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Planting Date Effects On The Germinability And Seedling Vigor Of Abutilon Theophrasti Seeds, R E. Nurse, A Ditommaso, Ricardo A. Ramirez

Biology Faculty Publications

Abutilon theophrasti (Malvaceae) is a troublesome annual weed in many maize and soybean cropping systems of Canada and the United States. Seeds of A. theophrasti exhibit physical dormancy. Differences in the growing environment of parent plants may influence the germinability of seeds and vigour of seedlings produced by this species because of variation in resource allocation to seed development. Thus, the germinability of seeds and subsequent seedling vigour were examined for A. theophrasti plants grown in monoculture at a density of 4.2 plants m -2 under varying natural photoperiods in central New York State. Treatments were established by transplanting A. …

Snakes Of The United States And Canada: Natural History And Care In Captivity, Alan H. Savitzky

Biology Faculty Publications

No abstract provided.

Tradeoffs In Community Properties Through Time In A Desert Rodent Community, Ethan P. White, S.K. Morgan Ernest, K. M. Thibault

Biology Faculty Publications

Resource limitation represents an important constraint on ecological communities, which restricts the total abundance, biomass, and community energy flux a given community can support. However, the exact relationship among these three measures of biological activity remains unclear. Here we use a simple framework that links abundance and biomass with an energetic constraint. Under constant energetic availability, it is expected that changes in abundance and biomass can result from shifts in the distribution of individual masses. We test these predictions using long-term data from a desert rodent community. Total energy use for the community has not changed directionally for 25 years, …

Temporal Dynamics In The Structure Andcomposition Of A Desert Rodent Community, K. M. Thibault, Ethan P. White, S.K. Morgan Ernest

Biology Faculty Publications

The rank-abundance distribution (RAD) represents the manner in which species divide resources. Community-specific division rules that determine resource allocation among species, and thereby the shape of the RAD, have been hypothesized to account for observed stability of local species richness over time. While the shape of the RAD has been well studied, the temporal dynamics of this distribution have received much less attention. Here we assess changes in the shape of the RAD through time in a desert rodent community in Arizona (USA). Because energy use may be more appropriate for studying resource division than abundance, we also evaluate an …

Similarities In Body Size Distributions Of Small-Bodied Flyingvertebrates, B. A. Maurer, J. Alroy, J. H. Brown, T. Dayan, B. Enquist, S.K. Morgan Ernest, E. Hadly, J. P. Haskell, D. Jablonski, K. E. Jones, D. M. Kaufman, K. Lyons, K. Niklas, W. Porter, K. Roy, F. A. Smith, B. Tiffney, M. R. Willig

Biology Faculty Publications

Since flight imposes physical constraints on the attributes of a flying organism, it is expected that the distribution of body sizes within clades of small-bodied flying vertebrates should share a similar pattern that reflects these constraints. We examined patterns in similarities of body mass distributions among five clades of small-bodied endothermic vertebrates (Passeriformes, Apodiformes + Trochiliformes, Chiroptera, Insectivora, Rodentia) to examine the extent to which these distributions are congruent among the clades that fly as opposed to those that do not fly. The body mass distributions of three clades of small-bodied flying vertebrates show significant divergence from the distributions of …

Similarity Of Mammalian Body Size Acrossthe Taxonomic Hierarchy And Across Space And Time, F. A. Smith, J. H. Brown, J. P. Haskell, S. K. Lyons, J. Alroy, E. L. Charnov, T. Dayan, B. J. Enquist, S.K. Morgan Ernest, E. A. Hadly, K. E. Jones, D. M. Kaufman, P. A. Marquet, B. A. Maurer, K. J. Niklas, W. P. Porter, B. Tiffney, M. R. Willig

Biology Faculty Publications

Although it is commonly assumed that closely related animals are similar in body size, the degree of similarity has not been examined across the taxonomic hierarchy. Moreover, little is known about the variation or consistency of body size patterns across geographic space or evolutionary time. Here, we draw from a data set of terrestrial, nonvolant mammals to quantify and compare patterns across the body size spectrum, the taxonomic hierarchy, continental space, and evolutionary time. We employ a variety of statistical techniques including “sib-sib” regression, phylogenetic autocorrelation, and nested ANOVA. We find an extremely high resemblance (heritability) of size among congeneric …

Two-Phase Species-Time Relationships In North American Land Birds, Ethan P. White

Biology Faculty Publications

The species-time relationship (STR) is a macroecological pattern describing the increase in the observed species richness with the length of time censused. Understanding STRs is important for understanding the ecological processes underlying temporal turnover and species richness. However, accurate characterization of the STR has been hampered by the influence of sampling. I analyzed species-time relationships for 521 breeding bird survey communities. I used a model of sampling effects to demonstrate that the increase in richness was not due exclusively to sampling. I estimated the time scale at which ecological processes became dominant over sampling effects using a two-phase model combining …

Hydrologic Variability, Organic Matter Supply, Anddenitrification In The Garonne River Ecosystem, Michelle A. Baker, P. Vervier

Biology Faculty Publications

1. Groundwater nitrate contamination has become a worldwide problem as increasing amounts of nitrogen fertilisers are used in agriculture. Alluvial groundwater is uniquely juxtaposed between soils and streams. Hydrological connections among these subsystems regulate nutrient cycling.

2. We measured denitrification using an in situ acetylene‐block assay in a nitrate‐contaminated portion of the Garonne River catchment along a gradient of surface water–ground water mixing during high (snowmelt) and low flow.

3. During high flow (mid‐April to early June) the water table rose an average of 35 cm and river water penetrated the subsurface to a great extent in monitoring wells. Denitrification …