Distribution and abundance of Saltcedar and Russian Olive in the western United States: Chapter 2

Public Law 109-320 calls for “…an assessment of the extent of saltcedar and Russian olive infestation on public and private land in the western United States.” Saltcedar (Tamarix spp.; also known as tamarisk) and Russian olive (Elaeagnus angustifolia) are now frequent and abundant components of the woody riparian vegetation along many Western U.S. rivers (Friedman and others, 2005; Ringold and others, 2008). Management strategies for dealing with these two species require knowledge of their distribution (extent of spread), abundance, and the ecological conditions that favor or hinder their spread or persistence. This chapter reviews the literature on five key areas related to the extent of saltcedar and Russian olive in the Western United States: (1) the history of introduction, planting, and spread; (2) current distribution; (3) current abundance; (4) factors that control current distribution and abundance; and (5) models to predict future distribution and abundance.