GCE Standards and Definitions

This page contains lists of site standards for reporting commonly-measured research parameters, as well as definitions of various acronyms used in the GCE Information System. The lists are divided into the following sections:

Site Standards

Geographic Measurements
Sample Labeling
Hydrographic Measurements
Chemical Measurements
Recommended Variable Names

GCE-IS Acronym Definitions

Research themes
LTER core research areas

Site Standards

Geographic Measurements

Parameter	Site Standard	Units	Measurement
Geographic coordinates	Latitude	decimal degrees (-90 to 90)	Differential GPS USGS DRG Maps*
	Longitude	decimal degrees (-180 to 180)	Differential GPS USGS DRG Maps*
	Universal Transverse Mercator, using WGS84 ellipsoid datum**	zone (number) easting (m) northing (m)	Differential GPS USGS DRG Maps*

* Coordinates can be read from 1:24,000 scale USGS Digital Raster Graphic maps using software provided by the Data Manager or using ArcGIS

** UTM coordinates will be converted to projection-free latitude and longitude, either by the Data Manager or by data contributors using approved geographic software, and added as new columns in the data set. Conversion from Lat/Lon to UTM/WGS84 will be provided as an option when requesting data sets online or using offline GCE-IS tools.

Sample Labeling

Sample labeling standards are generally expected to be investigator- or lab-specific, to meet the unique requirements of each investigator's research program. When designing labels to identify GCE samples, particularly for monitoring efforts, investigators should include the following information on each label:

distinct site or location identifier (e.g. GCE site, coordinates, LMER CTD station)
date and time of collection
group or treatment identifier (e.g. survey number, cast number, experiment group)
unique sample identifier (e.g. sequential number)

When location information other than geographic coordinates or GCE sites are used, the investigator will be asked to provide geographic information for each location at the time of data submission. If physical samples are retained and stored after analysis, the storage location should be included in the data documentation (Metadata Category V: Supplement_Materials).

Hydrographic Measurements

Hydrographic standards are pending. Use Practical Salinity Units for salinity and SI units as a general recommendation.

Chemical Measurements

Chemistry standards are pending. Use SI units as a general recommendation.

Other Measures

Make measurements using metric tools and report data in SI units whenever possible.

Variable Names

Investigators are strongly encouraged to use the variable name and unit recommendations listed in the table below whenever possible. This practice will enhance the consistency and readability of all data sets, dramatically easing analysis and comparisons.

When naming variables not listed below, choose descriptive names and capitalize the first letter of each word when concatenating multiple terms (note: spaces and commas are not allowed within variable name or unit strings). Avoid using names of generic properties, such as 'Mass' or 'Length', without including the name of the property measured as well (e.g. 'Leaf_Length').

Category	Parameter	Recommended Name	Recommend Units
Location	geographic coordinates	Latitude	decimal degrees (-90 to 90)
		Longitude	decimal degrees (-180 to 180)
		UTM_Zone	number
		UTM_Northing	m
		UTM_Easting	m
	permanent plot	Plot	number
	GCE site	Site	number
	GCE station	Station	text code (e.g. AL+02)
Date/Time (GMT)	date	Date	dd-mmm-yyyy (e.g. 05-Feb-2001)
	date	Date	MATLAB serial date
	time of day	Time	hh:mm (e.g. 23:30) hh:mm:ss (e.g. 22:30:30)
	year	Year	yyyy (e.g. 2001)
	month	Month	mm (e.g. 12)
	day	Day	dd (e.g. 28)
	Year day*	YearDay	day (e.g. 200)
	elapsed time	Hours	h (e.g. 0.55)
General	length	[Property]_Length (e.g. Stem_Length)	m
	height	[Property]_Height (e.g. Shoot_Height)	m
	distance	Distance	m
	mass	[Property]_Mass (e.g. Soil_Mass)	g
	percentage	[Property]_Percent (e.g. Organic_Percent)	%
Hydrography	temperature	Temperature	°C
	salinity	Salinity	PSU
	depth	Depth	m

* Year date, or Julian Date, is the number of days elapsed since January 1 of the same year

** Julian day or Julian day number is the number of days elapsed since a starting reference date, such as January 1, 0000 or January 1, 1900. When Julian days are used, be sure to include the starting year as part of your variable definition in the data documentation (Category IV: Data_Descriptions) or as part of the units string.

Acronym Definitions

Research Themes

Monitoring Studies
- ALG - Algal Productivity
- BCT - Bacterial Productivity
- FNG - Fungal Productivity
- HYD - Hydrography
- INS - Terrestrial Insect Ecology
- INV - Aquatic Invertebrate Ecology
- MET - Meteorology
- NUT - Nutrient Chemistry (general)
- ORG - Organic Matter Chemistry
- PHP - Phytoplankton Productivity
- POR - Pore-water Chemistry
- PLT - Plant Ecology
Directed Studies (in addition to Monitoring themes)
- ANT - Anthropology
- BOT - Botany
- CHM - Chemistry
- GEL - Geology
- GIS - Geographic Information System Analysis
- GPH - Geophysics
- MIC - Microbiology
- PHY - Physics, Physical Oceanography
- POP - Population Ecology