树轮木质部解剖特征及其与环境变化的关系

Anatomical characteristics of xylem in tree rings and its relationship with environments

树轮木质部解剖特征是树轮在细胞、亚细胞尺度上的表征,其往往能从微观尺度解释树轮宽度等宏观结构的变化。因此,探讨木质部解剖特征与环境变化的关系,可为年轮气候学统计结果提供生理解释,为研究树木生长对气候变化的适应过程与响应策略提供新视野。该文以树轮木质部解剖特征与气候关系为主线,概述了木质部解剖特征记录环境信号的基本原理和机制,阐述了木质部解剖过程中涉及的基本方法,探讨了木质部解剖特征与气候因子的关系,就现有研究中存在的问题指出今后可能的研究方向:(1)探寻径向和切向上木质部解剖特征的时空变异及其与环境变化的关系;(2)探索植物对环境塑性响应的阈值及其响应策略及适应过程;(3)探寻各树轮代用指标间的协同与拮抗作用及气候响应差异的形成机理,确定各时期主要气候因子对树轮形成的具体作用及贡献量。

The anatomical traits of xylem are the characteristics of tree rings at the cellular and subcellular scales, and are often reflection of environmental signals. Studying the relationships between anatomical traits of xylem and envi- ronmental change not only provide physiological explanations to the statistics in dendroclimatology, but can also provide a new vision for studying the adaptation process and response strategies of tree growth to climate change. In this paper, with the relationships between the anatomical characteristics of xylem in tree-rings （cell chronology） and climate change as a main thread, we first outline the basic principles and mechanisms of wood anatomical features to record environmental signals, and expounded the basic methods involved in the process of xylem anatomy. Secondly, we discuss the relationship between the anatomical features of xylem and climate factors. We then propose the following as possible directions of future research based on the existing knowledge gap in the topical area： （1） to explore the temporal and spatial variations in the anatomical characteristics of xylem in tree-rings along radial and tangential directions and the relationships with environmental changes; （2） to explore the threshold of tree growth response to environmental plasticity and adaptation processes; （3） to assess the syner- gistic and antagonistic effects as well as the formation mechanisms of climate response among different tree-ring proxies, and to determine the specific roles and contributions of major climatic factors during different periods of tree-ring formation.