Removal of the Invasive Shrub,Lonicera maackii(Amur Honeysuckle), from a Headwater Stream Riparian Zone Shifts Taxonomic and Functional Composition of the Aquatic Biota

Abstract

Riparian plant invasions can result in near-monocultures along stream and river systems, prompting management agencies to target invasive species for removal as an ecological restoration strategy. Riparian plant invaders can alter resource conditions in the benthos and drive bottom-up shifts in aquatic biota. However, the influence of management activities on the structure and function of aquatic communities is not well understood. We investigated how removal of a riparian invader, Lonicera maackii (Amur honeysuckle), influenced aquatic macroinvertebrate community functional and taxonomic diversity in a headwater stream. We hypothesized that removal of L. maackii from invaded riparia would result in (H 1 ) increased aquatic macroinvertebrate abundance, density, and diversity; (H 2 ) a taxonomic and functional shift in community composition; and, in particular, (H 3 ) increased functional diversity. Aquatic macroinvertebrates were sampled monthly from autumn 2010 to winter 2013 in headwater stream riffles with a dense riparian L. maackii invasion and those where L. maackii had been experimentally removed. We found macroinvertebrate density was significantly higher in the L. maackii removal reach (P < 0.05) and that macroinvertebrate community structure and functional trait presence was distinct between stream reaches and across seasons (P < 0.05). The removal reach exhibited greater functional richness during spring and summer and had more unique functionally relevant taxa (20% and 85%) compared with the L. maackii reach (5% and 75%) during summer and autumn seasons. Our results suggest bottom-up processes link restoration activities in the riparian corridor and aquatic biota through alterations of functional composition in the benthic community. Nomenclature: Amur honeysuckle, Lonicera maackii (Rupr.) Maxim.

Impacts of invasive Amur honeysuckle, Lonicera maackii, leaf litter on multiple trophic levels of detritus‐based experimental wetlands

“…In terrestrial ecosystems, L. maackii exhibits distinct microbial communities that differ from those of native species, which may contribute to rapid decay rates (Arthur et al., 2012). It is less likely that faster decomposition rates are due to macroinvertebrate shredders, as stream studies show that macroinvertebrate abundance declines when L. maackii is present (Fargen et al., 2015; McNeish et al., 2017). Differences in leaf composition and associated decomposition rates are likely to be linked to significant reductions in dissolved oxygen we observed, and which are reported in other studies (Berta, 2019; Borth et al., 2018; Custer et al., 2017; Hayes & Durtsche, 2011).…”

“…The food webs of many freshwaters, such as forested wetlands and headwaters of streams, are largely supported by allochthonous inputs of leaves from native terrestrial plants. Although changes in the quantity and quality of leaf litter are predicted to have widespread effects in detritus‐based food webs, relatively few studies have assessed the impacts of L. maackii on multiple trophic levels in freshwater food webs (Custer et al., 2017; McNeish et al., 2012, 2017). Collectively, our findings demonstrate a significant effect of L. maackii on the structure and composition of experimental wetland food webs, and on frog oviposition behaviour.…”

“…Previous laboratory and field studies are relatively limited in providing a comprehensive assessment of community‐level consequences of invasion by L. maackii , as such studies have often focused on specific taxonomic groups rather than more comprehensive components of wetland food webs. Such studies have separately investigated the impacts of L. maackii on adult amphibians (Watling et al., 2011a), larval amphibians (Adams & Saenz, 2012; Bucciarelli et al., 2014; Cotten et al., 2012; Sacerdote & King, 2014; Watling et al., 2011), zooplankton (Wilkins et al., 2020), and macroinvertebrate communities (Borth et al., 2018; McNeish et al., 2012, 2017). Using experimental mesocosm approaches, additions of leaves from L. maackii reduce survival and growth of larval salamanders, increase mosquito abundance, and produce oily surface sheens and odours indicative of poor water quality (Berta, 2019).…”

Invasive Alien Vines Affect Leaf Traits of Riparian Woody Vegetation

“…Indirectly, they can also influence aquatic community structure by altering riparian zone productivity and nutrient cycling [35,36]. McNeish et al [37] reported about significantly higher macroinvertebrate density in reach without the invasive alien shrub Lonicera maackii in comparison to that colonized with this species. In addition to all these effects, invasive alien vines overgrowing the riparian vegetation reduce incoming light for their hosts and increase the density of the canopy crowns, which can then become prone to breakage by wind and the weight of snow [15].…”

Effects of honeysuckle leaf blight (Insolibasidium deformans, Platygloeaceae) on Amur honeysuckle (Lonicera maackii, Caprifoliaceae) stand and stem structure in northern Kentucky

“…It has detrimental effects on herbaceous and woody plant species (Hutchinson and Vankat 1997;Luken et al 1997;Medley 1997;Gould and Gorchov 2000;Collier et al 2002;Gorchov and Trisel 2003;McCarthy 2004, 2007;Miller and Gorchov 2004;McKinney and Goodell 2010;Loomis et al 2015) and animal (Christopher and Cameron 2012;Loomis et al 2014Loomis et al , 2015 and microbial Arthur et al 2012;Shannon et al 2014;Ali et al 2015) communities. It also affects ecosystem water and nutrient dynamics Boyce et al 2012;McEwan et al 2012;Poulette and Arthur 2012;Kolbe et al 2015;Pfeiffer and Gorchov 2015;Hopfensperger et al 2017) and aquatic communities (Watling et al 2011;McNeish et al 2012McNeish et al , 2017Borth et al 2018;Robison et al 2021).Honeysuckle leaf blight (Insolibasidium deformans (C.J. Gould) Oberw.…”