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D013 Populus fremontii - Platanus wrightii - Celtis laevigata Southwest North American Flooded Forest Division
Type Concept Sentence: This lowland riparian forest and woodland type is dominated by broad-leaved deciduous trees (cottonwoods, sycamores, and hackberries) and palms that occur along perennial and intermittent rivers, springs and oases of the California Central Valley, Southwest U.S. deserts, and the Tamaulipan region of south Texas and adjacent Mexico.
Common (Translated Scientific) Name: Fremont Cottonwood - Arizona Sycamore - Sugarberry Southwest North American Flooded Forest Division
Colloquial Name: Western North American Interior Flooded Forest
Hierarchy Level: Division
Type Concept: This division is characterized by forests and woodlands growing along lowland perennial and seasonally intermittent rivers as well as in spring areas, from the Californian Central Valley and Coast Ranges, through the warm deserts of the Southwest U.S. (Chihuahuan, Sonoran and Mojave), to the Tamaulipan region of south Texas and northeastern Mexico. Elevations range from sea level to 1800 m (6000 feet). Stands are dominated by riparian phreatophyte broad-leaved deciduous trees and occasionally fan palms (conifers are uncommon). Stands typically have multi-layered canopies with various understories of shrubs and herbs (or they can be sparse). Western stands are characterized by Populus fremontii and the closely related Populus deltoides ssp. wislizeni along with Platanus racemosa, Platanus wrightii, Juglans major, and Juglans californica as canopy dominants in monotypic to mixed stands. Celtis laevigata var. reticulata may also codominate in the canopies, particularly on drier sites. Fraxinus anomala, Fraxinus velutina, Juglans microcarpa, Salix gooddingii, and Salix laevigata are typical subcanopy tree species. Other riparian trees that can be common include Acer negundo, Cephalanthus occidentalis, Salix amygdaloides, Salix lasiolepis, Salix lucida, and Sapindus saponaria plus upland species that can tolerate a degree of moist conditions (e.g., Quercus agrifolia or Quercus lobata). Eastern stands are dominated by riparian trees with Tamaulipan subtropical affinities and include Celtis laevigata var. laevigata, Salix nigra, Fraxinus berlandieriana, Taxodium mucronatum, and Ulmus crassifolia with Ebenopsis ebano, Prosopis glandulosa, Celtis ehrenbergiana, and Acacia farnesiana occurring on drier sites. A shrub layer of facultative and obligate wetland species may be present, including Baccharis salicifolia, Baccharis emoryi, Baccharis salicina, Salix exigua, and Salix geyeriana, particularly in early-successional stands. On drier sites of the floodplain Forestiera pubescens var. pubescens and Shepherdia argentea may common. The herbaceous layer is variable in composition across the range and can range from very sparse to a rich and luxuriant mix of mesic forbs and graminoids. In riparian areas on serpentine, Salix breweri, Hesperocyparis sargentii, Frangula californica ssp. tomentella, and Umbellularia californica may be present. Intermixed with the native riparian forests are ruderal forests and scrubs dominated by introduced woody species with Elaeagnus angustifolia and Tamarix spp. the typical dominants, but Ailanthus altissima, Eucalyptus spp., and Ulmus pumila may also be codominants. The division also includes palm oases dominated by Washingtonia filifera (west) or Sabal mexicana (east) with or without riparian deciduous trees.
Diagnostic Characteristics: This division is characterized by forests and woodlands dominated by riparian phreatophyte broad-leaved deciduous trees and occasionally palms. They grow along perennial and seasonally intermittent streams and springs in the warm desert (Sonoran and Mojave), Mediterranean and Tamaulipan regions of western North America, at low and moderate elevations. In western stands, strong diagnostic species in the overstory include Populus fremontii and the closely related Populus deltoides ssp. wislizeni along with Platanus racemosa, Platanus wrightii, Juglans major, and Juglans californica. Subcanopy strong diagnostics include Fraxinus anomala, Fraxinus velutina, Juglans microcarpa, Salix gooddingii, and Salix laevigata. Among eastern stands (Tamaulipan), moderate diagnostics include Fraxinus berlandieriana, Ulmus crassifolia, Ebenopsis ebano, and Taxodium mucronatum. Palm oases are characterized by Washingtonia filifera (west) or Sabal mexicana (east).
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: ~Tamaulipan Riparian Scrub Forest Group (G549)$$ in this division is a provisional group in the U.S. and in need of further research - it may be more closely related to Central American & Caribbean flooded forests [see 1.A.4.Ed ~Caribbean-Central American Flooded & Swamp Forest Division (D093)$$]. In California, riparian areas in the mountains of the Sierra Nevada and the northern Coast Ranges are included in 1.B.3.Ng ~Vancouverian Flooded & Swamp Forest Division (D193)$$. Higher montane groups of the Intermountain West and Rocky Mountains are included in the 1.B.3.Nc ~Rocky Mountain-Great Basin Montane Flooded & Swamp Forest Division (D195)$$. They may share some species in the transition to the lowland riparian associations. Some of the associations of 2.C.4.Nb ~Western North American Temperate & Boreal Freshwater Marsh, Wet Meadow & Shrubland Division (D031)$$ and 2.C.4.Nc ~Southwestern North American Warm Desert Freshwater Marsh & Bosque Division (D032)$$ are successional to the woodlands of this division and share several species.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Forests and woodlands that can have multi-layered canopies with various understories of shrubs and herbs (or they can be sparse). Tree heights among dominants can reach as much as 50 m (160 feet), but some stands are short-statured and approach shrublands in size. Young stands can be dense but often mature into open woodlands as trees senesce and die. This division also includes oases dominated by evergreen fan palms. A complex shrub and subshrub layer may or may not be present, and the herbaceous layer can vary from luxuriant to sparse in cover.
Floristics: Western stands are characterized by riparian phreatophyte broad-leaved deciduous trees and occasionally palms; conifers are uncommon. Populus fremontii and the closely related Populus deltoides ssp. wislizeni along with Platanus racemosa, Platanus wrightii, Juglans major, and Juglans californica are the characteristic canopy dominants that can form monotypic to mixed stands along streams and river channels. Celtis laevigata var. reticulata may also codominate in the canopies, particularly on drier sites. Fraxinus anomala, Fraxinus velutina, Juglans microcarpa, Salix gooddingii, and Salix laevigata are typical subcanopy tree species. Other riparian trees that can be common include Acer negundo, Cephalanthus occidentalis, Salix amygdaloides, Salix lasiolepis, Salix lucida, and Sapindus saponaria plus upland species that can tolerate a degree of moist conditions (e.g., Quercus agrifolia or Quercus lobata). Eastern stands are dominated by riparian trees with Tamaulipan subtropical affinities and include Celtis laevigata var. laevigata, Salix nigra, Fraxinus berlandieriana, Taxodium mucronatum, and Ulmus crassifolia with Ebenopsis ebano, Prosopis glandulosa, Celtis ehrenbergiana (= Celtis pallida), and Acacia farnesiana (= Vachellia farnesiana) occurring on drier sites. When a shrub layer is present, Baccharis salicifolia, Baccharis emoryi, and Forestiera pubescens var. pubescens are characteristic dominants, but the more widely distributed Baccharis salicina, Shepherdia argentea, Salix exigua, and Salix geyeriana can also occur either as monotypic or in mixed stands. The herbaceous layer is variable in composition across the range and can range from very sparse to a rich and luxuriant mix of mesic forbs and graminoids. In riparian areas on serpentine substrates, Salix breweri, Hesperocyparis sargentii (= Cupressus sargentii), Frangula californica ssp. tomentella (= Rhamnus tomentella), and Umbellularia californica may be present. The division also includes palm oases dominated by Washingtonia filifera (west) or Sabal mexicana (east) with or without riparian deciduous trees.
Intermixed with the native riparian forests are ruderal forests and scrubs dominated by introduced woody species. Elaeagnus angustifolia and Tamarix spp. are the typical dominants, but Ailanthus altissima, Eucalyptus spp., and Ulmus pumila may also be codominants.
Intermixed with the native riparian forests are ruderal forests and scrubs dominated by introduced woody species. Elaeagnus angustifolia and Tamarix spp. are the typical dominants, but Ailanthus altissima, Eucalyptus spp., and Ulmus pumila may also be codominants.
Dynamics: These are disturbance-driven systems where flooding, scour and deposition of new sediments are recurring events at intervals of up to 100 years, and usually much less. Since most of the dominant trees are relatively short-lived (100-150 years), periodic flooding and associated sediment scour are necessary to ensure tree reproduction and stand renewal. Sufficient base flows are also required. Hence, a hydrological regime that has been significantly impacted by dams and channelization leads to deeper groundwater depths, little overbank flooding, phreatophyte stand senescence and replacement by more xerophytic woodlands, shrublands (often the ruderal exotic-dominated communities), or grasslands. Salinity is low in the root zone, but can increase near the surface where evaporation leaves salt accumulations, particularly when flooding becomes infrequent. Fires do not play a significant natural role in these ecosystems.
Environmental Description: This division occurs along riparian corridors of low-gradient rivers and streams (<1%) with primarily perennial flows, but seasonally intermittent and spring-fed sites are also possible. Stands occur on floodplain bars and terraces where trees can reach river groundwater on a consistent basis during the growing season (there are also localized areas of serpentine river deposits that provide a special environment). Climatically, the division extends from the winter-rainfall-dominated Mediterranean region of California to the summer-rainfall-dominated Chihuahuan Desert and Tamaulipan thornscrub to the east. But it is the winter snow accumulations of upstream watersheds that are critical for delivering rejuvenating spring floods and sustaining base flows through the summer growing season. In the case of Washingtonia filifera, a relict species of the Miocene and Pliocene (Vogl and McHargue 1966), permanent subsurface water is required to maintain them. Reproduction of Washingtonia filifera is limited by water supply, surface salinity, rainfall, and fire. Fan palms are fire-tolerant, while understory species are not. Other diagnostic phreatophyte trees of the division are also fire-intolerant.
Environments that favor ruderal, exotic-dominated shrublands are commonly related to altered hydrological regimes caused by dam flow regulation and reservoir sediment capture. But species such as Elaeagnus angustifolia and Tamarix spp. are aggressive invaders even under natural free-flowing conditions.
Environments that favor ruderal, exotic-dominated shrublands are commonly related to altered hydrological regimes caused by dam flow regulation and reservoir sediment capture. But species such as Elaeagnus angustifolia and Tamarix spp. are aggressive invaders even under natural free-flowing conditions.
Geographic Range: This division of lowland river corridors extends from the coastal ranges of southern Oregon, southward to the Coastal Ranges and Central Valley of California, eastward through the Mojave, Sonoran and Chihuahuan Deserts and the Gulf Coastal Plain of south Texas, northward onto the Colorado Plateau into the Great Basin, and south into northern Mexico.
Nations: CA?,MX,US
States/Provinces: AZ, CA, MXBCN, MXBCS, MXCHH, MXCOA, MXNLE, MXSON, MXTAM, NM, NV, OR, TX
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.860360
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
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.3 Temperate Flooded & Swamp Forest Formation | F026 | 1.B.3 |
| Division | 1.B.3.Nd Western North American Interior Flooded Forest Division | D013 | 1.B.3.Nd |
| Macrogroup | 1.B.3.Nd.2 Interior Warm & Cool Desert Riparian Forest Macrogroup | M036 | 1.B.3.Nd.2 |
| Macrogroup | 1.B.3.Nd.90 Interior West Ruderal Flooded & Swamp Forest & Woodland Macrogroup | M298 | 1.B.3.Nd.90 |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: > Californian Riparian Deciduous Forest and Woodland (Brown et al. 1979) [This type is a subregional variant of a portion of this division concept.]
> Interior Southwestern Riparian Deciduous Forest and Woodland (Brown et al. 1979) [This type is a subregional variant of a portion of this division concept.]
> Interior Southwestern Riparian Deciduous Forest and Woodland (Brown et al. 1979) [This type is a subregional variant of a portion of this division concept.]
- Brown, D. E., C. H. Lowe, and C. P. Pase. 1979. A digitized classification system for the biotic communities of North America with community (series) and association examples for the Southwest. Journal of the Arizona-Nevada Academy of Science 14:1-16.
- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
- Mitsch, W. J., and J. G. Gosselink. 2000. Wetlands. Third edition. John Wiley & Sons, Inc., New York. 920 pp.
- 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.
- Patten, D. 1998. Riparian ecosystems of semi-arid North America: Diversity and human impacts. Wetlands 18(4):498-512.
- Vogl, R. J., and L. T. McHargue. 1966. Vegetation of California fan palm oases on the San Andreas fault. Ecology 47:532-540.