| Chongming Dongtan is a typical case of estuarine tidal flat wetland which has been diked continually in the past. This paper quantificationally analysized the present landscape pattern and its change over the past more than 10 years. The main content concludes work in four aspects as follows:1. The landscape types classification and identification. We built up a landscape classification system for Chongming Dongtan, and then executed the landscape classification map by using two-period SPOT image of Chongming Dao as information resource and with support of remote sensing image classification technique.2. The quantificational analysis on the landscape pattern of Chongming Dongtan. According to the gradual change of the intensity of anthropogenic activities & environmental factors, the landscape classification mape of 2002 was divided into three landscape zones(managerial landscape zone, semi-artificial landscape zone and natural landscape zone). With the support of FRAGSTATS, a landscape indices computing software, twenty metrics referring to the density and size of patches, shape, diversity, distance and contagion&interspersion of pathes or landscape. The results showed that landscape of these zones distinguished by sea walls was differentiated, possessing their particular characteristics. On this basis, this paper analyzed the impact of human disturbance on all the three landscape zones, with the characteristics of each landscape zone as the indication.3. The landscape pattern change analysis over the past 15 years. Through analyzing the dynamic development of Dongtan, the change of landscape pattern characteristics and the change of landuse, we concluded the landscape and its driven factors as follows:1) The landscape of Chongming Dongtan in the later 80s was rarely disturbed by the people, owning a high degree of landscape heterogeneity as a result. The anthropogenic activities such as frequent diking and cultivation led to the landscape fragmentation, low connectivity and the landscape differentiation of the zones distinguished by sea walls.2) On the one hand, the anthropogenic activities altered the landscape derectly. As for the previous area inside 92-bank, there remained acres of reed marsh which owned high degree of connectivity in Dongwangsha, and the interlacting landscape patches such as salt marsh, reed marsh, bare flat, swamp and creek showed high degree of heterogeneity. One the other hand, the anthropogenic activities altered the landscape inderectly. Wihin the diked but not assarted area enclosed by 92-bank and 98-bank, the evironmental factors are changed, which led to the quickened landscape succession and serious landscape fragmentation. Even in the tidal flat wetland area outside the 98-bank, the human disturbance brought the result of the change of landscape pattern characteristics, such as the reduction and degradation of tidal creeks, the subsequent change of reed marsh and salt marsh's shape, the decrease of patches' richness and evenness around the salt marsh, and the decline of landscape heterogeneity, et al.3) We found the important role palyed by creek in the landscape change of Chongming Dongtan. As the corridor of estuarine tidal flat landscape, the pattern change of creek led to the subsequent change of other landscape elements. The degradation of creek is connected closely to the decline of Inspersion&Juxtapositon Index(IJI), and the elevation of connectivity index(COHESION) of salt marsh, which affected the whole heterogeneity and connectivity of tidal flat wetland landscape.4. The analysis of ecological effects of the landscape change of Chongming Dongtan. Through the result from the landscape pattern analysis, we interpreted some ecological process. We deemed that the decrease of biological diversity, the structural and distribution change of macrozoobenthic community were related to the area reduction and fragmentation of reed marsh, the decline of IJI of salt marsh, and the decline of patches' heterogeneity...
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