Rodents and reptiles as bioindicators for assessing coastal dune restoration success following invasive acacia removal

Abstract

Although there is adequate knowledge on restoring many invaded habitats, information regarding faunal recovery is still lacking, particularly regarding sandy coastal ecosystems. An important challenge for assessing restoration effectiveness is the selection of an appropriate bioindicator. The current study examined the recovery of psammophilic rodents and reptiles following the removal of Acacia saligna from Mediterranean coastal dunes. Rodents and reptiles were monitored for 3 years after the tree removal. Rodent sampling included live trapping; reptile sampling included pitfall traps, track transect trails and transect walks (daylight and dark). Removing the invasive plants improved the recovery conditions for psammophilic reptiles and rodents, including endemic and threatened species. However, reptiles differ from rodents in their physiological and behavioral mechanisms, including thermoregulation, diet and territorial behavior, allowing them to respond to habitat changes quicker than rodents. Within the reptile group, faster recovery was observed for nonterritorial species than for territorial species. It is necessary to consider the suitable taxa, method, and time for evaluation of habitat recovery. Our study demonstrates that monitoring reptiles by combining three methods (1) pitfall traps, (2) track transect trails, and (3) transect walks during daylight and dark provides a more complete picture, which is difficult to achieve from a single method. Furthermore, in the case of invasive transformer plants such as A. saligna, which cause long-term effects, we conclude that monitoring both taxonomic groups is advantageous, as this provides a more reliable picture of ecological functioning and faunistic recovery (compared to monitoring only one of the taxa).