APES 2.1-2.3

Biodiversity

the diversity or variety of life forms in an ecosystem measured on 3 different levels.

Ecosystem Diversity

The variety of different habitats or ecosystems in a specific area

Species Diversity

The number of different species in an ecosystem and the balance or evenness of the population sizes of all species in the ecosystem.

Richness

the total number of different species found in an ecosystem

Evenness

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

Genetic Diversity

How different the genes are within individuals within a population. Variety of alleles present within a single species or population 

More Biodiversity =

high ecosystem/population health

Bottleneck Events

An environmental disturbance such as Natural Disaster, Deforestation, Flood that drastically reduces the population size and kills organisms randomly, regardless of their genome and reduce genetic diversity, making it more vulnerable to future environmental disturbances.

Inbreeding Depression

when organisms mate closely with related family members. This is seen in smaller populations (like endangered species) and leads to higher chances of offspring being born with harmful mutations. 

Ecosystem Resilience

The ability of an ecosystem to return to its original conditions after a major disturbance (wind storm, fire, flood, clear-cutting, etc.)

Redundancy

if one species declines due to a disturbance, others can compensate by taking over its function, helps maintain the balance of processes like energy transfer, nutrient cycling, and species interactions, making the ecosystem more adaptable and better able to recover from disruptions.

Ecosystem services

the direct and indirect benefits that humans derive from the functions of healthy ecosystems. These benefits are essential for human survival, well-being, and economic prosperity.

Provisioning services

The “products” obtained from ecosystems. Goods or products taken directly from an ecosystem or made from natural resources ex: food, fibers, medicines, fresh water

Regulating services

Benefits obtained from the regulation of ecosystem processes that moderate natural phenomena and prevent an ecosystem from going to one extreme or another and act as buffers to control or balance ecosystems, e.g., flood prevention, erosion control, pollination, seed dispersal.

Cultural services

Nonmarterial benefits obtained from ecosystems ex: educational, recreational, spiritual, stress relief

Supporting services

Services necessary for the production of all other ecosystem services ex: biodiversity, nutrient recycling, primary productivity.

Island Biogeography

The ecological field of study that examines the factors influencing the biodiversity and species richness of isolated natural communities, particularly islands. can be in the middle of the water, or they can be figurative habitat islands on land that are natural areas surrounded by human development

The larger the island the greater the..

ecosystem diversity because of more food and habitat resources & more niches or “roles” organisms can play in the ecosystem.

Larger population size =

more genetically diverse and more resistant to environmental disturbances.

Migration

Islands closer to the mainland are easier migrating organisms to get to, increasing population size and genetic diversity.

Generalist species

organisms that can thrive in a wide variety of environmental conditions, utilize a broad range of resources (like food), and are highly adaptable to change (e.g., raccoons )

Specialist species

organisms that thrive only in a narrow range of environmental conditions or have a limited diet and habitat, giving them a specific, narrow ecological niche (e.g., koalas eating only eucalyptus leaves 🐨)

Pressure

More pressure allows species to adapt to narrower niches resulting in unique species specially adapted to their specific island.

Adaptive Radiation

When a single species rapidly evolves into several new species to use different resources and reduce competition. A great example is the evolution of the Galapagos finches. A single colonizing species from the mainland quickly evolves into many slightly different species to adapt to new island conditions