I2+Intraspecific+Competition


 * Section I2-The Nature Of Competition**

__Density Dependence-__ Describes relationship between fitness and population size.
 * Negative Density Dependence**- A key population regulatory factor where declining fitness occurs as population density increases within a species due to intraspecific competition.

__Dispersal-__ When competition increases individuals may disperse away from areas of high population density.

Most plant species produce seeds that can be carried by wind, on the fur of animals, in the gut of fruit feeding birds and mammals or on water currents.



Dispersal provides away for individuals to avoid the cost of inbreeding (breed from closely related people or animals, esp. over many generations.)

Because of dispersal’s risky nature, it is believed that the individuals with **relatively low reproductive value** (younger members of the population) should be the ones to undertake the dispersion process. It would be unwise to have crucial reproducers of society to be the ones attempting to disperse. Should be the ones to undertake the dispersion process.

__Territoriality__- Can be described as when a numerous amount of species from different groups (including insects, birds and mammals), compete for areas of space. These areas are known as “territories”. Territories are spaces inhabited by many of these species. Each species has its own territory and ways of defending and maintaining them. For example, female red-winged blackbirds choose males on the basis of the males’ territory quality.



Territory size is determined by balance of “costs and benefits.” However, at some times the costs of maintaining the territory will begin to outweigh the possible benefits, making the maintenance process useless.

__Self Thinning-__
 * Self-Thinning** is the process in which an even-aged group of sessile (organisms unable to move) organisms, competing individuals cannot escape, and typically competition results in the survival of fewer individuals of larger and larger size. This relationship is known as **Yoda’s -3/2 Law** and has been seen in species such as barnacles and mussels.