The association of land cover with aeolian sediment production at Jornada Basin, New Mexico, USA

TitleThe association of land cover with aeolian sediment production at Jornada Basin, New Mexico, USA
Publication TypeJournal Article
Year of Publication2011
AuthorsFloyd KW, Gill TE
JournalAeolian Research
Accession NumberJRN00587
KeywordsBSNE, Chihuahuan Desert, dust collection, dust flux, Jornada Basin LTER, land cover, NPP sites, particle size, sand transport, vegetation communities

We investigated amounts and particle size distributions (PSDs) of aeolian sediments collected at five heights in five ecosystem types at the Jornada Basin, Chihuahuan Desert, New Mexico, USA. Particle size distributions, mass fluxes, and percent of dust-sized (650 lm) mass flux were determined for all heights and all ecosystem types. Differences between sites were determined using ANOVA followed by Tukey–Kramer post hoc tests to find groupings. For creosote shrublands, grasslands, and two tarbush-dominated alluvial flats, samples collected at 5, 10, and 20 cm had >80% sand-sized (>50 lm) particles, while one playa and tarbush site yielded ~45% dust-sized particles at 5 and 10 cm. The transition from saltation to suspension was ~20 cm for most sites. Two mesquite dune sites and an anthropogenically devegetated site, all with high overall mass fluxes, shifted to suspension at ~50 cm. Highest dust fluxes occurred at the devegetated site, followed by the playa, a mesquite site with unvegetated ‘‘streets,’’ and tarbush sites.
These field observations are consistent with laboratory-based dust emission experiments and remote sensing studies in the Chihuahuan Desert. Playas and tarbush sites are major dust producers due to high proportions of fines, whereas the mesquite site produces much dust because of greater overall mass flux. Mesquite dunes covering most of the basin likely produce the most dust overall, though playas and tarbush-
dominated alluvial flats (which cover about 8%) can emit large amounts of dust. Continuing shrubland encroachment will likely increase dust emissions from the Jornada Basin, as well as in other arid regions. © 2011 Elsevier B.V. All rights reserved.10.1016/j.aeolia.2011.02.002