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Full-Text Articles in Natural Resources and Conservation

Droughtscape, Summer 2011, Kelly Smith Jul 2011

Droughtscape, Summer 2011, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

New NDMC Website

Drought May Improve in Southeast and Southwest

Impacts Summary: Fire, Crop Loss and More

International Activities

NDMC Launches Ranch Planning Tool

Serving Data to Order

Workshop Builds Drought Planning Community


The Distribution And Life Cycle Of Alliaria Petiolate In Lincoln, Nebraska, Caleb Pharris Jul 2011

The Distribution And Life Cycle Of Alliaria Petiolate In Lincoln, Nebraska, Caleb Pharris

Department of Environmental Studies: Undergraduate Student Theses

Alliaria petiolata (Garlic Mustard) is a biennial alien invasive plant species of the Brassicacea family. It is responsible for displacing native plant species throughout North America and its management has proven to be extremely difficult. Recently several populations of Alliaria petiolata have been discovered in southwestern Lincoln, Nebraska. The spread of Alliaria petiolata is a concern for natural resource managers and the general public. Due to the difficulty of its control, Alliaria petiolata is capable of creating monocultures which diminish the aesthetic value of an ecosystem. While most commonly found in the understory of hardwood forests, it is capable of …


Spatial Accuracy Of Climate Networks In Nebraska, Andrea J. Coop Jul 2011

Spatial Accuracy Of Climate Networks In Nebraska, Andrea J. Coop

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

Climate data has become increasingly scrutinized for its accuracy because of the need for reliable predictions about climate change. The U.S. has taken great strides to keep up with the demand for accurate climate data. Over the last thirty years, vast improvements to instrumentation, data collection, and station siting have created more accurate data records. This study is to explore the accuracy of existing networks. This study analyzes three climate networks used in Nebraska: the U.S. Historical Climatology Network (HCN), the Automated Weather Data Network (AWDN), and the newest network, the U.S. Climate Reference Network (CRN). Each of these networks …


Late Holocene History Of Dune Activity Along The Elkhorn River In Northeastern Nebraska, Rebecca A. Young Jul 2011

Late Holocene History Of Dune Activity Along The Elkhorn River In Northeastern Nebraska, Rebecca A. Young

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

The Nebraska Sand Hills have been an important study area for dune activation and the nature of prehistoric drought events in the Great Plains. However, little has been done to understand the impact of these droughts to smaller dune fields along the eastern margin of the Great Plains. This study focuses on the Stanton dune field which is found about 145 km east of the Sand Hills along the southern edge of the Elkhorn River valley in northeastern Nebraska. With a wetter and slightly cooler climate regime than that of the Nebraska Sand Hills and most other central Great Plains …


Detecting Spatiotemporal Changes Of Corn Developmental Stages In The U.S. Corn Belt Using Modis Wdrvi Data, Toshihiro Sakamoto, Brian D. Wardlow, Anatoly A. Gitelson Jun 2011

Detecting Spatiotemporal Changes Of Corn Developmental Stages In The U.S. Corn Belt Using Modis Wdrvi Data, Toshihiro Sakamoto, Brian D. Wardlow, Anatoly A. Gitelson

School of Natural Resources: Faculty Publications

The dates of crop developmental stages are important variables for many applications including assessment of the impact of abnormal weather on crop yield. Time-series 250-m vegetation-index (VI) data acquired from the Moderate Resolution Imaging Spectroradiometer (MODIS) provide valuable information for monitoring the spatiotemporal changes of corn growth across large geographic areas. The goal of this study is to evaluate the performance of a new crop phenology detection method, namely, two-step filtering (TSF), for revealing the spatiotemporal pattern of specific corn developmental stages (early vegetative: V2.5; silking: R1; dent: R5; mature: R6) over an eight-year period (2001–2008) across Iowa, Illinois, and …


Effects Of Species, Water, And Nitrogen On Competition Among Three Prairie Grasses, Jerry L. Weatherford, Randall W. Myster Jun 2011

Effects Of Species, Water, And Nitrogen On Competition Among Three Prairie Grasses, Jerry L. Weatherford, Randall W. Myster

The Prairie Naturalist

We conducted an experiment to investigate effects of species, water (W), and nitrogen (N) on competition among little bluestem (Schizachyrium scoparium), sideoats grama (Bouteloua curtipendula), and indiangrass (Sorghastrum nutans). All biomass parameters and the root:shoot ratio of little bluestem were reduced by the presence off 1 of 2 other species, and its shoot biomass and total biomass were both increased by addition of N. Root and shoot biomass of sideoats grama were reduced by the presence of indiangrass and its total biomass was reduced by the presence of itself, whereas its shoot biomass was increased by addition of W at …


Assessing The Role Of Conspecific Attraction In Habitat Restoration For Henslow’S Sparrows In Iowa, Jennifer A. Vogel, Rolf R. Koford, David L. Otis Jun 2011

Assessing The Role Of Conspecific Attraction In Habitat Restoration For Henslow’S Sparrows In Iowa, Jennifer A. Vogel, Rolf R. Koford, David L. Otis

The Prairie Naturalist

The presence of conspecific individuals may provide important cues about habitat quality for territorial songbirds. We tested the ability of a conspecific song playback system to attract Henslow’s sparrows to previously unoccupied restored habitat. We successfully attracted Heslow’s sparrows to 3 of 7 treatment plots using conspecific song playbacks and we found no Henslow’s sparrows in control plots. The addition of social cues using playback systems in restored grassland habitats may aid conservation efforts of Henslow’s sparrows to available habitat.


Notes: River Otters Use Agricultural Field Along The Turtle Riveri In Eastern North Dakota As Crossover And Latrine Area, Maggie D. Triska, Steven C. Loughry, Thomas L. Sergass Jun 2011

Notes: River Otters Use Agricultural Field Along The Turtle Riveri In Eastern North Dakota As Crossover And Latrine Area, Maggie D. Triska, Steven C. Loughry, Thomas L. Sergass

The Prairie Naturalist

Recently, the Nearctic river otter (Lontra canadensis) has been re-colonizing portions of eastern North Dakota. The landscape in eastern North Dakota is dominated by agricultural fields and pastures, habitats which have received little research attention related to otter habitat use. During 2008, we searched shorelines to detect otter latrines, which is a common method for determining otter presence. Generally, latrines are locations along bodies of water where otters deposit scats, urine, and glandular secretions for olfactory communication, and groom, wrestle, and play, which may mat vegetation. In the northeastern United States, inland riverine system studies have shown latrines …


Calodium Hepaticum In White-Tailed Jackrabbits In South Dakota, Dustin J. Schaible, Charles D. Dieter, Regg D. Neiger, Michael B. Hildreth Jun 2011

Calodium Hepaticum In White-Tailed Jackrabbits In South Dakota, Dustin J. Schaible, Charles D. Dieter, Regg D. Neiger, Michael B. Hildreth

The Prairie Naturalist

White-tailed jackrabbits (Lepus townsendii) are common on the prairie, and an important species in prairie food webs (Lim 1987). Although it has been suggested that jackrabbits have cyclic populations (Donoho 1972, Gross et al. 1974, Anderson and Shumar 1986), there is concern that a general downward trend exists in populations in the Northern Great Plains (Feldhamer et al. 2003). Disease incidence in white-tailed jackrabbits is poorly known (Feldhamer et al. 2003), but may be an important factor in population changes. Tularemia, a disease caused by bacteria (Francisella tularensis), occurs throughout the Northern Hemisphere and can affect many mammals including hares, …


Resource Selection By Elk At Two Spatial Scales In The Black Hills, South Dakota, Mark A. Rumble, R. Scott Gamo Jun 2011

Resource Selection By Elk At Two Spatial Scales In The Black Hills, South Dakota, Mark A. Rumble, R. Scott Gamo

The Prairie Naturalist

Understanding resource selection by elk (Cervus elaphus) at multiple spatial scales may provide information that will help resolve the increasing number of resource conflicts involving elk. We quantified vegetation at 412 sites where the precise location of elk was known by direct observation and 509 random sites in the Black Hills of South Dakota during 1998– 2001. We obtained stand level variables from geographic information system coverages for a 250 m buffer around elk and random sites. We used classification and regression trees to simultaneously evaluate environmental thresholds of resources selected by feeding and bedded elk at the site and …


Multiple Bats Entangled On Cactus, Jon C. Pigage, Richard L. Bunn Jun 2011

Multiple Bats Entangled On Cactus, Jon C. Pigage, Richard L. Bunn

The Prairie Naturalist

Accidental deaths of bats by entanglement on plants and barbed wire are common (McNicholl 1988, Norquay et al. 2010). It has been hypothesized these incidents involve miscalculations by bats on how close they fly to plants or barbed wire or when chasing insects highly concentrated around vegetation (Norquay et al. 2010). Once the bats hit the plants or barbed wire, they become entangled and or impaled while struggling to free themselves. The earliest reports involved little brown bats (Myotis lucifugus) and unidentified bats entangled on burdock, Arctium sp. (Lyon 1925, Little 1925). Additional reports of bats becoming entangled in plants …


First Record Of The Least Weasel In The Black Hills Of South Dakota, Tim R. Mullican Jun 2011

First Record Of The Least Weasel In The Black Hills Of South Dakota, Tim R. Mullican

The Prairie Naturalist

The least weasel (Mustela nivalis) is a circumboreal species, occurring in North America from Alaska to the Appalachian Mountains (Jones et al. 1983). In the Great Plains, the least weasel recently expanded its range southward through Nebraska (Benedict et al. 2000) and Kansas (Choate et al. 1979, Bailey and Terman 1986) into Oklahoma (Clark and Clark 1988). Also, in recent decades, the least weasel has expanded from eastern and central Nebraska into western Nebraska (Benedict et al. 2000). In South Dakota, least weasels have been previously reported from the eastern 3/4 of the state (Jones et al. 1983, Higgins et …


Phragmites Australis In South Dakota: Historical Distribution And Environment, Carol A. Johnston, Kayla L. Miller Jun 2011

Phragmites Australis In South Dakota: Historical Distribution And Environment, Carol A. Johnston, Kayla L. Miller

The Prairie Naturalist

Common reed, Phragmites australis, has long been a component of Northern Plains wetlands, but impending invasion by the non-native P. australis haplotype M may displace native haplotypes in the future. To increase understanding of historical Phragmites occurrence, we developed a geographic information system (GIS) protocol to improve the georeferencing of specimens from South Dakota herbaria, and mapped the distribution of Phragmites relative to geology, physiographic regions, and water bodies. There were 91 Phragmites herbarium specimens from South Dakota and adjacent Wyoming. Phragmites collections occurred in nearly all physiographic regions of the state, with concentrations occurring in the Prairie Coteau of …


Crustaceous Zooplankton Transfer Between A Floodplain Wetland And The Missouri River, Shannon J. Fisher Jun 2011

Crustaceous Zooplankton Transfer Between A Floodplain Wetland And The Missouri River, Shannon J. Fisher

The Prairie Naturalist

Floodplain interactions are a critical riverine ecosystem function, including zooplankton transfer. Floodplain alternations have had an assumed impact on zooplankton productivity. I assessed floodplain wetland and main channel densities of crustaceous zooplankton, alluding to organism transfer in the Missouri River, North Dakota. Significant t-test differences (P < 0.05) were present between backwater and channel habitat zooplankton densities in 83, 75, 83, and 50% of the sample periods for cyclopoid copepods, copepod nauplii, Daphnia spp., and Bosmina spp. respectively, suggesting the presence of uncoupled zooplankton dynamics during portions of each annual cycle. Two relationships with increased flows were found, including a biologically significant decrease (P = 0.09) of backwater copepod nauplii numbers and a significant increase (P = 0.02) in the channel density of Daphnia spp. During the highest flow periods, fewer significant differences in zooplankton densities were present between the backwater and channel habitats, indicating moderate homogenization.


Habitat Selection By Female Swift Foxes (Vulpes Velox) During The Pup- Rearing Season, Indrani Sasmal, Jonathan A. Jenks, Troy W. Grovenburg, Shubham Datta, Greg. M. Schroeder, Robert W. Klaver, Kevin M. Honness Jun 2011

Habitat Selection By Female Swift Foxes (Vulpes Velox) During The Pup- Rearing Season, Indrani Sasmal, Jonathan A. Jenks, Troy W. Grovenburg, Shubham Datta, Greg. M. Schroeder, Robert W. Klaver, Kevin M. Honness

The Prairie Naturalist

The swift fox (Vulpes velox) was historically distributed in western South Dakota including the region surrounding Badlands National Park (BNP). The species declined during the mid-1800s, largely due to habitat loss and poisoning targeted at wolves (Canis lupis) and coyotes (C. latrans). Only a small population of swift foxes near Ardmore, South Dakota persisted. In 2003, an introduction program was initiated at BNP with swift foxes translocated from Colorado and Wyoming. We report on habitat use by female swift foxes during the pup-rearing season (May–July) in 2009. Analyses of location data from 13 radiomarked female foxes indicated disproportional use (P < 0.001) of some habitats relative to their availability within swift fox home ranges. Swift foxes used grassland (ŵ = 1.01), sparse vegetation (ŵ = 1.43) and prairie dog towns (ŵ = 1.18) in proportion to their availability, whereas they were less likely to use woodland (ŵ = 0.00), shrubland (ŵ = 0.14), pasture/agricultural-land (ŵ = 0.25) and development (ŵ = 0.16) relative to availability. Swift foxes typically are located in habitats that provide greater visibility, such as shortgrass prairie and areas with sparse vegetation; which allow detection of approaching coyotes (e.g., primary predator of swift foxes).


Distribution Of Crayfish Species In Select North Dakota Streams, Cari-Ann Hayer, Terrance L. Velazquez, Mclain S. Johnson, Brian Graeb Jun 2011

Distribution Of Crayfish Species In Select North Dakota Streams, Cari-Ann Hayer, Terrance L. Velazquez, Mclain S. Johnson, Brian Graeb

The Prairie Naturalist

Crayfish have an integral role in aquatic ecosystems, serving as herbivores, predators, detritivores, and prey for fishes and other aquatic and terrestrial animals (Momot 1995, Taylor et al. 1996, Martin 1997). Many crayfish populations are currently declining as a result of habitat alteration (Taylor et al. 1996) and invasive predators (e.g., rusty crayfish Orconectes rusticus [Girard; Lodge et al. 2000]). Knowledge of crayfish distribution and biology in North America and specifically North Dakota is sparse or lacking (Taylor et al. 1996) and baseline information is necessary to identify effects of anthropogenic alterations. Early inventories documented 3 crayfish species in North …


The Green, Blue And Grey Water Footprint Of Crops And Derived Crop Products, Mesfin Mekonnen, Arjen Y. Hoekstra May 2011

The Green, Blue And Grey Water Footprint Of Crops And Derived Crop Products, Mesfin Mekonnen, Arjen Y. Hoekstra

Daugherty Water for Food Global Institute: Faculty Publications

Abstract. This study quantifies the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996–2005. The assessment improves upon earlier research by taking a high-resolution approach, estimating the water footprint of 126 crops at a 5 by 5 arc minute grid. We have used a grid-based dynamic water balance model to calculate crop water use over time, with a time step of one day. The model takes into account the daily soil water balance and climatic conditions for each grid cell. In addition, the water pollution associated with the use of nitrogen …


Sensitivity To Foliar Anthocyanin Content Of Vegetation Indices Using Green Reflectance, Andrés Viña, Anatoly A. Gitelson May 2011

Sensitivity To Foliar Anthocyanin Content Of Vegetation Indices Using Green Reflectance, Andrés Viña, Anatoly A. Gitelson

School of Natural Resources: Faculty Publications

Anthocyanins are nonphotosynthetic water-soluble pigments associated with the resistance of plants to environmental stresses such as drought, low soil nutrients, high radiation, herbivores, and pathogens. Information on the absolute and relative amounts of anthocyanins allows evaluating the physiological conditions of plants and their responses to stress and has the potential for evaluating plant species diversity across broad geographic regions. As anthocyanins absorb radiation in the green region of the electromagnetic spectrum (with a peak of absorption at around 540–560 nm), broadband vegetation indices that use this spectral region in their formulation will exhibit sensitivity to their presence. In this letter, …


National Water Footprint Accounts: The Green, Blue And Grey Water Footprint Of Production And Consumption. Volume 1: Main Report, Mesfin Mekonnen, Arjen Y. Hoekstra May 2011

National Water Footprint Accounts: The Green, Blue And Grey Water Footprint Of Production And Consumption. Volume 1: Main Report, Mesfin Mekonnen, Arjen Y. Hoekstra

Daugherty Water for Food Global Institute: Faculty Publications

This study quantifies and maps the water footprints of nations from both a production and consumption perspective and estimates international virtual water flows and national and global water savings as a result of trade. The entire estimate includes a breakdown of water footprints, virtual water flows and water savings into their green, blue and grey components. The main finding of the study can be summarized as:

The global water footprint in the period 1996-2005 was 9087 Gm3/yr (74% green, 11% blue, 15% grey). Agricultural production contributes 92% to this total footprint.

About one fifth of the global water footprint relates …


Vadose Zone Mapping Using Geographic Information Systems And Geostatistics, Ruopu Li, Lin Zhao May 2011

Vadose Zone Mapping Using Geographic Information Systems And Geostatistics, Ruopu Li, Lin Zhao

School of Natural Resources: Faculty Publications

Characteristics of the vadose zone media are important for assessing contamination potentials for projects such as landfill siting and planning. However, accurate vadose zone maps at the regional scale are often not available. This study successfully mapped low-permeable components of the vadose zone across the Elkhorn River Basin, Nebraska, using geographic information systems (GIS), groundwater level data, and a test hole database. The map has the potential to land use planners for searching and planning landfill sites.


National Water Footprint Accounts: The Green, Blue And Grey Water Footprint Of Production And Consumption, Volume 2: Appendices, Mesfin Mekonnen, Arjen Y. Hoekstra May 2011

National Water Footprint Accounts: The Green, Blue And Grey Water Footprint Of Production And Consumption, Volume 2: Appendices, Mesfin Mekonnen, Arjen Y. Hoekstra

Daugherty Water for Food Global Institute: Faculty Publications

Contents

Appendix I. The water footprint of national production (Mm3/yr)

Appendix II. Virtual-water flows related to trade in crop, animal and industrial products, per country (Mm3/yr)

Appendix III. International virtual-water flows per product category (Mm3/yr)

Appendix IV. National water saving related to trade in agricultural and industrial products per country (Mm3/yr)

Appendix V. Global water saving related to trade in agricultural and industrial products, per product (Mm3/yr)

Appendix VI. The average water footprint per ton of commodity per country, weighted based on origin (WF* in m3/ton)

Appendix VII. …


A Watershed-Scale Assessment Of A Process Soil Co2 Production And Efflux Model, Diego Andrés Riveros-Iregui, Brian L. Mcglynn, Lucy A. Marshall, Daniel L. Welsch, Ryan E. Emmanuel, Howard E. Epstein May 2011

A Watershed-Scale Assessment Of A Process Soil Co2 Production And Efflux Model, Diego Andrés Riveros-Iregui, Brian L. Mcglynn, Lucy A. Marshall, Daniel L. Welsch, Ryan E. Emmanuel, Howard E. Epstein

School of Natural Resources: Faculty Publications

Growing season soil CO2 efflux is known to vary laterally by as much as seven fold within small subalpine watersheds (<5 >km2), and such degree of variability has been strongly related to the landscape-imposed redistribution of soil water. Current empirical or process models offer low potential to simulate this variability or to simulate watershed-scale dynamics of soil CO2 efflux. We modified an existing process soil CO2 production and efflux model to include spatially variable soil moisture, and applied it to a well-studied and moderately complex watershed of the northern Rocky Mountains. We started at the …


Ecotourism In Costa Rica: Environmental Impacts And Management, Emily Mckeone May 2011

Ecotourism In Costa Rica: Environmental Impacts And Management, Emily Mckeone

Department of Environmental Studies: Undergraduate Student Theses

Globally we are witnessing growing environmental destruction, particularly to the natural resource bases of underdeveloped countries. If ecotourism can generate profits for local economies, while protecting and conserving the natural resource base of that community, it could be a strong alternative for numerous countries. Evidence suggests that the ecotourism industry has been expanding at a rapid rate in recent decades (Dasenbrock 2002). It is important to understand the positive and negative ecological impacts of the industry as this rapid growth rate continues.

The main objective of this study is to highlight the strengths and weaknesses of the ecotourism industry in …


21rst Century Educational Farmstead, Trevis Carmichael May 2011

21rst Century Educational Farmstead, Trevis Carmichael

Department of Environmental Studies: Undergraduate Student Theses

When Europeans began settling in the United States, farmsteads were built across the Great Plains. Out of necessity, these had to function in a self-sufficient manner; meaning the people had to produce their own food, use local materials, and be energy efficient for their transportation. Parents had to teach their children how to do all of the practical work it took to maintain their lives. This was the foundation that America was built upon. Having completed the first decade of the 21st century, the time seems right for a mental re-settlement that follows some of those same principles. Teaching our …


Educating Young Adults About Sustainable Development, Meghan Lewis May 2011

Educating Young Adults About Sustainable Development, Meghan Lewis

Department of Environmental Studies: Undergraduate Student Theses

This qualitative study on the types of environmental education on different age groups was conducted in Lincoln, Nebraska. The purpose of this thesis is to identify what age group and educational methods would be most effective to educate Lincoln citizens on the importance and benefits of sustainable development. Environmental education is an important aspect in implementation of new, environmentally friendly ideas.

Lincoln environmentalists are working to improve the city’s sustainability. Finding a way to consistently educate Lincoln residents on the importance and benefits of sustainable development will increase the public’s awareness of their efforts, leading to a greater interest in …


Benthic Macroinvertebrate Response To The Restoration Of A Hypereutrophic Midwestern Reservoir, Jennifer L. Swanson May 2011

Benthic Macroinvertebrate Response To The Restoration Of A Hypereutrophic Midwestern Reservoir, Jennifer L. Swanson

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

Eutrophication has been the most challenging global threat to the quality of our freshwater resources (Likens, 2010). Reversing the effects of eutrophication can be difficult and takes a great deal of time and money. A hypereutrophic Midwestern reservoir underwent a restoration from 2000-2002, which added a sediment basin at the inlet, three islands, five rock jetties, and the removal of rough fish. The primary objective of this study was to determine changes in the benthic macroinvertebrate community in response to the restoration. Water quality and benthic macroinvertebrate samples were collected once per month in June, July, August, and September in …


Natural Selection And Age-Related Variation In Morphology Of A Colonial Bird, Mary Bomberger Brown May 2011

Natural Selection And Age-Related Variation In Morphology Of A Colonial Bird, Mary Bomberger Brown

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

In May 1996, inclement weather led to the deaths of thousands of Cliff Swallows (Petrochelidon pyrrhonota) in Nebraska. Survivors had larger skeletons, shorter wings and tails, and less wing asymmetry than non-survivors. This population was followed for 10 years to study 1) whether natural selection events result in permanent microevolutionary changes, 2) if variation in climate affects the development of morphological traits, and 3) if morphological traits vary systematically with age.

Patterns in morphology exhibited by swallows following the selection event were studied by measuring yearling birds. Wing and middle tail lengths decreased, beak length and width increased, …


A Mark–Recapture Technique For Monitoring Feral Swine Populations, Matthew M. Reidy, Tyler A. Campbell, David G. Hewitt May 2011

A Mark–Recapture Technique For Monitoring Feral Swine Populations, Matthew M. Reidy, Tyler A. Campbell, David G. Hewitt

United States Department of Agriculture Wildlife Services: Staff Publications

Techniques to monitor populations of feral swine (Sus scrofa) relative to damage control activities are needed on rangelands. Our objectives were to describe and assess a mark–recapture technique using tetracycline hydrochloride (TH) for monitoring feral swine populations. We established bait stations at study sites in southern and central Texas. During 1 d, we replaced normal soured corn bait with bait containing TH and counted the number of feral swine that consumed bait with observers. We conducted feral swine removal using box-style traps and helicopters, at which time we collected teeth for TH analysis. In southern Texas, we estimated …


Quantifying Evapotranspiration And Water Table Interactions In Regions Of Shallow Groundwater: Sensitivity To Soil Properties, Vegetation, And Climate Variability, Mehmet E. Soylu May 2011

Quantifying Evapotranspiration And Water Table Interactions In Regions Of Shallow Groundwater: Sensitivity To Soil Properties, Vegetation, And Climate Variability, Mehmet E. Soylu

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

Evapotranspiration (ET) is an important component of the water and energy balance, yet it is also one of the most challenging components to estimate. There has been great effort to understand the nature of controlling mechanisms and interactions between ET and other earth system processes. The controlling factors of ET can be grouped into two broad categories – namely moisture availability and energy availability (e.g., solar radiation). Soil moisture is a key factor that most of the land surface hydrologic processes are dependent on. While plant water use is mainly controlled by radiation, temperature is another key factor for ET …


Assessing Seasonal Features Of Tropical Forests Using Remote Sensing, Roberto Bonifaz-Alfonzo May 2011

Assessing Seasonal Features Of Tropical Forests Using Remote Sensing, Roberto Bonifaz-Alfonzo

Department of Geography: Dissertations, Theses, and Student Research

Tropical forests are key components of the biogeochemical cycles, complex in structure, diversity and dynamics, also, tropical regions have been deforested and modified by human activities particularly for agriculture. Understanding the inter-annual and intra-annual variation dynamics of tropical regions could give valuable information on temporal characteristics of ecosystems behavior which is important for mapping and monitoring. This dissertation assesses seasonal and inter-annual changes in the tropical land cover that may be related to changes in the natural environment and/or human activities. Research was focused on the Mayan forest located in southern Mexico and Northwest Guatemala, one of the northern-most important …