林窗边缘效应对马尾松和香樟凋落叶分解的影响

发布时间：2018-03-23 23:15

本文选题：林窗　切入点：边缘效应　出处：《应用与环境生物学报》2017年03期

【摘要】：为了解马尾松(Pinus massoniana)人工林不同面积林窗边缘凋落叶分解的养分释放规律,采用凋落袋分解实验,以长江上游低山丘陵区人为采伐形成的马尾松人工林7种不同大小林窗(G1:100 m~2;G2:225 m~2;G3:400 m~2;G4:625 m~2;G5:900 m~2;G6:1 225 m~2;G7:1 600 m~2)为研究对象,以林下为对照,探讨马尾松和香樟(Cinnamomum camphora)凋落叶的质量损失率和养分释放率.结果表明:除钾释放率外,林窗边缘两种凋落叶的质量损失率和养分释放率均显著高于林下.在1.5年分解过程中,两种凋落叶的质量损失率和碳释放率呈持续上升趋势.分解前90 d,两种凋落叶的质量损失速率和养分释放速率最快;分解90-360 d后,部分林窗出现氮和磷的富集现象;180-270 d和1.5年后,部分林窗出现钾的富集现象.随林窗面积增大,除钾释放率外,两种凋落叶在中型林窗边缘(400、600和900 m~2)具有较高的质量损失率和养分释放率.在凋落叶分解过程中,质量损失率和碳、氮释放率与土壤含水率均呈显著正相关.中型林窗(400-900 m~2)对凋落物的分解具有更显著的边缘效应,而这种边缘效应与物种有一定关联.因此,在马尾松低效林改造过程中,可利用中型林窗(400-900 m~2)边缘这一显著作用,引入乡土阔叶树种加速马尾松人工林的物质循环,维持林分地力.
[Abstract]:In order to understand the nutrient release rule of leaf decomposition in different areas of Pinus massoniana plantation, the litter bag decomposition experiment was carried out. In this study, 7 species of Pinus massoniana plantations of Pinus massoniana (Pinus massoniana) were felled by artificial felling in the lower hilly region of the upper reaches of the Yangtze River. The mass loss rate and nutrient release rate of leaves of Pinus massoniana and Cinnamomum camphora were studied. The results showed that, except for potassium release rate, the mass loss rate and nutrient release rate of the two litter leaves at the edge of the forest were significantly higher than those under the forest. The mass loss rate and carbon release rate of the two kinds of littered leaves showed a rising trend. 90 days before decomposition, the mass loss rate and nutrient release rate of the two kinds of littered leaves were the fastest, 90 to 360 days after decomposition. After 180-270 days and 1.5 years, the accumulation of potassium in some gaps was observed. With the increase of gap area, the rate of potassium release was increased. The two kinds of litter leaves had high mass loss rate and nutrient release rate at the edge of the middle forest canopy (400600 and 900mm2), and the mass loss rate and carbon loss rate during leaf decomposition. There was a significant positive correlation between nitrogen release rate and soil moisture content, and a more significant edge effect on litter decomposition was observed in medium forest canopy (400-900m ~ 2), which was related to species. Therefore, in the process of inefficiency forest transformation of Pinus massoniana, there was a significant marginal effect on litter decomposition in Pinus massoniana (Pinus massoniana). The significant effect of 400-900mm2) edge can be used to introduce native broad-leaved trees to accelerate the material cycle of Pinus massoniana plantation and to maintain the soil strength.
【作者单位】：四川农业大学林学院生态林业研究所生态林业工程重点实验室长江上游生态安全协同创新中心;
【基金】：国家自然科学基金项目(31370628) 国家科技支撑计划项目(2011BAC09B05) 四川省科技支撑计划项目(12ZC0017) 四川省科技厅应用基础项目(2012JY0047) 四川省教育厅科技创新团队计划项目(11TD006)资助~~
【分类号】：S714

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