In the field in Swedish Lapland we will manipulate the rhizosphere across the mountain birch forest-tundra
heath ecotone using experiments ('girdling'; removal of bark, including phloem tissues) to reduce phloem transport of organic C to the roots.
Karelin, "Resources of organic carbon in the soils of tundra and forest-tundra
ecosystems in Russia," Russian Journal of Ecology, vol.
Three types of zonal environments (ecoregions) were selected to investigate soil properties and C[O.sub.2] emission intensity: forest-tundra
, south-taiga, and forest-steppe.
Modeling the influence of topographic barriers on treeline advance at the forest-tundra
ecotone in northwestern Alaska.
Cryosolic soils of three geographic zones of Yakutia: taiga forests, tundra and forest-tundra
were objects of research (see Fig.
Previous surveys of small mammals in Alaska (Cook and MacDonald 2004, 2006) identified a contact zone between 2 closely related species of the cinereus complex of shrews (Van Zyll de Jong 1991; Demboski and Cook 2003) along the forest-tundra
ecotone in northern Alaska.
The Koryaks are native to northeastern Siberia, on the northern part of the Kamchatka Peninsula and on the adjoining mainland, from the Taigonos Peninsula to the Bering Sea, areas that are characterised by sub-Arctic forest-tundra
Moose appeared in the forest-tundra
zones in the 1950s, occupied the Ponoy River area in the 1960-1970s, and population growth occurred to the north of the forest zone along the tributaries and rivers flowing into the Barents Sea.
Most well-drained sites in the northern Quebec forest-tundra
are colonized by lichen-heath communities and scattered black spruce (Picea mariana (Mill.) BSP.), woodlands, and krummholz (stunted spruce).
The pollen and macrofossil assemblages of zone F4 are indicative of a shrub-tundra or forest-tundra
. The strongest evidence for vegetation response to a severe climatic cooling comes from the abundance of arctic/ alpine or boreal species in the macrofossil record, such as Vaccinium uliginosum, Salix herbacea, and Dryas integrifolia.
We established eight transects (50-100 m in length) along an elevation gradient in three tree-line zones (forest, forest-tundra
, and alpine-tundra) and recorded all species and cover of vegetation in contiguous 1 x 1 m quadrats.
To test both hypotheses, we analyzed macrofossil remains across a long transect from forest-tundra
to tundra, to determine whether or not the eastern Canadian forest limit shifted in unison with climate change during the late Holocene.