Parameter Tree:
EARTH SCIENCE > BIOSPHERE > TERRESTRIAL ECOSYSTEMS > SHRUBLAND/SCRUB

Definition:
Areas with vegetation dominated by shrubs (generally greater than 0.5 m or
1.5 ft tall, but less than 5 m or 16 ft tall) with individuals or
clumps overlapping to not touching (generally forming more than 25%
cover, trees generally less than 25% cover). 


Reference:
The Nature Conservancy
Glossary of Terms Used in the US National Vegetation
Classificaion Hierarchy, 1998