Environment
4:09 pm
Thu June 28, 2012

Sizzling Temperatures and No Rain Stress Fields and Streams

Wisconsin residents will be looking for relief from blistering heat over the next couple of days.

Forecasters say temperatures could reach the “triple digits”.

WUWM Environmental Reporter Susan Bence looked into a couple of “non human” ecosystems to see how they might cope with this rough patch of weather.

UW Extension expert says corn and soybeans can hold on a little bit longer, but rain is critical to a successful crop.
UW Extension expert says corn and soybeans can hold on a little bit longer, but rain is critical to a successful crop.

Bill Bland is fretting about the fate of fields dotted with this season’s crops.

“We’ve just been watching the evolving dry situation here in the state,” Bland says.

That’s his job as agricultural climatologist with the University of Wisconsin Extension.

“Earlier we were worried that we’d see the northwest part of the state again go into drought as it has a few times in the last decade; they’re plenty wet up there now,” Bland says.

This time around, Bland says southeastern Wisconsin is the agricultural worry zone.

“The southeastern 10 counties roughly where you are, even stream flows have started to be affected down there,” Bland says.

Despite the parched conditions, Bland says, crops in the fields can hang on a little bit longer.

That’s because two agricultural staples – soybeans and corn – have not yet reached the critical pollination stage.

Bland describes soybeans as “flexible” “They flower over a four week period,” Bland says.

But corn is a different story.

“As they come into their flowering period, their pollination period; there’s only about a two week window there, where that can happen and if the plants are really water stressed you can have a failure to set that seed,” Bland says.

Bland says farmers are counting on a real soaker during the next couple of weeks.

“We’ve had other years where we’ve had a very dry June and then subsequent rains allowed a record crop of corn and soy beans. bill 5 If we can start to get some rain in the next two weeks, .it’s imaginable that we’ll be fine,” Bland says.

DNR supervisor Scot Stewart would like to be able to say the same about fish that populate rivers and lakes in southern Wisconsin.

But, even before this week’s high temperature alert, a lack of rain coupled with warm weather earlier this month resulted in several fish kills.

Lake Sinissippi and a stretch of the Rock River - both in Dodge County – suffered the biggest hits.

Stewart says, when temperatures sizzle, fish sometimes die.

“Warm water is less able to hold as much oxygen; then if you couple that with a lot of vegetation in the water plus maybe some algae on top of that; the plants will respire at night and take up the oxygen and produce carbon dioxide and that’ll sometimes result in oxygen levels that are low enough that the levels are lethal to fish,” Stewart says.

Yet the biologist says aquatic ecosystems are remarkably resilient.

“Nature never stays the same. You might go through a period of time where bluegills may dominate as the panfish species; then through another set of years where cropies may dominate and summer kill may set the stage where you reshuffle the deck a little more quickly that might have occurred if you were just waiting for a species to get old and die off,” Stewart says.

Stewart says he marvels at ecosystems’ ability to rebound the assaults of weather extremes.

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