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Full-Text Articles in Life Sciences

Plant Community Composition And Structure Monitoring In Scotts Bluff National Monument, 2013 Annual Report, Isabel Ashton, Michael Prowatzke Oct 2013

Plant Community Composition And Structure Monitoring In Scotts Bluff National Monument, 2013 Annual Report, Isabel Ashton, Michael Prowatzke

United States National Park Service: Publications

Introduction

During the last century, much of the prairie within the Northern Great Plains has been plowed for cropland, planted with non-natives to maximize livestock production, or otherwise developed, making it one of the most threatened ecosystems in the United States. Within Nebraska, greater than 77% of the area of native mixed grass prairie has been lost since European settlement (Samson and Knopf 1994). The National Park Service (NPS) plays an important role in preserving and restoring some of the last pieces of intact prairies within its boundaries. The stewardship goal of the NPS is to “preserve ecological integrity and …


Remote Sensing Of Green Leaf Area Index In Maize And Soybean: From Close-Range To Satellite, Anthony L. Nguy-Robertson Jul 2013

Remote Sensing Of Green Leaf Area Index In Maize And Soybean: From Close-Range To Satellite, Anthony L. Nguy-Robertson

School of Natural Resources: Dissertations, Theses, and Student Research

This dissertation seeks to explore alternative methodologies for estimating green leaf area index (LAI) and crop developmental stages. Specifically this research [1] developed an approach for creating a Moderate Resolution Imaging Spectroradiometer (MODIS) high spatial resolution product for estimating green LAI on the base of data collected using two different close-range sensors. It was determined that the vegetation indices (VIs) Wide Dynamic Range Vegetation Index (WDRVI) and Enhanced Vegetation Index 2 (EVI2) were capable of accurate estimation of green LAI from MODIS 250 m data using models developed from hyperspectral (RMSE < 0.69 m2 m-2; CV < 33%) or multispectral sensors (RMSE < 0.69 m2 m-2; …


Proximal Sensing As A Means Of Characterizing Phragmites Australis, Travis Yeik Feb 2013

Proximal Sensing As A Means Of Characterizing Phragmites Australis, Travis Yeik

Department of Geography: Dissertations, Theses, and Student Research

Phragmites australis is an invasive wetland weed found throughout much of the United States. Documenting and mapping the growth and spread of this emergent macrophyte can be an important step in developing and implementing successful management strategies. Characterizing the phenology of a vegetation species with a sensor capable of hyperspectral resolution, positioned at close proximity to the canopy of interest, is often a first step necessary for understanding the basic species-specific reflectance patterns, and for quantifying the manner in which light interacts with the plants comprising particular communities. Spectral data over a P. australis canopy were collected during 22 field …


Plant Community Composition And Structure Monitoring For Agate Fossil Beds National Monument, 2012 Annual Report, Isabel W. Ashton, Stephen K. Wilson, Daniel J. Swanson, Michael Prowatzke, Phil Graeve Jan 2013

Plant Community Composition And Structure Monitoring For Agate Fossil Beds National Monument, 2012 Annual Report, Isabel W. Ashton, Stephen K. Wilson, Daniel J. Swanson, Michael Prowatzke, Phil Graeve

United States National Park Service: Publications

Executive Summary

Agate Fossil Beds National Monument (AGFO) plays a vital role in protecting and managing some of the last remnants of native mixed-grass prairie in the region. The Northern Great Plains Inventory & Monitoring Network (NGPN) and Fire Ecology Program (FireEP) surveyed 12 long-term monitoring plots in Agate Fossil Beds National Monument in 2012 as part of an effort to better understand the condition of plant communities in the park. We measured plant diversity and cover, looked for the presence of exotic species that may be newly invading the park, and evaluated the amount of human and natural disturbance …