Jackrabbit (<i>Lepus californicus</i>) herbivory changes dominance in desertified Chihuahuan Desert ecosystems.

TitleJackrabbit (Lepus californicus) herbivory changes dominance in desertified Chihuahuan Desert ecosystems.
Publication TypeJournal Article
Year of Publication2007
AuthorsRoth G.A., Whitford WG, Steinberger Y.
JournalJournal of Arid Environments
Date Published03/2007
ARIS Log Number212128
Keywordsbrowsing, compensatory growth, creosotebush, Flourensia cernua, Larrea tridentata, preferential feeding, tarbush
AbstractThis study addressed the question: can herbivory by a medium size herbivore, black-tail jackrabbits (Lepus californicus), change dominance in desertified ecosystems dominated by two species of shrubs. Shrubs that were pruned by jackrabbits in plant communities dominated by creosotebush (Larrea tridentate) and tarbush (Flourensia cernua) were compared to shrubs not browsed by the rabbits. In the missed shrub area, herbivory on F. cernua resulted in death of 46.6% of the shrubs, compared to only 4.8% of L. tridentate shrubs. There was no evidence of jackrabbit browsing of dead F. cernua in a tarbush monoculture area. The canopy volumes of F. cernua plants that survived repeated browsing were significantly smaller than predicted based on unbrowsed plants with the same basal stem areas. Jackrabbit browsing resulted in increased canopy volume of creosotebush shrubs. Creosotebush average canopy volume significantly exceeded predicted values because of compensatory growth of stems from nodes below the severed point. Close spatial association of lightly browsed creosotebush with heavily browsed tarbush may be a factor contributing to low utilization of creosotebush stems by jackrabbits. Differential browsing by the rabbits is shifting thee ecosystems toward an L. tridentate monoculture.