【作者】 徐涵湄；

【导师】 阮宏华；

【作者基本信息】 南京林业大学 ， 生态学， 2010， 硕士

【摘要】 2008年初,我国南方发生的严重冰雪灾害对森林生态系统的结构与功能产生了严重的干扰。为了研究雪灾干扰对森林生态系统物质循环与能量流动的影响,利用大样袋网袋法对武夷山3种受灾程度毛竹林样地中的凋落物分解进行连续2年的观测研究。结果表明:(1)毛竹林凋落物的分解失重呈先快后慢的趋势,不同受灾样地凋落物分解速率大小依次为重度>中度>轻度,分解速率随受灾程度的加重而显著加快。(2)3种不同受灾样地毛竹林凋落物的分解动态符合Olson指数衰减模型,且分解系数k大小排序与凋落物分解速率大小排序一致。(3)不同受灾竹林的分解速率均与土壤表层温度、雪灾输入林地生物量和受损率显著正相关,与郁闭度显著负相关,与土壤湿度相关不显著。(4)不同受灾样地凋落物C、N、P、K释放速率大小依次为重度>中度>轻度。重度受灾样地中C、N、K释放速率显著快于中度、轻度受灾样地,但P释放速率无显著差异。凋落物残留率与C、N、P、K的剩余百分率之间均呈显著性正相关。(5)在所有分解时间内下层的凋落叶分解速率、养分元素释放速率总体快于上层的凋落叶。轻度、中度受灾毛竹林内上下层凋落叶分解速率、C释放速率的差异性随着时间的推移逐渐表现出来,然而在整个分解阶段内,重度受灾毛竹林上下层凋落叶的分解速率、养分元素释放速率一直差异不明显。更多还原

【Abstract】 In January 2008, an extraordinarily serious snow storm occurred in southern China had serious disturbance and destroy on structure and function of forest ecosystem. We used big litterbag method to study the dynamics of leaf litter decomposition in different damaged level bamboo forests in Wuyi Mountain over two years for understanding the influences of snow storm on cycle of matter and energy flow. The result showed that:(1)Bamboo forest mass loss rate firstly was very quick, then slow down, and leaf decomposition rates followed to order of heavy level>middle level>low level, it increased with the damaged level significantly.(2)Decomposition dynamics in the different damaged level bamboo forests was accord with Olson model, and the order of leaf decomposition rates (k) was accord with the order of leaf decomposition rates.(3)The decomposition rate positively correlated with soil temperature、the aboveground biomass loss caused by the snow storm and the damaged level, but negatively correlated with the canopy closure significantly. It did not correlated with soil moisture.(4)The release rates of C、N、P、K in heavy level>middle level>low level, and C、N、K release rates in heavy level sites was significant faster than that in middle and low level sites, but there was no significant difference of P release rate among different damaged level sites. leaf litter remaining positively correlated with C、N、P、K remaining.(5)All over the decomposition process, the leaf litter decomposition rates and nutrient release rates of below leaf litter were quicker than that of above leaf. There gradually appeared significant differences of leaf litter decomposition rates and C release rates between above leaf litter and below leaf litter in middle level sites and low level sites with time, but there were no significant differences between above leaf litter and below leaf litter in heavy level sites in the whole decomposition periods.更多还原