invasives

There's an op-ed in today's New York Times by Hugh Raffles titled "Mother Nature's Melting Pot" which in essence says that invasive species aren't such a bad thing.

Many, perhaps most with ecology backgrounds will bash the opinions of Mr. Raffles. He's an anthropologist, and some of his ideas don't translate very well across disciplines. I'm going to critique him too, but I'll say up front that what he said needed to be said, and if he's guilty of gross oversimplification, then perhaps so are we ecologists.

First, the critique.

Mr. Raffles provides the words himself, in a metaphor which references human immigrants: "It is... the ever shifting diversity that immigrants like us bring to this country that keeps it dynamic and strong."

What he says may be true when speaking about humans, but it points out his lack of understanding of how plant and animal immigrants affect the ecosystem on at least a short-term timescale. Invasives usually decrease natural diversity, sometimes dramatically so. This is true at a variety of scales from local to continental. In extreme examples they displace most of the native community. Stands of Phragmites (common reed) are a good example. Not a lot grows under the monoculture. Not a lot lives there either. Even the lowly crayfish disappears.

What happens, typically, is that when an invasive plant takes over there is a loss of habitat structure. The complex interaction of hundreds of native species provides food and cover for a multitude of animals. Take that away, replace it with one kind of plant, all the same size and shape, and there's no place to hide, and not much to eat.

It's only a little better when the invasive is an animal. Carp do considerable damage to aquatic ecosystems. Bullfrogs (native to at least the southeastern U.S. but now found in most of the U.S.) are voracious predators on smaller native frogs.

So what we end up with is a simplified ecosystem. To revert to the anthropological example of Mr. Raffles,  it's as if when human immigrants arrived, they killed everything in their path instead of, at worst, displacing earlier residents from one neighborhood to another. Human immigration increases diversity at anything larger than a local scale. Plant and animal immigration, on a human time scale, more typically eliminates what was there before. There is no new neighborhood to move to, especially when humans have created barriers to migration in the form of cities and farmland.

The other problem is related to the pace of invasion. Mr. Raffles is correct that immigration is a natural process in the plant and animal world, and it has probably functioned as long as there have been plants and animals on earth. What's changed is the speed of immigration. Now, humans help the process along, either intentionally (carp, starlings) or unintentionally (gobies in ships ballast water, zebra mussels on the bottom of a pleasure boat).

Once, ecosystems had time to adapt to new arrivals, to assimilate a few at a time. Now the invasion is overwhelming. New things with no local predators arrive, and for a while they have a competitive edge. If a native community survives one, it may fall to the next one, or the one after that. There's no time to recover.

But now, here's my qualification. Not all invasives are created equal. While Phragmites or purple loosestrife can be devastating once they're well established, native biodiversity can persist fairly well in stands of some other species. It's a case by case thing.

More importantly, we ecologists are making the all too human mistake of looking at things only at the time scale of our own short lifetimes... or even less. We assume that what we see now will always be, or at least will be for a long time.

But even within the 25 years or so that I've been working in this field, I've seen changes. There's a place near where I grew up that was, when I was in high school, a thicket of buckthorn. When I went back there last summer, cottonwoods had overtopped the buckthorn and shaded it out. Most of the shrub cover had died back. What had been a successional field had become a forest. In another 100 years, those cottonwoods, a fast growing pioneer species with a relatively brief lifespan as trees go, will probably be giving way to something else.

Invasives undergo successional processes, just like anything else. Other species eventually outcompete them, or the presence of a near-monoculture eventually draws the attention of a browser or a parasite or a disease.

In most of the U.S., what was here at the time of white settlement was not natural. it was a fire-maintained ecosystem, kept artificially open by frequent native fire. Because native tribes had already been decimated by diseases which for the most part preceded scientists and other observers, the dynamic equilibrium which had existed for a few thousand years had probably already been altered to some extent. Fire suppression, logging, agriculture, and development thoroughly shuffled the deck, and invasive species stepped in to fill newly available gaps.

If humans disappeared today, it would take a while for the system to find a new dynamic equilibrium. It might take 150 or 200 years or more, but eventually new assemblages of species would find their niches.

Even if humans continue as we've been doing, which I expect to be the case at least until well beyond my lifetime and until whenever limits and cold hard reality finally catch up with clearly unsustainable economic systems, things will change. In another 20 years, some of the invasives we're very concerned about today will fade back, overtaken by other things. New species will arrive. It's all in flux, and we need to recognize that.

Fighting invasive species creates jobs, and it provides a mission for teams of enthusiastic volunteers, thus creating new networks, places for new connections to be made and creative new ideas forged and tested. Thus I'm going to advocate that we continue to fight invasives. However, it's best if we understand that we occupy a moment in time, and that very little is static. Change is the only constant.

It does not serve us well to take a simplistic viewpoint, no matter which side of this or any other debate we're on. Command and control mentalities are gradually being replaced with adaptive management for a good reason, although too many people seem to have not yet gotten the memo. We also need to think beyond this year, beyond this decade, beyond this century, even beyond several centuries.

metaphor

One of the frustrations of restoration work in California is navigating the state bureaucracy. A number of policies adopted by state agencies provide strong disincentives to restoring habitat by creating absurdly lengthy review processes, inconsistent guidance, and expensive requirements which typically add little or nothing to the on the ground benefit of the proposed project.

Last night it occurred to me that the career of our current Governor may provide a thought framework to evaluate ways to move forward.

Jerry Brown was Governor during the 1970s era when so many of our current environmental policies were formulated. At the time, as a first wave of regulation reining in heavy industry pollution and the like, the approach was command-and-control. For what needed to happen at that time, and as a starting point, that was probably a necessary phase.

The problem is that, at a regulatory level, little has changed since then in California.

Jerry Brown's thinking has evolved with the times, as evidenced by his apparent willingness to pursue serious budget negotiations... a refreshing change from the shell games of previous administrations. Finally, we're (I hope) confronting the problem in a meaningful way, with give and take asked of all sides.

The thinking of our state regulatory agencies has not evolved. Our world has changed, and with rare exceptions they have not. Bureaucratic inertia rules.

So my question is... how can we take the sort of adaptive management that seems to be manifesting in the Governor's office, and make it happen at the State and Regional Water Boards, at Fish and Game, at the Coastal Commission, and at other state agencies?

snakes

Spring is approaching, and with it groundbreaking on a variety of projects. I'm beginning to get requests to visit sites to complete required pre-construction surveys.

One of these sites is in the Sacramento Valley, and it's potential giant garter snake (Thamnophis gigas) habitat. We're not certain if the species actually occurs in the project area, which is currently in rice production, and the nearest documented locality is about six miles away. But it might be there, and as so often happens, it's more efficient to assume presence and mitigate.

There's some controversy about the habitat needs of the species. The agencies generally consider rice fields to be habitat, and it's true that snakes do sometimes enter them. Rice fields are wet in summer, and thus they mimic the presettlement wetlands of parts of the Central Valley which were once fed by now diverted Sierra snowmelt well into the summer. Rice fields also harbor tadpoles... Pacific tree frogs or introduced bullfrogs... and as the fields are drained in late summer, snakes may forage in the shrinking pools of water if there is more permanent vegetated wetland habitat nearby to provide cover and food in other seasons.

Rice fields are also subject to frequent disturbance, and they can concentrate pesticides and herbicides. They are structurally simple. In my opinion, they're marginal habitat for giant garter snakes, at best. They're used only because so little else exists.

Giant garter snakes persist on some of the National Wildlife Refuges in the area, but these tend to be command-and-control facilities driven by pumps, and managed for waterfowl. They are largely dry in the summer months, and thus they differ considerably from the historic condition. Where more permanent water is present, snakes can do well because vegetation is more structurally diverse and food sources more predictable.

It seems at first glance to be easy to restore the requisite habitat. In practice it may not be so easy, because the water control system is so vast. Yet there are certainly at least some areas where restoration is feasible, and indeed it's been done at a few mitigation banks. Overall though, the lack of imagination is striking, when considering this species.

While I'm out on those sites, I'm going to be looking around, getting a better understanding of the landscape, and of the possibilities.

following through

While I'm working through my current reading material, here are a few thoughts on an older project... one that worked pretty well for a while.

I was still pretty early in my consulting career, and the client... a California state agency... had already developed a mitigation concept. The previous consultant had botched a few things, and one day I got one of those "help" calls from one of our west coast offices. I spent about the next year completing permitting for the project, and making some minor adjustments to the design.

It was one of those things that had to be an improvement, because pre-project it was nothing but a straight-sided ditch with weedy banks. We ultimately restored a gently meandering tidal channel with bordering seasonal wetland and a short interpretive trail. Because it was the first restoration project that I'd worked on and actually seen built, I visited several times over the years to see how it was doing.

Through the five year monitoring program, things went well. The agencies signed off on a "success" and then... nothing. There was, as far as I can tell, no maintenance after that. I'm not even sure if anyone except me has looked at the site since then.

The tidal channel still looks pretty good, as of last summer. The brackish water does a pretty good job of keeping weeds out, so there's a nice bulrush-dominated community lining the channel.

The problem is that the project site borders a busy highway. Predictably, the area between the road and the channel has become pretty weedy. What's perhaps even more disappointing is that the interpretive signs are faded and unreadable, and weeds grow through cracks in the trail.

On the interior half of the site, across the tidal channel from the road, things are much better. I don't have access to the site and have chosen not to climb the fence, but as far as I can tell the seasonal wetland there is working as it was intended to. It's not pristine, but it's not unusually weedy either. That part of the site is contiguous with adjacent public open space, and it's functioning pretty nicely.

Overall, the disappointment is minor. There are a few lessons learned; one is that because no parking was provided for the interpretive trail, no one other than the kids from the adjacent subdivision ever seems to go out there. The local municipality has posted no parking signs along the road (they went in years after project completion), so it's just barely possible to squeeze one small car off the roadside by the trailhead.

I guess the project counts as 75% successful. There was never any stated intent to maintain a pristine native upland community, but the presence of invasives along the roadside is troublesome. The biggest lesson, for me, is that project sponsors can't always be counted on to maintain a mitigation site after the monitoring period, especially when all of the people involved have retired or moved to other jobs.

It's been about 18 years since the permits were issued and the project was built. I intend to revisit the site from time to time, every few years, to watch the trajectory. Never stop learning.

turn

For a variety of reasons, I've been delving into the literature on business strategy these past couple of days, and will be continuing that over the weekend and probably beyond. It's something I do every now and then, and since I have academic background in management it's relatively easy for me.

Although the original reason had little to do with habitat restoration, I'm already finding relevant lessons. I guess everything is connected.

More on this once I'm in a little deeper.

resources

Yesterday I spent a little time reorganizing and tidying my bookshelves. Handling old reference material, I couldn't help but notice one striking thing: Most of it isn't available online.

These days, we tend to look on the web first when we're researching a topic. Certainly there are some unique things online, things we can't easily obtain anywhere else, so in that sense it's an advance. The web is also useful when we're on a tight deadline and don't have the time to physically chase things down. But increasingly, we're lured into thinking that's enough... and now I'm not so sure that it is, at least for in-depth research.

I handled a lot of books yesterday, and of course older technical publications are pretty lengthy, and have a pretty limited audience, so it can be hard to justify posting. But it's the obscure gray literature stuff that can be especially useful and hard to find. For that matter it's not easy to find in a physical sense either; a lot of what's on my shelf had a very limited press run and most people never knew it existed. I picked a lot of it up at state agency or NGO offices, or received copies directly from authors. A few of these things find their way online, but not enough of them do.

It's a good reminder that newly available electronic resources can add to the knowledge base; if we don't simultaneously discard all that came before.

policy

I'm in the middle of writing a conference abstract for presentation this summer. In the past, I've tended to focus on technical and scientific things, usually related to field research. In the past few years, I've also presented a few papers that looked at more of a project implementation overview, case studies of restoration implementation. This time I'm moving in a policy direction. I'm attempting to summarize my restoration-related experiences as a small-town elected official. I'm finding that it's more difficult than I expected.

Unlike my past papers, there's nothing quantifiable here. The careful study designs and formulas and statistical analysis of science don't translate very well to the world of special interests and sound bites.

I'm realizing that this disconnect is exactly why it's important to talk about this. Scientists can't communicate effectively with policy makers unless they understand the mindset and are able to speak the language.

In my case, I'm the only member of our City Council with any ecology background. We have one fellow with an academic background, something in mathematics, and he's able to adapt easily enough. The others include a businessman, a rancher, and a state employee who works on the operations side. It's a safe assumption that most City Councils don't have anyone with a science background.

Instead, elected bodies are driven by political philosophy, constituency, and the realities of managing limited financial resources in difficult economic times. In California, there's generally also distrust of a state government that's been dipping a hand in local pockets for years to feed it's own dysfunctional bureaucracy and lack of fiscal restraint.

A Council might back a restoration project, if it doesn't cost too much or the money comes from someplace else, and if there is some perceived local benefit (a tourism draw, or mitigation for a badly needed infrastructure project). Surprisingly, the local Chamber of Commerce can sometimes be an advocate; birdwatchers at a local wetland restoration often stop on Main Street for lunch and stay in a local hotel.

Scientists are notoriously bad at converting complex technical knowledge into press-friendly sound bites, and they often aren't very good at building coalitions to push a project through a maze of funding constraints and regulatory hurdles. Yet, if we're actually going to build restoration projects, these are necessary skills. Someone needs to bridge the gap.