Data/hora: 11/06/2024 15:07:17

Biblioteca(s): | Embrapa Florestas.
Data corrente: | 03/10/2008
Data da última atualização: | 03/10/2008
Autoria: | MUYS, B.; VALCKX, J.; GOVERS, G.; HERMY, M.
Título: | Longterm ecosystem engineering: earthworms and biogenic landscape formation.
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:

More than 125 years ago Charles Darwin initiated the debate on the role of earthworms in soil
formation, geomorphic processes, and, ultimately, landscape genesis through bioturbation. This
discussion was reactivated by Meysman et al. (2006) claiming that bioturbation has extended
evolutionary and ecological consequences in both terrestrial and aquatic environments.
It is well accepted that soil (burrowing) organisms affect earth surface processes to various
extents. When these effects are disproportional with respect to the biomass or numbers of these
organisms, as in the case of earthworms, the activities of the latter are termed ecosystem
engineering. Ecosystem engineers shape to some extent their own environment, thereby
potentially steering natural selection and creating and sustaining dynamic feedback mechanisms
between the biotic and abiotic components of ecosystems. Recent studies support this
biogeomorphic paradigm and suggest that the earth surface processes and landforms not only
evolve as a result of physicochemical processes, but also as the result of the activity of ecosystem
engineers that modify their habitat in order to increase chances of survival and reproduction.
While this emerging theory sounds appealing, it needs support from field observations,
experimental data and process-based models showing that ecosystem engineers indeed have
a significant effect on earth surface processes at geological time scale. As the soil is the key
living environment for earthworms one could expect that earthworms will maintain the soil resource,
thereby counteracting processes (e.g. soil erosion) threatening this resource. In this paper we
contribute to an objective framework for examining the effects of ecosystem engineering
earthworms on water erosion. Our hypothesis is that earthworm activity encompasses both effects
which either stimulate or protect against water erosion, the outcome being very dependent on
site conditions (e.g. slope, soil texture, precipitation) and earthworm community composition
(e.g. presence of anecic species).
Based on a meta-analysis of literature and own experimental data we quantified soil physical
effects of earthworms for some species and communities in a number of soils and land cover
types of Western Europe. We included both potentially erosive effects (such as casting) and
potentially erosion reducing effects (such as the maintenance of a gallery network). These data
were then used for an upscaling exercise in space and time for a post-glacial Western Europe
landscape.
References: Meysman, F.J.R., Middelburg J.J., and Heip, C.H.R, 2006. Bioturbation: a fresh
look at Darwin?s last idea. Trends in Ecology and Evolution 21: 688-695

Categoria do assunto: | --
Registro original: | Embrapa Florestas (CNPF)
Exemplares: | CNPF - (43793-1) - UPE - PL - -- - CD0305 -  -  - DIS