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

-Insect larvae that always kill what they eat (larvae and pupae of other insects)

-EX. Wasps give sawfly larvae buried in the ground to their larvae.

-Coevolution keeps both populations in balance. As the sawflies begin to dig deeper and deeper into the ground.

Using Parasites as Control Agents

-Many parasites are raised in order to control the population of certain areas

-5 attributes of good biological controls:

1. Well adapted to a host species and habitat

2. Exceptionally good for searching the host

3. Population growth is higher than the host's

4. Offspring are mobile enough

5. Able to respond to changes of the host quickly

-Biological controls are risky

-Too many biological controls may be ineffective.

-Biological controls can unexpectedly target the wrong species.

Interspecific Competition:

-Populations of different species compete for one resource

-Two species can be similar, but never close as their own species.

-Hence, it is much less fierce than intraspecific competition.

-Some species have better talent to get the resource

-Some species have better access of the resource, and protect it from others

EX. Male