Download Ecosystem Essentials II

10/26/2010
Ecosystem Essentials
Ecosystem Components and Cycles
Biotic Ecosystem Operations
Ecosystems, Evolution, and Succession
Geog 1001: Climate and Vegetation
Lecture 17: Ecosystem Essentials
Professor Holly Barnard
October 26, 2010
The Web
of
Life
Basic terms I
Eco-logy: the study of our house
Focus: The relationship or interaction between
organisms (biotic) and their surrounding
environment (abiotic)
Bio-geography: the geography of living beings
Focus: The distribution of plants & animals,
including the biotic & abiotic processes, and in the
past & present (spatial & temporal)
Figure 19.1
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Ecosystem Components: Communities
Ecosystem Components I
Communities
Habitat
Def.: Animal populations interactions Plant
populations
Characteristics
Environment where an organism resides (or
biologically adapted to live)
Physical appearance
Richness (species present)
Abundance of each species
Complex patterns of interdependence
Trophic (feeding) structure
Requirements with limits & specific regimes of
sustaining nutrients
Ecosystem Components:
Communities
Biotic Interactions and
Competition
Def.: function or role of a life form within a
given community [when occupying a space]
Species interactions
simple interactions (two species, pairwise interaction, 5 scenarios,
three dominant).
Niche (to nest)
Way an organism obtain and sustain the
physical, chemical, & biological factors it needs
to survive
1.
2.
3.
4.
5.
Competition
Predation, Parasitism, Herbivory
Mutualism
Commensalism
Amensalism
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Mimicry
Adaptation and Acclimation
Biotic and Abiotic factors can create selection
pressure on a population of organisms.
Adaptation and acclimation are responses of
biological organisms to adjust to changes in
critical biotic and abiotic factors.
Generalists and specialists
Ecosystem Components II
Plants: The Essential Biotic component …Why?
Energy flow in Ecosystems:
Photosynthesis
Net Primary Productivity (NPP)
Abiotic & Biotic Ecosystem Components
Abiotic
Climate, water, minerals, insolation, heat E released
Limiting Factors
Life zones
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Vascular Plant
Anatomy
Photosynthesis
O2
CO2
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPS.html
H2O
Photosynthesis
unites CO2 and H
Photo-synthesis
photo = light
synthesis =
manufacturing
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Photosynthesis and Respiration
NET PHOTOSYNTHESIS
Figure 19.5
The Local Plant Carbon Cycle
Photosynthesis
Autotrophic
Respiration
of CO2
Energy Budget of the Biosphere
Litterfall
Heterotrophic
Respiration
of CO2
Root mortality
& exudation
Figure 19.7
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Global Carbon and Oxygen Cycles
Photosynthesis – Respiration=NPP
(Biomass)
Figure 19.8
Figure 19.10
Abiotic Ecosystem Components
Limiting Factors
Climate, weather, water, minerals, insolation,
heat E released (i.e. Physical or Chemical
components all but biotic!)
Determine to some extent where an organism
could regenerate, reproduce, and eventually
persists
Limiting Factors
Life zones
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Temperature and Precipitation
Limiting Factors
Def.: One physical or chemical abiotic
component that most inhibit biotic operation,
through either its lack or excess
Examples
Temps (low at high elevations)
H2O (lack in deserts & excess in bogs)
Nutrients
Changes in topography
Changes in climate
Figure 19.8
The Nitrogen Cycle
Figure 19.11
http://msucares.com/crops/fertilizer/index.html
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Atmospheric Nitrogen Deposition
N Saturation and Algal Blooms
The Gulf Coast Dead Zone
Ecosystem Components and Cycles
Communities
Plants: The Essential Biotic Component
Photosynthesis and Respiration
Abiotic Ecosystem Components
Figure 19.2.1
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