Changes in Ecosystems: Ecological Succession

Describe the changes you see occurring after the volcanic eruption Describe the changes you see occurring after the volcanic eruption. [Succession Video] Be specific. Notice what occurs first, did the land change? How small or big were the first plants? How Fast did this occur? https://www.youtube.com/watch?v=fL8fmWrE1f0

What is Ecological Succession? Natural, gradual changes in the types of species that live in an area

Two Types of Ecological Succession Can be primary or secondary

Primary Succession Begins in a place without any soil and No life Examples Sides of volcanoes Landslides Flooding

Pioneer Species First, lichens (that do not need soil to survive) grow on rocks Next, mosses grow to hold newly made soil Known as PIONEER SPECIES

Pioneer Species Low, growing moss plants trap moisture and prevent soil erosion Lichens break down rock to form soil.

Primary Succession Soil starts to form as lichens and the forces of weather and erosion help break down rocks into smaller pieces When lichens die, they decompose, adding small amounts of organic matter to the rock to make soil

Primary Succession Simple plants like mosses and ferns can grow in the new soil

Primary Succession The simple plants die, adding more organic material (nutrients to the soil) The soil layer thickens, and grasses, wildflowers, and other plants begin to take over

Primary Succession These plants die, and they add more nutrients to the soil Shrubs and trees can survive now

Primary Succession Insects, small birds, and mammals have begun to move into the area What was once bare rock, now supports a variety of life

Secondary Succession Begins after an event in a place that already has soil and was once the home of living organisms Occurs faster and has different pioneer species than primary succession Example: after forest fires

What Differences do you see?

Decide which of the following picture are Primary or Secondary Succession

Secondary Why? Because there are small plants (no pioneer species), and soil is present

Primary Why? Lichen (pioneer species) present, no soil

Secondary Why? Because there are small plants (no pioneer species), and soil is present

Secondary Why? soil is present, previous life existed

Primary Why? Lichen (pioneer species) present, no soil

Primary Why? Volcano whipped out existing life… and pioneer species (lichen) are present

Climax Community A stable group of plants and animals that is the end result of the succession process Does not always mean big trees Grasses in prairies Cacti in deserts

Ecological Succession - Natural, gradual changes in the types of species that live in an area

Primary Succession – no previous life Secondary Succession – was previously home to organisms

Compare Succession Chart Below (4 points) Primary Succession Secondary Succession No Soil No previous Life (Pioneer species) Lichen and Moss No biomass (living organisms) Event causing Removal of existing life Soil Present Seeds, roots, small plants present Has Biomass (some living organisms)