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Spatial Extent:

Conterminous USA

Spatial Resolution:

0.5 degree gridded

Temporal Characteristics:

 
Date Classes Represented:

Reference (Ref)
Time Steps Available:

N.A.
Dates represented:

N.A.

Please review the VEMAP2 Data Policy and register with VEMAP prior to ordering or using data from EOS-WEBSTER.

Please acknowledge the University of New Hampshire, EOS-WEBSTER Earth Science Information Partner (ESIP) as the data distributor for this dataset.

 

Summary:

Vegetation/Ecosystem Modeling and Analysis Project (VEMAP) gridded reference data used in the VEMAP Phase 1 and 2 biogeochemical model comparisons for the conterminous USA. Data includes 0.5-degree gridded products for elevation, land area, potential vegetation, and soil properties. Visit the VEMAP website for complete information about the VEMAP project and datasets.

EOS-WEBSTER has two VEMAP data collections. Additional VEMAP data can be found in the VEMAP2 Transient Dynamics (USA) data collection.

 

The VEMAP Reference Data collection contains the following datasets:

  • Geography - elevation, area, and percent land area for each VEMAP grid-cell.
  • Landcover - potential natural vegetation under current conditions.
  • Soil modes - the number of dominant (modal) soils in each VEMAP grid-cell for which soils data are available. Note that the VEMAP1 published simulations were based on the mineral soil component for modal soil 1.
  • Soils (mineral, organic, and total) - up to 18 variables that make up the mineral or organic component of the soil, or combined for a total soil value. Variables are available for each modal soil (1-4) and for an average soil. Many variables are available for an upper (0-50 cm) and lower (50 -150 cm) soil layer.

 

The following variables are available from the VEMAP Reference Data datasets:

Dataset

Variable

Description

Unit

Number of EOS-WEBSTER Holdings

Geography

elevation

mean grid-cell elevation

m

1

 

grid area

absolute area of each 0.5 degree grid cell

km2

1

 

land area**

absolute area of each 0.5 degree grid cell that is covered by land and in the VEMAP domain

km2

1

 

percent land area**

percent of the area of each 0.5 degree grid cell that is covered by land and in the VEMAP domain

Percent

1

Landcover

potential vegetation

major vegetation class based on natural processes

class

2

Soil modes*

soil modes

number of modal soil profiles (1-4) per 0.5 x 0.5 degree grid-cell

class

1

Soils (mineral)*

see Soils Table below

mineral soil properties and elements at 0.5 degree resolution; modal and average soil data for 1-2 layers [0-50 cm and 50-150 cm].

varies

80

Soils (organic)

see Soils Table below

organic soil properties and elements at 0.5 degree resolution; modal and average soil data for 1-2 layers [0-50 cm and 50-150 cm].

varies

30

Soils (total)

see Soils Table below

total (mineral + organic) soil properties at 0.5 degree resolution; modal and average soil data.

varies

14

*Note: the mineral soil component for modal soil 1 was used in the published VEMAP1 simulations.

**Absolute land area [km2] is determined as: (grid area) * (percent land area/100).

 

 

Table of Soil Variables:

Variable

Dataset(s)

Description

Unit

 

Mineral*

Organic

Total

   

bulk density

X

   

bulk density of mineral soil

g/cm3

rock fragments

X

X

 

rock fragments portion of soil

% by volume

soil area (absolute)

X

X

 

areal coverage of soil component

square-km

soil area (percent)

X

 

X

percent of areal coverage taken up by modal soil

% of cell land area

soil depth

X

X

 

depth of soil component

cm

soil organic carbon (0 -100 cm)

   

X

soil organic carbon in the upper 0-100 cm of soil

Mg C/ha

soil organic carbon (0 -20 cm)

   

X

soil organic carbon in the upper 0-20 cm of soil

Mg C/ha

texture (clay)

X

   

clay content of mineral soil

% by weight

texture (sand)

X

   

sand content of mineral soil

% by weight

texture (silt)

X

   

silt content of mineral soil

% by weight

texture (organic content)

X

   

organic content of mineral soil

% by weight

water holding capacity

X

X

 

water holding capacity of soil component

cm H2O

*Note: the mineral soil component for modal soil 1 was used in the published VEMAP1 simulations.

 

 

 

 

Major Vegetation Class Descriptions (EOS-WEBSTER provides this information as an auxiliary file with your order of VEMAP Reference (USA) potential vegetation data.)

TUNDRA

1 Tundra

FOREST

2 Boreal Coniferous Forest

(includes Boreal Transition & Subalpine Forests)

3 Maritime Temperate Coniferous Forest

4 Continental Temperate Coniferous Forest

5 Cool Temperate Mixed Forest

6 Warm Temperate/Subtropical Mixed Forest

7 Temperate Deciduous Forest

8 Tropical Deciduous Forest (not present)**

9 Tropical Evergreen Forest (not present)**

XEROMORPHIC WOODLANDS and FORESTS

10 Temperate Mixed Xeromorphic Woodland

11 Temperate Conifer Xeromorphic Woodland

12 Tropical Thorn Woodland (not present)**

SAVANNAS

13 Temperate/Subtropical Deciduous Savanna

14 Warm Temperate / Subtropical Mixed Savanna

15 Temperate Conifer Savanna

16 Tropical Deciduous Savanna (not present)**

GRASSLANDS

17 C3 Grasslands (Includes Short through Tall C3 Grasslands)

18 C4 Grasslands (Includes Short through Tall C4 Grasslands)

SHRUBLANDS

19 Mediterranean Shrubland

20 Temperate Arid Shrubland

21 Subtropical Arid Shrubland

Excluded Surface Types

90 Ice (not present)**

91 Inland Water Bodies (Includes ocean inlets)

92 Wetlands (Includes floodplains & strands)

** 'not present' means not present in the current distribution

of types for the US.

 

The complete Users Guide to the VEMAP Phase I Database which includes more information about this data set can be found at:

http://www-eosdis.ornl.gov/VEMAP/guides/users_guide.html.

 

 

VEMAP Reference Data Citations:

Kittel, T.G.F., N.A. Rosenbloom, T.H. Painter, D.S. Schimel, and VEMAP Modeling Participants (1995). The VEMAP integrated database for modeling United States ecosystem/vegetation sensitivity to climate change. J. Biogeog. 22:857-862.

Kittel, T.G.F., N.A. Rosenbloom, T.H. Painter, D.S. Schimel, H.H. Fisher, A. Grimsdell, VEMAP Participants (2000). VEMAP Phase 1 Database.

 

Data Providers:

The VEMAP Data Group at NCAR; VEMAP Participants; and Ben Felzer. P.O. Box 3000 Boulder, CO 80307-3000. Phone: (303) 497- 1000.

 

Last Data Update:

9/1/2001

Last Doc. Updated:

7/09/2003

Doc. Updated By:

Denise Blaha

 

 

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