Transcript Notes without questions - Department of Physics and Astronomy

Ecology and the Environmental
Sciences
12 November 2015
Physics
Chemistry
Astronomy
Geology/Ecology
Biology
High Elevation Forest Ecosystem in
Colorado
No Matter Where the Ecosystem is …
Agricultural Ecosystem
Coral Reef Ecosystem
Week 11: Ecology and
Environmental Science
A bit of history upon which to chew
 Functional unit of ecology: ecosystem
 Characteristics of ecological systems
 Systems ecology and feedback processes
 Environmental science: a few case studies
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Brief History of Ecology
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1800’s and before: natural history (observations on nature)
Through the mid-1900’s: challenge of new technologies and
environmental problems (e.g., Rachel Carson, harnessing the atom)
Mid-to-late 1900’s: new era in ecology
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Emergence of sub-disciplines of ecology (e.g., human ecology, marine
ecology)
Interdisciplinarity of ecology: mathematics, physics, chemistry, biology and
geology (unique feature of ecology)
2000 and continuing today …
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Interdisciplinary challenges (e.g., changing climate, deforestation, biodiversity,
Fukishima)
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Diffusion of ecology to the general public (e.g., debates on climate change,
water quality, mercury and human health, GMO’s, renewable energies, tropical
rain forests, aquifer depletion, pesticide)
Ecological Hierarchies: Why
Ecosystems?
Earth
Hierarchy Theory and Ecology
Biosphere
Biome
Ecosystem
Community
Population
Ecosystem Analogue:
Organism
Physics and Chemistry: atom
Biology: cell (coming soon to a lecture
near you!)
Ecosystems as “the” Functional Unit
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Central role of energy
Central role of cycling of elements and materials
Hierarchy theory
Species have niches
Cybernetics at play in ecosystems
Ecosystems
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Ecological systems - ecosystem
Components
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Biotic components
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Abiotic components
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All living organisms - plants, animals
and microbes
The “ecological community”
All non-living components - soil,
atmosphere, water, climate, nutrients,
etc.
Ecosystem
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Scientific understanding and
research
Unit of study and organization
Structure of Ecosystems: Energy
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Structure underpinned by flow of energy
Autotrophs: fix energy (C-C) from sunlight
(i.e., plants; 1st Law of Thermodynamics)
Heterotrophs: consume energy in C-C bonds
(2nd Law of Thermodynamics)
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Herbivores
Carnivores
Omnivores (combination of the above)
Decomposers (dead organic matter)
All organisms classified by their source of
energy
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Humans = __________.
Eagles = _________.
Corn plants = _______.
Microbes in a decomposing log = ___.
Trophic Levels of an Ecosystem
and Energy Rule of 10
10%
10%
10%
The Physics of Energy (Joules)
Flow in Ecosystems
Where does energy/J go?
Keys to Ecosystem’s Energy
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Energy flows through ecosystems unidirectionally
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As energy flows, amount of energy available to do work
always decreases (90%)
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First law of thermodynamics (physics again!)
Only 10% goes to the next higher trophic level (Rule of 10)
Second law of thermodynamics (physics … again)
Flow of energy limits the number of organisms in higher
trophic levels
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Predatory fishes (sharks)
Predatory birds (owls, hawks and eagles)
Predatory mammals (African Serengeti)
Energy Flow and
Nutrient/Element Cycling
10%
Sun
Herbivores/
Carnivores
Autotrophs
10%
Flow of
Energy
“Cycling” of
Nutrients/
Elements
Soil, air and
water
Decomposers
10%
Ecosystems as the Functional Unit
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Hierarchies in ecology
Role of energy
Cycling of elements and materials
Hierarchy theory
Species have niches
Cybernetics at play in ecosystems
Cycling of Materials and Elements in
Ecosystems: Track a Carbon Atom
Carbon atom in your arm came from where?
Simple Ecosystem Model - Cycling
of Elements (e.g., C) and Materials
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Attributes of model
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Biotic component
Abiotic components
Fluxes between
spheres/reservoirs
Cycle (contrast with
energy)
Example: carbon atom
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Star to atmosphere to
dinosaur to fossil fuel
to atmosphere to corn
plant to your femur and
then back to atmosphere
Energy
Element &
Material
Classic Carbon (C) Cycle Model
Standard Ecosystem Model of
Cycling in Ecosystems
Atmosphere
Biosphere
Keys
Reservoirs
Fluxes
Cycling
Linkage among all
reservoirs
Hydrosphere
Geosphere
Others: Water & Mercury
Attributes of Ecosystems
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Ecosystems comprised of both biotic and abiotic
components
Communities: collection of all plants, animals and
microbes
Energy flows through ecosystems in one direction
Materials cycle through ecosystems
Every species has a unique ecological niche
Ecosystems operate as cybernetic systems, being
controlled by feedback processes
Change in ecosystems: the norm (succession)
Geographical “Footprint” of American
Beech Tree and Black Bear
Geographical Footprint of the
Cultivated Grape
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Footprint: function of species niche
Every species: unique niche
Niche in Ecology
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Physical (e.g., temperature and
water) and biological (e.g., pest)
factors control the distribution
of species
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Each species: unique in the set
of factors that affect its “place”
in an habitat (physical and
biological factors)
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Example: lizard in the desert
Example: oak tree in forest
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Wetland Habitat
Forest Habitat
Niche in Ecology
Every species’
niche is unique
Niche-Specific Analysis
Niche of the Sandpiper
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Niche factors
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Abiotic Factors
1.
2.
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Biotic factors
1.
2.
Attributes of Ecosystems
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Ecosystems comprised of both biotic and abiotic
components
Communities: collection of all plants, animals and
microbes
Energy flows through ecosystems in one direction
Materials cycle through ecosystems
Every species has an ecological niche
Ecosystems operate as cybernetic systems, controlled by
feedback processes
Change in ecosystems: the norm not the exception
(succession) (this requires a re-thinking of ecology)
Change in Ecosystems: the Norm
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Disturbances are common (natural and anthropogenic)
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Fire
Hurricanes
Floods
Ice ages
Grazing animals
Invasive species
Deforestation
Weather and climate
Ecological Succession and Feedback
Processes
Ecology and the Environmental Science
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A bit of history upon which to chew
Functional unit of ecology: ecosystem
Characteristics of ecological systems
Systems ecology and feedback process
Environmental science: few case studies
Cybernetic Systems: Ecosystems
Positive
Feedback
Set Point
Control
Center/
Sensor
Effector
Negative
Feedback
Cybernetics of Human Body
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Feedbacks (+ and -),
homeostasis and cybernetics
Examples
 Thermostat
 Body temperature
Cybernetics of Ecological Systems
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Feedbacks (+ and -), and cybernetics
Examples
 Succession
 Climate change and temperature on
Earth’s surface
Cybernetics in Ecology: an
Example Using Ecological
Succession
Fire Disturbance and Ecosystem
Recovery: Succession
Ecology and the Environmental Science
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A bit of history upon which to chew
Functional unit of ecology: ecosystem
Characteristics of ecological systems
Systems ecology and feedback process
Environmental science: few case studies
Case Studies
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Ozone and UV-B in the atmosphere (text)
Acid rain (text)
Climate change and greenhouse gases (text and lecture)
Landfills and recycling (text)
Over-harvesting of marine fisheries
Biodiversity or loss of species
Mercury in the environment (lecture)
Endocrine disruptors (lecture)
Invasive species (text)
Climate Change
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First principles: radiatively-active greenhouse
gases (you know this)
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Retrospective analysis: what is it and what do
the data suggest?
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Prospective analysis: what is it (forward looking)
and why use models?
Radiative Properties
In absence of radiatively-active trace gases in atmosphere, temperature
would be 25 F degrees colder!!!
Trace Gases in the Atmosphere
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Carbon dioxide or CO2
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Methane or CH4
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Source: fossil fuel combustion (C-C to CO2)
Sources: rice patty agriculture and cattle
Radiatively active (meaning?)
Based on first principles of physics and chemistry (you know this
too!), YOU would predict that as CO2 in the atmosphere increases
~30% over five decades, temperature in the atmosphere would do
which of the following: decrease, increase or remain unchanged?
Retrospective Analysis of CO2
Retrospective Correlation: CO2 and
Temperature
First principles (couple slides ago) and now some experimental data
Retrospective Sea Level Change
1850
1900
1950
2000
Sea Level Rise Projection for
Changing Climate
Climate Change
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First principles of radiatively-active greenhouse
gases
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Retrospective analysis: what is it and what do
the data suggest?
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Prospective analysis: what is it (forward looking)
and why use models?
Prospective (Forward Looking)
Analysis: Modeling
Case Studies
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Ozone and UV-B in the atmosphere (text)
Acid rain (text)
Climate change and greenhouse gases (text and lecture)
Landfills and recycling (text)
Over-harvesting of marine fisheries
Biodiversity or loss of species
Mercury in the environment (lecture)
Endocrine disruptors (lecture)
Invasive species (text)
Mercury (Hg) in the Environment
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Mercury as an element (elemental Hg naturally occurring)
Mercury in the environment (methyl-Hg)
First principles: Hg cycles in ecosystems
Methyl-Hg: uneven distribution in the
environment - preference for higher trophic
levels
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predatory birds (e.g., eagles)
carnivorous fish (e.g., tuna)
predatory cats (e.g., panther)
humans
Periodic Table and Mercury
Mercury Cycling
Some Attributes of Mercury (Hg)
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Mercury cycles in the environment
Emergent/unexpected properties in ecosystem
(hierarchy theory)
Fate of Hg related to (i) organic form of Hg and
(ii) trophic structure in ecosystems
Purported human health concerns
At-risk groups: pregnant women and fish
consumption
 Health risk: neurological and cognitive functions
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Endocrine Disruptors in the
Environment
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What is the endocrine system?
What is a endocrine disruptor?
Examples of endocrine disruptors
 Phthalates (Bisphenol A, BPA)
Sources: natural and anthropogenic
Disruptors in the environment (cycles)
Observations in the environment
 Correlation vs cause and effect
Purported vs definitive health issues
Ecology and the Environmental Science
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A bit of history upon which to chew
Functional unit of ecology: ecosystem
Characteristics of ecological systems
Systems ecology and feedback process
Environmental science
A few case studies: lecture and text
Ecology and the Environmental Science






A bit of history upon which to chew
Functional unit of ecology: ecosystem
Characteristics of ecological systems
Systems ecology and feedback process
Environmental science
A few case studies: lecture and text