I think you should definitely continue to use the expression "so cool"... "groovy" works just as well! Michele
> > Jenny- > One of the interesting things about lichens in the Southwest (elsewhere > too!), is that they serve as good indicators of air quality...of course, > here in ALaska they are one of the primary food sources for caribou. > -Don > >> Date: Fri, 13 Mar 2009 11:56:26 -0700 >> Subject: [ENTS] Re: Roots? >> From: [email protected] >> To: [email protected] >> >> >> Gary, >> >> Sorry to be completely unintellectual - but Lichens are SO COOL! >> Trying to narrow down a paper topic for Botany class- one idea is gap >> dynamics in the NYBG forest and the other is Lichens....I think I'm >> going for the lichens. I have amazing lichen photos from Maine and >> Arizona, mostly on rocks (because rocks are SO COOL too....! - I'll >> try not to use this expression in paper...) >> >> Thanks for your info, >> Jenny >> >> On Mar 12, 5:46 pm, [email protected] wrote: >> > One interesting hypothesis is that early. Plants were an "inverted >> lichen", algae left the aquatic environment with the help of >> protofungi in a symbiotic relationship. The fungi provided the >> protection from dissication and also served as the interface between >> the macroscopic algae and soil. Symbiotic (both ecto and endo >> symbionts) relationships are probably underestimated in the >> functioning of terrestrial ecosystems. >> > >> > Gary >> > Sent via BlackBerry from T-Mobile >> > >> > -----Original Message----- >> > From: Lee Frelich <[email protected]> >> > >> > Date: Thu, 12 Mar 2009 11:23:54 >> > To: <[email protected]> >> > Subject: [ENTS] Re: Roots? >> > >> > Jenny: >> > >> > Regarding mycorrhizae, its one of those interesting questions where >> the >> > answer is yes and no. With very high soil fertility, trees can survive >> > and grow without them, and in isolation, they can often grow without >> > them. However, under most field conditions, and with the competition >> > from numerous other trees, they are necessary for an individual tree >> to >> > survive and grow, as well as for the function of the entire ecosystem. >> > >> > Regarding nitrogen fixation--its another case where both answers are >> > correct. Free living bacteria (Azotobacter and Clostridium, some >> > blue-green algae, and others) fix a small amount of nitrogen in the >> > soil. Rhizobium bacteria form a symbiotic relationship with roots, in >> a >> > nodule, which can easily be seen if you pull up a clover plant. This >> > occurs mainly in legumes (locust), but also in some other trees (via >> > other genera of microorganisms) such as alder, and shrubs such as >> Myrica >> > (sweet gale), and Shepherdia (buffaloberry). The presence of nitrogen >> > fixing plant species can fertilize the soils, thereby increasing the >> > growth of tree species that cannot form nitrogen fixing nodules. >> > >> > Whether the nodule forming microorganisms are considered part of the >> > tree depends on your point of view. They are halfway between ancient >> > microorganisms such as certain algae and bacteria that have become >> > chloroplasts in leaves, and mitochondria in cells of plants and >> animals >> > (which are clearly part of the organisms, and cannot live by >> > themselves), and microorganisms that cannot form a symbiotic >> > relationships with plants at all. Its a continuum, and where you make >> a >> > distincion along that continuum depends on the individual >> > >> > Lee >> > >> > JennyNYC wrote: >> > > Lee, et. al., >> > >> > > I would love to see one of these "rhizotrons". Fascinating. >> > >> > > I have questions if anyone can help me out: >> > >> > > 1. Are mycorrizae absolutely essential for young tree roots to grow >> > > and do trees have mycorrizae associations throughout their lives? >> > >> > > 2. I'm confused about the exact relationship between the bacteria in >> > > the soil that fix nitrogen and the tree root itself. I know this >> is >> > > a broad and vague question....just wondering it those bacteria are >> > > considered part of the tree organism? >> > >> > > Thanks, >> > >> > > Jenny >> > >> > > On Mar 12, 8:54 am, Lee Frelich <[email protected]> wrote: >> > >> > >> Ed et al.: >> > >> > >> We usually measure root biomass by taking soil cores (usually 2-4 >> inches >> > >> in dimeter, from 1-3 feet deep, depending on the purpose of the >> study), >> > >> and separating the roots so they can be dried and weighed. By >> taking a >> > >> number of such samples, we can estimate the biomass of roots per >> acre in >> > >> the forest. Roots are also studied in rhizotrons (underground rooms >> with >> > >> large windows all around). One can observe the root growth against >> the >> > >> windows, study how earthworms move, and how the soil zonation >> changes >> > >> over time, etc. The University of Michigan Biological Station and >> > >> Michigan Tech have rhizotrons that I have visited. There are also >> mini >> > >> rhizotrons that can be placed throughout the forest. >> > >> > >> Of course, these do not give you an estimate of the roots of one >> tree. >> > >> I have seen that done by blasting away the soil with high pressure >> > >> hoses, so that the root system can be mapped and measured. This is >> done >> > >> in a stand that is planned to be clearcut, or perhaps a few trees >> in an >> > >> experimental forest, and it only works in ecosystems with shallow >> soils >> > >> and/or rooting depths. >> > >> > >> Lee >> > >> > >> Edward Frank wrote: >> > >> > >>> Jenny >> > >> > >>> I am sure if there was some practical and non-destructive method >> of >> > >>> measuring the roots underground, we would give it a try. Ground >> Penetrating >> > >>> Radar is still a little expensive at the moment. >> > >> > >>> Ed >> > >>> ----- Original Message ----- >> > >>> From: "Jennynyc" <[email protected]> >> > >>> To: "ENTSTrees" <[email protected]> >> > >>> Sent: Wednesday, March 11, 2009 8:06 PM >> > >>> Subject: [ENTS] Re: Roots? >> > >> > >>> Russ, >> > >> > >>> Thanks for letting me know about this. >> > >> > >>> Jenny >> > >> > >>> On Mar 11, 2:27 pm, [email protected] wrote: >> > >> > >>>> Jen: >> > >> > >>>> No. That type of work is usually done by researchers looking for >> a >> > >>>> specific >> > >>>> piece of information about a tree or group of trees. >> > >> > >>>> Russ >> > >>>> **************Need a job? Find employment help in your area. >> > >>>> (http://yellowpages.aol.com/search?query=employment_agencies&ncid=emlc...) >> > > > _________________________________________________________________ > Express your personality in color! 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