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.