# The Effect of Green Areas on Urban Microclimate: A University Campus Model Case
## 3 Results and Discussion
### Functional Plant Traits and Their Role in Microclimate Regulation  
Plant species used in urban green spaces differ significantly in their ability to regulate temperature, largely due to physiological and structural traits such as LAI, canopy density, stomatal conductance, and specific leaf area (SLA). Broadleaved trees, for instance, generally exhibit higher LAI values (5-6), offering extensive canopy cover and effective shading,  
Figure 10: Contour plots of T, illustrating the interaction effects of variables on the response, with specific hold values for parameters A, M, WS, and AT for shrubs. which are critical for reducing solar radiation and surface temperatures [84; 85]. Shrubs, although smaller in height, contribute significantly through dense branching and moderate LAI values (-2-3), playing a key role in blocking low-angle solar rays and enhancing localized evapotranspiration [57; 62]. Groundwater plants and vines, while having lower vertical structures, increase surface cooling by modifying surface albedo and improving soil moisture retention through continuous, low-lying canopy layers [86; 87]. Furthermore, vertical variations in LAI influence carbon assimilation, gas exchange, and the thermal buffering capacity of vegetated areas [55]. [PERSON] et al., found that plant functional traits like the leaf-to-sapwood area ratio are highly responsive to seasonal water availability, suggesting that plant water use efficiency is closely linked to their cooling potential [56]. Additionally, recent studies using remote sensing techniques such as GEDI and GEE platforms have demonstrated that spatial variation in LAI and plant area index (PAI) strongly correlates with thermal regulation in forested and urban landscapes [57; 61]. These findings reinforce that the effectiveness of green infrastructure in mitigating urban heat depends not only on species' presence but also on their functional characteristics. Therefore, incorporating plant-specific structural parameters into urban landscape design can enhance microclimatic performance and resilience, particularly in regions experiencing rapid urbanization and climate stress. In recent years, the importance of plant-based microclimate regulation and green infrastructure design has been further emphasized in the context of climate change adaptation. For example, ref. [88] demonstrated that the morphological and seasonal traits of urban tree species significantly affect surface temperature modulation, highlighting the importance of species-specific strategies. Similarly, ref. [89] emphasized the role of green spaces in enhancing urban thermal comfort under heat stress, with a focus on their spatial distribution and connectivity. Additional findings by [90; 91] confirmed that plant physiological traits, such as transpiration capacity and canopy density, play crucial roles in mitigating urban heat. Moreover, ref. [92] argued that the integration of vegetation in compact urban forms contributes positively to long-term urban resilience. These recent studies reinforce the relevance of the current research and support the notion that functionally diverse vegetation not only enhances urban sustainability but also improves adaptive capacity under climatic extremes. The statistically significant interaction between M and AT observed across all vegetation types is underpinned by well-established microclimatic and plant physiological mechanisms. Humidity plays a critical role in regulating evapotranspiration, a key process in surface energy exchange, which is highly sensitive to ambient thermal conditions. Elevated temperatures tend to increase atmospheric demand for moisture, potentially accelerating transpiration rates; however, this response is modulated by ambient humidity levels, which influence vapor pressure gradients and stomatal behavior. Depending on the physiological characteristics of the plant species--such as leaf morphology, stomatal conductance, and canopy density--higher humidity under warm conditions may either amplify or suppress transpiration.