Ecological Change
Any organism considered harmful or inconvenient by humans (insects, weeds, fungus, bacteria).
Pest
Term used to describe fruits and vegetables grown on farms.
Produce
A pesticide that kills insects.
Insecticide
A type of populations that has all four factors acting (births, deaths, immigration, and emigration).
Open Population
Number of times a species reproduces each year.
Procreation Rate
The process that biological communities change over time (e.g. bare rock goes to a forest; re-growth after a forest fire).
Succession
A farming practice that alternates types of crops grown; nitrogen- demanding corn is alternated with nitrogen-giving soybean.
Rotated
A pesticide that kills weeds.
Herbicides
Happens when individuals of a species move into an ecosystem.
Immigration
The number of offspring of a species born each year.
Natality
The most stable stage in succession; ( e.g. boreal forest, grasslands, and deciduous forest).
Climax Community
Type of farm that does NOT use pesticides or chemical fertilizers.
Organic Farm
A pesticide that kills bacteria.
Bactericide
The maximum population of a species that can be supported indefinitely by an ecosystem.
Carrying capacity
Number of years an individual can reproduce.
Length of Reproductive Life
First organisms to arrive in an ecosystem with little (to no) need for soil or nutrients (e.g. lichens).
Colonizers
Waste products from herbivores (horses and cows) used to naturally fertilize farmer’s fields.
Manure
A pesticide that kills fungi.
Fungicide
The number of individuals of a species that die each year.
Mortality
Number of offspring that reaches reproductive age.
Capacity For Survival
The process of toxic chemicals building in the top trophic levels in ecosystems.
Bioaccumulation
Plants that contain nitrogen-fixing bacteria on their roots; do NOT require fertilizers.
Legume
The process where pests develop immunity to pesticides making the pesticide useless.
Resistance
A factor that affects a population regardless of the population size (e.g. forest fire).
Density-independent factor
The maximum number of offspring a species could produce if resources were unlimited.
Biotic Potential