Carrillo-Arizmendi Lizbeth, Vargas-Hernández J Jesús, Rozenberg Philippe, Pérez-Suárez Marlin, Martínez-Campos Angel Roberto
Instituto de Ciencias Agropecuarias y Rurales, Universidad Autónoma del Estado de México, Estado de México, Mexico.
Department of Forestry Sciences, Colegio de Postgraduados, Montecillo, Texcoco, Estado de México, Mexico.
Front Plant Sci. 2023 Sep 20;14:1072638. doi: 10.3389/fpls.2023.1072638. eCollection 2023.
Phenotypic plasticity (PP) could be an important short-term mechanism to modify physiological and morphological traits in response to climate change and global warming, particularly for high-mountain tree species. The objective was to evaluate PP response of growth ring traits to temperature and precipitation in Lindl. populations located at the ends of its elevational gradient on two volcanic mountains in central Mexico (La Malinche and Nevado de Toluca).
Increment cores collected from 274 P trees were used to estimate their PP through reaction norms (RN), which relate the ring width and density traits with climate variables (temperature and precipitation). We estimated the trees' sensitivity (significant RN) to climatic variables, as well as the relative proportion of RN with positive and negative slope. We also estimated the relationship between the PP of ring width and density traits using correlation and Principal Component (PC) analyses.
Over 70% of all trees showed significant RN to growing season and winter temperatures for at least one growth ring trait, with a similar proportion of significant RN at both ends of the gradient on both mountains. Ring width traits had mostly negative RN, while ring density traits tended to have positive RN. Frequency of negative RN decreased from lower to higher elevation for most traits. Average PP was higher at the lower end of the gradient, especially on LM, both for ring width and ring density traits, although high intrapopulation variation in PP was found on both mountains.
Results indicate that presents spatially differentiated plastic responses in width and density components of radial growth. PP was particularly strong at the lower elevation, which has higher temperature and water stress conditions, putting these populations at risk from the continuing global warming driven by climate change.
表型可塑性（PP）可能是一种重要的短期机制，可用于响应气候变化和全球变暖而改变生理和形态特征，特别是对于高山树种而言。目的是评估墨西哥中部两座火山（马林切山和托卢卡内华达山）海拔梯度两端的林德利松种群生长轮性状对温度和降水的PP响应。
从274棵P树采集的年轮芯用于通过反应规范（RN）估计其PP，反应规范将年轮宽度和密度性状与气候变量（温度和降水）联系起来。我们估计了树木对气候变量的敏感性（显著的RN），以及具有正斜率和负斜率的RN的相对比例。我们还使用相关性分析和主成分（PC）分析估计了年轮宽度和密度性状的PP之间的关系。
超过70%的树木至少有一个生长轮性状对生长季节和冬季温度表现出显著的RN，在两座山的梯度两端，显著RN的比例相似。年轮宽度性状大多具有负RN，而年轮密度性状往往具有正RN。大多数性状的负RN频率从低海拔到高海拔降低。梯度较低端的平均PP较高，特别是在马林切山上，无论是年轮宽度还是年轮密度性状，尽管在两座山上PP的种群内差异都很大。
结果表明，在径向生长的宽度和密度成分上呈现出空间差异的可塑性响应。PP在较低海拔处尤为强烈，那里温度较高且水分胁迫条件较大，这使这些种群面临气候变化导致的持续全球变暖的风险。
