The role of climate, forest fires and human population size in Holocene vegetation dynamics in Fennoscandia

Abstract

Questions We investigated the changing role of climate, forest fires and human population size in the broad‐scale compositional changes in Holocene vegetation dynamics before and after the onset of farming in Sweden (at 6,000 cal yr BP) and in Finland (at 4,000 cal yr BP). Location Southern and central Sweden, SW and SE Finland. Methods Holocene regional plant abundances were reconstructed using the REVEALS model on selected fossil pollen records from lakes. The relative importance of climate, fires and human population size on changes in vegetation composition was assessed using variation partitioning. Past climate variable was derived from the LOVECLIM climate model. Fire variable was reconstructed from sedimentary charcoal records. Estimated trend in human population size was based on the temporal distribution of archaeological radiocarbon dates. Results Climate explains the highest proportion of variation in vegetation composition during the whole study period in Sweden (10,000–4,000 cal yr BP) and in Finland (10,000–1,000 cal yr BP), and during the pre‐agricultural period. In general, fires explain a relatively low proportion of variation. Human population size has significant effect on vegetation dynamics after the onset of farming and explains the highest variation in vegetation in S Sweden and SW Finland. Conclusions Mesolithic hunter‐gatherer populations did not significantly affect vegetation composition in Fennoscandia, and climate was the main driver of changes at that time. Agricultural communities, however, had greater effect on vegetation dynamics, and the role of human population size became a more important factor during the late Holocene. Our results demonstrate that climate can be considered the main driver of long‐term vegetation dynamics in Fennoscandia. However, in some regions the influence of human population size on Holocene vegetation changes exceeded that of climate and has a longevity dating to the early Neolithic.

The environment they lived in: anthropogenic changes in local and regional vegetation composition in eastern Fennoscandia during the Neolithic

“…Mean Z-scores are then computed at 200-year intervals. For the study of fire dynamics at the regional scale, we used the composite charcoal curve already published in Kuosmanen et al (2018), constructed by grouping together all available records in southeast Finland. Differently from Kuosmanen et al (2018), where the authors focused on the period 10,000-1,000 (i.e.…”

“…soil characteristics, characteristic traits of plant species, extreme disturbance events) and/or land use factors. Recent studies have shown that climate and land use are important drivers of vegetation change during the Holocene in northern Europe and Fennoscandia (Reitalu et al 2013;Kuosmanen et al 2016Kuosmanen et al , 2018Marquer et al 2017). While climate is the dominant factor during the first half of the Holocene, land use becomes one of the primary drivers during the last 2,500 years.…”

The fire history in pine forests of the plain area in the Pechora-Ilych Nature Biosphere Reserve (Russia) before 1942: possible anthropogenic causes and long-term effects

“…The fires had an effect on the structure, dynamics and biogeochemical cycles in forests (Goldammer & Furyaev, 1996;Randerson et al, 2006;Smirnova et al, 2017). At present there is an ongoing debate on causes of fires and the role of traditional land use (Bowman et al, 2011;Vanniиre et al, 2016;Kipfmueller et al, 2017;Kuosmanen et al, 2018;Dietze et al, 2018). The arguments are going on for a long time because the occurrence and spread of fires in different territories depended on a variety of both anthropogenic and natural causes, which vary on spatial and temporal scales (Whitlock et al, 2010).…”

Millennial to centennial vegetation change

“…Dudová, Hájek, Petr, and Jankovská (), as well as Kuosmanen et al. (), use multivariate analysis to explore the strength of drivers for regional vegetation composition through time. They find that the strength of the altitudinal gradient increased through time in the Jeseníky Mts in Central Europe (Dudová et al., ) and identify climate change to explain most of the regional patterns in vegetation change in Fennoscandia (Kuosmanen et al., ).…”

“…(), use multivariate analysis to explore the strength of drivers for regional vegetation composition through time. They find that the strength of the altitudinal gradient increased through time in the Jeseníky Mts in Central Europe (Dudová et al., ) and identify climate change to explain most of the regional patterns in vegetation change in Fennoscandia (Kuosmanen et al., ). Although fire is an important disturbance agent and its frequency can determine vegetation patterns, it does not play an important role for the regional vegetation change in Fennoscandia (Kuosmanen et al., ).…”