FIELDTRIP TO MYSZYNIEC

On the 14th of October, we visited the pilot area in Myszyniec. First, we received a warm welcome at the headquarters of the Myszyniec Forest District of the Polish State Forest Administration (LP) by Marek Dzieżyk, Head of the Forest District, Michał Stępień, Deputy Head of the Forest District, Magdalena Stępień, Forest Service Senior Specialist for silviculture, tree selection, seed production and tree nursery, and Katarzyna Biedulska, Forest Service Specialist for forest protection, fire protection and education. The forest managers told us about the forest fire in May 2014, which burned and destroyed almost 100 hectares of pine forest. The fire was started by an arsonist. About 90 % of the burnt area is managed by the Polish State Forest Administration. The forest in this area stands on very poor and sandy soils. Rapid regeneration is important to protect the site from erosion. In some parts of the burnt area, there were even shifting sand dunes with almost no organic soil material. The biggest challenge during the firefighting operation was to provide access for the fire engines. The forest roads on the sandy ground were not stable enough for the heavy trucks. Fortunately, a storm with heavy rainfall helped the firefighters. To regenerate the degraded forests, it was decided to collaborate with local forestry scientists and establish three zones: a no-management zone with natural regeneration, a zone with artificial regeneration, and a combined option with natural and artificial regeneration. The research area was expanded to approximately130 hectares to include surrounding stands that were damaged but not destroyed by the fire. This study aimed to investigate the ability of natural regeneration to protect the soil from aeolian erosion. Scots pine (Pinus sylvestris) and birch (Betula pendula) were used for artificial regeneration, as only a few other tree species can survive these harsh conditions. Planting was a real challenge as 7,900 Scots pine seedlings per hectare were used to replant the pine forests and all trees were planted by hand. In some areas, up to 40 % mortality was recorded in the first year after planting due to drought. In the artificial regeneration zone, the soil was prepared for planting by ploughing furrows. This was done to facilitate the planting of trees, to reduce competing vegetation, and to create favorable small sites by directing rainwater to the seedlings. Unfortunately, soil preparation was not effective as the furrows were filled with the sandy soils of the surrounding small hills and covered the seedlings. Nevertheless, most of them managed to survive this.

10 years after the forest fire, the artificial regeneration measures showed good results. Aeolian erosion has been stopped within a few years by reforestation. To maintain the growth of Scots pine, protection against browsing is needed. As moose and red deer threaten the growth of the trees, the terminal shoots have been covered with a white substance to prevent damage by game. Scots pines planted and growing on the sand dunes had significantly smaller needles compared to those growing in fertile areas. The forest managers believe that such shorter needle sizes are a result of disproportionately higher allocation of resources to the development of healthy root systems compared to growth. Interestingly, natural regeneration also managed to establish itself even under these poor conditions, protecting the soil from erosion. But only birch was able to grow on a large scale. Other tree species were rarely found. Therefore, further information on the long-term development of birch stands is needed, as birch is mostly a pioneer species under these climatic conditions, which is not able to establish stable late successional and long-lived forests like Scots pine. In the unmanaged area, the deadwood of the burnt trees remained completely intact. It was evident that dead wood decomposes quickly here due to the relatively humid and warm climatic conditions. This shows that forest regeneration is very important to protect the sandy soils from aeolian erosion. Deadwood can only fulfil this function for a short time.

Written by Stefan Ebner