Cross-CZO -- Topographic Carbon Storage, GIS/Map Data, LiDAR, Land Cover -- Betasso -- (2010-2010)

The 'Stems' data are from an individual tree segmentation (Swetnam and Falk 2014) derived from the 2010 snow-off lidar and biomass-carbon allometric equations. The purpose of the dataset is to evaluate the distribution of aboveground carbon across an elevation gradient in temperature and precipitation.

The '10m Topo points' data are derived from a bare earth digital elevation model (DEM) generated from the 2010 snow-off lidar flight, these include the topographic metrics and the biomass-carbon for each pixel derived from the sum of STEMS. The purpose of the dataset is to evaluate the distribution of aboveground carbon across an elevation gradient in temperature and precipitation.

A total of three catchments in Boulder Creek were analyzed: Como Creek, Gordon Gulch, and Betasso Preserve.

Significance Statement:
Forest carbon reservoirs in complex terrain along an elevation-climate gradient spanning an 11 Celsius range in mean annual temperature (MAT) and a 50 cm yr-1 range in mean annual precipitation (MAP) did not exhibit the expected response of increasing in size with greater MAP and idealized MAT. Within catchments, the distribution of mean and peak carbon storage doubled in size for valleys versus ridges. These results suggest spatial variations in carbon storage relate more to topographically mediated water availability, as well as aspect (energy-balance) and topographic curvature (a proxy for soil depth and depth to ground water), than elevation-climate gradients. Consequently, lateral redistribution of precipitation across topographic position may either moderate or exacerbate regional climatic controls over ecosystem productivity and tree-level responses during drought.

“‘茎秆（Stems）’数据集源自2014年Swetnam与Falk提出的单木分割（individual tree segmentation）方法，其数据基于2010年无雪激光雷达（snow-off lidar）扫描结果与生物量-碳异速生长方程生成。本数据集旨在探究温度与降水梯度下，地上碳储量沿海拔梯度的分布特征。

‘10m地形点（10m Topo points）’数据集源自基于2010年无雪激光雷达（snow-off lidar）飞行扫描生成的裸地数字高程模型（digital elevation model, DEM），该数据集包含地形指标以及由所有茎秆数据求和得到的每个像素的生物量-碳储量。本数据集旨在探究温度与降水梯度下，地上碳储量沿海拔梯度的分布特征。

本研究共分析了博尔德溪（Boulder Creek）流域内的三个子流域：科莫溪（Como Creek）、戈登峡谷（Gordon Gulch）以及贝塔索保护区（Betasso Preserve）。

重要性说明：
本研究聚焦于海拔-气候梯度下的复杂地形森林碳库，该梯度的年均温（mean annual temperature, MAT）范围达11℃，年均降水（mean annual precipitation, MAP）范围达50 cm·yr⁻¹。研究发现，森林碳库并未呈现出随年均降水升高以及理想年均温条件下碳储量增大的预期响应。在子流域内部，山谷区域的平均碳储量与峰值碳储量相较于山脊区域翻倍增长。上述结果表明，碳储量的空间变异更多与地形介导的水分可获得性、坡向（能量平衡）以及地形曲率（可作为土壤深度与地下水埋深的替代指标）相关，而非海拔-气候梯度。因此，在干旱期间，降水沿地形位置的侧向再分配可能会缓解或加剧区域气候对生态系统生产力以及树木个体响应的调控作用。”