Dissertations / Theses on the topic 'Leaf Litter'
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1
Dale, Sarah Elizabeth. "Leaf litter decomposition in tropical forests : disentangling leaf litter quality, soil nutrients, climate and microbial decomposers." Thesis, Lancaster University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658223.
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Leaf litter decomposition in lowland tropical forests represents a significant flux of carbon (C) to the atmosphere, and is controlled by both extrinsic site conditions and intrinsic litter traits. However, there is a gap in the understanding about the relative importance of these two factors, and of the role of interactions between them. Global change drivers, such as mean annual precipitation (MAP) change and soil nitrogen (N) fertilisation by deposition, could affect both pathways simultaneously. In order to predict the response of the global C cycle to future change, a further understanding of such interactions is required, and is the focus of this thesis. Using a range of experimental factorial studies, in the field and laboratory, in mature tropical forests in Panama, the relative and interactive effects on decomposition of MAP, soil N and phosphorus (P) availability, litter species identity, and litter N and P status, were determined. Leaf litter species identity was a significant predictor of decomposition across the landscape, whilst soil C:N ratio was more important than MAP. Within species, elevated P concentration and decreased N:P ratio in litter was associated with decreased C mineralisation. Increased soil N availability altered microbial community composition, which increased decomposition of some leaf litter types. The results highlight litter traits as an important driver of decomposition via species identify and intra-species leaf litter chemistry. Also, the implications of decomposer activity and composition for decomposition will depend on litter traits. This thesis contributes valuable research evidence to augment current understanding of the importance of litter traits, and their interactions with decomposers, as a pathway through which global change drivers could affect the C cycle in tropical forests.
2
Sayer, Emma Jane. "Leaf litter manipulation in a tropical forest." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615132.
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Schindler, Markus. "Effects of litter diversity, leaf quality and water chemistry on litter decomposition in streams /." Zürich : ETH, 2006. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16789.
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Zukswert, Jenna Michelle. "How well do plant functional traits and leaf-litter traits predict rates of litter decomposition?" Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/57698.
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Foliar functional traits have been shown to strongly co-vary with each other and with rates of litter decomposition, demonstrating an “after-life effect” of foliar traits on ecosystem processes. Leaf-litter traits are often used to indicate substrate quality in decomposition studies. Chemical traits have been studied more extensively in the context of decomposition than physical traits such as specific leaf area (SLA) and leaf toughness, which impart information on litter structure and decomposer access. I investigated relationships among foliar and litter traits, and between traits and early mass-loss, in 14 plant species native to British Columbia. Both physical and chemical traits were measured in foliage and leaf litter of each species. Foliar traits novel to this kind of study include cuticle thickness and distance to lumen (DTL); novel litter traits include leaching loss and water uptake after 2 and 24 hours. Decomposition, as net proportion of mass lost over time, was measured in litterbags installed in a temperate rain forest at the University of British Columbia Farm in Vancouver. Mass loss was divided into two phases: Phase I from 0 to 3 months, and Phase II from 3 to 12 months. Foliar traits co-varied in ways predicted by the leaf economics spectrum hypothesis, and litter traits similarly co-varied. Trait-based relationships among species differed when using foliar traits and using litter traits, suggesting that the same traits measured in foliar and litter impart different meaning in the context of decomposition. Phase I was best predicted by leaching loss and litter traits, suggesting that leaching dominates Phase I, and Phase II was best predicted by foliar functional traits such as leaf dry matter content and nitrogen that relate to relative mesophyll abundance, suggesting that decomposer activity dominates Phase II. Physical traits predicted mass loss as well or better than chemical traits, and using both types of traits in correlative studies may provide insights into the processes that underlie litter decomposition.Forestry, Faculty of
Graduate
5
Li, Oi-yee. "Shredders and leaf litter breakdown in Hong Kong streams." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/b40203505.
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Li, Oi-yee, and 李靄儀. "Shredders and leaf litter breakdown in Hong Kong streams." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40203505.
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Leung, Hing-cheung. "Aspects of leaf litter decomposition in Kandelia candel (L.) Druce /." [Hong Kong : University of Hong Kong], 1986. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12326082.
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Schlief, Jeanette. "The fate of leaf litter in extremely acidic mining waters." Berlin dissertation.de, 2005. http://deposit.ddb.de/cgi-bin/dokserv?id=2828582&prov=M&dok_var=1&dok_ext=htm.
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梁慶祥 and Hing-cheung Leung. "Aspects of leaf litter decomposition in Kandelia candel (L.) Druce." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1986. http://hub.hku.hk/bib/B31207728.
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Osono, Takashi. "Fungal decomposition of leaf litter in a cool temperate forest." Kyoto University, 2002. http://hdl.handle.net/2433/78146.
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11
Zhang, Li, and n/a. "Bacterial Diversity of Australian Exotic Pine Forest Soil and Leaf Litter." Griffith University. School of Biomolecular and Biomedical Science, 2007. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20071128.094745.
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Forest plantations, widely grown for wood production, involve the selective promotion of single tree species, or replacement of natural species by exotic tree species. Slash pine (Pinus elliottii) has been chosen for reforestation of infertile sandy soils in southeast Queensland, Australia. These exotic pine plantations minimise soil and water losses, and are important scientific study sites. The soil environment of these plantations, though devoid of sufficient nutrients, oxygen and other factors, harbours innumerable bacteria that may play a crucial role in maintaining soil quality and ecosystem functions. These soil microorganisms also have the potential for use as sensitive biological indicators to reflect environmental changes. It is therefore essential to understand the interrelationships amongst bacterial communities and their environment by assessing their structural and functional diversity, and their responses to disturbances. The microbial community of an exotic pine plantation of subtropical Australia was analysed by both culture-dependent and culture-independent methods. In this study, a leaf litter-soil core sample (25 cm x 40 cm) was collected from a 22-year-old slash pine plantation in southeast Queensland, Australia in October, 2003. The core sample was divided into three fractions, namely, L layer leaf litter, F layer leaf litter, and forest soil 0-10 cm. In the culture-independent study, a modified DNA extraction and purification method was used to obtain highly purified high-molecular-weight DNA. This DNA was successfully used to amplify bacterial 16S rRNA genes with universal primers Fd1 and R6, to produce products of approximately 1500 bp. PCRamplified 16S rRNA genes were subsequently cloned and a total of 194 clones from leaf litter and soil were partially sequenced (about 510 bp). The 16S rRNA gene sequences were analysed and grouped into several phylogroups (the sequences with a similarity value ¡Ý 98 % were regarded as phylogenetically similar and grouped into one phylogroup). Sequencing representatives (¡Ö 1400 nucleotides) from each phylogenetic group confirmed that five bacterial phyla were represented in the forest soil clone library. Phylum Acidobacterium was the most abundant phylogenetic group in terms of the number of clones and accounted for 42 % of all examined soil clones. The Verrucomicrobiales and Proteobacteria were the second and third most abundant phylogenetic groups found in the soil clone libraries, accounting for 12 % and 11 % of the soil clones, respectively. About 8 % of all examined soil clones were Planctomycetes and 27 % of soil clones were phylogenetically unidentified. The large amount of unclassified clone sequences could imply that novel groups of bacteria were present in the forest soil. When the two fractions of leaf litter clone libraries were compared, Firmicutes was the only phylum represented in the L layer leaf litter clone library. Similarly, Firmicutes dominated the F layer leaf litter (79 % of the library), was followed by Proteobacteria (21 %). For the culture-dependent study, a total of 21 isolates which were considered to represent 334 colonies from the leaf litter and forest soil were identified by 16S rRNA gene sequence analysis, indicating that L layer leaf litter and F layer leaf litter were dominated by Firmicutes (48 %) and Proteobacteria (69 %) respectively, and 91 % of the isolates from the forest soil were Firmicutes. Using culture-independent methods, Actinobacteria appeared to be absent from the L and F layer leaf litter and forest soil samples. The results implied that either the nucleic acids of Actinobacteria were difficult to extract or Actinobacteria were over represented in the culture-dependent examinations. Phylum Acidobacteria appeared to be numerically dominant and active members in most soils. However, only one named species had been isolated from an acid mine drainage site and reported by Kishimoto and Tano (1987). Analysis by culture-dependent methods revealed a different bacterial diversity, compared to the bacterial diversity from the 16S rRNA gene clone sequences. The most significant result was the observation that, as revealed by both culture-dependent and culture-independent methods, the bacterial diversity presented in the leaf litter was greatly different from the community of the soil. During the culture-dependent bacterial diversity study, four novel strains were isolated from the forest soil and leaf litter samples and complete characterisations of these novel strains were carried out. Reports on the descriptions of Bacillus decisifrondis strain E5HC-32T from forest soil and Frondicola australicus strain E1HC-02T from L layer leaf litter have been published (appendix). The information provided by assessing the microbial communities in different fractions of leaf litter and forest soil improves our understanding of the phylogenetic relationship between soil and leaf litter. It is suggested, in this study, to perform both culture-dependent and culture-independent methods to characterise the bacterial structure and diversity in forest litter and soil samples, particularly in response to different forest management practices and global change. This study also provides the basis for further functional studies of the forest soil and leaf litter of exotic pine plantation in subtropical Australia.
12
Dieter, Daniela [Verfasser]. "Phosphorus and leaf litter turnover in temporary aquatic systems / Daniela Dieter." Berlin : Freie Universität Berlin, 2013. http://d-nb.info/1036130185/34.
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Nason, Mark A. "Decomposition of tree leaf litter and formation of soil organic matter." Thesis, Bangor University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409217.
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Riipinenn, Miira P. "Assessing the functional integrity of upland streams using leaf litter breakdown." Thesis, Manchester Metropolitan University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436208.
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Snaddon, Jake Lanion. "Biodiversity and ecosystem function within leaf-litter accumulations in Sabah, Malaysia." Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612445.
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16
Das, Mitali. "Microbial Community Structure and Interactions in Leaf Litter in a Stream." Kent State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=kent1144953748.
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17
Zhang, Li. "Bacterial Diversity of Australian Exotic Pine Forest Soil and Leaf Litter." Thesis, Griffith University, 2007. http://hdl.handle.net/10072/366994.
Full textAbstract:
Forest plantations, widely grown for wood production, involve the selective promotion of single tree species, or replacement of natural species by exotic tree species. Slash pine (Pinus elliottii) has been chosen for reforestation of infertile sandy soils in southeast Queensland, Australia. These exotic pine plantations minimise soil and water losses, and are important scientific study sites. The soil environment of these plantations, though devoid of sufficient nutrients, oxygen and other factors, harbours innumerable bacteria that may play a crucial role in maintaining soil quality and ecosystem functions. These soil microorganisms also have the potential for use as sensitive biological indicators to reflect environmental changes. It is therefore essential to understand the interrelationships amongst bacterial communities and their environment by assessing their structural and functional diversity, and their responses to disturbances. The microbial community of an exotic pine plantation of subtropical Australia was analysed by both culture-dependent and culture-independent methods. In this study, a leaf litter-soil core sample (25 cm x 40 cm) was collected from a 22-year-old slash pine plantation in southeast Queensland, Australia in October, 2003. The core sample was divided into three fractions, namely, L layer leaf litter, F layer leaf litter, and forest soil 0-10 cm. In the culture-independent study, a modified DNA extraction and purification method was used to obtain highly purified high-molecular-weight DNA. This DNA was successfully used to amplify bacterial 16S rRNA genes with universal primers Fd1 and R6, to produce products of approximately 1500 bp. PCRamplified 16S rRNA genes were subsequently cloned and a total of 194 clones from leaf litter and soil were partially sequenced (about 510 bp). The 16S rRNA gene sequences were analysed and grouped into several phylogroups (the sequences with a similarity value ¡Ã 98 % were regarded as phylogenetically similar and grouped into one phylogroup). Sequencing representatives (¡Ã– 1400 nucleotides) from each phylogenetic group confirmed that five bacterial phyla were represented in the forest soil clone library. Phylum Acidobacterium was the most abundant phylogenetic group in terms of the number of clones and accounted for 42 % of all examined soil clones. The Verrucomicrobiales and Proteobacteria were the second and third most abundant phylogenetic groups found in the soil clone libraries, accounting for 12 % and 11 % of the soil clones, respectively. About 8 % of all examined soil clones were Planctomycetes and 27 % of soil clones were phylogenetically unidentified. The large amount of unclassified clone sequences could imply that novel groups of bacteria were present in the forest soil. When the two fractions of leaf litter clone libraries were compared, Firmicutes was the only phylum represented in the L layer leaf litter clone library. Similarly, Firmicutes dominated the F layer leaf litter (79 % of the library), was followed by Proteobacteria (21 %). For the culture-dependent study, a total of 21 isolates which were considered to represent 334 colonies from the leaf litter and forest soil were identified by 16S rRNA gene sequence analysis, indicating that L layer leaf litter and F layer leaf litter were dominated by Firmicutes (48 %) and Proteobacteria (69 %) respectively, and 91 % of the isolates from the forest soil were Firmicutes. Using culture-independent methods, Actinobacteria appeared to be absent from the L and F layer leaf litter and forest soil samples. The results implied that either the nucleic acids of Actinobacteria were difficult to extract or Actinobacteria were over represented in the culture-dependent examinations. Phylum Acidobacteria appeared to be numerically dominant and active members in most soils. However, only one named species had been isolated from an acid mine drainage site and reported by Kishimoto and Tano (1987). Analysis by culture-dependent methods revealed a different bacterial diversity, compared to the bacterial diversity from the 16S rRNA gene clone sequences. The most significant result was the observation that, as revealed by both culture-dependent and culture-independent methods, the bacterial diversity presented in the leaf litter was greatly different from the community of the soil. During the culture-dependent bacterial diversity study, four novel strains were isolated from the forest soil and leaf litter samples and complete characterisations of these novel strains were carried out. Reports on the descriptions of Bacillus decisifrondis strain E5HC-32T from forest soil and Frondicola australicus strain E1HC-02T from L layer leaf litter have been published (appendix). The information provided by assessing the microbial communities in different fractions of leaf litter and forest soil improves our understanding of the phylogenetic relationship between soil and leaf litter. It is suggested, in this study, to perform both culture-dependent and culture-independent methods to characterise the bacterial structure and diversity in forest litter and soil samples, particularly in response to different forest management practices and global change. This study also provides the basis for further functional studies of the forest soil and leaf litter of exotic pine plantation in subtropical Australia.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Biomolecular and Biomedical Sciences
Faculty of Science and Technology
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Suzuki, Yoriko. "The effects of millipedes (Harpaphe haydeniana) on microbial decomposition of leaf litter." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/41623.
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Most estimates of litter decomposition rates do not account well for the effects of soil macrofauna, and so are suspect in ecosystems in which litter-transforming soil fauna are abundant. In coastal rainforests, millipedes consume substantial amounts of leaf litter, most of which is egested as faecal pellets. Little is known about the fate of this material, which hinders estimation of realistic rates of litter decomposition in these ecosystems.
In this study, I assess the influence of feeding by the millipede (Harpaphe haydeniana) on decomposition of leaf litter by comparing rates of CO₂ release during laboratory incubation from leaf litter which has been ingested by millipedes and transformed into faecal pellets with that from litter which has not been ingested by millipedes. Changes in litter microbial communities as a consequence of millipede ingestion are assessed by comparing the PLFA profiles of faeces and uningested litter during incubation.
Rates of CO₂ release from faeces and litter were similar. CO₂ release was higher in maple litter than Douglas-fir litter, and this difference persisted in the faeces from litter that millipedes fed on. Differences in bacterial abundance between litter types were also retained during millipede gut passage. Grinding of litter increased CO₂ release, as did grinding of faeces, indicating that structure of litter and millipedes’ faecal pellets may restrict microbial access and thus decrease the decomposition rates. Microbial activity and abundance did not differ between leaf litter and faeces incubated alone vs together.
19
Didham, Raphael K. "The effects of forest fragmentation on leaf-litter invertebrates in Central Amazonia." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299511.
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Read, H. J. "The effects of heavy metal pollution on woodland leaf litter faunal communities." Thesis, University of Bristol, 1987. http://hdl.handle.net/1983/e4ac1ab0-85c5-4718-a4a1-60621f60db3e.
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Lidman, Johan. "Decomposition of leaf litter in headwater streams. : Effects of changes in the environment and contribution of microbial and shredder activity on litter decomposition." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-105488.
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Headwaters, which are the most common stream order in the landscape, are mostly dependent on energy produced in the terrestrial system, largely consisting of leaf litter from riparian vegetation. The aim of this study was to investigate the decomposition in headwaters of leaf litter from three native (alder, birch, spruce) and one non-native (lodgepole pine) species and how decomposition responds to changes in the environment. Further, microbial and shredder influences on leaf-litter decomposition and aquatic decomposer ability to adapt to non-native species was investigated. By using field-data from this study, calculations were made to assess if microbes and shredders are resource limited. Litterbags were placed in 20 headwater streams in northern Sweden that varied in water chemistry, stream physical characteristics and riparian vegetation. The results revealed that species litter decomposition of different plant species was affected differently by changes in environmental variables. Alder and birch decomposition were positively associated, whereas lodgepole pine deviated from the other species in decomposition and its relationship with important environmental variables, indicating that the ability of the boreal aquatic systems to decompose litter differs between introduced and native species. When including macroinvertebrates, shredder fragmentation generally increased decomposition, but was not significant for all sites. Resource availability for microbes and shredders was controlled by litter input, and no risk of resource limitations was evident during the study period. These findings highlight a complexity of the decomposition process that needs to be considered when predicting changes due to human activities.
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Wookey, Philip Andrew. "Effects of dry deposited sulphur dioxide on the decomposition of forest leaf litter." Thesis, Lancaster University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328496.
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Bold, Richard P. "Influence of coarse woody debris dams on leaf litter dynamics in U.K.headwater streams." Thesis, Coventry University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251857.
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Kitson, Sarah R. "Upland forest leaf litter: Effects on growth and development of Lithobates sylvaticus tadpoles." Kent State University Honors College / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1367944142.
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Thoman, Heather Marie. "A Critical Temperature Threshold for Early Leaf Litter Decomposition and Microbial Enzyme Activity." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1399571419.
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Ashton, Elizabeth C. "Biodiversity and community ecology of mangrove plants : molluscs and crustaceans in two mangrove forests in Peninsular Malaysia in relation to local management practices." Thesis, University of York, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301686.
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Ataka, Mioko. "Effect of the moisture heterogeneity of leaf litter layer on temporal and spatial variation in the litter heterotrophic respiration in a warm-temperate forest." Kyoto University, 2015. http://hdl.handle.net/2433/199356.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第19032号
農博第2110号
新制||農||1031(附属図書館)
学位論文||H27||N4914(農学部図書室)
31983
京都大学大学院農学研究科地域環境科学専攻
(主査)教授 谷 誠, 教授 北山 兼弘, 教授 本田 与一
学位規則第4条第1項該当
28
Piepenschneider, Meike [Verfasser]. "Urban Grass and Grass-Leaf Litter Mixtures as Source for Bioenergy Recovery / Meike Piepenschneider." Kassel : Universitätsbibliothek Kassel, 2016. http://d-nb.info/108880148X/34.
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Downs, Michael Paul. "Effects of leaf litter on seedling emergence of bull thistle, Cirsium vulgare (Savi) Ten." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq30786.pdf.
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Vincent, Andrea Gaël. "Leaf litter manipulation and soil nutrient availability to plants in a Panamanian moist forest." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612997.
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Brown, Erin M. "VOC emissions from decomposing leaf litter: Revising the conceptual framework for decay-related emissions." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1456664.
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Yusof, Mohd Termizi Bin. "Application of a particle filtration method in the search for new bioactive natural products from fungi." Thesis, University of Canterbury. Biological Sciences, 2008. http://hdl.handle.net/10092/1927.
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Fungi have been an important source for producing a wide range of secondary metabolites of widely differing chemical structures, as well as biological activities. Many of their metabolites now play a major role in pharmaceutical and agricultural industries. A number of fungi were isolated from soil and leaf litter collected from Arthur’s Pass, West Coast and Kaituna Valley using a particle filtration technique. Fungi were selected based on their unusual morphology or observed cytotoxicity and antimicrobial activity for large scale culture and extraction. A pale yellow compound was isolated from cytotoxic extracts from the culture of Aspergillus versicolor. This compound was identified as sterigmatocystin and the identity confirmed by UV profile and mass spectrometry. Five compounds were isolated from extracts prepared from two different species of Penicillium of which three were active against P388 cells (mycophenolic acid, cycloaspeptide A and mevastatin), one was active against dermatophytes (griseofulvin) and one was not active (3,4,6,8-tetrahydroxy-3-methyl-3,4-dihydroisocoumarin). Two compounds were isolated from extracts prepared from two different species of Phoma. A dark red compound was found to be novel and showed activity against P388 cells and Bacillus subtilis. A second compound also showing cytotoxicity was identified as the known compound phomenone. A further new compound was isolated from extracts of an identified dematiaceous fungus. This alkyl glucoside, however, was not bioactive.
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Greenwood, David Robert. "The foliar physiognomic analysis and taphonomy of leaf beds derived from modern Australia rainforest." Title page, contents and abstract only, 1987. http://web4.library.adelaide.edu.au/theses/09PH/09phg8165.pdf.
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Aristizabal, Catalina. "Arbuscular Mycorrhizal Fungi Enhance the Acquisition of Mineral Nutrients from Leaf Litter by Morella cerifera." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_dissertations/94.
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Morella cerifera (L.) Small, the Wax Myrtle, forms both arbuscular mycorrhizas and cluster roots which generally are regarded as alternative adaptations for phosphorus acquisition. But whether or not arbuscular mycorrhizal fungi (AMF) provide any benefit to M. cerifera is not known. Nevertheless, AMF can proliferate extensively within the litter leaves that accumulate beneath M. cerifera. The main objective of this study was to determine if AMF are beneficial to M. cerifera host plants in the presence of leaf litter. In the field, I examined leaf traits that affect the colonization of leaf litter by AMF. I compared AMF colonization of labile versus recalcitrant leaves, and that of leaf pieces with obstructed versus non-obstructed veins. In pot experiments, I examined if labile or recalcitrant litter influences the potential benefit of AMF to M. cerifera, and if nitrogen (N) or phosphorus (P) fertilization influences that benefit in the presence of recalcitrant leaf litter. I found that AMF extensively colonize both labile and recalcitrant leaves, but that they colonize labile leaves more rapidly than recalcitrant leaves. I found significantly less colonization in leaf pieces with obstructed veins than in those with non-obstructed veins which suggests that penetration by the fungi primarily is mechanical and not enzymatic. The pot experiments showed that AMF are parasitic on M. cerifera except when recalcitrant leaf litter is present, and that the effects of AMF on M. cerifera are indirect and mediated through effects of AMF on N-fixing nodule dry weight. In both pot experiments, AMF enhanced litter decomposition and may have enhanced plant P-nutrition. AMF benefited M. cerifera growth in the absence of N fertilization but negatively affected M. cerifera growth when N was added. In the presence of litter, inoculation with AMF increased cluster root formation, suggesting that these two adaptations may be complementary in extremely nutrient-poor soils. Overall, this study shows that M. cerifera does benefit from association with AMF, and it suggests that AMF play a more important role in the acquisition of mineral nutrients from leaf litter than previously recognized.
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Hesselschwerdt, John [Verfasser]. "Impacts of invasive amphipods on the local benthic fauna and leaf litter decomposition / John Hesselschwerdt." Konstanz : Bibliothek der Universität Konstanz, 2009. http://d-nb.info/1020366109/34.
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Rossi, Florent. "Leaf Litter decomposition in streams subjected to global change : the role of heterotrophic microbial communities." Thesis, Université Clermont Auvergne (2017-2020), 2018. http://www.theses.fr/2018CLFAC101.
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L’activité humaine, au travers de l’industrie, l’urbanisation ou encore l’agriculture, a conduit à la production et au relargage d’une grande quantité de produits chimiques (dont les xénobiotiques) dans la biosphère. Une des problématiques liée aux composés xénobiotiques est leur transfert vers les écosystèmes aquatiques et l’altération de la diversité et des activités microbiennes. Ces communautés peuvent être impactées par ces composés, potentiellement affectant en retour les grands processus écosystémiques tels que le cycle du carbone. Ce travail de thèse vise donc à évaluer les effets d'une contamination chimique réaliste sur les processus de décomposition microbiens de la matière organique dans les écosystèmes lotiques via l’utilisation de la litière de feuilles comme descripteur.Une première partie de ces travaux de thèse a été consacrée à décrire et à comparer la décomposition microbienne (bactéries et champignons) de la litière de feuilles au travers de la structure des communautés microbiennes (structure génétique et biomasse) et les activités associées (activités enzymatiques extracellulaires) dans six bassins versants présentant des occupations des sols différentes (urbanisés, agricoles et forestier) et au cours de quatre saisons (printemps, été, automne et hiver). L'effet du gradient de contamination depuis l'amont vers aval sur ce processus a également été évalué. La décomposition microbienne s'est avérée légèrement plus élevée pour les bassins versants agricoles et urbanisés par rapport aux bassins versants forestier (contrôle), probablement en raison de l'effet de la compensation des nutriments sur les xénobiotiques. Cependant, cette compensation ne s’est avérée que partielle, la biomasse fongique ayant été considérablement réduite dans les bassins versants contaminés. Ces résultats mettent en évidence une meilleure efficacité des communautés microbiennes pour la décomposition des feuilles dans les bassins versants présentant une contamination chimique, probablement par l’intermédiaire de changements au niveau de la structure des communautés microbiennes.La deuxième partie de ces travaux de thèse consistait à évaluer in vitro les interactions entre l’eutrophisation des cours d’eau et des concentrations réalistes en pesticides (herbicides et fongicides, seuls ou en mélange) sur l’activité microbienne de décomposition de la litière de feuilles. Les fortes concentrations en nutriments (condition eutrophe) ont eu tendance à exacerber les effets des pesticides sur les taux de décomposition microbiens, suggérant que l'effet compensatoire des nutriments sur les pesticides observé dans la partie précédente dépend de la concentration et ne s'applique pas toujours aux communautés microbiennes aquatiques.De plus, une stimulation de l’activité laccase a été observée chez les communautés microbiennes exposées au fongicide, ce qui suggèrent l’utilisation de cette enzyme en tant que mécanisme de détoxification. Cependant, le fait que cette stimulation n’ait pas été observée en présence du mélange de pesticides (herbicide et fongicide) suggère que l’interaction entre ces deux composés peut altérer la capacité des communautés microbiennes à se défende contre le stress. Ces résultats constituent la première description de l'interaction potentielle entre un herbicide et un fongicide sur les communautés microbiennes associées à la litière de feuilles. (...)Human activity through industry, urbanization and agriculture, has led to the production and release of a large amounts of chemical compounds (including pesticides and pharmaceuticals) into the biosphere. One of the problematic related to the xenobiotic compounds fate is their transfer to aquatic ecosystems and the alteration of diversity and activity of microbial communities. Microbial communities associated with immersed leaf-litter can be impacted by these compounds, and in turn, alter global processes such as the carbon and nutrient cycling in the stream ecosystem. Accordingly, this thesis work aims to assess the effects of realistic chemical contamination on microbial leaf-litter decomposition process in streams.The first chapter of this thesis was focused on the comparison of microbial decomposition activity in alder leaves in six watersheds presenting different land uses (agricultural, urbanized, forested) over four seasons (spring, summer, autumn, winter). The effect of the gradient of contamination on microbial organic matter processing from upstream to downstream sections in each watershed was also assessed. Monitoring revealed that microbial decomposition of leaves was slightly higher in contaminated watersheds (agricultural and urbanized) in comparison with control ones (forested), probably because of the compensation effect by nutrients over xenobiotics. However, this compensation mechanism was partial since fungal biomass accumulated in leaves was greatly reduced in contaminated watersheds. Overall, this highlights microbial communities being more efficient for leaf decomposition in polluted watersheds than in the less contaminated ones, which is probably explained by changes in microbial community structure.The second chapter of this thesis aimed to evaluate in vitro the specific interactions between nutrients (nitrogen and phosphorus) and pesticides (herbicide and fungicide, alone or in mixture) exposure on microbial communities during leaf-litter decomposition. High nutrient concentrations (eutrophic conditions) tended to exacerbate the effects of pesticides on leaf decomposition rates suggesting that the compensatory mechanism of nutrients over pesticides observed in the previous part is probably concentration dependent and does not always apply to aquatic microbial communities. Moreover, a stimulation in laccase activity was observed when microbial communities were exposed to the fungicide, suggesting a role of this enzyme in detoxification mechanisms. However, the fact that such stimulation was not observed when exposed to the mixture of both pesticides (herbicide and fungicide) suggest that the interaction between these two molecules impaired the ability of microbial communities to display properstress response. These results constitute the first evidence of the potential interaction between an herbicide and a fungicide on leaf-associated microbial communities functioning. (...)
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Komosinski, Rachel. "Effects of leaf litter diversity on nutrients and mosquito communities in Neotropical artificial tree holes." VCU Scholars Compass, 2012. http://scholarscompass.vcu.edu/etd/410.
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Inputs from terrestrial habitats to aquatic habitats are important for structuring aquatic communities. Terrestrial producer diversity in the tropics may decline due to anthropogenic causes. I investigated how tree diversity affects aquatic communities. We used leaves from three timber-producing species (Dalbergia retusa, Pachira quinata, and Tectona grandis) to test the effects of leaf litter species composition and richness on invertebrate aquatic communities in Gamboa, Panama. We quantified macroinvertbrate species richness and abundances, leaf litter mass loss, and dissolved carbon to nitrogen ratios (C:N) after 4 weeks. We found that litter types differed in breakdown and C:N. Tectona grandis had lower dissolved C:N than both native species and supported the fewest number of invertebrates. C:N ratios declined with increasing litter diversity; however breakdown was not affected by litter richness. Mosquito abundance increased with litter species richness. Results of this study highlight the importance of diverse detritus in structuring aquatic treehole communities.
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Nakamura, Akihiro. "Development of Soil and Litter Arthropod Assemblages in Rainforest Restoration." Thesis, Griffith University, 2008. http://hdl.handle.net/10072/367553.
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Broadscale forest clearance is a major human-induced disturbance with devastating consequences for biodiversity. With a rise in public awareness of biodiversity, the last few decades have seen an increasing number of reforestation activities aimed at recreating natural habitat. To date, research on the outcomes of reforestation for biodiversity have mostly focused upon the recovery of vegetation structure and composition, with relatively little attention being paid to the recovery of fauna, especially invertebrates.
Arthropods inhabiting soil and leaf litter constitute a considerable proportion of the biomass and diversity of a given faunal community, and exhibit strong associations with ecological functioning (i.e. soil formation, decomposition). The recovery of soil and litter arthropods in restored landscapes is therefore important, not only for the recovery of biodiversity but also for the re-development of a functioning ecosystem, a goal of most types of reforestation programs. However, we know little about the patterns of development of arthropod assemblages in reforested landscapes or the mechanisms underpinning any such patterns.
The broad objective of this study was to investigate the effects of selected factors on the colonisation patterns of restored rainforest patches by soil and leaf litter arthropods. Criteria for selecting factors for study included their potential influence on the development of arthropod assemblages and their potential for manipulation by restoration practitioners. The study was conducted on the Blackall Range near Maleny, a mid-elevation (250-530 m a.s.l.) basaltic plateau in subtropical eastern Australia (26°S, 152°E). The plateau supported subtropical rainforest until European settlement in the 19th century, when most of the rainforest was cleared for pasture.
The factors selected for study, in relation to the colonisation of restored habitat patches by soil and litter arthropods, were as follows:
1. the isolation of restored habitat patches from remnant forest;
2. the efficacy of inoculation (re-introduction of rainforest soil and litter arthropods) to restored habitat patches;
3. the quality and quantity of substrate (i.e. mulch) used during the initial stages of rainforest restoration;
4. the degree of shading and depth of substrate, and their interaction; and,
5. the short- and longer-term impacts of glyphosate herbicide on arthropod assemblages.
To test explicitly the effects of these factors on arthropod colonisation of restored habitat patches, an experimental approach was adopted in this study. The first four factors were addressed by means of a manipulative field experiment. Small-scale habitat patches were created by adding sterilised mulch to an area previously treated with glyphosate herbicide, and covered with shadecloth, to simulate various conditions of forest restoration which may be experienced by colonising arthropods. In order to test for the impacts of a glyphosate herbicide on rainforest arthropods, I carried out a separate field experiment in which experimental patches were established within remnant rainforests. The experimental approach adopted in this study allowed for the construction of replicated units, while controlling for extraneous factors (e.g. heterogeneity of litter composition, habitat area, age of restoration), to enable robust examination of the effects of selected factors.
To monitor assemblage composition, arthropods were collected using two methods: pitfall traps and extraction from litter. Responses of arthropods were analysed at two main levels of taxonomic resolution: ‘coarse’ arthropods (all arthropods sorted to Order/Class) and ants, identified to species.
Before the field experiments, a survey was carried out to collect reference information on the distribution of soil and litter arthropods in remnant rainforests (undisturbed reference sites) and cleared pasture (disturbed reference sites) in the study region. Regardless of the sampling method (pitfall or litter extraction) or taxonomic resolution employed (coarse arthropods or ant species), the composition of arthropod assemblages clearly differed between rainforest and pasture. The information obtained from this survey generated potential bio-indicators of forested and cleared habitats, assisting interpretation of the data obtained from the field experiments.
The effects of habitat isolation and inoculation were tested using ‘restored’ habitat patches which were established within cleared pasture at increasing distances (0, 15, 100 and ca. 400 m) from the edges of rainforest remnants. After nine months, rainforest-dependent taxa were found to have only colonised the habitat patches closely adjacent to rainforest remnants. Attempts to increase the extent of arthropod establishment by inoculation were unsuccessful: the majority of rainforest arthropods from the raw inoculum failed to persist within the isolated plots. The results indicated that many forest-dependent soil and litter arthropods may have a limited capacity to colonise isolated restoration sites, and/ or small experimental plots in the short term. Inference from the experiment was potentially limited by the relatively small temporal and spatial scales of restoration treatments. Avoiding these limitations in future research may require controlled and replicated efforts in experimental restoration over larger areas, based on collaborations between researchers and practitioners.
To test the effects of quality and quantity of substrate on arthropod colonisation, habitat patches were established by adding either sterilised hay (a conventionally used mulching material in restoration projects) or woodchip mulch (a structurally more complex alternative), each at two depths (3-5 cm, 10-15 cm). Habitat patches were positioned within pasture adjacent to the edges of rainforest remnants to minimise the effect of isolation, and were all unshaded to create conditions similar to those during the initial stages of rainforest restoration. Despite its simple composition, hay performed better than woodchips in facilitating colonisation by arthropods characteristic of rainforest. However, neither hay nor woodchip mulch inhibited arthropods invading from the surrounding pasture. Shallow hay was favoured by ants characteristic of rainforest, but other groups of arthropods (e.g. Coleoptera, Isopoda) were associated with deep hay (10-15 cm). The optimum amount of hay may therefore vary among different groups of arthropods.
The effects of shading and mulch depth, and potential interactions between them, were tested using habitat patches created with varying degrees of shading (none, 50% or 90% shading) and two depths of woodchip mulch (3-5 cm or 10-15 cm deep). The presence of shading, at both 50% and 90%, encouraged colonisation of habitat patches by arthropods characteristic of rainforest. However, only the more complete shading treatment (90%) inhibited re-invasion of restored patches by arthropods from the surrounding pasture habitat. Effects of mulch depth were significant only for rainforest-associated ant species which responded positively to shallow mulch within shaded plots. These results suggest that moderate levels of canopy closure, as produced by tree spacings typical of timber plantations, may be sufficient to facilitate colonisation of reforested land by rainforest arthropods. However, greater canopy shading (90%) is likely to be needed to inhibit re-invasion of arthropods from surrounding pasture habitat. Using deeper woodchip mulch does not necessarily create more suitable conditions for rainforest arthropods or offset the deleterious effects of the lower levels of shading.
Paired herbicide-treated and control plots were created within rainforest remnants to test the short- (approximately three days) and long-term (approximately three months) impacts of herbicide application on soil and litter arthropod assemblages on the floor of the remnant rainforests. The results found no deleterious effects of glyphosate herbicide formulated as Roundup® Biactive™ on rainforest soil and litter arthropods; hence, this herbicide appears suitable for the control of unwanted plants in rainforest restoration projects, from the perspective of arthropod biodiversity.
The outcomes of this study also have a number of important implications for the monitoring of the development of soil and litter arthropod assemblages in restored rainforests. First, pitfall traps (a commonly used sampling technique) can provide sufficient information on the state of arthropod assemblages in the context of subtropical rainforest restoration projects, although samples collected by this method alone do not necessarily represent the whole suite of soil and litter arthropods (e.g. cryptic arthropods that live in soil and litter). Second, a combination of higher-taxon sorting of all arthropods, together with species-level sorting of a significant major taxon (ants), provides a feasible compromise between comprehensiveness and detail in monitoring responses of arthropods. Third, ‘composite habitat indices’, such as those developed in this study to quantify the extent to which a site resembles rainforest or pasture in terms of its arthropod assemblage, can help alleviate problems associated with the patchy distribution of arthropod taxa in monitoring samples.
The experimental approach adopted in this study provided information that would otherwise have been limited by post-hoc empirical studies alone. This study’s results demonstrated that the selected aspects of different restoration techniques and management affect the colonisation of soil and litter arthropod assemblages in rainforest restoration of old fields.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Faculty of Science, Environment, Engineering and Technology
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Noble, Virginia Rose. "The effects of tropical forest fragmentation and land use on leaf litter decomposition and nutrient cycling." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44711.
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Forest conversion and fragmentation are major causes of diminished ecosystem function and biodiversity loss at a global scale. Understanding landscape effects on leaf litter decomposition and recycling of available nutrients is critical for conservation, especially in diverse tropical rainforests. Here, we studied the effects of land conversion and forest fragmentation on these two processes in a tropical ecosystem. We examined decomposition and nutrient cycling during the wet season in 22 sites across four habitat types: continuous forests, large fragmented forest patches, small fragmented forest patches, and orange plantations, in the tropical moist forest zone of NW Guanacaste, Costa Rica. The study employed a two-by-two factorial design to explore the effects of leaf litter type (site-specific litter vs. control litter) and mesh size (9 mm vs. 1 mm) on decomposition rate across land cover types. Litter bags with different mesh sizes either included (9 mm) or excluded (1 mm) macroinvertebrates. We removed litter bags from the field after 3 and 8 weeks, and cleaned and weighed the contents. Additionally, we utilized Plant Root Simulator (PRS™) Probes to examine nutrient cycling of 10 cations and anions including N, P, K, Ca, and Mg in all site-specific litter types and both mesh treatments. We found that the rate of decomposition differed depending on habitat type, leaf litter type and mesh size. Decomposition was faster in orange plantations compared to any other forest type, and decomposition was faster in forest fragments compared to continuous forests. We determined that these differences in decomposition rates were due predominantly to differences in site-specific litter quality. Only in forest fragments did the distance to forest edge impact macroinvertebrate feeding behaviour (seen in control litter), presumably due to spatial variation in leaf litter quality. Finally, mineralization of organic nutrients differed across the four habitat types. For example, nitrogen, which is an important compound for plant cell structure and function, mineralized more quickly in orange plantations than in forest habitats. This study highlights the importance of litter quality differences due to fragmentation and land use in altering leaf litter decomposition and nutrient cycling.
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Choudhury, D. "The effect of honeydew on leaf-litter decomposition, soil non-symbiotic nitrogen fixation and nitrogen mineralization." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376903.
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Kalaw, Torreta Nimfa. "DYNAMICS OF NITROGEN AND ORGANIC CHEMICAL COMPONENTS DURING LEAF LITTER DECOMPOSITION IN A TROPICAL EVERGREEN FOREST." Kyoto University, 2000. http://hdl.handle.net/2433/181413.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第8092号
農博第1088号
新制||農||795(附属図書館)
学位論文||H12||N3349(農学部図書室)
UT51-2000-C42
京都大学大学院農学研究科地域環境科学専攻
(主査)教授 武田 博清, 教授 東 順一, 教授 谷 誠
学位規則第4条第1項該当
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Munasinghe, Prinith Sumudu. "Effects of atmospheric acid deposition and single versus mixed leaf litters on foliar litter decomposition, carbon, nitrogen, phosphorus and calcium dynamics in a regenerating forest." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5769.
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Thesis (M.S.)--West Virginia University, 2008.Title from document title page. Document formatted into pages; contains vi, 131 p. : ill. (some col.). Includes abstract. Includes bibliographical references.
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Uselman, Shauna M. "Production and fate of soluble organic carbon, nitrogen, and phosphorus during forest ecosystem development root versus leaf litter /." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3222985.
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Mora, Gómez Juanita. "Leaf litter decomposition in Mediterranean streams: microbial processes and responses to drought under current global change scenario." Doctoral thesis, Universitat de Girona, 2014. http://hdl.handle.net/10803/285841.
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This thesis studied the principal environmental controlling factors and microbial mechanisms involved in leaf litter decomposition in Mediterranean intermittent streams. Additionally, drought disturbance in both Mediterranean intermittent and Atlantic permanent streams was also evaluated. At the Mediterranean intermittent stream leaf litter decomposition varied mainly related to seasonal variations in temperature, conductivity and current velocity. Drought clearly affected microbial assemblages and functioning in these ecosystems although this did not resulted in changes on breakdown rates. In permanent streams drought disturbance also affected microbial activity and structure, reducing breakdown velocity due to emersion of leaves. Microbial communities from nutrient enriched streams were more resistant to drought disturbance. Results suggest that under more extreme environmental variation and dry conditions expected with the global change, microbial decomposers will be severely affected. However consequences in carbon recycling will depend on to the type of drought-related disturbance, interaction with other stressors and previous communities dwelling in.En aquesta tesi s’han estudiat els factors ambientals determinants i els mecanismes microbians involucrats en la descomposició de fullaraca en rius intermitents mediterranis. També s’ha avaluat l’efecte de la sequera en rius intermitents mediterranis i permanents atlàntics. En el riu intermitent mediterrani la descomposició de fullaraca s’ha vist afectada per la variació anual de la temperatura, conductivitat i velocitat de la corrent. La sequera clarament va determinar canvis en els microorganismes descomponedors i el seu funcionament en ambdós tipus de rius, malgrat no sempre va afectar la velocitat de descomposició. Els resultats suggereixen que en condicions extremes de variació ambiental i sequera, esperats pel canvi global, els microorganismes descomponedors de la fullaraca es veuran molt afectats. No obstant, les conseqüències en el reciclatge de carboni dependran del tipus de pertorbació relacionada amb la sequera, de la interacció amb altres impactes i de les comunitats descomponedores prèvies que habiten al riu.
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Ghosh, Arundhati. "Molecular studies of the laccase from the leaf-litter degrading white-rot basidiomycete Mycena galopus var. galopus." Thesis, King's College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251677.
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Reider, Kelsey. "The Effects of Simulated Peccary Extirpation on Leaf Litter Dynamics, Reptiles, and Amphibians in a Neotropical Forest." FIU Digital Commons, 2011. http://digitalcommons.fiu.edu/etd/483.
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Peccaries are known to play a significant role in shaping the diversity of habitats and structure of plants in rain forests. However, very little is known about their roles in regulating animal populations. I review the ways peccaries increase disturbance, create habitat diversity, provide resources, act as predators, and might otherwise directly and indirectly affect other animals. To determine effects of simulated peccary extirpation on the detrital food web, I examined the hypotheses that a reduction of peccary density on fenced exclusion plots would cause changes in the amount and quality of leaf litter as habitat for leaf litter reptiles and amphibians. I found that compared to open controls, exclusions had significantly deeper litter and more rapid cellulose decomposition. Exclusions were thus expected to provide more habitat and prey for litter amphibians and reptiles than control plots, but, paradoxically, encounters of reptiles and amphibians were greater on controls.
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Wild, Suzi. "The effects of blackberry (Rubus fruticosus L. agg.) leaf litter on aquatic macroinvertebrates in two urban streams." Thesis, Wild, Suzi (2002) The effects of blackberry (Rubus fruticosus L. agg.) leaf litter on aquatic macroinvertebrates in two urban streams. Honours thesis, Murdoch University, 2002. https://researchrepository.murdoch.edu.au/id/eprint/41539/.
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The processing of leaf litter in streams plays a key role in the cycling of energy in aquatic ecosystems. It has been suggested that the invasion of the riparian zone by exotic species such as European willow (Salix babylonica), may affect stream macroinvertebrate communities through the timing of leaf fall, litter quality and litter breakdown rates. This study investigated the effects of European blackberry (Rubus fruticosus), a highly invasive weed of the riparian zone, on macroinvertebrate assemblages in two urban streams, Bannister Creek and Bull Creek, on the Swan Coastal Plain.
The impact of riparian vegetation on macroinvertebrates was investigated using two methods; (A) sweep net samples were collected over two seasons to determine differences in macroinvertebrate assemblages between stream reaches with blackberry or native vegetation in the adjacent riparian zone. (B) breakdown rates and colonisation of blackberry and eucalypt (Eucalyptus rudis) were used to assess preferences of macroinvertebrates for either blackberry or eucalypt as a food source. Furthermore, the relative abundance of the freshwater crayfish Cherax quinquecarinatus at sites with blackberry and native vegetation was quantified and laboratory feeding experiments were conducted to determine preferences of C. quinquecarinatus for either blackberry or eucalypt leaves.
No significant differences were found in macroinvertebrate assemblages between reaches with either blackberry or native riparian vegetation at both Bannister Creek and Bull Creek. However, there was a trend for lower species richness at the sites with blackberry in the riparian zone. The richness of taxa colonising leaf bags containing blackberry and eucalypt leaves was not significantly different at either stream. However, the results indicated a paucity of shredder fauna at Bannister Creek suggesting macroinvertebrates were playing a minor role in leaf litter breakdown.
At Bull Creek, the relative abundance of the fresh water crayfish C. quinquecarinatus, an important shredder, was significantly higher in the blackberry site. The high abundance of C. quinquecarinatus at two of the sites resulted in significantly higher rates of blackberry leaf breakdown. Furthermore, C. quinquecarinatus exhibited a preference for blackberry leaf litter in laboratory experiments. These results suggest that this species plays a significant role in the processing of blackberry leaf litter at Bull Creek.
The removal of blackberry is often a major goal of stream restoration projects, however, this study suggests that in some situations blackberry may contribute significantly to energy cycling in stream ecosystems and its removal should be undertaken with caution.
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Nelson, Amanda. "CARBON AND NITROGEN CYCLING IN GIANT CANE (ARUNDINARIA GIGANTEA (WALT.) MUHL.) RIPARIAN ECOSYSTEMS." OpenSIUC, 2015. https://opensiuc.lib.siu.edu/dissertations/986.
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Large stands of Arundinaria gigantea (Walt.) Muhl., called canebrakes, were vital to wildlife and lowland ecosystem functions and historically covered millions of acres in the southeastern United States. Since European settlement, human disturbance (i.e, clearing for agriculture and fire suppression) has caused giant canebrakes to become critically endangered ecosystems. Increasing evidence suggests the loss of canebrakes has directly impacted riparian ecosystems, resulting in increased soil erosion, poorer water quality, and reduced flood control. Cane's ecological importance has led to an increased interest in canebrake restoration in riparian zones. To examine the role that cane plays in nutrient cycling and to attempt to determine targeted restoration sites, a four phase research strategy was designed to determine physical and chemical properties of existing riparian stands of native giant cane and their associated soils. Phase one was a GIS analysis to determine what geographical features may be used in selecting sites within a landscape suitable for canebrake restoration. First, common physical site characteristics for 140 existing southern Illinois canebrakes were determined. Soil taxonomy and pH were used to represent soil characteristics and percent slope was used as a topographic metric. These factors, combined with digital elevation models and land cover in GIS were used to identify the potential suitability of sites within the watershed for canebrake plantings and general riparian restoration. The following soil characteristics were determined to be associated with giant cane success: percentage of area containing slopes of 3 percent or less, fine to coarse-silty textures, pH of 5.3 - 6.7, effective cation exchange capacity of less than 30 units, available water holding capacity greater than 0.12, bulk density of 1.37 - 1.65 g cm-3, and percent clay of 11 - 55. Eighty-percent of existing giant cane sites were found within these slope and soil characteristics. The total area of potential riparian canebrake landscapes based on these parameters is 13,970 hectares (35,600 acres) within the Cache River watershed. The remaining three phases examined the role that cane plays in nutrient cycling. Phase two determined the pools and cycling of nitrogen and carbon in canebrakes and compared those to nearby agricultural and forested riparian areas. Phase three quantified the N2O and CO2 fluxes from canebrakes and adjacent forested areas. Phase four included methods to quantify nutrient content of leaf litter and live leaves from existing canebrakes to estimate the nutrient use efficiency of cane. Further, a decomposition study was conducted to calculate the decomposition rate of cane leaves and to explore the litter quality attributes of giant cane. The primary purpose of phase two was to compare the effects of perennial riparian vegetation (giant cane and forest) and annual crops on soil quality, nitrogen cycling, and physical properties. This was to determine if any of them have a significant influence on giant cane distribution, while focusing on nitrogen dynamics to help determine why giant cane is a successful riparian buffer species. Five study sites in the Cache River watershed that had cane, agricultural fields (corn-soybean rotation), and forested areas adjacent to one another were selected. Data were collected on soil texture, carbon/nitrogen ratios, bulk density, nitrogen content (as ammonia and nitrate), and net nitrogen mineralization rates. The crop sites had significantly lower soil C:N ratios than both forest and cane (9.8:1 vs. 10.9:1 and 10.7:1, respectively), though all sites had ratios less than 25:1, indicating a tendency toward nitrogen mineralization. Forest soils had significantly higher rates of net mineralization than cane (19.0 μg m-2 day-1 and 6.6 μg m-2 day-1, respectively), with crop not significantly different from either cane or forest (8.0 μg m-2 day-1). Cane had higher levels of soil carbon and nitrogen when compared to forest and crop soils. Cane can be successful in wetter areas than previously thought, implying that the range of conditions that will support cane is broader than previously thought. Overall, there were few identifiable soil controls on giant cane distribution, or those that differentiate long-standing canebrakes from the nearby crop and forest land. For Phase three, nitrous oxide and carbon dioxide emissions were measured monthly for one year in riparian canebrakes and forests in southern Illinois to determine the rates of greenhouse gas (GHG) fluxes in bottomland riparian areas. Carbon dioxide emissions had a strong correlation with soil temperature (p < 0.001, r2= 0.54), but not with soil water content (p > 0.05), and were greater during the warmer months. Nitrous oxide emissions had a correlation with soil water content (p=0.470, r2 = 0.11), but no relation with soil temperature (p > 0.05), nor a difference across time. Vegetation type did not appear to influence GHG fluxes. Riparian CO2 and N2O emission rates were higher than documented cropland emissions, indicating riparian restoration projects to reduce NO3 delivery to streams may affect N2O and CO2 emissions resulting in an ecosystem tradeoff between water quality and air quality. Leaf deposition, N resorption efficiency and proficiency, and decomposition rates were analyzed in riparian stands of Arundinaria gigantea in southern Illinois for the first time in Phase four. Leaf litter was collected from five established canebrakes monthly over one year and a decomposition study was conducted over 72 weeks. Live leaves, freshly senesced leaves, and decomposed leaves were analyzed for carbon and nitrogen content. Leaf litterfall biomass peaked in November at twice the monthly average for all but one site, indicating a resemblance to deciduous leaf fall patterns. Nitrogen and carbon levels decreased 48% and 30%, respectively, between live leaves and 72 weeks decomposed. High soil moisture appeared to slow decomposition rates, perhaps due to the creation of anaerobic conditions. Cane leaves have low resorption proficiency and nutrient use proficiency, suggesting that these riparian canebrakes are not nitrogen limited. These results will help improve our understanding of the role that giant cane plays in a riparian ecosystem and help focus cane restoration efforts in southern Illinois.
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Bastias, Álamo Elliot. "The role of leaf litter quality and streambed hydro-morphology on in-stream leaf litter dynamics = El rol de la qualitat de la fullaraca i de la hidro-morfologia del tram fluvial en les dinàmiques de la fullaraca als rierols." Doctoral thesis, Universitat de Barcelona, 2018. http://hdl.handle.net/10803/586045.
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Understanding the dynamics of leaf litter inputs in streams involves assessment of retention, spatial distribution and processing of leaf litter inputs. However, leaf litter dynamics in streams has been mostly studied by determining the controlling factors of leaf litter processing, ignoring if leaf litter inputs are retained within the streams, and how these inputs are spatially distributed within the streambed. Furthermore, leaf litter processing in streams is not an isolated process because it can be linked with the dynamics of solutes of these streams. In fact, leachates from leaf litter provide to the streams with dissolved organic matter (DOM), as well as, dissolved nutrients (i.e., nitrogen [N] and phosphorous [P]). Also, the mineralization of leaf litter inputs implies the releasing of dissolved forms of C and nutrients to the stream water column. In addition, microbial communities inhabiting leaf litter uptake dissolved forms from water column during leaf litter decomposition. Despite the obvious linkage between leaf litter processing and in-stream solute dynamics, few studies provided information about the main drivers controlling this connection.
In order to understand how leaf litter dynamics operates in stream ecosystems, the present thesis aims to examine (a) how the hydro-morphological characteristics of the recipient stream can influence the retention, spatial distribution, physical fragmentation and decomposition of leaf litter inputs. Moreover, we also examine (b) the interaction between leaf litter processing and in-stream dynamics of dissolved organic carbon and dissolved inorganic nitrogen and how it varies depending on the leaf litter species considered. To
approach this aim, we specifically examine how the leaf litter quality of different riparian tree species can influence: (b1) the chemical-composition and bioavailability of leaf litter leachates to streams (b2) the uptake of DIN and DOC from water column by microbial decomposers during decomposition process and how it is related to the activity of microbial decomposers and, (b3) how microbially-driven leaf litter decomposition vary among streams which covered a wide gradient of inorganic nutrient concentrations.
The present thesis reveals that heterogeneity of water velocity within a reach is a factor controlling different aspects of leaf litter dynamics in streams because not only influences the fraction of leaf litter retained but also how these inputs are spatially distributed and further processed within the streams. Therefore, we indicate that the relevance of leaf litter inputs as organic matter source to in-stream communities can be subjected to the hydro- morphological characteristics of the receiving stream reaches, since they determine the spatial heterogeneity of water velocity within the reach. In addition, we suggest that leaf litter quality influence on the chemical and structural properties of the leaf litter-leachates and also how these leaches are used by in-stream microbial assemblages. The quality of leaf litter can also dictate the microbial demands of dissolved C and N from the water column. Finally, we suggested that the influence of in-stream nutrient concentrations on leaf litter decomposition can be subjected to the leaf litter quality. Considering all our results together we suggest that riparian composition, which dictates the quality of leaf litter inputs, may control the linkage between leaf litter processing and in-stream C and N solute dynamics. However, the heterogeneity of water velocity may be the most relevant factor determining the importance of leaf litter to streams because it can control the probability that leaves contribute to the stream metabolism or to be exported downstream.Para comprender cómo funciona la dinámica de la hojarasca en arroyos, la presente tesis pretende examinar (a) cómo las características hidro-morfológicas del lecho del arroyo pueden influir en la retención, distribución espacial, fragmentación física y descomposición de la hojarasca. Además, también examinamos (b) la interacción entre el procesamiento de hojarasca y la dinámica del carbono orgánico disuelto y nitrógeno inorgánico disuelto del arroyo y cómo varía dependiendo de las especies de hojarasca consideradas. La presente tesis revela que la heterogeneidad de la velocidad del agua dentro de un tramo es un factor que controla diferentes aspectos de la dinámica de hojarasca en arroyos, ya que no solo influye en la fracción de hojarasca retenida, sino también en cómo estas entradas se distribuyen espacialmente y se procesan en los arroyos. Por lo tanto, indicamos que la relevancia de las entradas de hojarasca como fuente de materia orgánica para las comunidades del arroyo puede estar sujeta a las características hidro-morfológicas de dicho ecosistema, ya que determinan la heterogeneidad espacial de la velocidad del agua dentro del mismo. Además, sugerimos que la calidad de la hojarasca influye en las propiedades químicas y estructurales de los lixiviados de hojarasca y también cómo estos lixiviados son utilizados por los microorganismos del arroyo. La calidad de la hojarasca también puede dictar las demandas microbianas de C y N disuelto de la columna de agua. Finalmente, sugerimos que la influencia de las concentraciones de nutrientes del arroyo en la descomposición de la hojarasca puede estar sujeta a la calidad de la hojarasca. Teniendo en cuenta todos nuestros resultados, sugerimos que la composición del bosque de ribera, que determina la calidad de las entradas de hojarasca, puede controlar el vínculo entre el procesamiento de la hojarasca y la dinámica de solutos C y N del arroyo. Sin embargo, la heterogeneidad de la velocidad del agua puede ser el factor más relevante para determinar la importancia de la hojarasca en las corrientes, ya que puede controlar la probabilidad de que las hojas queden retenidas en el arroyo o se exporten aguas abajo, perdiéndose como fuente de materia y energía.
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Nakamura, Ryosuke. "Diversity of silicon uptake by tropical forest trees and its implication for biogenic silicon flux through leaf-litter." Doctoral thesis, Kyoto University, 2020. http://hdl.handle.net/2433/253319.
Full textAbstract:
付記する学位プログラム名: グローバル生存学大学院連携プログラム京都大学
0048
新制・課程博士
博士(農学)
甲第22483号
農博第2387号
新制||農||1075(附属図書館)
学位論文||R2||N5263(農学部図書室)
京都大学大学院農学研究科森林科学専攻
(主査)教授 北島 薫, 教授 神﨑 護, 教授 北山 兼弘
学位規則第4条第1項該当
Doctor of Agricultural Science
Kyoto University
DGAM