accidental species

accidental species

[¦ak·sə¦den·təl ′spē·shēz]
(ecology)
A species which constitutes less than one-fourth of the population of a stand.
References in periodicals archive ?
A high percentage of accidental species in forest communities indicates a more stable environment, while species listed as accessory are better adapted to the communities (Bernardi et al.
Bark-dwelling spiders have been classified according to how strongly connected they are to this habitat (Wunderlich 982) as follows: 1) Exclusive bark-dwellers are species that live on or under the bark during all or most part of their life cycle; 2) Facultative bark-dwellers are species that typically, but not exclusively, use this habitat; and 3) Accidental species are typically from other habitats and use bark habitats by chance or as an alternative.
The last benthic community shows a low affinity and includes accidental species with la < -0.
Recourse "Unto Mount Olivet" for the speaker is purely imaginative, even if excruciating: "A man so wrung with pains, that all his hair, / His skinne, his garments bloudie be" (lines 9-10) suggests a meditative sharing in Christ's sufferings, but poetic artifice renders sweet that which for another was truly agonizing, just as the accidental species of a Roman sacrament veil even as they embody their substantial counterpart.
The addition or deletion of a single species can change important properties of an ecosystem, influencing the regulation of energy flow and the cycling of chemicals, Vitousek reports after considering examples of deliberate and accidental species introductions.