A 250-year-long height-increment chronology for Pinus sylvestris at the northern coniferous timberline: A novel tool for reconstructing past summer temperatures?

2005 ◽  
Vol 22 (2) ◽  
pp. 75-81 ◽  
Author(s):  
Margus Pensa ◽  
Hannu Salminen ◽  
Risto Jalkanen
Keyword(s):  
Pinus Sylvestris ◽  
Height Increment ◽  
Summer Temperatures ◽  
Past Summer

scholarly journals Formation of ice layers by infiltration and refreezing of meltwater

1998 ◽  
Vol 26 ◽  
pp. 83-91 ◽  
Author(s):  
W. T. Pfeffer ◽  
N. F. Humphrey
Keyword(s):  
Opposite Effect ◽  
Initial Temperature ◽  
Initial Conditions ◽  
Ice Cores ◽  
Combined Processes ◽  
Threshold Values ◽  
Polar Ice ◽  
Summer Temperatures ◽  
Impermeable Layer ◽  
Past Summer

Melt-layer frequency and magnitude in polar and sub-polar ice cores have been interpreted as measures of past summer temperature, and calibrations have been proposed relating frequency of occurrence of ice layers in ice cores to past summer temperatures. But, observations in the percolation facies in Greenland and an analysis of the combined processes of meltwater infiltration and refreezing of water in snow indicate that, in addition to unusually high rates of meltwater input, formation of ice layers will also be facilitated by unusually cold initial conditions or early onset of melt. Uniform warming of both summer and winter conditions has the opposite effect and suppresses ice-layer formation in favor of uniform wetting and refreezing of the snowpack. Numerical modeling of infiltration and refreezing at a stratigraphic fine-to-coarse transition allows quantification of the effects of significant parameters (initial temperature, grain-size and density contrast across the stratigraphic transition, water-input rate and minimum impermeable-layer thickness). Calculations are made to distinguish threshold values of parameters at which infiltration progresses faster than refreezing, resulting in a break-through of water across the stratigraphic transition, from values leading to the formation of an ice layer when refreezing progresses faster than infiltration.

scholarly journals Formation of ice layers by infiltration and refreezing of meltwater

1998 ◽  
Vol 26 ◽  
pp. 83-91 ◽  
Author(s):  
W. T. Pfeffer ◽  
N. F. Humphrey
Keyword(s):  
Opposite Effect ◽  
Initial Temperature ◽  
Initial Conditions ◽  
Ice Cores ◽  
Combined Processes ◽  
Threshold Values ◽  
Polar Ice ◽  
Summer Temperatures ◽  
Impermeable Layer ◽  
Past Summer

Melt-layer frequency and magnitude in polar and sub-polar ice cores have been interpreted as measures of past summer temperature, and calibrations have been proposed relating frequency of occurrence of ice layers in ice cores to past summer temperatures. But, observations in the percolation facies in Greenland and an analysis of the combined processes of meltwater infiltration and refreezing of water in snow indicate that, in addition to unusually high rates of meltwater input, formation of ice layers will also be facilitated by unusually cold initial conditions or early onset of melt. Uniform warming of both summer and winter conditions has the opposite effect and suppresses ice-layer formation in favor of uniform wetting and refreezing of the snowpack. Numerical modeling of infiltration and refreezing at a stratigraphic fine-to-coarse transition allows quantification of the effects of significant parameters (initial temperature, grain-size and density contrast across the stratigraphic transition, water-input rate and minimum impermeable-layer thickness). Calculations are made to distinguish threshold values of parameters at which infiltration progresses faster than refreezing, resulting in a break-through of water across the stratigraphic transition, from values leading to the formation of an ice layer when refreezing progresses faster than infiltration.

scholarly journals Higher-than-present Medieval pine (Pinus sylvestris) treeline along the Swedish Scandes

2015 ◽  
Vol 42 ◽  
pp. 1-14 ◽  
Author(s):  
Leif Kullman
Keyword(s):  
Pinus Sylvestris ◽  
Ground Surface ◽  
Ice Age ◽  
Lapse Rate ◽  
Medieval Period ◽  
Climate Change And Variability ◽  
The Past ◽  
Northern Fennoscandia ◽  
Detection And Attribution ◽  
Summer Temperatures

The upper treeline of Scots pine (Pinus sylvestris L.) is renowned as a sensitive indicator of climate change and variability. By use of megafossil tree remains, preserved exposed on the ground surface, treeline shift over the past millennium was investigated at multiple sites along the Scandes in northern Sweden. Difference in thermal level between the present and the Medieval period, about AD 1000-1200, is a central, although controversial, aspect concerning the detection and attribution of anthropogenic climate warming. Radiocarbon-dated megafossil pines revealed that the treeline was consistently positioned as much as 115 m higher during the Medieval period than today (AD 2000-2010), after a century of warming and substantial treeline upshift. Drawing on the last-mentioned figure, and a lapse rate of 0.6oC/100 m, it may be inferred that Medieval summer temperatures were about 0.7 oC warmer than much of the past 100 years. Extensive pine mortality and treeline descent after the Medieval warming peak reflect substantially depressed temperatures during the Little Ice Age. Warmer-than-present conditions during the Medieval period concur with temperature reconstructions from different parts of northern Fennoscandia, northwestern Russia and Greenland. Modern warming has not been sufficient to restore Medieval treelines. Against this background, there is little reason to view further modest warming as unnatural.

scholarly journals Genotype by Environment Interaction in Pinus sylvestris L. in Southern Sweden

2008 ◽  
Vol 57 (1-6) ◽  
pp. 306-311 ◽  
Author(s):  
B. Hannrup ◽  
G. Jansson ◽  
Ö. Danell
Keyword(s):  
Pinus Sylvestris ◽  
Genetic Correlation ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Site Index ◽  
Genotype By Environment Interaction ◽  
Environment Interaction ◽  
Height Increment ◽  
Southern Sweden ◽  
Genotype By Environment

Abstract To estimate the amount of genotype by environment interaction (G x E) data was obtained within the Swedish breeding program of Pinus sylvestris L. The calculations were based on estimates of G x E expressed by the genetic correlations across trials. In total, 66 progeny trials were included coming from 17 different test series. The number of parents tested per progeny trial was in average 52. Some parents were tested in several series and in total 812 parents were represented in the study. The results of our study showed that the amount of G x E for growth traits in Pinus sylvestris in southern Sweden was low. The median genetic correlation across trials for height, height increment and diameter were in the range 0.75-0.80 and the pattern of interaction was largely unpredictable from site differences in site index, latitude, longitude and altitude.

scholarly journals Past Summer Temperatures Inferred From Dendrochronological Records of Fitzroya cupressoides on the Eastern Slope of the Northern Patagonian Andes

2018 ◽  
Vol 123 (1) ◽  
pp. 32-45 ◽  
Author(s):  
Aliénor Lavergne ◽  
Valérie Daux ◽  
Monique Pierre ◽  
Michel Stievenard ◽  
Ana Marina Srur ◽  
...  
Keyword(s):  
Eastern Slope ◽  
Summer Temperatures ◽  
Patagonian Andes ◽  
Past Summer ◽  
Fitzroya Cupressoides

scholarly journals Stimulating the growth of trees with ashes of various biofuels (wood, peat) on a cutaway peatland

2010 ◽  
Vol 52 (1) ◽  
pp. 60-71 ◽  
Author(s):  
Karin Kikamägi ◽  
Katri Ots
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Betula Pendula ◽  
Growing Season ◽  
Wood Ash ◽  
Height Increment ◽  
And Control ◽  
Positive Effect ◽  
Root Collar ◽  
Scots Pine Needles

Puittaimede kasvu stimuleerimine erinevate biokütuste (puit, turvas) tuha liikidega ammendatud freesturbaväljalThe aim of the study was to investigate the effect of fertilization on the growth of Silver birchBetula pendulaRoth and Scots pinePinus sylvestrisL. seedlings on a cutaway peatland (Ulila, 58°22'N, 26°26'E). Five treatments were established: wood ash (10 000 and 5000 kg/ha), peat and wood ash mixture (10 000 and 5000 kg/ha) and control (unfertilized field). Results of analysis showed that the pH of peat in the cutaway peatland was before treatment 3.5 and it rose after fertilization by up to 0.7 units by the end of the first growing season. The treatment with 10 000 kg/ha of wood ash gave the best results: the annual height increment of Silver birches during the first growing season after fertilization was 4.5 times higher and that of Scots pines 1.1 times higher than control. In the second growing season after fertilization the increment was respectively 16.3 and 3.3 times higher than control. The root collar diameters of Silver birches were 4.4 time larger these of Scots pines 2.1 times larger than control. Scots pine needles were 2.2 times longer than control and the leaf area of the Silver birches was 6 times larger than control, which also shows a positive effect of fertilization. Peat ash treatment was also favourable, although its effect was much smaller than the effect of wood ash.

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