38 terms

Chapter 6 Friedland

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Population
Second level of complexity after the individual, composed of all individuals of a single species that live in a specific area.
Community
Third level of complexity, all populations in da area. "How different species interact with each other."
Biome
Complexity level 4.5, group of ecosystems.
Ecosystem
Complexity level 3, communities exist in here, biotic+abiotic components in in a particular location.
Biosphere
Complexity level 5, Da livin world.
Dynamic
Constantly changing, used to describe populations.
Population ecology
The study of factors that cause populations to increase or decrease.
Population size
Total number of individuals within a defined area at a given time.
Population density
Number of individuals per unit area.
Population distribution
How individuals are grouped in respect to each other.
population Sex ratio
Ratio of Males:Females
Population Age Structure
How many individuals fit into particular age categories.
Density Dependent factors
Factors that impact survival and reproduction that are influenced by population size.
Limiting resource
Resource that is lacking and causes population decreases as a result
Carrying capacity
How many individuals an environment can sustain based on resources. Denoted as K
Density independent factors
Factors that affect survivability that is not affected by population of a species, like a tornado.
Population growth models
Mathematical equations that can be used to predict population size at any moment in time.
Growth rate
Number of offspring an individual can produce in a given time period minus the deaths of the individual and its offspring.
Intrinsic growth rate
Maximum potential of growth, even under perfect conditions.
Exponential growth model.
Nt=N0e^rt
Jshaped curve
The curve of an exponential graph.
Logistic growth model
A model of a population that shows initial exponential growth and then a plateau.
S Shaped curve
Curve of the logistic growth model
Overshoot
when a population grows to a size that the environment can not sustain.
Die-off
Effect of an overshoot when the extra individuals die from lack of food or other resources. Die offs and overshoots can be regular in an environment)
K-selected species
Species that have a small intrinsic growth rate so that when they reach the carrying capacity they do not have large die-offs if any because they had approached the carrying capacity gradually. Usually large species with long lives.
r selected species
Species that breed very quickly, and that have large population fluctuations because of that.
Survivorship curves
Patterns of survival that are plotted on these curves. Large species with long lives such as elephants and humans fit into type 1 survivorship curve, mosquitos and fruit flies fit into the type 3 survivorship curve and coral and squirrels that live kinda lengthy lives fit into type 2 survivorship curves.
Corridors
Strips of habitat that allow connectedness of species from population to population.
metapopulation
2 distinct populations that are linked by occasional individuals mingling between the two groups. Protects species from extinction
Fundamental niche
range of abiotic conditions that a species can tolerate
Able to disperse
Species need to be able to get to another physical location without human intervention to be present in an area.
Competition, predation, mutualism, commensalism
Self explanatory, categories of interaction between species.
Community ecology
Study of interspecies interactions
Competitive exclusion principle
two species that are competing for the same resource cannot coexist
Resource partitioning
Two species dividing a resource based on differences in the species behavior or morphology.
Temporal resource partitioning
Species using same resource but at different times.
Spatial resource partitioning
Reducing competition by using different habitats.