The individualistic and community-unit concepts as falsifiable hypotheses

  title={The individualistic and community-unit concepts as falsifiable hypotheses},
  author={Bill Shipley and Paul A. Keddy},
This study reformulates the community-unit and individualistic concepts of plant communities as hypotheses concerning the distribution of species' boundaries along a gradient. These hypotheses are tested by an analysis of deviance on data derived from a direct-gradient analysis of a freshwater marsh plant community in Breckenridge, Quebec, Canada. Boundaries are clustered at certain intervals along the gradient (p<0.001), contradicting the individualistic hypothesis. Upper boundaries are not… 
Influences of the individualistic concept of vegetation on syntaxonomy
The individualistic concept of vegetation is based on three principles: (1) vegetation continuum, (2) ecological and chorological individuality of species and (3) multidimensional variability of
Relations between community theory and community analysis in vegetation science: some historical perspectives
Relations between community theory and community analysis are elucidated from a historical viewpoint. Four groups of relevant aspects are distinguished. This paper concentrates on aspects of spatial
Evaluating the role of biotic interactions in structuring communities using a gradient analysis of multiple interacting guilds
This work used elements of metacommunity structure analysis to study the extent to which species distributions are non-independent and tested the hypothesis that combinations of two or more interacting guilds exhibit more coherence than single guilds.
Null model tests of clustering of species, negative co-occurrence patterns and nestedness in meta-communities.
The tests for clustering and nestedness of the occurrences of species and negative co-occurrence patterns provide four important innovations that can be incorporated in the null model so that patterns that might be caused by biotic interactions can be distinguished from patterns which are the result of differences in the suitability or accessibility of sites for the examined organisms.
Rediscovering the species in community-wide predictive modeling.
  • J. Olden, M. Joy, R. Death
  • Environmental Science
    Ecological applications : a publication of the Ecological Society of America
  • 2006
This study demonstrates the utility of a multiresponse artificial neural network (MANN) to model entire community membership in an integrative yet species-specific manner and discusses how the MANN approach provides a powerful quantitative tool for conservation planning and its potential for biomonitoring programs that currently depend on modeling discrete assemblage types to assess aquatic ecosystem health.
Explanation and prediction in vegetation science
A definition of vegetation science is given, spanning 6 levels of integration and stressing the interrelations among them. The problems of realism are discussed. The selection of levels is related to
Montane vegetation of the Mt. Field massif, Tasmania: a test of some hypotheses about properties of community patterns
Although total alpha diversity had a complex trend surface, the patterns for the alpha diversities of each structural group were unimodal, in accordance with hypothesis (5).
A new model for the continuum concept
A reformulation of the continuum concept is presented after considering the implications of the community/continuum controversy and current niche theory. Community is a spatial concept dependent on
Metacommunity structure of tropical forest along an elevation gradient in Puerto Rico
Abstract: The development of metacommunity theory, which suggests that the diversity and composition of communities is influenced by interactions with other communities, has produced new tools for
Fuzziness and Heterogeneity of Benthic Metacommunities in a Complex Transitional System
An extension to the metacommunity (MC) concept and a novel operational methodology that has the potential to refine the analysis of MC structure at different hierarchical levels are proposed and the possibility of integrating the continuum and community unit concepts and of developing the concept of a habMC ecological niche is offered.


Community Interactions on Marine Rocky Intertidal Shores
"The ultimate goal of an ecological survey should be to discover and measure the main dynamic relations between all organisms living on an area over some period of time" (Elton 31 ). This is a tall
Shoreline Vegetation in Axe Lake, Ontario: Effects of Exposure on Zonation Patterns
This study tests several hypotheses relating community structure to environmental disturbance, by testing for changes in the zonation patterns of lakeshore vegetation. Twenty—five transects were
On the Prevalence and Relative Importance of Interspecific Competition: Evidence from Field Experiments
  • J. Connell
  • Environmental Science
    The American Naturalist
  • 1983
The present survey illustrates how difficult it is to produce a clear and unambiguous demonstration of interspecific competition.
zonation of plants in freshwater lakes
Population Dynamics of Two Competing Annual Plant Species
Species zonation and outcrop community structure are therefore a consequence of shifting competitive superiority as physical conditions shift, and Sedum plants are stunted by increased abiotic stress although population densities may remain high.
New approaches to direct gradient analysis using environmental scalars and statistical curve-fitting procedures
The conceptual framework of direct gradient analysis (DGA) is discussed in relation to the functional, factorial approach to vegetation. Both approaches use abstract simplified environment gradients
The individualistic concept of the plant association
The units of vegetation, which form the subject of our discussions this week, were just as easily visible to primitive man as they are to us today. They were equally visible to the sages of Greece
A succession of paradigms in ecology: Essentialism to materialism and probabilism
Lewontin (1974a), in his provocative essay ‘Darwin and Mendel — The Materialist Revolution,’ suggests that by the time On the Origin of Species was published in 1859, the notion of evolving species
Plant zonation in an Alaskan salt marsh. II: An experimental study of the role of edaphic conditions
Puccinellia nutkaensis appears to be restricted to the outer mudflat because it is a poor competitor in the inner mudflat and riverbank levee zones, and may determine its seaward limit of distribution within the marsh.
Wave disturbance on lakeshores and the within-lake distribution of Ontario's Atlantic coastal plain flora
Analysis of substrate samples showed that the exposure gradient is a multivariate gradient including not only biomass removal by waves, but sorting of the shoreline substrate, which may allow the persistence of Atlantic coastal plain species in at least two different ways.