Response of vegetation to the increase in guanaco density after sheep removal in north-eastern Patagonian rangelands, Argentina

RODRÍGUEZ, MARÍA VICTORIA; GUSTAVO PAZOS; ANDREA MARINO; CECILIA LARREGUY

Saskatoon

Congreso; 10th International Rangelands Congress; 2016

International Rangeland Congress

In arid Patagonia, unsustainable practices in sheep production have typically led to vegetation and land degradation. Guanaco (Lama guanicoe) is the dominant native herbivore inhabiting these ecosystems. Lastly, ranchers and some government agents perceive this herbivore as a threat to livestock production and alerted on a hypothetical risk of vegetation deterioration by guanaco overgrazing because of the growth of some of their populations. In this work, we annually monitored during seven years the cover and composition of four plant communities in a wildlife reserve that was previously a typical sheep ranch. After sheep removal at the time of the reserve creation, a rapid increase of guanaco density was registered (Marino et al., 2015). Plant communities supporting territorial family groups of guanacos did not show signs of overgrazing and temporal variations appeared to be related with climatic variables. Non-territorial male groups deserve further attention because of the observed negative correlation with plant cover. These groups move massively and are capable of traveling long distances like migratory herbivores, which exploit intensively high productivity patches alternating among different zones. On the other hand, male groups are infrequent and exploit vegetation patches spatially crowded, while most of the study area is inhabited by territorial-family groups