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The productivity of regeneration may be improved

Datum: 2014.05.09

PhD thesis by Ville Kankaanhuhta, Finland

Centre pole for the circular sample plots and soil sample core (hanging from the belt) were the main equipment required. Photo: Ville Kankaanhuhta

Changing operational environment and non-existent feedback as a challenge

At the end of 1990’s, signs of poor implementation of forest regeneration activities, delayed operations, and poor quality of young stands were observable in the privately-owned forests of Southern Finland. Furthermore, the demands for increasing the cost-efficiency and competitiveness of the services began to rise at the turn of the millennium. Quality management and one of its main principles – systematic feedback based on field measurements – was proposed a solution for these challenges. UPM-Kymmene Corporation’s quality control system was set as a starting point for the quality management framework. Next the service processes were modelled, factors influencing the variation of the regenerations results and costs were analysed. Finally, the effect of quality management interventions on the activities of local Forest Owners’ Associations (FOAs) was studied through mail surveys.

Jointly set targets as a starting point for quality work

In Southern Finland, there is a limited set of regeneration chains, which represent the different varieties of the forest regeneration services. The most common of these varieties are planting of Norway spruce (Picea abies), direct seeding of Scots pine (Pinus sylvestris, planting of silver birch (Betula pendula), or natural regeneration of Scots pine. The two most common ones – Norway spruce planting and Scots pine direct seeding – were chosen for this study. In the case of Norway spruce planting, the definition used for a good regeneration result at stand level was 1600 conifer crop-trees per ha. Respectively, in the case of Scots pine direct seeding, a good regeneration result was defined as 3000 pine seedlings per ha at stand level. The number of pine seedlings consisted of both sown and naturally regenerated ones.

According to the results of this thesis, FOAs provided heterogeneous services with varying quality and costs. For example, in the context of Norway spruce planting, the proportion of good-quality stands varied from 30% to 90%. Respectively, in the case of Scots pine direct seeding, the proportion of good-quality stands varied from 0% to 80%. Since the assumptions of quality management for mass production in free markets were not completely valid, Lillrank’s classification of production processes was used in the construction of the applicable quality management framework. This classification fit well for the modelling of the service routines required. This tentative framework was created for the service providers for further testing.

Counting of the seedlings from the sample plot, the diameter of which was 2,52 m. Photo: Ville Kankaanhuhta

Framework for the development of local service routines

Main factors influencing good regeneration quality were the selection of appropriate regeneration methods and the way they were executed. The joint analysis of the main causes for variation, design of appropriate routines, and further development of these activities together with the forest owner will be the main elements for value-adding, long-lasting, customer relationships.

The cost–quality analysis of the two most common forest regeneration chains of Southern Finland revealed the improvement potential for cost-efficient forest regeneration services. In the case of Norway spruce planting, regeneration costs were only weakly related to quality. An extra investment of 100€ increased the number of crop-trees by 33/ha. In the case of Scots pine direct seeding, a significant positive correlation was found. An extra investment of 100€ increased the number of pine seedlings by 654/ha. However, the selection of this chain of regeneration for the MT (Myrtillus type) and more fertile site types produced poor regeneration results. In the case of Norway spruce planting, the most important factor explaining the outcomes was soil preparation: selection of mounding produced better results than patching and disc trenching. The further search for root causes behind the cost–quality relationship of Norway spruce planting and Scots pine direct seeding produced unexpected results. The hypothesised influence of more challenging site fertility and soil texture types on the cost of regeneration activities did not emerge as significant. There was no extra investment in regeneration activities, for example, on more fertile sites or fine soils.

Quality work enhanced the adoption of best practices

The jointly analysed feedback from the quality control inventories enabled development work that concentrated on the most significant causes for the variation of regeneration results. The effect of quality work could be observed in the resourcing of soil preparation operations, and in the change of prevailing soil preparation methods towards best practices. In addition, the efforts to increase the knowledge and skills of the operators of soil preparation machines and planting workers were at a higher level among the quality-work-participant FOAs compared with the non-participant ones.

Further information:

Ville Kankaanhuhta
Finnish Forest Research Institute, Suonenjoki Unit
Email: ville.kankaanhuhta(@)metla.fi

Dissertation:

http://dx.doi.org/10.14214/df.174
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