Thakur Dinesh, Rathore Nikita, Jandova Veronika, Münzbergová Zuzana, Dolezal Jiri
Institute of Botany of the Czech Academy of Sciences, Czech Republic.
University of South Bohemia, České Budějovice, Czech Republic.
Ann Bot. 2025 Sep 9. doi: 10.1093/aob/mcaf211.
Trait-based approaches have advanced our understanding of plant strategies, yet they often focus on leaf-level traits, overlooking the functional roles of stem anatomy and twig characteristics. We investigated intraspecific trait variation in Salix flabellaris, an alpine dwarf shrub, along climatic gradients in the Himalayas. Our goal was to identify distinct axes of trait variation related to stem, twig, and leaf traits, assess their environmental drivers, and evaluate population-specific growth responses to recent climate change.
We measured anatomical and morphological traits in stem, twig, and leaves across central and marginal populations along three Himalayan transects. Environmental gradients included variation in growing season temperature and soil moisture. Basal area increment from 2000 to 2021 was analyzed to assess long-term growth trends in different areas.
Trait dimensions were largely independent, reflecting distinct ecological strategies: (1) stem anatomical trade-off between hydraulic safety and conductivity; (2) twig dimension balancing construction costs and mechanical strength; and (3) leaf dimension along the exploitative-conservative axis. Higher temperatures enhanced performance manifested as larger twigs and reduced tissue construction costs but only under sufficient soil moisture conditions. Central populations at mid-elevations displayed the favorable trait combinations and highest growth rates. In contrast, marginal populations (higher and lower elevations) showed traits indicating structural reinforcement and conservative resource use. Climate warming over recent decades enhanced stem growth primarily in high-elevation populations, where low-temperature constraints were relaxed.
This study demonstrates that stem, twig, and leaf traits represent distinct yet complementary strategies, with environmental filtering shaping their expression along climate gradients. Central populations exhibit highest growth under current conditions, while climate change is shifting growth advantages toward higher elevations. These findings highlight the need for integrated, multi-organ trait assessments to predict species performance, persistence, and potential range shifts under future climatic scenarios.
基于性状的方法增进了我们对植物策略的理解，但这些方法通常侧重于叶片水平的性状，而忽视了茎解剖结构和小枝特征的功能作用。我们研究了高山矮灌木扇叶柳（Salix flabellaris）在喜马拉雅山脉沿气候梯度的种内性状变异。我们的目标是确定与茎、小枝和叶片性状相关的不同性状变异轴，评估其环境驱动因素，并评估特定种群对近期气候变化的生长响应。
我们沿着三条喜马拉雅山脉样带，测量了中部和边缘种群的茎、小枝和叶片的解剖学和形态学性状。环境梯度包括生长季节温度和土壤湿度的变化。分析了2000年至2021年的基部面积增量，以评估不同地区的长期生长趋势。
性状维度在很大程度上是独立的，反映了不同的生态策略：（1）茎解剖结构在水力安全性和传导性之间的权衡；（2）小枝维度在构建成本和机械强度之间的平衡；（3）叶片维度沿开拓性-保守性轴变化。较高的温度提高了表现，表现为更大的小枝和降低的组织构建成本，但仅在有足够土壤湿度的条件下。中海拔的中部种群表现出有利的性状组合和最高的生长速率。相比之下，边缘种群（较高和较低海拔）表现出表明结构强化和资源保守利用的性状。近几十年来的气候变暖主要促进了高海拔种群的茎生长，在这些地区低温限制得到了缓解。
本研究表明，茎、小枝和叶片性状代表了不同但互补的策略，环境筛选沿着气候梯度塑造了它们的表达。中部种群在当前条件下表现出最高的生长，而气候变化正在将生长优势向更高海拔转移。这些发现强调了需要进行综合的多器官性状评估，以预测未来气候情景下物种的表现、持久性和潜在分布范围变化。
