Download Species: “groups of actually or potentially interbreeding natural

ENTOM/CSS 444: Integrated Pest Management
January 27, 2012
2.1 Why Study Ecology?
2.1.1. Case Study: the cane toad, Bufo marinus
2.1.2. Pesticides
2.1.3. Low diversity
2.2. Ecological Concepts and Definitions
2.2.1. Biological Units
Species: “groups of actually or potentially interbreeding natural populations that are
reproductively isolated from other such groups” (Ernst Mayr)
Population: a collection of individuals of one species that exists in some defined geographical
area
Guild: a group of species that exploit the same resource in a similar manner
Community: a group of populations occurring in the same geographical area
Ecosystem: a community of living organisms and the abiotic framework that supports them
Landscape: a cluster of interacting ecosystems
2.2.2. Defining Concepts
Diversity: the level of variation in a given component of ecosystem organization (i.e. species
diversity, genetic diversity)
Trophic pyramid: representation of density (or energy/nutrients) at several trophic levels
Biological magnification: sucessive increase in toxin concentration up through a food pyramid
Trophic web: diagram of connections between trophic levels
Stability: the ability of an ecosystem to return to equilibrium following a perturbation
Succession: progressive changes in community structure through time
Selection: the differential reproduction of genotypes
Nutrient cycles: the cyclic transition of nutrients through multiple forms
Productivity: the amount of material or energy formed by a community in a specific time period