Strong correlation between summer temperature and pollen accumulation rates forPinus sylvestris, Picea abies andBetula spp. in a high-resolution record from northern Sweden

2007 ◽  
Vol 22 (7) ◽  
pp. 653-658 ◽  
Author(s):  
L. Barnekow ◽  
N. J. Loader ◽  
S. Hicks ◽  
C. A. Froyd ◽  
T. Goslar
Keyword(s):  
High Resolution ◽  
Picea Abies ◽  
Strong Correlation ◽  
Summer Temperature ◽  
Northern Sweden ◽  
Accumulation Rates ◽  
Pollen Accumulation Rates

scholarly journals Signals of tree volume and temperature in a high-resolution record of pollen accumulation rates in northern Finland

2012 ◽  
Vol 27 (6) ◽  
pp. 564-574 ◽  
Author(s):  
F. Mazier ◽  
A. B. Nielsen ◽  
A. Broström ◽  
S. Sugita ◽  
S. Hicks
Keyword(s):  
High Resolution ◽  
Accumulation Rates ◽  
Pollen Accumulation Rates

scholarly journals Linking modern pollen accumulation rates to biomass: Quantitative vegetation reconstruction in the western Klamath Mountains, NW California, USA

The Holocene ◽  
2021 ◽  
pp. 095968362098803
Author(s):  
Clarke A Knight ◽  
Mark Baskaran ◽  
M Jane Bunting ◽  
Marie Champagne ◽  
Matthew D Potts ◽  
...  
Keyword(s):  
Mean Squared Error ◽  
Plant Biomass ◽  
Source Area ◽  
Pollen Deposition ◽  
Accumulation Rates ◽  
Klamath Mountains ◽  
Plant Abundance ◽  
Circular Area ◽  
Value Analysis ◽  
Pollen Accumulation Rates

Quantitative reconstructions of vegetation abundance from sediment-derived pollen systems provide unique insights into past ecological conditions. Recently, the use of pollen accumulation rates (PAR, grains cm−2 year−1) has shown promise as a bioproxy for plant abundance. However, successfully reconstructing region-specific vegetation dynamics using PAR requires that accurate assessments of pollen deposition processes be quantitatively linked to spatially-explicit measures of plant abundance. Our study addressed these methodological challenges. Modern PAR and vegetation data were obtained from seven lakes in the western Klamath Mountains, California. To determine how to best calibrate our PAR-biomass model, we first calculated the spatial area of vegetation where vegetation composition and patterning is recorded by changes in the pollen signal using two metrics. These metrics were an assemblage-level relevant source area of pollen (aRSAP) derived from extended R-value analysis ( sensu Sugita, 1993) and a taxon-specific relevant source area of pollen (tRSAP) derived from PAR regression ( sensu Jackson, 1990). To the best of our knowledge, aRSAP and tRSAP have not been directly compared. We found that the tRSAP estimated a smaller area for some taxa (e.g. a circular area with a 225 m radius for Pinus) than the aRSAP (a circular area with a 625 m radius). We fit linear models to relate PAR values from modern lake sediments with empirical, distance-weighted estimates of aboveground live biomass (AGLdw) for both the aRSAP and tRSAP distances. In both cases, we found that the PARs of major tree taxa – Pseudotsuga, Pinus, Notholithocarpus, and TCT (Taxodiaceae, Cupressaceae, and Taxaceae families) – were statistically significant and reasonably precise estimators of contemporary AGLdw. However, predictions weighted by the distance defined by aRSAP tended to be more precise. The relative root-mean squared error for the aRSAP biomass estimates was 9% compared to 12% for tRSAP. Our results demonstrate that calibrated PAR-biomass relationships provide a robust method to infer changes in past plant biomass.

scholarly journals Mass Balance Sensitivity and Future Projections of Rabots Glaciär, Sweden

Climate ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 126
Author(s):  
Moon Taveirne ◽  
Laura Ekemar ◽  
Berta González Sánchez ◽  
Josefine Axelsson ◽  
Qiong Zhang
Keyword(s):  
Wind Speed ◽  
Mass Balance ◽  
Climate Scenario ◽  
Summer Temperature ◽  
Glacier Mass Balance ◽  
Northern Sweden ◽  
Dramatic Decrease ◽  
Future Projections ◽  
Modelling Studies ◽  
The Relationship

Glacier mass balance is heavily influenced by climate, with responses of individual glaciers to various climate parameters varying greatly. In northern Sweden, Rabots Glaciär’s mass balance has decreased since it started being monitored in 1982. To relate Rabots Glaciär’s mass balance to changes in climate, the sensitivity to a range of parameters is computed. Through linear regression of mass balance with temperature, precipitation, humidity, wind speed and incoming radiation the climate sensitivity is established and projections for future summer mass balance are made. Summer mass balance is primarily sensitive to temperature at −0.31 m w.e. per °C change, while winter mass balance is mainly sensitive to precipitation at 0.94 m w.e. per % change. An estimate using summer temperature sensitivity projects a dramatic decrease in summer mass balance to −3.89 m w.e. for the 2091–2100 period under climate scenario RCP8.5. With large increases in temperature anticipated for the next century, more complex modelling studies of the relationship between climate and glacier mass balance is key to understanding the future development of Rabots Glaciär.

scholarly journals A representative density profile of the North Greenland snowpack

2016 ◽  
Vol 10 (5) ◽  
pp. 1991-2002 ◽  
Author(s):  
Christoph Florian Schaller ◽  
Johannes Freitag ◽  
Sepp Kipfstuhl ◽  
Thomas Laepple ◽  
Hans Christian Steen-Larsen ◽  
...  
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Density Profile ◽  
Accumulation Rate ◽  
Sampling Technique ◽  
Data Sets ◽  
Accumulation Rates ◽  
The North ◽  
North Greenland ◽  
Good Agreement

Abstract. Along a traverse through North Greenland in May 2015 we collected snow cores up to 2 m depth and analyzed their density and water isotopic composition. A new sampling technique and an adapted algorithm for comparing data sets from different sites and aligning stratigraphic features are presented. We find good agreement of the density layering in the snowpack over hundreds of kilometers, which allows the construction of a representative density profile. The results are supported by an empirical statistical density model, which is used to generate sets of random profiles and validate the applied methods. Furthermore we are able to calculate annual accumulation rates, align melt layers and observe isotopic temperatures in the area back to 2010. Distinct relations of δ18O with both accumulation rate and density are deduced. Inter alia the depths of the 2012 melt layers and high-resolution densities are provided for applications in remote sensing.

scholarly journals Diatom ooze—A large marine mercury sink

Science ◽  
2018 ◽  
Vol 361 (6404) ◽  
pp. 797-800 ◽  
Author(s):  
Sara Zaferani ◽  
Marta Pérez-Rodríguez ◽  
Harald Biester
Keyword(s):  
High Resolution ◽  
Southern Ocean ◽  
Marine Sediment ◽  
Crucial Role ◽  
Anthropogenic Pollution ◽  
Atmospheric Mercury ◽  
Mercury Accumulation ◽  
Accumulation Rates ◽  
Sediment Data

The role of algae for sequestration of atmospheric mercury in the ocean is largely unknown owing to a lack of marine sediment data. We used high-resolution cores from marine Antarctica to estimate Holocene global mercury accumulation in biogenic siliceous sediments (diatom ooze). Diatom ooze exhibits the highest mercury accumulation rates ever reported for the marine environment and provides a large sink of anthropogenic mercury, surpassing existing model estimates by as much as a factor of 7. Anthropogenic pollution of the Southern Ocean began ~150 years ago, and up to 20% of anthropogenic mercury emitted to the atmosphere may have been stored in diatom ooze. These findings reveal the crucial role of diatoms as a fast vector for mercury sequestration and diatom ooze as a large marine mercury sink.

Yield capacity of planted Picea abies in northern Sweden

1996 ◽  
Vol 11 (1-4) ◽  
pp. 38-49 ◽  
Author(s):  
Björn Elfving ◽  
Kenneth Nyström
Keyword(s):  
Picea Abies ◽  
Northern Sweden ◽  
Yield Capacity

Rapid summer temperature changes during Termination 1a: high-resolution multi-proxy climate reconstructions from Gerzensee (Switzerland)

2012 ◽  
Vol 36 ◽  
pp. 103-113 ◽  
Author(s):  
André F. Lotter ◽  
Oliver Heiri ◽  
Stephen Brooks ◽  
Jacqueline F.N. van Leeuwen ◽  
Ulrich Eicher ◽  
...  
Keyword(s):  
High Resolution ◽  
Summer Temperature ◽  
Temperature Changes ◽  
Climate Reconstructions
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