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

Background Functional trait-based ecological research has been instrumental in advancing our understanding of environmental changes. It is still, however, unclear how the functional traits of urban plants respond to atmospheric particulate matter, and which trade-off strategies are shown. In order to explore the variation of plant functional traits with the gradient of urban atmospheric particulate matter, we divided atmospheric particulate matter into three levels according to road distance, and measured the variation of six essential leaf functional traits and their trade-off strategies. Results Here, we show that the functional traits of plants can be used as predictors of plant response to urban atmospheric particulate matter. Within the study, leaf thickness, leaf dry matter content, leaf tissue density, stomatal density were positively correlated with atmospheric particulate matter. On the contrary, chlorophyll content index and specific leaf area were negatively correlated with atmospheric particulate matter. Plants can improve the efficiency of gas exchange by optimizing the spatial distribution of leaf stomata. Under the atmospheric particulate matter environment, urban plants show a trade-off relationship of economics spectrum traits at the intraspecific level. Conclusion Under the influence of urban atmospheric particulate matter, urban plant shows a slow investment-return type in the leaf economics spectrum at the intraspecific level, with lower specific leaf area, lower chlorophyll content index, ticker leaves, higher leaf dry matter content, higher leaf tissue density and higher stomatal density. This finding provides a new perspective for understanding the resource trades-off strategy of plants adapting to atmospheric particulate matter.

Automated summary

Functional trait-based ecological research has greatly contributed to our understanding of environmental changes. This study found that urban plants exhibit a trade-off relationship of economics spectrum traits under atmospheric particulate matter, with certain traits positively correlated and others negatively correlated with particulate matter levels. Optimizing the spatial distribution of leaf stomata can help plants improve gas exchange efficiency in particulate matter environments.