Saproxylic Insects and Fire

Abstract

Fire plays a prominent role in many biomes, but the natural fire regime has been influenced by silvicultural management, changes in land use, climate changes, and fire suppression. Fire clearly induces profound changes in both habitat characteristics and assemblages of saproxylic insects. However, our current understanding on this is strongly biased toward coniferous boreal and temperate systems and specific taxonomic groups, e.g., beetles, whereas the information from other biomes and saproxylic groups is limited at best. Knowledge from coniferous boreal and temporal systems might not be applicable in other biomes; therefore, studies in those areas should have high priority. Although natural fire regimes vary among ecosystems, saproxylic insects adapted to fire, both with respect to physiology and behavior, can be found in many different ecosystems. Changes in fire regimes can therefore have strong effects on saproxylic species, especially specialist pyrophilous species. For example, disruption of fire regimes in the boreal region, due to silvicultural management, changes in land use, and fire suppression, is a serious threat to saproxylic species, and restoring natural fire regimes is of the essence. Fire has been used as an active management tool to benefit saproxylic species in Fennoscandia. However, the effects of fire on saproxylic species are rather short-lived which should be considered in landscape planning. It has also been suggested that some fire-adapted species must be able to maintain viable populations in the unburned forest matrix if it is of sufficient quality. Thus, our ability to maintain viable populations of pyrophilous and fire-favored saproxylic species might depend on the sum of all conservation efforts on the landscape level rather than fire restoration efforts alone.