Plantas invasoras en el Parque Nacional Torres del Paine (Magallanes, Chile): Estado del arte, distribución post-fuego e implicancias en restauración ecológica

Abstract

Torres del Paine National Park (TDP) is an area in which invasive plants are a growing threat for the biodiversity conservation. The growing number of visitors in TDP has allowed in the last years the increase of invasive species in places where tourism has a direct impact (e.g. camping areas, trails). In other occasions negligent tourists have set megafires that stimulate the dispersion of this plants. In this work we review the information concerning on alien plant species in TDP and we use a conceptual framework widely accepted to address this problematic. We present the results of two field experiences in which this conceptual framework has been applied: a) a prospection where the distribution and the abundance of post-fire exotics are evaluated; b) a field experiment in which we evaluated the effect of invasive plant control on Lenga seedlings. These seedlings were planted with reforestation purposes. Furthermore we give the background that allows the calculation of the monetary costs of the weed control. The investigation of alien plant species includes checklists that categorize a priori the invasive species, lacking of field ecologic information. We recorded the presence of 34 exotic plant species in burned places, some of them having a great post-fire invasibility potential. Meanwhile in the sites where reforestation occurs the survival of lenga beech seedlings is higher when the weeds has been controled by mechanical removal, likely by the facilitation induced by control. The costs of weed control fluctuate from CLP$ 700.000 to 1.400.000 per hectare (USD$ 1.135 to 2.270). This study highlights the need to consider the invasive plant species as a context-dependent phenomenon that may or may not persists, depending on the type of disturbance that facilitates their dispersion, severity, post-disturbance time and ecosistemic resilience.