Inventering av brandgynnade arter på Innerstön

Abstract: Today companies are working actively to put out uncontrolled fires to protect society and the economic value of the forest. Burning is done with the aim to create controlled environments due to human influence is unusual in today's landscape. Holmen Skog works actively with conservation, and burn at least 5 % of its forest holdings to achieve the certification requirements as FSC and PEFC. Innerstön is an island in Hudiksvall´s archipelago and is owned mostly by Holmen Skog AB, the plan is that the island will be burned for conservation purposes for at least 16 years. The island is divided into eight areas. Each of them will be burned every second year beginning in area 1, two years later in area 2, and so on. In that way area 1 will burn again 16 years after the first firing if the timetable is met. This will create a unique environment that suits favored fire and fire-dependent species. It sounds obvious that conservation burning is positive for fire-dependent and fire-favored species. As many large fire areas have been unusual for a long time in our country, many species have become rare and sometimes very threatened. Inventory of areas where conservation burnings occurred, detects if the environment created managed to create habitats for endangered species. The inventory at Innerstön was done the summer of 2015, two years after the first burning on the island. The species included in the inventory were Stephanopachys linearis and Stephanopachys substriatus, Melanophila acuminata, Geranium bohemicum and Daldinia zoculata. The survey conducted by circular plots (100 m2) were randomly selected by a grid laid out over an orthophoto of the island. The eight burning areas got five to seven plots depending on their size. The area surveyed in this work had five areas, one area was added later because it was interesting because it had a large amount of dead wood. On the areas the species above and the deadwood was inventoried. The species was also searched outside the plots, so-called “direct search”, because species could rather be found on suitable substrates which couldn´t be found within the plots. Suitable substrates was found for all species except Daldinia zoculata, which requires a greater amount of fire-killed wood of birch. Daldinia zoculata needs more fire killed birch forest. The other parts of the island that will be burned in the future contain more birch and therefore the species could be found in the future. Geranium bohemicum was not found on any plots, but was found during the “direct search”. The pine hood beetles were not found on the island, not too surprisingly when previous inventories did not indicate any findings on the east coast. The species might get a foothold in the future. This can be possible due to the increasing interest in conservation and burn. The fact that Innerstön will be burned for a long time, perhaps more than 20 years, it is of special interest. 1 The environmental protection burning that occurs on Innerstön is unique and can become a heaven for fire-favored and fire-dependent species. The frequent fires and the island's easily controlled geography makes species inventories easy. Today the Geranium bohemicum is to be found on the island and suspected cases of Melanophila acuminate was found. Those two specialized species are already on the island, which is positive. The fact that suitable substrate was found on the island makes it possible to find other fire-favored species.