The role of tree composition in Holocene fire history of the hemiboreal and southern boreal zones of southern Sweden, as revealed by the application of the Landscape Reconstruction Algorithm : Implications for biodiversity and climate-change issues

• We present a quantitative reconstruction of local forest history at two sites, Stavsåkra (hemiboreal zone) and Storasjö (southern boreal zone), in southern Sweden (province of Småland) to evaluate possible causes of contrasting Holocene fire histories in mid- and late Holocene. The Landscape Reconstruction Algorithm (LRA) is applied to evaluate between-site differences in the relative abundance of deciduous trees and Pinus (pine) and landscape/woodland openness during the Holocene. The LRA estimates of local vegetation abundance are compared with other proxies of local vegetation, that is, plant and beetle remains. The LRA results suggest that Pinus was a major tree taxon in the woodlands of Storasjö during mid- and late Holocene, while Tilia(linden) and Betula (birch) were dominant at Stavsåkra. The contrasting fire histories are shown to be strongly related to between-site differences in tree composition during mid-Holocene, 4000–2000 BC in particular. The archaeological/historical and beetle data indicate contrasting land uses from c. 1000BC (late Bronze Age/early Iron Age), grazing in open Calluna heaths at Stavsåkra and woodland grazing at Storasjö. Between-site differences in fire historyduring late Holocene were likely due to different land-use practices. Between-site differences in tree composition in mid-Holocene are best explainedby local climatic and geological/geomorphological differences between the hemiboreal and southern boreal zones of Småland, which might also be the primary cause of between-site differences in land-use histories during late Holocene. Maintenance of biodiversity at the landscape scale in the studyarea requires that existing old pine woodlands and Calluna heath are managed with fire and cattle grazing. Further climate warming might lead to higherprobabilities of climate-induces fire, in particular in pine-dominated woodlands.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Multidisciplinär geovetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geosciences, Multidisciplinary (hsv//eng)

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geologi (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geology (hsv//eng)

Nyckelord

biodiversity

climate change

fire

forest history

Holocene

Landscape Reconstruction Algorithm

Paleoecology

Paleoekologi

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)