Optimizing water use efficiency in urban green space of a hyper-arid megacity through tree species selection: a case study

ABSTRACT

Enhancing water use efficiency in urban green spaces is an increasing concern in hyper-arid megacities. Here we aimed to compare the efficacy of species selection vs. soil management as strategies for reducing water demand of ornamental trees in irrigated green spaces of the city of Lima, Peru. We compared the performance of a popular exotic shrub used as a living fence in Lima’s green spaces with an alternative native species when grown in soils with or without biochar at different levels of soil water availability. Plant water stress and mortality were measured over 6-months. The native species outperformed the exotic in terms of resistance to water stress and suffered less mortality at low levels of soil water. The addition of biochar did not significantly enhance the leaf water potential. Its concluded that improved selection of species could significantly augment water use efficiency in urban green spaces in Lima and beyond.

KEYWORDS:

• Myoporum
• Vallesia
• biochar
• soil water holding capacity
• drought tolerance
• survival

Acknowledgements

The authors would like to thank the Municipality of Lurin and Agricola Chapi SAC for providing plants and logistical support for this project. We also gratefully acknowledge the constructive and helpful advice of the peer reviewers.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by a seed grant from the Universidad Cientifica del Sur to Brenton Ladd (Project: Use of native plants of Peru’s coastal desert to achieve Water Smart Urban Design).