Russian-olive (Elaeagnus angustifolia) Biology and Ecology and its Potential to Invade Northern North American Riparian Ecosystems

Abstract

Russian-olive is a small tree or large multistemmed shrub that was introduced to Canada and the United States from Eurasia in the early 1900s. It was provisioned in large numbers during the last century to prairie farmers as a shelterbelt plant and remains a popular and widely available ornamental. Now invasive within some riparian ecosystems in the western United States, Russian-olive has been declared noxious in the states of Colorado and New Mexico. With traits including high shade tolerance and a symbiotic association with nitrogen-fixing bacteria, Russian-olive has the potential to dominate riparian vegetation and thus radically transform riparian ecosystems. Especially alarming is its capacity to influence nutrient dynamics within aquatic food webs. Our objective is to draw attention to Russian-olive as a potential threat to riparian ecosystems within Canada, especially in the southwest, where invasion is becoming commonplace. We review what is known about its biology and about the threats it poses to native organisms and ecosystems, and we summarize management and control efforts that are currently underway. We conclude by proposing a research agenda aimed at clarifying whether and how Russian-olive poses a threat to riparian ecosystems within western Canada.

The role of a non‐native tree in riparian vegetation expansion and channel narrowing along a dryland river

“…The ability to fix nitrogen and establish across a range of moisture and light conditions makes Russian olive a potentially disruptive invader of riparian ecosystems (DeCant, 2008;Jarnevich & Reynolds, 2011). Ecological concerns with regard to Russian olive include possible negative impacts to terrestrial wildlife, aquatic food webs, riparian nutrient dynamics, geomorphic processes, organic matter dynamics, and riparian plant communities (Collette & Pither, 2015;Katz, 2016;Pearce & Smith, 2001). Whereas studies into the effects of naturalized Russian olive on bird communities remain contradictory (Fischer et al, 2012;Stoleson & Finch, 2001), it is clear that Russian olive leaf litter can significantly increase N input to soils (DeCant, 2008) and in some riparian settings, facilitate the invasion of other non-native plant species (Tuttle, Katz, Friedman, & Norton, 2016).…”

Removal pattern mitigates negative, short‐term effects of stepwise Russian olive eradication on breeding birds

“…As a result, control and removal of these plants has become a major focus for managers of inland rivers and streams (Richardson et al. , Shafroth and Briggs , Collette and Pither ). Yet in many areas invasive trees are dominant components of the riparian system (Friedman et al.…”

“…In the western United States, broad expansion of invasive woody plants throughout riparian zones (Friedman et al 2005) has impacted hydrology (Tickner et al 2001, Birken and Cooper 2006, Cleverly et al 2006, nutrient cycling (Harner et al 2009, Mineau et al 2011, vegetation structure (Fleishman et al 2003, Katz andShafroth 2003), and faunal habitats (Knopf and Olson 1984, Zavaleta et al 2001, Pendleton et al 2011, Fischer et al 2015. As a result, control and removal of these plants has become a major focus for managers of inland rivers and streams (Richardson et al 2007, Shafroth and Briggs 2008, Collette and Pither 2015. Yet in many areas invasive trees are dominant components of the riparian system (Friedman et al 2005), and management efforts could have negative impacts on native fauna.…”

“…This large shrub is native to Eurasia but was introduced in the late nineteenth or early twentieth century for use in windbreaks, soil stabilization, shade, and wildlife habitat (Christiansen 1963, Katz andShafroth 2003). However, Russian olive is a highly successful competitor due to its shade tolerance (Collette and Pither 2015), lack of herbivore predation (Katz and Shafroth 2003), and diverse dispersal capabilities (Shafroth et al 1995, Pearce andSmith 2001). Further, its expansion has been exacerbated by the alteration of natural hydrologic processes such as dam construction and water withdrawals (Lesica and Miles 1999, Katz and Shafroth 2003, Stromberg et al 2009).…”

A Case for Assessing Allocasuarina and Casuarina Spp. For Use in Agroecosystem Improvement in Semi-Arid Areas With a Focus on Central Anatolia, Turkey

“…In the study of Yildiz et al [52] , Elaeagnus angustifolia was considered to offer significant potential for arid land reafforestation. Notably, this species is considered a seriously invasive species in Canada and the USA, and well adapted to infertile soil because its roots are nodulated by the nitrogen-fixing actinomycete, Frankia [53] . Mostly, Pinus nigra, has been planted, but its survival and growth can be far from optimal, especially in sites with greater water stress [52] , so a range of other indigenous species are under consideration [54] .…”