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Dendrochronological research in Southeast Asia is under development; however, the amount of tress with potential for dendrochronological studies is restricted. For example, teak trees from India, Myanmar, Thailand, and Java are valuable dendrochronologic studies for ready climate response. Teak from Java is best suited for studying the El Niño-Southern Oscillation and sea-surface temperatures, whereas Indian teak is used to reconstruct periods of drought in India. Further, Thai teak and Vietnamese cypress trees captured the long drought period that led to the demise of the Angkor reign (fourteenth–fifteenth century). Diverse techniques including anatomical observation, cambial markings, cell differentiation, and isotopic analysis prove the age and growth of invisible tropical tree rings. A number of invisible growth rings in trees from both tropical and subtropical forests have been identified, resulting in the advancement of dendrochronology. Climate change is a substantial challenge for most living things and natural resources. A greater understanding of tree species adaptation in this region is necessary. The understanding of long-term paleoclimate can be gained by researching old samples and archaeological materials from this region.  相似文献   

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Microbial control in Southeast Asia   总被引:1,自引:0,他引:1  
Beginning in the 1980s, concerns about the deleterious effects of synthetic pesticides have driven a significant Southeast Asian research and development effort directed towards alternative pest control strategies, including the use of microbial control agents. Despite this effort, use of microbial control agents has grown slowly in the region. This is the result of an interplay between internal factors such as economics, national research programs, farmer education, manufacturing capabilities and regulatory frameworks, and external factors such as the influence of neighboring countries (particularly China), the availability of competitive pest control products, import regulations on pesticide residues and the activities of donor agencies. The role of these factors in providing both incentives and barriers to the adoption of microbial control are explored, and examples of promising projects are examined as a means of pointing the way forward towards increased progress in the future.  相似文献   

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Eight polymorphic microsatellite markers were developed in Dryobalanops aromatica, an emergent tree in tropical rain forests in Southeast Asia, using an enriched library method. For the assessment of microsatellite variation, 36 individuals from a natural population were analysed. The number of alleles per locus ranged from three to 16, with observed heterozygosity of 0.056–0.833 and expected heterozygosity of 0.054–0.882. These microsatellite markers will be useful for studies of population genetics, reproductive ecology and regeneration dynamics of D. aromatica.  相似文献   

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Rapidly changing land use in Southeast Asia threatens plant diversity, and reduces the time we have left to document it. Despite over 200 years of scientific plant exploration, many plant species have yet to be discovered. Moreover, we still have a very poor understanding of the distribution of known taxa in this biogeographically complex region. We review the current state of biodiversity exploration, using plants in Indonesia as an example. Traditional methods of collecting and describing species have provided a solid foundation for our understanding of plant biodiversity, but are insufficient for the pragmatic task of rapidly discovering and documenting today’s biodiversity before it is gone, because general collecting expeditions tend to be infrequent, and documentation of most new species must await taxonomic revisions many years in the future. Solutions to this exploration and documentation crisis (i) could use the abundant resource of enthusiastic, networked, national biology students, (ii) should employ biodiversity informatics tools to efficiently engage both specialists and parataxonomists, and (iii) might require adoption of new types of α-taxonomy, utilizing increasingly low-cost molecular methods and high resolution photographs. We describe emerging technologies that will facilitate this taxonomic development. We believe that a new golden age of biodiversity exploration may be dawning, just as biodiversity itself is most threatened, and are hopeful that increasing knowledge of biodiversity will be a positive force to slow its loss.  相似文献   

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Genetic diversity within and among six natural populations of Nypa fruticans from China, Vietnam, and Thailand was assessed using SSR and ISSR analysis. Our results showed an extremely low level of genetic diversity of N. fruticans (at the species level, P = 11.76% and 2.88%, He = 0.0279 and 0.0113, I = 0.0470 and 0.0167 by SSRs and ISSRs, respectively) across a total of 183 individuals. No genetic variation was detected within any population except for the Thailand population by SSRs (P = 11.76%, He = 0.0417; I = 0.0622). The bottlenecks during glacial epochs, founder effects, and propagation pattern may be responsible for the extremely low level of genetic diversity of N. fruticans.  相似文献   

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The extinction of large-bodied taxa from the Pleistocene in Southeast Asia is examined. Although the chronological resolution of these extinctions is poor, and number of excavations in the region relatively few, broad characteristics of these extinctions can be described. Many taxa which became extinct appear to have been endemic to regions within Southeast Asia, while some taxa which experienced extinction or severe range reduction occurred in several regions. Members of the latter group include proboscideans (Stegodon and Palaeloxodon), the pygmy hippopotamus (Hexaprotodon), the orangutan (Pongo), hyenas (Crocuta and Hyaena), the giant panda (Ailuropoda), tapirs (Tapirus and Megatapirus), rhinoceroses (Rhinoceros), and the giant Asian ape Gigantopithecus. The loss of these species cannot be assigned to a single cause. Rather their disappearance is likely tied to both climatic and human agents. Unlike other regions which experienced megafauna extinctions, eustatic changes in sea level in Southeast Asia seems to have been an important factor.  相似文献   

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Biogeography of polypores distributed in the Malesian region is reviewed. Some of the species reported from this region are pantropical or paleotropical and widely distributed along the equator. Several species are restricted to lowland areas of Malesia and adjacent regions, and can be classified as Asian or Asian-Oceanian tropical species. Some species have only been recorded from lowland areas of Malesia at present, but detailed distributions are unclear for many of them. Some lowland Malesian species are also distributed in temperate areas of East Asia; among them, few species are circumglobal in the Northern Hemisphere, whereas many others are tropical species showing continuous distributions up to the warm temperate areas of East Asia. Species recorded from highland areas of Malesia include tropical species common to lowland Malesia, temperate species common to temperate Asia, and endemic species in highland areas of Malesia and adjacent regions. Regarding the factors that delimitate distribution of the Malesian polypores, I discuss polypore host preference, response to physical environmental factors, and dispersal ability. Systematics and ecological characteristics are briefly discussed for selected Malesian polypores: Corneroporus subcitrinus, Paratrichaptum accuratum, Postia stellifera and Roseofavolus eos.  相似文献   

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Dengue and hemorrhagic fevers of Southeast Asia   总被引:2,自引:0,他引:2  
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Modern maritime piracy has become one of the major threats to safety at sea. How to combat maritime piracy in Southeast Asia effectively is the major concern of this contribution. It is argued that some form of government cooperation involving most of the governments of the Southeast Asian region is the best way to combat maritime piracy, although it is not an easy task due to various political, economical, and historical reasons. A unilateral and expedient arrangement by one or a few governments to combat maritime piracy may be convenient but may also encounter resistance or raise suspicion from other governments.  相似文献   

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Swidden Transformations and Rural Livelihoods in Southeast Asia   总被引:1,自引:4,他引:1  
This paper explores the major interactions between the transformation of swidden farming and the pursuit of rural livelihoods in the uplands of Southeast Asia. The paper draws on selected literature, workshop reflections, and six case studies to describe the causal processes and livelihood consequences of swidden change. Household-level livelihood responses have included both the intensification and ‘dis-intensification’ of swidden land-use, the insertion of cash crops, the redeployment of household labour, and the taking on of broader (often non-rural) livelihood aspirations and strategies. At the community level there have been emerging institutional arrangements for management of land and forests, and varying degrees of participation in or resistance to government schemes and programs. Swidden change has led to the loss and also the reassertion, realignment, and redefinition of cultures and identities, with important implications for access to resources. The impacts of these changes have been varied. Cash crops have often improved livelihoods but complete specialisation for the market increases vulnerability. Thus swidden can still provide an important safety net in the face of market fluctuations. Improved access to markets and social provision of education and health care have mostly improved the welfare of previously isolated groups. However, growing differences within and between communities in the course of swidden transformations can leave some groups marginalized and worse off. These processes of differentiation can be accentuated by heavy-handed state interventions based on swidden stereotypes. Nevertheless, communities have not passively accepted these pressures and have mobilized to protect their livelihood assets and strategies. Thus swidden farmers are not resisting appropriate and supportive forms of development. They are adopting new practices and engaging with markets, but in many situations swidden is still important to their livelihood strategies, providing resilience in the face of turbulent change. Active involvement of local people is essential in planning, implementing, monitoring and evaluating development and conservation programs in swidden lands. Positive market incentives and supportive government policies are better than standardised, top-down directives.
R. A. CrambEmail:
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