Palms fanning out: a review of the ecological provisioning services provided by Washingtonia filifera and W. robusta in their native and exotic settings

ABSTRACT

Background

Dispersed by the horticultural industry, Washingtonia filifera and W. robusta have become one of the most ubiquitous ornamental palm species throughout all temperate zones.

Aims

This paper systematically reviews the state of knowledge of the ecological provisioning services provided by these palms.

Methods

Review of the extant literature based on a combination of systematic database searches with snowballing.

Results

Globally, Washingtonia are a major urban food source for native and invasive animal species. The majority of vectors contribute little to medium-or long-range dispersal. Avian and terrestrial species with a high connective potential facilitate long-distance dispersal. The dead leaves surrounding the stem serve as habitat for numerous native and invasive species.

Conclusions

The horticultural plantings of Washingtonia in areas adjacent to but contiguous with their endemic range have allowed a number of user species to expand their range, with one example (Icterus cucullatus) in excess of 1000 km. In non-contiguous areas of introduction (e.g. Europe, Middle East, South Africa or Australia) several species native to those ecosystems have adapted to feeding on Washingtonia drupes, but only few species have adapted to using Washingtonia as habitat.

Keywords:

• Adaptation
• Ecological provisioning services
• Exotic species
• Frugivory
• Novel ecosystems
• Range expansion

Conflict of interest

There is no conflict of interest to report.

Supplemental material

Supplemental data for this article can be accessed here.

Additional information

Funding

The study did not receive any external or internal grant funding.

Notes on contributors

Dirk H. R. Spennemann

Dirk H. R. Spennemann researches and teaches Cultural Heritage Management, Environmental History and Historic Ecology with an emphasis on the Indo-Pacific Region. His research foci are heritage theory; the physical manifestation of human responses to the Indo-Pacific environment during the nineteenth and early twentieth centuries; and the environmental history and ecology of palm species.

Author contribution statement

I am the sole author of the paper. All CRediT roles are mine.