Higher establishment of nonnative trees with increased harvest intensity in strip cuttings

• Autores: Dimarco, Romina; Nacif, Marcos Ezequiel; Garibaldi, Lucas Alejandro; Núñez, Martín
• Año de publicación: 2022
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Ciencias Exactas y Naturales; Clearcutting; Forestry; Invasibility; Ciencias Exactas y Naturales
• Institución: Universidad Nacional de Río Negro

Fil: Dimarco, Romina. Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
Fil: Nacif, Marcos Ezequiel. Universidad Nacional de Río Negro, Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural, San Carlos de Bariloche, Río Negro, Argentina
Fil: Garibaldi, Lucas Alejandro. Universidad Nacional de Río Negro, Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural, San Carlos de Bariloche, Río Negro, Argentina
Fil: Núñez, Martín. Grupo de Ecología de Invasiones, Instituto de Investigaciones en Biodiversidad y Medioambiente INIBIOMA, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional del Comahue (UNCo), San Carlos de Bariloche, Río Negro, Argentina
Fil: Dimarco, Romina. Grupo de Ecología de Poblaciones de Insectos, IFAB (INTA – CONICET), San Carlos de Bariloche, Río Negro, Argentina
Fil: Nacif, Marcos Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural, San Carlos de Bariloche, Río Negro, Argentina
Fil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural, San Carlos de Bariloche, Río Negro, Argentina
Proper management of woody ecosystems is fundamental for human livelihoods and biodiversity conservation. Strip cutting or selective harvesting are proposed as sustainable alternatives to clear-cut logging. However, their impacts are not fully understood, especially when we consider the harvesting intensity levels and the invasibility of an ecosystem by nonnative tree species. In this study we analyzed the impacts of different harvesting intensity levels on the establishment after 2 years of nonnative and native tree species. We conducted this study in a mixed forest dominated by Nothofagus antarctica, where we applied four strip harvesting levels: 0% (control), 30%, 50% and 70% percentage of vegetation removal in eight plots (1417.5 m2 each plot) Inside those plots, we had a total of 24 subplots (3 sites × 8 plots) were we sowed seeds of a total of six tree species, that can form dominant stands in the studied region. Three species were nonnative invasives in the region (Pinus ponderosa, Pinus contorta and Pseudotsuga mensiezii), and the other three were native species (Austrocedrus chilensis, Nothofagus obliqua and Araucaria araucana). We found that in the high harvesting intensity treatments, the establishment after 2 years of all nonnative trees and only one native species (A. araucana) was increased in spite of the ecological and structural differences (i.e., productivity levels) between sites. Invasion by nonnative tree species can have important negative economic and ecological consequences on the logged ecosystems, so their removal may be required to keep them away from colonizing and dominating the logged areas, especially at high harvesting intensities.
Proper management of woody ecosystems is fundamental for human livelihoods and biodiversity conservation. Strip cutting or selective harvesting are proposed as sustainable alternatives to clear-cut logging. However, their impacts are not fully understood, especially when we consider the harvesting intensity levels and the invasibility of an ecosystem by nonnative tree species. In this study we analyzed the impacts of different harvesting intensity levels on the establishment after 2 years of nonnative and native tree species. We conducted this study in a mixed forest dominated by Nothofagus antarctica, where we applied four strip harvesting levels: 0% (control), 30%, 50% and 70% percentage of vegetation removal in eight plots (1417.5 m2 each plot) Inside those plots, we had a total of 24 subplots (3 sites × 8 plots) were we sowed seeds of a total of six tree species, that can form dominant stands in the studied region. Three species were nonnative invasives in the region (Pinus ponderosa, Pinus contorta and Pseudotsuga mensiezii), and the other three were native species (Austrocedrus chilensis, Nothofagus obliqua and Araucaria araucana). We found that in the high harvesting intensity treatments, the establishment after 2 years of all nonnative trees and only one native species (A. araucana) was increased in spite of the ecological and structural differences (i.e., productivity levels) between sites. Invasion by nonnative tree species can have important negative economic and ecological consequences on the logged ecosystems, so their removal may be required to keep them away from colonizing and dominating the logged areas, especially at high harvesting intensities.