Effect of simulated warming on leaf functional traits of urban greening plants

Abstract

Background: Response and adaptation strategies of plants to the environment have always been the core issues in ecological research. So far, relatively little study exists on its functional traits responses to warming, especially in an urban environment. This information is the key to help understand plant responses and trade-off strategy to urban warming. Results: We chose the common greening trees of mature age in Beijing (Fraxinus pennsylvanica, Koelreuteria paniculata, and Sophora japonica) as the research subjects, and used infrared heaters to simulate warming for three gradients of natural temperature (CK), moderate warming (T1) and severe warming (T2). Results showed that:(1) Leaf dry matter content (LDMC), chlorophyll content (CHL), leaf tissue density (LTD), and stomatal density (SD) all increased with temperature warming. Specific leaf area (SLA), stomatal size (SS), and stomatal aperture (SA) decreased with simulated warming. (2) SLA was extremely significantly negatively correlated with CHL, LDMC, LTD and SD (P < 0.01), and was extremely significantly positively correlated with SS (P < 0.01). SA was extremely negatively correlated with SD (P < 0.01), and was extremely significantly positively correlated with SS (P < 0.01). There was a significant positive correlation between LDMC and LTD (P < 0.01). This showed that urban greening trees adapted to the environment by coordinating adjustment among leaf functional traits. (3) Under the T1 treatment, the R 2 and slope among the leaf traits were higher than CK, and the significance was also enhanced. The correlation between leaf traits was strengthened in this warming environment. Conversely, it will weaken the correlation between leaf traits under the T2 treatment. Conclusion: Our study demonstrated that there was a strong trade-off between leaf functional traits in the urban warming environment. Plants in the warming environment have adopted relatively consistent trade-offs and adaptation strategies. Moderate warming was more conducive to strengthening their trade-off potential. It is further verified that the global leaf economics spectrum also exists in urban ecosystems, which is generally tend to a quick-investment return type with the characteristics of thick leaves, strong photosynthetic capacity, low transpiration efficiency and long life in urban environments.

Leaf Morphological and Nutrient Traits of Common Woody Plants Change Along the Urban–Rural Gradient in Beijing, China

“…We found that increases in soil nutrient contents and air temperature, and decreases in air relative humidity attributable to urbanization contributed directly or indirectly to changes in plant traits closely related to the improved resource acquisition capacity of urban plants (greater leaf length, area, SLA, and leaf N and K contents) (Table 1 and Figures 2, 3) (Wright et al, 2004). This is consistent with previous studies that found urbanization favors plant species and individuals with the ability to quickly acquire resources related to higher soil fertility (Song et al, 2019) and higher air temperature (Zhu et al, 2020) in urban areas.…”

Intraspecific differences in plant functional traits are related to urban atmospheric particulate matter

“…Leaf tissue thickness was positively correlated with leaf water use efficiency, and is also closely related to leaf water storage capacity [ 42 ]. Studies have shown that the increase in leaf thickness or density was beneficial to increase the distance or resistance of water diffusion from the inside of the leaf to the leaf surface, and reduce the internal water loss in the plants [ 43 ]. In this study, we found that with the increase of atmospheric particulate matter pollution, the leaf thickness showed a significant increasing trend.…”

“…2e , leaf tissue density of T3 was higher than that of T1 and T2, but there was no significant difference. Studies have shown that the increase in leaf tissue density is beneficial to reducing transpiration, thus reducing water loss of plants [ 43 ]. Meanwhile, the increase in leaf tissue density can slow down the growth of plants and store more carbon for the construction of defense organizations [ 46 , 48 ].…”

Wheat morpho‐physiological traits and radiation use efficiency under interactive effects of warming and tillage management

“…The relatively high slope for A max ‐SLA revealed a high SLA at a given unit of photosynthetic rate under warming condition. It appeared that warming may shift the plants to quick investment‐return strategy with short leaf lifespan (Zhu, Zhu, Cao, et al, 2020; Zhu, Zhu, Zhang, et al, 2020).…”

“…Leaf photosynthesis capacity is mainly determined by the photosynthesis process per se and the arrangement of leaves within the canopy (Mantilla‐Perez & Salas Fernandez, 2017). The flag leaf's photosynthesis plays a major role as a source of grain saccharides (Sanchez‐Bragado et al, 2014; Thorne, 1973; Zhu, Zhu, Cao, et al, 2020; Zhu, Zhu, Zhang, et al, 2020). Changes in leaf morphological traits, including specific leaf area (SLA), leaf angle and leaf area, can have a major impact on photosynthesis rate, k and its distribution within the canopy (Mantilla‐Perez & Salas Fernandez, 2017; Valladares, Skillman, & Pearcy, 2002).…”