Identification and characterization of microsatellite markers for the population genetic structure in endemic red-tailed barb,Gonoproktopterus curmuca

Gonoproktopterus curmuca is an endangered red tailed barb found in Southern part of Western Ghat, India. As a part of stock-specific, propagation assisted rehabilitation and management program, polymorphic microsatellites markers were used to study the genetic diversity and population structure of this species from the three River systems of Southern Western Ghats, such as Periyar River, the Chalakkudy River, and the Chaliyar River. From selected eight polymorphic microsatellite markers, the number of alleles per locus ranged from 2 to 8, and the average number of alleles among 3 populations ranged from 5.0 to 5.75. The mean observed (H_ob) and expected (H_ex) heterozygosity ranged from 0.5148 to 0.5360 and from 0.5996 to 0.6067, respectively. Significant deviations from Hardy–Weinberg Equilibrium expectation were found at majority of the loci (except Gcur MFW72 and Gcur MFW19) and in all three populations in which heterozygote deficits were apparent. The analysis of molecular variance indicates that the percent of variance among populations and within populations were 6.73 and 93.27, respectively. The pairwise F_ST values between populations indicate that there were significant deviations in genetic differentiations for the red-tailed barb populations from these three Rivers of the Western Ghats, India. The microsatellites methods reported a low degree of gene diversity and lack of genetic heterogeneity in the population of G. curmuca, which strongly emphasize the need of fishery management, conservation and rehabilitation of G. curmuca.     

Climatic controls of vegetation vigor in four contrasting forest types of India—evaluation from National Oceanic and Atmospheric Administration’s Advanced Very High Resolution Radiometer datasets (1990–2000)

Ten-day advanced very high resolution radiometer images from 1990 to 2000 were used to examine spatial patterns in the normalized difference vegetation index (NDVI) and their relationships with climatic variables for four contrasting forest types in India. The NDVI signal has been extracted from homogeneous vegetation patches and has been found to be distinct for deciduous and evergreen forest types, although the mixed-deciduous signal was close to the deciduous ones. To examine the decadal response of the satellite-measured vegetation phenology to climate variability, seven different NDVI metrics were calculated using the 11-year NDVI data. Results suggested strong spatial variability in forest NDVI metrics. Among the forest types studied, wet evergreen forests of north-east India had highest mean NDVI (0.692) followed by evergreen forests of the Western Ghats (0.529), mixed deciduous forests (0.519) and finally dry deciduous forests (0.421). The sum of NDVI (SNDVI) and the time-integrated NDVI followed a similar pattern, although the values for mixed deciduous forests were closer to those for evergreen forests of the Western Ghats. Dry deciduous forests had higher values of inter-annual range (RNDVI) and low mean NDVI, also coinciding with a high SD and thus a high coefficient of variation (CV) in NDVI (CVNDVI). SNDVI has been found to be high for wet evergreen forests of north-east India, followed by evergreen forests of the Western Ghats, mixed deciduous forests and dry deciduous forests. Further, the maximum NDVI values of wet evergreen forests of north-east India (0.624) coincided with relatively high annual total precipitation (2,238.9 mm). The time lags had a strong influence in the correlation coefficients between annual total rainfall and NDVI. The correlation coefficients were found to be comparatively high (R²=0.635) for dry deciduous forests than for evergreen forests and mixed deciduous forests, when the precipitation data with a lag of 30 days was correlated against NDVI. Using multiple regression approach models were developed for individual forest types using 16 different climatic indices. A high proportion of the temporal variance (>90%) has been accounted for by three of the precipitation parameters (maximum precipitation, precipitation of the wettest quarter and driest quarter) and two of the temperature parameters (annual mean temperature and temperature of the coldest quarter) for mixed deciduous forests. Similarly, in the case of deciduous forests, four precipitation parameters and three temperature parameters explained nearly 83.6% of the variance. These results suggest differences in the relationship between NDVI and climatic variables based upon the time of growing season, time interval and climatic indices over which they were summed. These results have implications for forest cover mapping and monitoring in tropical regions of India.     

Assessment of genetic diversity and population structure of Bergenia stracheyi (Saxifragaceae) in the Western Himalaya (India)

Genetic diversity and population structure in Bergenia stracheyi, a threatened medicinal herb in the Western Himalaya of India was analysed using directed amplification of minisatellite DNA (DAMD) and inter simple sequence repeats (ISSR) markers. A total of 41 accessions of B. stracheyi representing three populations (Khillenmarg –KLM, Jalori Pass-JLP and Rohtang-RTG) were considered in the present study. The cumulative data analysis for 26 (10 DAMD + 16 ISSR) markers revealed 87.1% polymorphism. The maximum inter-population genetic distance was found between KLM and JLP, whereas the minimum genetic distance was found between RTG and JLP populations. The analysis of molecular variance (AMOVA) revealed maximum percentage of variation among individuals within populations (75%) than among the populations (25%). Clustering pattern of the three sample populations in STRUCTURE and PCoA analyses showed high genetic variation at population level. The present study revealed that distribution patterns, high altitudinal ranges, high habitat specificity, relatively high gene flow, small and isolated population size have shaped the current population structure of B. stracheyi in the Western Himalayan region. DAMD and ISSR markers have provided significant insights into characterization of B. stracheyi populations, and facilitate selection of appropriate accessions for further utilization in conservation and bioprospecting programmes.     

Tree species diversity and community composition in a human-dominated tropical forest of Western Ghats biodiversity hotspot,India

The structure, function, and ecosystem services of tropical forest depend on its species richness, diversity, dominance, and the patterns of changes in the assemblages of tree populations over time. Long-term data from permanent vegetation plots have yielded a wealth of data on the species diversity and dynamics of tree populations, but such studies have only rarely been undertaken in tropical forest landscapes that support large human populations. Thus, anthropogenic drivers and their impacts on species diversity and community structure of tropical forests are not well understood. Here we present data on species diversity, community composition, and regeneration status of tropical forests in a human-dominated landscape in the Western Ghats of southern India. Enumeration of 40 plots (50 m × 20 m) results a total of 106 species of trees, 76 species of saplings and 79 species of seedlings. Detrended Correspondence Analysis ordination of the tree populations yielded five dominant groups, along disturbance and altitudinal gradients on the first and second axes respectively. Abundant species of the area such as Albizia amara, Nothopegia racemosa and Pleiospermum alatum had relatively few individuals in recruiting size classes. Our data indicate probable replacement of rare, localized, and old-growth ‘specialists’ by disturbance-adapted generalists, if the degradation is continuing at the present scale.     

Ancient geographical gaps and paleo-climate shape the phylogeography of an endemic bird in the sky islands of southern India

Background

Sky islands, formed by the highest reaches of mountain tracts physically isolated from one another, represent one of the biodiversity-rich regions of the world. Comparative studies of geographically isolated populations on such islands can provide valuable insights into the biogeography and evolution of species on these islands. The Western Ghats mountains of southern India form a sky island system, where the relationship between the island structure and the evolution of its species remains virtually unknown despite a few population genetic studies.

Methods and Principal Findings

We investigated how ancient geographic gaps and glacial cycles have partitioned genetic variation in modern populations of a threatened endemic bird, the White-bellied Shortwing Brachypteryx major, across the montane Shola forests on these islands and also inferred its evolutionary history. We used Bayesian and maximum likelihood-based phylogenetic and population-genetic analyses on data from three mitochondrial markers and one nuclear marker (totally 2594 bp) obtained from 33 White-bellied Shortwing individuals across five islands. Genetic differentiation between populations of the species correlated with the locations of deep valleys in the Western Ghats but not with geographical distance between these populations. All populations revealed demographic histories consistent with population founding and expansion during the Last Glacial Maximum. Given the level of genetic differentiation north and south of the Palghat Gap, we suggest that these populations be considered two different taxonomic species.

Conclusions and Significance

Our results show that the physiography and paleo-climate of this region historically resulted in multiple glacial refugia that may have subsequently driven the evolutionary history and current population structure of this bird. The first avian genetic study from this biodiversity hotspot, our results provide insights into processes that may have impacted the speciation and evolution of the endemic fauna of this region.     

Exploring wild genetic resources of Musa acuminata Colla distributed in the humid forests of southern Western Ghats of peninsular India using ISSR markers

Musa acuminata ssp. burmannica, one of the wild progenitors contributing 'A genome' to the present-day dessert bananas, has a long evolutionary history intervened by human activities. In this study, ISSR markers were used to analyze the pattern of genetic variation and differentiation in 32 individuals along with two reference samples (viz., Musa acuminata ssp. burmannicoides, var. Calcutta 4 and Musa balbisiana) of wild Musa, which corresponded to three populations across the biodiversity-rich hot spot of southern Western Ghats of India. High levels of genetic diversity were revealed both at the species and population levels, using Nei's diversity indices. The hierarchical analysis of molecular variance showed pronounced genetic differentiation, as 96?% of the total variance was fixed within population and only 4?% among populations. Nei's genetic differentiation coefficient (G (ST)?=?0.1823) and low gene flow (Nm?=?1.18) further confirmed this. The positive correlation (Mantel test) between geographic distance and genetic distance (r?=?0.338 P?相似文献   

Fragmentation Genetics of Vateria indica: implications for management of forest genetic resources of an endemic dipterocarp

Tropical agro-forest landscapes are potentially valuable reserves of forest genetic resources for forestry and restoration of degraded forests. The Dipterocarpaceae is a dominant Southeast Asian family of tree species of global significance for the tropical timber industry. Very little information exists about how effective human modified landscapes are for conserving genetic diversity in dipterocarp species. This study provides a baseline for understanding how fragmented agro-forest landscapes in India sustain forest genetic resources in an endemic dipterocarp tree. We compare genetic diversity and fine-scale spatial genetic structure (FSGS) in the threatened tree species Vateria indica within an isolated and a continuous forest site in the Western Ghats, South India. We place these results in the context of dipterocarps from both the Seychelles and Borneo. Parentage analysis of 694 progeny using twelve nuclear microsatellite markers is applied to estimate pollen and seed dispersal. Using a nursery trial we evaluate effects of inbreeding on growth performance. Our results show that levels of FSGS, and gene dispersal are comparable between a small isolated and a large continuous site of V. indica. Realized long-distance pollen flow into the isolated patch appears to help maintaining genetic diversity. The nursery experiment suggests that selection favours outbred progeny. Individuals of V. indica in close proximity appear less related to each other than in another highly fragmented and endangered dipterocarp species from the Seychelles, but more related than in three dipterocarp species studied in continuous forest in Borneo. We discuss the wider implications of our findings in the context of conservation and restoration of dipterocarp forest genetic resources in fragmented populations.     

Genetic diversity of ectomycorrhizal Basidiomycetes from African and Indian tropical rain forests

Ectomycorrhizal (ECM) fungi have a worldwide distribution. However, the ecology of tropical ECM fungi is poorly documented, limiting our understanding of the symbiotic associations between tropical plants and fungi. ECM Basidiomycete diversity was investigated for the first time in two tropical rain forests in Africa (Western Upper Guinea) and in Asia (Western Ghats, India), using a fragment of the mitochondrial large subunit rRNA gene to type 140 sporocarps and 54 ectomycorrhizas. To evaluate taxonomic diversity, phylogenetic analyses were performed, and 40 sequences included from identified European specimens were used as taxonomic benchmarks. Five clades were recovered corresponding to six taxonomic groups: boletoids, sclerodermatoids, russuloids, thelephoroids, and a clade grouping the Amanitaceae and Tricholomataceae families. Our results revealed that the Russulaceae species display a great diversity with several putative new species, especially in Guinea. Other taxonomic issues at family/section levels are also briefly discussed. This study provides preliminary insights into taxonomic diversity, ECM status, and biogeographic patterns of ECM fungi in tropical two rain forest ecosystems, which appear to be as diverse as in temperate and boreal forests.     

Fine- and local- scale genetic structure of <Emphasis Type="Italic">Dysoxylum malabaricum,</Emphasis> a late-successional canopy tree species in disturbed forest patches in the Western Ghats,India

Dysoxylum malabaricum (white cedar) is an economically important tree species, endemic to the Western Ghats, India, which is the world’s most densely populated biodiversity hotspot. In this study, we used variation at ten nuclear simple sequence repeat loci to investigate genetic diversity and fine scale spatial genetic structure (FSGS) in seedlings and adults of D. malabaricum from four forest patches in the northern part of the Western Ghats. When genetic variation was compared between seedlings and adults across locations, significant differences were detected in allelic richness, observed heterozygosity, fixation index (F _IS), and relatedness (P < 0.05). Reduced genetic diversity and increased relatedness at the seedling stage might be due to fragmentation and disturbance. There was no FSGS at the adult stage and FSGS was limited to shorter distance classes at the seedling stage. However, there was clear spatial genetic structure at the landscape level (<50 km), regardless of age class, due to limited gene flow between forest patches. A comparison of the distributions of size classes in the four locations with published data from a more southern area, showed that large trees (diameter at breast height, DBH, >130 cm) are present in the southern sacred forests but not in the northern forest reserves. This pattern is likely due to stronger harvesting pressure in the north compared to the south, because in the north there are no cultural taboos regulating the extraction of natural resources. The implications for forest conservation in this biodiversity hotspot are discussed.     

Genetic structure and diversity of Coscinium fenestratum: a critically endangered liana of Western Ghats,India

Coscinium fenestratum is a critically endangered medicinal plant, well-known for its bioactive isoquinoline alkaloid berberine. The species has been over harvested from its natural habitats to meet the huge requirement of raw drug market and industrial consumption. This has lead to a rapid decline in the population size and has also led to local population extinction at few locations in the Western Ghats, India. In this study, inter-simple sequence repeat markers were used to investigate the genetic variation and population structure of seven extant populations of C. fenestratum from the central Western Ghats, India. Eight primer combination produced a total of 57 unambiguous bands, of which (47.1 %) were polymorphic. The species exhibited a moderate to low level of intra population genetic diversity (H _s = 0.347 ± 0.008; H _t = 0.378 ± 0.006 (POPGENE) and H _s = 0.262 ± 0.0028; H _t = 0.204 ± 0.020 (HICKORY)). The populations were low to moderately differentiated from one another (G _ST = 0.221) and geographical distance was not significantly correlated with genetic distance, suggesting that these long-lived, geographically distant remnant populations were once connected through gene flow. There was a significant amount of genetic variation among populations (19.85 %). The Bayesian software STRUCTURE and HICKORY were used to further reveal the genetic structure of C. fenestratum. The results revealed weak population structure (K = 2) with one single widespread gene pool, and indicated that gene flow and inbreeding are likely to be the major driving force in shaping current population genetic structure of C. fenestratum. Thus, an understanding of the genetic diversity and population structure of C. fenestratum can provide insight into the conservation and management of this species.     

Assessment of genetic diversity in Calamus thwaitesii BECC. (Arecaceae) using RAPD markers

Calamus thwaitesii Becc. is a potentially useful rattan found in the Western Ghats of India and Sri Lanka. The wild stock of this rattan species is greatly diminished due to overexploitation for the furniture industry and increasingly rare. Genetic diversity was estimated in 80 samples representing eight populations from the Western Ghats and Sri Lanka using Random Amplified Polymorphic DNA (RAPD) markers. RAPDs generated a total of 120 markers with 10 decamer primers, of which 85% were found to be polymorphic. The percentage of polymorphic loci varied from 40.00 to 60.83 and genetic distance between populations ranged from 0.0332 to 0.2777. Among the analysed populations, Goa was found to be genetically superior followed by Achenkovil, Sinharaja and Talakkaveri. Majority of the genetic diversity was distributed within populations (70.79%) and only (29.21%) among populations. Genetic relationships estimated by the unweighted pair-group method with arithmetic averaging (UPGMA) cluster analysis and principal co-ordinate analysis failed to separate Indian and Sri Lankan populations geographically into two distinct groups.     

Genetic structure and demographic history of the endangered tree species Dysoxylum malabaricum (Meliaceae) in Western Ghats,India: implications for conservation in a biodiversity hotspot

The impact of fragmentation by human activities on genetic diversity of forest trees is an important concern in forest conservation, especially in tropical forests. Dysoxylum malabaricum (white cedar) is an economically important tree species, endemic to the Western Ghats, India, one of the world's eight most important biodiversity hotspots. As D. malabaricum is under pressure of disturbance and fragmentation together with overharvesting, conservation efforts are required in this species. In this study, range‐wide genetic structure of twelve D. malabaricum populations was evaluated to assess the impact of human activities on genetic diversity and infer the species’ evolutionary history, using both nuclear and chloroplast (cp) DNA simple sequence repeats (SSR). As genetic diversity and population structure did not differ among seedling, juvenile and adult age classes, reproductive success among the old‐growth trees and long distance seed dispersal by hornbills were suggested to contribute to maintain genetic diversity. The fixation index (F_IS) was significantly correlated with latitude, with a higher level of inbreeding in the northern populations, possibly reflecting a more severe ecosystem disturbance in those populations. Both nuclear and cpSSRs revealed northern and southern genetic groups with some discordance of their distributions; however, they did not correlate with any of the two geographic gaps known as genetic barriers to animals. Approximate Bayesian computation‐based inference from nuclear SSRs suggested that population divergence occurred before the last glacial maximum. Finally we discussed the implications of these results, in particular the presence of a clear pattern of historical genetic subdivision, on conservation policies.     

Endemic Asian Chytrid Strain Infection in Threatened and Endemic Anurans of the Northern Western Ghats,India

The Western Ghats of India harbors a rich diversity of amphibians with more than 77% species endemic to this region. At least 42% of the endemic species are threatened due to several anthropogenic stressors. However, information on amphibian diseases and their impacts on amphibian populations in this region are scarce. We report the occurrence of Batrachochytridium dendrobatidis (Bd), an epidermal aquatic fungal pathogen that causes chytridiomycosis in amphibians, from the Western Ghats. In the current study we detected the occurrence of a native Asian Bd strain from three endemic and threatened species of anurans, Bombay Night Frog Nyctibatrachus humayuni, Leith''s Leaping Frog Indirana leithii and Bombay Bubble Nest Frog Raorchestes bombayensis, for the first time from the northern Western Ghats of India based on diagnostic nested PCR, quantitative PCR, DNA sequencing and histopathology. While, the Bd infected I. leithii and R. bombayensis did not show any external symptoms, N. humayuni showed lesions on the skin, browning of skin and sloughing. Sequencing of Bd 5.8S ribosomal RNA gene, and the ITS1 and ITS2 regions, revealed that the current Bd strain is related to a haplotype endemic to Asia. Our findings confirm the presence of Bd in northern Western Ghats and the affected amphibians may or may not show detectable clinical symptoms. We suggest that the significance of diseases as potential threat to amphibian populations of the Western Ghats needs to be highlighted from the conservation point of view.     

Hygrocybe rubida,a new species from Kerala State,India

Hygrocybe rubida, a new species in subsection Squamulosae of section Coccinea, collected from tropical evergreen forests of Western Ghats of Kerala is formally described. The species is characterized by a bright red, dry pileus and stipe; ovoid to subamygdaliform spores; a distinctly sterile lamella-edge with crowded cheilocystidia and a trichodermial pileipellis.     

Genetic diversity and phylogenetic analysis of blackbuck (Antilope cervicapra) in southern India

Blackbuck (Antilope cervicapra) is a threatened species endemic to the Indian subcontinent. Many populations of blackbuck are found in southern India. Populations of blackbuck are negatively affected in many places for various reasons, such as habitat destruction and poaching. Their range decreased sharply during the 20th century. There is very limited information available on the population dynamics of blackbuck in southern India. For the phylogenetic and genetic diversity analyses of blackbuck populations among different distribution ranges in southern India, we sequenced mt DNA of cytochrome b (Cyt b) for 120, cytochrome c oxidase subunit-1 (COI) for 137 and the control region (CR) for 137 fecal pellets from eleven different locations in southern India. We analyzed the genetic structure of three mitochondrial markers, the CR, Cyt b and the COI region, separately and in a combined dataset. The haplotype diversity and nucleotide diversity of CR were 0.969 and 0.047, respectively, and were higher than those of Cyt b and COI. A Bayesian phylogeny and an MJ network based on the CR and combined dataset (105 sequences) signified several distinct haplotype clusters within blackbuck, whereas no clusters were identified with the Cyt b and COI phylogenetic analyses. The analysis of molecular variance of the combined data set revealed 52.46% genetic variation within the population. Mismatch distribution analysis revealed that blackbuck populations underwent complex changes with analysis of the combined dataset in each population and analysis of each marker separately in the overall population. The results provide evidence that blackbuck in different geographic locations has a distinct population structure due to habitat fragmentation after the formation of the Western and Eastern Ghats.

     

Additions to Gliocephalotrichum species (anamorphic Hypocreales) from fruit litter of the medicinal plant Terminalia chebula in the Western Ghats, India

Two species of Gliocephalotrichum were isolated from fallen fruits of the medicinal plant Terminalia chebula collected from the forests of Western Ghats, India. On the basis of morphological characters and ITS1–5.8S–ITS2 sequence similarity, the fungi have been identified as Gliocephalotrichum longibrachium and G. bulbilium. For the former species, this is the first report of its occurrence from India, whereas the latter, showing significant morphological variability, has been known previously from India.     

Genetic variability and population structure in Sapindus emarginatus Vahl from India

Sapindus emarginatus is an economically important tropical tree species sparsely distributed in different geographical provinces like Gangetic Plains, Western Ghats, and Deccan Plateau in India. In the present paper estimation of genetic variability within and among 41 accessions representing five populations was carried out using 3 single primer amplification reaction (SPAR) methods viz. RAPD, DAMD and ISSR. The cumulative data analysis was carried out for all three SPAR methods, and showed 82.32% polymorphism across all the accessions of S. emarginatus. Jaccard's similarity values among 41 accessions ranged from 0.15 to 0.49 with an average value of 0.37. The intra-population genetic diversity revealed highest values of Nei's genetic diversity (0.19,) Shannon information index (0.29) and polymorphic loci (55.18%), among the accessions of Gujarat (GJ) population, while the corresponding lowest values were (0.10), (0.15) and (26.40%) respectively among the accessions of Rajasthan (RJ) population. The maximum inter-population average genetic distance (0.20) was between Karnataka (KA) and RJ, while the corresponding least genetic distance (0.06) was between Allahabad (AL) and Varanasi (VS) populations. The analysis of molecular variance (AMOVA) revealed maximum percentage of variation among individuals of populations (72%) followed by 16% among regions and 12% among populations. Principal coordinate analysis (PCA) of cumulative data also supported the clustering pattern in the UPGMA dendrogram. These results suggest that genetic diversity is corroborating with the geographical diversity. Mantel's test was performed which revealed a highly significant correlation between cumulative vs RAPD, and showed the maximum (0.93) correlation coefficient, followed by cumulative vs ISSR (0.78) and cumulative vs DAMD (0.91) respectively, and this clearly indicates that the SPAR methods (RAPD, DAMD and ISSR) are sufficiently informative and are suitable to analyze the genetic variability within and among the populations of S. emarginatus.     

Genetic variation and population structure inOryza malampuzhaensis Krish.et Chand. endemic to Western Ghats, South India

Oryza malampuzhaensis Krish.et Chand. (2n = 4x = 48; Poaceae,Oryza) is endemic to Western Ghats, South India, and shows a highly localized distribution over a small geographical area in this region. This is the most poorly understood taxon in genusOryza and is often misidentified asO. officinalis owing to their close morphology. We assessed the nature and distribution of genetic variation among 11 populations ofO. malampuzhaensis using random amplified polymorphic DNA markers. The analysis revealed low genetic variation inO. malampuzhaensis. Cluster analysis of pairwise genetic distances of populations revealed three distinct clusters and the grouping of populations largely corresponded to their geographical proximity. Restricted gene flow and a geography-dependent differentiation were evident among populations. The altitude-influenced differences in ecological factors among the natural habitats of the populations seem to be the cause of the geography-dependent differentiation. Genetically isolated smaller populations and a narrow genetic base inO. malampuzhaensis point to its vulnerability to genetic drift and genetic depauperation. ThusO. malampuzhaensis appears to be under the threat of extinction and needs to be conserved by use of suitable methods. The present study also identified molecular markers diagnostic forO. malampuzhaensis.     

Distinct Bacterial Communities Dominate Tropical and Temperate Zone Leaf Litter

Little is known of the bacterial community of tropical rainforest leaf litter and how it might differ from temperate forest leaf litter and from the soils underneath. We sampled leaf litter in a similarly advanced stage of decay, and for comparison, we also sampled the surface layer of soil, at three tropical forest sites in Malaysia and four temperate forest sites in South Korea. Illumina sequencing targeting partial bacterial 16S ribosomal ribonucleic acid (rRNA) gene revealed that the bacterial community composition of both temperate and tropical litter is quite distinct from the soils underneath. Litter in both temperate and tropical forest was dominated by Proteobacteria and Actinobacteria, while soil is dominated by Acidobacteria and, to a lesser extent, Proteobacteria. However, bacterial communities of temperate and tropical litter clustered separately from one another on an ordination. The soil bacterial community structures were also distinctive to each climatic zone, suggesting that there must be a climate-specific biogeographical pattern in bacterial community composition. The differences were also found in the level of diversity. The temperate litter has a higher operational taxonomic unit (OTU) diversity than the tropical litter, paralleling the trend in soil diversity. Overall, it is striking that the difference in community composition between the leaf litter and the soil a few centimeters underneath is about the same as that between leaf litter in tropical and temperate climates, thousands of kilometers apart. However, one substantial difference was that the leaf litter of two tropical forest sites, Meranti and Forest Research Institute Malaysia (FRIM), was overwhelmingly dominated by the single genus Burkholderia, at 37 and 23 % of reads, respectively. The 454 sequencing result showed that most Burkholderia species in tropical leaf litter belong to nonpathogenic “plant beneficial” lineages. The differences from the temperate zone in the bacterial community of tropical forest litter may be partly a product of its differing chemistry, although the unvarying climate might also play a role, as might interactions with other organisms such as fungi. The single genus Burkholderia may be seen as potentially playing a major role in decomposition and nutrient cycling in tropical forests, but apparently not in temperate forests.