Print Report

A3876 Juglans microcarpa Wet Scrub Alliance

Type Concept Sentence: This alliance comprises riparian shrublands with Juglans microcarpa as a dominant. It is found primarily along intermittently to temporarily flooded low-elevation (below 1500 m) streambeds and stream margins in desert canyons and valleys of Texas, New Mexico and Coahuila, Mexico.

Common (Translated Scientific) Name: Little Walnut Wet Scrub Alliance

Colloquial Name: Little Walnut Wet Scrub

Hierarchy Level:  Alliance

Type Concept: This alliance comprises riparian shrublands with Juglans microcarpa as a dominant. Other woody species can include Brickellia laciniata, Celtis laevigata var. reticulata, Fallugia paradoxa, Platanus occidentalis, Quercus spp., Salix gooddingii, Salix nigra, and Ungnadia speciosa. This alliance is found primarily along intermittently to temporarily flooded low-elevation (below 1500 m) streambeds and stream margins in desert canyons and valleys of Texas, New Mexico and Coahuila, Mexico. Stream gradients are gentle. The headwaters of these streams are in montane areas, and even when the streambed is dry, it is usually subirrigated. Following monsoonal rains, the streambed can be shallowly inundated for several weeks at a time.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: No Data Available

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This alliance consists of structurally variable broad-leaved deciduous shrublands. The woody vegetation varies in both height and density, and from shrubby growth to well-developed small trees. The canopy of the woody plants may be dense to somewhat open or consist of widely scattered individuals. Woody vines are common in some stands, and most have an herbaceous layer, usually dominated by graminoids.

Floristics: This alliance is composed of structurally and compositionally variable riparian shrublands, with Juglans microcarpa being the most abundant and characteristic woody species. Other woody shrubs and small trees that can be present can include Brickellia laciniata, Celtis laevigata var. reticulata, Chilopsis linearis, Fallugia paradoxa, Fraxinus velutina, Ostrya knowltonii, Platanus occidentalis, Quercus spp., Salix gooddingii, Salix nigra, and Ungnadia speciosa. The understory, particularly in the Texas examples, is composed primarily of perennial grasses typical of adjacent upland vegetation, such as Andropogon gerardii, Bothriochloa barbinodis (= var. barbinodis), Bouteloua curtipendula, Leptochloa dubia, and Schizachyrium scoparium var. scoparium (= Schizachyrium scoparium ssp. neomexicanum). Cladium mariscus ssp. jamaicense is the graminoid dominant in one association in Texas. Woody vines such as Vitis arizonica can be important in stands in New Mexico.

Dynamics:  Juglans microcarpa is shade-intolerant. Young individuals direct much of their energy into developing a large, deep taproot, which allows them to survive the periods of extreme drought that are common.
Environmental Description:  It is found primarily along intermittently to temporarily flooded low-elevation (below 1500 m) streambeds and stream margins in desert canyons and valleys. Stream gradients were reported by Szaro (1989) to be 8 to 9 m per kilometer, fairly low gradients. The headwaters of these streams are in montane areas, and even when the streambed is dry, it is usually subirrigated. Following monsoonal rains, the streambed can be shallowly inundated for several weeks at a time. In western Texas and the Edwards Plateau, this alliance occurs on limestone cobbles or flat-bedded limestone streambeds. New Mexico sites are reported to be bouldery or gravelly.
Geographic Range: This alliance has been reported form the Trans-Pecos and Edwards Plateau regions of Texas and from a few scattered localities in southern New Mexico. It is also found in the Mexican state of Coahuila.

Nations: MX,US

States/Provinces:  MXCOA, NM, TX


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: GNR

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.C Shrub & Herb Wetland Subclass S44 2.C
Formation 2.C.4 Temperate to Polar Freshwater Marsh, Wet Meadow & Shrubland Formation F013 2.C.4
Division 2.C.4.Nc Southwestern North American Warm Desert Freshwater Marsh & Bosque Division D032 2.C.4.Nc
Macrogroup 2.C.4.Nc.1 Warm Desert Lowland Freshwater Marsh, Wet Meadow & Shrubland Macrogroup M076 2.C.4.Nc.1
Group 2.C.4.Nc.1.b Honey Mesquite - Velvet Mesquite - False Willow species North American Warm Desert Riparian Low Bosque & Shrubland Group G533 2.C.4.Nc.1.b
Alliance A3876 Little Walnut Wet Scrub Alliance A3876 2.C.4.Nc.1.b
Association CEGL002707 Little Walnut / Sideoats Grama Wet Scrub CEGL002707 2.C.4.Nc.1.b
Concept Lineage: A.945, in part

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: ? Juglans microcarpa Community Type (Szaro 1989)
? Little Walnut Series (Dick-Peddie 1993)
Concept Author(s): G. Kittel, in Faber-Langendoen et al. (2013)

Author of Description: G. Kittel

Acknowledgements: No Data Available

Version Date: 09-26-14
  • Diamond, D. D. 1993. Classification of the plant communities of Texas (series level). Unpublished document. Texas Natural Heritage Program, Austin. 25 pp.
  • 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.
  • Szaro, R. C. 1989. Riparian forest and scrubland community types of Arizona and New Mexico. Desert Plants Special Issue 9(3-4):70-139.
  • Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.