Volume 57 – Issue 3 (Sep 1992)

The relationship of the tree and woody understory flora of sixteen 0.034 ha southern mixed hardwood forest stands to environmental characteristics was studied on the University of West Florida campus. Thirty-five tree and 65 woody understory species were recorded. The dominant tree species were Quercus hemisphaerica, Pinus glabra and Fagus grandifolia. In the woody understory, the dominant species were Ilex vomitoria and Illicium floridanum. The principal gradient of variation in species composition of both the trees and woody understory was related to slope angle and position. Gentle, upper slopes that had been previously logged were dominated by Pinus palustris trees, Q. hemisphaerica saplings and Ilex vomitoria in the woody understory. Steep, lower slope positions were characterized by relatively undisturbed F. grandifolia with Illicium floridanum in the understory. Soil parameters were of secondary importance although the proportion of evergreen species in the understory was related to soil pH, phosphorus and calcium.

The genetic and morphological variation in Portulaca umbraticola Kunth are analyzed and synthesized with data from the original descriptions, comparisons of herbarium and live specimens, and chromosome counts to support the maintenance of a single species, with two subspecies in the United States.

We sampled previously established permanent line-intercept transects (15 m length) in oak-saw palmetto scrub 6, 12, 18, 24, and 36 months after a fire and recorded cover by taxon in the 0-0.5 m and >0.5 m height layers to determine patterns of recovery. Transects were located in two stands that were seven years (six transects) and 11 years (four transects) since the last fire when burned. Shrubs and herbs recovered by sprouting with little change in species present or species richness. Regrowth of Serenoa repens after burning exceeded that of the oaks; its cover in the >0.5 m layer returned to preburn values within one year. Oak cover (>0.5 m layer) was less than preburn three years after the fire. Differences in growth rates resulted in changes in dominance of mixed oak-saw palmetto transects. We used detrended correspondence analysis ordination to examine resilience after fire. Oak-saw palmetto scrub is very resilient compared to most shrublands. All successional vectors returned toward original locations in fires at 7-11 year intervals. Patterns of recovery varied along the scrub composition gradient. Mixed oak-saw palmetto transects recovered more slowly and showed greater changes in their post-fire composition than saw palmetto-dominated transects three years after burning.

Expansion of an eastern hemlock (Tsuga canadensis) forest was studied in a north-facing ravine system in the eastern piedmont of Maryland. Based on size-class distributions, historical photographs, distribution of standing live and fallen decaying trees, and diameter growth rate regressions, the forest appears to be a climax community expanding throughout the ravine system, including deciduous upland areas between ravines. Coverage increased from 6.1 ha to 29.7 ha between 1938 and 1986 and is expected to reach at least 119 ha in the absence of fire, logging, overbrowsing by deer, and catastrophic wind.

Mr. Douglas Ogle is the recipient of the 2nd annual Richard and Minnie Windler Award for his paper entitled “Spiraea virginiana Britton: I. Delineation and Distribution” that appeared in Castanea 56(4):287-296.

An inventory was completed of the woody vegetation of a post oak flatwoods near Lake Sara, Effingham County, Illinois. This 3 ha forest, located in the Southern Till Plain Natural Division of Illinois, has a stand composition of 280.3 stems/ha (above 10 cm dbh) and a basal area of 19.5 sq m/ha. Of 12 woody species present, post oak is the leading dominant accounting for more than 50% of the importance value (IV of 104.8). Black oak ranks second in IV, followed by blackjack oak, white oak, shingle oak, and three hickory species. Tree seedlings average 25,209 stems/ha, but few saplings are present (41 stems/ ha), probably the result of yearly fires.

Ilex collina was first collected on 1 September 1933 by E.J. Alexander (Alexander 1934, 1941). Clark (1974) referred the species to Nemopanthus on the basis of “obviously apopetalous corollas of narrow petals, stamens that are free from the corolla, inconspicuous calyx lobes in staminate flowers and calyx lobes in pistillate flowers which are deciduous or semipersistent as the fruit matures.” Ilex collina is currently known from eight counties in the three states (Clark 1974, Harvill et al. 1986). Clark (1974) summarized its range as follows: from Swain County, North Carolina through southwest Virginia to Randolph County, West Virginia.

The 1992 winner of the Elizabeth Ann Bartholomew Award for public service is Dr. Edward E.C. Clebsch. The award was announced on April 10, 1992 at the annual meeting of the Association of Southeastern Biologists, which was held at the University of Alabama in Tuscaloosa. Ed is a Professor of Botany and Ecology at the University of Tennessee at Knoxville and his activities permeate almost every possible field of service.

The Eastern Red Cedar (Juniperus virginiana L.) is a relatively abundant tree in the Cumberland Plateau region of the southeastern United States. It is a commercially important tree for lumber as well as fragrance. Both wood and leaves are rich in terpene-derived natural products. Volatile oil from wood of J. virginiana, made up chiefly of cedrene (a terpene) and cedral (Runenberg 1960), has been used in perfumery (Ter Heide et al. 1988) and as an insect repellent (Yasuo et al. 1987), and the thickened oil has been used in microscopy as a clearing agent and for use with immersion lenses (Merck Index 1989). Leaf oil of J. virginiana has been found to contain mainly sabinene, as well as limonene, a-pinene, y-terpinene, terpinolene, 3-carene, myrcene, 4-terpineol, citronellol, elemol, eudesmol, and the aromatic ethers estragole, safrole, methyl eugenol, and elemicin (Vinutha and von Rudloff 1968).