Effect of gnawing by Microcavia australis (Rodentia, Caviidae) on Geoffroea decorticans (Leguminosae) plants.

TOGNELLI, MF; BORGHI, CARLOS EDUARDO; CLAUDIA MONICA CAMPOS

Journal of Arid Environments

Año: 1999 vol. 41 p. 79 - 85

0140-1963

<!-- @page { size: 21cm 29.7cm; margin: 2cm } P { margin-bottom: 0.21cm } --> The impact by gnawing of Microcaviaaustralis on the survival of Geoffroeadecorticans plants was studied in the Monte desert of Argentina. Sampled plants were selected randomly from two different colonies of M. australis. For each plant sampled we measured: the diameter of the trunk at ground level, the distance to the nearest burrow of M. australis, the proportion of the trunk perimeter that had been gnawed, and the condition of the plants. We found that gnawing by M. australis has a negative impact on the survival of G. decorticans plants. Damage of the plants is inversely related to the distance from the burrow systems (rs= -0.283, p<0.003), and to the proportion gnawed of the trunk perimeter (rs=-0.554, p<0.0001). The differential survival of plants with larger diameter of their trunk, and of plants farther away from M. australis colonies may have long-term effects on the abundance and distribution of G. decorticans.