Science 46-51 Flashcards
What does an ecosystem level approach consider in the management of natural resources?
The interconnected relationships between multiple biotic systems
Pools=
Amount or quantity
Fluxes=
Transfer or flows
What are some examples of ecosystem processes?
photosynthesis and decomposition
What do ecosystem level studies seek to understand?
The factors that determine the pools and fluxes of material energy in an ecosystem
Define ecosystem processes.
Ways that energy and materials are transferred from one pool to another
What is the ultimate source of energy?
The sun
What are the two forms of energy?
Kinetic and potential
Explain the first law of thermodynamics.
Energy cannot be created nor destroyed
Explain the second law of thermodynamics.
Energy disperses from being localized to spread out, unless it is prevented from doing so.
What are the two major steps of photosynthesis?
Harvesting energy from sunlight and the fixing of carbon to generate carbohydrates
What determines the supply of energy to organisms?
The rate of photosynthesis
Define autotrophic organisms.
Organisms which produce organic compounds
Define primary productivity.
The rate that sunlight is converted by autotrophic organisms via photosynthesis into organic compounds
What is Gross Primary Productivity (GPP)?
The total rate of photosynthesis or the total energy obtained by autotrophs.
The rate of energy stored after accounting for the energy expended is referred to as…
Net Primary Productivity (NPP)
What is biomass?
Stored energy found at a given area at a given time
What does ecosystem ecology study?
The links between multiple organisms and their physical environment as an integrated system
What controls the rates of primary productivity? (In a terrestrial ecosystem)
Temperature, heat, and nutrients
We see a pattern of increasing NPP with increasing ______________________.
Nutrient availability
What controls primary productivity in an aquatic ecosystem?
Temperature, light, and nutrient availability
Light availability decreases with the depth in what?
The water column
What perform the majority of the oceans primary productivity?
Free-floating algae, protists, and cyanobacteria
What are the two most important nutrients for phytoplankton?
Nitrate and phosphate
Define upwelling.
When cold, nutrient rich waters swell up to the surface to replace warm, nutrient lacking water which was previously on the surface
Certain bacteria have evolved to live without…
Sunlight
What is chemosynthesis?
The process by which microbes create energy by converting carbon molecules and nutrients into organic matter in the absence of sunlight
All animals, fungi, and some bacteria are…
Heterotrophs
Define heterotrophs.
Consuming plant or animal material for maintenance and growth
When heterotrophic organisms produce biomass it is known as?
Secondary production
Explain biogeochemical cycles.
Cycles of nutrient movement through ecosystem components
What is the key to nutrient recycling?
Decomposition
What are the dominant decomposers of dead animal material?
Bacteria
What are the dominant decomposers of plant material?
Fungi
The Undecomposed organic matter on the soil surface.
Litter
Define mineralization.
The process where bond between carbon molecules and inorganic nutrients are broken, making them available for uptake by plant roots
Where would decomposition occur at a faster rate?
Areas with warmer temperatures and greater amounts of moisture available
What must nitrogen be in the form of in order for plants to absorb it?
Ammonium or nitrate
What is nitrogen fixation
The assimilation of nitrogen into organic compounds
Where is the phosphate in the earth mainly stored?
Soil and rocks
