PGT01 Konza prairie grass species trait

Evolutionary history plays a key role driving patterns of trait variation across plant species. For scaling and modeling purposes, grass species are typically organized into C3 versus C4 plant functional types (PFTs). PFT groupings may obscure important functional differences among species. Rather, grouping grasses by evolutionary lineage may better represent grass functional diversity. We measured 11 structural and physiological traits in situ from 75 grass species within the North American tallgrass prairie. We tested whether traits differed significantly among photosynthetic pathways or lineages (tribe) in annual and perennial grass species. We hypothesized that tribe would be the best predictor of traits, more so than photosynthetic pathway. We further hypothesized that there would be substantial variation of traits in species among the seven C4 lineages represented at our site.演化历史是调控植物物种间性状变异格局的关键驱动因子。出于尺度推绎与模型构建的需求，禾本科物种通常被划分为C3与C4两类植物功能型（Plant Functional Types, PFTs）。然而这类基于植物功能型的分组方式，可能会掩盖物种间固有的重要功能差异。相较之下，依据演化谱系对禾本科物种进行聚类，或能更精准地反映禾本科类群的功能多样性。本研究于北美高草草原样地内，对75个禾本科物种的11项结构与生理性状开展了原位测定。针对一年生与多年生禾本科物种，我们检验了性状在不同光合途径或演化谱系（tribe，分类学族）间是否存在显著差异。我们提出假说：相较于光合途径，演化谱系是性状的更佳预测因子。我们进一步推测：本研究样地所涵盖的7个C4演化谱系中，不同物种的性状存在显著变异。