Carl D. Monk

Effects of Shade, Litter and Root Competition on Old-Field Vegetation in South Carolina

MONK, C. D. AND F. C. GABRIELSON (University of Georgia, Athens, GA 30602 and University of Alabama, Tuscaloosa, AL 35405). Effects of shade, litter and root competition on old-field vegetation in South Carolina. Bull. Torrey Bot. Club 112:383-392. 1985.-The effects of shade litter and root competition on old-field herbaceous vegetation were examined by using two different approaches: one involved the addition of shade and/or litter to plots in an old-field, while the other involved eliminating root competition by trenching along the side of singly-growing pine trees. Vegetation was sampled prior to treatment and again after one and two years of treatment. The normal course of succession was a decrease in density and biomass of annuals, while the density and biomass of perennials doubled. Species more characteristic of early old-field successional stages were more apt to be inhibited by treatment than species characteristic of later successional stages. In the experimental treatments, shade reduced biomass and density, except in Cynodon. Litter alone produced a major decrease in the number of individuals and in biomass; perennial grasses were affected the least and some (Andropogon, Aristida, Leptoloma) showed a major increase over controls. Shade + litter drastically reduced (60-70%) density and biomass (stems and leaves) of annuals and increased the density of perennials, especially Cynodon with shade and pine litter and Andropogon on shade and hardwood litter. In the trenching experiment, the annuals showed no real response in trenched, litter-intact quadrats, while the perennials increased fourfold in density. Annuals had higher densities (100% increase) in response to trenched + litter removal treatment; perennials showed no enhancement of density with the trenched, litter-removal treatment. The largest number of species invaded trenched, litter-removal quadrats. Plants on unshaded quadrats produced more root biomass than on shaded quadrats. More root biomass was produced on hardwood litter plots than under pine litter. Less root biomass was produced on shaded or unshaded + litter plots after two years. Annuals were inhibited by dense shade, root competition and litter. Root competition and shade were more important in suppressing perennials than was litter.

Stem Diameter and Dry Weight Relationships in Tsuga canadensis (L.) Carr.

Stem diameter and dry weight relationships in Tsuga canadensis (L.) Carr. William R. Santee and Carl D. Monk Botany Department, University of Georgia, Athens, Georgia 30602 SANTEE, WILLIAM R. and CARL D. MONK. (Dept. Bot., Univ. Georgia, 30602). Stem diameter and dry weight relationships in Tsuga canadensis (L.) Carr. Bull. Torrey Bot. Club. 108: 320-323. 1981.—Stem diameters and dry weight for bole, branches, bark and needles are given for twenty hemlock trees from the southern Appalachians. Simple allometric equations relating dry weights to dbh are also presented. Nutrient concentrations for fifteen elements are included.

Relationship of life forms and diversity in old-field succession

MONK, CARL D. (Bot. Dept., Univ. of Georgia, Athens, GA 30602). Relationship of life forms and diversity in old-field succession. Bull. Torrey Bot. Club 110: 449-453. 1983.-Fortyeight old-fields (f15 years old) were examined in terms of species diversity. The mean number of species was initially low following field abandonment; increased rapidly for 5-6 years; then the number decreased. Variability was sufficiently large that successive years exhibited no significant differences, but cumulative differences did occur. The information content diversity was quite variable, its pattern of change closely coupled with the shift in life form dominance. When the life span of the dominant species was short (annuals), diversity reached a maximum one year then declined the next. With a shift to perennial forbs and then perennial grasses, diversity increased to a maximum the first year of the life form dominance then declined over the next couple of years, then increased again. These data are briefly discussed in relation to some current succession theory.

Past and Present Influences on Reproduction in the William L. Hutcheson Memorial Forest, New Jersey

:MONK, CARL D. (U. Florida, Gainesville..) Past and prese.nt influences on reprodut· tion in the William E. Hutcheson Memorial Forest, New Jersey. Bull. Torrey Bot. Clul.J 88(3): 16i-175. 1961.-White oak and black oak colled1vely contribute 68 per cent to total basal area of canopy tree species; seedlings of these. species are fairly common while saplings are rare. On the other hand, sugar maple and Norway maple. eollectively contribute less than 1 per cent to total basal area, but seedlrngs of the.se two maples are common and their saplings are. more common than oak saplings. Sapling growth data for the 1956-58 seasons show that sugar maple saplings grew better in the shaded nreas of the forest than did other species studied. The pre.•eolonial fires appe.or to h,ive favored the oaks but excluded sugar maple. With the cessatiou of fire after settlement sugar maple seeded in from a nearby source on the flood plain or, as with Norwny mnple, from shade tre.e plantings.