Differences in stand characteristics between brook-side key habitats and managed forests in southern Finland

Abstract

Preservation of small habitat patches termed as "woodland key habitats" or "especially important habitats" in the Finnish Forest Act has become an integral part of biodiversityoriented forest management. Forest Act habitats belong to particular habitat types defined in the act, and they are supposed to have natural-like stand characteristics. However, very little is known about the actual stand structure in the designated habitats. Our aim was to compare stand characteristics between brook-side key habitats and comparable managed forests as controls. Seven study areas were selected from four regions across southern Finland. Within each study area ten key habitats and ten controls (140 stands) were randomly selected. Living and dead trees and cut stumps were measured in each stand within a 0.2 ha plot. The average degree of previous cutting was significantly lower whereas the volume of dead wood, volume of deciduous trees, and stand diversity were each significantly higher in key habitats than controls. The average volume of dead wood was 11.7 m 3 ha -1 in key habitats and 6.5 m 3 ha -1 in controls. However, there was considerable variation among individual stands, and a large part of key habitats could not be distinguished from randomly selected control stands with respect to stand characteristics. The preservation of natural brook channels with their immediate surroundings is undoubtedly important for maintaining aquatic and semiaquatic biodiversity. Nevertheless, when complementing the forest conservation network in the future, main emphasis in selecting potentially valuable stands should be placed on important structural features such as dead wood and old trees.

Fungal community dynamics in relation to substrate quality of decaying Norway spruce (Picea abies [L.] Karst.) logs in boreal forests

“…Tree volume was calculated using equations based on species, DBH, height and taper curve functions (Laasasenaho, ) and calculated with the KPL program (Heinonen, ) following Siitonen et al . (). Stage of decay was estimated according to stem hardness and habitus.…”

Linking substrate and habitat requirements of wood-inhabiting fungi to their regional extinction vulnerability

“…At the stand scale, a number of habitat variables were derived from the living‐tree and dead‐wood measurements within the sample plot. The volumes of both living trees and dead‐wood objects were calculated using volume equations based on the measured DBHs, diameters, heights, and lengths (Laasasenaho 1982, Siitonen et al 2008). For the present analyses, we calculated 1) the volume of living trees (m 3 ha −1 ), 2) the volume of CWD with a minimum basal diameter of 10 cm and a minimum length of 1.3 m (m 3 ha −1 ), and 3) the basal area of cut stumps (m 2 ha −1 ).…”

“…In reality, the forest landscape is hardly 'blackand-white'; also the matrix of managed forests provides habitat for many polypores. However, we still lack knowledge about to what extent different species can utilize the matrix of managed forests (Kruys et al 1999, Hottola andSiitonen 2008). The occurrence of polypores is also likely to vary as a result of other large-scale factors, because of differences in macroclimate, forest vegetation type, tree species composition, and landscape structure.…”

Diversity and distribution of Finnish aphyllophoroid and heterobasidioid fungi (Basidiomycota): An update

“…The decay stage classification (1-5) of dead wood was carried out according to Renvall (1995), with stage 1 referring to hard dead wood and stage 5 referring to completely decayed wood. This is widely used method for all tree species in the boreal forests (e.g., Korhonen 2009;Siitonen et al 2009). The diameter of dead wood was measured at chest height if the trunk was complete and from the middle if it was broken.…”