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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hi Wayne<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I agree with your comments. Some people consider most exotic plants as invasive in all situations regardless of where they occur. This includes many roadside weeds that survive in a hostile, manmade environment that many native plants cannot tolerate but these plants are only rarely found 100 yards away from the highway. At least that has been my observation here in upstate NY where I often wander off the road to see how far the invasive plants that dominate the roadside may be found. I read here that Portland, Oregon has an ordinance requiring the extermination of certain exotic plants, seemingly because they present a threat to the native ecosystem of the city of Portland? I am all in favor of protecting undisturbed ecosystems and other places of native biodiversity from exotic weeds but I wonder how many truly “undisturbed ecosystems” still exist in most of the US. I have been pleased to note on this list serve that the tone of the posts is moving more towards learning and understanding the processes that lead to weed invasions and then designing a carefully calculated approach to dealing with them as some of the posters here have done. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Bob<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> apwg-bounces@lists.plantconservation.org [mailto:apwg-bounces@lists.plantconservation.org] <b>On Behalf Of </b>Wayne Tyson<br><b>Sent:</b> Friday, March 11, 2011 5:08 PM<br><b>To:</b> apwg@lists.plantconservation.org<br><b>Subject:</b> Re: [APWG] NEWS: Invasive Species Widespread, but Not More Than at Home<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal><span style='font-family:"Arial","sans-serif"'>Yes, it would be interesting. For some reason, many people in the alien bashing business seem reluctant to discuss the difference between "invasive" plants that are largely restricted to disturbed sites and which do not "spread" significantly into or within undisturbed ecosystems (and when they do, attempting to understand that in those cases that the presence of the alien or other colonizing species within "undisturbed" ecosystems is possibly due to small areas of disturbance [e.g., gopher mounds] within them, or other relatively short-term phenomena that shift localized habitat factors in favor of the alien/colonizing species) and those which progressively invade undisturbed ecosystems. It appears that Sahara mustard belongs in the latter group, but disturbance magnifies the effect, particularly to the casual observer. </span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-family:"Arial","sans-serif"'>I also would be interesting to know (I haven't read the paper; no doubt it provides this information) in which of these general categories (I am calling them "obligate ruderals" and "true invasives," but am willing to consider other, better terms) those included in the study fall. Some alien species fall into both categories, still others might be considered mere waifs. </span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-family:"Arial","sans-serif"'>All species are likely to perform best (be most successful) where conditions favoring their requirements are all present at the right times, and will be less successful in more marginal habitats. </span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-family:"Arial","sans-serif"'>I have recently suggested that disturbances connected with control measures such as pulling and trampling, not the mention the use of vehicles, tend to favor many colonizing species, so won't repeat those remarks here. </span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-family:"Arial","sans-serif"'>I look forward to all comments, especially those revealing my errors. </span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-family:"Arial","sans-serif"'>WT</span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><blockquote style='border:none;border-left:solid black 1.5pt;padding:0in 0in 0in 4.0pt;margin-left:3.75pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>----- Original Message ----- <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:#E4E4E4'><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <a href="mailto:ialm@erols.com" title="ialm@erols.com">Marc Imlay</a> <o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>To:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <a href="mailto:apwg@lists.plantconservation.org" title="apwg@lists.plantconservation.org">apwg@lists.plantconservation.org</a> <o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Sent:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> Friday, March 11, 2011 2:41 AM<o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Subject:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> Re: [APWG] NEWS: Invasive Species Widespread,but Not More Than at Home<o:p></o:p></span></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><p><strong><span style='font-family:"Arial","sans-serif"'>It would be interesting to know if the only 2.5 sites per species in home ranges were natural sites or unnatural disturbed sites without competition from native species. Native Switch Grass has been found invasive in America in unnatural habitats but not in natural habitats and is a new invasive in Europe. </span></strong><o:p></o:p></p><div><p class=MsoNormal><strong><span style='font-family:"Arial","sans-serif";color:blue'> </span></strong><strong><span style='font-family:"Arial","sans-serif"'> <o:p></o:p></span></strong></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='color:navy'>Marc Imlay, PhD,</span></b><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='color:navy'>Conservation biologist, Park Ranger Office</span><o:p></o:p></b></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='color:navy'>(301) 442-5657 cell</span><o:p></o:p></b></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='color:navy'><a href="blocked::mailto:Marc.Imlay@pgparks.com" target="_blank" title="blocked::blocked::mailto:Marc.Imlay@pgparks.com
blocked::mailto:Marc.Imlay@pgparks.com
mailto:Marc.Imlay@pgparks.com"><span style='color:navy'>Marc.Imlay@pgparks.com</span></a> <a href="mailto:ialm@erols.com" title="blocked::mailto:ialm@erols.com">ialm@erols.com</a></span><o:p></o:p></b></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='color:navy'>Natural and Historical Resources Division</span><o:p></o:p></b></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='color:navy'>The Maryland-National Capital Park and Planning Commission</span><o:p></o:p></b></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='color:navy'><a href="http://www.pgparks.com/" title="blocked::http://www.pgparks.com/">www.pgparks.com</a></span><o:p></o:p></b></p></div><div><p class=MsoNormal><span style='font-family:"Arial","sans-serif"'> <o:p></o:p></span></p></div><p style='margin-bottom:12.0pt'><span style='font-family:"Arial","sans-serif"'><br><br><strong><span style='font-family:"Arial","sans-serif"'>-----Original Message-----</span></strong><b><br><strong><span style='font-family:"Arial","sans-serif"'>From: apwg-bounces@lists.plantconservation.org [</span></strong></b></span><a href="mailto:apwg-bounces@lists.plantconservation.org"><strong><span style='font-family:"Arial","sans-serif"'>mailto:apwg-bounces@lists.plantconservation.org</span></strong></a><strong><span style='font-family:"Arial","sans-serif"'>] On Behalf Of Reinhart, Kurt</span></strong><b><span style='font-family:"Arial","sans-serif"'><br><strong><span style='font-family:"Arial","sans-serif"'>Sent: Thursday, March 10, 2011 11:59 AM</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>To: apwg@lists.plantconservation.org</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>Subject: Re: [APWG] NEWS: Invasive Species Widespread,but Not More Than at Home</span></strong><br><br><strong><span style='font-family:"Arial","sans-serif"'>Okay, I'll bite & also do some shameless self promotion.</span></strong><br><br><strong><span style='font-family:"Arial","sans-serif"'>A contrary view to Firn et al. is provided using a single species (a prominent invasive tree species) that was carried out across 40 total populations with slightly more than half in its native range and nearly half in its non-native range in Reinhart et al. (2010, New Phytologist </span></strong></span></b><a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2009.03159.x/abst"><strong><span style='font-family:"Arial","sans-serif"'>http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2009.03159.x/abst</span></strong></a><br><strong><span style='font-family:"Arial","sans-serif"'>ract). This study concluded that measures of local relative abundance were considerably greater in the non-native than native ranges. This study may not seem like a direct comparison because the main topic relates to Enemy release but comparable data are in the supplement (which apparently hasn't been read by many). Others have made similar observations though often without quantitative evidence for species like spotted knapweed, garlic mustard, etc.</span></strong><b><span style='font-family:"Arial","sans-serif"'><br><br><strong><span style='font-family:"Arial","sans-serif"'>Firn et al's ELE study's main advantage over Reinhart et al.'s is their use of considerably more species (26 species, 12 grass and 14 forb</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>species) at 39 sites. They concluded species have similar levels of abundance in native vs. non-native ranges. A conclusion from their paper is that many of the grasses were common at home and away while many of the forbs were rare at home and away. However based on information in their supplement, I calculated that on average they have measurements for only 2.5 sites per species in home ranges and 7.6 sites per species in exotic ranges. Sampling more species per region is valued because many species have incredibly large distributions and local abundances are variable throughout. Sampling broadly is necessary to avoid forms of regional sampling bias though researchers have to balance logistics (also see Adams et al. 2009 as an example of an extensive sampling network</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>(</span></strong></span></b><a href="http://www.plantecology.org/Full%20text%20papers%20and%20abstracts/2009"><strong><span style='font-family:"Arial","sans-serif"'>http://www.plantecology.org/Full%20text%20papers%20and%20abstracts/2009</span></strong></a><br><strong><span style='font-family:"Arial","sans-serif"'>%20papers/Adams%20Bioinvasions%202009.pdf). Firn et al. help avoid this limitation by looking at numerous species though more than half represent relatively minor invasions.</span></strong><b><span style='font-family:"Arial","sans-serif"'><br><br><strong><span style='font-family:"Arial","sans-serif"'>I think what we would mostly like to know is what traits/processes/interactions can we attribute to the success of the most invasive species and whether their abundances, effects of enemies, etc. differ at biogeographical scales. Following the rule of 10s, these species represent the most improbable invasion scenarios. So we shouldn't be too surprised if such rare events can never be predicted without the benefit of hindsight. However, I wouldn't be surprised if further studies, focusing on highly invasive species which are the exceptions, reveal that most/many are cases where the species attain greater levels of local abundance/dominance in their non-native than native ranges. My 2 cents. You decide.</span></strong><br><br><strong><span style='font-family:"Arial","sans-serif"'>Kurt Reinhart</span></strong><br><br><strong><span style='font-family:"Arial","sans-serif"'> 31. NEWS: Invasive Species Widespread, but Not More Than at</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>Home</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'> Range (Olivia Kwong)</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>Message: 31</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>Date: Thu, 3 Mar 2011 08:27:30 -0600 (CST)</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>From: Olivia Kwong <plant@plantconservation.org></span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>To: apwg@lists.plantconservation.org</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>Subject: [APWG] NEWS: Invasive Species Widespread, but Not More</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>Than</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'> at Home Range</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>Message-ID:</span></strong><br><strong><span style='font-family:"Arial","sans-serif"'> <Pine.LNX.4.64.1103030826390.1121@cpanel1-bb.epconline.net></span></strong><br><strong><span style='font-family:"Arial","sans-serif"'>Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed</span></strong><br><br></span></b><a href="http://www.sciencedaily.com/releases/2011/03/110301111459.htm"><strong><span style='font-family:"Arial","sans-serif"'>http://www.sciencedaily.com/releases/2011/03/110301111459.htm</span></strong></a><br><br><strong><span style='font-family:"Arial","sans-serif"'>Invasive Species Widespread, but Not More Than at Home Range</span></strong><b><span style='font-family:"Arial","sans-serif"'><br><br><strong><span style='font-family:"Arial","sans-serif"'>ScienceDaily (Mar. 1, 2011) -- Invasive plant species have long had a reputation as being bad for a new ecosystem when they are introduced.</span></strong><br><br><strong><span style='font-family:"Arial","sans-serif"'>Stan Harpole, assistant professor of ecology, evolution and organismal biology at Iowa State University, is founding organizer of a team of more than 70 researchers working at 65 sites worldwide that tested that assumption.</span></strong><br><br><strong><span style='font-family:"Arial","sans-serif"'>See the link above for the full article text.</span></strong><br><br></span><strong><o:p></o:p></strong></b></p><div class=MsoNormal align=center style='text-align:center'><hr size=2 width="100%" align=center></div><p class=MsoNormal><br>_______________________________________________<br>PCA's Alien Plant Working Group mailing list<br>APWG@lists.plantconservation.org<br>http://lists.plantconservation.org/mailman/listinfo/apwg_lists.plantconservation.org<br><br>Disclaimer<br>Any requests, advice or opinions posted to this list reflect ONLY the opinion of the individual posting the message. <o:p></o:p></p><div class=MsoNormal align=center style='text-align:center'><hr size=2 width="100%" align=center></div><p class=avgcert>No virus found in this message.<br>Checked by AVG - <a href="http://www.avg.com">www.avg.com</a><br>Version: 10.0.1204 / Virus Database: 1435/3487 - Release Date: 03/07/11<o:p></o:p></p></blockquote></div></body></html>