Li Bo-Rui, Sun Nan, Xu Ming-Shan, Sun Qi-Xing, Wang Hui-Ming, Zhou Jie, Luo Xu, Lv Guang-Hui, Yang Xiao-Dong
Department of Geography & Spatial Information/Center for Land and Marine Spatial Utilization and Governance Research, Ningbo University, Ningbo, China.
Institute of Resources and Environment Science, Xinjiang University, Urumqi, China.
PLoS One. 2024 Dec 6;19(12):e0299976. doi: 10.1371/journal.pone.0299976. eCollection 2024.
Summer heatwaves have caused a distinct mortality between urban greening and native plants. However, there are insufficient studies revealing the underlying mechanisms. We hypothesized that differentiation in hydraulic traits and their integration cause the varied heatwave-induced damages between the two plant types. To prove it, three desert native species and five urban greening species were selected as the experimental objects. Then, the number of damaged individuals caused by summer heatwaves were investigated based on the 100 individuals for each species. The hydraulic traits (including hydraulic transport, photosynthetic and leaf traits) of 3-5 mature individuals were measured for each species. The comparative analysis (independent sample t test and one-way ANOVA) and the collaborative analysis (Pearson correlation and network analysis) were used to reveal the differences in heatwave-induced damage, hydraulic traits and their integration between urban greening and native plants. Our results showed that the heatwave-induced damage to urban greening plants was larger than that to native species. Water potentials of leaf and branch in pre-dawn and midday, P50, leaf dry matter content, net photosynthetic rate, transpiration rate and stomatal conductance of desert native species were significantly lower than those of urban greening plants (P < 0.05), while twig specific hydraulic conductivity, Huber value, wood density, intrinsic water use efficiency and the specific leaf area showed opposite patterns (P < 0.05). Trait integration of desert native species (0.63) was much higher than greening plants (0.24). Our results indicate that artificial urban greening plants are more susceptible to drought stress caused by heatwaves than native desert species. In the context of global climate change, in order to maintain the stability and function of urban ecosystems in extreme climate, the screening of greening plants should start from the perspective of hydraulics and trait integration, and more native species with strong drought adaptability should be planted.
夏季热浪导致城市绿化植物和原生植物之间存在明显的死亡率差异。然而，揭示其潜在机制的研究并不充分。我们假设水力特性的差异及其整合导致了这两种植物类型在热浪引发的损害方面存在差异。为了验证这一点，选取了三种沙漠原生植物物种和五种城市绿化植物物种作为实验对象。然后，基于每个物种的100株个体，调查了夏季热浪造成的受损个体数量。对每个物种的3 - 5株成熟个体测量其水力特性（包括水力运输、光合和叶片特性）。采用比较分析（独立样本t检验和单因素方差分析）和协同分析（皮尔逊相关性和网络分析）来揭示城市绿化植物和原生植物在热浪引发的损害、水力特性及其整合方面的差异。我们的结果表明，热浪对城市绿化植物造成的损害大于对原生植物的损害。黎明前和中午时，沙漠原生植物叶片和枝条的水势、P50、叶片干物质含量、净光合速率、蒸腾速率和气孔导度均显著低于城市绿化植物（P < 0.05），而细枝比水力导率、胡伯值、木材密度、内在水分利用效率和比叶面积则呈现相反的模式（P < 0.05）。沙漠原生植物的性状整合度（0.63）远高于绿化植物（0.24）。我们的结果表明，与原生沙漠物种相比，人工城市绿化植物更容易受到热浪引发的干旱胁迫影响。在全球气候变化的背景下，为了在极端气候条件下维持城市生态系统的稳定性和功能，绿化植物的筛选应从水力和性状整合的角度出发，种植更多具有强干旱适应性的原生物种。
