Ecosystems Characteristics of Ecosystems Structure 2 parts Living

Ecosystems

Characteristics of Ecosystems � Structure – 2 parts � Living (species) � Non-living (chemical & physical) Atmosphere, water, soil � Processes – 2 kinds � Chemical cycling � Flow of energy � Change – change ALWAYS occurs over time

Simplest Ecosystem � The ecological community in an ecosystem consists of at least one species that reproduces its own food from inorganic cmpds, and another sp. That decomposes the wastes of the first – plus a fluid medium – ex. Air, water.

Ecological Community � Set of interacting sp. Found in the same place and functioning together to make possible the persistence of life � (Hard to know ALL interacting sp. )

Species Interaction � � Feeding on one another is one way sp. Interact. Energy & chemical elements/cmpds are transferred this way.

Trophic Diagrams � � Show the relationship of organisms in terms of energy transfer Organisms are grouped into TROPHIC LEVELS

Trophic Levels � 1 st Trophic Level (bottom) � Producers � Autotrophs – make their own food � Energy source = SUN � Largest level � 2 nd Trophic Level � 1 st consumers � Herbivores – feed on trophic level 1

Trophic Levels � 3 rd Trophic Level � 2 nd consumers � Omnivores or Carnivores � 4 th Trophic Level � 3 rd consumers � Omnivores or Carnivores � Decomposers are the highest trophic level Bacteria, fungi Not shown on trophic level diagrams

Trophic Level Energy

Food chain � � � � FOOD CHAINS FOLLOW A SINGLE PATH AS ANIMALS EAT EACH OTHER. EXAMPLE: THE SUN provides food for GRASS The GRASS is eaten by a GRASSHOPPER The GRASSHOPPER is eaten by a FROG The FROG is eaten by a SNAKE The SNAKE is eaten by a HAWK.

Food Web FOOD WEBS SHOW PLANTS & ANIMALS ARE INTERCONNECTED BY DIFFERENT PATHS. � EXAMPLE: TREES produce ACORNS which act as food for many MICE and INSECTS. � Because there are many MICE, WEASELS and SNAKES have food. � The insects and the acorns also attract BIRDS, SKUNKS, and OPOSSUMS. � With the SKUNKS, OPPOSUMS, WEASELS and MICE around, HAWKS, FOXES, and OWLS can find food. � They are all connected! Like a spiders web, if one part is removed, it can affect the whole web.

� FOOD WEBS show plants and animals are connected in many ways to help them all survive. � FOOD CHAINS follow just one path of energy as animals find food.

Food Chain

Food Web

Differing Ecosystems � Size � Smallest puddle of water � Largest forest � Species � Small � � # of sp. In a small space Can be artificial – pond outside of a waste water treatment plant Can be managed – agriculture, forests, water, wildlife preserves