Assessment of the alpine plant species biodiversity in the western Himalaya using Resourcesat-2 imagery and field survey

Abstract

In the alpine ecosystem of the Himalaya, an observation of species diversity with habitat heterogeneity predicts some important factors that govern them. Information theory-based species biodiversity at the community level and habitat heterogeneity at the landscape level were studied. Resourcesat-2 linear imaging self-scanning sensor (LISS-III and LISS-IV)-based spectral diversity indices and species diversity indices of four summits with increasing elevation gradients were estimated. The species richness decreased with an increase in elevation. The southern aspect of the sub-alpine zone has the highest biodiversity having a 3.5 Shannon’ entropy (H). Despite receiving higher insolation, the increase in elevation leading to coldness and dominance of a few species make the southern aspects less diverse at the higher elevation. Both elevational gradients and microclimatic conditions define biodiversity in the Himalaya. Resolution from coarser (LISS-III) to finer (LISS-IV) to micro (field) scale showed an increasing range of values, H = 0.1, 0.2 and 2.1, respectively. There is significantly less correlation between field and satellite measured biodiversity indices (r, −0.5 to 0.3). To go closer to the field level of biodiversity assessment, there is a need to use satellite data having a higher spatial resolution. Spectral variation hypothesis does not hold good in the alpine ecosystem of the Himalaya.