Tuesday, July 11, 2017

What's Up in Mid July

We invite you to take a walk virtually (and listen in on our field trip discussions last weekend). Or bring these notes with you as you hike the trail.

To make it easier to find the numbered focal points if you bring this post into the field, the points are forks in the narrow footpaths. 

The Somme preserves harbor 501 native plant species. These include 17 on the Endangered or Threatened lists (ten present when we started and seven restored from other remnants) and many other uncommon or rare plants and animals. But more important that the individual species, this area and its stewards conserve and restore a rare ecosystem.

Somme Prairie Grove is one of the first places on the planet where an attempt is under way to restore remnants of a nearly vanished natural community – the black-soil bur oak savanna

A major challenge at Somme (and so many natural areas) is too many deer.
These beautiful animals are a natural and valuable part of the ecosystem.
But excessive numbers can badly damage the habitat for many other species.
We walk today entirely in the area burned this spring. This is much richer, more flowery, and more attractive to animals than unburned areas. Deer like the nutritious shoots where the fire enriched the soil. At one time, the mountain lions, wolves, and Native Americans knew to hunt there too. Previously, lightning (and, in the last few thousand years, indigenous people) ignited the fires which shaped these species and this type of community for about five million years. Now, things have changed; we have changed them; and we have to learn to be the stewards.
Michigan lily can be found in woods, wetlands, savanna, or prairie. In times of lower deer populations, 
a single stem may have ten or twenty blooms. This year most here had just one - a barometer of deer numbers. 

Here we start to see a great diversity of flowers and grasses. Indeed, we’re on the edge of a big patch of the unusual shrub, New Jersey tea, mixed with blooming butterfly-weed, wild quinine, leadplant, rattlesnake master, flowering spurge, and compass plant.

This tea has history. It got the name “revolutionary tea” when adopted by the patriots after they threw the British tea into Boston Harbor.  
 New Jersey tea 
Entomologist Dr. Ron Panzer says that New Jersey tea is a highly valuable nectar plant for many bee and butterfly species. 
Purple prairie clover (short pink-purple). Lead plant (long purple spikes). Rattlesnake master (blue-white balls).
Early goldenrod. (And the deeply cut leaves are compass plant.)
As we walk to the next point, we’ll pass through high quality grassland with an abundance of smooth phlox, prairie dropseed, and little bluestem. Then we enter a shrub patch we call “The Bird Thicket” – which has been a special focus of restoration in recent years. Birds that are regularly seen here during the nesting season include ruby-throated hummingbird, orchard oriole, kingbird, brown thrasher, yellow warbler, and indigo bunting.  
After a week, many of today's flowers will be replaced by maturing seeds.
But by then, other species will be in bloom. 
Bur oaks here were not reproducing, in part because deer ate them down to foot-tall shrubs. Exclusion cages (as above) protected saplings from the deer. But fire remained a challenge (note leafless outer limbs from this spring's fire).
With help, these classic savanna trees gradually surmount deer and fire pressures and become maturing bur oaks.
On the next section of the trail you'll start to see purple prairie clover (typical of fine prairies) joined by white prairie clover (even more typical of even finer prairies).
White prairie clover may seem like just another color form of its cousin purple.
But the two species are ecologically very different. 
In the early years of the restoration of Somme, we found very little white prairie-clover seed to broadcast, and the little we found didn’t seem to do very well. But in recent years the white seems to be increasing at a rapid pace – perhaps because it competes better as the restoration has continued to improve in quality.

A little further down the trail, look for a large patch of Canada milk vetch. 
Most species in these most open areas are typical prairie species. But note many charred young trunks as you walk south. Bur and scarlet oaks and hazelnut shrubs got cooked in last spring's controlled burn. Notice that they're all putting up new shoots from the base. They've been doing this every couple of years for decades. Sooner or later, some of the bur oaks will become trees that can withstand fire. These species are typical of savanna rather than prairie. Other common species here that suggest savanna rather than prairie include cream gentian, purple milkweed, Maryland snakeroot, carrion-flower, and purple vetch.   

As we walk toward point six, we look out over the ancient floodplain of the West Fork of the North Branch of the Chicago River. From here, long ago, you might have seen explorers or Native Americans paddling by in canoes. Today you see the Metra tracks that run alongside the river.
Butterfly weed with prairie coreopsis, lead plant, rattlesnake master, and black-eyed Susan.
As the trail starts to rise, it becomes more obvious that we're on the edge of the moraine. Savannas were especially common on the moraines, and many plants near this point may be more typical of savannas. These include Seneca snakeroot, grove sandwort, wild licorice, savanna blazing star, and rue anemone. None of these are now in bloom, but you may recognize the diversity east of here if you can identify plants by their leaves. 

Daisy fleabane (first slide in this post), dodder (below), and certain other species indicate opportunities. The fleabane is a "weed"(see http://woodsandprairie.blogspot.com/2014/10/weed-alien-invasive-malignant.html). Dodder seems to thrive where some "aggressive" species "irrationally exuberant" - perhaps because of some disturbance. For many years, we at Somme and others have spread seed where the presence of such species indicates an opening for diversity.
A golden vine is starting to wrap around this stand of mountain mint. It is dodder - a parasitic morning glory.
Dodder may kill over-abundant plants - thereby promoting healthy diversity.
As we walk to the next point, notice starry campion and wide-leaved panic grass in the open area – and then when we enter the woods: long-awned wood grass - an elegant grass with horizontal leaves and spiky seed heads.

Starry Campion
This oak woodland is "Vestal Grove" - the focus of the book “Miracle Under the Oaks” by New York Times science writer William K. Stevens. All the biggest old trees in the grove (indeed in all of Somme Prairie Grove) are bur oaks. This species has the bark and trunk best adapted to withstand hot fires.
In the woods you're likely to see butterflies - like this pearly eye.
We restore them too, as we restore the plants they depend on. 

Few of the woodland wildflowers are in bloom in early July. Starry campion and Michigan lily kick off the summer flora here. But more and more will bloom as the summer progresses. Thanks for visiting. Come back soon.

A more detailed and technical version of this walk can be found at:

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