a vegetation classification system applied to southern california

8/8/2019 A vegetation classification system applied to southern California

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United StatesDepartment of A Vegetation ClassificationgricultureForest Sewice System Applied to SouthernPacific SouthwestForest and Range Californiaxperiment StationGeneral TechnicalReport PSW-45 Timothy E. Paysen Jeanine A . Derby Hugh Black, Jr. Vernon C. Bleich John W. Mincks


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Authors:TIMOTHY E. PAYSEN, a research forester, is assigned to the Station's chaparral andrelated ecosystem research unit, with headquarters at Riverside, Calif. He eamed a B.S.degree in forest management at Humboldt State College (1969) and a Ph.D. degree inapplied statistics at the University of California, Riverside (1978). JEANINE A.DERBY is forest botanist, San Bernardino National Forest, San Bernardino, Calif. Shereceived a B.A. degree in biology (1974) at the University of California, Riverside, andan M.S. degree in biology (1979) at California State University, San Bernardino. HUGHBLACK, JR.,s supewisory wildlife biologist, Shasta-Trinity National Forest, Red-ding, Ca lif. He eamed a B.S . degree in wildlife management at Colorado State Univer-sity (1964). VERNON C. BLEICH is associate wildlife biologist, California Depart-ment of Fish and Game. He was graduated from California State University, Long Beach,with a B.S. degree in zoology (1970) and an M.S. degree in biology (1973). JOHN W.MINCKS is timber sales preparation officer, Groveland Ranger District, StanislausNational Forest, Groveland, Calif., and was formerly silviculturist, Angeles NationalForest, Pasadena, Calif. He received a B.S. degree in forest management at HumboldtState College (1967).

Acknowledgments:In 1977, the Forest Service, U.S. Department of Agriculture, established a research and

development program at this Station titled "Vegetation Management Alternatives forChaparral and Related Ecosystems." This 5-year program, with headquarters at Riverside,California, is an intensive effort to develop, test, and demonstrate a wide range ofoperations for maintaining or increasing the productivity of chaparral and related ecosys-tems in southern California.

Work toward the development of the Vegetation Classification System described inthis report was facilitated through the efforts of many persons. Ike Parker, ecologist,Tahoe National Forest, Forest Service,U.S. Department of Agriculture, made availablethe experience he obtained while working on the Forest Service's Pacif ic SouthwestRegion (R-5) pilot ecology program. William Harvey, range consewationist, InyoNational Forest, sewed as an advisor in matters pertaining to range management duringthe initial development of the system. Mona Myatt and T e q Yonkers, both ecologists,of the Southern California Mison Company, were a source of valuable advice, andgraciously provided plant community information from their Coastal Resources Inven-tory. Constmctive comments based on field tests of the system were received from WaldoBurford and John Sully, biologists, both of the California Department of Transportation;Jan Zabriskie of the University of California, Riverside, Deep Canyon Desert ResearchStation; and Bmce Smith, Maureen Hales, and John Hall, biologists, all of the Riversideoffice, Bureau of Land Management, U.S. Department of Interior.

Publisher:Pacific Southwest Forest and Range Experiment StationP.O. Box 245, Berkeley, California 94701December 1980


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A Vegetation Classification System Applied to Southern CaliforniaTimothy E . Paysen Jeanine A . Derby Hugh Black. Jr . Vernon C . Bleich John W . Mincks

CONTENTS

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Regionalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Classification System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Association . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Subformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Field Key to Subformations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Series Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Closed Forest Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Woodland Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Shm b Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Dwarf Shrub Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Herbaceous Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 A . Climate Regions of Southern California . . . . . . . . . . . . . . . . . . . . . . 29 B . Species Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 C. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33


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Figure1-Area covered by the Vegetation Classification Sys-tem extends from the Central Valley to the border.


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Figure2-Elements of the Conifer Forest Subformation n southern Califor-nia contrast sharply with the mosaic of Chaparral and Sofi Chaparral Sub-formations seen in the background. The conifers nearly hide the smog in thevalley bottom.

The Vegetat ion Classificat ion System for S outhern Cali-fornia was de veloped by an interagency, interdiscipli-nary team as an aid to communicat ion among resource m ana-gers, planners, special is ts , and their agencies. I ts specificfunction is to define and nam e units of vegetation, regardlessof their successional state. The area covered by the Systemextends south from the Central Valley of California to theborder (fig. l ) , and includes a variety of vegetational elemen tsuk.2 ) .The System was developed to meet an existing need for asing le, comm only accepted classification sy stem that can beused as a basic "language" in discussing organizations ofplants or plant assemblages. Existing classification systemsdid not have common acceptance because they were ei thertoo general or to o funct ional ly specific (as , for exam ple, a"t imber type" system) , or because they incorporated otherfactors along with plants into the S ystem. This issue is deal twith in greater depth in a forthcoming report . '

' Paysen, Timothy E ., Ike Parker, Jeanine A . Derby, and Hugh Black, Jr.Vegetation classification: the conceptual basis of a system, (Manuscript inprepxat ion .)

Commo n acceptance of a basic "language" system by abroad spectrum of discipl ines is mandatory. Therefore,representatives of various agencies were initially broughttogether to analyze the problem and to recommend a plan ofaction. The following agencies participated: Forest Service,U.S. Department of Agriculture; Bureau of Land Manage-ment and Fish and Wildl ife Service, U.S. Department ofInterior; and California Department of Fish and Game. Ateam from within this group was charged with the task ofdeveloping an acceptable system. Review of the System , asi ts development proceeded, was given to an even broaderspectrum of potential users, including staff mem bers of Statecol leges and universi t ies , other State agencies, and theSouthern California Edison Compan y.

Th e classification system that was developed is hierarchi-cal, in five levels of descriptive detail. It was designed toaccommoda te the kinds of information needed fo r manage-ment decisions at the project level or at the broad planninglevel .

The System shows categories of vegetation as they nowexist in southern Californ ia. In time, these categ ories will beupdated in order to keep the list of recognized Series relevant.The bas ic f ramework of the Sys tem al lows vegeta t ion


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categories to be ad ded or deleted at any level of the hierarchyin order to reflect new information. Although agencies andfunctions may need to extend or build upon the existingclassification, a uniform terminology can be maintained.

SYSTEM OVERVIEWDevelop ment of the Vegetation Classification System for

Southern C alifornia began w ith a review of existing systems(Browne and Lowe 1974, Cheatham and H aller,2 Driscol land other^,^ Kuchler 1964, Mueller-Dombois and Ellenburg1974, Munz 1973, Tho me 1976). The range and dis tribut ionof vegetation series were determined through literature re-view (M unz 197 3, 1974; Cri tchfield 1971; Griffin andCritchfield 1972; Horton 1960; Shreve and Wiggins 1 964;McM inn 1939; and Latting 1976), through personal contactwith many specialists throughout central and southern Cali-fornia, and from our field experience. This ClassificationSystem is broadly patterned after an outlined system pro-posed by Leven and Horton.The Vegetation Classification System for Southern Cali-fornia is compatible at al l levels with a nat ional landclassification system being proposed by the Forest Service3and wh ich incorp orates the international system for classify-ing vegetation (UN ESC O 1973). The System is based upon ahierarchical stratification of plant cove r as described below.

T h e Formation is the uppermost level in the hierarchy, a ndi ts elements are defined according to physiognomic cri teria.A given Form ation is an aggregate of individual plant com-munities with the same physiognomy or stand structure. Abroad unit of vege tation that is a mosaic of differen t physiog-nomic typ es, but is predominantly m ade up of one physiog-nomic typ e, such a s closed forest, is not itself a Form ation. Itis an aggregation of various Fo rmations, e ach of which corre-sponds to a distinct physiognomic type within the mosaic( f i g . 3).Exam ple: An annual grass commu nity is considereda membe r of the Herbac eous Formation, even though it mayoccur in an area that is generally dominated by stands ofconifers ( f i gs . 4, 5 ) . Within a given Formation, plant com-munities with dominant species that have the same generalleaf and stem morphology characteristics are grouped into aSubformat ion. The Closed Forest Formation is thereforecomposed of the Conifer and Broadleaf Subformations.

Cheatham, Norden H . , and Robert Haller. University of California nat-ural land and water reserves system, an annotated list of California habitattypes. (Manuscript in preparation.)

' Driscoll, Richard S ., John W. Russell , and Marv C. Meier. Recom-mended national land classification system for renewable resource as-sessments. (Report on file at Rocky Mountain Forest and Range ExperimentStation, Fort Collins, Colo.)

Leven , Andrew A ., and Lowell E. Horton. 1976. Inventory of ecologicalland units, resource analysis units, and management units. In Land useplanning training test materials. ( Report on file at Pacific Southwest Region(R-5 ), Forest Serv., U.S. Dep. Ag ric., San Francisco, Calif.)

Figure 3-Disturbance by fire has resulted in this complex of CloForest and Shrub Formations.

T he Series andAssociat ion are taxonomic uni ts. T hese twocategories address specific plant commu nities. Together theyform the heart of the Classification System. The Series is ageneralization of Associations w ith the same dominan t over-s tory. The Association is the basic unit of the C lassificationSystem. An Association is a plant community, growingunder uniform environmental conditions, with a particulardominant overstory species, and characteristic associatedspecies. The nom enclature for Association reflects the domi-nant specie s, -and he most prevalent (or distinguishing) asso-ciated species. The latter is most often an understory spe cies,but can be an associated overstory spe cies. Exam ples: Pinyonpinelmountain mahogany/phlox or interior live oaklman-zanitalneedlegrass.

T h e Phase is a category that allows us to deal with thevariability that must exist within given asso ciations ( f i g . 6)It can be used to specify growth stages or condition of vegeta-tion, o r it can be used to describe a particular realization oft h e A s s o c i a t i o n t h a t h a s a n e s p e c i a l l y n o t e w o r t h ycharacter-such as a stand (or portion of a stand ) with aparticularly dense overstory.The Associations have not yet been developed. They canbe identified on the ground on a project basis or identifieduniformly for the ent i re southern Cal ifornia area afteradequate field samples are taken.

RegionalizationIt is often useful to regionalize a classification system if icovers a large geographic area, or if it covers an extremely

diverse environment. This kind of stratification assists theuser by eliminating ambigu ities that must exist in an exten-sive system. It provides a sorting process that facilitatespractical application. T o this end , we are suggesting the useof climate regions, according to descriptions adapted fromA l r n q u i ~ t . ~While these climate regions do not represent

' Almquist, G.L. 1977. Macroclimatic regions of Southern California(Repor t on file at the Forest Fire Laboratory, Pacific Southwest Forest andRange Experiment Station, Riverside, Calif.)


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f C l o se d F o r e s t F o r m a t i o n C o n i f e r F o r e s t B r o a dl e af F o r e s t C o n i f e r F o r e s tfSu bfo rmat i on t -~y -Subfo rmat i on -7y-Subformation

\^gyFigure 4-This "typical conifer forest" is, in fact, a complex of two distinct Subformations: the Conifer Forest Subformation and the Broadleaf Forest

individual strata that are unique in a geographic sens e, theyd o provide a set of environmental strata that are useful de-scriptive qualifiers. Examp le: Th e Montane region exists in anumber of places in southern California; nevertheless, i t isuseful to dis t inguish elements of the Canyon Live Oak Seriesthat exist in a Montane region from those that exist in anInterior Valley region.

A number of climatic and geophysical variables affectvegetative growth, reproduction, and distribution. Some ofthe variables include tempe rature, prec ipitation, and relativehumidity, along with the seasonal distribution of these fac-tors; domina nt wind patterns; orographic influence ; and prox-imity to major land m ass cha nges. It is difficult to define allof these interactions with geo grap hic and elevational bound-aries, particularly in an are a of great diversity such as south- Figure 5-The Herbaceous Formation is represented in the middle fore-ern California. The adaptation of Almquist 's descriptions ground by an element of the Sedge Series, and in the meadow in the leftserves for the present as a regionalization of the southern middle ground by the Forb Series. The Lodgepole Pine Series representsCalifornia vegetation area . It may som eday be supplanted by the Closed Forest Formation in the middle ground and on the hill in thebackground, and the Dwarf Shrub Formation ills in the remainder of the hilla m ore general regionalizing system, or i t may remain a s a that is devoid of lodgepole pine.local subregionalization of one of these systems.

Vegetation distribution relative to climate regions ispresented in a table of the Series, along with the Field K ey,below. The Appendix contains descriptions of each region.

ApplicationThe Vegetation Classification System for Southern Cali-

fornia can be used to describe environmental settings, toprovide a basic framework for vegetation mapping, and toqual i fy map class descript ions. I t can also serve as the com-mon link between fu nctional or technical classification sy s-tems, thereby faci l i tat ing communicat ion between disci -plines. Figure 6-Two Phases of the Forb Series are evident in the foreground:The System will become most meaningful to land mana- The extreme oreground shows an early successional Phase resulting romgers wh en Assoc iations are identified for southern California equestrian overuse; the middle foreground containsa mature Phase of thevegetation. Significant Associations can be identified only Series.


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after careful evaluation of plant distribution patterns and theirassociated environmental settings. Resource managers andresearchers should work together in this process.Whe n Asso ciations are identified, their successional statusshould eventually b e determined. K nowledg e of the potentialinherent in a plant community has practical application inlocal resource m anag emen t. It can also facilitate response toshifts in management direction from the national level. Forexample, an increased emphasis on managing forests andwoodlands for recreation, wildlife, and energy productionmay bring abo ut a response to increase production of oaks insouthern California. Knowledge of sites that have potentialfor high oak produc tivity on an extended basis will eliminatefruitless attempts at oak management o n marginal oak sites.

CLASSIFICATION SYSTEM

This hierarchical stratification (fie. 7) has been designed todesc ribe existing vegetation-the dominan t and associatedvegetation which presently occupies the site. However, be-cause the System is descriptive and is based upon standphysiognomy and floristics, it can also be used to describepotential vegetation-which is simply the "present vegeta-t ion" of some future t ime.

A l t e rn a t i ve sn o t c h o s e n a l t e rn a t i ve ch o se n

Formation Shrublzzl1 1u bforma tion BroadleafWoodlandSeries I 1 Cottonwood 1 1 S y a more I

Association

25-6070 over-Phase sto ry cover1 0 -2 5 % u n d e r -

Figure 7-The hierarchy of the Vegetation Classification System asapplied to southern California is shown here inanexample. In he diagram,the classification of a stand becomes progressively more precise as itmoves through the levels recognized in the classification (Formation, Sub-formation, and Series). The most specific level is the plant community(Association). Finally, the appropriate descriptive Phases are determinedand the proper alternatives are chosen.

Perhaps the easiest way to understand the relationshibetween the various levels of the System is to start with itbasic unit, the Association, and work up the hierarchy fromit. The Sy stem is an aggregating system from the Associatioup through the Formation. In an aggrega ting (or agglome rative) system , the classes at a given level in the hierarchy argrou ped , according to prescribed similarities, to form classeof the next higher hierarchal level. The Phase category, othe o the r ha nd , subdivides the c lasses to which i t iapplied-this means that predetermined classes have beegenerated, and are each to be subdivided on the basis ointernal differences. See the paper by Bailey and other(1978) for a discussion of aggregative and subdivisive systems; the same concepts are discussed as agglomerative andivisive systems by Sneath and Sokal (1973) and by Pielo(1969). Logically, the Phase level of description could bapplied anywhere in the hierarchy, since Series, Subformation, and Formation are simply generalizations of the Association concept.

Figure8-A natural habitat modification, such as a landslide, may rein an Association that is distinct from the surrounding elements ofMixed Conifer Series.


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AssociationA plant Association is an assemblage of plants, with a

characteris t ic floris t ic composi t ion, that occurs under a uni-form set of environmental condit ions. This is the "standard"defini t ion of a plant community (Ecological Society ofA m e r i ~ a , ~chwartz and others 1976) . Unfor tunate ly , i t i sh ighly amb iguous . The meaning of a "uni form set o fenviro nme ntal conditions" is largely a function of the scaleof description being addressed by the Classification Systemitself. T o define precisely the sca le of description fo r this (orany ) classification system m ay not be entirely possible; thisproblem is dealt with in some depth in a forthcoming pape r. 'For the purpose of this presentat ion, a rule of thumb wil lserve unde r most situations: A plant Association is recogniz-able on the ground; the size of the uni t may vary, but theAssociation almos t a lways has single species dominance inthe overstory. Exceptions to this rule will probably be rare.

Field reconnaissance will be required to identify Associa-tions. Individual Associations may exist as a result of interac-t ions between "constant" environmental characteris t ics ,less predictable natural forces ( f i g .8) ,and human influences.Though not necessari ly permanen t , a plant Associat ion mustbe sufficiently long-lasting to affect managem ent policy. Fo rexample , d i f feren t envi ronmental factors and d i f feren tbiogeographic history may dete rmine that a stand of white firin the New York Mou ntains (Mojave Desert) and another inthe San Jacinto Mountains (Peninsular Ranges) representdifferent Associat ions w ithin the W hite Fir Series. Similarly,environmental and human factors may determine that adja-cent manz anita s tands on the coast s ide of the San BernardinoMoun tains represent different Associations.

SeriesSeries s imply general ize plant Associat ions. All plant As-sociations with a given domin ant overstory spe cies constitute

a Series that is named by that species. This category does notimply greater heterogeneity than the Association. It stillrecognizes the basic plant com mun ity, but does so at a gen-eral level . I t also al lows for reference to an ent ire set offloris t ical ly related communit ies . Example: A part icularplant community may be recognized as an Interior LiveOak/Eastwood Manzanita Associat ion, or i t may be recog-nized as an element of the Interior Live O ak Series. T he basicunit of precision-the plant community-has not chan ged,only the level of precision used to address it has changed.

SubformationA Subformation is an aggregation of Series with a given

physiognomic character, and a part icular s tem and leafmorphology in the dom inant overstory species. This category

Ecological Society of America. 1952. Report of the Committee onNomenclature. (Rep ort on file at Ecological Society of America and DukeUniversity Press, Durham, N.C.)

is included in the System to provide a set of classes that aremore dist inct than those at the Formation level . R eferencewill probably be made to this level more often than any otherin the Sys tem , because the distinctions that it makes relate tocommon general ized references to vegetat ion. Example:Coni fer versus broadleaf fores t s ; chaparra l versus sof tchaparral.

FormationA Formation is an aggregation of Subformations with a

given physiognomic character. Exa mple: All Subform ationsthat are characterized by an overstory of trees with a closedcanopy (60 to 100 percent crown cove r) make up the ClosedForest Formation. Five Formations are currently recognizedin southern California.

Although Phase is treated as a category of the classifica-tion, it is primarily a vehicle for management application ofthe System. It is a means of addressing variability within aplant commu nity, and therefore only the general pattern of i tsuse can be prescribed-strict definition of all potentiallyrelevant Phases of plant communities is not practical. Foreach Formation described, we have suggested some possibleterms that might be general ly useful to describe the kinds ofvariations that are included in the concept of Phase. Manyother such descriptors could be used in an actual inventory ofvegetat ion.

Phase descriptors are often chosen in relation to specificfunctional applications. A silviculturist may de fine Phases ofa plant community as different stand aggregations that callfor different silvicultural prescriptions. In this light, a sma llcluster of a given species within a community constitutes aPhase of that community. At a different level, the silvicul-turis t may view an age class within a plant community asdefining a u nique Phase. Similarly, a fuels special is t may beconcerned with various characteristics of a chaparral stand,such as age, species composi t ion, and vigor. A fuels spe-cial is t would therefore choose age, vigor, and probablymortal i ty as elements for defining Phase categories. Fordifferent reasons, a wildlife biologist may recognize the sam ecategories as the fuels specialist.

Outside the realm of pure classification, the Phase cate-gory is also a logical means for describing certain stages ofsuccession. Depending upon circumstances, such as man-agement goals or constraints , a plant assemblage may beviewed as in an early stage of development of one A ssocia-t ion or an advanced stage of development for another Asso-ciation (fig. 9). For example, a recently burned chaparralstand bears little resemblance to ch apar ral. The burned site isoften dominated by elements of the Herbaceou s Formation.Yet , know ledge of the chaparral successional cycle tel ls usthat, if chaparral seedlings and sprouts are present, th e recentbum i s a potential chaparral stand in a pioneer stage-andcontains a particular Phase of a potential chaparral Associa-


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Figure 9-This Jeffrey Pinelpinyon Pinelsageb rush Association wil l, atsome future date, become a Pinyon Pine/Sagebrush Association. Thepinyon pine union represents a pioneer Phase of the potential PinyonPineISagebrush Association.tion. This sa me logic can be applied to clearcuts in which theconifer reproduction has not yet attained dominant overstorystatus; a potential conifer stand exists and is described asbeing in a seedl ing Ph ase. W e cannot , however, describe abare gran ite slab as a pioneer Phase of a W hite Fir Associa-t ion, even though we may be clever enough to t race commu-nity developm ent forward to the potential existence of a standof white fi r. W hite fir seedlings must be clearly established ina pioneer Phase of a White Fir Association.

In using the Phase category for description of ecologicalstag es, we ar e viewing the site in the context of what we knowwill probably ha ppe n, in order to classify it more usefully forour needs. The system itself does not tell us anything aboutsuccession; it simply allows us to take ecological develop-ment and succession into consideration in our classification.In figure 10, the development of one Association withinanother is diagrammed. The bot tom strip shows how wemight classify the site over the course of its probable futuredevelopment. By establishing a sequence of Phases in thiswa y, w e provide a gu ide to classification of other sites repre-senting different coexisting stages of development.

Jef f rey Pine/Pin yon Pine/Sagebrush Commu*developi f Jef f reremain

ICommunity P inyon P ine /Sagebrushdevelopment +f ~ e f f r e y i ne P ha se 1 Phase 2 Phase 3 Phase 4 ...never existed I

- p r e s e n tTime +Phase sequenceto be used for 1classi f i ra t ion I

'a I-

Jef f rey Pine/Pinyon Pine /sagebrush ! Pinvon Pine /Saaebrush1 Phase 4 I Phase 5 I Phase 3 I Phase 4 1

Figure 10-The Phase category may be used to describe the ecolstage of the stand in figure 9. The two upper strips show the dopmental phase sequences from which the bottom strip-a successequence mov ing f r om Je f f r ey p i ne dominance t o p i nyondominance-is derived. The basis for this is that the Pinyon Sagebrush Association was present, though "hidden" in the Jpine/Pinyon pine/Sagebrush Association. Thus, when it emergesalready in the third phase.

Further discussion regarding this aspect of Phase, means by w hich we may classify vegetation for a particpoint in time and concurrently focus on the entire scessional spectrum of a vegetation co mm unit y, is includethe paper mentioned earlier.

To describe complex Phase categories , such as those we have sugge sted, a Phase code or index can be derivedthe basis of the elements used to define the Phase categ orFor example, the Phases suggested for the Closed FoFormation are based upon six diameter at breast hei(d .b .h . ) size class ranges , three overstory cove r ranges, three understory cover ranges. A stand with trees in second size class range (1 to 5 inches d.b .h .) , that is infirst overstory co ver category (less than 40 percen t) , anthe third understory cove r category (g reater than 70 percewould have a Phase Code of 2- 1-3. The use of a Phase codnot mandatory, but it can be useful for data recording pposes.

NOMENCLATURE

The name given to an Association should indicate the donant species and the dominant associated species. T he comnation of dominant and associated species should reflect entire character of the Association-to the degre e posswhen using only a few species names. The following exampwill illustrate the naming tech nique, and prov ide so me rulethumb.


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Th e first species listed in an Association n ame will alwaysbe the dominant species of the Association, and will be thedominant overstory species. Therefore, a Jeffrey Pinelsage-brush Association will have Jeffrey pine as the dominantoverstory species.

The order of species in the Association name reflects theorder of dominance in the Association. The order of domi-nance can be taken in two ways: W e can recognize the domi-nant spec ies in eac h layer of a multilayered stan d, and write thespecies names in descend ing order of dominance by layers; wecan recognize the dominant species in the dominant layer(overstory) of an Association, and recognize characteristicassociated species within the same layer. T he second approachis most appropriate f or single-layered Associations, but mayoccasionally be used fo r two-layered Associations when thereis good reason for doing so. Layer dominance should takeprecedence ove r within-layer species dominance when namingthe Association.

A multilayered Association will be named by the dominantspecies in each laye r, beginning with the overstory layer, andending with the herbaceous layer if one exists. Each speciesnam e wi l l be s epa ra t ed by a s l a s h . Exam pl e : J e f f r eyPine/Sagebrush/Squirreltail grass.

An Association with mixed species dominance will benamed in the usual manner, with the exception that the place inthe Association name that is normally relegated to a singledom i nan t s pec i es w i ll be o ccup i ed by m ore t han onespecies-separated by a hyph en. Exa mple : A Jeffrey Pine-White FirIManzanita Association.A single-layered Association will be named by the dominantspecies in the layer and the dominant associated species. Manychaparral Associations will be named in this manner (fig. 11).E x a m p l e s : A C h a m i s e - S c r u b O a k A s s o c ia t io n o r aCeanothus-Manzanita-Chamise Association; in both cases,the species that are named form a part of the single shrub layerof the Association.

Shrubs with trees and herbaceous vegetation with shrubs ortrees represent a specia l situation that warrants some attentio n.A classification system must provide criteria for class dis-crimination that are to some extent arbitrary. Consequently,we will find savann ah-like Associations with insufficient tree

Figure 11-A Chamise/Manzanita/SugarbushAssociation onMt. San Jacinto near Banning, California. Chamise dominatesthe shrub layer, and manzanita andsugarbush are the charac-teristic associated species of this community; for classificationpurposes, his would be considered a one-layered Association.

canopy cover to be called elements of the Woodland Forma-tion; yet there may be enough trees in the Association to beecologically significant. In cases like these, the "unrecog-nized" tree or shrub cover should be included in the Associa-tion name-at the end and enclosed in parentheses. Example:A Foxtail Fescue-Mustard (B lue Oak) Association. A rule ofthum b to follow in such cases is: Whenever an element of theShrub Formation has a tree canopy cover of 10 to 25 percent,or an element of the Herbaceous Formation has a tre e or shrubcanopy cover of 10 to 25 percent, the tree or shrub will beincluded parenthetically in the Association name.

Common names may be used for local application of theSystem , but Latin names should be used in official docume nts,reports , and regional , nat ional , or internat ional corres-pondence. Naming procedures will remain the same ; the Latinspecies names will simply replace the com mon species nam es.Example: A Foxtail Fescue-Mustard (Blue Oak) A ssociationwill be properly called a Festuca meg alura-B rassica (Quercusdoug lasii) Association, and will belong to the Festuc a Series(rather than the Fescue Series).

Given the appropriate perspective, any Association will fallinto the category of Ephemeral or Transient Associations. W ewill treat it from the standpoint of resource ma nagement p lan-ning and decisionmaking. Th e most consistent candidates forthis category will be certain elements of the Herbac eous For-mation. Many stands of nonperennial he rbs will appear onlybeca use of an especially heavy rainy season-and will disap-pear for a number of years; their reappearance will often bewith a different species dominance, and a different speciescomposition in general. Other stands may be composed ofpioneer species that appear after a recent disturbance; thecomposition of these stands may change from year to year.The se communities should not be treated with a greater degre eof precision than is warranted by current m anagement need s orby requirements for advancing the state of our knowledge . Itmay be sufficient to note the fact that there are elemen ts of theHerbaceous Formation o r perhaps classify them to Series . Onthe other hand, it may be de sirable to assign them to at least aprovisional Association without carrying out an extensive in-ventory. Judgm ent will have to be used in these kinds of cases.


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Table 1Serie distribution, by climate regions and habitats Table 1-Series distribution, by climate regions a nd habitats-continuedClimate regions' h i t a t s 2I 1 Climate regions' ~ a

Subformation andSeries AI HMO Mo Co Tr IV HDVLDV RipTr Alk Subformation andSeries A1 HMOMo Co Tr IV HDV-DVTr RClosed Forest Formation Shrub FormationConifer Forest 1 Chaparral ICypress Ceanothus x x x x

Bigcone Douglas-fir Chamise x x x xDouglas-fir Bush Chinquapin xSanta Lucia Fir Mountain Mahogany x x xWhite Fir Manzanita x x x xWestern Juniper Scrub Oak X X X xBishop Pine Prunus x xBristlecone Pine Redshank x xCoulter Pine Sumac x xKnobcone Pine Toyon x xLimber PineLodgepole PineMonterey PinePonderosa/JeffreyPine

Soft ChaparralBaccharisCalifornia BuckwheatCoastal SagebrushTorrey PineCoast Redwood

CrotonEnceliaMixed Conifer Lupine

Broadleaf ForestAlder x xRabbitbrushSalvia

Aspen x x Woody ShrubCalifornia Bay x ArrowweedEucalyptus x BlackbushIsland IronwoodMadrone xx x CatclawCreosote 1 x xBigleaf Maple X X X Greasewood xBlack Oak x x Ocotillo xCanyon Live Oak x x x Wild Rose x x x x xCoast Live Oak x x x x Sagebrush x xTanoak x x Saltbush x xSucculent ShrubWoodland Formation Agave x xConifer Woodland Iodine Bush x x x Juniper Opuntia x x xDigger PinePinyon Pine Dwarf Shrub Formation

Broadleaf WoodlandCalifornia BuckeyeCushion PlantBuckwheat

Cotton wood x x X X X Succulent Dwarf ShrubDesert Ironwood x x PickleweedMesquite X x SuaedaBlue Oak x xEngelmann OakInterior Live Oak x x x x Herbaceous FormationValley Oak x GraminoidPalo Verde x x Bromegrass x x x xSalt-cedar X X X Bulrush x x x x x x x x x Smoke Tree x x Cattail (Qpha) x x x x x x x x xSycamore x x x Cordgrass x x x Desert Willow x x Fescue x x xWillow x x x x x x x x x Galleta Grass X X X

Succulent WoodlandJoshua TreePalmMuhlenbergiaNeedlegrassWild OatsRicegrass

x

x

xx

x

xxx

x

x x

x

Wild Rye xSacaton x x x x Saltgrass x x x x Sedge (Carex) x x x x x x x x x xWiregrass(Juncus) x x x x x x x x X X


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Table 1-Series distrib ution , by climate regions an d habitats-continuedClimate regions '

Herbaceous Formation

Habitats2Subformation andSeries

ForbAmbrosiaColdeniaGoldenrodMustardWyethia

AquaticPondweedWater Hyac inthWater Milfoil

Al

CryptogamFernLichenMos s

Rip

xx

x xx x x x x

x x

Alk

x x x x x x x xx x x x x x x xx x x x x x x x

HMO

'A1 = Alp ine ; HMO = High Montane ; Mo = Monta ne ; Co = Coastal; Tr =Transition; IV = Inte r ior Valley; DTr = Desert Transition; HDV = HighDesert Valley; LDV = Low Desert Valley. For descr iption, see Appendix A .'Rip = Riparian; Alk = Alka line soil .

FIELD KEY TO SUBFORMATIONSMo Tr The following key may be used to identify Subformations in

southern California. It is arranged in two parts: a key toFormations, and a key to Subformations. Table 1 contains alist of Series keyed to the climate regions within which theymost often occu r. Series are identified by the dominant speciespresent in a stand; therefore a dichotomous Series key is notnecessary-aplant species key would be the necessary tool fordeterminin g Series. Associations will have to be identified atthe site; for the present time, a key to Associations is notfeasible.

DTro IV

Suggestions for Field Use of the Key. When using the keyan d table 1 to interpret vegetation on the ground,Look at the variability across the landscape.

Determine whether the variability can be explained bysom e ecological factor, i .e. , soil differenc es, aspect dif-ferences, evaluation differences, changes in land form, etc.Specific communities may be related to unique combinationsof these factors. For example: The Manzanita Series domi-nates northwest aspects , the Chamise Series dominatesridgetops and southeast aspects, and steep canyons contain theBigcone Douglas-fir Series.

If the overstory dominance is not clear, determinewhether you are operating in an ecotone. Are understory orassociated plants more characteristic of the Series present oneither end of the ecotone? For example: As elevation in-creases, creosote bush drops out of the overstory and juniper,although present, does not replace it in dominance. Are theassociated species more cha racteristic of the Creoso te Series orthe Juniper Series?Mak e the best interpretation possible based on your expe -rience and ability to distinguish patterns in situations whereinterpretation is difficult ( f ig . 12). Distribution patterns foroverstory species may be disrupted owing to local speciescompetition, seed dispersal mechanisms and patterns, firehistory, floristic history, or human u se of the site. M ost Asso-ciations that are identified in the field should be consideredprovisional until they can be placed within the context ofgeneral vegetation distribution patterns in a floristic region orzone.

HDVLDV

Figure 12-Intepreting vegetation on the ground can be com-plicated by a variety of Associations. Elements of the Red-shank, Chamise, Interior Live Oak, and Coulter Pine Seriesintermingle in the interface zone between brushland and tim-berland.


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KEY TO FORMATIONS

Overstory crown- 60 pet. Closed Fr cover

Tree overstory 1dominant (treecrown cover

L Overstory crowncover between Woodla25 pet. and 60 pet.Dominant shrubs < '12 m tall at bmaturity (10-20 yr after disturbancefor most sites-allow more time for Dwarf SAlpine sites) 1

L Dominant shrubs 5s- V z m tall ataturityTree overstory Shrunot dominant -(tree crown Well-establishedcover < 25 pet.) shrub seedlings orsprouts presentwill provide 2 25 pet.crown cover atmaturityshrub seedlings maybe present but will-Shrub crown Herbac- not provide 3 25 pet.-cover < 25 pet. crown cover atmaturity

Stand a- 5 y iold (5 yr or 1more since lastdisturbance)


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KEY TO SUBFORMATIONS

Leaves needlelike,scalelike, awl-shaped Conifer Forest 1Leaves not as forConifer Forest Broadleaf Forest

1 1tems or leaves succulent Succulent Woodland-eaves needlelike,scalelike, awl-shaped 'OniferNeither stems norleaves succulent

Leaves not as for Broadleaf WoodlandConifer Woodland

Stems or leavessucculent Succulent Dwarf ShrubStems woody, leaves Cushion Plant Iot succulentLeaves or stems Succulent Shrubsucculent

Leaves membranous, Woody ShrubLeaves not succulent, stems woody Istems woody orsemiwoody Stems woody ChaparralLeaves sclerophyllousor leathery

Stems partiallywoodyStand requires mechanicalsupport of water to main- Aquatictain physiognomic integrity ,

Dominant species Graminoidgrass orr grasslikeStand does not require themechanical support of Water Dominant vegetationDominant species cryptogamicnot grass norgrasslike L Dominant vegetationnot cryptogamic


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SERIES DESCRIPTIONS

Closed Forest FormationVegetation: The Series and Subformations of the Closed

Forest Formation are dominated by deciduous or evergreentrees that are at least 15 feet (5 m) tall, with crowns mostlyinterlocking (UNESCO 1973). Since many "forested" areasare only marginally capable of supporting a true closed forest,stands with an overstory crown cover of at least 60 percent willqualify as closed forests. The Closed Forest Formation iscomprised of the Conifer and Broadleaf Subforrnations. TheConifer Subformation contains Series that are dominated byconifer species, and the Broadleaf Subformation containsSeries that are dominated by evergreen or deciduous broadleafspecies-broadleaf forests are sometimes described ashardwood or mixed-evergreen forests.

Distribution: The Closed Forest Formation is worldwide indistribution. Elements of the Conifer Forest Subformationoccur from sea level near the coast to above 11,000 feet (3353m) in the interior of southern California. The Broadleaf ForestSubformation is found in the coastal and interior mountainranges of southern California, and also in some riparianhabitats.

Suggested Phases are:Size (d .b .h . , 2 inches) Cover (percent)O v e r m i y UnderuoryI . < I 1. 6 0 3. 25-504. 11-21 4. 50-705 . > 2 1 , < 1 8 0 yrs 5 . >706.>21,>180 yrs

Conifer Forest SubformationSeries within the Conifer Forest Subformation are named

for the dominant overstory species, usually that species whichmakes up 60 percent or more of the total crown cover. In aMixed Conifer Series, two or three specified codominantsmake up 60 percent or more of the total crown cover (fig. 13).Cypress Series

Vegetation: Dominant overstory may be Sargent cypress(Cupressus surgentii), Monterey cypress (C. mumcarpa),Gowan cypress (C. goveniana), Tecate cypress (C. forbesii),Cuyamaca cypress (C. stephensii), or Santa Cruz cypress (C.abramsiana). Disjunct stands of cypress, usually with onlyone dominant species per stand, occur within the Chaparraland Conifer Forest Formations. Chaparral shrubs often occurin the understory. Cypress stands occur on serpentine or low-nutrient soils.

Distribution: Localized populations of cypress are presentin the Santa Cruz Mountains (C. abrumsianu), Santa AnaMountains, Otay Mountains, Baja California (C. forbesii),and Monterey Peninsula (C . goveniana, C. mucrocarpa),

from Mendocino County to Santa Barbara County (C. satii), and on Cuyamaca Peak in San Diego County (C. stesii).Bigcone Douglas-fir Series

Vegetation: Overstory species is Pseudotsuga macrowith Quercus chrysolepis (canyon live oak) and occasiblack oak (Q. kelloggii). Dense stands are found in canyon north-facing slopes (fig. 14). Mature stands have aherbaceous layer. Younger stands may have a chaparralunderstory.

Distribution: The total range of bigcone Douglaswithin southern California, from near Mount Pinos inCounty south to San Diego County.Douglas-fir Series

Vegetation: Pseudotsuga menziesii is the dominant story species. Representatives of this Series may occextensive "pure" stands or be intermingled with elemethe Coast Redwood or Monterey Pine Series.

Distribution: The most extensive stands of Douglas-in western Oregon and Washington, though the species throughout the Western States ranging from British Colsouth to Mexico. Within California, the species domstands through the Klamath and Coast Ranges to theCruz Mountains. Isolated stands occur in Monterey Co

Santa Lucia Fir SeriesVegetation: Abies bracteata is the dominant species. S

are interspersed with the Broadleaf Forest Formation inrocky, fire-resistant habitats.

Distribution: This Series has a restricted distributionsisting of relict stands within 15 miles (24.14 km) of thein the Santa Lucia Mountains of Monterey and SanObispo Counties.

White Fir SeriesVegetation: Abies concolor is the dominant overstor

cies, and may occur in nearly pure stands. The undevegetation is sparse with a moderate accumulation of including needles and fallen branches.

Distribution: White fir is widely distributed in the WStates from Oregon to New Mexico and south into MSmall relict stands in the mountains of the north Mojave appear more closely related genetically to the white firRocky Mountains than to the white fir of California.

Western Juniper SeriesVegetation: Juniperus occidentalis is the dominant

story species, found in sparse stands with sparse shunderstory of Artemisia (sagebrush) and Chrysothamnubitbrush) species.

Distribution: Western juniper extends from southern ington throughout the Great Basin area of the Wesdisjunct populations in the mountains of southern CalifBishop Pine Series

Vegetation: Pinus muricata is the dominant speciechaparral shrubs in the understory. Growth habit ctwisted, when the tree is subjected to winds and salt spstraight with a broad crown where it is protected frowind.

Distribution: Intermittent relict stands range from boldt County south to Santa Barbara County and the C


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Islands. Bishop pine g row s within the fog belt along the PacificCoast.Bristlecone Pine Series

Vegetation: Pinus aristata (named P . longaeva by Bailey[1970]) is the dominant o verstory species occurring in sparsestands with limber pines. This Series is found on dolomiticsoils at the upper elevational limits of the conifer forest. It isinterspersed with the Dwarf Shru b Formation in alpinehabitats.Distribution: Bristlecone pine extends west from Utah intoInyo County in California w here it is found in the W hite, LastChance, Inyo, and Panamint Mountains.Coulter Pine Series

Vegetation: Pinus coulteri is the dominan t overstory specieswith chaparral shrubs or interior live oaks in the understory( f ig .15 ) .Th is Series interfaces with the Chaparral Formation.

Distribution: Coulter pine ranges from Contra Costa Coun tysouth to Baja California.Knobcone Pine Series

Vegetation: Pinus attenuata is the dominant overstory spe-cies with chaparral shrubs in the understory. T his Series inter-faces with the Chaparral Formation throughout much of itsrange and also occurs on serpentine soils with the ConiferForest Formation.

Distribution: Knobcone pine occurs from the Oregon Cas-cades south to Baja California.Limber Pine Series

Vegetation: Pinusflexilis is the dominant overstory species ,a subalpine tree growing in sparse stands with a spa rse under-story. Abov e 1 1,00 0 feet (3352 .8 m ) elevation, limber pinetends to form krumm holtz stan ds, the prostrate forms appear-ing more like shrubs than ancient trees.

Distribution: Limber pine ranges from Canada to NewMexico in the mountains of the Western United State s. South-em California stands are scattered on the highest peaks of theInyo, Panamint, San G abriel , San Bemardino, and San JacintoMountain ranges. Th e western limit is on M ount pinos in KernCounty.Lodgepole Pine Series

Vegetation: Pinus contorta is the dominant overstory spe-cies, in sparse stands within xeric, high-elevation habitats or indense stands surrounding meadows. Understory also variesaccording to habitat.

Distribution: Lodgepole pine ranges from Alaska to BajaCalifornia and east to South Dak ota. It grows in a w ider rangeof elevations-sea level to 12,0 00 feet (36 57.6 m)-than anyother pine (Griffin and Critchfield 1972). In southern Califor-nia , this Series is a dominant one above 8000 feet (2438.4 m).How ever, Bluff Lake Meadow, at 7200 feet (2 194.6 m), in theS a n B e r na r d ino M oun ta ins , sup por t s a sm a l l s t and o flodgepole pine including the Champion Lodgepole. '

Figure 13-A clasexample of the MixConifer Series steep, rugged terraAn admixture of blaoak can be seen wthe dominant sugpine and white fir. Bcause of the stetopography, litter acumulation is low.

Figure14-Repeated fires have often relegated the Bigcone Douglas-fiSeries to protected drainage bottoms in many parts of southernCalifornia.

Figure 15-An early Phase Coulter Pinelinterior Live Oak Association 5years after a fire. The emergent Coulter pine has attained sufficien' American Forestry Association. June 3 , 1963.Report to the Forest Super- dominance to qualify this stand as an element of the Closed Foresvisor, San Bemardino National Forest, San Bernardino, Calif. Formation. Ceanothus and manzanita can also be seen n the shrub layer


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Figure 16-A mature Jeffrey Pinellnterior Live OakIBromegrass Asso-ciation represents he Closed Forest Formation n the middle ground, andthe Herbaceous Formation can be seen n the foreground. Environmentalfactors have maintained the distinction between the herbaceous layer ofthe Closed Forest Formation and the Herbaceous Formation.

Figure17-The interior of a stand belonging o the Mixed Conifer Series.In spite of the heavy usegiven tothis stand (foot raffic), Jeffrey pine, whitefir, and black oak seedlings are well established in the understory.

Monterey Pine SeriesVegetation: Pinus radiata is the dominant overstory s

in open to moderately dense stands with live oaks and cyShrubs and perennial herbs occupy the understory.

Distribution: Relict stands are present within the coasbelt at three different locations in central CaliforniaNuevo, Monterey Peninsula, and Cambria Hills.PonderosaIJeffrey Pine Series

Vegetation: Dominant overstory species are Pinusderosa or P. jeffreyi with herbaceous or shrubby unde(fe. 16).Distribution: Ponderosa pine is present in dominant

in mountains throughout the Western States. Jeffreyranges from southern Oregon to mountains of Baja CalifJeffrey pine generally occurs on the drier or higher elevsites and ponderosa pine occupies the most mesic midelehabitats where the ranges of the two species coincide.

Torrey Pine SeriesVegetation: Relict stands of Pinus torreyana form a

overstory with soft chaparral shrubs in the understory.Distribution: Sea bluffs at Del Mar in San Diego Co

and on Santa Rosa Island are the only remaining habitarelict stands of Torrey pine.

Coast Redwood SeriesVegetation: Sequoia sempervirens is dominant in

stands with California laurel (Umhellularia californicaDouglas-fir (Pseudotsuga men-desii). Mosses and fernsgrow in the understory. A deep litter layer covers the

Distribution: Coast redwood occurs in discontinuous from southern Oregon south to San Luis Obispo CouCalifornia, growing within 30 miles (48.3 km) of the PCoast.

Mixed Conifer SeriesVegetation: Overstory components are a mix of Pinubertiana (sugar pine), Abies concolor (white fir), Pinus

derosa (ponderosa pine) , or Pinus jeffreyi (Jeffrey pineCalocedrus decurrens (incense-cedar) The overstory itistoried in dense stands with moderate to heavy litter aclations (fig. 17).

Distribution: Mixed Conifer occurs throughout the Cnia mountains, north into Oregon, and south into the San Pedro Martir of Baja California.Broadleaf Forest Subformation

Series within the Broadleaf Forest Subformation are nfor the dominant overstory species. Four represent sriparian habitats in southern California although theyoccur outside of riparian areas in more mesic environmOne (Eucalyptus) represents introduced species whichbecome naturalized.Alder Series

Vegetation: Ainus rhombifolia orA. rubru is the domoverstory species in this Series, which occurs in riphabitats with flowing water. Understory shrubs, such asandSalix species, with abundant herbaceous vegetation,this a multistoried, diverse habitat.

Distribution: Ainus rhombifolia (white alder) is throughout California, except for the Pacific Coast, whe


19/39

replaced by A. rubra (red alder). W hite alder ranges north intoBritish Columbia and east to Idaho.Aspen Series

Vegetation: Populus tremuloides is the dominant overstoryspecies. Th e Series occurs around moist mountain m eadows.

Distribution: Aspen ranges from Alaska through Canadaand the United States to Mexico. Southern California popula-tions are disjunct, occurring in the White Mountains and SanBernardino Mountains.California Bay Series

Vegetation: Dominant overstory is Umbellularia califor-nica with shrubs in the understory.

Distr ibut ion: California bay extends from San DiegoCounty north to southwest Oregon . It is present along stream-courses or springs in southern California and on coastal foot-hills north of Ventura County and on the Channel Islands.Eucalyptus Series

Vegetation: Eucalyptus occurs in dominant stands with adense litter layer and essentially no shrubs or herbaceousspecies in the understory.

Distribution: Native to Australia, this genus has beenplanted in dense stands widely scattered through Californiaand has become naturalized, with some reproduction occur-ring. No exact distribution inventory exists.

Island Ironwood SeriesVegetation: Dominant overstory is Lyonothamnusf loribun-

dus with a shrubby understory.Distribution: Island ironwood occurs in Santa Catalina Is-

land and a subspecies (aspleni fol ius)with pinnate leaves isfound on San Clemen te, Santa Rosa, and Santa Cruz Islands.

Madrone SeriesVegetation: Arbutus menziesii is the dominant overstory

species. The Series is often intermingled with both CoastRedwood and Douglas-fir Series.Distribution: Mad rone occur s in a few relict stands in south-em California-on Palom ar Mo untain, the Santa MonicaMountains, and Santa Cruz Islands. From the Santa LuciaMountains northward to British Columbia madrone is com-mon, both as a Series dominant and as a component of theCoast Redwood Series and Douglas-fir Series.

Bigleaf Maple SeriesVegetation: Acer mac rophyllum , a deciduous tree, is the

dom inant overstory spec ies. The Se ries is riparian in southernCaliforn ia, but spreads over hillsides away from streams in theNorth.

Distribution: Bigleaf maple is found along the coast fromBritish C olumbia to San Diego County in southern California.The Series occurs on the west slopes of the Sierra NevadaMountains and in the Peninsular and Transverse Range s, butdoes not follow rivers into the Central Valley.

Black Oak SeriesVegetation: Quercus kelloggii is the dominant overstory

species-a decidu ous tree which produces a well-developedlitter layer. Und erstory inc ludes shrub s, grasse s, and perennialforbs. Black o ak will sometim es survive fire and resprout fromthe crow n. If crowns are fire killed, it resprouts from the base.

Distribution: Black oak occurs from Oregon south to theLaguna Mountains in San Diego County { f i g . 18) .

Figure 18-The Black S e r i e s is a common Brleaf F o r e s t e l e m e nsouthern California.

Canyon Live Oak SeriesVegetation: Quercus chrysolepis is the dominant overstorytree. Th is Series can occ ur in riparian habitats, interfacing the

Chaparral Formation, or on mountain sideslopes at higheelevation s. This species is usually fire-killed, resprouting fromthe base rather than the crow n.

Distribution: Canyon live oak occurs from southwesternOregon to Baja California, east to central Arizona.Coast Live Oak Series

Vegetation: Qu ercus agrifolia is the dominant overstoryspecies (fif. 19 ). Under optimum growth the Series is a denseforest, but it sometimes forms open savannah-like grasslandsThis live oak has exceptional fire resistance. T rees grea ter than8 inches (20 .3 cm) d.b.h. will resist top kill, resprouting fromthe crown within 2 months after being total ly bla~kened.

Distr ibut ion: Coast l ive oak occurs from MendocinoCounty south to Baja California.Tanoak Series

Vegetution: Lithocarpus densijlorus is the dominant overstory species often associated with madrone (Arbutus menziesi i ) . Tanoak grows in a shrubby form on rocky, exposedridges.Distribution: Tanoak occurs from southwestern Oregonsouth to Santa Barbara County in California. It is the onlyNorth American representative of a large Asian genus.

Woodland FormationVegetation: Dominant trees a re more than 15 feet ( 5 m) tall,

with an open canopy. Crowns are not touching and canopycover is between 25 an d 60 percent. Both herbaceous andshmbby understories can be present. Trees may be deciduousor evergreen, and may be conifers or broadleaf species. Thr eeSubformations are included in the Woodland Form ation: The

' Plumb, T.R . 1976. Response of Southern California oaks to wildfire(Report on file at the Forest Fire Laboratory, Pacific Southwest Forest andRange Experiment Station, Riverside, Calif .)


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Conifer Woodland, Broadleaf Woodland, and SucculentWoodland Subfomations.

Distribution: Woodlands oc cur worldwide. In southern Cal-ifornia, they occupy riparian habitats, valley savannahs, andfoothill and mountain habitats. Seven Series in the WoodlandSubformation occupy desert riparian habitats exclusively, in-cluding dry washes and oases. Most of the remaining Seriesoccupy riparian as well as nonriparian habitats, varying indensity and understory as the habitat changes from xeric tomesic.

Suggested Phases are:Size ( d . b . h . , 2 inches) Cover (percent}

Overstory Understory1.


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Figure20-The Jeffrey pine stand near BigBear Lake (A) and the Jeffrey Pinelsag ebrush Association in B both raise the question as to wh ether a JeffrePine Series should b e included in the Conifer Woodland S ubformation. These stands m ay simply represent extreme, but acceptable, density variation withithe Closed Forest Formation.

Figure21-The Pinyon Pinelsagebrush Association is an element of theConifer Wood land Form ation. A distinct environmental break defines thelimit of the pinyon overstory and is an easily defined boundary for theSagebrush Association (Shrub Formation) in the foreground.Desert Ironwood SeriesVegetation: Olneya tesota is the dominant overstory spe-

cies. This is a drought-deciduous California Sonoran Desertriparian Series with a sparse understory. The wood is ex-tremely hard and den se, and weathe rs very slowly in the desertclimate. Ironwood has an ability to go dormant and survivedrought longer than riparian species. Seeds require scarifica-tion by tumbling in flash floods for germination.

Distribution: Desert ironwood ranges from the CaliforniaSonoran Desert to Arizona and south to Mexico.

Mesquite SeriesVegetation: The dominant overstory is either honey mes-

quite, Prosopis glandulosa var. torreyana, or screwbean mes-quite, P. pubescens. These are a drought-deciduous desertriparian species occupying dry washes, oase s, or moist seep s.Understory includes desert wash shrubs such as desert laven-der , Hyptis emoryi , or desert broom, Baccharis spp.

Distribution: Honey mesqu ite is more prevalent in the Cali-fornia Sonoran Desert and screwbean mesquite is the morecommon Mojave Desert species. Both range from the SanJoaquin Valley south and east to Texas and Mexico.

Blue Oak SeriesVegetation: Quercus douglasii is the dominant overstoryspecies with shrub or grass-forb understory. Blue oak is a

deciduous tree grow ing in open savannah -like stands on valleyfloors and forming woodlands in the foothills.

Distribution: Blue oak surrounds the Central Valley, reach-ing northward into Shasta County, and south to Los AngelesCounty, and Santa Cruz and Santa Catalina Islands.Engelmann Oak Series

Vegetation: Quercus engelmannii is the dominant overstoryspecies, with soft chaparral shrubs, grasses, and forbs in theunderstory.

Distribution: Englemann oak has a scattered distributionfrom Los Angeles County south to Baja California, but themajor extent of the Se ries distribution is in western San DiegoCounty.

Interior Live Oak SeriesVegetation: Quercus wislizenii is the dominant overstory

species with chaparral shrubs in the understory. This Seriesoccupies xeric habitats between Chaparral and Forest Fon na-tions, but follows intermittent streams into Chaparral. Thespecies is very sensitive to fire.8 Th e larger trees a re usuallylocated in areas that have not burned in 50 to 100years. Moreoften this live oak is present in dense shrublike thickets withmultiple stem s, the result of resprouting from the base follow -ing fire.

Distribution: Interior live oak is generally a California spe -cies ranging from Siskiyou County south to Baja California.

Valley Oak SeriesVegetation: Quercus lobata is the dominant overstory spe-

cies with shru b or grasslforb understory.Distribution: Valley oak follows the sa me distribution asblue oak, from Shasta County south to Los Angeles County

and the Channel Islands.Palo Verde SeriesVegetation: The dominant overstory tree is palo verde,

Cercidium floridum or C . microphyllum, with a sparse under-story. These are drought-deciduous riparian trees. T he Se riesis common in California Sonoran Desert dry washes or rockybajadas. Tumbling in flash floods or abrasion by some othermeans is necessary for seed germination.

Distribution: Palo verde ranges through both Californiadeserts to Arizona and Mexico.


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Salt-cedar SeriesVegetation: Tamarix spp. are the dominant overstory trees.All are introduced from Asia or the Mediterranean region.They form dense thickets competing aggressively with nativespecies. Tamarix has a high rate of transpiration and is some-times blamed for lowering water tables. This Series occupiesmoist seeps and streambanks in the desert. Tamarix is oftenplanted as a windbreak.

Distribution: Tamarix has become naturalized throughoutthe Southwest.Smoke Tree SeriesVegetation: Dalea spinosa is the dominant overstory tree.

This is a drought-deciduous desert riparian tree common to drywashes in the California Sonoran Desert. Seeds germinateafter scarification, usually from tumbling in flash floods. Theextent of past flooding can be inferred from the distribution ofsmoke trees ( fig. 22).

Distribution: Smoke tree ranges from the southern MojaveDesert through the California Sonoran Desert to Arizona andMexico.

Sycamore SeriesVegetation: The dominant overstory species is Platanusracemosa. Sycamores follow perennial and intermittentstreams with a soft chaparral shrub and herbaceous understory.

Distribution: California sycamore ranges from Baja Cali-fornia north to Shasta County.

Desert Willow SeriesVegetation: Chilopsis linearis is the dominant overstoryspecies. This is a drought-deciduous riparian species of theCalifornia Sonoran Desert and inland valleys of southern Cali-fornia. It is not related to willow, Salix spp., but has droopingelongated leaves similar to some willow species. Understoryvegetation is sparse to moderate, consisting of soft chaparraland desert shrub species.Distribution: Desert willow ranges from the Mojave andCalifornia Sonora Deserts south to Mexico and east to Texas.

Willow SeriesVeg etation : Salix lasiolepis (arroyo willow), S . gooddingii(black willow), S. hindsiana (sandbar willow), and otherSalixspp. are dominant overstory species. They may be trees orshrublike, and always indicate riparian habitats. The under-story is herbaceous. Since willows are deciduous, dense standshave deep litter layers.

Distribution: The genus has worldwide distribution at allelevations. In southern California, the Series may occur wher-ever surface water or subsurface seeps are present.Succulent Woodland Subformation

Joshua Tree Series ( fig. 23)Vegetation: The dominant overstory species is Yucca bre-vijolia. Understory shrubs include desert and chaparral spe-cies. The herbaceous understory varies from moderately densein mountain foothills to virtually absent on the Mojave Desert.Joshua trees occur more often as a component of the PinyonSeries, or of shrub Series that occur in desert climates, than asa dominant overstory.Distribution: The Joshua tree occurs in foothills and deserthighlands surrounding the Mojave Desert, from San Bemar-

din0 County north to Inyo County, into Nevada and nortArizona.

Palm SeriesVegetation: The dominant overstory is usually the Calnia fan palm (Washingtonia filifera ) with an understorshrubs and grasses. Occasionally date palms (Phoenix shave become naturalized, and occur as dominants in the ostory. Cottonwoods and mesquites are sometimes presen

Distribution: The Palm Series is found in the CalifoSonora Desert and oases, which often follow earthquake-lines.

Shrub FormationVegetation: Elements of the Shrub Formation are domin

by shrubs that are between 1%feet ($5 m) and 15 feet (3 mat maturity. Our definition of "shrub" includes succulstemmed species (such as cactus) that are not normally cashrubs. Evergreen sclerophyllous shrubs dominate Seriethe Chaparral Subformation; the shrubs are adapted toresprouting or germinating following fire. The Soft ChapaSubformation is dominated by shrubs with relatively woody tissue; woody tissue that is present is generally fined to the basal portions of the shrubs. In terms of sphysiognomy and shrub morphology, we can, for pracpurposes, describe the Woody Shrub Subformation amembranous-leaved analogue of the Chaparral Subformasome dominant species found in the Woody Shrub Subfortion have survival mechanisms that allow them to maintheir existence in a fire regime, but adaptation to fire is ndiagnostic character of this Subformation. The Woody SSubformation includes some plant communities that occudry desert habitats, and others that occur in menvironments with a readily available supply of moistDominant species in the Succulent Shrub Subformationsucculent stemmed (e.g., Opunfia spp.) or have succuleaves (Allenrolfeu spp. and Agave spp.).Distribution: The Shrub Formation is worldwide in distrtion, and occurs in a wide range of habitats.

Suggested Phases are:Cover (percent)

Overstory Understory Annual Litter1 . 7 0

Chaparral Subformation (fig. 24)Vege ta t ion : Chaparral is dominated by evergre

sclerophyllous shrubs, mostly less than 15 feet tall (3Shrubs are adapted to fire, resprouting or germinating folling fire. Shrub crown cover at maturity is often close to percent, although it can remain sparse on very steep or psites.Distribution: Chaparral occurs throughout California, bbest developed in southern California. The Subformationtends from southern Oregon to central Arizona and Baja Cfornia.


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Figur e 22-The Smoke Tree Series is a common representative of the Figure 23-One of the two Series currently in the Succulent WoodlandBroadleaf Woodland Subformation in dry desert washes. Subformation s represented by the Joshua TreeINevada Ephedra Asso-ciation. Other associated species in this stand are cottonthorn (Tet-radymia spinosa) and box-thorn (Lyciurn andersonii). Hairy Yerbasanta(Eriodictyon trichocalyx) occurs in disturbed areas.

Figure 24-A complex of Associations dominated by elements of the Chamise, Manzanita, and Ceanothus Series with inclusion of the Interior Live OaSeries s seen inA. The predominant Series s chamise with associated manzanita species. The foreground s dominated by the ChamiseIPointleaf ManzanitAssociation (B). Classification systems that use a broader descriptive level than ours might view the vegetation in A as a single community; the visuauniformity of the landscape cover will relegate most of the vegetation to a single "type" under some vegetation mapping systems. Most of the shrubs inA arfrom 2 to 3 feet (0.6 to 1 m) in height.


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may grow into small trees in optimum ha bitat. Desert apricot isa drought-deciduous shrub.

Distribution: Catal ina cherry occupies canyons on theChannel Islands and bitter cherry occupies rocky ridges orcanyons from San Dieg o County north. Desert apricot is foundon slopes above 4000 feet (1219.2 m) at the western edge ofthe California Sonoran Desert and extends south into BajaCalifornia.

Redshank Series (fie. 28)Veg etation: Adenostoma sparsifolium is the dominant over-story sh rub . Individual shrubs have open crowns and thereforea herbaceous understory may be present, even in maturestands.

Distribut ion: Redshank exists from San Luis ObispoCounty south along the coast to Los Angeles County, thenshifts in distribution inland to the Peninsular M ountain ran ges,following them south into Baja California.

Sumac SeriesVegetation: Rhus luurinu, R. ovatu, or R . integrifolia are

dominant overstory species. Sumacs are more often compo-nents of Scrub Oak or Manzanita Series than a dominantspecies. However, coastal and island slopes may support al-most pure stands of sumac.

Distribution: Rhus laurina an d R . inteerifolia occur near thecoast from San ta Barbara County south to Baja California andon the Channel Islands. R , o vu tu occurs away from the coast todesert edges throughout southern California.Toyon SeriesVegetation: Dominant overstory is Heteromeles arbutifolia

with other chaparral shrubs.Distribution: Toyon grows on coastal foothills north to

Humboldt County and on the Channel Islands.

Soft Chaparral Subformation (fie. 29)Vegetation: Soft Chaparral is dominated by evergreen ordeciduous soft shrubs (shrub form s with little woody tissue)mostly less than 5 feet (1.5m) tall. Shru b crown cover rangesfrom 25 to 100 percent, often with grasses and forbs codomin-ant. Trees, if present, have a crown cover of less than 25percent.

Distribution: Soft Chaparral is present at lower elevations(below the Chaparral Subformation [fiv. 30] ) , throughoutsouthern California, extending north along the coast and Cen-tral Valley.

Series within the Soft Chaparral Formation are named forthe dominant species present or the species representing 60percent of the total overstory cover. Grasses and forbs areusually present in all phases.

Baccharis SeriesVegetation: The d ominant shru b overstory isBuccharis spp.

Bucchnris pilulan's is common on coastal foothills. Riparianspecies are B. glu t inom, B . sergiloides, an d B . surathroides,the latter two being confined to desert riparian habitats.

Distribution: Biicchuris pilularis occurs from SonomaCounty southward through central and coastal California toSan Diego County, including the Channel Islands. The ripa-rian species occur from Inyo County south to Mexico and eastto Texas.

Figure 27-A Desert ApricotIMojave YuccaISilver Cholla Association isseen in the middle and foreground in A . Although plant density is lowerthan in communities found on more mesic habitats, the number of associ-ated species is relatively high. An interior view of this stand shows thedominance of buckwheat, bladder-sage, and silver cholla (B).

Figure 28-A RedshanAssociation 35 years afterfire (A) and in full flower (6This portion averages 1feet (4 m) tall; within thsame Association lesfavorable sites in thevicinitare producing stands ranging from 2 to 4 feet (0.6 t1.3 m) in height.


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--

Figure2 9-Asso ciations within the Soft Chaparral Subformation occur ina m osaic pattern that reflects moisture availability and heat load.

Fig ure 30-Soft Chaparral often invades cutbanks in the interface zonebetween habitats of the Soft Chaparral and the Chaparral Subformations.Variation in plant density within an Association can be seen along thiscutbank.

F igure31-The Creosote/Burrobush Association represents the WoodyShrub Subformation n this interface between Low Desert Valley and HighDesert Valley climate regions.

California Bu ckwheat SeriesVege tation: Eriogonum fasciculatum is the dominant over

story shrub, with herbaceous understory.Distribution: California Buckwheat Series is found at low

elevations in mountain foothills and valleys from San ta ClarCounty south to Baja California. Varieties of Californibuckw heat can occur at high elevations as an understory c omponent in several Forest or Woodland Series.

Coastal Sagebrush SeriesVeg etation: Artemisia c alifornica is the dominant shruoverstory with a grasslforb understory. Yucca whippleisometimes codominant in this Series, particularly in SantBarbara County.

Distribution: This Series is present on low-elevation coastafoothills and interior valleys from Baja Ca lifornia north to SaFrancisco Bay including the Channel Islands.

Croton SeriesVegetation: Croton wigginsii is the dominant vegetatiocovering desert sand dunes.Distribution: Croton Series is restricted to the d unes of th

California Sonoran Desert in southeastern California and intMexico.Encelia Series

Veg etation: Encelia farinosa or E . californica are dominanoverstory shrubs with a herbaceous understory.

Distribution: The Encelia Series occurs from Santa Barbarand Inyo Counties south to Baja California.

Lupine SeriesVegetation: Lupinus a rboreus or L . chamissonis -form th

dominant overstory, with other soft shrubs and herbaceouspecies in the understory.

Distribution: Lupine shrubs range from Ventura Countnorth along the California coastline. T he Lupine Series occuonly on coastal bluffs.Rabbitbrush Series

V e g e t a t i o n : C h r y s o t h a m n u s n a u s e o s u s o r o t h eChrywthamnus species form the dominant overstory, with grass and herbaceous understory.

Distribution: Rabbitbrush ranges throughout the GreBasin into western and southwestern Califo rnia. There armany varieties of Chrysothumnus nau seosus from low elevations to above 9000 feet (2743.2 m ).

Salvia SeriesVegetation: Purple sage (Salvia leucophylla), black sag

(Salvia me llifera), or white sage (Salvia apiana ) are dominanoverstory species with a herbaceous understory. The SalviSeries covers coastal and inland foothills at low elevations

Distribution: Salvia mellifera ranges from Contra CostCounty south to Baja California and the Channel Islands. Sleucophylla ranges from San Luis Obispo County to OrangCounty; S.apiana ranges from Santa Barbara County to BajCalifornia.

Woody Shrub SubformationArrowweed SeriesVegetation:Pluchea sericea is the dominant overstory vegtation in seeps or marshes and following canals.


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Distribution: Pluchea sericea occurs from Santa BarbaraCounty throughout cismontane southern California and east toTexas. The Series is common along the Colorado River andirrigation canals in the California Sonoran Desert.Blackbush Series

Vegetation: Coleogyne ramosissima is the dominant over-story shrub. Blackbush is drought-deciduous. Associated spe-cies vary, b ut usually include Ephedra spp . , Chrysothamnusspp., and California buckwheat (Eriogonum fasciculatum).Distribution: Blackbush occurs from the southern MojaveDesert north and east through the Great Basin.Catclaw Series

Vege tation: Acacia gregg ii, a winter-deciduous shrub, isthe dominant overstory with subshrubs in the understory. Thehabitat in California often follows washes or canyons wheresome soil moisture is available.

Distribution: Catclaw is found in the southern Mojave Des-er t , throughout the California Sonoran Desert , south toMexico, and east to Texas.

Creosote Bush SeriesVegetation: Larrea tridentatu, an evergreen shrub, is thedominant overstory. Understory plants vary, but burrobush

(Ambrosia dutno sa) is most often codominant in California( fi g. 3 1 ) .

Distribution: Creosote is found throughout both deserts,ranging south from Inyo County into Mexico and east intoTexas. Larreci spp. also occur in South America.Greasewood Series

Vege tation: Surcobatus vermiculatus is the dominant shruboccurring with saltbush (Atriplex sp p.) on strongly alkaline,saline soils.

Distribution: Greasewood occurs throughout the MojaveDesert north to Washington and east throughout the GreatBasin in suitable habitats.Ocotillo Series

Vegetation: Fouquieria splendens, a drought-deciduousshrub, is the dominant overstory, with subshrubs and stemsucculents present in the understory. The substrate is usuallyrocky.

Distribution: Ocotillo occurs from the southeastern MojaveDesert through the Sonoran Desert to Texas and Mexico.

Wild Rose Series (fig.32)V ege ta ti on : R os a ~ a l i j o r n i cu , . ~ t n n o cu r p c i ,or R. wood-

si i are dominant, forming thickets in moist soil.Distribution: Rosu species occur throughout the West in

many vegetation types. The Series usually occurs below 60 00feet ( 182 8.8 m) elevation in cismontane southern California.Sagebrush Series ( f i g . 3 3 )Vegetat ion:Artem isia tridentcita is the most common domi-nant shrub, although A . nova , A . arbuscula , or A. rothrockii

may also form the do minant ov erstory. These are all evergreenshrubs and may be associated with perennial grasses.

Distr ibut ion: The Sagebrush Series is found from themountains of southern C alifornia north to Oregon andthroughout the Great Basin. The Series occurs at 7000 feet(2133.6 m) elevation interspersed with Series of the ClosedForest or Woodland Formations, as well as in the MojaveDesert.

Figure 32-An element of the Rose Series(Woody Shrub Subformation) occurring in a moistopening in a landscape cover dominated by theClosed Forest Formation-near Big Bear Lake,California.

Figure 33-Portions of this range being used by cattle belong to thSagebrush Series of the Woody Shrub Subformation. Jeffrey pine (CloseForest Formation) flanks the Herbaceous Formation that occurs in thpastureland, while a mosaic comprised of elements of the Shrub Formatiocarries upward on the far slopes to the Closed Forest Formation hat occualong the ridge.


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Saltbush SeriesVegetation: Dominant overstory may be Atriplex confer-

tifolia, A. polycarpa, A. canescens, and other Atriplex spp .Saltbush species may be evergreen or drought-deciduousshrubs occurring on alkaline and saline soils.

Distribution: The Saltbush Series occurs in both Californiadeserts, north to eastern Oregon, and throughout the GreatBasin.Succulent Shrub SubformationAgave Series

Vegetation: Agave deserti is the dominant species, with ahighly diverse group of associated species. Th e Agave Seriesoccurs on foothills between the Desert Shrub and ChaparralFormations.

Distribution: Agav e occurs in the southern Mojave Desertand western California Sonoran Desert.Iodine Bush Series

Vegetatio n: Allenrolfea occiden talis, a low-growing succu-lent shrub, is the dominant species occurring with saltbush(Atriplex spp.) and seep-weed (Suaeda spp.). Soils are wet,strongly alkaline, and saline.Distribution: Iodine bush occurs in the Mojave Desert,Central Valley north to Oreg on, east to Utah, and south intoMexico.Opuntia Series ( f ig . 34)

V e g e t a t i o n : D o m i n an t o v e r s t o ry i s ch o l l a ( O punt iabigelovii and other Opuntia species), o r prickly pear (Opuntia

Figure 34-The Cholla Series dominates the middle and foreground ofthis scene (A). A closeup shows the sparse occurrence of dominant andassociated species, as well as the patterns of oxidation found on the rockand soil surfaces in desert environments (B).

Figure35-The Dwarf Shrub Formation s found in the remnants of tglacial tarn. To the left of the tarn is an element of the Lodgepole PSeries, and krummholtz imber pine can beseen on the right. The cushPlant Subformation is the grey texture in the bottom of the tarn.

spp.) occurring with barrel (Ferocactus aca nthode s) anhedgehog (Echinocereus spp.) cacti. Opuntia reproduces vegetatively when joints fall to the ground. The species are mooften associates of other Series than dominant stands.

Distribution: Opuntia bigelovii occurs from the southeaMojave Desert throughout the Sonoran D esert into Mexico. 0littoralis is a succulent-stemmed, prostrate shrub that occuwithin 50 miles ( 80 .4 km) of the coastline from Santa B arbaCounty south to Baja Califo rnia; varieties of the species occuup to 7000 feet (213 m) as a component of several other Series

Dwarf Shrub FormationVegetation: The shrubs that dominate this Formation aless than 1% feet ('/2 m) in height at maturity. Th e Cushio

Plant Subformation is dominated by nonsucculent (stem leaves) dwarf shrubs; in southern Ca lifornia, only one Series currently recognized with this Subformation. The SucculeDwarf Shrub Subformation contains all Series dominated bsucculent dwarf shrubs; two Series are currently recognizefor this Subformation in southern California.

Distribution: The Dwarf Shrub Formation has worldwiddistribution. It occurs in a wide range of habitats, from alpine n v i r o n m e n t s a b o v e t i m b e r l i n e t o a l k a l in e d e s eenvironments below sea level.

Suggested Phases are:Cover1. 7 0

Cushion Plan t SubformationBuckwheat SeriesVegetation: Dominant cover is Eriogonum spp. and othcushion plants. This Series is sometimes called "barren"because of the sparse vegetation cover (fie. 35).


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Distribution: The Buckwheat Series occurs throughout theWest on high mountain peaks above tree line. In southernCalifornia, this Series is interspersed am ong subalpine forestsof Limber Pine o r Bristlecone Pine Series.

Succulent Dw arf Shrub Subformat ionPickleweed SeriesVegetation: Salicornia spp. is the dominant vegetation oc-currin g in saltwater marshes. Most spe cies are winter dormant.Distribution: Pickleweed occurs in coastal salt marshes andaroun d inland saltwater lakes such as the Salton Sea and Mon o

Lake.Suaeda SeriesVegetation: Dominant overstory is Suaeda californica, S.fruticosa, or S. torreyana, all succulent shrubs or subshrubs

occupying salt marshes or alkaline marshes.Distribution: The Suaeda Series is present worldwide.Suaeda californica occurs along the coast from San Francisco

Bay to Baja California. S. torreyana ranges from easternOregon through inland California east to Texas and intoMexico. S . fruticosa extends from the San Joaquin Valleysouth to Mexico, but is also found in West Indies, Europe,Asia, and Africa (McMinn 1939).

Herbaceous FormationVegetation: The Herbaceous Formation is dominated bygrasses, s edge s, rushes, forbs, or freshwater aquatic plants. Atleast 2 percent of the land surface has an herbaceous cover. If

shrubs are present, they contribute less than 25 percent crowncover {f ig.36).Grasslands, wet meadows, marshes, and vege-tation in shallow freshwater ponds are all part of the Herbace-ous Formation (fig. 37).Herbaceous coastal strand plants andplants of coastal salt marshes are included. However, thissystem makes no attempt to cover marine or intertidal zones.

Distribution: Th e Herbaceous Formation occurs worldwidein appropriate habitats. F our Sub formations of the HerbaceousFormation are recognized; Grasses and Grasslike Plants(Graminoid), Forb, Aquatic, and Cryptogam Subformations.

Suggested Phases are:CoverProductivity Living Vegetation LitterPounds per I 70

Graminoid Subformat ionThe Series are named for the dominant genus or species,usually that plant compris ing more than 60 percent of th e totalherbaceous cover {f ig. 38).

Bromegrass SeriesVegetation: Dominant vegetation is Bromus rubens, B .

diandrus, B. moll is , or B. tectorum, all introduced species.

Figure 36-The Herbaceous Formation in the foreground is representeby the Bromegrass and the Wiregrass Series. Evidence indicates that thWild Rye Series is the most immediate potential vegetation for the entirstand; whether the change to this Series occurs or not will depend upofuture use of the range and disturbance.

Fig ur e 37-A temporaridrained lake provided an opportunity to observe thGraminoid Subformation in normally inaccessible ripariazone. Distinct zones occupieby the Herbaceous, Shrub, anWoodland Formations can bseen. The Closed Forest Fomation occurs in the background.

Figure 38-Sand dunes provide a unique habitat for the Graminoid Subformation in this desert environment; he grass is Panicum urvilleanum-apossible requirement or a Panicum Series. The Forb Subformation domnates the cover adjacent to the dunes.


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Pondweed SeriesVegetation: Dominant vegetation is Potamogeton species,submerged plants, barely reaching the water surface. ,Distribution: Potamogetons occur worldwide in quietfreshwaters.Water Hyacinth SeriesVegetation: Dominant vegetation is Eichornia crassipes, asubmerged and floating aquatic.

Distribution: Eichornia is a native of tropical Americawhich has b ecome

a vegetation classification system applied to southern california

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