Dynamic Ecosystems Flashcards
How is the ecosystem structure organized (smallest to largest)?
Individual - Population (total # individuals) - Community all pops of species in area) - Ecosystem (all biotic & abiotic components) - Biome (all similar ecosystems) - Biosphere
What are the 6 major biomes?
- tundra
- forest (deciduous & coniferous)
- marine
- desert
- grassland
- rainforest
Define biotic components
All living things. (ie, endemic, exotic, keystone, generalist, etc.)
Define abiotic components
All non-living things that impact the distribution of biotic components (ie, temp, water, light, nutrients, soil, wind, etc)
What is biodiversity?
The interactions between biotic and abiotic factors over time… healthy ecosystems have lots of biodiversity
What are the 3 types of diversity that make up biodiversity? Which is most important?
- Genetic Diversity
- Species Diversity
- Ecosystem Diversity
Genetic is most important because it will determine the other two
What is genetic diversity?
The variability in genetic makeup. Higher diversity means species will be able to withstand disease & disaster, and avoids inbreeding
What is species diversity?
The wide variety of different species in the world
What is ecosystem diversity?
The variety/range of ecosystems in an area
What is a biodiversity hotspot?
They have high numbers of endemic species, and tend to be tropical areas (closer to poles, less diversity because of water & temp distribution). Tropical areas have sped up decomposition, more nutrients and sped up evolution.
what is an endemic species?
It is found in one specific area (usually due to a geographical barrier.. ie, island) meaning high human impact can drastically impact these species.
Why are there few endemic species in Canada?
Because of the recent glaciation period, and there is wide range for existing species to wander (large country).
What are the key forces in biodiversity loss?
- Terrestrial habitat loss & fragmentation
- Invasive species
- Excessive nitrogen and other pollution
- Over-exploitation of species
- Climate change impacts
What is ecological succession?
As ecosystems change over time, one community can gradually be replaced by another as conditions change.
What is a primary colonizer?
A group of organisms that first establish an area (pioneer stages)
What is primary succession?
The first organisms to colonize bare rock (extreme conditions) meaning few species are able to withstand the conditions (ie, lichen). Simple plants will grow and add to organic matter (soil) when they die, until forests are created.
What does lichen do?
They work to break down rock over time, and when they die, they add to the organic matter to make soil
Give examples of when primary succession would occur
- glacier retreat
- volcanic eruption
(150-300 years)
What is secondary succession?
There is soil already present, but a disturbance has occurred (once vegetated land). It is a much shorter process than primary, so they have more complex primary colonizers.
Give examples of when secondary succession would occur
- forest fires
- agricultural field
(1-20 years)
What is a seral stage?
each stage of succession (ie, lichen, then shrubs - each own seral stage)
What is often the order of primary succession?
Rock - Lichen/mosses - Small herbs & shrubs - Heath mix (large “weeds”) - Trees
What is an alien/exotic species?
A general term for any organism found outside of normal range
What is an invasive species?
It is transported to new environment, and tend to rapidly multiply and outcompete native species which changes native habitats
What are the characteristics of an invasive species?
- rapid reproducers
- highly adaptable
- fast growing generalist
- have dispersal mechanisms
- associated with humans (ie, brought over on boat)
- OFTEN CAUSE SIGNIFICANT ISSUES
What is an example of invasive species? Explain
The Asian carp. Brought over to control algae, but now taking over native environments
What is a positive feedback loop? Example?
It initiates a response that increases change. Ex. polar amplification (melting sea ice) as reflective surface bounces sun’s energy back to atmosphere, but more melting ice means more sea exposure, so more radiation is absorbed & heats up the ocean (continues cycle)
What is a negative feedback loop? Example?
it initiates a response against change and helps to stabilize a system. Ex, predator-prey population relationship
