杨树刺槐混交林及纯林枯落叶分解

研究了杨树（Ｐｏｐｕｌｕｓｓｐｐ．）、刺槐（Ｒｏｂｉｎｉａｐｓｅｕｄｏａｃａｃｉａ）纯林及混交林枯落叶一年中的分解及养分动态变化规律．结果表明，杨树枯落叶分解速度较慢，刺槐较快，而混交林则较杨树有较大提高．在分解过程中，杨树枯落叶Ｎ、Ｐ释放困难，需经过长达１０个月的养分富积过程；刺槐枯落叶Ｎ、Ｐ元素释放较为容易；混交林枯落叶养分富积时间缩短、幅度下降，分解速度加快，说明杨树和刺槐混交有利于枯落叶分解和Ｎ、Ｐ循环．

Decomposition of leaf litter in pure and mixed stands of poplar and black locust.

One year's study on the decomposition and nutrient dynamics of leaf litter in pure and mixed stands of poplar and black locust shows that the decomposition of poplar leaf litter was slow, and that of black locust leaf litter was fast; the mixed stand had a faster decomposition speed of leaf litter than poplar. During decomposition the N and P release of poplar leaf litter was difficult,taking more than 10 months for nutrient immobilization; while than of black locust leaf litter was much easier. The time and range of N and P immobilization of leaf litter in mixed stand were cut down, and the decomposition speed of leaf litter increased, indicating that mixed planting with poplar and black locust was beneficial to the decomposition of leaf litter and the cycling of N and P.