Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
Ecophysio-Optical Traits Of Semiarid Nebraska Grasslands Under Different Juniperus Virginiana And Pinus Ponderosa Canopy Covers, Anastasios Mazis, Julie A. Fowler, Jeremy Hiller, Yuzhen Zhou, Brian Wardlow, David A. Wedin, Tala Awada
Ecophysio-Optical Traits Of Semiarid Nebraska Grasslands Under Different Juniperus Virginiana And Pinus Ponderosa Canopy Covers, Anastasios Mazis, Julie A. Fowler, Jeremy Hiller, Yuzhen Zhou, Brian Wardlow, David A. Wedin, Tala Awada
School of Natural Resources: Faculty Publications
Despite conservation efforts in the U.S. Great Plains, woody species have continued to expand at an unprecedented rate, threatening key ecosystem services and resilience. Cross-scale monitoring of these grasslands is key to successful integrative management strategies. In this study we measured plant optical traits derived from hyperspectral proximal sensing techniques with a field spectrometer, coupled with field-based measurements, including fluorescence and chlorophyll content, to determine the impacts of Juniperus virginiana and Pinus ponderosa expansion on grasslands health in Nebraska Sandhills, and investigated the use of optical-based approaches as indicators of successful monitoring of grasslands. Our results showed that higher woody …
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 …
Interannual Variability In Dry Mixed-Grass Prairie Yield: A Comparison Of Modis, Spot, And Field Measurements, Donald C. Wehlage, John A. Gamon, Donnette Thayer, David V. Hildebrand
Interannual Variability In Dry Mixed-Grass Prairie Yield: A Comparison Of Modis, Spot, And Field Measurements, Donald C. Wehlage, John A. Gamon, Donnette Thayer, David V. Hildebrand
School of Natural Resources: Faculty Publications
Remote sensing is often used to assess rangeland condition and biophysical parameters across large areas. In particular, the relationship between the Normalized Difference Vegetation Index (NDVI) and above-ground biomass can be used to assess rangeland primary productivity (seasonal carbon gain or above-ground biomass “yield”). We evaluated the NDVI–yield relationship for a southern Alberta prairie rangeland, using seasonal trends in NDVI and biomass during the 2009 and 2010 growing seasons, two years with contrasting rainfall regimes. The study compared harvested biomass and NDVI from field spectrometry to NDVI from three satellite platforms: the Aqua and Terra Moderate Resolution Imaging Spectroradiometer (MODIS) …
Do Species And Functional Groups Differ In Acquisition And Use Of C, N And Water Under Varying Atmospheric Co2 And N Availability Regimes? A Field Test With 16 Grassland Species, Peter B. Reich, David Tilman, Joseph Craine, David Ellsworth, Mark G. Tjoelker, Johannes M. H. Knops, David A. Wedin, Shahid Naeem, Dan Bahauddin, Jenny Goth, Wendy Bengtson, Tali D. Lee
Do Species And Functional Groups Differ In Acquisition And Use Of C, N And Water Under Varying Atmospheric Co2 And N Availability Regimes? A Field Test With 16 Grassland Species, Peter B. Reich, David Tilman, Joseph Craine, David Ellsworth, Mark G. Tjoelker, Johannes M. H. Knops, David A. Wedin, Shahid Naeem, Dan Bahauddin, Jenny Goth, Wendy Bengtson, Tali D. Lee
School of Natural Resources: Faculty Publications
Summary:
• To evaluate whether functional groups have a similar response to global change, the responses to CO2 concentration and N availability of grassland species from several functional groups are reported here.
• Sixteen perennial grassland species from four trait-based functional groups (C3 grasses, C4 grasses, non-leguminous forbs, legumes) were grown in field mono-cultures under ambient or elevated (560 μmol mol-1) CO2using free-air CO2enrichment (FACE), in low N (unamended field soil) or high N (field soil + 4 g N m-2 years-1) treatments.
• There were no CO …