scholarly journals Morisset, P. et Payette, S., édit. (1983): Tree-line ecology. Proceedings of the Northern Québec Tree-Line Conference, Centre d’études nordiques, Université Laval, Collection Nordicana, n 47, 188 p., ill., 21,5 x 26,5 cm, 15$ can.

1984 ◽  
Vol 38 (1) ◽  
pp. 90
Author(s):  
Louise Savoie
Keyword(s):  
Tree Line ◽  
Conference Centre ◽  
Universite Laval

Regionalization of wind-speed data to analyse tree-line wind conditions in the eastern Andes of southern Ecuador

Erdkunde ◽  
2015 ◽  
Vol 69 (1) ◽  
pp. 3-19 ◽  
Author(s):  
Julia Wagemann ◽  
Boris Thies ◽  
Rütger Rollenbeck ◽  
Thorsten Peters ◽  
Jörg Bendix
Keyword(s):  
Wind Speed ◽  
Tree Line ◽  
Wind Speed Data ◽  
Southern Ecuador

scholarly journals Carbon and nutrient physiology in shrubs at the upper limits: a multi-species study

2020 ◽  
Author(s):  
Xue Wang ◽  
Fei-Hai Yu ◽  
Yong Jiang ◽  
Mai-He Li
Keyword(s):  
Fine Roots ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Growing Season ◽  
Interactive Effects ◽  
Tree Line ◽  
Shrub Species ◽  
Nutrient Physiology ◽  
Upper Limits ◽  
Species Study

Abstract Aims Carbon and nutrient physiology of trees at their upper limits have been extensively studied, but those of shrubs at their upper limits have received much less attention. The aim of this study is to examine the general patterns of non-structural carbohydrates (NSCs), nitrogen (N) and phosphorous (P) in shrubs at the upper limits, and to assess whether such patterns are similar to those in trees at the upper limits. Methods Across Eurasia, we measured the concentrations of soluble sugars, starch, total NSCs, N and P in leaves, branches and fine roots (< 0.5 cm in diameter) of five shrub species growing at both the upper limits and lower elevations in both summer (peak growing season) and winter (dormancy season). Important Findings Neither elevation nor season had significant effects on tissue N and P concentrations, except for lower P concentrations in fine roots in winter than in summer. Total NSCs and soluble sugars in branches were significantly higher in winter than in summer. There were significant interactive effects between elevation and season for total NSCs, starch, soluble sugars and the ratio of soluble sugar to starch in fine roots, showing lower soluble sugars and starch in fine roots at the upper limits than at the lower elevations in winter but not in summer. These results suggest that the carbon physiology of roots in winter may play an important role in determining the upward distribution of shrubs, like that in the alpine tree-line trees.

scholarly journals A Comparison of some Upland and Valley Soils in the Ungava-Labrador Peninsula

2007 ◽  
Vol 38 (3) ◽  
pp. 243-256 ◽  
Author(s):  
William H. Hendershot
Keyword(s):  
Soil Temperature ◽  
Black Spruce ◽  
Carbon Accumulation ◽  
Shallow Depth ◽  
Soil Profiles ◽  
Tree Line ◽  
Climatic Regions ◽  
Coarse Texture ◽  
Active Mixing ◽  
Extractable Iron

ABSTRACT Thirteen soil profiles from northern Québec and Labrador, Canada, near the northern tree-line, were sampled and analysed. Five of these, located on poorly to imperfectly drained sites, are strongly cryoturbated soils with permafrost at a shallow depth. Below the surface horizon they have very uniform profile distributions of pH, carbon and extractable iron and aluminum due to the active mixing of the horizons. The eight soils from well-drained sites have profiles similar to those of soils in similar settings in more temperate climatic regions. One of these, developed in one of the most northerly valleys having a black spruce-larch forest vegetation, has the characteristics of a podzol (spodosol) except that the podzolic B (spodic) horizon is too thin. The other seven profiles all have color B horizons, although the coarse texture prevents their classification as cambic horizons; these soils all have carbon-rich A horizons varying in thickness from 1.5 to 20 cm. Soil temperature at 50 cm depth closely follows the elevational and latitudinal distribution of the soils; a range of 0 to 10° C was observed. Soil development, measured as depth of solum, organic carbon accumulation or degree of B horizon development, is closely related to soil temperature and site position. The presence of permanently frozen ice layers at shallow depth has a marked influence on soil genesis and the properties of the resultant soils.

Sign in / Sign up

Export Citation Format

Share Document