Ecology Unit

species diversity
species richness + species evenness
species richness
number of different species in an area
species evenness
the abundance of individuals within each of those species
niche structure
how many potential ecological niches could occur, how they differ/resemble each other, and how the species within them interact
geographical location
species diversity is highest in the tropics and declines as it moves north and south toward the poles
native species
those species that normally and thrive in a particular community
non-native species
other species that migrate into or are deliberately or accidently introduced into a community
indicator species
species that serve as early warnings of damage to an ecosystem
keystone species
a species that play a key role in its eco-system
foundation species
(type of keystone species) species that play a major role in shaping communities by creating and enhancing their habitat
interspecific competition
competition between species for a shared resource. Instead of fighting, this means its a race to adapt best
resource partitioning
when creatures using the same resource, evolve to share it
members of one species feed directly on all or part of a living organism
occurs when one species (the parasite) feeds on part of another (the host) who is harmed by the interaction
two species or a network of species interact in a way that benefits both or all
a relationship that benefits one species but has little, or no effect on the other species
ecological succession
the gradual change of species composition in an area
thre patters of population distribution
1. clumping2.

uniform dispersion3. random dispersion

population change=
(birth rate + immigration) – (death rate + emmigration)
biotic potential
capacity for growth
intrinsic rate of increase (r)
rate at which a population would grow if it had unlimited resources
environmental resistance
all factors that act to limit growth of a population
carrying capacity (K)
environmental resistance + biotic potential
r-selected species
high rate of population increase, usually small, parents do not care for children
k-selected species
small number of offspring, usually larger and live longer
regulate their body temperature by producing heat from within the body (warm blooded)
use heat from outside their body (cold-blooded)
unitary organism
each individual is formed directly from the zygote and the development is high predictable
modular organisms
have zygotes that develop into a module
intraspecific competition
competition occurring within the same species
interspecific competition
competition occurring between different species
competition between plants and toxins
three assumptions of lotka-volterra predator-prey model
1.there is one predator and one prey species in the interactions2. prety numbers decrease if predators rise and vice versa3. predator numbers increase when prey increases, and decreases when they fall