Fruits of Restoration

by Carl Strang

In earlier posts I have written about the restoration work going on at Mayslake Forest Preserve. Today I want to share some of the positive results that already are visible. The prairie was burned in late March, and as usual looked like a desolate moonscape afterward.

Mayslake burn 4b

This week that same area is green with vigorous growth.

Prairie 19MY 2b

Meanwhile, the slope between the friary and May’s Lake has greened with diverse plants.

Friary hill spring 4b

In places there are abundant oak seedlings, the potential next generation that had no chance beneath the dense buckthorn and honeysuckle brush that was cleared out over the winter. Members of both the white and red oak groups are visible here.

Oak seedlings b

In addition, Virginia waterleaf is flowering in good numbers all along the slope.

Waterleaf 1b

Toward the bottom of the hill some wild geraniums have begun to bloom.

Wild geranium b

Nearby are some Rubus which key out to common dewberry.

Common dewberry b

A red-osier dogwood was one of the woody plants carefully avoided by the brush-clearing crew, and it is flowering.

Red osier dogwood b

Earlier I showed the abundant trout lilies, toothworts, three species of buttercups, dutchman’s breeches, trilliums, violets, wood anemones and so forth. More will follow.

Some Herbivore Generalizations

by Carl Strang

 

Today I want to conclude this little series on leaf-eating insects by sharing a few generalizations and observations.

 

First, when I looked across all the insects and plants of the Maple Grove and Meacham Grove Forest Preserves in the 1980’s, I found that the more abundant a plant’s leaves were in the understories of these forests, the more kinds of damage they had. I take damage types to be an indication of herbivore types, so more abundant resources are exploited by more kinds of consumers.

 

Second, the amount of leaf surface a plant loses to herbivores is related to the length of time its leaves are out. Plants with leaves open for the entire growing season accumulate more loss than plants which are only out in spring, for example. An interesting demonstration of this pattern is that two kinds of plants, Virginia waterleaf and false rue anemone, send up new sets of leaves late in the season, too late for insects to focus on them. It seems likely that this allows the leaves to gather energy, free of consumers and in a time when the canopy is opening up again with leaf fall.

 

False rue anemone, Isopyrum biternatum

False rue anemone, Isopyrum biternatum

 

Third, the different insect species show few indications that they are interacting. Their abundance is kept low enough that they don’t impact one another most years. Also, they often feed on different plant parts, even on different parts of leaves. This may be a result of past competition selecting for this specialization, but nothing in my study addresses that possibility.

 

Finally, there are many patterns in the herbivore population ups and downs. Few are abundant every year. Most have years of high abundance and years of low abundance. One extreme was the ermine moth , which built up over several years to the point where it killed about 90% of its host, then collapsed and could not be found for years at a time. Another example is the day-flying moth Trichodezia, which in some years was seldom to be seen, and in other years up to 5 might be spotted in an hour by someone walking through the forest.

 

I will continue to follow at least the Euonymus and the maple leaf miners, and may go back to gather more information on other component communities of these forests.

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