Natural Communities

All forest is not the same. These trees are part of a unique natural community.

Looking at plants as communities from a design point of view is cool but it’s also cool to look at plants as they fit into natural communities. I’ve often wondered what kind of natural community my garden belonged to before it was timbered, farmed and then developed. I know it was forest but is there more to a forest than one would think? The answer is yes, there is more and I’ve recently discovered a website that explains just such a place known as Rock Creek Park, not more than a mile away from my garden. The website, a collaboration between NatureServe and the Research Learning Alliance of the National Park Service’s National Capital Region, examines 8 different natural communities within Rock Creek Park,  the oldest and largest urban national park in the U.S.

As I read about some of these communities it occurred to me my own garden may have been one of them at one time. It seems natural communities develop over time due to natural and unnatural forces. These forces such as rain, wind, sun, human development among others form small pockets of distinct areas with distinct landforms, soil, plants and animals. And underneath it all is the bedrock, often the main compositional ingredient.

The other day I went walking in Rock Creek Park to see if I could find and see the difference between some of these communities and I have to say while it was a bit of a challenge, I did notice a few.

Mesic Mixed Hardwood Forest can be found on rolling landscapes where the soil is loamy (made mostly of clay, sand and silt with a little organic matter)

The most wide ranging one is the Mesic Mixed Hardwood Forest. It can usually be found on rolling landscapes of the Piedmont and Coastal Plain of Virginia, Maryland, New York and New Jersey. It also has a wide range of vegetation such as American beech, red, white, black and scarlet oak, Christmas fern, sweetgum, red maple, blackgum, flowering dogwood, American holly, pawpaw and mapleleaf viburnum. It has a well-drained and mesic soil. I have a pretty good idea my garden was once part of this community.

A box-elder, part of the Tuliptree Small-Stream Floodplain Forest community.
The rich soil of the Tuliptree Small-Stream Floodplain Forest supports many herbaceous plants such as this pretty ground cover.

A very different community is the Tuliptree Small-Stream Floodplain Forest. It usually lies along floodplains of small streams such as Rock Creek. The rich soil here, made up of sediment that gets carried down the creek from upstream, supports plants like the tuliptree, red maple, box-elder, American sycamore and American hornbeam. Because the soil is often disturbed by flooding and human use, it also can be a haven for non-native plants as well as many other native plants. I heard lots of birds with unique, buzzy noises here. I’m guessing they were smaller warblers and such.

A white oak and mountain laurel in a Oak – Beech / Heath Forest community.

Another community I walked through was the Oak Beech Heath Forest. It usually can be found on steep slopes above streams and rivers where acidic and often rocky soil is perfect for plants such as mountain laurel, American beech, chestnut and white oak as well as blueberry and black huckleberry.

Although it takes a bit of exploring to get the idea, the website has a wealth of information about geology and ecology that I can apply to many things about my garden. In fact, I’ve found I’ve started looking at plants in a new way. Not as plants but as parts of communities, something that may be a big step towards ecological improvement. Not just for me but for all of us.