1. Interactions between species and their environment
Ecosystem Dynamics
Interactions between species and their environment

2. Does the Mountain care if the Wolf is there?
Yes?
No?

3. “Thinking like a Mountain”
“Only the mountain has lived long enough to listen objectively to the howl of the wolf.” –Aldo Leopold
“In wildness is the salvation of the world” ― Henry David Thoreau

4. Overview Questions
What are the abiotic and biotic components of an ecosystem?
How is life on Earth sustained?
How can the health of an ecosystem be evaluated?
How have humans impacted ecosystems?

5. Ecosystem Components- key physical and chemical factors
BIOTIC – living
Plants (producers)
Animals (consumers)
Bacteria (decomposers)
Fungi (decomposers)
Detritivores
Detritus feeders
Scavengers
ABIOTIC – non living
Aquatic: ( dissolved nutrients, pH, salinity, dissolved oxygen, temperature, light penetration,currents)
Terrestrial: (pH, nutrient availability, composition, temperature, humidity, sunlight, wind,fire frequency, altitude, latitude)

6. Biosphere (Ecosphere)
Ecosystem Structure
Individual Organism
Population
Community
Ecosystem
Biosphere (Ecosphere)

7. Biosphere Ecosystems Realm of ecology Communities Populations
Universe
Galaxies
Biosphere
Solar systems
Planets
Earth
Biosphere
Ecosystems
Ecosystems
Communities
Populations
Realm of ecology
Organisms
Communities
Organ systems
Organs
Figure 3.2
Natural capital: levels of organization of matter in nature. Ecology focuses on five of these levels.
Tissues
Cells
Populations
Protoplasm
Molecules
Atoms
Organisms
Subatomic Particles

8. Individual Organism- organisms are grouped into different species based on certain characteristics.
Black Footed Ferret ( Endangered species)
Photo credit: Ryan Hagerty ; U.S. Fish and Wildlife Service

9. Population Individuals of the same species living together in an area.
Photo credit by Kevin Bell; U.S. Fish and Wildlife Service

10. Community
All the various species ( plant and animal ) interacting in a particular area.
Photo Credit: George Gentry: U. S. Fish and Wildlife Service

11. Ask: What are the biotic and abiotic factors in the photo above
Ask: What are the biotic and abiotic factors in the photo above? How many can you list?
Ecosystem
The biotic (living) and abiotic (non-living) factors in a particular area.
Photo Credit: U. S. Fish and Wildlife Service

12. Biological Communities -Biological communities differ in the number and types of species
Species diversity- the number of different species a community contains.
Genetic diversity-variety in the genetic makeup among individuals within a species.
Ecological diversity-variety of forests, deserts, grasslands, oceans, streams, and lakes interacting with one another and with their nonliving environment.

13. BIODIVERSITY
Figure 3-15

14. Have You Thanked the Insects Today?
Many plant species depend on insects for pollination.
Insect can control other pest insects by eating them.

15. Silent Spring???
…if all insects disappeared, humanity probably could not last more than a few months [E.O. Wilson, Biodiversity expert].
Insect’s role in nature is part of the larger biological community in which they live.

16. It’s an Insect world!
Organisms, the different forms of life on earth, can be classified into different species based on certain characteristics.

17. Habitat or Niche?
The environment in which a species population ( or an individual organism) lives is called its HABITAT.
HABITAT = “HOME”
The relational position of a species in its ecosystem; how a species uses the resources in an area is called its ECOLOGICAL NICHE
NICHE = “OCCUPATION”

18. NICHE TYPES
The maximum range of environmental conditions under which an organism could exist if there were no competing species describes its fundamental niche.
Because of direct and indirect interactions with other organisms, species are usually forced to occupy a niche that is narrower than its fundamental niche. This is called the realised niche.

19. Intra-specific Competition:
Competition for resources between individuals of the same species.
Photo credit: Dave Menke and Christopher Serbeck; U.S. Fish & Wildlife Service
That’s my salmon!
Back off

20. Inter-specific Competition :
Competition for resources between different species living in the same
community.
Photo credit: Dave Menke and Christopher Serbeck; U.S. Fish & Wildlife Service

21. How can the health of an ecosystem be evaluated?
Indicator Species – a species who presence, absence, or abundance can be used to assess the health (presence of pollutants, etc) of an ecosystem.
Example: Frogs are a good indicator species because their life cycle includes phases in water and land.
Keystone Species – a species which plays a crucial role in maintaining the structure of the ecosystem despite its abundance. An ecosystem may experience a dramatic change if this species is removed or negatively impacted.
Example: Sea otters , sea stars, jaguars, alligators

22. Native Species A species indigenous to a given area. Example:
Whooping Crane; migratory crane
native to Texas. Also an endangered species due to habitat loss.
Photo credit: U.S. Fish and Wildlife Service

23. Invasive Species
A non-native species of plant or animal whose presence negatively impacts the balance of the ecosystem community. These species often are purposely or accidentally introduced by humans.
Example: European Starling – introduced to the U.S. as a plan to have all birds mentioned in the works of Shakespeare. Destroys crops and competes with native species.
Photo Credit: Dave Menke; U.S. Fish and Wildlife Service

24. Some Characteristics of Invasive Species
Rapid reproductive rate
Rapid growth
Tolerance to wide range of abiotic factors
Lack of natural predators or unusually effective defense mechanisms
Compete aggressively for resources
Estimated cost in the U.S. for damage and control of invasive species is $100 billion per year.
Photo credit:Kudzu; invasive Japanese non-native vine
Scott Ehart ( public domain)

25. Carrying capacity and Limiting factors
Carrying capacity – the maximum number of of a species that can be indefinitely sustained by a specific ecosystem given the resources available.
Limiting factor(s) – a population can be limited by the availability of matter and energy resources; Ex: food, water, space, temperature, and pH.

26. Range of Tolerance
A given population will thrive within a particular range of abiotic factors. Outside of that optimal range will be found less and less individuals of a population.
Example: pH range of tolerance for a species of fish in an aquatic ecosystem is between 6.9 and pH’s less than 6.9 and greater than 7.5 will have less individuals able to survive.

27. Range of Tolerance

28. Factors That Limit Population Growth
The physical conditions of the environment can limit the distribution of a species.

29. Human impacts on an Ecosystem
“H.I.P.P.O”
H – Habitat destruction, fragmentation or degradation
I- Invasive species
P – Pollution
P- Population increase of humans
O- Overhunting; overharvesting

30. Solutions Goals, strategies and tactics for protecting biodiversity.
Figure 3-16