Abstract
Earthworms, ants and termites are major ecological engineers that modulate the availability of ecosystem soil resources for other species. A subset of their engineering activity can be regarded as ‘Ecohydrological’ because all three taxa are prodigious burrowers that aerate soil, alter water flow pathways by creating networks of macropores and bury organic material. Earthworms, ants and termites all create soil macropores, which decrease soil bulk density, improve aeration and increase drainage. Flow through soil macropores by-passes much of the mineral soil ‘matrix’, leading to the non-uniform wetting of soils and a rapid subsurface transport pathway for nutrients and surface applied chemicals.
Ants and termites create major nest structures that concentrate resources from the local environment, leading to local ecological hotspots, but their impacts on the broader ecosystem are less well understood.
In this chapter, the ecohydrological services provided by earthworms, ants and termites are described and their key functions as both ecological and ecohydrological engineers are discussed in relation to their behaviour and social organisation. The effects of ants tend to peak in mid-latitude ecosystems, whereas termite effects on plant biomass are the strongest in the tropics. Earthworms have invaded many ecosystems, with alien species now well established throughout North America and Southern Australia. The impacts of these invasions and the effects of global warming on ecosystem stability and ecosystem services are still largely unknown.