Biology Faculty Research, Publications and Presentations: Recent submissions
Now showing items 21-40 of 185
-
Patch Dynamics of a Phytophagous Mite Population Effect of Number of Subpopulations
I conducted a field test of the hypothesis that the dynamics of a predator-prey interaction should be affected by the number of interacting subpopulations within an assemblage. I used a "successful" biological control ... -
Intraguild interactions and large-scale population patterns
Competitive interactions, including interference and intraguild predation, occur in many aquatic food webs and influence large-scale patterns of abundance, especially in lentic habitats. In a study of small coastal streams ... -
Invertebrate predation and lotic prey communities: Evaluation of in situ enclosure/exclosure experiments
The influence of the stonefly Kogotus nonus on prey communities was assessed by varying the predator density within small enclosures in a first-order stream in southwestern Alberta. Experimental containers with natural ... -
A Refuge for Red Scale the Role of Size-Selectivity by a Parasitoid Wasp
The presence of a physical refuge (an area where mortality due to parasitism is very low) has been demonstrated for California red scale, a pest of citrus. Density of red scale is very high, and parasitism by the principal ... -
Regulation of an Insect Population Under Biological-Control
California red scale is suppressed to very low densities by the parasitoid Aphytis melinus. The system also appears stable. We report on an experimental test of the hypothesis that stability is caused by a refuge for scale. ... -
Refuge dynamics and metapopulation dynamics: An experimental test
Red scale, an insect pest of citrus, is under control by the parasitoid Aphytis melinus in many areas, and in our study area the interaction appears dynamically stable. The bark on the interior branches and trunk of trees ... -
-
Acoustical features of song categories of the Adelaide's warbler (Dendroica adelaidae)
I identified acoustical features that distinguish the two song categories, A and B, of the Adelaide';s Warbler (Dendroica adelaidae). Like many other wood-warbler species, male Adelaide';s Warblers have functionally ... -
How Many Species Are There on Earth and in the Ocean?
The diversity of life is one of the most striking aspects of our planet; hence knowing how many species inhabit Earth is among the most fundamental questions in science. Yet the answer to this question remains enigmatic, ... -
Food-Web Structure of Seagrass Communities across Different Spatial Scales and Human Impacts
Seagrass beds provide important habitat for a wide range of marine species but are threatened by multiple human impacts in coastal waters. Although seagrass communities have been well-studied in the field, a quantification ... -
Free-Space Availability and Larval Substratum Selection as Determinants of Barnacle Population-Structure in a Developing Rocky Intertidal Community
Variation in settlement and recruitment of the barnacle Semibalanus balanoides (L.) was experimentally investigated in the high, mid and low intertidal zones at 2 adjacent sites (A and B) on a rocky shore in Nova Scotia, ... -
Variations in Sampling Procedure and Frequency Affect Estimates of Recruitment of Barnacles
The influence of variations in sampling procedure and frequency on estimates of recruitment of the barnacle Semibalanus balanoides (L.) on an intertidal rocky shore at Sandy Cove, Nova Scotia, Canada was determined from ... -
Fecal production by sea urchins in native and invaded algal beds
To examine the role of fecal production by the sea urchin Strongylocentrotus droobachiensis in native and invaded algal assemblages in Nova Scotia, Canada, we examined the quantity (production rate by urchin feeding ... -
Spatial heterogeneity of phytoplankton assemblages in tidepools: Effects of abiotic and biotic factors
In any ecological system, the factors that regulate the abundance of species vary with spatial scale; therefore, the sources of spatial variability should be described. We examined different sources of variability in the ... -
Top down and bottom-up regulation of phytoplankton assemblages in tidepools
We examined the relative importance of bottom-up (nutrient availability) and top-down (grazing) factors in regulating phytoplankton assemblages in tidepools on a rocky shore near Halifax, Nova Scotia, Canada. We manipulated ... -
Community structure and organization of tidepools
Although tidepools are conspicuous components of rocky intertidal shores, their biotic communities have not been studied as extensively as those on emergent substrata. We examine processes regulating the structure of ... -
Spatial and Temporal Variability of Macrobenthic Communities in Tidepools on a Rocky Shore in Nova-Scotia, Canada
Spatial and temporal patterns in the distribution and abundance of macroalgae and macrofauna were measured in 4 pools in each of 3 intertidal zones (mid, high and splash) on a rocky shore near Halifax, Nova Scotia, Canada. ... -
Variation in egg spawning among subpopulations of sea urchins Strongylocentrotus droebachiensis: a theoretical approach
Variation in zygote production, by determining the initial size of the larvalpool, can aff ect the population dynamics of marine invertebrates with a planktonic larval stage. In this paper, we model temporal and spatial ... -
Spatial and Temporal Variability of Tidepool Hyperbenthos on a Rocky Shore in Nova-Scotia, Canada
We examined the distribution and abundance of the hyperbenthos in tidepools on a rocky shore, near Halifax, Nova Scotia, Canada, at approximately monthly intervals between March and November 1991, and between April and ...