Download Ecosystem: Stability and Change

Ecosystem: Stability and Change
Stability
Is the ability to withstand or recover from
externally imposed changes or stress
• resistance, persistence, or inertia
• Resilience
• Constancy-maintain certain size
– Applies to organisms, populations, communities
ecosystems, and the ecosphere
– Provided that these external stresses are not too
severe
Factors Contributing to Ecosystem
Stability
• Food Web Complexity
• Homeostatis- internal systems counteracting
external stress.
• Continuous Dynamic Change
Movement of Matter and Energy
Replacement of Organisms
Ecological Succession- the natural replacement of one
community in particular area with a different, and
usually more complex community, over a period of
time
Primary Succession
Secondary Succession
Secondary Succession
Tolerance Range/Limits
Minimum and maximum limits for physical
conditions (such as temperature) and
concentration of chemical substances beyond
which no members of a particular species can
survive.
Limiting Factor Principles
Too much or too little and any abiotic factor
can limit or prevent growth of a population of
a species in an ecosystem, even if all the other
factors are at or near the optimal range of
tolerance for the species
Law of Tolerance
The existence, abundance, and distribution of
a species in an ecosystem are determined by
whether the levels of one or more physical
and chemical factors fall with the range
tolerate by the species.