Volume 53 – Issue 1 (March 1988)

Forest vegetation of the Obed River gorge system in the Cumberland Plateau in Tennessee was sampled using 327 0.04 ha plots. Environmental variables were recorded for each of the plots. Cluster analysis using a minimum information technique (MINFO) and canopy importance values was used to classify ten plant community types: river birch, beech-tulip poplar, tulip poplar, white oak, hemlock, sweet birch-hemlock-chestnut oak, chestnut oak-white oak, white pine-white oak-chestnut oak, white oak-scarlet oak, and Virginia pine types. Canopy basal area ranged from 19.8 m²/ha (Virginia pine type) to 35.5 m²/ha (river birch type); canopy density ranged from 353.9 stems/ ha (beech-tulip poplar type) to 520.2 stems/ha (tulip poplar type). Reciprocal averaging ordination identified two gradients, a gradient arraying plant populations from xeric to mesic taxa and a second gradient separating mesic deciduous taxa from hemlock. Ordination scores correlated to environmental variables such that the first axis represented a gradient incorporating topographic position and soil moisture and the second gradient related to gorge width and probably protection. Division of the data set into subsets and reordinating supported this interpretation. Negative exponential, negative-power, and polynomial regression models of the diameter distribution curves were statistically significant for each type and for the distributions of many individual canopy species. Disturbance history of the vegetation was reflected in the diameter-class distributions of arboreal species, but only the river birch, tulip poplar and sweet birch-hemlock-chestnut oak types appeared to be successional.

Vegetation response after natural fire was investigated in the Georgia Sea Islands. Nearly all above-ground stems were killed in the scrub and marsh communities. Within two years burned marshes strongly resembled unburned marshes in vegetation cover and species diversity. In the first year after burning, diversity increased in freshwater cordgrass (Spartina bakedi) marsh, but then fell again as water levels rose. By the second year, vegetation cover had returned to pre-burn levels. Sawgrass (Cladium jamaicense) marsh was lower in diversity and slower to return to potential pre-burn cover. Burned scrub regenerated into extremely dense vegetation and exceeded 2 m in height two years after the fire. Regrowth was almost exclusively woody. Mature hardwoods suffered high mortality only where the trees bordered the more flammiable scrub or dense pine. Mature individuals of Pinus palustris, P. serotina, and P. taeda survived all but the most severe burns. With the exception of pine species, the proportion of different species in post-fire regrowth was generally similar to pre-fire stand composition. With a potential fire rotation of 23 years or less, both oak and pine scrub communities on Cumberland Island are probably pyric dis-climaxes.

Leading dominants and size-class distribution analyses were performed on the vegetation data from 483 20 x 50 meter forest plots from the Bristol Hills of New York. Both analyses indicated the lack of replacement of Quercus species except on burned sites. Acer saccharum and A. rubrum are increasing in importance in Quercus dominated plots.

Aggrading upland forests of this region are tending towards one of three mature forest types. Tsuga canadensis, Acer saccharum forests are found in ravines, and wet areas at streamsides and around beaver ponds. Acer saccharum, Fagus grandifolia forests are found on lower elevation slopes. Upper slope forests are tending towards an increase of Acer rubrum in Quercus rubra and Q. prinus dominated stands.

Black alder, Alnus glutinosa, represented by 28 seed sources from various natural and planted stands, was studied for six years in the coastal plain of Maryland. Also included were one source of each, A. incana and A. cordata. Different populations of A. glutinosa ranged in survival from 58% to 100%, height from 3.4 m to 6.6 m, advance of flushing leaves (on April 23, 1984) from none to fully developed, infestation by the aphid,

Prociphilus tesselatus, on 0% to 37% of trees, developing of female flowers during the 4th and 5th growing seasons on 0% to 92% of trees, and producing male flowers during the 5th season on 0% to 100% of trees. A. glutinosa included five populations that were 10% to 18% taller than average.

The most noteworthy correlations in Alnus glutinosa were the earliness of leaf flush vs. the northern latitude (r=–0.59) and vs. the eastern longitude of the seed source (r=–0.62). Also correlated were the survival rates vs. one-year heights (r=0.54), the aphid infestation vs. altitude of the seed source (r=0.36), and early flower production vs. six-year height (r=0.35 to 0.54). Alnus cordata grew 11% taller than A. incana, and both these species were about average in comparison to A. glutinosa.

Sponsored by Beltsville Area, Agricultural Research Service, U.S. Department of Agriculture with the cooperation of Friends of Agricultural Research-Beltsville, Inc.

Ranunculus platensis Sprengel, an immigrant weedy annual species from South America, was collected first within the United States in Terrebonne Parish, Louisiana, in 1917. Since then, it has spread to six states (Alabama, Florida, Georgia, Mississippi, North Carolina, and Texas) and at least 39 counties and parishes. Based on its biology, the species may be expected to spread generally within the southeastern United States during the next half century.

Certain parts of the upper Piedmont of South Carolina are underlain extensively by metagabbro, diabase, or other basic rocks. The South Carolina Heritage Trust Program is nearing the completion of an overview of the natural communities and flora associated with these sites, especially concerning the Iredell soil series. The presence of two plant species on one such site is significant.

Botanists often locate plant collection sites on U.S. public land survey maps. Standard notation at the section level is exemplified by “Section 8, Township 5 North, Range 3 East, 1st Principal Meridian,” frequently abbreviated to “S8, T5N, R3E, 1 PM.” For reasons given below, it is suggested that the second and third parts of the notation, which disclose the survey coordinates of a particular 36-section township, be combined as follows: “Township (5 North, 3 East),” or “T(5N,3E).” The abbreviated notation then becomes “S8, T(5N,3E), 1PM.”

Although known as diverse botanical entities for hundreds of years, serious interest in growing carnivorous plants as horticultural specimens extends to the middle of the 19th Century when explorers returned to the Old World with specimens of strange pitcher plants found in the various parts of the world: the United States, Venezuela, Borneo, and Australia.

The private herbarium of Hannibal A. and Tyrecca E. Davis has been given to the Carnegie Museum in Pittsburgh. This consists of a 10,000 sheet general collection with emphasis on West Virginia, and 10,000 sheets of Rubus, mostly from eastern North America.