标题：Landscape Variables Influence over Active Restoration Strategies of <i>Nothofagus</i> Forests Degraded by Invasive <i>Castor canadensis</i> in Tierra del Fuego
摘要：North American beavers (<i>Castor canadensis</i>) are responsible for the major changes in the Tierra del Fuego Archipelago, altering riparian forests for the long-term. Passive restoration of the areas affected was ineffective in the medium-term (up to 20 years), being necessary active strategies. Plantations in abandoned ponds were made with <i>Nothofagus pumilio</i> and <i>N. antarctica</i> tree species across Tierra del Fuego island (Argentina). In the first experiment, we analysed the influence of biotic and abiotic factors in three micro-habitats in the impacted areas: front and tail of ponds, and cut not-flooded forest areas. Five-years-old <i>N. pumilio</i> 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 plant cover and soil moisture. Lower growth was recorded during year-1 (0.7–0.9 cm yr<sup>−1</sup>), but increased on time (1.9 cm yr<sup>−1</sup> front, 1.6 cm yr<sup>−1</sup> tail, 4.3 cm yr<sup>−1</sup> cut areas). A second experiment explores the alternative to substitute the tree species to face the harder conditions of the impact and climate change. For this, we conducted a new plantation at four locations across the main bioclimatic zones, where 10–40 cm <i>N. antarctica</i> plants attained 17% survival in meadows (front and tail) and 30% in cut areas, being higher with larger than smaller plants (25% vs. 18%), and where they are mainly influenced by rainfall (4% in sites <400 mm yr<sup>−1</sup> and 41% in >400 mm yr<sup>−1</sup>). The main damage was detected in the above-ground biomass due to dryness, but root survival allowed the emergence of new shoots in the following growing season. It is necessary to monitor different <i>Nothofagus</i> species across natural environments in the landscape to determine the feasibility and effectiveness of different strategies in restoration plans, considering the selection of climate-resilient tree species.
