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A0953 Alnus oblongifolia Riparian Forest Alliance

Type Concept Sentence: This is a riparian wooded alliance dominated by Alnus oblongifolia in the tall-shrub or small-tree canopy layer. Other species present in the canopy include Acer grandidentatum, Acer negundo, Hesperocyparis arizonica, Fraxinus velutina, Juglans major, Platanus wrightii, and/or Populus angustifolia. Stands are found in montane riparian zones of the dry southern mountains of New Mexico and Arizona. Elevations range from 1000 m to just over 2400 m. Flowing or standing water is always present in the streambed, and stream gradients appear to range from nearly flat to moderately steep.


Common (Translated Scientific) Name: Arizona Alder Riparian Forest Alliance

Colloquial Name: Arizona Alder Riparian Forest

Hierarchy Level:  Alliance

Type Concept: This alliance is characterized by the abundance of Alnus oblongifolia in a tall-shrub/small-tree canopy layer. Companion upper canopy species may include Acer grandidentatum, Acer negundo, Hesperocyparis arizonica, Fraxinus velutina, Juglans major, Platanus wrightii, and/or Populus angustifolia. Shrubs that may occur include Salix exigua, Prunus serotina or Symphoricarpos oreophilus. Common forb species can include Aquilegia chrysantha, Galium triflorum, Geranium spp., Maianthemum racemosum, Pteridium aquilinum, and Thalictrum fendleri. Common graminoids include Glyceria striata and species of Carex or Bromus. Examples of this alliance are found in montane riparian zones of the dry southern mountains of New Mexico and Arizona. Elevations range from 1050 m to just over 2400 m. Flowing or standing water is always present in the streambed, and stream gradients appear to range from nearly flat to moderately steep.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance is very poorly studied or reported in the literature. Alnus oblongifolia grows in southern Arizona and New Mexico and into the Sierra Madre of Mexico, and appears to be primarily a component of montane riparian woodlands dominated by species of Populus or Acer. In addition, it seems to more consistently be a small tree than some of the other Alnus species, and communities dominated by it may be more appropriately placed in deciduous woodlands or forests.

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

Physiognomy and Structure: This alliance is dominated by tall broad-leaved deciduous shrubs or small trees. A shorter shrubby understory is probably present in most stands. Shade-tolerant herbaceous species form a dense herbaceous layer.

Floristics: This alliance is characterized by the abundance of Alnus oblongifolia in a tall-shrub/small-tree canopy layer. At lower elevations of its range, Acer negundo, Hesperocyparis arizonica (= Cupressus arizonica), Fraxinus velutina, Juglans major, or Platanus wrightii may be codominant. At higher elevations, codominants can include Populus angustifolia or Acer grandidentatum. If Populus angustifolia is present, it is not in the form of an overstory canopy, rather is shorter saplings and pole-sized small individuals. The woody vines Vitis arizonica and Parthenocissus quinquefolia are common in most stands. Other shrubs in the understory may include Salix exigua, Prunus serotina or Symphoricarpos oreophilus. Aquilegia chrysantha, Galium triflorum, Geranium spp., Maianthemum racemosum, Pteridium aquilinum, and Thalictrum fendleri. Common graminoids include Glyceria striata and species of Carex or Bromus.

Dynamics:  No Data Available

Environmental Description:  Examples of this alliance are found in montane riparian zones of the dry southern mountains of New Mexico and Arizona. Elevations where it may be found range from 1050 to just over 2400 m. Flowing or standing water is always present in the streambed, and stream gradients appear to range from nearly flat to moderately steep. No other information on environment is available.

Geographic Range: This alliance is reported from mountain ranges of southern New Mexico and central to southern Arizona, particularly along the slopes and canyons of the Mogollon Rim. It is likely to occur in the mountainous regions of northern Mexico, but no reports document this.

Nations: MX?,US

States/Provinces:  AZ, NM




Confidence Level: Low

Confidence Level Comments: No Data Available

Grank: GNR

Greasons: No Data Available


Concept Lineage: A.953, with minor name change.

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: >< Alnus oblongifolia Community Types (Szaro 1989)
? Alder Series (Dick-Peddie 1993)

Concept Author(s): M.S. Reid, in Faber-Langendoen et al. (2013)

Author of Description: G. Kittel

Acknowledgements: No Data Available

Version Date: 12-18-14

  • Dick-Peddie, W. A. 1993. New Mexico vegetation: Past, present, and future. University of New Mexico Press, Albuquerque. 244 pp.
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Freeman, C. E., and W. A. Dick-Peddie. 1970. Woody riparian vegetation in the Black and Sacramento Mountain ranges, southern New Mexico. The Southwestern Naturalist 15(2):145-164.
  • Szaro, R. C. 1989. Riparian forest and scrubland community types of Arizona and New Mexico. Desert Plants Special Issue 9(3-4):70-139.