雨雪冰冻灾害对马尾松林植物多样性的影响

2008年雨雪冰冻灾害后,在崇义县设置马尾松(Pinus massoniana)人工林和马尾松天然林固定样地,连续5年监测雨雪冰冻灾害对其植物多样性的影响。结果表明,雨雪冰冻灾害后的5年内,人工马尾松林受害比天然马尾松林严重。2块样地乔木层植物阳性树种马尾松和枫香木(Liquidambar formosana)数量都减少了,中性和耐荫的树种数量增加。乔木层植物多样性指数变化较小,丰富度指数增减幅度不超过0.3,生物多样性指数和均匀度指数不超过0.2。2块样地林下植物物种种类变化较小,增减都为1种;林下植物数量增加较多,主要是铁芒萁(Dicranopteris dichotoma)增加,其株数占50%以上,盖度超过了60%。2块样地的林下植物多样性指数变化幅度很小,丰富度指数、生物多样性指数和均匀度指数增减的幅度都不超过0.2。

Effect of Freezing Rain and Snow Disaster on the Plant Diversity of Pinus Massoniana Forest

After freezing rain and snow disaster in 2008, one fixed plot of the Pinus massoniana plan- tation and one fixed plot of the natural forest of Pinus massoniana were selected to measure the effect on the plant diversity of Pinus massoniana forests in Chongyi County from 2008 -2012 year. The re- sult showed that the Pinus massoniana plantation suffered damage more serious than the natural for- est of Pinus massoniana within five years after the freezing rain and snow disaster. The quantity of the sunny species for Pinus massoniana and Liquidambarformosana was reduced ,but the quantity of the neutral and shade tolerance species was increased for the two fixed plot. The index of plant diversity changed little for the arbor layer in the two fixed plots. The extent of increasing and reducing was less than 0.3 for the Margalef index, and the extent of increasing and reducing was less than 0.2 for the Shannon-wiener index and the Pielou index. The species kind changed little for vegetation under for- est in the two fixed plots. Increasing and reducing of species kind was less than one kind. The quantity of species increased much for vegetation under forest in the two fixed plots. Dicranopteris linearis increased mainly, and its quantity accounted over 50%, and its coverage accounted over 60%. The index of plant diversity changed little under forest for the two fixed plots, and the extent of increasing and reducing was less than 02 for the Margalef index and the Shannon-wiener index and the Pielou index.