What are some of the ways organisms get energy from their environment?
- Photosynthesis (plants get energy from the sun)
- Chemosynthesis (organisms create their own energy)
- Consuming other organisms
A decrease in biodiversity is evidence that an ecosystem has been impacted by…
Human activities
What is a species richness? How is it found?
- The number of species in a given area
- Found by counting the number of different species present in a given area
What is species evenness? How is it found?
- How evenly distributed the species are
- Considers how common or rare each species is within the community
- Found by counting the number of different species present and the number of individuals of each species
What is a Climax Community?
- The final, stable stage of ecological succession in a given area
- Plant and animal species present are well-adapted to the local climate and conditions, reaching a state of equilibrium with minimal change over time
When trying to determine if a disturbed ecosystem has reached a Climax Community you need to consider the…
- The producers
- They stay in one place, heterotrophs are more likely to move in or out of the ecosystem.
What is the purpose of a control group in an experiment?
- Creates a baseline for comparison
- Allows researchers to see the effect of the independent variable
What is mono-cropping
The practice of growing the same crop year after year in the same location
-Is more likely to be wiped out due to lack of genetic diversity
What are the potential negative impacts of mono-cropping?
- Reduced biodiversity
- Soil degradation, which is harm to soil fertility
- Pesticide resistance
- Impact on pollinators
- Damage to natural environment
How can the biological diversity of an ecosystem be measured or assessed?
Simpson’s diversity index, which take into account both richness and evenness when calculating a single value representing overall biodiversity
Are all externalities negative?
No, they can be both positive or negative
Def) an effect of an economic activity that impacts a third party who is not directly involved in the transaction
Poss EX) someone planting a tree
Neg EX) factory polluting a river
Why are smaller populations more susceptible to population changes?
Genetic drift:
- In smaller populations, random fluctuations in allele frequencies are more likely to occur, leading to the loss of genetic diversity and potential negative impacts on the population’s ability to adapt
- More susceptible to bottlenecking due to lack of gene pool
What is the Island Biogeography Theory?
The number of species found on an island is directly related to its size and distance from the mainland
Larger and closer to mainland = more biodiversity
-Based on genetic diversity, biodiversity, and habitat diversity
What is the difference between a keystone specie and a indicator specie?
A keystone species actively shapes the ecosystem, while an indicator species passively reflects its condition
Keystone EX) Beavers which create wetlands that support a variety of other species by building dams
Indicator EX) Certain types of lichen, which are highly sensitive to air quality
What characteristics allow an ecosystem to recover from a disturbance?
Species diversity, genetic diversity, habitat diversity
= creates resilience
What are the 4 types of Ecosystem Services?
Provisioning - provide resources like food and lumber
Regulating - moderation of natural processes like pollination, filtering water, cleaning air
Cultural - aesthetic enjoyment
Supporting - necessary for every other ecosystem service like producing oxygen, nutrient cycling
What is the difference between fast growing tree species (coniferous) and slow growing tree species (deciduous).
Fast growing tree species (coniferous): Stay green year round (pine, ceder)
Slow growing tree species (deciduous): Leaves fall off in Autumn (oat, ash, beech, maple)
Species Richness
The number of species in an area
Slash and Burn Agriculture
A farming method that involves cutting down and burning vegetation to clear land for growing crops
- loss of habits, carbon dioxide release, trees lose ability to absorb carbon
- some nutrients that are in those producers get returned back to the soil
Anthropogenic
Environmental change caused or influenced by people, either directly or indirectly
Selective Pressure
An evolutionary force that causes a particular phenotype (observed characteristics) to be more favorable in certain environmental conditions
3 types:
-Directional: Most common
-Stabilizing
-Disruptive: Least common
Benthic
Anything ecosystem associated with or occurring on the bottom of a body of water
Coevolution
- Occurs when species evolve together with favorable characteristics
-Often happens in species that have symbiotic relationships
EX) flowering plants necks getting bigger and deeper = their pollinators are able to get pollen easier
