Dwight T. Kincaid

The Population Biology of the Genus Viola: I. The Demography of Viola Sororia

(1) A census of all plants of Viola sororia 1-yr-old or older was carried out at regular intervals over an 8-yr period in a forest site in New England. Over a 2-yr period seedlings were similarly recorded, and each leaf and reproductive structure on twenty selected plants was marked and its fate recorded at weekly intervals. (2) Calculations were made of population flux, age distribution, survivorship and life expectancy of 1-yr-old or older plants, and of seedlings. (3) Fluctuation in population size was small compared to the number of individual plants gained and lost in the population. There was a remarkably constant annual death risk, superimposed upon a seasonal cycle, May-September being a period of greater mortality than the winter months when the plants were inactive. (4) The life expectancy of a 1-yr-old plant was over 10 yr. While seedlings and adult plants exhibited a Deevey type-III mortality curve, leaves had a Deevey type-I curve. (5) It was also established that seedling survival and production-probability are a function of plant size; the relationship is exponential in the case of seed production. It is suggested that individual plant size is regulated by competition for environmental resources.

Studies on the Population Biology of the Genus Viola: III. The Demography of Viola Blanda and Viola Pallens

(1) All ramets one-year or older of Viola blanda and V. pallens were enumerated at regular intervals for up to 4 yr in two New England forest sites. Each seedling was similarly enumerated, and each leaf and reproductive structure in twenty plants was marked and their fate recorded at weekly intervals. (2) Calculations were made of population flux, age distribution, survival, and life expectancy for ramets one-year or older and for seedlings. (3) At one site, fluctuation in population size was small comnared with the large number of individual ramets gained and lost but at the other site the population declined and eventually disappeared. (4) On average individual ramets lived for 44 years. (5) The rate of seed production and the probability that a ramet will survive is a function of ramet size.

Studies on the Population Biology of the Genus Viola. VI. The Demography of V. Fimbriatula and V. Lanceolata

SUMMARY (1) The demographic behaviour of two Viola species ( V.fimbriatula and V. lanceolata) from open clearings is reported and compared with that of three woodland species. (2) Measurements were made of the size of the seedbank in the soil, germination, number and growth of seedlings, numbers of pre-reproductive and reproductive ramets, and fecundity over five years. Seedling growth, seed weight and number, leaf production and grazing losses, and investment in reproductive structures were also studied. (3) Seed banks of the clearing species were larger by a factor of five than those of the forest species. All showed plasticity in many characteristics, but the clearing species produced more seeds per plant, and lighter seeds. Clearing species grew faster than forest species. Irrespective of habitat, rhizomatous species produced more seed than stoloniferous species. (4) Conclusions are drawn from the entire series of papers. Viola populations appear to be demographically unstable.

The Vascular Flora of Five Florida Shell Middens

RICHARD STALTER (Dept. Biol. Sci., St. Johns Univ., Jamaica, NY 11439) AND DWIGHT KINCAID, (Dept. Biol. Sci., Lehman College CUNY, Bronx, NY 10468). The vascular flora of five Florida shell middens. J. Torrey Bot. Soc. 131:95-105. 2004.-This study described the vascular flora of five Florida shell middens: Fort George Shell Ring, Guana River State Park Shell Ring, Tomoka State Park Shell Midden, Green Mound, and Turtle Mound. These protected middens were located on state or National Park property. The vascular flora consisted of 190 species within 159 genera in 81 families. Poaceae and Asteraceae were the largest families and the largest genera were Cyperus, Quercus, Smilax, and Solidago. Native species composed 95.3% of the flora. Soil salinity and daily flooding affected the distribution of vascular plants at tidal midden sites. Calcareous soils influenced species distribution at upland shell midden sites. Each taxonomic entry in the checklist is accompanied by site location.

Targeted analysis of polyphenol metabolism during development of hop (Humulus lupulus L.) cones following treatment with prohexadione-calcium

Hops (Humulus lupulus), a main ingredient in beer, are valued as a source of bitter flavour and biologically active polyphenols. We treated immature hop cones with prohexadione-calcium (Pro-Ca), a flavanone-3-hydroxylase (F3H) inhibitor, to perturb the flavonoid pathway, and conducted a targeted analysis of 29 compounds from the phenolic acid, flavonoid, and terpenophenolic pathways, using photodiode array (UHPLC-PDA), and time of flight mass spectrometry (LC-TOF-MS) analysis. Hop cones were analysed over four stages of development spanning 22days following Pro-Ca treatment. The content of terpenophenolics as well as metabolic precursors upstream from F3H significantly increased, and levels of flavonoid products downstream from F3H decreased. The methods developed here serve to compliment flavour analysis of polyphenol rich foods, and our results suggest ways to improve upon traditional agricultural methods to produce hops with altered chemical profiles.

Community development following gamma radiation at a pine–oak forest, Brookhaven National Laboratory, Long Island, New York1

We investigated a unique source of forest disturbance: gamma radiation. While the temporal patterns of ecological succession are well understood for the forests of eastern North America, this is not the case for massively irradiated forests. Our objective was to compare vascular plant community change after irradiation at the five vegetation zones described in 1962 by Woodwell at Brookhaven National Laboratory, Long Island, New York. No follow-up studies have been done since the gamma radiation experiments were terminated in 1978. Ecological successional theory (e.g., Bormann and Likens, 1994, Likens and Bormann, 1995) does not explain long-term forest recovery after radiation damage. Our null hypothesis was that 47 yr after initial gamma ray exposure, the sites would have recovered such that floristic composition would be the same as the pine-oak forest control. This hypothesis was rejected statistically. In 2007/2008, the five concentric zones of vegetation centered about the gamma source retained their floristic heterogeneity as measured by Jaccard coefficients.

LEAF VARIATION IN A TREE OF POUROUMA TOMENTOSA (CECROPIACEAE) IN FRENCH GUIANA

In the flora of French Guiana we find considerable within-plant variation in leaf form. We observed entire, two-lobed, and three-lobed leaves within five separate levels (tiers) of the canopy of a single individual ofPourouma tomentosa subsp.maroniensis. Five branches from each of the five tiers of the tree were collected around the axis of the trunk. From these branches five secondary branchlets were selected and all leaves excised with information recorded as to nodal position, number of leaf nodes, and fertility status of the main branch. This design produced 1015 leaves representing about 20 m2 of foliar area and about 2.4 kg of blade dry weight. Our objectives were to determine if statistically significant patterns exist for leaf variation and to suggest improvements for future, general collections. The four lower tiers had 62% entire, 10% 2-lobed, and 28% 3-lobed leaves, in contrast to the top tier with 38% entire, 11% 2-lobed, and 51% 3-lobed leaves. The top tier had no fertile branches. in the lower tiers, fertile branches produced 68% entire leaves whereas nonfertile branches produced only 46% entire leaves. In the top tier, lobed leaves made up 73% of surface area, while in the lower tiers, lobed leaves made up only 48% of total surface area. We selected a random subset of 75 leaves from the 1015, for morphometric analysis using two-way ANOVA (tier×leaf type). The boundaries of leaf images were digitized and rendered into Fourier coefficients, yielding leaf surface area and two variables that quantify aspects of shape: dissection index and leaf complexity. The Fourier coefficients were averaged by tier and by leaf type to reconstruct synthetic, average leaf images. Logistic regression was used to predict the position of leaves on the tree and to provide visualization of the relationships between leaf position on the tree and leaf morphological variables. Within the tree crown, leaf surface area and leaf specific mass (LSM) increases with height, although leaf shape does not change with height. LSM does not vary with leaf form; and sun leaves are larger than shade leaves on this tree. We conducted computer sampling experiments based on exact randomization to simulate the process of obtaining all leaf shapes present in an individual tree when making field collections of varying numbers of duplicates. This also points out the importance of noting the presence of within-tree variation in leaf form on herbarium labeds. Failure to recognize leaf variation can lead to incorrect delimitation of species as well as cause overestimates of the number of species in diversity studies.

Life forms of the flora at Hempstead Plains, New York, and a comparison with four other sites'

STALTER, R. (Department of Biological Sciences, St. Johns University, Jamaica, NY 11439), DWIGHT T. KINcAm (Department of Biological Sciences, Lehman College, City University of New York, Bronx, NY 10468) AND Eiuc E. LAMoNT (New York Botanical Garden, Bronx, NY 10458). Life forms of the flora at Hempstead Plains, New York, and a comparison with four other sites. Bull. Torrey Bot. Club 118: 191-194 1991.-The 171 taxa of vascular plants of Hempstead Plains, Long Island, New York, were arranged into a Raunkiaer life form spectrum. Over eighty percent of the species have their perennating tissue protected during the unfavorable part of the year (hemicryptophytes, 38%; therophytes, 25%; cryptophytes, 20%). The Hempstead Plains spectrum was compared to spectra developed from species lists for an oak woods, Cold Spring Harbor, New York; Konza Prairie, Kansas; the South Carolina Sand Hills; and the North Carolina Piedmont. The life form spectrum at Hempstead Plains is statistically homogeneous (G-tests) with that of the Konza Prairie, and highly significantly different from the oak woods in Cold Spring Harbor, New York, the South Carolina Sand Hills, and the Piedmont of North Carolina. Based on Raunkiaer life form categories, the Hempstead Plains community is a true prairie.

First flow-thru analysis in ecosystem studies

Abstract We conduct a first flow-thru analysis of carbon transfer for a small hypothetical ecosystem. Material transfers are derived in an iterative non-duplicative manner such that all the material in the network is accounted for. This non-cyclic procedure is based on exhaustive search and data management rather than matrix manipulation. In addition to evaluating direct and indirect effects, the roles of each entity as entry, mediator, and receptor of carbon are quantified.

THE NON-NATIVE INVASIVE PHELLODENDRON AMURENSE RUPR. IN A NEW YORK CITY WOODLAND

Summary A quantitative census of woody taxa ≥ 2.0 cm diameter breast height (DBH) was performed within a contiguous 0.5 ha plot in a 167 ha wooded area of the 217 ha Forest Park in Queens County of New York City, USA. The census revealed a highly abundant non-native invasive tree, Amur corktree (Phellodendron amurense Rupr., Rutaceae) with no previous reporting on its ecology in NYC since its horticultural introduction to the park in 1935. The corktree is a dioecious, deciduous, compound leafed tree with deeply fissured corky bark and is native to Northern China, Korea and Japan. It is reported as shade-intolerant in Japan yet is shade-tolerant in this study of a New York City woodland. This study documents its movement into the canopy and up the ecological dominance hierarchy. Of the 22 sampled taxa (n = 771 trees), P. amurense ranked third in overall dominance behind Betula lenta and Quercus rubra with an importance value (IV) of 33.3%. At 20.5%, P. amurense ranked second in relative abundance with Betula lenta, the most abundant at 28.1%. Stem density for P. amurense was 316 stems ha−1 with a summed basal area that accounted for 2.9% of the total basal area, which was consistent with its small diameter size (4.76 cm mean DBH, SD 3.69). For tree height, 63.2% of the population of corktrees are < 6.0 m (4.90 m mean height, SD 2.08) and the maximum height measured 11.7 m. Bootstrap 95% confidence intervals of the observed 20.5% relative density suggest that parametric relative density of the corktree, across the larger woodland may range from a low 11.9% to a high 31.0% of trees. Its 95% confidence intervals for IV were found to overlap with those of Quercus rubra, Cornus florida and Q. velutina suggesting a corktrees inferential ecological dominance ranking lies from an IV rank of 2 to 5.