2.1 - Intro to Biodiversity

Biodiversity

Diversity of life forms in an ecosystem

ecosystem diversity

the number of different habitats available in a certain area

species diversity

the number of species in a given ecosystem and the balance/evenness of the population sizes of each species in the ecosystem

Genetic diversity

difference in the genes of individuals in a population (same species)

higher ecosystem + population resilience to disturbance

Higher biodiversity =

Richness (S)

Measure of the total number of species found in a ecosystem

- High richness = good sign of ecosystem health; correlated with higher ecosystem stability and resource availability.

Evenness

measure of how all the organisms in an ecosystem are balanced between species

- indicated whether there are one or two dominant species, or if population sizes are well balanced

Genetic diversity pt. 2

measure of how different the genomes (set of genes) are of the individuals within a population of a given species

- There is genetic diversity in all populations because random mutations in DNA copying and recombination of chromosomes in sex cells of parents lead to new gene combinations & new traits in offspring

- The more genetic diversity in a population, the better the population can respond to environmental stressors

like drought, disease, or famine

higher chance that some of the individuals in a pop. have traits that allow them to

survive the environmental stressor

More genetic diversity =

Bottleneck Effect

An environmental disturbance that dramatically reduces population sizes regardless of their genomes

- The surviving population is smaller and doesn't represent the genetic diversity of the original population

reduce; smaller and less

Bottleneck events________ genetic diversity. Because the population is ___________genetically diverse, it's even more vulnerable

to future env. disturbances

Habitat Loss

Loss of habitat leads to a loss of specialist species, followed by a loss of generalist species

Specialist species

an organism that can thrive only in a narrow range of environmental conditions or has a very limited diet, occupying a specific ecological niche

- ex. panda or koala

Generalist species

can thrive in many different environments and use a wide variety of food sources or resources; a wide ecological niche

- ex. mice or raccoons

Ecosystem resilience

the ability of an ecosystem to return to its original conditions after a major disturbance

- windstorm, fire, flood, clear-cutting, etc.

higher ecosystem resilience

Higher species diversity =

- High species diversity means greater likelihood that some plant species can survive the disturbance and stabilize the ecosystem (by providing food, habitat to animals, anchoring soil, cycling energy,

etc.)