Impacts of anthropogenic change on rainforest epiphytes due to increased treefalls.

Ongoing anthropogenic global change is expected to accelerate the rate of treefalls in tropical forests, due to altered climate, habitat clearance, and forest fragmentation. Canopy epiphyte communities are likely to be strongly affected by treefalls, both for epiphytes whose supporting tree has fallen, and for those on trees neighbouring the treefall. However, this remains poorly explored. Possible drivers include altered microclimate, and increasing herbivory pressure from mammals. This project will explore how accelerating treefall frequency is impacting the epiphytic flora, using a combination of field sampling of epiphytes at treefall sites at ground and canopy levels, rope access methods, microclimate mapping, experimental exclusion of ground-based mammalian herbivores, and collaboration with ongoing long-term vegetation monitoring in permanent plots. Field work will be conducted in Malaysian Borneo, which is home to the tallest tropical forests in the world, with some emergent trees rising to 100 m above the forest floor. In addition to focal surveys in Danum Valley Conservation Area, opportunistic sampling of recent treefalls around Malaysian Borneo will also be carried out, through the lead supervisor’s extensive network of contacts in this region, allowing construction of a treefall chronosequence. This project will inform conservation decisions to mitigate the impacts of ongoing anthropogenic global change on hyper-diverse lowland tropical ecosystems.