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Thursday, October 29, 2015

Ecosystem Conservation – Three Hypotheses

Many people seem to think that natural area conservation is a long established discipline – sure and unchanging. But it’s rather new and changing rapidly as we learn.

Yes, of course, long ago Thoreau, John Muir, Gifford Pinchot, and Aldo Leopold introduced many of the concepts. But their wisdom and ideas only recently led to definitive action, especially for the prairie region and for conservation of the animals and plants of oak woodlands. On-the-ground conservation principles have been developing out of the practices of many interacting agencies.

George Fell of Rockford helped launch the new era through the Nature Conservancy, Illinois Nature Preserves Commission, and Illinois Natural Areas Inventory (INAI).  But in its early years, the Illinois Nature Conservancy was essentially a real estate operation. Outside experts recommended acquisitions. TNC bought land, handed it over for management to state or county agencies, and they in turn often managed it under the guidance of the Nature Preserves Commission.  Once arguing began about what kinds of lands should be bought, the Inventory was launched to provide good scientific principles and a definitive list. 

Organized by the Natural Land Institute and the Illinois Department of Conservation, the INAI was a world first. It sought to define “nature” and identify all the gems that survived in Illinois. The result – 610 “significant natural areas” survived covering 7/100ths of 1% of Illinois. That’s why Illinois was first. This state was the most desperate. There was less left here than anywhere else – that actually had anything. Most types of natural areas along the east coast had been long gone even at the time of Thoreau. Since the Illinois country was Europeanized hundreds of years later, fragments of rich ecosystem still survived, hidden here and there.

Much has been written about and done to conserve those 610 prairies, woodlands, and wetlands. But what was “nature?” - or “a natural area?” The INAI technical report defined the nature of those 610 areas on pages 12, 21 and 280. Basically, the definition said that such a natural area had flora and fauna that reflected pre-European times along with enough buffer that it could be properly managed.
[1]
Our true natural areas are often tiny remnants in seas of corn, brush, or development. What's the best
management for such treasures? This post describes some of the options that have been proposed. 

Which Is Best?

Nothing comparable to the INAI has ever been done to nail down the meaning of “properly managed.” Some of us believe that we shouldn't answer that question too quickly. We should be managing by a variety of protocols and scientifically comparing the results. But we don’t even know by which standards to compare the alternatives. (Let’s debate standards, come to good consensuses, and test the emerging hypotheses.)

Consider three hypotheses ...
that have benefitted from a lot of good thinking ...
(if not much research):

HYPOTHESIS A:  The best approach is to save the best there is – and then leave it alone as much as possible.

In the sixties and early seventies George Fell and Robert Betz worked to preserve nature by rescuing it from people’s meddling. Betz wanted to build a cyclone fence around every prairie remnant. He got fences built around many. He used to say, starting with an intimidating glower (and ending with a cute smile), “Every Prairie should have a Cyclone Fence around it!!! With a Big Padlock!!! And NO ONE HAS THE KEY!!! (except me).” In the case of nature preserves, Fell had long management plans produced for each – consisting mostly of lists of meddlings and “intrusions” that would not be allowed.

Both Betz and Fell came to realize that even the most intact remnants need and deserve at least minimal “stewardship” – people to pull out invasives, remove artificial drainage, conduct controlled burns. How low could that minimum go? In 2004 a study by Marlin Bowles[2] showed that most of the region’s prairies, though owned by conservation agencies, were losing diversity. To maintain their plant diversity, prairies need to be burned at least once every two years, according to Bowles study.

Some nature preserves are still managed according to Hypothesis A. The small ones typically don’t seem to have very promising futures. Some may represent important opportunities to compare the “minimal” hypothesis to the next.

HYPOTHESIS B:  The best approach is to save the Grade A and B sites and restore them – and as much land around them as possible.

By the early eighties, there was a growing consensus that most remnant prairies (and many woods and wetlands) needed vigorous management and restoration – and even with that were too small for sustainability on their own. In fact, typically the sites needed more upkeep than resources allowed. And choices had to be made. Perhaps a remnant prairie preserve included a bit of former wet prairie in one corner, but that corner was now a dense stand of sandbar willow. That willow is “native,” but it can be malignant under contemporary conditions. Stewards would cut and herbicide willow to give the wet prairie a chance, but the ground would quickly fill with cattails – another native invasive species. Some stewards were happy with the cattails. But others decided to control them as well - and to find nearby seed of diverse natural wet prairie species to restore what would have been there. The edge of the wet-mesic prairie could then have a natural interaction with the wet prairie and perhaps sedge meadow, as it could not with the cattails.

But bringing in seed from outside a nature preserve was not an act approved quickly or lightly. Somme Prairie Nature Preserve is an example. The Inventory found about three acres of Very High Quality mesic prairie in a forest preserve of 70 acres of former cornfields, which by that point were a mix of brush and “old field.” The initial management plan called for cutting the brush and restoring with seeds from on site.

Annoying problems emerged during the early minimal-management years. Some species that had almost certainly been part of those seventy acres were no longer there[3]. And even for the species that survived in small numbers, to restore the site with its own seed required too much work. The volunteers of the North Branch Restoration Project mostly gathered its seed at other sites, in part because high quality prairies produce less seed than disturbed areas, where plants of a given species, when its seed was ripe, could be found in clumps rather than scattered.
  
Michigan lily pods. But if only one clump survived
in a preserve, perhaps all the seeds would be identical.
No genetic diversity. We debated, would it debase the site
- or help conservation - to bring in seeds from some nearby site?
Also, the small amount of seed gathered from the high-quality mesic three acres also was of no use in the large parts of the site that were naturally wet prairie, sedge meadow, or marsh. So the steward, Laurel Ross, and along with INPC staffer Steve Byers, made the decision to use the (highly local[4]) North Branch seed mix for restoration of the nature preserve.

Personally, I was initially disappointed (romantically?) by the decision to bring outside seed into Somme Prairie Nature Preserve[5]. Wouldn’t it be wonderful to restore this unique site exclusively with its own seed? Well, sure, fine. But how important was that goal compared to others (as discussed below). And where (keeping in mind that this was decades ago) would the resources have come from to abide by the original plan? The decision to use local off-site seed (made by the INPC, the FPD staff, and the steward) was good.

Thus, over time, the goal for Somme Prairie Nature Preserve was to leave the three Grade A acres alone (except for burning, deer control, weeding, and brush cutting) and to restore as well as possible full plant diversity of the remaining 67 acres.

HYPOTHESIS C:  One good approach is to find large Grade C’s (preferably with some high quality remnants included) and restore full diversity.

A new idea emerged from experience at the time when most INAI areas had been protected and management of them was under way. People began asking the following interrelated questions: What about sites large enough for animals of conservation concern – and for longer term evolutionary processes? The areas chosen by the Inventory started seeming too small for some conservation goals. No INAI black soil prairie (the kind that once covered most of “the Prairie State”) was big enough to support a single pair of nesting prairie birds. Was a prairie really a prairie without its animals? Would the ecosystem function without the predators that kept the insect and mammal herbivores in check? In these little (often flat and uniform) sites, what would happen during climate changes, when species might need to move up or down hill – or toward or away from water – or use genetic richness to evolve other solutions? No very high quality black soil savannas were found, though many beat up remnants survive, so we just forget about the species of this once major community?

In 1986 (or 1985?), leaders from the major agencies held a meeting to seek practical on-the-ground answers and, after agonizing, decided that it would indeed be a good idea to restore large areas that might not have much in the way of “high quality” plant communities but did have a lot of remnant components, especially animals (from snakes to butterflies to nematodes). An area in Lee and Ogle Counties was identified – later to be called Nachusa Grasslands – and The Nature Conservancy took the lead impressively.  After a quarter century, many former cornfields have the plant diversity of original prairies. More than 3,000 acres there are under restoration – prairies, wetlands, streams, savannas, and woodlands. Rare grassland and shrubland birds, turtles, and invertebrates thrive. Now the bison are back to enrich an experiment of epic proportions.

After debate, the Illinois Nature Preserves Commission approved and funded study of burning and restoration of black soil savannas and oak woodlands. Illinois hosted a national conference to develop goals and facilitate oak ecosystems conservation. Many projects emerged in Indiana, Illinois, Wisconsin, Iowa, Missouri, and other states.

Vast wetland initiatives are under way along the Illinois River, in the forest preserves, at Midewin, and elsewhere. These don’t replace the little INAI areas, but neither do those little high quality plant communities replace the recovering “large Grade C” ecosystems. Sites worth watching include the Orland Grassland, Rollins Savanna, Midewin, Emiquon, Hennepin and Hopper, and Deer Grove.

The savannas and woodlands at the Somme forest preserves make up a special case for Hypothesis C. Of about 600 acres of savanna and woodland remnants, only about 120 acres are currently under restoration, but the work has been fairly rigorous for more than four decades. No substantial Grade A black-soil savannas (and few fire-dependent oak woodlands) were identified by the INAI, and the examples at Somme are now considered by many to be some of the best. More than 490 natural plant species (most original, but more than 100 conservative species restored from local seed) continue to increase per-quadrat diversity and quality. Many rare birds have returned to nest. From what we know of them, amphibians, reptiles, invertebrates, and most likely hundreds of species of other biota (though most small biota are poorly studied) appear to be thriving vastly better than in nearby unmanaged land or in the small isolated “natural areas” that (rightly) were the focus of conservation attention for many years. The site supports a dozen plant species that are on the Illinois or federal Endangered or Threatened lists. Many plant species on the increase are currently listed by Lake or DuPage Counties as being under serious threat of extirpation in their county forest preserves – possibly because of the limitations of smaller sites receiving homogenous management.[6] 

In the judgment of many people, these Hypothesis C sites have shown promise and should continue to receive management and study.

A possible fourth hypothesis.

We could call it HYPOTHESIS D, but it may not be so well developed as the others:

Find the large areas of depauperate forest preserves, and treat them like as in Hypothesis A – as little meddling as possible. Burn (but mildly, compared with historic burns, because safety requires much less intense fire than would have been common historically). Cut alien species, but don’t cut the native trees. Let them decline if they don’t withstand fire. Don’t introduce seed from elsewhere. See what comes from the seed bank.

This is certainly a worthwhile experiment to do on selected sites, but some people advocate it as a principle to be observed everywhere.

Modified versions of this plan have also been proposed. Alternatives might include: Restore only plant species that have seeds or pollen that blow in the wind or ride on birds, as these would likely have seen their genetic alleles move around a lot. Don’t restore (or restore only from highly local seeds) insect-pollinated species that have no obvious long-distance dispersal mechanism, as these may have specially adapted local genotypes that may emerge from the seed bank, and if not they could be restored later.

Discussion

All these hypotheses are worth testing, but rather little of that testing is going on. Instead, there’s contention over whether to explore and compare them. Some people argue that individual managers should be empowered to follow their own preferences. Others recommend that agencies should standardize (and thereby in many cases change) site protocols without testing to determine what they’ve learned (or achieved) so far.

In some cases, as staff and stewards come and go, new people change the protocols to comply with their trainings and opinions. In cases where there’s been consistent work for many years, that’s the worst option: then there’s nothing to test, and all the efforts and resources (in some cases invested for decades) are wasted – at least as an opportunity to learn from comparing management regimes.

Some people promote what they consider to be a “conservative” approach: do the least possible, and see what happens – or “wait until all species have been studied” before impacting them. One problem with such approaches is that we know that many conservation sites are losing biota and soil rapidly. Related to that is the concern that diverse local sources of restorable seed and animals (including those on preserve land) are being lost annually. It is not more “conservative” in all cases to allow populations to be irrevocably lost while waiting.

Concern has been expressed that, on sites being seeded, any species in the seed bank may be lost to competition with seeded species. But the opposite may be true. A question worth testing is whether species from the seed bank re-establish better in bare soil or under the competition with diverse species that they are adapted to. Bare soil is frequent for many years when woodlands are being restored mostly by fire and removal of exotic species.

The “wait and see” approach also has ethical limits. These preserves are to some degree analogous to human patients, and managers are like doctors. Waiting for new cures as the patient dies is sometimes less good medicine than making the best judgments about available choices – prescribing, treating, and studying, so treatments can be compared and improved.

It would be valuable for these issues to be addressed in the policies and plans of conservation agencies. Many alternative approaches have been under way for years or decades and are “ready made” case-history experiments. It would be valuable if researchers and on-the-ground ecosystem managers were jointly to review and assess the variety of ongoing approaches from time to time. Varied approaches and possible changes could be analyzed, recommended, and tested as needed. Most land should be managed by the techniques that have so far proved best – as continual tests are made and analyzed to evaluate alternative approaches. With the results of such studies in hand, conservationists could not only be better ecosystem stewards but also better inform the interested public about the goals, issues, successes, and needs for resources and support for this pioneering work.

Comments from generous people who reviewed the draft
(Note: I’ll reach out, see if people would like to be quoted, and, if so, put proper attributions on these quotes as I receive them.)

Reviewer A:
“Some of the hypotheses posed above serve as historical landmarks but are not a reflection of contemporary doubt and indecision.  There are many voices out there and perhaps this cacophony, without the sufficient filter, can obscure first principles of conservation science.  

“A practical comparative monitoring program is achievable that puts best conservation practices in place while at the same time leaving ample room for independent investigations into methods and procedures for further advancement of restoration science.  A major limit is financial commitment.  The Forest Preserves of Cook County have demonstrated what well-coordinated groups of volunteers can accomplish – both as stewards and scientific monitors – when they are coordinated with the best expertise available.  Such energies need to be focused towards consensus goals.  The conservation community needs to rallying towards such goals.”

Reviewer B:
“There needs to be more communication among all those involved in natural areas management.  There are of course journals and conferences, but for some reason each agency feels like they should write the book and don't need to learn from the experiences of others.  Forest preserve land managers should tour each other’s projects and Nachusa for a more regional perspective. Definitely a huge criticism of many efforts is that we’re looking for new areas, when the ones we know about are in such bad shape.” 

Reviewer C:
“One concern of mine is the tendency to pour over "pre-settlement" maps to determine what used to grow there in order to reflect "what is meant to grow there".   As we know, it is a whole new world now and other than topography and local context, I'm not sure it matters what the landscape looked like in 1828, 1728, or even 1978.  The question should be how can this site best contribute in a regional context.”

Reviewer D:
All land restoration areas should have many learned hands and approaches applied.  Too many projects and agencies are isolated – with long-term questions obscured by short timelines.

Reviewer E:
“Hypothesis B and C are both critical and need to be done to restore the biodiversity of the region. We need to be aware that for the most part what we have protected to date is remarkable, but it really is not that much when you start evaluating the condition of what we have saved and are managing. We have lost ~85% of our oak ecosystems and only 0.3% percent of them are high quality. Much the same can be said for prairies and wetlands. We have lost a great deal and what remains is mostly in poor condition, region-wide.

“I love Ed Collins' comment about the Nippersink Creek remeandering Project, "We just changed the map for Glacial Park." What we are doing is also historic at Midewin, Illinois Beach, Calumet, Hackmatack, Nachusa and many smaller sites.

“We need to ask where the good restoration sites are. Who restored them, How, When? But we have to keep in mind that our priorities are driven by many factors. Funding must be cobbled together from sources that aren’t focused on biodiversity. It is a tremendous story at Somme; so is the re-introduction of Bison at Midewin. The GIV[7] sits there waiting for someone to use data to answer these questions. The investigation needs to be spatially driven, based on available data and ground-truthing.

“We have watched the mentors pass on during our time and now we need to step up. Swink and Betz and others laid the groundwork. We need to provide the framework for the next generation, and we need to start assembling this framework soon before we pass, it should be our legacy to improve upon what we were left with.”

ACKNOWLEDGEMENTS
Thanks to many for comments and criticisms that improved this post. Special thanks to John Taft, Ken Klick, Jim Anderson, John McCabe, Chris Benda, and Tom Vanderpoel.

ENDNOTES




[1] The Illinois Natural Areas Inventory Technical Report (1978) framed these issues as quoted below:

Page 12: “A natural area was defined as a tract of land or water with a natural configuration or sufficient buffer land to insure its potential for protection and proper management, that … contains relatively undisturbed terrestrial or wetland natural communities, which have fauna and flora that reflect as nearly as possible the conditions at the time of settlement…”

Page 21: “Category I: High quality terrestrial or wetland natural communities
            These areas have natural communities that are relatively undisturbed, so that they reflect as nearly as possible the natural condition at the time of settlement in the early 1800’s. Areas in this category were chosen because of their high natural quality as defined in appendix 22.”

Page 280: “Appendix 22 … Natural quality is defined as a measure of the effects of disturbance to a natural community … The grading system provides terms for describing the relative amount of successional instability or change in a community’s natural diversity, species composition, and structure due to disturbance…

“Grade A: Relatively stable or undisturbed communities. – Ideally, a Grade A community has a structure and composition that has reached stability and does not show the effects of disturbance by humans. However, this grade does include a range of conditions: the community may be gradually changing, or it may have been lightly disturbed. Examples: (1) old growth, ungrazed forest, (2) prairie with undisturbed soil and natural plant species composition, (3) wetland with unpolluted water, unaltered water level, and natural vegetation.

“Grade B: Late successional or lightly disturbed communities. – A grade B community is a former Grade A community that either (1) has recently been lightly disturbed, or (2) has been moderately to heavily disturbed in the past, but has recovered significantly. If the community was recently disturbed, it was not disturbed so heavily that the original structure and composition was destroyed. If the community was disturbed in the past, it has reverted so that it is reaching stability and is no longer rapidly changing. Examples: (1) old growth forest that was selectively logged 5 years ago, (2) old second growth forest that had a moderate grazing effect, but now is in the late recovery stage, (3) prairie with somewhat weedy composition because the soil was graded 15 years ago, (4) wetland in which the original water levels have been altered, which changes the species composition locally, but did not destroy the structure and natural diversity of the community”    

[2] Bowles, M. & M. Jones. 2004. Long term changes in Chicago region prairie vegetation in relation to fire management. Chicago Wilderness Journal 2(2)7-16.

[3] Simple example, there was no white or purple prairie clover. There was only one (or two?) leadplant(s). In seventy acres of mostly mesic prairie, experts agreed that there was little chance of a natural prairie having no white or purple prairie clover. Something had happened to them: perhaps some fenced-in grazing animal had wiped them out. Or consider leadplant: could there be any “natural” explanation for the presence of just one or two individuals? When the controlled burns began, an increasing population of dozens, then hundreds of plants began to expand out from the one or two plants. What does that tell us? Leadplant wants to be there. If the whole population eventually covering seventy acres were to come from one or two plants, we’d be preserving a species with a much-diminished chance of adapting to changing conditions. The leadplant and other seed gathered by the North Branch volunteers often came from threatened populations that would otherwise have their genetic alleles lost for good. The decision-makers at the time thought it best to give them a future in the nature preserve.

[4] All prairie seed came from spontaneous populations on similar soils within 15 miles. Hundreds of people worked for decades to gather it, as most of the donor sites were lost to development or neglect. After twenty years, most seed was being gathered from the North Branch preserves and thus represented the preserves original and “within 15 miles” ecotypes.

[5] As Field Representative for the INPC at that time, I had managed the dedication of this area, had been the first steward, and wrote the initial management plan, which called for restoration by on-site seed only.

[6] Examples of such species include bearded wheat grass (Elymus trachycaulus), Seneca snakeroot (Polygala senega), eared false-foxglove (Tomanthera auriculata), Bicknell’s geranium (Geranium bicknellii), and glade mallow (Napaea dioica). These species are said to be threatened by habitat loss, climate change, successional change, pollinator limitations, inappropriate management (such as too much or two little fire – for that species), excessive herbivory, genetic issues, and other challenges. It would seem wise to compare populations of such species over time on lands with various management protocols (including examples of the various hypotheses, above). Source: unpublished study papers by FPD staff of Lake and DuPage Counties.

1 comment:

  1. I think we all hoped for hypothesis A. However, people saw it was not working and moved on to hypothesis B. Hypothesis B was tried, but after a while people realized it was not enough and added a hypothesis C. These lessons are important so the next generation of conservation leaders knows where we have been so they understand why things were done and decisions were made.

    Hypothesis D is a combination of different thinking about the restoration process. My thought is “the thinning of native species” or “what is an appropriate source for seed” often seems irrelevant when an invasive species (native or non-native) threatens to completely dominate an ecosystem. I think the ecologists feel it is a waste of their time to discuss putting in a sky light or talking about where to buy the curtains when the house is burning down. It is less a matter of “let nature take its course” and more a matter of “nature will have to take care of itself while we focus on these cataclysmic threats.” The result of this unbalanced approach is a continued degradation of what little has been receiving management. The push to accomplish as much as possible on one problem, without addressing all of them, leads to a slightly larger area of diminished quality and none that are maintained really well.

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