Mammal abundance varies with geochemical specialisation in the underlying rock formations.

Abstract

<p>There has been little research on how the composition of underlying rock formation affects animal species’ distribution and abundance. The subject is worthy of consideration as, for example,  it has been shown that ultrabasic and serpentine rocks in particular can give rise to plant biodiversity hotspots with a high level of endemism. Corresponding studies of fauna are lacking. We aim to test the hypothesis that rock type affects mammal abundance and biodiversity.</p> <p>Here we present a comparative analysis of the abundance of mammals and its relationship with geological composition in the area of Gorny Altai, a mountainous region in Russia.</p> <p>We used GIS approaches to map the influence of rock types on mammal abundance, while holding other factors such as soil type, relief, etc. constant. The study reveals significant correlations between underlying geology and variation in mammal distribution even when other factors such as soil type, climate and vegetation are held constant.</p> <p>Intrusive rocks were found to have the greatest impact on variation in mammal distribution whereas sedimentary and metamorphic rocks have almost no effect. A characteristic feature of magmatic formations is their clear geochemical specialization, i.e. certain geochemical anomalies (Fe, Cu, Au, Hg, Ag, etc.) are confined to intrusions. We suggest that geophysical fields (magnetic and electric fields) and geochemical anomalies associated with intrusive rocks may have an impact on the distribution and species composition of mammals, as well as geodynamic processes such as fault activity. This finding has implications for further research into the phenomenon of animals’ anticipatory responses to earthquakes. </p>