Hydrological networks and associated topographic variation as templates for the spatial organization of tropical forest vegetation.
Hydrological networks and associated topographic variation as templates for the spatial organization of tropical forest vegetation.
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DOI：
10.1371/journal.pone.0076296
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Asner GP
中科院分区：
文献类型：
--
作者：
Detto M;Muller-Landau HC;Mascaro J;Asner GP
了解热带森林结构和生物量的空间变异性，以及支持这种变异性的机制，对于设计、解释和扩大区域碳清单的实地研究至关重要。利用基于激光雷达的巴拿马中部4930公顷热带森林的平均冠层高度和高程的高分辨率地图，研究了巴拿马中部热带森林植被的空间结构及其与水文网络和相关地形结构的关系。MCH与水文网络密切相关：在排水1公顷或更多的渠道附近的正凸度区域(山谷、凹陷)，冠层高度最高。随着凸度的减小(向山脊、山顶过渡)和与最近航道距离的增加，平均MCH显著下降。经小波分解后的谱分析表明，在∼30-600m尺度上，热带森林结构的方差具有分形相似性，并且与海拔高度变化有很强的相关性，峰值相关出现在∼250m尺度上，而以往对热带森林结构的地形相关性的研究只在一个或几个空间颗粒上进行分析，我们的研究发现相关性具有很强的尺度相关性。对MCH与坡度、坡向、曲率和拉普拉斯凸度的多尺度相关性分析发现，MCH与在20-300m尺度上测量的凸度关系最密切，这是一个很好的代表水文网络位置的地形变量。总体而言，我们的结果支持这样一种观点，即即使在这些中生森林中，水文网络和相关的地形变化也是在特定尺度范围内组织植被的模板。这些发现是朝着对这些模式的机械性理解迈出的重要一步，并可以指导扩大和缩小规模。
An understanding of the spatial variability in tropical forest structure and biomass, and the mechanisms that underpin this variability, is critical for designing, interpreting, and upscaling field studies for regional carbon inventories. We investigated the spatial structure of tropical forest vegetation and its relationship to the hydrological network and associated topographic structure across spatial scales of 10–1000 m using high-resolution maps of LiDAR-derived mean canopy profile height (MCH) and elevation for 4930 ha of tropical forest in central Panama. MCH was strongly associated with the hydrological network: canopy height was highest in areas of positive convexity (valleys, depressions) close to channels draining 1 ha or more. Average MCH declined strongly with decreasing convexity (transition to ridges, hilltops) and increasing distance from the nearest channel. Spectral analysis, performed with wavelet decomposition, showed that the variance in MCH had fractal similarity at scales of ∼30–600 m, and was strongly associated with variation in elevation, with peak correlations at scales of ∼250 m. Whereas previous studies of topographic correlates of tropical forest structure conducted analyses at just one or a few spatial grains, our study found that correlations were strongly scale-dependent. Multi-scale analyses of correlations of MCH with slope, aspect, curvature, and Laplacian convexity found that MCH was most strongly related to convexity measured at scales of 20–300 m, a topographic variable that is a good proxy for position with respect to the hydrological network. Overall, our results support the idea that, even in these mesic forests, hydrological networks and associated topographical variation serve as templates upon which vegetation is organized over specific ranges of scales. These findings constitute an important step towards a mechanistic understanding of these patterns, and can guide upscaling and downscaling.
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影响因子：
8.8
作者：
Englund, Goran;Leonardsson, Kjell
通讯作者：
Leonardsson, Kjell
影响因子：
4.8
作者：
KERSHAW, KA
通讯作者：
KERSHAW, KA
影响因子：
5.5
作者：
Ferry, Bruno;Morneau, Francois;Freycon, Vincent
通讯作者：
Freycon, Vincent
影响因子：
1.4
作者：
BECKER, P;RABENOLD, PE;SMITH, AP
通讯作者：
SMITH, AP
DOI：
10.1073/pnas.1004875107
发表时间：
2010-09-21
影响因子：
11.1
作者：
Asner, Gregory P.;Powell, George V. N.;Hughes, R. Flint
通讯作者：
Hughes, R. Flint