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11.
Only by providing the good conditions for the growth of plants can a favorable ecologicalenvironment on which human beings rely for existence be created. The upside-down-T dou-ble-layer water-conserving afforestation way is developed according to the situation of the short-age of water resources, low soil fertility and vast land in the arid areas. The characteristics of theafforestation way are to change the microenvironment in the root area of the plants, provide thefavorable conditions for the growth of plants, and reduce the necessary conditions for the growth ofplants in large areas in the arid regions. Meanwhile, the size of its water-conserving layer can bechanged according to the size of the planted trees. The different ways of the bottom wa-ter-conserving layer can be used according to the requirements. The afforestation way is suitablefor planting trees on a small scale and also for afforesting on a large scale under the adverse cir-cumstances in the arid areas, and has been effectively used in the afforestation in the hinterland ofTaklamakan Desert and the southern marginal zone of Gurbantonggut Desert. The prospects ofthe afforestation way are broad in afforestation and desertification control in the desert regions.  相似文献   
12.
The Xinjiang Uygur Autonomous Region covers nearly 1/6 territory of China, with vari-ous landscape patterns, environmental conditions and three key regions of biodiversity of China.The ecosystem here has a relatively simple structure and fragile ecological stability. The coverageof sparse vegetation here is only 2.1% which is far lower than 14%, the average coverage all overthe country. Although the fragile and unstable ecosystems are improved partly in the past, the totalsituation in Xinjiang has worsened (such as drying up of rivers and lakes, desertification andsalinization of soil, deterioration of meadow, reduction of biodiversity, etc.). Although the speciesnumbers of Xinjiang are few, the diversity of taxa is very high. The types of plant communities areabundant, and the flora abounds in one-species genus, one-genus family and few-species genus.Also, the fauna abounds in endangered species and endemic species, of which 108 species ofvertebrates were listed as nationally protected species. In addition, there are abundantanti-adversity gene pools. The present paper puts forwards several suggestions for biodiversityconservation in Xinjiang.  相似文献   
13.
The indigenous peoples of the Northwest Coast of North America are widely believed to have been true “hunter‐fisher‐gatherers,” lacking plant cultivation of any kind. This depiction of the region's indigenous inhabitants emerged within early colonial accounts and was perpetuated within the literatures of geography, anthropology, and archaeology. Still, there is ample evidence of plant cultivation available from archival, archaeological, and ethnographic sources. In particular, the peoples of coastal British Columbia created large gardens of edible estuarine plants, using sophisticated indigenous technologies. The oversight of these practices in written representations of the region reveals consistent patterns of bias, emanating from the agendas of colonial agents and early academics alike. In turn, this bias has undermined aboriginal traditions of cultivation and indigenous land claims.  相似文献   
14.
Ben Page 《Area》2003,35(4):357-370
This paper provides an analysis of some current trends in political ecology and then illustrates the intermingling of politics and ecology using a case study of the exploitation and conservation of Prunus africana in Cameroon. It argues that political ecology is still a lively field, but that some recent attempts to chart a way forward for this perspective risk shifting it away from its liminal position in relation to natural and social science by being disinclined to engage with ecological processes. The case study draws attention to the strengths and shortcomings in existing attempts to weave political and economic analysis into environmental debates over the sustainable management of this tree species, which has been incorporated into phytomedical markets in Europe. The fortunes of the tree reflect its botany and ecology as well as the trajectories of the local economy, intercontinental markets for alternative health products, the policies and practices of the Cameroonian state and the politics of international aid.  相似文献   
15.
The aim of this study is to assess the Iberian populations of Forsskaolea tenacissima L. according to its biogeographical interest, habitat, geographical range and conservation status. Results point out that they are restricted to gravel wadis of Tabernas Desert (SE Spain), are scarcely included in protected areas and represent historically isolated populations with relict behaviour. We also describe a new association, Senecioni-Forsskaoleetum tenacissimae. Conservation status of species is cause for concern and two conservation actions must be carried out. Firstly, protected areas should house Forsskaolea populations and secondly, phytosociological characterization of a community allows inventorying its habitat and directing conservation efforts to community level.  相似文献   
16.
植物地球化学应用于找矿的探讨   总被引:5,自引:0,他引:5  
伍静 《矿产与地质》2003,17(1):59-61
介绍植物地球化学应用于找矿的研究现状,阐述其工作原理和方法,以及相应的异常特性和有效性,提出在桂西北地区适合开展植物地球化学找矿研究的建议。  相似文献   
17.
超积累植物与找矿   总被引:13,自引:0,他引:13  
本文介绍了超积累植物的概念和它在地质找矿中的意义,回顾了国外超积累植物的研究历史,并对应用超积累植物进行找矿的发展方向进行了讨论。  相似文献   
18.
19.
The impact of tourism on coastal areas   总被引:5,自引:0,他引:5  
The manifold influences of tourism on coastal areas are analysed from three different angles: (1) The development of seaside tourism including the changes of socio-economic and settlement patterns; (2) its cultural impact on the local population; (3) its environmental aspects. Point 1 is described with the help of a model showing four peripheries in space and time: (I) the North Sea and Baltic coasts since the 18th century; (II) Southern Europe during the 19th century; (III) the North African shores around 1950; (IV) the tropical oceans after 1965. Within every periphery, several phases (pioneer, domestic, international) can be distinguished according to the origin of tourists, the investment, the know-how etc. While the beginning of every phase is dominated from abroad, later-on national actors play an increasing role. This applies also to point 2, which refers mainly to developing countries. As for point 3, mass tourism may result detrimentally on water supply, sensitive coastal landscapes, socio-cultural identity etc. Among the questions to be raised are: How far are industrial societies responsible for any negative impacts of tourism, and what are the chances for, and a general consciousness on, a sustainable tourism development?  相似文献   
20.
Tourism in Southern Africa is synonymous with the wildlife safari. In the post-colonial era the establishment of so-called ‘peaceparks’ that straddle the borders of states has come to be seen as a key not only to increasing tourism in the Southern African region, but also to the modernizing of conservation policies and the development of rural economies. This paper focuses on the global and continental presence of transfrontier conservation areas, the link between conservation and tourism development, and the current factors that constrain and influence the realization of an ‘African Dream’ — ‘establishment of the greatest animal kingdom’. The unstable political situation in Zimbabwe and how this negatively affects wildlife conservation and tourism in the Gonarezhou part of the Greater Limpopo Transfrontier Park, serves as a case study. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
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