Diversity, characteristics, and co-occurrence patterns of tree microhabitats in the tropical forests of the Western Ghats, India

Tree microhabitats have been identified as structure-based indicators of biodiversity in temperate forests. However, information on diversity and abundance of these structures are minimal from the tropical regions. To address this, an inventory was conducted to document the distribution pattern of tree microhabitats in the Western Ghats, India. Tree microhabitats belonging to nine categories and 33 sub-categories in the evergreen and moist deciduous habitats were documented and horizontal and vertical distribution patterns were assessed. The evergreen habitat exhibited higher occurrences, with the abundance of injuries at 16.64 +/- 6.31 per ha, epiphytes 20.48 +/- 12.02 per ha, fungal fruiting bodies 2.68 +/- 1.84 per ha, crown deadwood 5.12 +/- 2.82 per ha, cavities 6.59 +/- 1.37 per ha, growth forms 20.65 +/- 3.96 per ha, deadwood 5.94 +/- 1.97 per ha, and fresh exudates 0.99 +/- 0.46 per ha. In deciduous forests, the abundance of injuries was 10.55 +/- 2.95 per ha, epiphytes 6.88 +/- 2.01 per ha, fungal fruiting bodies 2.75 +/- 1.59 per ha, crown deadwood 6.58 +/- 2.79 per ha, cavities 4.2 +/- 1.51 per ha, growth forms 6.51 +/- 2.19 per ha, deadwood 4.29 +/- 1.52 per ha and fresh exudates 0.86 +/- 0.96 per ha. Co-occurrence of tree cavities with other tree microhabitats were also presented. Injuries, growth forms, fungal fruiting bodies and deadwood were observed to have strongly correlated with the formation of cavities.