Total cover of the shrub layer in percent. Includes shrubs (multiple-stemmed woody plants, generally less than 5 m in height at maturity under optimal growing conditions) and shorter trees (saplings). As with the tree stratum, other life forms present in this stratum may also be included (however, herbaceous life forms should be excluded, as their stems often die back annually and do not have as consistent a height as woody life forms). Where dwarf-shrubs (i.e. shrubs shorter than 0.5 m) form a distinct stratum (either as part of a series of strata, as in a forest, or as the top stratum of more open vegetation, such as tundra or xeric shrublands), they should be treated as a low version of the shrub stratum (or short shrub substratum). In many vegetation types, dwarf-shrubs may simply occur as one life form component of the herb stratum.