ECOSYSTEMS AND CONSERVATION ECOLOGY Flashcards
(27 cards)
What is an ecosystem?
An ecosystem consists of all the organisms living in a given area and the abiotic factors with which they interact
What are detrivores?
Detrivores are decomposers, which are heterotrophs that derive their energy from detritus (nonliving organic matter)
What trophic levels do decomposition connect?
Decomposition connects to all trophic levels
How does energy flow in ecosystems?
Energy flows through ecosystems
How do chemicals cycle in ecosystems?
Chemicals cycle within ecosystems
What is gross primary product (GPP)?
GPP is the total primary production in an ecosystem
What are the most productive ecosystems per unit area?
- Tropical rain forests
- Estuaries
- Coral reefs
How does size matter in GPP?
Marine ecosystems are relatively unproductive per unit area, but contribute much to global net primary production because of their area
What is net primary production (NPP)?
NPP is GPP minus the energy used by autotrophs for respiration and is the amount of new biomass added in a given period of time
Primary production in terrestrial ecosystems general increases with what?
- Temprature
- Moisture (precipitation)
- Solar energy
What is the most common limiting nutrient in terrestrial ecosystems?
Nitrogen
Where is phosphorus a limiiting nutrient?
Older soils
How does carbon cycle between ecosystem reservoirs?
Carbon moves from producers to consumers
What controls primary production in marine and freshwater ecosystems?
Light and nutrients
What nutrients are most often limiting primary production in marine ecosystems?
Nitrogen and phosphorus
What regulates nutrient cycling?
- Vegetation
- Retains nutrients
- Decomposition
- Releases nutrients by recycling vegetation
What is the main control of nutrient loss in a forest ecosystem?
Plants
What are the 3 levels of biodiversity?
- Genetic diversity in a population
- Species diversity in an ecosystem
- Community and ecosystem diversity across the landscape of an entire region
What are the 4 major threats to biodiversity?
- Habitat destruction
- Introduced species
- Overexploitation of resources
- Disruption of “interspecies interactions”
How does the human population disrupt chemical cycles?
- Agriculture and nitrogen cycling - removes soil nutrients
- Contamination of aquatic ecosystems - excess algae growth caused by runoff
- Acid precipitation - combustion of fossil fules
- Toxins in environment
- Greenhouse effect and global warming - rising of atmospheric CO2 levels and methane
- Depletion of atmospheric ozone - allows more UV penetration
What is the extinction vortex?
The extinction vortex is the downward spiral of population decline unique to small populations
What is the key factor driving the extinction vortex?
The loss of genetic diversity
What does a loss in genetic variability lead to?
Less ability to adapt to changes
If an organism is unable to adapt to changes, what happens?
Reproductive success and fitness are lowered, increasing mortality
