ARE BIODIVERSITY HOTSPOTS CORRELATED WITH CURRENT ECOCLIMATIC STABILITY - A PILOT-STUDY USING THE NOAA-AVHRR REMOTE-SENSING DATA

The GAC (Global Area Coverage) by the NOAA-AVHRR satellites represents an excellent data set for studying global and regional patterns of va riations in surface conditions driven in part by climatic variation, I n this pilot study we examined whether biodiversity 'hotspots', define d from peak concentrations of neoendemics as well as geographically re lict forms, differ in ecoclimatic stability from surrounding areas und er present-day climatic conditions, Coefficients of variation of the r atio between brightness surface temperature (Ts) and the Normalized Di fference Vegetation Index (NDVI) based upon 10 years' monthly composit ed scenes of tropical Africa revealed distinctive geographical pattern s of interannual variability in surface conditions, Regions with a pre dominance of old species are characterized by spatial uniformity in th e ecoclimatic variability, while regions where rapidly radiating group s dominate are spatially complex in this respect. However, the exact ' hotspots', with peak concentrations of endemic species, are characteri zed by a local reduction in ecoclimatic variability, or placement on t he boundary to a stable region. This relationship was supported statis tically by comparing ecoclimatic profiles across montane forests repre senting 'hotspots', and those of other montane forests, It is suggeste d that, because of interactions between prevailing atmospheric flows, topography and vegetation, the impact of extreme weather is moderated locally. The correlation between current stability and aggregates of n eoendemics as well as old relies indicate that local moderation of cli matic extremes persist through shifting climatic periods, permitting p opulations of unique species to survive in these places. The results a re used to identify study sites for better ground truthing and for pal eoclimatological studies which may be useful for more thorough studies of these relationships.