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92 Cards in this Set
- Front
- Back
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What stands for PAR?
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Photosynthesis active radiation
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between which numbers does photosynthesis active radiation go in between?
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400-700nm (heat)
x-ray u.v. >400 I.R. (radio) >700 |
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Solar constant =?
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=2calcm-2min-1
=2880 laingleys d-1 the amount of energy hitting the atmosphere |
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What percent of the solar constant reaches the earths surface?
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25-30%
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Light extinction in water
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patterns of primary production with depth
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What equation measures primary production in water?
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Iz = Ioe^kz
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z=?
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depth
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k=?
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extinction coefficient
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which devise can be used to accurately measure water depth?
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secchi disk
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production v productivity
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productivity is a short term measure, when you get a rate over a year is production
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biomass v standing crop
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when primary production occurs, biomass (aka standing crop) occurs
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what are come provisioning services through terrestrial primary production?
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40% -> food
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P.I. Curves = ?
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Photosynthesis irradiance curves
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What do P.I. curves describe?
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the photosynthetic efficiency of a plant
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p-max=?
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maximum productivity (photosynthetic) rate
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Iopt=
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the highest photosynthetic rate, the beginning of photo-inhibition
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What happens to light on the left of Iopt?
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light is subsidizing the production of organic matter
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What happens to the right of the Iopt?
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light is stressed
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Shade-adapted plants = ?
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more efficient at low light levels
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Shade-adapted plants = ?
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more efficient at high light levels
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How do you measure primary production?
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depends on type of ecosystems you're testing
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What two procedure can be used to measure primary production in aquatic ecosystems?
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1. oxygen evolution (light-dark bottles)
2. 14C (carbon) uptake (14 is radioisotope) |
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What three procedure can be used to measure primary production in forested ecosystems?
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1. leaf litter production (litter traps)
2. wood product (DBH measurements and allometric models) 3. belowground production (root ingrowth cores, rhizotrons, nutrients, and water) |
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DBH = ?
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diameter breast height (measures width of tree trunks)
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Primary production=
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net primary production=light
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respiration=
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net primary production=dark
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the difference between nnp in light bottles and npp in dark bottles =?
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GPP
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What 5 steps are used to measure primary production in herbaceous ecosystems?
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1. harvest all biomass (problems with spatial variability; requires mortality estimate).
2. non-destructive allometric techniques (need to harvest 1st to develop allometric models; problems with plants that have plastic growth characteristics; requires mortality estimate) 3. peak biomass (temperate systems only; requires mortality estimate). 4. Gas flux (chambers = whole plant; leaf specific measures; eddy covariance techniques) 5. belowground production (root ingrowth cores, rhizotrons) |
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What is step #1 in measuring primary production in herbaceous ecosystems?
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1. harvest all biomass (problems with spatial variability; requires mortality estimate).
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What is step #2 in measuring primary production in herbaceous ecosystems?
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2. non-destructive allometric techniques (need to harvest 1st to develop allometric models; problems with plants that have plastic growth characteristics; requires mortality estimate)
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What is step #3 in measuring primary production in herbaceous ecosystems?
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3. peak biomass (temperate systems only; requires mortality estimate).
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What is step #4 in measuring primary production in herbaceous ecosystems?
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4. Gas flux (chambers = whole plant; leaf specific measures; eddy covariance techniques)
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What is step #5 in measuring primary production in herbaceous ecosystems?
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5. belowground production (root ingrowth cores, rhizotrons)
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What is most important for photosynthesis?
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Visible light
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What happens with plants at different wavelengths?
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Different plant pigments absorb EM energy at different wavelengths: ROYGBIV
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Simple view =?
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limiting factors (i.e.-nutrients, nutrient limits, N:P ratios)
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What is nutrient limitation based on?
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stoichiometry of organism & environment
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Nutrient use efficiency = ?
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nutrient economy
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nutrient economy = ?
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conserving within it's own biomass
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nutrient live/nutrient dead = 1 =?
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not limiting
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Shelfords law of tolerance= ?
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too much of a good thing can cause stress & be a bad thing (e.g. photoinhibition).
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Primary factors limiting primary production = ?
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light, nutrients, & water (how do plants respond to limitations of each?)
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Positive feed back vs. negative feed back
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positive feed backs lead to uncontrolled behavior v negative feed back control the systems
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. Cybernetic systems = ?
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Regulated energy, usually low fee back pathways
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What is is key to stable ecosystem regulation?
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Redundancy of regulatory feedback pathways
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Pathway redundancy is directly related to ?
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biodiversity
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The key to regulation is ?
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communication of information
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Information is difference between?
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high & low energy systems.
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“embodied entropy” = ?
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energy to organize a complex system.
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“embodied entropy” = information = ?
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“embodied energy” (emergy).
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Through linkages & feedbacks, information flow coordinates ?
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nutrient cycling & other ecosystem functions
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Energy dissipation is a product of ?
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of information flow & regulation.
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Control manifest through ?
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information flow & feedbacks
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Community Succession = ?
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1. orderly process of change in species structure & community processes that is relatively directional
2. sequence of changes initiated by disturbance (Ricklefs). 3. sequence of changes in species composition that is supposed to be associated with a sequence of changes in community structure and function (Drury & Nisbet). |
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Disturbance =?
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removal of biomass
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I. Degree of disturbance is important to type of succession = ?
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Primary vs. secondary succession
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ii. Local environment is modified during succession = ?
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changes in light, nutrient availability, temperature, moisture. Soil development is prime example.
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III. Early succession (through pioneer species) affects outcome of process = what three ways?
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1. Facilitation (positive)
2. Inhibition (negative) 3. Tolerance (neutral) |
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Positive facilitation = ?
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shade, accumulation of organic matter, remove pioneer species (ie: early mature)
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Tolerance = ?
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Pioneer species increase in population and increase specialized = less nitch overlap= less competition
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Endpoint = ?
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climax
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Climax is defined by what two definitions?
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1. When new species, or loss of species, no longer changes the environment.
2. Once vegetation reaches tallest supportable growth form. |
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How do you measure/quantify succession ?
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1. Implies temporal sequence(s) of change.
2. Problem: These changes take place over long periods of time. |
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What is the solution to measuring succession at a faster rate?
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Use space as a surrogate for time.
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Community succession focuses only on ?
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biotic change
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Ecosystem development focuses on both ?
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abiotic structure & function AND on system energetics.
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Maximum Energy = ?
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As the ecosystem develops more energy is going into maintaining the system itself
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Strategy to ecosystem development = ?
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Ecosystem development follows a predictable sequence of structural, functional, & energetic changes that maximize homeostasis with the environment.
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The moving target trick = ?
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The target of homeostasis within the environment is always changing
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Universal energy flow model = ?
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-> energy split into two systems; a lot into biomass, a little into mature (maintenance aka respiration).
when biomass is built up, most of the energy goes into maintenance and a little goes into biomass. -see graph |
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Biomass supported/unit energy flow
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early- low
mature- high |
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Type of production
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early- quantity
mature- quality |
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Type of food chains
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early- simple, linear
mature- complex, webs |
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Total organic matter
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early- low
mature- high (soils) |
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Nutrient cycles
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early- open (to outside nutrients)
mature- closed nutrient cycles |
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Forms of nutrients
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early- inorganic
mature- organic |
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Species diversity
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early- low
mature- high |
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Niche specialization
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early - low
mature- high |
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Role of detritus in nutrient regeneration
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early- minimal (due to low amount of soil)
mature- large |
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Whole system entropy (urge to fall apart)
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early- relatively high
mature- low |
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Information content
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early- low
mature- high |
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Generally, system that are early in developmental process, they are focused on
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early- growth & production
mature- maintenance and stability |
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Climate VS. weather =
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Climate= regional scales/days-weeks
Weather= larger/decades-centuries |
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"Hockey Stick"=
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the combination of many factors showing dramatic increased change in climate
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Lake Mendota/NTL (LTER)
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winters are getting shorter and warmer due to climate change
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Future-predictions = GCM (General Circulation Model) Output =
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ICCP- responsiveness index
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Spatially articulate =
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simulate space and time spontaneously
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AZ and climate change =
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Hotter and dryer
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Measuring effects of climate change =
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FACE (Free Air CO2 Enrichment) and RaMP experiments (Rainfall Manipulation Plots)
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What is the least common denominator in global change?
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World population development
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Climate Change Disturbances: Biophysical
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Press:Drought, migration changes, changed biome boundaries, sea level rise
Pulse:Storms, fire |
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Climate Change Disturbances: Social (in direct effects)
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Press: Sea level rise, water security, food scarcity
Pulse: food scarcity, storms- infrastructure |
