Soil Science Commons^™

Lowland Tropical Forests Remain A Methane Sink Under Warming And Long-Term Hurricane Disturbance Recovery, Gabriele Larocca Conte, Lucia Zuvela, Rachel Cruz-Pérez, Tatiana Barreto-Vélez, Nibia Becerra-Santillan, Sophia F. Campbell, Hieu P. Chu, Trung Dam, Iana F. Grullón-Penkova, Miriam Kleit, Deyaneira A. Ortiz-Iglesias, Laura C. Rubio-Lebrón, Molly A. Cavaleri, Sasha C. Reed, Debjani Sihi, Tana E. Wood, Christine S. O'Connell

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Methane (CH₄) is a potent greenhouse gas, and tropical forests account for roughly one–third of global atmospheric CH₄ uptake by soils. Projected warming and more frequent hurricanes in these ecosystems may alter soil CH₄ sink strength, as warmer and wetter soils enhance methanogenesis activity. We measured soil CH₄ and CO₂ efflux during the calendar summer months of 2023 and 2024 alongside continuous records of soil moisture, soil and air temperature, and precipitation in an in–situ warming experiment (TRACE) located in a lowland tropical forest in Puerto Rico, six to seven years after Hurricanes Irma …

Grazed Pasture Effects On Greenhouse Gas Emissions In The Ozark Highlands, Tyler Buchanan

Graduate Theses and Dissertations

In the United States (US), grazinglands serve as the main foundation for the livestock industry, and, in Arkansas specifically, pastures are essential for rotational grazing and dairy operations. Climate change is increasingly becoming a concern in the agriculture industry, largely caused by anthropogenic activities increasing greenhouse gas (GHG) concentrations in the atmosphere, at least partly due to the nutrient recycling that occurs from animal manure additions in grazinglands. Therefore, quantifying GHG emissions from pastures is essential to better understanding the impacts of grazing on the environment. The objective of this study was to quantify and evaluate the potential effects of …

Impacts Of Climate-Smart Agriculture On Greenhouse Gas Emissions In Southeast Arkansas Cotton, Cassandra Seuferling

Graduate Theses and Dissertations

Increasing concerns of climate change have led to the evaluation of greenhouse gas (GHG) emissions [i.e., carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)] from agroecosystems, particularly cotton (Gossypium hirsutum) production. Technology improvement and conservation agriculture methods [i.e., reduced-tillage (RT) instead of conventional tillage (CT) and the use of cover crops (CC)] require further evaluation regarding GHG emissions from Arkansas cotton production. The first objective of the study was to evaluate four gas-flux-determination methods [i.e., linear or exponential regression models, with negative fluxes (WNF) included in the dataset or replacing negative fluxes (RNF)] on CO2, CH4, and N2O fluxes …

Climate Change Effects On Biomass And Greenhouse Gas Emissions Are Ameliorated By Nontoxic Endophytes In Southeastern Usa Transition Zone Tall Fescue Pastures, Rebecca Kay Mcgrail, Jonathan D. Moore, A. Elizabeth Carlisle, Jim A. Nelson, Rebecca L. Mcculley

Plant and Soil Sciences Faculty Publications

Background: The plant–microbe interaction between tall fescue and its endophyte Epichloë coenophiala can affect ecosystem responses to changing rainfall patterns and increasing temperatures. Endophyte-infected (E+) stands often exhibit improved stress tolerance and differing soil greenhouse gas (GHG) emissions compared to endophyte-free (E−) stands. However, it is unknown if mammalian nontoxic endophyte (NTE) strains introduced into some tall fescue cultivars confer differing stress tolerances or reduce soil GHG emissions.

Methods: We quantified the impact of fescue-NTE symbioses in Jesup and Texoma on biomass and GHG emissions in response to increased temperature (+3°C) and altered precipitation (50% lengthened interval between events) using …

Investigating The Microbial Communities In Freshwaters Of Northern Sweden, Maizy Wilcox

Undergraduate University Honors Capstones

Climate change is shifting the stability of sensitive ecosystems in the Arctic region due to global warming, with widespread impacts on permafrost regions, including the Stordalen Mire region of Sweden. Due to climate change, the Stordalen Mire is composed of thawing permafrost shifting into a wetland (V onk et al., 2015). As permafrost thaws, the landscape transforms due to changing water environmental conditions, causing lower pH changes and higher temperatures in the water, impacting the underlying soil chemistry and biology, vegetation, and microbial communities (Webb et al., 2022). The increased temperature can enhance methanogenic microbial growth by expanding the groundwater …

Early Holocene Interaction Of Aeolian, Alluvial, And Lacustrine Processes In A Dune-Dammed Valley In The Central Nebraska Sand Hills, Gpsia Mahoney, R. D. Mandel, P.R. Hanson, Sherilyn Fritz

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Unfolding Cascading Impacts Of Changing South Asia Monsoon On A Hindu Kush Himalayas Basin, Surendra Maharjan, Wenzhao Li, Shahryar Fazli, Arshad Ansari, Suraj Tiwari, Roma Thakurathi, Rejoice Thomas, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Study region

Study focus

New hydrological insights for the region

Implications For Grasslands Of The Response To Climate Change By The World Food System, Martin Parry, Cynthia Rosenzweig

IGC Proceedings (1977-2023)

A recent and preliminary assessment of the sensitivity of the world food trade to climate change has indicated the following: Assuming {unrealistically} no adjustments in inputs, global food grains production in 2060 is estimated to be reduced by l-7% from the level that would be expected under a future without climate change. Food prices, including feedstock prices, are estimated lo be increased as a consequence, The implications of lhese changes for grassland production systems are considered. Two broad types of adjustmenls in inputs can be envisaged: firstly, on-farm responses of crop type and management and, secondly, national and international policy …

Climate Change: Adapting Tropical And Subtropical Grasslands, G M. Mckeon, S M. Howden, N.O J. Abel, J M. King

IGC Proceedings (1977-2023)

Climate change as a result of increasing greenhouse gas concentrations or lhe repetition of historical climale variability will affect the management and production of tropical and subtropical grasslands that support about half the world's domestic herbivores. Previous studies of the regional impact of climate change and climate variability on intensive agriculture have shown lhat such evaluation should include the known and expected abilities of managers and governments to respond by reducing the negative impacts and taking advantage of positive opportunities, A high priority for grassland scientists is the development of similar evaluation capabilities for grassland systems, which are more complex …

Evaluating The Effects Of Climate Changes On Grasslands, Robert G. Woodmansee, William E. Riebsame

IGC Proceedings (1977-2023)

Determining the effects of climate change on cold region grasslands requires the integration of knowledge from the biological, physical and social sciences. That integration is dependent on new methods, technologies and facilitation techniques ! that allow evaluation and management of complexity rather than focusing on simplification. Specifically, grassland response can be defined as the interaction of 10 basic sectors: (I) wenther and climate (Including chemical factors}, (2) winter, (3) soil properties, (4) assemblages of organisms, (5) energy, (6) economic viability, (7) individual human behavior, (8) cultural and community viability, (9) organisational penalty, and (10) political, legal, policy, and regulatory Influences. …

Prediction Of Grassland Plant Responses To Global Change, B D. Campbell, J P. Grime

IGC Proceedings (1977-2023)

Global change is challenging the predictive power of biology. Increasingly, biologists are being asked to draw together existing knowledge and new experimental data, in order to provide predictions of the effects of global change at regional, national and global scales. In this paper we examine how well global change effects on grassland plants can be predicted, and what avenues might be used in future to improve predictive capabilities. Broad predictions of the direction of change in grassland vegetation can be made quite simply and from a limited set of data. Predictions of the rate and magnitude of change are more …

Variation In The Response Of Pasture Plants To Carbon Dioxide, B D. Campbell, W A. Laing, P.C D. Newton

IGC Proceedings (1977-2023)

The percentage increases in growth resulting from a doubling of atmospheric CO2 concentration were measured for 37 common pasture plants under strictly controlled conditions of temperature, nutrient supply and irradiance. A wide range of variation in potential response lo CO2 was detected in the day/night temperature range 12n°c to 28/ 23°C. C4 species responded litlle to elevated CO2 The mean ± standard deviation of the distribution of c3 species responses ranged from l±21% at 1m•c to 90±40% at 28/23°C. These responses varied with the stage of plant development. The response by Lolium perenne cv. Grasslands Nui was of intermediate size …

Will Subtropical Grasses Keep Spreading Through New Zealand?, B D. Campbell, R.J M. Hay

IGC Proceedings (1977-2023)

n this paper we briefly examine the effects that rising temperature and atmospheric CO2 concentrations may have on the spread of subtropical grasses in New Zealand. Data are presented from controlled-environment experiments measuring the growth and competitive suppression of white clover by a variety of local temperate and subtropical grasses at CO2 concentrations of 3S0 ppm and 700 ppm. These data support the prediction that some subtropical grasses may decline in aggressiveness relative to temperate species in New Zealand in the future as atmospheric CO2 levels rise. Some of the factors likely to modify the expression of temperature and CO2 …

Effect Of Carbon Dioxide Concentration On The Competitive Ability Of Clover: Measurements Of Growth And Rubisco, W A. Laing, D H. Greer, B D. Campbell

IGC Proceedings (1977-2023)

White clover (Trifolium repens cv. Grasslands Huia) was grown in competition with one of 10 established grass species or else grown alone. Plants were grown at either 350 or 700 ppm CO2, at 28/23°C and 700 µmol/m1/sec photon flux density. Plant growth and extractable ribulose bisphosphate carboxylase (rubisCO) were measured. Grass growth responded less to CO2 than clover. In the absence of grass competition, clover growth Increased 30% under 700 ppm CO2 compared with 350 ppm, but the response varied from 0% to 100% • when grass competition was present. Increased CO2 reduced extractable rubisCO activity (expressed on a …

Response Of Natural Turves Of Pasture To Elevated Carbon Dioxide In A Controlled Environment, P.C D. Newton, H Clark, C C. Bell, E M. Glasgow

IGC Proceedings (1977-2023)

Large natural turves from a ryegrass-white clover (Lolium pernne, trifolium repens) pasture were exposed to increasing day/nighl temperatures at 350 and 700 µVI CO2 over a 7•month period. Growth rate al the highest temperature (22/16°C day/night) was IS% higher at the elevated CO2 level; at lower temperatures the response to CO2 was reduced or even negative (-6% at 10/4°C). The growth rate of ryegrass was much lower at elevated CO2 while that of white clover and other grasses was increased. These results are compared with previous studies using synthetic communities, and the limited response to CO2 is noted …

Effect Of Elevated Carbon Dioxide On The Performance Of Nine Coexisting Grassland Species, J Watson, J D. Graves

IGC Proceedings (1977-2023)

Microcosms were constructed to represent a neutral grassland community under traditional agricultural management. During a season of fumigation at ambient and 600 µmot/mot CO2, plant performance was recorded. An increase of biomass for the whole community resulted at elevated CO2, but the response of individual species differed, There are indications that competitive interactions may change within a community due to the effects of CO2 enrichment; this may eventually result in a change in species composition.

Comparison Of Photosynthetic Responses To Carbon Dioxide In Pasture Species, D H. Greer, W A. Laing, B D. Campbell

IGC Proceedings (1977-2023)

Thirteen major pasture species were grown in controlled environments at 3 temperatures (12n, 18/13 and 28/23°C) and at 350 nnd 700 ppm CO2 for 4-8 weeks and net photosynthesis measured under these conditions. In C1 cultivars, short-term (within minutes) exposure to elevated CO2 had the greatest effect on photosynthesis, with an average of 55% higher rates than that at ambient CO2. There was also a response to long-term growth at high CO2, with a,1 average of 40% higher rates of photosynthesis than at ambient CO2 (both measured al their growth CO2) and a marked alteration in the temperature dependence Qf …

Modeling The Effects Of Climate Variability And Climate Change On A Pastoral Farming System, R J. Martin, D B. Baird, M J. Salinger, P R. Van Gardingen, D G. Mccall

IGC Proceedings (1977-2023)

A simulation model was used to investigate the pasture and animal production and gross margins of a typical all sheep permanent pasture farm in South Canterbury, New Zealand, using 60 years of current climate data, and also a climate change scenario. The model was run on a fixed management system at different stocking rates with and without destocking during feed shortages. Mean annual pasture production was 8060 kg/ha, with a coefficient of variation of 22%. Destocking enabled more stock to be carried on average, with higher, but rh.ore variable, returns. A climate change scenario of a 75% increase in CO2' …

Changes To Sheep Grazing Systems In Response To Climate Change, B M. Butler, S T. Morris, R S. Morris

IGC Proceedings (1977-2023)

Simulation models were used to predict changes in pasture growth and sheep farming systems as a result of changes in climate due to global warming. The results of long•lerm mean climate and 10 years' individual climate simulations show Iha! increases in stocking rate of up to 40% may be possible with climate change. Benefits of climate change included increased lamb carcass weight and pasture cover. Climate change also resulted in the feasibility of autumn lambing systems in an environment in which these systems are currently difficult lo maintain. A change from 100% spring lambing to 40% of the flock lambing …

Climate Change And Variability: Impacts On New Zealand Pastures, M J. Salinger, A S. Porteous

IGC Proceedings (1977-2023)

Climate change and variability influence the productivity and distribution of New Zealand pasture species. Temperature and rainfall scenarios are used to explore the sensitivity of New Zealand pastures to potential climate warming next century. Temperature affects the length of the growing season with present pasture species extending 200 m higher in altitude for every 1 •c temperature increase. The greater area of New Zealand that becomes frost free allows the spread of subtropical pasture grasses southwards. However, where low rainfall limits pasture production, changes to the rainfall amount have a significant effect. A rainfall change of I 0% changes the …

A Climate Change Perspective On Grasslands, A Barrie Pottock

IGC Proceedings (1977-2023)

Grasslands are the result of interactions between climate, soil, interspecies competition and natural or humnn distucbance. They are vital to human sustenance but vulnerable to human mismanagement and climatic stress.• Thece is now a strong scientific consensus that climate will change during the next century at a rate unprecedented since the end of the last glaciation. Expected climatic changes include not only increasing temperatures, but also changes in total rainfall and its seasonality, and systematic increases in rainfall intensity. Along with the direct effects of increasing carbon dioxide concentrations on plants, and changes in fire frequency, these environmental influences will …

Simulation Models As Decision Aids For Management Of Rangeland Ecosystems, J Ross Wight, Clayton L. Hanson

IGC Proceedings (1977-2023)

Rangeland simulation models have been used primarily as research tools to synthesise and organise information and to conceptualise and describe the interacting components of the ecosystem. Their application as decision aids for range management has not been developed. This paper discusses ways simulation models, such as SPUR· (Simulation of Production and Utilisation of Rangelands), can be used to forecast herbage p1oduction and the occurrence of biological windows, enhance monitoring, and predict the impacts of management and climate change on the soil, water, and plant resources including species composition.

A Seasonal Decomposition Comparison Between Forest And Turf Habitats: Implications For Climate Change, Amanda Shirmer

DePaul Discoveries

Decomposition is an essential ecosystem service in which microorganisms breakdown organic matter. This process improves soil health and acts as a vital step in global carbon cycles. In this study, we examined decomposition rates and associated soil properties in turf and forest habitats across summer and fall seasons in order to determine how land management practices and climate change may be altering local decomposition regimes. Our study determined that there was a statistically significant difference between decomposition rates in turf and forest ecosystems (P=0.003) and a significant difference in decomposition rate across season (P

Socio-Economic And Climate Change In Mongolia - Effects On Grassland Ecosystems, C Opp

IGC Proceedings (1977-2023)

In Mongolia, in combination with strong changes of the whole society during the past 76 years, from the feudal system to socialism and from the socialist system of planned development to the market economy, there are a lot of changes in the use of natural resources all over the country. In consequence of this a lot of effects on grassland ecosystems, caused by socio-economic and climate driving factors, were observed and studied in different scales: zonal, regional, local.

Long-Term Effects Of Co2 Enrichment And Temperate Increase On Forage Quality In A Temperate Grass, J F. Soussana, J M. Besle, I Chabaux, P Loiseau, P C. De Faccio Carvalho

IGC Proceedings (1977-2023)

Perennial ryegrass swards were grown during two years at two N fertilizer supplies in elevated (700 ppm) or ambient atmospheric CO2 concentration at outdoor temperature and at + 3°C in elevated CO2. Elevated CO2 and temperature increase had only minor impacts on the digestibility and on the fiber composition of the cut material. On average, the water soluble carbohydrate concentration of the leaf laminae was doubled in elevated CO2, whereas a 3°C temperature increase reduced this concentration by 25 %.

Co2 Enrichment And Temperature Effects On Productivity Of Field-Grown Phalaris And Subterranean Clover, J M. Lilley, T P. Bolger, R M. Gifford

IGC Proceedings (1977-2023)

Pure and mixed swards of Phalaris aquatica and Trifolium subterraneum were exposed to cool (ambient) and warm (cool +3oC) temperatures, at both 380 and 690 ppm CO2 concentrations in field temperature gradient tunnels for 5 months. In general, clover and the mixture had similar forage productivity in each treatment, while phalaris was less productive. Elevated CO2 increased clover production 40% in the monoculture and the mixture. Higher temperatures reduced clover regrowth at ambient CO2 and reduced the response to elevated CO2 in the monoculture but not in the mixture. In contrast, phalaris regrowth in the monoculture was not increased by …

Effects Of Climate Change On Grassland Production In Switzerland, J Fuhrer, M Riedo

IGC Proceedings (1977-2023)

A mechanistic model for productive grassland was used to simulate annual dry matter yield in relation to fluxes of C, N, and water, and to test the sensitivity to climate change and to elevated [CO2] (2xCO2). Local weather scenarios were derived from the results of two General Circulation Models (GCM) by statistical down-scaling. Annual yield increased by a maximum of 10% without 2xCO2 effects, by 1-16% in response to 2xCO2, and by 6-24% with the combination of climate change and 2xCO2. Decreased evapotranspiration and increased water use efficiency in response to 2xCO2 were partially offset by climate change. The simulations …

Breeding Cool-Season Forage Grasses For A Warming Climate, D. P. Malinowski, J. Ford, A. Stewart, D. Woodfield, W. E. Pinchak

IGC Proceedings (1977-2023)

In many parts of the world, changing climatic conditions are resulting in increased temperatures and more variable precipitation, intensifying the duration and severity of drought, especially in summer. Warming climate is considered one reason for the increasing failure of traditional, summer-active cool-season perennial grasses at the margin of their zone of adaptation in naturally C4 grass-dominated ecosystems of the Southern Great Plains of the USA. Two cool-season perennial forage grasses orchardgrass (Dactylis glomerata L.) and tall fescue (Lolium arundinaceum (Schreb.) Darbysh.) are of major economic and ecological importance in these regions. In 2008, we initiated a breeding program …

Exploring Profitable, Sustainable Livestock Businesses In An Increasingly Variable Climate, B. R. Cullen, M. T. Harrison, D. Mayberry, D. Cobon, N. Reichelt, A. Sinnet, Km Christie, F. Bilotto, D-A An-Vo, C. Stokes, L. Perry, T. Davison

IGC Proceedings (1977-2023)

Livestock production systems will need to change in many regions of the world to meet the dual challenges of adaptation to a changing climate and reducing net greenhouse gas (GHG) emissions. The ‘Nexus project’ is exploring these options using seven case studies in eastern Australia spanning a range of production systems from semi-arid beef production in northern Australia to mixed beef and sheep production in cool temperate climates of southern Australia. Regional reference groups, made up of 4-6 local farmers and advisers, identified a series of farm systems changes that could be made to meet these challenges. Options were categorised …

Public Policies For The Development Of A Sustainable, Forage-Based Cattle Sector In Colombia, Argentina, And Costa Rica: A Comparative Analysis, S. Burkart, M. Diaz, Moreno Lerma

IGC Proceedings (1977-2023)

Projected increases in global food demand highlight the importance of Latin America as one of the major future food suppliers, particularly regarding animal-source foods such as beef or milk. Despite the importance of the cattle sector for the region, its negative environmental impacts are numerous and the shift towards sustainability is perceived as slow and uncoordinated. This study aims to identify achievements and difficulties in the implementation of public policies for a sustainable cattle sector in Colombia, Argentina, and Costa Rica, for which policies focused on the use of silvo-pastoral systems and forage-based solutions are prioritized. Based on the review …