Mechanistically-grounded pathways connect remotely sensed canopy structure to soil respiration
Mechanistically-grounded pathways connect remotely sensed canopy structure to soil respiration
复制标题
机械接地路径将遥感冠层结构与土壤呼吸连接起来
DOI：
10.1016/j.scitotenv.2022.158267
复制
发表时间：
2022
影响因子：
9.8
通讯作者：
Gough, Christopher M.
中科院分区：
文献类型：
--
作者：
Hickey, Laura J.;Nave, Lucas E.;Nadelhoffer, Knute J.;Clay, Cameron;Marini, Alexandra I.;Gough, Christopher M.
土壤-大气C通量或土壤呼吸(Rs)的变化受一系列生物和非生物因素的影响，包括土壤温度、土壤水分和根生物量。然而，光探测和测距(激光雷达)衍生的冠层结构是否通过对这些驱动因素的同时影响而与土壤呼吸联系在一起，目前尚不清楚。我们评估了地上和地下植被密度和复杂性的测量之间的关系，并评估了RSIS是否通过已建立的生物和非生物机制介导的途径与遥感冠层结构相关联。我们的结果表明，在林分尺度上，冠层粗糙度和植被面积指数通过对光截获、土壤小气候和细根质量密度的影响而与土壤呼吸耦合，但这种联系在复杂性上更强。在林分尺度上，冠层和根系的复杂性在空间上没有耦合，随着林分的发展，冠层而不是根系的复杂性增加。我们的发现表明，遥感冠层复杂性可以用来推断Rs的空间变异，这种关系植根于已知的机械途径。通过遥感冠层复杂性对土壤呼吸进行广泛的空间推断需要对冠层结构和Rs进行多点观测，这是可能的，因为来自生态网络和卫星遥感平台的开放数据迅速增长。
Variation in the soil-to-atmosphere C flux, or soil respiration (Rs), is influenced by a suite of biotic and abiotic factors, including soil temperature, soil moisture, and root biomass. However, whether light detection and ranging (lidar)-derived canopy structure is tied to soil respiration through its simultaneous influence over these drivers is not known. We assessed relationships between measures of above- and belowground vegetation density and complexity, and evaluated whether Rsis linked to remotely sensed canopy structure through pathways mediated by established biotic and abiotic mechanisms. Our results revealed that, at the stand-scale, canopy rugosity–a measure of complexity–and vegetation area index were coupled to soil respiration through their effects on light interception, soil microclimate, and fine root mass density, but this connection was stronger for complexity. Canopy and root complexity were not spatially coupled at the stand-scale, with canopy but not root complexity increasing through stand development. Our findings suggest that remotely sensed canopy complexity could be used to infer spatial variation in Rs, and that this relationship is grounded in known mechanistic pathways. The broad spatial inference of soil respiration via remotely sensed canopy complexity requires multi-site observations of canopy structure and Rs, which is possible given burgeoning open data from ecological networks and satellite remote sensing platforms.