Warmer and drier climate conditions are negatively impacting conifers, which show different mechanisms to withstand drought stress including growth resilience. However, it is unclear which traits make trees and shrubs more resilient to drought in terms of growth recovery. We addressed this question by measuring and collecting from the literature several functional traits in 19 conifers of nine genera ( and ) from three families (Pinaceae, Cupressaceae, Taxaceae) inhabiting sites of contrasting climate conditions in Spain. These traits were correlated with three growth resilience indices derived from ring-width data (Rt, resistance; Rc, recovery; Rs, resilience) with and without accounting for their phylogenetic signal. Growth resistance (Rt) was negatively related to plant height ( = -0.52, = 0.04). Growth resilience (Rs) was negatively related to plant height ( = -0.93, < 0.001) and leaf life span ( = -0.51, = 0.03), but positively related to the thickness-to-span ratio ( = 0.80, < 0.001). However, the relationship between Rs and leaf life span was not significant ( = 0.155) after accounting for phylogenetic signals. Lastly, growth recovery was positively related to the growth responsiveness to climate, assessed as the correlation between ring-width indices and water balance ( = 0.66, = 0.002). Height and the thickness-to-span ratio, a surrogate of xylem resistance to cavitation, are linked to post-drought growth recovery in conifers subjected to seasonal dry conditions.

中文翻译：

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较小的针叶树更能抵抗干旱

温暖和干燥的气候条件对针叶树产生了负面影响，针叶树表现出不同的抵御干旱胁迫的机制，包括生长恢复力。然而，目前尚不清楚哪些特征使树木和灌木在生长恢复方面更能抵抗干旱。我们通过测量和从文献中收集来自西班牙气候条件截然不同的三个科（松科、柏科、红豆杉科）九属 19 种针叶树的几个功能性状来解决这个问题。这些性状与源自环宽数据的三个生长弹性指数（Rt，抗性；Rc，恢复；Rs，弹性）相关，无论是否考虑其系统发育信号。生长抗性 (Rt) 与株高负相关 (= -0.52, = 0.04)。生长恢复力 (Rs) 与株高 ( = -0.93, < 0.001) 和叶片寿命 ( = -0.51, = 0.03) 呈负相关, 但与厚度与跨度比 ( = 0.80, < 0.001) 呈正相关。然而，在考虑系统发育信号后，Rs 与叶片寿命之间的关系并不显着 (= 0.155)。最后，生长恢复与生长对气候的响应呈正相关，评估为环宽指数和水平衡之间的相关性（= 0.66，= 0.002）。高度和厚度与跨度之比（木质部对空蚀的抵抗力的替代指标）与针叶树在季节性干燥条件下的干旱后生长恢复有关。