Landscape pattern change in the upper valley of Min River

The upper valley of Min River (102° 59′ –104° 14′ E, 31° 26′ – 33° 16′ N), which is consisted of the counties Wenchuan, Maoxian, Lixian, Heishui, and Songpan, refers to the part up to Dujiangyan City, and locates on the transition zone from the Tibetan Plateau to the Si- chuan Basin. It is one of the most important forest areas in China, especially in Sichuan Province. Over past two decades, the landscape changed remarkably in the region. The 3S techniques (Remote Sensing (RS), Geographic Information System (GIS) and Global Position System (GPS)) were used to classify the images and analyze the landscape change. The remotely sensed data of Landsat TM 1986 and Landsat ETM+ 2000 were used to analyze the landscape change of the region. The landscape were classified into 10 types of cropland, for- est, shrub land, economic forest, grassland, build up land, river, lake, swamp, and unused land. The results showed that: 1) the woodland and grassland were dominating landscape types in the upper valley of Min River, which is more than 91% of the study area; 2) the alteration of the landscape was mainly happened among forest, shrub land, grassland, economic forest, cropland, and build up land, where forest de- creased from 51.17% to 47.56%; 3) the landscape fragmentation in the upper valley of Min River was aggravated from 1986 to 2000.

ANALYSIS OF HABITAT PATTERN CHANGE OF RED-CROWNED CRANES IN THE LIAO HE DELTA USING SPATIAL DIVERSITY INDEX

Habitat pattern change of red-crowned cranes (Grus japonensis) in t he Liaohe Delta between 1988 and 1998 was analyzed with the help of Spatial Dive rsity Index based on remote sensing data and field investigation. The result sho wed that the influence from human activities on the wetland habitat of red-crow ned cranes was prominent with the development of oil and agricultural exploitati on, and the habitat pattern of red-crowned cranes had been obviously changed by the human disturbance during the ten years. The areas with high Spatial Diversi ty values (SD≥0.65) and that with mid-high values (0.5≤SD< 0.65), which const ituted the main part of suitable habitat of red-crowned cranes,had reduced to 9142ha and 5576ha respectively, with the shrinking of natural land cover, such a s reed and Suaeda community. The habitat pattern became more fragmented, which w as caused by roads and wells during oil exploration. It was indicated that the s uitability and quality of habitat for red-crowned cranes in the Liaohe Delta we re degraded in the last decade. The results also showed that diversity index cou ld reflect the habitat suitability of red-crowned cranes quantitatively and des cribe the spatial pattern of the habitat explicitly. This study will provide a s cientific basis for habitat protection of red-crowned cranes and other rare spe cies in wetlands.

ECOLOGICAL RESTORATION:OUR HOPE FOR THE FUTURE?

Ecological restoration is widely employed from tens to millions of hectares in space,and from tens of days to thousands of years in time, which forces consideration of it thoroughly. We argue that three questions are the most important among the contents relevant of ecological restoration, including why, what and how to restore degraded systems. Why to restore determines whether or not the degraded ecological systems should be restored. What to restore is the goal of ecological restoration. The explicit goal of ecological restoration is necessary to guide ecological restoration workers in pursuit of excellence and prevent restoration from being swamped by purely technological activities. And how to restore means the methods and steps we should apply. To ensure the final success of ecological restoration, restored sites should be monitored and managed for long time to determine whether the selected methods are appropriate, and can be remedy better. Only to deal with these effectively, ecological restoration would be the hope for the future.