Tolerance to Water Table
1 = Species will grow on sites with soil water at or above field capacity, will grow when the water is ponded on the surface for several weeks at a time and will grow under marshy conditions. 

2 = Species will grow on sites with the soil water at or above field capacity for most of growing season.  It does not grow well when water is ponded on the surface for more than a few days at a time. 

3 = Species will grow on sites with the soil water at or above field capacity for several weeks in early spring.  It will not grow well on soils where the water is ponded on the surface during the growing season. 

4 = Species will grow on well-drained sites without a water table.