David and others: YOU ARE ABSOLUTELY RIGHT! Thanks for catching this brain fart on my part. (Speaking of mushy definitions!)
What I INTENDED to say is that "adapted" means that organisms may have evolved mechanisms to survive fire in some form, and indeed to proliferate following fire, those adaptations do not mean that reproduction will not or cannot occur in the absence of fire. Certain closed-cone pine cones, for example, have been found encased in the hearwood of knobcone pines. However, while this pine throws a lot of seed following a fire, there are other ways that the seeds can be released. I am only suggesting that "it ain't always necessarily so" that organisms MUST have fire to reproduce at all, but certainly fire does stimulate reproduction following fire on a large scale. I'm still a bit tired and distracted, so I hope you will give this intense scrutiny and perhaps come up with more corrections and interpretations. The generalization voiced by the fire official is a long-standing one that persists widely, possibly still amongst some botanists, foresters, and even ecologists, and I am sincere in wanting to see more clarity and evidence. In this case, the "authority" was referring broadly to California chaparral. I continue to welcome well-founded examples of fire DEPENDENCY from around the world, as distinguished to folklore, including "scientific" folklore. I am eager to be corrected--based on evidence and good, solid, science. WT ----- Original Message ----- From: <[email protected]> To: <[email protected]>; "Wayne Tyson" <[email protected]> Sent: Monday, October 08, 2012 10:22 AM Subject: Re: [ECOLOG-L] FIRE Wildland and Urban Interface Myth or Truth 1 Fire dependent plants? Wayne, help me to understand, because to me it looks like your two definitions are the same. Yet you clearly are trying to distinguish between the two terms in your earlier posts. Am I just two dense to read plain English? David McNeely ---- Wayne Tyson <[email protected]> wrote: > Ecolog: > > My standard for distinguishing between "dependent" and "adapted" is that if a > species or a group of species (say, "association" or "plant community"?) is > dependent upon fire, it would cease to exist permanently in the absence of > fire. If a species or association of species is adapted to fire, that means > that it MUST have fire to continue to exist. > > Is this correct or incorrect, more true than untrue, or more untrue than > true? > > WT > > Mushy definitions are escape valves for sloppy scholarship, but need not be > "black" or "white," they only need to have their "ifs," "ands," and "buts" > also clearly defined. > > > > ----- Original Message ----- > From: "David L. McNeely" <[email protected]> > To: <[email protected]> > Sent: Monday, October 08, 2012 8:10 AM > Subject: Re: [ECOLOG-L] FIRE Wildland and Urban Interface Myth or Truth 1 > Fire dependent plants? > > > Your commentary is interesting. In North America, we do consider the > prairies and their plants to be adapted to grazing, and that is true of > grasses in general around the world. They have meristems distributed in the > plant body so that they grow from the base, and regenerate if cut back almost > to the soil level. Many other prairie plants have below ground reproductive > structures in the form of tubers, bulbs, and roots. > > Some excellent examples, though generally small in extant, of "native" > prairie, have survived because they were grazed rather than converted to row > crops. Some other examples have survived because they were hay meadows, > mowed periodically. The Nature Conservancy (TNC) and some state and national > entities are now using grazing as one tool in conservation of protected > areas. For one example, see TNC Tall Grass Prairie Preserve just north of > Tulsa, Oklahoma. This preserve was a ranch that preserved native prairie > species not on purpose necessarily, but because its cattle grazing program > sort of mimicked grazing by bison. Today TNC maintains a herd of bison on > the preserve, and also sometimes moves bison from there onto smaller > preserves temporarily to promote the prairies there. TNC practices "flash > grazing," whereby a herd is moved onto a property and literally allowed to > trample and chew so that the landscape begins to look pretty beaten up. But > the prairie plants seem to thrive if then allowed to recover well before > another flash grazing episode. I do not know what the interval used is, and > that might vary from locale to locale depending on conditions. > > In the southern plains, under the grazing regime practiced by many ranches, > and on smaller landholdings where fire is excluded, Eastern Red Cedar, a > noxious native weed tree under those circumstances, soon crowds out the > native prairie. > > David McNeely > > ---- David Burg <[email protected]> wrote: > > I find this discussion very interesting. I am not a scientist, but have > > been looking for management studies that directly compare grazing, fire, > > and combinations of the two. My friend, paleoecologist Guy Robinson, was > > coauthor of a paper published in Science on changing conditions at the end > > of the pleistocene in North American. A consistent find all around the > > world seems to be that fire frequencies shoot up dramatically with the > > die-off of megafauna and the arrival of humans. Which leads me to wonder > > how many of the species we now consider fire dependent were also adapted to > > impacts of large animals? I see so many management prescriptions for fire > > in prairies and savannas, but fewer studies of impacts of various grazing > > regimes. Based on historic and ongoing conservation conflicts with > > agriculture one suspects a bias towards fire and against grazing. > > > > David Burg > > > > On Sun, Oct 7, 2012 at 3:28 PM, Thomas J. Givnish <[email protected] > > > wrote: > > > > > The list goes on and on and on. Bulbostylis in Venezuelan savannas flowers > > > within a few days after fires; several orchids in Australian woodlands > > > obligately depend on fires to trigger flowering; many other plants in > > > other > > > systems flower profusely a year or two after fires (e.g., Xanthorrhoea, > > > Xerophyllum, Lilium). Several species in Mediterranean scrub in sw > > > Australia, sw South Africa, and s California germinate in response to > > > compounds released in smoke. Hundreds of species in many genera (e.g., > > > Pinus, Cupressus, Eucalyptus, Hakea, Banksia, Protea) release their seeds > > > promptly from serotinous cones, follicles, etc. only in response to fire. > > > Many carnivorous or nitrogen-fixing plants are facilitated by fire. A > > > suite > > > of ca. 17 federally endangered species endemic to the Lake Wales Ridge in > > > south-central Florida are almost surely facilitated by the extraordinarily > > > high frequency of lightning strikes there. Long-term studies at Konza > > > Prairie and Cedar Creek show that different plant species are favored by > > > different long-term fire frequencies. The Karner Blue Butterfly has no > > > life > > > stages resistant to fire, but depends on fire to renew its habitat and > > > maintain an abundance of Lupinus perennis, the sole larval food plant. > > > > > > -- > > > Thomas J. Givnish > > > Henry Allan Gleason Professor of Botany > > > University of Wisconsin > > > > > > [email protected] > > > http://botany.wisc.edu/givnish/Givnish/Welcome.html > > > > > > > > > > > > > > > > > > On 10/07/12, "David L. McNeely" wrote: > > > > I apologize. I left off the list of references I compiled for this post. > > > Here it is: > > > > > > > > > > > http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1010&context=barkbeetles > > > > > > > > http://www.gffp.org/pine/ecology.htm > > > > > > > > http://www.esa.org/education_diversity/pdfDocs/fireecology.pdf > > > > > > > > http://www.fs.fed.us/database/feis/plants/tree/pinconl/all.html > > > > > > > > http://fireecology.org/docs/Journal/pdf/Volume08/Issue02/107.pdf > > > > > > > > http://www.na.fs.fed.us/pubs/silvics_manual/Volume_1/pinus/contorta.htm > > > > > > > > http://www.firescience.gov/projects/briefs/01B-3-1-01_FSBrief30.pdf > > > > > > > > http://www.fws.gov/southeastfire/what/ecology.html > > > > > > > > http://cee.unc.edu/people/graduate-students/theses/Kaplan_MA.pdf > > > > > > > > > > > > ---- "David L. McNeely" <[email protected]> wrote: > > > > > Wayne, I have heard this "fire dependent" terminology in reference to > > > both community types and specific plants. However, most often it has been > > > in reference to community types that included dominant fire adapted > > > species. I also have heard more convincingly that lodgepole pine, _Pinus > > > contorta_, was fire dependent due to serotinous cones. I accepted this > > > without judgement. However, one of these references suggests that though > > > serotinous, under warm enough conditions 45 - 50 C soil surface > > > temperature) the cones may open without fire. I wonder if soils in the > > > northern portions and higher elevations of the range get that hot, but I > > > don't know. > > > > > > > > > > I have also heard the term applied to Longleaf Pine, _Pinus palustris_ > > > , and the communities that it dominated prior to extensive exploitation of > > > the SE U.S. forests. My understanding has always been that in that case, > > > more shade tolerant species that have seeds that can reach the soil > > > surface > > > despite dense grassy understory replace the longleaf pine when fire is > > > absent from an area for extensive time. > > > > > > > > > > Here are some references, some of them secondary, that discuss these > > > phenomena. > > > > > > > > > > I am definitely not a forest or fire ecologist. > > > > > > > > > > David McNeely > > > > > > > > > > ---- Wayne Tyson <[email protected]> wrote: > > > > > > Ecolog: > > > > > > > > > > > > I just caught a video production on TV done by a major governmental > > > fire authority. It contained a mixture of truth and superstition, as well > > > as some questionable assumptions that y'all can help me clear up. > > > > > > > > > > > > 1. A uniformed fire official claimed that some plants are DEPENDENT > > > upon fire for their survival. He did not say that some plants are ADAPTED > > > to fire, he said "dependent." > > > > > > > > > > > > Please share your knowledge and references, please. > > > > > > > > > > > > Thanks, > > > > > > > > > > > > WT > > > > > > > > > > -- > > > > > David McNeely > > > > > > > > -- > > > > David McNeely > > > > > -- > David McNeely > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1427 / Virus Database: 2441/5317 - Release Date: 10/08/12 > -- David McNeely ----- No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1427 / Virus Database: 2441/5317 - Release Date: 10/08/12
