Attribute_Name	ORDER	Storage_Type	Measurement_Scale	Number_Type	UNITS	DESCRIPTION	CODES
date	1	a	date-time	n/a	nominalDay	collected twice a year from 1997-2000	month/day/year
Trt.	2	a	nominal	n/a	dimensionless	see reference: carbon isotopes of elevated and ambient OTC plants were measured for use in isotope labeling and plant water-use-efficiency measures. Leaf N and C are associated parameters were also measured.	a=ambient CO2 open-top-chamber; h=elevated (720ppm) CO2 OTC; c=nonchambered control
Rep	3	a	nominal	n/a	dimensionless	plot or block	1,2,3
species	4	a	nominal	n/a	dimensionless		bogr=Bouteloua gracilis pasm=Pascopyrum smithii
% N	6	f	ratio	real	number	percent nitrogen	
Atom %	7	f	ratio	real	number	percent 15N label	
% C	8	f	ratio	real	number	percent carbon	
PDB_vs_13C	9	f	ratio	real	number	carbon 13 vs. PDB standard	
Ci/Ca	10	f	ratio	real	number	intercellular vs extracellular CO2 conc. From gas exchage msrmt	
stat_value	5	a	nominal	n/a	dimensionless	statistical value being reported in the cell	mean or standard error
