How far north does lowland evergreen tropical rain forest go?

Abstract

Primary forest was studied at 530 m altitude at 27° 31′ N and 96° 24′ E in the Himalayan foothills in a plot at Haldibari in the Namdapha Tiger Reserve in Arunachal Pradesh in northeast India. The forest had all the structural attributes of the Lowland Evergreen Rain Forest Formation including frequent buttressing, large woody climbers, and a predominance of trees with leaves in the mesophyll and macrophyll size categories. It was species rich with at least 116 large (>10 cm dbh) tree or liana species in a 1 ha plot. The species affinities were tropical and included two species of Dipterocarpaceae, Dipterocarpus macrocarpus and Shorea assamica, which together accounted for 6.9% of the measured individual trees. The type of forest at Namdapha has the highest known latitude for what is certainly Lowland Evergreen Rain Forest although the Formation may extend to 28° 28′ N in China.