Carya illinoensis
Pecan

Mature Height: 100-180'     Longevity: 350 years

3-7 Water Range
Soil moisture tolerated by tree

5-9 Temperature Range
Hardiness Zones in which tree naturally occurs.

DEFENSE     Soil Moisture Key
3: No indication of presence in dry Xeric areas. At least some drought tolerance identified.

7: Appears to prefer well-drained soils but presence along riverbanks & some more heavily textured soils indicate that rare short term flooding may not be lethal to tree. Possibly only a 6 but will assign a 7.

DEFENSE (from Distribution Maps)
National Audubon Society (NAS) Map: (NORTH) Significant presence in Z5. (SOUTH) Intrusions into Z9 in LA & TX int Mexico. Natural range mostly along Mississippi River Valley & west into plain states.

Peterson Field Guide (PFG) Map: (NORTH) Same as NAS. (SOUTH) Less presence in Z9 evident but Mexico not shown on map.

4   Sun Strength

3   Shade Strength

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

Click here for Key
3.7 = slow to moderate
0 = not effective pioneer
+.1 = 2 Major, 1 Minor
-.2 = Sensitive
0 = No
+.3 = 120'
+.2 = 180'

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

Click here for Key
2.5 = intolerant
0 = not effective climax
+.1 = 2 Major, 1 Minor
-.2 = Sensitive
0 = No
+.2 = 120'
+.1 = 350

TOTAL SCORE (4.1): Listed with Bitternut Hickory as the "Fastest growing hickory." NRCS Plants database reports Pecan's height at 20 years slightly taller than Bitternut. Hickory's are still notoriously slow growers.

TOTAL SCORE (2.7): Identified by all sources as shade intolerant. Pecan is least shade tolerant of the hickories. Long life & large size ensures some long term presence.

3   Fire Strength

4   Wind Strength

DEFENSE
Base Score: low (Big Tree) = 3
Seems to be a concensus low fire tolerance tree. Bark is sensitive to fire in mature trees. Hickories are supposed to be amongst the most fire sensitive big trees & pecan is generally one of the weakest hickories. Decent growth rate, longevity and somewhat deep roots prevent assigning lowest Big Tree value.
Final Value = 3

DEFENSE
Base Score: ???
Hickories generally have very strong wood & are windfirm. Yet pecan is identified as having weaker, inferior wood to other hickories. In addition, pecan grows extremely tall and may be subject to serious wind loading. As such will rank pecan with slightly lower rating than other hickories.
Final Value = 4