Chapter 3: The Biosphere

Chapter 3 Outline 3-1: What is Ecology? 3-2: Energy Flow 3-3: Cycles of Matter

3-1: What is Ecology? Interactions and Interdependence Levels of Organization Ecological Methods

Interactions and Interdependence Ecology – the scientific study of interactions among organisms and between organisms and their environment Biosphere – The combined portions of the planet in which all life exists.

Levels of Organization in Biology

Levels of Organization Species – groups of organisms that can breed and produce fertile offspring. Population – group of organisms of the same species that live in the same area Community – all the living organisms found in an area. Ecosystem – all the organisms that live in a place, along with their environment. Biome – group of ecosystems that have the same climate and similar dominant communities. Biosphere – the combined portions on Earth where living things are found. More Inclusive

Ecologists study the environment in 3 ways: Observing Experimenting Modeling

3-2: Energy Flow Producers Consumers Feeding Relationships Energy From the Sun Energy Without Light Consumers Feeding Relationships Food Chains Food Webs Trophic Levels Ecological Pyramids

Producers Ecosystems need a source of energy to survive. For most ecosystems, the main source of energy is the Sun. Energy!

Like at this deep sea vent! For a few ecosystems, it comes from chemical energy from the earth. Chemosynthesis: Carbon dioxide + hydrogen sulfide carbohydrates + sulfur http://i.treehugger.com/images/2007/10/24/deep-sea%20hydrothermal%20vent-jj-001.jpg Energy! Like at this deep sea vent!

Producers A producer is an organism (like plants, algae or bacteria) that produces its own food Chemosynthesis – energy from inorganic chemical compounds is used to make food (some bacteria) Photosynthesis – energy from the Sun is used to make food (plants, algae, some bacteria) Producers are autotrophs because they make their own food.

Consumer A consumer is an organism that eats another organism Another word for consumer: heterotroph

Types of consumers(heterotrophs): Herbivores obtain energy from eating producers (autotrophs) Carnivores eat herbivores or other heterotrophs. Omnivores obtain energy from eating both autotrophs and heterotrophs. Detritovores obtain energy from eating plant and animal remains (detritus) Decomposers obtain energy from organic matter (things that were once alive).

Energy can be tracked throughout the ecosystem through feeding relationships

Food Chain A food chain is a series of steps in which organisms transfer energy by eating and being eaten. http://neuromanagement.files.wordpress.com/2009/03/food-chain.jpg

Food Web A food web is the network of complex interactions formed by the feeding relationships among the various organisms in an environment.

Food Web Each step in a food chain or a food web is called a trophic level. https://www.etap.org/demo/biology_files/lesson6/kep29.jpg

Food Web A food web shows all the possible feeding relationships in an ecosystem. How are food chains and food webs the same? How are they different? http://mrskingsbioweb.com/images/foodweb.gif

Only 10% of the energy is transferred to each trophic level.

Energy loss can be measured in biomass of organisms.

Energy loss and biomass comparison Energy flows one way in an ecosystem: Producers  1st Level Consumers  2nd Level Consumers  3rd Level Consumers

3-3: Cycles of Matter Recycling in the Biosphere The Water Cycle Nutrient Cycles The Carbon Cycle The Nitrogen Cycle The Phosphorus Cycle Nutrient Limitation

Recycling in the Biosphere Unlike energy, matter is recycled within and between ecosystems. Matter is passed from one organism to another and from one part of the biosphere to another through biogeochemical cycles.

The Water Cycle Section 3-3 Condensation Precipitation Evaporation Transpiration Evaporation Runoff Seepage Root Uptake

The Water Cycle Water can enter the atmosphere by evaporation and transpiration Evaporation – water changing from a liquid to a gas. Transpiration – water evaporating through tree leaves. Water cools in the air and condenses into clouds. Water falls to the ground as precipitation. Water makes its way to the ocean by runoff.

Nutrient Cycles A nutrient is a substance an organism needs to sustain life. Some common nutrients are: Carbon (C) Nitrogen (N) Phosphorous (P)

Carbon Important for: Co2 Released into the atmosphere by: Living tissue Animal skeletons Photosynthesis Cellular respiration Co2 Released into the atmosphere by: Breathing, volcanoes, burning trees & fossil fuels Absorbed by: Oceans, Plants (esp. trees, algae),

The Carbon Cycle Section 3-3 CO2 in Atmosphere CO2 in Ocean

Nitrogen Found in the air, and in dead things and poop: Important for: N2 = nitrogen gas – 78% of the atmosphere – unable to be used by producers NH3 = ammonia NO3- = nitrate found in dead things, able to be used by living things NO2- = nitrite Important for: Making proteins Some bacteria convert nitrogen gas into ammonia using nitrogen fixation, so producers can use them. N2  NH3 Some bacteria convert nitrates back into nitrogen gas using denitrification. NO3-  N2

The Nitrogen Cycle Section 3-3 N2 in Atmosphere NO3- and NO2- NH3

Phosphorous Important for: NOT found in the atmosphere Making nucleic acids (DNA, RNA) NOT found in the atmosphere Mostly found in rocks and soil minerals, and in ocean sediments.

Nutrient Limitation primary productivity – the rate at which organic matter is created by producers When an ecosystem has low primary productivity because it doesn’t have enough of a single nutrient, we call that a limiting nutrient. A common limiting nutrient is phosphorous (P).

Limiting Nutrient