Effects of water limitation and competition on tree carbon allocation in an Earth system modelling framework

作者：Jeremy W. Lichstein, Tao Zhang, Ensheng Weng, Caroline E. Farrior, Ray Dybzinski, Sergey Malyshev, Elena Shevliakova, Richard A. Birdsey, Stephen W. Pacala · 发表于：Journal of Ecology · 年份：2024 · DOI：10.1111/1365-2745.14416 · 被引用次数：5 · 研究领域：Plant Water Relations and Carbon Dynamics、Hydrology and Watershed Management Studies、Forest ecology and management

Abstract Earth system models (ESMs) have a limited capacity to represent plant functional diversity and shifts in trait distributions. Approaches to improving the representation of this complexity in ESMs include (i) optimality‐based approaches that predict trait–environment responses and (ii) explicitly modelling coexistence and community assembly. These approaches are expected to converge only when optimality‐based approaches identify competitively dominant strategies, which often differ from strategies that maximize ecosystem functioning or fitness components in monoculture. We used two models, LM3‐PPA (a vegetation demographic model designed as an ESM component) and BiomeE (a computationally efficient analog for LM3‐PPA), to explore how water limitation affects carbon allocation strategies of canopy trees. We compared competitive allocation strategies and those that maximize biomass or productivity in monoculture. We did not explicitly model coexistence or community assembly. Rather, we used model experiments to identify competitive and maximizing strategies in a two‐dimensional trait space under different precipitation and mortality scenarios. At 10 eastern US locations, we simulated historical, wet and dry climate scenarios, novel drought and three different mortality scenarios (low, medium or high sensitivity to water deficit). For each site and scenario, we identified the competitive strategy and three maximizing strategies (maximum biomass, productivity or drought‐to...