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The Global Invasive Species Team | |
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Global Invasive Species Team listserve digest #073 Wed Nov 29 2000 - 15:45:42 PST --CONTENTS-- 1. Snow geese, and burning Phalaris arundinacea (Illinois) 2. Impacts of snow geese (New York) 3. Herbicide impacts on damselflies (Hawaii) 4. Aquatic weed control class (Florida) 5. Glyphosate on insects (California) --------------------------------------- 1. Snow geese, and burning Phalaris arundinacea (Illinois) From: David Hodge (dhodge(at)tnc.org) A possible solution concerning snow geese would involve using dogs normally used for herding. In some areas in Chicago, golf courses use breeds of dogs such as border collies and Australian sheep dogs to try to "herd" Canada geese. Needless to say, the geese don't like this and leave. This may work for some areas that have problems with snow geese. I work in a high quality fen that is burned with some frequency. It has an infestation of reed canary grass (Phalaris arundinacea) that is burned every two to three years. We have not seen a decrease in reed canary grass. I realize that the burn frequency discussed was much greater than every two to three years. However, we have seen a decrease when we burned early in the spring, let it resprout and then hit it with herbicide. In the high quality area we use 2% Poast (2-[1-(ethoxyimino)butyl-5- [2-(ethylthio) propyl]-3-hydroxy-2-cyclohexen-1-one]), in the low quality area we use either 5% Roundup (Glyphosate) in upland areas or 5% Rodeo (Glyphosate) in wetter areas. In heavy infestations we may come back two to three times and spray what we have missed. --------------------------------------- 2. Impacts of snow geese (New York) From: Cris Winters (cwinters(at)tnc.org) I don't how to keep snow geese off the marshes, but in the course of producing a report I did in about 1994 related to the Delaware Bay Estuary health, I heard from some land managers at Bombay Hook NWR that the goose grazing has somewhat mixed impacts. It can clear large areas of marsh vegetation, making invasion by Phragmites more likely. However, it also results in more - and needed - feeding areas for migrating shorebird on the mud flats. --------------------------------------- 3. Herbicide impacts on damselflies (Hawaii) From: Pat Bily (pbily(at)tnc.org) Solber and Higgins, 1993, Wildlife Society Bulletin 21:299-307, discusses Rodeo (glyphosate) impact on invertebrates, as well as cattail and waterfowl. Invertebrate abundance was greater in untreated cattails within Rodeo treated wetlands than in control wetlands, and was less abundant in treated and natural openings. This implies a relationship between vegetated wetlands and invertebrates. There was also a mention of low doses of Rodeo not impacting Chorella algae, but high doses causing negative impact; Algae are an important component for some consumer invertebrates, and a disruption in the food chain could impact damselflies. Monsanto likely has more up-to-date information, and probably on specific species like damselflies. --------------------------------------- 4. Aquatic weed control class (Florida) From: Barry Rice (bamrice(at)ucdavis.edu) A short class on aquatic weed control is being held 13-18 May in Fort Lauderdale, Florida. It may be a little "urban" in emphasis. (I am not sure.) There is more information on the program at: http://www.ifas.ufl.edu/~conferweb/aw/index.html --------------------------------------- 5. Glyphosate on insects (California) From: Mike Kelly (mkellysd(at)aol.com) I have no specific info on the impact of glyphosate on damselflies. However, at our 1999 California Exotic Pest Plant Council's Symposium, Joel Trumbo of the California Dept. of Fish and Game presented a paper on glyphosate trials on amphibians in the lab and in the field and found a safety margin of more than 1000x when used according to the label. You have to use the aquatic approved version, Rodeo. The terrestrial version, Roundup Pro, contains a surfactant that does have an impact on some aquatic organisms. Pure glyphosate acts on an amino acid pathway that plants, but not animals have. I am familiar with most of the literature on glyphosate and wildlife, and can't recall anything specific on insects. |
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