Post on 19-Jan-2016
Chapter 4:Ecosystems: Components,
Energy Flow, and Matter Cycling
“The Earth’s thin film of living matter is sustained by grand-scale cycles of energy
and chemical elements.”G. Evelyn Hutchinson
What Is Ecology
The study of how organisms interact with one another and with their nonliving environment.
Connections in nature
Important Terminology (Biology Review)
OrganismAny form of life
CellEukaryotic cellProkaryotic cell
SpeciesGroups of organisms
PopulationGroup of interacting individuals of the same species that occupy a specific area at the same time
Genetic DiversityVariance in genetic makeup of populations
HabitatWhere a population normally lives
Levels Of Organization
Earth’s Systems
AtmosphereTroposphere/Stratosphere
HydrosphereLiquid water
Ice, icebergs, frozen soil layers
Water vapor
LithosphereCrust and upper mantle
BiosphereWhere living organisms exist
Life On Earth
Life depends on three interconnected factors
1. One-way flow of high-quality energy from the sun
2. Cycling of Matter
3. Gravity
Interconnected Factors
Ecosystem Concepts and Biomes
Terrestrial portion of the biosphere has been classified into biomes.
These biomes are characterized by:Distinct climate
• Long-term patters of weather
Specific landforms
Characteristics of Ecosystems
No distinct boundaries nor self-contained
Abiotic FactorsRange of tolerance
Limiting factor
Biotic FactorsProducers – autotrophs
Consumers - heterotrophs • Herbivores Carnivores
• Omnivores Scavengers
• decomposers
Food Webs and Energy Flow
Food Chain Food Web
Pyramids of Energy Flow
Biogeochemical Cycles
Nutrient cycles – the nutrient atoms, ions, and molecules that organisms need to live, grow, and reproduce are continuously cycled from the nonliving environment and then back again.
Water Cycle
Water Cycle – Human Impacts
Withdrawing large quantities of fresh water from streams, lakes, and underground sources.
Clearing vegetation from land for agriculture, mining, road and building construction, and other activities.
Modifying water quality
Carbon Cycle
Carbon Cycle – Human Impacts
Clearing trees and other plants that absorb CO2 through photosynthesis
Adding large amounts of CO2 by burning fossil fuels and wood
Nitrogen Cycle
Nitrogen Cycle – Human Impacts
Adding large amounts of nitric acid into the atmosphere when we burn any fuel.
Adding nitrous oxide to the atmosphere through the action of anaerobic bacteria on livestock wastes and commercial inorganic fertilizers
Removing nitrogen from topsoil
Phosphorous Cycle
Phosphorous Cycle – Human Impacts
Mining large quantities of phosphate rock for use in commercial inorganic fertilizers and detergents
Reducing the available phosphate in tropical forests by removing trees.
Adding excess phosphate to aquatic ecosystems:
Runoff of animal wastes
Runoff of commercial phosphate
Discharge of municipal sewage
Sulfur Cycle
Sulfur Cycle – Human Impact
Burning sulfur-containing coal and oil
Refining sulfur-containing petroleum
Using smelting to convert sulfur compounds of metallic minerals
Ecosystem Services
“All things come from earth, and to earth they all return.
Menander (342-290 B.C.)