Diversity and abundance of tree microhabitats in the tropical forests of southern Western Ghats, India

Abstract

Tree microhabitats (TMHs) are proven tools for assessing and monitoring diversity. These structures on trees are potential indicators of biota, but there is a huge gap in TMH-related knowledge from the tropical regions, the cradles of biodiversity. Thus, an inventory was made to document the TMHs in the tropical forests of southern Western Ghats, India. In evergreen forests, 3,637 TMH host and 450 cavity host trees were identified from the 6,363 trees sampled. The density of TMHs was 972.57{+/-}341.25 ha-1 and cavity density was 63.13{+/-}11.91 ha-1. In moist deciduous forests, out of 1,545 trees sampled, 1,108 hosted TMHs and 212 trees hosted cavities. The density of TMHs was 493.67{+/-}133.28 ha-1 and cavity density was 42.00{+/-}15.01 ha-1. TMHs were categorised into nine categories and 33 sub-categories. The TMH and cavity occurrences were significantly influenced by species richness, stand density, basal area, diameter and height of trees, and density of healthy, unhealthy and dead trees. Dominant and codominant individuals hosted more TMHs and cavities in the deciduous stands while in evergreen, intermediate and overtopped trees had more TMHs and intermediate and codominant had more cavities. In both the habitats the important species of the habitat were also major hosts for TMHs and cavities. HighlightsO_LIPrimary inventory of diversity of TMHs and their host trees in tropical forests C_LIO_LITMH and cavity occurrences are significantly influenced by stand characteristics C_LIO_LIKey species in the habitats also form major hosts for TMHs and cavities C_LIO_LIDominant and codominant individuals host more TMHs and cavities in deciduous stands C_LIO_LIIntermediate and overtopped trees host more TMHs, intermediate and codominant host more cavities in evergreen C_LI