Environmental Science 1401
Ch. 3 Ecosystems and Energy:
Basic ecological principles
Major components
Matter Cycles & Energy Flow
Ecosystem Studies
Abiotic vs. the Biotic World
Ecology – ‘eco’ – house
‘logy’ – study
Our house – The Environment consists of two parts:
Biotic: living environment
Abiotic: Nonliving, or physical world
What is Ecology?
Ecology
Study of relationships and interactions among organisms and their environment.
Organism = any form of life
Contributors to Ecology
Ernst Haeckel – developed concept of ecology and named the science discipline.
Aldo Leopold-
Naturalist, wild life ecologist
Decline of the Honey Bee
Exhibiting Colony Collapse Disorder.
US 90% decline in some areas.
Pollution?
Pesticides?
Diseases?
Neonicotinoids?
Key indicator species for eco-concerns.
1/3 US food supplies in danger.
How does Ecology fit into an organized biological world?
Life is highly organized:
Atoms organized into molecules
Molecules organized into cells
Multicellular organisms: cells organized into tissues,
Tissues to organs; Organs to body systems; to the individual organism
Organisms Classified According To Cell Structure
Cell = basic unit of life
Eukaryotic
- all organisms besides bacteria
- unicellular, plant, fungus, animal
Prokaryotic
- bacteria
Cyanobacteria
(blue-green algae)
Prokaryotic
– no distinct nucleus or other internal parts
Stromatolites
2.8 to 3.5 bya
Fossilized cyanobacteria
Single-celled colonies
Prokaryotic
Using photosynthesis produced O2 – AIR!
Nitrogen fixators
N2 NH3
Nitrogen to ammonia to biosynthesize cells into more complex life forms.
Geologic indicators
Eukaryotic: distinct nucleus
Organism to Species...
Zebra Mussels
Invasive Species from Eurasia
Damage to native vegetation
Clogs pipes
Filter pollen and nutrients out of water
Species
– groups of organisms that resemble one another in appearance, behavior, chemistry, and genetic endowment
Generally species will not interbreed with other species organisms BUT...
under natural conditions, some actually / potentially breed with one another & produce live, fertile offspring
Sexual Reproduction
- Producing offspring by combining sex cells or gametes (ovum and sperm) from both parents
Asexual Reproduction
mother cell divides to produce two identical daughter cells (clones or replicas)
common in single-cell organisms
Populations Genetic Diversity
Individuals of population vary slightly in genetic makeup
variation in appearance or behavior
human eye/hair/skin color
snail shell color/banding
Habitat - place where a population or individual organism normally lives
Community - place co-occupied by two or more populations
ONE Global Ecosystem
Community of various species interacting with one another and with the abiotic environment.
EARTH ECOSYSTEM
Biosphere
Biomes – climatic similarities, ecosystems
Communities
Populations
Organisms
Earth Ecosystem = 4 “spheres”
Atmosphere
Biosphere
Lithosphere
Hydrosphere
+ Anthrosphere
Air
Atmosphere
Composition of the atmosphere
~78% nitrogen
~21% oxygen
< 1% argon
< 1% trace gases,
Including water vapor and green house gases
Aurora: Borealis & Australis
Collision of charged particles directed by the Earth's magnetic field
Hydrosphere
Liquid = surface and ground water
Ice = caps, sheets, glaciers, bergs & permafrost
Vapor = in atmosphere & soil
Earth’s spheres cont.
Biosphere
All Life Forms
Living & Dead
in Air, Water
& Lithosphere
Lithosphere
Crust
+
Upper Mantle
Energy Drives Earth Systems
Energy - capacity to do work & transfer heat
Light energy
Heat energy
Electricity
Nuclear energy
Chemical energy
= stored in coal, sugar…
Mechanical energy of moving matter
= flowing water, wind & ice
Radiation - transmission of energy through space as particles or waves
Potential energy - stored energy
potentially available for use due to position
Kinetic energy - energy in motion
e.g.: wind, flowing water, heat, electricity,
moving bodies, electromagnetic radiation
Potential vs. Kinetic Energy
Law of Conservation of Matter
Antoine-Laurent Lavoisier (1743 – 1794)
Anne-Marie Lavoisier (1758 – 1836)
French nobleman; studied chemistry, biology; recognized/named O and H
Helped construct metric system
First list of elements
Law of Conservation of Matter
Matter is not consumed
Matter only changes form
do not create nor destroy atoms
Rearranged or recombined
First Law of Thermodynamics
Energy is neither created nor destroyed, changes through chemical & physical processes
Energy only changes form
Cannot get more energy out of a system than is present within it
Second Law of Thermodynamics
In every transformation, some energy is degraded to lower quality (usually Heat)
Cannot “break even” in terms of energy quality
Physical change - no change in composition
change in size
change in state
Chemical change - chemical composition altered
MAY include change of size and/or state
Reactant(s) Product(s)
carbon + oxygen carbon dioxide + energy
C + O2 CO2 + energy
Physical & Chemical Changes
Physical change
Exfoliation, root wedging, frost wedging, thermal stress, biologic breakdowns, water alteration (erosion)
Chemical change
Oxidation
Dissolution
Precipitation
Hydrolysis
Important Limiting Factors for Aquatic Environments
Temperature
Sunlight – what if it cannot penetrate deep into the ocean?
Salinity
Water currents
Dissolved oxygen content dependent on temp and pressure
Availability of nutrients (N and P)
Range of Tolerance
of population to physical & chemical characteristics in environment
Temperature/Saline density and circulation patterns
Hydrothermal Vents
Günter Wächtershäuser
Iron-sulfur world theory
life might have originated at hydrothermal vents.
amino-acid synthesis at vents along with hydrothermal fluids into cooler waters, where lower temperatures and the presence of clay minerals could have fostered the formation of peptides (amino acid chains)
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Chemosynthesis
Biological conversion of one or more carbon molecules (CO2 or methane) and nutrients into organic matter using the oxidation of inorganic molecules (hydrogen gas, hydrogen sulfide) or methane as a source of energy
No photosynthesis required.
Ecotone = transition zone between environments
Ecological Boundaries
Important Limiting Factors for Terrestrial Environments
Temperature
Oxygen
Sunlight
Precipitation
Wind
Soil
Fire frequency
Latitude – distance from equator
Altitude – distance above/below sea level
Sustaining Life on Earth
Energy flow
Cycles
Gravity
Sunlight Sustains Life on Earth
Lights and warms the planet
Supports photosynthesis
Powers the cycling of matter
Drives the climate and weather systems
Producers
autotrophs = self-feeders
green plants
algae
phytoplankton
some bacteria
Consumers
heterotrophs = depend directly or indirectly on producers
Consumers
Herbivores
Carnivores
Omnivores
eat both plants and animals
Bears…Turtles…Squirrels …
Scavengers
feed on dead organisms
Vultures…Flies…Hyenas…
Detritivores “biodegradable”
feed on & help decompose detritus
Food Chain = trophic levels of energy flow
Food Web = Interconnected Food Chains
Ecological Pyramids = energy distributions
Biodiversity
Different species (life forms) and life-sustaining processes -- best suited to survive the variety of conditions on earth
Diversity
Genetic Diversity
the total number of genetic characteristics in the genetic makeup of a species
Individuals of population vary slightly in genetic makeup variation in appearance or behavior
Species Diversity
the number of species in an area and also their relative abundance, how relative the number of species compared to the number of other species within an area.
Basic Principles of Ecosystem Services & Sustainability
In Summary...
Using solar energy as energy source
Recycling reasonably efficiently the nutrients needed for survival, growth & reproduction