Trees dim the light on spring flowers. (Biology).(blocked sun limits growth)(Brief Article)

A quirk of northern forests may shorten the time that wildflowers have in early spring to soak up bright sunlight reaching the forest floor. They harvest light for making seeds this year and for next year's initial phases of growth. All too soon, the trees overhead spread their leaves and block out the sun.

The little red wildflower Trillium erectum takes rising soil temperatures in the Spring as its cue to emerge, according to Marie-Claude Routhier and Line Lapointe of Laval University in Ste-Foy, Canada. The researchers compared trillium patches in three maple forests at increasingly northerly latitudes in Quebec. At all the patches, the plants …