Unraveling Plecoptera diversity in two protected areas of Argentine Patagonia

The Plecoptera taxonomy in Patagonia is well-documented, yet their distribution remains poorly understood, hindering comprehensive ecological and biogeographical studies. This study enhances knowledge of stonefly distribution in two Patagonian national parks: Nahuel Huapi and Los Alerces. Extensive fieldwork, georeferenced species records, and geographic information system data integration were conducted. Species richness was calculated using polygons (0.1° x 0.1° pixels) across ecoregions, with species indexed from rare to ubiquitous. Cluster analyses revealed faunal affinities across ecosystem complexes, and richness estimators (Jack1, Jack2, and Chao2) highlighted knowledge gaps. Results showed uneven species distribution, with the highest richness polygon (n = 19) in Los Alerces. The Northern Moist Forests hosted the most species, followed by the Transitional Cypress-Beech Forests. The rarest species were also found in these two complexes, as well as the Ecotone Steppe-Forest. Cluster analysis revealed strong affinities between the Northern Moist Forests of Nahuel Huapi and Ecotone Steppe-Forest. Richness estimators suggested up to 23 undocumented species. Though much remains to be learned about Plecoptera distribution in Patagonia, this study emphasizes the critical role of national parks in conserving biodiversity and provides a foundation for future conservation strategies, identifying new taxa records, including southernmost distributions.