Soils and topography drive large and predictable shifts in canopy dynamics across tropical forest landscapes.

Tropical forests can vary enormously in their 3D structure and dynamics across surprisingly small spatial scales. However, the drivers that underpin this local-scale variation in forest structure and dynamics remain poorly understood. We acquired repeat airborne laser scanning data across an old-growth tropical forest landscape in Malaysian Borneo, characterized by a steep gradient in soil fertility and topography that gives rise to large variability in canopy 3D structure.

Trait plasticity and adaptive strategies of vascular epiphytes to a large-scale experimental reduction of fog immersion in a tropical montane cloud forest.

Premise: Tropical montane cloud forests (TMCF) are characterized by frequent fog immersion and host a rich epiphyte community. Epiphytes rely on atmospheric inputs of water, making them susceptible to reductions in fog immersion, which are predicted with climate change.

Methods: We experimentally reduced the fog in a Peruvian TMCF to examine the ability of eight abundant species of vascular epiphytes in the families Orchidaceae, Bromeliaceae, Ericaceae, Dryopteridaceae, Piperaceae and Clusiaceae to respond to reduced fog immersion via plasticity in morphological and physiological traits.

Bornean tropical forests recovering from logging at risk of regeneration failure.

Active restoration through silvicultural treatments (enrichment planting, cutting climbers and liberation thinning) is considered an important intervention in logged forests. However, its ability to enhance regeneration is key for long-term recovery of logged forests, which remains poorly understood, particularly for the production and survival of seedlings in subsequent generations. To understand the long-term impacts of logging and restoration we tracked the diversity, survival and traits of seedlings that germinated immediately after a mast fruiting in North Borneo in unlogged and logged forests 30-35 years after logging.

Divergence of hydraulic traits among tropical forest trees across topographic and vertical environment gradients in Borneo.

Fine-scale topographic-edaphic gradients are common in tropical forests and drive species spatial turnover and marked changes in forest structure and function. We evaluate how hydraulic traits of tropical tree species relate to vertical and horizontal spatial niche specialization along such a gradient. Along a topographic-edaphic gradient with uniform climate in Borneo, we measured six key hydraulic traits in 156 individuals of differing heights in 13 species of Dipterocarpaceae.

Small tropical forest trees have a greater capacity to adjust carbon metabolism to long-term drought than large canopy trees.

The response of small understory trees to long-term drought is vital in determining the future composition, carbon stocks and dynamics of tropical forests. Long-term drought is, however, also likely to expose understory trees to increased light availability driven by drought-induced mortality. Relatively little is known about the potential for understory trees to adjust their physiology to both decreasing water and increasing light availability.

Amazonia trees have limited capacity to acclimate plant hydraulic properties in response to long-term drought.

The fate of tropical forests under future climate change is dependent on the capacity of their trees to adjust to drier conditions. The capacity of trees to withstand drought is likely to be determined by traits associated with their hydraulic systems. However, data on whether tropical trees can adjust hydraulic traits when experiencing drought remain rare.