Energy and Ecosystems Flashcards
describe a system
network of interacting components
are most environmental systems open or closed
open systems
positive feed-back loop
self-reinforcing ; drives the system toward one of the two extremes
negative feedback loop
drives the system in the opposite direction ; acts as an inhibitor/self-limiting ; stabilizes the ecosystems
what state are natural systems often in
dynamic equilibrium
what can contribute to homeostasis
dynamic equilibrium
what are two properties of homeostatic systems
resilience and resistance
natural systems often have _____ kind of properties
emergent
what approach do most environmental scientists take to study earth’s natural systems
holistic ; considers the interconnectedness of various aspects of the environment and society
what do delineations and definitions of systems depend on
the question being asked
what are the five main subsystems of Earth
- biosphere
- geosphere
- hydrosphere
- atmosphere
- anthroposphere
geosphere
includes the solid Earth
atmosphere
envelope of gases that surround the planet
main components of the hydrosphere
oceans ; glaciers ; ice caps ; ground water ; surface water bodies
what are the frozen parts of the hydrosphere known as
cryosphere
biosphere
living and recently deceased/decaying organisms
anthroposphere
human activities and impacts and the built environment
what makes up an ecosystem
all organisms (biotic) and non-living entities (abiotic)
ecosystems are biotic and abiotic entities that ______
occur and interact in a particular habitat at the SAME time
____ flows through an ecosystem
energy
___ is recycled in an ecosystem
matter
how is energy converted to biomass
through primary productivity
true or false
all ecosystems have the same level of primary productivity
FALSE
what limits primary production
available nutrients
adding what can boost productivity in an ecosystem
adding nutrients
is it beneficial to have excess nutrients in an ecosystem
NO - excess can alter an ecosystem in ways that can cause severe ecological and economic consequences
what do ecosystems provide us with
natural resources and wide variety of services
how do earth systems and processes differ
in their characteristic spatial and temporal scales
what can give scientists the ability to study highly complex systems or those with unwieldy temporal/spatial scales
studying subsystems and creating models
landscape ecologist POV
broad perspective on how landscape structure influences organisms
describe landscapes
consists of ecosystem patches spatially arrayed in a mosaic
what tech is assisting landscape ecology in conservation and regional planning
remote sensing technology
GIS (graphical information sensing)
four main biogeochemical cycles
- hydrologic cycle
- carbon cycle
- nitrogen cycle
- phosphorus cycle
what cycle moves water throughout the global environment
hydrologic cycle
human impacts on the water cycle
- Altering earth’s surface and vegetation = increase surface runoff and erosion
- Damming rivers to create reservoirs = increase evaporation
how do carbon flux between organisms and the atmosphere happen in carbon cycle
photosynthesis and respiration
where is most of the carbon contained
in sedimentary rock
where else (besides main reservoir) holds substantial amounts of carbon
- oceans
- soils
human impacts on carbon cycle
- human activity has moved carbon from long-term deposits (like fossil fuels) to the atmosphere
- Removing forests = remove carbon from vegetation reservoirs and release into the air
what are vital nutrients for plant growth
nitrogen and phosphorus
what must be done to nitrogen before plants can use it
nitrogen gas in the atmosphere must be “fixed” by specialized bacteria or lightning
can plants use nitrogen right from the atmosphere
NO - it has to be fixed first
human impact on nitrogen cycle
1.Fixing atmospheric nitrogen with fertilizers = increase flux of nitrogen from the atmosphere to earth’s surface
- Destroying wetlands = reducing nitrogen’s return to the air and reducing the amount of nitrogen picked up from nitrogen pollution
where is phosphorus the most abundant
sedimentary rock ; with substantial amounts in soil and oceans
is there appreciable atmospheric pools of phosphorus
NO
human impact on phosphorus cycle
runoff from agricultural land has contributed phosphates to surface water bodies = widespread eutrophication (ecosystems enriched with nutrients, increasing the amount of plant and algae growth) and hypoxia (lack of oxygen, strangulation) of organisms
open vs closed system
open ; Systems that receive inputs of both matter and energy and produce outputs of both
closed ; Systems that receive inputs of both matter and energy and produce outputs of energy NOT matter
example of negative feedback
predation-prey relationships
what type of feedback loop is rare in natue
positive feedback loop
example of positive feedback loop
erosion
dynamic equilibrium
Processes in a system move in opposing directions at equivalent rates resulting in their effects balancing out
homeostasis
Tendency of a system to maintain constant or stable internal conditions
resistance vs resilience
resistance ; strength of the system’s tendency to REMAIN CONSTANT ; resistance to disturbance
resilience ; measure of how readily the system will return to its ORIGINAL STATE after being disrupted
Emergent properties
Characteristics that are not evident in the individual components on their own
importance of the geosphere
○ Provides physical and chemical foundation for life on earth
○ Source of mineral nutrients and other materials that cycle through Earth system
what are the two MAIN gases in our atmosphere
nitrogen and oxygen
has the atmosphere changed since the formation of earth
YES - Chemical composition has changed from the formation of earth till now
is an atmosphere unique to earth
NO - other planets also have one
what are some examples of water NOT part of the hydrosphere/cryosphere
- Atmospheric water (part of the atmosphere)
- Water in living organisms (part of the biosphere)
- Water found in rocks and minerals (part of the geosphere)
process of motion of energy through an ecosystem
Energy arrives as radiation from sun —-> powers the system ——-> transformed (processes include photosynthesis and respiration and decay) ——–> exits as heat
what happens to the nutrients when organisms die
it REMAINS in the system
describe the relationship between energy and matter
The flow of energy through a system drives the constant recycling of matter
biomass
Organic material of which living organisms are formed ; results from photosynthesis
Gross primary production (GPP)
Conversion of solar energy to the energy of chemical bonds in sugars by autotrophs
Net primary production (NPP)
Energy that remains after respiration that is used to generate biomass
what primary production represents the energy or biomass that is available for consumption by heterotrophs
net primary production
Secondary production
Total biomass that heterotrophs generate by consuming autotrophs
High net primary production ecosystems
Ecosystems were plants convert solar energy to biomass rapidly (freshwater wetlands, tropical forests…)
Low primary production ecosystems
○ Tundra
○ Deserts
* Open oceans
Nutrients
Elements and compounds that organisms consume and require for survival
Macronutrients vs Micronutrients
macronutrients ; Elements and compounds that organisms need in large amounts
Micronutrients ; Nutrients needed in small amounts
describe Limiting factor in an ecosystem
If one of these nutrients (mainly nitrogen or phosphorus) is present in less than ideal amounts, it will place a limitation on plant or algal growth
Ecotone
Transitional zones where two ecosystems meet and interact (sharing elements)
patches (referring to ecosystems)
ecosystems or areas of habitat for a particular organism
Metapopulation
If patches of a species are distant enough = organism’s population might become divided into subpopulations each occupying a different patch
Remote sensing
Technologies that collect information about a target object from a distance (like satellite images)
Geographic information system (GIS)
Computer software that takes multiple types of spatially referenced data and combines them on a common set of geographical coordinates
Biogeochemical cycles
Movement of materials and energy through and among these systems
Characteristics of systems
○ Planetary-scale subsystems that make up earth system
○ Interaction of biotic and abiotic components
Diversity of temporal and spatial scales among natural systems and processes
Reservoir (pool)
Location where materials in a cycle remain for a period of time before moving to another reservoir
Residence time
Amount of time a material in a cycle remains in a given pool or reservoir before moving to another reservoir
Flux
Movement of materials among reservoirs
Sources
Reservoirs that release more nutrients than they accept
Sinks
Reservoirs that accept more nutrients than they release (stores)
Turnover time
The time it would take for all of the atoms of a particular material to be flushed through a reservoir
transpiration (water cycle)
the released of water vapor by plants through leaves
how does water return to earth
precipitation
how does water return to atmosphere
evaporation or transpiration
why is carbon (carbon dioxide) pulled out of the atmosphere
photosynthesis
how is CO2 released into the atmosphere
- Carbohydrates (like glucose) produced in photosynthesis are used by autotrophs to fuel their own respiration and release some back
driving force of climate change
Removing CO2 from the atmosphere back to the hydrosphere, geosphere and biosphere has not been able to keep pace with the CO2 entering
Nitrogen fixation
N2 must be fixed (combined) with hydrogen in nature to form ammonia and the water-soluble ions (ammonium) can be used by plants
two ways to accomplish nitrogen fixation
- Intense energy of lightning strikes
- Action of specialized bacteria (ex. Cyanobacteria)
Nitrification
Ammonium ions are converted into nitrite ions and then into nitrate ions
importance of decomposers in nitrogen cycle
Once the decomposers process the nitrogen compounds, they release ammonium ions = ions are now available to nitrifying bacteria to convert them once again to nitrates and nitrites
Dentification
○ Denitrifying bacteria convert nitrates in soil or water back into gaseous nitrogen
○ Completes cycle by releasing nitrogen back into atmosphere as gas
major steps of the nitrogen cycle
- nitrogen fixation
- nitrification
- dentification
is there extensive amounts of phosphorus available to organisms
NO - most is in rocks
how is phosphorus a limiting factor to plant growth
Very little phosphorus is available to organism = limiting factor for plant growth (plants can only take phosphorus up their roots when its dissolved in water)
major steps of the phosphorus cycle
- phosphorus is mobilized by weathering ; released phosphate ions into water
- Phosphate dissolves in lakes/oceans and precipitates into solid form before settling at the bottom and re-entering the geosphere as sediments
- Once plants uptake phosphorus by their roots, secondary consumers receive it by consuming the plants and release phosphorus through excretion
- Decomposers break down phosphorus-rich organisms and waste to return the phosphorus to the soil
Ecosystem ecology
study of energy and material flow among biotic AND abiotic components of systems
