Community and structural constraints on the complexity of eastern North American forests
Community and structural constraints on the complexity of eastern North American forests
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DOI：
10.1111/geb.13180
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发表时间：
2020-09-06
影响因子：
6.4
通讯作者：
LaRue, Elizabeth A.
中科院分区：
文献类型：
--
作者：
Gough, Christopher M.;Atkins, Jeff W.;LaRue, Elizabeth A.
目的冠层结构复杂性描述了植被密度的异质性程度，与许多生态系统功能密切相关，但导致站点到次大陆尺度复杂性变化的群落和结构特征尚未明确。我们研究了木本植物的分类和系统发育多样性、最大冠层高度和叶面积指数(LAI)与冠层粗糙度的关系，冠层粗糙度是衡量冠层结构复杂性的指标，与初级生产力、光捕获和资源利用效率相关。我们的分析使用了122个样地，分布在美国国家生态观测网(NEON)内横跨1,500公里纬度的10个生态和气候可变的森林中。时间段2016-2018。分类群研究木本植物。方法我们使用单变量和多变量模型来检验冠层粗糙度与群落和结构特征之间的关系，假设群落和结构特征在复杂性上驱动地点和次大陆的差异。结果站点内和次大陆间冠层粗糙度的空间变异与最大冠层高度呈显著正相关(r(2)=0.87)，多变量模型中物种丰富度的增加解决了次大陆上另外2%的变异。在次大陆尺度上，木本植物物种丰富度和系统发育多样性(r(2)=0.17~0.44)和LAI(r(2)=0.16)与冠层粗糙度呈弱至中度相关，并不一致地解释了立地内冠层粗糙度的空间差异。主要结论我们得出结论，最大冠层高度比北美东部森林内部和之间的多样性或叶面积指数更能预测复杂性，这表明冠层体积是结构复杂性发展的主要制约因素。鼓励和维持高温带森林树冠的管理和土地利用做法可能支持生态系统功能的更大复杂性和相关增加。
Aim Canopy structural complexity, which describes the degree of heterogeneity in vegetation density, is strongly tied to a number of ecosystem functions, but the community and structural characteristics that give rise to variation in complexity at site to subcontinental scales are poorly defined. We investigated how woody plant taxonomic and phylogenetic diversity, maximum canopy height, and leaf area index (LAI) relate to canopy rugosity, a measure of canopy structural complexity that is correlated with primary production, light capture, and resource-use efficiency. Location Our analysis used 122 plots distributed across 10 ecologically and climatically variable forests spanning a > 1,500 km latitudinal gradient within the National Ecological Observatory Network (NEON) of the USA. Time period 2016-2018. Taxa studied Woody plants. Methods We used univariate and multivariate modelling to examine relationships between canopy rugosity, and community and structural characteristics hypothesized to drive site and subcontinental variation in complexity. Results Spatial variation in canopy rugosity within sites and across the subcontinent was strongly and positively related to maximum canopy height (r(2) = .87 subcontinent-wide), with the addition of species richness in a multivariate model resolving another 2% of the variation across the subcontinent. Individually, woody plant species richness and phylogenetic diversity (r(2) = .17 to .44, respectively) and LAI (r(2) = .16) were weakly to moderately correlated with canopy rugosity at the subcontinental scale, and inconsistently explained spatial variation in canopy rugosity within sites. Main conclusions We conclude that maximum canopy height is a substantially stronger predictor of complexity than diversity or LAI within and across forests of eastern North America, suggesting that canopy volume places a primary constraint on the development of structural complexity. Management and land-use practices that encourage and sustain tall temperate forest canopies may support greater complexity and associated increases in ecosystem functioning.