Effects of current velocity, irradiance, and grazing on the
biomass, taxonomic structure, physiognomy, and chemical composition
of lotic algal assemblages were investigated. Four experiments,
lasting 32 to 75 days, were conducted in laboratory streams to
determine how these factors affect algal assemblages singly, and in
concert with each other.
Regardless...
Multiple successional sequences have been observed following disturbance in communities on marine hard substrata. Observations of the turf-forming alga, Iridaea cornucopiae Post. & Rupr. (Gigartinaceae), suggest that I. cornucopiae may assume its dominance by its ability to vegetatively pre-empt space. High limpet densities in the natural community, suggest that I....
The term "interaction" in evolutionary biology and ecology
describes the relationships among variables in two classes of causal
models. In the first, "interaction" refers to the influence of a
single putatively causal variable on a variable of interest. In the
second class of models, the term applies when a third...
Gradients of physical disturbance are central to
theories of community organization yet rarely are studies
performed in which physical factors are experimentally
manipulated. Pothole tidepool algal communities exhibit
distinct zonation patterns from top to bottom that result
from scouring by rocks and other debris in the pools.
Scouring is easily...
Two of the most powerful ways in which humans have altered ecosystems are by increasing productivity and changing the densities of important consumers. The bottom-up effects of productivity and the top-down effects of consumers have been identified as primary determinants of biological diversity, though the links between them remain unclear....
The influence of the physical environment on organisms has long been a subject of ecological research. But, the complex drivers of environmental variation, and the multiple scales at which this can occur, make studying this topic a difficult challenge. In rocky intertidal habitats, oceanographic- and climate-scale variability influence benthic communities...
The Nearshore Assessment Tool for Alaska: Southeast (NATAK-SE) is a standardized protocol for rapidly assessing the habitat and functions of a particular marine or estuarine shore segment (intertidal zone and immediately adjoining upland) anywhere in Southeast Alaska. It consists of data forms and a spreadsheet. It has a Rapid component...
Many phytoplankton and macroalgae release dissolved organic carbon (DOC). Many macroalgae also produce and store secondary metabolites which in some case have been shown to deter their grazers. The metabolites may be released into the surrounding seawater and could inhibit primary production. On the other hand, some phytoplankton can use...
The benthic microalgae of sediments of the two tidal flats in
Yaquina Bay, Oregon were investigated to determine the environmental
factors limiting the abundance and the horizontal and vertical distribution
of these organisms. The Southbeach tidal flat which is under the
marine realm of deposition consists of fine to medium...
