Study on land suitability for Hyloccreus undatus and some other plantsin karst area based on DEM-GRA

In light of adjust measures to local conditions, DEM is established based on GIS platform and land suitability for Hyloccreus undatus at 6 sample plots in Rengtun karst depression, Tiandeng County is analyzed comprehensively by means of GRA in the paper. The results prove that plot 2, 4 and 6 being gentler in gradient an d smaller in hill shadow as well as thicker in soil layer are quite suitable for Hyloccreus undatus; but plot 3 being thinner in soil layer and larger in hill shadow is not suitable for Hyloccreus undatus; plot 1 with higher gradient and other suitable conditions and plot 5 being laugher in hill shadow but suitable in other conditions are both suitable for Hylocereus undatus, which situated between the former two types. Among plot 2, 4 and 6, plot 2 is better correlated to the suitable conditions for Hyloccreus undatus and most suitable for Hyloccreus undatus growth. According to the above evaluations, the land suitability evaluation method is used in harnessing karst rock desert, and artificial replanting at suitable patches in Tuanle and Dushan as well as Xiaoshan karst basins is done with the survival rate of the replanted plants higher than 85% and grows well meanwhile.