Rice germplasm resources in Guizhou are rich in genetic diversity with relatively large variation of biological characters and various types by the natural evolution and artificial selection. Being identified and sorted systematically and comprehensively with the multi - disciplinary sciences, 5168 traditional varieties collected from 79 counties of Guizhou, accounting for about 10 of the total in China were reproduced and sent to the National Bank of Crops Germplasm Resources at CAAS for long - term con-servation. There were some of elite types including semi - dwarf, more grains per panicle, weight grain, good quality, cold and drought tolerance, resistance to diseases and pests as well. Other special elite characterized by restoring to CMS, wide compatibil-ity, and poly - embryonic seedlings were also screened. Working and administering system on rice genetic diversity by establish-ing databank for base and core collection was formed to utilize widely in rice breeding. It will be helpful to direct germplasm en-hancement and gene-pool enrichment with development of molecular biotechnology in application.

Yunnan is well known as a "Kingdom of Plant". Yunnan is also rich in natural resources of crop. Lots of studies on collection, conservation, protection, evaluation and utilization of crop genetic resources have been done in recent years. But there are some unfavourable factors, too. With the agricultural intensity, some new problem such as decreasing diversity, simplifying varieties and narrowing genetic basis of crop have arisen to restrict the development of agriculture in Yunnan. The only way to achieve a sustainable agriculture in Yunnan is doing our utmost to protect the crop diversity, develop new crop or new varieties and widen the genetic basis of crop varieties.

Implementing of "Production Responsibility System", utilizations of both land and bio - resources have turned to base on individual household. Economic development ofjinuo people, an ethnic group who live in the mountainous area and still prac-tice slash - and - bum cultivation, relies only on simple exploration of the natural resources with decrease of local forest resources and loss of biological species. A study has been conducted on fuel wood resources and species used by 60 percent of the house-holds in Baka Xiao Zhai village. It is found that 34.5 percent of fuel wood consumed is from fuel wood plantation, 14.5 percent from the community forests, 44.2 percent from the household forest, and 6.7 percent from nature reserve. In this paper, sugges-tion and recommendation are proposed, basing the study on changes in fuel wood supply and consumption and corresponding rea-sons.

This paper studies three kinds of cash crop cultivation under natural forests in Baka, a Jinuo village next to Menglun Nature Reserve, in Xishuangbanna, Yunnan, China. Based on extensive research, the social and ecological effects of this type of agroforestry have been evaluated. In addition, its relationship to rural development, natural resources management and natural conservation has been analyzed according the intensive investigations carried out through rapid rural appraisal, interviews, partici-pant observation, questionnaires, and sample plots surveys.

House garden is one of important land use types in rural area of Gaoligongshan region. Socio- economy situation of 27 households was investigated by using semi - structure interview. In which 14 house garden of 10 households were selected for agro-biodiversity assessment of by using household - based agrobiodiversity assessment and sampling methodologies. The results show that the land area of house garden is comparatively very small with low economic benefit. But some species with high useful value are cultivated in the house garden. The farmer' s management activities are relative to their cash income. The fanners who obtain more annual cash income cultivate more crops in their house garden than others do. The richest species in the house garden are common herbal vegetables meanwhile some wild or semi - domestic species are cultivated by some the best farmers in their house garden. Furthermore, the species richness and useful species proportion are quite different among different house gardens because fanners have different knowledge on plant species (crops) and cultivation techniques. The species richness is from 34 to 85 mean-while useful species are from 14 to 62 species. The highest useful species richness is 72.4 and the lowest one is 38. The species which included cultivated crops and wild plants in house garden are listed in the last part of this paper.

Eighteen sampling plots of 20x20m of upland and rubber plantation are investigated among nine households of Daka, Xishuangbanna, Yunnan. The results show that there are great disparities of plant species richness among different household Furthennore. hierarchical agglomerate graphics of upland and rubber plantation indicate that plant community similarity among different households were low. Meaningwhile, acceding to the semi - structure interview of sampling households, the autho. found that cash income from rubber plantation were different from each household. Species - household curves that similar to area - species curves of upland and of rubber plantation show the minimum sampling percentage were 15 and 13 based on the fit and assessment of model curve S = a + blnB. A list of folk utilizable plants found in sampling plots is attached .

Nine sampling plots of homegarden were investigated of nine households of Daka, Xishuangbanna, Yunnan. The re-sults show that there are great discrepancies of plant species richness among different households. Furthermore, hierarchical ag-glomerative graphics of homegarden indicated that plant community similarities among different households are low. Meaningwhile, according to the semi - structure interview of sampling households, the authors found that species economic value were different from each household. Species - household curve that similar to area - species curve of homegarden showes the minimum sampling percentage were 15 based on the fit and assessment of model curve S = a + blnB. A list of folk utilizable plants found in sam-pling plots is attached.

Ninety plant species are recorded in four sampling plots of community forests by using vegetation sampling method and agrobiodiveisity assessment method of PLEC BAG guidelines. Sixty three plant species are managed species, which occupy 70 of total species in sample plots, used for medicines, timbers, fuel wood, fodders, wild fruits, wild vegetables and industry oils. The results of two monitoring sampling plots indicate that plant species diversity and arbor numbers and timber volume are decreas-ing because of over logging of timer and fuel wood in community forests. The community forests are badly destroyed because the forest ownership are not stable and lack of efficient management measures. Some strategies for community forest development and conservation are also discussed in the paper.

The timber volume and important value index of plant species of tee layer in different land use stages of Daka and Ba-ka, Xishuangbanna were measured and studied. The results show that there is mutuality between timber volume and land manage-ment intensity. Timber volume of 3 -year fallow field only take 7.2% ofhoUyhiU, which was, considered as secondary forest in Daka.Furthermore, there was no timber volume of 2 - year fallow field in Baka. All indicated that resource degradation resulted from current slash - and - bum agriculture. Timber volume of natural forest which destroyed for building house only take 14.8% m Daka and 82.8% in Baka of holly hill that are well reserved by traditional custom. Resouree degradation was resulted from the increasing need of natural forest.

The authors have undertaken following investigations: 1. General investigation on economic development, population increase, conservation and management of forest resource of 124 administrative villages in Gaoligong Mountains. 2. Sampling in-vestigation on socio - economy and resource management of Baihualing administrative village. 3. sampling plot investigation of plant species among different land management patterns of Baihualing administrative village and Daba administrative village. The authors also have built database and attached models of interaction dynamism between socio - economy and biodiversity. The result shows that: 1. The interaction dynamism between population increase and natural resource is that population and family structure benefit the conservation of natural resource and stability of society when they fit the allocation policy of natural resource. Other-wise, they lead to the destroying of natural resource and non - stability of society when they unfit the latter. 2. The development of new product has changed the manner and number of consumption of biological resources, as well as destroyed the balance of product - consumption". The development of product of consumptive forest resource has accelerated the destroying of forest and increase of consumption. 3. The variation and non - stability of rural land policy and the unreasonable policy of exchange, espe-cially the non - stability of land tenure and variation of policy have lead to the steal of forest timber and waste of forest resource, as well as degradation of ecosystem. 4. The improvements of cash income and economics structure of rural area have affected the manner and number of consumption of forest resources indirectly.

The l998 Conference Of Parties to the Convention on Biological Dirersity asked naional govermments to demonstrate the importance Of biological diversity in supporting mnd communities. This paper introduces agrodiversity as the Primary way in which farmers use biological diversity and, more generally, the natural diversity of the environment for production, including their choice of crops, and management of land, waer and biota as a whole. Promting agrodiversity and understanding how it functions in tropical smallholder faming systems is the best way that importance may be shown.

The work reported in this special issue of Acta Botanica Yunnanica began in the l980s and took off in l990, follOwing a meeing betWeen Guo Huijun and others at the Kunming Institute Of Botany and Dr Nick Menzies of the Foal Foundation Bejing Office. Mainly with Ford Foundation support, the raditional Land Management Systems Researeh Programme was set up, expanding its activities after l992 under the title of the Yunnan Agroforestry Systems Researeh Proect and Indigenous Land Resources Management Programme (W). By l994, YAF had published l6 Working Papers. It was this work, carried out all over Yunnan, al-though focusing ultimately into a small number of main sites, that identified four main types of agroforestry in Yunnan, with 82 forms and 220 associations (Guo and padoch, l995). It also revealed the great dynamism of the systems, in response both to changing economic conditions and to the major innovations in national land tenure policy of the period since 1950.

Based on case studies in Xishuangbanna and Gaoligong Mountains, this paper proposed methodology of household -based agrobiodiversity assessment (HH/ABA) , a set of fundamental principles and practical guidelines for the collection of core agrobiodiversity data, such as the selection of sampling households and sampling plots. Instructions for analyzing data are also pro-vided, such as disparity and similarity analysis among different households, household - species curve analysis that similar to area - species curve, as well as analysis of management diversity. At last the author suggests the application of the result of household - based agrobiodiversity assessment, as well as approaches of in- situ conservation of agrobiodiversity.

There are 73 families, 139 genera and 179 species distributed in 0.1 ha of different land Use Stages of Daka and 70 families 146 genera 166 species distributed in 0.08 ha different different land use stages of Baka, Xishuangbanna. The cosmopolitan families, such as Gramineae, Compositae and Papiloinaceae take about 20% in Daka and 30% in Baka that agricultural activities caused decrease of tropical families and subtropical families comparing with tropical rainforest. Species α - diversity and β - diver-sity of different land Use Stages of Daka and Baka was measured and studied using the methods of Gleason' species richness index, Shannon-Wiennner index, Pielous' evenness index, Whittaker index and Jaccard' coefficient index. The results of the diversity indices varied greatly that means different land Use Stages had different species composition and led to different vegetation succession.

This paper provides definitions of essential agro - biodiversity terminology (Table 1) , a set of fundamental principles (Table 2) and practical guidelines (Table 3 and 4) for the collection of core PLEC plant species diversity data, and instructions for analysis and reporting of that data (Figure 1 - 4) . The tables and figures may be used in the field as a ' recipe' for collection and analysis of that core data, which will ultimately be included in a PLEC biodiversity database. The text provides supplementary information and explanations.