TABLE I. ECOLOGICAL OR LIFE ZONES OF THE TROPICS, SUB TROPICS, AND WARM TEMPERATE ZONES
Ecological Zones (1,2) |
Mean Annual Temperature (Deg. C) |
Average Annual Rainfall (mm) |
Symbol |
Tropical Desert Shrub |
24 or more |
125 - 250 |
Tx |
Tropical Thorn Steppe |
24 or more |
250 - 500 |
Tt |
Tropical Very Dry Forest |
24 or more |
500 - 1000 |
Tv |
Tropical Dry Forest |
24 or more |
1000 - 2000 |
Td |
Tropical Moist Forest |
24 or more |
2000 - 4000 |
Tm |
Tropical Wet Forest |
24 or more |
4000 - 8000 |
Tw |
Tropical Rain Forest |
24 or more |
8000 or more |
Tr |
Subtropical Desert Scrub |
18 - 24 |
125 - 250 |
Sx |
Subtropical Thorn Woodland |
18 - 24 |
250 - 500 |
St |
Subtropical Dry Forest |
18 - 24 |
500 - 1000 |
Sd |
Subtropical Moist Forest |
18 - 24 |
1000 - 2000 |
Sm |
Subtropical Wet Forest |
18 - 24 |
2000 - 4000 |
Sw |
Subtropical Rain Forest |
18 - 24 |
4000 or more |
Sr |
Warm Temperate Desert Bush |
12 - 18 |
125 - 250 |
Wx |
Warm Temperate Woodland |
12 - 18 |
250 - 500 |
Wt |
Warm Temperate Dry Forest |
12 - 18 |
500 - 1000 |
Wd |
Warm Temperate Moist Forest |
12 - 18 |
1000 - 2000 |
Wm |
Warm Temperate Wet Forest |
12 - 18 |
2000 - 4000 |
Ww |
Warm Temperate Rain Forest |
12 - 18 |
4000 or more |
Wr |
NOTE: In the Appendix you will see life zone symbols of more than two letters. For example, okra grows in life zones Wdm and Txm. The capital letters refer to tropical, subtropical or warm temperate climates. The small letters are for types of vegetation as determined by the life zones. Using the chart below you can see that okra will grow in warm temperate dry forests, warm temperate moist forests, tropical dessert scrub and tropical moist forest climates.
C = Cool temperate d = dry forest
T = Tropical m = moist forest
S = Subtropical r = rain forest
W = Warm temperate t = thorn steppe (if tropical) or woodland (if warm temperate)
B = Boreal v = very dry forest
w = wet forest
x = desert scrub (if tropical or subtropical) or bush (if temperate)