Degradation dynamics of surface earthworms casts in grasslands of the Eastern plains of Colombia

Earthworms are generally considered to fulfill the definition of ecosystem engineers. The casts they produce are recognised to have a great importance in the regulation of soil processes. Lifetimes and degradation rates of these structures remain poorly known. In this study, the dynamics of disappea...

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Autor principal: Decaëns, Thibaud
Formato: Capítulo de libro
Lenguaje:Inglés
Publicado: International Center for Tropical Agriculture 2001
Materias:
Acceso en línea:https://hdl.handle.net/10568/55177
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author Decaëns, Thibaud
author_browse Decaëns, Thibaud
author_facet Decaëns, Thibaud
author_sort Decaëns, Thibaud
collection Repository of Agricultural Research Outputs (CGSpace)
description Earthworms are generally considered to fulfill the definition of ecosystem engineers. The casts they produce are recognised to have a great importance in the regulation of soil processes. Lifetimes and degradation rates of these structures remain poorly known. In this study, the dynamics of disappearance and the changes in the physical properties of the surface casts of the anecic earthworm Martiodrilus carimaguensis were assessed in a native savanna and an intensive pasture. In both systems, casts were composed of superposed layers deposited by earthworms over a period of at least a few days. The half-life of casts ranged between 2 months to 11 months in the pastures (trampled and protected, respectively), and 5 months in the savanna. Some dry caets remained at the soil surface for more than I year after having been excreted. The disappearance of casts was mostly attributed to rain-drop impact and the effect of animal trampling. The bulk density of fresh casts was higher (+17%, P<0.05) or equivalent (-1%, P>0.05) to that of the surrounding soil, in the savanna and the pasture, respectively. Fresh cast aggregates were of larger size than bulk soil aggregates (about +70% in both systems, P<0.05). Bulk density and the size of cast aggregates decreased with cast ageing (from -29% to -24% for bulk density, and from -68% to -80% for size, in the pasture and the savanna, respectively). Macroinvertebrates were observed digging into casts, and were assumed to be partly responsible for the physical.
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spelling CGSpace551772025-10-28T10:12:08Z Degradation dynamics of surface earthworms casts in grasslands of the Eastern plains of Colombia Decaëns, Thibaud soil fauna lumbricidae soil chemicophysical properties savannas fauna del suelo propiedades físico - químicas suelo sabanas Earthworms are generally considered to fulfill the definition of ecosystem engineers. The casts they produce are recognised to have a great importance in the regulation of soil processes. Lifetimes and degradation rates of these structures remain poorly known. In this study, the dynamics of disappearance and the changes in the physical properties of the surface casts of the anecic earthworm Martiodrilus carimaguensis were assessed in a native savanna and an intensive pasture. In both systems, casts were composed of superposed layers deposited by earthworms over a period of at least a few days. The half-life of casts ranged between 2 months to 11 months in the pastures (trampled and protected, respectively), and 5 months in the savanna. Some dry caets remained at the soil surface for more than I year after having been excreted. The disappearance of casts was mostly attributed to rain-drop impact and the effect of animal trampling. The bulk density of fresh casts was higher (+17%, P<0.05) or equivalent (-1%, P>0.05) to that of the surrounding soil, in the savanna and the pasture, respectively. Fresh cast aggregates were of larger size than bulk soil aggregates (about +70% in both systems, P<0.05). Bulk density and the size of cast aggregates decreased with cast ageing (from -29% to -24% for bulk density, and from -68% to -80% for size, in the pasture and the savanna, respectively). Macroinvertebrates were observed digging into casts, and were assumed to be partly responsible for the physical. 2001 2015-01-28T14:17:31Z 2015-01-28T14:17:31Z Book Chapter https://hdl.handle.net/10568/55177 en Open Access International Center for Tropical Agriculture Decaëns, Thibaud. 2001. Degradation dynamics of surface earthworms casts in grasslands of the Eastern plains of Colombia. In: Jiménez Jaén, Juan José; Thomas, Richard J. (eds.). Nature`s plow: Soil macroinvertebrate communities in the neotropical savannas of Colombia. Centro Internacional de Agricultura Tropical (CIAT), Cali, CO. p. 176-192. (CIAT publication no. 324)
spellingShingle soil fauna
lumbricidae
soil chemicophysical properties
savannas
fauna del suelo
propiedades físico - químicas suelo
sabanas
Decaëns, Thibaud
Degradation dynamics of surface earthworms casts in grasslands of the Eastern plains of Colombia
title Degradation dynamics of surface earthworms casts in grasslands of the Eastern plains of Colombia
title_full Degradation dynamics of surface earthworms casts in grasslands of the Eastern plains of Colombia
title_fullStr Degradation dynamics of surface earthworms casts in grasslands of the Eastern plains of Colombia
title_full_unstemmed Degradation dynamics of surface earthworms casts in grasslands of the Eastern plains of Colombia
title_short Degradation dynamics of surface earthworms casts in grasslands of the Eastern plains of Colombia
title_sort degradation dynamics of surface earthworms casts in grasslands of the eastern plains of colombia
topic soil fauna
lumbricidae
soil chemicophysical properties
savannas
fauna del suelo
propiedades físico - químicas suelo
sabanas
url https://hdl.handle.net/10568/55177
work_keys_str_mv AT decaensthibaud degradationdynamicsofsurfaceearthwormscastsingrasslandsoftheeasternplainsofcolombia