Ch 42: Ecology Flashcards
Ecosystems
the sum of all organisms living within its boundaries (biotic community) and all the abiotic factors with which they interact.
Ecosystem ecology requires two processes
- Energy Flow
2. Chemical Cycling
primary producers
plants
Autotrophs
an organism that is able to form nutritional organic substances from simple inorganic substances such as carbon dioxide.
Heterotrophs
an organism deriving its nutritional requirements from complex organic substances.
Primary Consumers
herbivores, feeding on plants
Secondary Consumers
organisms that eat primary consumers for energy
Tertiary Consumers
an animal that obtains its nutrition by eating primary consumers and secondary consumers
Decomposers
an organism, especially a soil bacterium, fungus, or invertebrate, that decomposes organic material.
The amount of light energy converted to chemical energy by autotrophs is an ecosystem’s primary production
1%
The spending limit for the energy budget of the entire of the ecosystem=
all the photosynthetic production
Gross Primary Production (GPP)
total primary production in an ecosystem
Net Primary Production (NPP)
GPP – the energy used by the primary produces for their “autotrophic respiration” (Ra)
NPP
GPP – Ra
In aquatic systems, primary production is affected by two factors
Light availability
Nutrient availability (nitrogen and phosphorus)
A eutrophic lake
nutrient-rich and supports a vast array of algae. ( man-made runoff)
In terrestrial ecosystems, primary production is affected by(3)
Temperature
Moisture (most important annual precipitation)
Evapotranspiration – combines both factors
Only % of the available energy at each trophic level is passed on to the one above it.
10
At each level, energy is lost too
Heat, For movement, reproduction, and or other life processes
because of this loss food chains are short
If only 10% is passed on from primary producer to primary consumers then only 1% of net primary production (10% of 10%) is available to the secondary consumer
Ecological pyramids
diagrams that give insight into food chains, biomass, energy, and pyramid numbers
Restoration Ecology
The process of returning a degraded ecosystem to a more natural state
Bioremediation
use organisms to detoxify polluted ecosystems, This has been used to restore areas degraded by mining or polluted by oil or radioactive elements
Bioaugmentation
Introduction of desirable species such as nitrogen fixers to add essential nutrients.
