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CEGL000973 Quercus oblongifolia / Bouteloua curtipendula Scrub
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Mexican Blue Oak / Sideoats Grama Scrub
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This encinal association occurs in southeastern Arizona on gently to moderately sloping alluvial plains and bajadas to steep rocky slopes in canyons, foothills and mountains. Elevation ranges from 1370-1610 m (4500-5300 feet). Aspects are variable, but it appears more common on less xeric northern aspects and palustrine habitats in drier portions of its range. Soils are gravelly or stony sandy loams or sandy clay loams, derived from a mixture of alluvium and colluvium. The vegetation is characterized by an open to moderately dense evergreen tall-shrub layer (10-60% cover) dominated by Quercus oblongifolia. Shrub canopy is typically 3-5 m tall but may extend beyond 5 m and resemble a woodland or tree savanna. Quercus arizonica, Quercus emoryi, Prosopis spp., Juniperus deppeana, and occasional Pinus discolor may be present in the woody canopy. Associated shrubs and succulents include Agave palmeri, Acacia constricta, Arctostaphylos pungens, Brickellia spp., Dasylirion wheeleri, Ericameria laricifolia, Eriogonum wrightii, Eysenhardtia orthocarpa, Garrya wrightii, Mimosa aculeaticarpa var. biuncifera, Mimosa dysocarpa, Nolina microcarpa, Opuntia phaeacantha, Cylindropuntia spinosior, Rhus trilobata, and Yucca madrensis. The graminoid layer is moderately dense to dense (25-80% cover) and is typically dominated by medium-tall bunchgrasses such as Bouteloua curtipendula, Schizachyrium cirratum, or Muhlenbergia emersleyi, but it can also be very diverse. Other common graminoids may include Aristida ternipes, Bouteloua chondrosioides, Bouteloua eriopoda, Bouteloua gracilis, Bouteloua hirsuta, Bothriochloa barbinodis, Eragrostis intermedia, Leptochloa dubia, Muhlenbergia longiligula, and Piptochaetium fimbriatum. The usually sparse, but often diverse, forb layer is composed of Artemisia ludoviciana, Commelina spp., Chenopodium spp., Evolvulus spp., Hybanthus attenuatus, Ipomoea cristulata, Mirabilis longiflora, Viguiera spp., and many others. Diagnostic of this association is the dominance of Quercus oblongifolia in the tall-shrub canopy with at least 5% cover and a grassy understory.
Diagnostic Characteristics: Oak savannas on gentle slopes or deep alluvial soils with Quercus oblongifolia common (attaining >1% cover).
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Mature Quercus oblongifolia individuals are 7-8 m (20-25 feet) tall. The shrubland classification is not well-supported. Stuever and Hayden (1997b) treat this association as a Quercus oblongifolia / Bouteloua spp. savanna or open woodland habitat type. Kearney et al. (1969) describe Quercus oblongifolia as a small tree that can mature as a shrub at higher elevations. Niering and Lowe (1984) describe an "Open oak woodland" (10-20% cover) that occurs at 1300-1700 m elevation in the Santa Catalina Mountains and is dominated by scattered Quercus oblongifolia with Quercus emoryi and Juniperus deppeana. More research is needed to resolve the shrubland / woodland / savanna question.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: The vegetation is characterized by an open to moderately dense evergreen tall-shrub layer (10-60% cover) dominated by Quercus oblongifolia. Shrub canopy is typically 3-5 m tall but may extend beyond 5 m and resemble a woodland or tree savanna. Quercus arizonica, Quercus emoryi, Prosopis spp., Juniperus deppeana, and occasional Pinus discolor may be present in the woody canopy. Associated shrubs and succulents include Agave palmeri, Acacia constricta, Arctostaphylos pungens, Brickellia spp., Dasylirion wheeleri, Ericameria laricifolia, Eriogonum wrightii, Eysenhardtia orthocarpa, Garrya wrightii, Mimosa aculeaticarpa var. biuncifera, Mimosa dysocarpa, Nolina microcarpa, Opuntia phaeacantha, Cylindropuntia spinosior (= Opuntia spinosior), Rhus trilobata, and Yucca madrensis (= Yucca schottii). The graminoid layer is moderately dense to dense (25-80% cover) and is typically dominated by medium-tall bunchgrasses such as Bouteloua curtipendula, Schizachyrium cirratum (= Andropogon cirratus), or Muhlenbergia emersleyi, but it can also be very diverse. Other common graminoids may include Aristida ternipes, Bouteloua chondrosioides, Bouteloua eriopoda, Bouteloua gracilis, Bouteloua hirsuta, Bothriochloa barbinodis, Eragrostis intermedia, Leptochloa dubia, Muhlenbergia longiligula, and Piptochaetium fimbriatum. The usually sparse, but often diverse, forb layer is composed of Artemisia ludoviciana, Commelina spp., Chenopodium spp., Evolvulus spp., Hybanthus attenuatus, Ipomoea cristulata, Mirabilis longiflora, Viguiera spp., and many others. Diagnostic of this association is the dominance of Quercus oblongifolia in the tall-shrub canopy with at least 5% cover and a grassy understory.
Dynamics: No Data Available
Environmental Description: This encinal association occurs in southeastern Arizona on gently to moderately sloping alluvial plains and bajadas to steep rocky slopes in canyons, foothills and mountains. Elevation ranges from 1370-1610 m (4500-5300 feet). Aspects are variable, but it appears more common on less xeric northern aspects and palustrine habitats in drier portions of its range. Soils are gravelly or stony sandy loams or sandy clay loams, derived from a mixture of alluvium and colluvium.
Geographic Range: These shrublands occur in mountains in southeastern Arizona and the adjacent Mexican state of Sonora.
Nations: MX,US
States/Provinces: AZ, MXSON
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.688059
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: G4
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 1 Forest & Woodland Class | C01 | 1 |
| Subclass | 1.B Temperate & Boreal Forest & Woodland Subclass | S15 | 1.B |
| Formation | 1.B.1 Warm Temperate Forest & Woodland Formation | F018 | 1.B.1 |
| Division | 1.B.1.Nd Madrean-Balconian Forest & Woodland Division | D060 | 1.B.1.Nd |
| Macrogroup | 1.B.1.Nd.1 Alligator Juniper - Mexican Pinyon - Arizona White Oak Madrean Lowland Evergreen Woodland Macrogroup | M010 | 1.B.1.Nd.1 |
| Group | 1.B.1.Nd.1.a Arizona White Oak - Emory Oak - Mexican Blue Oak Woodland Group | G201 | 1.B.1.Nd.1.a |
| Alliance | A0791 Mexican Blue Oak Scrub Woodland Alliance | A0791 | 1.B.1.Nd.1.a |
| Association | CEGL000973 Mexican Blue Oak / Sideoats Grama Scrub | CEGL000973 | 1.B.1.Nd.1.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Quercus oblongifolia / Bouteloua (mixed) (Stuever and Hayden 1997b)
= Quercus oblongifolia / Bouteloua spp. PA (Larson and Moir 1987)
= Quercus oblongifolia / Bouteloua spp. PA (Larson and Moir 1987)
- Bourgeron, P. S., and L. D. Engelking, editors. 1994. A preliminary vegetation classification of the western United States. Unpublished report. The Nature Conservancy, Western Heritage Task Force, Boulder, CO. 175 pp. plus appendix.
- Cumming, K. J. 1951. The effect of slope and exposure on range vegetation in desert grassland and oak woodland areas of Santa Cruz County, Arizona. Unpublished thesis, University of Arizona, Tucson. 53 pp.
- Kearney, T. H., and R. H. Peebles, and collaborators. 1969. Arizona flora. University of California, Berkeley, CA. 1085 pp.
- Kincaid, D. R. 1959. The upper desert grassland of southern Arizona: A basic ecological analysis. Unpublished thesis, University of Arizona, Tucson. 38 pp.
- Larson, M., and W. H. Moir. 1987. Forest and woodland habitat types of northern New Mexico and northern Arizona. Edition 2. USDA Forest Service, Southwestern Region, Albuquerque, NM.
- Niering, W. A., and C. H. Lowe. 1984. Vegetation of the Santa Catalina Mountains: Community types and dynamics. Vegetatio 58:3-28.
- Schulz, K. A. 2004. Vegetation classification of Buenos Aires National Wildlife Refuge, Arizona. Unpublished report submitted to USDI Fish and Wildlife Service. NatureServe, Western Regional Office, Boulder, CO.
- Stuever, M. C., and J. S. Hayden. 1997b. Plant associations of Arizona and New Mexico. Volume 2: Woodlands. USDA Forest Service, Southwestern Region, Habitat Typing Guides. 196 pp.
- USFS [U.S. Forest Service]. 1987b. Forest and woodland habitat types (plant associations) of Arizona south of the Mogollon Rim and southwestern New Mexico. USDA Forest Service, Southwestern Region, Albuquerque, NM. Second edition, 168 pp. plus insert.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.
- Whittaker, R. H., and W. A. Niering. 1964. Vegetation of the Santa Catalina Mountains, Arizona. I. Ecological classification and distribution of species. Journal of the Arizona Academy of Science 3:9-34.
- Whittaker, R. H., and W. A. Niering. 1968. Vegetation of the Santa Catalina Mountains, Arizona. IV. Limestone and acid soils. Journal of Ecology 56:523-544.