The role of climate, human impact and fire on forestdynamics, landscape development and biodiversity during the last 10,500 calendar years in southern Sweden : a synthesis ofthe multiproxy study of Stavsåkra bog

• In this paper, we discuss the contribution of a multi-proxy approach to the study of long-term forest dynamics and biodiversity (at the species to landscape levels), using the records from a palaeoecological investigation at Stavsåkra, province of Småland, southern Sweden. The results from all the proxies, i.e. beetles, pollen, plant macrofossils, charred plant remains, andmicroscopical and macroscopical charcoal, are compared. The study of all charred material has the advantage of providing valuable information on the local plants that burnt (charred plant remains) and a more robust reconstruction of the local fire history and its regional representativeness. The plant macrofossil analysis allows specifying the origin of pollen from plants that may grow either on the coring site (fen or bog) or in the surrounding vegetation on dry land. This is particularly crucial for the interpretation of pollen types such as Gramineae, Cyperaceae, and Ericaceae (Calluna, Empetrum and Vaccinium species). The origin of Calluna pollen (bog, forest floor or open heaths) is often difficult to establish with certainty. In this study, the total absence of Calluna remains in the plant macrofossil record, and theoccurrence of beetle species dependant on Calluna heath ecosystems from the Late Neolithic (ca. 2000 BC) suggest that Calluna pollen originated from the surrounding vegetation, probably from the under-storey of the pine forests in early Holocene, and from the Calluna heaths during late Holocene. The beetle record further strengthens the inferred fire history by providing findings of species dependant on fire and, therefore, confirms the existence ofrelatively large burnt areas. Moreover, the insect analysis provides information on vegetation characteristics that cannot be inferred from pollen and plant macrofossil with certainty - or cannot be inferred at all - such as the forest structure in terms of openness, sun exposure, occurrence of dead wood and old trees. The results at Stavsåkra demonstrate that disturbances such as fire, forest clearance, and grazing can have both positive and negative impacts onbiodiversity, depending on the character and intensity of the disturbance in both time and space, and on the type of biota concerned, in this case plants and beetles.

Ämnesord

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

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

Nyckelord

Holocene

Climate

Human impact

Fire

Biodiversity

Southern Sweden

Quaternary geology

Kvartärgeologi

Miljövetenskap

Environmental Science

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)