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.
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.