| The study of forest vegetation characteristic and dynamic is restricted in the three gorges reservoir area, thanks to most of the forest resouce distributing in transport facilities inconvenient and complex terrain areas. In this paper, based on RS&GIS technique, using remotely-sensed imagery and GIS database to analyze the forest landscape spatial pattern in the three gorges reservoir area, China. Landscape features and the distributing law are explored and explained in the study area, for offering the information to study forest landscape dynamic changes,ecological restoration and landscape assessment. The results provided scientific basis for eco-construction and forest resources management in three gorges reservoir area. The results as follows show that:(1) 7 classes forest landscape distributes inequality. In whole forest area, the status of every class is different. Warm temperate conifer mixed forest and shrubbery have the major area. At the some regions, some classes as the main types control the whole landscape, so that the landscape diversity is low in the partly district. In the district of Chongqing, the area of broadleaved forest less than conifer forest. In the district of E'xi, the area of broadleaved forest also less than conifer forest, but the area percent of broadleaved forest of E'xi forest area is high than the one of Chongqing.(2) With elevation changing, different vegetation types distribute with single peak. The every type's area percent peak value appears in turn from low elevation to high elevation: warm temperate conifer forest< warm temperate conifer mixed forest and shrubbery< warm temperate conifer broadleaved mixed forest< deciduous broadleaved forest and cool temperate conifer forest< evergreen broadleaved forest. When the elevation less than 1800m, warm temperate conifer mixed forest,shrubbery and deciduous broadleaved forest own the major forest area, during 1800m-2600m, deciduous broadleaved forest,shrubbery,cool temperate conifer forest are the major vegetation type. After 2600m, evergreen broadleaved forest has the highest area percent to all forest area.(3) Erery vegetation class mostly distributes at the slope during 16°-35°, the area percent changes with normal distribution. Excepting evergreen broadleaved forest, the peak values of area percent of others appear at the slope during 26°-35°, but evergreen broadleaved as the belt vegetation, its peak values appears at the slope during 36°-45°, that proves it distributes in the strait and cragged terrain area. At the same slope range, shrubbery,warm temperate conifer mixed forest,deciduous broadleaved forest have the major area percent, the other class has less area percent of all forest area. (4) The area of each vegetation type changes unconspicuously at different aspects. But because the vegetation area and biology character is diffeent, when the aspect suited to one vegetation type growing, area percent of this suited-plant community to its all area at this aspect is higher than at other aspect.(5) In the model district of Chongqing, warm temperate conifer mixed forest is the main component of the present vegetation, shrubbery is the second component, the area of other types is less 5%, but all the edge density is small in the whole level. Refering to shape indexs, the avnormity degree of every class was ranged as follows: warm temperate conifer mixed forest> shrubbery> evergreen broadleaved forest> warm temperate conifer broadleaved mixed forest> deciduous broadleaved forest> cool temperate conifer forest. Every class was ranged as landscape fragmentation degree as follows: cool temperate conifer forest< warm temperate conifer broadleaved mixed forest< shrubbery< deciduous broadleaved forest< evergreen broadleaved forest< warm temperate conifer mixed forest. The reuniting degree was ranged from high to low valus as: evergreen broadleaved forest> warm temperate conifer mixed forest> warm temperate conifer broadleaved mixed forest> deciduous broadleaved forest,warm temperate conifer forest> shrubbery.(6) Compared with the model district of Chongqing, there is no main component among all the vegetation types in the model district of E'xi. evergreen broadleaved forest,warm temperate conifer broadleaved mixed forest,warm temperate conifer mixed forest,shurbbery have the same status. The edge density in the whole level is higher than the edge density of the model district of Chongqing. The landscape fragmentation was ranged as cool temperate conifer forest< shrubbery< warm temperate conifer forest< deciduous broadleaved forest< warm temperate conifer mixed forest< warm temperate conifer broadleaved mixed forest< evergreen broadleaved forest. The shape indexs was ranged as shrubbery> warm temporate conifer mixed forest> evergreen broadleaved forest> warm temporate conifer broadleaved mixed forest> warm temperate conifer forest> deciduous broadleaved forest> cool temporate conifer forest. The reuniting degree was ranged from high to low valus as: evergreen broadleaved forest> warm temperate conifer mixed forest> warm temperate conifer broadleaved mixed forest> deciduous broadleaved forest> warm temperate conifer forest> shrubbery> cool temperate conifer forest. In this district, all of these results appear the forest landscape succession trend, such as secondary conifer forest to deciduous broadleaved forest,evergreen broadleaved forest, and the vegetation restoration in the model district of E'xi is better than Chongqing. (7) At the vegetation landscape level, contagion index,aggregation index,interspersion juxtaposition index in the model district of E'xi is higher than the model district of Chongqing, the diversity index and evenness index also appear that Chongqing |
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