We examine the Forestry Commissions guide to good practice when carrying out whole-tree harvesting.
The title of this concise 1997 Forestry Commission document is “Whole-tree Harvesting – A Guide to Good Practice”. The guide was compiled by T Nisbet, J Dutch and A Moffat. The guide considers whole-tree harvesting in Britain, and focuses on site issues. The document defines whole-tree harvesting as “the removal of most branches and needles from a harvesting site in addition to the stem wood that is removed in conventional harvesting”. It describes the potential impacts of whole-tree harvesting systems, as well as the specific issues that need to be considered for different systems. The impacts on the environment are described under six headings:
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Soil physical damage, erosion and siltation of watercourses
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Impoverished soil fertility and associated silvicultural implications
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Acidification
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Freshwater eutrophication
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Degraded landscape
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Degraded habitat
The document then provides guidance to identify the above risks and mitigate them for different harvesting systems and other aspects. They are described under the following headings:
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Skyline (Cable crane)
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Skidders – the risk for ground damage and soil fertility loss is described for different soil types, along with management actions.
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Two-stage extraction with forwarders – After logs have been removed with the forwarders, they return and collect the brash.
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Siting of brash storage areas – this short section describes the location of brash storage areas such as landings.
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Site conservation – if necessary, live and/or dead trees should remain for ecological purposes.
A useful reference list is provided, which cites additional documents that contain guidance for whole-tree harvesting.
Source: www.forestenergy.org/openfile/14 1