Enhancement of soil nutrients around nest entrances of the funnel ant Aphaenogaster barbigula (Myrmicinae) in semi-arid eastern Australia

Abstract

The distribution of soil nutrients around nest entrances of the ant Aphaenogaster barbigula was studied in a semi-arid woodland in eastern Australia. The ants re-excavate their nest chambers after rainfall, trapping any litter which falls near the entrance, and blocking the passage of litter moving downslope by processes of overland flow. The entrapment of organic matter around nest entrances resulted in significantly higher levels of nitrogen, organic matter, and some cations compared with nest-free surfaces. Significant depth nest interactions suggest that these nutrients are being concentrated close to the surface.

The impact of ants on mineral soil properties and processes at different spatial scales

“…2005; Azcarate and Peco 2007; table 1). Only, the study of Eldridge and Myers (1998), who worked with nests of Aphaenogaster barbigula , showed lower K levels in the surface soil of nests. However, in the subsoil of the nest they also detected higher K levels compared to the control, whereas Nkem et al.…”

“…(1996) specified that only open nest entrances of Lasius neoniger nests contributed to enhanced infiltration in Sparta soils located in the lower Wisconsin river valley (USA), and that many nest entrances were closed during rainfall events, re‐opening within 2 h after the event. Eldridge and Myers (1998) suggested that increased infiltration rates in nest entrances of Aphaenogaster barbigula also facilitated the entrapment of plant leaves, an important food resource, that are transported by overland flow. In contrast to these studies, Sarr et al.…”

“…The bulk of information available on the effect of ants on soil chemical properties is related to organic carbon (C org ), pH and (different forms of) nitrogen (N), while only few studies focused on how ants alter the availability of other soil nutrients. Generally, the observed differences in C org and nutrient levels are attributed to the accumulation of food (leaves, seeds, ‘honeydew’) or excrements like saliva and droppings in nest areas or separation and translocation of food and soil material during nest building (Eldridge and Myers 1998; Folgarait 1998; Lavelle and Spain 2001; Frouz et al. 2003 and many others).…”

“…, and that many nest entrances were closed during rainfall events, re-opening within 2 h after the event. Eldridge and Myers (1998) suggested that increased infiltration rates in nest entrances of Aphaenogaster barbigula also facilitated the entrapment of plant leaves, an important food resource, that are transported by overland flow. In contrast to these studies, Sarr et al (2001) found that ants did not significantly affect infiltration rates in the Senegal and another study showed that some ant species (Acromyrmex landolti) even constructed turrets at the nest entrance to prevent water infiltration into their nests (Navarro and Jaffe 1985).…”

High diversity of ants in Australian vineyards

“…Ants are important ecosystem engineers and perform functional roles that strongly influence invertebrate (Carroll & Janzen 1973;Laakso 1999) and plant (Briese 1982;Samson et al 1992) assemblages, seed dispersal (Handel & Beattie 1990;Ness et al 2004), and soil conditions (Eldridge & Myers 1998;Lobry de Bruyn 1999). Ants are responsive to disturbance and have been widely used as bioindicators in various environmental assessments such as fire, mining and grazing (reviewed by Hoffmann & Andersen 2003).…”