Tucson Mountain District, Vegetation Inventory, Mapping,andCharacterization Report,Saguaro National Park of of meria bicolor). The typeisnotable due to the almost complete absence dentata), and afield stratum (<0.5m) dominated by white ratany (Kra by whitethorn acacia (Vachellia constricta) and creosote (Larrea tri- yellow paloverde (Parkinsonia microphylla ), asubcanopy co-dominated This community ischaracterized by avery open(<5%cover) canopy of Shrubland Association(P) (Saguaro) /Yellow paloverde/Creosote-Cactusapple(Whitethornacacia) /WhiteratanyWooded 6. (Carnegieagigantea) arbuscula), noteworthy field include Christmas cholla (Cylindropuntia leptocaulis), pencil cholla associate. White ratany (K. bicolor) isaconsistent (1.0)dominant, with cover ranging from 1%to 3%. Other and 2%,respectively. Buckhorn cholla (Cylindropuntia acanthocarpa ) isaconsistent (1.0),low-cover (1%) and creosote (L. tridentata)are very consistent (1.0)subcanopy dominants, with average cover around of 5% Ocotillo (Fouquieria splendens) isapatchy (0.67),low-cover (<1%)associate. Whitethorn acacia (V. gantea) isaconsistent (1.0)associate, with average cover around of 1%. mostly assmall trees upto four meters inheight. Saguaro (Carnegiea gi- habitat. Yellow paloverde (P. microphylla) averages 3%cover, growing farinosa), two species that tend to dominate communities sharing similar engelmannii American threefold dominated by alayer fine gravel, of with scattered rocks throughout. 3,100 ft). These hills are often bisected by shallow drainages and low-height interfluves. The surface cover is It spans alow-angle (<15%)and broad semi-alluvial section rolling of hills from 700to 945meters (2,300– Pictureof Rocks Road, near the Trail, and the other along the eastern boundary near Veterans Trail. This community covers the 0.5%(55ha/136 ac)of Tucson Mountain District intwo small locations, one south phe cooperi), and desertsenna (Sennacovesii ). triangle burragweed ( pinkflower hedgehog ( Vachellia constricta) ( Trixis californica), rough menodora Ambrosia deltoidea) and brittlebush

/ Parkinsoniamicrophylla/ ( Echinocereus fasciculatus),

/ KrameriabicolorWooded ShrublandAssociation(P) ( Menodora scabra), whitestem ( Encelia Larrea tridentata - Larreatridentata-Opuntia candy barrelcactus - • • • • • Common species

Krameria bicolor Vachellia constricta Larrea tridentata Parkinsonia microphylla Carnegiea gigantea ( paperflower (Psilostro- wislizeni ), ( Cylindropuntia constricta) Tucson Mountain District, Saguaro National Park