The Transformed Block Count

by Carl Strang

The developers who built my subdivision, in their wisdom, decided to plant mostly green ashes along the streets. That brilliance has been answered in the form of an insect, the emerald ash borer. This little invasive ash-killer has done a number on my neighborhood. A series of before-and-after shots follows, going around the block route I follow when I do my standard survey of singing insects in the warm months.

Looking north along my street in 2009.

Looking north along my street in 2009.

The same block now.

The same block now.

Turning west in 2009.

Turning west in 2009.

Same view, 2013.

Same view, 2013.

The next block, looking south in 2009.

The next block, looking south in 2009.

And now.

And now.

The final leg, facing east in 2009.

The final leg, facing east in 2009.

Hard to believe it’s the same block today, but it is.

Hard to believe it’s the same block today, but it is.

Most of the tree loss happened over a brief period of time, the second half of summer last year. Ever the opportunist, I made predictions about the response of the three singing insect species common enough for statistical comparisons between this year and last. Greater angle-wings are tree-dwelling katydids, and so I expected their counts to drop. Carolina ground crickets mainly live beneath foundation shrub plantings, so I expected no significant change. Finally, striped ground crickets prefer sun-lit lawns to shade, so I expected their numbers to increase. I was correct on two of the three predictions.

The Carolina ground cricket median count in 2013 was 7, not significantly different from 2012’s median of 5 (Mann-Whitney U-test of the ranks of all the counts led to a z statistic of 2.05, p>0.01). The median count of striped ground crickets in 2013 was 20, that in 2012 was 11. The comparison of ranks produced a statistically significant z value of 3.89 (p<0.01). I was somewhat surprised at the lack of a demonstrable difference for greater angle-wings (z = 1.00, p>0.01). The 2013 median count was 3, less than the 2012 median of 5, but the difference was not as large as one might expect. There were enough surviving trees of other species to sustain a population of the katydids, and also the removal of the nearer trees made more distant angle-wings more audible.

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Bored

by Carl Strang

The emerald ash borer has become a common tree-killer in northeast Illinois. I knew it was likely that, sooner or later, the green ash in my front yard would become infested, and now it has happened. My tree held out longer than most of the ashes in my subdivision, but it was on the decline before the borers came along, and now the symptoms are clear.

The top branches are dying, and the tree is responding by producing a dense growth of lower shoots (only a small part of that bunch of green is the tree’s Virginia creeper vine). This is a typical pattern, as the beetles lay eggs in the top of the tree first.

I haven’t yet seen the diagnostic D-shaped exit holes made by emerging adults of these bark beetles, but one of the lower dying branches had several woodpecker holes which are a further clue.

There were a number of holes just like this one, made by a woodpecker extracting a larva.

So, sometime within the next few months I’ll have to have the ash removed, and I am contemplating what kind of tree to put in its place.

First Garden Flowers

by Carl Strang

 

On April 3 I noticed that the first bloodroot flowers were blooming in my garden.

 

bloodroot-2b

 

This particular bunch is the one growing closest to the south face of my house, and so its soil warms relatively quickly. Others will bloom later. These were the first flowers of the year in my yard from a native species. They were not, however, the first flowers.

 

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That honor always goes to Siberian squills, whose bulbs I planted in several patches a number of years ago. The bloodroot flowers were in a tie with the first daffodils, planted in honor of two friends who passed away in the late 1990’s.

 

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Clearly I am not a purist when it comes to native species. To be sure, my gardens are heavily biased toward native plants (did you spot the redbud stem behind the daffodils?). I will share the different plantings in future posts, but today I want to focus on one point of landscape design. This is not my own idea, but one I learned from the Morton Arboretum’s former lead landscape architect, Tony Tyznik. He emphasized that it’s important to take a wide view, and consider one’s yard in the context of the surrounding neighborhood. My neighborhood is dominated by small yards, each typically a lawn with a green ash tree, some foundation shrubs, and a few flowers which almost entirely are of popular, non-native varieties.

 

My own yard is bigger than average because it is on a corner, and it has more trees than the others, 3 silver maples in addition to the ash. The extra trees allow me to minimize my lawn through the expansion of flowerbeds beneath the trees’ canopies. However, a thin strip of lawn remains to flow with those on either side (another Tyznik principle is to regard the lawn as the frame, not as the picture; a picture without a frame would be as unaesthetic as the typical suburban emphasis on the frame). Also, especially around the edges, I have scattered non-native annuals and perennials that reflect the popular choices of my neighbors. Behind those eye-catchers, there is a much larger area nearly pure in native plants. Despite the relatively low quality of my narrow lawn, I get frequent compliments from the neighbors: the small compromise of a few non-native flowers produces harmony in more than just the visual.

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