Data Package Metadata   View Summary

Wood alpha-cellulose stable C isotope ratios from New Hampshire and Vermont

General Information
Data Package:
Local Identifier:knb-lter-hbr.248.3
Title:Wood alpha-cellulose stable C isotope ratios from New Hampshire and Vermont
Alternate Identifier:DOI PLACE HOLDER
Abstract:

To quantify the effects of tree height and canopy position on delta13C of wood cellulose, we sampled 399 trees and saplings of eight species at nine forest stands across New Hampshire and Vermont, along with nearby saplings growing in the open. Samples were collected in 2017-18, and we analyzed the combined alpha-cellulose from growth rings formed in 2013-2017 for each tree.

These data are published in: Vadeboncoeur, M., K. Jennings, Ouimette, A. and Asbjornsen, H. (2019) Correcting tree-ring d13C time series for tree-size effects in eight temperate tree species. Tree Physiology. https://doi.org/10.1093/treephys/tpz138

Publication Date:2019-12-20

Time Period
Begin:
2013
End:
2017

People and Organizations
Contact:Hubbard Brook LTER Information Manager [  email ]
Creator:Vadeboncoeur, Matthew A (University of New Hampshire)
Creator:Jennings, Katie A (University of New Hampshire)
Creator:Ouimette, Andrew P (University of New Hampshire)
Creator:Asbjornsen, Heidi (University of New Hampshire)

Data Entities
Data Table Name:
Wood alpha-cellulose stable C isotope ratios
Description:
Wood alpha-cellulose stable C isotope ratios
Detailed Metadata

Data Entities


Data Table

Data:https://pasta-s.lternet.edu/package/data/eml/knb-lter-hbr/248/3/902207fc90b51047aa4a34f63af532ab
Name:Wood alpha-cellulose stable C isotope ratios
Description:Wood alpha-cellulose stable C isotope ratios
Number of Records:399
Number of Columns:13

Table Structure
Object Name:NH_VT_13C_tree_rings.csv
Size:26232 bytes
Authentication:56ef7b3b39f75879a76021cb35a9a7a6 Calculated By MD5
Text Format:
Number of Header Lines:1
Record Delimiter:\r\n
Orientation:column
Simple Delimited:
Field Delimiter:,

Table Column Descriptions
 
Column Name:tree_id  
species  
site  
dbh_cm  
ht_m  
crown_class  
sample_type  
growthrate_mm_y_1  
category  
d13cp  
discrim  
ci_ca  
iwue  
Definition:Unique alphanumeric identifier assigned to each sampleSpecies of sample, coded following the USDA PLANTS databaseLocation of sampled forest standDiameter of the sampled tree at a height of 1.35 metersHeight of the sampled treeCrown illumination index, assessed following Clark and Clark (1992). Scores are ordinal and range from 1-5.Indicator for whether the sample was an increment core or a twig . Codes: C = core, T = twigRadial growth rate, as measured for the 2013-2017 study period. Only measured for core samples.Category of tree size and crown position for analysisStable carbon isotope ratio of combined 2013-2017 cellulose extracted from the sample.Carbon isotope discrimination relative to the atmosphere, calculated following Farquhar et al. (1982)The ratio of foliar intracellular CO2 concentration (ci) to the CO2 concentration of the atmosphere (ca). Calculated following Farquhar et al. (1989)Intrinsic water-use efficiency (the ratio of stomatal conductance to photosynthesis) calculated following Farquhar et al. (1989) and McCarroll and Loader (2004)
Storage Type:string  
string  
string  
float  
float  
string  
string  
float  
string  
float  
float  
float  
float  
Measurement Type:nominalnominalnominalratiorationominalnominalrationominalratioratioratioratio
Measurement Values Domain:
DefinitionUnique alphanumeric identifier assigned to each sample
Allowed Values and Definitions
Enumerated Domain 
Code Definition
CodeTSCA
DefinitionTsuga canadensis (L.) Carriere
Source
Code Definition
CodePIRU
DefinitionPicea rubens Sarg.
Source
Code Definition
CodePIST
DefinitionPinus strobus L.
Source
Code Definition
CodeACRU
DefinitionAcer rubrum L.
Source
Code Definition
CodeQURU
DefinitionQuercus rubra L.
Source
Code Definition
CodeFAGR
DefinitionFagus grandifolia Ehrh.
Source
Code Definition
CodeACSA3
DefinitionAcer saccharum Marshall
Source
Code Definition
CodeFRAM2
DefinitionFraxinus americana L.
Source
Allowed Values and Definitions
Enumerated Domain 
Code Definition
CodeJ
DefinitionJones Property, Milton, NH
Source
Code Definition
CodeCP
DefinitionCone Pond Watershed, White Mountain National Forest, Thornton, NH
Source
Code Definition
CodeTF
DefinitionThompson Farm, Durham, NH
Source
Code Definition
CodeBJ
DefinitionBlue Job State Forest, Farmington, NH
Source
Code Definition
CodeHB
DefinitionHubbard Brook Experimental Forest (watershed 3 and adjacent areaa), Woodstock, NH
Source
Code Definition
CodeSR
DefinitionSleepers River Research Watershed (watershed 9), Danville, VT
Source
Code Definition
CodeSB
DefinitionSaddleback Mountain Property, Deerfield, NH
Source
Code Definition
CodeEF
DefinitionEast Foss Farm, Durham, NH
Source
Code Definition
CodeCW
DefinitionCollege Woods, Durham, NH
Source
Unitcentimeter
Typereal
Min
Max89.1 
Unitmeter
Typereal
Min0.2 
Max33.7 
Allowed Values and Definitions
Enumerated Domain 
Code Definition
Code1
DefinitionUnderstory very little access to either direct or lateral light
Source
Code Definition
Code1.5
DefinitionUnderstory with some diffuse light from nearby canopy gaps
Source
Code Definition
Code2
DefinitionUnderstory with moderate (primarily diffuse) light from nearby canopy gaps
Source
Code Definition
Code2.5
DefinitionUnderstory with direct lateral light or high diffuse light from nearby canopy gaps, but not direct vertical light
Source
Code Definition
Code3
DefinitionIntermediate: between 10% and 90% of the vertical projection of the crown is exposed to vertical light
Source
Code Definition
Code4
DefinitionCodominant: more than 90% of the vertical projection of the crown is exposed to vertical light
Source
Code Definition
Code4.5
DefinitionMarginal between codominant and dominant
Source
Code Definition
Code5
DefinitionDominant: fully exposed to vertical light and to lateral light from within a 90-degree inverted cone encompassing the crown
Source
Allowed Values and Definitions
Enumerated Domain 
Code Definition
CodeC
Definitioncore
Source
Code Definition
CodeT
Definitiontwig
Source
UnitmillimetersPerYear
Typereal
Min0.08 
Max6.55 
Allowed Values and Definitions
Enumerated Domain 
Code Definition
CodeU
DefinitionIntermediate, mid-canopy and understory trees growing in closed-canopy stands (crown classes 1-3), which are too large to count as saplings (DBH > 4 cm)
Source
Code Definition
CodeC
DefinitionCo-dominant or dominant trees growing in closed-canopy stands (crown classes 4 and 5)
Source
Code Definition
CodeUS
DefinitionUnderstory saplings (crown classes 1-3; DBH < 4 cm)
Source
Code Definition
CodeLSX
DefinitionSaplings growing in bedrock crevices in an open ledge environment. These samples were collected for qualitative comparison only, and are excluded from analyses.
Source
Code Definition
CodeOSX
DefinitionOne T. canadensis sampled in a small clearcut at Thompson Farm. Because we found no open-grown T. canadensis saplings of comparable size to those sampled for other species, this tree was excluded from analysis but is reported for qualitative comparison or inclusion in larger datasets.
Source
Code Definition
CodeSSX
DefinitionIntermediate, mid-canopy and understory trees growing in closed-canopy stands (crown classes 1-3), which are too large to count as saplings (DBH > 4 cm)
Source
Code Definition
CodeOS
DefinitionOpen-grown saplings (crown classes 4 and 5; DBH < 4 cm)
Source
Unitpermil
Typereal
Min-33.35 
Max-21.93 
Unitpermil
Typereal
Min13.79 
Max25.77 
Unitdimensionless
Typereal
Min0.33 
Max0.75 
UnitmicromolesPerMole
Typereal
Min23.15 
Max149.85 
Missing Value Code:              
CodeNA
ExplNA Indicates a value was not obtained
         
Accuracy Report:                          
Accuracy Assessment:                          
Coverage:                          
Methods:                          

Data Package Usage Rights

This information is released under the Creative Commons license - Attribution - CC BY (https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) is required to cite it appropriately in any publication that results from its use. The Data User should realize that these data may be actively used by others for ongoing research and that coordination may be necessary to prevent duplicate publication. The Data User is urged to contact the authors of these data if any questions about methodology or results occur. Where appropriate, the Data User is encouraged to consider collaboration or co-authorship with the authors. The Data User should realize that misinterpretation of data may occur if used out of context of the original study. While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed. All data are made available "as is." The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data. Thank you.

Keywords

By Thesaurus:
HBES Vocabularywater-use efficiency, carbon isotopes, ecophysiology, carbon fertilization, subcanopy gradients, Hubbard Brook Experimental Forest
LTER Controlled Vocabularycarbon , isotopes, wood, celllulose, tree rings
Project ThesaurusSleepers River, Thompson Farm, Cone Pond, New Hampshire
Project ThesarusVermont

Methods and Protocols

These methods, instrumentation and/or protocols apply to all data in this dataset:

Methods and protocols used in the collection of this data package
Description:

Tree core samples were collected in 2017-18 from eight common northeastern U.S. tree species which have some degree of shade tolerance in the sapling stage. Sampled stands were all naturally regenerated, fairly mature secondary forests with a closed canopy and no evidence of stand-scale disturbance in the past 30 years. To reduce variation in water status unrelated to tree size, we sampled in flat or mid-slope positions, avoiding microsites with unusually high or low soil moisture.

Our sampling methods were adapted from Brienen et al. (2017). Across all size classes present in each stand, we sampled trees of representative canopy position, health, and vigor for their size. We avoided sampling trees with evidence of a substantial recent change in canopy position. Some samples were collected in or near single-tree natural canopy gaps, but we avoided forest edges and multi-tree gaps. Sapwood samples were collected with a 4.3 mm-diameter increment borer, to a depth of at most 5 cm. One sample was collected per tree, at approximately 30 cm height, to minimize the effects of sampling on timber value and hydraulic function. The height of sampling on parts of the bole below well all live branches is not thought to systematically affect wood delta13Cp (Leavitt, 2010).

Diameter at breast height and canopy position were recorded for each sampled tree. The height of each sampled tree was measured from at least two vantage points using a Haglof Vertex IV hypsometer. Crown illumination categories were adapted from Clark and Clark (1992), with a greater focus placed on diffuse light below the canopy, due to the latitude of our study sites. These categories reflect judgements about summer mid-day illumination conditions, regardless of the season in which sampling occurred.

In stands where we could find them, saplings (defined here as any tree &lt; 4 cm DBH but at least 5 years old) were also included in the analysis, by collecting 5-year old twig segments from the upper, middle, and lower third of the crown. Twig segments were aged by counting terminal bud scars. Bark was removed before drying, and lengths proportional to the total 2013 growth of each twig segment were composited for processing.

For most species, additional twig samples were taken opportunistically from saplings growing nearby in fully illuminated conditions (in recent clearcuts, utility rights-of-way, and clearings around meteorological stations). These samples are intended to help separate the direct effect of size from those of canopy position, and to represent the initial growth conditions of trees that regenerated following canopy-removing disturbance. A small number of young saplings were also sampled in a recent strip-cut partial harvest at the Jones site, to provide comparable data for saplings with an intermediate light environment (no canopy directly overhead, but nearby trees &gt; 20 m tall providing shade for much of the day regardless).

After air-drying samples, growth rings from 2013-17 were identified, measured on a sliding-stage micrometer under 10-40X magnification, and separated with a razor blade from bark and older wood. Core and twig samples were extracted to alpha-cellulose using a Jayme-Wise procedure adapted from Leavitt and Danzer (1993) by Gregg and Brooks (2003). Homogenized samples were analyzed for delta13C on an Isoprime IRMS at the University of New Hampshire Instrumentation Center. Median delta13C precision (difference between duplicates) of 15 samples analyzed in duplicate was 0.03 per mil (maximum 0.23 per mil).

We calculated 13C discrimination and intrinsic water use efficiency for each sample following Farquhar et al. (1982, 1989) and McCarroll and Loader (2004), without attempting to account for post-photosynthetic C fractionation. For these calculations, we assumed that the atmospheric CO2 concentration was 401 ppm and the delta13C of the atmosphere was -8.44 per mil, which are the mean values observed at Mauna Loa in 2015 (Keeling et al., 2017; Scripps CO2 Program, 2019).

Brienen, R.J.W., Gloor, E., Clerici, S., Newton, R., Arppe, L., Boom, A., Bottrell, S., Callaghan, M., Heaton, T., Helama, S., Helle, G., Leng, M.J., Mielikainen, K., Oinonen, M., Timonen, M., 2017. Tree height strongly affects estimates of water-use efficiency responses to climate and CO2 using isotopes. Nat. Commun. 8, 288. https://doi.org/10.1038/s41467-017-00225-z

Clark, D.A., Clark, D.B., 1992. Life history diversity of canopy and emergent trees in a neotropical rain forest. Ecol. Monogr. 62, 315-344. https://doi.org/10.2307/2937114

Farquhar, G.D., Ehleringer, J.R., Hubick, K.T., 1989. Carbon Isotope Discrimination and Photosynthesis. Annu. Rev. Plant Physiol. Plant Mol. Biol. 40, 503-537. https://doi.org/10.1146/annurev.pp.40.060189.002443

Farquhar, G.D., O'Leary, M.H., Berry, J.A., 1982. On the relationship between carbon isotope discrimination and the intercellular carbon dioxide concentration in leaves. Aust. J. Plant Physiol. 9, 121-137. https://doi.org/10.1071/PP9820121

Gregg, J., Brooks, R., 2003. Operating procedures for holocellulose and alpha-cellulose extraction. US EPA Integrated Stable Isotope Research Facility, Corvallis, OR.

Keeling, R.F., Graven, H.D., Welp, L.R., Resplandy, L., Bi, J., Piper, S.C., Sun, Y., Bollenbacher, A., Meijer, H.A.J., 2017. Atmospheric evidence for a global secular increase in carbon isotopic discrimination of land photosynthesis. Proc. Natl. Acad. Sci. 201619240. https://doi.org/10.1073/pnas.1619240114

Leavitt, S.W., 2010. Tree-ring C-H-O isotope variability and sampling. Sci. Total Environ. 408, 5244-5253. https://doi.org/10.1016/j.scitotenv.2010.07.057

Leavitt, S.W., Danzer, S.R., 1993. Method for batch processing small wood samples to holocellulose for stable-carbon isotope analysis. Anal. Chem. 65, 87-89. https://doi.org/10.1021/ac00049a017

McCarroll, D., Loader, N.J., 2004. Stable isotopes in tree rings. Quat. Sci. Rev. 23, 771-801. https://doi.org/10.1016/j.quascirev.2003.06.017

Scripps CO2 Program, 2019. Scripps Institution of Oceanography [WWW Document]. URL http://scrippsco2.ucsd.edu/data/atmospheric_co2/mlo.html

People and Organizations

Creators:
Individual: Matthew A Vadeboncoeur
Organization:University of New Hampshire
Email Address:
matt.vad@unh.edu
Id:https://orcid.org/0000-0002-8269-0708
Individual: Katie A Jennings
Organization:University of New Hampshire
Email Address:
katie.jennings@unh.edu
Id:https://orcid.org/0000-0002-2385-9788
Individual: Andrew P Ouimette
Organization:University of New Hampshire
Email Address:
andrew.ouimette@unh.edu
Id:https://orcid.org/0000-0003-3016-5730
Individual: Heidi Asbjornsen
Organization:University of New Hampshire
Email Address:
heidi.asbjornsen@unh.edu
Id:https://orcid.org/0000-0001-8126-3328
Contacts:
Organization:Hubbard Brook LTER Information Manager
Email Address:
hbr-im@lternet.edu

Temporal, Geographic and Taxonomic Coverage

Temporal, Geographic and/or Taxonomic information that applies to all data in this dataset:

Time Period
Begin:
2013
End:
2017
Geographic Region:
Description:New Hampshire and Vermont
Bounding Coordinates:
Northern:  44.5Southern:  43.1
Western:  -72.2Eastern:  -70.9
Taxonomic Range:
Classification:
Rank Name:kingdom
Rank Value:Plantae
Classification:
Rank Name:subkingdom
Rank Value:Viridiplantae
Classification:
Rank Name:infrakingdom
Rank Value:Streptophyta
Classification:
Rank Name:superdivision
Rank Value:Embryophyta
Classification:
Rank Name:division
Rank Value:Tracheophyta
Classification:
Rank Name:subdivision
Rank Value:Spermatophytina
Classification:
Rank Name:class
Rank Value:Magnoliopsida
Classification:
Rank Name:superorder
Rank Value:Rosanae
Classification:
Rank Name:order
Rank Value:Sapindales
Classification:
Rank Name:family
Rank Value:Sapindaceae
Classification:
Rank Name:genus
Rank Value:Acer
Classification:
Rank Name:species
Rank Value:Acer rubrum
Classification:
Rank Name:kingdom
Rank Value:Plantae
Classification:
Rank Name:subkingdom
Rank Value:Viridiplantae
Classification:
Rank Name:infrakingdom
Rank Value:Streptophyta
Classification:
Rank Name:superdivision
Rank Value:Embryophyta
Classification:
Rank Name:division
Rank Value:Tracheophyta
Classification:
Rank Name:subdivision
Rank Value:Spermatophytina
Classification:
Rank Name:class
Rank Value:Magnoliopsida
Classification:
Rank Name:superorder
Rank Value:Rosanae
Classification:
Rank Name:order
Rank Value:Sapindales
Classification:
Rank Name:family
Rank Value:Sapindaceae
Classification:
Rank Name:genus
Rank Value:Acer
Classification:
Rank Name:species
Rank Value:Acer saccharum
Classification:
Rank Name:kingdom
Rank Value:Plantae
Classification:
Rank Name:subkingdom
Rank Value:Viridiplantae
Classification:
Rank Name:infrakingdom
Rank Value:Streptophyta
Classification:
Rank Name:superdivision
Rank Value:Embryophyta
Classification:
Rank Name:division
Rank Value:Tracheophyta
Classification:
Rank Name:subdivision
Rank Value:Spermatophytina
Classification:
Rank Name:class
Rank Value:Magnoliopsida
Classification:
Rank Name:superorder
Rank Value:Rosanae
Classification:
Rank Name:order
Rank Value:Fagales
Classification:
Rank Name:family
Rank Value:Fagaceae
Classification:
Rank Name:genus
Rank Value:Fagus
Classification:
Rank Name:species
Rank Value:Fagus grandifolia
Classification:
Rank Name:kingdom
Rank Value:Plantae
Classification:
Rank Name:subkingdom
Rank Value:Viridiplantae
Classification:
Rank Name:infrakingdom
Rank Value:Streptophyta
Classification:
Rank Name:superdivision
Rank Value:Embryophyta
Classification:
Rank Name:division
Rank Value:Tracheophyta
Classification:
Rank Name:subdivision
Rank Value:Spermatophytina
Classification:
Rank Name:class
Rank Value:Magnoliopsida
Classification:
Rank Name:superorder
Rank Value:Asteranae
Classification:
Rank Name:order
Rank Value:Lamiales
Classification:
Rank Name:family
Rank Value:Oleaceae
Classification:
Rank Name:genus
Rank Value:Fraxinus
Classification:
Rank Name:species
Rank Value:Fraxinus americana
Classification:
Rank Name:kingdom
Rank Value:Plantae
Classification:
Rank Name:subkingdom
Rank Value:Viridiplantae
Classification:
Rank Name:infrakingdom
Rank Value:Streptophyta
Classification:
Rank Name:superdivision
Rank Value:Embryophyta
Classification:
Rank Name:division
Rank Value:Tracheophyta
Classification:
Rank Name:subdivision
Rank Value:Spermatophytina
Classification:
Rank Name:class
Rank Value:Pinopsida
Classification:
Rank Name:subclass
Rank Value:Pinidae
Classification:
Rank Name:order
Rank Value:Pinales
Classification:
Rank Name:family
Rank Value:Pinaceae
Classification:
Rank Name:genus
Rank Value:Picea
Classification:
Rank Name:species
Rank Value:Picea rubens
Classification:
Rank Name:kingdom
Rank Value:Plantae
Classification:
Rank Name:subkingdom
Rank Value:Viridiplantae
Classification:
Rank Name:infrakingdom
Rank Value:Streptophyta
Classification:
Rank Name:superdivision
Rank Value:Embryophyta
Classification:
Rank Name:division
Rank Value:Tracheophyta
Classification:
Rank Name:subdivision
Rank Value:Spermatophytina
Classification:
Rank Name:class
Rank Value:Pinopsida
Classification:
Rank Name:subclass
Rank Value:Pinidae
Classification:
Rank Name:order
Rank Value:Pinales
Classification:
Rank Name:family
Rank Value:Pinaceae
Classification:
Rank Name:genus
Rank Value:Pinus
Classification:
Rank Name:species
Rank Value:Pinus strobus
Classification:
Rank Name:kingdom
Rank Value:Plantae
Classification:
Rank Name:subkingdom
Rank Value:Viridiplantae
Classification:
Rank Name:infrakingdom
Rank Value:Streptophyta
Classification:
Rank Name:superdivision
Rank Value:Embryophyta
Classification:
Rank Name:division
Rank Value:Tracheophyta
Classification:
Rank Name:subdivision
Rank Value:Spermatophytina
Classification:
Rank Name:class
Rank Value:Magnoliopsida
Classification:
Rank Name:superorder
Rank Value:Rosanae
Classification:
Rank Name:order
Rank Value:Fagales
Classification:
Rank Name:family
Rank Value:Fagaceae
Classification:
Rank Name:genus
Rank Value:Quercus
Classification:
Rank Name:species
Rank Value:Quercus rubra
Classification:
Rank Name:kingdom
Rank Value:Plantae
Classification:
Rank Name:subkingdom
Rank Value:Viridiplantae
Classification:
Rank Name:infrakingdom
Rank Value:Streptophyta
Classification:
Rank Name:superdivision
Rank Value:Embryophyta
Classification:
Rank Name:division
Rank Value:Tracheophyta
Classification:
Rank Name:subdivision
Rank Value:Spermatophytina
Classification:
Rank Name:class
Rank Value:Pinopsida
Classification:
Rank Name:subclass
Rank Value:Pinidae
Classification:
Rank Name:order
Rank Value:Pinales
Classification:
Rank Name:family
Rank Value:Pinaceae
Classification:
Rank Name:genus
Rank Value:Tsuga
Classification:
Rank Name:species
Rank Value:Tsuga canadensis

Project

Parent Project Information:

Title:Collaborative Research: Forest Water Use and the Influence of Acid Deposition
Personnel:
Individual: Matthew A Vadeboncoeur
Organization:University of New Hampshire
Email Address:
matt.vad@unh.edu
Id:https://orcid.org/0000-0002-8269-0708
Role:Principal Investigator
Funding: NSF: EAR-1562127

Maintenance

Maintenance:
Description:complete
Frequency:
Other Metadata

Additional Metadata

additionalMetadata
        |___text '\n    '
        |___element 'metadata'
        |     |___text '\n      '
        |     |___element 'unitList'
        |     |     |___text '\n        '
        |     |     |___element 'unit'
        |     |     |     |  \___attribute 'id' = 'micromolesPerMole'
        |     |     |     |  \___attribute 'multiplierToSI' = ''
        |     |     |     |  \___attribute 'name' = 'micromolesPerMole'
        |     |     |     |  \___attribute 'parentSI' = ''
        |     |     |     |  \___attribute 'unitType' = ''
        |     |     |     |___text '\n          '
        |     |     |     |___element 'description'
        |     |     |     |___text '\n        '
        |     |     |___text '\n        '
        |     |     |___element 'unit'
        |     |     |     |  \___attribute 'id' = 'permil'
        |     |     |     |  \___attribute 'multiplierToSI' = ''
        |     |     |     |  \___attribute 'name' = 'permil'
        |     |     |     |  \___attribute 'parentSI' = ''
        |     |     |     |  \___attribute 'unitType' = ''
        |     |     |     |___text '\n          '
        |     |     |     |___element 'description'
        |     |     |     |___text '\n        '
        |     |     |___text '\n        '
        |     |     |___element 'unit'
        |     |     |     |  \___attribute 'id' = 'millimetersPerYear'
        |     |     |     |  \___attribute 'multiplierToSI' = ''
        |     |     |     |  \___attribute 'name' = 'millimetersPerYear'
        |     |     |     |  \___attribute 'parentSI' = ''
        |     |     |     |  \___attribute 'unitType' = ''
        |     |     |     |___text '\n          '
        |     |     |     |___element 'description'
        |     |     |     |___text '\n        '
        |     |     |___text '\n      '
        |     |___text '\n    '
        |___text '\n  '

EDI is a collaboration between the University of New Mexico and the University of Wisconsin – Madison, Center for Limnology:

UNM logo UW-M logo