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Upland forest leaf litter: Effects on growth and development of Lithobates sylvaticus tadpolesKitson, Sarah R. 09 May 2013 (has links)
No description available.
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Epidemiology of Ustilago bullata Berk. on Bromus tectorum L. and Implication for Biological ControlBoguena, Toupta 15 August 2003 (has links) (PDF)
The seedling-infecting pathogen Ustilago bullata Berk. is a naturally occurring biological control agent for cheatgrass (Bromus tectorum L.). The effects of temperature and nutrients on pathogen teliospore germination behavior and the effects of temperature on host seed germination were examined. The effects of temperature on sporidial proliferation, host infection in a temperature-controlled environment and in a field setting for eight populations were investigated. The infection success of Ustilago bullata on Bromus tectorum in cultivated fields as a function of seeding date, inoculation method, inoculum density, supplemental watering, and litter was also investigated. Teliospores germinated faster on potato dextrose agar than on water agar. Teliospores germinated slowly at temperatures far from the optimum of 15 and 20 C. There were among population variations in teliospore germination and sporidial proliferation, but differences among populations were much more pronounced at temperatures below 15 C. Infection also decreased and varied far from the optimum with almost no infection at 2.5 C in a controlled-environment and in the field for the December-planted seeds. Warmer early fall rather than the colder late fall was suitable for successful infection. This agreed with both laboratory and controlled-environment experiments. Intratetrad mating was observed with teliospores at 2.5 C. Teliospore germination tracked seed germination closely with teliospore germination rate exceeding the host seed germination rate over the range of 10 to 25 C where both were measured. Below 10 C, teliospore germination rate fell below host seed germination. This phenomenon was associated with lower infection percentages, suggesting that teliospore germination needed to be ahead of the seed for maximum infection. Inoculum density was positively correlated with infection rate. Litter significantly increased infection, while supplemental watering significantly increased plant establishment. Since teliospores from different populations showed similar germination patterns at temperatures typical of autumn seedbeds in the Intermountain West, it may not be necessary to use locally-adapted pathogen populations in biological control program. A biocontrol program is most likely to be effective under a scenario where autumn precipitation permits emergence of most of the host seed bank as a fall cohort.
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Change in the Structure of Soil Microbial Communities in Response to Waste AmendmentsBuckley, Elan January 2020 (has links)
Soil microbial communities are affected extensively by addition of amendments to their environment. Of particular concern is the addition of poultry litter, which contains a substantial C, energy, and nutrient supply, but also antibiotic resistance genes (ARG), antimicrobials, and a multitude of microbial species. This project seeks to primarily assess if there is a change in bacterial community structure in response to poultry litter amendments to pasture land across geographically independent land across northern Georgia. It may be that changes in the relative abundance of bacterial communities also result in alteration in ARGs, and the community resistance to antibiotics (“resistome”) which in turn increases the potential threat of antibiotic resistance genes. While another part of this study will determine changes in integrons and specific ARGs, this project will focus on changes in bacterial communities and the potential functional changes in the community, which in turn have consequences for ARG levels and its horizontal transfer to various members of the soil community. Addition of waste from livestock is a historical method for increasing nutrients needed in the soil for the cultivation of crops, and in turn causes pronounced shifts in soil microbial communities due to the addition of large amounts of carbon, nutrients, foreign microbes, and other material. This study is unique because it utilizes a novel and relatively large landscape-scale to determine if there are discernable and repeatable patterns of bacterial community structure change in response to amendment regardless of exact soil type or source of chicken litter amendment. In the future, these data can also provide insight into the changes in the relative abundance antibiotic related genes associated with community change. / M.S. / Soil is complicated, both in terms of its physical makeup and the organisms that live inside of it. Predicting changes in soil based on the addition of foreign material such as chemicals or biological waste is not an easy process, and whether or not it is even possible to reliably predict those changes is a matter of some dispute. This study is designed to illustrate that such changes can in fact be reliably and consistently predicted even with regard to the addition of complicated materials to the soil. In this study, specifically, the material in question is chicken litter. A mix of the bedding and waste produced by chickens, litter is commonly handled by composting and is added to soil in farms as a fertilizer rich in organic matter. It is possible to point at specific elements of the soil such as the chemistry and bacteria and see how it is changed with the addition of chicken litter, which allows us to determine the nature and extent of the change that chicken litter has on soil. This study is conducted on a larger scale than similar experiments conducted in the past, making it apparent that these relationships exist on a repeated basis. It is the object of this study to pave the way and make it easier for scientists in the future to determine these relationships in other unique contexts.
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Peat exploitation on Thorne Moors. A case-study from the Yorkshire-Lincolnshire border 1626-1963, with integrated notes on Hatfield MoorsLimbert, Martin January 2011 (has links)
In its industrial heyday, Thorne Moors was the most extensive commercial peat operation in Britain. It became closely tied to nearby Hatfield Moors, and at both the methods of exploitation were essentially the same. Although much of Thorne Moors is situated in Yorkshire, the eastern extent lies in Lincolnshire. Recognizable differences in scale and methodology existed between the Yorkshire and Lincolnshire parts.
After regional drainage in the 1620-30s, there was increased trade in the peat of Thorne Moors along the River Don. A succession of uses included unrefined and refined fuel, products from carbonization and distillation, and moss litter for working horses. From the mid-19th century, companies were formed to exploit the new uses, especially moss litter, and export became increasingly focused on railways. In 1896, the British Moss Litter Co. Ltd was set up (restructured 1899) to assume the Thorne/Hatfield interests of several smaller companies, including the Anglo-Dutch Griendtsveen Moss Litter Co. Ltd. The British Moss Litter Co. was acquired by Fisons Ltd in 1963.
Following a contextual history, descriptions are given of both muscle-powered peat winning and transportation methodologies. These comprise exploitation in the 17th and 18th centuries, an examination of the 19th century writings of William Casson, and written allusions spanning 1863-1963. Information is imparted on the Griendtsveen Moss Litter Co. In addition to creating a 'Dutch' peat canal system, this company introduced an immigrant Dutch workforce, proficient in their native methods and intended inter alia to retrain local workers looking for employment with Griendtsveen. Dutch methodology persisted alongside the local methods for c.60 years. Accounts are also presented of the evolutionary limit of indigenous peat winning, and the use of narrow gauge railways. Finally the transition to mechanisation of peat cutting and narrow gauge haulage is outlined.
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Effects of Climate and Atmospheric Nitrogen Deposition on Early to Mid-Term Stage Litter Decomposition Across BiomesKwon, TaeOh, Shibata, Hideaki, Kepfer-Rojas, Sebastian, K. Schmidt, Inger, S. Larsen, Klaus, Beier, Claus, Berg, Björn, Verheyen, Kris, Lamarque, Jean-Francois, Hagedorn, Frank, Eisenhauer, Nico, Djukic, Ika, Network, TeaComposition 11 December 2023 (has links)
Litter decomposition is a key process for carbon and nutrient cycling in terrestrial
ecosystems and is mainly controlled by environmental conditions, substrate quantity
and quality as well as microbial community abundance and composition. In particular,
the effects of climate and atmospheric nitrogen (N) deposition on litter decomposition
and its temporal dynamics are of significant importance, since their effects might
change over the course of the decomposition process. Within the TeaComposition
initiative, we incubated Green and Rooibos teas at 524 sites across nine biomes. We
assessed how macroclimate and atmospheric inorganic N deposition under current and
predicted scenarios (RCP 2.6, RCP 8.5) might affect litter mass loss measured after 3
and 12 months. Our study shows that the early to mid-term mass loss at the global
scale was affected predominantly by litter quality (explaining 73% and 62% of the total
variance after 3 and 12 months, respectively) followed by climate and N deposition.
The effects of climate were not litter-specific and became increasingly significant as
decomposition progressed, with MAP explaining 2% and MAT 4% of the variation after
12 months of incubation. The effect of N deposition was litter-specific, and significant
only for 12-month decomposition of Rooibos tea at the global scale. However, in the
temperate biome where atmospheric N deposition rates are relatively high, the 12-
month mass loss of Green and Rooibos teas decreased significantly with increasing
N deposition, explaining 9.5% and 1.1% of the variance, respectively. The expected
changes in macroclimate and N deposition at the global scale by the end of this century
are estimated to increase the 12-month mass loss of easily decomposable litter by 1.1–
3.5% and of the more stable substrates by 3.8–10.6%, relative to current mass loss.
In contrast, expected changes in atmospheric N deposition will decrease the mid-term
mass loss of high-quality litter by 1.4–2.2% and that of low-quality litter by 0.9–1.5%
in the temperate biome. Our results suggest that projected increases in N deposition
may have the capacity to dampen the climate-driven increases in litter decomposition
depending on the biome and decomposition stage of substrate.
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Improving Capture Methods for Neonate UngulatesTurnley, Matthew T. 15 March 2022 (has links)
The capture of neonate ungulates has played an integral role in studies of habitat selection, phenology, survival, and other topics of ecological interest. However, neonates can be difficult for researchers to locate and capture. Neonate ungulates are born in habitats with reduced visibility, frequently spend time in a concealed, prone position, and may display cryptic coloration. In an attempt to improve researchers' likelihood of locating and capturing neonate ungulates, multiple capture methods have been developed. Much remains unknown about biases associated with capture methods and how to further improve capture methods once biases are understood. Our objectives were to determine if opportunistic captures of neonate mule deer (Odocoileus hemionus) bias estimates of litter size (Chapter 1) and to determine when searches for neonate elk (Cervus canadensis) should begin following parturition to maximize likelihood of capture while minimizing disturbance (Chapter 2). To complete our objectives, we analyzed data from 161 litters of mule deer and 55 attempted captures of neonate elk during 2019-2021 in Utah, USA. Estimates of litter size derived from opportunistic captures of mule deer were smaller than estimates derived from movement-based captures or captures completed with the aid of vaginal implant transmitters (VITs). The time elapsed between parturition and when searches were initiated for neonate mule deer did not influence estimates of litter size, but we could only analyze this relationship for VIT-aided captures within approximately 2 days of parturition. Until more data are available, we recommend that estimates of litter size for neonate mule deer be completed using movement-based or VIT-aided captures within approximately 2 days of parturition. When attempting to capture neonate elk, reducing the time elapsed between parturition and when searches were initiated resulted in a decreased search length, decreased distance traveled by the neonate, and increased likelihood of capture. We initiated searches as early as 3.6 hours post-parturition with no evidence of maternal abandonment and probability of capture was near or above 90% when searches were initiated within 10 hours of parturition. We recommend that searches for neonate elk be initiated 3.6-10 hours post-parturition. Future researchers can use utilize our results to perform captures of neonate ungulates that minimize bias, decrease disturbance, increase efficiency, and maximize the likelihood of capture success.
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EFFECTS OF FOREST EDGES, EXOTIC ANTS AND NONNATIVE PLANTS ON LOCAL ANT (HYMENOPTERA: FORMICIDAE) DIVERSITY IN URBAN FOREST FRAGMENTS OF NORTHEASTERN OHIOIvanov, Kaloyan January 2010 (has links)
No description available.
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Microbial Community Structure and Interactions in Leaf Litter in a StreamDas, Mitali 13 April 2006 (has links)
No description available.
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EFFECTS OF TREEFALL GAPS AND SOIL DISTURBANCE ON THE INVASION OF FOUR NON-NATIVE PLANT SPECIES IN A MATURE UPLAND FOREST IN MARYLANDEmsweller, Lauren N. 30 November 2015 (has links)
No description available.
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Influence of wood on the pyrolysis of poultry litterMante, Nii Ofei Daku 21 October 2008 (has links)
Pyrolytic oils produced from poultry litter differ in physico-chemical properties and the chemical composition. The litter is composed of manure and bedding material with traces of spilled feed and feathers. The type and amount of bedding material was varied to investigate its influence on the pyrolysis of layer manure. 400g of each feedstock: manure, wood (pine and oak), and mixtures of manure and wood in proportions (75:25 50:50, and 25:75 w/w %) respectively were subjected to fast pyrolysis at 450oC in a fluidized bed reactor. The total pyrolytic oil yield ranged from 43.3% to 64.5 wt%. The highest bio oil yield and the lowest char yield were obtained from oak wood. The manure oil had the highest HHV of 29.7 MJ/kg, the highest pH (5.89), the lowest density (1.14 g/cm3) and a relatively low viscosity of 130cSt. The oils had relatively high nitrogen content ranging from 5.88wt% to 1.36 wt%; low ash content (approximately <0.07wt %) and low sulfur content (<0.28wt %). FT-IR, 13CNMR, and 1HNMR analysis showed that manure oil was rich in aliphatic hydrocarbon and primary and secondary amides and the addition of wood introduced oxygenated compounds like aliphatic alcohols, phenols, aromatic ethers, and carbonyl/carboxylic groups into the oil. TG/DTG analysis also showed that the thermal decomposition of the oils were different depending on the amount and the type of wood in the manure/wood mixture.
The parametric variables used for the mixture of 50% manure and 50% pine wood shavings study were; temperature (400-550°C), nitrogen gas flow rate (12-24 L/min), and feed rate (160-480 g/h). The results showed that the pyrolysis product yields, physical properties and the chemical composition of the oil were influenced by all parameters. Temperature was the most influential factor and its effect on the liquid, char and gas yields were significant. It was evident that depending on the gas flow rate and the feed rate, a maximum oil yield (51.1wt.%) can be achieved between 400-500 oC. Also an increase in temperature significantly increased the oil viscosity and decreased the carbonyl/carboxylic and the primary aliphatic alcohol functional groups in the oil.
The study on the influence of wood on the stability of the oils when stored at ambient conditions for 8 months in a 30ml glass bottle showed that the viscosity of the oils increases when stored, however the manure oil was relatively more stable and the oil from the 50/50 mixture for both pine and oak was the least stable. It was found that the stability of the oils from the manure and wood mixtures were dependent on the amount and the type of wood (pine or oak) added to the manure. Also the addition of 10% solvent (methanol/ethanol) to the oil from 50% manure and 50% pine reduced the initial viscosity of the oil and was also beneficial in slowing down the increase in viscosity during storage. / Master of Science
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