Ecology Exam 2

Ecosystem Ecology

how energy and matter are transferred between abiotic and biotic components of the environment.

Biogeochemical Cycles

tracking matter as they are transferred between living organisms and the non living environment.

Carbon Cycle

How carbon gets from abiotic to biotic and back again

Carbon fixation

the atmospheric Co2 is fixed into organic molecules during photosynthesis. (abiotic- biotic)

Cellular Respiration

Co2 is released by organisms, (biotic-abiotic)

How do humans use this cycle

Humans use the fossil fuels created during the carbon cycle. (coal, petroleum)

Humans impact on carbon cycle

Deforestation, animal consumption, agriculture, burning of fossil fuelsarboC

Carbon Dating

Isotropic signaturas in the carbon can verify that the sources are carbon fossil fuels

What is the carbon cycle?

Photosynthesis, Consumption, Respiration, Decomposition, Combustion

Global Impact of carbon cycle

Increase in greenhouse gases- traps solar heat reflected from the planet- global warming.

Biotic Responses to Climate Change

The range shifts are a result of niche tracking that must occur.

Niche Tracking

as conditions change populations may move to new places to find suitable climate.

Pheonology

The study of timing of ecological events (leaves changing color, flowering timing)

Biotic Responses Negative

Extinction of species (golden toad, coral reef)

Climate Change Effects on Humans

Sea level rise, extreme weather, (drought, hurricanes) , human heath ( ticks)

Nitrogen Cycle

Cycle of nitrogen from abiotic to biotic to back again

Nitrogen Fixation

Bacteria in soil uses N2 to synthesize ammonia or nitrate (abiotic- biotic)

Denitrification

Other prokaryotes produce energy from converting nitride to N2. (biotic-abiotic) uN

Nitrogen Cycle Steps

Fixation, Consumption, Decomposition, Nitrification, Denitrification

Human Influence on Nitrogen Cycle

Deforestation, land change, fertilizers, human/animal waste

Neg Human Effect on Nitrogen Cycle

Available nitrogen has doubled in environment thanks to human influence

Eutrophication

excess nutrient can lead to an increase in primary production followed by dead zones

Example of dead zone

large bloom in algae in excess nutrient that then die and use large amounts of oxygen to decompose.

Nitrogen/ Oxygen Relationship

lows levels of nitrogen means more oxygen. inverse is also true

What hierarchical levels of ecology does conservation ecology cover

biosphere, communities, populations and organisms

What is conservation biology

a goal oriented science which relies on ecological knowledge

1. Save species from going extinct

2. Prevent loss of diversity

3. Prevent habitat loss

What is biodiversity

measured as the number of and relative frequency of all alleles in a species.

What is genetic biodiversity

total genetic variation contained within a species hat W

What factors influence genetic diversity

mutation, natural selection, genetic drift/ gene flow

Positives if genetic diversity

there is a better additive potential for a species

Inbreeding depression

breeding between genetically similar individuals that leads to the loss of diversity overtime.

Inbreeding depression negative effects

lower survivorship, lower reproductive rate

Extinction Vortex

Smaller populations have a greater risk of extinction.

1. Inbreeding/ Random Genetic Drift

2. Loss of genetic variability

3. Reductions in individual fitness

4. low reproduction/ high mortality

Importance of genetic diversity

Agriculture- Monocultres are more susceptible to disease climate change..

Species Diversity

number of species on planet

Endemic Species

species found no where else in the world

What is the concern about biodiversity hotspot

high areas of risk for extinction

Example of biodiversity hotspot

Madagascar

Importance of Species Diversity

1. higher productivity

2. more resistant and resilient to disturbances

3. high stability

How species diversity helps humans

1. Provisioning- provide food and water

2. Regulation- buffering against extreme climate, weather and disease

3. Supporting- pollinators, nutrient cycling

4. Cultural- spiritual and recreational use

Bioremediation

ecosystems can stabilize some toxic and render them harmless

How do vultures help human health

prevents human plague

Threats to biodiversity

Habitat loss- most important factor to cause decline of species

Habitat Fragmentation

Smaller habitat species are subject to increased edge effect

Overexploitation

Reduction of population to unsustainable level

Invasive Species

• non native

• grows in large populations

• disrupt native species

Endangered Species Act

established criteria for listing species and provides legal protection

Conservation Biology

reservation ecology

invasive species control

Darwin

• described how populations evolve via “descending” with modification

• did not know how inheritance works

Gregor Mendel

• studied the patten of inheritance by experimenting crossing pea plants

• Cells have two alleles

Homozygotes

have two copies of the same allele

Heterozygous

have tow diffrent alleles

Modern Evolution

combinations of Darwinism and mandalic genetics

Population Genetics

how allele frequencies change across generations.

Hardy-Weinberg

assumes : - no mutations, no gene flow, large population size, random mating, no natural selection

Allele freq: p+q=1

just know

Genotype Frequency p²+2pq+q²

know