Abstract:

Coastal Casuarina equisetifolia protection forest, especially main shelterbelt, takes very important role at improving ecological environment and promoting economy and society development. It is the base for classifying the type of main shelterbelt, measuring the term of protection maturity, and renewing and modifying main shelterbelt to quantitatively evaluate the protection effect of main shelterbelt. The protection effect of C. equisetifolia shelterbelt was evaluated with the quantitative theoryⅠ. The results showed: it could estimate the protection effect of main shelterbelt using the equation educed form quantitative theoryⅠ, and it had the higher precision. DBH, width of tree crown, and height decided the protection effect obviously, the type of physiognomy and stand density also effected it, but bole length had not obvious effect. The definition was given for the lower-effective plantation whose score of protection effect was lower than 0.440. Protection effect score—0.613 was regarded as the threshold for deciding the initial stage and telophase of protection maturity.

Key words: Casuarina equisetifolia, Main shelterbelt, Protection effect, Quantitative theory Ⅰ