| Land use and its effects on the environment have become the hot points and focus of many international and multidisciplinary research projects. In this thesis, the impacts of land use and pattern on the eco-environmental systems in North China Plain were evaluated through two case studies, including biodiversity investigation in Dongbeiwang village, Beijing and soil organic carbon change in Quzhou county, Hebei province. Carabid beetle was selected as bioindicators and pitfall trapping was used as sampling method for animal biodiversity evaluation; for flora evaluation, both field experiment and releve approach were used with assistance of remote sensing image; for the evaluation of soil organic carbon change, a Regional Resources and environmental information system was established; and RS, GIS and biogeochemistry model were all used to evaluate the soil organic carbon change. The research results and conclusion were summarised as follows:1) Seasonal dynamics of carabid community were little effected by land use type that the seasonal trend of individuals number of carabid community were almost same in different land uses. However, species had the highest abundance in different seasons.2) The effect of land use type on the spatial distribution of Carabid community was obvious. Great differences of the individual number among habitats were observed that there were much more individuals in woodland and field margin than that in croplands. Significant differences of species numbers among habitats were found too: there were the highest species number in the field margin, higher in woodland and field that was adjacent to the field margin, and the lowest in the crop field. In general, it seems that the field margin and woodland were much fitter for carabid living than cropland; and it was beneficial to protect and establish such habitat for the biodiversity in agro-ecosystem.3) Because of the long-term intensively agricultural land using and rapid urbanization, the vegetation in the Dongbeiwang village was extremely homogeneous. Crop was the dominant cover in the area, and the planted woody vegetation was the second one. Little spontaneous vegetation was found with totalled 3.2% area of surveyed area in 2002; and their occurrence was restricted to sites that cannot be used for any other purposes in their current state (rubble heaps, ruins and area with thin-soil). However, due to the rapid urbanization, farmland were transform to buildings quickly, the state of vegetation diversity was still not optimistic.4) There were 295 spontaneously growing vascular plants identified during the survey at the Dongbeiwang village; Of these, 18 plants occurred with a degree of presence > 10% . 64 spontaneously growing vascular plants were identified at the experiment field; Of these, 11 plants occurred with a degree of presence >10% . There was great discrepancy between the taxa that would potentially be expected to occur in the study area and those that were actually found. Only plants with high seed production and wide tolerance range for different growing sites can grow in intensively disturbed agricultural land.5) The farm management measures, including irrigation, fertilization, straw return to filed, had no significant effect on the individual number of carabid community; However, plowing in autumn improved the individual number in the field margin greatly. It was indicated that the modest disturbance in some instance was beneficial to biodiversity conservation. Field experiment also showed that the colonisation and development of vegetation was slowly although open ground and favourable starting conditions offered, because there were the extremely limited range of species in the soil seed bank andno natural remnant biotopes or non-crop landscape elements in the immediate vicinity area. So, in the agro-landscape that was long-term strongly disturbed by human being, reasonable management measures were also essential for biodiversity conservation and improvement besides the establishing landscape...
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