An Understory Survey of Baber Woods, Edgar County, Illinois

Several vegetation studies have been undertaken in Baber Woods, Edgar County, Illinois, in the past 20 years. After looking at the data of these studies it was decided that an additional study was needed to determine if the increasing importance value (IV) of Acer saccharum was indeed important. It appears that this species is starting to take over the native oak-hickory woods as well as decreasing the diversity of the herbaceous understory (Ebinger, 1986). The present study was undertaken to determine of Acer saccharum has increased enough to justify implementation of some type of forest management. Environmental parameters at the study site were measured for 24 hours during each season, May 2, 3, and 4, July 14 and 15, and October 2, 3, and 5, 1986. During these 24 hour periods the following were recorded: soil temperature at the 4 underground level, relative humidity and air temperature at the 1m level. Wind speed and incident solar radiation were monitored during the sample times during maximum radiation at the 1m mark. Vegetative sampling was done by establishing four east/west transects 100m long, randomly located throughout the woods. Along each transect 100 1/10m circular plots were randomly located at one meter intervals. Once the quadrate was in place all herbaceous and woody species under 1m in height were counted by a harvest method. A total of 54 species were recorded from the plots. During the spring the number of individuals of all species was 151.1 plants per square meter. It should be noted, however, that of the 151.1, 112.8 of that density was from two species, Claytonia virginica and Dentaria laciniata. The number of individuals dropped dramatically during the summer when there were 14.66 plants per square meter. And again in the fall there was a drop to 8.78 plants per square meter. Acer saccharum and Ulmus rubra seedlings were not present in relatively high numbers the other woody species were not commonly encountered. By converting density to number per acre. Acer saccharum shows the largest increase, the 1965 count showed 5,369 individuals per acre, 1983, 2,421 plants, and in the present, 1986 study there were 13,466 individuals per acre. The spring had an overall herbaceous density of 142.6 individuals (per square meter). In the summer the overall herbaceous density dropped to 9.35 individuals per square meter with the most common species being Smilacina racemosa. The fall density dropped to 3.16 with the most abundant species being Ozmorhiza longistylis with 1.4 individuals per square meter. Only three species were found during all three sampling periods, Circaea latifolia, Ozmorhiza longistylis, and Sanicula greggaria