Biodiversity: Concepts, Patterns,
and Measurement
| 1. | What is biodiversity? |
| 2. | Relative abundance: Common species and rare ones |
| 3. | Measuring and estimating species richness |
| 4. | Species diversity indices |
| 5. | The spatial organization of biodiversity |
| 6. | Estimating β and γ diversity from samples |
| 7. | Species-area relations |
Life on Earth is diverse at many levels, beginning with genes and extending to the wealth and complexity of species, life forms, and functional roles, organized in spatial patterns from biological communities to ecosystems, regions, and beyond. The study of biodiversity encompasses the discovery, description, and analysis of the elements that underlie these patterns as well as the patterns themselves. The challenge of quantifying patterns of diversity at the species level, even when the organisms are known to science, is complicated by the problem of detecting rare species and the underlying complexity of the environmental template.
α, β, and γ diversity. The species diversity (or richness) of a local community or habitat (α), the difference in diversity associated with differences in habitat or spatial scale (β), and the total diversity of a region or other spatial unit (γ)
biodiversity. The variety of life, at all levels of organization, classified both by evolutionary (phylogenetic) and ecological (functional) criteria
diversity index. A mathematical expression that combines species richness and evenness as a measure of diversity
evenness. A measure of the homogeneity of abundances in a sample or a community
functional diversity. The variety and number of species that fulfill different functional roles in a community or ecosystem
rarefaction curve. The statistical expectation of the number of species in a survey or collection as a function of the accumulated number of individuals or samples, based on resampling from an observed sample set
relative abundance. The quantitative pattern of rarity and commonness among species in a sample or a community
richness estimator. A statistical estimate of the true species richness of a community or larger sampling universe, including unobserved species, based on sample data
species accumulation curve. The observed number of species in a survey or collection as a function of the accumulated number of individuals or samples
species-area relation. The generally decelerating but ever-increasing number of species as sampling area increases
species richness. The number of species in a community, in a landscape or marinescape, or in a region
Although E. O. Wilson first used the term biodiversity in the literature in 1988, the concept of biological diversity from which it arose had been developing since the nineteenth century and continues to be widely used. Biodiversity encompasses the variety of life, at all levels of organization, classified both by evolutionary (phylogenetic) and ecological (functional) criteria. At the level of biological populations, genetic variation among individual organisms and among lineages contributes
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Questia, a part of Gale, Cengage Learning. www.questia.com
Publication information:
Book title: The Princeton Guide to Ecology.
Contributors: Simon A. Levin - Editor.
Publisher: Princeton University Press.
Place of publication: Princeton, NJ.
Publication year: 2012.
Page number: 257.
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