Environmental change in time series - An interdisciplinary study in the Sahel of Mali and Senegal

Author(s)
Martin Brandt, Clemens Romankiewicz, Raphael Spiekermann, Cyrus Samimi
Abstract

Climatic changes and human activities have caused major environmental change in the Sahel. Remote sensing studies detect various vegetation trends; however, explanations are rarely studied in detail. We present a methodology using time series, high-resolution imagery and fieldwork to validate trend analyses for two regions in the Sahel of Mali and Senegal. Both study areas show significant greening trends from 1982 to 2010. Reasons can be very site-specific, but several factors are valid for both research areas: (1) farmer-managed agro-forestry, (2) planting programs and protection laws, (3) widespread dispersion of robust species, which replace the former diverse woody vegetation and simulate a greening which conceals a shift in biodiversity and (4) an increase of annual rainfall. However, the situation is still far from the pre-drought conditions, which are reconstructed by Corona imagery (1965) and interviews with the local population. Rather a transformation is observed: a decrease in natural vegetation, tree density and diversity. Reasons are climatic and anthropogenic: (1) drought events, less rain and higher temperatures, (2) increased demand for cropping areas and wood, especially in times of droughts. Our example validates that climatic factors are important drivers of change, but much of today's environment and vegetation composition is controlled by humans.

Organisation(s)
Department of Geography and Regional Research
External organisation(s)
Universität Bayreuth, Paris-Lodron Universität Salzburg
Journal
Journal of Arid Environments
Volume
105
Pages
52-63
No. of pages
12
ISSN
0140-1963
DOI
https://doi.org/10.1016/j.jaridenv.2014.02.019
Publication date
03-2014
Peer reviewed
Yes
Austrian Fields of Science 2012
507005 Cultural geography, 105408 Physical geography
Keywords
ASJC Scopus subject areas
Earth-Surface Processes, Ecology, Evolution, Behavior and Systematics, Ecology
Portal url
https://ucrisportal.univie.ac.at/en/publications/84c9c16b-3898-447c-af3b-b73a7c4d6d46