Degradation risks of tropical forest ecosystems – modeling of landscape vulnerability to preserve the potential of biodiversity on São Tomé

São Tomé (854 km²) is located in the Gulf of Guinea. The island is a strato-volcano, characterized by very high relief intensity (highest peak: 2.024 above sea level), high humidity and temperatures as well as torrential tropical precipitation.

Because of the isolation from the African continent São Tomé evolved to be a remarkable hot spot of biodiversity with a high percentage of endemic species.

An intensive plantation industry (sugar cane, coffee, cocoa) is been practiced during colonial era (1486-1975). That led to large-area clearance of primary forest and depletion of fertile soils.

Today, the land use pressure is increasing continuously as a result of the bad economic situation and fast growing population, which is overusing the existing agricultural areas, practicing illegal logging and selectively cutting down economically valuable trees. Strong erosion and loss of soil are the results of steep slope transformation into agriculturally used fields. Through the augmentation of new oil palm plantation areas the ecosystems are being disturbed or even destroyed on a much bigger scale. That is causing depletion and erosion of soils as well as a serious ongoing decline of biodiversity.

The main objective of this project is to understand the cause- and consequence-complexes of landscape degradation and environmental changes on São Tomé. The potential driving forces that lead to degradation are being identified as well as interrelations between risk criteria and landscape degradation are being determined. The landscape vulnerability is being spatially acquired, analyzed and evaluated based on remote sensing and GIS modeling. The satellite data of the optical sensors like Landsat, EO-1 and radar data of Envisat ASAR is being used in this study.

Deforestation on São Tomé 

Project start: 2010

The project was supported by the Rufford Small Grants Foundation for a research stay on São Tomé (02-04/2013).