Chapter 3: The Biosphere What is ecology?

Ecology Ecology – the study of interactions among organisms and between organisms and environment (Haeckel, 1866) Interdependence – dependence between or among individuals or things

Levels of Organization 1.Biosphere – largest level, portions of planet where life exists (land, H 2 O, air) –8 km above to 11 km below

2.Biome – group of ecosystems that share similar climates (temp. and rainfall) Levels of Organization

3.Ecosystem – collection of all organisms in a particular place together with the abiotic (physical) environment. Levels of Organization

4.Community – groups of different populations that live together in a defined area. 5.Population – groups of individuals of same species that live in same area. 6.Species – group of organisms that can breed and produce fertile offspring.

Levels of Organization

Biotic and Abiotic Factors Biotic – living part of the environment –Plants, Animals,Mold, Fungi, Bacteria, Protist Abiotic – Nonliving part of the environment –Sunlight, heat, soil, wind, water, temperature Environment – all conditions or factors surrounding an organism; includes both biotic and abiotic factors.

3.2 Energy, Producers, and Consumers At the core of every organism’s interaction with the environment is its need for ENERGY to power life’s processes

Producers (Autotrophs) Use solar or chemical energy to produce food by assembling inorganic compounds into complex organic molecules –Plants –Some protist –Some bacteria

Primary Producers Photosynthesis – captures solar energy and converts it to chemical energy sunlight 6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2 Chemosynthesis – Chemical energy used to produce carbohydrates –bacteria in harsh environments –deep sea volcanic vents or hot springs

Consumers (Heterotrophs) Can’t trap energy directly; must acquire it from other organisms –Herbivores – eat plant leaves, roots, seed or fruits (cow, catepillar, deer) –Carnivores – eat other animals (snakes, dogs cats) –Omnivores – eat both plant and animal (human, bear, pigs)

Scavengers – consume carcasses of other animals (vultures and hyenas) Decomposers – break down organic matter (bacteria and fungi) – produces detritus (small pieces of dead and decaying plant and animal remains) Detritivores – feed on detritus (earthworms and many types of snails, mites, shrimp, crabs) Consumers (Heterotrophs)

3.3 Energy Flow in Ecosystems  Food Chains  Food Webs

Food Chains and Food Webs SUN AutotrophsHeterotroph 1.Food Chain – energy trapped by producers passed on when organisms eat and are eaten 2.Food Web – relationship more complex than a chain

Food Web Activity

Trophic Levels and Ecological Pyramids Trophic Levels – each step in a food chain/web Ex: producers, then consumers Ecological Pyramids – shows relative amount of energy at each trophic level of a food chain or web. Biomass – total amount of living tissue within a trophic level

3.4 Cycles of Matter *Recycle Matter*

Carbon Cycle Photosynthesis – uses CO 2 from atmosphere –Happens in the CHLOROPLAST 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 Respiration – returns CO2 to atmoshere –Happens in the MITOCHONDRIA C 6 H 12 O 6 + O 2 H 2 O + CO 2

Carbon Cycle

The Carbon Cycle 1.Volcanoes, respiration, fossil fuels, and decomposition add CO 2 to atmosphere. 2.Plants take CO 2 and make carbohydrates 3.Plants are eaten by animals and carbohydrates are passed through the food chain. 4.As the animal breathes and eventually dies and decomposes CO 2 is return to atmosphere.

Carbon Cycling

Water Cycle

1.Water enters the atmosphere by: EvaporationEvaporation – water changes from a liquid to a gas TranspirationTranspiration – Evaporation through leaves 2.As water rises it cools condenses into tiny droplets that form clouds. 3.Droplets returns to Earth as precipitation. 4.Water enters the rivers, ground water, ocean or plant roots to restart cycle.

Nitrogen Cycle

1.Nitrogen gas makes up 78% of atmosphere 2.Nitrogen Fixation: bacteria take nitrogen gases and turn it into ammonia, nitrite, and nitrate. 3.Plants and animals use nitrate to make amino acids. 4.Animal dies and decomposes returning nitrates to the soil. 5.Denitrification: other bacteria convert nitrates into nitrogen gas. Nitrogen Cycle

The Phosphorus Cycle

Phosphate – parts of DNA/RNA Found in rocks that are worn down Washes into rivers/streams/oceans for marine organisms Taken in by plants and turned into organic compounds

Nutrient Limitation Primary Productivity – the rate at which organic molecules are created by producers If nutrients are in short supply, they are called LIMITING NUTRIENTS Ex: Nitrogen is often limiting in water; if there is suddenly as input of N (fertilizer runoff), organisms can grow rapidly (Algal Bloom)

Chapter 4: Ecosystems and Communities 4-1 The Role of Climate

Climate Climate: long-term, over entire biome area –Weather: short-term, local Greenhouse Effect –It’s a good thing! –CO 2, H 2 O, CH 4 all trap heat and hold it next to the surface –Keeps the temperature suitable for life VIDEO CLIP

The Effect of Latitude on Climate Earth has 3 climate zones due to unequal heating because of the angle of the sun –Polar –Temperate –Tropical

Heat Transport Ocean and wind currents help produce Earth’s climates They are affected by land masses and Earth’s rotation

4-2 Niches and Community Interactions

The Niche Niche – where and how something lives; the way the species obtains what it needs to survive and reproduce –Habitat is the general place where an organism live (address) –Niche is the organism’s how it interacts with biotic and abiotic factors (occupation)

Community Interactions 1.Competition Organisms compete for resources Ex: Food, Mates, Shelter Competitive Exclusion Principle – no 2 organisms occupy exactly the same niche in exactly the same habitat at exactly the same time. winner and a loser 2.Predation One organism (predator) captures and feeds on another (prey).

Community Interactions 3.Symbiosis Mutualism – both species benefit Ex: Flowers & insects, Clown Fish & Sea Anemone, Egrets & Alligators Commensalism – one benefits, the other is not helped nor harmed Ex: Barnacle (gets food) & Whale Parasitism – one benefits, other is harmed Ex: tapeworms, fleas, ticks, lice

Examples of Symbiosis Aphid – destructive insect pests Grey shark with pilot fish Bed bugs 5 min video

4.3 Ecological Succession Ecological Succession - change in an ecosystem 1.Primary Succession – no remnants of an older community (volcanic eruption or bare rock) o 1 st species to colonize barren areas are called “pioneer species” o Ex: lichens -composite, symbiotic organisms 2.Secondary Succession – disturbance affects the community - soil exists (wild fires, clear cutting, plowed for farming) 3.Succession in a Marine Ecosystem – happens when a large whale dies and sinks to the bottom 4.Climax Community – fairly stable, dominant community established after succession.

4-4 Land Biomes