Common (Translated Scientific) Name: Californian Ruderal Forest Group

Colloquial Name: Californian Ruderal Forest

Hierarchy Level:  Group

Type Concept: These ruderal forests and woodlands are generally found in cismontane California and Baja California, Mexico. Stands have an open to dense tree canopy (>10% tree cover), 5-50 m tall that is strongly dominated (>90% relative cover) by exotic tree species. Exotic dominant/diagnostic species include Acacia cyclops, Acacia dealbata, Acacia melanoxylon, Acacia redolens, Ailanthus altissima, Eucalyptus camaldulensis, Corymbia citriodora, Eucalyptus cladocalyx, Eucalyptus globulus, Eucalyptus polyanthemos, Eucalyptus pulverulenta, Eucalyptus sideroxylon, Eucalyptus tereticornis, Eucalyptus viminalis, Ficus carica, Myoporum laetum, Pinus halepensis, Prunus mahaleb, Robinia pseudoacacia, Schinus molle, and Schinus terebinthifolius. This type also includes degraded natural forests and woodlands with an understory strongly dominated by exotic species (>90% relative cover). Stands occur from near sea level to up to 300 m elevation. Habitats include coastal canyons, foothill and mountain slopes, valleys, and roadsides. Although sites may be relatively mesic, riparian stands are not included in this group. Many of these species were planted as groves and windbreaks, and then naturalized. Birds disperse the colored fruits allowing seedlings to establish in wildland vegetation. Many of the trees are common ornamentals that have escaped from cultivation. Understories in groves of these fast-growing, long-lived trees are usually depauperate. With dominance of Eucalyptus, a buildup of allelopathic chemicals may occur in the soil and high volumes of debris inhibit establishment of other plants.

Diagnostic Characteristics: These ruderal forests and woodlands occur in generally cismontane California and Baja California, Mexico, and are strongly dominated (>90% relative cover) by exotic tree species such as Acacia cyclops, Acacia dealbata, Acacia melanoxylon, Acacia redolens, Ailanthus altissima, Eucalyptus camaldulensis, Corymbia citriodora, Eucalyptus cladocalyx, Eucalyptus globulus, Eucalyptus polyanthemos, Eucalyptus pulverulenta, Eucalyptus sideroxylon, Eucalyptus tereticornis, Eucalyptus viminalis, Ficus carica, Myoporum laetum, Pinus halepensis, Prunus mahaleb, Robinia pseudoacacia, Schinus molle, and Schinus terebinthifolius. This type also includes degraded natural forests and woodlands with an understory strongly dominated by exotic species (>90% relative cover).

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Stands have not been a high priority for descriptive sampling. Therefore, the further evaluation of other ruderal stands containing non-native Acacia (several species of Australasian origin) or other tree or shrub taxa are not well-understood in California or adjacent Pacific states and northern Baja California, Mexico. Differentiation between old plantings and adventive stands is sometimes difficult, especially with native species of Cupressus or Pinus radiata. In addition, some of the characteristic exotic tree species such as species of Schinus and Myoporum are shared with ruderal types that occur in riparian areas in California such as ~Interior West Ruderal Riparian Forest & Scrub Group (G510)$$ (Sawyer et al. 2009). Most stands in this group have native overstory (often oaks) with an exotic herbaceous understory. The criteria defining some of these semi-natural or ruderal stands are more narrowly defined in the USNVC than criteria in Sawyer et al. (2009) requiring >90% relative cover of exotics tree versus >80%.

Similar NVC Types: No Data Available

note: No Data Available