Jonathan, I realize this is an old post, and perhaps I should have replied to you but I did not have actual specifications to offer. I only have qualitative remarks based upon some reading, which unfortunately I cannot cite. This question has become important to my work so I am trying to resurrect it. I am including the Ecolog-L list because I thought others could contribute to this discussion. I did not notice any replies to you on the list, but if you did, or have any to share that were sent directly to you, I would appreciate them.
My qualitative remarks are thus: I read some time ago that native riparian plantings do not respond well to "excessive watering". The article did not refer to the effects of over-watering, or the physiological consequences of oxygen starvation in the roots (i.e. flooding stress), but rather to long-term effects such as inappropriate growth form and wood strength. I am really sorry that I do not have this citation any longer, because they must have data to support those statements. And my recollection might be poor at this point. Nevertheless as I recall, the plantings that were "excessively" watered, which I am guessing meant more than what would be available locally on average, grew quite fast. Although fast growth might be looked upon favorably in the short term, it does not necessarily produce healthy plantings that are prepared to continue to mature. Indeed, a colleague of mine has seen oaks at some sites simply fall over, break, and die because they were tall and spindly, which he attributed to fast growth. In essence, I believe what faster growth means is less wood density per unit length. I would appreciate some assistance from the tree biologists at this point, but I think the hardwoods are harder than the softwoods because they grow relatively slower. I suppose there is some overlap in that relationship, and with all things being equal some species are able to grow faster than others irrespective of wood strength, but if I am correct the generality should hold true. Therefore, if you help a tree grow faster than it is adapted to, you run the risk of reducing the wood's strength and increasing the tree's vulnerability. So providing as much water as a plant can drink without causing flooding stress is not always a good thing. Plants are adapted to the conditions experienced by their ancestors, and their health and long-term vitality is an expression of that very complex relationship. If we change part of that relationship, even if we think we are improving one component, we can unbalance it. I would assume that significantly changing soil fertility, outside of the range normally encountered by the tree species could have significant effects. And even if I come across too cynically, I can safely say those effects are not necessarily going to be good. I can offer a somewhat related story on "fertility". I met a poultry feed scientist outside of a grocery store awhile back; he was sitting with his two Great Danes. I am a fan of the breed, and noticed they were relatively small, so I asked him if they were young. He said no, that they were full grown, but smaller than average because he fed them a low protein diet (lamb and rice dog food as I recall). He did so because his research found that poultry fed low protein diets had fewer health problems than those fed high protein diets. There is the reason why I included this story, but let me finish for other reasons: he tried it with his Great Danes, and found that they did indeed have few health problems and they did not grow as large as their over-breeding usually dictates. So they had fewer bone/joint problems. Sounds like a tree response to excessive watering, so maybe this is a good analogy. So what do we do from here? Maybe we should be asking: How much fertilizer and irrigation - IF ANY? (I have worked with soil scientists to create amendment specifications to reduce soil fertility in the hope of controlling invasive species recruitment, and compensated by specifying methods to help establish a mycorrhizal community.) Certainly we would need to contend with higher mortality rates and replanting, but the individuals (genotypes?) that survived should be better adapted to the site and be as healthy as possible. On a conceptual level, perhaps we need to dispel the myth that agricultural conditions are the best conditions. Or at least avoid the mental trap of thinking "higher" equals "better". I think it is safe to say that some species do not acclimate well to agricultural conditions. I hope that is enough to start a discussion, 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 Jonathan Adams Sent: Thursday, April 06, 2006 12:18 PM To: [email protected] Subject: How much fertilizer to give seedlings of wild trees? My colleagues and I are are setting up a common garden experiment on = populations of various oaks (Q. rubra, Q. phellos, Q. alba, Q. = prinus/montana), red maple and tulip poplar from various latitudes to = look at variation in plant defenses (by the way if anyone wants to come = and measure some aspect of inter-population variability along = latitudinal gradients, we would welcome the extra collaboration).=20 The seedlings are doing great at the moment in just Promix which has no = nutrients, but soon they will start to run out of their seed reserves. I = have spoken to various people interested in horticulture but no-one = seems quite sure how much to give to a wild tree seedling to ensure it = both grows well now and stays tough enough to survive the rigors of = being planted outdoors.=20 Can anyone suggest how much and how often we should feed our baby trees, = and with what brand of fertilizer? Thank you!! Jonathan Adams P.S. If you live in the Southland and curently have red maples seeding = near you, we'd really welcome a bag of seeds! We have relatively few = southerly populations of red maple.
