primary succession Flashcards
succession
a directional change in a community over time
process of primary succession
bare rock, pioneer species, climax comm
deflected succession
when succession is prevented from running its course
sere
each complete stage of succession
example of primary succession
volcanic eruption
where does primary succession take place
on land with no soil and no living organisms
pioneer species
lichens and mosses
why is the biodiversity of climax comm higher than the pioneer comm
more nutients in soil
increased n of species
inc n niches
more food available for species
what happens when climax comm get water logged
lack of oygen to roots
climax species would die
plants tolerant to waterlogged soil would outcompete other plants
adaptations of pioneer species
ability to tolerate extreme conditions
mutualistic rel w/N fixing bacteria in their root nodules
what do plants change in every seral stage and why
abitoic conditions
land becomes more stable for the next plants to move in
why might BD decrease at climax
species domination
foods webs at climax comm
more complex
stage 1
pioneer species- lichens grow in rock break rock release minerals used to from soil
stage 2
pioneer species die and decompose- humus
as soil deepens more nutrient rich can retain more water
grass colonise areas
animals move in
humus
decomposed organic material in soil
role of humus
supports growth in small annual plants/mosses
stage 3
shrubs compete w/smaller plnts to become more dominant
BD increases
soil thickens
abiotic conditions get more favourble
final stage
climax comm reached
stable state, little change over time
large trees move in- more dominant
species in comm depend on climate
example of intermediate species
shrubs
examples of climax communities
rainforest
alpine
in which ecosystem can all stages of succession be seen at once
sand dunes
exapmples of humans causing succession defection
weeding a garden
farm animals grazing a field
