Succession of fungi and fauna during decomposition of needles in a small area of Scots pine litter

Abstract

During micromorphological investigations on Scots pine litter, several decomposition stages have been recognized on fallen pine needles, each being associated with the activity of animal and microbial organisms, both. To well-known fungal successions that have been so far described by mycologists we must add succession of animal groups such as nematodes, amoebae, enchytraeids, sciarid larvae, oribatid mites and earthworms. A bacterial development was observed in the L 2 layer, following penetration by microfauna (nematodes, amoebae).After that stage pine needles were actively tunnelled by enchytraeids, sciarid larvae and oribatid mites and at the same time were nibbled on by epigeic earthworms (L 2 and F 1 layers). When the fine root system of pine developed through accumulated old needles (F 1 layer), mycorrhizal fungi penetrated the needles and seemed to impede any further bacterial development. Pine foliar tissues were progressively incorporated into the fecal material of earthworms and other members of the soil fauna. A more realistic scheme was suggested for plant litter decomposition in moder humus.

Humusica 1, article 8: Terrestrial humus systems and forms – Biological activity and soil aggregates, space-time dynamics

“…Decomposition rate is initially controlled by litter quality and only thereafter, once litter becomes more palatable, soil fauna exerts a more prominent role in a second step of the decay process (Mori et al, 2009). This confirms previous evidence indicating that litter decomposition rates are more strongly related to which soil fauna groups are involved and the way they succeed each other (e.g., pre-conditioning of litter (softening) by bacteria and fungi and thereafter penetration by microfauna and mesofauna) than to the chemical nature of the litter (Ponge, 1991). Furthermore, macrofauna digestion, excretion and enrichment activities increase microbial attack.…”

Origin of the nitrogen assimilated by soil fauna living in decomposing beech litter

“…In moder humus, most litter is processed by small animals, which may pass through several animal guts before being incorporated into stable humus, forming the H layer (Ponge, 1991b).…”

Soil microbial properties under different vegetation types on Mountain Han

“…This inconsistency of fungal biomass and fungal catabolic activity under L was probably because the fungal community composition under L was relatively similar so that there were not enough kinds of fungi to utilize the various C sources. As Ponge [48] found that succession of fungi happened during decomposition of pine needles, not all fungi existed at one individual phase of decomposition. Therefore, fungal biomass was not always consistent with fungi diversity.…”