华北落叶松与白桦叶凋落物混合分解及其养分动态

摘要

Using the method of the litter bag decomposition,we studied the effects of adding the birch leaf litter into the leaf litter of Larix principis-rupprechtii on decomposition of the latter,through analyzing the rate of decomposition and the dynamic changes of nutrients.The results showed that birch leaf litter could promote the decomposition of leaf litter of Larix principis-rupprechtii in the whole decomposition process.On the 120,360,420,480 and 540 days after litter decomposition,the decomposition rate increased with increase of the number of Betula platyphylla leaves,and the change was significant.The leaf litter of the Betula platyphylla inhibited the release of nitrogen and phosphorus,and promoted the release of potassium and carbon,which disappeared gradually after litter decomposition after 540 days.It can be seen that the addition of birch leaf litter can promote the decomposition of Larix principis-rupprechtii leaf litter,shorten the time of nutrient cycling,and benefit the maintenance of soil fertility,but there is some differences in nutrient release.%为了揭示添加白桦叶凋落物对华北落叶松叶凋落物分解的影响,通过网袋法对2种叶凋落物的混合分解速率及其养分动态进行了分析测定.结果显示,在整个分解过程中,通过添加白桦叶凋落物,加速了华北落叶松叶凋落物的分解,在分解的120 d、360 d、420 d、480 d和540 d表现出明显促进作用,并且这种趋势随着白桦叶数量的增加而增加;混合分解对N、P的释放有抑制作用;对K、C的释放有促进作用,但在分解的540 d影响作用逐渐消失.可见,添加白桦叶凋落物使华北落叶松叶凋落物分解速率加快、周转时间缩短,有利于地力的维持,但在养分释放方面有一定的差异性.