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1.
Although Asia is thought to have played a critical role in the radiation of artiodactyls, the fossil record of stem selenodonts (“dichobunoids”) remains dramatically poor in tropical Asian regions. In this study, we report a new dichobunid genus and species Cadutherium kyaukmagyii and a new basal ruminant genus and species Irrawadymeryx pondaungi, from the late Middle Eocene Pondaung Formation, Central Myanmar. Although the scarcity of the present material prevents any attempts to investigate the phylogenetic relationships of Cadutherium with contemporaneous forms from other Holarctic landmasses, this new form shed new light on the diversity of these small rabbit-like ungulates during a key period of their evolutionary history. Reexamination of the small-bodied artiodactyls from Pondaung leads us to propose new identifications of certain published specimens and, in turn, to investigate the temporal and geographic distribution of taxa recognized in the Pondaung Formation. Although fragmentary, these potential new taxa reveal an unsuspected diversity of small forms among artiodactyls of Pondaung. This addition to the Eocene record of dichobunoids and early ruminants provides further insight in the diversity of dental patterns among small artiodactyls from the Pondaung Formation and attests to the antiquity of these groups in Southeast Asia.  相似文献   
2.
采用HJ星数据、Landsat TM数据以及MODIS卫星数据,对距中缅边境线100公里的缅方一侧区域进行了监测和分析,结果发现:监测区2001-2009年森林覆盖面积呈下降趋势,但是森林覆盖率降幅有所放缓;监测区内每年的森林火点分布广,且燃烧过的林地,大部分变为农田,一些农田撂荒成为草地。分析认为,当地传统的刀耕火种耕作方式也是该地区森林面积减少原因之一。  相似文献   
3.
Land-use planning using geographic information systems (GIS) commonly emphasizes biophysical spatial data; however planning can be improved by integrating spatial sets of socioeconomic data into the GIS. As an example, we compared a traditional GIS-aided forestry planning protocol that considered only biophysical suitability, with an integrated GIS-aided approach that incorporated both biophysical and socioeconomic suitability. The analyses were conducted for the planning of plantation investments in the Kyaukpadaung Township in the dry zone of central Myanmar. The traditional approach used three biophysical layers for suitability: land use, slope, and accessibility. In contrast, the integrated GIS approach included biophysical suitability data, perceptions and preferences of local villagers towards forestry (social suitability), and quantitative socioeconomic data. The results indicated that the integrated approach provided two principal benefits over the traditional method. First, the integrated method resulted in a more precise idea of suitable sites for plantation investment that could benefit more rural people and also lead to greater investment efficiency. Second, incorporating social preference into the GIS takes into account the crucial element of social capital (viz., social preference), which should lead to higher levels of community acceptance of plantation projects because those plantations would be established on socially suitable land. A second GIS exercise showed how conservation investment decisions could be informed using the integrated method. The results of this study support the idea that GIS-aided planning activities can be enhanced through the incorporation of social data into the analysis. When applicable, spatial data collection efforts for GIS-based planning exercises should incorporate spatial socioeconomic data.  相似文献   
4.
We reconstructed the history of Chatthin Wildlife Sanctuary (CWS) to understand how social and economic events, and policy changes affected the sanctuary's condition. We surveyed 25 villages surrounding CWS to evaluate past and present ecological conditions, compare the results with historical accounts and identify causal relationships. During the first half of the 20th century, the primary threat was the government's reduction of old growth forest to supply fuel wood for the British-built railway. The railroad opened the area to colonization, but the villagers' impact on timber and wildlife was low. From 1945 to 1988, villagers became the primary force of landscape degradation. The post-war windfall of firearms increased hunting pressure, and populations of large mammal started to decline. With the economic decline of the 1970s and 1980s, the community's demand for game and forest products intensified, and the large mammal fauna was reduced from eleven to four species. From 1988-2003, the forests surrounding the sanctuary were fragmented and degraded. The absence of large predators rendered the park safe for livestock, and the combined effects of grazing and removal of forest products seriously degraded habitat within CWS. Major threats to CWS during the past two decades have resulted from land use decisions in which government-planned economic enterprises caused encroachment by villagers. Stabilization and recovery of this sanctuary will require management compatible with human needs, including expanded buffer zones, better core area protection, community forestry projects, and probably relocation of villages within the park.  相似文献   
5.
中老缅泰交界地区土地利用变化信息挖掘与国别对比   总被引:2,自引:0,他引:2  
基于Landsat TM/ETM数据,从土地利用空间分布特征、时空变化规律、土地利用程度三个方面,对中老缅泰交界地区1990-2010年土地利用变化特征进行分析。研究表明:① 橡胶园、茶园为增幅最大的土地利用类型,轮歇农地、建设用地、长期性农地也有一定幅度的增加,有林地、灌木林、草地、水域有所减少。② 有林地、灌木林之间的转移及其与长期农地、轮歇农地、橡胶园之间的转移,决定着中老缅泰交界地区土地利用变化特征。中老缅泰交界地区土地利用变化本质上受到市场经济、国家政策、人口迁移、基础设施建设等因素的影响。③ 橡胶园和茶园的时空变化基本表现为面积净值增加,空间位置交换变化非常小。长期农地面积变化不大,但存在较大幅度的空间位置转变;水域、轮歇农地变化以空间位置交换为主。草地、灌木林、有林地、建设用地交换变化和净变化比例相当。④ 1990-2010年,中老缅泰交界地区土地利用程度有所增加,其中,泰国境内土地利用程度最高,老挝和缅甸境内的土地利用程度最低。2000年后中老缅泰交界地区土地利用程度增幅明显加大。其中,中国和缅甸境内土地利用程度后期增幅减小,泰国境内土地利用程度后期增幅变大,老挝境内土地利用程度实现了由前期减少到后期增加的转变。  相似文献   
6.
缅甸皎漂农村地区以水塘水为主要饮用水水源,此类水源普遍存在金属离子超标的问题.针对该问题,选取拟新建水塘选址地内不同深度的土壤样品,并对其进行理化指标、金属含量测定,同时对其进行浸泡及金属元素赋存形态提取实验.结果表明,土壤中除Ni元素含量超过农用地土壤污染风险筛选值外,其他金属元素含量均低于筛选值,且在垂直尺度空间上分布较均匀.通过浸泡实验发现,不同土层的浸泡液中Al、Fe、Mn、Ni元素浓度均超过了我国饮用水标准,其中,中层土(1.2~2.4 m)释放的金属离子浓度最高,释放速率最快,而深层土(>2.4 m)释放的Al、Fe、Ni离子较少.比较浸泡前后金属赋存形态发现,不同深度土壤中金属离子的释放与弱酸态、可氧化态含量变化有关,深层土中弱酸态Al、Fe、Ni释放量较少,同时通过弱酸态、可氧化态释放的金属离子被铁锰氧化物大量吸附转化为可还原态,所以其释放量低于浅层土(0~1.2 m)和中层土.Mn主要以弱酸态和可氧化态赋存于不同深度的土壤中,因此具有较高的迁移性.本文提出了以释放金属离子少的深层土作为水塘内壁的分质用土方案,以减少饮用水源金属离子释放风险,保障皎漂农村地区饮用水安全,并可为其他有类似饮用水问题的国家和地区提供参考.  相似文献   
7.
High levels of species richness and endemism make Myanmar a regional priority for conservation. However, decades of economic and political sanctions have resulted in low conservation investment to effectively tackle threats to biodiversity. Recent sweeping political reforms have placed Myanmar on the fast track to economic development—the expectation is increased economic investments focused on the exploitation of the country’s rich, and relatively intact, natural resources. Within a context of weak regulatory capacity and inadequate environmental safeguards, rapid economic development is likely to have far-reaching negative implications for already threatened biodiversity and natural-resource-dependent human communities. Climate change will further exacerbate prevailing threats given Myanmar’s high exposure and vulnerability. The aim of this review is to examine the implications of increased economic growth and a changing climate within the larger context of biodiversity conservation in Myanmar. We summarize conservation challenges, assess direct climatological impacts on biodiversity and conclude with recommendations for long-term adaptation approaches for biodiversity conservation.  相似文献   
8.
Coastal deforestation in the Ayeyarwady Delta, Myanmar (formerly Burma) is addressed through the promotion of native-species mangrove plantations on cleared land formerly sustaining natural mangrove forests. To date there are no attempts to determine the optimal mangrove plantation strategy to maximize economic returns for private or communal plantation owners. We integrated empirical biological and economic data to suggest optimal mangrove plantation strategies in the region. We censused 4-yr oldAvicennia officinalis mangrove plantations in two townships to calculate survival and growth rates of mangroves planted using different techniques across an inundation gradient. We used the calculated rates to forecast the production of fuelwood, poles and posts at 10, 13 and 15 yr after establishment. We calculated the compound rate of growth for the three commodities over a 7-yr period, and then forecast commodity price for the same harvestintervals. Integration of those parameters in our model led us to conclude that both profit and the internal rate of return would be greatest for plantations of seedlings raised in polyethylene bags as opposed to bare-root or direct propagule planting. Therefore, the use of potted seedlings should be promoted, despite higher initial costs. The optimal rotation period varies according to ground level and planting technique. Optimizing economic returns for coastal plantations does not necessarily require a sacrifice of ecological benefits. Due to a discrepancy between official conversion quotes and local real value no conversion estimate in USD is given.  相似文献   
9.
Coastal deforestation in the Ayeyarwady Delta, Myanmar (formerly Burma) is addressed through the promotion of native-species mangrove plantations on cleared land formerly sustaining natural mangrove forests. To date there are no attempts to determine the optimal mangrove plantation strategy to maximize economic returns for private or communal plantation owners. We integrated empirical biological and economic data to suggest optimal mangrove plantation strategies in the region. We censused 4-yr oldAvicennia officinalis mangrove plantations in two townships to calculate survival and growth rates of mangroves planted using different techniques across an inundation gradient. We used the calculated rates to forecast the production of fuelwood, poles and posts at 10, 13 and 15 yr after establishment. We calculated the compound rate of growth for the three commodities over a 7-yr period, and then forecast commodity price for the same harvest intervals. Integration of those parameters in our model led us to conclude that both profit and the internal rate of return would be greatest for plantations of seedlings raised in polyethylene bags as opposed to bare-root or direct propagule planting. Therefore, the use of potted seedlings should be promoted, despite higher initial costs. The optimal rotation period varies according to ground level and planting technique. Optimizing economic returns for coastal plantations does not necessarily require a sacrifice of ecological benefits. Due to a discrepancy between official conversion quotes and local real value no conversion estimate in USD is given.  相似文献   
10.
Policy and practice in Myanmar's protected area system   总被引:1,自引:0,他引:1  
Myanmar's protected area (PA) system began nearly 150 years ago under royal patronage. Park policies and practices, embodied in 19 pieces of legislation developed sporadically during and after the colonial period. As a result of the FAO-UNDP's Nature Conservation and National Parks Project (1981-1985) the government established the Nature & Wildlife Conservation Division and placed it within the Forest Department as the agency responsible for PA management. As a consequence the number of parks increased from 14 to 33. Myanmar's median park size is less than 50 km(2), but only five parks (15%) are larger than 1000 km(2). Most parks conserve terrestrial habitats; parks encompassing inland wetlands, mangrove, and marine habitats are limited in number and size. Existing PAs unequally represent Myanmar's ecosystems; the Malay Transition, Burmese coast, Burmese Transition and Cardamom Mountains bio-units are under-represented within the system. The effective total PA size (i.e., area of all parks less the area of 13 paper parks) is currently about 2.1%. Budgetary support for parks increased 11% since 1996, but is insufficient to address park needs, particularly in remote parks that are understaffed. Limited education and training of PA staff is a major factor limiting effective park management. Fifty-eight percent of park wardens are educated as foresters, and 42% have university degrees. The average posting in a park is 4 years, which is less than ideal for management continuity. Recommended actions to secure Myanmar's PAs include evaluation and reformulation of policies, increasing representation of Myanmar's habitats within the PA system, management planning, and standardizing protocols for anti-poaching patrols and other forms of law enforcement. Improved leadership training for wardens and range forest officers can also improve park management. Funding for community relations and more integrated management of parks and people can reduce conflicts, while environmental education and outreach activities can provide some needed services. Finally, new ways and means are needed to support these activities. Myanmar's PAs need creative and sustainable means of support, including partnerships with non-government organizations to supplement traditional means of support.  相似文献   
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