Anthropogenic impacts allowed for the invasion of understory species, affecting the sustainability of management practices in southern Patagonia

YM ROSAS; PL PERI; JM CELLINI; MV LENCINAS; S KEPFER ROJAS; I KAPPEL SCHMIDT; S PECHAR; MD BARRERA; G MARTÍNEZ PASTUR

LAND

MDPI

Año: 2024 vol. 13

2073-445X

Forest management aims to preserve integrity and ecosystem resilience. Conservationand species invasion patterns must be determined in managed landscapes. The objectives of thisstudy were to identify proxies that allowed plant species invasion (natives and exotics) and definethresholds of human impacts to improve management. We also wanted to identify indicator speciesfor different impacts and environments. A total of 165 plots were measured in Nothofagus antarcticaforests and associated open lands (dry and wet grasslands) in Tierra del Fuego (Argentina). Wefound differences in the studied variables across the landscape and among different uses and impacts.Human impacts influence land types, emphasizing the importance of managing intensities. Indicatorplant species allowed for the identification of potential ecological thresholds related to human impactsand the establishment of species linked to ecological and economic degradation, e.g., Bolax gummiferaand Azorella trifurcata (cushion plants) were associated with high grazing pressure in grasslands andfires in forested areas, while Rumex acetosella and Achillea millefolium (erect herbs), typically associatedwith forested areas, were related to high harvesting pressures and fire impacts. These findingscontribute to our understanding of the long-term effects of some human impacts (e.g., harvesting andranching) and allow us to define variables of monitoring and indicator species for each impact type.