城市树木作为绿地的重要组成部分，提供了多种生态系统服务，对增进城市居民福祉有重要作用。树木所提供的生态系统服务，与其性状密切相关，例如叶表面粗糙或被毛的树木具有更好的滞尘效果。而公园绿地中往往包含多种树木树种，代表着不同性状特点的组合，决定着该绿地可提供的具体生态系统服务。深入全面地理解树木性状与所提供的生态系统服务之间的联系、以及常见城市树木树种的性状特点，有助于深入理解城市树木与生态系统服务的关联，为植树计划中的树种选择搭配、城市绿地精细化管理提供科学依据。为此，本研究以北京市双秀公园和湖北省荆州市监利市滨江公园为例，基于实地调查，揭示研究区树木的多样性及分布。构建基于树木性状评估生态系统服务的框架，评估公园游人感知最明显的四项生态系统服务。并与常用的LAI与i-Tree模型生态系统服务评估结果进行对比，呈现各项生态系统服务的空间格局，讨论三种方法的适用场景。论文的主要内容和结论如下：

（1）双秀公园和滨江公园的树木在种类、生长状况等方面有较高的相似度，但也存在差异化的细节。两公园均着重运用乡土树种，其中双秀公园偏重常绿树种的使用（数量占比51%），而滨江公园中则存在更多落叶树种（数量占比56%）。双秀公园建成时间早于滨江公园近30年，园中大多树木处于青年期和半成熟期，少数孤植造景的树木胸径达到了70cm以上。而滨江公园大多数树木尚处于幼年期和青年期。

（2）LAI法核算了树木固碳释氧、净化空气污染物（包括SO₂、NO_x、PM₁₀）和蒸腾方面的效益。i-Tree模型对公园树木固碳释氧、净化空气（包括O₃、CO、NO₂、PM_2.5、PM₁₀和SO₂）、减少径流和致敏方面的效益均进行了测算，并对不同树种提供的生态系统服务加以区分。

（3）根据性状评估框架，对比公园主要树种提供的生态系统服务，发现双秀公园树木主要提供遮荫和滞尘服务，且园中只能提供单一类型生态系统服务的树种运用较多。滨江公园注重选择能够同时提供多样化生态系统服务的树种，且整体非常突出观赏和滞尘服务。分析发现两公园树种分别可分为全面型、遮荫型、观赏型和滞尘型。对比发现两个研究区对有致敏风险的树种和观赏型树种的处理呈现不同的结果。双秀公园并没有规避游人与致敏树种的接触，但在滨江公园内，除了悬铃木，其他致敏树种多利用排布使其能发挥良好的滞尘或观赏效益，同时避免与游人近距离接触。对于观赏型树种，双秀公园的排布依据公园的功能分区，主要在较为寂静、游客往往坐下欣赏景观的区域布设。而滨江公园主要配合游客的动线，分布在游客集中的区域。

As an important component of urban green spaces, trees provide a variety of ecosystem services that contribute significantly to the well-being of city dwellers. The provision of these services is closely related to the traits of trees, with certain traits determining their ability to provide specific ecosystem services, such as the ability of trees with rough or hairy leaves to retain dust. Since urban green spaces typically contain a mix of tree species with different trait characteristics, it is important to understand the links between tree traits and ecosystem services. This understanding can inform the selection of tree species for planting programs and enable more effective management of urban green spaces. In this study, field surveys were conducted in Shuangxiu Park in Beijing and Jianli Binjiang Park in Jingzhou City, Hubei Province, to assess the overall condition of trees in the study areas. A framework for assessing ecosystem services based on tree traits was developed to evaluate the four most noticeable ecosystem services perceived by park visitors. The study results were then compared with those of commonly used models, such as LAI and the i-Tree model, to analyze the spatial patterns of each ecosystem service and discuss the applicability of the three methods. The main contents and conclusions are as follows:

(1) The trees in Shuangxiu Park and Binjiang Park not only share many similarities in species and growth conditions but there are also differentiated details. Both parks utilize native tree species, with Shuangxiu Park dominated by evergreen tree species (51%), and Binjiang Park having a higher percentage of deciduous tree species (56%). Shuangxiu Park was built approximately 30 years earlier than Binjiang Park, resulting in most of its trees in the park being in the youth and semi-mature stages. Furthermore, a few of the trees planted alone have a DBH of more than 70cm. However, most of the trees in Binjiang Park are still in their infancy and youth.

(2) The LAI method was used to calculate the benefits of these trees in terms of carbon fixation, oxygen release, air pollution purification (including SO₂, NO_x, PM₁₀), and transpiration. Particularly, the i-Tree model was employed to calculate the benefits of trees in parks in terms of carbon fixation and oxygen release, air purification (including O₃, CO, NO₂, PM_2.5, PM₁₀, and SO₂), runoff reduction and sensitization, and to differentiate the ecosystem services provided by different tree species.

(3) Based on the framework of character assessment, comparing the ecosystem services provided by the main tree species in the park, it is found that trees in Shuangxiu Park mainly provide shade and dust retention services and the tree species that can only provide a single type of ecosystem services are more adopted. Binjiang Park not only focuses on the selection of tree species that can provide diverse ecosystem services but highlights the ornamental and dust retention services. The analysis results showed that tree species in the two parks can be divided into comprehensive type, shade type, ornamental type, and dust retention type respectively. By making a comparison, it is found that the two study areas have different ideas on the treatment of risky tree species and ornamental tree species. The layout of Shuangxiu Park does not avoid visitors’ contact with risky tree species. However, in Binjiang Park, risky tree species (i.e., except for the sycamore) are well-arranged so that they can play a good role in dust retention or viewing benefits while avoiding close contact with visitors. For ornamental tree species, the layout of these species is based on the functional zoning of the park, and they are mainly in the quiet area where tourists tend to sit and enjoy the landscape. But in Binjiang Park, the arrangement of ornamental tree species which is distributed in the tourist concentration area is mainly matched with the tourist line.