Abstract: Ecological security is one of the fundamental guarantees for the social and economic sustainable development of urban agglomeration. However, nowadays the ecological security of urban agglomeration is greatly threatened. According to land cover/ecosystem types extracted from Landsat TM/ETM+OLI in 2000, 2005 and 2010, combined with analysis of social and economic factors, the evolution pattern and driving mechanism of ecosystems in Urban Agglomeration in Fujian Delta Region were analyzed from the dimensions of area change, type shift and spatial pattern of ecosystems in this study. The results showed that the area of urban ecosystem presented positive growth from 2000 to 2015, while the forest and farmland ecosystem were in negative growth, and the shrub, wetland, grassland and other ecosystems remained relatively stable. The area proportion of ecosystems was in the order of forest > farmland > urban > shrub > wetland > grassland > other ecosystems. The intensity of mutual transfer of ecosystem was weak from 2000 to 2005, but strong from 2005 to 2010 with the input of urban ecosystem and the output of otherecosystems being the largest during this period. The intensity was still strong from 2010 to 2015 with both the largest output of other ecosystem and the largest input of forest ecosystem. From 2000 to 2015, the forest ecosystem was distributed unevenly in different regions, while the farmland and urban ecosystems were mainly distributed in the central and eastern Urban Agglomeration in Fujian Delta Region, and the distribution of wetlands was consistent with that of rivers; the grassland, shrub and other ecosystems were in scatted distribution. At the same time, the landscape pattern was basically stable without significant changes in patch number, patch density and clustering characteristics, but there were significant differences among different ecosystems. The spatial pattern of ecosystems in the Urban Agglomeration in Fujian Delta Region was basically stable from 2000 to 2015, while the different ecosystems were in unbalanced changes, and the transfer intensity of various ecosystems in different periods was significantly distinct from each other. The economic and industrial development, urbanization, and urban pattern change significantly affected the pattern evolution of the ecosystems, especially forest, farmland and urban ecosystems.

Key words: seasonal variation, impact contribution rate, water use efficiency (WUE), Platycladus orientalis