Title of symposium:
Changing environments & changing forests: spatial and temporal variation in the dynamics of Southeast Asian forests

Principal organizer:
Sabrina E. Russo
School of Biological Sciences, University of Nebraska – Lincoln, USA

Stuart J. Davies
Smithsonian ForestGEO, USA, Davies

Symposium summary:
Forests are continually changing, but the rapid environmental changes occurring in Southeast Asia are reshaping the forests of this region. Shifts in patterns of land-use are fragmenting once continuous tracts of forest, causing habitat loss and making remaining forests vulnerable to a host of stressors. Increased hunting and poaching pressures affect patterns of seed dispersal, seed and seedling predation, and, ultimately tree recruitment. Climate change is causing shifts in rainfall regimes and altering the frequency and severity droughts. These anthropogenic drivers of change operate on top of existing natural environmental gradients, causing the responses of forests to these drivers to be complex. The aim of the proposed Symposium is to integrate results from a network of long-term forest monitoring plots across Southeast Asia in order to quantify these responses and reconcile natural versus anthropogenically driven reasons for forest change.

These diverse drivers of forest change have different effects on tree species’ growth, recruitment, and mortality, as well as the spatial and temporal variation in these vital rates. This variation arises because these drivers have their greatest effects at different tree life stages and sizes and on tree species with, for example, particular functional and physiological properties, with particular kinds of interactions with animals, or with particular habitat associations. As a result, some tree species are favored over others in the novel environments currently forming, which can result in dramatic changes in forest composition and structure. The research to be presented in this Symposium quantifies contemporary changes in the composition and structure of a wide range of forest types, including lowland mixed dipterocarp, typhoon, and pre-montane forests across six countries in Southeast Asia. The presentations analyze the potential role of anthropogenic drivers of change, including altered patterns of plant-animal interactions, as well as responses to shifting rainfall regimes and disturbances like typhoons and stand-replacing fires, and their consequences for forest function and carbon storage. By examining how the responses of tree species to these drivers depend on natural environmental gradients (e.g., soil fertility, elevation), the Symposium will uncover functional and demographic bases of forest change and contribute a synthetic understanding of the urgent challenges facing Southeast Asian forests now and in the future. The Symposium will close with an interactive panel discussion, moderated by the organizers and including the Symposium speakers, as well as other local experts, to consider these challenges and how they can be addressed given current frameworks for research and conservation.

List of Speakers and Title Presentations:

  1. Sabrina E. Russo & Stuart J. Davies, Introduction to the Symposium
  2. Xu Han, Research Institute of Tropical Forestry, Chinese Academy of Forestry,
    Title (authors): Do legume trees facilitate neighbor diversity and productivity in natural forests globally?
  3. Akira Itoh, Osaka City University, Japan
    Title (authors): Species-specific drought effects: consequences for species and phylogenetic diversity of Bornean rain forest trees (Akira Itoh, Satoshi Nanami, Ting-Ting Yin, Seiya Okuno, Shuhei Matsuyama, Mohizah Mohamad, Sylvester Tan, Stuart J. Davies)
  4. Yao Tze Leong, Forest Research Institute Malaysia
    Title (authors): Habitat-related tree species distribution and diversity in a Peninsular Malaysian rainforest (Yao Tze Leong, Christine D. Fletcher, Stuart J. Davies, Sabrina E. Russo)
  5. Matthew Luskin, Asian School of the Environment, Nanyang Technological University, Singapore
    Title (authors): 'Long-term changes in tree sapling abundance and aggregation dynamics in two Asian forests (Matthew Scott Luskin, Matteo Detto, Sabrina E. Russo, Yu-Yun Chen, Yao Tze Leong, Sylvester Tan, Stuart J. Davies)
  6. Ngo Kang Min, Nanyang Technological University, Singapore
    Title (authors): Short-term variation of tree growth rates in tropical forests of Singapore (Kang Min Ngo, Nik Faizu Nik Hassan, Mohamad Fairoz B. Mohamed, Shawn Lum)
  7. Hjh Mohizah Binti Mohamad, Forest Department Sarawak, Malaysia,
    Title (authors): Temporal change in species composition and abundance at Lambir National Park, Sarawak, Malaysia (Hjh Mohizah Binti Mohamad, Sabrina E. Russo, Ryan Chisholm, Stuart J. Davies, Tawan Cheksum)
  8. Musalmah Binti Nasardin, Forest Research Institute Malaysia
    Title (authors): Habitat-related mortality patterns of trees in Pasoh Forest Reserve over 25 years (Musalmah Binti Nasardin, Sabrina E. Russo, Yao Tze Leong, Stuart J. Davies)
  9. Sabrina E. Russo & Stuart J. Davies: Concluding Remarks and Moderated Discussion: The future of Southeast Asian forests; We will extend invitations to other ATBC attendees to be part of the panel, in addition to speakers in the Symposium.