Department of Biology, Virginia Commonwealth University, Box 842012, 1000 West Cary Street, Richmond, Virginia, 23284, USA.
Department of Natural Resources and the Environment, Center for Environmental Sciences and Engineering, University of Connecticut, 1376 Storrs Road, Storrs, Connecticut, 06269, USA.
Ecology. 2019 Oct;100(10):e02864. doi: 10.1002/ecy.2864. Epub 2019 Aug 30.
Structure-function relationships are central to many ecological paradigms. Chief among these is the linkage of net primary production (NPP) with species diversity and canopy structure. Using the National Ecological Observatory Network (NEON) as a subcontinental-scale research platform, we examined how temperate-forest NPP relates to several measures of site-level canopy structure and tree species diversity. Novel multidimensional canopy traits describing structural complexity, most notably canopy rugosity, were more strongly related to site NPP than were species diversity measures and other commonly characterized canopy structural features. The amount of variation in site-level NPP explained by canopy rugosity alone was 83%, which was substantially greater than that explained individually by vegetation area index (31%) or Shannon's index of species diversity (30%). Forests that were more structurally complex, had higher vegetation-area indices, or were more diverse absorbed more light and used light more efficiently to power biomass production, but these relationships were most strongly tied to structural complexity. Implications for ecosystem modeling and management are wide ranging, suggesting structural complexity traits are broad, mechanistically robust indicators of NPP that, in application, could improve the prediction and management of temperate forest carbon sequestration.
结构-功能关系是许多生态范式的核心。其中最重要的是净初级生产力（NPP）与物种多样性和冠层结构的联系。本研究利用国家生态观测网络（NEON）作为次大陆尺度的研究平台，考察了温带森林 NPP 与几种场地水平冠层结构和树种多样性衡量指标的关系。描述结构复杂性的新型多维冠层特征，尤其是冠层粗糙度，与站点 NPP 的关系比物种多样性衡量指标和其他常见的冠层结构特征更为密切。仅用冠层粗糙度解释站点水平 NPP 的变化量为 83%，明显大于植被面积指数（31%）或香农物种多样性指数（30%）单独解释的变化量。结构更复杂、植被面积指数更高或物种多样性更高的森林吸收更多的光，并更有效地利用光来为生物量生产提供动力，但这些关系与结构复杂性密切相关。对生态系统建模和管理的影响范围很广，这表明结构复杂性特征是 NPP 的广泛、机械稳健的指标，在应用中，可以提高对温带森林碳固存的预测和管理。
