Energy in Ecosystems Ch

All organisms need? ENERGY Where does all of the energy on planet earth come from?

Types of Energy Chemical (stored/potential energy) – Found in food – Potential energy is stored in the bonds between chemical elements – Ex: glucose (sugar) Free (usable energy) – Break bonds in chemical compounds from food – Use that energy for cellular work – ATP – cell’s usable energy for activities ATP

In General… Autotrophic – Take energy from sun to make food – Plants, bacteria, and algae Heterotrophic – Obtain energy from eating Herbivore – plants Carnivore - meat Omnivore – plants and meat – Animals, fungi, protists

Energy in Ecosystems Life creates a pyramid when converting energy Each level is called a trophic level

Traveling up the pyramid With every step in a Trophic Level: – Organisms lose 90% of their energy to heat – Only 10% of energy is passed on Ex: an organism on one trophic level needs to eat 10x more than an organism one trophic level below

Producers Green plants (some bacteria & algae) that are able to make their own food – Lowest trophic level

Primary Consumers Primary (1 °) consumers are herbivores Ex: Some insects, deer, or mice

Secondary Consumers Secondary (2 °) consumers are carnivores They feed on herbivores – Ex: Small birds, amphibians

Tertiary Consumers Tertiary (3 °) consumers are carnivores – Ex: Snakes and hawks

Scavengers Scavengers feed on dead organisms they did not kill – Ex: earthworms, ants, and vultures

Decomposers or Detritivore Detritivores break down organic matter – Recyclers: turn waste into materials for producers – Ex: bacteria and fungi

Food Chain Food chain: – a relationship of organisms that depend on each other for energy or food. – Arrows point in direction of energy flow EX: algae is food for fish which are food for squid which are food for sharks.

Food Web – a group of interrelated food chains

Delicate Balance Diversity is key! Sometimes the removal of one species results in the collapse of the ecosystem – Ex: sea otter controls urchin population; if no sea otters, urchins overgraze and collapse ecosystem

Overview: Energy in Ecosystem From sun (light energy) Transferred by photosynthetic plants To chemical energy (found in food) Through food chains/webs Make ATP energy (usable energy in cells) Free energy (released as heat) Matter is returned to ecosystem by decomposers