Abstract:

Slash Pine(Pinus elliottii) is an introduced tree species that can adapt different site types. Since 1970s, in order to enrich the tree species resource, Slash Pine was planted on the cut-over area of Casuarina equisetifolia protection forest in Chishan Protection Forest Farm of Dongshan County, Fujian Province. It could prevent soil fertility from degeneration, improve forest productivity and provide fundamental data for soil ecological management to study the soil nutrient content and enzyme activities of different age stands of Slash Pine. The effect of Slash Pine on fertility of coastal sandy land was studied in this paper. The results showed that it would make the soil acid to plant Slash Pine on the cut_over area of C.equisetifolia protection forest Compared, because the pH value was declined as the growth of Slash Pine stand, and it declined to 3.96(0～20 cm) and 3.87(20～40 cm) when Slash Pine stand was 26 a; Compared with the second generation coastal protection forest of C.equisetifolia the nutrients content in the soil of 26 a Slash Pine stand were lower than that in the soil of the second generation forest, especially for available P, available K, and total N. The CEC in soil layer of 0～20 cm was obviously effected by Slash Pine. In this soil layer, the CEC was increased as the growth of Slash Pine stands, and it was as 1.22 times as the content in the soil of the second generation forest. There was no obvious effect on urease activity, but the activities of phosphataese, polyphenol oxidase, and peroxidase were declined by planted Shash Pine on the cut_over area of Casuarina protection forest.

Key words: Sandy soil in coastal areas, Pinus elliottii, Soil nutrient content, Enzyme activity