Cardinal flowers, great blue lobelias and sweet black-eyed Susans bedazzle an understory that had been largely dead for decades. |
That big tree in the background is a swamp white oak. The relationship between this oak and the herb layer is key to this ecosystem. |
The amputated limbs aren't just ugly. The flowers in this photo aren't just beautiful. In a sustainable natural system (like what we're trying to restore), this sunny matrix would also support little, reproducing swamp white oaks among the wildflowers. The future of the oaks is tied to the diverse flowers, grasses, and sedges that form the nursery bed of the next generation. In contrast, on bare ground, fast-growing trees like cottonwood or box elder win out. Oaks thrive on challenges. Their thick bark withstands fire. Their large seeds compete in a competitive turf.
Equally important - the diverse plants are interdependent with diverse (now rare) animals.
As you may know, last winter we cut - and next winter we will continue to cut - invading trees out from under the oaks. But that's just the first step. Below, check out a photo of a bit of woods that had its big buckthorns cut in the winter of 2016/17.
What's wrong with this picture? |
Below, you can see an area where the invasive sprouts have been herbicided.
With the buckthorn sprouts gone, this area can be planted with diverse seed this fall. |
If you're not familiar with "sampling a transect" - here's how we do it. We permanently mark a line through the woods. In this case, the line goes from tree, to tree, to easily findable tree. Then we put the sampling hoop beside the tape at the five, ten, fifteen, etc. meter mark. We identify all plant species present and estimate the area covered by each species' leaves. We record both. As you can see, taking the "before" data doesn't take us long.
The line, in this case, starts in an area where the main cutting and herbiciding has already been completed, and then runs through the area shown below:
Here, as in most of Somme Woods, you must fight your way through solid buckthorn. Here no restoration has yet been done. This is a true "before" sample. Here we record a lot of buckthorn.
Our first two "anchor trees" were white oaks. the next tree was a bur oak (above). This mighty giant still has some of its lower limbs - dead but still holding on. For a century, it has not reproduced. When shade builds up, the bur oaks are the first to stop reproducing. Their seedlings require the most light.
We record the circumference of each anchor tree along with the distance and direction from the previous anchor.
Since this is a progress report, two more photos seem needed:
Doll's eyes seeds reaching out of their cage |
Doll's eyes seeds, bagged for action. |
2 comments:
Just beautiful! Great-hearted, visionary community is key to the success of this work.
One note asked about the process of selecting which species to restore - and where? There are many theories and hypotheses on this. I submit that none of them are "right" - in the sense that everyone should follow the same one at every site. Instead, especially given the lack of certainty about the many questions we'd like to have answered as we make those decisions, many and varied approaches should be followed. I also submit that the volunteers and/or professionals responsible for a given restoration site should select an approach or protocol, write it up, record it in some way that others can access it, make sure it has all the approvals it needs - and stick to it. If a variety of approaches and carefully followed, in time we will be able to compare how well they fulfill various conservation values. One approach is to restore all the species that reasonably, likely were at a given site. Then ultimately let them compete it out. Somme has used a version of that approach for 40 years. Specific protocols were developed for the North Branch Restoration Project by FPD and volunteer staff, scientists, and practitioners over the years. They'e incorporated in the NBRP Seed Plan, site plans, and related documents on file with the Forest Preserves, at the Chicago Botanic Garden, and on line. I’ll try to post a summary on this blog when I can.
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