Late Holocene Changes in Vegetation of the Mrągowo Lakeland (Ne Poland) as Registered in the Pollen Record From Lake Salęt

Abstract

Pollen analysis of sediments from the upper part of bottom deposits from Lake Salęt allowed reconstruction of main stages of the Late Holocene vegetation transformation in the Mrągowo Lake District (from ca. 3600 cal. years BC) and to correlate some of these changes with immigration and economic activity of local human groups. Significant spreading of secondary semi-natural birch forest, development of horn beam forest and increasing importance of anthropogenic open communities were the most characteristic features of vegetation evolution. A definite break down of elm took place between 2900 and 2500 cal. years BC, slightly after increased contribution of birch in wood lands. Disappearance of hazel around 1200 cal. years BC, accompanied by expansion of horn beam has been observed and should be linked with activity of the Ząbie-Szestno type culture and the Lusatian culture tribes during the Bronze Age, but not with a climate change. Considerable intensification of settlement processes recorded in the younger part of the Subatlantic chronozone was one of the important reasons that were responsible for quick changes in forest structure. Strong and continued deforestation started as early as the end of the 10th century AD and was substantially intensified in the first half of the 13th century.

Was it ‘terra desolata’? Conquering and colonizing the medieval Prussian wilderness in the context of climate change.

“…This species was particularly devastated in periods of intensive settlement, whereas periods of reduced anthropopressure allowed a partial regeneration of hornbeam. This last process is evident in pollen spectra from the Lake Salęt profile, related to the decline of older prehistoric cultures (Szal et al, 2014a, 2014b), and in some other studies from this region of Poland (e.g. Wacnik et al, 2012).…”

“…The pollen diagrams presented in this paper include two pollen zones, Carpinus-Betula-Quercus and Pinus-Picea-NAP (Figures 3-5). Their place within the full Holocene pollen succession registered in the Lake Salęt profile was presented in previous papers (Szal et al, 2014a(Szal et al, , 2014b. Both these pollen zones were divided into subzones, which reflect four subsequent phases of natural and anthropogenic changes in vegetation during the period from the mid-10th to the mid-16th centuries AD.…”

“…AD 950-1020. This is the final developmental stage of the Betula-dominated forests (Szal et al, 2014a(Szal et al, ,2014b. These woodlands were secondary semi-natural communities, which formed in habitats transformed by exploitation during the earlier settlement stage.…”

Temporal variation of prehistoric human settlement recorded in the oxbow lake deposits of San river (Sandomierz Basin, SE Poland)

“…The changes in the settlement intensity could have stimulated a secondary succession on postagricultural fallow lands and unused grasslands. The local range of this phenomenon is supported by the fact that it has not been known from the Sandomierz Basin so far but it was observed for example in northern and northeastern Poland (Wacnik et al, 2012;Szal et al, 2014). Significant decrease of arboreal taxa (such as pine, oak, and spruce) which started already in the 1 st century AD suggest the renewed reduction of the woodland cover.…”

Last 2400 yrs. Environmental changes and human activity recorded in the gyttja-type bottom sediments of the Młynek Lake (Warmia and Masuria Region, northern Poland)

“…Młynek Lake sediments is caused by a very local record from a small lake. Decline of Fagus sylvatica is related to continental climate and is visible in a pollen diagram from Salęt Lake (Szal et al 2014a), Mikołajki Lake (Ralska-Jasiewiczowa 1989), Żabińskie Lake (Wacnik et al 2016) and Wigry Lake (Kupryjanowicz 2007 constant settlement in the neighborhood of the Salęt Lake occurred with a very short decline of human impact only in 880-980 AD (Szal et al 2014a). Cited examples of palynological reconstruction of vegetation changes under climatic conditions and human impact reflect differences between a record from the Młynek Lake and much larger and predisposed regional view of environmental history.…”