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CEGL002686 Platanus wrightii - Alnus oblongifolia / Baccharis salicifolia Riparian Forest

Type Concept Sentence: No Data Available


Common (Translated Scientific) Name: Arizona Sycamore - Arizona Alder / Mule-fat Riparian Forest

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This is a lowland forested riparian association known from the Gila River watershed in New Mexico and potentially occurs elsewhere in southwestern New Mexico and southern Arizona. This association is known to occur at elevations ranging between 1650-1750 m (5380-5750 feet), along rivers that have moderate gradients (1.2%), and coarse bouldery/cobbly riverbeds. The community often occurs on younger terraces and elevated sidebars that are above the active channel (discharge ratios range from 3.0-4.3), with variable flooding frequencies that range from yearly to every 50 years. Streamflows are either intermittent or perennial and fed by springs or snowmelt. Channels are often deeply incised within narrow valleys. Soils are coarse, well-drained, and moderately or poorly stratified. They are sandy at the surface, and generally remain coarse-textured throughout the profile. Cobbles and rock are also present on the surface or buried near the surface and at lower depths. Soils are primarily moist, poorly developed Aeric Fluvaquents and Oxyaquic Ustifluvents, while some "soils" consist solely of loose deposits of sands, gravels, and cobbles (riverwash). They tend to be dry within 1 m of the surface most of the year, but may be periodically moist at depths still within the rooting zone during most years, particularly during spring high waters. Platanus wrightii dominates the canopy with Alnus oblongifolia as a canopy codominant or subdominant. Reproduction of Platanus wrightii and Alnus oblongifolia is common in the understory, but young saplings of Juglans major and Acer negundo may also be present. The stand forms a moderately closed to closed canopy. The shrubby understory consists primarily of Baccharis salicifolia. Other shrubs are common, but not abundant. Herbaceous species are diverse and variable with 62 herbaceous species recorded for the type, but only 16 more than once. Native wetland indicator species include Carex microptera, Adiantum capillus-veneris, Aquilegia chrysantha, Equisetum laevigatum, Mimulus guttatus, Rudbeckia laciniata, and Veronica americana.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: In middle-aged groves of Platanus wrightii - Alnus oblongifolia (usually closer to the banks), there is a scattered shrub layer of Baccharis salicifolia. Due to the deep layer of fine sediments on the ground surface, the herbaceous layer is generally sparsely grassy. Woody species are well-established and fully adapted to seasonal flooding. In time, the Platanus wrightii become more isolated from the Alnus oblongifolia and Baccharis salicifolia. The community is usually established on bare cobble bars or on bank sediments. As they mature on higher terraces, the Alnus oblongifolia and Baccharis salicifolia are left behind on the lower, wetter sites. This process may take several years as ensuing floods continue to deposit sediments and woody debris. Sediments are coarse with high amounts of gravel and cobble mixed with sand.

Similar NVC Types: No Data Available
note: No Data Available

Physiognomy and Structure: No Data Available

Floristics: Platanus wrightii dominates with Alnus oblongifolia as a canopy codominant or subdominant. Reproduction of the Platanus wrightii and Alnus oblongifolia is common in the understory, but young saplings of Juglans major and Acer negundo may also be present. The stand forms a moderately closed to closed canopy. The shrubby understory consists primarily of Baccharis salicifolia. Other shrubs are common but not abundant. Herbaceous species are diverse and variable with 62 herbaceous species recorded for the type, but only 16 more than once. Native wetland indicator species include Carex microptera, Adiantum capillus-veneris, Aquilegia chrysantha, Equisetum laevigatum, Mimulus guttatus, Rudbeckia laciniata, and Veronica americana. Exotic species can be well-represented to abundant and include Melilotus officinalis, Polygonum lapathifolium, Agrostis gigantea, Cynodon dactylon, Poa pratensis, and Polypogon monspeliensis.

Dynamics:  No Data Available

Environmental Description:  This community type is known to occur at elevations ranging between 1650 and 1750 m (5380-5750 feet), along rivers that have moderate gradients (1.2%), and coarse bouldery/cobbly riverbeds. The community often occurs on younger terraces and elevated sidebars that are above the active channel (discharge ratios range from 3.0 to 4.3), with variable flooding frequencies that range from yearly to 50-year intervals. Streamflows are either intermittent or perennial and fed by springs or snowmelt. Channels are often deeply incised within narrow valleys. Soils are coarse, well-drained, and moderately or poorly stratified. They are sandy at the surface and generally remain coarse-textured throughout the profile. Cobbles and rock are also present on the surface or buried near the surface and at lower depths. Soils are primarily moist, poorly developed Aeric Fluvaquents and Oxyaquic Ustifluvents, while some soils consist solely of loose deposits of sands, gravels, and cobbles (riverwash). They tend to be dry within 1 m of the surface most of the year but may be periodically moist at depths still within the rooting zone during most years, particularly during spring high waters.

Geographic Range: This association is restricted to the Gila River watershed in southwestern New Mexico (Catron and Grant counties) and probably elsewhere in southwestern New Mexico and in southeastern Arizona.

Nations: US

States/Provinces:  AZ?, NM




Confidence Level: Low - Poorly Documented

Confidence Level Comments: No Data Available

Grank: G2

Greasons: No Data Available


Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: = Arizona Sycamore-Arizona Alder/Seepwillow CT (Muldavin et al. 2000a)

Concept Author(s): E. Muldavin et al. (2000a)

Author of Description: E. Muldavin et al.

Acknowledgements: No Data Available

Version Date: 08-02-04

  • Muldavin, E., P. Durkin, M. Bradley, M. Stuever, and P. Mehlhop. 2000a. Handbook of wetland vegetation communities of New Mexico. Volume I: Classification and community descriptions. Final report to the New Mexico Environment Department and the Environmental Protection Agency prepared by the New Mexico Natural Heritage Program, University of New Mexico, Albuquerque.
  • NHNM [Natural Heritage New Mexico]. No date. Unpublished data on file. Natural Heritage New Mexico, University of New Mexico, Albuquerque.
  • Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.