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Click on the the photo to hear John Dick introduce the
characteristics of disturbance-maintained ecosystems
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Transcript of the Audio with John Dick
Disturbance-maintained ecosystems are multi-aged, savannah-like
forests and grasslands in dry climates. The structure of these
forests is maintained by regular (< 10 year return period)
ground fires.
The main characteristics of disturbance-maintained forests
include:
- Uneven-aged forests interspersed with grassy and shrubby
openings.
- Periodic surface fires consume woody fuels and rejuvenate
herb and shrub layers.
- Fire maintains species composition, stand structure and
regulates fuel loading.
- The timing of fires is critical: too frequent seriously
affects tree regeneration; too infrequent increases understory
growth and fuel loadings, which may ultimately result in a
catastrophic fire.
- These forests are generally comparatively low in biodiversity,
though often have very high endemism, which means it contains
a lot of species that are naturally confined to those areas
and those areas only. Large ungulates and associated predators
are usually a significant component of biodiversity in these
ecosystems.
- Diversity is very closely related to stream courses, springs
and moist depressions, and small wetlands.
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