Lesson 5: Biodiveristy

The impact of biodiveristy

Biodiveristy allows for difference between organisms of the same species. 

This leads to differences in:

• Appearance

• Ability

• Behaviours

This can allow a species to react to a negative factor (disease, predation, abiotic threats) and have a high chance o survival as a whole.

High Biodiveristy

An ecosystem with high biodiverity you would expect to see:

• High amounts of different species

• Lots of different traits (adaptations) within a single species

• Highly interweaved food webs

• High resistance to disasterous events

A highly diverse ecosystem will have developed over many generations and will have organisms immigrating and emigrating into and out of the ecosystem to maintain it's diviersity

Low Biodiveristy

An ecosystem with high biodiverity you would expect to see:

• Lowamounts of different species

• Very similar looking organisms in one species

• Simple food webs

• Vulnerability to disaster

A undiverse ecosystem will be isolated, this can be from a recient disaster or could be caused by a geography that is difficult to get to (high mountains, low sea). This leads to the organisms that live there only being able to change or adapt through long periods of time.

Factors Affecting Population Sizes

There are four main factors that can determine a populatios size:

• Birth Rate (Natality)

  • The speed at which organisms reproduce to make the next generation of offspring

• Death Rate (Mortality)

  • The speed at which organisms die.

• Emigration

  • The number of individuals leaving the ecosystem

• Immigration

  • The number of individuals enetering the ecosystem