I believe I remember hearing a story of a pine that wouldn't grow in Pacifi= c islands until its mycorrhizal symbiont was introduced though I couldn't f= ind any publications about that specific case. I'd like to hear more about = this topic. =20 Here's some information from the U.N.'s website:=20 =20 FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS http://www.fao.org/docrep/006/j1467e/J1467E06.htm#TopOfPage =20 ...care should be exercised over the introduction of exotic mycorrhizae to = promote the growth of forestry trees. In general, these introductions may b= e expected to be beneficial, but it is extremely difficult to anticipate or= assess the impact of such species on an ecosystem (Case Study 19). Introdu= ctions of these species should therefore be approached with caution (partic= ularly in the case of oceanic islands) and efforts made to monitor their su= bsequent establishment, spread and ecological impact. =20
Case Study 19: Possible impacts of mycorrhizal introductions associated wit= h forestry trees=20 There is relatively little information on the impact of introduced mycorrhi= zal fungi, except on their direct benefit to associated trees. Their possib= le effect on the invasiveness of their associated trees (or other ecologica= l effects) has not been widely investigated. Introductions of symbiotic mycorrhizae may increase the invasiveness of exo= tic plants, but at present there is little evidence of this. However, there= is clear evidence from Hawaii that fungal symbionts of alien tree species = can significantly alter the natural ecosystem. In Hawaii, Myrica faya, an i= nvasive alien tree, forms a symbiotic relationship with Frankia spp. (an ac= tinomycetal genus that forms nitrogen-fixing root nodule symbioses). It is = not known whether Frankia was naturally present in the soil in Hawaii, but = the interaction between M. faya and Frankia significantly increases soil ni= trogen levels. These high nitrogen levels, in turn, provide a nutrient-rich= substrate for other fast-growing alien species, which can outcompete slowe= r-growing native species. The high-nitrogen soil also attracts worms (anoth= er alien to Hawaii) that in turn attract pigs (also alien). The pigs distur= b the soil looking for worms, creating germination sites for invasive alien= weed species. There is thus a whole series of negative impacts associated = with this particular tree-mycorrhizal relationship. In New Zealand, the introduced ectomycorrhizal fungus Amanita muscaria has = become naturalized in some Nothofagus forests. This fungus was introduced t= o New Zealand relatively recently, but before 1997 it had only been reporte= d in three or four native forests within the Nelson Lakes National Park. Re= cent records, however, suggest that it is now widespread in indigenous fore= sts in the northern half of the South Island. In most localities where it i= s found, Amanita muscaria is present at numerous separate sites. This distr= ibution may be due to some local characteristic of the environment, the fun= gus, or the host, or it may be the result of local spread following a singl= e invasion. So far, it has been recorded only in association with Nothofagu= s spp., with no reports of it occurring with the only other indigenous ecto= mycorrhizal trees in New Zealand, Leptospermum scoparium or Kunzea ericoide= s. This system provides an ideal opportunity to research various questions rel= ating to the effect of mycorrhizal species on the forest ecosystem, includi= ng: The effect of these exotic mycorrhizal associates on the indigenous Nothofa= gus particularly with respect to nutrient uptake, resistance to root diseas= es, etc. The impact of these invasive fungi on the diversity of native ectomycorrhiz= al fungi normally expected at the invaded sites. The possible effect of these exotic mycorrhizal fungi on the invasion of No= thofagus forests by exotic mycorrhizal trees. For example, in New Zealand, = there is no evidence that exotic conifers can utilize indigenous mycorrhiza= l fungi, and it could be that this restricts the spread of these conifers i= nto New Zealand's native forests. However, since Amanita muscaria is often = found as a mycorrhizal associate of introduced conifers (e.g. Pinus spp. an= d Pseudotsuga menziesii), establishment of the fungus in native forests may= make it easier for Pinus spp. to invade them.=20 Sources: http://www.landcareresearch.co.nz/research/biosecurity/fungal/; Ca= ndace J. Felling, personal communication, 2002; Tim Low, personal communica= tion, 2002; Peter Johnston, personal communication, 2002. See also Lutzow-F= elling et al. (1995); Vitousek (1986, 1992). > Date: Fri, 7 Dec 2007 13:00:= 22 -0500> From: [EMAIL PROTECTED]> Subject: Re: "Bio-dynamic" composting sta= rters> To: [email protected]> > Dear Thomas,> > The potential for s= oil invasions seems real. I have often wondered about the> generic "mycorrh= izae in a can" being attractively marketed in organic> gardening catalogs. = Terrestrial ecologists are still revealing so much about> this long underap= preciated community. By the way, one cheap and local way to> introduce soil= biota into your compost pile is mixing some of your soil in> the pile.> > = Scott> ---> > Scott Ruhren, Ph.D.> Senior Director of Conservation> Audubon= Society of Rhode Island> 12 Sanderson Road> Smithfield, RI 02917> > 401-94= 9-5454> > -----Original Message-----> From: Ecological Society of America: = grants, jobs, news> [mailto:[EMAIL PROTECTED] On Behalf Of Thomas = Hardy> Sent: Friday, December 07, 2007 12:01 PM> To: [EMAIL PROTECTED] EDU> Subject: "Bio-dynamic" composting starters> > Does anyone know if use = of commercial preparations of bio-dynamic compost> starters. chock-full of = bacteria, soil fungi and perhaps a nematode or two,> if used in other regio= ns of the world might raise questions of> "exotics-transfer"? Or are soil m= icro-flora pretty much "homogenized" after> millions of years of climatic "= adjustments", regardless of location?> > Thomas Hardy> > > ----------------= -----------------> Looking for last minute shopping deals? Find them fast w= ith Yahoo! Search. _________________________________________________________________ Share life as it happens with the new Windows Live.Download today it's FREE= ! http://www.windowslive.com/share.html?ocid=3DTXT_TAGLM_Wave2_sharelife_1120= 07=
