Abstract: Based on the measurement of light intensity, air temperature, soil temperature, soil humidity, and relative humidity (RH) in a typical karst rocky desertified catchment of Huajiang Gorge of Guizhou Province, this paper compared and analyzed the distribution characteristics and daily changes of these microclimatic parameters on latent (L), slight (SL), medium (M), and strong (ST) rocky desertified lands. The results showed that light intensity, air temperature, and their changing amplitude followed the order of SE>M>SL>L, soil temperature and soil humility followed the order of M>SE>SL>L, and RH and its changing amplitude followed the order of SE>M>SL>L. Compared with those on latent rocky desertified land, the daily average RH on strong rocky desertified land was 13% less in rainy season and 35% less in dry season, light intensity was 4 times more, air temperature was 3 ℃ higher in rainy season, surface soil (0～5 cm) temperature had a 16.5 ℃ difference, and daily average soil water content was 4.97% less. All of these demonstrated that the modulation ability of karst ecosystem decreased seriously with increasing degree of karst rocky desertification.

Key words: Soil bioremediation, Mineral oil, PAHs, Plant, Microbes