Key message

The results showed a significant relationship between the potential evapotranspiration of the provenance collection site and the leaf turgor loss point and significant positive differences in drought tolerance between provenances and subspecies of B. pendula.

Abstract

The ecosystem services provided by urban trees make substantial contributions to the quality of urban living and securing resilience towards the challenges posed by a changing climate. Water deficits are a major abiotic stress for trees in urban environments and, in many regions, this stress is likely to be amplified under future climate scenarios. Although wide variation in drought tolerance exists at the species level, many species also show substantial intraspecific variation in drought tolerance. The aim of this study is to evaluate how drought tolerance, inferred from the water potential at leaf turgor loss point (Ψ_P0), varies in Betula pendula from different geographical origins and determine if the observed drought tolerance can be related to the local climate and seasonal water balance from the provenance of origin, despite the trees now being established in similar soil and climatic conditions within a single botanical collection. Six subsp. betula, five subsp. mandshurica and two subsp. szechuanica were evaluated, giving a total of 12 different provenances. The results showed a significant relationship between the potential evapotranspiration of the provenance collection site and the leaf turgor loss point and significant positive differences in drought tolerance between provenances and subspecies of B. pendula. By directing efforts towards identifying more drought-tolerant genotypes, it will be possible to diversify the palette of trees that could confidently be integrated by urban tree planners and landscape architects into the urban landscape. The results of this study on different ecotypes of B. pendula clearly show that it is possible to find more drought-tolerant plant material.

中文翻译：

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Betula pendula基因型的种内耐旱性：使用植物集合中叶片膨大损失的评估

关键信息

结果表明，种源潜在的蒸散与叶片膨大点之间的关系，与芒蓬亚种之间的耐旱性显着正相关。

抽象

城市树木提供的生态系统服务为城市生活质量和确保抵御气候变化带来的挑战的复原力做出了巨大贡献。缺水是城市环境中树木的主要非生物压力，在许多地区，这种压力在未来的气候情景下可能会加剧。尽管在物种水平上抗旱性存在很大差异，但许多物种在抗旱性方面也显示出种内差异。这项研究的目的是探讨如何耐旱性，从推断在叶子的膨压损点水势（Ψ _P0），在不同垂枝桦来自不同地理起源的国家，并确定观察到的干旱耐受性是否与起源地区的当地气候和季节性水平衡有关，尽管目前已在单一植物收藏中以相似的土壤和气候条件建立了树木。六个子空间。betula，五个子区。水ds和两个亚种。对szechuanica进行了评估，总共提供了12种不同的出处。结果表明，种源的潜在蒸散量与叶片膨大损失点之间存在显着的关系，而种间和亚种的抗旱性之间存在显着的正相关。。通过努力确定更多的耐旱基因型，将有可能使树木的选择多样化，这些树木可以由城市树木规划师和景观设计师自信地整合到城市景观中。这项针对不同生态类型的B. pendula的研究结果清楚地表明，有可能找到更多的耐旱植物材料。