.

    2011-01-01

    Recent interdisciplinary studies by the U.S. Geological Survey have resulted in substantial progress toward understanding the influence that climate and hydrology have on the geochemical signatures of mineral deposits and the resulting mine wastes in the eastern United States. Specific areas of focus include the release, transport, and fate of acid, metals, and associated elements from inactive mines in temperate coastal areas and of metals from unmined mineral deposits in tropical to subtropical areas; the influence of climate, geology, and hydrology on remediation options for abandoned mines; and the application of radiogenic isotopes to uniquely apportion source contributions that distinguish natural from mining sources and extent of metal transport. The environmental effects of abandoned mines and unmined mineral deposits result from a complex interaction of a variety of chemical and physical factors. These include the geology of the mineral deposit, the hydrologic setting of the mineral deposit and associated mine wastes, the chemistry of waters interacting with the deposit and associated waste material, the engineering of a mine as it relates to the reactivity of mine wastes, and climate, which affects such factors as temperature and the amounts of precipitation and evapotranspiration; these factors, in turn, influence the environmental behavior of mineral deposits. The role of climate is becoming increasingly important in environmental investigations of mineral deposits because of the growing concerns about climate change.

  5. Psychosocial Environment and Affective Outcomes in Technology-Rich Classrooms: Testing a Causal Model

    ERIC Educational Resources Information Center

    Dorman, Jeffrey P.; Fraser, Barry J.

    2009-01-01

    Research investigated classroom environment antecedent variables and student affective outcomes in Australian high schools. The Technology-Rich Outcomes-Focused Learning Environment Inventory (TROFLEI) was used to assess 10 classroom environment dimensions: student cohesiveness, teacher support, involvement, investigation, task orientation,…

  6. The Experimental Control of Littering

    ERIC Educational Resources Information Center

    Clark, Roger N.; And Others

    1972-01-01

    Behavior, incentives, and education programs were researched as factors relating to littering. Experiments in theaters, forest campgrounds, and hiking and dispersed car camping areas indicate incentive systems are necessary and feasible for curbing litter problems. (BL)

  7. Distribution of beach litter along the coastline of Cádiz, Spain.

    PubMed

    Williams, Allan Thomas; Randerson, Peter; Di Giacomo, Carlo; Anfuso, Giorgio; Macias, Ana; Perales, José Antonio

    2016-06-15

    A total of 59 categories of litter items were found at 20 beaches (13 mechanically cleaned, 7 non-cleaned) in the Cádiz tourist environment, Spain. Cluster Analysis and Principal Components Analysis were used to highlight similarities and contrasts between sites and/or associations between litter categories. Multivariate analyses separated beaches according to the total numbers of litter items present. Non-cleaned sites showed a variety of litter category abundance with distinct origins and abundant, ubiquitous items (plastic and glass fragments). Of the 7 non-cleaned beaches (49 litter categories) river-mouth sites were distinct due with high numbers of litter items. The sheltered inner part of Cádiz Bay beaches had a wide range of litter type. Many sites were associated with locally deposited recreational litter categories; while industrial/commercial/fishing categories were abundant only at a few sites, indicating items transported onto the shore from the Guadalete river. PMID:27117354

  8. Mediterranean marine biodiversity under threat: Reviewing influence of marine litter on species.

    PubMed

    Deudero, Salud; Alomar, Carme

    2015-09-15

    The Mediterranean Sea is one of the most polluted seas worldwide, especially with regard to plastics. The presence of this emerging man made contaminant in marine environments precludes large effects and interactions with species exposed to massive litter quantities. In this review, available data of floating and seafloor litter around Mediterranean sub-basins are reported. A review of scientific literature on the interaction of plastic with marine biota resulted in the identification of 134 species, several taxa and feeding strategies affected from 1986 to 2014. Data from 17,334 individuals showed different levels of ingestion and effects on catalogued IUCN species (marine mammals and sea turtles) in addition to several pelagic fish and elasmobranchs. Biodiversity is certainly under threat, and knowledge of the extent of taxa affected is of concern considering the increasing plastic loads in the Mediterranean Sea and worldwide. PMID:26183308

  9. Labile compounds in plant litter reduce the sensitivity of decomposition to warming and altered precipitation.

    PubMed

    Suseela, Vidya; Tharayil, Nishanth; Xing, Baoshan; Dukes, Jeffrey S

    2013-10-01

    Together, climate and litter quality strongly regulate decomposition rates. Although these two factors and their interaction have been studied across species in continent-scale experiments, few researchers have studied how labile and recalcitrant compounds interact to influence decomposition, or the climate sensitivity of decomposition, within a litter type. Over a period of 3 yr, we studied the effects of warming and altered precipitation on mass loss and compound-specific decomposition using two litter types that possessed similar heteropolymer chemistry, but different proportions of labile and recalcitrant compounds. Climate treatments immediately affected the mass loss of the more recalcitrant litter, but affected the more labile litter only after 2 yr. After 3 yr, although both litter types had lost similar amounts of mass, warming (c. 4°C) and supplemental precipitation (150% of ambient) together accelerated the degradation of alkyl-carbon and lignin only in the more recalcitrant litter, highlighting the role of initial litter quality in determining whether the chemistry of litter residues converges or diverges under different climates. Our finding that labile compounds in litter reduce the climate sensitivity of mass loss and the decomposition of recalcitrant matrix is novel. Our results highlight the potential for litter quality to regulate the effect of climatic changes on the sequestration of litter-derived carbon. PMID:23822593

  10. The influence of litter quality and micro-habitat on litter decomposition and soil properties in a silvopasture system

    NASA Astrophysics Data System (ADS)

    Tripathi, G.; Deora, R.; Singh, G.

    2013-07-01

    Studies to understand litter processes and soil properties are useful for maintaining pastureland productivity as animal husbandry is the dominant occupation in the hot arid region. We aimed to quantify how micro-habitats and combinations of litters of the introduced leguminous tree Colophospermum mopane with the grasses Cenchrus ciliaris or Lasiurus sindicus influence decomposition rate and soil nutrient changes in a hot desert silvopasture system. Litter bags with tree litter alone (T), tree + C. ciliaris in 1:1 ratio (TCC) and tree + L. sindicus 1:1 ratio (TLS) litter were placed inside and outside of the C. mopane canopy and at the surface, 3-7 cm and 8-12 cm soil depths. We examined litter loss, soil fauna abundance, organic carbon (SOC), total (TN), ammonium (NH4-N) and nitrate (NO3-N) nitrogen, phosphorus (PO4-P), soil respiration (SR) and dehydrogenase activity (DHA) in soil adjacent to each litter bag. After 12 months exposure, the mean residual litter was 40.2% of the initial value and annual decomposition rate constant (k) was 0.98 (0.49-1.80). Highest (p < 0.01) litter loss was in the first four months, when faunal abundance, SR, DHA and humidity were highest but it decreased with time. These variables and k were highest under the tree canopies. The litter loss and k were highest (p < 0.01) in TLS under the tree canopy, but the reverse trend was found for litter outside the canopy. Faunal abundance, litter loss, k, nutrient release and biochemical activities were highest (p < 0.01) in the 3-7 cm soil layer. Positive correlations of litter loss and soil fauna abundance with soil nutrients, SR and DHA demonstrated the interactions of litter quality and micro-habitats together with soil fauna on increased soil fertility. These results suggest that a Colophospermum mopane and L. sindicus silvopasture system best promotes faunal abundance, litter decomposition and soil fertility. The properties of these species and the associated faunal resources may be

  11. Labile Compounds in Plant Litter Reduce the Sensitivity of Decomposition to Warming and Altered Precipitation

    NASA Astrophysics Data System (ADS)

    Suseela, V.; Tharayil, N.; Xing, B.; Dukes, J. S.

    2013-12-01

    Together, climate and litter quality strongly regulate decomposition rates. While these two factors and their interaction have been studied across species in continent-scale experiments, few researchers have studied how labile and recalcitrant compounds interact to influence decomposition, or the climate sensitivity of decomposition, within a litter type. Over a period of three years, we studied the effects climate change on mass loss and compound-specific decomposition using two litter types that differed in the relative proportions of labile and recalcitrant compounds, but that had heteropolymers with similar molecular structure. We examined how warming and altered precipitation affected the decomposition of two types of Polygonum cuspidatum (Japanese knotweed) litter (stem litter that was either newly senesced or one year old), at the Boston-Area Climate Experiment (BACE), in Massachusetts, USA. We placed litter bags in an old-field ecosystem exposed to four levels of warming (up to 4oC) and three levels of precipitation (ambient, drought (-50%) and wet (+50%) treatments. The compound-specific degradation of litter was assessed using Diffuse Reflectance Infrared Fourier Transform Spectroscopy and 13C Nuclear Magnetic Resonance Spectroscopy. Climate treatments immediately affected mass loss of the more recalcitrant litter, but affected the more labile litter only after two years. After three years, although both litter types had lost similar amounts of mass, warming (~4oC) and supplemental precipitation (150% of ambient) together accelerated degradation of alkyl-carbon and lignin only in the more recalcitrant litter, highlighting the role of initial litter quality in determining whether the chemistry of litter residues converges or diverges under different climates. The results from this study indicate that the effect of climate on litter decomposition depends on the quality of litter; litter with a greater initial proportion of labile compounds was less

  12. Leaf litter decomposition in three Adirondack lakes

    SciTech Connect

    Francis, A.J.; Quinby, H.L.; Hendrey, G.R.; Hoogendyk, C.G.

    1983-04-01

    Decomposition of terrestrial leaf litter in three Adirondack lakes with water pH values approximately 5, 6, and 7 was studied. Litter bags containing leaves of American beech, sugar maple, red maple, leather leaf, and red spruce were placed in the lakes. Samples were removed periodically over a 3-year period and analyzed for loss in weight, changes in leaf surface area, carbon, nitrogen, and bacterial populations. The rate of decomposition of litter depended on the leaf species tested as well as on the lake water in which they were incubated. Of the five leaf species tested, red maple decomposed much faster and red spruce more slowly, i.e., red maple > sugar maple > beech > leather leaf > red spruce. Further, the data indicated that the rate of decomposition of the leaves differed among the lakes in the order Woods (pH approx. 5) < Sagamore (pH approx. 6) < Panther (pH approx. 7), and that the microbial colonization of some leaf species was affected. Accumulations of leaf litter in acid lakes due to reduction in microbial decomposition may affect nutrient recycling in lake ecosystems. 8 references, 4 tables.

  13. Experiences and Implications of Social Workers Practicing in a Pediatric Hospital Environment Affected by SARS

    ERIC Educational Resources Information Center

    Gearing, Robin Edward; Saini, Michael; McNeill, Ted

    2007-01-01

    This phenomenological study's purpose was threefold: to detail the experiences of social workers practicing in a hospital environment affected by severe acute respiratory syndrome (SARS), to describe essential themes and structures of social work practices within this crisis environment, and to explore recommendations for better preparedness to…

  14. 49 CFR 520.5 - Guidelines for identifying major actions significantly affecting the environment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... significantly affecting the quality of the human environment,” as used in this part, shall be construed with a... actions should ordinarily be considered as significantly affecting the quality of the human...

  15. 49 CFR 520.5 - Guidelines for identifying major actions significantly affecting the environment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... significantly affecting the quality of the human environment,” as used in this part, shall be construed with a... actions should ordinarily be considered as significantly affecting the quality of the human...

  16. Early prediction of student goals and affect in narrative-centered learning environments

    NASA Astrophysics Data System (ADS)

    Lee, Sunyoung

    Recent years have seen a growing recognition of the role of goal and affect recognition in intelligent tutoring systems. Goal recognition is the task of inferring users' goals from a sequence of observations of their actions. Because of the uncertainty inherent in every facet of human computer interaction, goal recognition is challenging, particularly in contexts in which users can perform many actions in any order, as is the case with intelligent tutoring systems. Affect recognition is the task of identifying the emotional state of a user from a variety of physical cues, which are produced in response to affective changes in the individual. Accurately recognizing student goals and affect states could contribute to more effective and motivating interactions in intelligent tutoring systems. By exploiting knowledge of student goals and affect states, intelligent tutoring systems can dynamically modify their behavior to better support individual students. To create effective interactions in intelligent tutoring systems, goal and affect recognition models should satisfy two key requirements. First, because incorrectly predicted goals and affect states could significantly diminish the effectiveness of interactive systems, goal and affect recognition models should provide accurate predictions of user goals and affect states. When observations of users' activities become available, recognizers should make accurate early" predictions. Second, goal and affect recognition models should be highly efficient so they can operate in real time. To address key issues, we present an inductive approach to recognizing student goals and affect states in intelligent tutoring systems by learning goals and affect recognition models. Our work focuses on goal and affect recognition in an important new class of intelligent tutoring systems, narrative-centered learning environments. We report the results of empirical studies of induced recognition models from observations of students

  17. Reducing Children's Littering on a Nature Trail

    ERIC Educational Resources Information Center

    LaHart, David E.; Bailey, Jon S.

    1975-01-01

    This study compared incentives and educational methods to motivate children to pick up litter and to prevent littering. Incentives did aid in getting litter picked up. One-sentence anti-litter statements, educational materials, and lectures reduced littering, but incentives did not. (MR)

  18. Effects of radionuclide contamination on leaf litter decomposition in the Chernobyl exclusion zone.

    PubMed

    Bonzom, Jean-Marc; Hättenschwiler, Stephan; Lecomte-Pradines, Catherine; Chauvet, Eric; Gaschak, Sergey; Beaugelin-Seiller, Karine; Della-Vedova, Claire; Dubourg, Nicolas; Maksimenko, Andrey; Garnier-Laplace, Jacqueline; Adam-Guillermin, Christelle

    2016-08-15

    The effects of radioactive contamination on ecosystem processes such as litter decomposition remain largely unknown. Because radionuclides accumulated in soil and plant biomass can be harmful for organisms, the functioning of ecosystems may be altered by radioactive contamination. Here, we tested the hypothesis that decomposition is impaired by increasing levels of radioactivity in the environment by exposing uncontaminated leaf litter from silver birch and black alder at (i) eleven distant forest sites differing in ambient radiation levels (0.22-15μGyh(-1)) and (ii) along a short distance gradient of radioactive contamination (1.2-29μGyh(-1)) within a single forest in the Chernobyl exclusion zone. In addition to measuring ambient external dose rates, we estimated the average total dose rates (ATDRs) absorbed by decomposers for an accurate estimate of dose-induced ecological consequences of radioactive pollution. Taking into account potential confounding factors (soil pH, moisture, texture, and organic carbon content), the results from the eleven distant forest sites, and from the single forest, showed increased litter mass loss with increasing ATDRs from 0.3 to 150μGyh(-1). This unexpected result may be due to (i) overcompensation of decomposer organisms exposed to radionuclides leading to a higher decomposer abundance (hormetic effect), and/or (ii) from preferred feeding by decomposers on the uncontaminated leaf litter used for our experiment compared to locally produced, contaminated leaf litter. Our data indicate that radio-contamination of forest ecosystems over more than two decades does not necessarily have detrimental effects on organic matter decay. However, further studies are needed to unravel the underlying mechanisms of the results reported here, in order to draw firmer conclusions on how radio-contamination affects decomposition and associated ecosystem processes. PMID:27110974

  19. Warming and Nitrogen Addition Increase Litter Decomposition in a Temperate Meadow Ecosystem

    PubMed Central

    Gong, Shiwei; Guo, Rui; Zhang, Tao; Guo, Jixun

    2015-01-01

    Background Litter decomposition greatly influences soil structure, nutrient content and carbon sequestration, but how litter decomposition is affected by climate change is still not well understood. Methodology/Principal Findings A field experiment with increased temperature and nitrogen (N) addition was established in April 2007 to examine the effects of experimental warming, N addition and their interaction on litter decomposition in a temperate meadow steppe in northeastern China. Warming, N addition and warming plus N addition reduced the residual mass of L. chinensis litter by 3.78%, 7.51% and 4.53%, respectively, in 2008 and 2009, and by 4.73%, 24.08% and 16.1%, respectively, in 2010. Warming, N addition and warming plus N addition had no effect on the decomposition of P. communis litter in 2008 or 2009, but reduced the residual litter mass by 5.58%, 15.53% and 5.17%, respectively, in 2010. Warming and N addition reduced the cellulose percentage of L. chinensis and P. communis, specifically in 2010. The lignin percentage of L. chinensis and P. communis was reduced by warming but increased by N addition. The C, N and P contents of L. chinensis and P. communis litter increased with time. Warming and N addition reduced the C content and C:N ratios of L. chinensisand P. communis litter, but increased the N and P contents. Significant interactive effects of warming and N addition on litter decomposition were observed (P<0.01). Conclusion/Significance The litter decomposition rate was highly correlated with soil temperature, soil water content and litter quality. Warming and N addition significantly impacted the litter decomposition rate in the Songnen meadow ecosystem, and the effects of warming and N addition on litter decomposition were also influenced by the quality of litter. These results highlight how climate change could alter grassland ecosystem carbon, nitrogen and phosphorus contents in soil by influencing litter decomposition. PMID:25774776

  20. In situ characterization of forest litter using ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    André, Frédéric; Jonard, François; Jonard, Mathieu; Lambot, Sébastien

    2016-03-01

    Decomposing litter accumulated on the soil surface in forests plays a major role in several ecosystem processes; its detailed characterization is therefore essential for thorough understanding of ecosystem functioning. In addition, litter is known to affect remote sensing radar data over forested areas and their proper processing requires accurate quantification of litter scattering properties. In the present study, ultrawideband (0.8-2.2 GHz) ground-penetrating radar (GPR) data were collected in situ for a wide range of litter types to investigate the potential of the technique to reconstruct litter horizons in undisturbed natural conditions. Radar data were processed resorting to full-wave inversion. Good agreement was generally found between estimated and measured litter layer thicknesses, with root-mean-square error values around 1 cm for recently fallen litter (OL layer) and around 2 cm for fragmented litter in partial decomposition (OF layer) and total litter (OL + OF). Nevertheless, significant correlations between estimated and measured thicknesses were found for total litter only. Inaccuracies in the reconstruction of the individual litter horizons were mainly attributed to weak dielectric contrasts amongst litter layers, with absolute differences in relative dielectric permittivity values often lower than 2 between humus horizons, and to uncertainties in the ground truth values. Radar signal inversions also provided reliable estimates of litter electromagnetic properties, with average relative dielectric permittivity values around 2.9 and 6.3 for OL and OF litters, respectively. These results are encouraging for the use of GPR for noninvasive characterization and mapping of forest litter. Perspectives for the application of the technique in biogeosciences are discussed.

  1. Riparian litter inputs to streams in the central Oregon Coast Range

    USGS Publications Warehouse

    Hart, Stephanie K.; Hibbs, David E.; Perakis, Steven S.

    2013-01-01

    Riparian-zone vegetation can influence terrestrial and aquatic food webs through variation in the amount, timing, and nutritional content of leaf and other litter inputs. We investigated how riparian-forest community composition, understory density, and lateral slope shaped vertical and lateral litter inputs to 16 streams in the Oregon Coast Range. Riparian forests dominated by deciduous red alder delivered greater annual vertical litter inputs to streams (504 g m−2 y−1) than did riparian forests dominated by coniferous Douglas-fir (394 g m−2 y−1). Deciduous forests also contributed greater lateral litter inputs per meter of stream bank on one side (109 g m−1 y−1) than did coniferous forests (63 g m−1 y−1). Total litter inputs from deciduous forests exceeded those from coniferous forests most strongly in November, coincident with an autumn peak in litter inputs. Lateral litter inputs contributed most to total inputs during winter in both forest types. Annual lateral litter movement increased with slope at deciduous sites, but only in spring/summer months at coniferous sites. Neither experimental removal of understory vegetation nor installation of mesh fences to block downslope litter movement affected lateral litter inputs to streams, suggesting that ground litter moves <5 m downslope annually. N concentrations of several litter fractions were higher at deciduous sites and, when combined with greater litter amounts, yielded twice as much total litter N flux to streams in deciduous than coniferous sites. The presence of red alder in riparian forests along many small streams of the deeply incised and highly dendritic basins of the Oregon Coast Range enhances total fluxes and seasonality of litter delivery to both terrestrial and aquatic food webs in this region and complements the shade and large woody debris provided by large coniferous trees.

  2. Size dependent differences in litter consumption of isopods: preliminary results

    PubMed Central

    Vilisics, Ferenc; Szekeres, Sándor; Hornung, Elisabeth

    2012-01-01

    Abstract A series of experiments were applied to test how leaf orientation within microcosms affect consumption rates (Experiment 1), and to discover intra-specific differences in leaf litter consumption (Experiment 2) of the common isopod species Porcellio scaber and Porcellionides pruinosus. A standardised microcosm setup was developed for feeding experiments to maintain standard conditions. A constant amount of freshly fallen black poplar litter was provided to three distinct size class (small, medium, large) of woodlice. We measured litter consumption after a fortnight. We maintained appr. constant isopod biomass for all treatments, and equal densities within each size class. We hypothesized that different size classes differ in their litter consumption, therefore such differences should occur even within populations of the species. We also hypothesized a marked difference in consumption rates for different leaf orientation within microcosms. Our results showed size-specific consumption patterns for Porcellio scaber: small adults showed the highest consumption rates (i.e. litter mass loss / isopod biomass) in high density microcosms, while medium-sized adults of lower densities ate the most litter in containers. Leaf orientation posed no significant effect on litter consumption. PMID:22536112

  3. Study type and plant litter identity modulating the response of litter decomposition to warming, elevated CO2, and elevated O3: A meta-analysis

    NASA Astrophysics Data System (ADS)

    Yue, Kai; Peng, Changhui; Yang, Wanqin; Peng, Yan; Fang, Junmin; Wu, Fuzhong

    2015-03-01

    Plant litter decomposition is one of the most important ecosystem carbon flux processes in terrestrial ecosystems and is usually regarded as sensitive to climate change. The goal of the present study was to examine the effects of changing climate variables on litter decomposition. By synthesizing data from multiple terrestrial ecosystems, we quantified the response of the litter decomposition rate to the independent effects of warming, elevated carbon dioxide (CO2), elevated ozone (O3), and the combined effects of elevated CO2 + elevated O3. Across all case studies, warming increased the litter decomposition rate significantly by 4.4%, but this effect could be reduced as a result of the negatively significant effects of elevated CO2 and elevated CO2 + elevated O3. The combined effects of elevated CO2 + elevated O3 decreased the litter decomposition rate significantly, and the magnitude appeared to be higher than that of the elevated CO2 per se. Moreover, the study type (field versus laboratory), ecosystem type, and plant litter identity and functional traits (growth form and litter form) were all important moderators regulating the response of litter decomposition to climate warming and elevated CO2 and O3. Although litter decomposition rate may show a moderate change as a result of the effects of multiple changing climate variables, the process of litter decomposition would be strongly altered due to the differing mechanisms of the effects of each climate change variable, suggesting that the global carbon cycle and biogeochemistry could be substantially affected.

  4. Mower/Litter Removal

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Burg Corporation needed to get more power out of the suction system in their Vac 'N Bag grass mower/litter remover. The president submitted a problem statement to the Marshall Space Flight Center Technology Transfer Office, which devised a way to guide heavier items of trash to a point where suction was greatest, and made changes to the impeller and the exhaust port, based on rocket propulsion technology. The improved system is used by highway departments, city governments and park authorities, reducing work time by combining the tasks of grass cutting and vacuuming trash and grass clippings.

  5. Phosphatase activities in soil after repeated untreated and alum-treated poultry litter applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Repeated additions of untreated and aluminum sulfate (alum)-treated poultry litter to soil affect ecology and consequent nutrient dynamics. The objective of this study was to determine how repeated annual poultry litter additions affected phosphatase activities in concert with changes in soil phosph...

  6. Effect of mountain climatic elevation gradient and litter origin on decomposition processes: long-term experiment with litter-bags

    NASA Astrophysics Data System (ADS)

    Klimek, Beata; Niklińska, Maria; Chodak, Marcin

    2013-04-01

    Temperature is one of the most important factors affecting soil organic matter decomposition. Mountain areas with vertical gradients of temperature and precipitation provide an opportunity to observe climate changes similar to those observed at various latitudes and may serve as an approximation for climatic changes. The aim of the study was to compare the effects of climatic conditions and initial properties of litter on decomposition processes and thermal sensitivity of forest litter. The litter was collected at three altitudes (600, 900, 1200 m a.s.l.) in the Beskidy Mts (southern Poland), put into litter-bags and exposed in the field since autumn 2011. The litter collected at single altitude was exposed at the altitude it was taken and also at the two other altitudes. The litter-bags were laid out on five mountains, treated as replicates. Starting on April 2012, single sets of litter-bags were collected every five weeks. The laboratory measurements included determination of dry mass loss and chemical composition (Corg, Nt, St, Mg, Ca, Na, K, Cu, Zn) of the litter. In the additional litter-bag sets, taken in spring and autumn 2012, microbial properties were measured. To determine the effect of litter properties and climatic conditions of elevation sites on decomposing litter thermal sensitivity the respiration rate of litter was measured at 5°C, 15°C and 25°C and calculated as Q10 L and Q10 H (ratios of respiration rate between 5° and 15°C and between 15°C and 25°C, respectively). The functional diversity of soil microbes was measured with Biolog® ECO plates, structural diversity with phospholipid fatty acids (PLFA). Litter mass lost during first year of incubation was characterized by high variability and mean mass lost ranged up to a 30% of initial mass. After autumn sampling we showed, that mean respiration rate of litter (dry mass) from the 600m a.s.l site exposed on 600m a.s.l. was the highest at each tested temperature. In turn, the lowest mean

  7. Litter-of-origin trait effects on gilt development.

    PubMed

    Vallet, J L; Calderón-Díaz, J A; Stalder, K J; Phillips, C; Cushman, R A; Miles, J R; Rempel, L A; Rohrer, G A; Lents, C A; Freking, B A; Nonneman, D J

    2016-01-01

    The preweaning litter environment of gilts can affect subsequent development. In a recent experiment designed to test the effects of diet on gilt development, litter-of-origin traits including individual birth weights, immunocrits (a measure of colostrum intake), sow parity, number weaned, and individual weaning weights were collected for approximately 1,200 gilts that were progeny of approximately 300 sows. Subsequently, BW, LM area, and backfat were measured at 100 d of age and at 28-d intervals until slaughter (260 d of age). From 160 d of age to slaughter, gilts were observed daily for estrus. At slaughter, the reproductive tract and 1 mammary gland were recovered. The reproductive tract was classified as cyclic or prepubertal; the number of corpora lutea was counted. Uterine horn lengths and ovarian dimensions were measured. Uterus and ovary samples from every 10th gilt were prepared for histological evaluation of uterine gland development and follicle counts, respectively. Mammary gland tissue protein and fat were assayed. Day of the estrous cycle at slaughter was calculated using the first day of the most recent standing estrus (d 0) recorded previous to slaughter. Each gilt development trait was analyzed for association with each litter-of-origin trait, after adjusting for dietary treatment effects. Uterine length, ovarian dimensions, mammary gland protein and fat, and uterine gland development were also adjusted for day of the estrous cycle at slaughter. All litter-of-origin traits were associated ( < 0.05) with growth traits. Top-down (backward elimination) multiple regression analysis indicated that BW and LM accretion in gilts was positively associated with immunocrit ( < 0.01), birth weight ( < 0.01), preweaning growth rate ( < 0.01), and parity ( < 0.01). Backfat accretion was positively associated with preweaning growth rate ( < 0.01), number weaned ( < 0.05), and parity ( < 0.05). Age at puberty was associated with birth weight (positive; < 0

  8. Influence of habitat, litter type, and soil invertebrates on leaf-litter decomposition in a fragmented Amazonian landscape.

    PubMed

    Vasconcelos, Heraldo L; Laurance, William F

    2005-07-01

    Amazonian forest fragments and second-growth forests often differ substantially from undisturbed forests in their microclimate, plant-species composition, and soil fauna. To determine if these changes could affect litter decomposition, we quantified the mass loss of two contrasting leaf-litter mixtures, in the presence or absence of soil macroinvertebrates, and in three forest habitats. Leaf-litter decomposition rates in second-growth forests (>10 years old) and in fragment edges (<100 m from the edge) did not differ from that in the forest interior (>250 m from the edges of primary forests). In all three habitats, experimental exclusion of soil invertebrates resulted in slower decomposition rates. Faunal-exclosure effects were stronger for litter of the primary forest, composed mostly of leaves of old-growth trees, than for litter of second-growth forests, which was dominated by leaves of successional species. The latter had a significantly lower initial concentration of N, higher C:N and lignin:N ratios, and decomposed at a slower rate than did litter from forest interiors. Our results indicate that land-cover changes in Amazonia affect decomposition mainly through changes in plant species composition, which in turn affect litter quality. Similar effects may occur on fragment edges, particularly on very disturbed edges, where successional trees become dominant. The drier microclimatic conditions in fragment edges and second-growth forests (>10 years old) did not appear to inhibit decomposition. Finally, although soil invertebrates play a key role in leaf-litter decomposition, we found no evidence that differences in the abundance, species richness, or species composition of invertebrates between disturbed and undisturbed forests significantly altered decomposition rates. PMID:15942762

  9. Forest composition modifies litter dynamics and decomposition in regenerating tropical dry forest.

    PubMed

    Schilling, Erik M; Waring, Bonnie G; Schilling, Jonathan S; Powers, Jennifer S

    2016-09-01

    We investigated how forest composition, litter quality, and rainfall interact to affect leaf litter decomposition across three successional tropical dry forests in Costa Rica. We monitored litter stocks and bulk litter turnover in 18 plots that exhibit substantial variation in soil characteristics, tree community structure, fungal communities (including forests dominated by ecto- or arbuscular mycorrhizal host trees), and forest age. Simultaneously, we decomposed three standard litter substrates over a 6-month period spanning an unusually intense drought. Decay rates of standard substrates depended on the interaction between litter identity and forest type. Decomposition rates were correlated with tree and soil fungal community composition as well as soil fertility, but these relationships differed among litter types. In low fertility soils dominated by ectomycorrhizal oak trees, bulk litter turnover rates were low, regardless of soil moisture. By contrast, in higher fertility soils that supported mostly arbuscular mycorrhizal trees, bulk litter decay rates were strongly dependent on seasonal water availability. Both measures of decomposition increased with forest age, as did the frequency of termite-mediated wood decay. Taken together, our results demonstrate that soils and forest age exert strong control over decomposition dynamics in these tropical dry forests, either directly through effects on microclimate and nutrients, or indirectly by affecting tree and microbial community composition and traits, such as litter quality. PMID:27236291

  10. Solubility of leaf litter phosphorus and nitrogen from taiga and lowland tropical forest

    NASA Astrophysics Data System (ADS)

    Schreeg, L.; Mack, M. C.; Turner, B. L.

    2011-12-01

    Leaf litter returns significant quantities of phosphorus (P) and nitrogen (N) to the soil environment in terrestrial ecosystems. The release of litter nutrients during decomposition can occur through mineralization of organic material and leaching. While leaching is an important component in our conceptual models of decomposition, the role of leaching in P and N release from leaf litter has been little investigated. Here we synthesize the results from two studies using recently senesced litter from taiga in Siberia and lowland tropical forest in Panama. We show that leaf litter P is highly soluble. On average, 35±10% (mean ± standard deviation) of total litter P was soluble from 41 species of trees and lianas from a lowland tropical forest during a 4 h extract. Similarly, the soluble fraction of litter P was high for recently senesced litter from the taiga - an average of 40±15% of total P was water soluble during a 24 h extract across nine species, which included a sedge, a tree and shrubs spanning two topographical positions (i.e., floodplain and upland). For both systems P extracted per gram litter mass was strongly predicted by total P concentration in initial litter (r2=0.66, p<0.001 in tropical forest; r2=0.63, p<0.001 in taiga). In addition, greater than 80% of the soluble P was inorganic P, suggesting leached P is readily available to plants and microbes. In contrast, litter N was relatively less soluble (<10±5% of the total leaf N on average for both systems), water soluble N per unit litter mass was only weakly predicted by total litter N (r2<0.35 for both systems), and organic N was prominent in extracts. The similarity in solubility results from two distinct latitudes and multiple life forms suggests differences in litter P and N solubility may be fundamental to how these two key nutrients cycle in terrestrial ecosystems across the globe.

  11. Countervailing effects on pine and oak leaf litter decomposition in human-altered Mediterranean ecosystems.

    PubMed

    Sheffer, Efrat; Canham, Charles D; Kigel, Jaime; Perevolotsky, Avi

    2015-04-01

    Species affect the dynamics of litter decay through the intrinsic properties of their litter, but also by influencing the environmental conditions imposed by their canopy, roots, and litter layers. We examined how human-induced changes in the relative abundances of two dominant Mediterranean trees-Pinus halepensis and Quercus calliprinos-impact leaf litter decomposition. A reciprocal transplant experiment tested decomposition of pine, oak, and mixed leaf litter in oak woodland and pine forest ecosystems with different relative abundances of pine and oak. Using likelihood methods, we tested the importance and magnitude of the environmental effects of local species abundance, litter layer composition, and soil properties on litter mass loss. Oak litter decomposition was slower than pine, and had an antagonistic effect on mixed litter decay. These results differ from other reported pine-oak associations, and are probably associated with a higher content of tannins and phenols in oak compared to pine litter in our study sites. The environmental effects of the two species were opposite to their litter decomposition dynamics. An increased proportion of pine in the oak woodlands and a higher content of pine needles in the litter layer of pine forests reduced decay rates. The presence of more oak and broadleaf litter in the litter layer accelerated decomposition in pine forests. Our results highlight the importance of considering multidimensional species effects mediated by both chemical and physical properties, and imply that man-made changes in the composition and configuration of plant communities may result in complex unpredicted consequences to ecosystem biogeochemistry. PMID:25680333

  12. Runoff quality from no-till cotton fertilized with broiler litter in subsurface bands.

    PubMed

    Adeli, A; Tewolde, H; Shankle, M W; Way, T R; Brooks, J P; McLaughlin, M R

    2013-01-01

    Surface broadcast of broiler litter to no-till row crops exposes the litter and its nutrients to risks of loss in runoff water and volatilization and may limit the potential benefit of litter to the crops. Subsurface banding of litter could alleviate these risks. A field study was conducted in 2008 and 2009 on an upland Falkner silt loam soil to determine the effect of broiler litter placement on runoff nutrient losses from no-till cotton ( L.). Treatments included surface broadcast broiler litter applied manually, subsurface-banded litter applied by tractor-drawn equipment, and no broiler litter, all in combination with or without winter wheat ( L.) cover crop residue. Broiler litter rate was 5.6 Mg ha. The experimental design was a randomized complete block with a split-plot arrangement of treatments replicated three times. In 2008, simulated rainfall was used to generate runoff 27 d after litter application. Subsurface-banded litter reduced runoff total C, N, P, NH, NO, Cu, Zn and water-soluble P (WP) concentrations by 72, 64, 51, 49, 70, 36, 65, and 77%, respectively, compared with surface broadcast. The reductions were greater in 2009 where runoff occurred 1 d after litter application. Bacterial runoff was decreased by one log with subsurface-banded litter compared to surface broadcast. Except for C, NH, N, and WP, the presence of winter cover crop residue did not affect the load or runoff nutrient concentrations in either year. The results indicate that subsurface banding litter to no-till cotton substantially reduces nutrient and bacterial losses in runoff compared with surface broadcasting. PMID:23673763

  13. Assessing the Utility of a Virtual Environment for Enhancing Facial Affect Recognition in Adolescents with Autism

    ERIC Educational Resources Information Center

    Bekele, Esubalew; Crittendon, Julie; Zheng, Zhi; Swanson, Amy; Weitlauf, Amy; Warren, Zachary; Sarkar, Nilanjan

    2014-01-01

    Teenagers with autism spectrum disorder (ASD) and age-matched controls participated in a dynamic facial affect recognition task within a virtual reality (VR) environment. Participants identified the emotion of a facial expression displayed at varied levels of intensity by a computer generated avatar. The system assessed performance (i.e.,…

  14. Adolescents' Cognitive "Habitus", Learning Environments, Affective Outcomes of Schooling, and Young Adults' Educational Attainment

    ERIC Educational Resources Information Center

    Marjoribanks, Kevin

    2006-01-01

    A moderation-mediation model was constructed to examine relationships among adolescents' cognitive "habitus" (their cognitive dispositions), learning environments, affective outcomes of schooling, and young adults' educational attainment. Data were collected as part of a longitudinal survey of Australian youth (4,171 females, 3,718 males). The…

  15. Can Mood-Inducing Videos Affect Problem-Solving Activities in a Web-Based Environment?

    ERIC Educational Resources Information Center

    Verleur, Ria; Verhagen, Plon W.; Heuvelman, Ard

    2007-01-01

    The purpose of this study was to examine whether a video-induced positive and negative mood has a differential effect on subsequent problem-solving activities in a web-based environment. The study also examined whether task conditions (task demands) moderated the mood effect. As in traditional experimental mood-effect studies, the affective video…

  16. 49 CFR 520.5 - Guidelines for identifying major actions significantly affecting the environment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Guidelines for identifying major actions significantly affecting the environment. 520.5 Section 520.5 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURES FOR CONSIDERING ENVIRONMENTAL...

  17. 49 CFR 520.5 - Guidelines for identifying major actions significantly affecting the environment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Guidelines for identifying major actions significantly affecting the environment. 520.5 Section 520.5 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURES FOR CONSIDERING ENVIRONMENTAL...

  18. 49 CFR 520.5 - Guidelines for identifying major actions significantly affecting the environment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Guidelines for identifying major actions significantly affecting the environment. 520.5 Section 520.5 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURES FOR CONSIDERING ENVIRONMENTAL...

  19. Litter manipulation and associated invertebrate fauna in secondary forest, central Amazonia, Brazil

    NASA Astrophysics Data System (ADS)

    Santos, Evanira M. R.; Franklin, Elizabeth; Luizão, Flávio J.

    2008-11-01

    Plant litter from selected tree species has been used for improving soil productivity in low-input systems of secondary vegetation in Central Amazon, leading to different conditions for invertebrates. Soil invertebrate assemblages were monitored to test the effects of adding litter types of contrasting nutritional quality and periods of exposure on the development of the community. We established four second growth plots with 80 subplots of 3 m 2 from which the original litter was removed and replaced in 60 subplots. Twenty subplots received Hevea brasiliensis leaves, 20 others Carapa guianensis leaves, and another 20 an equal mixture of H. brasiliensis, C. guianensis and Vismia guianensis. Twenty subplots were left with the original litter. Litter and mineral soil (5 cm deep) sub-horizons were collected after 45, 100, 160, 240 and 300 days of exposure. The invertebrates were extracted using Kempson apparatus. At the day 210, the litter was replenished to match the surrounding litter. Regression analyses showed no significant effect of litter type, but the period of exposure did affect the community in both sub-horizons. Only after the litter replenishment, the type of litter and periods of exposure affected the community in the litter sub-horizon. Because we tried to isolate the effects of litter composition from other large-scale phenomena, several factors interfered in the experiment and potential problems were identified to optimize the investigation. The sampling design must be improved by using a larger number of subsamples for each kind of litter within each plot. Coarse parameters of Order and Family were suited to detect major environmental patterns on soil invertebrates, but taxonomic resolution to species and/or morphospecies is required to detect more subtle effects. Future manipulations should also be done on a longer time scale, and the replicates need to be spread over larger areas to capture the natural variations within the ecosystems.

  20. Challenges in researching violence affecting health service delivery in complex security environments.

    PubMed

    Foghammar, Ludvig; Jang, Suyoun; Kyzy, Gulzhan Asylbek; Weiss, Nerina; Sullivan, Katherine A; Gibson-Fall, Fawzia; Irwin, Rachel

    2016-08-01

    Complex security environments are characterized by violence (including, but not limited to "armed conflict" in the legal sense), poverty, environmental disasters and poor governance. Violence directly affecting health service delivery in complex security environments includes attacks on individuals (e.g. doctors, nurses, administrators, security guards, ambulance drivers and translators), obstructions (e.g. ambulances being stopped at checkpoints), discrimination (e.g. staff being pressured to treat one patient instead of another), attacks on and misappropriation of health facilities and property (e.g. vandalism, theft and ambulance theft by armed groups), and the criminalization of health workers. This paper examines the challenges associated with researching the context, scope and nature of violence directly affecting health service delivery in these environments. With a focus on data collection, it considers how these challenges affect researchers' ability to analyze the drivers of violence and impact of violence. This paper presents key findings from two research workshops organized in 2014 and 2015 which convened researchers and practitioners in the fields of health and humanitarian aid delivery and policy, and draws upon an analysis of organizational efforts to address violence affecting healthcare delivery and eleven in-depth interviews with representatives of organizations working in complex security environments. Despite the urgency and impact of violence affecting healthcare delivery, there is an overall lack of research that is of health-specific, publically accessible and comparable, as well as a lack of gender-disaggregated data, data on perpetrator motives and an assessment of the 'knock-on' effects of violence. These gaps limit analysis and, by extension, the ability of organizations operating in complex security environments to effectively manage the security of their staff and facilities and to deliver health services. Increased research

  1. Research Into the Role of Students’ Affective Domain While Learning Geology in Field Environments

    NASA Astrophysics Data System (ADS)

    Elkins, J.

    2009-12-01

    Existing research programs in field-based geocognition include assessment of cognitive, psychomotor, and affective domains. Assessment of the affective domain often involves the use of instruments and techniques uncommon to the geosciences. Research regarding the affective domain also commonly results in the collection and production of qualitative data that is difficult for geoscientists to analyze due to their lack of familiarity with these data sets. However, important information about students’ affective responses to learning in field environments can be obtained by using these methods. My research program focuses on data produced by students’ affective responses to field-based learning environments, primarily among students at the introductory level. For this research I developed a Likert-scale Novelty Space Survey, which presents student ‘novelty space’ (Orion and Hofstien, 1993) as a polygon; the larger the polygons, the more novelty students are experiencing. The axises for these polygons correspond to novelty domains involving geographic, social, cognitive, and psychological factors. In addition to the Novelty Space Survey, data which I have collected/generated includes focus group interviews on the role of recreational experiences in geology field programs. I have also collected data concerning the motivating factors that cause students to take photographs on field trips. The results of these studies give insight to the emotional responses students have to learning in the field and are important considerations for practitioners of teaching in these environments. Collaborative investigations among research programs that cross university departments and include multiple institutions is critical at this point in development of geocognition as a field due to unfamiliarity with cognitive science methodology by practitioners teaching geosciences and the dynamic nature of field work by cognitive scientists. However, combining the efforts of cognitive

  2. Foliar litter decomposition in an alpine forest meta-ecosystem on the eastern Tibetan Plateau.

    PubMed

    Yue, Kai; Yang, Wanqin; Peng, Changhui; Peng, Yan; Zhang, Chuan; Huang, Chunping; Tan, Yu; Wu, Fuzhong

    2016-10-01

    Litter decomposition is a biological process fundamental to element cycling and a main nutrient source within forest meta-ecosystems, but few studies have looked into this process simultaneously in individual ecosystems, where environmental factors can vary substantially. A two-year field study conducted in an alpine forest meta-ecosystem with four litter species (i.e., willow: Salix paraplesia, azalea: Rhododendron lapponicum, cypress: Sabina saltuaria, and larch: Larix mastersiana) that varied widely in chemical traits showed that both litter species and ecosystem type (i.e., forest floor, stream and riparian zone) are important factors affecting litter decomposition, and their effects can be moderated by local-scale environmental factors such as temperature and nutrient availability. Litter decomposed fastest in the streams followed by the riparian zone and forest floor regardless of species. For a given litter species, both the k value and limit value varied significantly among ecosystems, indicating that the litter decomposition rate and extent (i.e., reaching a limit value) can be substantially affected by ecosystem type and the local-scale environmental factors. Apart from litter initial acid unhydrolyzable residue (AUR) concentration and its ratio to nitrogen concentration (i.e., AUR/N ratio), the initial nutrient concentrations of phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were also important litter traits that affected decomposition depending on the ecosystem type. PMID:27220105

  3. The effects of physical environments in medical wards on medication communication processes affecting patient safety.

    PubMed

    Liu, Wei; Manias, Elizabeth; Gerdtz, Marie

    2014-03-01

    Physical environments of clinical settings play an important role in health communication processes. Effective medication management requires seamless communication among health professionals of different disciplines. This paper explores how physical environments affect communication processes for managing medications and patient safety in acute care hospital settings. Findings highlighted the impact of environmental interruptions on communication processes about medications. In response to frequent interruptions and limited space within working environments, nurses, doctors and pharmacists developed adaptive practices in the local clinical context. Communication difficulties were associated with the ward physical layout, the controlled drug key and the medication retrieving device. Health professionals should be provided with opportunities to discuss the effects of ward environments on medication communication processes and how this impacts medication safety. Hospital administrators and architects need to consider health professionals' views and experiences when designing hospital spaces. PMID:24486620

  4. Effects of chemically amended litter on broiler performances, atmospheric ammonia concentration, and phosphorus solubility in litter.

    PubMed

    Do, J C; Choi, I H; Nahm, K H

    2005-05-01

    The effects of 6 different litter amendments on broiler performance, level of atmospheric ammonia (NH3) concentration, and soluble reactive phosphorus (SRP) in litter was determined. Through 3 experiments conducted on 2 different commercial farms, one chemical amendment was added to the litter and then was compared with a control. Broiler performance was not affected by any of the amendments except the ferrous sulfate amendment for which mortality was 25.5%. Application of aluminum chloride (AlCl3 x 6H2O) to the litter lowered atmospheric ammonia concentrations at 42 d by 97.2%, whereas ferrous sulfate (FeSO4 x 7H2O) lowered it by 90.77%. Ammonia concentrations were reduced by 86.18, 78.66, 75.52, and 69.00% by aluminum sulfate [alum or Al2(SO4)3 x 14H2O)], alum + CaCO3, aluminum chloride + CaCO3, and potassium permanganate (KMnO4), respectively, when compared with each control at 42 d. Each amendment except KMnO4 significantly reduced SRP contents. Alum and aluminum chloride were the effective compounds evaluated on the commercial farms with respect to reducing ammonia contents, phosphorus solubility, and mortality. PMID:15913178

  5. Litter contribution to soil organic carbon in the agriculture abandons processes

    NASA Astrophysics Data System (ADS)

    Novara, Agata; Francaviglia, Dario; La Mantia, tommaso; Gristina, Luciano; La Bella, Salvatore; Tuttolomondo, Teresa

    2015-04-01

    Mechanisms of litter decomposition, translocation and stabilization into soil layers are fundamental processes in ecosystem functioning as it regulates the cycle of soil organic matter (SOM), CO2 emission into the atmosphere, carbon sequestration into the soil. In this study, it was investigated the contribution of litters of different stages of Mediterranean secondary succession on Carbon sequestration, analyzing the role of earthworms on translocation of SOM into soil profile. For this purpose δ13C difference between meadow C4-C soil and C3-C litter were used in a field experiment. Four undisturbed litters of different stages of succession were collected (45, 70, 100 and 120 since agriculture abandon) and placed on the top of isolated soil cores. The litter contribution to C stock was affected by plant species and increased with the age of the stage of secondary succession. The soil organic carbon after 1 year since litter position increased up to 40% in comparison to no litter treatment in soil with litter of 120 years since abandon. The new carbon derived from C3-litter was decomposed and transferred into soil profile thanks to earthworms and dissolved organic carbon leaching. After 1 years the carbon increase attributed to earthworm activity ranged from 6% to 13% in soil under litter in field abandoned since 120 and 45 years, respectively.

  6. Increased rainfall variability and N addition accelerate litter decomposition in a restored prairie.

    PubMed

    Schuster, Michael J

    2016-03-01

    Anthropogenic nitrogen deposition and projected increases in rainfall variability (the frequency of drought and heavy rainfall events) are expected to strongly influence ecosystem processes such as litter decomposition. However, how these two global change factors interact to influence litter decomposition is largely unknown. I examined how increased rainfall variability and nitrogen addition affected mass and nitrogen loss of litter from two tallgrass prairie species, Schizachyrium scoparium and Solidago canadensis, and isolated the effects of each during plant growth and during litter decomposition. I increased rainfall variability by consolidating ambient rainfall into larger events and simulated chronic nitrogen deposition using a slow-release urea fertilizer. S. scoparium litter decay was more strongly regulated by the treatments applied during plant growth than by those applied during decomposition. During plant growth, increased rainfall variability resulted in S. scoparium litter that subsequently decomposed more slowly and immobilized more nitrogen than litter grown under ambient conditions, whereas nitrogen addition during plant growth accelerated subsequent mass loss of S. scoparium litter. In contrast, S. canadensis litter mass and N losses were enhanced under either N addition or increased rainfall variability both during plant growth and during decomposition. These results suggest that ongoing changes in rainfall variability and nitrogen availability are accelerating nutrient cycling in tallgrass prairies through their combined effects on litter quality, environmental conditions, and plant community composition. PMID:26216200

  7. Decomposition of Phragmites australis litter retarded by invasive Solidago canadensis in mixtures: an antagonistic non-additive effect

    PubMed Central

    Zhang, Ling; Zhang, Yaojun; Zou, Jianwen; Siemann, Evan

    2014-01-01

    Solidago canadensis is an aggressive invader in China. Solidago invasion success is partially attributed to allelopathic compounds release and more benefits from AM fungi, which potentially makes the properties of Solidago litter different from co-occurring natives. These properties may comprehensively affect litter decomposition of co-occurring natives. We conducted a field experiment to examine litter mixing effects in a Phragmites australis dominated community invaded by Solidago in southeast China. Solidago had more rapid mass and N loss rate than Phragmites when they decomposed separately. Litter mixing decreased N loss rate in Phragmites litter and increased that of Solidago. Large decreases in Phragmites mass loss and smaller increases in Solidago mass loss caused negative non-additive effect. Solidago litter extracts reduced soil C decomposition and N processes, suggested an inhibitory effect of Solidago secondary compounds. These results are consistent with the idea that nutrient transfer and secondary compounds both affected litter mixtures decomposition. PMID:24976274

  8. Decomposition of Phragmites australis litter retarded by invasive Solidago canadensis in mixtures: an antagonistic non-additive effect

    NASA Astrophysics Data System (ADS)

    Zhang, Ling; Zhang, Yaojun; Zou, Jianwen; Siemann, Evan

    2014-06-01

    Solidago canadensis is an aggressive invader in China. Solidago invasion success is partially attributed to allelopathic compounds release and more benefits from AM fungi, which potentially makes the properties of Solidago litter different from co-occurring natives. These properties may comprehensively affect litter decomposition of co-occurring natives. We conducted a field experiment to examine litter mixing effects in a Phragmites australis dominated community invaded by Solidago in southeast China. Solidago had more rapid mass and N loss rate than Phragmites when they decomposed separately. Litter mixing decreased N loss rate in Phragmites litter and increased that of Solidago. Large decreases in Phragmites mass loss and smaller increases in Solidago mass loss caused negative non-additive effect. Solidago litter extracts reduced soil C decomposition and N processes, suggested an inhibitory effect of Solidago secondary compounds. These results are consistent with the idea that nutrient transfer and secondary compounds both affected litter mixtures decomposition.

  9. Consequences of biodiversity loss for litter decomposition across biomes.

    PubMed

    Handa, I Tanya; Aerts, Rien; Berendse, Frank; Berg, Matty P; Bruder, Andreas; Butenschoen, Olaf; Chauvet, Eric; Gessner, Mark O; Jabiol, Jérémy; Makkonen, Marika; McKie, Brendan G; Malmqvist, Björn; Peeters, Edwin T H M; Scheu, Stefan; Schmid, Bernhard; van Ruijven, Jasper; Vos, Veronique C A; Hättenschwiler, Stephan

    2014-05-01

    The decomposition of dead organic matter is a major determinant of carbon and nutrient cycling in ecosystems, and of carbon fluxes between the biosphere and the atmosphere. Decomposition is driven by a vast diversity of organisms that are structured in complex food webs. Identifying the mechanisms underlying the effects of biodiversity on decomposition is critical given the rapid loss of species worldwide and the effects of this loss on human well-being. Yet despite comprehensive syntheses of studies on how biodiversity affects litter decomposition, key questions remain, including when, where and how biodiversity has a role and whether general patterns and mechanisms occur across ecosystems and different functional types of organism. Here, in field experiments across five terrestrial and aquatic locations, ranging from the subarctic to the tropics, we show that reducing the functional diversity of decomposer organisms and plant litter types slowed the cycling of litter carbon and nitrogen. Moreover, we found evidence of nitrogen transfer from the litter of nitrogen-fixing plants to that of rapidly decomposing plants, but not between other plant functional types, highlighting that specific interactions in litter mixtures control carbon and nitrogen cycling during decomposition. The emergence of this general mechanism and the coherence of patterns across contrasting terrestrial and aquatic ecosystems suggest that biodiversity loss has consistent consequences for litter decomposition and the cycling of major elements on broad spatial scales. PMID:24805346

  10. Environmentally-friendly animal litter

    DOEpatents

    Boxley, Chett; McKelvie, Jessica

    2013-09-03

    An animal litter composition that includes geopolymerized ash particulates having a network of repeating aluminum-silicon units is described herein. Generally, the animal litter is made from a quantity of a pozzolanic ash mixed with an alkaline activator to initiate a geopolymerization reaction that forms geopolymerized ash. This geopolymerization reaction may occur within a pelletizer. After the geopolymerized ash is formed, it may be dried and sieved to a desired size. These geopolymerized ash particulates may be used to make a non-clumping or clumping animal litter or other absorbing material. Aluminum sulfate, clinoptilolite, silica gel, sodium alginate and mineral oil may be added as additional ingredients.

  11. Environmentally-friendly animal litter

    DOEpatents

    Boxley, Chett; McKelvie, Jessica

    2012-08-28

    An animal litter composition including geopolymerized ash particulates having a network of repeating aluminum-silicon units is described herein. Generally, the animal litter is made from a quantity of a pozzolanic ash mixed with a sufficient quantity of water and an alkaline activator to initiate a geopolymerization reaction that forms geopolymerized ash. After the geopolymerized ash is formed, it is dried, broken into particulates, and sieved to a desired size. These geopolymerized ash particulates are used to make a non-clumping or clumping animal litter. Odor control is accomplished with the addition of a urease inhibitor, pH buffer, an odor eliminating agent, and/or fragrance.

  12. Subsurface band application of poultry litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Broiler litter is commonly used as a fertilizer on pastures and cropland. Poultry litter is typically land-applied by broadcasting the litter on the soil surface. Rain falling on soil to which poultry litter has been applied, may carry phosphorus (P) and nitrogen (N) nutrients from the soil into s...

  13. External built residential environment characteristics that affect mental health of adults.

    PubMed

    Ochodo, Charles; Ndetei, D M; Moturi, W N; Otieno, J O

    2014-10-01

    External built residential environment characteristics include aspects of building design such as types of walls, doors and windows, green spaces, density of houses per unit area, and waste disposal facilities. Neighborhoods that are characterized by poor quality external built environment can contribute to psychosocial stress and increase the likelihood of mental health disorders. This study investigated the relationship between characteristics of external built residential environment and mental health disorders in selected residences of Nakuru Municipality, Kenya. External built residential environment characteristics were investigated for 544 residents living in different residential areas that were categorized by their socioeconomic status. Medically validated interview schedules were used to determine mental health of residents in the respective neighborhoods. The relationship between characteristics of the external built residential environment and mental health of residents was determined by multivariable logistic regression analyses and chi-square tests. The results show that walling materials used on buildings, density of dwelling units, state of street lighting, types of doors, states of roofs, and states of windows are some built external residential environment characteristics that affect mental health of adult males and females. Urban residential areas that are characterized by poor quality external built environment substantially expose the population to daily stressors and inconveniences that increase the likelihood of developing mental health disorders. PMID:24464242

  14. Enriching early adult environment affects the copulation behaviour of a tephritid fly.

    PubMed

    Díaz-Fleischer, Francisco; Arredondo, José; Aluja, Martín

    2009-07-01

    Early adult experiences in enriched environments favours animal brain and behavioural development ultimately resulting in an increased fitness. However, measuring the effect of environmental enrichment in animal behaviour in nature is often a complicated task, considering the complexity of the natural environment. We expanded previous studies to evaluate how early experience in an enriched environment affects copulation behaviour when animals are confronted with a complex semi-natural environment. Anastrepha ludens flies are an ideal model system for studying these effects because their natural habitats differ significantly from the cage environments in which these flies are reared for biological control purposes. For example, in the field, males form leks of up to six individuals. Each male defends a territory represented by a tree leaf whereas in rearing cages, territories are completely reduced because of the high population density. In a series of three experiments, we observed that male density represented the most influential stimulus for A. ludens male copulation success. Males that experienced lower densities in early adulthood obtained the highest proportion of copulations. By contrast, female copulation behaviour was not altered by female density. However, exposure to natural or artificial leaves in cages in which flies were kept until tested influenced female copulation behaviour. Females that were exposed to enriched environments exhibited a shorter latency to mate and shorter copulation durations with males than females reared in poor environments. We discuss the influence of early experience on male copulation success and female-mating choosiness. PMID:19525439

  15. Statistical analysis of litter experiments in teratology

    SciTech Connect

    Williams, R.; Buschbom, R.L.

    1982-11-01

    Teratological data is binary response data (each fetus is either affected or not) in which the responses within a litter are usually not independent. As a result, the litter should be taken as the experimental unit. For each litter, its size, n, and the number of fetuses, x, possessing the effect of interest are recorded. The ratio p = x/n is then the basic data generated by the experiment. There are currently three general approaches to the analysis of teratological data: nonparametric, transformation followed by t-test or ANOVA, and parametric. The first two are currently in wide use by practitioners while the third is relatively new to the field. These first two also appear to possess comparable power levels while maintaining the nominal level of significance. When transformations are employed, care must be exercised to check that the transformed data has the required properties. Since the data is often highly asymmetric, there may be no transformation which renders the data nearly normal. The parametric procedures, including the beta-binomial model, offer the possibility of increased power.

  16. Centrifugal spreader mass and nutrients distribution patterns for application of fresh and aged poultry litter.

    PubMed

    Temple, W D; Skowrońska, M; Bomke, A A

    2014-06-15

    A spin-type centrifugal spreader was evaluated using fresh and aged poultry litter upon dry mass, product nitrogen (N), phosphorus (P) and potassium (K), incubation study soil available N and particle size distribution patterns. Relative to the aged litter (37% moisture content), the fresh litter (17% moisture content) had greater <1.00 mm particle size fraction weights and atmospheric particulate was launched, which posed as a potential fallout to adjacent fields, waterways and residences. Relative to the aged litter, the broadcast fresh litter resulted in higher coefficients of variation (CV) over its transverse distance, a narrower calculated space distance between passes for uniform spread and lower soil available N concentrations. For nitrogen application over the broadcast transverse distance the fresh litter displayed a high R(2) best fit 4th order polynomial distribution pattern, while the aged litter showed high R(2) best fit 6th order polynomial distribution pattern. A soil incubation study of the fresh and aged broadcast litter resulted in a more variable or lower R(2) best fit 2nd order polynomial distribution pattern. For both the fresh and aged litter, the calculated distance between passes to achieve a uniform mass distribution was greater than that required for the broadcast of soil available N. For the fresh litter, the soil available N and litter P concentration levels strongly correlated (relatively high p and R(2) values) with the <1.00 mm fraction weight, while for the aged litter this relationship was not as significant. In addition to reducing the health risk (i.e. pathogens, antibiotic residues and resistant bacteria) and/or environment issues (particulate fallout onto waterways, adjacent fields and/or residences) our study mass, particulate and N distribution patterns results suggest that poultry litter should be allowed to age before broadcast application is attempted. PMID:24705099

  17. Arsenic speciation and reactivity in poultry litter

    USGS Publications Warehouse

    Arai, Y.; Lanzirotti, A.; Sutton, S.; Davis, J.A.; Sparks, D.L.

    2003-01-01

    Recent U.S. government action to lower the maximum concentration levels (MCL) of total arsenic (As) (10 ppb) in drinking water has raised serious concerns about the agricultural use of As-containing biosolids such as poultry litter (PL). In this study, solid-state chemical speciation, desorbability, and total levels of As in PL and long-term amended soils were investigated using novel synchrotronbased probing techniques (microfocused (??) synchrotron X-ray fluorescence (SXRF) and ??-X-ray absorption near-edge structure (XANES) spectroscopies) coupled with chemical digestion and batch experiments. The total As levels in the PL were as high as ???50 mg kg-1, and As(II/III and V) was always concentrated in abundant needle-shaped microscopic particles (???20/ ??m x 850 ??m) associated with Ca, Cu, and Fe and to a lesser extent with S, CI, and Zn. Postedge XANES features of litter particles are dissimilar to those of the organo-As(V) compound in poultry feed (i.e., roxarsone), suggesting possible degradation/transformation of roxarsone in the litter and/or in poultry digestive tracts. The extent of As desorption from the litter increased with increasing time and pH from 4.5 to 7, but at most 15% of the total As was released after 5 d at pH 7, indicating the presence of insoluble phases and/or strongly retained soluble compounds. No significant As accumulation (< 15 mg kg-1) was found in long-term PL-a mended agricultural surface soils. This suggests that As in the PL may have undergone surface and subsurface transport processes. Our research results raise concerns about long-term PL amendment effects on As contamination in surrounding soilwater environments.

  18. The Effect of Leaf Litter Cover on Surface Runoff and Soil Erosion in Northern China

    PubMed Central

    Li, Xiang; Niu, Jianzhi; Xie, Baoyuan

    2014-01-01

    The role of leaf litter in hydrological processes and soil erosion of forest ecosystems is poorly understood. A field experiment was conducted under simulated rainfall in runoff plots with a slope of 10%. Two common types of litter in North China (from Quercus variabilis, representing broadleaf litter, and Pinus tabulaeformis, representing needle leaf litter), four amounts of litter, and five rainfall intensities were tested. Results revealed that the litter reduced runoff and delayed the beginning of runoff, but significantly reduced soil loss (p<0.05). Average runoff yield was 29.5% and 31.3% less than bare-soil plot, and for Q. variabilis and P. tabulaeformis, respectively, and average sediment yield was 85.1% and 79.9% lower. Rainfall intensity significantly affected runoff (R = 0.99, p<0.05), and the efficiency in runoff reduction by litter decreased considerably. Runoff yield and the runoff coefficient increased dramatically by 72.9 and 5.4 times, respectively. The period of time before runoff appeared decreased approximately 96.7% when rainfall intensity increased from 5.7 to 75.6 mm h−1. Broadleaf and needle leaf litter showed similarly relevant effects on runoff and soil erosion control, since no significant differences (p≤0.05) were observed in runoff and sediment variables between two litter-covered plots. In contrast, litter mass was probably not a main factor in determining runoff and sediment because a significant correlation was found only with sediment in Q. variabilis litter plot. Finally, runoff yield was significantly correlated (p<0.05) with sediment yield. These results suggest that the protective role of leaf litter in runoff and erosion processes was crucial, and both rainfall intensity and litter characteristics had an impact on these processes. PMID:25232858

  19. How mothers influence the development of litter-mate preferences in Belding's ground squirrels.

    PubMed

    Holmes; Mateo

    1998-06-01

    We performed three experiments to examine the role of mothers in the development of litter-mate preferences in captive juvenile Belding's ground squirrels, Spermophilus beldingi. First, when observed in the absence of mothers, juveniles did not play preferentially with litter-mates, which suggests that mothers somehow influence the ontogeny of litter-mate preferences. Second, when mothers were present but unable to intervene in social interactions, juveniles displayed litter-mate preferences, which suggests that mothers do not influence their offsprings' social development by directly intervening in social interactions. In another group, mothers were removed daily, a few hours before nocturnal immergence, and returned the following morning. Juveniles in this group did not display litter-mate preferences and at night they occupied burrows with many more non-litter-mates than litter-mates. These results suggest that associating with non-litter-mates can compromise the development of litter-mate preferences, and implies that mothers indirectly influence social development by affecting the identities of sleeping partners. Third, newly emergent juveniles that interacted only with litter-mates for 3 days in the absence of mothers subsequently preferred litter-mates over non-litter-mates as play partners. This result demonstrates that once litter-mate preferences are instilled, due in part to social experiences during juveniles' initial days above-ground, the preferences are expressed even in the absence of mothers. Collectively, the results demonstrate that the presence of S. beldingi mothers is important to juvenile social development, but that mothers do not actively direct the ontogeny of their offsprings' social relationships. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9642000

  20. Manganese Cycling in a Long-term Plant Litter Decomposition Time Series

    NASA Astrophysics Data System (ADS)

    Keiluweit, M.; Nico, P. S.; Kleber, M.; Bougoure, J.; Harmon, M. E.; Pett-Ridge, J.

    2012-12-01

    Climate change is predicted to affect the chemical composition of plant litter, and global warming may increase microbial and enzymatic activity, with uncertain consequences for litter decomposition rates in soils. This uncertainty has highlighted the need to better understand the controls on litter decomposition rates and pathways. A key controlling processes that is poorly understood is the coupling between decomposition pathways and the inorganic resources available in fresh litter or the underlying soil. For example, a strong correlation was established between the concentration of manganese (Mn) in needle litter and the degradation of litter lignocellulose across boreal forest ecosystems, suggesting that litter decomposition proceeds more efficiently in the presence of Mn. There is good reason to assume that this is due to the critical role of Mn(III)-ligand complexes acting as potent oxidizers in the fungal decomposition of lignocellulose. Here we investigated how litter decomposing organisms redistribute and repurpose the Mn inherently present in fresh plant litter in order to enhance decomposition. For this purpose, we used two 7-year litter decomposition time series collected at sites at the H.J. Andrews Experimental Forest with widely differing decomposition rates. Spatially-resolved X-ray absorption spectroscopy and wet-chemical extractions were used to track pathways of microbially-mediated Mn transport and associated changes in its speciation in each annual litter layer. The cycling of Mn and other metal cations (e.g., Ca and Fe) was then related to changes in the litter chemistry as documented by 13C TMAH and FTIR. Our results show that, as litter decomposition progresses, reduced Mn in the vascular system of fresh needles is transformed into oxidized forms concentrated in Mn oxide precipitates. This transformation of Mn into more reactive forms proceeds faster at the site of greater decomposition. Our imaging data suggests that during this process Mn

  1. Interactions of tissue and fertilizer nitrogen on decomposition dynamics of lignin-rich conifer litter

    USGS Publications Warehouse

    Perakis, Steven S.; Matkins, Joselin J.; Hibbs, David E.

    2012-01-01

    High tissue nitrogen (N) accelerates decomposition of high-quality leaf litter in the early phases of mass loss, but the influence of initial tissue N variation on the decomposition of lignin-rich litter is less resolved. Because environmental changes such as atmospheric N deposition and elevated CO2 can alter tissue N levels within species more rapidly than they alter the species composition of ecosystems, it is important to consider how within-species variation in tissue N may shape litter decomposition and associated N dynamics. Douglas-fir (Pseudotsuga menziesii ) is a widespread lignin-rich conifer that dominates forests of high carbon (C) storage across western North America, and displays wide variation in tissue and litter N that reflects landscape variation in soil N. We collected eight unique Douglas-fir litter sources that spanned a two-fold range in initial N concentrations (0.67–1.31%) with a narrow range of lignin (29–35%), and examined relationships between initial litter chemistry, decomposition, and N dynamics in both ambient and N fertilized plots at four sites over 3 yr. High initial litter N slowed decomposition rates in both early (0.67 yr) and late (3 yr) stages in unfertilized plots. Applications of N fertilizer to litters accelerated early-stage decomposition, but slowed late-stage decomposition, and most strongly affected low-N litters, which equalized decomposition rates across litters regardless of initial N concentrations. Decomposition of N-fertilized litters correlated positively with initial litter manganese (Mn) concentrations, with litter Mn variation reflecting faster turnover of canopy foliage in high N sites, producing younger litterfall with high N and low Mn. Although both internal and external N inhibited decomposition at 3 yr, most litters exhibited net N immobilization, with strongest immobilization in low-N litter and in N-fertilized plots. Our observation for lignin-rich litter that high initial N can slow decomposition

  2. Evaluation of litter type and dietary coarse ground corn inclusion on broiler live performance, gastrointestinal tract development, and litter characteristics.

    PubMed

    Xu, Y; Stark, C R; Ferket, P R; Williams, C M; Nusairat, B; Brake, J

    2015-03-01

    Two 49 d floor pen studies were conducted to evaluate the effects of litter type and dietary coarse ground corn (CC) inclusion on broiler live performance, gastrointestinal tract (GIT) development, and litter characteristics. Experiment 1 was a 2×2 factorial arrangement of 2 genders (male or female) and 2 CC levels (0 or 50%). From 15 to 35 d, the addition of CC decreased feed intake (P<0.01) and BW gain (P<0.05) of males but not females. The inclusion of CC decreased feed intake (P<0.01) and BW gain (P<0.01) from 0 to 49 d but improved adjusted feed conversion ratio (AdjFCR) from 35 to 49 d (P<0.05). Male broilers exhibited better live performance than females during the study as evidenced by greater feed intake (P<0.01) and BW gain (P<0.01), and improved FCR (P<0.01), but with increased mortality (P<0.05). The inclusion of CC increased relative gizzard weight (P<0.01) and decreased relative proventriculus weight (P<0.01) at 49 d. Experiment 2 was a 2×2 factorial arrangement of 2 CC levels (0 or 50%) and 2 litter types (ground old litter or new wood shavings litter). The inclusion of CC decreased feed intake throughout the experiment without affecting final BW when only males were used and improved FCR after 25 d (P<0.01). New litter improved FCR from 1 to 14 d (P<0.01). At 49 d, the birds fed the CC diet had reduced excreta nitrogen (P<0.05) and litter moisture (P<0.05). In conclusion, 50% CC inclusion initially produced negative effects on live performance that became positive as BW increased. The effects of CC became evident at an earlier age for males. New litter had only a marginal benefit on broiler live performance. PMID:25681480

  3. Effects of broiler litter management on runoff N and P from bermudagrass forage based system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Management of broiler litter to provide nutrients for crop growth has generally been based on crop N requirements. Because broiler litter has a lower N/P ratio than harvested crops, N-based broiler management often oversupplies the crop-soil system with P, which can be lost into the environment and ...

  4. Person-centered work environments, psychological safety, and positive affect in healthcare: a theoretical framework.

    PubMed

    Rathert, Cheryl; May, Douglas R

    2008-01-01

    We propose that in order to systematically improve healthcare quality, healthcare organizations (HCOs) need work environments that are person-centered: environments that support the careprovider as well as the patient. We further argue that HCOs have a moral imperative to provide a workplace where professional care standards can be achieved. We draw upon a large body of research from several disciplines to propose and articulate a theoretical framework that explains how the work environment should be related to the well-being of patients and careproviders, that is, the potential mediating mechanisms. Person-centered work environments include: 1. Climates for patient-centered care. 2. Climates for quality improvement. 3. Benevolent ethical climates. Such a work environment should support the provision of patient-centered care, and should lead to positive psychological states for careproviders, including psychological safety and positive affect. The model contributes to theory by specifying relationships between important organizational variables. The model can potentially contribute to practice by linking specific work environment attributes to outcomes for careproviders and patients. PMID:18839753

  5. Effect of moisture content on the heating profile in composted broiler litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Moisture content can affect the magnitude of heat generation during composting. Temperature was recorded every 2 min for 7 d at 10-cm increments throughout the vertical profile of broiler litter treated with five quantities of water addition. Water additions were applied to achieve litter moisture...

  6. Nitrous Oxide Emissions from a Bermudagrass Pasture: Interseeded Winter Rye and Poultry Litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of poultry litter applications and interseeded winter rye on nitrous oxide (N2O) emissions from pasture is not well documented. This study was conducted to estimate soil surface N2O fluxes as affect by poultry litter applications and interseeded winter rye as well as weather and soil vari...

  7. Effects of broiler litter rate, timing and cover crop on cotton yield and residual soil N

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Timing of broiler litter applications has critical effect on the availability of litter-derived nutrients and should affect cotton (Gossypium spp.) growth and yield. This experiment was conducted on a Leeper silty clay loam (fine, montmorillionitic, nonacid, thermic Vertic Haplaquepts) soil at Missi...

  8. Effects of personal relevance and simulated darkness on the affective appraisal of a virtual environment

    PubMed Central

    Houtkamp, Joske M.; Vreugdenhil, Paul E.

    2016-01-01

    This study investigated whether personal relevance influences the affective appraisal of a desktop virtual environment (VE) in simulated darkness. In the real world, darkness often evokes thoughts of vulnerability, threat, and danger, and may automatically precipitate emotional responses consonant with those thoughts (fear of darkness). This influences the affective appraisal of a given environment after dark and the way humans behave in that environment in conditions of low lighting. Desktop VEs are increasingly deployed to study the effects of environmental qualities and (architectural or lighting) interventions on human behaviour and feelings of safety. Their (ecological) validity for these purposes depends critically on their ability to correctly address the user’s cognitive and affective experience. Previous studies with desktop (i.e., non-immersive) VEs found that simulated darkness only slightly affects the user’s behavioral and emotional responses to the represented environment, in contrast to the responses observed for immersive VEs. We hypothesize that the desktop VE scenarios used in previous studies less effectively induced emotional and behavioral responses because they lacked personal relevance. In addition, factors like signs of social presence and relatively high levels of ambient lighting may also have limited these responses. In this study, young female volunteers explored either a daytime or a night-time (low ambient light level) version of a desktop VE representing a deserted (no social presence) prototypical Dutch polder landscape. To enhance the personal relevance of the simulation, a fraction of the participants were led to believe that the virtual exploration tour would prepare them for a follow-up tour through the real world counterpart of the VE. The affective appraisal of the VE and the emotional response of the participants were measured through self-report. The results show that the VE was appraised as slightly less pleasant and

  9. Effects of personal relevance and simulated darkness on the affective appraisal of a virtual environment.

    PubMed

    Toet, Alexander; Houtkamp, Joske M; Vreugdenhil, Paul E

    2016-01-01

    This study investigated whether personal relevance influences the affective appraisal of a desktop virtual environment (VE) in simulated darkness. In the real world, darkness often evokes thoughts of vulnerability, threat, and danger, and may automatically precipitate emotional responses consonant with those thoughts (fear of darkness). This influences the affective appraisal of a given environment after dark and the way humans behave in that environment in conditions of low lighting. Desktop VEs are increasingly deployed to study the effects of environmental qualities and (architectural or lighting) interventions on human behaviour and feelings of safety. Their (ecological) validity for these purposes depends critically on their ability to correctly address the user's cognitive and affective experience. Previous studies with desktop (i.e., non-immersive) VEs found that simulated darkness only slightly affects the user's behavioral and emotional responses to the represented environment, in contrast to the responses observed for immersive VEs. We hypothesize that the desktop VE scenarios used in previous studies less effectively induced emotional and behavioral responses because they lacked personal relevance. In addition, factors like signs of social presence and relatively high levels of ambient lighting may also have limited these responses. In this study, young female volunteers explored either a daytime or a night-time (low ambient light level) version of a desktop VE representing a deserted (no social presence) prototypical Dutch polder landscape. To enhance the personal relevance of the simulation, a fraction of the participants were led to believe that the virtual exploration tour would prepare them for a follow-up tour through the real world counterpart of the VE. The affective appraisal of the VE and the emotional response of the participants were measured through self-report. The results show that the VE was appraised as slightly less pleasant and more

  10. Effects of multiple but low pesticide loads on aquatic fungal communities colonizing leaf litter.

    PubMed

    Talk, Anne; Kublik, Susanne; Uksa, Marie; Engel, Marion; Berghahn, Rüdiger; Welzl, Gerhard; Schloter, Michael; Mohr, Silvia

    2016-08-01

    In the first tier risk assessment (RA) of pesticides, risk for aquatic communities is estimated by using results from standard laboratory tests with algae, daphnids and fish for single pesticides such as herbicides, fungicides, and insecticides. However, fungi as key organisms for nutrient cycling in ecosystems as well as multiple pesticide applications are not considered in the RA. In this study, the effects of multiple low pesticide pulses using regulatory acceptable concentrations (RACs) on the dynamics of non-target aquatic fungi were investigated in a study using pond mesocosm. For that, fungi colonizing black alder (Alnus glutinosa) leaves were exposed to multiple, low pulses of 11 different pesticides over a period of 60days using a real farmer's pesticide application protocol for apple cropping. Four pond mesocosms served as treatments and 4 as controls. The composition of fungal communities colonizing the litter material was analyzed using a molecular fingerprinting approach based on the terminal Restriction Fragment Length Polymorphism (t-RFLP) of the fungal Internal Transcribed Spacer (ITS) region of the ribonucleic acid (RNA) gene(s). Our data indicated a clear fluctuation of fungal communities based on the degree of leaf litter degradation. However significant effects of the applied spraying sequence were not observed. Consequently also degradation rates of the litter material were not affected by the treatments. Our results indicate that the nutrient rich environment of the leaf litter material gave fungal communities the possibility to express genes that induce tolerance against the applied pesticides. Thus our data may not be transferred to other fresh water habitats with lower nutrient availability. PMID:27521943

  11. Neural networks underlying affective states in a multimodal virtual environment: contributions to boredom

    PubMed Central

    Mathiak, Krystyna A.; Klasen, Martin; Zvyagintsev, Mikhail; Weber, René; Mathiak, Klaus

    2013-01-01

    The interaction of low perceptual stimulation or goal-directed behavior with a negative subjective evaluation may lead to boredom. This contribution to boredom may shed light on its neural correlates, which are poorly characterized so far. A video game served as simulation of free interactive behavior without interruption of the game’s narrative. Thirteen male German volunteers played a first-person shooter game (Tactical Ops: Assault on Terror) during functional magnetic resonance imaging (fMRI). Two independent coders performed the time-based analysis of the audio-visual game content. Boredom was operationalized as interaction of prolonged absence of goal-directed behavior with lowered affect in the Positive and Negative Affect Schedule (PANAS). A decrease of positive affect (PA) correlated with response amplitudes in bilateral insular clusters extending into the amygdala to prolonged inactive phases in a game play and an increase in negative affect (NA) was associated with higher responses in bilateral ventromedial prefrontal cortex (vmPFC). Precuneus and hippocampus responses were negatively correlated with changes in NA. We describe for the first time neural contributions to boredom, using a video game as complex virtual environment. Further our study confirmed that PA and NA are separable constructs, reflected by distinct neural patterns. PA may be associated with afferent limbic activity whereas NA with affective control. PMID:24348366

  12. How Environment Affects Galaxy Metallicity through Stripping and Formation History: Lessons from the Illustris Simulation

    NASA Astrophysics Data System (ADS)

    Genel, Shy

    2016-05-01

    Recent studies have found higher galaxy metallicities in richer environments. It is not yet clear, however, whether metallicity-environment dependencies are merely an indirect consequence of environmentally dependent formation histories, or of environmentally related processes directly affecting metallicity. Here, we present a first detailed study of metallicity-environment correlations in a cosmological hydrodynamical simulation, in particular, we focus on the Illustris simulation. Illustris galaxies display similar relations to those observed. Utilizing our knowledge of simulated formation histories, and leveraging the large simulation volume, we construct galaxy samples of satellites and centrals with matching formation histories. This allows us to find that ∼ 1/3 of the metallicity-environment correlation is due to different formation histories in different environments. This is a combined effect of satellites (in particular, in denser environments) having on average lower z = 0 star formation rates (SFRs), and of their older stellar ages, even at a given z = 0 SFR. Most of the difference, ∼ 2/3, however, is caused by the higher concentration of star-forming disks of satellite galaxies, as this biases their SFR-weighted metallicities toward their inner, more metal-rich parts. With a newly defined quantity, the “radially averaged” metallicity, which captures the metallicity profile but is independent of the SFR profile, the metallicities of satellites and centrals become environmentally independent once they are matched in formation history. We find that circumgalactic metallicity (defined as rapidly inflowing gas around the virial radius), while sensitive to environment, has no measurable effect on the metallicity of the star-forming gas inside the galaxies.

  13. Prospects for phosphorus recovery from poultry litter.

    PubMed

    Szogi, A A; Vanotti, M B

    2009-11-01

    Land disposal of poultry litter is an environmental concern often associated to excess phosphorus (P) in soils and potential water pollution in regions with intense poultry production. Although poultry litter can be moved off the farm and traded as fertilizer, its transportation becomes less economical with increasing distances from the farm. Thus, new litter management alternatives are needed to reduce the environmental impact of P litter application to land. This paper summarizes established and emerging alternative technologies in the U.S. that facilitate handling, concentration, and transporting of litter P. Furthermore, it examines the potential integration of technologies into poultry litter management systems that could reduce poultry litter volume and increase P content in litter byproducts. The adoption of alternative technologies may encourage new opportunities to produce bio-energy, fertilizer, and other valuable P byproducts from poultry litter while reducing environmental impact and promoting sustainable poultry production. PMID:19394817

  14. Negative and positive interactions among plants: effects of competitors and litter on seedling emergence and growth of forest and grassland species.

    PubMed

    Loydi, A; Donath, T W; Otte, A; Eckstein, R L

    2015-05-01

    Living plant neighbours, but also their dead aboveground remains (i.e. litter), may individually exert negative or positive effects on plant recruitment. Although living plants and litter co-occur in most ecosystems, few studies have addressed their combined effects, and conclusions are ambivalent. Therefore, we examined the response in terms of seedling emergence and growth of herbaceous grassland and forest species to different litter types and amounts and the presence of competitors. We conducted a pot experiment testing the effects of litter type (grass, oak), litter amount (low, medium, high) and interspecific competition (presence or absence of four Festuca arundinacea individuals) on seedling emergence and biomass of four congeneric pairs of hemicryptophytes from two habitat types (woodland, grassland). Interactions between litter and competition were weak. Litter presence increased competitor biomass. It also had positive effects on seedling emergence at low litter amounts and negative effects at high litter amounts, while competition had no effect on seedling emergence. Seedling biomass was negatively affected by the presence of competitors, and this effect was stronger in combination with high amounts of litter. Litter affected seedling emergence while competition determined the biomass of the emerged individuals, both affecting early stages of seedling recruitment. High litter accumulation also reduced seedling biomass, but this effect seemed to be additive to competitor effects. This suggests that live and dead plant mass can affect species recruitment in natural systems, but the mechanisms by which they operate and their timing differ. PMID:25381837

  15. Patterns of litter disappearance in a northern hardwood forest invaded by exotic earthworms.

    PubMed

    Suárez, Esteban R; Fahey, Timothy J; Yavitt, Joseph B; Groffman, Peter M; Bohlen, Patrick J

    2006-02-01

    A field study was conducted to evaluate the effects of exotic earthworm invasions on the rates of leaf litter disappearance in a northern hardwood forest in southcentral New York, USA. Specifically, we assessed whether differences in litter quality and the species composition of exotic earthworm communities affected leaf litter disappearance rates. Two forest sites with contrasting communities of exotic earthworms were selected, and disappearance rates of sugar maple and red oak litter were estimated in litter boxes in adjacent earthworm-free, transition, and earthworm-invaded plots within each site. After 540 days in the field, 1.7-3 times more litter remained in the reference plots than in the earthworm-invaded plots. In the earthworm-invaded plots, rates of disappearance of sugar maple litter were higher than for oak litter during the first year, but by the end of the experiment, the amount of sugar maple and oak litter remaining in the earthworm-invaded plots was identical within each site. The composition of the earthworm communities significantly affected the patterns of litter disappearance. In the site dominated by the anecic earthworm Lumbricus terrestris and the endogeic Aporrectodea tuberculata, the percentage of litter remaining after 540 days (approximately 17%) was significantly less than at the site dominated by L. rubellus and Octolasion tyrtaeum (approximately 27%). This difference may be attributed to the differences in feeding behavior of the two litter-feeding species: L. terrestris buries entire leaves in vertical burrows, whereas L. rubellus usually feeds on litter at the soil surface, leaving behind leaf petioles and veins. Our results showed that earthworms not only accelerate litter disappearance rates, but also may reduce the differences in decomposition rates that result from different litter qualities at later stages of decay. Similarly, our results indicate that earthworm effects on decomposition vary with earthworm community

  16. Strong stoichiometric resilience after litter manipulation experiments; a case study in a Chinese grassland

    NASA Astrophysics Data System (ADS)

    Xiao, C. W.; Janssens, I. A.; Zhou, Y.; Su, J. Q.; Liang, Y.; Guenet, B.

    2014-07-01

    Global climate change has generally increased net primary production which leads to increasing litter inputs. Therefore assessing the impacts of increasing litter inputs on soil nutrients, plant growth and ecological Carbon (C) : nitrogen (N) : phosphorus (P) stoichiometry is critical for an understanding of C, N and P cycling and their feedback processes to climate change. In this study, we added plant litter to the 10-20 cm subsoil layer under a steppe community at rates equivalent to 0, 150, 300, 600 and 1200 g (dry mass) m-2 and measured the resulting C, N and P content of different pools (above and below ground plant biomass, litter, microbial biomass). High litter addition (120% of the annual litter inputs) significantly increased soil inorganic N and available P, aboveground biomass, belowground biomass and litter. Nevertheless small litter additions, which are more realistic compared to the future predictions, had no effect on the variables examined. Our results suggest that while very high litter addition can strongly affect C : N : P stoichiometry, the grassland studied here is quite resilient to more realistic inputs in terms of stoichiometric functioning. This result highlights the complexity of the ecosystem's response to climate change.

  17. Role of leaf litter nitrogen immobilization in the nitrogen budget of a swamp stream

    SciTech Connect

    Qualls, R.G.

    1984-01-01

    Attempts were made to determine if immobilization-mobilization of N in the litter layer is of a sufficient magnitude to affect the concentrations of inorganic N in the overlying water, and to determine the effect of concentrations of dissolved nutrients and hydroperiod on litter decomposition, N uptake, and N release by litter. The study was conducted in two blackwater stream swamps in North Carolina: Creeping Swamp (CR) and Chicod Creek (CH). With the low levels of dissolved nutrients in CR, there was little difference in litter decomposition rate along elevation gradients. Decomposition was faster at the inundated sites in CH and the faster decomposition was associated with nutrient enrichment. Exogenous N immobilized in litter reached higher levels in the enriched swamp CH. Despite faster decomposition in CH, no substantial mineralization of litter N had occurred prior to June. A budget of litter N and dissolved inorganic N inflow showed that immobilization by flooded litter over 1 linear km of CR during the sampling period was 87 kg, equivalent to about 25% of the inorganic N inflow. This proportion shows that litter can play a significant role in controlling N concentration in stream water in small swamp streams. 24 references, 3 figures, 3 tables.

  18. Litter contribution to soil organic carbon in the agriculture abandons processes

    NASA Astrophysics Data System (ADS)

    Novara, A.; Rühl, J.; La Mantia, T.; Gristina, L.; La Bella, S.; Tuttolomondo, T.

    2015-02-01

    Mechanisms of litter decomposition, translocation and stabilization into soil layers are fundamental processes in ecosystem functioning as it regulates the cycle of soil organic matter (SOM), CO2 emission into the atmosphere, carbon sequestration into the soil. In this study, it was investigated the contribution of litters of different stages of Mediterranean secondary succession on Carbon sequestration, analyzing the role of earthworms on translocation of SOM into soil profile. For this purpose δ13C difference between meadow C4-Csoil and C3-Clitter were used in a field experiment. Four undisturbed litters of different stages of succession were collected (45, 70, 100 and 120 since agriculture abandon) and placed on the top of isolated soil cores. The litter contribution to C stock was affected by plant species and increased with the age of the stage of secondary succession. The soil organic carbon after 1 year since litter position increased up to 40% in comparison to no litter treatment in soil with litter of 120 years since abandon. The new carbon derived from C3-litter was decomposed and transferred into soil profile thanks to earthworms and dissolved organic carbon leaching. After 1 years the carbon increase attributed to earthworm activity ranged from 6 to 13% in soil under litter in field abandoned since 120 and 45 years, respectively.

  19. Litter contribution to soil organic carbon in the processes of agriculture abandon

    NASA Astrophysics Data System (ADS)

    Novara, A.; Rühl, J.; La Mantia, T.; Gristina, L.; La Bella, S.; Tuttolomondo, T.

    2015-04-01

    The mechanisms of litter decomposition, translocation and stabilization into soil layers are fundamental processes in the functioning of the ecosystem, as they regulate the cycle of soil organic matter (SOM) and CO2 emission into the atmosphere. In this study the contribution of litters of different stages of Mediterranean secondary succession on carbon sequestration was investigated, analyzing the role of earthworms in the translocation of SOM into the soil profile. For this purpose the δ13C difference between meadow C4-C soil and C3-C litter was used in a field experiment. Four undisturbed litters of different stages of succession (45, 70, 100 and 120 since agriculture abandon) were collected and placed on the top of isolated C4 soil cores. The litter contribution to C stock was affected by plant species and it increased with the age of the stage of secondary succession. One year after the litter position, the soil organic carbon increased up to 40% in comparison to soils not treated with litter after 120 years of abandon. The new carbon derived from C3 litter was decomposed and transferred into soil profile thanks to earthworms and the leaching of dissolved organic carbon. After 1 year the carbon increase attributed to earthworm activity was 6 and 13% in the soils under litter of fields abandoned for 120 and 45 years, respectively.

  20. Effects of Elevated CO2 on Litter Chemistry and Subsequent Invertebrate Detritivore Feeding Responses

    PubMed Central

    Dray, Matthew W.; Crowther, Thomas W.; Thomas, Stephen M.; A’Bear, A. Donald; Godbold, Douglas L.; Ormerod, Steve J.; Hartley, Susan E.; Jones, T. Hefin

    2014-01-01

    Elevated atmospheric CO2 can change foliar tissue chemistry. This alters leaf litter palatability to macroinvertebrate detritivores with consequences for decomposition, nutrient turnover, and food-web structure. Currently there is no consensus on the link between CO2 enrichment, litter chemistry, and macroinvertebrate-mediated leaf decomposition. To identify any unifying mechanisms, we presented eight invertebrate species from aquatic and terrestrial ecosystems with litter from Alnus glutinosa (common alder) or Betula pendula (silver birch) trees propagated under ambient (380 ppm) or elevated (ambient +200 ppm) CO2 concentrations. Alder litter was largely unaffected by CO2 enrichment, but birch litter from leaves grown under elevated CO2 had reduced nitrogen concentrations and greater C/N ratios. Invertebrates were provided individually with either (i) two litter discs, one of each CO2 treatment (‘choice’), or (ii) one litter disc of each CO2 treatment alone (‘no-choice’). Consumption was recorded. Only Odontocerum albicorne showed a feeding preference in the choice test, consuming more ambient- than elevated-CO2 birch litter. Species’ responses to alder were highly idiosyncratic in the no-choice test: Gammarus pulex and O. albicorne consumed more elevated-CO2 than ambient-CO2 litter, indicating compensatory feeding, while Oniscus asellus consumed more of the ambient-CO2 litter. No species responded to CO2 treatment when fed birch litter. Overall, these results show how elevated atmospheric CO2 can alter litter chemistry, affecting invertebrate feeding behaviour in species-specific ways. The data highlight the need for greater species-level information when predicting changes to detrital processing–a key ecosystem function–under atmospheric change. PMID:24465985

  1. Differential responses of ammonia/ammonium-oxidizing microorganisms in mangrove sediment to amendment of acetate and leaf litter.

    PubMed

    Wang, Yong-Feng; Li, Xiao-Yan; Gu, Ji-Dong

    2014-04-01

    The effects of acetate and leaf litter powder on ammonia/ammonium-oxidizing microorganisms (AOMs) in mangrove sediment were investigated in a laboratory incubation study for a period of 60 days. The results showed that different AOMs responded differently to the addition of acetate and leaf litter. A higher diversity of anaerobic ammonium-oxidizing (anammox) bacteria was observed when acetate or leaf litter was added than the control. However, acetate and leaf litter generally inhibited the growth of anammox bacteria despite that leaf litter promoted their growth in the first 5 days. The inhibitory effects on anammox bacteria were more pronounced by acetate than by leaf litter. Neither acetate nor leaf litter affected ammonia-oxidizing archaea (AOA) community structures, but promoted their growth. For ammonia-oxidizing bacteria (AOB), the addition of acetate or leaf litter resulted in changes of community structures and promoted their growth in the early phase of the incubation. In addition, the promoting effects by leaf litter on AOB growth were more obvious than acetate. These results indicated that organic substances affect AOM community structures and abundances. The study suggests that leaf litter has an important influence on the community structures and abundances of AOMs in mangrove sediment and affects the nitrogen cycle in such ecosystem. PMID:24169949

  2. Fungi vectored by the bark beetle Ips typographus following hibernation under the bark of standing trees and in the forest litter.

    PubMed

    Persson, Ylva; Vasaitis, Rimvydas; Långström, Bo; Ohrn, Petter; Ihrmark, Katarina; Stenlid, Jan

    2009-10-01

    The bark beetle Ips typographus has different hibernation environments, under the bark of standing trees or in the forest litter, which is likely to affect the beetle-associated fungal flora. We isolated fungi from beetles, standing I. typographus-attacked trees, and forest litter below the attacked trees. Fungal identification was done using cultural and molecular methods. The results of the two methods in detecting fungal species were compared. Fungal communities associated with I. typographus differed considerably depending on the hibernation environment. In addition to seven taxa of known ophiostomoid I. typographus-associated fungi, we detected 18 ascomycetes and anamorphic fungi, five wood-decaying basidomycetes, 11 yeasts, and four zygomycetes. Of those, 14 fungal taxa were detected exclusively from beetles that hibernated under bark, and six taxa were detected exclusively from beetles hibernating in forest litter. The spruce pathogen, Ceratocystis polonica, was detected occasionally in bark, while another spruce pathogen, Grosmannia europhioides, was detected more often from beetles hibernating under the bark as compared to litter. The identification method had a significant impact on which taxa were detected. Rapidly growing fungal taxa, e.g. Penicillium, Trichoderma, and Ophiostoma, dominated pure culture isolations; while yeasts dominated the communities detected using molecular methods. The study also demonstrated low frequencies of tree pathogenic fungi carried by I. typographus during its outbreaks and that the beetle does not require them to successfully attack and kill trees. PMID:19444498

  3. Radiocesium leaching from contaminated litter in forest streams.

    PubMed

    Sakai, Masaru; Gomi, Takashi; Naito, Risa S; Negishi, Junjiro N; Sasaki, Michiko; Toda, Hiroto; Nunokawa, Masanori; Murase, Kaori

    2015-06-01

    In Japanese forests suffering from the Fukushima Daiichi Nuclear Power Plant accident, litter fall provides a large amount of radiocesium from forests to streams. Submerged litter is processed to become a vital food resource for various stream organisms through initial leaching and subsequent decomposition. Although leaching from litter can detach radiocesium similarly to potassium, radiocesium leaching and its migration are poorly understood. We examined both radiocesium and potassium leaching to the water column and radiocesium allocation to minerals (glass beads, silica sand, and vermiculite) in the laboratory using soaked litter with and without minerals on a water column. The mineral types did not affect radiocesium leaching from litter, but soaking in water for 1, 7, and 30 days decreased the radiocesium concentration in litter by ×0.71, ×0.66, and ×0.56, respectively. Meanwhile, the 1-, 7-, and 30-day experiments decreased potassium concentration in litter by ×0.17, ×0.11, and ×0.09, respectively. Leached radiocesium remained in a dissolved form when there was no mineral phases present in the water, whereas there was sorption onto the minerals when they were present. In particular, vermiculite adsorbed radiocesium by two to three orders of magnitude more effectively than the other minerals. Because radiocesium forms (such as that dissolved or adsorbed to organic matter or minerals) can further mobilize to ecosystems, our findings will increase our understanding regarding the dynamics of radiocesium in stream ecosystems. PMID:25791899

  4. Decomposition and nitrogen dynamics of 15N-labeled leaf, root, and twig litter in temperate coniferous forests

    USGS Publications Warehouse

    van Huysen, Tiff L.; Harmon, Mark E.; Perakis, Steven S.; Chen, Hua

    2013-01-01

    Litter nutrient dynamics contribute significantly to biogeochemical cycling in forest ecosystems. We examined how site environment and initial substrate quality influence decomposition and nitrogen (N) dynamics of multiple litter types. A 2.5-year decomposition study was installed in the Oregon Coast Range and West Cascades using 15N-labeled litter from Acer macrophyllum, Picea sitchensis, and Pseudotsuga menziesii. Mass loss for leaf litter was similar between the two sites, while root and twig litter exhibited greater mass loss in the Coast Range. Mass loss was greatest from leaves and roots, and species differences in mass loss were more prominent in the Coast Range. All litter types and species mineralized N early in the decomposition process; only A. macrophyllum leaves exhibited a net N immobilization phase. There were no site differences with respect to litter N dynamics despite differences in site N availability, and litter N mineralization patterns were species-specific. For multiple litter × species combinations, the difference between gross and net N mineralization was significant, and gross mineralization was 7–20 % greater than net mineralization. The mineralization results suggest that initial litter chemistry may be an important driver of litter N dynamics. Our study demonstrates that greater amounts of N are cycling through these systems than may be quantified by only measuring net mineralization and challenges current leaf-based biogeochemical theory regarding patterns of N immobilization and mineralization.

  5. Litter Size Variation in Hypothalamic Gene Expression Determines Adult Metabolic Phenotype in Brandt's Voles (Lasiopodomys brandtii)

    PubMed Central

    Zhang, Xue-Ying; Zhang, Qiang; Wang, De-Hua

    2011-01-01

    Background Early postnatal environments may have long-term and potentially irreversible consequences on hypothalamic neurons involved in energy homeostasis. Litter size is an important life history trait and negatively correlated with milk intake in small mammals, and thus has been regarded as a naturally varying feature of the early developmental environment. Here we investigated the long-term effects of litter size on metabolic phenotype and hypothalamic neuropeptide mRNA expression involved in the regulation of energy homeostasis, using the offspring reared from large (10–12) and small (3–4) litter sizes, of Brandt's voles (Lasiopodomys brandtii), a rodent species from Inner Mongolia grassland in China. Methodology/Principal Findings Hypothalamic leptin signaling and neuropeptides were measured by Real-Time PCR. We showed that offspring reared from small litters were heavier at weaning and also in adulthood than offspring from large litters, accompanied by increased food intake during development. There were no significant differences in serum leptin levels or leptin receptor (OB-Rb) mRNA in the hypothalamus at weaning or in adulthood, however, hypothalamic suppressor of cytokine signaling 3 (SOCS3) mRNA in adulthood increased in small litters compared to that in large litters. As a result, the agouti-related peptide (AgRP) mRNA increased in the offspring from small litters. Conclusions/Significance These findings support our hypothesis that natural litter size has a permanent effect on offspring metabolic phenotype and hypothalamic neuropeptide expression, and suggest central leptin resistance and the resultant increase in AgRP expression may be a fundamental mechanism underlying hyperphagia and the increased risk of overweight in pups of small litters. Thus, we conclude that litter size may be an important and central determinant of metabolic fitness in adulthood. PMID:21637839

  6. Long-term marine litter monitoring in the remote Great Australian Bight, South Australia.

    PubMed

    Edyvane, K S; Dalgetty, A; Hone, P W; Higham, J S; Wace, N M

    2004-06-01

    , fishing-related litter in the Bight has reduced at a slower rate than domestic litter. While the level of glass and soft plastics on the beach have both reduced by almost 93% (i.e. 103-7 kg and 119-8 kg, respectively), the level of hard plastics, has diminished at a slower rate, with reductions of only 75% (i.e. 122-30 kg). Some fisheries (i.e. rock lobster, Southern Shark Fishery) have shown marked reductions in fishing-related litter. This is probably due, to some extent, to significant reductions in fishing effort in the region, although this requires further investigation. The information from the Anxious Bay beach litter survey is crucial in monitoring trends in ocean litter in Australia's southern oceans and compliance with international litter regulations. While fishing-related litter remains the major source of ship-based or ocean litter in Australia's southern oceans, the continued reduction in ship-based litter since 1991 supports increasing compliance to MARPOL (Annex V) by commercial fisheries and shipping in the Great Australian Bight. While Australia participates in marine debris monitoring programs in the Antarctic (under CCAMLR), there is currently no national program or management framework to assess, manage and monitor ocean-based litter along Australia's coasts, and monitor compliance with MARPOL. Apart from the commitments under CCAMLR for Antarctic (and sub-Antarctic) marine environments, there are no other regional programs, guidelines or monitoring protocols or to assess and manage ocean litter in the Southern Ocean. PMID:15172812

  7. The maternal environment affects offspring viability via an indirect effect of yolk investment on offspring size.

    PubMed

    Warner, Daniel A; Lovern, Matthew B

    2014-01-01

    Environmental conditions that reproductive females experience can influence patterns of offspring provisioning and fitness. In particular, prey availability can influence maternal reproduction and, in turn, affect the viability of their offspring. Although such maternal effects are widespread, the mechanisms by which these effects operate are poorly understood. We manipulated the amount of prey available to female brown anole lizards (Anolis sagrei) to evaluate how this factor affects patterns of reproductive investment (total egg output, egg size, yolk steroids) and offspring viability (morphology, growth, survival). Experimental reduction of yolk in a subset of eggs enabled us to evaluate a potential causal mechanism (yolk investment) that mediates the effect of maternal prey availability on offspring viability. We show that limited prey availability significantly reduced egg size, which negatively influenced offspring size, growth, and survival. Experimental yolk removal from eggs directly reduced offspring size, which, in turn, negatively affected offspring growth and survival. These findings show that maternal environments (i.e., low prey) can affect offspring fitness via an indirect effect of yolk investment on offspring size and highlight the complex set of indirect effects by which maternal effects can operate. PMID:24642545

  8. Considerations on the effects of tidal regimes in the movement of floating litter in an estuarine environment: Case study of the estuarine system of Santos-São Vicente, Brazil.

    PubMed

    Fernandino, Gerson; Elliff, Carla Isobel; Frutuoso, Gabriela Amado; Silva, Eric Vinícius Nascimento Malaquias da; Gama, Guilherme Santiago; Sousa, João Henrique de Oliveira; Silva, Iracema Reimão

    2016-09-15

    Floating litter in the estuarine system of Santos-São Vicente is common and is part of day-to-day activities of various users of the area. The objective of the present study was to carry out a quali-quantitative evaluation of the occurrence of floating litter, to infer their sources, and to identify environmental factors that are likely to control occurrence and distribution, with particular emphasis on the effects of tidal regimes. Six sampling stations were selected along the aforementioned estuary and visited monthly between July 2010 and January 2012. Floating litter was counted from a fixed sampling station. Plastics prevailed (89.64%) and their main source was domestic activities (55.41%). More litter was found during ebb spring tides, with higher concentrations obeying confluence patterns of the estuary's channels. Results indicated that occurrence can be attributed to the deficiency in basic sewage system in the area and the deliberate disposal into the estuary by the local population. PMID:27263980

  9. Above and belowground controls on litter decomposition in semiarid ecosystems: effects of solar radiation, water availability and litter quality

    NASA Astrophysics Data System (ADS)

    Austin, A. T.; Araujo, P. I.; Leva, P. E.; Ballare, C. L.

    2008-12-01

    The integrated controls on soil organic matter formation in arid and semiarid ecosystems are not well understood and appear to stem from a number of interacting controls affecting above- and belowground carbon turnover. While solar radiation has recently been shown to have an important direct effect on carbon loss in semiarid ecosystems as a result of photochemical mineralization of aboveground plant material, the mechanistic basis for photodegradative losses is poorly understood. In addition, there are large potential differences in major controls on above- and belowground decomposition in low rainfall ecosystems. We report on a mesocosm and field study designed to examine the relative importance of different wavelengths of solar radiation, water availability, position of senescent material above- and belowground and the importance of carbon litter quality in determining rates of abiotic and biotic decomposition. In a factorial experiment of mesocosms, we incubated leaf and root litter simultaneously above- and belowground and manipulated water availability with large and small pulses. Significant interactions between position-litter type and position-pulse sizes demonstrated interactive controls on organic mass loss. Aboveground decomposition showed no response to pulse size or litter type, as roots and leaves decomposed equally rapidly under all circumstances. In contrast, belowground decomposition was significantly altered by litter type and water pulses, with roots decomposing significantly slower and small water pulses reducing belowground decomposition. In the field site, using plastic filters which attenuated different wavelengths of natural solar radiation, we found a highly significant effect of radiation exclusion on mass loss and demonstrated that both UV-A and short-wave visible light can have important impacts on photodegradative carbon losses. The combination of position and litter quality effects on litter decomposition appear to be critical for the

  10. The effects of litter carrying on rifle shooting.

    PubMed

    Tharion, W J; Rice, V; Sharp, M A; Marlowe, B E

    1993-08-01

    This study investigated whether the use of a shoulder harness would affect shooting accuracy after patient litter carrying. Two- and four-person teams, 12 male and 9 female soldiers, fired at targets before and after (1) a 15-minute bout of rapid, short litter carries and lifts, and (2) a moderate speed 30-minute litter carry with and without a harness for both types of carries. Shooting accuracy was 10% poorer (p < 0.05) after the 15-minute bout (mean +/- SD = 8.9 +/- 1.9 mm) than after the 30-minute carry (8.1 +/- 1.7 mm). Four-person teams using litter-carriage harnesses had 17% tighter shot groups (45.5 +/- 30.4 mm2) (p < 0.05) than four-person teams that did not use harnesses (54.5 +/- 26.1 mm2) and two-person teams with (56.3 +/- 29.1 mm2) or without harnesses (54.9 +/- 30.7 mm2). The harness can potentially improve shooting accuracy after litter carrying. PMID:8414084

  11. Assessing the Utility of a Virtual Environment for Enhancing Facial Affect Recognition in Adolescents with Autism

    PubMed Central

    Crittendon, Julie; Zheng, Zhi; Swanson, Amy; Weitlauf, Amy; Warren, Zachary; Sarkar, Nilanjan

    2014-01-01

    Teenagers with autism spectrum disorder (ASD) and age-matched controls participated in a dynamic facial affect recognition task within a virtual reality (VR) environment. Participants identified the emotion of a facial expression displayed at varied levels of intensity by a computer generated avatar. The system assessed performance (i.e., accuracy, confidence ratings, response latency, and stimulus discrimination) as well as how participants used their gaze to process facial information using an eye tracker. Participants in both groups were similarly accurate at basic facial affect recognition at varied levels of intensity. Despite similar performance characteristics, ASD participants endorsed lower confidence in their responses and substantial variation in gaze patterns in absence of perceptual discrimination deficits. These results add support to the hypothesis that deficits in emotion and face recognition for individuals with ASD are related to fundamental differences in information processing. We discuss implications of this finding in a VR environment with regards to potential future applications and paradigms targeting not just enhanced performance, but enhanced social information processing within intelligent systems capable of adaptation to individual processing differences. PMID:24419871

  12. The affect of a clearcut environment on woody debris respiration rate dynamics, Harvard Forest, Massachusetts

    NASA Astrophysics Data System (ADS)

    Vanderhoof, M. K.; Williams, C. L.

    2011-12-01

    At an ecosystem scale, the distribution of carbon is largely a function of stand development and disturbance processes. Clearcut logging remains a common practice both in the United States and globally and typically results in elevated storage of carbon in onsite woody debris and detritus. The residence time and decomposition rate of this woody debris and detritus will affect the rate of CO2 efflux to the atmosphere and thus affect the long term consequences of such disturbances on carbon flux and storage. The removal of a forest canopy also affects a site's microclimate including the albedo, air temperature, air humidity, as well as soil temperature and moisture, many of the same factors that affect the rate of woody debris decomposition. Thus it could be expected that differences in woody debris characteristics (e.g. size, abundance, state of decay), as well as differences in microclimate, between mature and recently clearcut forest sites, would result in differences in piece and site-level woody debris decomposition rates. Although woody debris stocks post-harvest have been well characterized, few studies have explored post-disturbance woody debris respiration rates, which directly measures carbon emissions from woody debris, distinguishing decomposition from mass loss due to fragmentation or leaching. This study addressed the question: does a clearcut environment in a temperate forest affect the rate of decomposition of coarse woody debris? The rate of respiration of downed spruce logs were repeatedly measured in-situ using an LI-6250 gas analyzer in Harvard Forest, Petersham, Massachusetts. Treatments included clear-cut, shaded clear-cut, mature spruce stand, and transfer (from clearcut to spruce stand). Gas analyzer measurements were accompanied by measurements of log temperature and percent water, soil temperature, moisture and pH, as well as light levels, air temperature and humidity to determine dominant drivers of respiration rates.

  13. [Decomposition and phosphorus dynamics of the litters in standing and litterbag of the Hangzhou Bay coastal wetland ].

    PubMed

    Shao, Xue-xin; Liang, Xin-qiang; Wu, Ming; Ye, Xiao-qi; Jiang, Ke-yi

    2014-09-01

    Wetlands litter decomposition affects wetlands nutrient cycling. The decomposition progress of standing litter was monitored and the litterbag simulation experiment was carried out in order to analyze dynamics of litter decomposition and phosphorus release in Phragmites australis (PA), Spartina alterniflora (SA) and Scirpus mariqueter (SM) marshes of Hangzhou Bay coastal wetland. Results show that the dry mass of standing litter and P concentration decrease gradually and the litter drops to the sediment surface after 180 d. There are distinctive stages of the plant litter decomposition in litterbag simulation experiments. The loss rate is faster during 0- 15 d than that of later days. The loss rate in root decomposition of three plants are SM > PA > SA, while the trend is opposite for that of aboveground tissues. The time needed for 95% of dry mass decomposition in the plant tissues is between 1. 2- 8. 3 a. The P concentration in litters decreases rapidly in the initial stage and then increases slowly while the net P pools decreases all the time. Pearson's correlation coefficient shows that there is no significant correlation between the litter decomposition rate and C/N ratio. However, the litter C/P ratio affects greatly on plant decomposition rate. Environmental factors in the atmospheric temperature also have an impact on the decomposition rate of leaves. The different decomposition progresses between standing litter and litterbag are caused by environmental factors. PMID:25518655

  14. Injecting poultry litter into orchardgrass hay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traditional surface application of poultry litter leaves nutrients vulnerable to loss through volatilization and runoff. However, injection can increase capture of these nutrients in agricultural fields. Therefore, a field experiment was conducted to determine the effects of poultry litter injection...

  15. Effects of arctic shrub expansion on biophysical vs. biogeochemical drivers of litter decomposition.

    PubMed

    DeMarco, Jennie; Mack, Michelle C; Bret-Harte, M Syndonia

    2014-07-01

    Climate warming in arctic tundra may shift dominant vegetation from graminoids to deciduous shrubs, whose functional traits could, in turn, alter biotic and abiotic controls over biogeochemical cycling of carbon (C) and nitrogen (N). We investigated whether shrub-induced changes in microclimate have stronger effects on litter decomposition and nutrient release than changes in litter quality and quantity. In arctic tundra near Toolik Lake, Alaska, USA, we incubated a common substrate in a snow-addition experiment to test whether snow accumulation around arctic deciduous shrubs altered the environment enough to increase litter decomposition rates. We compared the influence of litter quality on the rate of litter and N loss by decomposing litter from four different plant functional types in a common site. We used aboveground net primary production values and estimated decay constant (k) values from our decomposition experiments to calculate community-weighted mass loss for each site. Snow addition had no effect on decomposition of the common substrate, and the site with the highest abundance of shrubs had the lowest decomposition rates. Species varied in their decomposition rates, with species from the same functional type not always following similar patterns. Community-weighted mass loss was 1.5 times greater in the high shrub site, and only slightly decreased when adjusted for soil environment, suggesting that litter quality and quantity are the primary drivers of community decomposition. Our findings suggest that on a short time scale, the changes in soil environment associated with snow trapping by shrubs are unlikely to influence litter nutrient turnover enough to drive positive snow-shrub feedbacks. The mechanisms driving shrub expansion are more likely to do with shrub-litter feedbacks, where the higher growth rates and N uptake by shrubs allows them to produce more leaves, resulting in a larger litter N pool and faster internal cycling of nutrients. PMID

  16. COVERING THEIR BUTTS: RESPONSES TO THE CIGARETTE LITTER PROBLEM

    PubMed Central

    Smith, Elizabeth A.; McDaniel, Patricia A.

    2011-01-01

    Background Cigarette butt litter is a potential target of tobacco control. In addition to its toxicity and non-biodegradability, it can justify environmental regulation and policies that raise the price of tobacco and further denormalize its use. This paper examines how the tobacco industry has managed the cigarette butt litter issue and how the issue has been covered in the media. Methods We searched the Legacy Tobacco Documents Library (http://legacy.library.ucsf.edu) using a snowball strategy. We analyzed data from approximately 700 documents, dated 1959–2006, using an interpretive approach. We also searched two newspaper databases, Lexis/Nexis and Newsbank, and found 406 relevant articles, dated 1982–2009 which we analyzed quantitatively and qualitatively. Results The tobacco industry monitored and developed strategies for dealing with the cigarette litter issue because it affected the social acceptability of smoking, created the potential for alliances between tobacco control and environmental advocates, and created a target for regulation. The industry developed anti-litter programs with Keep America Beautiful (KAB) and similar organizations. Media coverage focused on industry-acceptable solutions, such as volunteer clean-ups and installation of ashtrays; stories that mentioned KAB were also more frequently positive toward the tobacco industry. Among alternative approaches, clean outdoor air laws received the most media attention. Conclusions Cigarette litter, like secondhand smoke, is the result of smoker behavior and affects nonsmokers. The tobacco industry has tried and failed to mitigate the impact of cigarette litter. Tobacco control advocates should explore alliances with environmental groups and propose policy options that hold the industry accountable for cigarette waste. PMID:20966130

  17. Bacterial communities from shoreline environments (costa da morte, northwestern Spain) affected by the prestige oil spill.

    PubMed

    Alonso-Gutiérrez, Jorge; Figueras, Antonio; Albaigés, Joan; Jiménez, Núria; Viñas, Marc; Solanas, Anna M; Novoa, Beatriz

    2009-06-01

    The bacterial communities in two different shoreline matrices, rocks and sand, from the Costa da Morte, northwestern Spain, were investigated 12 months after being affected by the Prestige oil spill. Culture-based and culture-independent approaches were used to compare the bacterial diversity present in these environments with that at a nonoiled site. A long-term effect of fuel on the microbial communities in the oiled sand and rock was suggested by the higher proportion of alkane and polyaromatic hydrocarbon (PAH) degraders and the differences in denaturing gradient gel electrophoresis patterns compared with those of the reference site. Members of the classes Alphaproteobacteria and Actinobacteria were the prevailing groups of bacteria detected in both matrices, although the sand bacterial community exhibited higher species richness than the rock bacterial community did. Culture-dependent and -independent approaches suggested that the genus Rhodococcus could play a key role in the in situ degradation of the alkane fraction of the Prestige fuel together with other members of the suborder Corynebacterineae. Moreover, other members of this suborder, such as Mycobacterium spp., together with Sphingomonadaceae bacteria (mainly Lutibacterium anuloederans), were related as well to the degradation of the aromatic fraction of the Prestige fuel. The multiapproach methodology applied in the present study allowed us to assess the complexity of autochthonous microbial communities related to the degradation of heavy fuel from the Prestige and to isolate some of their components for a further physiological study. Since several Corynebacterineae members related to the degradation of alkanes and PAHs were frequently detected in this and other supralittoral environments affected by the Prestige oil spill along the northwestern Spanish coast, the addition of mycolic acids to bioremediation amendments is proposed to favor the presence of these degraders in long-term fuel pollution-affected

  18. Early Life in a Barren Environment Adversely Affects Spatial Cognition in Laying Hens (Gallus gallus domesticus)

    PubMed Central

    Tahamtani, Fernanda M.; Nordgreen, Janicke; Nordquist, Rebecca E.; Janczak, Andrew M.

    2015-01-01

    Spatial cognition in vertebrates is adversely affected by a lack of environmental complexity during early life. However, to our knowledge, no previous studies have tested the effect of early exposure to varying degrees of environmental complexity on specific components of spatial cognition in chickens. There are two main rearing systems for laying hens in the EU: aviaries and cages. These two systems differ from one another in environmental complexity. The aim of the present study was to test the hypothesis that rearing in a barren cage environment relative to a complex aviary environment causes long-lasting deficits in the ability to perform spatial tasks. For this purpose, 24 white Dekalb laying hens, half of which had been reared in an aviary system and the other half in a conventional cage system, were tested in a holeboard task. Birds from both treatment groups learnt the task; however, the cage-reared hens required more time to locate rewards and had poorer levels of working memory. The latter finding supports the hypothesis that rearing in a barren environment causes long-term impairment of short-term memory in chickens. PMID:26664932

  19. Effects of subsidy quality on reciprocal subsidies: how leaf litter species changes frog biomass export.

    PubMed

    Earl, Julia E; Castello, Paula O; Cohagen, Kara E; Semlitsch, Raymond D

    2014-05-01

    Spatial subsidies are resources transferred from one ecosystem to another and which can greatly affect recipient systems. Increased subsidy quantity is known to increase these effects, but subsidy quality is likely also important. We examined the effects of leaf litter quality (varying in nutrient and tannin content) in pond mesocosms on gray treefrog (Hyla versicolor) biomass export, as well as water quality and ecosystem processes. We used litter from three different tree species native to Missouri [white oak (Quercus alba), northern red oak (Quercus rubra), and sugar maple (Acer saccharum)], one non-native tree [white pine (Pinus strobus)], and a common aquatic grass [prairie cordgrass (Spartina pectinata)]. We found that leaf litter species affected almost every variable we measured. Gray treefrog biomass export was greatest in mesocosms with grass litter and lowest with white oak litter. Differences in biomass export were affected by high tannin concentrations (or possibly the correlated variable, dissolved oxygen) via their effects on survival, and by primary production, which altered mean body mass. Effects of litter species could often be traced back to the characteristics of the litter itself: leaf nitrogen, phosphorus, and tannin content, which highlights the importance of plant functional traits in affecting aquatic ecosystems. This work and others stress that changes in forest species composition could greatly influence aquatic systems and aquatic-terrestrial linkages. PMID:24399483

  20. Effects of anthropogenic heavy metal contamination on litter decomposition in streams - A meta-analysis.

    PubMed

    Ferreira, Verónica; Koricheva, Julia; Duarte, Sofia; Niyogi, Dev K; Guérold, François

    2016-03-01

    Many streams worldwide are affected by heavy metal contamination, mostly due to past and present mining activities. Here we present a meta-analysis of 38 studies (reporting 133 cases) published between 1978 and 2014 that reported the effects of heavy metal contamination on the decomposition of terrestrial litter in running waters. Overall, heavy metal contamination significantly inhibited litter decomposition. The effect was stronger for laboratory than for field studies, likely due to better control of confounding variables in the former, antagonistic interactions between metals and other environmental variables in the latter or differences in metal identity and concentration between studies. For laboratory studies, only copper + zinc mixtures significantly inhibited litter decomposition, while no significant effects were found for silver, aluminum, cadmium or zinc considered individually. For field studies, coal and metal mine drainage strongly inhibited litter decomposition, while drainage from motorways had no significant effects. The effect of coal mine drainage did not depend on drainage pH. Coal mine drainage negatively affected leaf litter decomposition independently of leaf litter identity; no significant effect was found for wood decomposition, but sample size was low. Considering metal mine drainage, arsenic mines had a stronger negative effect on leaf litter decomposition than gold or pyrite mines. Metal mine drainage significantly inhibited leaf litter decomposition driven by both microbes and invertebrates, independently of leaf litter identity; no significant effect was found for microbially driven decomposition, but sample size was low. Overall, mine drainage negatively affects leaf litter decomposition, likely through negative effects on invertebrates. PMID:26774191

  1. Variability of aboveground litter inputs alters soil physicochemical and biological processes: a meta-analysis of litterfall-manipulation experiments

    NASA Astrophysics Data System (ADS)

    Xu, S.; Liu, L.; Sayer, E. J.

    2013-03-01

    Global change has been shown to greatly alter the amount of aboveground litter inputs to soil, which could cause substantial cascading effects on belowground biogeochemical cyling. Although having been studied extensively, there is uncertainty about how changes in aboveground litter inputs affect soil carbon and nutrient turnover and transformation. Here, we conducted a comprehensive compilation of 68 studies on litter addition or removal experiments, and used meta-analysis to assess the responses of soil physicochemical properties and carbon and nutrient cycling under changed aboveground litter inputs. Our results suggested that litter addition or removal could significantly alter soil temperature and moisture, but not soil pH. Litter inputs were more crucial in buffering soil temperature and moisture fluctuations in grassland than in forest. Soil respiration, soil microbial biomass carbon and total carbon in the mineral soil increased with increasing litter inputs, suggesting that soil acted as a~net carbon sink although carbon loss and transformation increased with increasing litter inputs. Total nitrogen and the C : N ratio in the mineral soil increased with increased litter inputs. However, there was no correlation between litter inputs and extractable inorganic nitrogen in the mineral soil. Compared to other ecosystems, tropical and subtropical forests are more sensitive to variation in litter inputs. Increased or decreased litter inputs altered the turnover and accumulation of soil carbon and nutrient in tropical and subtropical forests more substantially over a shorter time period compared to other ecosystems. Overall, our study suggested that, although the magnitude of responses differed greatly among ecosystems, increased litter inputs generally accelerated the decomposition and accumulation of carbon and nutrients in soil, and decreased litter inputs reduced them.

  2. Use of rice husk litter at different depths for broiler chicks during summer.

    PubMed

    Haque, M I; Chowdhury, S D

    1994-12-01

    1. Four groups of 36 one-day-old broiler chicks were reared for 8 weeks during summer on rice husk litter spread to depths of 20, 30, 40 or 50 mm. 2. The depth of the litter did not significantly affect live weight gain, food consumption, food conversion ratio, liveability or production number. 3. It was concluded that rice husks can be used as litter at depths of between 20 and 50 mm during summer to raise broilers without affecting performance. PMID:7719744

  3. 46 CFR 108.709 - Litter.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Litter. 108.709 Section 108.709 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Miscellaneous Equipment § 108.709 Litter. Each unit must have a litter that is— (a) Stowed in a location that...

  4. Poultry Industry Trends for Litter Utilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Broiler litter utilization falls primarily into two broad categories, as fertilizer or in litter-to-energy processes. Without economic, environmentally sound litter uses, potential or real regional litigation may force alternative management that can be detrimental to the grower’s bottom line as wel...

  5. Galling by Rhopalomyia solidaginis alters Solidago altissima architecture and litter nutrient dynamics in an old-field ecosystem

    SciTech Connect

    Crutsinger, Greg; Habenicht, Melissa N; Classen, Aimee T; Schweitzer, Jennifer A; Sanders, Dr. Nathan James

    2008-01-01

    Plant-insect interactions can alter ecosystem processes, especially if the insects modify plant architecture, quality, or the quantity of leaf litter inputs. In this study, we investigated the interactions between the gall midge Rhopalomyia solidaginis and tall goldenrod, Solidago altissima, to quantify the degree to which the midge alters plant architecture and how the galls affect rates of litter decomposition and nutrient release in an old-field ecosystem. R. solidaginis commonly leads to the formation of a distinct apical rosette gall on S. altissima and approximately 15% of the ramets in a S. altissima patch were galled (range: 3-34%). Aboveground biomass of galled ramets was 60% higher and the leaf area density was four times greater on galled leaf tissue relative to the portions of the plant that were not affected by the gall. Overall decomposition rate constants did not differ between galled and ungalled leaf litter. However, leaf-litter mass loss was lower in galled litter relative to ungalled litter, which was likely driven by modest differences in initial litter chemistry; this effect diminished after 12 weeks of decomposition in the field. The proportion of N remaining was always higher in galled litter than in ungalled litter at each collection date indicating differential release of nitrogen in galled leaf litter. Several studies have shown that plant-insect interactions on woody species can alter ecosystem processes by affecting the quality or quantity of litter inputs. Our results illustrate how plant-insect interactions in an herbaceous species can affect ecosystem processes by altering the quality and quantity of litter inputs. Given that S. altissima dominates fields and roadsides and that R. solidaginis galls are highly abundant throughout eastern North America, these interactions are likely to be important for both the structure and function of old-field ecosystems.

  6. Annual litter fall in an intact mixed dipterocarp forest of Brunei Darussalam

    NASA Astrophysics Data System (ADS)

    Roh, Yujin; Lee, Jongyeol; Lee, Sohye; Abu Salim, Kamariah; Davies, Stuart James; Son, Yowhan

    2016-04-01

    Estimating litter dynamics in an intact tropical forests is important for understanding tropical forests. Litter fall varies with seasonality, forest type or species composition, forest age, soil water retention, and soil fertility. These parameters are known to be strongly affected by elevation. The objective of this study was to estimate annual litter fall along a relative elevation in an intact mixed dipterocarp forest of Brunei Darussalam. This study was conducted in the Kuala Belalong lowland MDF, which is part of the Ulu Tembulong National Park, Brunei Darussalam. Five 0.36 ha plots were established within the permanent 25 ha UBD-CTFS plot. The plots were divided into three groups by relative elevation of the site: 1) high (N = 1), 2) middle (N = 2) and 3) low (N = 2). In January 2015, nine litter traps were installed in each plot and falling litter was collected every month from February to November, 2015. The collected litter was separated into leaves and other materials, and then weighed after drying at 80oC. The average annual litter fall in this site was 8.70 ± 0.16 Mg ha-1 yr-1, and this was within the range reported in previous studies which were conducted in tropical forests. Litter fall at high, middle and low plots was 9.09 ± 0.46, 8.90 ± 0.29 and 8.06 ± 0.29 Mg ha-1 yr-1, respectively. Litter fall was not significantly different among the groups (P>0.05). The results of regression analysis showed that litter fall was not significantly increased with altitude. We suppose that litter fall may be relatively constant in this site. *Supported by research grants from the Korea Forest Service (S121314L130100)

  7. Winter broiler litter gases and nitrogen compounds: Temporal and spatial trends

    NASA Astrophysics Data System (ADS)

    Miles, D. M.; Rowe, D. E.; Owens, P. R.

    Understanding how animal activities, management, and barn structure affect litter gases and nutrients is fundamental to developing accurate emission models for meat-bird facilities. This research characterized the temporal and spatial variability of litter ammonia (NH 3) and nitrous oxide (N 2O) flux via a chamber method, as well as determined litter nitrogen (N) compounds by intensive sampling in two commercial broiler houses on aged litter. Thirty-six grid samples were taken during a winter flock in Mississippi on days 2, 22, and 45. On day 45, eight additional samples were taken near the feeders and waterers (F/W). Geostatistical contour plots indicate NH 3 flux on day 2 was elevated in the brood area of house one (H1) where litter and air temperatures were highest; a commercial litter treatment held the NH 3 flux near zero for approximately 45% of the brood area in house two (H2). Day 45 NH 3 fluxes were similar, averaging 694 mg m -2 h -1 in H1 vs. 644 mg m -2 h -1 in H2; both houses exhibited greater NH 3 flux near the cooling pads. Ammonia flux, litter moisture and pH were diminished at the F/W locations. Heavy cake near the exhaust fans provided the lowest recorded litter pH, highest litter moisture and ammonium (NH 4) with no NH 3 flux at the flock's end. Trends in litter condition based on bird activity were evident, but individual differences persisted between the houses. The importance of cake formation over the litter surface and differences based on location, both related to bird activity and house structure, should be considered in NH 3 mitigation strategies.

  8. ARTIE: An Integrated Environment for the Development of Affective Robot Tutors

    PubMed Central

    Imbernón Cuadrado, Luis-Eduardo; Manjarrés Riesco, Ángeles; De La Paz López, Félix

    2016-01-01

    Over the last decade robotics has attracted a great deal of interest from teachers and researchers as a valuable educational tool from preschool to highschool levels. The implementation of social-support behaviors in robot tutors, in particular in the emotional dimension, can make a significant contribution to learning efficiency. With the aim of contributing to the rising field of affective robot tutors we have developed ARTIE (Affective Robot Tutor Integrated Environment). We offer an architectural pattern which integrates any given educational software for primary school children with a component whose function is to identify the emotional state of the students who are interacting with the software, and with the driver of a robot tutor which provides personalized emotional pedagogical support to the students. In order to support the development of affective robot tutors according to the proposed architecture, we also provide a methodology which incorporates a technique for eliciting pedagogical knowledge from teachers, and a generic development platform. This platform contains a component for identiying emotional states by analysing keyboard and mouse interaction data, and a generic affective pedagogical support component which specifies the affective educational interventions (including facial expressions, body language, tone of voice,…) in terms of BML (a Behavior Model Language for virtual agent specification) files which are translated into actions of a robot tutor. The platform and the methodology are both adapted to primary school students. Finally, we illustrate the use of this platform to build a prototype implementation of the architecture, in which the educational software is instantiated with Scratch and the robot tutor with NAO. We also report on a user experiment we carried out to orient the development of the platform and of the prototype. We conclude from our work that, in the case of primary school students, it is possible to identify, without

  9. ARTIE: An Integrated Environment for the Development of Affective Robot Tutors.

    PubMed

    Imbernón Cuadrado, Luis-Eduardo; Manjarrés Riesco, Ángeles; De La Paz López, Félix

    2016-01-01

    Over the last decade robotics has attracted a great deal of interest from teachers and researchers as a valuable educational tool from preschool to highschool levels. The implementation of social-support behaviors in robot tutors, in particular in the emotional dimension, can make a significant contribution to learning efficiency. With the aim of contributing to the rising field of affective robot tutors we have developed ARTIE (Affective Robot Tutor Integrated Environment). We offer an architectural pattern which integrates any given educational software for primary school children with a component whose function is to identify the emotional state of the students who are interacting with the software, and with the driver of a robot tutor which provides personalized emotional pedagogical support to the students. In order to support the development of affective robot tutors according to the proposed architecture, we also provide a methodology which incorporates a technique for eliciting pedagogical knowledge from teachers, and a generic development platform. This platform contains a component for identiying emotional states by analysing keyboard and mouse interaction data, and a generic affective pedagogical support component which specifies the affective educational interventions (including facial expressions, body language, tone of voice,…) in terms of BML (a Behavior Model Language for virtual agent specification) files which are translated into actions of a robot tutor. The platform and the methodology are both adapted to primary school students. Finally, we illustrate the use of this platform to build a prototype implementation of the architecture, in which the educational software is instantiated with Scratch and the robot tutor with NAO. We also report on a user experiment we carried out to orient the development of the platform and of the prototype. We conclude from our work that, in the case of primary school students, it is possible to identify, without

  10. Influence of litter chemistry and stoichiometry on glucan depolymerization during decomposition of beech (Fagus sylvatica L.) litter

    PubMed Central

    Leitner, Sonja; Wanek, Wolfgang; Wild, Birgit; Haemmerle, Ieda; Kohl, Lukas; Keiblinger, Katharina M.; Zechmeister-Boltenstern, Sophie; Richter, Andreas

    2012-01-01

    highly correlated to cellulase activities, suggesting that cellulose was the primary substrate for glucan depolymerization at this stage of decomposition. Litter stoichiometry did not affect glucan depolymerization or glucose consumption rates early in decomposition. At later stages, however, we found significant negative relationships between glucan depolymerization and litter C:N and AUR:N ratio and a positive relationship between glucan depolymerization and litter N concentration. Litter C:N and C:P ratios were negatively related to cellulase, peroxidase and phenoloxidase activities three and six months after incubation, further corroborating the importance of resource stoichiometry for glucan depolymerization after the initial pulse of starch degradation. PMID:22761539

  11. Marine Litter Distribution and Density in European Seas, from the Shelves to Deep Basins

    PubMed Central

    Pham, Christopher K.; Ramirez-Llodra, Eva; Alt, Claudia H. S.; Amaro, Teresa; Bergmann, Melanie; Canals, Miquel; Company, Joan B.; Davies, Jaime; Duineveld, Gerard; Galgani, François; Howell, Kerry L.; Huvenne, Veerle A. I.; Isidro, Eduardo; Jones, Daniel O. B.; Lastras, Galderic; Morato, Telmo; Gomes-Pereira, José Nuno; Purser, Autun; Stewart, Heather; Tojeira, Inês; Tubau, Xavier; Van Rooij, David; Tyler, Paul A.

    2014-01-01

    Anthropogenic litter is present in all marine habitats, from beaches to the most remote points in the oceans. On the seafloor, marine litter, particularly plastic, can accumulate in high densities with deleterious consequences for its inhabitants. Yet, because of the high cost involved with sampling the seafloor, no large-scale assessment of distribution patterns was available to date. Here, we present data on litter distribution and density collected during 588 video and trawl surveys across 32 sites in European waters. We found litter to be present in the deepest areas and at locations as remote from land as the Charlie-Gibbs Fracture Zone across the Mid-Atlantic Ridge. The highest litter density occurs in submarine canyons, whilst the lowest density can be found on continental shelves and on ocean ridges. Plastic was the most prevalent litter item found on the seafloor. Litter from fishing activities (derelict fishing lines and nets) was particularly common on seamounts, banks, mounds and ocean ridges. Our results highlight the extent of the problem and the need for action to prevent increasing accumulation of litter in marine environments. PMID:24788771

  12. Marine litter distribution and density in European seas, from the shelves to deep basins.

    PubMed

    Pham, Christopher K; Ramirez-Llodra, Eva; Alt, Claudia H S; Amaro, Teresa; Bergmann, Melanie; Canals, Miquel; Company, Joan B; Davies, Jaime; Duineveld, Gerard; Galgani, François; Howell, Kerry L; Huvenne, Veerle A I; Isidro, Eduardo; Jones, Daniel O B; Lastras, Galderic; Morato, Telmo; Gomes-Pereira, José Nuno; Purser, Autun; Stewart, Heather; Tojeira, Inês; Tubau, Xavier; Van Rooij, David; Tyler, Paul A

    2014-01-01

    Anthropogenic litter is present in all marine habitats, from beaches to the most remote points in the oceans. On the seafloor, marine litter, particularly plastic, can accumulate in high densities with deleterious consequences for its inhabitants. Yet, because of the high cost involved with sampling the seafloor, no large-scale assessment of distribution patterns was available to date. Here, we present data on litter distribution and density collected during 588 video and trawl surveys across 32 sites in European waters. We found litter to be present in the deepest areas and at locations as remote from land as the Charlie-Gibbs Fracture Zone across the Mid-Atlantic Ridge. The highest litter density occurs in submarine canyons, whilst the lowest density can be found on continental shelves and on ocean ridges. Plastic was the most prevalent litter item found on the seafloor. Litter from fishing activities (derelict fishing lines and nets) was particularly common on seamounts, banks, mounds and ocean ridges. Our results highlight the extent of the problem and the need for action to prevent increasing accumulation of litter in marine environments. PMID:24788771

  13. Sampling of riverine litter with citizen scientists--findings and recommendations.

    PubMed

    Rech, S; Macaya-Caquilpán, V; Pantoja, J F; Rivadeneira, M M; Campodónico, C Kroeger; Thiel, M

    2015-06-01

    The quantity and composition of litter at riversides and in the surface waters, as well as the occurrence of illegal dumping sites, were studied along four rivers in Chile. Data generated by volunteers were compared to the results from a professional survey, using an identical protocol. Litter was found in considerable quantities at the riversides and in the surface waters at all the sites investigated. A generalized linear mixed model analysis showed that the recorded litter densities did not differ between volunteers and professionals, even after controlling for river, site, or distance between sampling locations, demonstrating that the volunteers successfully applied the sampling protocol. Differences occurred with respect to litter composition, which is most likely due to difficulties in the classification of litter items and particles and to the underestimation of litter present in surface water samples. Even though this study was only conducted at a small number of rivers and sites, a comparatively consistent pattern of direct and intentional litter deposition at riversides was recorded, highlighting that river basins require more protection. The results also show that the citizen science approach can be a suitable means for more extensive litter surveys at riversides and in other natural environments. PMID:25957193

  14. Using experimental manipulation to assess the roles of leaf litter in the functioning of forest ecosystems.

    PubMed

    Sayer, Emma J

    2006-02-01

    The widespread use of forest litter as animal bedding in central Europe for many centuries gave rise to the first litter manipulation studies, and their results demonstrated that litter and its decomposition are a vital part of ecosystem function. Litter plays two major roles in forest ecosystems: firstly, litterfall is an inherent part of nutrient and carbon cycling, and secondly, litter forms a protective layer on the soil surface that also regulates microclimatic conditions. By reviewing 152 years of litter manipulation experiments, I show that the effects of manipulating litter stem from changes in one, or both, of these two functions, and interactions between the variables influenced by the accumulation of litter can result in feedback mechanisms that may intensify treatment effects or mask responses, making the interpretation of results difficult.Long-term litter removal increased soil bulk density, overland flow, erosion, and temperature fluctuations and upset the soil water balance, causing lower soil water content during dry periods. Soil pH increased or decreased in response to manipulation treatments depending on forest type and initial soil pH, but it is unclear why there was no uniform response. Long-term litter harvesting severely depleted the forests of nutrients. Decreases in the concentrations of available P, Ca, Mg, and K in the soil occurred after only three to five years. The decline in soil N occurred over longer periods of time, and the relative loss was greater in soils with high initial nitrogen concentration. Tree growth declined with long-term litter removal, probably due to lower nutrient availability. Litter manipulation also added or removed large amounts of carbon thereby affecting microbial communities and altering soil respiration rates. Litter manipulation experiments have shown that litter cover acts as a physical barrier to the shoot emergence of small-seeded species; further, the microclimate maintained by the litter layer may be

  15. Recent social environment affects colour-assortative shoaling in juvenile angelfish (Pterophyllum scalare).

    PubMed

    Gómez-Laplaza, Luis M

    2009-09-01

    Theory predicts that fish should show colour-assortative shoaling in order to avoid the oddity effect whereby individuals that differ in some feature from the group majority appear to incur increased risk of predation. It has also been shown that early experience plays an important role in affecting social preferences in some fish species. In this study, the importance of colour phenotype in promoting assortative shoaling and the role played by the recent social environment on its expression were investigated in juvenile angelfish, Pterophyllum scalare. Individuals of the uniformly black and golden colour morphs were housed in a group with conspecifics of like and unlike body colour to themselves, as well as in mixed-colour groups for 4 weeks. Subsequently, they were subjected to a binary choice to shoal with a group of conspecifics composed of unfamiliar fish of either a like or unlike colour phenotype to themselves. The response of the individuals to the colour attributes of the shoals was related to their recent social environment. Fish in like- and mixed-colour previous treatments showed a preferential association with like colour conspecifics. In contrast, the shoaling behaviour exhibited by fish previously maintained with a group of unlike-coloured conspecifics (cross-housed treatment) indicated no significant preference for any of the shoals. The results suggest that angelfish use body colouration as an intraspecific shoaling cue and that learning, in the form of recent familiarization with a specific colour phenotype of conspecifics, can affect colour-assortative shoaling preferences in this species. This learning component of the choice need not be restricted to early developmental stages. PMID:19376208

  16. Genetic Based Plant Resistance and Susceptibility Traits to Herbivory Influence Needle and Root Litter Nutrient Dynamics

    SciTech Connect

    Classen, Aimee T; Chapman, Samantha K.; Whitham, Thomas G; Hart, Stephen C; Koch, George W

    2007-01-01

    It is generally assumed that leaf and root litter decomposition have similar drivers and that nutrient release from these substrates is synchronized. Few studies have examined these assumptions, and none has examined how plant genetics (i.e., plant susceptibility to herbivory) could affect these relationships. Here we examine the effects of herbivore susceptibility and resistance on needle and fine root litter decomposition of pi on pine, Pinus edulis. The study population consists of individual trees that are either susceptible or resistant to herbivory by the pi on needle scale, Matsucoccus acalyptus, or the stem-boring moth, Dioryctria albovittella. Genetic analyses and experimental removals and additions of these insects have identified trees that are naturally resistant and susceptible to these insects. These herbivores increase the chemical quality of litter inputs and alter soil microclimate, both of which are important decomposition drivers. Our research leads to four major conclusions: Herbivore susceptibility and resistance effects on 1) needle litter mass loss and phosphorus (P) retention in moth susceptible and resistant litter are governed by microclimate, 2) root litter nitrogen (N) and P retention, and needle litter N retention are governed by litter chemical quality, 3) net nutrient release from litter can reverse over time, 4) root and needle litter mass loss and nutrient release are determined by location (above- vs. belowground), suggesting that the regulators of needle and root decomposition differ at the local scale. Understanding of decomposition and nutrient retention in ecosystems requires consideration of herbivore effects on above- and belowground processes and how these effects may be governed by plant genotype. Because an underlying genetic component to herbivory is common to most ecosystems of the world and herbivory may increase in climatic change scenarios, it is important to evaluate the role of plant genetics in affecting carbon and

  17. Factors Affecting the Hydrogen Environment Assisted Cracking Resistance of an AL-Zn-Mg-(Cu) Alloy

    SciTech Connect

    Young, G A; Scully, J R

    2002-04-09

    Precipitation hardenable Al-Zn-Mg alloys are susceptible to hydrogen environment assisted cracking (HEAC) when exposed to aqueous environments. In Al-Zn-Mg-Cu alloys, overaged tempers are used to increase HEAC resistance at the expense of strength but overaging has little benefit in low copper alloys. However, the mechanism or mechanisms by which overaging imparts HEAC resistance is poorly understood. The present research investigated hydrogen uptake, diffusion, and crack growth rate in 90% relative humidity (RH) air for both a commercial copper bearing Al-Zn-Mg-Cu alloy (AA 7050) and a low copper variant of this alloy in order to better understand the factors which affect HEAC resistance. Experimental methods used to evaluate hydrogen concentrations local to a surface and near a crack tip include nuclear reaction analysis (NRA), focused ion beam, secondary ion mass spectroscopy (FIB/SIMS) and thermal desorption spectroscopy (TDS). Results show that overaging the copper bearing alloys both inhibits hydrogen ingress from oxide covered surfaces and decreases the apparent hydrogen diffusion rates in the metal.

  18. The geomagnetic environment in which sea turtle eggs incubate affects subsequent magnetic navigation behaviour of hatchlings

    PubMed Central

    Fuxjager, Matthew J.; Davidoff, Kyla R.; Mangiamele, Lisa A.; Lohmann, Kenneth J.

    2014-01-01

    Loggerhead sea turtle hatchlings (Caretta caretta) use regional magnetic fields as open-ocean navigational markers during trans-oceanic migrations. Little is known, however, about the ontogeny of this behaviour. As a first step towards investigating whether the magnetic environment in which hatchlings develop affects subsequent magnetic orientation behaviour, eggs deposited by nesting female loggerheads were permitted to develop in situ either in the natural ambient magnetic field or in a magnetic field distorted by magnets placed around the nest. In orientation experiments, hatchlings that developed in the normal ambient field oriented approximately south when exposed to a field that exists near the northern coast of Portugal, a direction consistent with their migratory route in the northeastern Atlantic. By contrast, hatchlings that developed in a distorted magnetic field had orientation indistinguishable from random when tested in the same north Portugal field. No differences existed between the two groups in orientation assays involving responses to orbital movements of waves or sea-finding, neither of which involves magnetic field perception. These findings, to our knowledge, demonstrate for the first time that the magnetic environment present during early development can influence the magnetic orientation behaviour of a neonatal migratory animal. PMID:25100699

  19. A review on factors affecting microcystins production by algae in aquatic environments.

    PubMed

    Dai, Ruihua; Wang, Pinfei; Jia, Peili; Zhang, Yi; Chu, Xincheng; Wang, Yifei

    2016-03-01

    Microcystins, a toxin produced by Microcystis aeruginosa have become a global environmental issue in recent years. As a consequence of eutrophication, microcystins have become widely disseminated in drinking water sources, seriously impairing drinking water quality. This review focuses on the relationship between microcystins synthesis and physical, chemical, and biological environmental factors that are significant in controlling their production. Light intensity and temperature are the more important physical factors, and in many cases, an optimum level for these two factors has been observed. Nitrogen and phosphorus are the key chemical factors causing frequent occurrence of harmful algal blooms and microcystins production. The absorption of nutrients and metabolic activities of algae are affected by different concentrations and forms of nitrogen and phosphorus, leading to variations in microcystins production Metal ions and emerging pollutants are other significant chemical factors, whose comprehensive impact is still being studied. Algae can also interact with biological agents like predators and competitors in aquatic environments, and such interactions are suggested to promote MCs production and release. This review further highlights areas that require further research in order to gain a better understanding of microcystins production. It provides a theoretical basis for the control of microcystins production and releasing into aquatic environments. PMID:26874538

  20. Second-Hand Eating? Maternal perception of the food environment affects reproductive investment in mice

    PubMed Central

    Schwartz, Tonia S.; Gainer, Renee; Dohm, Erik D.; Johnson, Maria S.; Wyss, J. Michael; Allison, David B.

    2015-01-01

    Objective Little information exists on how perception of the food (or ‘energetic’) environment affects body composition and reproductive investment. We test the hypothesis that female mice, who are themselves consuming standard chow diets, but who are exposed to conspecifics eating a rich “cafeteria diet”, will exhibit altered weight gain and reproductive investment. Design and Methods Female C57BL/6 mice were raised on a cafeteria diet. At maturity, subjects were switched to a standard chow diet and their cage-mate was assigned to consume either a cafeteria diet (treatment, n=20), or standard chow (control, n=20). Subjects were mated, and pups raised to weaning. Subjects and pups were analyzed for body composition. Results Treatment had no discernable effect on dam body weight or composition, but caused pups to have lower body weight (p=0.036), and less fat mass (p=0.041). We found a nearly significant treatment effect on ‘time to successful reproduction’ (avg. 55 vs. 44 days) likely due to increased failed first pregnancies (14/19 versus 8/19, p=0.099). Conclusions These data indicate that perceived food environment (independent of the diet actually consumed) can produce small pups with less body fat, and possibly induce difficulties in pregnancy for dams. Replication and mechanistic studies should follow. PMID:25864567

  1. Crack growth rates of irradiated austenitic stainless steel weld heat affected zone in BWR environments.

    SciTech Connect

    Chopra, O. K.; Alexandreanu, B.; Gruber, E. E.; Daum, R. S.; Shack, W. J.; Energy Technology

    2006-01-31

    Austenitic stainless steels (SSs) are used extensively as structural alloys in the internal components of reactor pressure vessels because of their superior fracture toughness. However, exposure to high levels of neutron irradiation for extended periods can exacerbate the corrosion fatigue and stress corrosion cracking (SCC) behavior of these steels by affecting the material microchemistry, material microstructure, and water chemistry. Experimental data are presented on crack growth rates of the heat affected zone (HAZ) in Types 304L and 304 SS weld specimens before and after they were irradiated to a fluence of 5.0 x 10{sup 20} n/cm{sup 2} (E > 1 MeV) ({approx} 0.75 dpa) at {approx}288 C. Crack growth tests were conducted under cycling loading and long hold time trapezoidal loading in simulated boiling water reactor environments on Type 304L SS HAZ of the H5 weld from the Grand Gulf reactor core shroud and on Type 304 SS HAZ of a laboratory-prepared weld. The effects of material composition, irradiation, and water chemistry on growth rates are discussed.

  2. Nest Bacterial Environment Affects Microbiome of Hoopoe Eggshells, but Not That of the Uropygial Secretion

    PubMed Central

    Martínez-García, Ángela; Martín-Vivaldi, Manuel; Rodríguez-Ruano, Sonia M.; Peralta-Sánchez, Juan Manuel; Valdivia, Eva; Soler, Juan J.

    2016-01-01

    The study of associations between symbiotic bacterial communities of hosts and those of surrounding environments would help to understand how bacterial assemblages are acquired, and how they are transmitted from one to another location (i.e. symbiotic bacteria acquisition by hosts). Hoopoes (Upupa epops) smear their eggshells with uropygial secretion (oily secretion produced in their uropygial gland) that harbors antibiotic producing bacteria. Trying to elucidate a possible role of nest material and cloaca microbiota in determining the bacterial community of the uropygial gland and the eggshells of hoopoes, we characterized bacterial communities of nest material, cloaca, uropygial gland and eggshells by the ARISA fingerprinting. Further, by adding material with scarce bacteria and antimicrobial properties, we manipulated the bacterial community of nest material and thus tested experimentally its effects on the microbiomes of the uropygial secretion and of the eggshells. The experiment did not influence the microbiome of the uropygial secretion of females, but affected the community established on eggshells. This is the first experimental evidence indicating that nest material influences the bacterial community of the eggshells and, therefore, probability of embryo infection. Some of the bacterial strains detected in the secretion were also in the bacterial communities of the nest material and of cloaca, but their occurrence within nests was not associated, which suggests that bacterial environments of nest material and cloaca are not sources of symbiotic bacteria for the gland. These results do not support a role of nest environments of hoopoes as reservoirs of symbiotic bacteria. We discuss possible scenarios explaining bacterial acquisition by hoopoes that should be further explored. PMID:27409772

  3. Nest Bacterial Environment Affects Microbiome of Hoopoe Eggshells, but Not That of the Uropygial Secretion.

    PubMed

    Martínez-García, Ángela; Martín-Vivaldi, Manuel; Rodríguez-Ruano, Sonia M; Peralta-Sánchez, Juan Manuel; Valdivia, Eva; Soler, Juan J

    2016-01-01

    The study of associations between symbiotic bacterial communities of hosts and those of surrounding environments would help to understand how bacterial assemblages are acquired, and how they are transmitted from one to another location (i.e. symbiotic bacteria acquisition by hosts). Hoopoes (Upupa epops) smear their eggshells with uropygial secretion (oily secretion produced in their uropygial gland) that harbors antibiotic producing bacteria. Trying to elucidate a possible role of nest material and cloaca microbiota in determining the bacterial community of the uropygial gland and the eggshells of hoopoes, we characterized bacterial communities of nest material, cloaca, uropygial gland and eggshells by the ARISA fingerprinting. Further, by adding material with scarce bacteria and antimicrobial properties, we manipulated the bacterial community of nest material and thus tested experimentally its effects on the microbiomes of the uropygial secretion and of the eggshells. The experiment did not influence the microbiome of the uropygial secretion of females, but affected the community established on eggshells. This is the first experimental evidence indicating that nest material influences the bacterial community of the eggshells and, therefore, probability of embryo infection. Some of the bacterial strains detected in the secretion were also in the bacterial communities of the nest material and of cloaca, but their occurrence within nests was not associated, which suggests that bacterial environments of nest material and cloaca are not sources of symbiotic bacteria for the gland. These results do not support a role of nest environments of hoopoes as reservoirs of symbiotic bacteria. We discuss possible scenarios explaining bacterial acquisition by hoopoes that should be further explored. PMID:27409772

  4. Effects of nutrient enrichment on mangrove leaf litter decomposition.

    PubMed

    Keuskamp, Joost A; Hefting, Mariet M; Dingemans, Bas J J; Verhoeven, Jos T A; Feller, Ilka C

    2015-03-01

    Nutrient enrichment of mangroves, a common phenomenon along densely populated coastlines, may negatively affect mangrove ecosystems by modifying internal carbon and nutrient cycling. The decomposition of litter exerts a strong influence on these processes and is potentially modified by eutrophication. This study describes effects of N and P enrichment on litter decomposition rate and mineralisation/immobilisation patterns. By making use of reciprocal litter transplantation experiments among fertiliser treatments, it was tested if nutrient addition primarily acts on the primary producers (i.e. changes in litter quantity and quality) or on the microbial decomposers (i.e. changes in nutrient limitation for decomposition). Measurements were done in two mangrove forests where primary production was either limited by N or by P, which had been subject to at least 5 years of experimental N and P fertilisation. Results of this study indicated that decomposers were always N-limited regardless of the limitation of the primary producers. This leads to a differential nutrient limitation between decomposers and primary producers in sites where mangrove production was P-limited. In these sites, fertilisation with P caused litter quality to change, resulting in a higher decomposition rate. This study shows that direct effects of fertilisation on decomposition through an effect on decomposer nutrient availability might be non-significant, while the indirect effects through modifying litter quality might be quite substantial in mangroves. Our results show no indication that eutrophication increases decomposition without stimulating primary production. Therefore we do not expect a decline in carbon sequestration as a result of eutrophication of mangrove ecosystems. PMID:25497680

  5. Effects of litter addition on ectomycorrhizal associates of a lodgepole pine (Pinus contorta) stand in Yellowstone National Park

    NASA Technical Reports Server (NTRS)

    Cullings, Kenneth W.; New, Michael H.; Makhija, Shilpa; Parker, V. Thomas

    2003-01-01

    Increasing soil nutrients through litter manipulation, pollution, or fertilization can adversely affect ectomycorrhizal (EM) communities by inhibiting fungal growth. In this study, we used molecular genetic methods to determine the effects of litter addition on the EM community of a Pinus contorta stand in Yellowstone National Park that regenerated after a stand-replacing fire. Two controls were used; in unmodified control plots nothing was added to the soil, and in perlite plots perlite, a chemically neutral substance, was added to maintain soil moisture and temperature at levels similar to those under litter. We found that (i) species richness did not change significantly following perlite addition (2.6 +/- 0.3 species/core in control plots, compared with 2.3 +/- 0.3 species/core in perlite plots) but decreased significantly (P < 0.05) following litter addition (1.8 +/- 0.3 species/core); (ii) EM infection was not affected by the addition of perlite but increased significantly (P < 0.001) in response to litter addition, and the increase occurred only in the upper soil layer, directly adjacent to the added litter; and (iii) Suillus granulatus, Wilcoxina mikolae, and agaricoid DD were the dominant organisms in controls, but the levels of W. mikolae and agaricoid DD decreased significantly in response to both perlite and litter addition. The relative levels of S. granulatus and a fourth fungus, Cortinariaceae species 2, increased significantly (P < 0.01 and P < 0.05, respectively) following litter addition. Thus, litter addition resulted in some negative effects that may be attributable to moisture-temperature relationships rather than to the increased nutrients associated with litter. Some species respond positively to litter addition, indicating that there are differences in their physiologies. Hence, changes in the EM community induced by litter accumulation also may affect ecosystem function.

  6. Biodegradation of veterinary ionophore antibiotics in broiler litter and soil microcosms.

    PubMed

    Sun, Peizhe; Cabrera, Miguel L; Huang, Ching-Hua; Pavlostathis, Spyros G

    2014-01-01

    Ionophore antibiotics (IPAs) are polyether compounds used in broiler feed to promote growth and control coccidiosis. Most of the ingested IPAs are excreted into broiler litter (BL), a mixture of excreta and bedding material. BL is considered a major source of IPAs released into the environment as BL is commonly used to fertilize agricultural fields. This study investigated IPA biodegradation in BL and soil microcosms, as a process affecting the fate of IPAs in the environment. The study focused on the most widely used IPAs, monensin (MON), salinomycin (SAL), and narasin (NAR). MON was stable in BL microcosms at 24-72% water content (water/wet litter, w/w) and 35-60 °C, whereas SAL and NAR degraded under certain conditions. Factor analysis was conducted to delineate the interaction of water and temperature on SAL and NAR degradation in the BL. A major transformation product of SAL and NAR was identified. Abiotic reaction(s) were primarily responsible for the degradation of MON and SAL in nonfertilized soil microcosms, whereas biodegradation contributed significantly in BL-fertilized soil microcosms. SAL biotransformation in soil microcosms yielded the same product as in the BL microcosms. A new primary biotransformation product of MON was identified in soil microcosms. A field study showed that MON and SAL were stable during BL stacking, whereas MON degraded after BL was applied to grassland. The biotransformation product of MON was also detected in the top soil layer where BL was applied. PMID:24494860

  7. [Relationships between decomposition rate of leaf litter and initial quality across the alpine timberline ecotone in Western Sichuan, China].

    PubMed

    Yang, Lin; Deng, Chang-chun; Chen Ya-mei; He, Run-lian; Zhang, Jian; Liu, Yang

    2015-12-01

    The relationships between litter decomposition rate and their initial quality of 14 representative plants in the alpine forest ecotone of western Sichuan were investigated in this paper. The decomposition rate k of the litter ranged from 0.16 to 1.70. Woody leaf litter and moss litter decomposed much slower, and shrubby litter decomposed a little faster. Then, herbaceous litters decomposed fastest among all plant forms. There were significant linear regression relationships between the litter decomposition rate and the N content, lignin content, phenolics content, C/N, C/P and lignin/N. Lignin/N and hemicellulose content could explain 78.4% variation of the litter decomposition rate (k) by path analysis. The lignin/N could explain 69.5% variation of k alone, and the direct path coefficient of lignin/N on k was -0.913. Principal component analysis (PCA) showed that the contribution rate of the first sort axis to k and the decomposition time (t) reached 99.2%. Significant positive correlations existed between lignin/N, lignin content, C/N, C/P and the first sort axis, and the closest relationship existed between lignin/N and the first sort axis (r = 0.923). Lignin/N was the key quality factor affecting plant litter decomposition rate across the alpine timberline ecotone, with the higher the initial lignin/N, the lower the decomposition rate of leaf litter. PMID:27111995

  8. Litter Size Predicts Adult Stereotypic Behavior in Female Laboratory Mice

    PubMed Central

    Bechard, Allison; Nicholson, Anthony; Mason, Georgia

    2012-01-01

    Stereotypic behaviors are repetitive invariant behaviors that are common in many captive species and potentially indicate compromised welfare and suitability as research subjects. Adult laboratory mice commonly perform stereotypic bar-gnawing, route-tracing, and back-flipping, although great individual variation in frequency occurs. Early life factors (for example, level of maternal care received) have lasting effects on CNS functioning and abilities to cope with stress and therefore may also affect stereotypic behavior in offspring. Access to maternal resources and care are influenced by the number of pups in a litter; therefore, we examined both litter size and its potential correlate, weight at weaning, as early environmental predictors of adult stereotypic behavior in laboratory mice. Further, we assessed the effects on offspring stereotypic behavior of delaying the separation of mother and pups (weaning) beyond the standard 21 d of age. Analyzing stereotypic behavior in 3 different mouse colonies composed of 2 inbred strains (C57BL/6N and C57BL/6J) and an outbred stock (CD1[ICR]) revealed significant positive correlation between litter size and stereotypic behavior in female, but not male, mice. Weight and age at weaning did not significantly affect levels of stereotypy in either sex. Litter size therefore may be a useful indicator of individual predisposition to stereotypic behavior in female laboratory mice. PMID:23043805

  9. Exploring Undergraduate Students' Mental Models of the Environment: Are They Related to Environmental Affect and Behavior?

    ERIC Educational Resources Information Center

    Liu, Shu-Chiu; Lin, Huann-shyang

    2015-01-01

    A draw-and-explain task and questionnaire were used to explore Taiwanese undergraduate students' mental models of the environment and whether and how they relate to their environmental affect and behavioral commitment. We found that students generally held incomplete mental models of the environment, focusing on objects rather than on…

  10. Climate and litter quality differently modulate the effects of soil fauna on litter decomposition across biomes

    PubMed Central

    García-Palacios, Pablo; Maestre, Fernando T.; Kattge, Jens; Wall, Diana H.

    2015-01-01

    Climate and litter quality have been identified as major drivers of litter decomposition at large spatial scales. However, the role played by soil fauna remains largely unknown, despite its importance for litter fragmentation and microbial activity. We synthesized litterbag studies to quantify the effect sizes of soil fauna on litter decomposition rates at the global and biome scales, and to assess how climate, litter quality and soil fauna interact to determine such rates. Soil fauna consistently enhanced litter decomposition at both global and biome scales (average increment ~27%). However, climate and litter quality differently modulated the effects of soil fauna on decomposition rates between biomes, from climate-driven biomes to those where climate effects were mediated by changes in litter quality. Our results advocate for the inclusion of biome-specific soil fauna effects on litter decomposition as a mean to reduce the unexplained variation in large-scale decomposition models. PMID:23763716