A tabular model for ecological succession of the autogenic, autotrophic type
|
Ecosystem characteristic
|
Trend in ecological development early stage to climax
Or
youth to maturity
or
growth stage to steady state
|
Community structure
|
Species composition
|
Changes rapidly at first, then more gradually
|
|
Size of individuals
|
Tends to increase
|
|
Number species of autotrophs
|
Increases in primary and often early in secondary succession; may
decline in older stages as size of individuals increases
|
|
Number species of heterotrophs
|
Increases until relatively late in the sere
|
|
Species diversity
|
Increases initially, then becomes stabilized or declines in older
stages as size of individual increases
|
|
increases
|
|
|
Nonliving organic matter
|
increases
|
Energy flow (community metabolism)
|
Gross production (P)
|
Increases during early phase of primary succession; little or no
increase during secondary succession
|
|
Net community production (yield)
|
decreases
|
|
Community respiration (R)
|
Increases
|
|
P/R ratio
|
P>R to P = R
|
|
P/B ratio
|
Decreases
|
|
increases
|
|
|
Food chains
|
From linear chains to more complex food webs
|
Biogeochemical cycles
|
Mineral cycles
|
Become more closed
|
|
Turnover time
|
increases
|
|
Role of detritus
|
increases
|
|
Nutrient conservation
|
increases
|
Natural selection and regulation
|
Growth form
|
From r – selection (rapid growth) to K – selection (feedback control)a
|
|
Quality of biotic components
|
increases
|
|
niches
|
Increasing specialization
|
|
Life cycles
|
Length and complexity increases
|
|
Symbiosis (living together)
|
Increasingly mutualistic
|
|
entropy
|
decreases
|
|
informationb
|
increases
|
|
Overall stability
|
increases
|
0 Response to "A tabular model for ecological succession of the autogenic, autotrophic type"
Post a Comment