关键词: 退化, 草毡寒冻雏形土, CO₂释放速率, 季节变化, 日变化

Abstract: Based on the 1973, 1988, and 2006 remote sensing data, and with the model of pixel dichotomy and normalized vegetation index, the vegetation coverage in the Lianjiang River Basin of China was calculated. In meantime, DEM terrain elevation data and regression and correlation analysis methods were adopted to analyze the relations of vegetation coverage with altitude, aspect, and slope. The results showed that at altitude 200-1600 m, aspect 90°-160°, and slope 10°-30°, the vegetation coverage was high and had good quality, due to few human activities and good water and temperature conditions. The spatial distribution of the vegetation coverage was mainly affected by altitude, lesser by aspect, and least by slope. In recent 33 years, the vegetation coverage in the river basin was mainly centered in the fast increasing and stable vegetation areas, mostly distributing in the forest farm, natural reserve, and plantation areas with good habitat conditions.

Key words: Degenerated, Mat cryo sod soil, CO₂ emission rate, Seasonal dynamic, Daily variation