Journal Article

2016

Karthik TeegalapalliAparajita Datta

Field to a forest: Patterns of forest recovery following shifting cultivation in the Eastern Himalaya

The patterns of vegetation recovery in shifting cultivation landscapes that undergo a cycle of clearing,cultivation and forest regeneration are not well understood in Asian tropical forests. We determined for-est recovery patterns by comparing species composition, richness and forest structure in early and latefallows formed following shifting cultivation and in an uncut forest site in a mid-elevation subtropicalforest in the Indian Eastern Himalaya. We also examined changes in functional traits of tree species tounderstand recovery processes with succession. Tree species richness in the 12, 25 and 50-year old siteswas 37%, 54% and 82% the value of the richness in uncut forest, respectively, while basal area was 33%,25% and 41% of the value in uncut forest, respectively. Species composition recovery, however, waslow; with even the oldest fallow (50-year fallow) being less than 50% similar to uncut forest in termsof composition. Successional sites that recover over long periods may differ compositionally from uncutforest within a shifting cultivation landscape as these forests are often prone to other anthropogenic dis-turbances. Functional trait analysis revealed that early fallows were colonized by tree species that areanimal-dispersed, insect-pollinated with small fruits and seeds, whereas uncut forest and late succes-sional forests were dominated by species that were tall, self-dispersed, wind-pollinated and of high wooddensity that are dominant mature forest species in the Himalaya. These results are in contrast with thepatterns in functional traits of tree species in successional sites from the Neotropics. This points to theimportance of site-specificity in succession following shifting cultivation.

Forest Ecology & Management http://dx.doi.org/10.1016/j.foreco.2016.01.006