Ecosystems and the Relationships in Them!

Today’s Objectives Explain the interaction of biotic and abiotic factors in an ecosystem Explain why ecosystems with similar characteristics can exist in different geographical locations Identify biotic and abiotic factors in a given scenario or diagram Describe the relationships between abiotic and biotic elements within an ecosystem, including: Air, water, soil, light, temperature (abiotic) Bacteria, plants, animals (biotic)

Ecosystems and the Relationships in Them! Ecosystem: a region that has abiotic components (oxygen, water, nutrients, light and soil) that interact with biotic components (plants, animals, and micro-organisms). They are contained within Biomes

How big are they?? Ecosystems can be very large – eg. Coastal Douglas Fir ecosystem Or… very small – eg. A small tide pool or rotting log

Within Ecosystems are habitats A habitat is a place in which an organism lives

The Structure So Far Biomes Ecosystems Habitats Made up of Made up of

Interactions within an Ecosystem - Biotic with Abiotic The abiotic factors in an ecosystem are just as important as the biotic factors because they all interact with each other. Plants and animals (biotic) cannot survive without oxygen, water, and nutrients (abiotic) Eg. Plants need light for Photosynthesis – a process that converts light energy into chemical energy for the plant.

Example #1: Abiotic Factor = Sunlight in Deep water… abiotic factor = limited sunlight biotic factor = little if any plant growth because without sunlight can’t carry on photosynthesis

Example #2: Abiotic Factor = Sunlight in Rainforest Canopy… abiotic factor = sunlight Biotic factor = top of canopy gets lots of sunlight = lots of plant growth Biotic factor = lower canopy gets less sunlight = only plants that can grow with less sun

Abiotic factor = Soil… Soil provides nutrients for plants and a home for many small organisms (insects, bacteria, etc…) Did you know… a square meter of soil can contain as many as 1000 species of invertebrate (no backbone) species!!

Interactions within an Ecosystem - Biotic with Biotic Biotic things will also interact with each other – animals with plants, plants with plant, and animals with animals, microbes with plants, etc… But first we have to understand the interactions and what the groups are called that interact.

The pattern of Interaction Species – a Group of closely related organisms that can reproduce with each other. Eg. Bears (Grizzly species vs. Black species vs. Polar bear species) Population – all members of a particular species within an Ecosystem Eg. All Polar bears in Canadian arctic Community – all the populations of different species within an ecosystem Eg. All different species in the Canadian arctic

Energy Flow in Ecosystems The flow of energy from interactions within an ecosystem is called energy flow. Eg. When a deer eats grass, the energy that was in the grass transfers or “flows” to the deer The Grass is a producer – produces food in the form of carbohydrates during photosynthesis The deer is a consumer – consumes or feeds on the food/energy of something else.

When the deer dies, it’s energy is absorbed by decomposers – organisms that break down dead organisms and organic waste and turn it into useable nutrients (snails, fungus). The energy is now recycled from the decomposers back to the producers(plants) that use the nutrients to grow. And so continues the cycle of energy flow!

See the Pattern?? Based on this picture…What do you think Herbivore, omnivore, detritivore and carnivore mean??

Types of Consumers Herbivore – consumers of plants (grasshopper, deer, sheep) Omnivore – consumer of plants and animals (bears, pigs) Carnivore – animal (meat) eaters only (wolves, spiders) Detritivore – eats dead organisms (plant/animal) and animal waste (pill bugs, snails, bacteria)

So how do we easily show Energy Flow? Food webs/chains/pyramids are a quick portrait of the feeding patterns and energy transfer within an Ecosystem. Each step in the food chain is called a Trophic Level So producers are at the start of the food chain so they are the FIRST Trophic level

Trophic Levels

Food Chain Secondary consumers – eat primary consumers Tertiary consumers – eat primary AND secondary consumers Food Chain Secondary consumers – eat primary consumers Primary consumers – eat primary producers Primary producers – produce the initial food

Food Web

Food Pyramid