Wednesday, April 6, 2011

The Grass is Green!

Spring green-up has arrived in Chicago! Seemingly overnight the lawns have gone from brown to green…or at least mostly green. In my neighborhood, we had thunderstorms on Sunday night (4/3/11) and the next day I noticed how much greener everything looked. The thunderstorms probably contributed to green-up in a couple of ways; they provided a nice soaking rain and a burst of nitrogen fertilization. Lightning converts the nitrogen gas in the atmosphere to a form plants can absorb. It won’t be long before I need to start up the lawn mower!

Did you know spring green-up is a phenophase transition observable from space? Scientists are using satellite images to assess changes in timing of green-up. Unfortunately, we’ve only been collecting these images since 1972 so we don’t have a long historical record to which we can compare contemporary records. Nevertheless, satellite images are providing g a new tool for those who study phenology that will become even more valuable in years and decades to come.

Kay Havens

(Editor's note: Kay Havens is on travel and asked me to submit this for her.)

1 comment:

  1. We are also seeing a lot of greenup in lawns in the central Rocky Mountains, but since there was not much snow this winter it also varies from place to place depending on much people have been watering! the native prairie is still pretty brown

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