Spatial Variation in Canopy Structure across Forest Landscapes
Spatial Variation in Canopy Structure across Forest Landscapes
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DOI：
10.3390/f9080474
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发表时间：
2018-08-01
期刊：
影响因子：
2.9
通讯作者：
Gough, Christopher M.
中科院分区：
文献类型：
--
作者：
Hardiman, Brady S.;LaRue, Elizabeth A.;Gough, Christopher M.
森林冠层结构(CS)控制着许多生态系统功能，并且在不同景观之间具有很高的变异性，但这种变异的幅度和规模还不是很清楚。我们使用便携式冠层LiDAR系统来表征美国东部6个森林景观中N=3个样带(140-800米长)上5类CS的变化。计算每个横断面各亚段的累积变异系数，以确定各个CS指标的稳定点。然后，我们在增量自相关分析中使用Moran的I来量化CS自相关的规模。所有CS指标在300米范围内都达到了稳定值，但在森林景观内和森林景观之间差异很大。CS指标300m的稳定点对应于许多生态系统功能被测量和建模的空间范围。此外，CS度量在40到88米处具有空间自相关性，这表明斑块尺度干扰或环境因素驱动了这些格局。我们的研究表明，CS在10 S尺度上在温带森林景观中具有异质性，需要这样的分辨率才能将CS遥感提升到大空间尺度。
Forest canopy structure (CS) controls many ecosystem functions and is highly variable across landscapes, but the magnitude and scale of this variation is not well understood. We used a portable canopy LiDAR system to characterize variation in five categories of CS along N = 3 transects (140-800 m long) at each of six forested landscapes within the eastern USA. The cumulative coefficient of variation was calculated for subsegments of each transect to determine the point of stability for individual CS metrics. We then quantified the scale at which CS is autocorrelated using Moran's I in an Incremental Autocorrelation analysis. All CS metrics reached stable values within 300 m but varied substantially within and among forested landscapes. A stable point of 300 m for CS metrics corresponds with the spatial extent that many ecosystem functions are measured and modeled. Additionally, CS metrics were spatially autocorrelated at 40 to 88 m, suggesting that patch scale disturbance or environmental factors drive these patterns. Our study shows CS is heterogeneous across temperate forest landscapes at the scale of 10 s of meters, requiring a resolution of this size for upscaling CS with remote sensing to large spatial scales.