Master of Science (MS)
Semester of Degree Completion
John E. Ebinger
A vegetation survey was undertaken at the Iroquois County Conservation Area and the Hooper Branch Nature Preserve in Iroquois County, Illinois. Dry sand savanna, dry-mesic sand savanna, and Pin Oak flatwoods were the three communities under study at the Iroquois County Conservation Area. Carex pensylvanica had the highest relative frequency of any ground layer species present at both the dry and the dry-mesic sand savannas. In both of these sand savanna communities the dominant overstory tree was Quercus velutina. These two communities differed mainly in the composition of their woody ground layer species. Rubus hispidus obovalis had the highest relative frequency of any ground layer species at the Pin Oak flatwoods. The understory vegetation was much less diverse in this community than in either of the sand savannas. The dominant overstory tree was Quercus palustris, which formed a much denser canopy layer than did Q. velutina at the dry and dry-mesic sand savannas.
A ground layer vegetation survey, and a woody overstory and understory vegetation survey also was undertaken at the Hooper Branch Nature Preserve. Sampling from a site that had been burned every spring over the past three years was compared to a site that had received only one burn over this same three year period. Carex pensylvanica had the highest relative frequency of any ground layer species at both sites. No differences existed in the overstory vegetation between the two sites, both of which had as the dominant tree Quercus velutina. The site that had been under the three year prescribed burning management showed fewer woody seedlings present in the understory than the site that had not been burned as often. More years would have to elapse before any significant differences in vegetational composition would become apparent between these two sites.
Johnson, Kenneth, "Black Oak Savannas and Pin Oak Flatwoods in Iroquois County, Illinois" (1990). Masters Theses. 2271.