Forb Profusion

The reconstruction of Lily's Prairie has been an interesting experiment for us over the years.  When we began to focus energy on converting the old hayfield into a dry-mesic prairie back in 2008, we decided to try and introduce native prairie forbs into the existing grass matrix without the ruthless use of herbicides.  However, after four years of burning and overseeding the old hayfield with native species, it was apparent that the Smooth Brome (Bromus inermis) monoculture was unwilling to cede its dominance to the native species we were stewarding for.  Three years ago, we began to employ a strategy of late-spring annual burning to reduce to the vigor of the cool-season, early growing Bromus inermis.  The strategy appeared to be working to some degree, because the fires would top-kill the early growing grass, which had already spent a large amount of energy growing up to that point.  The early fires would also allow sunlight to hit the surface of the ground which helped to stimulate the growth and germination of native prairie forbs throughout the prairie.

Late spring burns from previous years helped to reduce the dominance
of Bromus inermis in the Lily's Prairie reconstruction unit

This spring, the polar vortex lingered much longer into the spring than we had anticipated it would. As a result of the late spring, we were forced to conduct an early season burn on Lily's Prairie due to the time contraints from my trip home (April 4-7th, 2014).  Our worry was that the early burn would reset our previous efforts to suppress the Bromus inermis in Lily's Prairie, because the cool season grass had not begun to grow at that point, and the early season burn would only help stimulate its growth.  By stimulating the Bromus inermis, we thought that it would cause the native forbs that have been developing in the prairie to be outcompeted and not flower, set seed, etc.  However, the results have been much different than we had anticipated...

Yellow Coneflower (Ratibida pinnata), Black-Eyed Susans (Rudbeckia hirta), and various other
non-flowering forbs are developing nicely this year after the early season burn.

My guess is that the late-season burns that we have been conducting has helped suppress the growth of Bromus inermis over the past few years.  Additionally, it appears that the native forbs have been in the development stage the whole time, and by allowing them to start early this year (due to the early season burn), they were able to tap into more energy reserves and flower at a more prolific rate.  Whatever the case, the prairie appears to be as healthy as ever.  It will be interesting to see how it continues to develop over the rest of the growing season.

You Can't Tell A Book By Its Cover

 by Jim Lloyd

I can’t separate my interest in historical preservation with my interest in natural history.  I have long been fascinated by the huge trees that line many of our “less remodeled” roadways.  When European settlers came to this part of Michigan (primarily from upstate New York) beginning in the 1830s, Oakland County greeted them with a diverse mix of oak/hickory forests intermixed with modest open areas of native tallgrass prairie now known as “oak openings”.  Also there were numerous lakes and wetlands that had their own wetland complex vegetations.  In less than 100 years the settlers had cut down and logged nearly every tree in the state. Up until the 1960s agriculture was king and the landscape was largely devoid of any trees. After that agriculture was replaced with land speculation which allowed many of the forests in our community to regenerate nicely. Many oak species have a life expectancy of at least 400 years, so we can be quite sure that there are but few survivors.

Today most of our oldest trees line our roadways, many of which our European ancestors laid out on surveyed section lines. But there is the occasional roadway that was originally a Native American Indian trail. These can be spotted as roads that do not adhere to the section line grid. In as much as I gasp when I see one of these trees cut down (remember that Oakland County was named after the magnificent oaks that the settlers found), at the same time I am fascinated to discover the age of the tree. Fortunately the modern, huge professional chain saws that it takes to cut one of these beasts are usually well maintained and leave a pretty smooth cut that lets me closely inspect the growth rings.

In December 2013 one of these trees was removed on White Lake Road (which originally was the Shiawassee Trail) in White Lake Township.  I rushed over there in bitter cold weather to get a peek at the trunk rings that would allow me to document the age of this tree. This tree had a irregularly shaped trunk section indicative of a tree that had grown in the open much of its life and had huge low branches. I measured an approximate diameter of 60 inches and an age of 170 years. Many of the growth rings in this tree were quite thick, typical of a tree that grew in the open and never had to compete for sunlight or nutrients.

   

    

Two years prior, I documented another Oak tree that had blown down in a very wet site in a very old closed canopy forest. This tree measured only 24 inches in diameter with a very round trunk section and 30 feet of clear wood to the lowest branch which is typical for trees grown in a forest environment where they must compete for sunlight  by reaching upward relentlessly. The rings of this tree were extremely tight (24 per inch in the oldest layers) providing a visual demonstration of why old growth lumber is so strong, stable, dense and highly prized. Young plantation grown trees produce lumber that is much different in appearance. Although this tree was only 24 inches in diameter it was 146 years old.

Even though these two trees were approximately the same age, they were dramatically different sizes due to their different site conditions. Even the larger at 170 years was well short of the life expectancy of an oak tree and the trunk had only slight distress. It also was only a small seedling in 1843 when the first European settlers were cutting down its ancestors to build their homes and barns, burn for fuel and clear the land for the European version of agriculture. I will never see an original native oak tree because there aren’t any.  Such is the legacy of man.

2013 in Review

I thought it would be good to highlight a few things that happened in 2013, which happened to be an interesting and productive year.  A lot of moisture fell this summer, and plant growth was as good as ever.  Unfortunately/fortunately it was a busy year and I only got a chance to go home once.  As a result, I've been lagging with updates regarding our progress on restoration projects.

In the past, our focus has been primarily on reconstructing/converting overgrown pasture and hayfields to native prairie through burning and overseeding with native species.  This year however we decided to spend a little more time working on our forest ecosystems at Black Cherry Hollow (BCH), which includes all of the land south of White Lake Road.  BCH is primarily forested (and has an abundance of Black Cherry trees) due to years of fire suppression.  Historically, this area was a combination of Oak Openings and Dry-Mesic Southern Forest in the uplands, with Rich Tamarack Swamp and/or Southern Hardwood Swamp in the lowlands (MNFI Natural Communities).

Today, the uplands retain their mature Oak and Hickory canopy in most areas.  However, due to years of fire suppression (fire was a common natural disturbance in this type of forest historically), a dense understory of Red Maple, American Elm, and White Ash has developed in the forest.  With the presence of the Emerald Ash Borer and Dutch Elm Disease pathogen, Red Maple has assumed dominance in the understory and is threatening to convert the forest in the long-term.  The dense shade caused by the abundance of Red Maple in the understory has limited the amount of oak seedlings that are able to grow because oak seedlings need more light to grow and compete with other species.  Historically, the fires that swept through the forest on a regular basis thinned out competing tree species, including Red Maple, and allowed oaks to retain dominance generation after generation.

The lowlands which were historically thought to be Rich Tamarack Swamp (MNFI Presettlement Vegetation Maps), are now a mixture of Emergent Marsh and Southern Shrub-Carr.  This conversion of wetland communities was caused by the construction of Highland Hills Drive which dammed the downstream end of the wetland, causing significant flooding over the past 50+ years.

My trip home (April 18-22) was marked by nice dry weather, which allowed us to work hard.  We were able to do some understory thinning of Red Maple, Elm and Ash in our forests, and conduct prescribed burns at both BCH and Pinefield.  Here are some pics of our work: