Estimates of global sources and sinks of carbon from land cover and land use changes

The distribution of sources and sinks of carbon over the land surface is dominated by changes in land use such as deforestation, reforestation, and agricultural management. Despite, the importance of land-use change in dominating long-term net terrestrial fluxes of carbon, estimates of the annual flux are uncertain relative to other terms in the global carbon budget. The interaction of the nitrogen cycle via atmospheric N inputs and N limitation with the carbon cycle contributes to the uncertain effect of land use change on terrestrial carbon uptake. This study uses two different land use datasets to force the geographically explicit terrestrial carbon-nitrogen coupled component of the Integrated Science Assessment Model (ISAM) to examine the response of terrestrial carbon stocks to historical LCLUC (cropland, pastureland and wood harvest) while accounting for changes in N deposition, atmospheric CO2 and climate. One of the land use datasets is based on satellite data (SAGE) while the other uses population density maps (HYDE), which allows this study to investigate how global LCLUC data construction can affect model estimated emissions. The timeline chosen for this study starts before the Industrial Revolution in 1765 to the year 2000 because of the influence of rising population and economic development on regional LCLUC. Additionally, this study evaluates the impact that resulting secondary forests may have on terrestrial carbon uptake. The ISAM model simulations indicate that uncertainties in net terrestrial carbon fluxes during the 1990s are largely due to uncertainties in regional LCLUC data. Also results show that secondary forests increase the terrestrial carbon sink but secondary tropical forests carbon uptake are constrained due to nutrient limitation.

Wildlife as a Priority in Park Development: A Study of Illinois Park Professionals

The purpose of this thesis is to consider the factors that impact decision making in city park settings, with specific emphasis given to wildlife. Additionally, professional bias was considered as a possible response determinant. Studies connecting perceptions of wildlife and Illinois park managers have been rare or nonexistent, but offer the potential for the improvement of management strategies and recreational opportunities. Data was collected using mixed methods. City recreation practitioners statewide were invited to complete a self-administered questionnaire considering wildlife as a decision-making factor in land acquisition or restoration decisions. A small follow-up sample of park managers was interviewed via telephone for further explanation of their response. Analysis of responses from questionnaires and interviews suggested that wildlife habitat is a factor in land use decision making, but is not considered one of the highest importance. Respondents identified that nuisance wildlife, access to wildlife, and public value of wildlife were also factors in decision making. Factors associated with a high-ranking of the importance of wildlife were agencies with a high number of natural area acres, a high number of overall park acreage, personnel devoted to natural area management, the presence of hiking trails, and cities with a large population. Professional bias of recreation managers was suggested via anecdotal interview data, but could not be empirically connected with wildlife-related decision-making processes, as no managers identified themselves as having completed formal wildlife-related training. As a result, management implications include separate training for both practitioners and public. This study broadens the understanding of wildlife management in city park settings, and reaffirms that further understanding of public and pracitioner values of wildlife will lead to improved land use decisions and recreationally valuable experiences.