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Decomposition

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Articles 1 - 30 of 32

Full-Text Articles in Ecology and Evolutionary Biology

The Effects Of Aboveground Herbivory On Root Traits And Root Decomposition, Emily A. Chavez May 2024

The Effects Of Aboveground Herbivory On Root Traits And Root Decomposition, Emily A. Chavez

All Graduate Theses and Dissertations, Fall 2023 to Present

Soil holds more carbon (C) than the Earth's atmosphere and vegetation combined. Soil loses carbon through soil respiration and releases CO2 from the soil. The soil respiration rate can vary based on the chemistry of the plant litter inputs and physical factors, such as soil temperature and nutrient content. In Alaska's Yukon-Kuskokwim (YK) Delta, grazing by geese affects the chemistry of plants and the soil's physical qualities, thus altering the rate of soil respiration. Although we know that goose herbivory leads to changes in the rate of soil respiration, we know very little about how goose herbivory affects the …

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Deconstructing The Mangrove Carbon Cycle: Gains, Transformation, And Losses, M. F. Adame, N. Cormier, P. Taillardat, N. Iram, A. Rovai, T. M. Sloey, E. S. Yando, J. F. Blanco-Libreros, M. Arnaud, T. Jennerjahn, C. E. Lovelock, D. Friess, G. M. S. Reithmaier, C. A. Buelow, S. M. Muhammad-Nor, R. R. Twilley, R. A. Ribeiro Jan 2024

Deconstructing The Mangrove Carbon Cycle: Gains, Transformation, And Losses, M. F. Adame, N. Cormier, P. Taillardat, N. Iram, A. Rovai, T. M. Sloey, E. S. Yando, J. F. Blanco-Libreros, M. Arnaud, T. Jennerjahn, C. E. Lovelock, D. Friess, G. M. S. Reithmaier, C. A. Buelow, S. M. Muhammad-Nor, R. R. Twilley, R. A. Ribeiro

Biological Sciences Faculty Publications

Mangroves are one of the most carbon-dense forests on the Earth and have been highlighted as key ecosystems for climate change mitigation and adaptation. Hundreds of studies have investigated how mangroves fix, transform, store, and export carbon. Here, we review and synthesize the previously known and emerging carbon pathways in mangroves, including gains (woody biomass accumulation, deadwood accumulation, soil carbon sequestration, root and litterfall production), transformations (food web transfer through herbivory, decomposition), and losses (respiration as CO2 and CH4, litterfall export, particulate and dissolved carbon export). We then review the technologies available to measure carbon fluxes in …

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Filamentous Green Algae (Cladophora Glomerata) In Near Shore Lake Ontario: An Investigation Of Tissue And Water Nutrient Dynamics Through A Period Of Growth And Decomposition., James L. Wagner Jr Oct 2022

Filamentous Green Algae (Cladophora Glomerata) In Near Shore Lake Ontario: An Investigation Of Tissue And Water Nutrient Dynamics Through A Period Of Growth And Decomposition., James L. Wagner Jr

Biology Theses

Cladophora glomerata, a filamentous green alga abundant in the Laurentian Great Lakes, has long been considered a nuisance throughout the region. Previous phosphorus (P) abatement practices and legislation successfully reduced the abundance of the algae, but with the introduction of dreissenid mussels, a resurgence has been observed. Though there is substantial literature and modeling of the growth cycle of Cladophora, relatively little research has been dedicated to the decomposition stage of the algae, a period which may contribute to a substantial influx of nutrients to near-shore environmental regions. By first examining a period of in-situ growth within Lake …

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Effects Of Forest Restoration On The Recovery Of Dead Wood, Associated Arthropods, And Insect-Mediated Wood Decomposition, Estefania Fernandez Barrancos Jun 2022

Effects Of Forest Restoration On The Recovery Of Dead Wood, Associated Arthropods, And Insect-Mediated Wood Decomposition, Estefania Fernandez Barrancos

Dissertations

Dead wood represents 8% of terrestrial carbon stocks and is an important source of habitat and food for decomposer and non-decomposer arthropods. However, anthropogenic disturbance reduces the amount of dead wood, putting at risk the presence of a habitat that is essential for many arthropods and other organisms that rely on it for food and shelter. Forest restoration aims to assist the recovery of ecosystems that have been damaged or destroyed and could be a means to recover both dead wood and its associated arthropod communities. This doctoral dissertation lies at the intersection of climate change, biodiversity loss and ecological …

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The Role Of Leaf Decomposition In Macroinvertebrate Colonization, Bethany Mabel Lian Schorr, Kevin Geedey Mar 2022

The Role Of Leaf Decomposition In Macroinvertebrate Colonization, Bethany Mabel Lian Schorr, Kevin Geedey

Independent Research Projects

Decomposition plays an important ecological role in carbon and nutrient cycling that supply food and energy resources to food webs. This study investigates the potential role that leaf decomposition of different leaf species may play in macroinvertebrate assemblages in upper Midwest streams. We hypothesized that the different decomposition rates experienced with different leaf species and in different streams would have an effect on invertebrate colonization due to the variance in nutrient availability. Due to altered fire regimes and other influences, forests are experiencing declines in fire-adapted, heliophytic species such as oaks and compositional shifts toward shade-tolerant, mesophytic species such as …

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Frayed Connections: How Long-Term Nitrogen Additions Disrupt Plant-Soil Interactions And The Carbon Cycle Of A Temperate Forest, Brooke A. Eastman Jan 2022

Frayed Connections: How Long-Term Nitrogen Additions Disrupt Plant-Soil Interactions And The Carbon Cycle Of A Temperate Forest, Brooke A. Eastman

Graduate Theses, Dissertations, and Problem Reports

Forests are expected to mitigate some of the negative effects of climate change by sequestering anthropogenic carbon (C) from the atmosphere, but the degree to which they drawn down C will depend on the availability of key nutrients, such as nitrogen (N). There is a fair amount of uncertainty in the future of the forest C sink, mostly owing to the fate of soil organic matter (SOM) and soil heterotrophic respiration to future conditions. In N limited systems, plants allocate a significant amount of their photosynthate belowground for the acquisition of nutrients, but under conditions of chronic N deposition, plants …

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Coarse Woody Debris Decomposition Assessment Tool: Model Validation And Application, Zhaohua Dai, Carl C. Trettin, Andrew J. Burton, Martin F. Jurgensen, Deborah S. Page-Dumroese, Brian T. Forschler, Jonathan S. Schilling, Daniel L. Lindner Jul 2021

Coarse Woody Debris Decomposition Assessment Tool: Model Validation And Application, Zhaohua Dai, Carl C. Trettin, Andrew J. Burton, Martin F. Jurgensen, Deborah S. Page-Dumroese, Brian T. Forschler, Jonathan S. Schilling, Daniel L. Lindner

Aspen Bibliography

Coarse woody debris (CWD) is a significant component of the forest biomass pool; hence a model is warranted to predict CWD decomposition and its role in forest carbon (C) and nutrient cycling under varying management and climatic conditions. A process-based model, CWDDAT (Coarse Woody Debris Decomposition Assessment Tool) was calibrated and validated using data from the FACE (Free Air Carbon Dioxide Enrichment) Wood Decomposition Experiment utilizing pine (Pinus taeda), aspen (Populous tremuloides) and birch (Betula papyrifera) on nine Experimental Forests (EF) covering a range of climate, hydrology, and soil conditions across the continental USA. …

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Controls On Autotrophic Respiration, Heterotrophic Respiration, And Decomposition In Northern Forested Rivers, Renn Schipper Jan 2021

Controls On Autotrophic Respiration, Heterotrophic Respiration, And Decomposition In Northern Forested Rivers, Renn Schipper

Dissertations, Master's Theses and Master's Reports

Autotrophic respiration (AR), heterotrophic respiration (HR), and decomposition are important contributors to the carbon cycle in streams. It is important to understand how different environmental factors, such as canopy cover and dissolved organic carbon (DOC), influence these processes. DOC concentrations in northern forested streams are increasing, which may affect light and carbon availability. To examine the effects of DOC and canopy cover on these processes we measured gross primary production, ecosystem respiration and decomposition at 8 sites in 4 streams in the Upper Peninsula of Michigan and used quantile regression to estimate AR and HR. Among sites, AR and decomposition …

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The Environmental Microbiome In A Changing World: Microbial Processes And Biogeochemistry, Stephanie Juice Jan 2020

The Environmental Microbiome In A Changing World: Microbial Processes And Biogeochemistry, Stephanie Juice

Graduate College Dissertations and Theses

Climate change can alter ecosystem processes and organismal phenology through both long-term, gradual changes and alteration of disturbance regimes. Because microbes mediate decomposition, and therefore the initial stages of nutrient cycling, soil biogeochemical responses to climate change will be driven by microbial responses to changes in temperature, precipitation, and pulsed climatic events. Improving projections of soil ecological and biogeochemical responses to climate change effects therefore requires greater knowledge of microbial contributions to decomposition. This dissertation examines soil microbial and biogeochemical responses to the long-term and punctuated effects of climate change, as well as improvement to decomposition models following addition of …

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Use Of Uav Imagery And Nutrient Analyses For Estimation Of The Spatial And Temporal Contributions Of Cattle Dung To Nutrient Cycling In Grazed Ecosystems, Amanda Shine Dec 2019

Use Of Uav Imagery And Nutrient Analyses For Estimation Of The Spatial And Temporal Contributions Of Cattle Dung To Nutrient Cycling In Grazed Ecosystems, Amanda Shine

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nutrient inputs from cattle dung are crucial drivers of nutrient cycling processes in grazed ecosystems. These inputs are important both spatially and temporally and are affected by variables such as grazing strategy, water location, and the nutritional profile of forage being grazed. Past research has attempted to map dung deposition patterns in order to more accurately estimate nutrient input, but the large spatial extent of a typical pasture and the tedious nature of identifying and mapping individual dung pats has prohibited the development of a time- and cost-effective methodology. The first objective of this research was to develop and validate …

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Effects Of Light And Macroinvertebrate Consumers On Detrital Microbial Biofilms In Streams, Cheyenne M. Brady Aug 2019

Effects Of Light And Macroinvertebrate Consumers On Detrital Microbial Biofilms In Streams, Cheyenne M. Brady

Master's Theses

In lotic freshwater systems, aquatic macroinvertebrates are key processors of biofilms that grow upon organic matter. Although macroinvertebrate effects on biofilms may depend on light availability, the combined effects of consumers and light remain unexplored. Here, I conducted experiments to test effects of presence/absence of the omnivorous shrimp Macrobrachium ohione and the shredding caddisfly Pycnopsyche sp. on Liriodendron tulipifera litter biofilms in experimental streams under light or darkness. I measured litter-associated algal, fungal and bacterial biomasses and production rates, as well as litter decomposition, over 49 days. Both experiments exhibited significant positive effects of light on algal productivity and interactions …

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Hierarchical Variation In Cellulose Decomposition Across Southern Ontario Reference Streams, Jenna R. Webb Oct 2018

Hierarchical Variation In Cellulose Decomposition Across Southern Ontario Reference Streams, Jenna R. Webb

Electronic Thesis and Dissertation Repository

The cotton strip assay (CSA) has been promoted as a method of incorporating functional indicators into standardized river assessments by study of organic-matter decomposition. However, operationalization of the CSA as an indicator requires testing the spatial and temporal controls of variance associated with decomposition of cotton strips at regional reference sites. I conducted a hierarchically structured study of decomposition rates in Ontario, Canada. Cotton strips were deployed during the spring, summer and fall in pool and riffle habitats of 22 streams located in three distinct physiographic regions. Partitioning of variation among hierarchical scales associated with rates of decomposition were examined …

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Dead Wood And Decomposition In A Tropical Forest : Vertical Patterns, Long-Term Processes, And The Role Of Lightning., Evan Matthew Gora Aug 2018

Dead Wood And Decomposition In A Tropical Forest : Vertical Patterns, Long-Term Processes, And The Role Of Lightning., Evan Matthew Gora

Electronic Theses and Dissertations

This dissertation investigates the distribution, production, and decomposition of dead wood (or woody debris) in a lowland tropical forest within the Barro Colorado Nature Monument in Panama. Although the importance of woody debris is widely accepted, information describing components of WD pools and fluxes is generally separated in both time and space, particularly in understudied tropical forests. Here I provide a comprehensive inventory of woody debris in a lowland tropical forest (Chapter 1). Woody debris is highly aggregated and difficult to quantify, and this study demonstrates that historic estimates of woody debris pools and fluxes underestimate their uncertainty. In a …

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The Role And Contribution Of Saprotrophic Fungi During Standing Litter Decomposition Of Two Perennial Grass Species, Schizachyrium Scoparium And Schizachyrium Tenerum, Matthew Lodato May 2018

The Role And Contribution Of Saprotrophic Fungi During Standing Litter Decomposition Of Two Perennial Grass Species, Schizachyrium Scoparium And Schizachyrium Tenerum, Matthew Lodato

Master's Theses

In terrestrial ecosystems, most of the plant biomass produced enters the detrital pool, where microbial decomposers colonize, enzymatically degrade, and assimilate plant litter carbon and nutrients in amounts sufficient to bring about the decomposition of plant litter. Here, I estimated the biomass and production of fungi and microbial respiration associated with decaying Schizachyrium scoparium and Schizachyrium tenerum leaf litter, and constructed a partial organic matter budget estimating C flow into and through fungal decomposers. Significant losses in S. scoparium (57%) and S. tenerum (68%) leaf mass was observed during litter decomposition along with concomitant increases in fungal biomass, which reached …

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Patterns Of Carbon Metabolism, Storage, And Remineralization In Seagrass Ecosystems, Jason Lee Howard Mar 2018

Patterns Of Carbon Metabolism, Storage, And Remineralization In Seagrass Ecosystems, Jason Lee Howard

FIU Electronic Theses and Dissertations

Coastal marine sediments have recently been identified as globally important stocks of organic carbon (Corg) that, if compromised, could significantly exacerbate global greenhouse gas emissions. While resource managers and policy makers are eager to incorporate this ecosystem service into seagrass ecosystem valuation frameworks, similar to those already in existence for terrestrial forests, there has been insufficient information regarding how environmental conditions and seagrass ecology control carbon storage. These include the influence of the seagrass to the production and preservation of soil organic matter, the fate of stored carbon following conversion of coastal wetlands, and the interactions between organic …

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Standing Dead Trees Are A Conduit For The Atmospheric Flux Of Ch4 And Co2 From Wetlands, Mary Jane Carmichael, Ashley M. Helton, Joseph C. White, William K. Smith Jan 2018

Standing Dead Trees Are A Conduit For The Atmospheric Flux Of Ch4 And Co2 From Wetlands, Mary Jane Carmichael, Ashley M. Helton, Joseph C. White, William K. Smith

Biology Faculty Scholarship

In vegetated wetland ecosystems, plants can be a dominant pathway in the atmospheric flux of methane, a potent greenhouse gas. Although the roles of herbaceous vegetation and live woody vegetation in this flux have been established, the role of dead woody vegetation is not yet known. In a restored wetland of North Carolina’s coastal plain, static flux chambers were deployed at two heights on standing dead trees to determine if these structures acted as a conduit for methane emissions. Methane fluxes to the atmosphere were measured in five of the chambers, with a mean flux of 0.4±0.1 mg m-2 h-1. …

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Silica Uptake And Release In Live And Decaying Biomass In A Northern Hardwood Forest, Wim Clymans, Daniel J. Conley, John J. Battles, Patrick J. Frings, Mary Margaret Koppers, Gene E. Likens, Chris E. Johnson Nov 2016

Silica Uptake And Release In Live And Decaying Biomass In A Northern Hardwood Forest, Wim Clymans, Daniel J. Conley, John J. Battles, Patrick J. Frings, Mary Margaret Koppers, Gene E. Likens, Chris E. Johnson

Civil and Environmental Engineering

In terrestrial ecosystems, a large portion (20–80%) of the dissolved Si (DSi) in soil solution has passed through vegetation. While the importance of this “terrestrial Si filter” is generally accepted, few data exist on the pools and fluxes of Si in forest vegetation and the rate of release of Si from decomposing plant tissues. We quantified the pools and fluxes of Si through vegetation and coarse woody debris (CWD) in a northern hardwood forest ecosystem (Watershed 6, W6) at the Hubbard Brook Experimental Forest (HBEF) in New Hampshire, USA. Previous work suggested that the decomposition of CWD may have significantly …

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Nutrient Cycling In The Amazon: A Comparison Of Soil Characteristics, Insects, Root Types And Decomposition Rates Between Varzea And Terra Firme Habitats In The Ecuadorian Amazon, Mira Ensley-Field Apr 2016

Nutrient Cycling In The Amazon: A Comparison Of Soil Characteristics, Insects, Root Types And Decomposition Rates Between Varzea And Terra Firme Habitats In The Ecuadorian Amazon, Mira Ensley-Field

Independent Study Project (ISP) Collection

Decomposition and nutrient cycling form the basis of every ecosystem. Nutrient availability in the soil affects plant species composition, richness, and productivity. The Amazon rainforest is known for its unusually fast nutrient cycle, but many aspects lack detailed study and analysis. This comparative study carried out in the Ecuadorian Amazon had four primary objectives related to understanding the nutrient cycle in the Amazon; 1.) analyze soil characteristics, 2.) assess insect diversity in the leaf litter layer, 3.) examine root characteristics, and 4.) measure the decomposition rate between Varzea and Terra Firme habitats alongside the Rio Napo. Forty 0.25 x 0.25m …

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Elevated Co2 Induced Changes In The Chemistry Of Quaking Aspen (Populus Tremuloides Michaux) Leaf Litter: Subsequent Mass Loss And Microbial Response In A Stream Ecosystem, Steven Rier, Nancy Tuchman, Robert Wetzel, James Teeri Dec 2015

Elevated Co2 Induced Changes In The Chemistry Of Quaking Aspen (Populus Tremuloides Michaux) Leaf Litter: Subsequent Mass Loss And Microbial Response In A Stream Ecosystem, Steven Rier, Nancy Tuchman, Robert Wetzel, James Teeri

Nancy Tuchman

No abstract provided.

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Effects Of Water Column P-Availability And Litter Microbial Mediated Processes And Stoichiometry In Aquatic Systems, Ayla Smartt Dec 2014

Effects Of Water Column P-Availability And Litter Microbial Mediated Processes And Stoichiometry In Aquatic Systems, Ayla Smartt

Graduate Theses and Dissertations

Anthropogenic nutrient enrichment of aquatic ecosystems is prevalent and can have detrimental effects on biological condition. Many of these effects have been attributed directly or indirectly to changes in autotrophic processes. However, in detrital-based streams changes in course detrital stoichiometry and decomposition have been related to changes community structure and production at higher trophic levels highlighting the importance of considering the heterotrophic microbial responses to enrichment. Leaf litter stoichiometry, which is determined in part by the tree species source and the microbial communities that comprise the associated biofilm, is likely related to decomposition rates, but few studies examine these variables …

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Breaking The Enzymatic Latch: Impacts Of Reducing Conditions On Hydrolytic Enzyme Activity In Tropical Forest Soils, Steven J. Hall, Jonathan Treffkorn, Whendee L. Silver Oct 2014

Breaking The Enzymatic Latch: Impacts Of Reducing Conditions On Hydrolytic Enzyme Activity In Tropical Forest Soils, Steven J. Hall, Jonathan Treffkorn, Whendee L. Silver

Steven J. Hall

The enzymatic latch hypothesis proposes that oxygen (O2) limitation promotes wetland carbon (C) storage by indirectly decreasing the activities of hydrolytic enzymes that decompose organic matter. Humid tropical forest soils are often characterized by low and fluctuating redox conditions and harbor a large pool of organic matter, yet they also have the fastest decomposition rates globally. We tested the enzymatic latch hypothesis across a soil O2 gradient in the Luquillo Experimental Forest, Puerto Rico, USA. Enzyme activities expressed on a soil mass basis did not systematically decline across a landscape O2 gradient, nor did phenolics accumulate, the proposed mechanism of …

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Effects Of The Interception Of Litterfall By The Understory On Carbon Cycling In Eucalyptus Plantations Of South China, Long Yang, Jun Wang, Yuhui Huang, Dafeng Hui, Meili Wen Jun 2014

Effects Of The Interception Of Litterfall By The Understory On Carbon Cycling In Eucalyptus Plantations Of South China, Long Yang, Jun Wang, Yuhui Huang, Dafeng Hui, Meili Wen

Biology Faculty Research

For the purposes of forest restoration, carbon (C) fixation, and economic improvement, eucalyptus (Eucalyptus urophylla) has been widely planted in South China. The understory of eucalyptus plantations is often occupied by a dense community of the fern Dicranopteris dichotoma, which intercepts tree canopy leaf litter before it reaches the ground. To understand the effects of this interception of litterfall on C cycling in eucalyptus plantations, we quantified the mass of intercepted litter and the influences of litterfall interception on litter decomposition and soil respiration. The total mass of E. urophylla litterfall collected on the understory was similar to that collected …

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Dissolved Nutrient Ratios And Concentrations Affect Fungal Reproduction And Community Structure Associated With Submerged Leaf Litter And Wood, Jennifer Fitzgerald May 2014

Dissolved Nutrient Ratios And Concentrations Affect Fungal Reproduction And Community Structure Associated With Submerged Leaf Litter And Wood, Jennifer Fitzgerald

Electronic Theses and Dissertations

Litter-associated fungi are important intermediaries in carbon and energy flow in streams. They can obtain nitrogen (N) and phosphorus (P) from both the substrate and the water column. I tested the effects of dissolved nutrients (dissolved inorganic nitrogen (DIN) 40-975 µg/L, soluble reactive phosphorus (SRP) 2-135 µg/L, N:P ratios 2:1, 16:1, 128:1) on fungi associated with leaf litter (maple and rhododendron) and wood in streamside channels at Coweeta Long Term Ecological Research site, North Carolina. This study addressed two main questions: (1) will fungal reproduction (sporulation rate of aquatic hyphomycetes) peak at a dissolved N:P ratio similar to nutrient stoichiometry …

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Continuous, Pulsed And Disrupted Nutrient Subsidy Effects On Ecosystem Productivity, Stability, And Energy Flow, Michael J. Weber, Michael L. Brown Feb 2013

Continuous, Pulsed And Disrupted Nutrient Subsidy Effects On Ecosystem Productivity, Stability, And Energy Flow, Michael J. Weber, Michael L. Brown

Natural Resource Management Faculty Publications

Resource pulses and subsidies can supply ecosystems with an important source of nutrients that supports additional productivity at multiple trophic levels. Common carp Cyprinus carpio provide ecosystems with a continuous nutrient subsidy through bioturbation and excretion but may also initiate a nutrient pulse through carcass decomposition. We examined how continuous (common carp foraging and excretion), pulsed (carcass decomposition) and disrupted (carp introduced and then removed) nutrient subsidies differed in their ability to alter nutrient availability, ecosystem productivity and stability and energy flow. Nitrogen and phosphorus availability and primary production were highest in pulsed, intermediate in continuous and lowest for disrupted …

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Continuous, Pulsed And Disrupted Nutrient Subsidy Effects On Ecosystem Productivity, Stability, And Energy Flow, Michael J. Weber, Michael L. Brown Feb 2013

Continuous, Pulsed And Disrupted Nutrient Subsidy Effects On Ecosystem Productivity, Stability, And Energy Flow, Michael J. Weber, Michael L. Brown

Michael J Weber Dr

Resource pulses and subsidies can supply ecosystems with an important source of nutrients that supports additional productivity at multiple trophic levels. Common carp Cyprinus carpio provide ecosystems with a continuous nutrient subsidy through bioturbation and excretion but may also initiate a nutrient pulse through carcass decomposition. We examined how continuous (common carp foraging and excretion), pulsed (carcass decomposition) and disrupted (carp introduced and then removed) nutrient subsidies differed in their ability to alter nutrient availability, ecosystem productivity and stability and energy flow. Nitrogen and phosphorus availability and primary production were highest in pulsed, intermediate in continuous and lowest for disrupted …

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Effects Of Dissolved Nutrient Ratios And Concentrations On Litter-Associated Microbial Activity In Streamside Channels, Timothy Burns Jan 2013

Effects Of Dissolved Nutrient Ratios And Concentrations On Litter-Associated Microbial Activity In Streamside Channels, Timothy Burns

Electronic Theses and Dissertations

Heterotrophic consumers, such as microorganisms and invertebrates, play a fundamental role in the flow of carbon and energy in streams. The effects of dissolved nutrient concentrations, and especially ratios, on litter—associated microorganisms and decomposition rates of detritus are poorly understood. This study addressed the responses of heterotrophic microbes to a wide range of concentrations and ratios of dissolved inorganic nitrogen (N) and phosphorus (P) in streamside channels simulating headwater streams. Two main questions were: (1) do microbial parameters and litter decomposition rates peak at a dissolved N:P ratio that approaches the nutrient ratio of microbial biomass, and (2) does microbial …

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Nitrogen Deposition Effects On Production And Decomposition Of Coarse Woody Debris, Bethany Jeanne Lyons Jan 2012

Nitrogen Deposition Effects On Production And Decomposition Of Coarse Woody Debris, Bethany Jeanne Lyons

Dissertations, Master's Theses and Master's Reports - Open

Atmospheric nitrogen deposition has the potential to impact forest productivity, microbial associations, nutrient cycling, decomposition and stand dynamics. However, among the least studied aspects of these processes are the production and decomposition of dead woody biomass, or coarse woody debris (CWD). Coarse woody debris is made up of dead woody material on the ground called down dead wood (DDW) and dead standing trees which are often referred to as snags. Observed reductions in decomposition of CWD have been linked to substrate quality and microbial communities. If the decomposition effect is ubiquitous among litter types, CWD density, C:N, and biomass are …

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Insect-Damaged Corn Stalks Decompose At Rates Similar To Bt-Protected, Non-Damaged Corn Stalks, R. Michael Lehman, Shannon L. Osborne, Deirdre A. Prischmann-Voldseth, Kurt A. Rosentrater Aug 2010

Insect-Damaged Corn Stalks Decompose At Rates Similar To Bt-Protected, Non-Damaged Corn Stalks, R. Michael Lehman, Shannon L. Osborne, Deirdre A. Prischmann-Voldseth, Kurt A. Rosentrater

Kurt A. Rosentrater

The relative decomposability of corn (Zea mays L.) residues from insect (Bt)-protected hybrids and conventional hybrids cultivated under insect pressure was investigated in two studies. Above-ground biomass, residue macromolecular composition, and stalk physical strength were also measured. In the first decomposition study, chopped residues (stalks and leaves) were used from a corn rootworm-protected (Cry3Bb1) hybrid and its non-Bt near isoline that were grown in replicated plots infested with corn rootworms (Diabrotica spp.). In the second study, residue (intact stalk sections) was used from three European corn borer (ECB, Ostrinia nubilalis Hübner)-resistant (Cry1Ab) hybrids representing different seed manufacturer/maturity date series, their …

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Decomposition Dynamics In Restored And Naturally Recovering Atlantic White Cedar (Chamaecyparis Thyoides) Wetlands, Edward Ratcliffe Crawford Jan 2002

Decomposition Dynamics In Restored And Naturally Recovering Atlantic White Cedar (Chamaecyparis Thyoides) Wetlands, Edward Ratcliffe Crawford

Biological Sciences Theses & Dissertations

Restoration efforts and ecologically based management practices for Atlantic white cedar wetlands have recently focused on soil organic matter sequestration and aggradation as critical ecosystem functions in the maintenance of this imperiled community type. This work addresses how developmental stage, litter quality and environmental conditions influenced above ground leaf litter and below ground root decay in naturally regenerating and restored Atlantic white cedar wetlands. Using standard litterbags for leaf litter and a modified litterbag technique for roots, decay dynamics of naturally regenerating and restored Atlantic white cedar stands were measured to compare ecosystem development trends with restoration conditions. Effects on …

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Effects Of Elevated Atmospheric Co2 On Root Growth, Turnover And Decomposition In A Scrub Oak Ecosystem, John Joseph Dilustro Jul 2000

Effects Of Elevated Atmospheric Co2 On Root Growth, Turnover And Decomposition In A Scrub Oak Ecosystem, John Joseph Dilustro

Biological Sciences Theses & Dissertations

Atmospheric carbon dioxide levels are increasing and predicted to double this century. The implications of this rise on vegetation structure and function are not well understood. Measurement of root growth response to elevated atmospheric carbon dioxide is critical to understanding soil carbon input. I investigated the effects of elevated carbon dioxide on fine root growth and decomposition using open top chambers with both ambient and elevated (700 PPM) CO2 treatments in an oak-palmetto scrub ecosystem at Kennedy Space Center, Florida. Minirhizotron tubes were installed in each elevated and control chamber to allow observation of roots. Each tube was sampled …

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