Holozäne Vegetationsentwicklung im hinteren Klostertal (Vorarlberg, Österreich) und Hinweise zur prähistorischen Landwirtschaft auf Grund palynologischer Untersuchungen

Both climate change and anthropogenic disturbance affect vegetation composition, but it is difficult to separate these drivers of vegetation change from one another. A better understanding of past vegetation dynamics is necessary to disentangle the influence of different forcing factors and assess future vegetation change. Here we present the first multi-proxy palaeoecological study combining sedimentary ancient DNA (sedaDNA), pollen, spores, stomata, charcoal and plant macrofossils from the Alps. We reconstructed the Holocene vegetation dynamics and fire history at Lago Inferiore del Sangiatto (1980 m asl), a small lake in the subalpine belt of the Ossola region, Italian Lepontine Alps. Afforestation in response to climate warming started at 10,700 cal yr BP with Larix decidua and tree Betula, which formed open forests together with Pinus cembra from 10,500 cal yr BP onwards. Human impact on the regional vegetation started at 5100 cal yr BP, resulting in expansions of Picea abies and Alnus viridis and the collapse of Abies alba. Species response models and ordination analysis show that livestock grazing and fire were major drivers of vegetation change at Lago Inferiore del Sangiatto during the late Holocene. Finally, increasing human impact during the Bronze (ca. 4200–2900 cal yr BP) and Iron Age (ca. 2900–2000 cal yr BP) led to the formation of species-rich larch meadows and alpine pastures that are still dominant today. The palaeoecological data suggest that under projected climate change and land abandonment, the treeline ecotone will likely shift to higher altitudes, leading to important changes in species composition and increasing the risk of biodiversity loss.

Pollen analysis supported by 25 accelerator mass spectrometry (AMS) 14C dates from the Tăul Negru peat bog (1143 m) in the Lăpuş Mountains (Eastern Carpathians, Romania) is used to reconstruct the Holocene vegetation history of this mountain region. The vegetation record at Tăul Negru starts at c. 10,500 cal yr BP with dense montane forests dominated by Picea abies (spruce) and Ulmus (elm). Corylus avellana (hazel) spread after 10,000 cal yr BP and reached maximum frequencies between 9000 and 7000 cal yr BP before decreasing. Thereafter, Picea prevailed in the forests with Carpinus betulus (hornbeam) expanding after 5700 cal yr BP, attaining maximum representation at 4200 cal yr BP. Fagus sylvatica (beech) spread from 4800 cal yr BP onwards with a short decline around 3700 cal yr BP. Mass expansion resumed afterwards, leading to the ultimate recession of Picea, Corylus and Ulmus. Fagus predominates the forests to the present. Small-scale human influence on the landscape (cereal-type pollen grains, Poaceae, and Plantago lanceolata) first appeared after 6000 cal yr BP. Further anthropogenic impact was detected after 5000 cal yr BP, and was slightly stronger between 2300 cal yr BP and the twelfth century AD with regular and increasing appearances of primary and secondary cultural indicators. Large-scale forest clearing in the lowlands and foothills with more agriculture led to the development of the modern cultural landscape in the last 500 years.

Treeline and timberline dynamics on the northern and southern slopes of the Retezat Mountains (Romania) during the late glacial and the Holocene

Long-term vegetation dynamics along altitudinal and longitudinal gradients in the Hyrcanian forest region (northern Iran)

The Carpathian Mountains were one of the main mountain reserves of the boreal and cool temperate flora during the Last Glacial Maximum (LGM) in East-Central Europe. Previous studies demonstrated late glacial vegetation dynamics in this area; however, our knowledge on the LGM vegetation composition is limited due to the scarcity of suitable sedimentary archives. Here we present a new record of vegetation, fire and lacustrine sedimentation from the youngest volcanic crater of the Carpathians (Lake St Anne, Lacul Sfânta Ana, Szent-Anna-to) to examine environmental change in this region during the LGM and the subsequent deglaciation. Our record indicates the persistence of boreal forest steppe vegetation ( Pinus sylvestris , Pinus mugo , Pinus cembra , Betula , Salix , Populus , Picea abies ) in the foreland and low mountain zone of the East Carpathians and Juniperus shrubland at higher elevation. We demonstrate attenuated response of the regional vegetation to maximum global cooling. Between ~22,870 and 19,150 cal yr BP we find increased regional biomass burning that is antagonistic with the global trend. Increased regional fire activity suggests extreme continentality likely with relatively warm and dry summers. We also demonstrate xerophytic steppe expansion directly after the LGM, from ~19,150 cal yr BP, and regional increase in boreal woodland cover with Pinus and Betula from 16,300 cal yr BP. Plant macrofossils indicate local (950 m a.s.l.) establishment of Betula nana and B . pubescens at 15,150 cal yr BP, Pinus sylvestris at 14,700 cal yr BP and Larix decidua at 12,870 cal yr BP. Pollen data furthermore hints at the regional presence of some temperate deciduous trees during the LGM ( Fagus sylvatica , Carpinus betulus , Corylus avellana , Fraxinus excelsior , Ulmus ). We also present pollen based quantitative climate reconstruction from this site and discuss its connection with other climate reconstructions and climate modeling results.

The absence of disturbances promoted Late Holocene expansion of silver fir (Abies alba) in the Bohemian Forest

Timing of major forest compositional changes and tree expansions in the Retezat Mts during the last 16,000 years

Holocene vegetation history in the upper forest belt of the Eastern Romanian Carpathians

Глобальні зміни клімату вже зараз суттєво змінили умови ведення лісового господарства в Українських Карпатах. Зокрема внаслідок масового всихання ялини багато підприємств змушені переорієнтовувати свої лісівничі заходи на вирощування товарної деревини інших порід. Виявлено два основних напрями кліматогенних змін у лісах регіону: зміна едафотопів лісових ділянок у напрямі покращення їхньої родючості з одночасним зменшенням вологості, зміна конкурентоздатності різних деревних видів, зміна породного складу лісів. Найбільші зміни відбуваються в ялинових лісах, де місце ялини, що всихає, природним шляхом займають ялиця і бук, однак під час створення лісових культур вибір головної породи може бути й іншим. Тому актуальним є виявлення закономірностей цих змін для правильного вибору головних порід за типами лісу і висотними рослинними смугами. Тенденції динаміки лісорослинних умов і породного складу лісів регіону були ідентифіковані за відомчими даними метеостанцій та лісовпорядкування. Встановлено, що кліматогенні зміни лісів Українських Карпат відбуваються у таких напрямах: а) дубово-букові ліси трансформуються в буково-дубові зі зміною гігротопу зі «свіжого» на «сухий»; б) буково-ялицеві ліси – в ялицево-букові зі зміною гігротопу з «вологого» на «свіжий»; в) грабово-букові ліси – в грабово-дубово-букові зі зміною гігротопу з «вологого» на «свіжий»; г) смереково-буково-ялицеві ліси – в смереково-ялицево-букові або ялицево-букові зі зміною гігротопу з «вологого» на «свіжий»; д) буково-ялицево-смерекові ліси – в смереково-ялицево-букові або ялицево-букові зі зміною гігротопу з «сирого» і «вологого» на «свіжий»; е) щільнодернинні луки та полонини інтенсивно заростають смерековими, ялівцевими та душекієвими угрупованнями. Констатується нагальна потреба в лісотипологічному картуванні лісогосподарських підприємств Карпатського регіону під час проведення їх повторного лісовпорядкування.

Abstract. The ongoing ecological conversion of mountain forests in central Europe from widespread Picea monocultures to mixed stands conceptually also requires a historical perspective on the very long-term, i.e. Holocene, vegetation and land-use dynamics. Detailed sources of information for this are palynological data. The Erzgebirge in focus here, with a maximum height of 1244 m a.s.l., represents an extreme case of extensive historical deforestation since the Middle Ages due to mining, metallurgy, and other industrial activities, as well as rural and urban colonisation. For this regional review we collected and evaluated 121 pollen diagrams of different stratigraphic, taxonomic, and chronological resolution. This number makes this region an upland area in central Europe with an exceptionally high density of palynological data. Using well-dated diagrams going back to the early Holocene, main regional vegetation phases were derived: the Betula–Pinus phase (ca. 11 600–10 200 cal yr BP), the Corylus phase (ca. 10 200–9000 cal yr BP), the Picea phase (ca. 9000–6000 cal yr BP), the Fagus–Picea phase (ca. 6000–4500 cal yr BP), the Abies–Fagus–Picea phase (ca. 4000–1000 cal yr BP), and the anthropogenic vegetation phase (ca. 1000–0 cal yr BP). Some diagrams show the presence or even continuous curves of potential pasture and meadow indicators from around 2000 cal BCE at the earliest. Even cereal pollen grains occur sporadically already before the High Medieval. These palynological indications of a local prehistoric human impact also in the higher altitudes find parallels in the (geo-)archaeologically proven Bronze Age tin placer mining and in the geochemically proven Iron Age metallurgy in the Erzgebirge. The pollen data show that immediately before the medieval clearing, i.e. beginning at the end of the 12th century CE, forests were mainly dominated by Fagus and Abies and complemented by Picea with increasing share towards the highest altitudes. According to historical data, the minimum of the regional forest cover was reached during the 17th–18th centuries CE. The dominance of Picea in modern pollen spectra is caused by anthropogenic afforestation in the form of monocultures since that time. Future palynological investigations, preferably within the framework of altitudinal transect studies, should aim for chronologically and taxonomically high-resolution and radiometrically well-dated pollen diagrams from the larger peatlands.

Response of prehistoric human activity to environmental changes since 7,000 cal yr BP in Nenjiang River Basin, northeast China

Vegetation and environmental responses to climate forcing during the Last Glacial Maximum and deglaciation in the East Carpathians: attenuated response to maximum cooling and increased biomass burning

Late Quaternary dynamics of forest vegetation on northern Vancouver Island, British Columbia, Canada

Postglacial vegetation history of Orcas Island, northwestern Washington

Late-Glacial and Holocene forest dynamics at Steregoiu in the Gutaiului Mountains, Northwest Romania