Ulmus americana
American Elm

Mature Height: 50-200'     Longevity: 400 years

2-8 Water Range
Soil moisture tolerated by tree

2-9 Temperature Range
Hardiness Zones in which tree naturally occurs.

DEFENSE     Soil Moisture Key
2: Literature indicates moderate drought tolerance. Does not prefer upland sites but can survive so long as prolonged drought not a factor.

8: Most common on swamp edges. Tolerates non-growing season inundation but, does not tolerate prolonged inundation during growing season. Hydric indicator FACW.

DEFENSE (from Distribution Maps)
National Audubon Society (NAS) Map: (NORTH) Solid Z3 w/ enough presence in Z2 to warrant inclusion. (SOUTH) Solid Z9.

Peterson Field Guide (PFG) Map: Same as NAS.

7   Sun Strength

6   Shade Strength

DEFENSE
Growth Rate:
Succession:
Soil Range:
Salt Tol.:
Allelopath:
Avg Height:
Max Height:

Click here for Key
6.5 = Rapid
0 = Not pioneer
+.4 = 3 Major & 1 Minor
+.3 = High
0 = No
0 = 75'
+.2 = 200'

DEFENSE
Shade Tol.:
Succession:
Soil Range:
Salt Tol.:
Allelopath:
Avg Height:
Longevity:

Click here for Key
5 = Intermediate
+.3 = Climax Capable
+.4 = 3 Major & 1 Minor
+.3 = Some
0 = No
0 = 75'
+.3 = 400+

TOTAL SCORE (7.4): Rapid growing tree that occurs on all three major soil orders. Borderline 7/8 tree. May pioneer occassionally but chose not to assign +.3 on account of susceptibility to disease.

TOTAL SCORE (6.3): Only intermediate in shade value but combination of good performance in all other ranking categories boosts strength.

3   Fire Strength

2   Wind Strength

DEFENSE
Base Score: Low (Big Tree) = 3
Fire Effects (FEIS) database indicates tree is easily damaged by fire. But tree is fairly large w/ some fire resistant morphology so will assign lower mid value.
Final Value = 3

DEFENSE
Base Score: ???
Literature indicates tree is fairly windfirm. Univ. Florida indicates susceptible to breakage & Iowa state report also lists as susceptible. Since tree is susceptible to disease & grows so high will only assign a 2.
Final Value = 2