The Effects of a Trophic Cascade
The events we have illustrated are best viewed as a trophic
cascade - runaway consumption by a herbivore.
This leads to:
Destructive removal of underground plant parts
(grubbing by spring staging geese)
Overgrazing of above-ground plant parts by breeding
and molting geese in summer
Disrupted soil and plant processes
Desertification and hypersalinity
Diminished nitrogen fixing by soil microbes
Slow plant community recovery and succession to
non-forage associations
Only a reduction in populations will allow coastal wetland
ecosystems the opportunity to recover or re-develop. Such
declines are unlikely without significant changes to human
management practices. Until and unless the changes occur, we need
to continue to monitor populations and conduct research on the
critical processes and components at all ecosystem scales to aid
in our understanding and attempts to influence recovery.
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revised - 12/18/02