A familiar sight around the Midwest is a clump of trees here and there, shelter-belts planted to break the wind as it blows across large open expanses of field and pasture. Now researchers at Iowa State University are designing a new kind of planting design, to slow down water, not wind.
Ag meteorologist Gene Takle says the international Food and Agriculture Organization heard about his research and called to ask him to add some studies of how living "bio-shields" could stall the damaging force of tidal waves and hurricanes. It’s been a natural process for protecting villages against strong tidal waves. Takle says we don’t think about it here in the Midwest, but in many tropical countries, coastal forests serve a valuable function.
Takle says big tropical storms leave the land vulnerable to damage beyond what the wind and water do during the hurricane. "It exposes the shoreline much more to the damaging effect of these storms and waves," he says. "So a bio-shield or a tropical forest is one way to suppress the damage of these types of events." In the Midwest we may use pine, oak or poplar for windbreak plantings, and Takle says local trees are also used in the tropical bio-shields.
There are 52 species of mangrove growing along those shores and they’re a particularly good choice, a they’ll actually grow out into the water. An occasional flooding of fresh water will let them flourish in salt water, so they’d be a good choice for planting on the leading edge. Up to now he’s studied how Midwest shelter-belts can be designed to control soil erosion and direct the drifting of snow from winter storms.
"The same principles apply," Takle says, whether you’re trying to slow the wind so it’ll drop its snow, or slow the wind and water coming onshore to reduce its damage. He says unfortunately, ISU researchers will not be obliged to visit tropical islands to monitor the studies in person.