FERAL BUFFALOS IN REBIO DO GUAPORÉ AND SURROUNDINGS: AREA BUSY, POPULATION SURVEY AND ENVIRONMENTAL IMPACTSInvasive Alien Species, Remote Sensing, Ramsar Site, Protected Areas, Pau D'Oleo Farm
Invasive alien species (IES) generate major environmental and economic problems in the regions where they settle, and their introduction and dispersion is one of the main threats to the planet's biodiversity. In Brazil, current legislation prohibits the introduction of ERA in a conservation unit (UC), but around 271 UC have already been affected by these species. This is the case of the Guaporé Biological Reserve and adjacent areas, where the invasive alien species Bubalus bubalis was introduced in 1953Since then, buffaloes have become feral, becoming a threat to populations, communities and natural ecosystems protected by the reserve. As a starting point for the introduction of mitigating measures, this study aimed to carry out a population and occupied area survey, as well as carry out remote sensing analysis to verify possible environmental impacts caused by buffaloes in the interior and adjacent areas of the Guaporé Biological Reserve. Overflight was performed on transects to survey population and occupied area, as well as multitemporal analysis of environmental impacts by remote sensing (Landsat images, 30 m resolution) to investigate possible environmental changes caused by these animals. The population and occupied area survey overflight resulted in a number of 4,782 ± 533.27 buffaloes in an occupied area of 966.22km² (96,622 ha), with a population density of 4.9 ± 0.55 buffaloes per km². The multitemporal analysis by remote sensing showed significant changes in the “flooded” feature over the years, resulting in a loss of 48% of flooded areas in the region occupied by buffaloes in the last 34 years. The REBio do Guaporé had the highest percentage of area occupied and affected by the EEI, however adjacent areas located in the Pedras Negras State RESEX were also affected. Urgent measures must be taken by the government in order to prepare and execute a plan for the control and eradication of the EEI, and thus mitigate the environmental impacts caused not only to the affected protected areas, but also to the Ramsar Site established in 2018, a wetland of international importance that corresponds to the territory of Guaporé Biological Reserve.