IADIZA   20886
INSTITUTO ARGENTINO DE INVESTIGACIONES DE LAS ZONAS ARIDAS
Unidad Ejecutora - UE
artículos
Título:
Effects of bark damage by feral herbivores on columnar cactus Echinopsis (=Trichocereus) terscheckii reproductive output
Autor/es:
PECO, B.; BORGHI, C.; MALO,J.; ACEBES, P.; ALMIRÓN, M.; CAMPOS, C.
Revista:
AUSTRAL ECOLOGY
Editorial:
Wiley-Blackwell
Referencias:
Lugar: Adelaide, Australia; Año: 2009
ISSN:
1442-9985
Resumen:
Abstract Columnar cacti are an important feature of the arid “cardonal” landscape in South America. The predominant columnar cactus in the southern zone is Echinopsis (=Trichocereus) terscheckii. At some sites, the species suffers considerable trunk damage which previous studies have attributed to feral livestock (donkey and cattle). In order to understand the potential impact of this damage on columnar cactus populations, we investigated whether reproductive output (flower, fruit and seed production) of E. terscheckii individuals was related to damage,  controlling for the effect of individual plant size and habitat characteristics measured at meso and micro-scale. Cactus trunk damage negatively affects the reproductive parameters of plants by reducing their number of flowers (more than 15%) and fruits (8%), while fruit size is not affected. We also found significant effects of meso and micro-habitat conditions on all the analyzed reproductive parameters. Plant size was also positively related to flower and fruit production. These results show that bark damage can be more than a aesthetic problem for cacti, and that large feral herbivores can have serious effects on desert populations of cactus species, thus highlighting the need for a management program to monitor populations trends of these plants and also exotic herbivores. Columnar cacti are an important feature of the arid “cardonal” landscape in South America. The predominant columnar cactus in the southern zone is Echinopsis (=Trichocereus) terscheckii. At some sites, the species suffers considerable trunk damage which previous studies have attributed to feral livestock (donkey and cattle). In order to understand the potential impact of this damage on columnar cactus populations, we investigated whether reproductive output (flower, fruit and seed production) of E. terscheckii individuals was related to damage,  controlling for the effect of individual plant size and habitat characteristics measured at meso and micro-scale. Cactus trunk damage negatively affects the reproductive parameters of plants by reducing their number of flowers (more than 15%) and fruits (8%), while fruit size is not affected. We also found significant effects of meso and micro-habitat conditions on all the analyzed reproductive parameters. Plant size was also positively related to flower and fruit production. These results show that bark damage can be more than a aesthetic problem for cacti, and that large feral herbivores can have serious effects on desert populations of cactus species, thus highlighting the need for a management program to monitor populations trends of these plants and also exotic herbivores.