Etude de la biodiversite des lombriciens et leurs relations avec les proprietes du sol dans differents etages bioclimatiques, dans l’est Algerien.

Abstract

The objective of our work is to describe the biodiversity of earthworm fauna in Eastern Algeria, along a gradient from the coast to the desert and their relations with soil (pH, electrical conductivity, organic matter and soil texture) and climatic factors. Eighteen species are identified in this study: Aporrectodea trapezoides, Aporrectodea rosea, Allolobophora molleri, Aporrectodea montícola, Octodrilus complanatus, Aporrectodea carochensis, Octodrilus maghrebinus, Eisenia fetida, Dendrobaena byblica, Aporrectodea tetramammalis, Eiseniella tetraedra, Proctodrilus antipae, Octolasion lacteum, Aporrectodea caliginosa, Allolobophora chlorotica, Microscolex dubius, Microscolex phosphoreus and Hormogaster redii. The species Ap. trapezoids dominates throughout the field of study (PDC = 50,37%). Regarding the demoecology, the average values of density and earthworm biomass, reduce from the north (40,50 ± 11,86 individuals / m2 and 6,92 ± 4,88 g / m2) to the south (3,89 ± 2,80 individuals / m2 and 1,07 ± 0,83 g / m2) of the study transect. Species Aporrectodea rosea and Aporrectodea trapezoides Allolobophora molleri can withstand environments rich in sand. Their substrates are rich in nitrogen. However, Octolasion lacteum, Octodrilus maghrebinus, Dendrobaena byblica, Aporrectodea carochensis and Microscolex dubius show trends towards high levels of organic matter and clay. The group of Aporrectodea caliginosa, Aporrectodea monticola Octodrilus complanatus, Allolobophora chlorotica and Hormogaster redii is related to parameters CaCO3, Ca ++, the silt fraction and poor sites in organic matter. It seems that both species Aporrectodea rosea and Aporrectodea trapezoides can withstand hot, dry climate like that of Algeria.