CADIC   02618
CENTRO AUSTRAL DE INVESTIGACIONES CIENTIFICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Suitable conditions for natural regeneration in variable retention harvesting of Nothofagus pumilo forests of South Patagonia
Autor/es:
MARTÍNEZ PASTUR, G; CELLINI, JM; SOLER, R; LENCINAS, MV; PERI, P; PEÑA, KA
Lugar:
San José
Reunión:
Congreso; Tercer Congreso Latinoamericano de IUFRO; 2013
Institución organizadora:
IUFRO
Resumen:
Forest harvesting with variable retention (aggregated and dispersed) for southern Patagonian Nothofagus allows for biodiversity conservation and natural regeneration by opening the canopy. Harvesting generates different microenvironments and presents dissimilar conditions for seedling establishment and the subsequent survival and growth, due to differential influences (positive or negative) on the biotic and abiotic factors. In this study, the objective was to evaluate regeneration at different microenvironment conditions within the harvested stands after 5 years of the operations. Tested hypotheses were: (i) the remnant overstorey following variable retention harvesting (comprising both aggregates and dispersed trees) modifies microclimate particularly through rainfall and solar radiation interception at ground level and consequently affects regeneration dynamics and growth, (ii) extreme values (low and high) of soil water content and solar radiation negatively affects regeneration performance, and (iii) regeneration modify its biomass compartmentalization according to soil water content and solar radiation offered for each microenvironment. Three stands were selected for the samplings, where seven microenvironments were selected, and 105 plots were measured (3 stands x 7 microenvironments x 5 replicas). Regeneration and forest structure were characterized. Univariate and multivariate methods were used to compare treatments and stands. Forest structure and micro-climate variables (radiation and soil moisture) significantly changes with micro-environments in the harvested forests, and at landscape level among stands. These greatly influenced in the regeneration establishment, growth and biomass allocation. The proportion of the different microenvironments in these harvested forests will determine the natural recruitment of regeneration after harvesting at stand level, and consequently the success of the proposed silvicultural management. Traditional forest practices must be manipulated to increase the proportion of some favourable microenvironments, allowing greater natural regeneration success in the first years after harvesting.