A COMPARATIVE STUDY ON LANDSCAPE PATTERNS OF PEAK CLUSTER DEPRESSIONS DIFFERENT IN ROCK DESERTIFICATION DEGREE

Based on field investigation, analysis was done of the landscape conditions and indexes and their ecological significance of 5 separate peak cluster-depressions, different in rock desertification degree at the southern slope of the Huajiang Karst Gorge. Results indicate that the landscape spatial patterns of all the 5 peak cluster- deperssions have no direct relation with landform grade and physiognomy positions, and the cause of the formation of patches is diversification. The diversity index shows a decreasing trend while the dominance index an increasing trend significantly with the increase in rock desertification degree. The landscape of potential rock desertified peak cluster-depressions is more even than lightly or moderately rock desertified peak cluster-depressions, but the most fragmentized among all peak cluster-depressions. The evenness index increases when rock desertification develops further, or when fragmentation of the landscape increases. With its index of isolation rising, the patch area of naked rock increase gradually. But when the index of isolation of grasslands, shrub and woodland increases their patch area decreases. The landscapes and development modes of potential and strong peak cluster-depressions are typical of rock desertification in the karst mountain areas, Southwest China. Therefore, landscape patterns, landscape diversity, and patches closely correlating with rock desertification process must be taken into account in the assessment of the rock desertification degrees.