Ch. 42 Ecology (Ecosystems and Energy) Flashcards
Regardless of an ecosystem’s size, it’s dynamics involve what two main processes
Energy flow and chemical aging
Consists of all the organisms living In a community as well as the abiotic factors with which they interact
Ecosystem
Difference between energy and matter in an ecosystem
Energy flows through an ecosystem while matter cycles within it
What do ecologists study
The transformations of energy and matter within ecosystems
Energy cannot be created nor destroyed, it is only transferred or transformed
First law of thermodynamics
In what form does energy enter an ecosystem and to what form is it transformed into
Enters as solar radiation
Transformed into chemical energy by photosynthetic organisms and is dissipated as heat
Every exchange of energy increases the entropy of the universe
Second law of thermodynamics
What is required to maintain energy flow in earths ecosystems
Continuous input from the sun
Matter cannot be created or destroyed
Conversion of mass
What happens to chemical elements within ecosystems
Continually recycled
How do nutrients enter and exit a forest ecosystem
Enter as dust or solutes
Carried away in water
Absorbs energy and mass and releases heat and waste products
Open system ecosystems
Happens if a mineral nutrients outputs exceed its imputs
It will limit production in that system
Build molecules themselves using photosynthesis or chemosynthesis as an energy source
Autotrophs
Depend on the biosynthetic output of other organisms
Heterotrophs
What connects all trophic levels
Composition
The amount of light energy converted to chemical energy by auto troughs during a given period of time
Primary production
What sets the spending limit for an ecosystems energy budget
Extent of photosynthetic production
What limits the photosynthetic output of ecosystems
The amount of solar radiation
Measure does the conversion of chemical energy from photosynthesis per-unit time
Gross primary production
gross primary production minus energy used by primary producers for autotrophic respiration
Net primary production
What is the equation for net primary production
NPP=GPP-Ra
New biomass in a given time period
Net primary production
WhAt is net primary production only available to?
Consumers
The total biomass of photosynthetic autotrophs at a given time
Standing crop
A measure of the total biomass during a given period
Net ecosystem production
Gross primary production minus the total respiration of all organisms
Net ecosystem production
What is the equation for net ecosystem production
NEP=GPP-Rt
What controls primary production in marine and freshwater ecosystems
Light and nutrients
What effects primary reduction in the photic zone of an ocean or lake
Depth of light penetration
What also limits primary reduction in geographic regions of the oceans and lakes
Nutrients
Element that must be added for production to increase in an area
Limiting nutrient
What are the nutrients that most often limit marine production
Nitrogen and phosphorus
What if experiment with suction on a large scale in terrestrial ecosystems
Temperature and moisture
Primary production increases with..
Moisture
Water transpired by plants and evaporated from landscape
Evapotranspiration
What is evapotranspiration affected by
Precipitation temperature and solar energy
What is often the limiting factor in primary production on a more local scale
Soil nutrient
Is most common limiting nutrient interest real ecosystems
Nitrogen
Phosphorus can also be a limiting nutrient especially in older soils
The amount of chemical energy in food converted to new bio mass during a given period of time
Secondary production
What is an organisms production efficiency
Net secondary production times 100 over assimilation of primary production
The percentage of production transferred from one trophic level to the next
Trophic efficiency
What does trophic efficiency take into account
Energy lost through respiration and contained in feces as well as the energy stored in unconsumed portions of the food source
Represents the loss of energy with each transfer in a food chain
Pyramid of not production
The ratio of standing crop Biomass to production
Turnover time
Play a key role in the general pattern of chemical cycling
Decomposers other known as Detrivores
What controls the rate of decomposition
Temperature moisture a nutrient availability
Biotic and abiotic components in nutrient cycles in ecosystems
Biogeochemical cycles
What you carbon reservoirs include
Fossil fuels Soils and sediments Solutes in oceans Plants and animal biomass The atmosphere Sedimentary rocks
How does The carbon cycle work
Photosynthetic organisms convert CO2 to organic molecules that are used by heterotrophs
CO2 is taken up by the process of photosynthesis and released into the atmosphere through cellular respiration
Process where nitrogen must be converted to ammonium or nitrate for uptake by plants
Nitrogen fixation and this is done by bacteria
Organic nitrogen is decomposed to ammonium by
Ammonification
Ammonium is decomposed to nitrates by
Nitrification
Convert nitrates back to nitrogen
Denitrification
It is the most important in organic form of phosphorus
Phosphate
Largest reservoirs for phosphorus
Sedimentary rocks
Seeks to initiate or speed up the recovery of degraded ecosystems
Restoration ecology
What are two key strategies for restoration ecology
Buy a remediation and augmentation
Use of organisms to detoxify ecosystems
Bioremediation
Where organisms are usually used for bioremediation
Prokaryotes fungi plants
Uses organisms to add essential materials to a degraded ecosystem
Biological augmentation
