Transcript Earth as a Living System

Earth as a Living System
Ecosystem Functions and
Ecosystem Services
4 Main Systems
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Lithosphere
Hydrosphere
Atmosphere
Biosphere
The
Elements
Carbon (C)
• Biogeochemcial (element) cycles
Carbon (C )
Oxygen (O)
Hydrogen (H)
Nitrogen (N)
Phosphorus (P)
Potassium (K)
Sulfur (S)
Calcium (Ca)
Sodium (Na)
Magnesium (Mg)
Manganese (Mn)
Molybdenum (Mo)
Cobalt (Co)
Zinc (Zn)
Aluminum (Al)
Copper (Cu)
Iron (Fe)
others
Fig 5.5
© 2005 John Wiley and Sons Publishers
The Geologic Cycle
• The Geologic Cycle:
– The processes responsible for formation and
change of Earth materials
– Best described as a group of cycles:
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Tectonic
Hydrologic
Rock
Biogeochemical
Tectonic Cycle
• Tectonic cycle:
– Involves creation and destruction of the solid
outer layer of Earth, the lithosphere
The Hydrologic Cycle
• The Hydrologic Cycle:
– The transfer of water from the oceans to the
atmosphere to the land and back to the
oceans. Includes:
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Evaporation of water from the oceans
Precipitation on land
Evaporation from land
Runoff from streams, rivers, and sub-surface
groundwater
The Rock Cycle
• The rock cycle:
– Numerous processes that produce rocks and
soils
– Depends on other cycles:
• tectonic cycle for energy
• Hydrologic cycle for water
– Rock is classified as
• Igneous (granite)
• Sedimentary (sandstone)
• Metamorphic (marble)
Biogeochemical Cycles and Life:
Limiting Factors
• Macronutrients
– Elements required in large amounts by all life
– Include the “big six” elements that form the
fundamental building blocks of life:
carbon
hydrogen
nitrogen
oxygen
phosphorus
sulfur
• Limiting factor
– When chemical elements are not available at the right
times, in the right amounts, and in the right
concentrations relative to each other
Fig 5.6
© 2005 John Wiley and Sons Publishers
Biosphere central to movement
The carbon cycle
Basic Carbon Facts
• Key element of life
• In its reduced form as organic c comprises 45 –
50% of the mass of all plants and animals
• Found as:
• Elemental carbon (in lithosphere)
• As organic carbon (e.g. C6H12O6)
• As inorganic carbon
– Gaseous CO2, CO
– Dissolved as HCO3, H2CO3
– Carbonite minerals as FECO3, CO3, CaCO3
The carbon cycle
Atmosphere
• CO2, CH4, CO
• CO2, greenhouse gas
• Mauna Loa Curve
The Mauna Loa Curve
• During winter in the
northern hemisphere,
photosynthesis ceases
when many plants lose
their leaves, but
respiration continues.
• At spring, photosynthesis
resumes and atmospheric
CO2 concentrations are
reduced.
Terrestrial Biosphere
• Phytosphere
– Trees, grass, leafs
– Photosynthesis
– Aerobic respiration
• GPP is around twice the size of NPP
• Daily cycles, annual cycles
– Deforestation and land-use
• Soils
– Upper layers
• Litter from plants, decay, becomes humus, some released as
gas, or enters the ocean or waters
Vegetation
Photosynthesis:
energy (sunlight) + 6CO2 +
H2O =>C6H12O6 + 6O2
Respiration:
C6H12O6 (organic matter)
+ 6O2 => 6CO2 + 6 H2O
+ energy
Hydrosphere
• Surface ocean
– Organic form as plants algae
– Inorganic as calcerous or HCO3
Movement
• To atmosphere through diffusion, carbon partial
pressure
• Photosynthesis from marine biota
• Erosion
• Uppwelling of cold deep water
Fig 5.16
© 2005 John Wiley and Sons Publishers
Deep Ocean
Form:
– Organic form as plants algae
– Inorganic as calcerous or HCO3
• Movement
– Downwelling of warmer surface waters
– Biopump (10%)
Lithosphere
• Crust, rocks, stones
• Movement:
– Sedimentation
– Erosion and ?
The Missing Carbon
• 1,9 gigatonnes carbon released from
human activities are unaccounted for
• Evidence points to higher sequestration by
land mass somehow than anticipated
• NASA, LANDSAT, MODIS
• Remote sensing
The carbon cycle
The Phosphorus Cycle
• The phosphorus cycle:
– Involves the movement of phosphorus
throughout the biosphere and lithosphere
– Important because phosphorus is an essential
element for life and often is a limiting nutrient
for plant growth.
Fig 5.20
© 2005 John Wiley and Sons Publishers
The Nitrogen Cycle
• The nitrogen cycle:
– Cycle responsible for moving important nitrogen
components through the biosphere and other Earth
systems
– Extremely important because nitrogen is required by
all living things
• Nitrogen fixation:
– The process of converting inorganic, molecular
nitrogen in the atmosphere to ammonia or nitrate
• Denitrification:
– The process of releasing fixed nitrogen back to
molecular nitrogen
Fig 5.19
© 2005 John Wiley and Sons Publishers
Earth as a Living System
Earth itself a system of
biological communities
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Biota:
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All the organisms of all
species living in an area
or region up to and
including the biosphere
Biosphere:
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That part of a planet
where life exists
The planetary system
that includes and
sustains life
Ecosystem
• Ecosystem:
– A community of organisms and its local
nonliving environment in which matter
(chemical elements) cycles and energy flows.
– Life sustained by interactions of many
different organisms, functioning together, and
interacting through their physical and
chemical environment
– Inherently complex
Basic Characteristics of
Ecosystems
• Structure
– Living (Ecological Communities) – Hierarchical interactions
– Non-living (physical/chemical environment)
• Processes
– Cycling of chemical elements – important and complex
• Inflows, recycling, no waste in nature, interactions
• Food webs
– Flow of energy
• Between tropic levels
• Change
– Evolution
– Succession
The Community Effect
• Population: group of individuals belonging
to the same species living in the same
area
• Species interact directly and indirectly
– Symbiosis
– Competition
– Predator prey
Community level interactions
• Community-level interactions
– Generalists vs specialists
– Niches
• Keystone species
– Have large effects on it’s community or ecosystem
– Its removal changes the basic nature of the
community
– Ex. Sea otter
• Holistic View Needed
Change
• Evolution – change in genetic
material
• Succession
– The sequential change in the relative
abundances of the dominant species in a
biological community converging to a climax
state
Change
• Stages of Succession
– Early: plants typically small with short lifecycles
(annuals…), rapid seed dispersal, environmental
stabilizers.r selected, generalists
– Middle: plants typically longer lived, slower seed
dispersal, and in woodland systems: larger.
– Late: plants and animal species are those associated
with older, more mature ecosystem. K-selected
species, niches
– “Climax”? - followed by a disturbance
Resiliency
• An ecosystem is resilient if it can maintain
its functional integrity when subjected to
some disturbance
– Property of the system
• How to maintain?
– Threshold
– Keystone species
– Diversity
Evolution
• The process of change over time
• Biological evolution
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Change in the genetic material via
Mutations
Genetic drift
Natural selection
• Genotypes
• Phenotypes
– Survival of the fittest
– “fittest”?
Co-evolution
• One species is affected by the evolution of
another species
• A species is affected by change in the
environment
• Coevolution between environment and the
economy
– Insitutions e.g.
• Can you think of any examples of
coevolution?
Ecosystem functions - services
Ecosystem Functions/Services
• Are the conditions and processes through which
natural ecosystems and the species that make
them up, sustain and fulfill human life.
• Biophysical necessities for human life provided
by natural ecosystems
• Functions provide goods and services
• Currently threatened by most human activities
• Important (but new) conservation tool
Ecosystem functions/services
• Cover a wide range of processes and scales
– Global scale
• Carbon sequestration
• Global warming
– Landscape scale
• Water purification
• Erosion prevention
– Community scale
• Crop pollination
• Pest control
– Field, plot or individual person scale
• Local nutrient levels
• Disease and pest prevention
Ecosystem Functions and services
• Complex
• Dynamic
• Interact
• Multiple within an ecosystem
MEA approach - Ecosystem
Services
Consequences of ecosystem
change for human well-being
Step 1: Classification of Services
A) The MEA approach
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Supporting
Provisioning
Regulating
Cultural
B) de Groot et al.
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Regulation functions
Habitat functions
Production functions
Information functions
C) Goulder and Kennedy
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Provision of production inputs (inputs from environment)
Sustaining plant and animal life (life support services)
Provision of existence value (Amenity services)
Provision of option value (future services)
The MEA Approach
1. Supporting
– Nutrient cycling
– Soil formation
– Primary production
2. Provisioning
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Food
Wood
Fresh water
Fuel
The MEA Approach
3. Regulating
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Climate regulation
Flood prevention
Disease prevention
Water purification
4. Cultural
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Aesthetic
Spiritual
Recreational
Educational
Groot et al. approach –
classifying functions
1.Regulation functions – Maintenance of essential ecological
processes and life support systems.
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gas regulation (UVB regulation, climate, air quality)
climate regulation (maintaining favorable climate)
disturbance prevention (Storm prevention, flood prevention)
water regulation (drainage, natural irrigation)
water supply (provision of water for consumptive use)
soil retention (maintenance of arable land)
soil formation (maintenance of productivity)
nutrient regulation (maintenance of healthy soils)
waste treatment (pollution control – detox)
Pollination (pollination of crops)
biological control (control of pests and diseases)
Ecosystem Functions - Services
2. Habitat functions
– i. Refugium function (maintaining harvested species)
– ii. Nursery function
3. Production services
– i. food – conversion of solar energy into edible plants
and animals, food and energy
– ii. raw materials
– iii.genetic resources (drugs and pharmaceuticals)
– iv.medicinal resources (drugs and pharmaceuticals – and
others)
– v. Ornamental resources (resources for fashion, etc)
Ecosystem Functions - Services
4. Information functions
– i. Aesthetic value (enjoyment of scenery)
– ii. Recreation (travel to natural ecosystems)
– iii.Cultural and artistic information (use of nature as a
motive)
– iv.Spiritual and historic information (use for religious
purpose)
– v. Science and education (use for schools)
Step 2: identification
• Identify what species and processes are
required to perform each service
– Depends on the ecosystem
– Scale issues
– Separability
Step 3 Valuation
• Value the importance of those services
using economic evaluation
– E.g. the value of carbon sequestration
– Different methods for different services