Saturday, June 30, 2007

Cottonwoods


Every summer, starting in mid-June in Missouri, cottonwoods begin dispersing their small, non-descript seeds. When the wind blows, the air fills with the seed's fluffy white plant down which often carpets the ground and clogs up outdoor air conditioning units.

Found in floodplains and along rivers, streams and lakes throughout America, cottonwoods play an important role in bird nesting behavior. Rose-breasted and evening grosbeaks feed on the seeds, but many more bird species use the plant down for lining their nests. Farmers in southeast Missouri have converted some their traditional row crops into cottonwood plantations for the pulpwood industry. These fast growing plantations have provided some habitat benefits not found in soybean crops, but a recent study conducted by the pulpwood company has revealed that while several species of breeding birds use individual cottonwoods for nesting, most species prefer nesting in virgin forest than in monoculture plantations. A handful of indigo buntings used a nearby cottonwood plantation for nesting last season, which was a handful more than nested in the previously planted soybean crops.

Cottonwoods colonize recently drained lands. They are fast growing trees, often achieving heights of 50 feet in 6 years. They are commonly used in streambank restoration projects because, like their family member, the willow tree, 3 ft. long sections of cottonwoods can be stuck in moist soils where they will grow into mighty trees within a few years. Along the Mississippi River floodplain in areas altered by levee systems or affected by natural changes in the river's course, cottonwoods grow in thick stands, shading out other understory and canopy plants. At the confluence of the Missouri and Mississippi Rivers, efforts are underway to return a cottonwood forest to its presettlement marsh and riverbank forest. Thick stands of cottonwoods may have been present in small numbers along the river's batture 100 years ago, but with the alterations to the river and its floodplain, the original, biologically diverse riverfront forests and marshes have all but disappeared, having been replaced by cottonwood stands. The restoration project is a difficult one for land managers: while dynamic flood cycles have returned to the area, in order for the cottonwood forest to die, it must be inundated with water for several years during the growing season.

With an average life span of 75-100 years, cottonwoods, like many other early successional species like persimmon and black oaks, are generally short lived trees. But every season, about this time, thousands of seeds are produced. Attatched to each floating bit of plant down is a seed, ready to find a moist area to set down a root.

1 comment:

Farm said...

I read your entire blog today not even sure how i found it.
I'm a farmer girl (family owned.. they do exist) in semo in one of the little towns you mention often.
Would love to talk to you. I mean OMG!! You saw a prairie chicken!!
I'm jealous.....