Ecosystems Flashcards
(21 cards)
What is the biogeochemical cycles
Cycle of certain compounds move between biotic and abiotic compartments in the environment
What is required by all organisms and part of membranes and nuclei acids
Phosphorus
What is a food chain
Single flow (linear) interactions between species
What is a food web
Complex interactions (non linear) between species in food webs.
A permeable underground layer of rock, sand and gravel saturated with groundwater
Aquifer
Upper, unconfined portion of groundwater which flows into streams and is partly accessible to plants
Water table
Becomes available to organisms almost entirely through metabolic activities of few genera of bacteria
Nitrogen
Heterotrophs must obtain organic molecules synthesized by
Autotrophs
The total amount of energy fixed per unit of time minus amount of energy expended by metabolic activities of photosynthetic organisms in the community
Net primary productivity
What is the percent of sunlight captured by photosynthesis
1%
Element present in small amounts to limit growth of plants
Phosphorous
What percent of CO2 does photosynthesis fix?
10% of CO2 in atmosphere
What are detritivores
Organisms that break down organic matter
What doesn’t undergo biogeochemical cycles
Energy
Where does the water that reaches the atmosphere come from
Plant transportation
Nitrogen fixers are
Prokaryotes
Scarcity of which two elements limits plant growth
Nitrogen
Phosphorus
How does energy mainly enter the ecosystem
Photosynthesis
What contains no species that are autotrophs
Fungi
What are primary consumers
Herbivores
Amount of organic matter produces in given time available for heterotrophs
Net primary productivity
