Area Networks for Conserving Iberian Insects: A Case Study of Dung Beetles (col., Scarabaeoidea)

Abstract

Possibilities to create an efficient network of areas for the conservation of Iberian dung-beetle biodiversity were investigated. Data were taken from ‘BANDASCA’, a 15,740 record dung-beetle database with information for 101,996 specimens. The greatest species richness and phylogenetic diversity are found in the Iberian Central System cordilleras, while those of range-size rarity are in the southernmost corner of the Iberian Peninsula and in the coastal plains of the Guadalquivir basin. Additionally, broad regional score trends of these variables reach a maximum in a smaller northeastern, and a larger southeastern region (Baetic and sub-Baetic mountains). Major Central and Southern Spain dung-beetle hotspots contain many of the UTM grid cells which delimit the near-minimum-set of areas hosting maximum dung-beetle biodiversity scores. They are viewed as the nucleus of a potential network of reserves. A UTM grid cell (30TXK1) where Onthophagus albarracinus, an endemic and demographically rare species inhabits the Sierra of Albarracin and ‘Montes Universales’, was detected as an irreplaceable area. Because of recent land use changes and rapid human-induced habitat transformation threatening dung-beetle fauna, caution should be taken not to recommend an in memoriam network of areas no longer hosting a fauna extinct today. The abandoning of traditional herding management in Europe threatens the preservation of grasslands where dung-feeding beetles play a major ecological role in maintaining pasture quality and livestock health. A return to more traditional herding methods would require stable dung-beetle populations. Any insect conservation planning in Spain would benefit from more biogeographical information for other insect groups.