Data/hora: 21/06/2024 05:00:00

Biblioteca(s): | Embrapa Florestas.
Data corrente: | 02/10/2008
Data da última atualização: | 02/10/2008
Autoria: | FABER, J. H.; HOUT, A. VAN DER; MARTAKIS, G. F. P.; KOOLS, S. A. E.
Título: | Density dependent functioning of Lumbricus rubellus in soil processes.
Ano de publicação: | 2008
Fonte/Imprenta: | In: INTERNATIONAL COLLOQUIUM ON SOIL ZOOLOGY, 15; INTERNATIONAL COLLOQUIUM ON APTERYGOTA, 12., 2008, Curitiba. Biodiversity, conservation and sustainabele management of soil animal: abstracts. Colombo: Embrapa Florestas. Editors: George Gardner Brown; Klaus Dieter Sautter; Renato Marques; Amarildo Pasini. 1 CD-ROM.
Idioma: | Inglês

Conteúdo:

The earthworm Lumbricus rubellus is a key species amongst litter decomposing fauna in
temperate soils (Heemsbergen et al., 2004, Science 306: 1019-1020). From a perspective of
sustainable land use it is therefore of interest to quantify the functioning of this species in soil
processes as related to population density. Such knowledge may be applied in soil management
to optimise ecosystem services resulting from earthworm ecological functioning. We used
laboratory microcosms with L. rubellus present in various densities to study functional responses
with respect to decomposition processes and soil characteristics. Litter fragmentation and litter
mass loss showed linear increases with earthworm density, while soil respiration, remaining
litter organic matter content and soil organic matter increase followed quadratic patterns. The
latter results show specific stimulatory effects on soil processes at intermediate densities of
earthworms compared to low or high densities. It was shown for quadratic responses that different
soil processes reached maximum rates at specific earthworm density levels. Microbial activity,
as indicated by soil respiration rate, was enhanced by earthworms, and was sustained for a
longer time with earthworm densities that correspond to low or moderate field population sizes
(110-180 m-2). The introduction of organic matter into the soil also followed a quadratic
relationship with animal density, rating up to 1% LOI in 36 days; a maximum increase was
achieved at a corresponding field density of 340 m-2. L. rubellus enhanced leaf litter fragmentation,
and showed a preference for leaf fragments in the 5-8 mm size class. Overall, the results suggest
optimal and prolonged soil functioning at intermediate densities of L. rubellus. Thus, key species
field density is emphasized as an essential parameter of functional biodiversity in quantative
analyses of soil ecosystem functioning.

Categoria do assunto: | --
Registro original: | Embrapa Florestas (CNPF)
Exemplares: | CNPF - (43767-1) - UPE - PL - -- - CD0305 -  -  - DIS