沿海防护林防海煞危害初探

Protection effect of salt damage by coastal windbreak forest

通过后牧村海岸防护林带附近空气中主要盐离子飘尘（即海煞）的观测分析表明，林带对大气盐尘有吸附和截留作用，无林带地区平均沉降量为４．３４μｇ·ｍ（－３）·１００ｍ（－１），通过林带时为１８．４０６４４ｇ·ｍ（－３）·１００ｍ（－１）．林带的吸附量与树种、枝叶形状有关，侧柏对Ｃｌ－和Ｎａ＋的吸附量分别为６３３０和３３５０ｍｇ·ｋｇ（－１），而黑松为１５７０和９５０ｍｇ·ｋｇ（－１）．空气中盐尘受天气条件特别是风速的影响．阴天，风速越大，空气中盐尘含量越大，输送距离越远．

Observation and analysis of salty dust in the air near coastal windbreak forest show thatatmospheric salty dust can be intercepted and adsorbed by the windbreaks, its mean subsidence amount is 4. 3μg· m-3·100m(-1)in the region without windbreaks, and is 18. 4μg·m(-3)·100m(-1)in the region with ones. The adsorption amount of it by the windbreaks la related to the tree species and their size of branches and leaves. The adsorption amount ofCI- and Na+ by Platycladus orientalis is 6330 and 3350mg· kg(-1),but that by Pines thunforii is 1570 and 950 mg· kg(-1) The atmospheric salty dust is depended on the weatherand wind speed. On cloudy day, the greater wind speed is,the higher salt content in theair and the farther transported distance are.