模拟氮沉降和降雨对华西雨屏区常绿阔叶林凋落物分解的影响

发布时间：2018-05-12 02:40

本文选题：氮沉降 + 降雨　；参考：《生态学报》2017年02期

【摘要】：从2013年11月至2015年5月,采用凋落物分解袋法,设置了对照(CK)、氮沉降(N)、减雨(R)、增雨(A)、氮沉降+减雨(NR)、氮沉降+增雨(NA)6个处理水平,研究了模拟氮沉降和降雨对华西雨屏区常绿阔叶林凋落物分解的影响。结果表明:华西雨屏区常绿阔叶林凋落叶分解较快,凋落枝分解较慢;凋落物夏季分解较快,其他季节分解较慢。经过18个月的分解后,凋落叶和枝的质量残留率分别为45.86%和86.67%,凋落叶分解50%需要的时间为1.42 a,比枝短6.19 a。各处理凋落物叶分解系数表现为:k(A)k(CK)k(NA)k(N)k(R)k(NR),凋落枝质量残留率表现为:NNRRNACKA。模拟氮沉降、减雨和增雨处理凋落叶分解50%分别需要1.79、1.94a和1.36a,凋落枝分解50%分别需要8.84、8.63 a和6.47 a。各处理凋落叶分解95%需要5.37—11.33 a,凋落枝分解95%需要27.41—33.84 a。同一氮沉降条件下,增雨处理促进凋落叶分解,减雨处理抑制凋落叶分解;同一降雨条件下,氮沉降抑制凋落叶分解。氮沉降或降雨对凋落物的分解产生显著影响(P0.05),其交互作用影响不显著(P0.05)。可见,在氮沉降持续增加和降雨格局改变的背景下,增雨促进了华西雨屏区天然常绿阔叶林凋落物的分解,氮沉降和减雨抑制了凋落物的分解,模拟氮沉降和降雨对凋落物的分解交互作用表现不明显。
[Abstract]:From November 2013 to May 2015, using litter decomposition bag method, six treatment levels were set up: CK, N deposition, RN, RN, An, NRN and NAA. The effects of simulated nitrogen deposition and rainfall on litter decomposition of evergreen broadleaved forest were studied. The results showed that the litter decomposition of evergreen broad-leaved forest was faster and the decomposition of litter branches was slower, and the decomposition of litter was faster in summer and slower in other seasons. After 18 months of decomposition, the mass residue rates of leaves and branches were 45.86% and 86.67, respectively, and the time required for decomposition of 50% leaves was 1.42 a, 6.19 a shorter than that of branches. The leaf decomposition coefficients of each treatment were as follows: 1 / KG AK ~ (1) K ~ (+) K ~ (1) NK ~ (+) ~ (1) NK ~ (+) ~ (1) ~ (1) NK ~ (+) ~ (1) N ~ (+) K ~ (+) ~ (1) ~ (1) ~ (1)? Simulated nitrogen deposition, rain abatement and rain increasing treatments required 1.79 ~ 1.94 a and 1.36 a for leaf decomposition, respectively, and 8.84 ~ 8.63 a and 6.47 a for 50% branch decomposition, respectively. The decomposition of leaves and branches needed 5.37-11.33a and 27.41-33.84a respectively. Under the condition of the same nitrogen deposition, the precipitation treatment promoted the decomposition of the litter leaves, while the precipitation treatment inhibited the decomposition of the fallen leaves, while under the same rainfall condition, the nitrogen deposition inhibited the decomposition of the litter leaves. Nitrogen deposition or rainfall had a significant effect on the decomposition of litter, but the interaction of nitrogen deposition or rainfall on litter decomposition was not significant. It can be seen that under the background of the continuous increase of nitrogen deposition and the change of rainfall pattern, the precipitation of natural evergreen broad-leaved forest litter is promoted, and nitrogen deposition and rain abatement inhibit the decomposition of litter. The interaction of simulated nitrogen deposition and rainfall on litter decomposition was not obvious.
【作者单位】：四川农业大学林学院四川省林业生态工程省级重点实验室;
【基金】：国家“十二五”科技支撑资助项目(2010BACO1A11) 国家自然科学基金资助项目(31300522)
【分类号】：S714

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