1. Ecosystems & Living Organisms
photo: Tim Beaulieu

2. evolution = cumulative genetic changes that occur over time in a population of organisms
natural selection = process in which better-adapted individuals – those with genetic traits better suited to environmental conditions – are more likely to survive and successfully reproduce, increasing their proportion in the population

3. adaptation in action.
photo: Jessica Lopez

4. What is the driving force of evolution?

5. symbiosis = intimate association between members of two or more species; the result of coevolution

6. not all flowers smell sweet…
photo: Jennifer Schlick

7. mutualism = both species benefit
photo: Stella Styles

8. photo: Tim McCready
commensalism = one species benefits; the other is neither harmed nor helped

9. predation = one species (predator) kills & eats another species (prey)
photo: Newfie Bullett
predation = one species (predator) kills & eats another species (prey)

10. parasitism = one species (parasite) obtains nourishment from another species (host), often weakening it

11. What type of symbiosis is this?
photo: Johann Mader

12. What type of symbiosis is this?

13. biological community = association of interdependent organisms that live & interact in the same place at the same time; communities often lack precise boundaries & are nested within one another

14. community interactions in an oak forest.

15. diagram: Michael Pidwimy
community succession = the process of community development over time, during which biological communities are gradually replaced by other biological communities

17. ecosystem = a biological community and its abiotic (nonliving) environment

18. habitat = the environment in which an organism lives
photo: Michael Righi

19. ecological niche = the totality of an organism’s adaptations & lifestyle, including physical, chemical and biological interactions with surrounding organisms and environments; no two species have identical ecological niches

20. habitat = “address” niche = “profession”
wetland, pond, river or stream
eat wetland plants & tree bark
build dams > create ponds > habitat for fish, insects, amphibians, moose, waterfowl, aquatic plants
fell trees > thin forests > more sun reaches the forest floor > increased germination & growth of seedlings
build lodges, which are also used by muskrat, otter, snakes & sunning turtles
prey for coyotes, bears & humans
photo: Keith Williams

21. What is the ecological niche of a sugar maple?
photo: Tim Lindenbaum

22. competition = interaction between organisms that vie for the same resources (food, sunlight, space) in an ecosystem

23. resource partitioning = different species living in the same ecosystem use resources differently (time or location of feeding, nesting, etc) to avoid competition

24. wolves hunted to extinction
keystone species = a species, often a predator, that exerts a profound influence on its community, in excess of that expected by its relative abundance
wolves hunted to extinction
populations of elk & deer explode
overgrazing
plant species disappear
plant-dependent birds, insects & small mammals also disappear
photo: Dick Randall

26. ecosystem services = environmental benefits that ecosystems provide to people, including air & water purification, decomposition, soil fertility, carbon storage, flood prevention, etc.
….valued at $30 TRILLION a year!

27. ecosystem services = environmental benefits that ecosystems provide to people
photo: gari.baldi
photo: Hyland Seeds
fungi & other decomposers break down organic matter, making nutrients available for growing food, wood & fuel

28. ecosystem services = environmental benefits that ecosystems provide to people
oysters & other shellfish filter water (up to 50 gallons per oyster per day!), improving water quality

29. ecosystem services = environmental benefits that ecosystems provide to people
salt marshes absorb wave energy, protecting coastal areas from floods & storm surges; filter pollutants & excess sediment out of runoff, improving water quality; and serve as a nursery for commercially-valuable fish & shellfish

30. ecosystem services = environmental benefits that ecosystems provide to people
forests stabilize soil, preventing erosion that can damage property & impair water quality; they also store & sequester carbon, mitigating the effects of climate change

32. Questions?