40 terms

Chapter 6 Friedland

nature levels
- individual
- population
- community
- ecosystem
- biosphere
individuals that belong to the same species and live in a given area at a specific time
incorporates all of the populations of organisms within a given area
population ecology
study of factors that cause populations to increase or decrease
population characteristics
- size
- distribution
- sex ratio
- age structure
density-dependent factors
influence an individual's probability of survival and reproduction in a manner that depends on the size of the population
ex. food
density-independent factors
have the same effect on an individual's probability of survival and amount of reproduction at any population size
ex. natural disasters
limiting resource
resource that a population cannot live without
carrying capacity
limit to how many individuals an environment can sustain
growth rate
number of offspring an individual can produce in a given time period minus the deaths of the individual or its offspring during the same period
J-shaped curve
exponential growth, rapid growth
S-shaped curve
slow growth
K-selected species
low intrinsic growth rate
Type I survivorship curve
ex. elephants, humans
intrinsic growth rate
maximum potential for growth
r-selected species
high intrinsic growth rate
Type III survivorship curve
ex. fishes
Type II survivorship curve
constant decline in survivorship curve
survivorship curves
plot the proportion of individuals alive at each age
group of spatially distinct populations that are connected by occasional movements of individuals between them
community ecology
study of species interactions
species interactions
- competition
- predation
- mutualism
- commensalism
struggle of individuals to obtain a limiting resource
competitive exclusion principle
when 2 species compete for the same limiting resource they cannot coexist
resource partitioning
two species divide a resource based on differences in the species behavior or morphology
temporal partitioning
use same resource at different times
spatial partitioning
reduce competition by using different habitats
morphological partitioning
evolution in differences in body size or shape
use of one species as a resource by another species
- true predators
- herbivores
- parasites
- parasitoids
true predators
kill their prey and consume most of what they kill
consume plants as prey
live on or in the organism they consume
the disease that parasites cause in their host
organisms that lay eggs inside other organisms
help each other out
one benefits and the other is not harmed
symbiotic relationship
relationship of 2 species that live in close association with each other
- commensalism
- predation
- mutualism
keystone species
species that plays a role in a community that is super important than its relative abundance might suggest
ex. starfish
ecological succession
replacement of one group by another over time
primary succession
occurs on surfaces with no soil
secondary succession
areas that have been disturbed but did not lose their soil
pioneer species
ability to colonize a land rapidly