Ecosystems can change slowly over time through processes like eutrophication where organic matter and nutrients build up, or more suddenly due to natural disturbances from events like hurricanes, fires, or volcanic eruptions. Succession describes how ecological communities develop and change over time. Primary succession occurs on new areas without soil as pioneer species move in and help form soil. Secondary succession happens on existing soils, where grasses are typically followed by other plants and forests over 100 years. Climax communities represent stable, mature ecosystems dominated by well-adapted species until a further disturbance occurs. Biodiversity increases as succession progresses, making the ecosystem more stable.

1. Life science

2.  Slowly:
 pond can develop into meadow
 Eutrophication: organic matter &
nutrients slowly build up in a body water
 when these organisms die decaying
matter sinks to the bottom of pond

3.  This organic matter fill the pond then
become soil that grasses can grow in
 Ecosystem changes can be caused by
seasonal or long term changes in
climate

4.  Suddenly :
 Due to catastrophic natural disturbance
 Hurricanes strong wind blow trees & destroy
vegetation in few hours
 Lightning can start a forest fire that clear plant
away & alters animal habitats

5. Volcano can erupt & cause massive
destruction to ecosystem

6. Succession is slow of development
of an ecological community by
another one
We have primary succession &
secondary succession

7. Primary succession:
Area that has no soil
Pioneers species are the first
organisms that live in an area
Ex: lichens
Lichens grow on rocks and help to
form soil

8. Secondary succession:
Areas that have soil
1 crabgrass often grows first
2 new wild plants appear
3 100 years a forest may form
4 conifers die hardwood replace

9. We have climax & biodiversity species
Climax species:
 A community of producers form first
 Followed by decomposers &consumer
 A stabled balanced ecosystem forms
 Community matures become dominated by
well adapted climax species
 Ex: redwoods in temperate rain forest
 This ecosystem will be stable till its disturbed

10. Biodiversity:
 While moving along ,richer soil, nutrients
&other resources become available
 This increasment established more species
 Biodiversity is number & variety of species
that are present in an area
 A divers forest is more stable & less likely to
be destroyed by sudden changes
 Ex: insect invasion

11. DONE BY MAYA
GRADE 8C
TO MY LOVELY T.
KHOLOD