Post on 01-Jan-2016
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ECOSYSTEM• A LIMITED AREA IN WHICH
LIVING AND NONLIVING THINGS INTERACT
• IT IS SHAPED BY:1. ABIOTIC FACTORS - THE
NONLIVING FACTORS / PHYSICAL ENVIRONMENT
2. BIOTIC FACTORS- LIVING ORGANISMS
ACTIVITY #1
PLACE THE EAGLES IN THE
PROPER CATEGORIES,
DEPENDING ON WHETHER THEY
ARE DESCRIBING AN ABIOTIC
FACTOR OR A BIOTIC FACTOR.
ENERGY FLOW
Two types of energy sources:
1. 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.”
• PRODUCERS – autotrophs MANUFACTURE THEIR OWN FOOD – via PHOTOSYNTHESIS or CHEMOSYNTHESIS.
• CONSUMERS – heterotrophs rely on other organisms for their energy and food supply.
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)
• 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.
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
Energy 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.
Biomass Pyramid
Represents the amount ofliving organic matter at each trophic level. Typically, thegreatest biomass is at the base of the pyramid.
Pyramid of Numbers
Shows the relative number of Individual organisms at eachtrophic level.
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 25C 5000, 500, and 50D 1, 25, and 250
In the food chain, what percentage of the energy stored in the krill probably would be transferred to the cod?
A. More than 90 percentB. About 75 percentC. About 50 percentD. Less than 15 percent
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
BIOMASS PYRAMID:
PYRAMID OF NUMBERS:
Producers
1st Level Consumers
2nd Level Consumers
3rd Level Consumers
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 onlyB. ii only E. i, ii, and iii C. i and ii only
BIOMASS PYRAMID:
PYRAMID OF NUMBERS:
Producers
1st Level Consumers
2nd Level Consumers
3rd Level Consumers
CYCLES OF MATTER
Only 4 elements –
oxygen
carbon
hydrogen
nitrogen
-make up over 95% of the body in most organisms.
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 Cycle
Geologic Processes
Abiotic reservoir
Nutrients avail. to producers
Producers
Consumers
Detritivores
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.
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.
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.
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.
Levels of Organization
BIOSPHERE- part of Earth in which life exists including land ( lithosphere), water (hydrosphere), and air ( atmosphere.)
Earth’s Surface
8km ~ 5miles
11km ~ 6.8miles
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
Ten Major BiomesBiome Precipitatio
nTemperature Soil Diversity Trees Grasses
Tropical Rain Forest
high hot poor high dense sparse
Tropical Dry Forest
variable mild rich moderate medium medium
Tropical Savanna
variable mild clay moderate sparse dense
Desert low variable poor moderate sparse sparse
Temperate Grassland
moderate summer hot rich moderate absent dense
Temperate woodland and Shrubland
summer low, winter moderate
summer hot poor low medium medium
Temperate Forest
moderate summer moderate, winter cold
rich high dense sparse
Northwestern Coniferous Forest
high summer mild, winter cold
rocky, acidic
low dense sparse
Boreal Forest moderate summer mild, winter cool
poor, acidic moderate dense sparse
Tundra low summer mild, winter cold
poor low absent medium
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
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?
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.
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.
Community Interactions
When organisms live together, they interact.
Interactions such as COMPETITION, PREDATION, and SYMBIOSIS help shape the ecosystem in which they live.
• 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.
• 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
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.