The state and conservation of Southeast Asian biodiversity

Southeast Asia is a region of conservation concern due to heavy losses of its native habitats. In this overview, we highlight the conservation importance of Southeast Asia by comparing its degree of species endemism and endangerment, and its rate of deforestation with other tropical regions (i.e., Meso-America, South America, and Sub-Saharan Africa). Southeast Asia contains the highest mean proportion of country-endemic bird (9%) and mammal species (11%). This region also has the highest proportion of threatened vascular plant, reptile, bird, and mammal species. Furthermore, not only is Southeast Asia’s annual deforestation rate the highest in the tropics, but it has also increased between the periods 1990–2000 and 2000–2005. This could result in projected losses of 13–85% of biodiversity in the region by 2100. Secondary habitat restoration, at least in certain countries, would allow for some amelioration of biodiversity loss and thus potentially lower the currently predicted extinction rates. Nonetheless, urgent conservation actions are needed. Conservation initiatives should include public education, sustaining livelihoods, and ways to enhance the sustainability of agriculture and increase the capacity of conservation institutions. Furthermore, these actions should be country-specific and not ignore areas heavily populated by humans, as they can also harbour high numbers of threatened species. We urge that cooperative conservation initiatives be undertaken and support (e.g., capacity-building) be given by more developed countries in the region and beyond.     

Effects of pesticide practices on insect biodiversity in peach orchards

To examine the effects of pesticides on insect biodiversity, a population survey was conducted in conventionally managed, low-input, and organic peach orchards. Pitfall traps were used to sample a total of 6489 insects representing 151 species at seven study sites. Results of a population survey suggest that pesticide application adversely affected insect biodiversity in peach orchards and that the magnitude of the adverse effect might be greater for herbicide application than for insecticide application. The usefulness of carabids and ants as biological indicators of the effects of pesticides was also evaluated. Results suggest that the ant species Tetramorium tsushimae is a good indicator in peach orchards. In contrast, carabids are not suitable indicators.     

Use of traditional health practices by Southeast Asian refugees in a primary care clinic.

To determine the prevalence of use of traditional health practices among different ethnic groups of Southeast Asian refugees after their arrival in the United States, we conducted a convenience sample of 80 Cambodian, Lao, Mien, and ethnic Chinese patients (20 each) attending the University of Washington Refugee Clinic for a new or follow-up visit. Interpreters administered a questionnaire that dealt with demographics, medical complaints, traditional health practices, health beliefs, and attitudes toward Western practitioners. In all, 46 (58%) patients had used one or more traditional health practices, but the prevalence varied by ethnic group. Coining and massage were used by all groups except the Mien, whereas moxibustion and healing ceremonies were performed almost exclusively by the Mien. Traditional health practices were used for a variety of symptoms and, in 78% of reported uses, patients reported alleviation of symptoms. The use of traditional health practices is common among Southeast Asian refugees. Clinicians who care for this population should be aware of these practices because they may supersede treatments prescribed by physicians or leave cutaneous stigmata that may be confused with disease or physical abuse. Good patient care may necessitate the use or tolerance of both Western and traditional modalities in many Southeast Asian refugees.     

Diversity of the bacterial community in the rice rhizosphere managed under conventional and no-tillage practices

Bacterial diversity in the rice rhizosphere at different rice growth stages, managed under conventional and no-tillage practices, was explored using a culture-based approach. Actinobacteria are among the bacterial phyla abundant in the rice rhizosphere. Their diversity was further examined by constructing metagenomic libraries based on the 16S rRNA gene, using actinobacterial- and streptomycete-specific polymerase chain reaction (PCR) primers. The study included 132 culturable strains and 125 clones from the 16S rRNA gene libraries. In conventional tillage, there were 38% Proteobacteria, 22% Actinobacteria, 33% Firmicutes, 5% Bacteroidetes, and 2% Acidobacteria, whereas with no-tillage management there were 63% Proteobacteria, 24% Actinobacteria, 6% Firmicutes, and 8% Bacteroidetes as estimated using the culture-dependent method during the four stages of rice cultivation. Principal coordinates analysis was used to cluster the bacterial communities along axes of maximal variance. The different growth stages of rice appeared to influence the rhizosphere bacterial profile for both cultivation practices. Novel clones with low similarities (89–97%) to Actinobacteria and Streptomyces were retrieved from both rice fields by screening the 16S rRNA gene libraries using actinobacterial- and streptomycete-specific primers. By comparing the actinobacterial community retrieved by culture-dependent and molecular methods, it was clear that a more comprehensive assessment of microbial diversity in the rice rhizosphere can be obtained using a combination of both techniques than by using either method alone. We also succeeded in culturing a number of bacteria that were previously described as unculturable. These were in a phylogenetically deep lineage when compared with related cultivable genera.     

Evidence of extreme habitat stability in a Southeast Asian biodiversity hotspot based on the evolutionary analysis of neotenic net-winged beetles

The diversification of neotenic beetle lineages has not been studied, despite the potential for defining biodiversity hotspots and elucidating the history of regional faunas. Additionally, neotenics may provide insight into the process of speciation in small populations with extremely low dispersal ability and a limited range. Here, we used two rDNA and three mtDNA markers to investigate the phylogeny of Scarelus, a neotenic lineage endemic to Southeast Asian rainforests. Most genetic differentiation was associated with Palaeogene geographical divisions, which remain distinct despite temporary connections. Dispersal events were rare, with only two inferred for Scarelus: from Borneo to the Philippines 28.3 million years ago (Ma) and from Sumatra to Java 13.9 Ma. We suggest that speciation resulted from allopatric range fragmentation, and Scarelus diversified readily when conditions were favourable; in this case, at different times in the eastern (19.3-39.1 Ma) and western (3.5-13.9 Ma) parts of Sundaland. The observed strong phenotypic similarity was preserved under speciation through complete allopatry. Neotenic Lycidae have survived for a long time in very stable habitats, and extremely low dispersal activity has not limited their persistence; however, the long-term diversification rate of neotenics is low and diversification is nonexistent under stable conditions. The modern ranges of neotenic lineages are indicative of ancient rainforest refugia and may be used in biodiversity conservation management. Most neotenics are at risk of extinction because of their small ranges and a low dispersal potential.     

Effects of previous intensive agricultural management on microorganisms and the biodiversity of soil fauna

In this study effects of previous intensive management on microorganisms and soil fauna were investigated. It was hypothesized that a former but now abandoned intensive management practice still causes negative effects years after conversion into conventional management.Two agricultural fields were investigated. Until 1990 one field (preINT) had been managed with the intensive crop hops (Humulus lupulus), whereas the second one (preCON) had been under crop rotation. In consequence the main difference between the two fields was the high copper load of preINT. In the period during this study both fields were cultivated the same way (1991: winter wheat, 1992: spring barley).Microbial biomass, species numbers and abundances of collembola as well as of earthworms were much lower in preINT in the first year of investigation. In 1992, earthworm biomass was still extremely low, whereas the microbial biomass and total collembola had reached the values of preCON. Between the collembola populations there were still distinct differences in species abundances. In preCON,Folsomia quadrioculata, Onychiurus armatus, and theMesaphorura krausbaueri group each made up about 1/4 of the total population. In preINT nearly 60% of the population consisted of theMesaphorura krausbaueri group, followed byIsotoma notabilis andOnychiurus armatus.Folsomia quadrioculata andIsotomiella minor in preINT exhibited extremely small abundances during the whole investigation period. Thus, in comparative field studies their abundances could serve as indicators for copper contamination.Supplementary microcosm studies had shown that severe reductions of earthworm numbers, especially with simultaneous high mesofauna abundances, will be accompanied by increased mineralization rates. Therefore changes in soil fauna composition caused by copper contamination could have pronounced effects on mineralization rates and nutrient fluxes.     

转基因抗虫水稻对生物多样性的影响

水稻是我国最重要的粮食作物,然而虫害造成的产量损失每年高达一千万吨以上。研究表明,转基因抗虫水稻对二化螟、三化螟和稻纵卷叶螟等水稻主要鳞翅目害虫具有高抗性,可以大幅度减少化学杀虫剂的使用。在不使用农药的情况下,在抗虫转基因水稻田中的害虫密度大幅度减少的同时,可以显著地增加中性昆虫及捕食性天敌数量和种类,显示出稻田生态系统和生物多样性的向良性发展的趋势。转基因水稻花粉向非转基因水稻品种的基因飘流实验表明,随着栽种距离的增大而显著减小,到间隔6.2 m时基因飘流频率已低于0.01%。转基因抗虫水稻的应用,对于保障我国粮食安全,保持农业可持续发展,保护生物多样性和生态环境尤其是在大幅度减少农药使用量方面具有重要意义。文章综述了转基因抗虫水稻研制进展及其对生物多样性的影响,并对农作物害虫防治的未来研究方向和发展趋势进行展望,以期为转基因抗虫水稻更好的应用提供借鉴。     

Avian biodiversity in the coastal wetlands of the Okahukura Peninsula

The Tapora Landcare Group, operating on the Okahukura Peninsula, has the long-term goal of making this region predator fenced. The aim of this study was to obtain information on the current status of avian biodiversity and the bird community across the band of coastal wetlands on the Okahukura Peninsula. Bird counts were conducted and playback lures used to detect three cryptic wetland species: fernbirds (Bowdleria punctata); spotless crakes (Porzana tabuensis); and banded rails (Gallirallus philippensis). Fernbirds and banded rails were detected at seven of the eight wetland sites sampled whereas spotless crakes were detected at two sites. The native species with the highest relative abundance across the eight sites were silvereyes (Zosterops lateralis) and South Island pied oystercatchers (Haematopus finschi). Changes in avian biodiversity over time in the region can now be monitored, and comprehensive long-term data on the status of avian biodiversity over time obtained.     

东南亚留学生神经病学见习课教学浅谈

目的:探讨如何上好东南亚留学生神经病学见习课,为促进医学高等教育国际化提供依据.方法:在神经病学见习课教学中采用提高教师英语素质、充分准备病例、采用肢体语言及结合影像学资料等方法对东南亚留学生神经病学见习课进行教学.结果:上述方法能使这些留学生对神经病产生兴趣,从而达到较好的教学效果.结论:根据东南亚留学生的特殊情况,在神经病学见习中多种教学方式的灵活运用能达到理想的教学效果.     

Seed bank potential of moist-soil managed wetlands in east-central Texas

Proper management techniques on moist-soil wetlands provide methods for enhancement of established wetlands, restoration of former wetlands, and creation of new wetland habitat. These techniques also create suitable wetland habitat for non-breeding waterfowl and other wetland dependent species during winter. To understand moist-soil managed wetland vegetative patterns, aspects such as plant species distribution, reproductive strategy, seed bank composition and viability should be thoroughly characterized. We investigated soil seed bank potential of moist-soil managed wetlands on Richland Creek Wildlife Management Area, Texas to determine which treatment (i.e., drawdown or flooded) produced the most desirable moist-soil plants. A total of 27 species germinated, producing 3,731 and 3,031 seedlings in drawdown and flooded treatments, respectively. There were also differences in stem densities between treatments of desirable and non-desirable species. Drawdown treatments had more seedlings germinate than flooded treatments, validating the notion that drawdown treatments provide favorable conditions for seed germination. Drawdown and flooding techniques, when properly timed, will allow managers to drive and directly influence managed wetland plant communities based on seed bank composition and response to presence or absence of water during the germination period.     

东南亚生物多样性热点地区的形成与演化

东南亚地处热带,生物多样性极为丰富,可分为4个热点地区:印度-缅甸区的中南半岛、巽他区(含马来半岛、婆罗洲、苏门答腊岛)、菲律宾区(菲律宾群岛)、华莱士区(苏拉威西岛、爪哇岛、马鲁古群岛、小巽他群岛等)。中南半岛在泥盆纪便已是欧亚大陆的一部分,在印度板块撞击欧亚大陆之后受挤压而出;巽他区来自于冈瓦纳古陆和澳洲古陆;菲律宾群岛部分来自于劳亚古陆的碎片向南漂移,部分来自于太平洋西南岛弧的向北迁移;华莱士区则是劳亚古陆碎片、太平洋西南岛弧以及澳洲古陆北侧碎片的组合。巽他区地处赤道,常年温湿;菲律宾区、华莱士区、中南半岛则都受到不同程度的季风气候决定的干湿季变动。地质历史和季风气候影响程度的不同,奠定了东南亚4个生物多样性热点地区的雏形。华莱士区保存有大量的早期被子植物原始类群如睡莲目(Nymphaeales)和木兰藤目(Austrobaileyales),是现代被子植物起源地和冰期避难所之一。巽他区(婆罗洲)和中南半岛是亚洲热带植物的现代分布中心和"进化前沿",是整个东南亚地区重要的种源;而华莱士区的爪哇岛和小巽他群岛主要是物种迁入和中转的种库。这样的物种形成历史与迁移格局,塑造了东南亚4个...     

Effects of agricultural activities and best management practices on water quality of seasonal prairie pothole wetlands

Long-term effects of within-basin tillage can constrain condition andfunction of prairie wetlands even after uplands are restored. Runoff wassignificantly greater to replicate wetlands within tilled basins with orwithoutvegetated buffer strips as compared to Conservation Reserve Program restorationcontrols with revegetated uplands (REST). However, mean water levels for nativeprairie reference sites were higher than for REST controls, becauseinfiltrationrates were lower for native prairie basins, which had no prior history oftillage. Nutrient dynamics changed more in response to changes in water leveland vegetation structure than to increased nutrient inputs in watershed runoff.Dissolved oxygen increased between dry and wet years except in basins or zoneswith dense vegetation. As sediment redox dropped, water-column phosphatedeclined as phosphate likely co-precipitated with iron on the sediment surfacewithin open-water or sparsely vegetated zones. In response, N:P ratios shiftedfrom a region indicating N limitation to P limitation. REST sites, with densevegetation and low DO, also maintained high DOC, which maintains phosphate insolution through chelation of iron and catalysis of photoreduction. Referencesites in native prairie and restored uplands diverged over the course of thewet-dry cycle, emphasizing the importance of considering climatic variation inplanning restoration efforts.     

Estimating biodiversity: a case study on true bugs in argentinian wetlands

The species richness and relative abundance of faunas in defined areas are the raw materials in biodiversity science. The research methodology to acquire these data is inventory, and inventory quality depends on a number of parameters, for example collecting methods, season, and collector experience. To assess the ability of rapid inventory techniques to estimate local richness seven collectors sampled the fauna of true bugs in the Iberá watershed (Corrientes, Argentina) with seven methods during early spring, summer, and late summer (December, May, September) of 1 year. Twenty-three families, 225 spp. and 4,678 adults were found. We also applied various statistical techniques to correct the observed data for undersampling bias, which suggested the lower bound of annual heteropteran species richness at Pellegrini was about 250–300 species. Among heteropteran families, the particular inventory methodology was especially efficient in sampling Miridae. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The impact of river regulation on the biodiversity intactness of floodplain wetlands

Alteration of natural flow regime is considered a major threat to biodiversity in river floodplain ecosystems. Measurements of quantitative relationships between flow regime change and biodiversity are, however, incomplete and inconclusive. This hampers the assessment of human impact on riverine floodplain wetlands in global biodiversity evaluations. We systematically reviewed the scientific literature and extracted information from existing data sets for a meta-analysis to unravel a general quantitative understanding of the ecological consequences of altered flow regimes. From 28 studies we retrieved both ecological and hydrological data. Relative mean abundance of original species (mean species abundance, MSA) and relative species richness were used as effect size measures of biodiversity intactness. The meta-analysis showed that alteration of a natural flow regime reduces the MSA by more than 50 % on average, and species richness by more than 25 %. Impact on species richness and abundance tends to be related to the degree of hydrological alteration. These results can be used in strategic quantitative assessments by incorporating the relationships into global models on environmental change and biodiversity such as GLOBIO-aquatic.     

Effects of irradiance and spectral quality on seedling development of two Southeast Asian Hopea species

 Seedling developmental responses to understory shade combine the effects of reductions in irradiance and changes in spectral quality. We studied the seedling development of two Southeast Asian dipterocarp trees in response to differences in irradiance (photosynthetic photon flux density, PPFD) and spectral quality (red to far-red ratio, R:FR). The two species, Hopea helferei and H. odorata, are taxonomically closely related but differ in their ecological requirements; H. helferei is more drought-tolerant and typically grows in more open habitats. Seedlings were grown in six different replicated shadehouse treatments varying in percentage of solar PPFD and R:FR. The two species differed in the influence of light variables on most seedling characters, particularly for final height, internode distance, branch/trunk internodes, stem length/mass, leaf area/stem length, petiole length, and growth/mol of photons received. Most of the characters in both taxa were primarily influenced by PPFD, but spectral quality also influenced some characters – more so for H. odorata. The latter species grew more rapidly, particularly in the low PPFD treatments, and its leaves were capable of higher photosynthesis rates. However, growth in H. helferei was not reduced in direct sunlight. The growth of this taxon may be constrained by adaptations, particularly in leaves, for drought tolerance. Received: 14 April 1996 / Accepted: 8 October 1996     

Persistence of Pasteurella multocida in wetlands following avian cholera outbreaks

Avian cholera, caused by Pasteurella multocida, affects waterbirds across North America and occurs worldwide among various avian species. Once an epizootic begins, contamination of the wetland environment likely facilitates the transmission of P. multocida to susceptible birds. To evaluate the ability of P. multocida serotype-1, the most common serotype associated with avian cholera in waterfowl in western and central North America, to persist in wetlands and to identify environmental factors associated with its persistence, we collected water and sediment samples from 23 wetlands during winters and springs of 1996-99. These samples were collected during avian cholera outbreaks and for up to 13 wk following initial sampling. We recovered P. multocida from six wetlands that were sampled following the initial outbreaks, but no P. multocida was isolated later than 7 wk after the initial outbreak sampling. We found no significant relationship between the probability of recovery of P. multocida during resampling and the abundance of the bacterium recovered during initial sampling, the substrate from which isolates were collected, isolate virulence, or water quality conditions previously suggested to be related to the abundance or survival of P. multocida. Our results indicate that wetlands are unlikely to serve as a long-term reservoir for P. multocida because the bacterium does not persist in wetlands for long time periods following avian cholera outbreaks.     

Effects of intensive forest management practices on insect infestation levels and loblolly pine growth

Intensive forest management practices have been shown to increase tree growth and shorten rotation time. However, they may also lead to an increased need for insect pest management because of higher infestation levels and lower action thresholds. To investigate the relationship between intensive management practices and insect infestation, maximum growth potential studies of loblolly pine, Pinus taeda L., were conducted over 4 yr using a hierarchy of cultural treatments. The treatments were herbaceous weed control (H), H + irrigation (I), H + I + fertilizer (F), and H + I + F + pest control (P). These treatments were monitored for differences in growth and insect infestation levels related to the increasing management intensities. The Nantucket pine tip moth, Rhyacionia frustrana (Comstock), was consistently found infesting study trees. In the third field season, the H + I + F + P treatment had significantly more southern pine coneworm, Dioryctria amatella (Hulst), attacks than the H and H + I treatments. There were significant differences in volume index (D2H) among all treatments after each of the four growing seasons. This study indicated that tree fertilization can increase coneworm infestation and demonstrated that tip moth management can improve tree growth initially. Future measurements will determine if the growth gains from tip moth management are transitory or sustainable.     

不同除草剂用量对水稻生产的影响研究

对施用不同剂量除草剂丁草胺和农得时的稻田处理研究表明,该配方在常量和倍量下能够较好防除沈阳地区稻田杂草,药后35d对杂草株数防效和鲜重防效分别达80％和90％以上,但对水稻株高和分蘖有一定抑制作用,且杂草一定程度表现出抗性;在不施用除草剂和施用半量除草剂的情况下,杂草竞争使水稻在株高和分蘖等方面部有一定的补偿作用,但水稻产量分别下降36．01％和54．80％,主要是因为有效穗和每穗实粒数的减少;除草剂狭义经济效益良好．     

Role of culturally protected forests in biodiversity conservation in Southeast China

Culturally protected forests (CPFs), preserved and managed by local people on the basis of traditional practices and beliefs, have both social and ecological functions. We investigated plant species richness and diversity within the tree layer, shrub layer and herb layer in three types of CPFs (community forests, ancestral temple forests, cemetery forests) as well as nearby forests without cultural protection (NCPFs) in Southeast China. A total of 325 species belonging to 85 families and 187 genera were recorded in CPFs, including 17 protected species in China Species Red List and IUCN Red List, which accounted for 17 % of counties’ endangered species. Compared with NCPFs, the tree layer of CPFs had larger DBH and lower species density, especially in the cemetery forests. CPFs had higher alpha diversity values generally, particularly in the tree layer. The differences in tree layer were substantial, and CPFs covered nearly 85.4 % of the tree species in the surveyed sites. The similarities between CPFs and NCPFs were higher in the herb and shrub layers than in the tree layer. These differences of species diversity may be attributed to differences in resource use and management between CPFs and NCPFs. Our field investigation results suggested that local CPFs harbor many plant species, high biodiversity, and contribute to the conservation of a substantial proportion of the local species pool.