DOCSLIB.ORG

Should We Care About Purple Loosestrife? the History of an Invasive Plant in North America

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Should We Care About Purple Loosestrife? the History of an Invasive Plant in North America Biol Invasions (2010) 12:1967–1999 DOI 10.1007/s10530-009-9600-7 ORIGINAL PAPER Should we care about purple loosestrife? The history of an invasive plant in North America Claude Lavoie Received: 7 November 2008 / Accepted: 2 October 2009 / Published online: 20 October 2009 © Springer Science+Business Media B.V. 2009 Abstract Purple loosestrife (Lythrum salicaria L., Introduction Lythraceae) is considered one of the worst invasive plant species in the world. In this paper, I reconstruct With the globalization of trade and the improvement how purple loosestrife quickly became, after a long in modes of transportation, biological invaders are (150 years) period of indifference, the persona non expected to become increasingly numerous and grata of North American wetlands. I then compare harmful to the ecosystems and the economies of a the portrayal of the species in newspapers (907 large number of countries (Perrings et al. 2005; articles) to that supported by the scientific literature McCullough et al. 2006; Westphal et al. 2008). It is (38 peer-review papers). The depiction of purple therefore crucial to conduct studies on invasive loosestrife in scientific studies (lacking definition) is plants and animals to rapidly identify the species far removed from that in newspapers (alarming). with the greatest impact, as the first step toward the Some native species likely suffer from an invasion, development of appropriate control measures. but stating that this plant has large negative impacts Nearly 900 invasive species were studied by ecol­ on wetlands is probably exaggerated. If purple ogists between 1980 and 2006; plants and insects loosestrife is not a primary cause of extinction or a accounted for two-thirds of the taxa studied. How­ major contributor to the decline of other species, but ever, some species have been studied far more than is instead an indicator of anthropogenic disturbances, others, such as the zebra mussel (Dreissena poly­ the resources and efforts devoted to removing this morpha (Pallas), Dreissenidae) or the Argentine ant species might be better focused on more effective (Linepithema humile (Mayr), Formicidae). Purple means to protect wetlands against disturbances. loosestrife (Lythrum salicaria L., Lythraceae) is one of the five most intensively studied invasive species Keywords Biological control . (Pysˇek et al. 2008). This species is reputed to Invasive plant species . Lythrum salicaria . outcompete native plants, form monocultures in Media . Purple loosestrife . Wetland wetlands and degrade habitats for wildlife, espe­ cially amphibians and birds (Blossey et al. 2001; Brown et al. 2006). Purple loosestrife is considered one of the 100 worst invasive alien species in the C. Lavoie (&) world by the International Union for the Conserva­ ´ Ecole supe´rieure d’ame´nagement du territoire et de tion of Nature (Invasive Species Specialist Group de´veloppement re´gional, Universite´ Laval, Quebec City, QC G1V 0A6, Canada 2008); it ranks second on the Prioritized List of e-mail: [email protected] Invasive Alien Plants in Natural Habitats in 123 1968 C. Lavoie Canada, which measures species with the most Purple loosestrife: from indifference to celebrity serious impact (Catling and Mitrow 2007). South of the Canadian border, purple loosestrife has been Purple loosestrife was probably introduced in North declared a noxious weed in 32 states (United States America both inadvertently and for horticulture. Department of Agriculture 2008). Purple loosestrife seeds were sold in American and Intriguingly, purple loosestrife was long ignored Canadian nurseries as early as 1829 (Mack 1991; prior to its rapid ascension to its current status. Purple Delisle et al. 2003), but the species was also likely loosestrife is not a newcomer to North America. introduced by ships dumping ballast (sand) contain­ Introduced at the beginning of the nineteenth century, ing seeds, or by raw wool or sheep imported from it was already invading hundreds of hectares of Europe and contaminated with seeds (Thompson wetlands in the 1930s. However, it was not until the et al. 1987). The oldest herbarium specimens of end of the 1980s that this plant attracted the attention purple loosestrife were collected in Massachusetts of ecologists and environmental managers. In the (1831), Pennsylvania (1852), British Columbia 1990s, purple loosestrife rapidly became the ‘‘icon of (1857), New York (1864) and Quebec (1865). The invasive exotics’’ (Washington Post, 16 Apr. 2005), species rapidly spread to reach most other states and not only for invasion ecologists, but also in the provinces between 1940 and 1985 (Stuckey 1980). popular press. Nationwide education campaigns were Abundant populations were reported in the Boston undertaken in the United States and Canada to area in 1921 (Knowlton and Deane 1921), in New prevent the sale of the species for horticulture, and York state south of the Adirondacks in 1924 (House millions of European beetles were released in nature 1924), and along the Hudson River valley in 1929 as a result of a major biological control program. (Torrey 1929). By the end of the 1990s and the beginning of the In Quebec, purple loosestrife spread along the St. 2000s, a debate began about whether purple loose- Lawrence River valley from 1923 to 1946 (Delisle strife had really had an impact on wildlife and the et al. 2003); massive infestations of marshes in the ecological functions of wetlands (Anderson 1995; 1930s and the 1940s were reported by Fernald (1938) Hager and McCoy 1998; Blossey 1999; Blossey et al. and Louis-Marie (1944). The Commune de la Baie du 2001). However, relatively few data existed at that Febvre, a floodplain near Lake St. Pierre (a widening time to support the assertions of either party (for or of the St. Lawrence River) used as pasture since the against a major impact). Since then, numerous studies beginning of the eighteenth century, was probably the attempting to detect the consequences of a purple largest and the most severely infested wetland in loosestrife invasion on wetland ecosystems have been Quebec during this period. The purple loosestrife published, shedding new light on the topic. This invasion was impressive (1,375 ha; Fig. 1), but even unique extensive research effort may answer ques­ there, at least 39 other vascular plant species tions on biological invasions that would likely be coexisted with the invader (Doyon 1953). Louis- unobtainable with other, less studied species. A Marie (1944) attempted to eradicate the plant, but review of these studies is therefore important to most trials (crushing, hand-pulling, harrowing, mow­ anyone concerned with invasive plants. In this paper, ing, fire) were unsuccessful. The spraying of herbi­ I reconstruct how purple loosestrife quickly became, cides (2.4-D) associated with the seeding of reed after a long (150 years) period of indifference, the canarygrass (Phalaris arundinacea L., Poaceae) was persona non grata of North American wetlands. I the only effective eradication method. This method then compare the portrayal of the species in news­ was used on 24 ha in 1951, but there is no indication papers to that supported by the scientific literature. In that it was repeated in subsequent years (Doyon particular, I examine whether the press accurately 1953). reported ecologists’ findings on the impact of this After the work of Louis-Marie (1944) and Doyon species on wetlands. I conclude with an analysis of (1953), the species was almost completely forgotten the consequences of focusing particular attention on by ecologists until the publication of a historical this invasive plant, and on the relevance of the reconstruction of the spread of the plant in North intensive efforts to control purple loosestrife in America by Stuckey (1980). This remarkable work Canada and the United States. presents an exhaustive survey of the historical 123 Should we care about purple loosestrife? 1969 North America. Lee (2002) documented the Canadian consequences of the publication of this report. The Canadian Wildlife Service initiated (1990–1991) an informal survey across the country to verify whether purple loosestrife was causing problems. Since most wetland managers suspected major impacts on wild­ life, a campaign was undertaken in collaboration with Ducks Unlimited Canada to alert the public to the perils this plant presented to natural habitats. The task was to ‘‘convince the public that behind the beauty was a beast’’ (Lee 2002, p. 255). In 1991, a brochure entitled Beautiful Killer was published and distrib­ uted coast-to-coast. In 1992, a new brochure was distributed, and a national workshop on the manage­ Fig. 1 A large purple loosestrife population at the Commune ment of the species took place. In 1993, a biological de la Baie du Febvre, a floodplain of the St. Lawrence River (Quebec), in 1951, just before the spraying of herbicides (from control program was initiated, and 1 year later, two Doyon 1953) television networks presented documentaries on pur­ ple loosestrife. According to Lee (2002), this cam­ paign against purple loosestrife was a real success: literature and herbarium specimens of purple loose- ‘‘The newspaper-style headlines dramatizing the strife collected throughout the United States and impact of this plant on wetlands left many uneasy Canada. It nevertheless contains a sentence that is and uncomfortable. But with the wisdom of hindsight, symptomatic of many later scientific reports on it is now possible to say ‘it worked!’ Phones began to purple loosestrife: ‘‘As the history of its spread in ring, interviews were sought and given, school and North America reveals, L. salicaria has the ability to community projects started’’ (p. 254). (…) eliminate other species in both natural and Indeed, purple loosestrife rapidly attracted the artificial wetland habitats’’ (p. 15). Unfortunately, attention of the popular press. According to the herbarium specimens—the main data source of this Factiva electronic database (Dow Jones & Company study—cannot provide the type of information nec­ 2008), at least 907 articles published in American and essary to support this assertion.
Load more

Recommended publications
  • The Changing Face of American White Supremacy Our Mission: to Stop the Defamation of the Jewish People and to Secure Justice and Fair Treatment for All
    A report from the Center on Extremism 09 18 New Hate and Old: The Changing Face of American White Supremacy Our Mission: To stop the defamation of the Jewish people and to secure justice and fair treatment for all. ABOUT T H E CENTER ON EXTREMISM The ADL Center on Extremism (COE) is one of the world’s foremost authorities ADL (Anti-Defamation on extremism, terrorism, anti-Semitism and all forms of hate. For decades, League) fights anti-Semitism COE’s staff of seasoned investigators, analysts and researchers have tracked and promotes justice for all. extremist activity and hate in the U.S. and abroad – online and on the ground. The staff, which represent a combined total of substantially more than 100 Join ADL to give a voice to years of experience in this arena, routinely assist law enforcement with those without one and to extremist-related investigations, provide tech companies with critical data protect our civil rights. and expertise, and respond to wide-ranging media requests. Learn more: adl.org As ADL’s research and investigative arm, COE is a clearinghouse of real-time information about extremism and hate of all types. COE staff regularly serve as expert witnesses, provide congressional testimony and speak to national and international conference audiences about the threats posed by extremism and anti-Semitism. You can find the full complement of COE’s research and publications at ADL.org. Cover: White supremacists exchange insults with counter-protesters as they attempt to guard the entrance to Emancipation Park during the ‘Unite the Right’ rally August 12, 2017 in Charlottesville, Virginia.
    [Show full text]
  • REPORT to COUNCIL City.Of Sacramento 23 915 I Street, Sacramento, CA 95814-2604 Www
    REPORT TO COUNCIL City.of Sacramento 23 915 I Street, Sacramento, CA 95814-2604 www. CityofSacramento.org Staff Report May 11,2010 Honorable Mayor and Members of the City Council Title: Leases - Digital Billboards on City-owned Sites Location/Council District: Citywide Recommendation: Adopt a Resolution 1) approving four separate leases between the City of Sacramento and Clear Channel Outdoor, Inc. governing the installation and operation of digital billboards on four city-owned sites located at the north side of Interstate 80 east of Northgate Boulevard (APN: 237-0031-36), Business 80 and Fulton Avenue (3630 Fulton Avenue, APN: 254-0310-002), west side of Highway 99, south of Mack Road (APN: 117-0170-067), and west side of Interstate 5 south of Richards Boulevard (240 Jibboom Street, APN: 001-0190-015); 2) authorizing the City Manager to execute the leases on the City's behalf. Contact: Tom Zeidner, Senior Development Project Manager, 808-1931 Presenters: Tom Zeidner, Senior Development Project Manager Department: Economic Development Division: Citywide Organization No: 18001031 Description/Analysis Issue: Overview. On August 25, 2009, the City Council granted Clear Channel Outdoor, Inc. the exclusive right to negotiate with the City for the installation and operation of digital billboards on City-owned sites near major freeways. On March 23, 2010, staff reported to the City Council that negotiations were complete successfully, that the resulting terms were being incorporated into separate leases for each of the four new proposed billboards, that proceeding with the digital-billboards project required an amendment to the City's Sign Code, and that as part of the project CCO would remove a number of existing "static" billboards.
    [Show full text]
  • RHS the Garden Magazine Index 2020
    GardenThe INDEX 2020 Volume 145, Parts 1–12 Index 2020 January 2020 February 2020 March 2020 April 2020 May 2020 June 2020 1 2 3 4 5 6 Coloured numbers campestre ‘William ‘Voodoo’ 9: 78 ‘Kaleidoscope’ lauterbachiana Plas Brondanw, North in bold before the page Caldwell’ 3: 32, 32 ‘Zwartkop’ 7: 22, 22; 11: 46, 46 1: 56, 57 Wales 12: 38–42, 38–42 number(s) denote the x freemanii Autumn 8: 54, 54 ‘Lavender Lady’ 6: 12, macrorrhizos 11: 33, 33 Andrews, Susyn, on: part number (month). Blaze (‘Jeffersred’) Aeschynanthus 3: 138 12; 11: 46–47, 47 micholitziana 2: 78 hollies, AGM cultivars Each part is paginated 10: 14, 14–15 Aesculus ‘Macho Mocha’ Aloe Safari Sunrise (‘X5’) 12: 31, 31 separately. griseum 1: 49; 2: 14, 14– hippocastanum 11: 46, 47 6: 12, 12 Anemone: 15; 11: 34, 35; 12: 10, 10; ‘Hampton Court ‘Mayan Queen’ 11: 46 Aloysia: ‘Frilly Knickers’ 9: 7, 7 Numbers in italics 12: 83 Gold’ 3: 89, 89 ‘Pineapple Express’ citrodora (lemon Wild Swan denote an image. micrantham 10: 80 ‘Wisselink’ 3: 89, 89 11: 47 verbena) 6: 87, 87, 88; (‘Macane001’) 5: 74, palmatum 4: 74–75; x neglecta ‘Silver Fox’ 11: 47 to infuse gin 4: 82, 83 74, 76 Where a plant has a 12: 65, 65 ‘Erythroblastos’ Aglaonema (Chinese gratissima angelica root to infuse Trade Designation ‘Garnet’ 10: 27, 27 3: 88, 88 evergreen): 1: 57; 7: 34, (whitebrush or gin 4: 82, 82 (also known as a selling platanoides Agapanthus: 5: 82, 83 34; 12: 32, 32 spearmint verbena) Angelonia Serena Series name) it is typeset in ‘Walderseei’ 3: 87, 87 ‘Blue Dot 9: 109 ‘King of Siam’ 1: 56, 57 6: 86, 88 8: 16, 17 a different font to pseudoplatanus ‘Bressingham Blue’ pictum ‘Tricolor’ Alstroemeria: angel’s trumpet (see distinguish it from the ‘Brilliantissimum’ 9: 109 1: 44, 45 Indian Summer Brugmansia) cultivar name (shown 3: 86, 86–87 ‘Cally Blue 9: 109 Agrostis nebulosa (‘Tesronto’) 8: 16, 16 Angwin, Kirsty, on: in ‘Single Quotes’).
    [Show full text]
  • Co-Production Forum
    CO-PRODUCTION FORUM 1 CONTENT PITCH SESSION : GAP FINANCING SESSIONS PITCHER BAYO BAYO BABY KANAKI FILMS - SPAIN 4 by Amaia Remírez & Raúl de la Fuente PITCHER BIRDS DON’T LOOK BACK SPECIAL TOUCH STUDIOS - 5 by Nadia Nakhlé FRANCE DIRTY LAND PITCHER BRO CINEMA - PORTUGAL 6 by Luis Campos PITCHER DREAMING OF LIONS PERSONA NON GRATA 7 by Paolo Marinou-Blanco PORTUGAL PITCHER AN ENEMY POKROMSKI STUDIO - POLAND 8 by Teresa Zofia Czepiec PITCHER FIRES CODE BLUE PRODUCTION D.O.O. - 9 by Nikola Ljuca MONTENEGRO PITCHER THE GLASS HOUSE DIRECTORY FILMS - UKRAINE 10 by Taras Dron PITCHER OUR FATHER THIS AND THAT PRODUCTIONS 11 by Goran Stankovic SERBIA PITCHER SOULS ON TAPE VILDA BOMBEN FILM AB 12 by Carl Javér SWEDEN PITCH SESSION : UP : UP-AND-COMING PRODUCERS PITCHER ARTURO’S VOICE MATRIOSKA - ITALY 14 by Irene Dionisio PITCHER AUTONAUTS OF THE COSMOROUTE IKKI FILMS - FRANCE 15 by Olivier Gondry & Leslie Menahem PITCHER CLEAN CARTOUCHE BVBA - BELGIUM by Koen Van Sande 16 PITCHER THE FURY RINGO MEDIA - SPAIN 17 by Gemma Blasco GROUND ZERO PITCHER RADAR FILMS - UKRAINE 18 by Zhanna Ozirna PINOT FILMS - POLAND PITCHER IN BETWEEN 19 by Piotr Lewandowski PITCHER SHINY NEW WORLD MAKE WAY FILM - NETHERLANDS 20 by Jan van Gorkum THREE SONGS CORTE A FILMS - SPAIN PITCHER 21 by Adrià Guxens PITCHER THE VIRGIN AND THE CHILD PLAYTIME FILMS - BELGIUM 22 by Binevsa Berivan PITCHER ZEJTUNE (UNTITLED GHANA PROJECT) LUZZU LTD - MALTA 23 by Alex Camilleri TIMETABLE 24 PITCH SESSION : GAP FINANCING SESSIONS 3 BAYO BAYO BABY - FICTION SPAIN Every night Aminata patrols the streets of Freetown searching for girls being exploited by pimps.
    [Show full text]
  • Purple Loosestrife Lythrum Salicaria L
    Weed of the Week Purple Loosestrife Lythrum salicaria L. Native Origin: Eurasia- Great Britain, central and southern Europe, central Russia, Japan, Manchuria China, Southeast Asia, and northern India Description: Purple loosestrife is an erect perennial herb in the loosestrife family (Lythraceae), growing to a height of 3-10 feet. Mature plants can have 1 to 50 4-sided stems that are green to purple and often branching making the plant bushy and woody in appearance. Opposite or whorled leaves are lance-shaped, stalk-less, and heart-shaped or rounded at the base. Plants are usually covered by a downy pubescence. Flowers are magenta-colored with five to seven petals and bloom from June to September. Seeds are borne in capsules that burst at maturity in late July or August. Single stems can produce an estimated two to three million seeds per year from a single rootstock. The root system consists of a large, woody taproot with fibrous rhizomes. Rhizomes spread rapidly to form dense mats that aid in plant production. Habitat: Purple loosestrife is capable of invading wetlands such as freshwater wet meadows, tidal and non-tidal marshes, river and stream banks, pond edges, reservoirs, and ditches. Distribution: This species is reported from states shaded on Plants Database map. It is reported invasive in CT, DC, DE, ID, IN, KY, MA, MD, ME, MI, MN, MO, NC, NE, NH, NJ, NY, OH, OR, PA, RI, TN, UT, VA, VT, WA, and WI. Ecological Impacts: It spreads through the vast number of seeds dispersed by wind and water, and vegetatively through underground stems at a rate of about one foot per year.
    [Show full text]
  • F a C T S H E E T Purple Loosestrife
    JEFFERSON COUNTY NOXIOUS WEED CONTROL BOARD F A C T S H E E T PURPLE LOOSESTRIFE (Lythrum salicaria) Purple loosestrife can be ten feet tall at maturity. The multiple stems are squarish with four to six sides. The leaves are up to four inches long, usually lance- shaped, with smooth edges. The magenta-colored flowers, which bloom from July to October, appear tightly clustered on tall spikes. Loosestrife family. LOOK ALIKES: Fireweed, (Epilobium angustifolium— native), commonly grows in drier ground than purple loosestrife, and does not have a square stem. Cooley’s hedgenettle, (Stachys cooleyae—native) seldom grows taller than four feet, and the plants are not branched or bushy. The leaves are nettle-like, with toothed edges. Butterfly bush, (Buddleja spp.), is a WHY BE CONCERNED? garden ornamental which invades riparian areas. It has a round stem, and Purple loosestrife invades wetlands and the bright purple flowers grow in a tightly displaces native vegetation. packed flower head. It supplies little food or habitat to wildlife. Purple loosestrife is a Class B Noxious Weed. Control is required in Jefferson County. Hardhack, (Spiraea douglasii— native), has a round stem and fluffy, pinkish flowers arranged in tight clusters. 380 Jefferson Street, Port Townsend WA 98368 360 379-5610 Ext. 205 [email protected] http://www.co.jefferson.wa.us/WeedBoard DISTRIBUTION: Purple loosestrife has been found in at least 8 locations in Jefferson County. Most are small, have been hand-pulled and will be monitored closely. One large infestation responded very well to bio-control. ECOLOGY: Purple loosestrife grows in wet sites, especially ones that have been disturbed by human activity.
    [Show full text]
  • What the 'New Intergovernmentalism' Can Tell Us About the Greek Crisis
    What the ‘new intergovernmentalism’ can tell us about the Greek crisis blogs.lse.ac.uk/europpblog/2015/08/26/what-the-new-intergovernmentalism-can-tell-us-about-the-greek-crisis/ 8/26/2015 A number of authors have argued that a ‘new intergovernmentalism’ has come to characterise EU decision-making since the financial crisis, with decisions increasingly made through intergovernmental negotiations such as those in the European Council. Christopher Bickerton writes on what the theory can tell us about the Greek crisis, noting that it helps illustrate both the febrile nature of domestic politics in Greece and why the Syriza government was ultimately unsuccessful in its attempts to secure concessions from the country’s creditors. Just as some thought it was over, the Greek crisis has entered into a new and dramatic stage. The Prime Minister, Alexis Tsipras, has declared snap elections to be held on 20 September. This comes just as the European Stability Mechanism had transferred 13 billion euros to Athens, out of which 3.2 billion was immediately sent to the European Central Bank to repay a bond of that amount due on 20 August. Tsipras has calculated that with public backing for the third bail-out, he can use the election to rid himself of the left block faction (Popular Unity) within Syriza, which has been vigorously opposing the bail-out deal. He can then recast himself as a more centrist figure, while the left-wing faction re-launches itself as an anti-austerity, anti-bailout party. The new intergovernmentalism and the Greek crisis What might the new intergovernmentalism have to tell us about the Greek crisis? It is always tricky to use theories to explain a moving target, especially one as protean as the Greek crisis, but there are at least three insights into the crisis that the new intergovernmentalism can provide us with.
    [Show full text]
  • Purple Loosestrife May Impede Boat Travel
    Pickeral Weed: Fireweed: Why Should Purple Pontederia cordata Epilobium angustifolium Loosestrife Concern Flowers 2-lipped, spikes Fatter spikes of 4-petaled, 3”-4”; leaves heart shaped, stalked flowers; alternate, You? single; water, 1’ to 3’ toothed leaves; northern plant of drier areas; 2’ to 6’ False Dragonhead: Plant diversity in wetlands Physostegia virginiana ✤ Tubular flowers, dissimilar petals; declines dramatically and toothed leaves; 1’ to 5’ (Other large mint many rare and endangered family plants: Hedge Nettle, Giant Hyssop) plants found in our remaining Swamp Loosestrife: Smartweed: wetlands are threatened. Decodon verticillatus Polygonum sp. Flowers bunched at (many native well-separated leaf species) - Tiny Most wetland animals that Look-a-likes ✤ bases; leaves whorled flowers, skinny depend on native plants for in 3s or 4s; stems spikes 1” to 4”; food and shelter decline usually arching, 1’ to 8’ alternate leaves clasp stem at base; significantly. Some species, stems jointed, 1’ to 6’ such as Baltimore butterflies, marsh wrens, and least bitterns may disappear entirely. Lupine: Blue Vervain: Lupinus perennis Verbena hastata Pea-like flowers; alternate, PURPLE (+ other Verbena sp.) ✤ Recreational uses of wetlands palm-like leaves; dry, LOOSESTRIFE Flowers tiny, pencil thin for hunting, trapping, fishing, sandy places; 2’ to 4’ spikes; toothed, oval, stalked leaves; moist bird watching and nature study to dry places; 2’ to 6’ decrease. Thick growth of purple loosestrife may impede boat travel. Winged Loosestrife: Steeplebush: ✤ Wetlands may store and filter Lythrum alatum Spiraea tomentosa less water. Smaller, single flowers DO NOT CONFUSE THESE Tiny flowers, conical at well-separated leaf set of flower spikes; bases; upper leaves NATIVE SPECIES WITH alternate, oval ✤ Millions of dollars spent to single; southern PURPLE LOOSESTRIFE! leaves; woody stem preserve wetlands would be prairies, 2’ to 3’ 1’ to 4’ wasted.
    [Show full text]
  • (Lythrum Salicaria) an Invasive Threat to Freshwater Wetlands? Conflicting Evidence from Several Ecological Metrics
    WETLANDS, Vol. 21, No. 2, June 2001, pp. 199±209 q 2001, The Society of Wetland Scientists IS PURPLE LOOSESTRIFE (LYTHRUM SALICARIA) AN INVASIVE THREAT TO FRESHWATER WETLANDS? CONFLICTING EVIDENCE FROM SEVERAL ECOLOGICAL METRICS Elizabeth J. Farnsworth New England Wild Flower Society 180 Hemenway Road Framingham, Massachusetts, USA 01701 E-mail: [email protected] Donna R. Ellis Department of Plant Science, Unit 4163 University of Connecticut Storrs, Connecticut, USA 06269 E-mail: [email protected] Abstract: Con¯icting interpretations of the negative impacts of invasive species can result if inconsistent measures are used among studies or sites in de®ning the dominance of these species relative to the com- munities they invade. Such con¯icts surround the case of Lythrum salicaria (purple loosestrife), a widespread exotic wetland perennial. We describe here a 1999 study in which we quanti®ed stand characteristics of L. salicaria and associated vegetation in arrays of 30 1-m2 plots in each of ®ve wet meadows in Connecticut, USA. We explored linear and non-linear relationships of above-ground plant biomass, stem density, and indices of species richness, diversity, and composition to gradients of L. salicaria dominance, including stem density, percent cover, and biomass. Species richness, other diversity metrics, and stem density of other species were not signi®cantly correlated with the density or percent cover of L. salicaria stems. The relative importance values (number of quadrats in which they were found) of co-occurring species in low-density L. salicaria quadrats were signi®cantly correlated with their relative importance in high-density L. salicaria quadrats, indicating that only modest shifts in abundance occurred as L.
    [Show full text]
  • Effects of Distance from Invasive Lythrum Salicaria On
    EFFECTS OF DISTANCE FROM INVASIVE LYTHRUM SALICARIA ON POLLINATOR VISITATION RATE AND REPRODUCTIVE SUCCESS IN NATIVE LYTHRUM ALATUM A Thesis Presented to The Graduate Faculty of The University of Akron In Partial Fulfillment of the Requirements for the Degree Master of Science Anthony Steven Kinyo August, 2005 EFFECTS OF DISTANCE FROM INVASIVE LYTHRUM SALICARIA ON POLLINATOR VISITATION RATE AND REPRODUCTIVE SUCCESS IN NATIVE LYTHRUM ALATUM Anthony Kinyo Thesis Approved: Accepted: ______________________________ _____________________________ Advisor Department Chair Dr. Randall J. Mitchell ______________________________ ______________________________ Committee Member Dean of the College Dr. Stephen C. Weeks Dr. Charles B. Monroe ______________________________ ______________________________ Committee Member Dean of the Graduate School Dr. Peter H. Niewiarowski Dr. George R. Newkome ______________________________ Date ii ACKNOWLEDGEMENTS Numerous people have helped me during this project and I could not have completed the research without all of their generous support. I would like to begin by thanking Dr. Randy Mitchell for his constant enthusiasm and positive encouragement throughout the research process. Thanks Randy, you have helped me to become a better scientist and researcher and I appreciate all that you have done for me. I would also like to thank my committee members Dr. Steve Weeks and Dr. Peter Niewiarowski, who provided feedback and assistance throughout the research process. Next, I would like to the Cuyahoga Valley National Park, Summit County Metroparks, and Ottawa National Wildlife Refuge for allowing me to pursue my research on their land. The University of Akron Biology Department provided financial assistance. Robert Jean, Donald Webb, Martin Hauser, and John Ascher deserve thanks for helping me to identify the numerous pollinators collected during the experiment.
    [Show full text]
  • The Evolution of Commercial Rap Music Maurice L
    Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2011 A Historical Analysis: The Evolution of Commercial Rap Music Maurice L. Johnson II Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] THE FLORIDA STATE UNIVERSITY COLLEGE OF COMMUNICATION A HISTORICAL ANALYSIS: THE EVOLUTION OF COMMERCIAL RAP MUSIC By MAURICE L. JOHNSON II A Thesis submitted to the Department of Communication in partial fulfillment of the requirements for the degree of Master of Science Degree Awarded: Summer Semester 2011 The members of the committee approve the thesis of Maurice L. Johnson II, defended on April 7, 2011. _____________________________ Jonathan Adams Thesis Committee Chair _____________________________ Gary Heald Committee Member _____________________________ Stephen McDowell Committee Member The Graduate School has verified and approved the above-named committee members. ii I dedicated this to the collective loving memory of Marlena Curry-Gatewood, Dr. Milton Howard Johnson and Rashad Kendrick Williams. iii ACKNOWLEDGEMENTS I would like to express my sincere gratitude to the individuals, both in the physical and the spiritual realms, whom have assisted and encouraged me in the completion of my thesis. During the process, I faced numerous challenges from the narrowing of content and focus on the subject at hand, to seemingly unjust legal and administrative circumstances. Dr. Jonathan Adams, whose gracious support, interest, and tutelage, and knowledge in the fields of both music and communications studies, are greatly appreciated. Dr. Gary Heald encouraged me to complete my thesis as the foundation for future doctoral studies, and dissertation research.
    [Show full text]
  • Purple Loosestrife (Lythrum Salicaria L.) in a Southeastern Sedge Meadow John L
    University of Wisconsin Milwaukee UWM Digital Commons Field Station Bulletins UWM Field Station Spring 1989 Purple loosestrife (Lythrum salicaria L.) in a southeastern sedge meadow John L. Larson University of Wisconsin - Milwaukee Follow this and additional works at: https://dc.uwm.edu/fieldstation_bulletins Part of the Forest Biology Commons, and the Zoology Commons Recommended Citation Larson, J.L. 1989. Purple loosestrife (Lythrum salicaria L.) in a southeastern sedge meadow. Field Station Bulletin 22(1): 1-11 This Article is brought to you for free and open access by UWM Digital Commons. It has been accepted for inclusion in Field Station Bulletins by an authorized administrator of UWM Digital Commons. For more information, please contact [email protected]. PURPLE LOOSESTRIFE (Lythrum salicaria L.) IN A SOUTHEASTERN WISCONSIN SEDGE MEDOW John L. Larson Department of Biological Sciences University of Wisconsin-Milwaukee Milwaukee, Wisconsin 53201 ABSTRACT Floristic and seed bank composition of a sedge meadow containing purple loosestrife was examined in 1987 and 1988. Eleocharis spp., Spiraea tomentosa. Triadenum vircrinicum, and Lycopus spp. were widespread while infrequent or absent in nearby sedge meadows without purple loosestrife, suggesting that these species have similar microsite requirements. Changes noted in some species over time probably resulted from changes in climatic and soil moisture conditions. The seed bank reflected the dominant herbaceous vegetation but lacked a few species having moderate frequencies in the established vegetation. Limited samples, unsuitable germination conditions in the greenhouse, autumn seed germination by some species and inability to survive prolonged inundation may explain the paucity of seed of some species that were frequent in the vegetation.
    [Show full text]