1. ECOLOGY AND ECOSYSTEMS

2. ECOLOGY
IS THE STUDY OF THE INTERACTIONS BETWEEN ORGANISMS AND THEIR ENVIRONMENTS

3. ECOSYSTEM A LIMITED AREA IN WHICH LIVING AND NONLIVING THINGS INTERACT
IT IS SHAPED BY:
ABIOTIC FACTORS - THE NONLIVING FACTORS / PHYSICAL ENVIRONMENT
BIOTIC FACTORS- LIVING ORGANISMS

4. ACTIVITY #1
PLACE THE EAGLES IN THE PROPER CATEGORIES, DEPENDING ON WHETHER THEY ARE DESCRIBING AN ABIOTIC FACTOR OR A BIOTIC FACTOR.

5. Ecosystem Dynamics
TWO KEY PROCESSES:
ENERGY FLOW
2. CHEMICAL CYCLING

6. Two types of energy sources:
ENERGY FLOW
Two types of energy sources:
Light Energy- the main energy source for life on Earth; used by autotrophs to carry out photosynthesis.
2. Inorganic Chemical Compounds- are used by autotrophs that can produce food in the absence of light. The process is called “chemosynthesis.”

7. PRODUCERS – autotrophs MANUFACTURE THEIR OWN FOOD – via PHOTOSYNTHESIS or CHEMOSYNTHESIS.
CONSUMERS – heterotrophs rely on other organisms for their energy and food supply.

8. TYPES OF CONSUMERS - Heterotrophs
HERBIVORES- eat only plants
CARNIVORES – eat animals
OMNIVORES – eat both plants and animals
DETRITIVORES – feed on animal remains or other dead matter ( crabs, earthworms, ants)
DECOMPOSERS- break down organic matter ( bacteria, fungi)

9. What’s for dinner?

10. FOOD CHAINS- a series of steps in which organisms transfer energy by eating and being eaten.
FOOD WEBS- link all the food chains in the ecosystem together.
TROPHIC LEVEL- each step in a food chain. Producers – first level, consumers- second, third or higher.

13. Ecological Pyramids
Ecological pyramid is a diagram that shows the amounts of energy or matter contained within each trophic level.
3 Types:
ENERGY PYRAMID
BIOMASS PYRAMID
PYRAMID of NUMBERS

14. Energy Pyramid Pyramid of Numbers Biomass Pyramid
Shows the relative amount of
energy available at each trophic
level. Organisms use about 10
percent of this
energy for life processes.
The rest is lost as heat.
Pyramid of Numbers
Shows the relative number of
Individual organisms at each
trophic level.
Biomass Pyramid
Represents the amount of
living organic matter at each
trophic level. Typically, the
greatest biomass is at the
base of the pyramid.

15. How much energy is available to first-, second-, and third-level consumers, if there are 50,000 kcal available at the producers’ trophic level? A 250, 25, and 1 B 3000, 250, and 25 C 5000, 500, and 50 D 1, 25, and 250

16. In the food chain, what percentage of the energy stored in the krill probably would be transferred to the cod? A. More than 90 percent B. About 75 percent C. About 50 percent D. Less than 15 percent

17. What is true about the pyramid of numbers?
BIOMASS PYRAMID:
PYRAMID OF NUMBERS:
3rd Level Consumers
2nd Level Consumers
1st Level Consumers
Producers
What is true about the pyramid of numbers?
i 1st level consumers compose the greatest number of individuals.
ii There are more 3rd level consumers than 2nd level consumers.
iii There are more producers than 1st level consumers.
A. i only D. ii and iii only
B. ii only E. i, ii, and iii
C. i and ii only

18. What can you conclude based on the two pyramids?
BIOMASS PYRAMID:
PYRAMID OF NUMBERS:
3rd Level Consumers
2nd Level Consumers
1st Level Consumers
Producers
What can you conclude based on the two pyramids?
i The producers are probably small, like single-celled algae in a body of water.
ii The producers are probably large, like trees in a forest.
iii No reasonable conclusion can be drawn from the information given.
A. i only D. ii and iii only
B. ii only E. i, ii, and iii
C. i and ii only

19. CYCLES OF MATTER Only 4 elements – oxygen carbon hydrogen nitrogen
-make up over 95% of the body in most organisms.
Composition of a human body: Oxygen 65%, Carbon 18%, Hydrogen 9.5%, Nitrogen 3.3%, , less than 0.01%- calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium.

20. Cycles of Matter
Unlike the one-way flow of energy, matter is recycled within and between ecosystems.
The process of chemical recycling in an ecosystem, involving both biotic and abiotic factors- is called Biogeochemical Cycle;
Biogeochemical:
Bio- life
Geo- geologic process ( water cycle- evaporation, precipitation)
Che- chemical – some chemical elements require “ processing”. Nitrogen, for example. 80% of the atmosphere is nitrogen; however, the plants can only use nitrogen in the forms of ammonium and nitrate. Certain root bacteria converts atmospheric nitrogen into ammonium, that plants can absorb.

21. BioGeoChemical Cycle Consumers Producers Detritivores
Nutrients avail. to producers
Sun supplies ecosystems with energy, but there are no extraterrestrial sources of the chemical elements life requires. Ecosystems depend on a recycling of these chemical elements.
Abiotic reservoir
Geologic Processes

22. The Water Cycle Condensation Precipitation Evaporation Transpiration
Runoff
Seepage
Root
Uptake

23. The Water Cycle
There are 3 major processes driven by solar energy: Precipitation, Evaporation, and Transpiration - that continuously move water between the land, oceans, and atmosphere.
Over the oceans, evaporation > precipitation;
Water vapor in clouds gets carried by winds across the land.
On land, precipitation > evaporation and transpiration. The excess precipitation forms lakes, rivers, and groundwater- that flow back to the sea, completing the water cycle.

24. The Carbon Cycle CO2 in Atmosphere CO2 in Ocean
Photosynthesis and respiration are mainly responsible for the cycling of carbon between the biotic and abiotic world.
The return of CO2 to the atmosphere by respiration balances its removal by photosynthesis. However, the increased burning of wood, and fossil fuels is steadily raising the level of CO2, causing significant environment problems, including global warming.

25. The Carbon Cycle
Carbon- major ingredient of all organic molecules. Its abiotic reservoir is atmosphere, oceans, rocks, soil; biotic- organisms.
Photosynthesis, respiration, and decomposition take up and release carbon and oxygen.
Erosion and volcanic activity release carbon dioxide
Decomposition- leads to fossil fuels, carbon underground.
Human activities- mining, burning fuels, etc. release carbon dioxide.

26. The Nitrogen Cycle
N2 in Atmosphere
NO3-
and NO2-
NH3

27. The Nitrogen Cycle
The main reservoir- atmosphere. Ingredient of amino acids; Cycles through the soil and organisms.
Although atmosphere contains 79% nitrogen gas, only certain types of bacteria can use this form directly. The bacteria lives in the soil, plant roots and binds nitrogen to hydrogen to form ammonia
(process called “nitrogen fixation”); Other bacteria performs “nitrification”- convert ammonia into nitrates and nitrites.
Denitrification- nitrates converted into nitrogen gas.

28. Phosphorus Cycle Part of DNA and RNA; does not enter atmosphere.
Main abiotic reservoir- rock, which upon weathering releases phosphorus.
Some phosphate cycles between organisms and the soil on land.

29. Levels of Organization
Individual – organ system- organ- tissue- cell- molecule- atom

30. Levels of Organization
BIOSPHERE- part of Earth in which life exists including land ( lithosphere), water (hydrosphere), and air ( atmosphere.)
8km ~ 5miles
Earth’s Surface
11km ~ 6.8miles

31. Levels of Organization
BIOME- a group of ecosystems that have the same climate and dominant communities ( plants & animals.)
Examples: Tropical Rain Forest
Desert
Temperate Grassland
Tundra
Tropical Rain Forest- Tall trees , flowers, fruits all year; lots of rain, warm temperature all year; South America, Asia, Africa, Australia
Desert- few plants, special plants- cactuses; dry, very little rain; parts of Africa, Asia, Australia
Temperate Grassland- tall thick grass, not enough rain for trees to grow, warm summers, cool winters; Central North America
Tundra- no trees, only grasses and shrubs, dry, windy, frozen ground all year, Northern North America

32. 10 MAJOR BIOMES

33. Ten Major Biomes Biome Precipitation Temperature Soil Diversity Trees
Grasses
Tropical Rain Forest
high
hot
poor
dense
sparse
Tropical Dry Forest
variable
mild
rich
moderate
medium
Tropical Savanna
clay
Desert
low
Temperate Grassland
summer hot
absent
Temperate woodland and Shrubland
summer low, winter moderate
Temperate Forest
summer moderate, winter cold
Northwestern Coniferous Forest
summer mild, winter cold
rocky, acidic
Boreal Forest
summer mild, winter cool
poor, acidic
Tundra
summer mild, winter cold

34. The Role of Climate Sunlight Sunlight Most direct sunlight Sunlight
The equator receives the greatest degree of solar radiation. Hot air rises, then it cools, forms clouds and drops rain.
After losing moisture, dry air spreads away from the equator- desert biomes.
Temperate zones- wet but cool
Uneven heating of Earth causes rain and wind.
Other factors that affect climate- bodies of water & mountains.
Sunlight
Sunlight

35. Levels of Organization
ECOSYSTEM- all organisms in a particular area, along with the abiotic factors with which they interact.
Examples: Lakes, Forests, Marshes, etc.
Two general categories of ecosystems:
Terrestrial
Aquatic

36. Levels of Organization
COMMUNITY – all of the organisms living in a specific place.

37. Levels of Organization
POPULATION – groups of individuals that belong to the same species and live in the same area/ecosystem.
Can a group of rabbits and a group of mice make up the same population in an ecosystem?

38. Levels of Organization
INDIVIDUAL SPECIES – a group of organisms that are similar to one another and can breed and produce fertile offspring;
Organism- the smallest living unit of the biosphere.

39. BIODIVERSITY- the number and variety of species living within an ecosystem.
CARRYING CAPACITY– the ability of the ecosystem to support the organisms in its ecosystem.

40. Community Interactions
When organisms live together, they interact.
Interactions such as COMPETITION, PREDATION, and SYMBIOSIS help shape the ecosystem in which they live.

41. Predation- one organism captures and feeds on another.
Competition- organisms compete for the same limited resource ( water, nutrients, light, food, or space.)
“ Competitive exclusion principle”- no two species can occupy the same niche in the same habitat at the same time.
Predation- one organism captures and feeds on another.

42. Symbiosis- “living together”:
Mutualism – both organisms benefit
Commensalism- one organism benefits and the other is neither harmed nor helped
Parasitism- one organism, the parasite, benefits; and the other, the host, is harmed

43. Test your knowledge:
1. The anemone is found attached to the shell in which the hermit crab lives. When crab searches for food, the anemone is brought into contact with a greater supply of food. The crab doesn’t mind his host; anemone's stinging cells protects him too.
2. Tapeworms have no gut, so they rely on their host to provide them with already digested food. The host later suffers harm.
3. Oxpeckers run over the backs of hippopotami. These birds rid their partners of injurious and annoying pests and in doing so obtain a ready supply of food.
4. Spiders build their webs on trees.
5. Phoretic mite attaches the fly for transportation only.