Surveying biodiversity of soil herpetofauna: towards a standard quantitative methodology

Soil herpetofauna biodiversity is conservatively estimated as 2775 species, made up of 10% and 28% of Amphibia and Squamata, respectively. Neglect in their taxonomy, ecology and standard sampling methodologies suggests that proportions, as well as numbers, are likely to be far higher. Like invertebrate soil macrofauna, the majority of species live within the first few centimetres of leaf litter and soil. Results of 30 quantitative and 52 semi-quantitative surveys in nine regions of three continents show that these are infrequently encountered, whereas dedicated subterranean burrowers can be found at high densities, up to 0.844 individuals m−2 ( ). This suggests that a two tier sampling approach may be most appropriate, with superficial excavations in a large quadrat (e.g. 25 m2) in addition to a smaller deeper subsample. It is hoped that this contribution will stimulate further discussion towards a consensus, filling the gap for a standard method of quantitative surveying of soil herpetofauna biodiversity.