Premium
Temporal and Spatial Variation of Episodic Wind Erosion in Unburned and Burned Semiarid Shrubland
Author(s) -
Whicker Jeffrey J.,
Breshears David D.,
Wasiolek Piotr T.,
Kirchner Thomas B.,
Tavani Rebecca A.,
Schoep David A.,
Rodgers John C.
Publication year - 2002
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2002.5990
Subject(s) - shrubland , environmental science , aeolian processes , erosion , wind speed , spatial variability , hydrology (agriculture) , atmospheric sciences , vegetation (pathology) , arid , spatial ecology , ecosystem , geology , ecology , geomorphology , oceanography , medicine , geotechnical engineering , pathology , biology , paleontology , statistics , mathematics
Redistribution of soil, nutrients, and contaminants is often driven by wind erosion in semiarid shrublands. Wind erosion depends on wind velocity (particularly during episodic, high‐velocity winds) and on vegetation, which is generally sparse and spatially heterogeneous in semiarid ecosystems. Further, the vegetation cover can be rapidly and greatly altered due to disturbances, particularly fire. Few studies, however, have evaluated key temporal and spatial components of wind erosion with respect to (i) erosion rates on the scale of weeks as a function of episodic high‐velocity winds, (ii) rates at unburned and burned sites, and (iii) within‐site spatial heterogeneity in erosion. Measuring wind erosion in unburned and recently burned Chihuahuan desert shrubland, we found (i) weekly wind erosion was related more to daily peak wind velocities than to daily average velocities as consistent with our findings of a threshold wind velocity at approximately 7 m s −1 ; (ii) greater erodibility in burned vs. unburned shrubland as indicated by erosion thresholds, aerodynamic roughness, and near‐ground soil movement; and (iii) burned shrubland lost soil from intercanopy and especially canopy patches in contrast to unburned shrubland, where soil accumulated in canopy patches. Our results are among the first to quantify post‐fire wind erosion and highlight the importance of accounting for finer temporal and spatial variation in shrubland wind erosion. This finer‐scale variation relates to semiarid land degradation, and is particularly relevant for predictions of contaminant resuspension and redistribution, both of which historically ignore finer‐scale temporal and spatial variation in wind erosion.