Having watched robins and waxwings feed in our eastern redcedar over the past week, I was interested in "Battling a Green Glacier" discussed in the autumn issue of Living Bird, a publication of the Cornell Ornithology Lab. The article discusses the advance of redcedars into grassland ecosystems of the Great Plains.
Eastern redcedars, common throughout the eastern half of the U.S., are junipers and members of the Cypress Family. Planted on the Great Plains as windbreaks and snow-fences and to beautify the landscape on farms and in towns, they are now spreading into the prairies and ranchlands. Wildfire suppression has augmented their spread which is also mediated by avian dispersal of seeds. Ecologists are alarmed by the loss of habitat for grasslands species and ranchers are disturbed by the loss of grazing land; both groups also point out that these woodlands accelerate the reduction of groundwater. Of course, agriculture, industry and suburban sprawl are also responsible for grassland habitat destruction but are not discussed to any degree in this article.
Redcedars have always been pioneer trees, among the first to colonize abandoned farms and rocky glades. The Green Glacier decried in the article is just another consequence of human impact on natural ecosystems. We introduced the trees and suppressed wildfires. The redcedars are just doing their thing.
