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News > WAVeTrends: Trends in Woody and Herbaceous Vegetation

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WAVeTrends: Trends in Woody and Herbaceous Vegetation

Map of vegetation change in West Africa.

Concurrent woody and herbaceous vegetation changes between the 1982-1991 and 2004-2013 decades of the Sudano-Sahel region of Africa. (A) Map of vegetation change categories. (B) Chart showing the conceptual position and the relative abundance of each category in a 2-D space.

Woody and Herbaceous Vegetation Change across the Savannas of West Africa, 1982-2013

The West African Vegetation Trends (WAVeTrends) dataset is a 0.05 degree (5.55 km) vegetation change product spanning the West African Sudano-Sahel region. Pixel-wise information is provided on concurrent woody and herbaceous vegetation trends across this savanna region over a 32-year period (1982-2013). Change in woody vegetation was derived using long-term rain use efficiency (RUE) sensitivity which is the per-pixel comparison of the difference of mean RUE between the first and last decades of the 32-year time series. Herbaceous vegetation change was defined for short-term RUE sensitivity by comparing the slope of the RUE relationship (productivity vs. precipitation) between both decades using per-pixel Analysis of Covariance (ANCOVA). Categorical vegetation change was then determined for each pixel using the direction of the change and a significance level of p<0.05. The assumption that rainfall is a significant positive driver of net production in drylands was not always met and validity flags are included for each pixel location. This dataset provides spatially explicit regional scale information on how each vegetation category has evolved separately over the past few decades and can address questions about the land degradation/desertification process, long-term climate change, and food security in the region.

Data Citation: Anchang, J.Y., L. Prihodko, A.T. Kaptue, C.W. Ross, W. Ji, S.S. Kumar, B. Lind, M.A. Sarr, A.A. Diouf, and N.P. Hanan. 2020. Woody and Herbaceous Vegetation Change across the Savannas of West Africa, 1982-2013. ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/1738