Warm Up 1. What is the difference between an open and a closed system? 2. What are Earth’s 4 sphere’s? 3. What was the problem with DDT? 4. What is the percentage of gases in the atmosphere?

Chapter 2 Section 3 - Ecology

Ecosystems Ecology Ecosystems Study of complex relationships between living and nonliving things Ecosystems Many different sizes Largest: Biosphere

Ecosystems Most ecosystems have balance of plants and animals Producers Consumers

Balancing Forces Organisms use matter and energy Population growth- limited Carrying Capacity Largest population environment can support

Responses to Change Change can affect ecosystems in unpredictable ways Sudden disturbances- damage and disrupt ecosystems

Energy Transfer Sun—Ultimate source of energy Photosynthesis Energy transfer in ecosystems Solar energy to plants to animals to decomposers

Autotrophs or Producers Autotrophs – use energy from the environment to produce living tissue

Energy from the Sun Main autotrophs on: Land – plants Ocean – algae Cyanobacteria – tidal flats and salt marshes

Consumers or Heterotrophs Heterotrophs – organisms that rely on other organisms for energy and food Herbivores Carnivores Omnivores Detritivores Decomposers

Herbivores Herbivores – obtain energy by only eating plants Cows Caterpillars Deer

Carnivores Carnivores – eat other animals Snakes Dogs Owls

Omnivores Omnivores – eat both plants and animals Humans Bears Crows

Detritivores Detritivores – Feed on plant and animal remains called detritus Mites Earthworms Snails Crabs

Decomposers Decomposers – break down organic matter Bacteria Fungus

Feeding Relationships Energy flows through an ecosystem in one direction 1. Sun or inorganic compounds 2. Autotrophs or Producers 3. Heterotrophs or Consumers

Food Chains Food Chain – series of steps in which organisms transfer energy by eating or being eaten Zooplankton – microscopic consumer _____ steps removed from the producer

Food Webs Most feeding relationships are complicated Food Web – links all the food chains in an ecosystem together A group of food chains intertwined

Trophic Levels Trophic Level – each step in a food chain / web Producers – 1st level Consumers – 2nd, 3rd, 4th, etc. Each depend on level below for energy