Table Of Content

Archive Document Historic, Do not assume content reflects current scientific knowledge, policies, or practices. United States ^ 0 / The Douglas-Fir/White Department ^ ofAgriculture ForestService Spirea Habitat Type in Intprmoiintain Research Station Central Idaiio: Succession General Technical and IVIanagement H % April 1994 u Robert Steele Kathleen Geier-Hayes bS o THE AUTHORS and 45 herb layertypes are categorized by a hierarchi- cal taxonomic classification. Diagnostic keys based on ROBERT STEELE is a Research Forester assigned to indicator species are provided for field identification the Conifer Ecology and Regeneration Research Work of the layer types. Unit at Boise, ID. Since joining the Intermountain Implications for natural resource management are Research Station in 1972, he has concentrated on provided based on field data and observations. These development of forest habitat type classification and implications include: potential for pocket gopherdamage on classification and management of successional and success of tree plantations by site preparation forest communities. He earned a B.S. degree in forest treatments, initial growth rates of tree seedlings and management and an M.S. degree in forest ecology at yield capability of mature trees, microsite needs of the University of Idaho. natural tree seedlings, big-game and livestock forage KATHLEEN GEIER-HAYES is a Research Forester in preferences for specific shrub and herb layertypes, the Conifer Ecology and Regeneration Research Work and responses of major shrub and herb layer species Unit. She has worked part time on the classification to various disturbances. Species composition data for and management of successional forest communities each of the sampled shrub and herb layertypes are since the beginning of this project in 1979, joining the displayed in appendixes. Intermountain Station full time in 1986. She earned a B.S. degree in biology at Boise State University and an ACKNOWLEDGMENTS M.S. degree in forest science at the University of Idaho. Staff of the Boise and Payette National Forests RESEARCH SUMMARY provided logistical support and helpful information during field sampling. Phil Straub (Boise National A succession classification system forthe Douglas- Forest, retired) and Glenn Jacobsen (Payette National fir/white spirea habitat type is presented. It is based Forest) provided support and advice during the study's on reconnaissance sampling of 202 stands: 55 undis- development. Bob Keane (Intermountain Research turbed sites, 14 pairs of undisturbed and disturbed Station) and Ron Hamilton (Intermountain Region) sites, and 119 additional disturbed sites. A total of offered many helpful suggestions. 10 potential tree layertypes, 35 shrub layertypes. Intermountain Research Station 324 25th Street Ogden, UT84401 CONTENTS Page Site Index and Yield Capability 40 Page Pocket Gophers 40 Introduction 1 Snow Damage to Pine Plantations 40 Methods 1 Vegetation Responses 42 The PSME/SPBE HabitatType 1 Burning 42 Pinusponderosa (PlPO) Phase 2 Scarification 42 Calamagrostis rubescens (CARD) Phase 4 Competition With Tree Seedlings 43 Spiraea betulifolia (SPBE) Phase 5 Wildlife and Livestock 47 Successional Features 6 Deer 47 Classification 6 Elk 48 The Tree Layer 7 Cattle 50 Size Class Notations 9 Sheep 52 Populus tremuloides Layer Group Black Bear 52 (POTR LG.) 10 References 52 Pinus contorta Layer Group (PICO LG.) 10 Appendixes: Pinusponderosa Layer Group (PlPO L.G.) 11 A-1 Palatability ratings, constancy, and average Pseudotsuga menziesiiLayer Group . percent canopy cover of shrub layer species (PSME L.G.) 12 by layertype in the PSME/SPBE h.t., The Shrub Layer 12 PlPO phase 56 Artemisia tridentata Layer Group A-2. Palatability ratings, constancy, and average (ARTR LG.) 14 percent canopy cover of shrub layer species Purshia tridentata Layer Group by layertype in the PSME/SPBE h.t., (PUTR LG.) 17 CARU phase 60 Ceanotiius velutinus Layer Group A-3. Palatability ratings, constancy, and average (CEVE LG.) 19 percent canopy cover of shrub layer species Ribes cereum Layer Group (RICE L.G.) 20 by layertype in the PSME/SPBE h.t., Salixscouleriana Layer Group SPBE phase 63 (SASC LG.) 20 B-1 Palatability ratings, constancy, and average Prunus virginiana Layer Group . percent canopy cover of herb layer species (PRVI LG.) 20 by layertype in the PSME/SPBE h.t., Amelancliierainifolia LayerGroup PlPO phase 65 (AMAL L.G.) 21 B-2. Palatability ratings, constancy, and average Sympiioricarpos oreophilus Layer Group percent canopy cover of herb layer species (SYOR LG.) 21 by layertype in the PSME/SPBE h.t., Spiraea betulifolia Layer Group (SPBE L.G.) 21 CARU phase 73 The Herb Layer 22 B-3. Palatability ratings, constancy, and average Annuals Layer Group (ANN. L.G.) 29 percent canopy cover of herb layer species Bromus carinatus Layer Group (BRCA L.G.) 29 by layertype in the PSME/SPBE h.t., Potentilla glandulosa Layer Group SPBE phase 77 (POOL LG.) 29 C. Succession and managementfield form for lliamna rivularis Layer Group (ILRI L.G.) 30 the Douglas-fir/white spirea h.t 81 Geranium viscosissimum Layer Group (GEVI LG.) 30 TABLES Apocynum androsaemifolium Layer Group Fr(agAaPrAiNa vLeGs.c)a Layer Group (FRVE L.G.) 3311 1. EinlepvhaatsioensalofrtahnegePSanMdE/imSpPoBrtEanht.ttree species 2 CarexgeyeriLayer Group (CAGE L.G.) 32 2. Phase designations of the PSME/SPBE h.t. Calamagrostis rubescens Layer Group suggested by various studies 2 (CARU LG.) 33 3. Key to tree layer groups and layertypes, Management Implications 33 with codes, in the PSME/SPBE h.t 9 Natural Tree Establishment 33 4. Successional roles and maximum heights Pinus contorta 35 of major shrub species in phases of the Pinusponderosa 36 PSME/SPBE h.t 13 Pseudotsuga menziesii 37 5. Key to shrub layer groups and layertypes, Planted Tree Establishment 38 with codes, in the PSME/SPBE h.t., Growth and Yield 39 PlPO phase 16 Age to Breast Height 39 , 6. Key to shrub layer groups and layertypes, 2. A stand of Pinusponderosa on a with codes, in the PSME/SPBE h.t., PSME/SPBE h.t. northeast of CARD and SPBE phases 18 Lowman, ID, in 1980 7. Successional roles of Important herb layer 3, Distribution of the PSME/SPBE h.t., species in phases of the PSME/SPBE h.t 22 CARU phase in Idaho 8. Key to herb layer groups and layer types, 4, Distribution ofthe PSME/SPBE h.t., with codes, in the PSME/SPBE h.t 26 SPBE phase in Idaho 9. Occurrence of natural tree seedlings 5. Relative successional amplitudes of major (percent) by silvicultural method and over- tree species in the PSME/SPBE h.t story composition for the PSME/SPBE h.t., 6, Succession classification diagram ofthe PlPO, CARU, and SPBE phases 34 tree layer in the PSME/SPBE h.t., 10. Occurrence of natural tree seedlings PlPO phase (percent) by site preparation method 7. Succession classification diagram ofthe forthe PSME/SPBE h.t., PlPO, CARU, tree layer in the PSME/SPBE h.t., and SPBE phases 35 CARU phase 11. Regeneration efficiency classes of seed- 8, Succession classification diagram ofthe beds for natural tree seedlings in the PSME/ tree layer in the PSME/SPBE h.t., SPBE h.t., PlPO, CARU, and SPBE phases 36 SPBE phase 12. Regeneration efficiency classes of shrub 9. A sapling POTR-pole POTR tree layer cover and other microsites for natural tree type northeast of Idaho City, ID, in 1985 seedlings in the PSME/SPBE h.t., PlPO, 10, An old PIPO-pole PSME tree layertype CARU, and SPBE phases 37 on Hitt Mountain west of Cambridge, ID, 13. Occurrence of natural tree seedlings by tree in 1980 and shrub layer groups in the PSME/SPBE h.t., 11 Relative successional amplitudes of major PlPO, CARU, and SPBE phases 38 shrub species in the PSME/SPBE h.t 14. Success of tree plantations by site treatment 12, Succession classification diagram of the in the PSME/SPBE h.t., PlPO phase 39 shrub layer in the PSME/SPBE h.t., 15. Site index and yield capability oftree species PlPO phase in the PSME/SPBE h.t., PlPO phase 40 13, Succession classification diagram of the 16. Responses of major shrub and herb layer shrub layer in the PSME/SPBE h.t., species to various disturbances in the CARU phase PSME/SPBE h.t 43 14, Succession classification diagram of the 17. Relative index classes for big-game and shrub layer in the PSME/SPBE h.t., livestock forage preferences by shrub layer SPBE phase type in the PSME/SPBE h.t., PlPO phase 48 15, Relative successional amplitudes of major 18. Relative index classes for big-game and herb layer species in the PSME/SPBE h.t .. livestock forage preferences by shrub layer 16, Succession classification diagram of the type in the PSME/SPBE h.t., CARU phase 49 herb layer in the PSME/SPBE h.t., 19. Relative index classes for big-game and PlPO phase livestockforage preferences by shrub layer 17, Succession classification diagram of the type in the PSME/SPBE h.t., SPBE phase 49 herb layer in the PSME/SPBE h.t., 20. Relative index classes for big-game and CARU phase livestock forage preferences by herb layer 18 Succession classification diagram of the type in the PSME/SPBE h.t., PlPO phase 50 herb layer in the PSME/SPBE h.t., 21 Relative index classes for big-game and SPBE phase . livestock forage preferences by herb layer 19 An APAN-APAN herb layer type east type in the PSME/SPBE h.t., CARU phase 51 of Idaho City, ID, in 1985 22. Relative index classes for big-game and 20 Occurrence of sites with and without livestock forage preferences by herb layer pocket gopher mounds following various type in the PSME/SPBE h.t., SPBE phase 51 disturbances in the PSME/SPBE h.t., PlPO phase FIGURES 21 Height-age relationships of free-growing tree seedlings and important shrub species 1. Distribution ofthe PSME/SPBE h.t., in the PSME/SPBE h.t., PlPO phase PlPO phase in central Idaho 3 The Douglas-Fir/White Spirea Habitat Type in Central Idaho: Succession and Management Robert Steele Kathleen Geier-Hayes INTRODUCTION growth characteristics in relation to site treatment, microsite conditions, and competingvegetation. This report is the fifth ofa series deahngwith suc- 5. To determine the number ofyears required for cession and managementofforesthabitattypes in each tree species to reach breast height (4.5 feet, 1.4 central Idaho (Steele and Geier-Hayes 1987b, 1989b, meters) inthe PSME/SPBE h.t. when plant compe- 1992, 1993). It explores the responses ofvegetation tition is minimized. to specific disturbances and some resource values in 6. To provide abasis for developingpreliminary one ecosystem, thePseudotsuga menziesiilSpiraea management implications by serai communitytjrpe. hetulifolia habitattype (PSME/SPBE h.t.) (Steele and others 1981). It is intended for site-specific ap- METHODS plication, providing disturbance responses forexist- ingand potential plant species on a particular site. The methods used in this study are identicalto Because ofthe waythese reports are developed (see those used in the previous four studies; details are Methods), the reader should focus on the relative available in the earliestreport (Steele and Geier- nature ofthe data presented ratherthanthe abso- Hayes 1987b). IngenergJ, samplingmethods were lutevalues. similarto those used in the central Idaho habitat This reportuses a classification concept (Steele type study(Steele and others 1981). Circular plots 1984) thatrecognizes the somewhatindependent (375 square meters or 4,035 square feet) were sub- successions ofthetree, shrub, and herb layers in jectivelylocated to representthe site conditions and forest ecosystems (often due to layer-specific distur- vegetation diversitythroughoutthe geographic bances such as selective tree harvestingorgrazing). range ofthe habitattype. Recorded observations in- Ittreats these three layers with separate succession cluded age oflast disturbance (such as a fire orlog- classifications. It recognizes the potential diversity ging), plantcoverage (by species), percent survival in early and midseralvegetation and the relative ofplanted tree seedlings and the age at which they foragevalues for livestock and biggame. Interrela- reach 4.5 feet (1.4 meters), occurrence ofpocket go- tionships ofsite treatment, planted tree survival, pher mounds, snow damage to tree seedlings, meth- competingvegetation, and pocket gopherpopula- ods oflogging, slash disposal, site preparation, and tions are also addressed. Perhaps most important, thickness ofthe dufflayer. Plant coverage data succession classifications provide a common ecologi- were usedto develop a succession classification cal frameworkfor communication amongvarious (Steele 1984); latertheywere assembled in S3mthe- disciplines. sis tables (Mueller-Dombois and Ellenberg 1974) The objectives ofthis report are: toverifythe early seraito climax arrangement of 1. To develop a classification ofserai community stands as indicated bythe classification. types in the PSME/SPBE h.t. based on indicator THE PSME/SPBE HABITAT TYPE species and vegetation structure. 2. To identifythe successional hierarchyofcom- munitytypes, relatingthese communities to the The PSME/SPBE h.t. is distributed mainly across managementtreatments thatgive rise to them. central Idaho. Small portions ofthe habitattype ex- 3. To present species composition and canopy tend northward to the Selway-BitterrootWilderness coverage information for each ofthe shrub and herb (Cooper and others 1991) and into western Montana layers sampled, indicatingthe relative value of (Pfister and others 1977). It also occurs as a minor these layers as forage forbiggame and livestock. type in eastern Idaho and westernWyoming (Steele 4. To describe suitable conditions fornatural and others 1983) and extends into eastern Oregon and artificial establishment oftrees and their early (Johnson and Simon 1987). 1 — Table 1 Elevational range and importanttree species in more favorable climate. Northward through this phases ofthe PSME/SPBE h.t. area the climate becomes more maritime, and the Phases and elevational range (ft) PSME/SPBE h.t. occupies increasingly severe topo- PIPO CARU SPBE graphic positions that reflect environmental equiva- OTjmOUow." Rnnn. R (;nn. lents ofthe extensive acreages ofthe PSME/SPBE Tree species^ 6,600 7,900 8,100 h.t. in the Boise River drainage. — — To the northeast, a more continental climate is Abiesgrandis a^ evident, and PSME/SPBE merges with the Douglas- Abieslasiocarps a fir/pinegrass and Douglas-fir/commonjuniper habi- Picea engelmannii a a Pinuscontorta (s) (S) (s) tat types. Both ofthese types occupy more severe sites than the PSME/SPBE h.t., which often occu- Pinus flexilis a a pies the more favorable topographic positions in this Pinusponderosa S area. Substrates are more varied, including quartz- PPospeuulduoststurgeamumleonizdieessii (cS) (cS) (Cs) ite, andesite, dacite, quartz monzonite, and occasionally granitics. Consequently, the PSME/SPBE ^'Revisedfrom Steeleandothers (1981). h.t. is more variable in eastern portions ofits distri- = major climax; S= majors—erai; a=accidental;s= minorserai; bution than elsewhere in central Idaho. ()=occursinpartofthephase; = absent. The PSME/SPBE h.t. ranges in elevation from about 3,300 to 8,100 feet (1,006 to 2,469 meters). This broad range is segmented elevationally and In central Idaho, the PSME/SPBE h.t. appears geographically by three phases. Elevational range most frequently in the Boise River drainage that and occurrence oftree species in the various phases dissects the southernmostlobe ofthe Idaho batholith. are shown in table 1. Geographic differences are Here substrate conditions are mainlycoarse-textured outlined in table 2. granitics that retain little moisture and dry rapidly following spring snowmelt. In these situations, ad- Pinusponderosa (PIPO) Phase jacent drier sites are usually the Douglas-fir/elk sedge habitat type; adjacent moister sites, ifnot The PIPO phase occurs mainly in western por- riparian, are mainly the Douglas-fir/ninebark or tions ofcentral Idaho (fig. 1) and extends into north- Douglas-fir/mountain maple habitat types. North ern Idaho and western Montana (table 2). It is ofthis area the PSME/SPBE h.t. becomes less fre- found mostly in the Boise, Payette, and Weiser quentbut is found onvolcanic substrates as well as River drainages where it ranges from about 3,300 granitics. to 6,600 feet (1,006 to 2,017 meters) in elevation and To the northwest ofthe Boise River drainage, the represents the warm, low-elevation extremes ofthe PSME/SPBE h.t. is often replaced by the Douglas- habitattype. The potential to support naturally es- fir/common snowberry habitat type, which has a tablished ponderosa pine is the diagnostic charac- similar appearance but is found in areas receiving teristic ofthis phase. slightly more moisture. The increased moisture can Because the environment ofthis phase is the most result from either finer textured substrates or a moderate of the three phases, it supports the greatest — Table2 Phase designations ofthe PSME/SPBE h.t. suggested by various studies Eastern Northern Western Central Eastern Idaho, Oregon Idaho Montana Idaho Western Wyoming (Johnson (Cooper (Pfister (Steele (Steele Defined and Simon and Others and Others and Others and Others phases 1987) 1991) 1977) 1981) 1983) None X X PIPO 0 0 0 X CARU X X SPBE 0 X X 'X=phasedefined; 0 =phasesuggestedbydataortext. 2 soon dominates these early serai shrub layers. Its deep root system and rhizomatous growth habit en- able Spiraea to survive most disturbances and in- crease rapidly. Certain herbaceous species also in- dicate early serai conditions. Bromus carinatus, WASHINGTON Potentillaglandulosa, or assorted annuals such as species ofBromus, Epilobium, Galium, and Gayo- phytum maybecome well represented after a severe disturbance. High coverages ofBromus carinatus generally occur on scarified sites thatreceive little orno grazing. The Potentilla responds mainlyto scarification withoutburning on either grazed or ungrazed sites. Assorted annuals (appendix B-1) may appear following severe burning or scarification; theirpresence, alongwithPotentilla, is often prolonged bythe yearly disturbances ofgrazing. OREGON Mid- to late-seral conditions generally support a large complement ofponderosa pine that provides the shelter often needed for Douglas-fir establish- WYOMING ment on these sites. As shade fi"om the pine canopy increases, the shrub layer changes. The shade- intolerant shrubs,Artemisia, Purshia, Ceanothus, and Ribes, decline, leavingthe more tolerant Salix NEVADA UTAH scouleriana orPrunus spp. as indicators ofmidseral Figure 1—Distribution ofthe PSME/SPBE stages. Neither ofthese species can persistindefi- h.t., PlPO phase in central Idaho. nitely as the denser Douglas-fir canopy achieves dominance. Consequently, the shrub layer becomes shorter and less diverse toward climax. Inthe herbaceous layer, the early serai species decline sub- stantiallywith increased shade. More shade- number ofspecies. These species are most evident tolerant taxa such as Geranium viscosissimum in early serai communities. Early serai conditions andApocynum androsaemifolium maypersist and supportfew naturally established trees, but most serve as indicators ofmid- to late-seral conditions. ofthese sites have been planted toPinusponderosa Climaxtaxa such as Calamagrostis rubescens and with varying degrees ofsuccess. Plantations of Arnica cordifolia, both ofwhich spread byrhizomes, Pseudotsuga menziesii have mostlyfailed. Unlike mayalreadybe dominatingthesemidseral associates. some other habitat types, Populus tremuloides only occasionally develops atree layer in the PSME/ As stands approach climax, Douglas-fir is the SPBE h.t. WherePopulus communities have been ldoowmicnoavnertatgreese,ofofptoenndfeorromsianpgipnuermeasytapnedrss.isHtodwueevetor, found, the sites are usuallytransitional to some that species'greaterheight andlonglifespan. Shrub other habitat type containing finertextured soils or layersbecome increasinglysimple, consistingmainly more moisture. Likewise, Pinus contorta is usually ofSymphoricarposoreophilus,Amelanchieralnifolia, restricted to sites that accumulate more cold air than normal in the PSME/SPBE h.t. GeneraUy and Spiraea. Onlythe Spiraea is rhizomatous; its vegetative reproduction allows itto dominate the these sites are transitional to a cooler habitat type. shrub layer. The number ofspecies in the herba- Consequently, tree layer succession on most sites ceous layeralso decreases. Thelayerconsists mainly in the PIPO phase is relatively simple, consisting ofLupinus spp. and shade-tolerant rhizomatous mainly ofponderosa pine and Douglas-fir. Early se- species. Asterconspicuus, Carexgeyeri,Arnica rai shrub layer conditions are characterized mainly cordifolia, Calamagrostis rubescens, and Thalictrum hyPurshia tridentata or Ceanothus spp.; occasion- occidentale are the primary species found in near- allyAr^e/n^s^a tridentata orRibes spp. are well rep- climaxherb layers. resented. ThePurshia orRibes result mainly fi'om Before the advent offire control, these areas were scarification; Ceanothus responds mainlyto burning maintained in midseral condition bylow-intensity but can respond to scarification, though to a lesser degree. TheArtemisia invades bare soil exposed by surface fires occurring every 10 to 20 years (Steele and others 1986). The largerPinusponderosa gen- burning or scarification. Unless the site has been intensivelyburned or scarified, Spiraea betulifolia erally survived the fires, forming open stands 3 (fig. 2). The Salix andPrunus would resprout after represents a transition between the Douglas-fir/ each fire along with Geranium Apocynum. The white spirea and Douglas-fir/pinegrass habitat near-climaxspecies noted above wotdd also resprout. tjT)es. These sites range from 6,000 to 7,900 feet Because the fires were oflow intensity, they gener- (1,829 to 2,408 meters) in elevation and appearto be ally did not create extensive areas for early serai too cool forPinusponderosa to establish natiu-ally. species to establish. But scattered patches ofCea- Pinus contorta may occur as a major serai species nothus, Ribes, andArtemisia could appear wherever where cold air accumulates. Elsewhere in this phase, concentrations offuel resulted in higher fire inten- Pseudotsugamenziesiiistheonlymajortreespecies. sity. Stands maintained in this condition by fre- Early serai conditions are usually dominated by quent surface fires were quite resistantto less fre- shrubs in the CARU phase. However, these shrub quent stand-destroyingfires. Wide spacingmade layers are less diverse and more poorly developed the pines resistanttobarkbeetle attack. The under- than in the PIPO phase due to the cooler growing burning also killed the lower limbs ofsurviving conditions. Artemisia tridentata ssp. vaseyana often trees, reducing the chance ofmistletoe infection. invades bare soil exposed by burning or scarifica- This scenario falls within Fire Group Three de- tion. Ceanothus velutinus germinates from buried scribed by Crane and Fischer (1986). seed following burning, and occasionally scarification, but does so only on the warmer sites lacking Calamagrostis rubescens (CARU) frost pockets. Ribescereum, and sometimesR. Phase viscosissimum, appear following scarification. The Ribes cereum usually grows in a tall vase-shaped The CARU phase occurs mainly in the Salmon form as opposed to its more widespread rounded River drainage between the towns ofStanley and form. All ofthese shrubs are indicative ofearly ser- Salmon; it is a minor phase in eastern Idaho (fig. 3). ai conditions, yet seldom do they achieve densities The main distribution largely coincides with that comparable to those reached in the warmer PIPO ofa major pinegrass zone and a core area ofthe phase. Early serai herbaceous layers may have Douglas-fir/pinegrass habitattype, pinegrass phase alarge number ofspecies, and these species may in central Idaho. The CARU phase in general have high coverages. Potentillaglandulosa, and Figure2—A stand of Pinusponderosaon a PSME/SPBE h.t. northeast of Lowman, ID, in 1980. Several fires have burned through this stand, maintaining the open parklike condition thatwas common in this habitat type priorto fire control. 4