Ecosystem context illuminates conflicting roles of plant diversity in carbon storage

• Published in: Ecology letters Vol. 21; no. 11; pp. 1604 - 1619
• Main Authors: Carol Adair, E., Hooper, David U., Paquette, Alain, Hungate, Bruce A., Fukami, Tadashi
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.11.2018
• Subjects: Biodiversity; Biotic factors; Carbon sequestration; community‐weighted mean; Ecological monitoring; Ecosystem assessment; ecosystem functioning; ecosystem services; Ecosystems; functional diversity; functional traits; Herbivores; interactive factors; phylogenetic diversity; Plant diversity; Plant production; Pools; species richness; state factors; Trees; functional diversity; interactive factors; species richness; biodiversity; ecosystem functioning; functional traits; phylogenetic diversity; community-weighted mean; ecosystem services; state factors
• ISSN: 1461-023X; 1461-0248
• DOI: 10.1111/ele.13145

Plant diversity can increase biomass production in plot‐scale studies, but applying these results to ecosystem carbon (C) storage at larger spatial and temporal scales remains problematic. Other ecosystem controls interact with diversity and plant production, and may influence soil pools differently from plant pools. We integrated diversity with the state‐factor framework, which identifies key controls, or ‘state factors’, over ecosystem properties and services such as C storage. We used this framework to assess the effects of diversity, plant traits and state factors (climate, topography, time) on live tree, standing dead, organic horizon and total C in Québec forests. Four patterns emerged: (1) while state factors were usually the most important model predictors, models with both state and biotic factors (mean plant traits and diversity) better predicted C pools; (2) mean plant traits were better predictors than diversity; (3) diversity increased live tree C but reduced organic horizon C; (4) different C pools responded to different traits and diversity metrics. These results suggest that, where ecosystem properties result from multiple processes, no simple relationship may exist with any one organismal factor. Integrating biodiversity into ecosystem ecology and assessing both traits and diversity improves our mechanistic understanding of biotic effects on ecosystems.