Browsing by Author "Dr. Heather Cheshire, Committee Member"

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Effects of Land Use and Land Cover on Freshwater Mussel Populations in the Upper Neuse River Basin, NC: A GIS Approach
(2002-12-03) Andersen, Elizabeth F.; Dr. Hugh Devine, Committee Chair; Dr. Jay Levine, Committee Member; Dr. Heather Cheshire, Committee Member
Land use practices can adversely affect water quality and freshwater mussel populations. Water quality can become degraded by siltation from development, pesticides and nutrients from agricultural fields, heavy metals and other toxins from urban runoff. The relationship between land use/land cover and freshwater mussel populations was investigated in the upper Neuse River basin in North Carolina. Mussel surveys were conducted from April to August of 2001 in the Eno, Flat, Smith, New Light, and Little River watersheds. Surveys (n=44) were conducted along 300-m transects upstream and downstream of bridges to examine the effect of bridge crossing structures on mussel assemblages. Geographic Information Systems (GIS) hydrological modeling tools were used to delineate upstream catchments of each sample site and to determine drainage areas. GIS was used to quantify land use/land cover within multiple spatial areas: upstream catchment, upstream riparian buffers (100 m and 250 m widths), and local riparian buffers (100 m and 250 m widths) immediate to the sample sites. Other environmental variables included stream slope, road density, water chemistry, and habitat quality assessment scores. No significant differences (p< .05) between mean mussel abundances due to location (upstream or downstream), distance from the bridge, or their interaction were observed in a split plot block design analysis. However, a slight decline in abundance was observed within the first 50 m downstream of the bridge. Future studies in additional subbasins of the Neuse and/or in other river basins could show a significant decline. Detrended Correspondence Analysis (DCA) and Nonmetric Multidimensional Scaling (NMS) ordinations described some of the variation in the mussel community structure (67% and 46% total variation respectfully). Both of the ordinations yielded similar community structures and environmental gradients. Moderate associations (r>.5) were observed between DCA and NMS axis 1 and several environmental factors including drainage area, localized urban regions, and habitat scores. Strophitus undulatus (Creeper) and Pyganodon cataracta (Eastern Floater) were the most strongly associated species with ordination axis 1 and occurred in sites characterized by small drainage areas, small habitat quality assessment scores, and low percentages of urban land cover immediate to the site. A GIS-based proximity analysis examined the relationship between mussel populations and distance to the nearest land cover type (urban, forest, row crop agriculture and non-row crop agriculture). Linear regressions revealed significant relationships (p<.05) between mussel assemblages and non-row crop agriculture (r², = .11) and urban land uses (r², = .11), but accounted for only 11% of the total variability in each case. Further investigation is needed to determine the environmental factors that contribute to mussel community structure. The study sampling design selected for highly forested areas. Inclusion of more urbanized regions could yield very different results. The upper Neuse study area was characterized by high mussel abundance and species richness and could be compared to other subbasins in the Neuse or other watershed in future studies. Repeat visitation to the sample sites could also investigate temporal and seasonal variations in mussel populations.
Modeling the Diameter Distribution in Juvenile Loblolly Pine (Pinus taeda L.) from Diverse Genetic Provenances under Deficient and Optimum Nutrition Regimes.
(2007-12-07) Smith, Benjamin Christian; Dr. Bronson Bullock, Committee Chair; Dr. Steven McKeand, Committee Member; Dr. Heather Cheshire, Committee Member
The ability to predict diameter distributions is an important tool for the forest manager. By accurately predicting the diameter distribution, the manager may make better-informed decisions regarding the silvicultural treatments for a stand, such as when and how to conduct a thinning operation. This study compares the suitability of the gamma, lognormal, and two-parameter Weibull distributions for modeling diameter distributions in juvenile loblolly pine from ages 5 to 11. Using the most appropriate distribution as determined by the Anderson-Darling goodness-of-fit statistic, the two-parameter Weibull distribution, the study also determines the most suitable method for estimating distributional parameters from stand level characteristics such as mean basal area, relative spacing, quadratic mean diameter, and age. The methods tested were a parameter prediction method (PPM), a parameter recovery method (PRM), and a percentiles-based method (PCT). Comparisons were made from ages 5 to 10 using a modification of the Reynold's error index, weighted by basal area. Final parameter estimation equations were developed from data from ages 5 to 11. The parameter recovery method of parameter estimation proved to be most appropriate for modeling these data. Although the PPM had a slightly lower Reynold's error index than the PRM, the shape parameter was predicted within a very narrow range about the mean, while the distribution of shape parameters recovered by the PRM was much closer to the empirical distribution. In addition, the PRM required fewer inputs into the model, and as such was more desirable for modeling purposes. An application is presented to demonstrate the construction of stand tables from the output parameters. A second study examined the relationships among the maximum likelihood fitted parameters of the two-parameter Weibull distribution and the treatment effects due to fertilization, genetic provenances, and open-pollinated genetic families. Both the scale and shape parameters differed significantly between the non-fertilized control treatment and the optimally fertilized treatment. Further research utilizing the three-parameter Weibull might lead to significant differences among the location parameter instead of the scale and shape parameters. No significant differences were observed in the shape parameters between genetic provenances, but significant differences did exist in the younger ages between provenances in the scale parameters. Family means tended to increase over time for the scale parameter, and family mean rankings were relatively stable within and across fertilization treatments. The shape parameter family mean rankings were less stable over time, with the means tending to increase in the non-fertilized treatment and decrease in the fertilized treatment, reflecting the differences in stand development. As stand development progressed, year to year rank changes were minor, but less stable family mean rankings over time were observed.
Movement, Activity, and Habitat Use of Adult Male White-tailed Deer at Chesapeake Farms, Maryland
(2007-07-29) Tomberlin, James Weatherman; Dr. Richard Lancia, Committee Chair; Dr. Mark Conner, Committee Member; Dr. Chris DePerno, Committee Member; Dr. Heather Cheshire, Committee Member
Despite extensive research on white-tailed deer (Odocoileus virginianus) specific research on the impacts of seasonal changes and climatic factors on movement, activity, and habitat use of adult males managed under a Quality Deer Management (QDM) philosophy is lacking. This research focused on movement, activity, and habitat use of adult male white-tailed deer on a privately owned 1,330-ha agricultural/wildlife research farm under QDM since 1994. Eighteen adult males were fitted with global positioning system (GPS) radio telemetry collars that provided detailed data of movement, activity, and habitat use in relation to seasonal changes and climatic factors. I looked for changes in seasonal patterns of adult males during four 3-week intervals between September and December. Seasonal changes focused primarily on pre-breed, breed, and post-breed periods predetermined by fawning data. Impacts of climatic factors focused on precipitation, barometric pressure, temperature, and lunar cycles and were analyzed using multiple regression (PROC MIXED, SAS, 2001) with repeated measures and random effects. Habitat selection was determined from GPS positional data overlaid on geographic information system (GIS) maps of Chesapeake Farms and calculated using compositional analysis (Aebischer et al. 1993). Mean home range was 299.6 ha with breed (298.6 ha, F6, 80 = 3.95, P = 0.006) and pre-breed2 (285.5 ha, F6, 80 = 3.95, P = 0.007) ranges being significantly larger than summer (114.7 ha). Breed (46.9 ha, F6, 80 = 4.15, P = 0.014) and pre-breed2 (46.7 ha, F6, 80 = 3.95, P = 0.008) core areas were also significantly larger than summer (13.8 ha). Intensity of use ranged from 12% during summer to 16.7% during post-breed with a mean of 14.8%. Adult males increased movement and activity from summer to the breed season with a subsequent decrease during post-breed. Average daily movement during the breed season (4 km .25 km) was significantly higher than during pre-breed1 (F6,485 = 40.32, P < 0.001). Relative activity during the breed season was significantly higher than during pre-breed1 and post-breed (F6,487 = 15.22, P < 0.001). Period of day and temperature were the most consistent predictors of adult male movement and activity across all seasons. Diel movement and activity fluctuated across seasons, but was generally lowest during daytime. Adult male movement and activity was inversely related to temperature. Cultivated vegetation was the predominant cover type used during August and September. Use of cultivated vegetation decreased post-harvest with woodlands more selected through December. Adult males selected closed habitats during the day and open habitats at night. Crop phenology influenced movement in addition to breeding. Behavior of adult males will vary across the landscape with the onset of rutting behavior and seasonal changes in habitat availability. Understanding this behavior is the foundation for understanding how to address issues (i.e., human-deer conflicts and harvest strategies) surrounding the sustainable use of deer populations.
Reforestation planning in the West Usambara Mountains of Tanzania
(2002-12-19) Halperin, James J.; Dr. Theodore Shear, Committee Chair; Dr. Heather Cheshire, Committee Member; Dr. Thomas Wentworth, Committee Member
Rural reforestation planning is critical to the success of many conservation initiatives in the humid tropics. Although often neglected, careful planning can have a profound impact on the success or failure of such initiatives. The first step in developing a conservation intiative is to accurately quantify existing forest resources for prioritization of areas for intervention efforts. Next, planners must consider the interaction of people and environment to develop site-specific plans which maximize potential sustainability. This thesis develops a reforestation planning methodology for communities adjacent to mountain rainforests in Tanzania. The forests within this 2,200 km2 mountain range harbor many endemic species and provide critical water catchment protection. The study first quantifies forest distribution using LandSat 7 ETM satellite image data for one of the more signifcant ranges in the Eastern Arc Mountains, the West Usambaras. The study then describes forest fragmentation using a variety of landscape metrics. The planning process then focuses on one watershed, the Mkolo River drainage in the southeastern West Usambaras. Using GIS and remote sensing techniques, this study incorporates environmental needs assessments, forest regeneration potential, and socioeconomic requirements of local communities to account for the varying services that tree planting provides. This study accounts for these services accounted in a spatially explicit forestry intervention need index (FINI). This multi-stage assessment of natural resource distribution and use develops a procedural methodology that is critical in planning and implementing reforestation projects in species-rich tropical regions.
Remote Sensing Procedures to Update Forested Geospatial Datasets after a Landscape Altering Event
(2006-02-15) Shedd, Justin McEachern; Dr. Hugh A. Devine, Committee Chair; Dr. Heather Cheshire, Committee Member; Dr. Stacy Nelson, Committee Member
The creation of accurate geospatial datasets like vegetation and fire fuel loads is a time consuming effort and these datasets are routinely used by resource managers. Therefore the accuracy of these datasets is vital. Vegetation and fire fuel load datasets often represent a dynamic landscape and landscape altering events such as a wildland fire or a hurricane can drastically change that landscape. The goal of this research is to investigate the use of automated change detection techniques that can not only indicate areas of change but also quantify the magnitude of change that occurred as well. Hurricane Isabel did extensive damage to the forest landscapes of central Virginia in September of 2003, specifically Petersburg National Battlefield. The Rocky Top Fire occurred in July of 2002 in Shenandoah National Park, resulting in a mosaic pattern of burns, covering roughly 1500 acres. The objective of this research was to test the use of remote sensing procedures to update vegetation and fire fuel load spatial datasets. First, using digital orthorectified photomosaics, the automated feature extraction technique Visual Learning System's Feature Analyst, was employed to delineate forest damage following Hurricane Isabel. Second, the satellite based remote sensing technique Normalized Burn Ratio, was utilized to delineate and quantify burn severity on vegetation after the Rocky Top Fire. A third objective was to estimate fire behavior differences between the existing pre-event and the remotely sensed post-event fuel load datasets using the FARSITE model, thereby cataloging the potential need for vegetation and fuel load updates. The results of this research show that, 1) VLS Feature Analyst is an excellent indicator of downed woody debris, 2) the Normalized Burn Ratio is the best technique available for indicating and quantifying the effects of a wildland fire on the landscape, 3) changes in assigned Fuel Models, especially in the Logging Slash group, affect FARSITE outcomes, and 4) Fuel Models should be assigned based on expected fire behavior, not on the total fuel loading.
Scale and Strategy in Environmental Assessment of Regional Development Policies
(2008-11-18) Carrasco, Luis Eduardo; Dr. Subhrendu Pattanayak, Committee Member; Dr. Gary B. Blank, Committee Chair; Dr. Heather Cheshire, Committee Member; Daniel J. Robison, Committee Member; Dr. Erin O. Sills, Committee Co-Chair
Since the 1970s multiple research efforts around the world have focused on identifying potential environmental, economic, and social impacts of development. It is well understood that local project assessment approaches fail to identify, or worse quantify, indirect or cumulative effects, when they do not provide an appropriate baseline framework to understand the local and the regional environment as a connected entity. A conceptual approach based on several environmental assessment and spatial analysis tools suggests that we need to consider multi-scale methods that can help describe the different processes that occur within a region. This would help project managers and researchers to better evaluate ongoing regional policies by retrieving a wide characterization of the application and impacts of policies within the whole geographical spectrum. Within each policy assessment, these methods could evolve into a framework for environmental management practices at both local and regional scales that could be updated with new information through time. We analyze two regional policy case studies: poverty targeting in Sri Lanka, and payments for ecosystem services in Costa Rica.