Forest ecosystem response to environmental pressures along an urban-to-wildland gradient in southwestern Ohio

<p>Unprecedented population growth and urban expansion are rapidly transforming natural and agricultural settings into highly modified urban and suburban landscapes across the United States. A myriad of anthropogenic environmental disturbances invariably accompany such dramatic shifts in land use, including increases in pollution, soil degradation, introduction of non-native species, land cover transitions, and habitat fragmentation. Disentangling the effects of these multiple stresses on natural ecosystems poses a major challenge as the world’s urban population continues to increase, and achieving a comprehensive understanding of their impacts is a crucial step in establishing environmentally sustainable strategies for management and development.</p><p>Investigations of urbanization gradients, when combined with detailed, quantitative assessments of environmental change along the gradient, have the potential to distinguish the relative influences of multiple anthropogenic environmental disturbances on ecosystems. The purpose of this study was to utilize an urban-to-wildland gradient to examine the effects of urban expansion on forest tree communities and soil nutrient cycling in southwestern Ohio. An extensive database of vegetation characteristics and environmental variables along the gradient was assembled using a combination of field censusing and sampling, laboratory analyses, and remote sensing and GIS techniques. A quantitative assessment of natural and anthropogenic environmental variation clearly demonstrates systematic variation in degree of anthropogenic disturbance along the gradient. Likewise, the ecological characteristics of tree communities vary meaningfully and significantly among urban, exurban, and wildland settings. The observed ecological patterns can be related to natural and anthropogenic environmental factors, and a number of interesting results emerge, including variation in the relative influence of anthropogenic disturbance on tree community characteristics both along the gradient as a whole and within individual settings, and the influence of individual environmental variables, such as proximity of roads, on the ecological characteristics of tree communities. Furthermore, a detailed examination of two disturbance-related impacts, land use change and the introduction of the prolific invasive shrub, <i>Lonicera maackii</i>, also demonstrates their importance in determining the carbon and nitrogen sequestration potential of soils in southwestern Ohio.</p>

Name thesis:degree_name

PhD

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Arts and Sciences: Geology

Grantor dc:publisher

University of Cincinnati

Year dc:date

2012

Author dc:creator

• Kolbe, Sarah E.

Contributors dc:contributor

• Miller, Arnold

• Geology
• urbanization
• forest
• carbon
• nitrogen
• gradient analysis
• soil

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=ucin1352993756

OAI identifier oai:identifier

oai:etd.ohiolink.edu:ucin1352993756