排序方式： 共有36条查询结果，搜索用时 15 毫秒
21.
Tran Van Do Osamu Kozan Mamoru Yamamoto Vo Dai Hai Phung Dinh Trung Nguyen Toan Thang Hoang Van Thang Tran Duc Manh Vu Tien Lam Nguyen Huu Thinh 《Small-Scale Forestry》2018,17(4):555-568
Most tropical forests outside protected areas have been or will be selectively logged because the timber industry is a main income-generating resource for many developing countries. Therefore, understanding the composition of commercial timber species and logging types is key for sustainable forest management in countries like Vietnam as they move toward fulfilling Reducing Emissions from Deforestation and Forest Degradation (REDD+) agreements. Seven 1-ha plots were surveyed in the Central Highland of Vietnam, and 18 commercial tree species from these plots, whose timber is widely used by local people for housing and furniture making and timber is easily sold at local markets for high prices, were analyzed. In total, 151 tree species with a diameter at breast height (DBH) of ≥?10 cm were recorded. The 18 commercially valuable species assessed in this study accounted for 33.2% of all stems (total of 524 stems ha?1 for all species), 47.1% of basal area (total of 34.35 m2 ha?1 for all species), and 50.8% of aboveground biomass/AGB (total of 262.68 Mg ha?1 for all species). Practicing diameter-limit harvesting of all commercially valuable species with DBH of ≥?40 cm, which is widely performed in Vietnam, will reduce the number of stems by 7%, basal area by 31.6%, and AGB by 38.2%. Because such harvesting practices cause severe ecological impacts on the remaining forest, logged forests may require >?40 years to recover the structure status of a pre-logged forest. In addition, the recovery of the 18 commercially valuable species may require a much longer time because they comprised 33.2% of stems. Permission for logging natural forests should be given in Vietnam to sustain lives of local communities, where logging has been prohibited. However, alternative harvesting systems, such as reduced-impact logging systems, should be considered. The systems selected must simultaneously generate economic returns for local people and respect the REDD+ agreements with regard to protecting biodiversity and reducing carbon emissions. 相似文献
22.
亚洲主要国家竹种资源与利用 总被引：5，自引：4，他引：1
亚洲是世界竹子的主要分布区，竹林培育和加工利用历史最为悠久，竹种资源、竹林面积和竹产业产值均位居全球首位。亚洲竹资源主要分布在东亚、东南亚和南亚国家，在中亚、西亚和北亚国家少有分布。以中国为代表的东亚国家竹种丰富，竹产业发达；以越南、马来西亚为代表的东南亚国家竹产业发展迅速；以印度为代表的南亚国家竹林面积最大，竹产业欠发达。文章分析了亚洲具有代表性的17个国家的竹资源及利用现状，以期为加强亚洲各国竹产业合作、推动区域竹产业高质量发展提供参考。 相似文献
23.
Hard choices: Making trade-offs between biodiversity conservation and human well-being 总被引：4，自引：0，他引：4
Thomas O. McShane Paul D. Hirsch Tran Chi Trung Alexander N. Songorwa Ann Kinzig Bruno Monteferri David Mutekanga Hoang Van Thang Juan Luis Dammert Manuel Pulgar-Vidal Meredith Welch-Devine J. Peter Brosius Peter Coppolillo Sheila O’Connor 《Biological conservation》2011,(3):966-972
Win–win solutions that both conserve biodiversity and promote human well-being are difficult to realize. Trade-offs and the hard choices they entail are the norm. Since 2008, the Advancing Conservation in a Social Context (ACSC) research initiative has been investigating the complex trade-offs that exist between human well-being and biodiversity conservation goals, and between conservation and other economic, political and social agendas across multiple scales. Resolving trade-offs is difficult because social problems – of which conservation is one – can be perceived and understood in a variety of disparate ways, influenced (in part at least) by how people are raised and educated, their life experiences, and the options they have faced. Pre-existing assumptions about the “right” approach to conservation often obscure important differences in both power and understanding, and can limit the success of policy and programmatic interventions. The new conservation debate challenges conservationists to be explicit about losses, costs, and hard choices so they can be openly discussed and honestly negotiated. Not to do so can lead to unrealized expectations, and ultimately to unresolved conflict. This paper explores the background and limitations of win–win approaches to conservation and human well-being, discusses the prospect of approaching conservation challenges in terms of trade-offs and hard choices, and presents a set of guiding principles that can serve to orient strategic analysis and communication regarding trade-offs. 相似文献
24.
Nguyen Toan Thang Tran Van Do Tamotsu Sato Nguyen Trong Binh Osamu Kozan Ngo Van Cam 《Small-Scale Forestry》2016,15(2):229-239
Chestnuts have historical importance as a food source worldwide. Planting of chestnuts has focused on a few species, including Castanea dentata, Castanea sativa, Castanea mollissima, and Castanea crenata, although others species are also edible. Castanea species are members of the beech family (Fagaceae) and are native to tropical and temperate areas. In this study, the yield and nut quality of Castanopsis piriformis in natural forests of the Central Highlands of Vietnam were investigated to provide evidence that C. piriformis is worth growing as a food species. Data were collected from 12 plots of 50 m × 50 m size located in four altitude zones. Nuts were collected from three to five chestnut trees in each plot judged to be of typical sized based on diameter at breast height and crown diameter. Average dry yield of nuts was found to be elevation-dependent, being highest at 500–1000 m (1152 kg/ha/year), decreasing to 815 kg/ha/year below 500 m, and to 770 kg/ha/year at 1000–1500 m. The lowest yield was observed at above 1500 m (252 kg/ha/year). Protein and lipid contents in the kernels of C. piriformis chestnut were 4.4 and 0.1 %, respectively. Glucose accounted for 73.1 % and was significantly higher than that of commercially grown Castanopsis boisii chestnuts in Northern Vietnam. With the current price of 0.6 US$/kg nuts, collecting nuts growing in natural forest can bring at least 480 US$/ha/year to local people. These results indicate the possibility of growing and consuming C. piriformis chestnut as a crop to decrease poverty. However, governmental support is required for the sustainable development of C. piriformis. 相似文献
25.
Li CY Tsai WJ Damu AG Lee EJ Wu TS Dung NX Thang TD Thanh L 《Journal of agricultural and food chemistry》2007,55(23):9436-9442
The methanolic extract of Piper lolot, having shown potent inhibitory activity on platelet aggregation induced by arachidonic acid (AA) and platelet activating factor (PAF), was subjected to activity-guided isolation to yield twelve new amide alkaloids, piperlotine A-L (1-12), along with twenty-nine known compounds. Their structures were elucidated on the basis of spectroscopic analysis. The isolated compounds were tested for their inhibitory activity on the rabbit platelet aggregation. The compounds piperlotine A (1), piperlotine C (3), piperlotine D (4), piperlotine E (5), 3-phenyl-1-(2,4,6-trihydroxyphenyl)propan-1-one (21), 3-(4-methoxyphenyl)-1-(2,4,6-trihydroxyphenyl)propan-1-one (22), 1-trans-cinnamoylpyrrolidine (24), sarmentine (26), pellitorine (27), methyl 3-phenylpropionate (32), and (10S)-10-hydroxypheophorbide a methyl ester (40) showed potent antiplatelet aggregation activity. 相似文献
26.
27.
斑点免疫金渗滤法检测边虫病的研究 总被引：6，自引：2，他引：6
应用自行制备的直径２５ｎｍ～３０ｎｍ的胶体金标记ＳＰＡ，建立了检测抗边虫抗体的斑点免疫金渗滤试验（ＤＩＧＦＡ），同时作与补体结合试验（ＣＦＴ）、团集凝集试验（ＣＡＴ）比较试验，结果表明ＤＩＧＦＡ是一种检测边虫病抗体的敏感性高、特异性强、重复性好的快速、简便易行方法。 相似文献
28.
Luong Bui Bich Hanh Phung Thi My Rinh Pham Dinh Trang Pham Minh Thang Do Trong Stephen Harper 《Communications in Soil Science and Plant Analysis》2019,50(1):102-107
Inductively coupled plasma-mass spectroscopic (ICP-MS) analysis of leaves from 22 cabbage crops in the Sa P? and B?c Hà districts of Láo Cai Province, North-Western Vi?t Nam, revealed unexpectedly high concentrations of chromium (Cr) and nickel (Ni). The concentrations were strongly linearly related (r2 = 0.94), indicating sample contamination during grinding through a stainless-steel hammer mill. We tested this hypothesis in two ways. First, brown rice ground through the same mill was contaminated not only by Cr and Ni, but also cobalt (Co), iron (Fe) and molybdenum (Mo). Second, scanning electron microscopy/energy dispersive analysis of x-rays (SEM/EDS) of the ground samples revealed small fragments with co-located Fe, Cr and Ni, consistent with stainless steel wear fragments. Other grinders may perform differently and we suggest that quality assurance protocols for trace metal analysis of plants should include testing for grinder wear metals. Lastly, brown rice appears to be convenient for investigating contamination of plant tissues during grinding. 相似文献
29.
Andrew M. Song Viet Thang Hoang Philippa J. Cohen Transform Aqorau Tiffany H. Morrison 《Asia Pacific viewpoint》2019,60(3):310-324
Vietnamese ‘blue boats’ – small wooden‐hulled fishing boats – are now entering the territorial waters of Pacific Island countries and illegally catching high‐value species found on remote coastal reefs. Crossing several international boundaries and traversing a distance of over 5000 km, these intrusions have alarmed Oceanic countries, including Australia. Lacking administrative capacity as well as jurisdictional authority to effectively control the vast stretches of island coastlines individually, governments and intergovernmental bodies in the region have called for strengthened coordination of surveillance efforts while also pressuring Vietnam diplomatically. This paper reviews these latest developments and is the first to provide a focused assessment of the issue. Through the lens of Copenhagen School of securitisation theory, we analyse responses of national and regional actors and their portrayal in online media to understand how blue boats are constructed as a security threat within a narrative of maritime, food and human security. Arguably, Australia together with the Forum Fisheries Agency, who advise on the governance of offshore tuna resources, have so far acted most decisively – in a way that might see them extend their strategic role in the region. We propose a comprehensive empirical research agenda to better understand and manage this nascent, flammable and largely unpredictable inter‐regional phenomenon. 相似文献
30.
Thang Nguyen Dinh Tu Le Dinh Le Na Nguyen Thi Trang Ngo Thi Nghia Phan Tuan 《International Aquatic Research》2019,11(3):303-310
International Aquatic Research - Viral diseases are a serious issue for the shrimp aquaculture industry. White spot syndrome virus (WSSV) has been considered one of the most dangerous pathogens... 相似文献