Bryophytes are a diverse plant group and are functionally different from vascular plants. Yet, their peculiarities are rarely considered in the theoretical frameworks for plants. Currently, we lack information about the magnitude and the importance of intraspecific variability in the ecophysiology of bryophytes and how these might translate to local adaptation—a prerequisite for adaptive evolution. Capitalizing on two ecologically distinct (hummock and hollow) phenotypes of Sphagnum magellanicum, we explored the magnitude and pattern of intraspecific variability in this species and asked whether the environmental-mediated changes in shoot and physiological traits are due to phenotypic plasticity or local adaptation. Size, pigmentation, and habitat type that distinguished the phenotypes in the field did not influence the trait responses under a transplant and factorial experiment. In addition, the magnitude and pattern of trait variability (e.g., branch, stem and capitulum mass) changed with the treatments, which suggest that trait responses were due largely to phenotypic plasticity. The trait responses also suggest that the ecophysiological needs for mosses to grow in clumps, where they maintain a uniform growth may have an overriding effect over the potential for a fixed adaptive response to environmental heterogeneity, which would constrain local adaptation. We conclude that extending the trait-based framework to mosses or making comparisons between mosses and vascular plants under any theoretical framework would only be meaningful to the extent that growth form and dispersal strategies are considered.

苔藓植物是不同的植物群，其功能与维管植物不同。但是，在植物的理论框架中很少考虑它们的特殊性。当前，我们缺乏有关苔藓植物生态生理中物种内变异性的大小和重要性以及它们如何转化为局部适应性（适应性进化的先决条件）的信息。充分利用麦哲伦的两个生态学上不同的（表型和表型）表型，我们探索了该物种内种内变异性的大小和模式，并询问环境介导的枝条和生理性状变化是由于表型可塑性还是局部适应性。区分表型的大小，色素沉着和生境类型不会影响移植和析因实验下的性状响应。另外，性状变异性的大小和模式（例如，分支，茎和头皮质量）随处理而改变，这表明性状反应主要是由于表型可塑性引起的。性状反应还表明，苔藓以团块形式生长并保持均匀生长的生态生理需求，可能会对针对环境异质性的固定适应性反应的潜力产生压倒性影响，这将限制局部适应。我们得出结论，将基于特征的框架扩展到苔藓，或者在任何理论框架下对苔藓和维管植物进行比较，仅在考虑了生长形式和扩散策略的情况下才有意义。