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CEGL003043 Hesperocyparis macnabiana Forest
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Macnab''s Cypress Forest
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: Stands of the Hesperocyparis macnabiana forest occur from 300-800 m elevation in northwestern California and southwestern Oregon. The climate of this region is distinctly Mediterranean with droughty summers and moist winters. Annual precipitation varies across the region and with elevation, from roughly 30 cm to 80 cm/year. Stands of this forest type are typically on upper slopes and underlain by a variety of infertile parent materials including basalt, conglomerates, gabbro, greenstone, and ultramafic serpentine. Hesperocyparis macnabiana is the sole or dominant tree. Several other conifers may occur and be codominant, including Pinus attenuata, Pinus sabiniana, and Hesperocyparis sargentii. Broad-leaved trees may also be present, such as the deciduous Quercus douglasii and the evergreen Quercus wislizeni. Shrubs typically include Ceanothus cuneatus and Arctostaphylos viscida, and on serpentine substrates Quercus durata and/or Ceanothus jepsonii.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: The species composition among the stands dominated by Hesperocyparis macnabiana varies widely and is composed of associates of several other alliances occurring in this region. However, stands are extensive enough, and have some consistency in habitat characteristics as well as species composition, to warrant recognition. Keeler-Wolf (1990) reports on density and basal area of a few stands in Colusa County. Further plot-based, quantitative surveys are needed.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: In stands of this forest, the needle-leaved evergreen tree Hesperocyparis macnabiana (= Cupressus macnabiana) is the sole or dominant tree. Several other conifers may occur and be codominant, including Pinus attenuata, Pinus sabiniana, and Hesperocyparis sargentii (= Cupressus sargentii). Broad-leaved trees may also be present, such as the deciduous Quercus douglasii and the evergreen Quercus wislizeni. The height of the trees is typically less than 10 m, and the canopy may be continuous, intermittent or open. Shrubs are common or infrequent, the most common associates being the broad-leaved evergreen Ceanothus cuneatus, Arctostaphylos viscida, and Eriodictyon californicum. Associated shrubs that are restricted to serpentine outcrops are Quercus durata, Ceanothus jepsonii, and Garrya congdonii (= Garrya flavescens ssp. congdonii). The herbaceous layer is sparse.
Dynamics: As with most other Hesperocyparis species, Hesperocyparis macnabiana is dependent upon fire to open its serotinous cones, allowing seeds to be shed. Germination is rapid, an adaptation to allow utilization of winter rains for seedling establishment. Necessary fire-return intervals are unknown for most Hesperocyparis species.
Environmental Description: Stands occur from 300-800 m elevation in the northern Sierra Nevada and southern Cascades Mountains, and the eastern portion of the Siskiyous. The climate of this region is Mediterranean in character, with a distinct summer dry season, and most of the annual precipitation falling as rain during the late fall and winter months. The amount of annual precipitation is variable across the region and with elevation, from roughly 30 cm to perhaps as high as 80 cm. Sites supporting stands are typically on upper slopes and underlain by a variety of parent materials, including basalt, conglomerates, gabbro, greenstone, and ultramafic serpentine. The soils are rocky and range from clay loams more than 1.5 m deep, to silty loams only a few cm deep. In all cases, the soils derived from these parent materials are infertile.
Geographic Range: Occurs in scattered groves in the inner north Coast Ranges bordering the Sacramento Valley, and in the southern Cascade and foothills of the northern Sierra Nevada Ranges of northern California. This is the most widely distributed alliance of Cupressus species in California.
Nations: US
States/Provinces: CA, OR
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.689174
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: G2
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.1 Warm Temperate Forest & Woodland Formation | F018 | 1.B.1 |
| Division | 1.B.1.Nc Californian Forest & Woodland Division | D007 | 1.B.1.Nc |
| Macrogroup | 1.B.1.Nc.1 California Live Oak - California Laurel - Western Cypress species Forest & Woodland Macrogroup | M009 | 1.B.1.Nc.1 |
| Group | 1.B.1.Nc.1.b Western Cypress species - Pine species Forest & Woodland Group | G198 | 1.B.1.Nc.1.b |
| Alliance | A3355 Sargent''s Cypress - MacNab''s Cypress - Modoc Cypress Woodland Alliance | A3355 | 1.B.1.Nc.1.b |
| Association | CEGL003043 Macnab''s Cypress Forest | CEGL003043 | 1.B.1.Nc.1.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: < Callitropsis mcnabiana (Keeler-Wolf 1990a)
- Cheatham, N. H., and J. R. Haller. 1975. An annotated list of California habitat types. Unpublished report. University of California, Natural Land and Water Reserves System.
- Griffin, J. R., and W. B. Critchfield. 1972. The distribution of forest trees in California. Research Paper PSW-82/1972. USDA Forest Service, Pacific Southwest Forest and Range Experiment Station, Berkeley, CA. 114 pp.
- Keeler-Wolf, T. 1990a. Ecological surveys of Forest Service Research Natural Areas in California. General Technical Report PSW-125. USDA Forest Service, Pacific Southwest Research Station, Berkeley, CA. 165 pp.
- Sawyer, J. O., and T. Keeler-Wolf. 1995. A manual of California vegetation. California Native Plant Society, Sacramento. 471 pp.
- Vogl, R. J., W. P. Armstrong, K. L. White, and K. L. Cole. 1988. The closed-cone pines and cypresses. Pages 295-358 in: M. G. Barbour and J. Major, editors. 1988. Terrestrial vegetation of California: New expanded edition. California Native Plant Society, Special Publication 9, Sacramento. 1030 pp.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.