Trends in Woody and Herbaceous Vegetation in the Savannas of West Africa

Remote Sensing

Lara Prihodko¹  AbdoulA. Diouf²  MamadouA. Sarr²  ArmelT. Kaptué³  JuliusY. Anchang⁴  ChristopherW. Ross⁴  Brianna Lind⁴  Wenjie Ji⁴  SanathS. Kumar⁴  NiallP. Hanan⁴ 

[1] Animal and Range Sciences, New Mexico State University, PO Box 30003 MSC 3-I, Las Cruces, NM 88001, USA;Centre de Suivi Ecologique, PO Box 15532, Dakar, Senegal;Fujitsu Consulting Inc., 7101 Ave. Parc, Montreal, QC H3N 1X9, Canada;Plant and Environmental Sciences, New Mexico State University, PO Box 30003 MSC 3Q, Las Cruces, NM 88001, USA;

关键词: sudano-sahelian;    semi-arid drylands;    land degradation;    re-greening;    rain use efficiency;   

DOI  :  10.3390/rs11050576

来源: DOAJ

【 摘 要 】

We assess 32 years of vegetation change in the West African Sudano-Sahelian region following the drought events of the 1970s and 1980s. Change in decadal mean rain use efficiency is used to diagnose trends in woody vegetation that is expected to respond more slowly to post-drought rainfall gains, while change in the slope of the productivity–rainfall relationship is used to infer changing herbaceous conditions between early and late periods of the time series. The linearity/non-linearity of the productivity–rainfall relationship and its impact on the interpretation of overall greening trends, and specific woody and herbaceous vegetation trends, is also examined. Our results show a mostly positive association between productivity and rainfall (69% of pixels), which can be best described as linear (32%) or saturating (37%). Choosing the ‘best’ model at a specific location using Akaike Information Criterion has no discernible effect on the interpretation of overall greening or herbaceous trends, but does influence the detection of trends in woody vegetation. We conclude that widespread recovery in woody vegetation is responsible for the post-drought greening phenomenon reported elsewhere for the Sahel and Sudanian sub-regions. Meanwhile, trends in herbaceous vegetation are less pronounced, with no consistent indication towards either herbaceous degradation or recovery.

【 授权许可】

Unknown