Flashcards in Succession Deck (68)
What is succession central to
Ecology as evolution is to biology
What is succession
Species change over time (turnover)
What effect does disturbance have on succession
It is started directed and redirected by it. Climate events, landuse change, conversion of rainforests etc
What is the incorrect thought about succession
It is thought to progress towards climax but in reality it is complex and multidirectional
What are the types of succession
What is primary succession
From sterile beginnings with no existing communities
Example of primary succession
Facts about volcanoes
3000 active ones.
60-70 erupt annually affecting 500 million people.
Facts about glaciers
10% earths surface
90% of that in Greenland and Antarctica.
75% of glaciers in retreat - get primary terrain left to look at succession over time
How do glaciers create disturbance
As they move through landscapes they peel vegetation away, grinding it up and creating a less biodiversity environment but there are microbes under them.
How much are glaciers retreating
20m per year
What is secondary succession
On previously colonised land after major disturbance
Examples of secondary succession
What are the source of new colonisers in secondary succession
Propagules (seeds) organism in the soil, bacteria, fungi, plants that can recover
What are the two types of succession processes
What is autogenic process
Species change due to activities organisms themselves - biotic. Competitive and interactions for niches and water
What is allogenic process
Species change due to external, non biological factors - abiotic. Like climate change and silting of waters
What are the two general trends for plant community succession
Early successional species
Late successional species
Characteristics of early successional species
Small and fast growing.
Produce many small seeds for dispersal.
No dormancy requirement.
Often N fixers.
Allocate more energy to reproduction than biomass.
Example of N fixers
What can colonisers ‘ruderals’ cope with
Warm and cold conditions
Examples of dormancy periods
Some seeds have to be eaten by animals, some have to be frozen to be colonisers
What is an advantage in a nutrient limited enivonrkwbt
Ability to fix atmospheric nitrogen and turn it to an amino acid
Why do early successional species allocate energy to reproduction not biomass
To increase chances they have successful next generations
What are early successional species classed as
What are late successional species classed as
Characteristics of late successional species
Large, slow growing (trees)
Late seeds, animal dispersal sometimes.
Competitive (canopy species)
Allocate energy to biomass not reproduction.
What are canopy species
Dominate and control light resource. Plants that dominate resources like light has impact on other plants - selection process goes on e.g plants that tolerate lower light.
Early advantage in late successional species
Big seeds. More energy for seed to produce energy and grow quickly