South East Asian biodiversity: An impending disaster

Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Republic of Singapore.
Trends in Ecology & Evolution (Impact Factor: 16.2). 01/2005; 19(12):654-60. DOI: 10.1016/j.tree.2004.09.006
Source: PubMed


Southeast Asia has the highest relative rate of deforestation of any major tropical region, and could lose three quarters of its original forests by 2100 and up to 42% of its biodiversity. Here, we report on the current state of its biota and highlight the primary drivers of the threat of extinction now faced by much of the unique and rich fauna and flora of the region. Furthermore, the known impacts on the biodiversity of Southeast Asia are likely to be just the tip of the iceberg, owing to the paucity of research data. The looming Southeast Asian biodiversity disaster demands immediate and definitive actions, yet such measures continue to be constrained by socioeconomic factors, including poverty and lack of infrastructure. Any realistic solution will need to involve a multidisciplinary strategy, including political, socioeconomic and scientific input, in which all major stakeholders (government, non-government, national and international organizations) must participate.

Download full-text


Available from: Lian Pin Koh
  • Source
    • "In Southeast Asia, conditions for flying foxes are especially critical. The relative deforestation rate and associated wildlife habitat loss in Southeast Asia is the highest for all tropical regions (Sodhi et al. 2004). In Thailand, loss of natural forests exceeded 50% within 3 decades (1961–1998; Waggener 2001). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Hunting and loss of natural habitats increasingly threaten tropical biodiversity and ecosystems, particularly in Southeast Asia. Flying foxes often persist in anthropogenic areas where other wildlife has vanished, and where they play a significant ecological role in vegetation regeneration in disturbed habitats. Detailed knowledge on the foraging behavior of flying foxes is crucial for understanding how they survive in degraded habitats and for the management of human-wildlife conflicts. Thailand still harbors large colonies (several thousand individuals) of Lyle’s flying fox (Pteropus lylei), a species ranked as Vulnerable on the International Union for Conservation of Nature (IUCN) Red List, at temples situated in agricultural landscapes. We used high-resolution global positioning system (GPS) loggers to study the movement and foraging behavior of this species at 2 temples in central Thailand during 2 seasons. We analyzed GPS and acceleration data of 19 tagged individuals, and assessed habitat use and diet. Foraging individuals commuted between day roosts and foraging areas each night, followed by small-scale movements in foraging areas, and showed high site fidelity during the study period. Maximum linear distances between day roosts and foraging areas varied greatly between individuals (2.2–23.6 km) but were similar between seasons. Tracked bats mostly foraged in farmland, plantations, and gardens, yet our data indicate that small mangrove remnants constitute important habitat components for Lyle’s flying fox. We recorded a highly diverse diet of 34 food plant species, comprised of exotic crops and native plants as available. Our results suggest that conservation and landscape managers should preserve remaining native trees and natural vegetation in the study area as resources for Lyle’s flying fox, at the same time reducing potential for conflicts between bats and humans on crops. They can further be used for public information campaigns integrating the potential of Lyle’s flying fox as dispersers of useful plants and the human health risks through zoonotic diseases associated with hunting and consumption of this species.
    Full-text · Article · Aug 2015 · Journal of Wildlife Management
  • Source
    • "Arthropods and microscopic organisms represent the majority of this diversity; however, due to their small sizes, it is difficult and often impractical to characterize their communities using traditional survey methods. Recent efforts to describe the full diversity of arthropods in a Panamanian tropical rainforest found 6144 species in less than one-half hectare, and estimated that 25 000 arthropod species exist within a 6000-ha reserve (Basset et al. 2012).The rainforests of Southeast Asia are currently threatened by anthropogenic activities, including the highest relative rates of deforestation compared with other tropical regions (Sodhi et al. 2004). Many organisms may lose their habitat before their existence is even recognized, as the vast biodiversity of arthropods and other small eukaryotes in Southeast Asian rainforests is still virtually unknown. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The biodiversity of tropical forests consists primarily of small organisms that are difficult to detect and characterize. Next-generation sequencing (NGS) methods can facilitate analyses of these arthropod and microbial communities, leading to a better understanding of existing diversity and factors influencing community assembly. The pitchers of carnivorous pitcher plants often house surprisingly discrete communities and provide ideal systems for analysis using an NGS approach. The plants digest insects in order to access essential nutrients while growing in poor soils; however, the pitchers are also home to communities of living organisms, called inquilines. Certain arthropods appear to have coevolved with their pitcher plant hosts and are not found in other environments. We used Illumina amplicon sequencing of 18S rDNA to characterize the eukaryotes in three species of Nepenthes (Nepenthaceae) pitcher plants – N. gracilis, N. rafflesiana and N. ampullaria – in each of three different parks in Singapore. The data reveal an unexpected diversity of eukaryotes, significant differences in community diversity among host species, variation in host specificity of inquilines and the presence of gregarine parasites. Counts of whole inquiline arthropods from the first collection year were roughly correlated with scaled 18S sequence abundances, indicating that amplicon sequencing is an effective means of gauging community structure. We barcoded a subset of the dipteran larvae using COI primers, and the resulting phylogenetic tree is mostly congruent with that found using the 18S locus, with the exception of one of five morphospecies. For many 18S and COI sequences, the best BLASTn matches showed low sequence identity, illustrating the need for better databases of Southeast Asian dipterans. Finally, networks of core arthropods and their host species were used to investigate degree of host specificity across multiple hosts, and this revealed significant specialization of certain arthropod fauna.
    Full-text · Article · Aug 2015 · Austral Ecology
  • Source
    • "The presence of many specialist and endemic species in these regions creates great risk of extinction due to deforestation. For example, 59.6% of the 29 375 vascular plant species in Indonesia do not occur anywhere else on the planet and local disappearance would mean global extinction (Sodhi et al. 2004). Of all areas in the humid tropics, Southeast Asia experiences the highest relative rate of deforestation (Achard et al. 2002) and a recent analysis showed that globally, Indonesia exhibited the largest increase in forest loss from 2000-2012 (Hansen et al. 2013). "

    Full-text · Technical Report · Jul 2015
Show more