植物生态学报 ›› 2017, Vol. 41 ›› Issue (10): 1081-1090.DOI: 10.17521/cjpe.2016.0393

所属专题: 生态化学计量

• 研究论文 • 上一篇    下一篇

马尾松人工林林窗边缘效应对油樟化学计量特征的影响

宋思梦1, 张丹桔1,2, 张健1,2,*(), 杨万勤1,2, 张艳1, 周扬1, 李勋1   

  1. 1四川农业大学生态林业研究所, 华西雨屏区生态环境监测站, 成都 611130
    2四川省长江上游生态安全协同创新中心, 成都 611130
  • 出版日期:2017-10-10 发布日期:2017-12-24
  • 通讯作者: 张健

Edge effects of forest gap in Pinus massoniana plantations on the ecological stoichiometry of Cinnamomum longepaniculatum

Si-Meng SONG1, Dan-Ju ZHANG1,2, Jian ZHANG1,2,*(), Wan-Qin YANG1,2, Yan ZHANG1, Yang ZHOU1, Xun LI1   

  1. 1Monitoring Station for Eco-environments in the Rainy Zone of Southwest China, Institute of Ecology & Forestry, Sichuan Agriculture University, Chengdu 611130, China;

    2Collaborative Innovation Center of Ecological Security in the Upper Reaches of Yangtze River, Chengdu 611130, China
  • Online:2017-10-10 Published:2017-12-24
  • Contact: Jian ZHANG

摘要:

马尾松(Pinus massoniana)是长江上游低山丘陵区退耕还林的一个主要造林树种。为了解林窗调控下, 马尾松人工林更新优势种在化学计量特征水平上受边缘效应的影响, 该文选取四川省宜宾市高县马尾松人工林人工砍伐形成的7种面积不等的林窗, 以林下为对照, 分析了人工更新优势植物油樟(Cinnamomum longepaniculatum)叶片化学计量特征及其季节动态。结果表明: 马尾松人工林林下与不同面积林窗边缘相比, 不同季节各林窗边缘油樟叶片碳(C)含量、碳氮比(C:N)和碳磷比(C:P)均显著高于林下。随着林窗面积增大, 油樟叶片C含量、C:N、C:P和N:P均先升后降, 在中型林窗(400-900 m2)边缘出现最大值。从春季到冬季, 油樟叶片N、P含量显著下降后上升, C:N和C:P显著上升后下降, 均在夏季有拐点。夏秋季林窗边缘油樟对养分吸收利用优于春冬季, 边缘效应更显著。主成分分析结果显示, 马尾松人工林不同大小林窗边缘油樟化学计量特征主要受林窗面积、相对光强及月平均气温影响。研究结果表明: 625 m2林窗边缘油樟有机质储存及养分利用效率在不同季节均有最大值, 在化学计量特征水平上具有更显著的边缘效应。

关键词: 林窗大小, 边缘效应, 化学计量学, 油樟, 马尾松人工林

Abstract:

Aims Pinus massoniana is one of the major plantation tree species in the low hilly lands along the upper reaches of the Yangtze River Valley in China’s “Grain for Green” project. The objective of this study was to explore the edge effects of forest gap on the ecological stoichiometry of dominant tree species in a P. massoniana plantation forest.Methods We collected Cinnamomum longepaniculatum leaves in a 39-year-old P. massoniana plantation forest with seven forest gap sizes (G1: 100 m2; G2: 225 m2; G3: 400 m2; G4: 625 m2; G5: 900 m2; G6: 1 225 m2; G7: 1 600 m2, and the control: closed canopy) located in Gao County, south Sichuan Province during different seasons. The contents of C, N and P in leaves were measured, and the effects of edges, seasons and their interaction on leaf C, N and P contents and C:N:P stoichiometry were evaluated.Important findings The leaf C content, C:N and C:P of C. longepaniculatum at the edge of forest gaps in different seasons were all significantly higher than those of understory plants in P. massoniana plantation. With increasing size of forest gaps, leaf C content and C:N ratio, C:P and N:P of C. longepaniculatum increased initially and then decreased with the maximum at medium size (400-900 m2). From spring to winter, leaf N and P contents of C. longepaniculatum increased after an obvious decrease; and the C:N and C:P increased first but then decreased. However, the inflection point all appeared in the summer. The nutrient utilization of C. longepaniculatum at the edge of forest gaps was more efficient in summer and autumn than in spring and winter, indicating significant edge effects. The results of principal component analysis (PCA) suggested that gap size, relative light intensity and monthly average air temperature were the main environmental factors affecting the stoichiometry of C. longepaniculatum at the different edge of forest gaps in the P. massoniana plantation. These results indicated that forest gap with size 625 m2 had the highest organic matter storage and nutrient utilization efficiency in the edge areas in all seasons, and therefore had the most significant edge effect on leaf element stoichiometry.

Key words: gap size, edge effect, stoichiometry, Cinnamomum longepaniculatum, Pinus massoniana plantation