Matheny Ashley M, Mirfenderesgi Golnazalsadat, Bohrer Gil
Department of Civil, Environmental, and Geodetic Engineering, The Ohio State University, Columbus, OH, USA.
Plant Divers. 2016 Nov 24;39(1):1-12. doi: 10.1016/j.pld.2016.10.001. eCollection 2017 Feb.
Land surface models and dynamic global vegetation models typically represent vegetation through coarse plant functional type groupings based on leaf form, phenology, and bioclimatic limits. Although these groupings were both feasible and functional for early model generations, in light of the pace at which our knowledge of functional ecology, ecosystem demographics, and vegetation-climate feedbacks has advanced and the ever growing demand for enhanced model performance, these groupings have become antiquated and are identified as a key source of model uncertainty. The newest wave of model development is centered on shifting the vegetation paradigm away from plant functional types (PFTs) and towards flexible trait-based representations. These models seek to improve errors in ecosystem fluxes that result from information loss due to over-aggregation of dissimilar species into the same functional class. We advocate the importance of the inclusion of plant hydraulic trait representation within the new paradigm through a framework of the whole-plant hydraulic strategy. Plant hydraulic strategy is known to play a critical role in the regulation of stomatal conductance and thus transpiration and latent heat flux. It is typical that coexisting plants employ opposing hydraulic strategies, and therefore have disparate patterns of water acquisition and use. Hydraulic traits are deterministic of drought resilience, response to disturbance, and other demographic processes. The addition of plant hydraulic properties in models may not only improve the simulation of carbon and water fluxes but also vegetation population distributions.
陆面模型和动态全球植被模型通常通过基于叶型、物候和生物气候限制的粗略植物功能类型分组来表征植被。尽管这些分组对于早期模型来说既可行又实用，但鉴于我们在功能生态学、生态系统人口统计学和植被 - 气候反馈方面的知识进步速度，以及对提高模型性能的不断增长的需求，这些分组已经过时，并被认为是模型不确定性的一个关键来源。最新一波的模型开发集中在将植被范式从植物功能类型（PFTs）转变为基于灵活性状的表征。这些模型旨在改善由于将不同物种过度聚合到同一功能类中导致信息丢失而产生的生态系统通量误差。我们主张通过全株水力策略框架在新范式中纳入植物水力性状表征的重要性。众所周知，植物水力策略在调节气孔导度从而调节蒸腾和潜热通量方面起着关键作用。典型的情况是，共存植物采用相反的水力策略，因此具有不同的水分获取和利用模式。水力性状决定了干旱恢复力、对干扰的响应以及其他种群动态过程。在模型中加入植物水力特性不仅可以改善碳和水通量的模拟，还可以改善植被种群分布的模拟。
