Population and Community Ecology Flashcards
Ecology
Relations of organisms to one another and to their physical surroundings
Population
Group of individuals of the same species in an area
Community
Group of populations in an area
Ecosystem
Community of interacting organisms and their physical environment
Biosphere
Any region of the earth that contains living things
Regions of the surface, atmoshere, and hydrosphere occupied by living organisms
habitate
Type of place where a certain organisms usually lives
May explain the temperature, soil type, water slinity, or other organisms living there
Niche
Any biotic/abiotic resource used by an organism in their environment
Environment or resource will change a s a result of the niche of an organism living there
Evolutionary result of a species’ morphology (physical structure), physiological, and behvioural adaptations to its surroundings
Population Ecology
Growth, abundance, distribution of populations
Size
Total number of individuals living in a population
Density
Total number of organisms per area/volume occupied
Dispersion
Way that individuals are distributed in a population
i..e Clumped- humans in cities, uniform- orchard trees, random- forest trees
Age Structure
Describes amount of individuals of a species at each age
Pyramid shaped diagram= rapidly growing population (lot of young individuals)
Equal width tiers= zero population growth- ZPG
Survivorship Curves
Describes varying mortality of individuals of a species over their lifetime
Type I Survivorship Curve
Most organisms survive to middle age, then the majority die afterwards
i.e humans
Type II Survivorship Curve
Random rates of survival
Likelihood of mortality is the same at every age
Type III Survivorship Curve
Majority die young, with few surviving to adulthood
Common in species with larvae (marine plankton), where most are eaten and don’t make it to adulthood
Biotic Potential
Max growth rate of a species under perfectly ideal conditions (unlimited resources, no restrictions)
Depends on age at reproductive maturity, number of offspring during reproduction, how frequently reproduction occurs, and survivorship of offspring
Carrying Capacity
Maximum number of organisms in a population that can be sustained by their habitat
Limiting Factors
Anything that prevents a species from reaching their biotic potential
Density Dependent Factors
Bigger population= greater effect/limitations
i..e transition of parasites and diseases, competition for food
Density Independent Factors
Effect is not dependent on population size
i.e. natural disasters, extreme climates
Intrinsic Rate of Growth
When reproductive rate is at maximum (biotic potential)
Exponential Population Growth
Reproductive rate is greater than 0
Growth of population rises quickly
Logistic Population Growth
Limiting factor preventing exponential growth from occurring
Population size becomes restricted to its carrying capacity
Effects of Burning Fossil Fuels
Biological Magnification
Acid rain
Increase in atmospheric CO2
Ozone depletion
K Selected Population
Members have low reproductive rate
Carrying capacity is density dependent
i..e humans
R Selected Population
Rapid exponential population growth
Numerous offspring
Affected by density independent factor
Opportunistic species
Organisms (i.e. insects) that quickly infect an area, reproduce, and die
