Animal foraging as a mechanism for sediment movement and soil nutrient development: Evidence from the semi-arid Australian woodlands and the Chihuahuan Desert

TitleAnimal foraging as a mechanism for sediment movement and soil nutrient development: Evidence from the semi-arid Australian woodlands and the Chihuahuan Desert
Publication TypeJournal Article
Year of Publication2012
AuthorsEldridge DJ, Koen TB, Killgore A, Huang N, Whitford WG
JournalGeomorphology
Volume157-158
Start Page131
Pagination131-141
Date Published01/01/2012
Accession NumberJRN00591
ARIS Log Number283929
Keywordsarid, Australia, Biopedturbation, foraging, Jornada, patchiness, rodents, soil formation, soil movement, vertebrates
Abstract

An emerging area of interest in geomorphology over the past two decades has been the effects of biota on ecosystemprocesses.We examined the roles of a rangeof vertebrates on soil disturbance in two markedly different environments, the semi-arid woodland of eastern Australia and a Chihuahuan Desert grassland–shrubland in the south-western United States. Foraging pits of soil-disturbing vertebrates varied markedly from small scratchings of heteromyid (mainly Dipodomys spp.) rodents (1.8×10-4m3) to deep (1.0×10-2 m3) excavations of the burrowing bettong (Bettongia leuseur) and greater bilby (Macrotis lagotis). Vertebrates moved substantial volumes of soil in both environments, and activity was highly temporally and spatially variable. At large spatial scales, soil disturbance by echidnas (Tachyglossus aculeatus) and Gould's sand goannas (Varanus gouldii) was substantially greater in communities dominated by shrubs, and where domestic livestock had been excluded. Heteromyid rodents tended to excavate more foraging pits in coarse-textured vegetation communities (both grasslands and shrublands). In both environments, foraging was concentrated close to perennial plants such as grass tussocks and tree canopies rather than in the interspaces. Foraging pits of Chihuahuan desert animals tended to be higher in labile carbon and support greater levels of infiltration, though this was plant community-dependent. Overall our results indicate that animal foraging is an important geomorphic mechanism capable of mobilizing substantial volumes of soil in arid and semi-arid environments and with potential effects on soil function. © 2011 Elsevier B.V. All rights reserved.

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DOI10.1016/j.geomorph.2011.04.041