杨树人工林下根系的氮素循环与动态特征  

Nitrogen cycling and its dynamic feature in fine roots of poplar trees and herbs.

作　　者：范世华[1] 李培芝[2] 王力华[2] 许思明[2] 

机构地区：[1]东北大学理学院,沈阳110004 [2]中国科学院沈阳应用生态研究所,沈阳110016

出　　处：《应用生态学报》2004年第3期387-390,共4页Chinese Journal of Applied Ecology

基　　金：中国科学院沈阳生态实验站资助项目

摘　　要：研究了辽宁沈阳地区人工林杨树细根及林下草本植物根系的N循环、积累和动态变化特征 .结果表明 ,杨树人工林分条件下活细根中N储量为 2 0 .3kg·hm-2 ,净积累量 10kg·hm-2 ,吸收量 14 .7kg·hm-2 ,年存留量和归还量分别为 9.6和 5 .1kg·hm-2 .周转期 4年 .整个生长季节杨树细根中N含量与土壤中水解N、NH3 N无明显相关 .杨树细根中N浓度与活细根生物量的变化趋势大体一致 ,两者呈显著正相关 .根据杨树活细根中N含量可以估测杨树活细根生物量 .该林分下的草本植物根系主要吸收NH3 N ,草根中N含量浓度变化与土壤中NH3 N的变化趋势相同 。The nitrogen cycling and its dynamic feature in fine roots of poplar trees and herbs were studied in Shenyang of Liaoning Province. The results showed that the nitrogen content in the standing biomass of fine roots of poplar trees and herbs was 20.3 kg·hm -2,and its net accumulation was 10.0 kg·hm -2. With regard to the biological cycling of nitrogen,the annual uptake was 14.6 kg·hm -2 of which,the retention and the return was 9. 6 and 5.1 kg·hm -2·yr -1 respectively,and the turnover period was 4 year. The relationship between total nitrogen in roots of poplar trees, and herbs and the available nitrogen in soil was also studied, which indicated that there were similar dynamic trends between total nitrogen in herb roots and the NH 3-N in soil in growth season. The total nitrogen in fine roots of poplar trees was positively related to the biomass.

关 键 词：杨树 人工林 根系 细根 氮素 生物循环 动态变化 森林生态系统 养分循环 

分 类 号：S718.5[农业科学—林学]