ecological succession: be able to describe the process of primary and secondary succession in a...
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Ecological Succession:
Be able to describe the process of primary and
secondary succession in a named habitat.
Ecological Succession:
Be able to describe the process of primary and
secondary succession in a named habitat.
Environmental SystemsEnvironmental Systems
Primary succession: The gradual establishment, through stages, of a climax ecosystem, that has not been occupied before.
Primary succession: The gradual establishment, through stages, of a climax ecosystem, that has not been occupied before.
Primary succession will occur after a volcanic eruption
Primary succession will occur after a volcanic eruption
Primary succession occurs after a glacier retreats
Primary succession occurs after a glacier retreats
Glacier Bay, AlaskaGlacier Bay, Alaska
Secondary succession: The reestablishment, through stages, of a climax ecosystem, that has been cleared by natural or human means.
Secondary succession: The reestablishment, through stages, of a climax ecosystem, that has been cleared by natural or human means.
Secondary Succession: A bare patch of ground covered in
grasses two years later
Secondary Succession: A bare patch of ground covered in
grasses two years later
Secondary SuccessionSecondary Succession
When natural vegetation has been disturbed, removed or destroyed.
Abandoned farms
Burned forests
Heavy pollution
Deforestation
A huge storm
When natural vegetation has been disturbed, removed or destroyed.
Abandoned farms
Burned forests
Heavy pollution
Deforestation
A huge storm
Some Definitions:Some Definitions: Sere: Another name for succession. A set of stages
of evolution of an ecosystem.
Pioneer stage: First stage in a sere which is dominated by opportunist species. (r-strategists)
Climax community: Populations of organisms living together in the climax stage. (K-strategists)
Climax stage: Final stage in a sere where all species are in balance. For example: A mature forest
Sere: Another name for succession. A set of stages of evolution of an ecosystem.
Pioneer stage: First stage in a sere which is dominated by opportunist species. (r-strategists)
Climax community: Populations of organisms living together in the climax stage. (K-strategists)
Climax stage: Final stage in a sere where all species are in balance. For example: A mature forest
Pioneer SpeciesPioneer Species
Pioneer species tend to be r-strategists Pioneer species tend to be r-strategists
Small adultsize Short lifespanRapidreproduction
HabitattemporaryHabitat patchyLongdistancedispersalMany smallseeds
High densityindependent mortality
Climax Species tend to be K-strategists
Climax Species tend to be K-strategists
K - strategistsK - strategists
Large adultsize Large lifespan SuccessfulseedingestablishmentrareLarge adultsize
Habitat uniformDispersallocalFew largeseedsHigh densitydependent mortality
Sequoia (redwood) trees are K-strategistsSequoia (redwood) trees are K-strategists
Lithosere: Succession on landLithosere: Succession on land The evolution of bare ground to forest. The evolution of bare ground to forest.
Pioneer species……………………………………Climax forest
Hydrosere: Succession of
ponds and lakes to forests.
Hydrosere: Succession of
ponds and lakes to forests.
Describe the changes that you see.
Describe the changes that you see.
Hydrosere:Hydrosere: The gradual conversion of ponds and lakes to forest
ecosystems.
With time ponds and lakes are gradually filled with eroded sediments.
The sediments moves in the shorelines and eventually fills in the lake.
The plant sequence is as follows: lake plants, reeds, grasses, shrubs, & trees.
The gradual conversion of ponds and lakes to forest ecosystems.
With time ponds and lakes are gradually filled with eroded sediments.
The sediments moves in the shorelines and eventually fills in the lake.
The plant sequence is as follows: lake plants, reeds, grasses, shrubs, & trees.
Succession along a beach:Succession along a beach: The gradual conversion of sandy beaches and desert margins to
forest.
Wind moves sand into dunes
Organic material, seeds, and moisture are blown in behind the dune.
Hardy salt tolerant grasses and vines establish themselves trapping more soil.
Plant succession follows the lithosere.
The gradual conversion of sandy beaches and desert margins to forest.
Wind moves sand into dunes
Organic material, seeds, and moisture are blown in behind the dune.
Hardy salt tolerant grasses and vines establish themselves trapping more soil.
Plant succession follows the lithosere.
Succession along a beach:Succession along a beach:
Be able to describe and explain the changes during succession.Be able to describe and explain the changes during succession.
Changes during successionChanges during succession
Pioneer species: lichens and mosses that extract nutrients from dust and bare rock.
Then: Bacteria, fungi, insects, small worms add organics to the soil
Early succession plants: grasses, herbs Midsuccessional plants: grass and low scrubs Late successional plants: trees Climax community: depends largely on climate
and edaphic factors
Pioneer species: lichens and mosses that extract nutrients from dust and bare rock.
Then: Bacteria, fungi, insects, small worms add organics to the soil
Early succession plants: grasses, herbs Midsuccessional plants: grass and low scrubs Late successional plants: trees Climax community: depends largely on climate
and edaphic factors
Climatic factorsClimatic factors
Precipitation
Temperature
Insolation (Incoming Solar Radiation)
Precipitation
Temperature
Insolation (Incoming Solar Radiation)
Edaphic FactorsEdaphic Factors
Factors having limiting affects on plant growth that are not climatic. Soil Factors
Examples:
Alkalinity of soil
Extreme acidity
Iron toxicity
Zinc deficiency
Low nutrients in soil
Factors having limiting affects on plant growth that are not climatic. Soil Factors
Examples:
Alkalinity of soil
Extreme acidity
Iron toxicity
Zinc deficiency
Low nutrients in soil
Rate of Primary SuccessionRate of Primary Succession
Primary succession is fastest in humid tropics.
It is slowest in the dry polar areas.
Why?
Primary succession is fastest in humid tropics.
It is slowest in the dry polar areas.
Why?
Succession after a forest fire
Succession after a forest fire
Secondary Succession after a fireSecondary Succession after a fire
Nutrient release to soil Regrowth by remnant roots and seeds Invasions from neighboring
ecosystems Rapid restoration of energy flow and
nutrient cycling
Nutrient release to soil Regrowth by remnant roots and seeds Invasions from neighboring
ecosystems Rapid restoration of energy flow and
nutrient cycling
Secondary succession after farming
Secondary succession after farming
Changes during successionChanges during succession
Biomass increases Resource allocation; nutrients initially
stored in soils become stored in vegetation.
Mineral cycling slows
Biomass increases Resource allocation; nutrients initially
stored in soils become stored in vegetation.
Mineral cycling slows
Changes in Energy FlowChanges in Energy Flow Trophic levels increase from 2 levels to 4 -5
levels. More trophic levels transfer more energy. Food webs become more complex. The total productivity of an ecosystem
increases. Biomass and biodiversity is maximized in a
climax ecosystem.
Trophic levels increase from 2 levels to 4 -5 levels.
More trophic levels transfer more energy. Food webs become more complex. The total productivity of an ecosystem
increases. Biomass and biodiversity is maximized in a
climax ecosystem.
Changes in ProductivityChanges in Productivity
Abiotic ChangesAbiotic
Changes
pH: 8 5.5N: increasesC: increasesExchangeable ions decrease
Know the factors affecting the nature of climax communities.Know the factors affecting the nature of climax communities.
The Nature of climax communities.
The Nature of climax communities.
The system is in a stable equilibrium
Remember the system is open Matter and energy may cross system boundary. Inputs are in proportion to outputs.
The system changes less thus keeping habitats intact over time.
The system is in a stable equilibrium
Remember the system is open Matter and energy may cross system boundary. Inputs are in proportion to outputs.
The system changes less thus keeping habitats intact over time.
The Climax Community:The Climax Community: Specialization is encouraged as all niches are occupied.
Each species must enhance competitive abilities and take care of young.
High nutrients available (but used) due to large amounts of biomass.
High moisture available as forests capture their own transpiration and encourage rain.
Specialization is encouraged as all niches are occupied.
Each species must enhance competitive abilities and take care of young.
High nutrients available (but used) due to large amounts of biomass.
High moisture available as forests capture their own transpiration and encourage rain.
Climax Community:Climax Community:
Mineralized nutrients (Nitrogen) increases. Organic matter in the soil increases Mineral cycling decreases as plants are adapted
to maintaining themselves and not growing or establishing themselves.
These nutrients become less available to plants as they adhere to soil particles or are stored as dead matter in ground.
Mineralized nutrients (Nitrogen) increases. Organic matter in the soil increases Mineral cycling decreases as plants are adapted
to maintaining themselves and not growing or establishing themselves.
These nutrients become less available to plants as they adhere to soil particles or are stored as dead matter in ground.
Compare early to late successionCompare early to late succession Biomass Productivity Food chains Species diversity Niche specialization Feeding relationships Size of individuals Life cycles Population control mechanisms Fluctuation Mineral cycles Stability
Biomass Productivity Food chains Species diversity Niche specialization Feeding relationships Size of individuals Life cycles Population control mechanisms Fluctuation Mineral cycles Stability
Early succession Late succession
Biomass small HighProductivity high LowFood chains Short Long, complexSpecies diversity Low HighNiche specialization Broad NarrowFeeding relationships General SpecializedSize of individuals Smaller Larger?Life cycles Short LongPopulation control density density
independent dependentFluctuation More Less pronouncedMineral cycles Open Tend to be closedStability Low High
Early succession Late succession
Biomass small HighProductivity high LowFood chains Short Long, complexSpecies diversity Low HighNiche specialization Broad NarrowFeeding relationships General SpecializedSize of individuals Smaller Larger?Life cycles Short LongPopulation control density density
independent dependentFluctuation More Less pronouncedMineral cycles Open Tend to be closedStability Low High
Source of this PowerPoint:www.nido.cl/~doehlke/successio
n.ppt
Source of this PowerPoint:www.nido.cl/~doehlke/successio
n.ppt