Restoration of native forests from Gorse‐dominated shrublands in North Patagonia, Chile: early structural development of mixed plantations
Jan R. Bannister, Natalia Cáceres, Osvaldo J. Vidal, Natalia Carrasco‐FariasAbstract
Introduction
Gorse ( Ulex europaeus ) is currently one of the most invasive shrub‐forming species in the world. Active management has been proposed for its control, including mechanical removal, followed by Gorse suppression by competition through planted forests.
Objectives
In this study, we evaluate the development of 7‐year‐old mixed native plantations on Chiloé Island, North Patagonia, which were established following the removal of Gorse‐dominated shrublands, and define which microsite conditions can facilitate stand structural development.
Methods
For this, we carried out a forest inventory based on 35 circular plots of 200 m 2 randomly established in seven stands (total planted area: 86.6 ha).
Results
Seven years after planting, stands presented dissimilar early structural development in terms of mean diameter at breast height (6.3–8.8 cm), mean height (3.6–5.9 m), mean density (238.7–1512 trees/ha), mean basal area (0.8–9.8 m 2 /ha), mean volume (2.1–29.2 m 3 /ha), and mean biomass (3.1–40.1 Mg/ha). Stands also presented abundant natural regeneration and 36 non‐planted vascular species. Among site variables, soil phosphorus, litter depth, and Gorse maximum and dominant height showed the strongest positive correlations with stand structural variables, while soil pH was negatively correlated with stand structural development.
Conclusions
Our results show that in the case of intense Gorse infestations, planting mixed native plantations represents an effective treatment to create continuous forest cover and to facilitate the natural regeneration process. These outcomes were primarily driven by the pioneer species, whose acquisitive functional traits enabled rapid height growth and early canopy closure under the initial high‐light conditions.