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The Global Invasive Species Team | |
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Global Invasive Species Team listserve digest #063 Fri, 2 Jun 2000 16:15:35 -0700 (PDT) --CONTENTS-- 1. Krenite herbicide (Indiana) 2. Hairy willow herb (Wisconsin) 3. Giant hogweed or water hemlock (New York) 4. Burning bush honeysuckle (Wisconsin) 5. Reviews on articles (Nationwide) --------------------------------------- 1. Krenite herbicide (Indiana) From: Ellen Jacquart (ejacquart(at)tnc.org) Has anyone out there used "Krenite" herbicide? We are thinking about using it on multi-flora rose (Rosa multiflora) and are interested in hearing from anyone who's had experience with the stuff (especially in terms of non-target damage). --------------------------------------- 2. Hairy willow herb (Wisconsin) From: Steve Richter (srichter(at)tnc.org) Should we be concerned with Hairy Willow Herb? No, you won't find this in the bulk food section of your local organic food co-op. It is a alien plant (Epilobium hirsutum) that grows in a wet prairie swale at a Wisconsin TNC site. I do not see it anywhere else in the state. It has been present for at least five years, and the population hasn't increased dramatically. It seems to compete well with cattail. Does anyone have any experience with this species? --------------------------------------- 3. Giant hogweed or water hemlock (New York) From: Chris Winters (cwinters(at)tnc.org) Do you know of any person or program working on control of giant hogweed (Heracleum mantegazzianum) or water hemlock (Cicuta spp.)? --------------------------------------- 4. Burning bush honeysuckle (Wisconsin) From: Nancy Braker (nbraker(at)tnc.org) We have a location (Lulu Lake) where we had a significant understory of bush honeysuckle (Lonicera), buckthorn (Rhamnus and Frangula) and other shrubs (natives included). We have burned a small section of this site every year for 10 years, to see if we could reduce the shrub layer. We have significantly reduced all shrubs, and have virtually eliminated the honeysuckle. Drawbacks to this approach are the other potential impacts on the vegetation such as reducing native spring wild flowers that don't get a change to set seed, or eliminating fire intolerant, but native species. You really need to burn frequently or you don't make any headway on the shrubs. Because this site has a good oak overstory, a thick layer of oak leaves was available for fuel, our fires were hot enough to get the shrub kill effect. We'd be happy to talk to Tim some more about this if he wants to call myself or Steve Richter. --------------------------------------- 5. Reviews on articles (Nationwide) From: John Randall (jarandall(at)ucdavis.edu) **Articles on Impacts of Invasive Plants Lippincott, C.L. 2000. Effects of Imperata cylindrica (L.) Beauv. (cogongrass) invasion on fire regime in Florida Sandhill (USA), Natural Areas Journal, 20:140-149. Carol Lippincott examined attributes of fine-fuels and fire behavior in sandhill areas invaded by the non-native cogongrass (Imperata cylindrica) and compared them with adjacent uninvaded sites. Invaded sites had significantly greater fine-fuel loads, horizontal continuity, and vertical distribution. Fires in invaded sites were more horizontally continuous and had higher maximum temperatures at greater heights. Rate of fire spread and calculated fire intensity were similar in invaded and uninvaded sites, however. Fire-induced mortality of juvenile longleaf pine (Pinus palustris; the dominant tree in these systems) was greater in invaded sites. After fires, fine fuels accumulated more rapidly in invaded sites. Lippincott notes that cogongrass is distinctly different from native grasses. She suggests that these differences effect fire behavior and fuel accumulation in way that may result in higher mortality of native herbaceous and woody plants leading to a shift in species composition from species rich pine-savanna to grassland dominated by cogongrass just as has already occurred in some previously forested systems in southeast Asia. Schulz, K. and Thelen, C. 2000. Impact and control of Vinca minor L. in an Illinois Forest preserve (USA), Natural Areas Journal, 20:189-196. Species richness, evenness and combined diversity were not significantly different between a Vinca minor infested plot and an uninfested reference plot at a natural area in southwestern Illinois. A combined cutting and glyphosate application treatment reduced Vinca minor cover in the infested plot by about 50% and increased cover of non-vegetated surface and species richness. Species composition in the treated portion of the infested plot more closely resembled that in the uninfested reference plot than did the untreated portion of the infested plot. Note that this was a case study from just one site, that treatments were not replicated and that the researchers have no data describing the vegetation before Vinca invaded. **Articles on Impacts of Control Haney, R.L., Senseman, S.A., Hons, F.M. and Zuberer, D.A. 2000. Effect of glyphosate on soil microbial activity and biomass, Weed Science, 48:89-93. This study found that glyphosate added to a cropland soil significantly stimulated soil microbial activity as measured by C and N mineralization but did not affect soil microbial biomass. Cumulative C mineralization and mineralization rate increased as the amount of glyphosate added increased and the relationship indicated that glyphosate was the direct cause of the enhanced microbial activity. These trends continued for 38 to 56 days depending on the amount of glyphosate added. Glyphosate appeared to be directly and rapidly degraded by soil microbes, even at high application rates. It should be noted that the soil used was taken from cropland that was unfertilized but which had presumably been treated with herbicide repeatedly in the past. Heard, T.A. and Winterton, S.L. 2000, Interaction between nutrient status and weevil herbivory in the biological control of water hyacinth, Journal of Applied Ecology, 37:117-127. Water hyacinth (Eichhornia crassipes) growth and the impacts of two weevil species on that growth were measured under high and low nutrient concentrations. Results confirmed that biocontrol of water hyacinth is more likely to be effective in low nutrient waters where water hyacinth grows more slowly. In high nutrient waters, one of the two biocontrol species, Neochetina bruchi, is significantly more effective against water hyacinth than another, closely related biocontrol agent, N. eichorniae. Luken, J.O. and Shea, M. 2000. Repeated prescribed burning at Dinsmore Woods State Nature Preserve (Kentucky, USA): responses of the understory community, Natural Areas Journal, 20:150-158. Conducting autumn prescribed burns for two or three consecutive years did not significantly effect garlic mustard (Alliaria petiolata) abundance or relative importance in upland or lowland sites. This corroborates other research demonstrating that dormant season (autumn) burning does not control garlic mustard. |
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