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 commented on what we'd 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.
- - - - - - - - - - -
... 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.
