Monday, July 29, 2013

Planning Notes for 2014


Updated Feb. 15, 2018 - but including the public comments (at the end) made in response to the original post.

This post is intended for people who are interested in the details of ecological restoration. It consists of five “cases” – with photos that exhibit problems or opportunities and comments on possible solutions.
The initial "Diagnoses" and "Prescriptions" were written in 2014.
In 2018 we comment on what we've actually done and learned since then.

First, a definition of a word used often below:
conservative – a species that is most common under long-evolved natural conditions – and rarely is found away from them. In fine prairie remnants, the conservatives are among the most common plants. In most “restored” or degraded prairies, they are rare or non-existent. A more detailed note on conservatives is at the end of this post.


Case 1

Diagnosis: Weeds here are under control. Yet few conservative species are established. Most of what’s here are short termers – species likely to mostly give way to others, for better or ill, before long. The early goldenrod, for example will likely be replaced excessively by big bluestem (present now in small numbers) if nothing is done but burn.

2014 Prescription: Broadcast seed of conservative species. Especially important are little bluestem and prairie dropseed – to head off the big bluestem. One place to sow seed of conservative species is the denser early goldenrod areas. These areas are ready.

2018 Comment: We do some of this, but not enough. We haven't sufficiently remembered this good advice at seed-gathering and seed-mixing time. We need to map opportunity areas more carefully this summer, plant some and hold back some as controls, and monitor the results. We are putting the needed mapping and seeds goals on our 2018 summer and fall priorities calendars.



Case 1A: close-up of a different part of area 1

Patches like the one shown above strike me as receptive to our most-prized conservative seed. There is currently little aggressive tall grass here. The commonest plants shown (early goldenrod, black-eyed Susan, fleabane) are among the quickest to move out of the way for quality species. Sow such classy species as cream false indigo, Leiberg’s panic grass, white and purple prairie clovers, prairie dropseed, alumroot, shooting star, prairie gentian, yellow stargrass, prairie cinquefoil, etc.

However, if you look closely at the photo above, you'll see quite a bit of gray dogwood and grape. Shrubs and vines may be holding this area back, especially if it doesn't get burned frequently. Woody plant shade may be progressively killing off most seedlings in most areas until the next burn - at which time the whole process starts over with more fleabane etc. Perhaps we may want to laboriously cut and herbicide those prairie-killing shrubs. Or perhaps you we to schedule this plot for annual burns until a more competitive herb flora wins out. 

2018 Comment: We've watched this area and are more impressed than ever that "burn-off-and-regrow" shrub dynamics are ruling this area. Is that a good or bad? Certainly shrub dynamics are a component of the savanna dynamic. But are we missing half the species here that once made up that dynamic? Some say the principal shrubs were hazel and oak. Perhaps the grasses and forks that grew with them in this context aren't here now. And if so, is this now just a "retarded" weedy area that's stuck? We should install a transect of permanent plots and monitor plants here over time, to see if this area is changing, and how. Then we'll be better equipped to decide whether some change in protocols might improve it.

Case 1B: close-up area 2

This patch shows quite a bit of young big bluestem, dense patches of mountain mint, young ash trees, and dogwood shrubs. A patch like this may be less prime for conservative seed. Given how little seed we have of the high conservatives, we might want to seed this area sparingly. Perhaps it’s a place to add somewhat aggressive species like rattlesnake master, prairie dock, and compass plant – to increase the diversity of niches that the high conservatives will use to gradually become established from better areas nearby over the decades.

2018 Comment: Yeah, fine, 2014 commentator. But we really don't know the answer unless we monitor with permanent plots. Tom Vanderpoel assures us that prairie clover and shooting star will help break down dense big bluestem areas over time. Yes, we've seen that too. We've also seen areas where the bluestem resists other species for, it seems, decades. We would benefit from more permanent monitoring plots in seeded areas of dense big bluestem, mountain mint, tall goldenrod, and other resistant areas, to see what species might do best there. 

Case 2

Here two high conservatives dominate (purple prairie clover and prairie dropseed).  Early goldenrod (which was dominant here years ago) has retreated to the frequency you might expect in stable, high-quality grassland. Although we see a little rattlesnake master, compass plant, and rough blazing star – the
overall diversity seems low. It might not work so well to sow the high conservatives of mid-summer here; the competition could be tough to overcome. Perhaps this is a place to sow spring species such as prairie betony, shooting star, and cream false indigo, which might then open up more niches.

On the other hand, this area is currently a great seed source for dropseed and prairie clover, so perhaps there’s no need to do much here in the short term. The best next step could be a variety of little inter-seeding experiments. First, find out which species will compete against these conservatives – before investing a lot of seed in an area, which might be slow to accept it.

2018 Comment: Ahh, yes. More experiments. Good ideas. So many plants and plots, and so little time.

Case 3
Two big questions here:
First, what do we do with the new planting shown below? It has good wildflower diversity but is weak on grass (and thus, unstable). As we study the vegetation that's emerging from the first seedings here, it’s hard to know whether this plot wants to be more mesic or wet-mesic overall. we’re thinking that we should especially sow dropseed and little bluestem in the drier parts – and switch grass and Dudley’s rush in the wetter parts. (At Somme, Dudley's rush seems especially common in many of the highest quality wet-mesic areas and is an especially "works-well-with-others" plant, that many conservative and endangered species thrive in when their seeds are broadcast.)
But, second, perhaps the biggest question here is what to do with all those trash trees in the background. This whole area was so dense with buckthorn that essentially no grasses or wildflowers survived. But in the foreground area, a grassy turf survived with only scattered invading trees, and when we cleared them, an on-the-way-to-quality seems to have come back. But under the large numbers of ash, cherry, elm, and box elder trees in the background, the quality is still poor. Strategically, it would take too big a big chunk of our volunteer time to cut and burn them. But there’s now no sensible community to try to restore on the former prairie or savanna land underneath them. So our short-term strategy has been to plant natural species that may keep out the invasives and then wait until we have more time or a better answer. If you look closely, you may be able to see brown leaves on some of the trees to the right. That’s where fire singed some of the branches. Maybe fire will do most of our work for us here, over time, while we invest our resources on other areas where the prescriptions are clearer.
2018 Comment: since 2014 we've cut a few big basswoods and box elders out of that wooded area and spread a bit more "Intermediate" light-level seed. Mostly we've ignored the area except for being happy that the burns have carried through at least some of it. Our impression is that vegetation diversity and conservatism is improving. But we have no monitoring transects here. It continues not to seem like a big priority, for now.

Case 4
            The above patch of scarlet oak savanna seemed to be getting increasing diversity and quality – until recently.
            Around the tree on the right, notice wild quinine, butterfly weed, ox-eye sunflower, big bluestem, wild bergamot, rattlesnake master, and others.
            Then woodland sunflower (Helianthus strumosus or perhaps hirsutus) started wiping out much of that diversity. Perhaps this is a temporary stage, and diversity will come back? Or perhaps this sunflower is helpfully erasing species that aren’t so well adapted here, which will then be replaced by better-adapted species, if we broadcast their seed.
        
2018 Comment: In many areas, depauperate patches of woodland sunflower are spreading. It seems worth our time to monitor these areas to get to understand them better – and experiment by inter-seeding likely associates, if we can identify good candidates. (Check out lists of associates. The old Swink and Wilhelm was little help, but the new "The Flora of the Chicago Region" by Wilhelm and Rericha seems to have a lot more to study.)
           
Case 5
Diagnosis: About half the trees in the center isolated grove shown above are dead. Some died from fire and others from Dutch elm or Emerald ash borer diseases. The few oaks are fine. Because we hadn’t had time to focus on it, we’ve left this dying grove to “nature.”  Of course, “nature” isn’t happening here, and the result is an increasingly unsustainable weedy and brushy mess. It will soon be another buckthorn monstrosity if we let current processes continue.
Possible Prescriptions:
            We might plant some of our precious mixes of rare grasses and wildflowers around the edge. One mix is designed for the "Intermediate" semi-shade of the edge. A "Woods" mix might compete well in the darker shade of the interior). That could help keep the buckthorn at bay, but it could also be a waste of seed and effort. Throwing rare seed into nasty buckthorn re-sprouts is a recipe for failure. Also, the Intermediate species that would grow there in the short term would not be adapted to the less shady conditions that are coming – as these mostly non-oak trees continue to die from disease and fire. Why waste rare seed that would have more payback elsewhere?
            Perhaps we could broadcast the seed of some of the easier-to-get semi-shade herb species in the shadier, inner, non-buckthorn areas. We'd hope that those species would seal the wound and ward off the brush? Perhaps. Or we could plant natural shrub-copse species in hopes to build another native shrub island that we could experiment with (much appreciated by the significant bird species that nest at Somme).
            Or we could short-circuit the misery and cut the out-of-place trees this winter. That would seem easiest. We could then just plant the open savanna/prairie mix (as in the foreground here), which would then be easily sustainable with little added effort beyond regular burns. But we’re trying to restore the natural savanna here, and we already have more than enough of the “prairie” component.
            We could plant hazelnuts and bur oak acorns and protect them from voles, rabbits, deer and fire in the early years. Perhaps some of the box elders and basswoods can for the next 15 or 20 years provide the amount of shade that oak and hazel will someday provide, and the community can transition gradually from non-oak to oak. This challenging area still needs a lot of observation, experimentation, and thought.

2018 Comment: So here's what we've actually done. Nothing in the denser, interior parts. Discovered many possible components of a good shrub thicket around the edge (hazel, pussy willow, black haw, nanny berry, silky and gray dogwoods, bur and scarlet oak). We've cut back some of the dense buckthorn edge that was overwhelming these areas. We've caged one hazel from the deer. We cut one tall patch of buckthorn and planted plugs of two-year-old wild plum, ninebark, and indigo bush inside a large cage. In one wet edge, we cut the buckthorn and planted wet prairie seeds. But 90% of this mess is like it was in 2014. We progress. We learn. We hope.

Final 2018 Comment: This is how the Somme experiment works: We prioritize as best we can and keep trying to do what seems strategic. It's like that old juggler's trick of keeping a lot of plates spinning, and we run back and give a bit more attention to what seems to need it – except that, when we get some area or aspect right, it just keeps succeeding forever, as the world turns. And we stewards seem to be happier all the time as, more and more, rare bits of ecosystem thrive richly on their own. Year round, we walk through and notice new successes and opportunities. We smile inside and thank our lucky stars for the opportunity to do this wonderful work.

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... finally as promised ...

a longer note on ecological conservatives

In many ways, the main and most challenging goal of ecosystem restoration is to restore and maintain plentiful conservatives. If such plants and animals are diverse and common, all the others will be intermixed with them, and we will have achieved ecosystem conservation. Monitoring and analyzing the results according to floristic and animal quality is an important part of any conservation project or program.

In the most commonly used Floristic Quality Assessment system, conservativeness is ranked on a scale of 0 to 10, with 10 being the highest. Examples of Chicago-region plants in the 0 range include ragweed, annual fleabane, and common milkweed. Typical alien weeds like dandelion would also be given a zero rating if these ratings weren’t reserved for native species.

Examples in the 9 and 10 range include prairie dropseed, white prairie clover, fringed gentian, prairie gentian, cream false indigo, prairie lily, Leiberg’s panic grass, prairie cinquefoil, prairie sundrops, heart-leaved Alexanders, and the prairie white-fringed orchid.

Conservative animals may or may not require conservative plants. But the ecosystem is less without them. Examples of conservative butterflies found by Ron Panzer to require conservative vegetation include the regal fritillary, Aphrodite, and the Edwards hairstreak. Birds of conservation concern may live for a time in large pastures of alien grasses. But they’ll live sustainably in large high-quality prairies.

Introductions to conservativeness and the Floristic Quality Index are at
and
and


Note to readers: We always appreciate questions and comments. Thanks.

5 comments:

Anonymous said...

Stephen, This is another great blog post. First off I think Pedicularis canadensis would be a great plant to seed into areas where competitive grasses are beginning to get established or have begun to out compete forbs. The volunteers at Nachusa have mentioned their successes frequently with P. canadensis. In areas where Cornus racemosa is present I would suggest sowing seeds of plants that do equally well in sun or shade. Plants that survive the transition from open conditions to a canopy of Cornus racemosa and back include at least Maianthemum stellatum and one of the Triosteums. I’m sure there are more, but I cannot remember them at the moment. If I were to give you one criticism, it would be that you need to mention the spring growing graminoides, like many sedges, when you speak of your mixes. Finally, for the island surrounded by dead trees I would plant species that are found just as frequently in prairies as in open woodlands like Elymus canadensis and Zizia aurea. However, the best course for the island of trees really depends on what you envision for the area.
Sincerely,
James

Daniel said...

Stephen,

A truly educational and thought-provoking post. Some thoughts:

Case 1B: Is it safe to say that areas of non-conservative grasses (big bluestem, switchgrass, cord grass, etc.), young weedy trees, and shrubs are not good candidates for seed because of the shade that they cast? Or is the fact that many prairie grasses have massive underground networks of roots that can soak up water and nutrients too much for a tiny seed hoping to germinate?

Case 2: From a restoration standpoint, is it better to strive for a stable, conservative community or a dynamic, mixed one? I imagine that a dynamic, mixed community would always hold more potential to be attacked by invasives, but it seems as though you suggest that creating niches for conservatives is the most important goal for ecosystem restoration.

Case 3: Why do grasses signal stability in a plant community?

Why is there no "sensible community" to try to restore under the trash trees? Aren't there other areas of Somme that started out at deserts under a buckthorn canopy? Isn't there a possibility there is a native seed bank lying there in the soil?

Case 4: The woodland sunflower invasion you're experiencing highlights, in my opinion, the hardest part of being a steward. We all know that the ecosystem needs our help to thrive. When does a steward decide that an invasion from a native plant crosses the line from a "natural occurrence" to a "serious threat" and when does that warrant human intervention? Similar to the parasitic Dodder you have at Somme, when does a steward decide that a plant is or is not providing a natural/needed disturbance?

I know most of these questions do not have a single answer. The challenge is to adapt to whatever site you are working on and make decisions that will work best there. Thanks again for a fascinating look at what goes through a steward's mind on a daily basis. It makes what you all do even more admirable.

Stephen Packard said...

Daniel, thanks for the perceptive and helpful questions. I'll respond, but first I should mention that your good detail reminds me of the limitations of this medium. Who'll have the time to read deep into so many questions? There must be better ways.
As to1B, I don't know the mechanism(s), but I do know that the tiny seeds of prairie betony and shooting star will establish well in dense big bluestem, but the bigger seeds of prairie dropseed seem not to do so. My experience suggests to me that many of the twenty or so conservatives I'll plant will do better (establish in larger numbers) in the more complex turf of smaller species. Perhaps dense shade in summer is the bigger problem (which is avoided by spring ephemerals). Big grasses, shrubs and trees may kill seedlings that need to get sun all summer long. On the other hand, I've had good luck seeding prairie clover into dense big bluestem. Lots of study and experiment are needed here. Possibly many people have done it but haven't shared their results.
Case 2: I believe that a community with plentiful conservatives is both stable (in that it somewhat resists brush and invasive species) as well as dynamic (with many species constantly replacing each other).
Case 3. One reason why grasses promote stability is that they assure good fires. Diverse grasses provide diverse niches for the establishment of diverse species.
There's little native seedbank in most prairie and woodland situation (but there is in wetlands).
There's probably no "sensible" community under box elder etc. because without prairie grasses or oak leaves it probably won't burn easily. The only likely fires would be extreme fires under extreme conditions, after which the ecosystems would start over. Somme doesn't have the species for that dynamic.
Case 4. The problem with woodland sunflower is that it seems to kill off most of the competition. Perhaps that's part of a natural process that gets to diversity. But perhaps it becomes a destructive imbalance that harms diversity in the "intensive care" condition that Somme is in. Perhaps, for example, we should try scything woodland sunflower in some areas a few times and see if it then become a part of a diverse community. Or perhaps my current thinking on this is too short-sighted. Many experiments are worth while.
Daniel, thanks again for the good thoughts.

Pat said...

Thanks for this. Wonderful. I offer this comment about aggressive native growers and let nature take its course in managing them over the decades. It would seem that little attention is given to the fact that we've lost a great majority of our natural disturbances that would help to keep these guys in check. Great herds of large animals trampling, grazing, fighting, mating, or just plopping down to rest, or die. Large volumes of smaller clawed animals prone to scratch and burrow. The natural order of disturbance is greatly out of order so it would seem people have to step in to put aggressive natives in check.

Anonymous said...

Stephen, The following blog post by Chris Helzer is insightful regarding mechanisms for seedling establishment where there exists competition with a dominant grass. Like you, Mr. Helzer is also studying the ability of species to establish from seed after reducing the competitiveness of a dominating species.

http://prairieecologist.com/2011/03/15/using-defoliation-of-dominant-grasses-to-increase-prairie-plant-diversity/

Sincerely,
James