ABSTRACT: Southern African savannas are an important dryland ecosystem, as they account for up to 54% of the landscape, support a rich variety of biodiversity, and are areas of key landscape change. This paper aims to address the challenges of studying this highly gradient landscape with a grass–shrub–tree continuum. This study takes place in South Luangwa National Park (SLNP) in eastern Zambia. Discretely classifying land cover in savannas is notoriously difficult because vegetation species and structural groups may be very similar, giving off nearly indistinguishable spectral signatures. A support vector machine classification was tested and it produced an accuracy of only 34.48%. Therefore, we took a novel continuous approach in evaluating this change by coupling in situ data with Landsat-level normalized difference vegetation index data (NDVI, as a proxy for vegetation abundance) and blackbody surface temperature (BBST) data into a rule-based classification for November 2015 (wet season) that was 79.31% accurate. The resultant rule-based classification was used to extract mean Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI values by season over time from 2000 to 2016. This showed a distinct separation between each of the classes consistently over time, with woodland having the highest NDVI, followed by shrubland and then grassland, but an overall decrease in NDVI over time in all three classes. These changes may be due to a combination of precipitation, herbivory, fire, and humans. This study highlights the usefulness of a continuous time-series-based approach, which specifically integrates surface temperature and vegetation abundance-based NDVI data into a study of land cover and vegetation health for savanna landscapes, which will be useful for park managers and conservationists globally.
ABSTRACT: Protected areas are important conservation tools, as they can be managed to preserve baseline ecosystem health, including that of vegetation dynamics. Understanding long-term ecosystem dynamics within a protected area enables one to understand how this static park landscape responds to outside pressure and changing drivers. In this study, a repeat photography analysis was used to analyze changes in the vegetation pattern and abundance at Gorongosa National Park in Mozambique across seventy-two years of the parks history. Archival photographs dating as far back as 1940 were selected for sites that could be relocated in a subsequent field visit in 2012. Qualitative and quantitative analysis on vegetation abundance by structural group was undertaken using Edwards’ Tabular Key. Results when comparing the photographic pairs show that, in general, tree cover has increased on average from 25 percent to 40 percent over the last seventy-two years. This 15 percent increase may be in response to environmental drivers such as human management, herbivory, fire, and precipitation. Contrary to many recent studies on shrub encroachment in southern Africa, this study finds an increase in tree cover. Such analysis and results are valuable in that they demonstrate long-term ecological change within a managed protected area.
The University of Florida is looking for a new faculty member in the area of ‘Health and Social Change in Africa’. This preeminence position is for exceptional candidates at the Assistant level, or Associate or Full Professors. This position would be in the College of Liberal Arts and Sciences (CLAS) which is home to many departments, including Geography, and will also link directly to the Center for African Studies.
A geographer would be an excellent fit given the topics of interest, which include, but are not limited to: health policy and institutions, demography, migration, environmental change, war and conflict, political and/or cultural change, economic development, political economy of health and healthcare, globalization, or other major aspects of social change and transition in Africa. If joining Geography, the faculty would join an exciting and engaged group of scholars already working in Africa (Drs. Brian Child, Jane Southworth, Peter Waylen, Sadie Ryan, Barbara McDade-Gordon, Michael Binford, Abe Goldman, Jason Blackburn and Greg Glass) and in Health and Disease (Drs. Sadie Ryan, Greg Glass, Jason Blackburn and Liang Mao).
Applications commence review on January 11th and if you wish to find the full job advertisement and to apply please see below: http://explore.jobs.ufl.edu/cw/en-us/job/495251/preeminence-associatefull-professor-in-public-health-social-change-in-africa