APES unit 2

biodiversity

variability among species, between species, and of ecosystems

ecosystem diversity

types of habitats that can be found in a specific area.

high ecosystem diversity =

1. abundant natural resources

2. large genetic diversity

3. complex food web

4. lots of species

genetic diversity

all genetic traits making up a gene pool for one species.

species diversity

number of diff species in an area

what factors increase diversity

1. disturbances in the habitat

2. diverse habitats

3. envi conditions with low variation

4. evolution

5. middle states of succession

6. trophic levels w high diversity

what factors decrease diversity

1. environmental stress

2. extreme amounts of disturbance

3. extreme envis

4. extreme limitations of a resource

5. geographic isolation

6. introduction of other species that can affect the foood web

species richness

the number of different kinds of species in an area

+richness = more diverse

species eveness

the amount there is of each species compared to the opther species in that area

+even = more diverse cause there isnt a super dominant soecies

antropogenic activity

means relating to human activity

anthropogenic activities that reduce biodiversity

[ activity → how it reduces → how we can fix ]

1. burning of fossil fuels → acid rain ph changes → taxes, incentives, renewable energy.

2. deforestation → less homes for animals → replanting, selective cutting.

3. modern industrial agriculture → one crop covering massive area → planting more diff kinds.

4. overfishing → thretens keystone species, messes up food web → penalize overfidshing, quotas, tighter enforcement.

5. pesticides → kill pests + beneficial organisms → management.

population bottleneck

a large reduction in the size of a single population (not at a community or larger ecosystem level) due to a catastrophic environmental event (e.g., disease, drought, fire, or flood).

minimum viable population size = smallest possible size at which a population can exist without facing extinction

Loss of Habitat =

Loss of Specialist Species

generalist species

• low maintenance

• eat anything

• can live in diff kinds of enviorments

• for example racoons

specialist species

• require unique resources

• limited diet

• specific habitat

• for example pandas

types of ecosystem services

1. Cultural (e.g., spiritual and recreational benefits)

2. Provisioning (e.g., production of food and water)

3. Regulating (e.g., control of climate and disease)

4. Supporting (e.g., nutrient cycles and crop pollination)

cultural service

recreational actvites like walking, hiking etc.

provisioning service

tangible goods and materials like timber, milk, wool

regulating service

natural cycles like water cycle, carbon cycle (e.g., control of climate and disease)

supporting service

(e.g., nutrient cycles and crop pollination) support humans

island biogeograhy can be determined by

size + distance from mainland

island closer to mainland =

• more species able to immigrate there

• higher risk of invasive species

• higher biodiversity

island larger =

• larger habitats

• more diverse habitats

• reduces probabilty of extinction

• more random dispersion on organisms so more species diversity

factors influences species diversity

1. degree of isolation

   a. closer = more diverse

   b. farther = less diverse

2. habitat fragmentation

   a. edges of habitats have fewer species

   b. interior of habitats have more species

3. habitat suitability

   a. climate

   b. initial plant and animal composition

   c. current species composition

4. human activity

5. location to ocean currents influences bird, fish, nutrient patterns, pathways.

table

high immigration = closer to mainland

high extinction = smaller island

whats the main threat to terrestrial biodiveristy ??

habitat fragmentation

Law of Tolerance

states that the existence, abundance, and distribution of species depend on the tolerance level of each species to both physical and chemical factors within its environment

optimum tolerant = more likely to survive

law of tolerance graph

if factors/conditions that the organism is in are beyond their tolerance level, organism will die.

if factors are too low for tolerance level, organism will die then too.

flooding effects

1. Kills wildlife and their food source

2. Soil is no longer held in place by roots.

3. saturated soils can kill plants by drowning the plant roots.

4. water and nutrients to run off across land surfaces.

5. Burrows, dens, and nests can be destroyed, forcing surviving animals to relocate.

6. Flood plains, which are flat areas along rivers that flood when the river rises above its banks, are inhabited by species that have adapted to occasional flooding.

7. deposits nutrient-rich sediment along stream banks.

Volcanic Eruptions effects

1. Kills wildlife and their food source

2. Soil is no longer held in place by roots.

3. Volcanic materials ultimately break down and weather to form some of the most fertile soils on Earth

4. water source from steam

5. sulfur gas being trapped in atmosphere makes it cooler

wildfire effects

1. kills organisns

2. moves soil

3. helps clear out dead vegetation so surviving plants can get more sunlight

4. ash and charcoal left adds nutrients

5. some plants require fire in their life cycles

episodic

occurring occasionally and irregularly

el nino every 2-7 years

periodic

occurring at repeated intervals

tides

random

lacking a regular pattern

meteorite impacts

why has earths climate changed

• Changes in ocean and atmosphere circulation patterns

• Plate tectonics—continents “drifting” to different latitudes

• Varying concentrations of atmospheric carbon dioxide

• Volcanic eruptions

Sea level has varied significantly as a result of

• changes in the amount of glacial ice on Earth over geological time 30%

• temp of ocean 30%

• shape of oceans 40%

why does wildlife migrate

• harsh weather

• natty disasters

• natty resources

short-term adaptation

• develops in response to temporary changes in the environment

• involves temporary changes

• is not inherited

• nor does DNA change

• plays no role in evolutionary processes.

long-term adaptations

changes in DNA

ecological succesion

the process where an empty area gradually changes into a complex ecosystem, like a forest, as different plants and animals move in over time.

Facilitation

one species modifies an environment to the extent that it meets the needs of another species.

Inhibition

one species modifies the environment to an extent that is not suitable for another species.

Tolerance

when species are not affected by the presence of other species.

pioneer species

generalists

early species

pioneer plants

short reproductive times (annuals)

pioneer animals

low biomass and fast reproductive rates

successional species

larger perennial plants and animals with greater biomass, longer generational times, and higher parental care.

Primary succession

The evolution of a biological community’s ecological structure in which plants and animals first colonize a barren, lifeless habitat. no soil here at first.

Secondary succession

which plants and animals recolonize a habitat after a major disturbance; e.g., a devastating flood, lava flow, or wildfire significantly alters an area but has not rendered it completely lifeless

climax community

GP high but balanced by R

net productivity approaches 0

stable community

most resilient stage of succesion

primary succesion stages

1. Bare rocks

2. Pioneer microorganisms

3. Plants (lichens and mosses)

4. Grassy stage

5. Smaller shrubs, and trees

6. Animals begin to return when there is food there for them to eat.

7. When it is a fully functioning ecosystem reaches climax communtity

secondary succesion stages

1. A stable deciduous forest community exists.

2. A disturbance (e.g., wildfire) destroys the forest and burns it to the ground.

3. The fire leaves behind soil.

4. Grasses and other herbaceous plants grow back first.

5. Small bushes and trees begin to colonize the area.

6. Fast-growing evergreen trees develop while shade- tolerant trees develop in the understory.

7. The short-lived and shade-intolerant evergreen trees die as the larger deciduous trees survive. The ecosystem is now back to a state similar to how it began.

keystone species

extinction would lead to the extinction of other forms of life. a small number of individuals from a keystone species have a very large and disproportionate impact on how ecosystems function.

exmaples:

• bat species

• grizzly bears

• prairie dogs

• sea stars

indicator species

whose presence, absence, or abundance reflects a specific environmental condition and can indicate the health of an ecosystem.

• Caddisflies, mayflies, and stoneflies—require high levels of dissolved oxygen in the water

• Lichens—some species indicate air pollution Mollusks—indicate water pollution
  Mosses—indicate acidic soil
  Sludge (Tubifex) worms—indicate stagnant, oxygen-poor water