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Niche structure of an anole community in a tropical rain forest within the Choco region of Colombia

Description: Ten species of anoles at Bajo Calima within the Choco of Western Colombia separate into two principal microhabitat groups: forest species, and those inhabiting openings and edges. The ten anoles further separate according to ground and vegetation dwellers. There is a relation at Bajo Calima between the number of anole species and vegetational structural diversity.
Date: May 1988
Creator: Castro-Herrera, Fernando
Partner: UNT Libraries

Ecological Enhancement of Timber Growth: Applying Compost to Loblolly Pine Plantations

Description: This study explored the application of compost onto a small loblolly pine tree forest in northeast Texas. Its purpose was to determine if the application of various amounts of compost would provide for accelerated rates of growth for the trees. Soil parameters were also monitored. A total of 270 trees were planted and studied in a northeast Texas forest ecosystem. Compost rates of 5, 25, and 50 tons per acre with either soil or compost backfill were utilized and compared to a control without compost. Nonparametric and parametric ANOVA and Chi-Square tests were utilized. The results indicated that greater application rates retained greater moisture and higher pH levels in the soil. Compost applications also yielded a greater survival rate as well as larger tree height and diameter when compared to the control. The 25 ton/acre application backfilled in native soil achieved the greatest average in height and diameter when compared to the averages for the control plot. Greater growth differences for the 25S application can be attributed to additional nutrients coupled with a stable pH consistent with native soil acidity.
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Date: December 1999
Creator: Stuckey, Harold Troy
Partner: UNT Libraries

Measuring and Monitoring Carbon in the Agricultural and Forestry Sectors

Description: Proposals to reduce emissions of carbon dioxide and other greenhouse gases often include the use of forestry and agricultural practices and lands for carbon sequestration. However, uncertainty about the accuracy of measuring carbon from these activities has led some to question this potential. Basic approaches for measuring forest and agricultural carbon include on-site measurement; indirect measurement from off-site tools; and estimation using models or inferences. Because of challenges associated with balancing the cost and accuracy of these measurement tools, any practicable system for measuring forest and agricultural carbon might require a mix of these approaches.
Date: October 6, 2008
Creator: Gorte, Ross W. & Johnson, Renée
Partner: UNT Libraries Government Documents Department

Acid Rain: Does it Contribute to Forest Decline?

Description: This minibrief describes the major hypothesis explaining why acid rain may be contributing to forest decline, along with the major arguments against this hypothesis. For additional information on acid rain and current legislation for pollutant emissions controls, see IB83016 -- Acid Rain: Current Issues, and IB83005 -- Clean Air Act: An Overview.
Date: January 24, 1985
Creator: Backiel, Adela
Partner: UNT Libraries Government Documents Department

Modeling Complex Forest Ecology in a Parallel Computing Infrastructure

Description: Effective stewardship of forest ecosystems make it imperative to measure, monitor, and predict the dynamic changes of forest ecology. Measuring and monitoring provides us a picture of a forest's current state and the necessary data to formulate models for prediction. However, societal and natural events alter the course of a forest's development. A simulation environment that takes into account these events will facilitate forest management. In this thesis, we describe an efficient parallel implementation of a land cover use model, Mosaic, and discuss the development efforts to incorporate spatial interaction and succession dynamics into the model. To evaluate the performance of our implementation, an extensive set of simulation experiments was carried out using a dataset representing the H.J. Andrews Forest in the Oregon Cascades. Results indicate that a significant reduction in the simulation execution time of our parallel model can be achieved as compared to uni-processor simulations.
Date: August 2003
Creator: Mayes, John
Partner: UNT Libraries

An examination of the riparian bottomland forest in north central Texas through ecology, history, field study, and computer simulation

Description: This paper explores the characterization of a riparian bottomland forest in north central Texas in two ways: field study, and computer simulation with the model ZELIG. First, context is provided in Chapter One with a brief description of a southern bottomland forest, the ecological services it provides, and a history of bottomland forests in Texas from the nineteenth century to the present. A report on a characterization study of the Lake Ray Roberts Greenbelt forest comprises Chapter Two. The final chapter reviews a phytosocial study of a remnant bottomland forest within the Greenbelt. Details of the ZELIG calibration process follow, with a discussion of ways to improve ZELIG's simulation of bottomland forests.
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Date: August 2001
Creator: Holcomb, Sheralyn S.
Partner: UNT Libraries

Impact of elevated CO2 and O3 on insect-mediated ecosystem processes in a northern deciduous forest

Description: Rising concentrations of atmospheric CO{sub 2} and O{sub 3} are altering the structure and function of forest ecosystems. Herbivorous insects are the major consumers in temperate deciduous forests, with the capacity to dramatically alter tree growth (via outbreaks), forest community composition and ecosystem dynamics (e.g., nutrient cycling). Until recently, however, experimental quantification of the impacts of CO{sub 2} and O{sub 3} on canopy herbivore communities and rates of defoliation and nutrient flux has not been addressed. This research, conducted at the Aspen FACE (Free Air CO{sub 2} Enrichment) facility in northern Wisconsin, U.S.A., evaluated the independent and interactive effects of CO{sub 2} and O{sub 3} on (1) the abundance and diversity of forest canopy insect communities, and (2) rates of insect herbivory and transfer of material (leaf greenfall and insect frass) from the canopy to the forest floor. Results of studies of individual insects revealed that elevated CO{sub 2} and O{sub 3} influence the performance of individual species of damaging insect pests, but the magnitude of impact is influenced by both insect species and their host tree species. Censuses of canopy insects showed that some species were positively affected, some negatively affected, and some not affected by elevated CO{sub 2} and O{sub 3}. Moreover, overall species diversity was generally not strongly affected by CO{sub 2} and O{sub 3}. In summary, the effects of CO{sub 2} and O{sub 3} on forest insects is highly variable among species and over time, and thus difficult to generalize across broad taxonomic groups. Estimates of foliar damage revealed that CO{sub 2} and O{sub 3} have pronounced effects on canopy damage by insect herbivores. Averaged over three years, foliar biomass lost to insect feeding increased 86% in high CO{sub 2} environments and decreased 12% in high O{sub 3} environments. The increases/decreases were greater for aspen than ...
Date: November 20, 2011
Creator: Lindroth, Richard L.
Partner: UNT Libraries Government Documents Department

Ecological Association Between the Red-Cockaded Woodpecker and Southern Pine Beetle in the Homochitto National Forest: a Geographic Information System Approach

Description: Since the introduction of management practices by the Forest Service to stabilize red-cockaded woodpecker (RCW) populations, the number of cavity trees killed by southern pine beetles (SPB) has increased. A model of the landscape ecology of RCW and SPB in the Homochitto National Forest was created using data collected from the Forest Service and Global Atmospherics. The conclusions of the study were that the RCW and SPB utilize the same type of habitat and the stand hazard maps are an accurate means of determining the locations of SPB infestations. The functional heterogeneity maps created for the SPB and RCW would be useful predictors of future occurrences of either species if complete data were obtained.
Date: December 1998
Creator: Skordinski, Karen R. (Karen Renee)
Partner: UNT Libraries

Riparian Forest Width and the Avian Community in a Greenbelt Corridor Setting

Description: The forest avian community of the Ray Roberts Greenbelt (Denton Co., Texas) was characterized for two years using point count station sampling, from fall 1998 to summer 2000. Richness data for both breeding seasons were correlated with two-spatial metrics: width of the riparian forest and distance to the nearest edge. There were significant correlations between forest interior species richness and both spatial metrics, for both breeding seasons. Based on these data, a minimum riparian forest width threshold of 400-meters is suggested to provide habitat for forest interior species, which have lost considerable habitat through forest fragmentation. Partners in Flight breeding bird priority concern scores were used to create a habitat priority index for the Trinity River bottomland hardwood forest system
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Date: May 2001
Creator: Hoffman, Karl W.
Partner: UNT Libraries