environmental geography chapter 5 part 1
TRANSCRIPT
GEOG 106: ENVIRONMENTAL GEOGRAPHYChapter 5: Ecosystems and the Bioclimatic Environment
Pages 67-91
6 and 8 October 2009
Chapter 5 Outline:• Evolution of Earth’s atmosphere,
biosphere, hydrosphere, and lithosphere,
• Organization of food chains and food webs,
• Biogeography,• Climate regions, biomes, and plant
productivity,
Chapter 5 Outline:• Terrestrial ecosystems,• Marine ecosystems,• Altitudinal zonation,• Ecological succession,• Land use: intersection of physical
and natural systems, and• Human impact upon ecosystems.
5.1: Introduction:• Our Solar System formed
approximately 4.5 to 5 billion years ago,
• Life in Earth’s oceans has been evolving for the past 3 billion years,
• Life on Earth’s land has been evolving for the past 500 million years,
• Terrestrial plants have been evolving for approximately 100 million years,
5.1: Introduction:• Plants (producers) remain the
dominant organisms on Earth, in terms of total biomass,
• Of the terrestrial animals, insects are the dominant species, with millions of species identified so far, and
• Reptiles, birds, and mammals (that’s us!) represent the smallest group of life on Earth.
Fig. 5.1: Example of three simple food chains (top) and food webs (bottom). Food chains describe energy flow through an ecosystem.
Where is the Biosphere?
Where is the Biosphere?
5.2: Form and Function of an Ecosystem:
• All ecosystems are comprised of food chains,
• Insolation is the energy source that drives ecosystems and food chains, and
• Food chains are…
Food Chain/Food Web:• Describes NRG transformations
within an ecosystem.• These transformations occur in a
series of steps or trophic levels.
Food Chain/Food Web:• First Trophic Level: Producers (otherwise
known as plants… photosynthesis!).• Second Trophic Level: Primary Consumers
(otherwise known as herbivores).• Third Trophic Level: Secondary Consumers
(otherwise known as carnivores).• Fourth Trophic Level: Tertiary Consumers
(otherwise known as “top carnivores”).• Decomposers: Include bacteria and fungi that
break down organic material and recycle nutrients back into the ecosystem.
Food Chain/Food
Web:
Which trophic level(s) can
you identify in this image?
Food Chain/Food Web:
Energy Pyramid:
Ecology:• The study of the interrelationships
of organisms to one another and to the environment.
Ecosystem:• Interaction of living and non-living
components of the environment.
Ecosystem:• Organism,• Population,• Community,• Ecosystem, and• Ecosphere.
Ecosystem:
Can you identify both
living and non-living
components of this
ecosystem?
NRG flow in the Biosphere:
Energy Pyramid
Fig. 5.2: An energy pyramid showing the 90 percent energy attenuation between each trophic level. Note the importance of the detrivores within the food chain and energy pyramid.
5.3: Plant Productivity:Feeding Ecosystems:
• Photosynthesis,• Plant productivity,• Efficiency,• Principle of five limiting factors,• Climatic limitations, and• Human impacts on plant
productivity.
Insolation receipt by vegetation:
Fig. 5.3
Climatic Limitations on Plant Productivity:
Fig. 5.4: Environments with no limitations, seasonal limitations, and permanent limitations.
Productivity of Terrestrial Vegetation:
Fig. 5.5: Productivity per square meter for seven major climatic zones. Note the extreme productivity within tropical forest climate regions.
5.4: Types of Ecosystems and Their Characteristics:
• Terrestrial, saltwater, and freshwater ecosystems,
• Biomes and ecotones,• Biological organization,• Biomass,• Symbiosis, and• Biogeography.
Biomes:• Includes the total assemblage of
plant and animal life interacting within an ecosystem (similar to a community).
• We will focus on selected plant/vegetative biomes.
Major Biomes on Earth:
Major Biomes on Earth:• Tropical rainforest,• Tropical deciduous forest,• Tropical scrub,• Tropical savanna,• Desert,• Mediterranean woodland and
shrub,
Major Biomes on Earth:• Midlatitude grassland,• Midlatitude deciduous forest,• Boreal forest,• Tundra, and• Mountains and ice caps.
Tropical Rainforest Biome:
Tropical Deciduous Forest Biome:
Tropical Scrub Biome:
Tropical Savanna Biome:
Desert Biome:
Mediterranean Woodland and Shrub Biome:
Midlatitude Grassland Biome:
Midlatitude (Deciduous) Forest Biome:
Midlatitude (Deciduous) Forest Biome:
Boreal Forest Biome: