Special ecological effects of ravines in Danxia Landform, China

Danxia Mountain in Guangdong Province was investigated on the special ecological effects of ravines in Danxia Landform. The results showed that its geomorphologic ecological effects could be manifested in the following two aspects. Firstly, multitudinous ridgy stone peaks and hollow ravines were shaped in the forming process of Danxia Landform. Ecological factors were different between the ravines and other open regions. Relatively close microclimate and high moisture condition in ravines could provide suitable living environment for tropical species which preferred hot and humid environment. Geomorphologic environment in ravines, like smooth degree of surrounding cliffs, would affect intensity of light reflected into ravines. All the aspects had influence on the temperature and humidity in ravines. Secondly, the special ecological effects of ravines in Danxia Landform provided a possibility to gestate a group of taxa with greater tropical characteristics. There, tropical plant flora was markedly increased in comparison with other vegetations at similar latitude. Tropical plant distributions were obvious in most ravines of Danxia Landform. Its proportion was 10% more than that of other regions at the similar latitude. The ravines in Danxia Landform were rich in liana, ferns and other plants with high water-logging resistance. Collectively, the phenomena that some typical species in south subtropical regions appeared in mid-subtropical regions revealed latitudinal shift of plant distribution. This kind of climax communities, which were coordinated and balanced with their geomorphologic environments due to the special ecological effects of ravines in Danxia Landform, could be called geo-climax communities.