模拟酸雨对华南典型树种生长及营养元素含量的影响

我国是世界上的第3大酸雨区,而华南地区是我国酸雨比较严重的地区之一。越来越严重的酸雨将对森林生态系统林木生长产生负面影响。本文采用盆栽试验模拟研究酸雨对华南典型树种尾叶桉和马尾松幼树生长及营养元素含量的影响。酸雨水平有4个:pH6.8(CK)、pH5、pH4和pH3。幼树生长期间观察并记录其酸雨受害症状,每隔10a测量一次树高,4个月后统计生物量、叶面积情况,并分析植株样品中的N、P、K、Ca、Mg等元素的质量分数。试验结果表明,在不同酸度酸雨的协迫下,尾叶桉和马尾松幼苗表现出不同程度的受害症状,酸度越高受害越严重。酸雨显著地抑制尾叶桉和马尾松的树高生长,降低幼苗生物量,减少叶面积生长。与对照相比,生长四个月后,pH5、pH4和pH3处理分别导致尾叶桉生物量降低10.79%、19.21%和27.25%,马尾松降低12.78%、22.98%和28.70%。尾叶桉植株内P、Mg、Ca质量分数不同程度地受到酸雨的影响,而N、K质量分数不受酸雨影响;马尾松除了P元素以外,其它元素质量分数在各个酸雨处理之间差异不显著。

Impact of simulated acid rain on growth and nutrient elements uptake by Eucalyptus urophylla and Pinus massoniana

Impact of simulated acid rain on growth and nutrient elements uptake of Eucalyptus urophylla and Pinus massoniana had been conducted for four months. Four different pH i.e. 6.8, 5.0, 4.0 and 3.0 were used for simulated acid rain experiments. The results showed that different foliar symptoms were seen after E. urophylla and P. massoniana exposed to acid rain. Tree height, biomass and leaf area were significantly inhibited by acid rain. Compared to control, total biomass of E. urophylla declined 10.79%, 19.21% and 27.25% respectively at pH 5.0, pH 4.0 and pH 3.0, whereas that of P. massoniana declined 12.78%, 22.98% and 28.70% respectively. The uptake of P, Mg and Ca in E. urophylla was affected by acid rain, while there were no differences between treatments for N and K uptake. Besides uptake of P in P. massoniana, no differences between treatments were seen for the other nutrient elements.