Throwing Out the Bathwater but Keeping the Baby: Lessons Learned from Purple Loosestrife and Reed Canarygrass

Historic ignorance of species’ native range, expansion due to unintentional involvement by vectors, and their quiet evolution has caused several invasive species to become “poster children,” such as purple loosestrife (Lythrum salicaria), reed canarygrass (Phalaris arundinacea), and others. Common misconceptions on how these became problematic have involved a variety of causes, including ignorance of species’ ability to intercross and create introgressive hybrids, lack of insects for control, wind pollination, and intercontinental distribution from their native range. Current research focuses on how misappropriating the historical contexts can reverse our misconceptions of native species being noninvasive and how this affects control by land managers. Purple loosestrife and reed canarygrass will be used as example species to demonstrate challenges that native vs. exotic, intra-, and interspecific differences confer to land managers. Issues such as a lack of phenotypic differences challenge land managers’ charge to control invasive individuals yet retain the noninvasives. This is fraught with challenges when native vs. exotic status is invoked or cultural values are entwined. To avoid a monumental impasse, particularly when native and exotic types are phenotypically indistinguishable, this dilemma could be solved via modern techniques using molecular biology.

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The biology of Canadian weeds. 100. Lythrum salicaria

Canadian Journal of Plant Science ◽

10.4141/cjps92-164 ◽

1992 ◽

Vol 72 (4) ◽

pp. 1305-1330 ◽

Cited By ~ 78

Author(s):

Tarun R. Mai ◽

Jon Lovett-Doust ◽

Lesley Lovett-Doust ◽

G. A. Mulligan

Keyword(s):

Native Species ◽

Competitive Ability ◽

Lythrum Salicaria ◽

Water Levels ◽

Purple Loosestrife ◽

Low Density ◽

Biological Control Agents ◽

Extreme Sensitivity ◽

Root Buds ◽

Wetland Habitats

Lythrum salicaria is a serious weed of wetlands in Canada, particularly in Ontario and Quebec. Indeed some assessments suggest that this exotic is now responsible for the conversion of more wetland habitat than is current human development pressure¡ Lythrum is a heterostylous species and clones by means of root buds. Despite its tristylous breeding system, Lythrum is a successful colonizer, and can produce prodigious numbers of seeds. It is likely that control can be achieved by hand-pulling in low-density populations, but once the species is established it generally becomes abundant and often approaches a monoculture. This species is particularly difficult to control because of its strong competitive ability, the extreme sensitivity of wetland habitats, and the likelihood of serious repercussions for wetland wildlife and fisheries if herbicides are used to control it. We see better possibilities for control through cultural techniques (e.g., manipulation of water levels to favour native species), enhancement of North American herbivores, and, possibly, the introduction of biological control agents from Europe and Asia.Key words: Purple loosestrife, Lythrum salicaria, wetlands, introduced weed

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What’s for Dinner? Assessing the Value of an Edible Invasive Species and Outreach Actions to Promote Its Consumption

10.21203/rs.3.rs-200905/v1 ◽

2021 ◽

Author(s):

Inês Cerveira ◽

Vânia Baptista ◽

Maria Alexandra Teodósio ◽

Pedro Morais

Keyword(s):

Invasive Species ◽

Native Species ◽

Aquatic Invasive Species ◽

Native Range ◽

Invasive Fish ◽

Press Releases ◽

Cynoscion Regalis ◽

The Public ◽

Native Resources ◽

A New Species

Abstract Promoting the consumption of edible aquatic invasive species has gained popularity to minimize its impacts while easing pressure on native resources. Weakfish Cynoscion regalis (Bloch & Schneider, 1801) is one of the most recent invasive fish species in the Iberian Peninsula (Europe) which once sustained an important fishery in the native range (Northwest Atlantic Ocean). Portugal ranks third in the list of the world’s top fish consumers, so promoting a weakfish fishery could at least help minimize the impacts upon native species, since weakfish have innate traits that are likely appreciated by Portuguese fish consumers. However, introducing a new species to consumers is challenging owing to consumers’ habits and unfamiliarity with the species. So, we aimed to (i) evaluate the acceptance of weakfish by a panel of Portuguese fish consumers and (ii) create outreach actions – partnerships with local Chefs and press releases – to explain to a broader public what invasive species are and promote the consumption of edible aquatic invasive species. The survey that we conducted to Portuguese fish consumers showed that weakfish has great chances of being well accepted by the public – 90% of consumers would buy weakfish because they appreciated its appearance, flavour, and texture, besides being a wild fish. The outreach actions reached a few million people because 46 online articles were published, and three news pieces broadcasted on national television. Overall, our strategy greatly increased the public’s awareness about invasive species, which can be replicated elsewhere in the world.

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Lepidium latifolium (perennial pepperweed).

10.1079/cpc.115209.20210104108 ◽

2021 ◽

Author(s):

Sonja Stutz ◽

Hariet Hinz ◽

Chris Parker

Keyword(s):

Soil Moisture ◽

Environmental Factors ◽

Native Species ◽

Southern Europe ◽

Native Range ◽

Riparian Areas ◽

Plant Composition ◽

Salt Ions ◽

Threatened And Endangered Species ◽

Western Asia

Abstract L. latifolium is an erect, branching perennial native to southern Europe and western Asia. It was accidentally introduced into countries outside of its native range as a contaminant of seeds such as Beta vulgaris. L. latifolium exhibits a wide ecological adaptation to different environmental factors, tolerating a range of soil moisture and salinity conditions, which has allowed it to spread explosively in recent years in wetlands and riparian areas especially in the western USA. L. latifolium thrives in many lowland ecosystems and is extremely competitive, forming monospecific stands that can crowd out desirable native species and a number of threatened and endangered species. L. latifolium alters the ecosystem in which it grows, acting as a 'salt pump' which takes salt ions from deep in the soil profile and deposits them near the surface, thereby shifting plant composition and altering diversity.

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Aspects of floral modification and style-morph frequencies in a colonizing weed, Lythrum salicaria (Purple loosestrife)

10.14321/j.ctt1pwtcm0.27 ◽

1995 ◽

pp. 471-482

Author(s):

Tarun K. Mal

Keyword(s):

Lythrum Salicaria ◽

Purple Loosestrife

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Effect ofGalerucellaspp. on survival of purple loosestrife (Lythrum salicaria) roots and crowns

Weed Science ◽

10.1017/s0043174500091906 ◽

1999 ◽

Vol 47 (3) ◽

pp. 360-365 ◽

Cited By ~ 16

Author(s):

Elizabeth J. Stamm Katovich ◽

Roger L. Becker ◽

David W. Ragsdale

Keyword(s):

Plant Stress ◽

Growing Season ◽

Lythrum Salicaria ◽

Purple Loosestrife ◽

Biological Control Agents ◽

Plant Mortality ◽

Galerucella Calmariensis ◽

Galerucella Pusilla ◽

Crown Tissue ◽

Severe Leaf

Starch levels, used as a measure of plant stress, were not consistently reduced in root or crown tissue of purple loosestrife plants after 2 yr of severeGalerucella calmariensisorGalerucella pusilla(Coleoptera: Chrysomelidae) defoliation. Early in the season, defoliation fromGalerucellaspp. approached 100%, but the majority ofLythrum salicariaplants regrew by the end of August, resulting in an average reduction of 81% of the aboveground biomass compared to the control. The stress imposed byGalerucellaspp. defoliation was less than that achieved from more severe stress imposed by mechanical shoot clipping at 2- or 4-wk intervals from June to October. Both shoot-clipping treatments killed the majority of plants after one growing season.Galerucellaspp. feeding reduced plant stature, which may reduce competitiveness. However, considering the extensive carbohydrate reserves present in the large woody crowns ofLythrum salicaria, it will require in excess of 2 yr of consistent, severe leaf defoliation to cause plant mortality. A combination of stresses, such as winter crown injury, or other biological control agents in addition toGalerucellaleaf defoliation may be required for plant mortality.

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Mild segregation in the breeding preferences of an invasive anuran (Discoglossus pictus) and its main native competitor (Epidalea calamita) in ephemeral ponds

Amphibia-Reptilia ◽

10.1163/15685381-20191149 ◽

2019 ◽

Vol 40 (4) ◽

pp. 425-435 ◽

Cited By ~ 2

Author(s):

Eudald Pujol-Buxó ◽

Gabriel M. Riaño ◽

Gustavo A. Llorente

Keyword(s):

Alien Species ◽

Native Species ◽

Evolutionary History ◽

Reproductive Season ◽

Breeding Sites ◽

Ecological Segregation ◽

Ephemeral Ponds ◽

Interspecific Differences ◽

Discoglossus Pictus ◽

Epidalea Calamita

Abstract The choice of breeding sites by pond-breeding anurans has notable consequences for the fitness of larvae. Hence, beyond pond typology and phenology, adults can also discriminate according to several other features, for instance to favour allotopy with potential competitors. However, the lack of shared evolutionary history might impede proper ecological differentiation with alien species during the first stages of invasions. Here, we studied several possible sources of ecological segregation between the invasive Discoglossus pictus and the native Epidalea calamita in ephemeral ponds, where the native toad hardly had competition before the arrival of the invasive frog. During spring of 2016, we periodically surveyed 69 ephemeral ponds in three areas with different invasion histories to detect the presence/absence of eggs and tadpoles of these species. Invasive D. pictus started breeding earlier than E. calamita, but differences were not significant. Similarly, there were not clear differences among areas with different invasion histories. However, we found for both species a mutual tendency to directly avoid larval syntopy at the end of the reproductive season. We also found interspecific differences in the features that both species use for pond choice, preferring the native species shallower and less vegetated ephemeral ponds. Globally however, co-occurrence was high, pointing at other processes as key to the coexistence between both species in these habitats.

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Influence of Nontarget Neighbors and Spray Volume on Retention and Efficacy of Triclopyr in Purple Loosestrife (Lythrum salicaria)

Weed Science ◽

10.1017/s0043174500093681 ◽

1996 ◽

Vol 44 (1) ◽

pp. 143-147 ◽

Cited By ~ 6

Author(s):

Elizabeth J. Stamm Katovich ◽

Roger L. Becker ◽

Brad D. Kinkaid

Keyword(s):

Plant Density ◽

Spray Deposition ◽

Soil Surface ◽

Lythrum Salicaria ◽

Purple Loosestrife ◽

Central Target ◽

Basal Portion ◽

Spray Volume ◽

Vegetative Propagules ◽

Target Plant

Greenhouse studies were conducted to determine the influence of plant density and spray volume on the retention, spray deposition, efficacy, and translocation of the amine salt of triclopyr in purple loosestrife. More spray solution was retained on leaves at 935 Lha−1than at 94 Lha−1at populations of 0, 4, or 8 nontarget neighbors. Spray coverage decreased with decreasing height within the plant canopy when spray cards were placed in the top, middle, and soil surface adjacent to the central target plant. Within a population, spray card coverage generally increased as spray volume increased. Regrowth from the crown was affected by spray volume, and uniform spray coverage of the plant was required for adequate control of vegetative regrowth and was achieved with spray volumes of 374 and 935 L ha−1spray volume. Regrowth of purple loosestrife was greater at 94 Lha−1at all three plant populations indicating that less herbicide penetrated the canopy to reach the basal portion of the plant. A laboratory experiment was conducted to investigate the translocation of radiolabelled triclopyr to roots and crowns of purple loosestrife. Only 0.3 to 1.4% of absorbed14C-labelled material was translocated to roots and crowns. Low spray volumes and dense stands of purple loosestrife would likely result in poor control because inadequate amounts of triclopyr reach the basal portion of the plant and translocate to vegetative propagules.

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The extent of grazing release from epiphytism forSargassum muticum(Phaeophyceae) within the invaded range

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315408003226 ◽

2009 ◽

Vol 89 (2) ◽

pp. 303-314 ◽

Cited By ~ 17

Author(s):

James A. Strong ◽

Christine A. Maggs ◽

Mark P. Johnson

Keyword(s):

Northern Ireland ◽

Native Species ◽

Sargassum Muticum ◽

Saccharina Latissima ◽

Native Range ◽

Epiphytic Algae ◽

Macroalgal Species ◽

Strangford Lough ◽

Fucus Serratus ◽

Japan And China

The overall biotic pressure on a newly introduced species may be less than that experienced within its native range, facilitating invasion. The brown algaSargassum muticum(Yendo) Fensholt is a conspicuous and successful invasive species originally from Japan and China. We comparedS. muticumand native macroalgae with respect to the biotic pressures of mesoherbivore grazing and ectocarpoid fouling. In Strangford Lough, Northern Ireland,S. muticumthalli were as heavily overgrown with seasonal blooms of epiphytic algae as native macroalgal species were. The herbivorous amphipodDexamine spinosawas much more abundant onS. muticumthan on any native macroalga. When cultured with this amphipod,S. muticumlost more tissue than three native macroalgae,Saccharina latissima(Linnaeus) Laneet al.,Halidrys siliquosa(Linnaeus) Lyngbye andFucus serratusLinnaeus.Sargassum muticumcultured with both ectocarpoid fouling and amphipods showed a severe impact, consistent with our previous findings of large declines in the density ofS. muticumobserved in the field during the peak of fouling. Despite being a recent introduction into the macroalgal community in Strangford Lough,S. muticumappears to be under biotic pressure at least equal to that on native species, suggesting that release from grazing and epiphytism does not contribute to the invasiveness of this species in Strangford Lough.

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