Data/hora: 07/06/2024 04:48:30

Biblioteca(s): 	Embrapa Florestas.	
Data corrente: 	22/09/2008	
Data da última atualização: 	22/09/2008	
Autoria: 	BLANCHART, E.; MARILLEAU, N.; CAMBIER, C.; DROUGOUL, A.; PERRIER, E.; CHOTTE, J. L.	
Título: 	SWORM: an agent-based model to simulate the effects of earthworms on soil structure.	
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: 	Soil structure can be defined as the spatial organization of solid mineral and organic particles,
and pore space or as the spatial heterogeneity of different components or soil properties. It is of
great importance for soil functioning as it influences water regime, infiltration, aeration, nutrient
retention and availability, and soil microbial activity. It is thus a major soil parameter driving
ecosystem services (carbon sequestration, emission of greenhouse gases, nutrient cycling,
primary productivity?) (Millenium Ecosystem Assessment).
Soil structure results from biotic and abiotic factors. Among biotic factors, numerous studies
have shown the importance of organic matter (polysaccharides, plant debris), microorganisms
(bacteria, fungi), and soil invertebrates in soil aggregation, and of large invertebrates and roots
in the development of burrows and channels. Earthworms are known to play a major role in soil
structure formation and maintenance through a continuous production of biogenic structures.
To better understand the effect of earthworms on soil structure and subsequently on ecosystem
services, it is necessary to increase our knowledge on this effect through experimentation and
modelling. Only few models aims to describe or quantify the effect of soil invertebrates on soil
aggregation and porosity. Modelling their effect is faced to the difficulty to describe the physical
soil environment.
Creating a model of a soil leads to complexity problems because a soil is a multi-scale
heterogeneous, three-dimensional and dynamic environment. An approach based on fractal
theory (often used in soil sciences) was chosen to model such a real complex environment; it
was integrated into a Multi-Agent System (MAS). MAS allows to simulate situated agents (e.g.
earthworms) in an virtual world (e.g. soil). It is a bottom-up approach that allows describing a
system at a micro level (e.g. earthworms and their local soil environment) in order to observe,
during simulation, macroscopic changes (e.g. soil structure evolution, organic matter dynamics,
and microbial functions).
In this paper we describe the simulator and presents the simulation applied to a case-study. The
effect of earthworms on the structure of Lamto?s savannas soil in Côte d?Ivoire has been widely
studied. It was shown that soil structure is due to antagonistic effects of compacting (large
earthworms such as Millsonia anomala) and decompacting earthworms species (small Eudrilid
earthworms). Large earthworms produce large, compact and stable macroaggregates while
small earthworms can re-ingest aggregates from large earthworms and produce small and labile
casts. Quantitative and graphical outputs (e.g. thin sections of the virtual soil) indicated that the
simulator was able to reproduce the effects of both compacting and decompacting species.
The simulator is highly perfectible. One of the improving ways if to link this simulator with other
models in order to model gas or water fluxes in soil, microbial activity, carbon or nutrients dynamics.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Florestas (CNPF)	
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