Roadsides are often planted with nonnative, disturbance-tolerant, herbaceous vegetation to enhance plant survival under highly disturbed soil conditions. We investigated vegetation and soils along the Ohio River, West Virginia, USA, at a new bridge crossing (Blennerhassett Island), a bridge crossing 45 yr old (Buckley Island), and an island with no bridge crossing (Muskingum Island) and at three distances from the bridge or center point at each site (0 m [under the bridge], 100 m away, 300 m away). Overall, 170 species (131 herbaceous, 10 shrubs, and 29 trees) were observed. Percent herbaceous cover and basal area of trees were lower at quadrats under the bridges (p < 0.05). Species composition differed at quadrats under the bridges in comparison to distant quadrats (p < 0.05) with exotics such as Japanese millet (Echinochloa crus-galli var. frumentacea P. Beauv.), and Italian perennial rye grass (Lolium perenne L.) prevalent under the new bridge. Numerous soil properties had highly altered levels at quadrats under bridges (p < 0.05). We found bridges influence vegetation directly beneath them by creating an environment with nonnative, disturbance-tolerant, herbaceous vegetation with low percent cover and basal area. Differing vegetative parameters between sites were due to natural vegetative communities, while the presence of a bridge was responsible for differences between distances. The bridge was also found to alter soil chemistry and physical properties in the soil likely due to the application of fertilizer and road salts and disturbance during construction.

Research regarding the pollination mechanism of federally endangered Hexastylis naniflora was conducted during spring and summer 2009 in Cleveland County, North Carolina. Research focused on the possible role of insect pollinators in pollination success. Caging was used to exclude insects from 30 flowers, from 30 different plants, in order to examine differences in a final percent seed set of fruits developed from both caged and open flowers. Though caged flowers did show partial seed set, a significant difference in percent seed set was found between the control and experimental groups (t = 3.678, df = 26.482, p = 0.001, n = 29 flowers) indicating pollination is the result of a compound, facultative mechanism, which includes both entomophily and some other, undetermined, self-pollinating capability.

Studies of historic forest disturbances provide an important context for the ecological dynamics that affect forest structure and successional trajectory. Previous historical disturbance research in the Missouri Ozark Highlands has highlighted the dynamics of fire regimes. However, little is known concerning canopy disturbance regimes in this region. The primary objective of this study was to reconstruct the history of multiple disturbances at a site that was known for having both historic Native and Euro-American activity. We analyzed the radial growth of shortleaf pine (Pinus echinata Mill.) and white oak (Quercus alba L.) to infer growth release events and documented historic fire events based on fire-scarred P. echinata. The majority of trees (87%) exhibited at least one growth release between 1624 and 2000 with the earliest growth release occurring in 1645. A total of 39 fires were documented between 1706 and 1915. Mean duration of growth releases for both species was approximately six years. We documented five stand-wide canopy disturbance events between 1740 and 2000. However, most growth release events were asynchronous, suggesting that gap dynamics was an important process in this forest. Trees exhibiting multiple releases that on average lasted six years suggest that trees required multiple gap openings to attain canopy status. We speculate that even with a high historic fire frequency (MFI = 5.5 years), gap dynamics was the primary process for P. echinata and Q. alba to attain canopy status in this forest.

Aspects of the dispersal characteristics of two nonnative shrubs, Elaeagnus umbellata and Ligustrum sinense, were compared with those of two native shrubs, Cornus amomum and Frangula caroliniana, to identify factors that contribute to successful invasion of the nonnative species. For each species, the following aspects were examined: shrub abundance, physical characteristics and nutritional values of fruits, arrangement of fruits along the stem and number of fruits per branch, phenology of fruit maturation and foliage coloration, and animal interactions. The two native shrubs and E. umbellata were similar in abundance, but L. sinense was significantly more abundant than the others. Cornus amomum and F. caroliniana present bicolored displays of fruits that are rapidly dispersed during autumn avian migration. Elaeagnus umbellata produces moisture- and protein-rich fruits during summer that are also rapidly removed. In contrast, L. sinense produces high numbers of fruits in late autumn that remain available to frugivores throughout the winter. The large quantities and prolonged availability of L. sinense fruits enable the dispersal of this shrub by a diverse array of frugivores and contribute at least partially to its successful invasion of new habitat and its observed abundance.

Arthonia biseptata is shown to be a species of Mycoporum, likely narrowly endemic to high elevations of the southern Appalachian Mountains and the new combination M. biseptatum is proposed. Lecidea degelii is shown to apply to the sorediate morphotype of Porpidia albocaerulescens. The results of molecular phylogenetic analyses of nrITS and mtSSU sequence data of sorediate and esorediate populations of P. albocaerulescens are presented. These analyses recovered the sorediate and esorediate morophotypes together in a single clade as strongly supported monophyletic entities. As a result the new combination Porpidia degelii is proposed, the species illustrated, and the North American distribution of P. degelii with respect to P. albocaerulescens is discussed. These data refute the notion that “species pairs” do not exist in Porpidia. Lecidea subtilis is placed in synonymy with Pyrrhospora varians.

Weakley, Alan S., J. Christopher Ludwig, and John F. Townsend. 2012. Flora of Virginia. Bland Crowder, ed. Foundation of the Flora of Virginia Project Inc., Richmond. Fort Worth: Botanical Research Institute of Texas Press. 1572 p. Hardcover, $89.99. ISBN-13: 978-1-889878-38-6.