ecosystems Flashcards
what are ecosystem services
direct + indirect contribution of ecosystems to human well being
list 4 ecosystem services
- Regulating (of ecosystem processes): climate, air quality, soil retention, pollination
- Provisioning (obtained from ecosystem): fresh water, raw materials, pharmaceutical
- Culture (non-material benefits): intellectual development, recreation, spiritual
enrichment, aesthetic values - Supporting (necessary for production of all ecosystem services): habitat, primary
production, soil formation
open vs closed system?
Open system: flow transfer between system and outside system
Closed system: contained flow
define pools. abiotic vs biotic?
Pools: quantity of energy or material in an ecosystem compartment
- Abiotic (H20, soil) and biotic (flora and fauna)
define fluxes. ex?
Fluxes: flow of energy or materials form one pool to another
- Weathering, evaporation, absorption, consumptions
temporal scales?
Stationarity -what happens in one place also happens in the same way somewhere else
Discontinuities- successions and disturbances
Non-linear movements-not always a 1:1 relationship
what is a model
abstraction of reality
describe early view of ecosystems
Early view: assumed natural ecosystems are in equilibrium
- Closed system: internal recycling
- Stable endpoints; deterministic dynamics
- Absence of distributions
- Material recycled
- Movement is predictable
non-equilibrium view - describe
Non-equilibrium view:
- Past events, internal and external forces shape ecosystems
- Unbalanced inputs and outputs
- Not stable
- Human activities and disturbances
describe steady state ecosystem
Steady State Ecosystem: conceptual advance
- Open system but inputs=outputs
- Temporal and spatial variation
- No long-term directional trend in ecosystem properties
- Fluctuations by distributions and random factors changing climate
why was steady state a conceptual advance?
onceptual advance à emphasized controls over processes rather than descriptions of patterns
what are the five state factors?
Five State Factors: set the bounds for the characteristics of an ecosystem
- Are independent meaning not influenced themselves by ecosystem
characteristics
1. Topography
2. Climate
3. Parent Material (rock that gives rise to soil)
4. Potential Biota (orgs present in the region that could potentially occupy a site AND can
be called species pool)
5. Time
describe climate - what does it determine
Most strongly determines ecosystem structure and processes
Example: global climate explains distributions of biomes
describe parent material influence
Strongly influences the types of soils that develop and explains regional variation in ecosystem
processes
Movement of plates caused: ground oil, mountains (subduction of plates), soil
topography - describe
nfluences microclimate and soil development at a local scale
Slope angle: drainage, erosion (increase slope=increase microclimate)
Aspect: temperature and precipitation (exposure to light based on the angle)
bc vs alberta topography ex?
The BC vs Alberta side of the Rockies have different biota b/c the air is forced to go up at the
peaks which cools the air, condenses, rains making it more wet on the BC side thus a different
climate and ecology.
describe potential biota
Govern type and diversity of organisms that will occupy a site
Especially dominate factor on island ecosystems; usually less diverse because differences in
potential biota (new species reach islands often)
describe time influence
ime
Influences the development of soil and evolution of organism very long-time scales
Important components of succession, development and change in communities and ecosystems
over time
what do ecosystem processes do?
Ecosystem processes both respond to and control the factors that directly govern their activity
what are interactive controls
factors that operate at the ecosystem scale and both control and respond to
ecosystem characteristics. Thus, they effect and are affected by the ecosystem
4 interactive controls?
- Microenvironment – rate of ecosystem processes
- Resources
- Disturbances
- Biotic Communit
ex of interactive controls
Example: Soil fertility (resource) may control the dominant plant community that develops, but
responds to weathering rates OR microenvironment control decomposition rate, but responds to
topography
what largely determines ecosystem characteristics
state factors and interactive controls largely determine ecosystem
characteristics and processes
what is wrong with state factors idea?
They are not independent. For example, biota can alter the climate- water pump for transpiration
of trees to the top of the trees which creates humidity that facilities more rain. Removing the tree
results in evaporation of water. This changes the climate. OR plant material depends on the
community of lichens and moss which secrets acid thus changing the rate of weathering
