Matter and Energy in The Environment LS CH 20

ECOLOGY The study (science) of the interactions between organisms and their environment. Study of ecosystems Includes everything in a given area: Living things (biotic factors) Nonliving things (abiotic factors)

What do Ecologists Study? (think-pair-share)

Abiotic Factors Any nonliving thing in an ecosystem Examples: Still impacts organisms Examples: Sunlight Atmospheric gases Climate Temperature Soil Water Human impacts

The Sun The ultimate source of energy for our planet Sun  Producers (photosynthesis)  Primary consumers  Secondary consumers  etc. Also plays a role in many other abiotic factors Evaporates water Creates wind and weather due to heating patterns on Earth Controls temperature

Why do we experience seasons?

The Earth is Tilted on its Axis In our summer, the Northern Hemisphere tilts towards the sun, giving us more direct sunlight and keeping it warmer The Southern Hemisphere tilts away, giving them winter In our winter, the Northern Hemisphere is tilted away from the sun, giving us less direct sunlight (sunlight is spread out more) and cooling it down. The Southern Hemisphere tilts towards the sun, giving them summer

Atmospheric Gases The atmosphere is the layer of gases surrounding Earth Atmospheric composition (learn these percentages) Oxygen is breathed in by many organisms, and made by others Nitrogen is used by many organisms

Climate and Weather Climate is the average weather conditions in an area over a long period of time NOT THE SAME AS WEATHER! Includes precipitation, temperature, and wind Weather is the current condition A vast majority of scientists and researchers (97% who work in this area of research) believe that humans are changing the climate Could have drastic impacts to many ecosystems

Temperature How hot or cold something is (sort of… at least until Physical Science) Most organisms can only survive within a certain range of temperatures Polar bears in the desert, cacti in Antarctica…

Soil Made up of rock fragments, water, air, and bits of living things Essential for survival of plants, and therefore all organisms Bacteria within the soil break down dead organisms

Water Availability and quality important Only raw material that all organisms on earth need All organisms are made up of water Animals drink it to stay alive Plants need it for energy production and photosynthesis Marine life and many protists live in it While most of the earth is covered in water, it is not all in the proper form for all organisms to use

Human Impacts General Theme in Ecology We tend to mess things up rather a lot Humans are biotic factors, but we create a lot of abiotic factors Pollution impacts ecosystems greatly Buildings and roads fragment ecosystems We also impact other abiotic factors Water pollution Climate change

Matter is cycled in nature Matter Cycles Water Nitrogen Carbon-Oxygen Others we won’t be exploring

The Water Cycle Terms: Evaporation-Liquid to gas Condensation-Gas to liquid Precipitation-Water falling to earth’s surface Transpiration-Water leaving plants Exhalation-Water leaving as organisms exhale Run-off- Water that travels over surfaces Groundwater- The water stored underground

The Carbon-Oxygen Cycle Oxygen is needed by much of the life on earth Essential for the production of ATP during cellular respiration Oxygen is produced by plants and phytoplankton (includes tiny plants, some bacteria, and some protists) during photosynthesis The oxygen is then taken in by organisms to allow respiration to occur Provides ATP so that cells can do their jobs During respiration, Carbon Dioxide is produced

The Carbon-Oxygen Cycle Cont. Carbon is found in the air in the form of carbon dioxide Comes from: Exhalation of organisms (created in cellular respiration) Burning of fossil fuels Fossil fuels are fuels made from the remains of organisms Contributes significantly to climate change Natural release of carbon from soil Forest fires Deforestation Taken in by: Soil Photosynthetic organisms

CO2 As A Greenhouse Gas Carbon dioxide absorbs radiation from the sun This traps it on earth (similar to a greenhouse trapping heat), increasing global temperatures Global Warming (not a myth) Over time, the average temperatures throughout the planet have increased Climate change (also not a myth. Actually very terrifying) Carbon Dioxide is not alone Other gases (especially methane) are greenhouse gases However, increased CO2 emissions are accelerating climate change faster than other gases

The Nitrogen Cycle Nitrogen is the most abundant gas in the atmosphere Atmospheric electricity (lightning) causes nitrogen compounds to fall to the surface Nitrogen is a component of DNA and of proteins Organisms get nitrogen into their body by eating other organisms Animals release Nitrogen into the soil through waste (fertilizer) Also, when an organism dies, bacteria decompose the organism and turn the nitrogen into forms that plants can use They also release nitrogen from the soil back into the atmosphere

Movement of Energy in an Ecosystem Every living thing needs energy The ultimate source of energy is the sun Also a little bit of energy from Earth’s interior and hydrothermal vents in the ocean The Law of Conservation of Energy Energy cannot be created or destroyed. It can change forms. (More Physical Science!)

Types of Organisms (Review) Producers Able to make their own “food” (energy sources) Can be done by photosynthesis or chemosynthesis Chemosynthesis is like photosynthesis, only it uses chemical energy instead of sunlight Occurs near hydrothermal vents Often uses sulfur compounds Consumers Organisms that must consume food to get energy Classified by type of food sources

Classifications of Consumers Herbivores Eat only plants Carnivores Mostly eat other animals Omnivores Able to eat both plants and animals Humans, regardless of their diet, are omnivores Decomposers Feed on dead or decaying organisms

Transferring Energy in an Ecosystem It all starts with the sun (or hydrothermal vents in some oceanic ecosystems) Producers capture the sunlight and use it to make sugars Consumers then eat the producers, collecting the sugars Consumers and producers eventually die, and provide energy for decomposers At each level, only about 10% of the energy is able to go on to the next level Around 90% of the energy is used by the organism Cannot be destroyed Transferred to the environment as heat due to metabolism

Modeling Energy Transfer Food chains Very simple diagram showing one way that energy can be transferred Not even close to complete Very simplistic. Your teacher is not a fan… Food Web A more complex diagram showing many (or ideally all of) the feeding relationships in an ecosystem Can still be sort of simple Can be extremely complex In either case, the arrows point to WHERE THE ENERGY IS GOING!

Energy Pyramids A different sort of diagram, related to the others Shows how much energy is passed on to the next level

Food Web Drawing Requirements Must include the sun (NOT AN ORGANISM!) 10 organisms (must be real, and must live in same ecosystems (i.e. no dragons, bigfoot, etc., and no sharks in a desert ecosystem. Questions, ask!) At least 1 each of the following: 1 producer 1 herbivore 1 carnivore 1 decomposer Label each organism with its common name, and what type of organism it is (producer, consumer, etc.) Must be neat and include appropriate colors.