Burrowing and casting activities of three endogeic earthworm species affected by organic matter location

作者：Le Couteulx Alexis^*; Wolf Cedric; Hallaire Vincent; Peres Guenola

来源：Pedobiologia, 2015, 58(2-3): 97-103.

DOI：10.1016/j.pedobi.2015.04.004

• Soil structure
• Behaviour
• Allolobophora chlorotica
• Allolobophora icterica
• Aporrectodea caliginosa

Earthworms are crucial for production and maintenance of soil structure and their activities can strongly impact soil functioning (e.g. water regulation, nutrient dynamics). This laboratory study investigated the bioturbation activity of three endogeic species, Alloiobophora chiorotica, Allolobophora icterica and Aporrectodea caliginosa, as affected by different locations of organic matter (OM) in the soil profile: OM scattered on the soil surface (surface-OM) or homogeneously mixed into the soil (mixed-OM). Microcosms, each containing a combination of one species (three individuals) and one OM location, were subjected to controlled environmental conditions (temperature, humidity and day/night cycle) for 60 days. At the end of the experiment, microcosms were cut into multiple horizontal cross-sections every centimetre and bioturbation activities were analyzed based on the number of burrows, the burrowed area and the percentage of burrowed area totally refilled with casts.
Results showed that regardless of species, there was significantly fewer burrows and a greater percentage of burrowed area refilled with casts under mixed-OM than under surface-OM. A. chlorotica and A. caliginosa had a significantly greater burrowed area under mixed-OM than under surface-OM. Regardless of OM location, as depth increased, burrow number and area decreased for A. chlorotica and generally increased for A. icterica. In contrast, burrowing activity of A. caliginosa was affected by OM location as depth increased: under mixed-OM, burrow number decreased but burrowed area remained constant, whereas under surface-OM, burrow number remained constant and burrowed area increased.
These results improve understanding of effects of endogeic species on soil structure and highlight effects of OM location on earthworm bioturbation. Especially this study gives information about the burrowing activity of A. icterica which has so far been little documented, and also informs about refilled burrows which is a major parameter for soil functioning.

• 出版日期2015