1. APES
Unit 03

2. Ecosystems and Ecosystem Management
Chapter 6
Ecosystems and Ecosystem Management

3. Basic Characteristics of Ecosystems
Sustained life on Earth is a characteristic of ecosystems, not of individual organisms or populations
Structure (two major parts)
Living (Ecological Communities)
Non-living
Processes (two basic kinds)
Cycling of chemical elements
Flow of energy
Change
Predictable – succession
Unpredictable change

4. Ecological Communities and Food Chains
Ecological Communities are defined in two ways:
1. A set of interacting species that occur in the same place defined by the way they derive energy: Food chains, food webs, trophic levels (autotrophs)
2. A set of all species found in one area. EG. Zoo animals

5. Food Chains and Food Webs
A Terrestrial Food Chain
Four trophic levels:
Example:
Autotrophs
Herbivores
Carnivores
Decomposers
People are omnivores

9. Food Chains and Food Webs Continued…
An Oceanic Food Chain
Involve more species and tend to have more tropic levels. See figure 6.6
The Food Web of the Harp Seal
Shows how complex a real-life food web truly is.

12. The Community Effect
Species interact directly (symbiosis & competition) and indirectly
Community-level interactions
Indirect interactions.
Keystone species
Have large effects on it’s community or ecosystem
Its removal changes the basic nature of the community
See Sea Otter example figure 6.8. Sea otters influence the abundance of sea urchins
Holistic View
An ecological community is more than the sum of its parts.

14. How Do You Know When You Have Found an Ecosystem?
Vary greatly in structural complexity.
The watershed is a common, practical delineation.
What is a watershed?
Common to all ecosystems is energy flow and cycling of chemical elements.

15. Ecosystem Management
Ecosystem management is the key to conservation of life on Earth, but it is difficult to know the exact limits of the system and is equally difficult to know all of the interactions that take place within it.
If ecosystems cease to function we must supplement with our own actions.
Must consider chemical cycling, energy flow, community-level interactions, and natural changes.

16. Chapter 7
Biological Diversity

17. Biological Diversity and Biological Evolution
Biological Diversity (biodiversity)
The variety of life-forms commonly expressed as the number of species in an area
Biological Evolution
The change in inherited characteristics of a population from generation to generation
One of the features that distinguishes life from everything else in the universe

18. Four Processes that Lead to Evolution
Mutation
Natural Selection
Migration
Genetic Shift

19. Mutation A chemical change in a DNA molecule
Affects the expressed characteristics when cells or individual organisms reproduce

20. Natural Selection 4 Characteristics: Species: Genetic Variability
Environmental Variability
Differential Reproduction
Environmental Influence
Species:
a group of individuals that reproduce with each other and produce fertile offspring

21. Peppered Moth Example Originally White Now more black than white
Causes
Industrial Pollution
Soot covered trees
Industrial Melanism

22. Migration
Two new species evolve from an original species due to isolation
Ex: land bridge

23. Genetic Drift
Changes in the frequency of a gene in a population due to chance
Can be a problem for rare or endangered species

24. Basic Concepts of Biological Diversity
Genetic Diversity
Habitat Diversity
Species Diversity
Species Richness
Species Evenness
Species Dominance

29. Species
A group of organisms that can reproduce and produce fertile offspring.
Ubiquitous species
Worldwide distribution
Overly common in an area
Endemic species
Organisms unique to one place only.
Indicator species
The first native organisms in an ecosystem, to show the effects of environmental problems.

30. The Number of Species of Life on Earth
No one knows the exact number
About 1.4 million species have been identified and named
Insects and plants make up moth of these species
Number will increase

31. The Competitive Exclusion Principles
2 species that have exactly the same requirements cannot coexist in exactly the same habitat
Ex) introduction of the gray squirrel into Great Britain

34. Professions and Places: The Ecological Niche and the Habitat
Habitat: where a species lives
Ecological Niche: a species profession
The reason more species do not die out from competition is that they have developed a niche, and thus avoid competition

35. What is the effect of each species on the other?

36. Species Engage in 3 Basic Interactions
1. Competition
2. Symbiosis
3. Predation-Parasitism
Each affect evolution, persistence of a species and the overall diversity of life
Organisms have evolved together and therefore adjusted to one another
Human interventions upset these adjustments

37. Symbiosis
The relationship between two organisms that is beneficial to both and enhances each organisms chances of persisting
Mutualism, parasitism, commensalism
Obligate symbionts:
a symbiotic relationship between two organisms in which neither by themselves can exist without the other
Ex) stomach of a reindeer

42. Chapter 8
Biogeography Part I

43. Why Were Introductions of New Species into Europe So Popular Long Ago?
Biogeography:
The large scale geographic pattern in the distribution of species, and the causes and history of this distribution

44. Wallace’s Realms: Biotic Provinces
Major biogeographic regions of Earth that are based upon fundamental features of the plants and animals found in those regions
Taxa:
Categories that identify groups of living organisms based upon evolutionary relationships or similarity of characteristics (ex: species, families, orders)
Biotic Provinces:
A geographical region (realm) inhabited by a characteristic set of taxa, bounded by barriers that prevent the spread of those distinctive kinds of life to other regions.

45. The main biogeographic realms for animals are based on genetic factors .

46. The major vegetation realms are also based on genetic factors

47. Biomes
A biome is a kind of ecosystem. Similar environments provide similar opportunities for life and similar constraints.
Rainforest
Grasslands
Desserts

48. Climate is the most important factor in determining the type of biome that will be found in an area

50. Convergent Evolution
The process by which species evolve in different places of times and, although they have different genetic heritages, develop similar external forms and structures as a result of adaptation to similar environments
Ex) shapes of sharks

51. Divergent Evolution
Organisms with the same ancestral genetic heritage migrate to different habitats and evolve into species with different external forms and structures, but continue to use the same type of habitats
Ex) Ostrich

52. Island Biogeography Theory of Island Biogeography Adaptive Radiation:
Islands have fewer species than continents
The smaller the island, the fewer the species
Adaptive Radiation:
The process that occurs when a species enters a new habitat that has unoccupied niches and evolves into a group of new species, each adapted to one of these niches.
Ecological Island:
An area that is biologically isolated so that a species occurring within the area rarely mixes with any other population of the same species

54. 1. Islands far from the mainland tend to have a lower rate of immigration
2. Small islands have higher rates of extinction.
Which island would have the largest population based on 1 & 2?

55. Islands have fewer species than the mainland
Islands have fewer species than the mainland. This is a product of size as is seen on this graph.