Forest Preserve District of Cook County, Illinois
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Nature Bulletin No. 71   June 22, 1946
Forest Preserve District of Cook County
Clayton F. Smith, President
Robert Mann, Superintendent of Conservation

This is a lush year. The grass and weeds grew tall and thick much earlier than at any time in the past decade. Unless we have a long hot dry spell, we should have a bumper crop of wild blackberries, raspberries and strawberries. The tree leaves are exceptionally large for this time of year. They appear to be longer, broader and thicker.

The number of leaves per tree is about the same as in other years since spring weather affects the rate of growth but not the number of leaves . This is because most of them, with the exception of those on the terminal twigs of branches and those on fast growing sprouts, develop from buts formed the year before.

1945 was another lush year. In both years the spring weather followed the same abnormal pattern. Vegetation got a fast early start. February averaged 4 degrees warmer than normal In both years. March averaged 14 degrees warmer in 1945 and 13 degrees warmer in 1946, April was 3 degrees and 4 degrees warmer, respectively. May was a little cooler than normal both years.

In 1945, February and March were rather dry but April and May were very wet, with an excess of almost 6 inches of rainfall in the latter two months. In 1946, the precipitation in February was normal, March had a surplus of one inch, April a deficiency of slightly more than one inch, and May was normal.

The foresters say that unusually heavy leaf growth is also stimulated by a preponderance of cool cloudy days. So far, however, the woods and thickets are unusually dense and dark underneath although, seen against the sun. the leaves still have the pale translucence of early spring. From below the effect is much as if one were standing beneath a rich green skylight.

Take a walk in the woods.

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