岩溶区和非岩溶区两种优势植物凋落叶分解的比较研究

应用野外分解网袋法对岩溶地区和非岩溶地区两种优势树种桂花和青冈栎凋落叶的分解速率和养分释放规律进行研究。结果表明:分解1年后,凋落叶失重率桂花大于青冈栎,同一物种岩溶区大于非岩溶区。凋落叶各元素浓度随分解时间变化也有一定差异,C含量均表现为初期上升,后下降,最后上升的趋势;N含量前半年呈波动状态,后半年逐渐上升;P含量处波动状态,总体呈上升趋势。N、P含量和凋落叶失重率均表现为极显著正相关,而C:N、C:P、N:P与凋落叶失重率呈极显著负相关(P<0.01),说明凋落叶分解过程中失重率与N、P含量及C:N、C:P、N:P关系密切。凋落叶桂花N、P含量比青冈栎高,分解速率也比较快。

Comparative study on decomposition of leaf litters from two dominant species under karst and non-karst terrains

The decomposition rate and nutrient decomposing variation of litters of two dominant species Osmanthus fragrans and Cyclobalanopsis glauca under karst and non-karst terrains were studied by using field litter bag technique.The results showed that after one year,the litter weight loss rates of O.fragrans were higher than that of C.glauca,and the litter weight loss rates of samples form karst were higher than non-karst.Elements concentration in litter remainder varied in the course of decompositon,which C content tended to be increased initially,then decreased and finally increased,while N content fluctuated in the first half year but increased thereafter,and P content showed fluctuating increased.Litter loss rate(weight) was significantly positive correlated with N and P contents,and were significantly negative correlated with C:N,C:P and N:P ratio,indicating litter decomposition rates relied on litter N,P composition and C:N,C:P and N:P ratio.Sample from O.fragrans litter contained higher N,P than that from C.glauca and presented a higher decomposition rate.