Glyphosate, steam and cutting for non‐native plant control in Alberta fescue grassland restoration

Abstract

Question What are the effects of cutting, glyphosate application and steam application on abundance and diversity of non‐native grasses and forbs and non‐target native grasses and forbs in restoration of a complex disturbed fescue grassland? Location Waterton Lakes National Park, Alberta, Canada. Methods Cutting, glyphosate application and steam application treatments were implemented at three disturbed sites in an incomplete block design with a control. Plant communities were evaluated for four growing seasons, one before and three after management treatment implementation. Results Glyphosate reduced non‐native grass cover for three growing seasons following application and non‐native forbs for one growing season. Glyphosate led to significant increases in non‐native forb cover, more than double pre‐existing values 2 and 3 yr after application. Native species abundance and diversity were more negatively impacted by glyphosate on sites with higher abundance and diversity prior to management treatments. Low frequency cutting over 2 yr did not consistently control non‐native species, steam reduced non‐native grass cover at the most heavily invaded site. Conclusions Site‐specific conditions must be considered to develop effective control methods for non‐native species. No treatment effectively re‐established native grassland communities. Glyphosate application reduced non‐native grasses, but not non‐native forbs. When native forbs were abundant prior to management, glyphosate reduced them. Steam may have potential and should be further investigated. This is one of only a few studies to investigate methods to manage multiple non‐native species occurring with native species, rather than management of a single undesirable species, and is the first to assess steam as a management option for native grasslands.

Academic‐conservation partnership reveals trade‐offs in treatment method and frequency needed to restore invaded floodplain

“…We confirmed that glyphosate herbicide reduced stiltgrass abundance, which supports previous findings that glyphosate can eradicate stiltgrass and other invasive plants (Judge et al 2005; Kyser et al 2012; Stover et al 2017). Our study builds on this work to find that frequency of application dictates the long‐term effectiveness of herbicide.…”

“…1), managers haphazardly applied glyphosate herbicide to invasive stiltgrass patches in the summer (herbicide treatment). Glyphosate is a broad‐spectrum herbicide known to negatively affect non‐target plants (Judge et al 2008; Kyser et al 2012; Stover et al 2017). However, practitioners used glyphosate at this site because they were simultaneously treating for other invasive species, including privet and autumn olive ( Elaeagnus umbellata ), and they did not have the resources to use selective herbicides for different species.…”

Restoration management of cattle resting place in mountain grassland

“…This requires an integrated approach using multiple techniques, such as mechanical disturbance, fire, and in some cases the use of herbicides [ 6 ]. Among the various methods, the use of herbicide has been found to be an effective way to reduce or control weeds in grassland ecosystems, especially when mechanical control is expected to be too damaging [ 7 ]. Different types of herbicides are used, sometimes with formulations designed to target specific species such as Rumex spp., and others that are non-selective.…”

Controlling the invader Urochloa decumbens: Subsidies for ecological restoration in subtropical Campos grassland

“…Herbicides can be a useful tool to reduce cover of invasive grasses in grassland ecosystems (Barnes, ); however, their use is controversial. Several studies show that repeated herbicide applications are needed to reduce invasive grasses cover in temperate (Adams & Galatowitsch, ; Bakker et al., ; Stover, Naeth, & Wilkinson, ) and tropical (Machado et al., ) grasslands, and it is not clear if native species can recover the land after large‐scale herbicide application (Rinella, Maxwell, Fay, Weaver, & Sheley, ). Moreover, repeated herbicide applications may negatively impact seed banks of native species (Rodriguez & Jacobo, ), and may make some native species rare and susceptible to local extinctions (Rinella et al., ).…”

“…Moreover, repeated herbicide applications may negatively impact seed banks of native species (Rodriguez & Jacobo, ), and may make some native species rare and susceptible to local extinctions (Rinella et al., ). Besides the reduction of invasive grasses, herbicide applications can allow a significant increase in non‐native forbs (Adkins & Barnes, ; Stover et al., ). Moreover, glyphosate residues in soil might be taken up through roots, injuring the existing plants (Cornish & Burgin, ).…”