SE Asia (se + asia)

Distribution by Scientific Domains


Selected Abstracts


Distributions of forest birds and butterflies in the Andaman islands, Bay of Bengal: nested patterns and processes

ECOGRAPHY, Issue 1 2002
Priya Davidar
The distributional patterns of forest birds and butterflies in the Andaman islands, an oceanic chain located off SE Asia, were tested for nestedness. Both taxa were highly nested. Nestedness could be due to colonization or extinction processes, area or distance effects or nestedness of habitats. Nestedness in forest bird distributions were strongly influenced by area and habitat related factors. Habitats were significantly nested in all three island groups, however most strongly for the North Andamans. However forest bird distributions in the North Andamans, as indicated by row order in the packed matrix, was not correlated with habitat diversity, suggesting that habitat related factors alone cannot account for these patterns. Other causal influences could be passive sampling, where common and abundant species and habitats are more likely to have a widespread distribution than rare species and habitats. The nested subset pattern seen in two unrelated taxa suggests that the Andamans are extinction dominated and that the protection of forests on large islands is critical for the conservation of its biodiversity. [source]


Responses of gas exchange and growth in Merkus pine seedlings to expected climatic changes in Thailand

GLOBAL CHANGE BIOLOGY, Issue 6 2001
Jarkko Koskela
Abstract Responses of gas exchange and growth in Merkus pine (Pinus merkusii Jungh. et de Vriese) seedlings to changing climate were analysed for high- and low-altitude sites in Thailand. A gas exchange model, based on the optimality approach, derived the effect of drought from the probability of rains. A carbon-and nitrogen-balance growth model applied structural regularities of a tree and a modification of functional balance between foliage and fine roots as growth- guiding rules. Adaptation to local climates was incorporated in the models. The simulations yielded physiologically reasonable behaviour for annual photosynthesis (A) and transpiration (E) in relation to the distributions of precipitation over the course of a year. An annual temperature increase of 2 °C and a prolonged dry season (scenario 2) reduced A by 5,11% and E by 5,8% as compared to present climate (scenario 1). Doubled CO2 concentration and the increased temperature (scenario 3) enhanced A by 56,59% and E by 14%. Simultaneously these changes (scenario 4) increased A by 41,53% and E by 1,5%. Simulated growth in scenario 1 fitted reasonably well to field data. By the age of five years, simulated total biomass (TB) and height (h) were reduced by 31,67% and 12,42%, respectively, in scenario 2 compared to scenario 1. In scenario 3, TB and h increased by 279,330% and 94,191%, and in scenario 4, by 83,241% and 55,69%, respectively. Large increases in TB and h are explained by the exponential growth phase of the young seedlings. These results suggest that climatic changes enhance growth and thus shorten the duration of the grass stage in these seedlings. However, the effects of climatic changes on growth depend strongly on how rainfall seasonality is altered in SE Asia because prolonged drought episodes may retard the fertilizing effects of the increasing CO2 concentration. [source]


Discovery of ten new specimens of large-billed reed warbler Acrocephalus orinus, and new insights into its distributional range

JOURNAL OF AVIAN BIOLOGY, Issue 6 2008
Lars Svensson
We here report the finding of ten new specimens of the poorly known large-billed reed warbler Acrocephalus orinus. Preliminary identifications were made on the basis of bill, tarsus and claw measurements, and their specific identity was then confirmed by comparison of partial sequences of the cytochrome b gene with a large data set containing nearly all other species in the genus Acrocephalus, including the type specimen of A. orinus. Five of the new specimens were collected in summer in Afghanistan and Kazakhstan, indicating that the species probably breeds in Central Asia, and the data and moult of the others suggest that the species migrates along the Himalayas to winter in N India and SE Asia. The population structure suggests a stable or shrinking population. [source]


Molecular phylogenetic analysis of the white-crowned forktail Enicurus leschenaulti in Borneo

JOURNAL OF AVIAN BIOLOGY, Issue 2 2005
Robert G. Moyle
Comparison of 1017 nucleotides of mitochondrial ND2 and ND3 DNA sequences of 26 individuals of white-crowned forktail Enicurus leschenaulti from SE Asia revealed multiple evolutionary lineages within Borneo. Montane birds were genetically homogeneous across localities, but diverged by more than 4.3% from all other samples. Lowland birds formed two distinct clades, one consisting of individuals from northern Borneo, and the other including individuals from western Borneo, as well as Sumatra and Malaya. Relationships among the subspecies were not well resolved. These findings indicate another example of montane and north Bornean endemicity, support the separation of the montane and lowland species, and define areas of conservation interest. [source]


A record of Late Pleistocene and Holocene carbon accumulation and climate change from an equatorial peat bog (Kalimantan, Indonesia): implications for past, present and future carbon dynamics

JOURNAL OF QUATERNARY SCIENCE, Issue 7 2004
S. E. Page
Abstract A 9.5,m core from an inland peatland in Kalimantan, Indonesia, reveals organic matter accumulation started around 26,000,cal.,yr,BP, providing the oldest reported initiation date for lowland ombrotrophic peat formation in SE Asia. The core shows clear evidence for differential rates of peat formation and carbon storage. A short period of initial accumulation is followed by a slow rate during the LGM, with fastest accumulation during the Holocene. Between ,13,000 and 8000,cal.,yr,BP, >,450,cm of peat were deposited, with highest rates of peat (>,2,mm,yr,1) and carbon (>,90,g,C,m,2,yr,1) accumulation between 9530 and 8590,cal.,yr,BP. These data suggest that Kalimantan peatlands acted as a large sink of atmospheric CO2 at this time. Slower rates of peat (0.15,0.38,mm,yr,1) and carbon (7.4,24.0,g,C,m,2,yr,1) accumulation between ,8000 and 500,cal.,yr,BP coincide with rapid peat formation in coastal locations elsewhere in SE Asia. The average LORCA (long-term apparent carbon accumulation rate) for the 9.5,m core is 56,g,C,m,2,yr,1. These data suggest that studies of global carbon sources, sinks and their dynamics need to include information on the past and present sizeable peat deposits of the tropics. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Introduction of a Nuclear Marker for Phylogenetic Analysis of Nepenthaceae

PLANT BIOLOGY, Issue 6 2006
H. Meimberg
Abstract: Nepenthaceae, the pitcher plants of the Old World tropics show a remarkable diversity in SE Asia, especially on the islands of Borneo and Sumatra. This region is considered as a secondary center of diversity. Sequence analysis of the cpDNA trnK intron supports this hypothesis showing the species of the Malay Archipelago as neighbour group to the isolated species from Sri Lanka, the Seychelles, and Madagascar. Based on phylogenetic reconstructions an origin of recent Nepenthaceae in the Indian subcontinent is assumed. A recent investigation focused on a non-plastid, translocated copy of the trnK intron has revealed an incongruence to tree topology based on the cpDNA trnK intron. Although the translocated copy emerged as insufficient for phylogenetic reconstruction of Nepenthaceae some taxa showed, contrary to the cpDNA dataset, relatively high distances to the rest of the taxa. These results indicated that the phylogeny of the trnK intron could not reflect true phylogenetic relationships. We investigated the peptide transferase 1 (PTR1), to develop a phylogenetic marker that is based on a nuclear low copy gene in Nepenthes. All sequences obtained were probably functional, indicated by the ratio of point mutations of the single codon positions in exon and intron regions. Comparative analysis showed that this locus is of similar variability as the cpDNA trnK intron and, contrary to the translocated copy of trnK, potential useful for phylogenetic reconstruction. While in parts congruent to the plastid trnK intron phylogeny, a higher divergence of some sequences in PRT1 and in the previously reported, non cpDNA dataset indicates that remnants of an older species stock persisted east of Wallace's line and on the Sunda Shelf. This suggests that plastid haplotypes existing today in the main distribution center of the Nepenthaceae could be descendants of more recently dispersed lineages that had been transmitted to an old species stock. [source]


Seed Dispersal by Birds and Bats in Lowland Philippine Forest Successional Area

BIOTROPICA, Issue 4 2009
Regielene S. Gonzales
ABSTRACT In the tropical forests of SE Asia, only a few studies have dealt with the role animal dispersal plays in early forest succession and rehabilitation, and a comparison of bird and bat dispersal is even rarer. We investigated seed dispersal by birds and bats in a successional area in the lowland dipterocarp forest of the Subic Watershed Forest Reserve (SWFR) in Luzon Island, Philippines. Using pairs of day and night traps, we collected seeds during 3 mo of wet season and 3 mo of dry season in a 1.2-ha study site. Bird-dispersed seeds predominated over those dispersed by bats in terms of both seed abundance and number of seed species. The most abundant endozoochorous seed species were significantly biased toward either bird or bat dispersal. Birds and bats appeared to compete more strongly for fruit resources during the dry season than during the wet season, and bats responded more to changes in the seasons than birds did. GLM analyses showed that the factor that had the strongest influence on overall seed distribution was the number of fleshy-fruited trees surrounding the traps, and that the distribution pattern of day-dispersed seeds was affected by more physical factors (number of trees, size of trees, presence of fleshy-fruited and conspecific trees) in the study site than the pattern of night-dispersed seeds were. Given that birds are the more important dispersers in the study site, restoration efforts in SWFR might benefit by focusing on attracting these dispersers into its degraded habitats. [source]


Community Structure of Large Mammals in Tropical Montane and Lowland Forest in the Tenasserim-Dawna Mountains, Thailand

BIOTROPICA, Issue 3 2008
Robert Steinmetz
ABSTRACT Montane evergreen forest in SE Asia is structurally and floristically different from lowland habitats. The response of large mammals to this variation is largely unexplored. We used sign transects to compare community structure of large mammals in montane (>1100 m), and lowland (<1100 m) forest types over 4 yr in western Thailand. Relative abundance of most ungulate species was significantly higher in lowland forest, except for elephant (Elephas maximus) and tapir (Tapirus indicus), which were most abundant in montane forest (based on chi-square tests of sign encounter rates). Sexual segregation was apparent for gaur (Bos gaurus): breeding herds were concentrated in the lowlands, whereas single males were most abundant in montane forest. Large cat abundance was similar in both elevation zones. Tapir, single gaur, and bears (Ursus spp.) characterized the montane mammal community, whereas most other ungulate species and social groups were indicative of lowland forest (based on discriminant function analysis). Results pertain only to the dry season; seasonal movements could alter the patterns we observed. Differences in community structure between elevation zones are hypothesized to result from differences in habitat structure, resource availability, and human impacts. Lowland forests provide bamboo, grass, and mineral licks, probably accounting for higher ungulate densities despite higher levels of hunting. These resources are scarce in montane forest. However, montane forest functions as a refuge for at least three globally threatened large mammal species, because commercial hunting is concentrated in the more accessible lowlands. [source]