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Accueil du site → Doctorat → États-Unis → 1986 → Spatial and temporal patterns of decomposition and microarthropod assemblages in decomposing surface leaf-litter on a Chihuahuan Desert watershed

New Mexico State University (1986)

Spatial and temporal patterns of decomposition and microarthropod assemblages in decomposing surface leaf-litter on a Chihuahuan Desert watershed

Cepeda Pizarro JG

Titre : Spatial and temporal patterns of decomposition and microarthropod assemblages in decomposing surface leaf-litter on a Chihuahuan Desert watershed

Auteur : Cepeda Pizarro JG

Université de soutenance : New Mexico State University

Grade : Doctor of Philosophy (PhD) 1986

Résumé
Mass loss and changes in the microarthropod assemblages were monitored in six types of decomposing surface leaf-litter confined in mesh-bags and set across a Chihuahuan Desert watershed for 17 months. High initial mass losses were observed in all litter types. Except for black grama grass litter, mass loss trends were described by the double exponential decay model. For creosotebush, six out of 15 comparisons of curve overlap trends indicated differences in litter disappearance across the watershed. Except for fluffgrass, site-dominant litter-type and creosotebush differed in mass loss trends. The results showed that microsite and litter characteristics were important factors in controlling mass loss of the surface leaf-litter. Cluster analysis showed that overall dissimilarity among microarthropod assemblages extracted from the decomposing litter and soil cores was rather low. But the configuration of the seasonal dendrograms displayed both the spatial relationships present in the watershed and the effect of edaphic conditions and seasonal disturbances. Across seasons and in the plane of the first two principal axes, microarthropod assemblages were frequently segregated in 34 clusters. The "compactness" and composition of clusters varied through time, giving support to the idea that microarthropod assemblages are not only spatially but also temporally dynamic. These assemblages fluctuated less in the better structured and protected habitats than in the less structured and more exposed ones. The relationships between site and seasonal factors and changes in abundance distribution patterns of the most common species are discussed. The study supported the idea that depth and stability of the surface litter determine the size of the microarthropod community. The data did not provide clear evidence of the role played by the microarthropod fauna on surface litter breakdown

Mots Clés : decomposition, microarthropod, distribution, ,temporal patterns, transect, decomposition, transect, microarthropods

Annonce (NMSU Library)

Jordana (NMSU)

Page publiée le 13 février 2016, mise à jour le 29 décembre 2019