Table Of Content

Document Historic, Arcliive Do assume not content reflects current scientific l<nowleclge, policies, or practices. The Grand United States Fir/Mountain Department of Agriculture Maple Type Habitat Forest Service in Intermountain Research Station Central Idaho: Sucpessidn General Technical ^ and Management Report INT-284 I ^ March 1992 Robert Steele 03 Kathleen Geier-Hayes > —41 So CP THE AUTHORS (Payette National Forest) provided support and advice during development of this study. Steve Arno (Inter- ROBERT STEELE is a research forester assigned to mountain Research Station) and Charles Johnson the Conifer Ecology and Regeneration research work (Wallowa-Whitman National Forest) shared their insight unit at Boise, ID. Since joining the Intemountain on similar forest successions and offered many helpful Station in 1972, he has concentrated on development suggestions while reviewing the manuscript. of forest habitat type classification, and on classification and management of successional forest communi- RESEARCH SUMMARY ties. He earned a B.S. degree in forest management and an M.S. degree in forest ecology at the University A succession classification system for the grand fir/ of Idaho. mountain maple habitat type is presented. It is based KATHLEEN GEIER-HAYES is a research forester in on reconnaissance sampling of 164 stands: 21 old- the Conifer Ecology and Regeneration research work growth sites, 19 pairs of old-growth versus disturbance unit. She has worked part-time on the classification sites, and 105 additional disturbed sites. A total of 15 and management of successional forest communities potential tree layertypes, 34 shrub layer types, and 55 since the beginning of this project in 1979 and joined herbaceous layertypes are categorized by a hierarchi- the Intermountain Station on a full-time basis in 1986. cal taxonomic classification. Diagnostic keys based on She earned a B.S. degree in biology at Boise State indicator species are provided forfield identification of University and an M.S. degree in forest science at the layer types. the University of Idaho. Implications for natural resource management are provided based on field data and observations. These ACKNOWLEDGMENTS implications include: potential for pocket gopher damage and success of tree plantations by site preparation Financial support for this study was provided by treatments, initial growth rates of tree seedlings and the Intermountain Region of the Forest Service, U.S. yield capability of mature trees, microsite needs of Department of Agriculture, through a memorandum natural tree seedlings, big-game and livestock forage of understanding with the Intermountain Research preferences of shrub and herb layer types, and responses of major shrub and herb layer species to Station. various disturbances. Species composition data for Staff of the Boise and Payette National Forests assisted at various times with logistical support and each of the tree, shrub, and herb layer types that helpful information during field sampling. Phil Straub were sampled are displayed in appendices. (Boise National Forest, retired) and Glenn Jacobsen Intermountain Research Station 324 25th Street Ogden. UT 84401 CONTENTS Page Page A-2. Constancy and Average Canopy Cover Introduction 1 (Percent) of Trees by Layer Type in the Objectives 2 ABGR/ACGL H.T., PHMA Phase, Metliods 2 Showing Size Class Distribution and The ABGR/ACGL Habitat Type 2 Average Basal Area 63 Distribution 2 B-1 Palatability Ratings, Constancy, and . Acerglabrum (ACGL) pliase 3 Average Canopy Cover (Percent) of Physocarpus malvaceus (PHMA) phase 3 Shrubs by Layer Type in the ABGR/ Description 3 ACGL H.T., ACGL Phase 68 Successional Features 4 B-2. Palatability Ratings, Constancy, and Succession Classification 4 Average Canopy Cover (Percent) of The Tree Layer 6 Shrubs by Layer Type in the ABGR/ACGL Size class notations 6 H.T., PHMA Phase 71 Populus tremuloides Layer Group (POTR C-1. Palatability Ratings, Constancy, and LG.) 8 Average Canopy Cover (Percent) of Pinus ponderosa Layer Group (PlPO L.G.) 8 Herb Layer Species by Layer Type in Pseudotsuga menziesiiLayer Group (PSME the ABGR/ACGLH.T., ACGL Phase 74 LG.) 10 C-2. Palatability Ratings, Constancy, and Picea engelmanniiLayer Group (PIEN L.G.) 10 Average Canopy Cover (Percent) of Abies grandis Layer Group (ABGR L.G.) 11 Herb Layer Species by Layer Type in Management Implications 11 the ABGR/ACGLH.T., PHMA Phase 82 Summary of Tree Layer Section 17 D. Succession Classification Field Form The Shrub Layer 17 forthe Grand Fir/Mountain Maple H.T 90 Ceanothus velutinus Layer Group (CEVE L.G.) .21 Ribes viscosissimum Layer Group (RIVI L.G.) ....23 TABLES Salix scouleriana Layer Group (SASC L.G.) 23 AInus sinuata Layer Group (ALSI L.G.) 26 1 . Elevational range and important tree species Spiraea betulifolia Layer Group (SPBE L.G.) 26 in phases of the ABGR/ACGL h.t 3 Rubusparviflorus Layer Group (RUPA L.G.) 26 2. Key to tree layer groups and layer types, Acerglabrum Layer Group (ACGL L.G.) 26 with ADP codes, the ABGR/ACGL h.t 7 > Physocarpus malvaceus Layer Group (PHMA 3. Success of tree p.antations by site treatment L.G.) 27 in the ABGR/ACGL h.t., ACGL phase 14 Management Implications 27 4. Success of tree plantations by site treatment Summary of Shrub Layer Section 40 in the ABGR/ACGL h.t., PHMA phase 15 The Herb Layer 40 5. Growth and yield characteristics of trees in Annuals Layer Group (ANN. L.G.) 41 the ABGR/ACGL h.t 17 Bromus carinatus Layer Group (BRCA L.G.) 41 6. Successional role of major shrub species in Potentilla glandulosa Layer Group (POGL L.G.) .47 phases of the ABGR/ACGL h.t 18 Epilabium angustifolium Layer Group (EPAN 7. Key to shrub layer groups and layertypes, L.G.) 48 with ADP codes, in the ABGR/ACGL h.t 21 Castilleja miniata Layer Group (CAMI L.G.) 48 8. Relative index classes to big game and lives- Pteridium aquilinum Layer Group (PTAQ L.G.)...48 tock forage preferences by shrub layertype Fragaria vesca Layer Group (FRVE L.G.) 49 in the ABGR/ACGL h.t., ACGL phase 28 Asterconspicuus Layer Group (ASCO L.G.) 49 9. Relative index classes to big game and lives- Arnica cordifolia Layer Group (ARCO L.G.) 50 tock forage preferences by shrub layer type Thalictrum occidentale Layer Group (THOC in the ABGR/ACGL h.t., PHMA phase 29 L.G.) 50 10. Responses of major shrub species to various Management Implications 51 disturbances 31 Summary of Herb Layer Section 55 1 1 . Occurrence of natural tree seedlings (percent) References 55 by silvicultural method and overstory compe- Appendixes: tition forthe ABGR/ACGL h.t., ACGL and A-1 Constancy and Average Canopy Cover PHMA phases 35 . (Percent) of Trees by Layer Type in the 12. Occurrence of natural tree seedlings (percent) ABGR/ACGL H.T., ACGL Phase. by site preparation method forthe ABGR/ Showing Size Class Distribution ACGL h.t., ACGL and PHMA phases 36 and Average Basal Area 58 23 Page Page 13. Regeneration efficiency (RE) classes of 8. Dense pole ABGR-mature ABGR tree layer seedbeds for natural tree seedlings in the type in Fall Creek drainage southeast of ABGR/ACGL h.t.. ACGL and PHMA phases 36 Council, ID, in 1979 11 14. Occurrence of natural tree seedlings 9. Occurrence of sites with pocket gopher (percent) by shrub canopy coverforthe mounds (solid bars) and sites without mounds ABGR/ACGL h.t., ACGL and PHMA phases 36 (hollow bars) following various disturbances 15. Regeneration efficiency (RE) classes of in the ABGR/ACGL h.t., ACGL phase 1 shrub cover and other microsites for natural 10. Occurrence of sites with pocket gopher tree seedlings in the ABGR/ACGL h.t 37 mounds (solid bars) and sites without mounds 16. Occurrence of natural tree seedlings (percent) (hollow bars) following various disturbances by tree and shrub layer groups in the ABGR/ in the ABGR/ACGL h.t., PHMA phase 1 ACGL h.t., ACGL and PHMA phases 38 1 1. Relative successional amplitudes of major 17. Roles of important herb layer species in shrub species in the ABGR/ACGL h.t 19 the ABGR/ACGL h.t 41 12. Succession classification diagram of the 18. Key to herb layer groups and layertypes, shrub layer in the ABGR/ACGL h.t., with ADP codes, in the ABGR/ACGL h.t 44 ACGL phase 20 19. Relative index classes to big-game and live- 13. Succession classification diagram of the stock forage preferences by herb layertype shrub layer in the ABGR/ACGL h.t., in the ABGR/ACGL h.t., ACGL phase 52 PHMA phase 20 20. Relative index classes to big-game and live- 14. RIVI-RIVI shrub layertype on West Mountain stock forage preferences by herb layertype west of Cabarton, ID, in 1987 24 in the ABGR/ACGL h.t., PHMA phase 53 15. RIVI-ALSI shrub layer type in Pine Creek drainage west of Smiths Ferry, ID, in 1984 24 FIGURES 16. SASC-PHMA shrub layertype west of Smiths Ferry, ID, in 1984 25 ABGR/ACGL ACGL 1. Distribution of the h.t., 17. Height-age relationships of free-growing phase in Idaho 2 tree seedlings and important shrubs in the ABGR/ACGL PHMA 2. Distribution of the h.t., ABGR/ACGL h.t 32 phase in Idaho 3 18. CEVE-CEVE shrub layertype that resulted 3. Relative successional amplitudes of major from a clearcut and broadcast burn in 1968 32 tree species in the ABGR/ACGL h.t 5 19. CEVE-CEVE shrub layertype that resulted 4. Succession classification diagram of the from a clearcut and broadcast burn in 1967 33 tree layer in the ABGR/ACGL h.t 5 20. Relative successional amplitudes of important 5. Pole POTR-pole POTR tree layertype herb layer species in the ABGR/ACGL h.t 42 in Mica Creek drainage southeast of 21 Succession classification diagram of the herb . Council, ID, in 1982 9 layer in the ABGR/ACGL h.t., both phases 43 6. Sapling PIPO-sapling PIPO tree layer type 22. Constancy and average number per acre of west of Tamarack, ID, in 1984 9 pocket gopher mounds in various herb layer ABGR 7. Old-growth PIPO-pole tree layertype in types 54 Johnson Creek drainage west of Council, ID, in 1980 10 The Grand Fir/Mountain Maple Habitat Type in Central Idaho: Succession and Management Robert Steele Kathleen Geier-Hayes INTRODUCTION variables: time and environment. Environment, as it affects vegetation, can be delineated by habitat Use ofhabitat type classifications over much ofthe types or potential climax communities (Daubenmire West has increased professional awareness ofveg- 1952) that are relatively stable barring disturbance. etation and its variability. Managers ofnatural re- In a similar manner time, as it relates to succession, sources now recognize the need to foresee the changes can be dehneated by community types or serai stages in vegetation that may result from management ac- that can be obliterated, slightly altered, or even ad- tivities. But many factors influence vegetal change, vanced through various disturbances. Habitat type and in order to understand and communicate change, classifications have proven useful in much ofthe one must consider the often bewildering integral of West (Layser 1974) and by focusing on climax poten- cause and effect, and random, cyclic, and temporal tial, enable investigators to hold time constant while relationships that are manifest in succession dy- grouping plant communities that have similar en\d- A namics. logical first step is to reduce the complex- ronments. Conversely, environment can be held ity ofserai vegetation to a manageable number of relatively constant by using habitat types while units in the form ofa classification. focusing on serai vegetation over time. Habitat type classifications focus on the environ- This report explores the changes in vegetation and mental (site) differences affecting vegetation. They related resource values occurring over time in one provide a logical framework for studying succession forest environment, theAbiesgrandis/Acerglabrum and occasionally infer successional relationships but habitat type (ABGR/ACGL h.t.) (Steele and others offer no classification of serai communities. As one 1981). The classification approach used here accom- approach to meeting this need, we presentherein a modates the individual nature of specific sites in classification of serai vegetation designed for general terms ofexisting and potential species composition. field use. In so doing we have attempted to exploit It also accommodates the land managers' need for the fact that natural classification, in contrast to site-specific guidelines for intensive management technical ones designed for a specific use, have purposes. In this regard management implications broader application and often provide greater pre- for many species can be derived from each species' diction capability. The widely accepted habitat type reaction to a particular disturbance and its succes- system ofclassification is an outstanding example of sional strategy. This report can be applied to spe- a natural classification, and as its originators, R. and cific sites by using the successional characteristics J. Daubenmire (1968), have pointed out "...that sys- presented for each major species that occurs or may tem may be considered the closest to a natural one occur on your particular site. Throughout this re- that allows the most predictions about a unit from port users should focus on the relative nature of a mere knowledge ofits position in the system." We data presented rather than absolute values, because developed the following classification with these cri- relative values such as shade tolerance and succes- teria in mind so that the relative position ofa classi- sional amplitude are more easily applied than nu- fied unit in the system can help predict the succes- merical values. Because this report was developed sional status ofthat unit. In doing this we found through a series ofapproximations, it is subject to that some types of serai vegetation are related to further refinement. We welcome suggestions and a specific disturbance; other types develop mainly comments. through uninterrupted succession. These cause and This report uses a classification system (Steele effect relationships are presented in the sections 1984) that recognizes the somewhat independent dealing wdth classification as well as those dealing nature of succession between the tree, shrub, and with management implications. herbaceous layers (often due to layer-specific distur- Throughout this text the reader must remember bances such as selective tree harvesting or grazing). that vegetation is influenced by two independent It treats these three successions with separate 1 classifications. It recognizes the high potential di- verify the early serai to climax arrangement of versity ofearly and mid-seral vegetation and the stands as indicated by the classification. relative forage values to livestock and big game. It also indicates some interrelationships ofsite treat- THE ABGR/ACGL HABITAT TYPE ment, planted tree survival, competing vegetation, and pocket gopher populations. Perhaps most im- Distribution portant, it provides a common framework for com- munication amongvarious disciplines. The ABGR/ACGL h.t. occurs mainly in west central Idaho (figs. 1, 2) but extends into northeastern Oregon (Johnson and Simon 1987). In Idaho, its Objectives southern and eastern limits nearly coincide with the The objectives ofthis report are: geographic limits ofgrand fir, beyond which Douglas-fir/mountain maple and subalpine fir/moun- 1. To develop a classification ofserai plant com- tain maple habitat types occupy similar terrain. munity types in the ABGR/ACGL h.t. based on indi- Avariant ofthis habitat type extends into northern cator species and vegetal structure. Idaho where it is called the grand fir/ninebark habi- 2. To identify successional relationships ofplant tat type (Cooper and others 1991). A similar asso- community types and relate these communities to ciation is recognized in northeastern Oregon as the management treatments that gave rise to them. ABGR/ACGL-PHMA (Johnson and Simon 1987). 3. To present species composition and canopy cov- In central Idaho the ABGR/ACGL h.t. consists of erage information for each shrub layer and herba- two phases: a cool, moist (Acerglabrum) phase and ceous layer sampled and the relative value ofthese a warmer, drier {Physocarpus malvaceus) phase. layers as forage for big game and livestock. Although both phases are quite distinct and com- 4. To describe suitable conditions for natural and mon, the environmental and floristic gradient be- artificial establishment oftree seedlings and early tween the two is strongly intermediate. growth characteristics oftrees in relation to site treatment, microsite conditions, and competing vegetation. 5. To determine the number ofyears required for each tree species to reach breastheight (4.5 feet, 1.4 m) in the ABGE/ACGL h.t. when competition is minimized. 6. To provide a basis for developing preliminary management implications by serai community type. Methods This report is the third ofa series on succession and management in forest habitat types. The methods used herein are identical to those used previously, and method details are available in the earli- est final report (Steele and Geier-Hayes 1987). In general, sampling methods were similar to those used in the central Idaho habitat type study (Steele and others 1981). Circular plots (375 m^ in size) were subjectively located so as to represent the range ofsite conditions and vegetal diversity characteristic ofthe habitat type. Recorded observations included age oflast disturbance, plant coverage by species, percent survival and age to 4.5 feet (1.4 m) ofplanted tree seedlings, occurrence ofpocket gopher mounds and snow damage to tree seedlings, methods oflogging, slash disposal, site preparation, and thickness ofdufflayer. The plant coverage data were used to develop a succession classification (Steele 1984) and were later assembled in synthesis tables (Mueller-Dombois and Ellenberg 1974) to 2 — Table 1 Elevational range and importanttree species in CANADA phases of the ABGR/ACGL h.t.'' Phases^ Important ACGL PHMA tree species (4,000-6,400 ft) (4,200-6,100 ft) p r\Ui^o yicUlUlO \j \j Abies lasiocarpa (c) a Picea engelmannii (S) a Pseudotsuga menziesii S S Pinusponderosa (S) S Larix occidentalis (s) (s) Pinus contorta a a Populus tremuloides (S) (S) ^Revised from Steeleand others 1981. = serai; s = minorserai; C = majorclimax; c= minor climax; 0 = occurs in partofthe phase; a = accidental occurrences. PHYSOCARPUSMALVACEUS (PHMA) PHASE PHMA The phase denotes the warmer, drier segment ofthe habitat type. Its elevational range var- ies from 4,200 to 6,100 ft (1,280 to 1,860 m), with most sites occurringbetween 4,600 and 5,200 ft (1,402 and 1,585 m). It often occurs in the same VADA ACGL area as the phase but tends to occupy slightly ACGL drier aspects. Like the phase, it rarely occurs Figure 2—Distribution of the ABGR/ACGL h.t., on southeast to southwesterly slopes. Its lowermost PHMA phase in Idaho. elevations are on steep northerly slopes where it grades into the Douglas-fir/ninebark habitat type. In fact, this phase can be visualized as a Douglas-fir/ ninebark habitat type with adequate moisture for ACER GLABRUM (ACGL) PHASE grand fir. These sites are well suited for Pinuspon- The ACGL phase denotes a cooler, wetter segment derosa and Pseudotsuga but not Pinus contoria or ofthe habitat type and occurs mainly in central Picea (table 1), Idaho and adjacent Oregon. Similar sites farther north encounter a stronger maritime climatic influ- Description ence. Generally they support Clintonia, Coptis, or Linnaea and are assigned to habitat types or phases Because the ACGL and PHMAphases share most which bear those names. The ACGL phase occurs ofthe same species, successional changes are quite mainly on cool aspects (northeast to northwest) that similar. In early serai condition, the two phases may be quite steep. It ranges in elevation from may appear the same except for the prevalence of 4,000 to 6,400 ft (1,220 to 1,951 m) with most sites Acerglabrum in the ACGL phase. TheAcer is a occurring between 4,400 and 5,400 ft (1,341 to deeply rooted species seldom removed by distur- PHMA 1,646 m). Although these sites are relatively moist bance, and is poorly represented in the phase. and generally free offrost pockets, they are often too Picea is rare andAlnus is virtually absent in the PHMA cool for luxuriant Physocarpus development. The phase due to the drier conditions. Toward ACGL phase may be locally confined to the cold air climax Physocarpus becomes the prominent shrub PHMA channel ofsharp ravines, yet it rarely supports in the phase in lieu ofAcer; otherwise succes- stands ofPinus contorta that are linked to frost sional description ofthe two phases are similar. pockets at these elevations. In general, the ACGL Early serai conditions often differ according to the phase is characteristic ofenvironments having ad- kind ofdisturbance. Following burning, Iliamna equate moisture for most local conifers but with riuularis may appear in direct proportion to inten- moderate temperatures best suited forPinuspon- sity ofthe bum being most abundant where piled derosa, Pseudotsuga, andAbiesgrandis (table 1). slash was burned. This herbaceous perennial can quickly achieve high coverages by germinating from 3 accumulations ofseed stored in the soil (Kramer imderstory. Planted stands ofPinusponderosa are 1984). Burning can also result in a dense layer of common, but no sites were found where the pine oc- shrubs. Ceanothus velutinus and, at the lower el- curred naturally in pure stands. evations, C. sanguineus are the most common early Late serai to climax herb layers are often depau- serai shrubs on burned sites. These Ceanothus perate. Late serai stages may consist ofAster shrub layers often dominate the site within 7 to 8 conspicuus,Arnica cordifolia, and on drier sites, years followingburning and truncate the reign of Carexgeyeri or Calamagrostis rubescens. The cli- early serai herbaceous species such as Iliamna. max dominant appears to be Thalictrum occidentale, Following scarification without burning, Potentilla but it does not always occur on all sites. Where glandulosa, Carex rossii, andAstragalus canadensis Thalictrum is absent, theAster,Arnica, Carex, or are the common early serai herb layer species. Calamagrostis may occupy the climax role. These species can develop high coverages as a result Sometimes dense stands oftimber may exclude ofnumerous seeds stored in the soil. Shrub layer re- the shrub layer. In these cases, climax herb layer sponse to scarification is mainlyRibes which can species are needed to key the site to habitat type. dominate the site within 4 years. The Ribes (mainly Steele and others (1981) listAdenocaulon bicolor R. viscosissimum and R. lacustre) originates from and Disporum trachycarpum as alternate indicators seed that has accumulated in the soil. The resulting ofABGR/ACGL. Since 1981,Adenocaulon has been shrub canopy is less dense than Ceanothus and does found beyond the dry limits ofABGR/ACGL on sev- not exclude early serai herb layer species or shade- eral occasions. For this reason we suggest using intolerant tree seedlings. only Disporum as an alternate indicator and only Early serai conditions generally support few trees when dense tree canopies have excluded the shrub (naturally established), but open stands ofPopulus layer. tremuloides may be present. The Populus usually Shade-tolerant shrubs such asLonicera utahensis, survives the burning or scarification and resprouts Vaccinium globulare, Physocarpus malvaceus, from a previously established root system. Planta- Sorbus scopulina, andAcerglabrum are the major tions ofyoung saplingPinusponderosa and Pseudo- shrub components oflate serai to climax stages. tsuga may be present but notyet forming a tree Sometimes the tree canopy becomes so dense that layer. Naturally established seedlings or young even these tolerant shrubs are virtually excluded, saplings ofPseudotsuga, Picea, orAbies may be and the sparse shrub layer belies the shrub poten- scattered through the site. tial ofthese sites. Mid-seral stages usually contain minor amounts Late serai to climax tree layers are dominated by ofearly serai species in a declining state. The mid- Abiesgrandis with an occasional Pseudotsuga or seral species, most ofwhich established in early se- Picea. The tree canopy is generally multilayered rai stages, are now prominent on the site. In the with many suppressedA6jes in the understory. herb layerFragaria vesca (by stolons) and Circaea These conditions were not uncommon in ABGR/ alpina,Apocynum androsaemifolium, and Pteridium ACGL xmtil the late 1970's when attempts to con- aquilinum (by rhizomes) can increase vegetatively. vert these stands to Pinusponderosa and Pseudo- These species can develop high coverages in small tsuga were accelerated. These attempts met with openings or partial shade and maintain their cover- limited success in some areas, and inspection ofre- age beneath mid-seral shrub or tree canopies. maining climax stands reveals that often only one The mid-seral shrub layers are characterized by generation oftrees has dominated the site since the species ofintermediate shade tolerance such as lastfire. Apparently theAbies established beneath Salixscouleriana,Alnus sinuata, Spiraea betulifolia, a dense layer ofshrubs instead ofreplacing a andRubusparviflorus. The Salix establishes in Pseudotsuga or Picea tree canopy. clearings from windblown seed and persists beneath openings in the tree canopy. The Alnus occurs only SUCCESSIONAL FEATURES on the wetter sites and through wind-dispersed seed invades areas cleared by fire or logging. It then de- Succession Classification velops thickets, which persist in mid-seral tree- A dominated seres. The Spiraea andRubus spread by systematic classification ofserai vegetation rhizomes; thus these species develop high coverages within the ABGR/ACGL h.t. was developed as part ofthis study. The basic approach (Steele 1984) was beneath semiopen tree canopies. Mid-seral tree layers may contain remnants of to recognize the two primary factors affecting veg- previous Populus tremuloides stands but are usually etal change: time and environment. Environmental variation has been categorized by the habitat type dominated by mixtures ofPinusponderosa or Pseudotsuga with Picea appearing on the wetter classification system (Steele and others 1981). The sites. UsuallyAbiesgrandis is common in the habitat type system uses indicator species according 4