Hey volunteers! I wanted to let you all know about a cool new thing TLC is doing to keep our stewardship volunteers informed! Throughout the year, we will be writing short articles about the progress TLC has made on certain sites, or about the philosophy behind why we're doing certain activities, or feature some of the work our staff does when not leading volunteer workdays. There are a few articles on  this page on our website, just look for the blue links and click on them to learn about our success at planting prairies or our struggles and achievements with reed canary grass and phragmites. For now, please enjoy this article featuring our thought process on when to leave trees and when to remove them.
Winter 2016: Can there be too many trees?
The natural world around us is changing quickly. When settlers first arrived in McHenry County the landscape was dominated by largely treeless ecosystems of wetlands, prairie and barrens, and about a third of the county was dominated by oak savannas– widely spaced open grown oaks. A very small percent of the county was true woodland with more than 50% canopy cover from trees. Click here for info more on that.
History:
As settlers moved in they plowed up the prairie to plant their crops and used the oak savannas as grazing areas for livestock. Grazing the savannas kept the structure of the widely spaced oaks intact, but in many cases it degraded the ground layer of plants and almost completely wiped out the shrub layer. In 

settlement times hazelnut shrubs were widespread, and were widely documented as the most common shrub in the region. When was the last time you saw a hazelnut in nature? 

Changes in the landscape can easily be detected by looking at aerial photographs. The earliest aerial photos from this county were taken in 1939 at which time it was very easy to spot individual oaks. In the 1980s most of our woodlands began being invaded by invasive brush, and by the 2000s the unmanaged savannas had a completely closed canopy. What happened? Widespread introduction of nonnative plants into home landscapes that become invasive species, lack of fire in our ecosystems, and a complete absence of grazers as part of our native fauna are some factors that are making our natural areas less healthy.

Nonnative shrubs like honeysuckle, buckthorn,  autumn olive, winged burning bush, and others are often times the most numerous plants in our woodlands. Other native species like cherry and box elder are far too numerous because fire would have historically kept their numbers down. Without fire they are free to grow as fast as they can, which is typically faster than the oak trees grow. 
Woodlands are an important ecosystem and are incredibly beautiful, but everything should be in moderation. Read on to see some neat aerial photographs and to find out what TLC is doing with our preserves and to find out how you can help!


Then vs. Now:
These photos show our Yonder Prairie Site in 1939 and again in 2009.

The red outline shows the boundary of part of our Yonder Prairie site, a total of 66 acres. Notice how few trees were present in 1939. I created a layer of blue dots over where those trees were and overlaid it on the 2009 aerial photo. Look at how many trees grew up during that time!
You can go to Rosefarm Road and look at the wooded area in the northwest corner of our property and still see each one of those three trees that were present in 1939. Two massive bur oaks stand tall in a forest of relatively young trees, and farther down is one gnarled and twisted snag of a massive oak that has fallen to a 45 degree angle into some cherry trees.
We all love trees, so why wouldn't it be a good thing that our natural lands have an abundance of trees growing on them?
To answer that question we must think about how much the landscape has changed just in the last 20 years. It would be foolhardy to try and recreate what was present in 1939 since humans have made an irreversible impact on the landscape. There are certain activities that we can do and should do as good land stewards. 


TLC's approach:
We remove every non-native, invasive species and thin out certain native species. Cherry trees (and other native trees that are over-abundant in our woods currently) still provide important ecosystem benefits, but we want them to occur in appropriate numbers that add to habitat value rather than to diminish it. Cherries produce fruit that birds and mammals eat, leaves that are an important food source for caterpillars of over 400 species of butterflies and moths, flowers that offer nectar and pollen for pollinators, and food and shelter for hundreds of species of insects, including mites (yes, mites are important too!)
However, if there are too many trees the canopy cover negatively impacts other species, like red-headed woodpeckers, bluebirds, and barred owls.
Our solution varies from site to site, but in this instance we to cut most of the cherry trees but left some clumps throughout the preserve to have the best of both worlds. Our goal on every site is to maximize diversity and strive to create the landscape that the indigenous animals and plants need to survive.

 


These photos show the progress we’ve made with brush clearing at our Yonder Prairie site from 2009 to 2015. The blue dots are still those oaks that were present in 1939. Our volunteers are still working along the eastern property line where the dense canopy cover still remains. 
In areas where the brush clearing has occurred you can see that the remaining trees closely follow the pattern of where trees were present in 1939, although there are about 10 oaks for every one oak that was present in 1939. Is this good, and 
how do we know we are doing the right thing?
After we conducted our brushing, whooping cranes stopped over on their long migration north- the first time that has been recorded on that site. Animals that need open areas to perform their courtship display, such as woodcocks or common snipes can be heard throughout the preserve on a warm spring night. The deafening calls of frogs, the great abundance of snakes, and the super highways of small mammals let us know that although we don’t have all the answers, we are certainly pointed in the right direction. 

Trees have a special place in the heart of human beings. When we strive to manage our natural areas it is important to remember that we’re trying to do what’s best for nature, and not focus solely on what humans view as pleasing. Sometimes people just simply have to think about a different frame of mind, and instead of focusing on how much we love trees, enjoy the passion of the prairie. Enjoy the openness.
If you would like more information or if you would like to help, come to a volunteer work day! TLC is a small not for profit organization, so almost all of our brush clearing is done with volunteers! 
The Land Conservancy of McHenry County | mgrycan@conservemc.org |
815-337-9502 | www.ConserveMC.org