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Articles 1 - 11 of 11
Full-Text Articles in Physical Sciences and Mathematics
Arima-Based Forecasting Of The Effects Of Wildfire On The Increasing Tree Cover Trend And Recurrence Interval Of Woody Encroachment In Grazing Land, Mazbahul Ahamad
Arima-Based Forecasting Of The Effects Of Wildfire On The Increasing Tree Cover Trend And Recurrence Interval Of Woody Encroachment In Grazing Land, Mazbahul Ahamad
School of Natural Resources: Faculty Publications
Invasive tree removal from grazing lands using costly brush management practices is widely employed. However, wildfire-like natural events can prevent the increasing trend of woody tree encroachment in grazing lands at no cost, instead of cost-oriented prescribed burning. This study aims to estimate the effects of wildfire in 2002 on woody tree encroachment trends during the post-wildfire period (2003–20), as well as the recurrence interval of the encroachment of a wildfire site in the United States. An autoregressive integrated moving average (ARIMA) model was employed to forecast the tree cover during the post-wildfire period. We found that the pre-wildfire tree …
Coupling Spectral And Resource-Use Complementarity In Experimental Grassland And Forest Communites, A. K. Schweiger, J. Cavender-Bares, P. Townsend, M. Madritch, J. Grossman, H. Gholizadeh, R. Wang, J. Gamon
Coupling Spectral And Resource-Use Complementarity In Experimental Grassland And Forest Communites, A. K. Schweiger, J. Cavender-Bares, P. Townsend, M. Madritch, J. Grossman, H. Gholizadeh, R. Wang, J. Gamon
School of Natural Resources: Faculty Publications
No abstract provided.
Remotely Detected Plant Function In Two Midwestern Prairie Grassland Experiments Reveals Belowground Processes, J. Cavender-Bares, A. Schweiger, J. Gamon, H. Gholizadeh, K. Helzer, C. Lapadat, M. Madritch, P. Townsend, Z. Wang, S. Hobbie
Remotely Detected Plant Function In Two Midwestern Prairie Grassland Experiments Reveals Belowground Processes, J. Cavender-Bares, A. Schweiger, J. Gamon, H. Gholizadeh, K. Helzer, C. Lapadat, M. Madritch, P. Townsend, Z. Wang, S. Hobbie
School of Natural Resources: Faculty Publications
No abstract provided.
Monitoring Grassland Seasonal Carbon Dynamics, By Integrating Modis Ndvi, Proximal Optical Sampling, And Eddy Covariance Measurements, Enrica Nestola, Carlo Calfapietra, Craig A. Emmerton, Christopher Y. S. Wong, Donnette R. Thayer, John A. Gamon
Monitoring Grassland Seasonal Carbon Dynamics, By Integrating Modis Ndvi, Proximal Optical Sampling, And Eddy Covariance Measurements, Enrica Nestola, Carlo Calfapietra, Craig A. Emmerton, Christopher Y. S. Wong, Donnette R. Thayer, John A. Gamon
School of Natural Resources: Faculty Publications
This study evaluated the seasonal productivity of a prairie grassland (Mattheis Ranch, in Alberta, Canada) using a combination of remote sensing, eddy covariance, and field sampling collected in 2012–2013. A primary objective was to evaluate different ways of parameterizing the light-use efficiency (LUE) model for assessing net ecosystem fluxes at two sites with contrasting productivity. Three variations on the NDVI (Normalized Difference Vegetation Index), differing by formula and footprint, were derived: (1) a narrow-band NDVI (NDVI680,800, derived from mobile field spectrometer readings); (2) a broad-band proxy NDVI (derived from an automated optical phenology station consisting of broad-band radiometers); and (3) …
Integrated Analysis Of Productivity And Biodiversity In A Southern Alberta Prairie, Ran Wang, John A. Gamon, Craig A. Emmerton, Haitao Li, Enrica Nestola, Gilberto Z. Pastorello, Olaf Menzer
Integrated Analysis Of Productivity And Biodiversity In A Southern Alberta Prairie, Ran Wang, John A. Gamon, Craig A. Emmerton, Haitao Li, Enrica Nestola, Gilberto Z. Pastorello, Olaf Menzer
School of Natural Resources: Faculty Publications
Grasslands play important roles in ecosystem production and support a large farming and grazing industry. An accurate and efficient way is needed to estimate grassland health and production for monitoring and adjusting management to get sustainable products and other ecosystem services. Previous studies of grasslands have shown varying relationships between productivity and biodiversity, with most showing either a positive or a hump-shaped relationship where productivity peaks at intermediate diversity. In this study, we used airborne imaging spectrometry combined with ground sampling and eddy covariance measurements to estimate the spatial pattern of production and biodiversity for two sites of contrasting productivity …
Seasonal Variation In The Ndvi–Species Richness Relationship In A Prairie Grassland Experiment (Cedar Creek), Ran Wang, John A. Gamon, Rebecca A. Montgomery, Philip A. Townsend, Arthur I. Zygielbaum, Keren Bitan, David Tilman, Jeannine Cavender-Bares
Seasonal Variation In The Ndvi–Species Richness Relationship In A Prairie Grassland Experiment (Cedar Creek), Ran Wang, John A. Gamon, Rebecca A. Montgomery, Philip A. Townsend, Arthur I. Zygielbaum, Keren Bitan, David Tilman, Jeannine Cavender-Bares
School of Natural Resources: Faculty Publications
Species richness generally promotes ecosystem productivity, although the shape of the relationship varies and remains the subject of debate. One reason for this uncertainty lies in the multitude of methodological approaches to sampling biodiversity and productivity, some of which can be subjective. Remote sensing offers new, objective ways of assessing productivity and biodiversity. In this study, we tested the species richness–productivity relationship using a common remote sensing index, the Normalized Difference Vegetation Index (NDVI), as a measure of productivity in experimental prairie grassland plots (Cedar Creek). Our study spanned a growing season (May to October, 2014) to evaluate dynamic changes …
Linking Flux Network Measurements To Continental Scale Simulations: Ecosystem Carbon Dioxide Exchange Capacity Under Non-Water-Stressed Conditions, Katherine B. Owen, John Tenhunen, Markus Reichstein, Quan Wang, Eva Falge, Ralf Geyer, Xiangming Xiaos, Paul Stoy, Christof Ammann, Altaf Arain, Marc Aubinet, Mika Aurela, Christian Bernhofer, Bogdan Chojnicki, Andre Granier, Thomas Gruenwald, Julian Hadley, Bernard Heinesch, David Hollinger, Alexander Knohl, Werner Kutsch, Annalea Lohila, Tilden Meyers, Eddy Moors, Christine Moureaux, Kim Pilegaard, Nobuko Saigusa, Shashi Verma, Timo Vesala, Chris Vogel
Linking Flux Network Measurements To Continental Scale Simulations: Ecosystem Carbon Dioxide Exchange Capacity Under Non-Water-Stressed Conditions, Katherine B. Owen, John Tenhunen, Markus Reichstein, Quan Wang, Eva Falge, Ralf Geyer, Xiangming Xiaos, Paul Stoy, Christof Ammann, Altaf Arain, Marc Aubinet, Mika Aurela, Christian Bernhofer, Bogdan Chojnicki, Andre Granier, Thomas Gruenwald, Julian Hadley, Bernard Heinesch, David Hollinger, Alexander Knohl, Werner Kutsch, Annalea Lohila, Tilden Meyers, Eddy Moors, Christine Moureaux, Kim Pilegaard, Nobuko Saigusa, Shashi Verma, Timo Vesala, Chris Vogel
School of Natural Resources: Faculty Publications
This paper examines long-term eddy covariance data from 18 European and 17 North American and Asian forest, wetland, tundra, grassland, and cropland sites under nonwater- stressed conditions with an empirical rectangular hyperbolic light response model and a single layer two light-class carboxylase-based model. Relationships according to ecosystem functional type are demonstrated between empirical and physiological parameters, suggesting linkages between easily estimated parameters and those with greater potential for process interpretation. Relatively sparse documentation of leaf area index dynamics at flux tower sites is found to be a major difficulty in model inversion and flux interpretation. Therefore, a simplification of the …
Climate Variability Has A Stabilizing Effect On The Coexistence Of Prairie Grasses, Peter B. Adler, Janneke Hille Ris Lambers, Phaedon C. Kyriakidis, Qingfeng Guan, Jonathan M. Levine
Climate Variability Has A Stabilizing Effect On The Coexistence Of Prairie Grasses, Peter B. Adler, Janneke Hille Ris Lambers, Phaedon C. Kyriakidis, Qingfeng Guan, Jonathan M. Levine
School of Natural Resources: Faculty Publications
How expected increases in climate variability will affect species diversity depends on the role of such variability in regulating the coexistence of competing species. Despite theory linking temporal environmental fluctuations with the maintenance of diversity, the importance of climate variability for stabilizing coexistence remains unknown because of a lack of appropriate long-term observations. Here, we analyze three decades of demographic data from a Kansas prairie to demonstrate that interannual climate variability promotes the coexistence of three common grass species. Specifically, we show that (i) the dynamics of the three species satisfy all requirements of ‘‘storage effect’’ theory based on recruitment …
The Relative Importance Of Patch Area And Perimeter–Area Ratio To Grassland Breeding Birds, Christopher J. Helzer, Dennis E. Jelinski
The Relative Importance Of Patch Area And Perimeter–Area Ratio To Grassland Breeding Birds, Christopher J. Helzer, Dennis E. Jelinski
School of Natural Resources: Faculty Publications
Habitat fragmentation has been implicated as a major cause of population decline in grassland birds. We tested the hypothesis that a combination of area and shape determines the use of grassland patches by breeding birds. We compared both species richness and individual species presence in 45 wet meadow grasslands in the floodplain of the central Platte River, Nebraska. Bird data were collected through the use of belt transects and supplemented by walking and listening outside transects. Our data supported our primary hypothesis that perimeter–area ratio, which reflects both the area and shape of a patch, is the strongest predictor of …
Modeling Canopy Stomatal Conductance In A Temperate Grassland Ecosystem, Joon Kim, Shashi B. Verma
Modeling Canopy Stomatal Conductance In A Temperate Grassland Ecosystem, Joon Kim, Shashi B. Verma
School of Natural Resources: Faculty Publications
No abstract provided.
Modeling Canopy Photosynthesis: Scaling Up From A Leaf To Canopy In A Temperate Grassland Ecosystem, S. B. Verma
Modeling Canopy Photosynthesis: Scaling Up From A Leaf To Canopy In A Temperate Grassland Ecosystem, S. B. Verma
School of Natural Resources: Faculty Publications
No abstract provided.