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Changes in Vegetation Structure in Seeded Nesting Cover in the Prairie Pothole Region

出版	U.S. Department of the Interior, Fish and Wildlife Service, 1982
URL	http://books.google.com.hk/books?id=i4hYyxqql1UC&hl=&source=gbs_api
EBook	FULL_PUBLIC_DOMAIN

註釋A spample of 365 stands of seeded nesting cover (mixtures of cool-season grasses and legumes) was studied in the glaciated prairie pothole region during 1977-79. Measurements of species composition, canopy cover, plant height, and visual obstruction values differed with stand age but only in a general way when results from over the entire region were pooled. Maximum values for plant height and visual obstruction occurred once per stand during the first 10 growing seasons. Although the year of maximum growth was variable and unpredictable, stands showed trends of degeneration in height and visual obstruction after the year of maximum growth.