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Conditions of Use

The re-use of scientific data has the potential to greatly increase communication, collaboration and synthesis within and among disciplines, and thus is fostered, supported and encouraged. Permission to use this dataset is granted to the Data User free of charge subject to the following terms:

1) Acceptable use. Use of the dataset will be restricted to academic, research, educational, government, recreational, or other not-for-profit professional purposes. The Data User is permitted to produce and distribute derived works from this dataset provided that they are released under the same license terms as those accompanying this Data Set. Any other uses for the Data Set or its derived products will require explicit permission from the dataset owner.
2 ) Redistribution. The data are provided for use by the Data User. The metadata and this license must accompany all copies made and be available to all users of this Data Set. The Data User will not redistribute the original Data Set beyond this collaboration sphere.
3 ) Citation. It is considered a matter of professional ethics to acknowledge the work of other scientists. Thus, the Data User will properly cite the Data Set in any publications or in the metadata of any derived data products that were produced using the Data Set. Citation should take the following general form: Creator, Year of Data Publication, Title of Dataset, Publisher, Dataset identifier. For example:

Shaver, G. 1989. Above ground biomass in acidic tussock tundra experimental site, 1989, Arctic LTER, Toolik, Alaska. Arctic LTER, Marine Biological Lab, Woods Hole, Ma 02543. 1989gsttbm 

4 ) Acknowledgement. The Data User should acknowledge any institutional support or specific funding awards referenced in the metadata accompanying this dataset in any publications where the Data Set contributed significantly to its content. Acknowledgements should identify the supporting party, the party that received the support, and any identifying information such as grant numbers. For example:

Data sets were provided by the Arctic LTER. This material is based upon work supported by the National Science Foundation under Grants #DEB-981022, 9211775, 8702328; #OPP-9911278, 9911681, 9732281, 9615411, 9615563, 9615942, 9615949, 9400722, 9415411, 9318529; #BSR 9019055, 8806635, 8507493.

5 ) Notification. The Data User will notify the Data Set Contact when any derivative work or publication based on or derived from the Data Set is distributed. The Data User will provide the data contact with two reprints of any publications resulting from use of the Data Set and will provide copies, or on-line access to, any derived digital products. Notification will include an explanation of how the Data Set was used to produce the derived work.
6 ) Collaboration. The Data Set has been released in the spirit of open scientific collaboration. Data Users are thus strongly encouraged to consider consultation, collaboration and/or co-authorship with the Data Set Creator.

By accepting this Data Set, the Data User agrees to abide by the terms of this agreement. The Data Owner shall have the right to terminate this agreement immediately by written notice upon the Data User's breach of, or non-compliance with, any of its terms. The Data User may be held responsible for any misuse that is caused or encouraged by the Data User's failure to abide by the terms of this agreement.


While substantial efforts are made to ensure the accuracy of data and documentation contained in this Data Set, complete accuracy of data and metadata cannot be guaranteed. All data and metadata are made available "as is". The Data User holds all parties involved in the production or distribution of the Data Set harmless for damages resulting from its use or interpretation.

Dataset URLs:METADATA: HTML, Rich Text, XML(EML compliant)
DATA: Comma Delimited, Excel file with Metadata and data, Dataset via LTER Data Portal
Dataset ID:SoilsummaryAbisko.05
Dataset Title:Soil ergoserol concentration from Abisko Sweden 2007.
Investigator 1: 
First Name:Howard
Last Name:Drossman
Organization:Department of Chemistry and Biochemistry
Address line 2:Environmental Science Program
Address line 3:Colorado College
City:Colorado Springs
Zip Code:80903
Investigator 2: 
First Name:John
Last Name:Hobbie
Organization:Ecosystems Center
Address line 2:Marine Biological Laboratory
Address line 3:
City:Woods Hole
Zip Code:02543
Investigator 3: 
First Name:Erik
Last Name:Hobbie
Organization:Complex Systems Center
Address line 2:University of New Hampshire
State:New Hampshire
Zip Code:03824
Associate Investigators:
Keywords:Abisko, soil, ergosterol, fungi, biomass
Abstract:The data set describes soil ergosterol concentration, which is unique to fungal membranes., from samples from Abisko, Sweden. The samples from Abisko, Sweden, were collected by E.A. Hobbie at a birch forest site and a tundra site. The Abisko sites are described in
For questions about the Metadata and data contact the Investigators.
For information about this web site contact:
Arctic LTER Information Manager
The Ecosystems Center
Marine Biological Lab
7 MBL St
Woods Hole, MA 02543
Phone (508) 289 7496
Online URL:
Data File URL
Data File Name SoilsummaryAbisko.csv
Beginning Date 7/27/2007
End Date 9/12/2007
Number of Data Records 112
Other Files to Reference SoilsummaryAlaska.xls
Availability Status 1
Quality Control Information
Maintenance Description
Log of Changes: Version 1: 3Jan2011 Subbmitted to Arctic LTER. Jim L
Version 2: 21Sep11 Updated metadata form and correced the harvest list path to xml. Jim
Version 3: Updated to newer metadata with site sheet. CH March 2013.
Version 3: Checked Keywords against the LTER controlled list. Jim 11FEb14
Version 5: Changed Distrubution URL since the LTER network DAS system is being discontinued. JimL 9Apr2015
RESEARCH LOCATION:                  
Location Name Birch forest Abisko Tundra near Abisko, Sweden Select Site or enter New One Select Site or enter New One Select Site or enter New One Select Site or enter New One Select Site or enter New One Select Site or enter New One  
Geographic Description Birch forest near Abisko, Sweden. See Tundra near Abisko, Sweden See Enter Description Enter Description Enter Description Enter Description Enter Description Enter Description  
Location Bounding Box                  
West Bounding Coordinate                  
East Bounding Coordinate                  
North Bounding Coordinate                  
South Bounding Coordinate                  
OR if single point location                  
Latitude 68.3256 68.3018 In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees  
Longitude 18.8333 18.8536 In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees  
Elevation In Meters In Meters In Meters In Meters In Meters In Meters In Meters In Meters  
Link to Google Map View on Google Map View on Google Map              
Organisms studied
Methods:The method , the complete references, and similar results from Alaska are described in Hobbie, J. E., E. A. Hobbie, H. Drossman, M. Conte, J. C. Weber, J. Shamhart, and M. Weinrobe. 2009. Mycorrhizal fungi supply nitrogen to host plants in Arctic tundra and boreal forests: N-15 is the key signal. Canadian Journal of Microbiology 55:84-94. Methods used are in de Ridder-Duine, A. S., Smant, W., van der Wal, A., van Veen, J. A., and de Boer, W. 2006. Evaluation of a simple, non-alkaline extraction protocol to quantify soil ergosterol. Pedobiologia, 50: 293-300.
Bth, E. 2001. Estimation of fungal growth rates in soil using 14C-acetate incorporation into ergosterol. Soil Biol. Biochem. 33: 2011-2018.

Methods for ergosterol in 2007

Sampling. In 2007, a 10-20 cm deep, 6 cm diameter core was taken at a representative site next to known ectomycorrhizal plants. After collection, soil samples were immediately placed on ice and frozen within six hours. In the laboratory, each core from the 2007 transect was thawed and sectioned into three approximately equal depth organic layers and two approximately equal depth mineral layers for analysis of ergosterol, soil moisture, and soil organic matter.

Ergosterol. This fungal-specific sterol, a component of the cell membrane, estimates living fungal biomass in soils. We modified the saponification methods described by Bth (2001) and de Ridder-Duine et al. (2006) for HPLC quantification of ergosterol. In the laboratory, thawed samples were sectioned by horizon (e.g., organic and mineral), each layer sub-sectioned by depth, and each subsection sieved (2 mm screen). Duplicate or triplicate sub-samples (0.5 g) of the sieved soil fractions were saponified by heating for 90 min at 70?C in 2 ml of methanol and 0.5 ml of 2 M NaOH after brief vortex mixing. After cooling, 1 ml methanol and 3 ml pentane were added and samples vortex-mixed for 20 s. Samples were centrifuged briefly to eliminate emulsions and the upper pentane phase, containing ergosterol, was collected. The pentane addition, extraction and centrifugation was repeated twice more, but with 2 ml pentane per extraction step. The pentane (upper) phase was collected and combined with previous extracts. The combined pentane extracts were dried under nitrogen flow, dissolved in 1.0 ml methanol, filtered through a 0.45 m pore size PTFE syringe filter (Millipore, Corporation, Billerica, Massachusetts, USA) and injected into a Waters Acquity UPLC system with a binary solvent manager, a sample manager, and a photodiode array detector (PDA) (Waters Corporation, Milford, Massachusetts, USA). Separation was on an Acquity UPLC BEH C18 1.7 micron pore size, 2.1 x 50 mm reverse phase column maintained at 40C. A 5 l injection of each extract was eluted with 92% methanol-8% water at a flow rate of 0.5 ml min-1. Using Millenium software (Waters) the UV spectrum of the ergosterol peak at ~2 min was compared with standard ergosterol (Fluka Company, St. Louis, Missouri, USA) and was quantified at 282 nm with calibration standards in the range of 0.05 20 ppm. Calibration provided linear fit (r2 > 0.999) with standards in all runs with a limit of detection (S/N 3:1) of ~ 30 ppb. Spike recoveries determined by the method of de Ridder-Duine et al. (2006) are 824%, in agreement with prior literature values (Bth 2001). Variance for duplicate or triplicate samples resulting from sample inhomogeneity, extraction, and instrumental sources were generally less than 5% and are calculated as standard deviation for each sample.

Soil moisture was determined gravimetrically on a separate sub-sample by drying to constant weight. Soil organic matter was calculated from the loss in mass of the dry soil after heating at 500 deg C for 12 hours.

Fungal biomass. Several conversion factors have been used to calculate fungal biomass from ergosterol. Montgomery et al. (2000) proposed a factor of 4 mg fungal biomass per g ergosterol based on a calibration with six species of cultured saprotrophic fungi while Salmanowicz and Nylund (1988) proposed a factor of 3 mg fungal biomass per g ergosterol based on cultures of three different species of ectomycorrhizal fungi. We followed Clemmensen et al. (2006) and used 3 mg g-1 as this reflects the fungal taxa most commonly observed at our sampling sites.

Data Table

Variable Name Variable Description Data Type Units DateTime Format Code Information Missing Value Code
Samples Sample name text        
ug/g dry the concentration of ergosterol per gram dry weight of soil number microgramPerGram      
% organic the % organic matter in the sample of soil number percent      
Site the site where the sample was collected text        
Collection Date Date sample collected datetime   dd-mmm-yyyy    
Location Samples are from Abisko, Sweden; a tundra or birch forest site text        
Sample# Sample number text        
RelativePosition A top, B bottom. If three, then A top, B middle, C bottom text        
Replicate# Replicate number number number      

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