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Palaeolimnological and sedimentary responses to Holocene forest retreat in the Scandes Mountains, west-central Sweden

Hammarlund, Dan LU ; Velle, G; Wolfe, BB; Edwards, TWD; Barnekow, Lena LU ; Bergman, Jonas LU ; Holmgren, S; Lamme, S; Snowball, Ian LU and Wohlfarth, B, et al. (2004) In The Holocene 14(6). p.862-876
Abstract
A suite of analyses was performed on sediments accumulated during the last 10 700 years in Lake Spaime, a small, hydrologically open water body in the modern alpine tundra zone of the Scandes Mountains, west-central Sweden. The study aimed to evaluate (1) the nature of climate changes that forced the late-Holocene lowering of altitudinal tree limit in the region, the timing of which is known from prior studies based on radiocarbon dating of subfossil wood, and (2) the impact of these vegetational changes on an aquatic ecosystem. Arboreal pollen and plant macrofossil data confirm the persistence of trees in the lake catchment at least from c. 9700 cal. BP until c. 3700 cal. BP. Although growing-season temperature is commonly believed to be... (More)
A suite of analyses was performed on sediments accumulated during the last 10 700 years in Lake Spaime, a small, hydrologically open water body in the modern alpine tundra zone of the Scandes Mountains, west-central Sweden. The study aimed to evaluate (1) the nature of climate changes that forced the late-Holocene lowering of altitudinal tree limit in the region, the timing of which is known from prior studies based on radiocarbon dating of subfossil wood, and (2) the impact of these vegetational changes on an aquatic ecosystem. Arboreal pollen and plant macrofossil data confirm the persistence of trees in the lake catchment at least from c. 9700 cal. BP until c. 3700 cal. BP. Although growing-season temperature is commonly believed to be the dominant factor driving boreal forest tree-limit variations in the region, a chironomid-based reconstruction of mean July air temperature suggests that local deforestation during the late Holocene was not accompanied by a significant cooling. The tree-limit retreat was more likely caused by increasing effective moisture and declining length of the growing season. The ecohydrological response of Lake Spaime to this combination of climate and vegetational changes included a decline in primary productivity, as indicated by an abrupt decrease in sediment organic matter content, while associated increases in organic delta(13)C, delta(15)N and C/N point to diminished fluxes and altered balance of catchment-derived nutrients following deforestation. The decline in aquatic productivity is also marked by a distinct change in the mineral magnetic properties, from a high magnetic concentration assemblage dominated by fine-grained magnetite of biogenic origin to one dominated by background levels of coarse-grained detrital magnetite. (Less)
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keywords
Sweden, environmental magnetism, chironomidae, stable isotope geochemistry, lacustrine nutrient cycling, lake sediments, Holocene palaeoecology, alpine tree-limit dynamics
in
The Holocene
volume
14
issue
6
pages
862 - 876
publisher
SAGE Publications Inc.
external identifiers
  • wos:000225101900007
  • scopus:8644290242
ISSN
0959-6836
DOI
10.1191/0959683604hl756rp
language
English
LU publication?
yes
id
702b9183-49c6-484a-896e-383be7cf11ae (old id 260949)
date added to LUP
2007-10-29 11:14:16
date last changed
2017-11-05 03:42:50
@article{702b9183-49c6-484a-896e-383be7cf11ae,
  abstract     = {A suite of analyses was performed on sediments accumulated during the last 10 700 years in Lake Spaime, a small, hydrologically open water body in the modern alpine tundra zone of the Scandes Mountains, west-central Sweden. The study aimed to evaluate (1) the nature of climate changes that forced the late-Holocene lowering of altitudinal tree limit in the region, the timing of which is known from prior studies based on radiocarbon dating of subfossil wood, and (2) the impact of these vegetational changes on an aquatic ecosystem. Arboreal pollen and plant macrofossil data confirm the persistence of trees in the lake catchment at least from c. 9700 cal. BP until c. 3700 cal. BP. Although growing-season temperature is commonly believed to be the dominant factor driving boreal forest tree-limit variations in the region, a chironomid-based reconstruction of mean July air temperature suggests that local deforestation during the late Holocene was not accompanied by a significant cooling. The tree-limit retreat was more likely caused by increasing effective moisture and declining length of the growing season. The ecohydrological response of Lake Spaime to this combination of climate and vegetational changes included a decline in primary productivity, as indicated by an abrupt decrease in sediment organic matter content, while associated increases in organic delta(13)C, delta(15)N and C/N point to diminished fluxes and altered balance of catchment-derived nutrients following deforestation. The decline in aquatic productivity is also marked by a distinct change in the mineral magnetic properties, from a high magnetic concentration assemblage dominated by fine-grained magnetite of biogenic origin to one dominated by background levels of coarse-grained detrital magnetite.},
  author       = {Hammarlund, Dan and Velle, G and Wolfe, BB and Edwards, TWD and Barnekow, Lena and Bergman, Jonas and Holmgren, S and Lamme, S and Snowball, Ian and Wohlfarth, B and Possnert, G},
  issn         = {0959-6836},
  keyword      = {Sweden,environmental magnetism,chironomidae,stable isotope geochemistry,lacustrine nutrient cycling,lake sediments,Holocene palaeoecology,alpine tree-limit dynamics},
  language     = {eng},
  number       = {6},
  pages        = {862--876},
  publisher    = {SAGE Publications Inc.},
  series       = {The Holocene},
  title        = {Palaeolimnological and sedimentary responses to Holocene forest retreat in the Scandes Mountains, west-central Sweden},
  url          = {http://dx.doi.org/10.1191/0959683604hl756rp},
  volume       = {14},
  year         = {2004},
}