Positive feedback interactions, as between plants and their abiotic environment, may have the
consequence that an ecosystem has alternate stable equilibrium states. As a result, a gradual change in
environmental conditions may lead to discontinuous, catastrophic shifts in such ecosystems. Until
now, the occurrence of catastrophic shifts is hardly predictable. However, a recently developed idea is
that self-organized vegetation patterns might serve as an indicator for imminent catastrophic shifts.
Because self-organized vegetation patterns are a common feature of northern peatland bogs, we
examine to what extent these causally related concepts (positive feedbacks, alternate stable states,
spatial self-organization and catastrophic shifts) might contribute to a better understanding of this
type of ecosystems. Empirical and theoretical studies reveal that many positive feedbacks can be
present in bogs, which may generate alternate stable states. Furthermore, stratigraphic peat analysis
has shown that large and abrupt transitions do occur in bogs. However, the relative contribution of
each of these feedbacks to the self-organized vegetation patterns in bogs and the possible relation
with catastrophic shifts remain unclear. Conclusively, a research design is discussed that addresses
the current gaps in knowledge about the way positive feedbacks may lead to alternate stable states
and spatial self-organization in bogs, and its possible indication of catastrophic shifts