2.1-2.2 Biodiversity and Ecosystem Services

Biodiversity

The variety of life on Earth

How many life forms is diversity measured on?

Three

Ecosystem diversity

The number of different habitats available in a given 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

Genetic diversity

How different the genes are of individuals within a population (group of the same species)

If there’s higher biodiversity, then…

Higher ecosystem/population health

If there’s habitat loss…

There’s a loss of biodiversity

Generalists

Species with broad niches that can use a wide array of habitats and resources. Able to live in many different places. Tend to be more adaptable to disturbances

Specialists

Species with narrow niches and very specific requirements. Extremely good at what they do, but vulnerable to change. The first to go due to habitat loss and disturbances

Richness

Total number of different species found in an ecosystem

Is high richness good or bad for an ecosystem?

A good sign of ecosystem health, usually means more quality resources like H20 and soil

Evenness

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

What does evennness indicate?

There are one or two dominant species, or if population sizes are well balanced

Why is it good if there’s more genetic diversity in a population?

The population can respond to environmental stressors and disturbances like drought, disease, or famine

What happens if there’s more genetic diversity?

Higher chance that some of the individuals have traits that allow them to survive the environmental stressor

Mutations

A change in the DNA sequence of a cell

Adaptive trait (adaptation)

A change/process by which an organism/species becomes better suited to its environment

Fitness

An organism’s ability to survive and reproduce in a particular environment (natural selection)

Bottleneck event

An environmental disturbance that drastically reduces population size and kills organisms regardless of their genome

What do bottleneck events do?

Reduce genetic diversity

Why doesn’t the surviving population represent the genetic diversity of the original population?

Surviving population is smaller and individuals died randomly, not by natural selection

What are the problems with a bottleneck event?

Could cause difficulty adapting to ecosystem changes, inbreeding, harmful mutations, population collapse

Resilience

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

What does higher species diversity mean?

Higher ecosystem resilience, more plant species to repopulate disturbed ground, anchor soil, and provide food and habitat for animal species

Ecosystem services

Goods and services provided by natural ecosystems that are beneficial to humans

What decreases the value of ecosystem services

Human activities disrupt the ability of ecosystems to function (ecological and economic consequences)

Cultural services

The non-material benefits people obtain from ecosystems

Examples of cultural services

Aesthetic inspiration, cultural identity, spiritual experiences, tourism and recreation, education

What is disrupted by deforestation, pollution, and urbanization?

Cultural services

Provisioning services

Resources or goods harvested from an ecosystem

What are examples of provisioning services?

Food, lumber, freshwater, fisheries, medicines

What is disrupted by over harvesting, water pollution, and clearing land for agriculture/urbanization

Provision services

Regulating services

Maintains the quality of natural resources

Examples of regulating services

Climate regulation, maintaining of air quality and water quality, flood prevention, pollination

What is disrupted by deforestation

Regulating services

Supporting services

Natural ecosystems supporting processes we do ourselves, making them cheaper and easier

Examples of supporting services

Nutrient cycling, habitat for different species, maintaining biodiversity, and photosynthesis

What is disrupted by habitat loss, and filling in wetlands for development

Supporting services