Harvesting and silviculture synergy to improve the South African forest industry value chain...

by Simon Ackerman (FESA) and Diana Rietz (ICFR)

Large stumps, harvesting residue and slopes can hamper silviculture and future harvesting operations.

Timber waste in pine saw timber harvesting requires particular residue management procedures when replanting compartments.	The use of the right machines to load timber within the compartment can limit the impact on soils and live stumps.

Harvesting and re-establishment silviculture are two forestry operations that follow each other in close succession in plantation management, as we reap the benefit from one rotation and seek to ensure the best available production from the next rotation. Typically, these operations are managed as separate functions; with costs measured per ton or m3 for one and per hectare for the other. Technically quite different with apparently dissimilar success criteria, opportunities for integration are not always apparent, and yet the efficiency and success of both operations are closely linked.

Re-establishment silviculture faces challenges presented by harvesting operations such as:

• stumps, and whether they represent an impediment or are a source of coppice to create the next crop;
• the quantity and distribution of harvest residue remaining on a site;
• rutting and compaction of soils from harvesting equipment operations.

Similarly, harvesting inherits the consequences of re-establishment silviculture in aspects like:

• the spacing and orientation of tree rows;
• straightness of tree rows;
• Tree size uniformity – or rather the lack thereof.

The options for performing harvesting and silviculture operations have never been so varied in South African forestry. An increase in innovation is fast occurring in both manual and mechanised harvesting and silviculture operations. Through this process, it is increasingly important for management to use the opportunity to contain costs, improve safety performance and better achieve production goals. These objectives would be better served by a greater synergy between harvesting and silviculture. In this period of widespread and rapid change, there is a clear opportunity to leverage improved efficiency through better integration of operational objectives.

To help forest managers realise the benefits available from better coordinated harvesting and silviculture practices, FESA and the ICFR have embarked on a new project that will seek to identify opportunities and recommend changes in both harvesting and silviculture practices, aimed at reducing overall cost and increasing the productivity of our planta- tions in South Africa. This project aims to address all parts of the forestry value chain in:

• Identifying, defining and quantifying areas in the value chain that are not operating in synergy
• Using existing knowledge (from FESA and ICFR) to improve synergy in these areas, and
• Prioritising any areas requiring research to improve synergy.

Direct benefit outputs from this project to the industry will be user-friendly guidelines and tools to improve the efficiency and profitability of the forestry industry in South Africa.

For more information on this initiative, contact Simon Ackerman (fesa@icfr.ukzn.ac.za) or Dr Diana Rietz (diana.rietz@icfr.ukzn.ac.za) at the ICFR (call 033 386 2314).

Changing of planting spacing with large 'inter-rows' optimising harvester reach and allowing access for post canopy closure silviculture operations.

Published in October 2013