Condit et al. 2013). The extent to which faunal groups might respond to such variations within the baseline transect is unknown, though given the relationship between vascular plants and faunal groups detected in the gradsects, some effects due to host plant specificity (for instance on herbivorous insects) might be expected. However, the present study focuses on modified forest landscapes where biota are responding to multiple changes along disturbance gradients and differing patterns selleckchem of modification (forest and non-forest). The study was not
intended to examine how location and scale related influences—for example proximity to primary forests, size of habitat, and landscape connectivity—might be detected and understood. Human-induced habitat modification has a major impact on biodiversity in both study areas (Sumatra and Mato Grosso). Although the literature is rich in methods for assessing disturbance and related land use intensity (Watt et al. 1998), unambiguous, quantitative units remain elusive (Jackson et al. 2012). The present study showed that subjectively determined land use intensity and disturbance gradients correspond closely with changes
in plant species and PFT diversities. Pristine lowland forests supported more PFTs but also more plant species per PFT than secondary or more heavily disrupted forests, thus indicating higher levels of niche complementarity at the scale of our sample-units. As more ecological niches become available for different PFTs with increasing disturbance (here indicated mainly by changes in vegetation structure and aboveground carbon), RG7420 mouse this ratio decreases until in freshly opened agricultural land or in extreme (e.g. degraded) conditions, the ratio approaches unity (Gillison 2002). In the present study,
when regional data were combined, the spp.:PFTs ratio became the strongest overall predictor of faunal species diversity thus suggesting a generally consistent response to disturbance across all biota, though with some Farnesyltransferase exceptions at intermediate disturbance levels (cf. Watt et al. 1998; Sheil and Burslem 2003), for example termite diversity in Brazil. Habitat disturbance (measured here as loss of phytomass—see Appendices S1 and S2, Online Resources) corresponded closely with decreasing spp.:PFTs ratio, supporting the use of the latter as an effective indicator of biodiversity where disturbance is a major driver of ecosystem performance. Combining regional data resulted in an almost two-fold increase in the overall number of significant or near-significant generic indicators and a three-fold increase in numbers of indicators significant at the P ≤ 0.0001 level, supporting the conclusion that such indicators may be applied with relative confidence in similar lowland tropical forested regions and with minimum effort.