Data from: Dryness is accelerating degradation of vulnerable shrublands in semiarid Mediterranean environments

Semiarid Mediterranean regions are highly susceptible to desertification
processes. This study investigated the influence of increasing climate
aridity in explaining the decline in vegetation cover in highly vulnerable
gypsum semiarid shrublands of the Mediterranean region. For this purpose,
we have used time series of the percentage of vegetation coverage obtained
from remote sensing imagery (Landsat satellites). We found a dominant
trend toward decreased vegetation cover, mainly in summer and in areas
affected by the most severe water stress conditions (low precipitation,
higher evapotranspiration rates and sun-exposed slopes). We show that past
human management and current climate trends interact with local
environmental conditions to determine the occurrence of vegetation
degradation processes. The results suggest that degradation could be a
consequence of the past overexploitation that has characterized this area
(and many others in the Mediterranean region), but increased aridity,
mainly related to global warming, may be triggering and/or accelerating
the degradation processes. The observed pattern may be an early warning of
processes potentially affecting more areas of the Mediterranean, according
to the most up to date climate change models for the 21st century.