Successiom Flashcards
What is succession
What is basics theory behind it
The process in which an ecosystem chnages over time
Here it happens in different stages, at each stage the species in an area slowly makes a chsnged in the environmental conditions, allowing OTHER SPECIES TO NOW LIVE THERE
This means the biotic conditions change as the abiotic conditions change,nwhoch leads to organisms SUCCEEDING ONE ANOTHER ( by a more dominant species each time)
Two types = primary and secondary
Primary succession
Thid occurs on areas of land that has been NEWLY FORMED or exposed like bare rock, there is no soil or organic matter to being with ever , no life
So newly formed piece of land like bare rock woth no soil or organic matter like bare rock, often after volcanoes
What is secondary succession then?
Example ?
Occurs on areas of land where soil is present , but it contains no life of plant and animal
Example would be bare earth after a forest fire in rainforest
Summary
- primary succession is when succession takes olace on land newly formed with no organic matter or life at all so bare rock volcano
+ but secondary is when there is organic matter just no life , so like bare earth after rsinforest
When does primary succession occur? (4)
So newly formed land =
- volcanoes erupt cooling and forming rock
- sand blows by wind or deposited by the sea to create sand dunes
- slot and mud deposited at rivers
- glaicers retreat exposing rubble and rock
Okay so how do succession take place, what are these stages called and again what happens each time basically
Each time succession takes place in steps called SERAL STAGES , at each seral stage , a key species can be idenfitifed that causes the abiotic factors, especially the soil to chsnge, making it more easier for another organism to live and succeed, which will change the abiotic again and this repeats
What are the seral stages we need to know?
Form barren land
Pioneer community
Intermediate community
Climax community
Pioneer community seral stage
Primary succession begins with the colonisation of an inhospitable environment by a PIONEER SPECIES
- plants, these arrive as spores / seeds carried by wind from nearby land masses / droppings of birds or animals . For example algae / lichen
What are the harsh conditions but how can pioneer species still able to survive!
Conditions
- limited water as no soil retains rains
- few minerals because no soil
- high light intensity, no insulation , exposure to wind and rain because directly exposed
Adaptations
- produce huge amount of spores and seeds so can colonise
- these germinate very auicky
- can photosynthesise and produce own energy
- tolerance to extreme environment (like marram grass salty)
- NEED TO BE ABLE TO FIX NITROGEN SO CAN GET NITRSTES Z
- DIGESR ROCKS if fungi with enxymes release nutrients
How do pioneer species change the abiotic condition for the intermediate ?
What is humus
Why is humus good for second
- weathering of rocks make a kind of soil
- pioneer die , and microorganisms decompose dead organic material to release thid and mixes with btec soil to make a nd fork a kind of soil called HUMUS which has nutirenrs
This can then support the next plant better , and continual nitrogen fixing only helps
2) has nutirentd like nitrstes , and as a soil can retain some water
Why humus good for second
Has some nutrients like nitrstes
-can retain some water beign s soil
Intermediate comminuted seral stage!
Multiple stages what happens first (moss) then after change then what comes after then after change and then what comes after at the end
- again arrive as spores and seeds , like mosses
- can be some animals too if pioneer provide a food source for the,
Now more decomposition and more nitrogen fixing improved the soil , better water better nutrients
NEXT with better condition better species can arrive like FERNS, (terirwry co,noise) and these are species that survive WITHOUT TOO MUCH WATEr
Again rock erodes and organic matter increases and more nutrients , retain more water
3) finally conditions right for small flowering plants like grasses , shrubs and SMALL TREES
As succession toes on, what happens to the ecosystem ( still in intermidste )
Which speciee stay however as more and more begin to come?
Better soil. More species arrive and life beside, increasing diversity , animals arrive
2) as more species come they begin to outcompete one another snd the most dominant one survives, which is thr most abundant by mass and also has the GREATEST EFFECT ON THE Abitoic conditojs
Ur eventually it reaches a CLIMAX COMMUNITY
-
What is climax community seral stage
This is when the ecosystem is suporiting the maximum complexity of species or can, csnt change anymore and is in a STABLE STATE
- dominant soefied stay here now, like big trees and woodlands or shrubs depends on the climate
This is basically trees
When is max bidovierodty achieved?
This happens when mid succession, because climax community actually dominant soeciss outvompetes little ones so species diviersity decreases due ti evened decreasing
Animal succession?
Why slower
Happens along side plant , initially worms and insect move in, then as stable foods survey provided along with habitats from plants secondary and then eventually terirwry
It tends to be slower because they scytsllu have to MOVE PHYSCISLLY TONTHE AREA (csnt fly like spores ) , snd so especially if GEOGRAPHICALLY ISOLATED
