Holdridge Life Zones Data Set

Documentation for Holdridge Life Zones Data Set at UNEP/GRID-Geneva
The Holdridge Life Zones data set is from the International
Institute for Applied Systems Analyses (IIASA) in Laxenburg,
Austria. The data set shows the Holdridge Life Zones of the
World, a combination of climate and vegetation (ecological)
types, under current, so-called "normal" climate conditions. It
has a spatial resolution of one-half degree latitude/longitude,
and a total of 38 life-zone classes (see enclosed legend). The
proper reference to this data set is "Leemans, Rik, 1990. Global
data sets collected and compiled by the Biosphere Project,
Working Paper, IIASA-Laxenburg, Austria."  

The Holdridge Life Zones data set includes a total of four data
files. The first is as described in the paragraph above; the
second shows how the Life Zones would change given an assumed
doubling of atmospheric C02 (according to a General Circulation
Model from the U.K. Office of Meteorology); while the third and
fourth files show only those Life Zone areas which would undergo
changes, before and after the doubling of C02.  

The Holdridge Life Zones data file consists of 360 rows (lines)
by 720 columns (elements/pixels/samples) of data, and one
byte/eight bits per pixel. Its origin is at 90 degrees North
latitude and 180 degrees West longitude, and it covers the entire
globe to 90 degrees South latitude and 180 degrees East
longitude. At one-half degree spatial resolution, this data file
comprises 259.2 kilobytes. 

Holdridge classification (Leemans, 1989)

1     Polar desert
2     Subpolar dry tundra
3     Subpolar moist tundra
4     Subpolar wet tundra
5     Subpolar rain tundra
6     Boreal desert
7     Boreal dry scrub
8     Boreal moist forest
9     Boreal wet forest
10    Boreal rain forest
11    Cool temperate desert
12    Cool temperate desert scrub
13    Cool temperate steppe
14    Cool temperate moist forest
15    Cool temperate wet forest
16    Cool temperate rain forest
17    Warm temperate desert
18    Warm temperate desert scrub
19    Warm temperate thorn steppe
20    Warm temperate dry forest
21    Warm temperate moist forest
22    Warm temperate wet forest
23    Warm temperate rain forest
24    Subtropical desert
25    Subtropical desert scrub
26    Subtropical thorn woodland
27    Subtropical dry forest
28    Subtropical moist forest
29    Subtropical wet forest
30    Subtropical rain forest
31    Tropical desert
32    Tropical desert scrub
33    Tropical thorn woodland
34    Tropical very dry forest
35    Tropical dry forest
36    Tropical moist forest
37    Tropical wet forest
38    Tropical rain forest