Tamarix biological control in North America [Chapter 28]

Plant Community Response to Control of a Dominant Invader at Multiple Scales

Distribution and Abundance of Southwestern Willow Flycatchers (Empidonax traillii extimus) on the Upper San Luis Rey River, San Diego County, California—2021 Data Summary

New locality for the tamarisk (Tamarix spp.) biological agent Diorhabda spp. in southeastern Arizona

Applying Satellite-based Habitat Models to Inform Riparian Habitat Restoration and Management Actions for Two Listed Riparian Species, the Southwestern Willow Flycatcher and the Yellow-billed Cuckoo 

  James Hatten1, Jennifer Holmes2, and Matthew Johnson3* 

An Integrated Pest Management Plan for the Bill Williams River National Wildlife Refuge. This plan outlines the biological degradation of native riparian forest habitat along the Lower Colorado River and the invasive species management actions needed to protect and restore riparian forests and marshlands of the Bill Williams River. 

DeRango, B., 2023. Integrated Pest Management Plan Bill Williams River National Wildlife Refuge.

A look into the use of invasive Tamarix (saltcedar, tamarisk) as habitat for birds in the southwestern United States and its implications for Tamarix control. While Tamarix habitat supports fewer birds than native habitat, data from Arizona Breeding Bird Atlas and Birds of North America demonstrate that 49 bird species use Tamarix as breeding habitat. The use and quality of Tamarix as bird habitat varies depending on geographic location and species and few studies have quantified the effects of Tamarix habitat on bird survivorship and productivity.

Researchers looked at non-structural carbohydrate storage in different genotypes of Tamarix from an experimental common garden. Results suggest that Tamarix from colder locations cope with freeze events by maintaining large storage pools to support tissue regrowth, but with the trade-off of overall reduced growth and reproduction.

A two-part study looking at how changes in soil salinity affect tamarisk growth and how beetle-induced defoliation affects tamarisk growing in soils with different salinities. Results showed that tamarisk plants grow better in soils with a similar salinity to their own origin site and that lower salinity does not benefit tamarisk plants adapted to higher saline conditions.

A look at beetle-occupied tamarisk sites 11-13 years after initial occupancy to determine long-term vegetative community response. Study found that Tamarix cover across sites initially declined an average of ca. 50% in response to the beetle, but then recovered. Changes in the associated plant community were small but supported common management goals, including a 47% average increase in cover of a native shrub (Salix exigua), and no secondary invasions by other non-native plants.