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Soil organic matter

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Full-Text Articles in Life Sciences

Soil Quality Under Permanent And Annual Pastures: Its Implications For Soil Microbial Activity And Nutrient Turnover, R. J. Haynes, R. M. Milne, N. Miles Aug 2023

Soil Quality Under Permanent And Annual Pastures: Its Implications For Soil Microbial Activity And Nutrient Turnover, R. J. Haynes, R. M. Milne, N. Miles

IGC Proceedings (1997-2023)

Dairy farming in humid, subtropical parts of South Africa is based on permanent kikuyu grass (Pennisetum clandestinum) swards. However, there is a shortage of feed during the winter because low temperatures limit kikuyu growth. As a result, annual pastures incorporating temperate grasses, are grown for winter feed production. The grasses used are typically annual ryegrass (Lolium multiflorum) and sometimes perennial ryegrass (Lolium perenne). Kikuyu is so invasive in the locality that it becomes dominant within a few years, even if the field is sown to perennial ryegrass. For that reason, the swards are usually …


Role Of Grasslands And Grassland Management For Biogeochemical Cycles And Biodiversity. Setting Up Long-Term Manipulation Experiments In France, G. Lemaire, Jean-François Soussana, J. C. Emile, A. Chabbi, F. Louault, P. Loiseau, Bertrand Dumont, X. Charrier Aug 2023

Role Of Grasslands And Grassland Management For Biogeochemical Cycles And Biodiversity. Setting Up Long-Term Manipulation Experiments In France, G. Lemaire, Jean-François Soussana, J. C. Emile, A. Chabbi, F. Louault, P. Loiseau, Bertrand Dumont, X. Charrier

IGC Proceedings (1997-2023)

Land use for grassland is recognised to have some beneficial effects for biodiversity and the environment: (i) regulation of the water cycle and protection of soils against erosion, (ii) accumulation of organic matter in soil and sequestration of atmospheric C, (iii) regulation of the N cycle and attenuation of the risk for N leaching, (iv) recycling of nutrients and improvement of soil quality, (v) improvement of biodiversity of vegetation, soil microbes and micro- and meso-fauna. All these effects depend upon the management of the grassland: cutting vs. grazing, stocking density, level of N inputs. Management decisions often result from short- …


Changes And Relationships Of Soil Aluminum, Organic Matter, And Hydrogen Ion Concentration With Rye Cover Crop, Arron Wilder Jan 2023

Changes And Relationships Of Soil Aluminum, Organic Matter, And Hydrogen Ion Concentration With Rye Cover Crop, Arron Wilder

Cal Poly Humboldt theses and projects

Soil acidity is a common agricultural problem worldwide, as approximately 50% of all potentially arable soils are affected by pH limitations. At soil pH 3+) is considered to be the chemical form of aluminum in acid soil that hinders plant growth the most. Potentially, soil organic matter (SOM) can ameliorate the toxic effects of Al3+ on plants and microbes by binding with Al3+, thus preventing Al3+ (and other species of aluminum) from interacting in the rhizosphere. Increasing SOM also increases soil health indicators (i.e., microbial activity, soil water holding capacity, aggregate stability, porosity, etc.) while the …


Critical Soil Health Parameters To Improve Crop Production, Gretchen F. Sassenrath, Bruno C. Pedreira, Carlos B. Pires Jan 2023

Critical Soil Health Parameters To Improve Crop Production, Gretchen F. Sassenrath, Bruno C. Pedreira, Carlos B. Pires

Kansas Agricultural Experiment Station Research Reports

Soil health is a critical determinant of plant performance. This manuscript describes how the physical, chemical, and biological components within the soil interact to create good soil health. Soil structure is important to provide support for plants, nutrient and water cycling, decreased compaction, and more efficient carbon storage. Measurements of soil properties are presented that can be done in the field on any soil.


Attachment Issues: Microbes, Minerals, And The Persistence Of Soil Organic Matter, Md Shafiul Islam Rion Jan 2023

Attachment Issues: Microbes, Minerals, And The Persistence Of Soil Organic Matter, Md Shafiul Islam Rion

Graduate Theses, Dissertations, and Problem Reports

The remnants of microorganisms are now understood to account for the majority of organic matter in many mineral soils. Despite the significance of this microbial necromass for soil carbon storage, we know relatively little about how the traits of microorganisms interact with soil minerals to determine the stability of microbe derived carbon in soil. Soil minerals differ in their surface area and chemistry potentially influencing microbial attachment, biofilm formation, and the persistence of microbial necromass. To address this knowledge gap, we grew twelve bacterial species from four broad groups of varying cell wall morphology (Gram positive, Gram negative, filamentous actinobacteria, …


Organic Matter Transformation Processes Of Soils In Native Steppe Grass Communities, E. Forró Nov 2022

Organic Matter Transformation Processes Of Soils In Native Steppe Grass Communities, E. Forró

IGC Proceedings (1997-2023)

It has been well known that higher plant density provides more effective protection for soils. However, the influence of different vegetation on the soil properties has been less well recognised. The high density of grass communities, a high number of plant species and density of roots have advantageous effects on soil properties and conditions, particularly on the organic matter cycling and structure of soils.


Characterisation Of Soil Organic Matter From Pensacola Bahiagrass Pastures Grazed For Four Years At Different Management Intensities, J. C. B. Dubeux Jr., Lynn E. Sollenberger, N. B. Comerford, Ana C. Ruggieri, K. M. Portier Nov 2022

Characterisation Of Soil Organic Matter From Pensacola Bahiagrass Pastures Grazed For Four Years At Different Management Intensities, J. C. B. Dubeux Jr., Lynn E. Sollenberger, N. B. Comerford, Ana C. Ruggieri, K. M. Portier

IGC Proceedings (1997-2023)

Soil fertility and agricultural system sustainability depend upon soil organic matter (SOM), particularly in the tropics, because of highly weathered soils and low fertiliser inputs. Because of the beneficial effects of SOM on chemical, physical, and biological soil properties, Greenland (1994) suggested that SOM is an indicator of agro-ecosystem sustainability. Pasture management may affect SOM by altering the production/decomposition ratio of residues (Johnson, 1995). The objective of this study was to characterise the SOM of Pensacola bahiagrass pastures grazed for four years at a range of management intensities.


Effect Of Different Carbon And Nitrogen Inputs On Soil Chemical And Biochemical Properties In Maize-Based Forage Systems In Northern Italy, S. Monaco, D. Hatch, L. Dixon, C. Grignani, D. Sacco, L. Zavattaro Nov 2022

Effect Of Different Carbon And Nitrogen Inputs On Soil Chemical And Biochemical Properties In Maize-Based Forage Systems In Northern Italy, S. Monaco, D. Hatch, L. Dixon, C. Grignani, D. Sacco, L. Zavattaro

IGC Proceedings (1997-2023)

In agroecosystems, manure application and straw return affect carbon (C) and nitrogen (N) cycling and affect soil organic matter (SOM), nutrient supply and losses to the environment. We examined effects of different organic sources on crop production, N uptake and surplus and SOM in maize systems.


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 …


Carbon Accumulation In Soils Under Brachiaria Pastures In The Atlantic Forest Region Of The South Of Bahia, Brazil, R. M. Tarré, R. Macedo, R. B. Cantarutti, C. De P. Rezende, J. M. Pereira, E. Ferreira, B. J. R. Alves, S. Urquiaga, R. M. Boddey Dec 2021

Carbon Accumulation In Soils Under Brachiaria Pastures In The Atlantic Forest Region Of The South Of Bahia, Brazil, R. M. Tarré, R. Macedo, R. B. Cantarutti, C. De P. Rezende, J. M. Pereira, E. Ferreira, B. J. R. Alves, S. Urquiaga, R. M. Boddey

IGC Proceedings (1997-2023)

The objective of this study was to investigate the change in carbon stocks in soil following deforestation of the Atlantic forest in the South of Bahia State (Brazil) and replacement with productive pastures of Brachiaria humidicola either in monoculture or with the introduction of the forage legume Desmodium ovalifolium. Carbon stocks in the 0-30 cm layer were 44.5 Mg ha-1 under the original forest and found to be approximately 42 Mg ha-1 C 10 years later. At this time pastures of B. humidicola with or without the presence of D. ovalifolium were formed and grazed continuously for …


Earthworm And Soil Data For Ottawa National Forest, Blair Orr Nov 2021

Earthworm And Soil Data For Ottawa National Forest, Blair Orr

Michigan Tech Research Data

Two types of analysis were run.

I. Probability of finding L. terrestris in habitat types of the Ottawa National Forests.

Abstract: Parts of the Ottawa National Forest (ONF) provide suitable habitat for invasive earthworms. Extensive earthworm invasion is a relatively recent event on the ONF and this study captures the current state of the earthworm invasion through a four-stage invasive species distribution model (iSDM). The random distribution of earthworms indicates early colonization by earthworms which is moderated by habitat (forest type, soil group, and drainage class). CART modeling was used to determine probability of earthworm invasion. The CART model had …


Soil Microbial Carbon, Nitrate And Ammonium Nitrogen Dynamics In Urochloa Grass Cultivated In Sub-Humid Kenya, K. W. Ndung’U-Magiroi, M. N. Koech, M. C. Mutoko, M. Kamidi, Elias M. Gichangi, Donald M. G. Njarui Oct 2021

Soil Microbial Carbon, Nitrate And Ammonium Nitrogen Dynamics In Urochloa Grass Cultivated In Sub-Humid Kenya, K. W. Ndung’U-Magiroi, M. N. Koech, M. C. Mutoko, M. Kamidi, Elias M. Gichangi, Donald M. G. Njarui

IGC Proceedings (1997-2023)

A study was conducted to monitor the dynamics of available soil phosphorus (P), soil microbial biomass carbon (SMBC), nitrogen (SMBN), ammonium and nitrate nitrogen under seven Urochloa grass cultivars at Kitale, Kenya. The Urochloa cultivars: Urochloa brizantha cvs. Marandu, MG-4, Piata, Xaraes, U. decumbens cv. Basilisk, U. hybrid cv. Mulato II and U. humidicola cv. Llanero was compared with two popularly grown forages, Rhodes grass (Chloris gayana cv. KAT R3), Napier grass (Pennisetum purpureum cv. KK1) and annual weeds. The treatments were tested in a randomized complete block design arranged in a split plot treatment structure with two …


Characterization Of Soil Properties Under Legume And Non‐Legume Tree Canopies Occurring In Signal Grass (Brachiaria Decumbens Stapf.) Pastures, José C. B. Dubeux Jr., M. A. Lira, M. V. F. Santos, D. M. Barros, M. A. Silva, Alexandre C. L. De Mello Jan 2021

Characterization Of Soil Properties Under Legume And Non‐Legume Tree Canopies Occurring In Signal Grass (Brachiaria Decumbens Stapf.) Pastures, José C. B. Dubeux Jr., M. A. Lira, M. V. F. Santos, D. M. Barros, M. A. Silva, Alexandre C. L. De Mello

IGC Proceedings (1997-2023)

No abstract provided.


Long-Term Changes In Soil Surface Properties As Affected By Management Practices In A Wheat-Soybean, Double-Crop System, Machaela L. Morrison, Kristofor R. Brye University Of Arkansas Jan 2021

Long-Term Changes In Soil Surface Properties As Affected By Management Practices In A Wheat-Soybean, Double-Crop System, Machaela L. Morrison, Kristofor R. Brye University Of Arkansas

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Long-term agricultural sustainability and productivity are controlled by the integrative effects of different management practices on the soil. Many Arkansas producers use the double-crop system to grow soybeans [Glycine max (L.) Merr] and wheat (Triticum aestivum L.). The objective of this study was to evaluate the effects of agricultural management practices, including residue level, tillage, irrigation, burning, and soil depth on the change in various soil properties from 2010 to 2020 in a long-term, wheat-soybean, double-crop system on a silt-loam soil (Glossaquic Fraglossudalfs) in eastern Arkansas. Soil nutrients tended to accumulate over time, the most in the top 10 cm, …


Resilience Of Ecosystem Structure And Function During Succession Following Prescribed Burning In A Shrub‐Steppe Ecosystem In Wyoming, Usa, E. Pendall, M. B. Cleary, B. E. Ewers, K. Naithani, H. Kwon Sep 2020

Resilience Of Ecosystem Structure And Function During Succession Following Prescribed Burning In A Shrub‐Steppe Ecosystem In Wyoming, Usa, E. Pendall, M. B. Cleary, B. E. Ewers, K. Naithani, H. Kwon

IGC Proceedings (1997-2023)

No abstract provided.


Investigations On Soil Fertility Of Medicago Varia And Bromus Inermis Stands, Yongliang Zhang, Kai Gao Aug 2020

Investigations On Soil Fertility Of Medicago Varia And Bromus Inermis Stands, Yongliang Zhang, Kai Gao

IGC Proceedings (1997-2023)

No abstract provided.


How To Measure, Report And Verify Soil Carbon Change To Realize The Potential Of Soil Carbon Sequestration For Atmospheric Greenhouse Gas Removal, Pete Smith, Jean Francois Soussana, Denis Angers, Louis Schipper, Claire Chenu, Daniel P. Rasse, Niels H. Batjes, Fenny Van Egmond, Stephen Mcneill, Matthias Kuhnert, Cristina Arias-Navarro, Jorgen E. Olesen, Ngonidzashe Chirinda, Dario Fornara, Eva Wollenberg, Jorge Álvaro-Fuentes, Alberto Sanz-Cobena, Katja Klumpp Jan 2020

How To Measure, Report And Verify Soil Carbon Change To Realize The Potential Of Soil Carbon Sequestration For Atmospheric Greenhouse Gas Removal, Pete Smith, Jean Francois Soussana, Denis Angers, Louis Schipper, Claire Chenu, Daniel P. Rasse, Niels H. Batjes, Fenny Van Egmond, Stephen Mcneill, Matthias Kuhnert, Cristina Arias-Navarro, Jorgen E. Olesen, Ngonidzashe Chirinda, Dario Fornara, Eva Wollenberg, Jorge Álvaro-Fuentes, Alberto Sanz-Cobena, Katja Klumpp

Rubenstein School of Environment and Natural Resources Faculty Publications

Global Change Biology published by John Wiley & Sons Ltd There is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international ‘4p1000’ initiative and the FAO's Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and …


Integrated Crop–Livestock Systems In Paddy Fields: New Strategies For Flooded Rice Nutrition, Luiz Gustavo De O. Denardin, Amanda P. Martins, Felipe De C. Carmona, Murilo G. Veloso, Gabriela I. Carmona, Paulo César De F. Carvalho, Ibanor Anghinoni Jan 2020

Integrated Crop–Livestock Systems In Paddy Fields: New Strategies For Flooded Rice Nutrition, Luiz Gustavo De O. Denardin, Amanda P. Martins, Felipe De C. Carmona, Murilo G. Veloso, Gabriela I. Carmona, Paulo César De F. Carvalho, Ibanor Anghinoni

Department of Entomology: Faculty Publications

Integrated crop–livestock systems (ICLSs) appear as a good alternative to increase nutrient use efficiency (NUE) in rice (Oryza sativa L.) through the improvement in nutrient cycling and soil chemical attributes in paddy fields. The objective of this study was to evaluate the impact of an ICLS on soil chemical attributes and on the fertilization requirement of N, P, and K by flooded rice in the Brazilian subtropical region. Nutritional status, yield, and NUE of flooded rice were evaluated by fertilization trials through rice response to different fertilization rates of N, P, and K. Soil chemical attributes were evaluated at …


Dual Use Of Cover Crops For Forage Production And Soil Health In Dryland Crop Production, A. K. Obour, J. D. Holman, L. M. Simon, S. K. Johnson Jan 2020

Dual Use Of Cover Crops For Forage Production And Soil Health In Dryland Crop Production, A. K. Obour, J. D. Holman, L. M. Simon, S. K. Johnson

Kansas Agricultural Experiment Station Research Reports

Integrating a cover crop (CC) into dryland crop production in the semiarid central Great Plains (CGP) can provide several ecosystem benefits. However, CC adoption is slow and not widely popular in the CGP because CCs utilize water that other­wise would be available for the subsequent cash crop. Grazing or haying CCs can provide economic benefits to offset revenue loss associated with decreased crop yields when CCs are grown ahead of a cash crop. Objectives of the current research were to 1) determine forage production of CC mixtures, and 2) evaluate the impacts of removing CCs for forage on subsequent crop …


Losses Of Mineral Soil Carbon Largely Offset Biomass Accumulation Fifteen Years After Whole-Tree Harvest In A Northern Hardwood Forest, Matthew A. Vadeboncoeur, Steven P. Hamburg, Chris E. Johnson, Jonathan Sanderman May 2019

Losses Of Mineral Soil Carbon Largely Offset Biomass Accumulation Fifteen Years After Whole-Tree Harvest In A Northern Hardwood Forest, Matthew A. Vadeboncoeur, Steven P. Hamburg, Chris E. Johnson, Jonathan Sanderman

Earth Systems Research Center

Changes in soil carbon stocks following forest harvest can be an important component of ecosystem and landscape-scale C budgets in systems managed for bioenergy or carbon-trading markets. However, these changes are characterized less often and with less certainty than easier-to-measure aboveground stocks. We sampled soils prior to the whole-tree harvest of Watershed 5 at the Hubbard Brook Experimental Forest in 1983, and again in years 3, 8, and 15 following harvest. The repeated measures of total soil C in this stand show no net change in the O horizon over 15 years, though mixing with the mineral soil reduced observed …


Condensation And Polymerization Explain The Humification Of Lignin Into Aliphatic And Aromatic Structures In Soil, Patrick G. Hatcher, Hongmei Chen, Seyyedhadi Khatami, Derek C. Waggoner Jan 2019

Condensation And Polymerization Explain The Humification Of Lignin Into Aliphatic And Aromatic Structures In Soil, Patrick G. Hatcher, Hongmei Chen, Seyyedhadi Khatami, Derek C. Waggoner

Chemistry & Biochemistry Faculty Publications

Soil organic matter (SOM) constitutes a global reservoir of carbon that is more than twice that of either atmospheric carbon or aquatic carbon; however, the manner in which it forms from degraded plant biomass is poorly understood. Some have recently questioned whether plant biomass is involved directly in SOM formation and suggest that it is microbial carbon that constitutes the main source of stable SOM. Such a view implies that above and below ground plant biomass is rapidly decomposed and mineralized. This view contrasts significantly with traditional ones that involve the transformation of plant biomass to recalcitrant humic materials fueled …


Climate And Plant Controls On Soil Organic Matter In Coastal Wetlands, Michael J. Osland, Christopher A. Gabler, James B. Grace, Richard H. Day, Meagan L. Mccoy, Jennie L. Mcleod, Andrew S. From, Nicholas M. Enwright, Laura C. Feher, Camille L. Stagg Jun 2018

Climate And Plant Controls On Soil Organic Matter In Coastal Wetlands, Michael J. Osland, Christopher A. Gabler, James B. Grace, Richard H. Day, Meagan L. Mccoy, Jennie L. Mcleod, Andrew S. From, Nicholas M. Enwright, Laura C. Feher, Camille L. Stagg

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Coastal wetlands are among the most productive and carbon‐rich ecosystems on Earth. Long‐term carbon storage in coastal wetlands occurs primarily belowground as soil organic matter (SOM). In addition to serving as a carbon sink, SOM influences wetland ecosystem structure, function, and stability. To anticipate and mitigate the effects of climate change, there is a need to advance understanding of environmental controls on wetland SOM. Here, we investigated the influence of four soil formation factors: climate, biota, parent materials, and topography. Along the northern Gulf of Mexico, we collected wetland plant and soil data across elevation and zonation gradients within 10 …


A Smartphone-Based Device For Measuring Soil Organic Matter, Meng Lu Jun 2017

A Smartphone-Based Device For Measuring Soil Organic Matter, Meng Lu

Meng Lu

The project evaluated the potential of utilizing a smartphone-based system for the in-field analysis of Soil Organic Matter. Although it demonstrated that the performance of the smartphone-based spectrometer can be comparable to commercial spectrometers, the results suggest that it is challenging to identify the spectral “signatures” of the SOM due to the morphology and moisture variation of soil samples.


A Tree Species Effect On Soil That Is Consistent Across The Species’ Range: The Case Of Aspen And Soil Carbon In North America, Jerome Laganiere, Antra Boča, H. Van Miegroet, David Paré Apr 2017

A Tree Species Effect On Soil That Is Consistent Across The Species’ Range: The Case Of Aspen And Soil Carbon In North America, Jerome Laganiere, Antra Boča, H. Van Miegroet, David Paré

Wildland Resources Faculty Publications

Trembling aspen covers a large geographic range in North America, and previous studies reported that a better understanding of its singular influence on soil properties and processes is of high relevance for global change questions. Here we investigate the potential impact of a shift in aspen abundance on soil carbon sequestration and soil carbon stability at the continental scale by conducting a systematic literature review using 23 published studies. Our review shows that aspen’s effect on soil carbon is relatively consistent throughout the species range. Aspen stores less C in the forest floor but similar amounts in the mineral soil …


Soil Properties' Response To Wheat And Corn Stubble Residue Management In Louisiana, Autumn Danielle Acree Jan 2017

Soil Properties' Response To Wheat And Corn Stubble Residue Management In Louisiana, Autumn Danielle Acree

LSU Master's Theses

Crop residue plays an important role in improving soil fertility. Crop residue affects soil biological and chemical properties by increasing soil organic matter, nutrient status and availability, and microbial activity. The degree of the effects of crop residue on soil fertility depends on the crop residue management practice. Samples were collected in 2014 in wheat (Triticum spp.) stubble and corn (Zea mays) stubble residue. A second soil sample collection under wheat stubble residue was taken in 2015 in the prescribed fire and no-till sections. A total of 342 soil samples (0-2.5cm) were collected across conventional tillage, no-till, and prescribed fire …


Effect Of Exotic Invasive Old World Climbing Fern (Lygodium Microphyllum) On Soil Properties, Pushpa G. Soti, Krish Jayachandran Dec 2016

Effect Of Exotic Invasive Old World Climbing Fern (Lygodium Microphyllum) On Soil Properties, Pushpa G. Soti, Krish Jayachandran

Biology Faculty Publications and Presentations

Old World climbing fern (Lygodium microphyllum) has become one of the most serious ecological threats to the integrity of the greater Everglades ecosystem of south Florida. In this study, we analyzed the effects of Old World climbing fern on surfacesoil characteristics at invaded sites in Florida. We compared soil characteristics of six invaded and adjacent uninvaded plots at three different locations. Our results show that the fern can grow and thrive in a wide range of soil types and the impact on the soil was site specific with effects being more prominent in sites with low nutrient status. Additionally, there …


Lignin Decomposition Is Sustained Under Fluctuating Redox Conditions In Humid Tropical Forest Soils, Steven J. Hall, Whendee L. Silver, Vitaliy I. Timokhin, Kenneth E. Hammel Jul 2015

Lignin Decomposition Is Sustained Under Fluctuating Redox Conditions In Humid Tropical Forest Soils, Steven J. Hall, Whendee L. Silver, Vitaliy I. Timokhin, Kenneth E. Hammel

Steven J. Hall

Lignin mineralization represents a critical flux in the terrestrial carbon (C) cycle, yet little is known about mechanisms and environmental factors controlling lignin breakdown in mineral soils. Hypoxia is thought to suppress lignin decomposition, yet potential effects of oxygen (O2) variability in surface soils have not been explored. Here, we tested the impact of redox fluctuations on lignin breakdown in humid tropical forest soils during ten-week laboratory incubations. We used synthetic lignins labeled with 13C in either of two positions (aromatic methoxyl or propyl side chain Cb) to provide highly sensitive and specific measures of lignin mineralization seldom employed in …


Environmental And Adaptive Buffers That Mediate The Response Of Subalpine Ecosystems To Environmental Change, Lafe G. Conner Jun 2015

Environmental And Adaptive Buffers That Mediate The Response Of Subalpine Ecosystems To Environmental Change, Lafe G. Conner

Student Works

This document reports the results of 4 studies of subalpine ecosystem ecology, describing ways that spatial heterogeneity in soils and plant communities mediate ecosystem responses to environmental change. Ecosystem responses to environmental change are also mediated by regional climate patterns and interannual variability in weather. In the first chapter we report the results of an experiment to test for the mediating effects of associational resistance in a forest community that experienced wide-spread beetle kill. We found that Engelmann spruce were more likely to survive a beetle outbreak when growing in low densities (host dilution) and not through other types of …


Environmental And Adaptive Buffers That Mediate The Response Of Subalpine Ecosystems To Environmental Change, Lafe G. Conner Jun 2015

Environmental And Adaptive Buffers That Mediate The Response Of Subalpine Ecosystems To Environmental Change, Lafe G. Conner

Theses and Dissertations

This document reports the results of 4 studies of subalpine ecosystem ecology, describing ways that spatial heterogeneity in soils and plant communities mediate ecosystem responses to environmental change. Ecosystem responses to environmental change are also mediated by regional climate patterns and interannual variability in weather. In the first chapter we report the results of an experiment to test for the mediating effects of associational resistance in a forest community that experienced wide-spread beetle kill. We found that Engelmann spruce were more likely to survive a beetle outbreak when growing in low densities (host dilution) and not through other types of …


Reaping The Benefits Of Conservation Tillage: Implications Of Increased Soil Organic Matter And Aggregation In Surface Soils, Kenna Elizabeth Rewcastle May 2015

Reaping The Benefits Of Conservation Tillage: Implications Of Increased Soil Organic Matter And Aggregation In Surface Soils, Kenna Elizabeth Rewcastle

Chancellor’s Honors Program Projects

No abstract provided.