Modeling the effects of individual-tree size, distance and species on understory vegetation based on neighborhood analysis
Modeling the effects of individual-tree size, distance and species on understory vegetation based on neighborhood analysis
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基于邻域分析模拟单棵树的大小、距离和物种对林下植被的影响
DOI：
10.1139/cjfr-2013-0111
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发表时间：
2013
影响因子：
2.2
通讯作者：
Owari T.
中科院分区：
文献类型：
--
作者：
Tatsumi S.;Owari T.
量化林下植被如何响应个别相邻的树木是了解森林动态的关键。为此，我们使用了空间邻域的方法来量化个体的竞争效应的密度和高度的矮生竹（Sasa senanensis（法国）。et Savat.）在日本北方的北海道岛上的针阔混交林中。利用多层贝叶斯模型，分析了相邻树木的影响如何随树干大小、与矮竹的距离和树种而变化。当树体达到中等大小（33.0-45.0 cm胸径）时，邻体效应达到最大值，当树体较大时，邻体效应降低。随着距离的增加，相邻竹种的影响逐渐减弱。对于较大的树木，下降的斜率较平缓。针叶树的平均效果是阔叶树的7.2倍。耐荫性高的树种影响较大。晚叶片冲洗和早期落叶的物种往往发挥较小的影响。我们的研究结果提供的证据表明，邻域分析是一种有效的方法，量化个别树木对林下植被的影响，并代表了一个关键的一步，了解林下植被和树木之间的细尺度相互作用如何影响整体森林动态。
Quantifying how understory vegetation responds to individual neighboring trees is critical to understanding forest dynamics. To do so, we used a spatial neighborhood approach to quantify the competitive effect of individual trees on the density and height of dwarf bamboo (Sasa senanensis(Franch. et Savat.) Rehder) in a mixed conifer–broadleaf forest on the island of Hokkaido, northern Japan. Using hierarchical Bayesian models, we analyzed how the effect of neighboring trees varies with stem size, distance to the dwarf bamboo, and tree species. The effect of neighbors peaked when the tree reached a medium size (33.0–45.0 cm in diameter at breast height) and decreased for larger trees. The effect of neighbors decreased with increasing distance to the dwarf bamboo. The slope of the decrease was gentler for larger trees. Conifers exerted an average of 7.2 times the effect of broadleaved trees. Species with higher shade tolerance exerted larger effects. Species with late leaf flush and early defoliation tended to exert smaller effects. Our results provide evidence that neighborhood analysis is an effective approach for quantifying the effects of individual trees on understory vegetation and represents a critical step toward understanding how fine-scale interactions between understory vegetation and trees influence overall forest dynamics.