Abstract: In this paper, horizontal and vertical strips including ten types of ecosystems in Jian-fengling Nature Reserve of Hainan Island were chosen to study the spatial heterogeneity of soil properties in this region. The results showed that on horizontal strip, the organic carbon, total ni-trogen and available nitrogen contents in 0-20 cm soil layer ranked in the order of tropical mountain rain forest＞natural secondary forest＞Caribbean pine, Chinese fir and tea-oil camellia plantations. On vertical strip, the contents of organic carbon, total nitrogen and total phosphorus in 0-20 cm soil layer were the highest in tropical mountain rain forest, and had a decreasing trend towards higher and lower altitudes, with significant difference between test ecosystems. Soil available nitrogen,available phosphorus, and cation exchange capacity had different variation se-quences with other soil properties, but significantly correlated with soil pH. The tropical mountain rain forest located at mid-high altitude with slight anthropogenic disturbance had the highest soil nutrient-holding capacity and integrated soil quality index. Among the disturbed forest types, natural secondary forest had the best integrated soil quality index. At altitude gradient, tropical evergreen monsoon forest was the most vulnerable and sensitive forest type. Soil quality mainte-nance would be of significance in protecting tropical original forest and promoting its natural resto-ration after destroyed.

Key words: Pseudomonas fluorescens, Allelopathy, Cultivated solution, Dilution, Crops