Ecology Quiz 2 Flashcards
(33 cards)
What does “bio” mean?
life
What does “diversity” mean?
variety
Biodiversity
The variety of life on Earth and the essential interdependence of all living things.
What do we get from biodiversity?
- Food and clean water
- They cycling of nutrients
- The conversion of atmospheric carbon and biomass (which affects climate and weather)
- The pollination of crops and natural vegetation
- The balance of processes such as growth and decomposition.
- Beauty and spirituality
Why are we concerned about biodiversity?
The Earth is losing species at an alarming rate. 3 species per hour go extinct and 20 000 per year. With every species that goes extinct, it affects other species as well.
Greater biodiversity offers:
More food resources
More habitats
More resilience in the face of environmental change (more complex food web)
Why does biodiversity matter, in summary?
All things on the planet are interconnected and rely on one another.
It keeps things balanced
All living things are connected by what they eat and breathe.
Biodiversity increases productivity and functionality of ecosystems, preventing the development and severity of threats and disasters it may face.
Greater diversity = greater stability
Dominant species
- Most abundant in the ecosystem -increased biomass.
- Removal of these can cause a decrease in biodiversity.
- These are always producers
Ex. American Chestnut Tree
Keystone species
- These can greatly affect population numbers and the health of a ecosystem, either good or bad.
- Generally not abundant.
- Can be plants or animals
Ex. Prairie Dogs.
Indicator species
- Organisms that are easily affected by changes in the environment.
- They show if and when a problem exists.
Ex. frogs or amphibians.
Ecosystem Engineers
- A species that causes such dramatic changes to a landscape that it creates a new ecosystem.
Ex. Beavers.
Ecological Niche
- This is an organism’s “job” or role in an ecosystem.
- This includes:
Its place in the food web, where it lives/hunts, and the time of day it is active.
- Each organism in an ecosystem has a different niche to help limit competition.
Native species
A species that has lived in an ecosystem for a long time.
Introduced species
A species that is new to an ecosystem. These can arrive naturally (animals moving, seeds being blown) or unnaturally by humans, typically to try and control another species.
Impacts of Invasive species.
These usually cause problems in an ecosystem because they have no predators, reproduce faster than native species, and compete for a niche with the native species already there.
They can:
Take over habitats
Invade other’s bodies (parasites, fungi)
Disrupt ecosystems
Compete with native species for food and habitat.
Ex. Asian Carp in river, Wild Boars in sask, Zebra Mussels, Cane Toads in australia.
Ways to prevent invasive species
Do not release alien plants or animals into the wild (live bait included)
Do not bring fruit, vegetables, plants, or animals with you across borders.
Before taking a recreational trip, be sure to inspect and clean equipments, boats, trailers, etc that may harbour insects, etc.
Do not transport over long distances firewood or other wood with bark attached. This is where eggs can live.
Population
an interbreeding group of individuals that occupy the same general area.
Population characteristics
all populations can be described by three main characteristics:
1) Population 2) Spatial Distribution
3) Growth Rate
Population density
The number of individuals in an specific area.
population density = # of individuals/unit area
What affects the size of a population?
Limiting factors - a factor that causes population growth to –> decrease. <–
Types of limiting factors
Density - Dependent factors
Density - Independent factors
Density - Dependent factors
depends on the size of the population. This can only happen when the population is very high. Typically biotic or involve biotic things, but not always.
Ex. predation, disease, competition, parasites.
Density - Independent factors
These are independent of the population size. It doesn’t matter if there is one or 100. Usually abiotic or involve abiotic things, but not always.
Ex. deforestation, overfishing, natural disasters, extreme temperatures, etc.
Spatial distribution
refers to the pattern/layout of a population’s spacing in an area.
There are three types:
Uniform (evenly distributed)
Random (scattered)
Clumped
Why are they different? It is the result of dispersion, typically caused by resource availability (food, water, shelter, no predators, etc).
