Effect of acid rain and water addition on decomposition of Schima superba and Pinus massoniana leaf litter | 模拟酸雨及降水量对木荷、马尾松叶凋落物分解的影响

chinois. 在室内条件下，将木荷和马尾松叶凋落物置于不同水量、pH条件下进行模拟分解试验，研究酸雨pH及降水量对2种叶凋落物分解的影响．结果表明：（1）每月向20g木荷叶凋落物添加200mL以上的水分，即降水量达到200mL以上时，能极显著提高其分解速率，在一定范围内，水分越充足其分解越快；每月向20g马尾松叶凋落物添加50mL水分，即降水量达到50mL时，能极显著提高其分解速率，但分解速率并不总随水分的增多而加快，每月添加200mL水分，即降水量达到200mL以上时甚至会抑制其分解．（2）除pH=6．0处理的木荷叶凋落物分解速率显著快于pH=2．5处理外，其他处理间的差异不大，即酸雨pH的大小对其分解速率影响不明显；不同pH处理间马尾松叶凋落物分解速率的差异较大，各处理凋落物分解速率的大小为：pH=3．5处理〉pH=6．0处理〉pH=2．5处理〉pH=3．0处理〉pH=4．5处理〉CK，即酸雨pH为3．5时最有利于马尾松叶凋落物的分解，pH为4．5或3．0时会在一定程度上抑制其分解．[著者文摘]

anglais. The effects of different pH water addition on decomposition of Schima superba and Pinus massoniana leaf litter from mid-subtropical zone were studied using a self-designed lysimeter. The results showed that decomposition rates of S. superba and P. massoniana leaf litter from mid-subtropical zone would all be obviously accelerated by adding distilled water. And to some extend, adding more than 200 mL water, S. superba leaves decomposed more quickly. The decomposition rate of P. massoniana needles also would be accelerated by adding 50 mL/20 g monthly, but didn＇t the more water, the quicker decomposition, and when adding 200 mL water the decomposition would be restrained. Compared with CK, the effects of a certain quantities of distilled water were stronger than its pH to S. superba leaves. To P. massoniana needles the decomposition rates of adding different pH water were in the sequence of pH = 3.5 〉 pH = 6.0 〉 pH = 2.5 〉 pH = 3.0 〉 pH = 4.5 〉 CK. P. massoniana needles decomposition could be more obviously accelerated when pH value of water was 3.5, and was restrained when pH value of water was 3.0 and 4.5. P. massoniana needles decomposition was sensitive to pH variation.