Restoring a Degraded Rangeland: Using Fire and Herbivory to Control Opuntia Cacti Encroachment

Abstract

Innovative restoration strategies are critically needed in the South Texas Plains for controlling increased Opuntia cacti invasions. Using a replicated and randomized experimental study, I have examined the effects of fire seasonality and herbivory on the dominant cacti and herbaceous plant species in this semi-arid ecosystem. Results from this study demonstrate that the combination of fire and wildlife herbivory significantly reduces Opuntia cactus cover. I was able to empirically demonstrate that prescribed fire decreases prickly pear cactus cover. Moreover, this decrease is further exacerbated by the effects of large mammalian herbivores consuming and/or disturbing recently burned mottes. In the absence of fire, both mottes with and without herbivore exclosures increased in size. The ecological insights gained from this study will contribute to the development of management strategies of Opuntia cacti, while promoting the restoration and long-term sustainability of Texas rangelands.