I headed out with the idea that I was going to walk through the winter mowed fields to check on their growth rates. Then I decided to look for the Blue Grosbeaks and their recently vacated nest. No signs of any nest in what I thought was a likely spot, so I wandered off in the direction the birds had taken to see if I might locate them in another field. Birds displaying blue coloration were not to be found, except for the Blue Jays of course, but I did find a nice bluish flower. The Scaly Blazing Star,
Liatris squarrosa, seem to have synchronized their bloom period this year and are all flowering at once.
This is probably my favorite of the many Blazing Stars. The blooms on squarrosa are spaced far enough apart to allow appreciation of each individual component of the flower heads. I especially like the stiffly pointed bracts that surround the base of the flower head. The whole arrangement looks like a tiny bouquet wrapped in fancy paper.
The plant is rather short and can get hidden by even moderately tall grasses. You can be almost on top of them before you notice the splashes of violet among the grass leaves.
The prairie grasses, adapted to surviving extremely dry conditions, are taking full advantage of the frequent rains. Areas that normally show patches of bare ground are now completely covered by grass.
It’s the Big Bluestem that’s taking over the slopes this year. The density of Big Bluestem in the stand has been increasing steadily over the last 20 years. In a dry year these dry hillsides can grow Big Bluestem that reaches ten feet tall. I’m wondering what kind of height they’ll reach this year.
Years like this really help to boost the organic matter content of the soil. The decaying grass leaves will invigorate the soil biota and the soil will show a slight improvement. I’ve noticed that many prairie wildflowers show increased vigor in the second year following a rainy season. I’m guessing that’s the point at which the nutrients from the decomposing grass become most available.
The flowers are working to keep up with the grass. This Western Sunflower,
Helianthus occidentalis, maintains most of its leaves near the ground, but the flower stalk may reach six feet into the air. These plants took advantage of plentiful sunlight before the grasses started to grow. They’ve just reached the stage where they are beginning to produce the flower stalk.
I found this Monarch caterpillar feeding on a Green Milkweed, Asclepias viridiflora. This milkweed species is smaller and has much less leaf mass than the Common Milkweed. Some of the plants could easily have their leaves stripped by a hungry caterpillar. This particular plant didn’t show any signs of feeding activity other than this one leaf. It’s possible that the caterpillar moved to this plant after stripping the leaves from another nearby milkweed. Leaving one plant to find another can be a risky venture. I wonder if the caterpillars have some way of sensing the best direction to go in search of a new food source.
This is the time of year for the tall grasses to flower. It’s not always easy to see these small flowers and many people walk by without giving them a glance. There’s got to be a flower in order to get a seed and the tall grasses are master seed producers. Flowering of the Big Bluestem, Andropogon gerardii, is now at its peak at Blue Jay Barrens.
I’ve seen a steady increase in Big Bluestem over the past 25 years. When I first began managing the property, Big Bluestem was uncommon and at one point I even wondered if it might be lost from this area. It’s just been in the last five years that I’ve come to view Big Bluestem as a dominant grass in the Blue Jay Barrens landscape.
When you actively manage a property, you expect certain responses to your actions. You can have a general idea of what those responses will be, but it’s hard to predict specifics. I’m wondering if this explosion of Big Bluestem is directly related to my management activities or if it’s a natural next step in the evolution of the ecosystem that’s developing on this site.
In 1994 I began a serious program of clearing to bring sunlight to prairie openings that were in danger of being shaded by invading woody species. I cleared two to three acres each year for the next ten years. I’m puzzled by the fact that time of clearing didn’t seem to influence the rate of Big Bluestem appearance in the fields. If my clearing was the catalyst for an increase in Big Bluestem, the grass should have been found first in those earliest clearings. Instead, the increase occurred in all clearings at about the same time.
Big Bluestem has taken hold in the most bare of the barrens, areas that are not much more than crushed stone over bedrock. These areas are inhospitable enough that woody species never got a chance to grow to block the sunlight. They’ve been open for decades, so why is it just now that Big Bluestem has found them a suitable place to grow? I can make changes and set things on a new course, but this is an ecological system I’m working with and it has an inherent direction that it is trying to take. As a manager, about all I can do is remove obstacles that might hinder its progress and hope the result is something spectacular.
