Impact of land protection in soil quality properties and in earthworm biomass in Venezuelan savannas

We studied soil parameters and the earthworm biomass and density in a protected savanna (PS) from fire and cattle raising for more than forty years located at Estación Biológica de los Llanos, Venezuela (EBLL), and an adjacent non-protected savanna (NS) under frequent burning and agricultural activities, located less than 1 km apart. Earthworm sampling was carried out at the end of the dry season (April), and at the peak of the wet season (July-August) using a hand sorting extraction method. In each plot, five to seven sampling units were selected corresponding to soil monoliths of 25x25x30 cm. The main physical, chemical, microbial (biomass) and enzymatic activities of soils in both systems were estimated. Thepresence of an abundant litter layer under the tree canopies in the PS have increased the soil water retention capacity, the organic-C, C-microbial biomass, dehydrogenase activity and fertility levels respect NS. This may allow for an increase in the density and biomass of earthworms in the PS compared with the adjacent NS. The systems were characterized by abundance in juvenile individuals belonging to the Glossoscolecidae family; two different morphotypes of the genus Aicodrilus were registered. Earthworms found were located in an endo-anecic ecological category. Results suggest that, agricultural management in savannas by modification of physical and biochemical soil properties can decrease an important fraction of pedofauna, particularly their earthworm communities. However, earthworm populations and soil quality indicators can be restored after long-term protection.

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Bibliographic Details
Main Authors: López-Hernández,D, Hernández,L, Ojeda,A, Quintero,E, Caipo,S
Format: Digital revista
Language:English
Published: Chilean Society of Soil Science / Sociedad Chilena de la Ciencia del Suelo 2014
Online Access:http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162014000400013
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