Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 23 of 23

Full-Text Articles in Life Sciences

Modeling Experiments For Evaluating The Effects Of Trees, Increasing Temperature, And Soil Texture On Carbon Stocks In Agroforestry Systems In Kerala, India, Ann E. Russell, B. Mohan Kumar Sep 2019

Modeling Experiments For Evaluating The Effects Of Trees, Increasing Temperature, And Soil Texture On Carbon Stocks In Agroforestry Systems In Kerala, India, Ann E. Russell, B. Mohan Kumar

Natural Resource Ecology and Management Conference Papers, Posters and Presentations

Research Highlights: Agroforestry systems in the humid tropics have the potential for high rates of production and large accumulations of carbon in plant biomass and soils and, thus, may play an important role in the global C cycle. Multiple factors can influence C sequestration, making it difficult to discern the effect of a single factor. We used a modeling approach to evaluate the relative effects of individual factors on C stocks in three agricultural systems in Kerala, India. Background and Objectives: Factors such as plant growth form, management, climate warming, and soil texture can drive differences in C storage among ...


Importance Of Scale, Land Cover, And Weather On The Abundance Of Bird Species In A Managed Forest, Alexis R. Grinde, Gerald J. Niemi, Brian R. Sturtevant, Hannah Panci, Wayne Thogmartin, Peter Wolter Dec 2017

Importance Of Scale, Land Cover, And Weather On The Abundance Of Bird Species In A Managed Forest, Alexis R. Grinde, Gerald J. Niemi, Brian R. Sturtevant, Hannah Panci, Wayne Thogmartin, Peter Wolter

Natural Resource Ecology and Management Publications

Climate change and habitat loss are projected to be the two greatest drivers of biodiversity loss over the coming century. While public lands have the potential to increase regional resilience of bird populations to these threats, long-term data are necessary to document species responses to changes in climate and habitat to better understand population vulnerabilities. We used generalized linear mixed models to determine the importance of stand-level characteristics, multi-scale land cover, and annual weather factors to the abundance of 61 bird species over a 20-year time frame in Chippewa National Forest, Minnesota, USA. Of the 61 species modeled, we were ...


Temporal Variability Of Soil Respiration In Experimental Tree Plantations In Lowland Costa Rica, James W. Raich Jan 2017

Temporal Variability Of Soil Respiration In Experimental Tree Plantations In Lowland Costa Rica, James W. Raich

Ecology, Evolution and Organismal Biology Publications

The principal objective of this study was to determine if there is consistent temporal variability in soil respiration from different forest plantations in a lowland tropical rainforest environment. Soil respiration was measured regularly over 2004 to 2010 in replicated plantations of 15- to 20-year-old evergreen tropical trees in lowland Costa Rica. Statistically significant but small differences in soil respiration were observed among hours of the day; daytime measurements were suitable for determining mean fluxes in this study. Fluxes varied more substantially among months, with the highest average emissions (5.9 μmol·m−2·s−1) occurring in September and low ...


Interannual Water-Level Fluctuations And The Vegetation Of Prairie Potholes: Potential Impacts Of Climate Change, Arnold G. Van Der Valk, David M. Mushet Dec 2016

Interannual Water-Level Fluctuations And The Vegetation Of Prairie Potholes: Potential Impacts Of Climate Change, Arnold G. Van Der Valk, David M. Mushet

Ecology, Evolution and Organismal Biology Publications

Mean water depth and range of interannual water-level fluctuations over wet-dry cycles in precipitation are major drivers of vegetation zone formation in North American prairie potholes. We used harmonic hydrological models, which require only mean interannual water depth and amplitude of water-level fluctuations over a wet–dry cycle, to examine how the vegetation zones in a pothole would respond to small changes in water depth and/or amplitude of water-level fluctuations. Field data from wetlands in Saskatchewan, North Dakota, and South Dakota were used to parameterize harmonic models for four pothole classes. Six scenarios in which small negative or positive ...


Methane Emissions From Global Rice Fields: Magnitude, Spatiotemporal Patterns, And Environmental Controls, Bowen Zhang, Hanqin Tian, Wei Ren, Bo Tao, Chaoqun (Crystal) Lu, Jia Yang, Kamaljit Banger, Shufen Pan Aug 2016

Methane Emissions From Global Rice Fields: Magnitude, Spatiotemporal Patterns, And Environmental Controls, Bowen Zhang, Hanqin Tian, Wei Ren, Bo Tao, Chaoqun (Crystal) Lu, Jia Yang, Kamaljit Banger, Shufen Pan

Ecology, Evolution and Organismal Biology Publications

Given the importance of the potential positive feedback between methane (CH4) emissions and climate change, it is critical to accurately estimate the magnitude and spatiotemporal patterns of CH4 emissions from global rice fields and better understand the underlying determinants governing the emissions. Here we used a coupled biogeochemical model in combination with satellite‐derived contemporary inundation area to quantify the magnitude and spatiotemporal variation of CH4 emissions from global rice fields and attribute the environmental controls of CH4 emissions during 1901–2010. Our study estimated that CH4 emissions from global rice fields varied from 18.3 ± 0.1 Tg CH4 ...


The Costs Of Photorespiration To Food Production Now And In The Future, Berkley J. Walker, Andy Vanloocke, Carl J. Bernacchi, Donald R. Ort Jan 2016

The Costs Of Photorespiration To Food Production Now And In The Future, Berkley J. Walker, Andy Vanloocke, Carl J. Bernacchi, Donald R. Ort

Agronomy Publications

Photorespiration is essential for C3 plants but operates at the massive expense of fixed carbon dioxide and energy. Photorespiration is initiated when the initial enzyme of photosynthesis, ribulose-1,5-bisphosphate carboxylase/ oxygenase (Rubisco), reacts with oxygen instead of carbon dioxide and produces a toxic compound that is then recycled by photorespiration. Photorespiration can be modeled at the canopy and regional scales to determine its cost under current and future atmospheres. A regional-scale model reveals that photorespiration currently decreases US soybean and wheat yields by 36% and 20%, respectively, and a 5% decrease in the losses due to photorespiration would be worth ...


Recent Afforestation In The Iowa River And Vorskla River Basins: A Comparative Trends Analysis, Yury G. Chendev, Jason A. Hubbart, Edgar A. Terekhin, Anthony R. Lupo, Tom J. Sauer, C. Lee Burras Jan 2016

Recent Afforestation In The Iowa River And Vorskla River Basins: A Comparative Trends Analysis, Yury G. Chendev, Jason A. Hubbart, Edgar A. Terekhin, Anthony R. Lupo, Tom J. Sauer, C. Lee Burras

Agronomy Publications

Afforestation trends were compared between two continentally-distinct, yet similar ecoregions to characterize similarities or differences in forest advancement due to natural and anthropogenic forcings. Temporal changes in forest cover were analyzed using high resolution aerial and satellite photographs for Southeast Iowa, USA, and satellite photographs for the western Belgorod Oblast, Russia. An increase in forested area was shown to occur over a 44-year period from 1970–2014 in Iowa where afforestation was reflected by the aggregation of smaller forest units. In the Belgorod region the opposite occurred in that there was an increase in the number of smaller forested units ...


Farmers And Climate Change: A Cross-National Comparison Of Beliefs And Risk Perceptions In High-Income Countries, Linda S. Prokopy, J. Gordon Arbuckle, Andrew P. Barnes, V. R. Haden, Anthony Hogan, Meredith T. Niles, John Tyndall Aug 2015

Farmers And Climate Change: A Cross-National Comparison Of Beliefs And Risk Perceptions In High-Income Countries, Linda S. Prokopy, J. Gordon Arbuckle, Andrew P. Barnes, V. R. Haden, Anthony Hogan, Meredith T. Niles, John Tyndall

Sociology Publications

Climate change has serious implications for the agricultural industry—both in terms of the need to adapt to a changing climate and to modify practices to mitigate for the impacts of climate change. In high-income countries where farming tends to be very intensive and large scale, it is important to understand farmers’ beliefs and concerns about climate change in order to develop appropriate policies and communication strategies. Looking across six study sites—Scotland, Midwestern United States, California, Australia, and two locations in New Zealand—this paper finds that over half of farmers in each location believe that climate change is ...


Effects Of Climate And Plant Phenology On Recruitment Of Moose At The Southern Extent Of Their Range, Kevin L. Monteith, Robert W. Klaver, Kent R. Hersey, A. Andrew Holland, Timothy P. Thomas, Matthew J. Kauffman Aug 2015

Effects Of Climate And Plant Phenology On Recruitment Of Moose At The Southern Extent Of Their Range, Kevin L. Monteith, Robert W. Klaver, Kent R. Hersey, A. Andrew Holland, Timothy P. Thomas, Matthew J. Kauffman

Natural Resource Ecology and Management Publications

Climate plays a fundamental role in limiting the range of a species, is a key factor in the dynamics of large herbivores, and is thought to be involved in declines of moose populations in recent decades. We examined effects of climate and growing-season phenology on recruitment (8–9 months old) of young Shiras moose (Alces alces shirasi) over three decades, from 18 herds, across a large geographic area encompassing much of the southern extent of their range. Recruitment declined in 8 of 18 herds during 1980–2009, whereas others did not exhibit a temporal trend (none showed a positive trend ...


Responses Of Global Terrestrial Evapotranspiration To Climate Change And Increasing Atmospheric Co2 In The 21st Century, Shufen Pan, Hanqin Tian, Shree R. S. Dangal, Qichun Yang, Jia Yang, Chaoqun (Crystal) Lu, Bo Tao, Wei Ren, Zhiyun Ouyang Jan 2015

Responses Of Global Terrestrial Evapotranspiration To Climate Change And Increasing Atmospheric Co2 In The 21st Century, Shufen Pan, Hanqin Tian, Shree R. S. Dangal, Qichun Yang, Jia Yang, Chaoqun (Crystal) Lu, Bo Tao, Wei Ren, Zhiyun Ouyang

Chaoqun (Crystal) Lu

Quantifying the spatial and temporal patterns of the water lost to the atmosphere through land surface evapotranspiration (ET) is essential for understanding the global hydrological cycle, but remains much uncertain. In this study, we use the Dynamic Land Ecosystem Model to estimate the global terrestrial ET during 2000–2009 and project its changes in response to climate change and increasing atmospheric CO2 under two IPCC SRES scenarios (A2 and B1) during 2010–2099. Modeled results show a mean annual global terrestrial ET of about 549 (545–552) mm yr−1 during 2000–2009. Relative to the 2000s, global terrestrial ET ...


Climate-Smart Agriculture In Midwest Cropping Systems: Evaluating The Benefits And Tradeoffs Of Cover Crops, Andrea Diane Basche Jan 2015

Climate-Smart Agriculture In Midwest Cropping Systems: Evaluating The Benefits And Tradeoffs Of Cover Crops, Andrea Diane Basche

Graduate Theses and Dissertations

Climate-smart agriculture is a framework to develop and implement agricultural systems that facilitate reduced greenhouse gas emissions and increase resilience and productivity in the context of a changing climate. Winter cover crops are known to decrease soil erosion, increase soil carbon, improve water retention and have been hypothesized to reduce nitrous oxide emissions. Therefore they offer the potential to buffer projected climate change impacts for Midwestern agriculture, including increased rainfall variability. The overall objective of this dissertation research was to evaluate the mitigation and adaptation potential of cover crops in determining their efficacy as a climate-smart agricultural practice. In a ...


Accumulation Of Organic Carbon In Chernozems (Mollisols) Under Shelterbelts In Russia And The United States, Yu. G. Chendev, T. J. Sauer, A. N. Gennadiev, L. L. Novykh, A. N. Petin, V. I. Petina, E. A. Zazdravnykh, C. L. Burras Jan 2015

Accumulation Of Organic Carbon In Chernozems (Mollisols) Under Shelterbelts In Russia And The United States, Yu. G. Chendev, T. J. Sauer, A. N. Gennadiev, L. L. Novykh, A. N. Petin, V. I. Petina, E. A. Zazdravnykh, C. L. Burras

Agronomy Publications

Shelterbelts that were created in place of meadow and meadowsteppe landscapes of the forest steppe zone of northern continents serve as areas of carbon accumulation and participate in the formation of soil organic matter. In the Great Plains of the United States (in North Dakota, South Dakota, and Nebraska) and on the Central Russian Upland (Belgorod, Voronezh, and Kursk oblasts), a general tendency toward an increase in the Corg pool in the topsoil (0–30 cm) from the marginal parts of the shelterbelts toward their cen tral parts by about 3.5–10.0 t per each 10 m has ...


A Novel Ruminant Emission Measurement System: Part I. Design Evaluation And Description, Guilherme D. N. Maia, Brett C. Ramirez, Angela R. Green, Luis F. Rodríguez, Jacob R. Segers, Daniel W. Shike, Richard S. Gates Jan 2015

A Novel Ruminant Emission Measurement System: Part I. Design Evaluation And Description, Guilherme D. N. Maia, Brett C. Ramirez, Angela R. Green, Luis F. Rodríguez, Jacob R. Segers, Daniel W. Shike, Richard S. Gates

Agricultural and Biosystems Engineering Publications

Methane (CH4) generated by cattle is both a major source of greenhouse gas emissions and a powerful indicator of feed conversion efficiency; thus, accurate quantification of CH4 production is required for addressing future global food security without neglecting environmental impacts. A newly developed Ruminant Emission Measurement System (REMS) supports research on the relationships between bovine nutrition, genetics, and management strategies by measuring eructated CH4 emissions from ruminal activity. REMS is a substantial improvement and extension of the chamber technique, which is considered the standard method to quantify ruminant CH4 generation. Part I of this two-part series describes the design and ...


A Novel Ruminant Emission Measurement System: Part Ii. Commissioning, Guilherme D. N. Maia, Brett C. Ramirez, Angela R. Green, Yi Sun, Luis F. Rodríguez, Daniel W. Shike, Richard S. Gates Jan 2015

A Novel Ruminant Emission Measurement System: Part Ii. Commissioning, Guilherme D. N. Maia, Brett C. Ramirez, Angela R. Green, Yi Sun, Luis F. Rodríguez, Daniel W. Shike, Richard S. Gates

Agricultural and Biosystems Engineering Publications

The Ruminant Emission Measurement System (REMS) supports research on the relationships between bovine nutrition, genetics, and management strategies by measuring eructated CH4 emissions from ruminal activity. Part I of this series provides the description and design evaluation of the newly developed REMS using uncertainty analysis tools. Part II of this series describes REMS commissioning and documents the whole system and subsystem performance. Subsystem assessments included verification of chamber positive pressurization, thermal environmental control performance, and integrity of the gas sampling system. Integrity of the entire system was verified through a steady-state mass recovery percent (SSMRP) analysis, which compared the ...


Climate And Land Use Controls On Soil Organic Carbon In The Loess Plateau Region Of China, Yaai Dang, Wei Ren, Bo Tao, Guangsheng Chen, Chaoqun (Crystal) Lu, Jia Yang, Shufen Pan, Guodong Wang, Shiqing Li, Hanqin Tian May 2014

Climate And Land Use Controls On Soil Organic Carbon In The Loess Plateau Region Of China, Yaai Dang, Wei Ren, Bo Tao, Guangsheng Chen, Chaoqun (Crystal) Lu, Jia Yang, Shufen Pan, Guodong Wang, Shiqing Li, Hanqin Tian

Chaoqun (Crystal) Lu

The Loess Plateau of China has the highest soil erosion rate in the world where billion tons of soil is annually washed into Yellow River. In recent decades this region has experienced significant climate change and policy-driven land conversion. However, it has not yet been well investigated how these changes in climate and land use have affected soil organic carbon (SOC) storage on the Loess Plateau. By using the Dynamic Land Ecosystem Model (DLEM), we quantified the effects of climate and land use on SOC storage on the Loess Plateau in the context of multiple environmental factors during the period ...


Moving Forward In Global-Change Ecology: Capitalizing On Natural Variability, Inés Ibáñez, Elise S. Gornish, Lauren Buckley, Diane M. Debinski, Jessica Hellmann, Brian Helmuth, Janneke Hillerislambers, Andrew M. Latimer, Abraham J. Miller-Rushing, Maria Uriarte Jan 2013

Moving Forward In Global-Change Ecology: Capitalizing On Natural Variability, Inés Ibáñez, Elise S. Gornish, Lauren Buckley, Diane M. Debinski, Jessica Hellmann, Brian Helmuth, Janneke Hillerislambers, Andrew M. Latimer, Abraham J. Miller-Rushing, Maria Uriarte

Ecology, Evolution and Organismal Biology Publications

Natural resources managers are being asked to follow practices that accommodate for the impact of climate change on the ecosystems they manage, while global-ecosystems modelers aim to forecast future responses under different climate scenarios. However, the lack of scientific knowledge about short-term ecosystem responses to climate change has made it difficult to define set conservation practices or to realistically inform ecosystem models. Until recently, the main goal for ecologists was to study the composition and structure of communities and their implications for ecosystem function, but due to the probable magnitude and irreversibility of climate-change effects (species extinctions and loss of ...


Us Food Security And Climate Change: Agricultural Futures, Eugene Takle, David Gustafson, Roger Beachy, Gerald C. Nelson, Daniel Mason-D’Croz, Amanda Palazzo Jan 2013

Us Food Security And Climate Change: Agricultural Futures, Eugene Takle, David Gustafson, Roger Beachy, Gerald C. Nelson, Daniel Mason-D’Croz, Amanda Palazzo

Agronomy Publications

Agreement is developing among agricultural scientists on the emerging inability of agriculture to meet growing global food demands. Changes in trends of weather conditions projected by global climate models will challenge physiological limits of crops and exacerbate the global food challenge by 2050. These climate- and constraint-driven crop production challenges are interconnected within a complex global economy, where diverse factors add to price volatility and food scarcity. Our scenarios of the impact of climate change on food security through 2050 for internationally traded crops show that climate change does not threaten near-term US food security due to the availability of ...


Century-Scale Responses Of Ecosystem Carbon Storage And Flux To Multiple Environmental Changes In The Southern United States, Hanqin Tian, Guangsheng Chen, Chi Zang, Mingliang Liu, Ge Sun, Arthur Chappelka, Wei Ren, Xiaofeng Xu, Chaoqun Lu, Shufen Pan, Hua Chen, Dafeng Hui, Steven Mcnulty, Graeme Lockaby, Eric Vance Jun 2012

Century-Scale Responses Of Ecosystem Carbon Storage And Flux To Multiple Environmental Changes In The Southern United States, Hanqin Tian, Guangsheng Chen, Chi Zang, Mingliang Liu, Ge Sun, Arthur Chappelka, Wei Ren, Xiaofeng Xu, Chaoqun Lu, Shufen Pan, Hua Chen, Dafeng Hui, Steven Mcnulty, Graeme Lockaby, Eric Vance

Chaoqun (Crystal) Lu

Terrestrial ecosystems in the southern United States (SUS) have experienced a complex set of changes in climate, atmospheric CO2 concentration, tropospheric ozone (O3), nitrogen (N) deposition, and land-use and land-cover change (LULCC) during the past century. Although each of these factors has received attention for its alterations on ecosystem carbon (C) dynamics, their combined effects and relative contributions are still not well understood. By using the Dynamic Land Ecosystem Model (DLEM) in combination with spatially explicit, long-term historical data series on multiple environmental factors, we examined the century-scale responses of ecosystem C storage and flux to multiple environmental changes in ...


Impacts Of Tropospheric Ozone And Climate Change On Net Primary Productivity And Net Carbon Exchange Of China's Forest Ecosystems, Wei Ren, Hanqin Tian, Bo Tao, Arthur Chappelka, Ge Sun, Chaoqun (Crystal) Lu, Mingliang Liu, Guangsheng Chen, Xiaofeng Xu May 2011

Impacts Of Tropospheric Ozone And Climate Change On Net Primary Productivity And Net Carbon Exchange Of China's Forest Ecosystems, Wei Ren, Hanqin Tian, Bo Tao, Arthur Chappelka, Ge Sun, Chaoqun (Crystal) Lu, Mingliang Liu, Guangsheng Chen, Xiaofeng Xu

Chaoqun (Crystal) Lu

We investigated how ozone pollution and climate change/variability have interactively affected net primary productivity (NPP) and net carbon exchange (NCE) across China's forest ecosystem in the past half century. Using the dynamic land ecosystem model (DLEM) in conjunction with 10-km-resolution gridded historical data sets (tropospheric O3 concentrations, climate variability/change, and other environmental factors such as land-cover/land-use change (LCLUC), increasing CO2 and nitrogen deposition), we conducted nine simulation experiments to: (1) investigate the temporo-spatial patterns of NPP and NCE in China's forest ecosystems from 1961–2005; and (2) quantify the effects of tropospheric O3 pollution alone ...


A Possible Constraint On Regional Precipitation Intensity Changes Under Global Warming, W. J. Gutowski Jr., E. S. Takle, K. A. Kozak, J. C. Patton, R. W. Arritt, J. H. Christensen Dec 2007

A Possible Constraint On Regional Precipitation Intensity Changes Under Global Warming, W. J. Gutowski Jr., E. S. Takle, K. A. Kozak, J. C. Patton, R. W. Arritt, J. H. Christensen

Geological and Atmospheric Sciences Publications

Changes in daily precipitation versus intensity under a global warming scenario in two regional climate simulations of the United States show a well-recognized feature of more intense precipitation. More important, by resolving the precipitation intensity spectrum, the changes show a relatively simple pattern for nearly all regions and seasons examined whereby nearly all high-intensity daily precipitation contributes a larger fraction of the total precipitation, and nearly all low-intensity precipitation contributes a reduced fraction. The percentile separating relative decrease from relative increase occurs around the 70th percentile of cumulative precipitation, irrespective of the governing precipitation processes or which model produced the ...


Impacts Of Climate Change On Streamflow In The Upper Mississippi River Basin: A Regional Climate Model Perspective, Manoj K. Jha, Zaitao Pan, Eugene S. Takle, Roy R. Gu May 2004

Impacts Of Climate Change On Streamflow In The Upper Mississippi River Basin: A Regional Climate Model Perspective, Manoj K. Jha, Zaitao Pan, Eugene S. Takle, Roy R. Gu

Civil, Construction and Environmental Engineering Publications

Impact of climate change on streamflow in the Upper Mississippi River Basin is evaluated by use of a regional climate model (RCM) coupled with a hydrologic model, Soil and Water Assessment Tool (SWAT). The RCM we used resolves, at least partially, some fine-scale dynamical processes that are important contributors to precipitation in this region and that are not well simulated by global models. The SWAT model was calibrated and validated against measured streamflow data using observed weather data and inputs from the U.S. Environmental Protection Agency Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) geographic information systems/database ...


How Rapidly Can Maternal Behavior Affecting Primary Sex Ratio Evolve In A Reptile With Environmental Sex Determination?, Carrie L. Morjan Aug 2003

How Rapidly Can Maternal Behavior Affecting Primary Sex Ratio Evolve In A Reptile With Environmental Sex Determination?, Carrie L. Morjan

Zoology and Genetics Publications

Theoretical models identify maternal behavior as critical for the maintenance and evolution of sex ratios in organisms with environmental sex determination (ESD). Maternal choice of nest site is generally thought to respond more rapidly to sex ratio selection than environmental sensitivity of offspring sex (threshold temperatures) in reptiles with temperature‐dependent sex determination (TSD, a form of ESD). However, knowledge of the evolutionary potential for either of these traits in a field setting is limited. I developed a simulation model using local climate data and observed levels of phenotypic variation for nest‐site choice and threshold temperatures in painted turtles ...


The Impacts Of Climate Change On Stream Flow In The Upper Mississippi River Basin: A Regional Climate Model Perspective, Manoj K. Jha, Zaitao Pan, Eugene S. Takle, Roy R. Gu Jul 2003

The Impacts Of Climate Change On Stream Flow In The Upper Mississippi River Basin: A Regional Climate Model Perspective, Manoj K. Jha, Zaitao Pan, Eugene S. Takle, Roy R. Gu

CARD Working Papers

We evaluate the impact of climate change on stream flow in the Upper Mississippi River Basin (UMRB) by using a regional climate model (RCM) coupled with a hydrologic model, the Soil and Water Assessment Tool (SWAT). The SWAT model was calibrated and validated against measured stream flow data using observed weather data and inputs from the Environmental Protection Agency’s BASINS (Better Assessment Science Integrating Point and Nonpoint Sources) geographical information/database system. The combined performance of the SWAT and RCM was examined using observed weather data as a lateral boundary condition in the RCM. The SWAT and RCM were ...