Philip, One enclosure does not a study make! Sorry, I am not sure why Yoda possessed me. Certainly I am not as wise as he, but in any case if you want data that can be analyzed you will need to design a study that can be statistically tested. It sounds like there is already an experimental study with enclosure plots to keep out deer, so the purpose of any additional study is to study oak regeneration and the impact of deer browse on that process eh? In order to adequately study that relationship you will need to design an experiment.
Can you hire an ecologist, one who specializes in forest ecological research? I would strongly urge you to do so. I am not a forest ecologist, but I can at least give you some feedback on your statements in regards to planning a scientific study, from the perspective of an ecologist that (ab)uses statistics... And let me say again, my blurb below is not a thorough review of the process you will need to undertake in order to plan a field research experiment. As others have alluded to already, one enclosure may enclose conditions that are peculiar to that area alone, and not representative of the site as a whole. I do not want to get into the minutiae of sampling theory and the requirements of statistical testability, but at the very least you will need to acquire a random sample of site conditions; meaning you will need to randomly allocate plots (i.e. enclosures and such) in your study site. If you have funding for a 3 acre enclosure, you certainly should have enough funding for some smaller plots. But how many plots? Most field ecologists would love to have the time and funding to perform a pilot experiment (others have noted you will need to study the site, they mean in order to gain an appreciation of the natural variability onsite) so that when you design your study you will gather a large enough sample size in order to have enough statistical "power" to find significant differences among treatments. In the case of a simple enclosure study, with no other treatments, you will need to demarcate areas (in a way that will not bother the deer...) that are not enclosed as overall "control" sites. Some ecologists who have enough experience with an area and with the type of study that you wish to perform can estimate the sample size needed. It's a risk that you will not know until you analyze your data, but funding and time sometimes require it. The Forester's idea to make this an "experimental" study of oak regeneration has merit, simply because experimental studies generally afford us a better understanding of systems. But that will require a larger study, because you would be adding an additional treatment that would need to be incorporated into your design. Just a wild guess, but you would need to have experimental plots that are and are not enclosed, as well as enclosed plots that are not experimental and the aforementioned overall control plots. However, even though I have no experience in oak forest restoration in the Northeast, I paused after reading your summary of the state forester's recommended methods. He recommends clear cutting at least 3 acres, nuking the whole area with herbicide, and then planting acorns. Again, I do not specialize in forest restoration, but I have some experience with it in riparian habitat restoration and that is NOT a method that anyone has ever recommended. Sounds like a method for encouraging weed recruitment. I will leave the comments to those who specialize with oak forests in the NE, but one herbicide spraying does not a weed control program make... and there are better ways than those used by industrial agriculture. Perhaps you should solicit comments from the folks over at the Society for Ecological Restoration (http://www.ser.org/) on this topic. In regards to your question about the impacts of converting white pine to oak-hickory, or halting the conversion to white pine (sorry I am not familiar with your region), you should be able to discuss this with your state's fish and wildlife agency. Are the species that inhabit white pine or oak-hickory habitat threatened or endangered? There are probably some local NGOs that could offer feedback on that choice as well. Hope that helps, David Thomson M.S. Restoration Ecologist/Wetlands Scientist Schaaf & Wheeler 100 N. Winchester Blvd., Suite 200 Santa Clara, CA 95050-6566 (408) 246-4848 x119 (408) 246-5624 (fax) [EMAIL PROTECTED] -----Original Message----- From: Ecological Society of America: grants, jobs, news [mailto:[EMAIL PROTECTED] On Behalf Of =?ISO-8859-1?Q?Philip_Shirk?= Sent: Friday, August 18, 2006 5:40 PM To: [email protected] Subject: Re: Deer browsing ... Recently, the camp started a forestry program with the intended goals of maintaining biodiversity while encouraging valuable hardwood growth. Small selective harvests are done on sections of the forest every few years for income, to encourage forest regeneration, and to select (to a degree) for more valuable species. All this is done in a non-invasive manner so that visitors to the camp are not affected. The camp would like to know how to encourage oak regeneration in order to maintain the current oak-hickory stand for future generations. The camp would like to know if deer (which are very prevalent in the area) are surpressing oak regeneration. They approached the state for state funding for a deer exclosure, but the state forester maintains that shade, not just deer, are preventing the oaks from regenerating. Therefore, the state forester wants to clearcut at least 3 acres, roundup the area to kill all weeds, and plant acorns. The forester working with the camp wants only to install deer exclosures, claiming that the shade will only slow oak growth, not prevent it. The camp's objective is to maintain biodiversity and an oak-hickory stand. Even if 3 acres were clear cut and turned into a stand of oak, this method could not and would not be repeated on other sections of the camp, as it is quite invasive and disturbing for many camp visitors. However, the state forester claims that this is the only way to prevent white pine (which is also abundant) from taking over the whole forest. The idea of multiple smaller plots to compare oak growth in clear cut, thinned, and undisturbed areas (each with both a deer exclosure plot and a control plot) is currently being run by all parties involved. Several earlier responses mentioned troubles with oak regeneration across the northeast. What factors have been identified? Is deer browsing often the biggest cause, shade, something else (such as fire cycles), or a combination? Should the camp be looking at other methods of encouraging oak regeneration? Are there any ecological benefits or harm in keeping the forest as an oak-hickory forest and preventing it from becoming a white pine forest, as the state forester claims it will become naturally in the next few decades? Also, if no agreement can be reached (and therefore no state funding available for research), the camp is interested in an inexpensive study, such as a deer density study, as a quick easy method to find a way to help their oaks regenerate. (This would assume that if the deer density is too high, they are at least partly to blame for the lack of regeneration and therefore decreasing the local population would help oak regeneration.) Should this be looked at more seriously to begin with? Are there others potential hindrences to oak growth that could be inexpensively examined? I hope this has cleared things up a bit, and thanks for all the helpful comments so far, Philip Shirk
