How effective are agri-environment schemes for protecting and improving herpetofaunal diversity in Australian endangered woodland ecosystems?

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Summary

  1. Agricultural intensification is a major cause of reptile and amphibian decline world-wide, prompting concern on how to best protect biodiversity in commodity production landscapes and meet global food demands. Agri-environment schemes (AES) attempt to integrate biodiversity conservation in agricultural landscapes but are often compromised by a lack of baseline data, monitoring and evaluation. Few studies have examined the benefits of AES in protecting biodiversity relative to the wider farming landscape, and no studies have explicitly quantified the effectiveness of AES to increase herpetofaunal diversity.
  2. To examine whether AES protect and increase herpetofauna, we established a landscape-wide biodiversity monitoring programme in threatened semi-arid and temperate woodland communities in south-eastern Australia.
  3. With 31 species recorded, regional herpetofaunal diversity was relatively high, whereas local diversity was low. Herpetofaunal richness and reptile assemblage structure did not differ significantly between sites under AES and sites managed for livestock production. A gradient in species richness as a function of time-since-management intervention was not evident, although the abundance of one lizard species increased under vegetation management. Reptile richness and frog abundance differed significantly among vegetation types.
  4. Herpetofaunal richness was positively related to native plant richness and bare ground cover, whereas Boulenger's skink Morethia boulengeri was negatively affected by bare ground cover. The ragged snake-eyed skink Cryptoblepharus pannosus was positively related to the amount of woody debris.
  5. Synthesis and applications. In this system, strong habitat specificity implies local-scale management interventions under agri-environment schemes (AES) may not significantly increase herpetofaunal diversity in the short term. Vegetation management is likely to increase the abundance of common lizard species rather than increase local species richness due to barrier effects. Future incentive schemes should focus on improving habitat connectivity, enhancing pasture condition and increasing woody debris in the agricultural matrix to dissolve dispersal barriers and mitigate the legacy of historical land-use practices. We propose that AES, which manage mosaics of intergrading vegetation types at multiple spatial scales, will protect maximum herpetofaunal diversity. These recommendations have implications for AES world-wide, many of which currently do not adequately address the habitat requirements of herpetofauna.

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