林窗大小对马尾松林下3种更新草本植物N、P化学计量研究

Forest Gaps Size on Pinus massoniana Plantation of Three Natural Regeneration Herb N and P Stoichiometry

林窗大小与植物计量化学的耦合关系是林分管理的基础,马尾松人工林相关研究尚欠缺。本文以宜宾高县来复镇41 a生马尾松(Pinus massoniana)人工林为研究对象,设置8个梯度不同大小林窗(CK:0 m^2、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),通过调查,选取自然更新优势草本铁芒萁(Dicranopteris dichotoma)、芒(Miscanthus sinensis)和皱叶狗尾草(Setaria plicata)进行叶片N,P生态化学计量特征探究。结果发现:研究区优势草本叶片平均N含量为15.25 mg·g^(-1),P含量为1.19 mg·g^(-1),更新植物受限元素主要为N元素;随林窗面积增大,林内光照强度、温度和湿度均显著增加,优势草本叶片N、P含量受林窗大小显著影响,各物种P含量随林窗面积增大呈降低趋势;不同物种N含量随林窗大小改变的变化规律不同,芒萁N含量随林窗面积增大而显著下降,芒和皱叶狗尾草随林窗面积增大N含量显著增加;在叶片N、P化学计量水平上,芒萁的最适林窗面积为100~225 m^2,芒和皱叶狗尾草最适林窗面积为1 225~1 600 m^2。上述结果说明通过调整林窗来进行近自然改造和森林抚育等措施,能够促进人工林内养分循环,有利于提高马尾松人工林生态系统生产力。

Forest gap size and plant metering chemical coupling relationship are the basis of forest management, and Pinus massoniana plantation in related research is still lacking. Our research object is located in Yibin County town of 41-year P. massoniana plantation. Weset up eightdifferent size forest gaps （CK ：0 m^2, GI：100 m^2, G2：225 m^2, G3：400 m^2, G4：625 m^2, G5：900 m^2, G6：l 225 m^2 and G7：l 600 m^2）, and through th plicata on 15.25 mg e investigation, selected natural update herb Dicranopteris dichotoma, Miscanthus sinensis and Setaria leaf N, P stoichiometric features to explore. Advantage herb average N content in the study area was -1 ·1^- g , the average of P content was 1. 19 mg · g^-1 , and the update plant was mainly restricted