Science Behind Environmental Science Chapter 2 Science Behind Environmental Science

Today: I’m going to start off with a brief discussion of the water cycle and biotic vs. abiotic factors. Then, we will go to the lab to start the terraria.

Natural Cycles Living organisms mostly composed of carbon, hydrogen, nitrogen, and oxygen

Natural Cycles These elements used over and over again Carbon atom found in sugar molecule of plant Sugar consumed by an animal Atom becomes part of animal muscle When animal dies, it enters decomposers Eventually, atom taken up by a plant again

Water One of most important resources environmental effects and benefits maintains more even temperature in environment erosion dilutes and flushes away contaminants

Water Biological effects and benefits required nutrient controls temperature of organisms solvent for nutrients cools surface of skin and leaves provides protection for some species

Water Cycle Water moves from What drives the water cycle? ocean to atmosphere to land in form of rain and snow to rivers and stream back to ocean What drives the water cycle? solar energy and gravity

Water Cycle Water enters atmosphere evaporation from oceans transpiration controlled evaporation from pores in plant leaves sweating breathing Moisture from these sources forms clouds

Water Cycle Moisture collects in atmosphere to form clouds Clouds release stored water rain and snow Gravity draws water to Earth’s surface Gravity draws water back to ocean

Conservation of Matter Matter can be changed from one form to another Cannot be created or destroyed by ordinary physical or chemical processes

Conservation of Matter In nature Organisms use food supply Little waste generated Natural processes can recycle this waste

Conservation of Matter Human population generates waste that is not easily disposed of may persist in nature indefinitely may be harmful or toxic

Ecosystems Organisms and surrounding environment Abiotic Biotic all the biotic and abiotic components Abiotic nonliving components of ecosystem Biotic living components of ecosystem

Biotic versus Abiotic Biotic Abiotic trees decaying logs deer wolves squirrels worms in soil bacteria in soil Abiotic water oxygen gas atmosphere amount of sunlight acidity of water type of soil acidity of soil

Next: Make a list of at least 5 biotic and 5 abiotic factors that might effect your terrarium. You will want to talk about these in your lab report when we are done with this lab so think of some good ones! You will then look for any changes in these when you make your observations each day. You will write another lab report when this is over, but it will be 1 per group.

Terrarium: The whole point of this project is to observe the water cycle in action and create your own little artificial ecosystem. You will be placing rocks, dirt, seeds, and water into bottle or jar and covering it with plastic. We will then let them sit for a few days and you guys will need to come down during recess each day to make your observations. I will be in the lab during that time so it will be unlocked.

Energy Laws First Law of Energy Energy cannot be created or destroyed Can be converted radiant to chemical energy chemical energy to heat or kinetic energy chemical energy to thermal energy thermal energy to electrical energy

Energy Laws Second Law of Energy Every time energy is converted . . . some energy is lost as heat

Flow of Energy An ecosystem is an energy system All processes depend on energy Nothing happens without flow of energy Energy = ability to do work moves from concentrated areas to become dispersed and unorganized

Flow of Energy Energy source in most ecosystems = sun

Energy Flow Complete ecosystem has three types of organisms Producers Transformers Decomposers

Energy Flow Producers Transformers Decomposers produce new food from photosynthesis usually green plants Transformers change food into more complex organic molecules Decomposers break down organic materials for reuse

Energy Flow Four fundamental biotic processes synthesis photosynthesis respiration decomposition

Synthesis Change in composition, size, shape, structure Organisms use nutrients, minerals, water to produce growth and reproduction Synthesis means “to make or form”

Photosynthesis Converts water and carbon dioxide into sugar requires a catalyst chlorophyll green pigment requires energy from sun

Photosynthesis Photosynthesis original source of most food also produces oxygen

Respiration Breaks down food to release energy converts sugar into water, carbon dioxide, and energy Both plants and animals undergo respiration

Decomposition A special type of cellular respiration Organic matter broken down to smaller organic compounds Recycles chemicals in bodies of organisms Follow-up Questions: Oxygen is converted to what molecule during cellular respiration? Glucose is converted to what molecule during cellular respiration? What waste product is given off during decomposition?

Ultimate Concept John Muir Everything on Earth part of an ecosystem “When we try to pick out anything by itself, we find it hitched to everything else in the universe.” Everything on Earth part of an ecosystem Everything is connected Doing something to one part affects some or all parts of system