Landscape Variables Influence over Active Restoration Strategies of Nothofagus Forests Degraded by Invasive Castor canadensis in Tierra del Fuego

G MARTÍNEZ PASTUR; JM CELLINI; MV LENCINAS; YM ROSAS; J HENN; PL PERI

Sustainability

MDPI

Lugar: Cham; Año: 2021 vol. 13

North American beavers (Castor canadensis) are responsible for the major changes in theTierra del Fuego Archipelago, altering riparian forests for the long-term. Passive restoration of theareas affected was ineffective in the medium-term (up to 20 years), being necessary active strategies.Plantations in abandoned ponds were made with Nothofagus pumilio and N. antarctica tree speciesacross Tierra del Fuego island (Argentina). In the first experiment, we analysed the influence of bioticand abiotic factors in three micro-habitats in the impacted areas: front and tail of ponds, and cutnot-flooded forest areas. Five-years-old N. pumilio seedlings had 39% survival in front, 21% in tails,and 46% in cut areas at year-3 of the restoration experiments, being negatively influenced by plantcover and soil moisture. Lower growth was recorded during year-1 (0.7?0.9 cm yr􀀀1), but increasedon time (1.9 cm yr􀀀1 front, 1.6 cm yr􀀀1 tail, 4.3 cm yr􀀀1 cut areas). A second experiment exploresthe alternative to substitute the tree species to face the harder conditions of the impact and climatechange. For this, we conducted a new plantation at four locations across the main bioclimatic zones,where 10?40 cm N. antarctica plants attained 17% survival in meadows (front and tail) and 30% incut areas, being higher with larger than smaller plants (25% vs. 18%), and where they are mainlyinfluenced by rainfall (4% in sites 400 mm yr􀀀1). The main damage wasdetected in the above-ground biomass due to dryness, but root survival allowed the emergence ofnew shoots in the following growing season. It is necessary to monitor different Nothofagus speciesacross natural environments in the landscape to determine the feasibility and effectiveness of differentstrategies in restoration plans, considering the selection of climate-resilient tree species.