Brownfield Woods, Illinois: Woody Vegetation and Changes Since 1925

Abstract

The first complete inventory of the woody vegetation of Brownfield Woods since 1925 was completed in 1960. This 60-acre woodland is a remnant of a large prairie grove that once occupied an area of 10 square miles northeast of Urbana, Champaign County, Illinois. The stand is mixed mesophytic in composition with 113 trees per acre (3 inches and above in diameter) and a basal area of 114 sq. ft. Twenty-five woody species were tallied with sugar maple (Acer sac- charum Marsh) the leading dominant. The most striking change in the vegetation since 1925 was the 60% increase in the basal area of sugar maple, and a corresponding decrease in that of elm (Ulmus americana L. and U. rubra Muhl.). The latter is due to mortality from phloem necro- sis and the Dutch elm disease. A heavy understory, dominated by sugar maple, has developed. Nearly two-thirds of the trees less than one inch in diameter are sugar maple thus suggesting a continued, or increasing dominance of this species. There have been striking changes in the woody vegetation of Brownfield Woods during the past 35 years. Many of the large trees mentioned by Telford (1926) are still alive, but mortality has been heavy, particularly among the elms. A heavy understory of seedlings and small saplings has developed, aided no doubt by more than 20 years of complete protection from fire, grazing, and public use. Some of these changes, and their implications, are discussed in this paper.