The Sudanian savanna is a key vegetation biome in West Africa providing
food and vital ecosystem services. Recently, it has been reported alarming ve
getation loss in this biome, calling for more investigation, relevant to tackle
land degradation and ensure food security. However, vegetation dynamics in
this area remains a matter of debate, and one of the main challenges is to
document consistently the underlying driving factors. This study aimed at
assessing vegetation trends and driving factors from 2000 to 2022. NDVI
trend, detected using the Mann-Kendall’s monotonic trend test, was used as
proxy to express vegetation dynamics. In addition to the non-parametric
Spearman correlation analysis, variables importance scores, derived from
Random Forest (RF) classifications, were used to determine key driving fac
tors among climatic, topographic, edaphic, accessibility and demographic
factors. During 2000-2022, no significant trends largely characterised the ve
getation cover of the study area. However, patterns of strong (weak) brown
ing and strong (weak) greening affected 7.1% (10.6%) and 12.8% (19.1%) of
the study area respectively. According to the driving factors analysis, the ob
served vegetation trends were mainly driven by rainfall dynamics (trend and
mean annual), population growth and anthropogenic activities. The results of
this study can support the development of efficient strategies for safeguarding
vegetation cover in the Sudanian savanna of Burkina Faso.

Vegetation Trends, NDVI, Sudanian Savanna, Burkina Faso, West Africa