Rainfall intensity switches ecohydrological runoff/runon redistribution patterns in dryland vegetation patches.

Publicado en Ecological Applications, v. 25(8):2094-100
Autores

Magliano, P.N., Breshears, D.D., Fernández, R.J. and Jobbágy, E.G.

Año de publicación 2015
DOI http://dx.doi.org/10.1890/15-0550.1
Afiliaciones
  • Grupo de Estudios Ambientales&ndashIMASL, Universidad Nacional de San Luis and CONICET, Ejército de los Andes 950, D5700HHW, San Luis, Argentina
  • School of Natural Resources and the Environment, and Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721 USA
  • IFEVA-CONICET/Facultad de Agronomía, Universidad de Buenos Aires, Avenue San Martín 4453, C1417DSE, Buenos Aires, Argentina
  • Grupo de Estudios Ambientales&ndashIMASL, Universidad Nacional de San Luis and CONICET, Ejército de los Andes 950, D5700HHW, San Luis, Argentina
Programa

CRN3

Proyecto CRN3095
Keywords

Abstract

Effectively managing net primary productivity in drylands for grazing and other uses depends on understanding how limited rainfall input is redistributed by runoff and runon among vegetation patches, particularly for patches that contrast between lesser and greater amounts of vegetation cover. Due in part to data limitations, ecohydrologists generally have focused on rainfall event size to characterize water redistribution processes. Here we use soil moisture data from a semiarid woodland to highlight how, when event size is controlled and runoff and interception are negligible at the stand scale, rainfall intensity drives the relationship between water redistribution and canopy and soil patch attributes. Horizontal water redistribution variability increased with rainfall intensity and differed between patches with contrasting vegetation cover. Sparsely vegetated patches gained relatively more water during lower intensity events, whereas densely vegetated ones gained relatively more water during higher intensity events. Consequently, range managers need to account for the distribution of rainfall event intensity, as well as event size, to assess the consequences of climate variability and change on net primary productivity. More generally, our results suggest that rainfall intensity needs to be considered in addition to event size to understand vegetation patch dynamics in drylands.