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A0502 Juniperus californica Mojave Scrub Alliance

Type Concept Sentence: This semi-arid and desert woodland is dominated by Juniperus californica. Other trees present may include Quercus turbinella, Yucca brevifolia, Pinus quadrifolia, and Pinus monophylla. Stands of this desert woodland alliance occur in southern California in the inner central Coast Ranges, the montane Transverse and Peninsular ranges, south and east through Baja California, Mexico, and the Mojave Desert.

Common (Translated Scientific) Name: California Juniper Mojave Scrub Alliance

Colloquial Name: Mojave California Juniper Scrub

Hierarchy Level:  Alliance

Type Concept: This semi-arid open woodland alliance is found in the Mojave Desert, southern California, and the Baja Peninsula. The vegetation is characterized by an open woodland is dominated by Juniperus californica. Other trees present with low cover may include Quercus turbinella, Yucca brevifolia, Pinus quadrifolia, and Pinus monophylla. An open or intermittent shrub layer may include Artemisia tridentata, Coleogyne ramosissima, Hesperoyucca whipplei, Yucca schidigera, Ephedra spp., Purshia stansburiana, and Lepidospartum squamatum. The herbaceous layer is sparse or dominated by graminoids. Stands are found from 600-2450 m elevation and grow on ridges, slopes and valleys on soils derived from bedrock or alluvium.

Diagnostic Characteristics: Juniperus californica occurs as a small tree or large shrub with >1% absolute cover and no other tree (or tall shrub) with equal or greater cover (>50% relative cover) (Sawyer et al. 2009).

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: It''s difficult to determine if this alliance is centrally distributed in the Mojave Desert and warrants placement in this group. California ecologists recommend this alliance be moved from this group because Juniperus californica Woodland Alliance (Sawyer et al 2009) is primarily a Mediterranean alliance that crosses into the western Mojave Desert and occurs in transitional areas between Mediterranean woodland and Mojavean scrubland (T. Keeler-Wolf pers. comm. 2014). However, occurrences in the Mojave Desert have characteristic Mojave Desert indicator species present, such as Coleogyne ramosissima, Nolina bigelovii, and Yucca schidigera, it will remain in this group for the time being. However, another way to address Mojave Desert Juniperus californica associations included in this alliance would be to assign them to other alliances in this group. For example, proposed USNVC association Juniperus californica / Coleogyne ramosissima could by move to ~Coleogyne ramosissima Mojave Desert Scrub Alliance (A3144)$$, proposed USNVC association Juniperus californica / Yucca schidigera / Pleuraphis rigida could be moved to ~Yucca schidigera Scrub Alliance (A3147)$$, and proposed USNVC association Juniperus californica / Nolina bigelovii (provisional) could be moved to ~Nolina parryi - Nolina microcarpa Scrub Alliance (A3145)$$. Most stands of these proposed USNVC associations have an open to sparse Juniperus californica tree canopy so the Juniperus californica trees form an emergent woody layer, but often do not dominate the site. More classification review is needed.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This rounded-crown, temperate or subpolar, needle-leaved evergreen woodland forms an open tree canopy less than 5 m in height. The shrub layer is intermittent to open. The herbaceous layer is sparse or grassy.

Floristics: This semi-arid and desert woodland is dominated by Juniperus californica. Other trees present with low cover may include Quercus turbinella, Yucca brevifolia, Pinus quadrifolia, and Pinus monophylla. An open or intermittent shrub layer may include Artemisia tridentata, Coleogyne ramosissima, Hesperoyucca whipplei (= Yucca whipplei), Yucca schidigera, Ephedra spp., Purshia stansburiana (= Purshia mexicana var. stansburiana), and Lepidospartum squamatum. The herbaceous layer is sparse or dominated by graminoids.

Dynamics:  This alliance of semi-arid southern California and the Mojave Desert does not tolerate fire. If a stand of this alliance burns, it is succeeded by chaparral.
Environmental Description:  This woodland alliance of the Mojave Desert, southern California, and the Baja Peninsula, grows on ridges, slopes and valleys. Stands are found from 600 to 2450 m elevation. Annual precipitation totals are quite low, varying from 20 to 40 cm. The precipitation is strongly seasonal, with the bulk falling between November and April. Soils are shallow, porous, rocky, coarse, sandy or silty derived from bedrock or alluvium (Sawyer et al. 2009).
Geographic Range: Stands of this desert woodland alliance occur in southern California in the inner central Coast Ranges, the montane Transverse and Peninsular ranges, south and east through Baja California, Mexico, and the Mojave Desert.

Nations: MX,US

States/Provinces:  CA, MXBCN, NV


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: G4

Greasons: No Data Available
Type Name Database Code Classification Code
Class 3 Desert & Semi-Desert Class C03 3
Subclass 3.B Cool Semi-Desert Scrub & Grassland Subclass S11 3.B
Formation 3.B.1 Cool Semi-Desert Scrub & Grassland Formation F033 3.B.1
Division 3.B.1.Ne Western North American Cool Semi-Desert Scrub & Grassland Division D040 3.B.1.Ne
Macrogroup 3.B.1.Ne.1 Yellow Rabbitbrush - Blackbrush / Indian Ricegrass Dry Shrubland & Grassland Macrogroup M171 3.B.1.Ne.1
Group 3.B.1.Ne.1.a Joshua Tree - Eastern Mojave Buckwheat - Rough Joint-fir Mixed Desert Scrub Group G296 3.B.1.Ne.1.a
Alliance A0502 California Juniper Mojave Scrub Alliance A0502 3.B.1.Ne.1.a
Association CEGL003058 California Juniper Mojave Scrub CEGL003058 3.B.1.Ne.1.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Juniperus californica (California juniper woodland) Alliance (Sawyer et al. 2009) [89.100.00]
= Juniperus californica Alliance (California juniper woodland) (Buck-Diaz et al. 2012)
>< Juniperus californica Wooded Shrubland Alliance (Evens et al. 2014)
= Juniperus californica Woodland Alliance (Evens et al. 2012)
= Juniperus californica Woodland Alliance (CNPS 2017) [89.100.00]
= California juniper series (Sawyer and Keeler-Wolf 1995)
>< Cismontane Juniper Woodland and Scrub (#72400) (Holland 1986b)
>< Mojavean Juniper Woodland and Scrub (#72220) (Holland 1986b)
>< Peninsular Juniper Woodland and Scrub (#72320) (Holland 1986b)
Concept Author(s): J.O. Sawyer, T. Keeler-Wolf, and J. Evens (2009)

Author of Description: K.A. Schulz

Acknowledgements: We have incorporated significant descriptive information previously compiled by M. Schindel.

Version Date: 12-18-14
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