Dmuchowski Wojciech, Baczewska-Dąbrowska Aneta, Gozdowski Dariusz, Brągoszewska Paulina, Gworek Barbara, Suwara Irena, Chojnacki Tadeusz, Jóźwiak Adam, Swiezewska Ewa
Institute of Environmental Protection-National Research Institute, Warsaw, Poland.
Polish Academy of Sciences Botanical Garden-Center for Conservation of Biological Diversity, Warsaw, Poland.
PeerJ. 2021 Jan 28;9:e10577. doi: 10.7717/peerj.10577. eCollection 2021.
The benefits of trees in urban areas include the following: an increase in ecosystem health, an increase in human health, the mitigation of the effects of heat and drought at microclimate level, the storage and sequestration of carbon, and a reduction in air pollution and noise. These ecosystem services can be provided only by trees that are in good health. The main cause of salt stress in urban environments is the use of de-icing salts on the streets in winter. Salt stress is a complex process that includes changes in plants on the physiological, histological, cellular and molecular levels, leading to limitations in nutrient uptake, disrupting the ionic balance of trees and resulting in the death of roadside trees. In response to salinity, trees have developed a variety of defence mechanisms that allow them to minimize the effects of stress and maintain homeostasis.
The reactions of two species species: and , which have different sensitivities to the unfavourable conditions of the urban environments (mainly salt stress), were investigated. The research included two experiments: a field experiment with city trees and a controlled pot experiment with young trees treated with increasing doses of salt. In both experiments, the following were performed: an assessment of the health condition of the trees and the content of macroelements as well as the Cl and Na in leaves and a qualitative and quantitative analysis of polyprenols.
had a more specific strategy than for dealing with Na and Cl, which resulted in undamaged leaves. Under the same conditions, contained more Cl and Na and were severely damaged. The disruption of the ion balance due to salt stress was lower in than in . Compared with , synthesized more polyprenols in the field experiment. This ability was acquired during the process of acclimation, because it occurred only in the mature trees in the field experiment and not in the young trees in the pot experiment.
The use of two experimental methods (i.e., the field and pot experiments) allowed for a more complete assessment of tree strategies to mitigate salt stress. displayed a more specific strategy than . This strategy was based on several elements. limited Cl and Na transport to the leaves, which resulted in a lack of damage to those organs. Under the same conditions, individuals contained more Cl and Na in their leaves and were seriously damaged. synthesized larger amounts of polyprenols, which probably have the ability to mitigate salt stress. This ability was acquired during the process of acclimation, because it occurred only in the mature trees in the field experiment and was not observed in the young trees in the pot experiment.
城市树木的益处包括以下几点：提升生态系统健康水平、增进人类健康、在微气候层面缓解高温和干旱影响、储存和固碳以及减少空气污染和噪音。这些生态系统服务只有健康的树木才能提供。城市环境中盐胁迫的主要原因是冬季在街道上使用除冰盐。盐胁迫是一个复杂的过程，包括植物在生理、组织学、细胞和分子水平上的变化，导致养分吸收受限，扰乱树木的离子平衡，进而导致路边树木死亡。为应对盐度，树木已形成多种防御机制，使它们能够将胁迫影响降至最低并维持体内平衡。
研究了对城市环境不利条件（主要是盐胁迫）敏感度不同的两个树种（树种： 和 ）的反应。该研究包括两个实验：一个针对城市树木的田间实验和一个对用递增剂量盐处理的幼树进行的可控盆栽实验。在两个实验中，均进行了以下操作：评估树木的健康状况、叶片中大量元素以及氯和钠的含量，以及对多萜醇进行定性和定量分析。
在处理钠和氯方面比 有更具体的策略，这使得其叶片未受损伤。在相同条件下， 含有更多的氯和钠且受到严重损伤。盐胁迫导致的离子平衡破坏在 中比在 中更低。与 相比， 在田间实验中合成了更多的多萜醇。这种能力是在驯化过程中获得的，因为它只出现在田间实验中的成熟树木中，而在盆栽实验中的幼树中未出现。
使用两种实验方法（即田间实验和盆栽实验）能够更全面地评估树木缓解盐胁迫的策略。 比 表现出更具体的策略。该策略基于几个因素。 限制了氯和钠向叶片的运输，这使得这些器官未受损伤。在相同条件下， 个体的叶片中含有更多的氯和钠并受到严重损伤。 合成了大量的多萜醇，这些多萜醇可能具有缓解盐胁迫的能力。这种能力是在驯化过程中获得的，因为它只出现在田间实验中的成熟树木中，而在盆栽实验中的幼树中未观察到。
