Research article2009Peer reviewed
Forest history and the development of old-growth characteristics in fragmented boreal forests
Jonsson, Mari T.; Fraver, Shawn; Jonsson, Bengt Gunnar
Abstract
Can small and isolated high-conservation value forests (e.g. designated woodland key habitats) maintain old-growth forest characteristics and functionality in fragmented landscapes? To what extent have past disturbances (natural and anthropogenic) influenced the development of old-growth characteristics of these forests? How long does it take for selectively cut stands to attain conditions resembling old-growth forests?Southern boreal zone of central Sweden.We linked multiple lines of evidence from historical records, biological archives, and analyses of current forest structure to reconstruct the forest history of a boreal landscape, with special emphasis on six remaining core localities of high-conservation value forest stands.Our reconstructions revealed that several of these stands experienced wildfires up to the 1890s; all had been selectively harvested in the late 1800s; and all underwent substantial structural and compositional reorganization over the following 100-150 years. This time interval was sufficient to recover considerable amounts of standing and downed dead wood (mean 60.3 m(3) ha(-1)), a range of tree ages and sizes (mean basal area 32.6 m(2) ha(-1)), and dominance of shade-tolerant spruce. It was insufficient to obtain clearly uneven tree age structures and large (> 45 cm diameter) living and dead trees. Thus, these forests contain some, but not all, important compositional and structural attributes of old-growth forests, their abundance being dependent on the timing and magnitude of past natural and anthropogenic disturbances. Our landscape-level analysis showed marked compositional and structural differences between the historical forest landscape and the present landscape, with the latter having a greater proportion of young forests, introduction of non-native species, and lack of large trees and dead wood.The remnant high-conservation value stands were not true representatives of the pre-industrial forests, but represent the last vestige of forests that have regenerated naturally and maintained a continuous tree cover. These traits, coupled with their capacity for old-growth recovery, make them valuable focal areas for conservation.
Keywords
Coarse Woody Debris; Dendrochronology; Fire Ecology; Historical Records; Land-Use History; Picea Abies; Southern Boreal Zone; Stand Dynamics; Stand Reconstruction; Sweden; Woodland Key Habitats
Published in
Journal of Vegetation Science
2009, Volume: 20, number: 1, pages: 91-106
Sustainable Development Goals
Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss
UKÄ Subject classification
Environmental Sciences related to Agriculture and Land-use
Publication identifier
DOI: https://doi.org/10.1111/j.1654-1103.2009.05394.x
Permanent link to this page (URI)
https://res.slu.se/id/publ/27659