ecology

group of individuals all of the same species living in the same area

group of populations living in the same area

interrelationships between the organism in a community and their physical environment

all the regions of the earth that contain living things.

• where an organism usually lives
• may include physical and chemical environment

• all the biotic (living) and abiotic (nonliving) resources in the environment used by an organism
• certain resources being consumed or certain qualities of life are changed in some way by the presence of the organism

study of the growth, abundance, and distribution of populations

• represented by N
• total number of individuals in a population

total number of individuals per area or volume occupied

• how individuals in a population are distributed
• may be: clumped, random, uniform

• abundance of individuals of each age
• horizontal:expresses the frequency of individuals in an age group
• vertical line:divides each age group into males and females
• rapid growing:large portion of the population is young (pyramid shaped)
• when tiers are equal=zero (stable) population growth

how mortality of individuals in a species varies during their lifetimes

species in which most individuals survive to middle age. after that age, mortality is high

• length of the survivorship is random
• likelihood of death is the same at any age

• most individuals die young
• few survive to reproductive age or beyond
• ex: oysters, plankton