Volume 69 – Issue 1 (Mar 2004)

A study of the vegetation of Dean Hills Nature Preserve in Fayette County, Illinois was undertaken to document the composition and structure of the vascular flora and to provide information for land management decisions. A total of 313 species in 85 families and 204 genera were collected at the 30-hectare preserve which occurs on a glacial kame and has a rugged ridge and ravine topography. Mature mesic and dry-mesic forest covers much of the preserve. The canopy is dominated by white oak (Quercus alba), red oak (Quercus rubra), and sugar maple (Acer saccharum). Data suggest that sugar maple is regenerating more successfully than the oaks. This same result has been found in several other studies of oak-hickory forests in Illinois. If management such as prescribed burning is not implemented, it is predicted that sugar maple will increase and oaks will decrease in dominance within the preserve.

In an effort to clarify vegetation gradients in a Mississippi Embayment Coastal Plain forest, we classified sixty-one forest stands in Natchez Trace State Forest (NTSF). Ten dominance types were delineated from cluster analysis that matched seven alliances of The Nature Conservancy’s (TNC) National Vegetation Classification System. Ordination analysis clearly separated upland and lowland (floodplain and bottoms) dominance types, but differences among upland dominance types were more subtle and related to a topographic gradient involving slope position and aspect. NTSF is still recovering from severe anthropogenic disturbances (early in the 1900s), so a variety of early and mid-successional species are found throughout, e.g., Liquidambar styraciflua and Quercus alba. This successional component weakens vegetation-environment relationships and complicates interpretation of stand composition. Upland forests are succeeding to mesophytic dominance, especially by Fagus grandifolia. Vegetation was a mix between typical Coastal Plain forests, with Ilex opaca common, and typical Central Hardwood forests.

Asexual reproduction has been observed to be more frequently associated with marginal habitats or with higher levels of disturbance. Here we examined frequencies of clonal reproduction across populations of Fagus grandifolia with varying levels of disturbance and habitat quality. We used ISSRs to identify clonal genotypes at each of five sites. Three of the sites were typical temperate habitats with relatively low densities of stems and were below 1,100 m, and two sites were above 1,370 m, possessed a high density of stems, and were characteristic of sub-alpine beech gap populations. The frequency of clonal reproduction varied substantially across sites and appears to be greater where disturbance is more severe.

We described overstory tree age and composition among hemlock stands that varied in physiographic structure at Delaware Water Gap National Recreation Area located in northeastern Pennsylvania and northwestern New Jersey. Hemlock stands were comprised primarily of eastern hemlock (Tsuga canadensis), chestnut oak (Quercus prinus), black birch (Betula lenta), Eastern white pine (Pinus strobus), and white oak (Quercus alba). Forest stands characterized by steep slopes and high gradients supported the highest basal area of hemlock. Trees within hemlock stands ranged in age from 68.0-148.0 years. These data are valuable because as eastern hemlocks decline throughout the mid-Atlantic region of the United States due to infestation of the exotic insect pest, the hemlock woolly adelgid (Adelges tsugae), hardwood species will likely become more prominent in these stands in the future. The documentation and description of tree composition of a threatened ecosystem prior to its decline is important for future restoration efforts and potential tree replacement in forest stands.

We investigated dispersal opportunities for the endangered pondberry, Lindera melissifolia (Lauraceae). In 199 hours of observation at 5 fruiting colonies in the Delta National Forest, Sharkey County, Mississippi, we recorded 82 bird species in the vicinity of a colony. Of these, 12 were observed on pondberry plants, and two consumed ripe pondberry fruits. Of these, the northern cardinal, Cardinalis cardinalis (Cardinalidae), was a seed predator. The other, hermit thrush, Catharus guttatus (Turdidae), was a dispersal agent for the plants. Numbers of fruits declined rapidly after hermit thrushes arrived in October and no fruits remained by January. Winter behavior of hermit thrushes constrains their dispersal of seeds to short distances. Without establishment of additional colonies, pondberry dispersal by birds to unoccupied patches of suitable forest is unlikely.

The federally-endangered species Dalea foliosa (leafy prairie clover) is a short-lived herbaceous perennial found in dolomite prairie. In Illinois, only five populations are known including one at the Midewin National Tallgrass Prairie (MNTP). In this paper, I present the results of a third year of re- productive success data and determine variation between years in reproductive success for this small isolated population. As in 1998 and 1999, 2000 reproductive success was high, although variation between years was found. Although the studied population of D. foliosa is small, isolated, and found in a fragmented habitat, these conditions do not appear to affect reproductive success.

Noteworthy Collections: Middle Tennessee

The federally endangered hemiparasite, Schwalbea americana L. (Scrophulariaceae), is a fire-dependent species primarily associated with the southeastern Coastal Plain (United States Fish and Wildlife Service 1992, 1995). Historically, S. americana ranged from New York to Texas (Pennell 1935), but due to fire suppression and habitat fragmentation, it has been reduced to a fraction of its original range (United States Fish and Wildlife Service 1992, 1995). Knowledge of the species biology of S. americana is limited. While conducting a study to isolate potential factors controlling the fire induced flowering response of S. americana (Norden 2002, Norden and Kirkman in press), we observed severe insect herbivory in one particular treatment across three of our study sites.

This is by far the handiest single volume on knowing and growing the familiar wildflowers of the region. It is designed to be a concise guide, giving clear information on their habitats, growth forms, and garden uses. Jan Midgley has extensive experience with many species and she presents a good deal of information in user-friendly form for the beginner and the expert – all in the context of understanding and utilizing native plants in cultivated situations.

In case you missed its d6but a few years ago, I am calling your attention again to this slim volume dealing with one of the unique habitats found in the Southeastern United States. When you think of unusual Southeastern habitats, you might list the sandhills, Carolina bays, and pocosins of the coastal plain along with the heath balds, spray ledges, and boulder fields of the mountains. However, when it comes to the Piedmont, a zone than stretches from New York down through Alabama, there are fewer special places.