Isotope-based water-use efficiency of major greening plants in a sponge city in northern China.

Changchao Li,Ruilian Sun,Ruiqi Zhao,Shuping Ji,Miansong Huang,Di Zhao,Jian Liu,Xiao Guo

doi:10.1371/journal.pone.0220083

Abstract

To tackle urban water issues, the Chinese government has promoted the construction of sponge cities in recent years. Thirty cities have been designated as experimental sites to serve as models for future sponge city construction, as more than 80% of the built-up urban areas in China must reach the standards of sponge cities by 2030. Greening plants play an important role in sponge cities, and water-use efficiency (WUE) is a vital index to determine whether plants could adapt to and grow healthily in environments with water deficits. In this study, WUE of greening plants was quantified by measuring the stable carbon isotope fractionation. Suitable plants for the green spaces in Guyuan sponge city, in northern China, were selected based on their WUE, and the main factors affecting WUE were studied in four habitats within the city. Plant species identity had the greatest effect on WUE, while habitat and plant life form had lower effect, illustrating that WUE is a relatively stable and reliable index for the classification of plant species. We can improve the WUE and ecological function of green spaces in sponge cities by using isotope technology to select suitable plant species with high WUE. To our knowledge, this study is the first to select plant species for sponge city by using this method, providing a quick and scientific method for the selection of greening plants for future sponge cities.

Highlights

Sponge city is a new type of urban stormwater management concept
The results of soil pH, soil organic matter (SOM) content, total phosphorus (TP) content, total nitrogen (TN) content, NH4+-N content, and NO3−-N content were list in Table 1, and the soil samples were evaluated according to the results of the second national soil survey in China
The choice of plants in sponge cities is especially important because sponge cities, like Guyuan, often face water shortages, and water availability is a major limiting factor in community structure and ecosystem function

Summary

Introduction

Sponge city is a new type of urban stormwater management concept. The sponge city absorbs, accumulates, seeps, and purifies water. When needed, it releases and uses the stored water [1]. The concept of sponge cities in China is similar in function to Low Impact Development, Sustainable Drainage Systems, and Best Management Practice in other countries.

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Conclusion