Transcript Environmental Problems, Their Causes, and the Issue of

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)
Organism
Any form of life
Cell
Eukaryotic cell
Prokaryotic cell
Species
Groups of organisms
Population
Group of interacting individuals of the same species that occupy a
specific area at the same time
Genetic Diversity
Variance in genetic makeup of populations
Habitat
Where a population normally lives
Levels Of Organization
Earth’s Systems
Atmosphere
Troposphere/Stratosphere
Hydrosphere
Liquid water
Ice, icebergs, frozen soil
layers
Water vapor
Lithosphere
Crust and upper mantle
Biosphere
Where 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 Factors
Range of tolerance
Limiting factor
Biotic Factors
Producers – autotrophs
Consumers - heterotrophs
• Herbivores
• Omnivores
• decomposers
Carnivores
Scavengers
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.)