Environmental Science Chapter 6

Two types of interactions/competitions

intraspecific and interspecific

Intraspecific competition

members of the same species competing for resources

Interspecific competition

members of different species competing for resources

Competitive exclusive principle

two species that directly compete for resources cannot coexist

Ecological niche

the role an organism fills within its habitat

fundamental niche

complete range of areas in which an organism could exist

Realized niche

range in which an organism actually exists due to competition

Niche differentiation

division or resources and the potential competitors that may exist

Two types of mechanisms or competition

exploitation and interference

Exploitation competition

consume the resource the fastest (siblings fighting over food at dinner/first come first served)

Interference competition

stop the other competitors from consuming the resource (more defensive/hiding the resource)

Herbivores

organisms that feed on plant material. their digestive systems are specialized to be able to get the most out of vegetative material and detoxify plant chemicals. (some bigger animals such as some reptiles and many smaller bugs)

Coevolution

symbiosis. the prey and the species that it consumes benefit from each other (milkweed and the monarch butterfly)

Predators

capture, kill, and consume prey. they hunt various species. (not going to starve if their favorite prey item isn’t available.)

Prey

are hunted by predators but adapt defences to protect themselves.

Parasites

keep predators in check. they depend on the host for nourishment. don’t usually kill the host because then they don’t have a food source anymore.

4 parasite disease factors

1. abundance of hosts

2. accessibility of hosts

3. transmission rate of parasites

4. length of life of an infected host

ways to control pests

disrupt reproduction either through prey or stopping them from reproducitng

symbiosis

Intimate relationship between two species. three different kinds. commensalism, parasitism, mutualism

Mutualism

Both species benefit

ex. figs and wasps… wasps get food, fig seeds get dispersed.

Commensalism

one species benefits and the other is uneffected.

Energy flow

the transfer and transformation of energy

Organism classification

by trophic level which is based upon food source… where they get their food from

Decomposers

organisms that feed on nonliving organic material. they make use of all the waste in the rest of the trophic levels.

1st trophic level

primary producers. (plants) this level uses photosynthesis to make oxygen and glucose.

2nd trophic level

primary consumers (herbivores). specialized structures to consume different kinds of plants

3rd trophic level

secondary consumers (carnivores)

4th trophic level

tertiary consumers (apex predator/top carnivore)

Biomass energy

food that can be consumed by higher trophic level

trophic level efficiency

much energy available in the prey is used by the predator… leaving less than 10% for the next trophic level.

Food webs

depict all of the feeding relationships. they are more detailed than food chains. the more complex a food web is, the greater stability that is provided

keystone species

these species created stability in a food web. The removal of this species causes a collapse. many of these species are plants but there are a few animals as well.

trophic cascade

loss of carnivores results in an explosion of herbivores that destroy primary producers