Chapter 3 The Biosphere

Objectives for Today Identify the levels of organization that ecologists study. Describe the methods used to study ecology.

Section 3.1 What is Ecology? Left side activity… How do animals benefit plants? Directions: With your partner, brainstorm 3 ways how animals benefit plants in their environment.

Study of interactions between organisms and their environment Ecology Study of interactions between organisms and their environment

The Biosphere Portion of earth that can support life Includes land, water, and atmosphere

Levels of Organization Organism (species)  population  community  ecosystem  biome  biosphere

Organism One individual in a species Species: organisms that can breed and produce fertile offspring Ex. Zebra

Population A group of organisms of the same species that live in the same area Ex. Herd of zebras (zeal)

Community Populations of different species living together and interacting Ex. Zebras, giraffes, lions, trees, grasses

Ecosystem All orgs. that live in one area (community), together with their nonliving (physical) environment Ex. water, climate, precipitation, etc.

Biome Group of ecosystems with same climate and similar communities The whole African savannah

Biomes

Ecological Methods Ecologists study the living world using 3 approaches Observing Experimenting Modeling

1. Observing First step Can be simple to complex

2. Experimenting Test hypotheses In a laboratory In the natural world

3. Modeling Some phenomena are very complex ex. Global warming Use models to make predictions

3. Modeling

What method of research is this ecologist using? An ecologist is studying in the field. She records each time that a robin visits a bird feeder. She also records each time that a robin is scared away from a bird feeder by a hawk. What method of research is this ecologist using? At what level of organization is this ecologist studying?

Section 13.2 Ecosystem

Biotic vs. Abiotic Factors biotic factor: living organisms that play an important role in the ecosystem Ex.) plant, animal abiotic factor: nonliving things that determines which living things can survive in a particular environment Ex.) moisture, temperature, wind, sunlight, and soil

Biodiversity is the assortment, or variety, of living things in an ecosystem

Keystone Species A is a species that has an unusually large effect on its ecosystem

Section 3.2: energy flow

Autotrophs Auto = “self” Troph = “feeding” Organisms that can make their own food (ex. plants, some bacteria) Also called producers Main source of energy?? Sunlight!

Photosynthesis Uses light energy to produce “food” such as sugar and starches

Chemosynthesis Uses chemical energy to produce food Some bacteria make food this way Found at deep sea hydrothermal vents

Heterotrophs Any organism that must consume their energy Also called consumers

Heterotrophs Herbivores Carnivores Omnivores Scavengers/ Detritivores Name What they eat Examples Herbivores Carnivores Omnivores Scavengers/ Detritivores Decomposers

How many consumers can you identify?

Show how energy flows in ecosystem Food Chains & Food Webs Show how energy flows in ecosystem Sun  Producers  Consumers

Food Chain Arrows show where energy is going to when one org. consumes another Each step is called a trophic level

Trophic levels Quaternary Consumers Tertiary Consumers Secondary Consumers Primary Consumers Primary Producers

Food Web Links all food chains in an ecosystem Consumers not limited to one trophic level More realistic than food chain b/c orgs rarely eat only one food or are eaten by only one predator

Identify the: Herbivores Carnivores Omnivores   Producers Primary Consumers Secondary Consumers Tertiary Consumers

Identify the Herbivores, Carnivores, and Omnivores Identify the Herbivores, Carnivores, and Omnivores. Identify the Producers, Primary Consumers, Secondary Consumers, and Tertiary Consumers

Food Web Activity

Ecological Pyramids Energy pyramid – shows energy available at each trophic level

Energy Pyramid Only 10% of energy is transferred to next trophic level Other 90%?? Tertiary Consumers (0.1%) Secondary Consumers (1%) Primary Consumers (10%) Producers (100%)

Biomass Pyramid Biomass – total amount of living tissue w/in a trophic level Potential food available for each trophic level

Pyramid of Numbers Based on numbers of individual orgs at each trophic level

Warm Up Page 73 – Answer the green “Writing in Science” question. Draw an energy pyramid for your chosen food chain. Show the energy available at each trophic level. Start with 100% energy at the producer level.

Objectives Describe how matter cycles among the living and nonliving parts of an ecosystem. Explain why nutrients are important in living systems. Describe how the availability of nutrients affects the productivity of ecosystems.

3.3 Nutrient Cycles Materials can be recycled through an ecosystem, energy cannot Water, carbon, nitrogen and phosphorus are constantly recycled

Water Cycle Evaporation/Transpiration Condensation Precipitation (4 Types) Runoff/Groundwater

Water Cycle

Carbon Cycle CO2 is released into the environment from: Burning of fossil fuels and forests Respiration

Carbon Cycle Plants consume CO2 during photosynthesis (used to make sugars) Carbon is then passed to consumers

Carbon Cycle

Nitrogen Cycle ~79% of atmosphere is nitrogen You cannot get nitrogen you need by breathing it in Must eat protein to get nitrogen

Nitrogen Cycle Bacteria convert the atmospheric nitrogen into useful nitrates Plants absorb nitrates through roots Cosumers eat plants (or other consumers) Organisms return nitrogen to the ecosystem when they die or decay

Nitrogen Cycle

Phosphorous Cycle Main source of phosphorous: weathering rock Plants take in phosphorous from soil Animals get phosphorous by eating plants When animals die, they decompose and the phosphorous is returned to the soil to be used again

Phosphorus Cycle

Nutrient Cycles http://glencoe.mcgraw- hill.com/sites/0078695104/student_view0/ unit1/chapter2/concepts_in_motion.html #

Primary Productivity Rate at which producers create organic matter Depends on the amount of nutrients

Limiting nutrient A nutrient that is in short supply Results in limited growth of organisms in that ecosystem Adding fertilizers boosts primary productivity

Algal bloom Runoff water containing fertilizers from farms can enter aquatic ecosystems Can greatly increase the amount of algae

Algal bloom