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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 http://ecosystems.mbl.edu/arc/terrest/biomass/index.shtml 

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.

Disclaimer

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 Poral
Dataset ID:2011_MAT_89_06_NP_Enzyme_JCM.02
Dataset Title:Extracellular enzyme activities in soils from Arctic LTER moist acidic tundra nutrient addition plots, Toolik Field Station, Alaska, sampled July 2011.
Investigator 1: 
First Name:John
Last Name:Moore
Organization:Natural Resource Ecology Laboratory
Address line 2:200 West Lake Street
Address line 3:
City:Fort Collins
State:CO
Zip Code:80523-1499
Country:USA
Investigator 2: 
First Name:Matthew
Last Name:Wallenstein
Organization:Natural Resource Ecology Laboratory
Address line 2:200 West Lake Street
City:Fort Collins
State:CO
Zip Code:80523-1499
Country:USA
Investigator 3: 
First Name:Akihiro
Last Name:Koyama
Organization:Natural Resource Ecology Laboratory
Address line 2:200 West Lake Street
City:Fort Collins
State:CO
Zip Code:80523-1499
Country:USA
Investigator 4: 
First Name:Rodney
Last Name:Simpson
Organization:Natural Resource Ecology Laboratory
Address line 2:200 West Lake Street
City:Fort Collins
State:CO
Zip Code:80523-1499
Country:USA
Investigator 5: 
First Name:Greg
Last Name:Selby
Organization:Natural Resource Ecology Laboratory
Address line 2:200 West Lake Street
City:Fort Collins
State:CO
Zip Code:80523-1499
Country:USA
Associate Investigators:
Keywords:moist acidic tundra, potential enzyme activity, tundra, soil, arctic, fertilization
Abstract:Soil samples were collected from control, and N+P plots from within a set of treatments in Arctic LTER Moist Acidic Tundra plots established in 1989 and in 2006 . At the time of sampling the soil was separated into organic horizon, organic/mineral interface, and the upper 5cm of the mineral soil. In the lab the potential activities of seven hydrolytic enzymes was determined using fluorometric techniques (Saiya-Cork et al. 2002) modified following Steinweg et al(.2012).
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
Email: arc_im@mbl.edu
Online URL: http://ecosystems.mbl.edu/ARC/
DATA FILE INFORMATION:
Data File URL http://metacat.lternet.edu/das/dataAccessServlet?docid=knb-lter-arc.10494&urlTail=terrest/bulk/data/2011_MAT_89_06_NP_Enzyme_JCM.csv
Data File Name 2011_MAT_89_06_NP_Enzyme_JCM
Beginning Date 7/1/2011
End Date 7/31/2011
Number of Data Records 204
Other Files to Reference
Availability Status Type 1
Quality Control Information
Maintenance Description
Log of Changes: Version 2:Checked keywords against the LTER network preferred list and replaced non-preferred terms. Jim L 11Feb14
 
RESEARCH LOCATION:                  
Location Name LTER Moist Acidic Tussock Tundra LTER Low Nutrient Moist Acidic Tussock Tundra 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 Arctic LTER Experimental Plots: Moist Acidic Tussock Tundra (MAT) Northeast corner block 1 near Toolik Field Station, North Slope, Alaska. Low Nutrient Moist Acidic Tussock Tundra (LMAT) Northeast corner Block 1 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 68.624411 68.622865 In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees  
Longitude -149.609589 -149.608545 In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees In Decimal Degrees  
Elevation 750 758 In Meters In Meters In Meters In Meters In Meters In Meters  
Link to Google Map View on Google Map View on Google Map              
                   
 
TAXONOMIC COVERAGE:
Organisms studied
 
Methods:In July 2011, soil samples were collected from control, and N+P plots from within a set of treatments in Moist Acidic Tundra plots established in 1989. A set of Control and N+P plots established on an adjacent hillslope in 2006 with both equivalent (high) and half (low) the fertilization rate of the 1989 plots were also sampled. At the time of sample collection we separated the soil into organic horizon, organic/mineral interface, and the upper 5cm of the mineral soil, and measured the depth of each layer.

We quantified potential activities of seven hydrolytic enzymes (Table 1) for each sample using fluorometric techniques (Saiya-Cork et al. 2002) modified following Steinweg et al(.2012). We measured the activities of four enzymes hydrolyzing C-rich substrates (BG, CB, XYL and AG), two for N-rich substrates (NAG and LAP) and one for a P-rich substrate (PHOS). Subsamples (1 g for organic and interface soils, and 2.75 g for mineral soils) were homogenized with 91 mL of 50 mM sodium acetate (pH 4.5) using a blender (Waring, New Hartford, CT, USA). Plates with 96 deep-wells were used for the enzyme assay as well as reference standards, in which samples were arranged in columns and different enzymes and standards in rows. Aliquots (800 L) of each homogenized sample were pipetted into seven wells in one of the 12 columns of a plate using an 8-channel pipetter. When the plate was filled with homogenized samples (up to 12 samples for a plate), 200 L of each substrate dissolved in DI water was added to each aliquot of sample. Each of the seven substrates was pipetted into wells in a given row (up to 12 wells). The concentration of each substrate was determined based on tests prior to the experiment. We employed 600 molL-1 of CB and PHOS for the organic and interface soils, and 200 molL-1 for the rest of the substrates so that 200 L of substrate would not be completely degraded by enzymes during an incubation period. After a lid was firmly placed on the plate after substrate addition, the plate was inverted several times to mix soil samples and substrates well, and immediately placed in an incubator. Reference standards were prepared in a similar manner as the soil samples described above using the same apparatus. In the standard plates, we added fluorescent standards, instead of the substrates, in seven concentrations ranging from zero to up to 600 M. We used two types of fluorescent standards, 7-amino-4-methylcoumarin (MUC) and 4-methylumbelliferone (MUB). MUC standards were used for LAP, and MUB the others (Table 1).

We used four different incubation temperatures (5, 15, 25 and 35C) to assess the temperature sensitivity of potential enzyme activities in soils. For a set of 12 samples, we set up four plates, each of which was incubated at one of the four temperatures. Four additional plates were prepared as reference standards. Of the four standard plates, two were used for MUC and the other two MUB. One set of MUC and MUB standards were incubated at 5C and the other at 25 C along with the soils samples. The standard set incubated at 25C was used to calculate potential enzyme activities at 15, 25 and 35C (Steinweg et al. 2012). Incubation periods were 23, 6, 3 and 1.5 hours for 5, 15, 25 and 35?C, respectively.

After incubation, the plates were centrifuged at 350 g for three minutes, the supernatant was removed from each well and pipetted into a corresponding well of a 96-well black plate. Fluorescent activities were immediately measured using an Infinite M500 spectrofluorometer (Tecan, Mnnedorf, Switzerland) with a set of wavelength at 365 and 450 nm for excitation and emission, respectively. Readings of the fluorescent activities from standards were used to calculate potential enzyme activities for each sample.

An article including this data set has been published (Koyama et al. 2013).

References
Arrhenius S (1889) ber die Reaktionsgeschwindigkeit bei der Inversion von Rohrzucker durch Suren. Zeitschrift fr physikalische Chemie 4: 226-248.
Koyama A, Wallenstein MD, Simpson RT, Moore JC (2013) Carbon-Degrading Enzyme Activities Stimulated by Increased Nutrient Availability in Arctic Tundra Soils. PLoS ONE 8: e77212.
Saiya-Cork KR, Sinsabaugh RL, Zak DR (2002) The effects of long term nitrogen deposition on extracellular enzyme activity in an Acer saccharum forest soil. Soil Biol Biochem 34: 1309-1315.
Steinweg JM, Dukes JS, Wallenstein MD (2012) Modeling the effects of temperature and moisture on soil enzyme activity: Linking laboratory assays to continuous field data. Soil Biol Biochem 55: 85-92.

Data Table

Variable Name Variable Description Data Type Units DateTime Format Code Information Missing Value Code
Block Arctic LTER blocks text        
Soil Layer Soil Layer text     O/M = Organic/Mineral  
Plot Array Distinguished between 1989 and 2006 plots text        
Treatment Control vs +NP treatments for each plot array text     1989 +NP = Fertilization treatment since 1989 | 2006 Low+NP = Low fertilization treatment since 2006 | 2006 High+NP = High fertilization treatment since 2006  
Incubation Temperature Incubation temperature in the lab number celsius     -9999 = missing
BG b-Glucosidase number micromolePerGramPerHour     -9999 = missing
CB Cellulase number micromolePerGramPerHour     -9999 = missing
NAG Chitinase number micromolePerGramPerHour     -9999 = missing
PHOS Phosphatase number micromolePerGramPerHour     -9999 = missing
XYL Xylosidase number micromolePerGramPerHour     -9999 = missing
AG a-Glucosidase number micromolePerGramPerHour     -9999 = missing
LAP Protease number micromolePerGramPerHour     -9999 = missing

Please contact arc_im@mbl.edu with questions, comments, or for technical assistance regarding this web site.