Broadscale Outcome and Monitoring Assessment to Evaluate Protected Area Effectiveness in Northern Patagonia

Biomes worldwide have been affected by biodiversity loss and habitat degradation for more than a century. Protected Areas (PAs) have been established in almost every country, as they represent one of the most important tools in biodiversity conservation. Nevertheless, the relentless biodiversity loss trend has not stopped. Concern about PA effectiveness has risen, and several methods to evaluate it have been implemented over the last few decades. Nahuel Huapi National Park (NHNP) is the first PA in Argentina and one of the largest. The area is considered a biodiversity hotspot, and its conservation is essential, as unique ecological and evolutionary processes have resulted in a high degree of endemism and mutualism. Three levels of protection have been designated in NHNP, Strict Natural Reserve (SNR), National Park (NP), and National Reserve (NR), corresponding to IUCN levels Ia, II, and VI respectively. In this study we evaluated NHNP effectiveness, comparing outcomes at each level of protection and the neighboring unprotected area. We assessed the effectiveness using two complementary approaches: broadscale outcome based on remote sensing data, and direct monitoring of the small mammal community. We evaluated broadscale outcomes based on 20 years of Normalized Difference Vegetation Index (NDVI) data from the period 2000-2020. We included other variables in our analysis such as dominant tree species, precipitation, elevation, temperature, and wildfires. We assessed its small mammal community using a capture-mark-recapture study conducted over two consecutive summers with a total trapping effort of 41,600 trap/nights, resulting in 1259 individuals identified, from eight native species. Both assessments suggested that a key role is played by the highest level of protection, SNR. Nevertheless, lack of investment and the effects of climate change threaten the future of NHNP. We also analyzed variation of small mammal communities by developing multiple occupancy models to understand species distributions, co-occurrence, and habitat use at a small scale, supporting previous findings about differences among effectiveness of the three levels of protection, species-by-species, and providing evidence at a fine-scale regarding those differences.