Sustainable timber harvesting in Venezuela: a modelling approach

Authors

  • Ludwig Kammesheidt,

    Corresponding author
    1. Institut für Waldbau, Abt. II: Waldbau der Tropen, Universität Göttingen, Büsgenweg 1, D-37077 Göttingen, Germany; and
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  • Peter Köhler,

    1. Center for Environmental Systems Research, University of Kassel, Kurt-Wolters-Str. 3, D-34109 Kassel, Germany; and
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    • §

      Present address: UFZ Centre for Environmental Research Leipzig-Halle, Department of Ecological Modelling, Permoserstr. 15, D-04318 Leipzig, Germany.

  • Andreas Huth

    1. UFZ Centre for Environmental Research, Department of Ecological Modelling, PO Box 500136, D-04301 Leipzig, Germany
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*Present address and correspondence: L. Kammesheidt, Visiting scientist at Institut für Weltforstwirtschaft, Bundesforschungsanstalt für Forst- und Holzwirtschaft, Leuschnerstr. 91, 21031 Hamburg, Germany (e-maillkammes@ufobi6.uni-forst.gwdg.de).

Summary

  • 1 Reliable data on the growth and yield of logged-over forest, to determine sustainable cutting cycles, are widely missing for the tropics.
  • 2 We used the process-based model formind2.0 to analyse the growth and yield of logged-over forest in Venezuela under different logging scenarios over a period of 240 years, and compared results with unlogged stands. The performance of the model was evaluated with a detailed stability and sensitivity analysis.
  • 3 In the absence of further logging, the logged-over stand approached the stand structure of mature forest in terms of bole volume and basal area after about 50–100 years.
  • 4 Thirty-year cutting cycles with conventional logging methods and net extraction volumes of 45 and 60 m3 ha−1 cycle−1 did not provide sustainable yields under either of two minimum felling diameters (35 and 50 cm) that were applied. Only the 60-year cutting cycle provided sustainable yields under conventional and reduced-impact logging, with the different minimum felling diameters and a range of net volumes extracted (30–60 m3 ha−1 cycle−1).
  • 5 With the longest cutting cycle (60 years), bole volume recovered to levels similar to the mature unlogged stand, but the species composition was very different.
  • 6 Scenarios with reduced-impact logging provided a significantly higher timber volume than under conventional logging. The conservation of forest resources will only be possible with long cutting cycles (at least 60 years) in combination with reduced-impact logging.

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