Abstract

Vertical greenery provides a number of ecosystem services, yet its potential remains underexploited in urban areas. Further, existing designs use a narrow range of species chosen for ornamental rather than environmental traits. Knowledge of species options is limited, but its importance is mounting as stormwater irrigation technologies evolve and vertical greenery’s potential as an evapotranspiration mechanism grows. To identify additional species that can maintain high water evapotranspiration in wellwatered conditions and low evapotranspiration in drought regimes, we selected eight native, herbaceous perennials from similar habitats, placed them in vertical, “green wall trays” under greenhouse conditions, and compared their growth responses to water shortages ranging from one to six weeks. Two species, Knautia arvensis and Geranium sanguineum, presented both of the desired water-use traits. More generally, species with a degree of succulence of root, shoot, or leaves dealt best with drought conditions. Armeria maritima, Campanula persicifolia and Saxifraga granulata survived the best under extended drought. The performance of Dianthus deltoides, Hypericum perforatum and Leucanthenum vulgare was inadequate for both water use and drought survival. The study confirms that the trait relevant for absolute volume of water transpiration is plant biomass. Further, irrespective of species’ drought strategy, degree of succulence is shown to have the greatest impact on a plant’s ability to survive drought.

Keywords

Evapotranspiration; Green walls; Plant traits; Stormwater; Vertical greenery

Published in

Urban Forestry and Urban Greening
2020, Volume: 54, article number: 126772

SLU Authors

• Emilsson, Tobias

  • Department of Landscape Architecture, Planning and Management, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Make cities and human settlements inclusive, safe, resilient and sustainable


UKÄ Subject classification

Agricultural Science
Landscape Architecture


Publication identifier

DOI: https://doi.org/10.1016/j.ufug.2020.126772

Permanent link to this page (URI)

https://res.slu.se/id/publ/106975