DISTRIBUTION AND OCCURRENCE
SPECIES: Ostrya knowltonii | Knowlton Hophornbeam 



GENERAL DISTRIBUTION : 
Knowlton hophornbeam is found in southeastern Utah, northern Arizona,
southeastern New Mexico (in the Guadalupe and Sacramento mountains in
Eddy County), and northern Trans-Pecos Texas.  It is not a common tree
and its occurrence is sporadic even in these areas [9,10,18,23].


ECOSYSTEMS : 
   FRES21  Ponderosa pine
   FRES32  Texas savanna
   FRES35  Pinyon - juniper


STATES : 
     AZ  NM  UT  TX


ADMINISTRATIVE UNITS : 
     CANY  CARE  CACA  GLCA  GRCA  GUMO


BLM PHYSIOGRAPHIC REGIONS : 
   12  Colorado Plateau
   13  Rocky Mountain Piedmont


KUCHLER PLANT ASSOCIATIONS : 
   K019  Arizona pine forest 
   K023  Juniper - pinyon woodland
   K031  Oak - juniper woodlands
   K032  Transition between K031 and K037
   K086  Juniper - oak savanna


SAF COVER TYPES : 
   210  Interior Douglas-fir
   237  Interior ponderosa pine
   239  Pinyon - juniper
   241  Western live oak


SRM (RANGELAND) COVER TYPES : 
NO-ENTRY


HABITAT TYPES AND PLANT COMMUNITIES : 
Knowlton hophornbeam is commonly found in oak (Quercus spp.) woodlands,
pinyon (Pinus spp.)-juniper (Juniperus spp.) woodlands, and lower
ponderosa pine (Pinus ponderosa) forest zones [9].  In Texas it is a
component of the gray oak (Quercus grisea)-true pinyon (Pinus
edulis)-alligator juniper (Juniperus deppeana) association at 5,000 to
7,000 feet (1,524-2,133 m) and the ponderosa pine-Douglas fir
(Pseudotsuga menziesii) association at 6,000 to 7,500 feet (1,828-2,286
m).  In Texas it is also associated with Texas madrone (Arbutus
texana), southwestern white pine (Pinus strobiformis), chinkapin oak (Q.
muehlenbergii), and bigtooth maple (Acer grandidentatum) [18].  In
deciduous canyon woodlands of Guadalupe Mountains National Park, Texas,
Knowlton hophornbeam will increasingly replace wavyleaf oak (Q.
undulata), alligator juniper, Riogrande cottonwood (Populus deltoides
ssp. wislizenii) and little walnut (Juglans microcarpa) as the moisture
gradient goes from xeric to mesic.  Knowlton hophornbeam is replaced by
bigtooth maple and chinkapin oak, especially on upper terraces, around
springs and in canyonheads [6,13].  

Related categories for Species: Ostrya knowltonii | Knowlton Hophornbeam