Ecology: The Study of Ecosystems

Imagine you are in this meadow. Make a list of all the things you see, hear, smell, feel… Classify these items as ALIVE or NOT ALIVE

What is an Ecosystem? An ecosystem includes all the living and non-living things in a given area Biotic Factors: Living Things Ex: (from your list!) Abiotic Factors: Non-Living Things

How does the ecosystem get energy?

Autotrophs Living things that can make their own food photosynthesis Autotrophs are also known as “Producers” because they produce the energy for the ecosystem

How do the rest of us get energy?

We’ve got to EAT!!! Heterotrophs: Can’t conduct photosynthesis Aka Consumers

Herbivores Eat only plants

Carnivores Eat only meat

Omnivores Eat both plant and animal material

Is there another type of feeder? Decomposers: Live off of dead living things and wastes

Scavengers Consumers that eat animals that are already dead

How can we organize the different types of feeders? Food chain & Food web- A diagram of what eats what Trophic Levels- A name for the feeding levels within a food chain Producers, Primary Consumers, Secondary Consumers, Tertiary Consumers, Decomposers

Food Webs Many interconnected food chains within an ecosystem Can be very complicated

Ecosystems Part II

Matter is recycled How is matter recycled? -Food web! -Decomposers take it down into soil -Cycled into producers

What is recycled & how is it done? Remember the Carbon cycle? How about Nitrogen? How about Phosphorous? How about Sulfur?

What about energy??? Where does the energy come from??? Energy moves through the food chain, from producers to consumers to decomposers BUT it is NOT recycled!!!! Why not? The “Law of Conservation of Energy” aka “The First Law of Thermodynamics”……

Energy Cannot be Created or Destroyed!!!

Where does the energy go? Most of the energy at each trophic level is used by the living things to conduct their metabolism, in hunting/killing/consuming food, and in other life activities (growing, reproduction) Much is lost as HEAT Not all living material is consumed, ex: bones, bark, etc. These parts will be decomposed So where does this energy go?

The Law of 10% At each trophic level, 90% of the available energy is used, with most of it being “lost” as heat to the atmosphere. Only 10% of the energy at each level is available to the next trophic level (when they get EATEN!) So if a producer has 10,000 Calories (or kilocalories) of energy, how much energy would each level after that have?

Energy Pyramid At each higher trophic level, the amount of energy decreases by 10%! Which will get more energy from its prey- primary consumers tertiary consumers?

Energy Can also be measured in Joules (J)

What does this mean for higher level consumers? -There’s less energy in the food they eat! -This means there are FEWER higher level consumers and MORE producers and lower level consumers What will happen to an ecosystem if all of the producers are killed? (Think deforestation, forest fire, drought, etc)

Quick Quiz: What only eats plants? Who always starts a food chain? Who eats plants AND animals? Who only eats animals? How is a Food Web different from a Food Chain?

Quick Quiz, cont. Who eats EVERYBODY when they’re dead? What do we call producers (like plants) who make their own food? What is the other name for consumers? What is the name for living things in the environment? What is the name for non-living things in the environment?

NON-FEEDING RELATIONSHIPS IN ECOSYSTEMS SYMBIOSIS: Mutualism – relationship where both organisms benefit Commensalism - relationship where one organism benefits and the other organism is unaffected Parasitism – relationship where one organism benefits and the other organism is harmed (sometimes this is a feeding relationship)

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Energy Pyramid How much energy is available at each level if the Producers have 100,000 Calories available? Write it next to each level. Color the autotrophs GREEN Color the herbivores RED Color the secondary consumers BLUE Color the tertiary consumers YELLOW Color the quaternary consumer ORANGE ADD BACTERIA with arrows to show matter transfer ADD in arrows to show where the lost energy goes COLOR THE KEY!!!

Food Chains & Webs (both sides) Color the autotrophs GREEN Color the herbivores RED Color the secondary consumers BLUE Color the tertiary consumers YELLOW Color the quaternary consumer ORANGE Color the decomposers PURPLE