SummaryEcosystems and species at serious risk from unnatural fire regimes. In California, suppression of fires has lead to long intervals between fires, which can affect natural processes. These processes can recover once fire regimes are restored. General Information about this IndicatorWhat is it?: In California, most plant community and ecosystem types have adapted to certain ranges of fire frequencies, extents, and severity. Changes in fire ecology can change native ecosystems and may eventually pose risks to human communities and ecosystem services, such as reliably-timed clean water and natural control of flooding.