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Recovery of Amphibian and Reptile Communities During Tropical Secondary Forest SuccessionThompson, Michelle E 23 March 2018 (has links)
The extensive clearing and modification of natural systems from anthropogenic activities is a pressing global concern. Forest habitats and animal communities within forests are among the most highly impacted, globally. Forest destruction has been repeatedly documented as a driver of biodiversity loss. However, little is known about how animal communities respond when altered landscapes are abandoned and left to regenerate into secondary forests. It is thought that the regrowth of secondary forests may help reverse biodiversity loss by restoring habitats to similar conditions as prior to land conversion. Of the forest cover that remains, over half is secondary forest, and in many countries secondary forest cover has been steadily increasing. Therefore, it is important to understand how and if faunal communities recover during secondary forest regeneration.
I combined meta-analytic, field-survey-based, and lab-based experimental techniques to determine how amphibians and reptiles respond to habitat change in general, and secondary forest regeneration on landscapes previously cleared for use as pasture. I addressed five specific questions: 1) what are the effects of habitat alteration on amphibians and reptiles?, 2) what are the effects of secondary forest succession on amphibians and reptiles?, 3) what is the relative importance of stochastic and deterministic effects on community assembly during secondary forest succession?, 4) how do amphibian and reptile species composition, probability of occurrence, and species richness change over the course of secondary forest succession?, and 5) is thermal quality of habitat an important mechanism of species response to secondary forest succession? I found that secondary forest has high conservation value for many amphibian and reptile species, environmental changes associated with secondary forest succession have a significant effect on shaping amphibian and reptile community composition, thermal quality is an important mechanism for species response and that strength of response is mediated by species-specific thermal biology. I also highlight the importance of riparian corridors in maintaining species diversity in modified habitats.
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First-year changes in oak regeneration, understory competitors, and resource levels in response to two overstory treatments and prescribed burning at Chuck Swan State ForestJackson, Samuel Wayne, January 2002 (has links) (PDF)
Thesis (M.S.)--University of Tennessee, Knoxville, 2002. / Title from title page screen (viewed Sept. 4, 2002). Thesis advisor: David S. Buckley. Document formatted into pages (xi, 112 p.). Vita. Includes bibliographical references (p. 104-111).
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Respone of tree-ring width and regeneration in conifer forests of Mongolia to climate warming and land useMookhor, Khishigjargal 15 July 2013 (has links)
No description available.
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The role of seed dispersal, seed predation and drought in the restoration of Ngel Nyaki Forest, Nigeria.Roselli, Sasha Mahani January 2014 (has links)
Abstract
The restoration of degraded landscapes has become one of our most valuable tools for conservation, however there are many factors which can restrict natural regeneration and impede active restoration attempts. The purpose of this study was to investigate three key processes which commonly limit the establishment of forest tree species into abandoned pasture in tropical forests: i) dispersal limitation, ii) seed predation, and iii) competition from the grass sward.
Seed dispersal
I identified 59 species of birds that were using the grassland habitat. Through 216 hours of focal tree observations I established that isolated trees in the grassland that had larger canopies, and those that were providing a food source (i.e. flowers or fruit) had significantly higher bird visitation rates and average stay lengths. I found evidence of the “perch effect” as patches of remnant trees encouraged more birds into areas of grassland, and the density of seedlings under tree canopies was significantly positively correlated with bird visitations. 95% of the seedlings found beneath tree canopies in grassland were of a different species to that of the tree canopy above them, demonstrating the dispersal of seeds from elsewhere into these microhabitats. 98% of these seedlings are grassland or forest edge species showing forest core species are still dispersal or microsite limited despite the effect of these trees.
Seed predation
Removal rates of seeds from experimentally laid out seed piles varied among seed species, the habitat the pile was in, and the predator guild able to access the piles. Preliminary results indicate that these trends are driven by the ecology of the seed predator. Removal of seeds by vertebrates was highest in the core forest, while ant predation was constant across all habitats. Vertebrates removed the larger seeds (Entandrophragma angolense and Sterculia tragacantha) while ants preferred the smaller Celtis gomphophylla and Croton macrostachyus. Overall predation rates in grassland were lower than those in the forest, and the presence of remnant trees did not influence predation rates, a positive sign for regeneration and the survival of seeds dispersed into these areas.
Competition from the grass sward
While the grass sward provides shade for seedlings of forest tree species it is also a harsh environment for them, as the grass competes with seedlings for water. Removing the grass and covering planted seedlings with artificial shading structures significantly increased both the survival and growth of these seedlings.
Recommendations
From this study I was able to make recommendations for a low input restoration program at Ngel Nyaki. Planting seedlings in small „islands‟ takes advantage of the natural increase in dispersal of seeds under isolated trees, while low seed predation rates increase the chance of survival of these seeds to germination. Planting these seedlings under shade will lead to increases both their growth rates and their survival. Once the secondary forest develops, under-planting seedlings of core forest trees will introduce them to the system, as the natural establishment of these seeds appears to be limited in the current environment. This study has also served to remind us how little we know about this particular forest-grassland system, and has led to the development of ideas for further investigations into several more aspects of regeneration.
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Abundance patterns for vascular epiphytes in a tropical secondary forest, Costa RicaKull, Matthew Austin. January 2007 (has links)
Thesis (M.S.)--State University of New York at Binghamton, Department of Biological Sciences, 2007. / Includes bibliographical references.
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Regeneration patterns on some modified staggered-setting clearcuts on the H.J. Andrews experimental forest /Franklin, Jerry F. January 1961 (has links)
Thesis (M.S.)--Oregon State University, 1961. / Typescript. Includes bibliographical references (leaves 48-49). Also available on the World Wide Web.
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Post-hurricane growth and recruitment of plant species used by birds in northern Puerto Rico /Sustache Sustache, José A. January 2004 (has links) (PDF)
Thesis (M.S.)--University of Puerto Rico, Mayagüez Campus, 2004. / Tables. Printout. Abstract in English and Spanish. Includes bibliographical references (leaves 30-38).
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Effects of atmospheric acid deposition and single versus mixed leaf litters on foliar litter decomposition, carbon, nitrogen, phosphorus and calcium dynamics in a regenerating forestMunasinghe, Prinith Sumudu. January 2008 (has links)
Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains vi, 131 p. : ill. (some col.). Includes abstract. Includes bibliographical references.
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Fire effects and litter accumulation dynamics in a montane longleaf pine ecosystemBale, Adam M. Guyette, Richard P. January 2009 (has links)
The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on October 16, 2009). Thesis advisor: Dr. Richard P. Guyette. Includes bibliographical references.
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Evaluation of willow oak acorn production and the effects of midstory control and flooding on underplanted willow oak seedlings in two Arkansas greentree reservoirsThornton, Rory Owen, January 2009 (has links)
Thesis (M.S.)--Mississippi State University. Department of Forestry. / Title from title screen. Includes bibliographical references.
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