©
iForest -Biogeosciences and Forestry
IntroductionUnderstanding ecosystem responses to disturbance at different scales is fundamental to develop sound strategies for forest management and nature conservation (Kremen 2005). To this end, biomonitoring -i.e., the analysis of the reactive components of ecosystems in response to environmental changes to assess deviations from the normal situation (Spellerberg 1991, Nimis et al. 2002 -and ecological indicators can be used to quantify the magnitude of stress, the degree of exposure or the ecological response to stresses (Dale & Beyeler 2001), thereby providing a simple and efficient method to assess the composition, structure and function of complex ecological systems (Karr 1991).Fire is one of the most important disturbances in many natural and semi-natural ecosystems worldwide (Granström 2001), including the Mediterranean Region (Pausas 2004). Fire also has an ecological role in influencing ecosystem biodiversity and guaranteeing the conservation of a variety of habitats (Hadjibiros 2001, Moreira et al. 2001, Blondel et al. 2010) and changing landscapes (Gillson 2009). The soil biota is one of the first soil components to respond to fire exposure, as fire alters the species composition and decreases the zoocenotic density (Bezkorovainaya et al. 2007).Fire may have direct or indirect effects on soil fauna. One of the principal direct impacts on the edaphic microarthropod community is the exposure of forest fauna to high temperatures, which can cause alterations in species composition and decrease the abundance of some taxonomic groups (Sgardelis et al. 1995, DeBano et al. 1998, Bezkorovainaya et al. 2007). Contrastingly, some authors claimed that the direct effects of fire on most soil vertebrates are minimal (Ream 1981, Neary et al. 1999). Indirect fire impacts include changes in habitat and food availability for these organisms. After a fire, alterations of hydrothermal conditions, litter mass and pH have an impact on animal survival, particularly the stenoecious species which suffer high temperatures as well as light and moisture extremes, with subsequent habitat loss (Roloff et al. 2005, Bezkorovainaya et al. 2007). While some changes of the edaphic community can be irrelevant in the short-term after fire, the subsequent postfire, aboveground succession can determine changes in soil fauna, affecting the age and trophic structure of soil animals (Bezkorovainaya et al. 2007).Edaphic microarthropods play an important role in regulating the rate of decomposition (Wallwork 1983, Seastedt 1984 and nutrient cycling (Heneghan & Bolger 1998) through interactions with the microbial and fungal communities (Seastedt 1984, Seastedt & Crossley 1984, Lussenhop 1992, and they also contribute to soil structure and humus formation (Wallwork 1983, Norton 1985, Striganova 2000. For all these reasons, the preservation of soil biodiversity should be considered an integral component of forest management practices (Marshall 2000). Therefore, understanding the reaction of a forest to fir...
