Ecosystems

Factors of Community:

1. Interactions between the climate and topography

a. “Rainfall, soil, temperature”

2. The food and resources that grow

3. Other specific resources necessary for a species to survive and adapt to. (Ecological niche)

4. Species interaction

5. Physical disturbances, addition/removal of certain species

-These factors determine population sizes of an ecosystem.

-Conditions of arctic regions don’t allow many animals to live there due to the low temperature.

Niches: (all relationships in which species engage in order to survive and reproduce)

-Fundamental Niche is a theoretical niche, where there are no constraints or limited resources)

-Realized Niche is the actual niche, where there are constraints on resources)

Symbiosis: (“living together” Species interacting in +, -, and = ways)

Mutualism (++)

-Both species in interaction benefit

-Obligatory Mutualism

-One species cannot grow/reproduce without another species

EX. Yucca plants are only pollinated by Yucca moths.

-Yucca moths only grow in the yucca plant and only eat Yucca seeds.

Co-evolution

-The prey and predator build better defenses and counters to the other’s abilities.

-Since the best of the prey/predator survive more often, they have more chance to reproduce.

-Soon only the strong survive, thus, the best ways of countering reach the entire population.

-EX. Camouflage, Mimicry (faking a characteristic), Spewing toxins, showing teeth, etc

Carrying Capacity

-Maximum number of individuals that resources of environment can maintain.

-Predator-Prey populations can fluctuate.

-Predators may not adjust quickly enough to the abundance of prey.

-Additional predators could also influence the rate.

-As more predators reproduce and eat more prey, the prey population decreases.

-As more prey dies, predators have less to eat and begin to die off.

-With fewer predators, the prey once again starts to reproduce at a faster pace.

Predator- Animals that feed on living organisms, but do not live on them

Prey- targets of predators that are killed

Parasites- Feeds on tissues of living organisms and live on them

Host- the organism a parasite feeds on

Effects of Parasites

-Feeds off the host’s tissue’s nutrition.

-Alters how much energy enters the organism, and weakens it.

-Can alter birth rates, can sterilize, or make organisms less attractive to mates.

-Can open prey to diseases and infections.

-Usually does not want to cause death, so that it can reproduce for a longer period of time

Microparasites

-Rapid reproducers and personally infect the body.

EX. Bacteria, Viruses, Protozoan

Macroparasites

-Directly lay their eggs on the host.

EX. Fleas, ticks, mites, lice

Social Parasites

-Manipulate the social behavior of another species.

EX. Cuckoos lay their eggs in nests of other species, which push the rightful eggs out.

-The mother of the original eggs ends up feeding the cuckoos.

Parasitoids