Management of border zone forests of transmission line corridors

Abstract

The resilience of power transmission has been required in Finland by the electricity market act since 2013. As a consequence, Finnish electricity companies began to manage border zone forests of transmission lines more extensively. Five years later, the experiences of experts representing different interest groups in border zone forest management projects along medium-voltage (MV) and high-voltage (HV) transmission lines were summed and analysed in this study utilising argument Delphi method. The first-round interview included 13 experts, and the second-round survey 33 experts representing electricity companies, forest management associations, forest companies and forest machine operators.

According to the results, landowners’ knowledge of border zone forest management should be increased by video clips linked to electricity companies’ web-pages, project-specific work demonstrations and demonstrations in exhibitions and other events. Increased knowledge and activation of landowners is crucial when a new MV transmission line corridor is being built. This could offer cost-efficient possibilities to extend joint harvestings in the vicinity forests.

Planning of border zone forest operations and marking estate borders, border zone forests and dangerous spots were found helpful and increase the safety and productivity of harvesting operators. Harvestings by cut-to-length harvesters in the vicinity of transmission lines require calm and experienced harvester operators.

According to the experts, on MV transmission lines, the corridor should be utilised in harvesting operation if possible. If a strip road is needed, it should be placed next to the transmission line corridor, enabling felling away from the transmission line. In HV transmission line border forest operations, the closest strip road to transmission line should be placed on the border zone. Strip road planning of individual thinning nearby transmission lines should consider the need for strip road in the border zone as well.

As a conclusion, information exchange between interest groups of border zone forest management projects and guidance for landowners is crucial for successful border zone forest management projects and needs to be further enhanced.