Below is an exerpt from an email I sent to a client that requested information about using FQA in conjunction with mitigation banks. I hadn't thought about the subject before and just assumed that FQA was a perfectly acceptable thing to use wherever plants are found. But when I considered the true application of FQA, I wasn't so sure. Any thoughts?
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I have used FQA in conjunction with mitigation monitoring in Indiana and didn’t really find it to be a great match. The problem is that FQA is designed to evaluate the floristic quality of “natural” communities. With this comes the assumption that all the taxa existing in situ are there of their own volition, demonstrative of the level of past disturbance of the site and represent taxa of a natural reproducing community existing in perpetuity (given that no bulldozers or invasive species interfere).
Mitigation sites and restoration sites don’t necessarily have these qualities. Take the wetland at Shaw Nature Reserve for example. It looks like a decent wetland creation, but many of the taxa planted and seeded there would not have occurred there “naturally” and most of them (Bald Cypress, for one) will probably not reproduce in situ. So to base an FQA off planted and/or seeded taxa is sort of misrepresenting them as being “natural”.
Another example is if I conducted a FQA of the landscaping around my house, which is all native, I would have a phenomenal list and corresponding numbers. However, if I don’t weed and trim and shape the landscape, the “system” would quickly crumble and the floristic quality would degrade dramatically. Just because for a brief snapshot of time I can assemble a group of taxa, doesn’t mean said taxa form a functioning natural community. Just something to consider.
I agree with you, mostly. It sounds like you are assuming that all mitigation and restoration involves planting and seeding. I've been involved in projects where tile was removed and the natural seed bank was allowed to revegetate the site. In that case, I think that FQA can be a useful tool. I also think that as these sites mature, things that don't belong will not reproduce and persist (like the bald cypress you mention in your first example). Once a restoration site reaches a certain age, maybe FQA would be more valuable; however, there still may be plants on the site that didn't occur at that specific site naturally if they were seeded or planted, are appropriate, but just didn't occur there historically.
ReplyDeleteIt's an interesting topic, and it really goes much more in depth than just looking at the FQA. How many species are being installed in places they never grew naturally? How does this change their distribution and abundance in 100 years? What about the population genetics? Is "restoration" really a good thing?
By the way, I only have one site that I can think of where there are FQA requirements. However, this is a bank, and the requirement is that the bank FQA has to be higher than any impact sites. Although no plant species have been installed at the site for several years, it still is home to several conservative species that were installed that may not persist as the site matures.
Scott.
I couldn't agree more. The main reason I raised the issue is to shed light on the assumptions "restorationists" have made. I cringe when I see or hear of prairie plantings and mitigations as being "successful". The ill-informed practitioners of both are often blissfully sightless. I was wondering if there might be some justification for using FQA under artificial circumstances, but it seems like there is none. None other than the old "what else ya gonna do" mentality.
ReplyDeleteI'm not so sure that mitigations can't be "successful," though. Depends on how you define "success," I guess. Karen and I have visited a few of our old mitigation projects (5-10 years old, that is), and they seem to be developing into functioning wetland systems. Exotics always seem to be an issue, but even the highest quality natural wetlands around here have exotic issues these days. I've also seen a few prairie plantings that look alright, but they still definitely lack the structure of natural prairies.
ReplyDeleteSadly, I think we are in agreement. But I have to say more, if only to clarify my point.
ReplyDeleteBasically, being able to emmulate the flora of a wet road ditch or to assemble a hodge-podge of native species that lack any structural distribution and lack the functional elements of a native, natural wetland is closer to gardening than conservation. Natural wetlands (fens, cedar swamps, small wetlands in beech/maple forests, skunk cabbage seeps, prairie swales, etc.) are, much like humpty-dumpty, impossible to reconstruct.
There are, of course, exceptions. Areas where tile is broken and native species rise from the dead simply by restoring hydrology on an existing seed bank are very much true restorations (or very close). But, scraping a hole in a cornfield outside a hydric soil unit and planting a handful of showy wetland plants is certainly not, no matter how much tending, weeding and spraying. Neither is an old field, once forest, converted to Big Bluestem and Ironweed a prairie. To say otherwise is an insult to fine wetlands and prairies everywhere.