Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald Duchesne, L. C.; Lelu, M. A; von Aderkas, P.; Charest, Klimaszewska, K 1989. Plantlet development from imma­ P. J. 1992. Microprojectile-mediated DNA delivery in ture zygotic embryos of hybrid through somatic haploid and diploid embryogenic cells of Larix spp. embryogenesis. Science. 63: 95-103. Canadian Journal of Forest Research. [In press]. Klimaszewska, K; Ward, C.; Cheliak, W. M. 1992. Cryo­ Ellis, D. D.; McCabe, D.; McInnis, S.; Martinell, B.; preservation and plant regeneration from embryogenic Roberts, D.; McCown, B. 1991. Transformation of white cultures oflarch (Larix x eurolepis) and black spruce spruce by electrical discharge particle acceleration. In: (Picea mariana). Journal of Expermental Botany. 43: Haissing, B. E.; Kirk, T. K; Olsen, W. L.; Raffa, K F.; 73-79. Slavicek, J. M., eds. Applications of biotechnology-to Lelu, M. A; Klimaszewska, K K; Jones, C.; Ward, C.; culture, protection and utilization. United States von Aderkas, P.; Charest, P. J. 1992. A laboratory guide Department of Agriculture, Forest Service, Columbus, to somatic embryogenesis in spruce and larch. Petawawa OH:I02. National Forestry Institute. Information Report. Huang, Y.; Diner, AM.; Karnosky, D. F. 1991. Agrobacter­ PI-X-Ul (submitted for publication). ium rhizogenes-mediated genetic transformation and von Aderkas, P.; Klimaszewska, K K; Bonga, J . M. 1990. regeneration of a : oorix decidua. In: Vitro Cell. Diploid and haploid embryogenesis in Larix leptolepis, Dev. BioI. 27P: 201-207. L. decidua and their reciprocal hybrids. Canadian Jour­ nal of Forest Research. 20: 9-14.

Knowledge-Based Systems for Larix Forests Jjmmie D. Chew and Elizabeth D. Reinhardt

We have the information necessary to manage natural function. The interpretation of changes will be used to de­ resources wisely, but it is often difficult to access and use. sign desired landscapes. Differences between current and The information is often fragmented, unwieldy, and time desired landscapes can identify where management ac­ consuming to use. Methods of sharing, distributing, and tivities are needed to achieve and maintain ecosystem applying this knowledge are not well developed. But so­ functioning. cial demands have resulted in increasing complexity in re­ source management, and economic considerations demand that we look for more efficient ways to capture our knowl­ edge and make it usable. STAND DIAGNOSIS SYSTEM A combination of fundamental concepts from systems Whether or not one has used a landscape-level analysis science and principles from artificial intelligence can be to identify large, contiguous areas of stands that need to used to develop a broad category of decision support sys­ be evaluated for treatment needs, the stand diagnosis ex­ tems known as knowledge-based systems. For the Larix pert system (Chew 1989) is available. This knowledge­ forests of the Northern Rockies, several knowledge-based based system is called an expert system because it cap­ systems exist in various stages of development to help tures the expertise of silviculturists in diagnosis in the make information accessible and to interpret it for appli­ silvicultural prescription process. This step compares the cation. These systems cover the range of scales from existing stand to a desired future condition, a target stand, landscape analysis to individual stand prescriptions. and identifying possible treatment needs. Silviculturists' and other resource specialists' knowledge in identifying stand conditions that are necessary to meet specific re­ LANDSCAPE ANALYSIS SYSTEM source objectives on specific types of sites, is captured A knowledge-based system is currently being developed within the target stands. Stocking level concepts in the to provide a framework for the application of the Forest Regional Silvicultural Practices Handbook are a funda­ Service's Northern Region's ecosystem management effort. mental part of the target stand. Limitations on harvest This system will use concepts associated with landscape methods identified by Forest Plans or habitat type guide­ structure, function, and change. Rule-based components lines are used. Insect and disease information is incorpo­ will be used to identify structure and make inferences for rated as hazard ratings. The system captures local vari­ function. Knowledge on ecosystem processes will be used ables such as how suitable leave are defined and to identify the probability of change in both structure and how one determines the feasibility of removing oversto­ ries. The system is available for National Forests within the Northern Region. Jimmie D. Chew is Forester, Subalpine Silviculture Research Work The treatment alternatives developed by the system are Unit, and Elizabeth D. Reinhardt is Research Forester, Fire Effects Re­ not prescriptions. Additional interdisciplinary work is search Work Unit, United States Department of Agriculture, Forest Ser­ vice, Intermountsin Research Ststion, Missoula, MT 59807, U.S.A. necessary before a choice can be made from the possible

476 treatments. For the chosen treatment, the silviculturist experience. A knowledge-based system (Reinhardt and has to develop a sequence of detailed activities that com­ others, in press) was developed to retrieve both technical pose the prescription. and qualitative information and interpret it for applica­ tion. Site data and the manager's objectives for treating the site with prescribed fIre are user inputs to the expert STAND CULTURE SYSTEM system. The system develops a fIre prescription: ranges of acceptable fIre effects, a description of the desired fIre To help prepare the detailed prescriptions, another sys­ treatment, and a range of conditions under which to bum tem is being developed to use the existing research knowl­ to achieve the desired treatments and effects. The system's edge that is available for stand culture. The results of re­ performance was validated using data from research bums search at Miller Creek and Coram Experimental Forest in a variety offorest types throughout the Interior West on thinning and regeneration of western larch will pro­ of the United States. It performed well within the limited vide the initial basis for the system. Concepts in stand geographical domain of that area. dynamics will be incorporated into the system. This know­ ledge will be combined with many tools that are currently available at the Forest and District level such as rating REFERENCES guides for thinning stands. The system will provide a ve­ hicle for technology transfer and consistency in making Chew, J. D. 1989. An expert system for the diagnosis of sure knowledge is applied at the prescription level. stand treatment needs. In: ArtifIcial intelligence and growth models for forest management decisions confer­ ence proceedings. International Union of Forest Re­ PRESCRIBED FIRE SYSTEM search Organizations, September 18-22, 1989. Vienna, Austria: 288-297. Prescribed fIre is used to manipulate forest ecosystems Reinhardt, E. D.; Wright, A. H.; Jackson, D. H. [In press]. to accomplish a variety of resource management objec­ Development and validation of a knowledge-based sys­ tives. Managers use information from a variety of sources tem to design fIre prescriptions. AI Applications. 6(4). that include results of scientifIc research and of their own

Can Western Larch Plantations Survive and Grow on the East Slope of the Montana Rockies? Dennis M. Cole and JackA. Schmidt

With minor local exceptions, the range of western larch the plantations, neither percent survival nor the origin (Larix occidentalis Nutt.) is restricted to mountainous of planting stock could be determined in most cases. maritime-influenced areas west of the Continental Divide However, from visual examinations, we conclude that in the United States and Canada. Frost effects on the some of the larch in each plantation will likely persist­ flowering and production phases are often factors perhaps even to maturity. limiting natural regeneration of western larch. However, The major factor limiting fully successful establishment it has long been known that planted western larch can sur­ at all sites was frost damage to terminal leaders. This vive and grow east of the Continental Divide in Montana. For some years, we have heard of western larch being planted on different eastside Ranger Districts in National \"\ 21 Forests, so we made a survey of them, and of personnel of "', other agencies, to fInd out more. We were informed of 15 \ 3 "\, western larch plantings east of the Divide and were able .. ' to locate nine of them (fIg. 1), each representing a differ­ ( ____ Continental Divide ent forest habitat type (table 1). Elevations of the plant­ """': ing sites ranged from 1,340 to 2,164 m, and ages of the plantings ranged from 11 to 25 years. \5 4 Montana General differences in survival, development, and con­ ..- dition of the planted western larch could be seen between ... /6·····.) the different plantations. Because few records exist on 7

Dennis M. Cole is Research Silviculturist, United States Department of Agriculture, Forest Service, Intermountain Research Station, Bozeman, MT. Jack A Schmidt is Forester, Intermountain Research Station, Missoula, MT. Figure 1-Locations of plantations.

477 Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald of abnormal meiosis. Around 16 percent of its PMC's were strobili were aborted either by contact with pollination degenerated, and 12.4 percent of cells formed aberrant bags or by frost damage. microspores. We believe that high frequency of meiotic irregularity in Siberian larch was partly due to its earli­ Degeneration of Female Gametophytes ness in meiosis. Abortion of ovules before fertilization, which gave rise Pollen Germination to flat , was observed in 4 to 6.8 percent of ovules depending on the species. Tamarack showed the highest germination rate (78.7 percent) while European larch was the lowest (46.5 per­ Fertilization Frequency cent). The germination tests revealed that there was little correlation between frequency of meiotic abnormality and Frequency of ovules in which fertilization had occurred pollen germination. For example, the pollen germination ranged 75 to 90 percent depending on the cross. The cross rate of Siberian larch was higher than that of Japanese between tamarack and European larch was the lowest, larch, which had the lowest in frequency of meiotic abnor­ while the cross between European larch and Japanese mality. This result indicated that some meiotic irregular­ larch was the highest. It seemed that there might be a cer­ ities could recover to form normal pollen, while pollens that tain degree of incompatibility between some larch species. seemed cytologically normal may have other deficiencies. Embryo Degeneration Pollination Frequency Embryo degeneration during early stages of develop­ Pollination frequencies were more than 90 percent ex­ ment was common in all four species. Embryos degener­ cept in tamarack, whose frequency was 75 percent. Fur­ ated in 20 to 40 percent of the fertilized ovules depending thermore, most of the ovules were pollinated with more on the cross but were most common in the tamarack X than one pollen. This fact indicated that pollen quality European larch cross. The frequency of polyembryony was not the major factor reducing seed yield. at the early stage of embryo development influenced later stage embryo condition. It is possible that competition Abortion of Female Strobili among embryos in a seed contributed to degeneration of embryos. Strobili abortion soon after pollination was high in all four species. In Siberian larch, about 80 percent of

Larix Lyallii and Larix Occidentalis Within USDA Forest Service Research Natural Areas Angela G. Evenden

The Forest Service, U.S. Department of Agriculture, In these cases, prescribed management actions may be participates in a federal program to develop a national required to restore the processes upon which the natural network of Research Natural Areas. The major goal of communities and species depend. this network is to preserve a representative array of all Habitat type and plant association classification sys­ significant natural ecosystems and their inherent pro­ tems are often employed to set targets for ecosystems cesses as ecological baseline areas. The Forest Service to include within the Research Natural Areas network. has established nearly 300 Research Natural Areas na­ Larix lyallii (alpine larch) and L. occidentalis (western tionwide. These areas are important ecological reference larch) are represented in these areas within a variety of sites and are used for scientific studies, education, and classified vegetation types. Larix lyallii is found at high long-term ecological monitoring. The areas are managed elevations, often near treeline, in Abies lasiocarpa forest to maintain natural conditions, with as little human in­ types ofIdaho, Montana, and Washington. Table 1 lists tervention as possible. However, in some ecosystems, the eight areas in the Northwestern United States con­ human activities have interrupted natural processes. taining L. lyallii. Larix occidentalis is a seral component of mid-elevation Pseudotsuga menziesii forest types. Old­ growth and mature stands of L. occidentalis occur within Angela G. Evenden is Natural Areas Program Manager, Intermountain 27 areas in Idaho, Montana, Oregon, and Washington Research Station, Forest Service, U.S. Department of Agriculture, Missoula, (table 2). Common overstory dominants in these RNAs MT 59807, U.s.A.

483 Table 1-List of Research Natural Areas (RNA) on National Forest System lands in Idaho and Montana representing subalpine forests dominated by Larix Iya/lii ParI. (alpine larch). National Forest, RNA size (hectares), elevation range (meters), and associated species are also presented

RNA RNA elevation State and RNA National Forest size range Associated tree species ha m IDAHO Allan Mountain Sawtooth 668 2,912 to 3,707 Abies lasiocarpa Grave Peak Clearwater 146 2,088 to 2,524 Pinus albicaulis, Abies lasiocarpa Salmon Mountain Bitterroot 778 1,939 to 2,682 Pinus albicaulis, Picea engelmannii, Abies lasiocarpa MONTANA Bass Creek Bitterroot 803 1,244 to 2,564 Pinus albicaulis (proposed) Carlton Ridge • Lolo 372 1,700 to 2,500 Pinus albicaulis (overlaps with Larix occidentalis at lower limits in RNA) Dexter Basin Deerlodge 448 2,347 to 3,899 Abies lasiocarpa (proposed) Sapphire Divide Bitterroot 546 2,316 to 2,708 Pinus albicaulis, (proposed) Deerlodge Picea engelmannii, Abies lasiocarpa Tuchuck Flathead 835 1,585 to 2,220 Pinus albicaulis, Abies lasiocarpa

Table 2-List of Research Natural Areas (RNA) on National Forest System lands in Idaho, Montana, Oregon, and Washington representing subalpine forests dominated by Larix occidentalis Nutt. (western larch). National Forest, RNA size (hectares), elevation range (meters), and associated species are also presented

RNA RNA elevation State and RNA National Forest size range Associated tree species ha m IDAHO Aquarius Clearwater 1,579 488 to 1,218 Thuja plicata, Pinus monticola, Abies grandis, Pseudotsuga menziesii Bear Creek Payette 126 2,106 to 2,537 Pseudotsuga menziesii Cuddy Mountain Payette 425 1,474 to 2,754 Pseudotsuga menziesii Hunt Girl Creek Idaho Panhandle 609 1,200 to 1,900 Thuja plicata, Tsuga heterophylla, Pinus monticola, Abies grandis Montford Creek Idaho Panhandle 118 930 to 1,341 Pseudotsuga menziesii, Abies grandis, Pinus monticola Upper Fishhook Idaho Panhandle 130 1,823 Thuja plicata, Abies grandis, Pinus monticola, Pseudotsuga menziesii Upper Shoshone Idaho Panhandle 534 1,090 to 1,954 Pseudotsuga menziesii, Creek Pinus contorta (con.)

484 Table 2 (Con.)

RNA RNA elevation State and RNA National Forest size range Associated tree species ha m MONTANA Bass Creek Bitterroot 803 1,244 to 2,564 Pseudotsuga menziesii, (proposed) Abies grandis Barktable Ridge Lolo 341 1,646 to 1,905 Pinus ponderosa, (proposed) Pinus monticola, Pseudotsuga menziesii Big Creek Kootenai 77 745 to 800 Pinus ponderosa, Pseudotsuga menziesii Carlton Ridge Lolo 372 1,700 to 2,500 Abies lasiocarpa, Picea engelmannii, Pinus contorta (overlaps with Larix Iyallii at upper limits in RNA) Coram Flathead 340 1,060 to 1,440 Pseudotsuga menziesii, Abies lasiocarpa Lower Ross Creek Kootenai 368 866 to 1,402 Thuja plicata, (proposed) Pinus contorta Petty Creek Lolo 125 1,200 to 1,500 Pseudotsuga menziesii, Pinus contorta, Abies grandis Plant Creek Lolo 105 1,500 Pseudotsuga menziesii, Pinus contorta Pyramid Creek Lolo 210 1,600 to 2,460 Pseudotsuga menziesii Swan River Flathead 276 942 to 1,049 Pinus contorta, Pinus monticola, Pseudotsuga menziesii Ulm Peak Kootenai 279 1,273 to 1,953 Pseudotsuga menziesii, Wolf-Weigel Kootenai 101 1,082 to 1,311 Pseudotsuga menziesii

OREGON Canyon Creek Malheur 284 1 ,433 to 1,798 Pseudotsuga menziesii, Abies grandis Indian Creek Wallowa Whitman 396 1,872 to 2,125 Pseudotsuga menziesii, Pinus contorta, Abies lasiocarpa, Tsuga mertensiana Metolius Deschutes 581 850 to 1,460 Pseudotsuga menziesii, Pinus ponderosa, Arctostaphylos patula Mill Creek Mt. Hood 330 790 to 1,040 Abies grandis, Pinus ponderosa Ochoco Divide Ochoeo 777 1,250 to 1,650 Pseudotsuga menziesii Rainbow Creek Umatilla 170 1,100to 1,440 Abies grandis, Pseudotsuga menziesii WASHINGTON Meeks Table Wenatchee 27 1,280 to 1,585 Pseudotsuga menziesii, Calamagrostis rubescens Salmo Colville 563 1,158 to 2,080 Thuja plicata, Tsuga heterophylla

are Pseudotsuga menziesii, Abies grandis, Thuja plicata, monitoring. Permission to utilize an area for research and Pinus monticola. may be obtained through the National Forests and the All Research Natural Areas are available to the scientific Forest Service Research Stations. community for nonmanipulative research and ecological

485 Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald The Role of Epicormic Branches in the Life History of Western Larch

Ronald M. Lanner

Abstract-As a western larch (Larix occidentalis) tree matures, MATERIALS AND METHODS its first-order branches decline, die, and are replaced by clustered Observations of standing western larch have been made epicormics that form a replacement crown. These epicormics at several Montana locations: Seeley Lake and vicinity, grow from dormant at first-order branch-bases, appearing Morrell Lake Trail (Lolo National Forest), and Coram Ex­ at successively higher positions in the crown, eventually making perimental Forest. Stands at Coram were aged 45 years, up entire crowns of old trees. Crown replacement is a normal 60 to 70 years, and 350 to 500 years (residual old growth) life-history trait which prolongs the life span, not an injury re­ (Shearer 1992). Trees at the other locations were old sponse. It occurs in Larix, Pseudotsuga, Abies, Picea, Tsuga, growth, aged 300 to 500 years. Elevations of the observed Sequoia, and Sequoiadendron. stands ranged from 900 to 1,375 m. Associated species at Coram Experimental Forest were white spruce (Picea glauca), Douglas-fll', western white pine (Pinus mantic­ The first-order branches of larch originate from the ola), and lodgepole pine (P. contorta). Associates on the elongation of axillary buds formed on the leading shoot. Morrell Falls Trail were Engelmann spruce (P. engelman­ As leader growth continues over the years, a first-order nii), subalpine fir (Abies lasiocarpa), Douglas-fir, and branch that was at the time of its formation the upper­ lodgepole pine. Trees were measured with an Abney level most branch in the crown finds itself progressively lower and diameter tape, and branches were viewed with 10 x in the crown and eventually becomes the lowermost live binoculars. branch. After a period of decline, it may die and eventu­ ally fall from the tree. During this process of crown for­ mation and recession, a branch's characteristics change, RESULTS as well as its position in relation to other branches. It The 45-year-old stand on the South Fork of Abbott grows longer, it spreads laterally by producing one or more additional orders of branching, and it grows in di­ Creek had been thinned about 30 years prior to examina­ ameter. Its orientation changes from an acute angle to tion. A sample of four typical trees was 20 to 25 cm diam­ a right angle. The stress at its junction with the bole is eter at breast height (d.b.h.) ex = 23) and 20 to 23 m in increased not only by the weight of new biomass but by height ex = 20.9). Height to the fll'st live branch (base of snow-loading, rain-soaking, wind-torque, birdnests, live crown) was 2 to 5 m ex = 4.1). These trees and 16 oth­ mistletoe witchesbrooms, and epiphytic lichens. Each ers were examined for the presence of epicormic shoots year's suite of foliage is farther from the source of its wa­ arising from the bole and from lower first-order branch ter and more exposed to drying winds. In the meantime bases. About half the trees had such shoots, the longest its light environment is changing from unshaded to pro­ of which were about 0.3 m in length (fig. 1). Several of gressively more heavily shaded. these had sprouted 2 years previously and were un­ In this paper I maintain that those changes set limits branched. Some of the epicormics arose from the bole and on the size, and therefore the age, that a branch can at­ some from branch bases. Due to the difficulty in seeing tain, and they eventually lead to its death. The death where all of them originated, however, the percentages of a branch, however, is not detrimental to the tree as a of each category cannot be stated. None were in clusters. whole because larch is equipped with embryonic replace­ The fll'st-order branches that made up the crowns were ment branches whose release mitigates the effects of the in distinct whorls and appeared evenly spaced around the loss. These replacements are of epicormic origin-they circumference of the bole. result from the outgrowth of dormant buds located at the The trees in the 65 to 70-year-old stand were widely in­ base of the first-order branches. Finally, the new replace­ terspersed among Douglas-firs and lodgepole and western ments, which eventually dominate the crown, prolong the white pines. Four typical trees ranged from 38 to 46 cm tree's life. d.b.h. ex = 41.9) and from 24 to 26 m in height ex = 24.6). This argument is based on preliminary data and obser­ Some of these sample trees were adjacent to a meadow vations reported here, through analogy with Douglas-fir and had live branches to within 30 cm of the ground sur­ (Pseudotsuga menziesii), and on speculation. face. On one tree an epicormic shoot about 45 cm long had sprouted several years previously from the stub of a 7.6-cm diameter branch that had been broken off at a height of 5 m. In several instances epicormic shoots emerged sin­ Paper presented at the Symposium on Ecology and Management of gly or in groups of two or three from the bases oflower Larix Forests: A Look Ahead, Whitefish, MT, U.S.A, October 5-9, 1992. Dr. Ronald M. Lanner is Professor, Department of Forest Resources, limbs that were still alive. The first-order branches Utah State University, Logan, UT, 84322-5215, U.S.A.

323 the crown (table 1), and in all trees except the one with a dead spike, there was a zone in midcrown in which both categories of branches occurred (fig. 2).

DISCUSSION If we interpret the branching characteristics of these trees of various ages to represent a developmental con­ tinuum, an interesting pattern emerges. Apparently, the original first-order branches eventually die and are re­ placed by clusters of epicormics that often emerge from the bases of those first-order branches ("primaries") while the primaries still live. This process of primary branch replacement begins at the crown base and continues grad­ ually upward. When carried to completion, the replace­ ment process results in a crown comprised entirely of branches of epicormic origin. Thus, trees living on into old age would eventually be totally supported by replace­ ment crowns whose components originated as epicormic branches. An interesting physiological question is: What triggers the emergence of these epicormic branches? Epicormics are often symptoms of injury or stress that result from the release of inhibited buds in the tree bole or on major limbs. Release has been variously attributed to thinning shock (Fowells 1965), (Cosens 1952), or air pollutant stress ("Angsttriebe," Westman and Lesiilski 1985). The mistaken notion that epicormics are rare in has Figure 1-Epicormic shoots arising from long persisted (Harlow and others 1979). In an earlier the base of a first-order branch on a 4S­ study on epicormic branching in Douglas-fir, Bryan and year-old western larch on the Coram Ex­ Lanner (1981) were unable to find any evidence that such perimental Forest, MT. branching depends on perturbations for its expression. Instead, they regarded the appearance of epicormics as "a routine event in the normal life cycle of the tree" and speculated that no exogenous triggering mechanism was composing the tree crowns tended to be evenly spaced required. around the circumference of the boles and in distinct My observations reported here shed no new light on this whorls. question. The 45-year-old stand and the old-growth stand The old-growth western are along the South had been previously thinned or partially cut, so we cannot Fork Road at the southwest corner of the Coram Experi­ exclude the possibility that a change in stand density mental Forest Natural Area. The stand consists of emer­ stimulated epicormic branching. Such an influence does, gent, scattered larches with an understory oflodgepole and western white pines, white spruce, and northern black cottonwood (Populus trichocarpa). Six typical trees (i = (table 1) ranged from 76 to 99 cm d.b.h. 82.5) and 44 Table 1-Grown characteristics of six 3S0- to SOO-year-old western to 49 m in height (i = 46.6). Heights to base of live crown larches on the Coram Experimental Forest, MT were 9 to 18 m (i = 14.1). In most of these trees' crowns, two distinctive branch types could be discerned. The Height lower limbs of all the trees emerged from the bole in clus­ Diameter To first To highest To first ters of usually two or three contorted or drooping branches. at breast epicormic epicormic live primary Many of these were associated with the conspicuous stubs Tree height Total cluster cluster branch of fallen first-order branches. The upper limbs of all but em ------Meters ------one tree appeared to be relatively straight first-order limbs emerging singly from the bole. The only tree lack­ 99 48.2 9.1 39.6 24.4 ing these limbs had a 9-m long dead spike-top and a crown 2 76 46.3 17.7 39.0 46.S below the spike made up entirely of clustered branches. 3 81 43.9 12.8 34.8 29.3 Due to visibility problems (parallax, epiphytic lichen 4 81 46.6 12.8 37.2 32.3 S 79 48.8 17.1 39.6 28.0 growth, dense branching) it was never possible to be cer­ '6 79 4S.7 1S.2 36.6 none tain of the height of the uppermost clustered branches or Mean 82.S 46.6 14.1 37.8 32.1 the lowermost single first-order limbs. In all cases, how­ ever, the clustered branches made up the major part of 'Uppermost 9 m is dead.

324 45- like those of western larch, which frequently and systemi­ cally become infected by dwarf mistletoe, can act as con­ duits for the parasite into the tree's bole. The longer an 40- infected limb persists, the greater a threat it is for its par­ ent tree. Weir (1916) called attention to the "secondary crown" of epicormics that results after infected branches, 35- laden with brooms, are "lopped" from larch crowns by the wind. He illustrated a trunk cross section showing four UI "generations" of a regenerating branch base. Heaps of -... 30- G) fallen witchesbrooms were often found at the base of in­ ...G) E fected larches. 25- It is thus advantageOt~s for western larch to allow its -.c... primary limbs a limited life-span, replacing them with C) 'a; clusters of wiry little branches that emerge from long­ ::z::: 20- dormant buds residing within the bases of the very bran­ ches they are replacing, that are economical to maintan, and that could be shed when they start to become liabili­ 15 - ties. I have recently observed this process occurring commonly on European larch (L. decidua) in the Swiss Alps 10 - and in alpine larch (L. lyallii) in northwestern Montana. Figure 2-A typical old-growth western In addition to the widespread occurrence of epicormic larch with its crown of first-order replacement branches in Douglas-fir (Bryan and Lanner branches being replaced by clusters 1981) and larch, I have also observed it in Abies, Tsuga, 5- of epicormic branches, from the crown base upward. The dimensions of this Picea, Sequoiadendron, and Sequoia. tree are mean values of trees 1 through Thus, a genetically programmed "ontogenetic shift" in 5 in table 1. branch formation appears among several important conif­ erous genera. Not surprisingly, ontogenetic changes occur in these long-lived organisms. During its early years, a tree is in competition for the atmospheric volume it needs however, seem extremely unlikely in the old-growth to grow into, so its growth strategy must emphasize stand, where 75 percent of the total crown lengths of the "shoots of exploration," rapidly elongating axes that cap­ six sampled trees consists wholly or in part of epicormic ture volume. Later, its major need is to produce less ener­ branches and where spacing was wide even before partial getically demanding "shoots of exploitation" that bear cutting. Further, similar observations in unthinned old­ masses of foliage on minor axes (Edelin 1977; Thiebaut growth stands, as along the Morrell Lake trail, disclose and others 1981). A better understanding of this shift can the same behavior pattern in old larches. only emerge from detailed study of old trees-a category Epicormic branching is not necessarily induced in larch of research that has been sorely neglected in forestry. by exogenous effects but may indeed occur routinely even in the absence of such effects. For example, Nairn (1958) REFERENCES reported "adventitious branches" on tamarack (L. laricina) following sawfly attack, and Burns and Honkala (1990) Bryan, James A.; Lanner, R. M. 1981. Epicormic branch­ stated that western larch responds to release by produc­ ing in Rocky Mountain Douglas-fir. Canadian Journal ing "sprouts from adventitious buds on the upper bole." of Forest Research. 11: 190-199. But according to Pierce (1960), western larch produces Burns, Russell M.; Honkala, B. H. 1990. Silvics of epicormics upon self-pruning, the replacement process North America. Vol. 1, Conifers. Agric. Handb. 654. that is the subject of this paper. Washington, DC: U.S. Department of Agriculture, An obvious question from the standpoint of evolutionary Forest Service. 674 p. ecology might be: What possible advantage is there in re­ Cosens, R. B. 1952. Epicormic branching on pruned white placing established branches with new ones? This offers fir. Journal of Forestry. 50: 939-940. fertile ground for speculation. Edelin, Claude. 1977. Images de l'architecture des Big persistent limbs have several liabilities. They are coniferes. Montpelier: Universite des Sci. et. Tech. du heavy, especially when loaded with rain-soaked lichens, Languedoc. 255 p. These. snow, birds nests, and witchesbrooms. Thus, they require Fowells, Harry. 1965. Silvics of forest trees of the United for support a large woody mass with its considerable need States. Agric. Handb. 271. Washington, DC: U.S. De­ for maintenance respiration. If they cannot create that partment of Agriculture, Forest Service. 762 p. necessary support they may break off, leaving a large Harlow, William H.; Harrar, E. S.; White, F. M. 1979. wound on the trunk and broken branches. Textbook of dendrology. 6th ed. New York. McGraw­ Big limbs high in the crown act dangerously like sails Hill. 510 p. in the wind, increasing susceptibility to windthrow. Limbs

325 Nairn, L. D. 1958. The importance of adventitious growth Thiebaut, B.; Payri, C.; Vigneron, Ph.; Puech, S. 1981. in tamarack. Canada Department of Agriculture, Forest Observations sur la croissance et la floriason due hetre. Biology Division Bimonthly Progress Report. 14(6): 2-3. Nat. Monspeliensa series Botanique: 48: 1-25. Pierce, William B. 1960. Dwarfmistletoe and its effect Wier, James R. 1916. Larch mistletoe: some economic con­ upon the larch and Douglas-fir of western Montana. siderations of its injurious effects. Bull. 317. Montana State University Bulletin. 10: 38 p. Washington, DC: U.S. Department of Agriculture. 25 p. Shearer, Raymond C. 1992. [Personal communication.] Westman, Lars; Lesmski, J. 1985. Thinning out of the June 10. Missoula, MT: U.S. Department of Agricul­ tree crown-what is hidden in that integrated measure ture, Forest Service, Intermountain Research Station, of forest damage? In: Inventorying and monitoring en­ Forestry Sciences Laboratory. dangered forests: IUFRO conference: Proceedings; 1985; Zurich: 223-228.

326 Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald S 30 REFERENCES

Madsen, S~ren Fl. 1985. Compatible tree taper and volume functions for five different conifers. (Danish, English summary). Forstl. Fors~gsv. Danm., XXXX (1): 95-140. Madsen, S~ren Fl. 1987. Volume equations for some im­ portant Danish forest tree species, standard and form class equations, total and merchantable volumes. (Danish, English summary). Forstl. Fors~g8V. Danm., XLI (2): 41-242. Madsen, S~ren Fl. 1992. Computer program for exploita­ tion of the stem-taper functions for Norway spruce, 15 sitka spruce, Douglas-fir, Japanese larch, European silver fir, and grand fir in Denmark. (English). Danish Forest and Landscape Research Institute. 13 p. Madsen, S~ren Fl.; Heuserr, Maurice. 1992. Volume and 10 stemtaper functions for Norway spruce in Denmark. (English). Danish Forest and Landscape Research Institute. 27 p.

5

o ~~~~~~~~~~~~~~~~~ - 30-25 - 20-15 -10 -5 0 5 10 152025 30 Stem radius, em Figure 1-Stem taper equation for Japanese larch by development in tree size as for tree 349 in the permanent sample plot GV, Giesegaard estate, in every 10 years of the period 1915 to 1965.

Effect of 20 Years of Regulated Stand Densities on Bole Form of Young Western Larch Ward W. McCaughey, Wyman C. Schmidt, and Jack A. Schmidt

Because of economic factors such as increasing mill costs Bole form varies considerably between species within and diminishing wood supplies, accurate tree volumes the Intermountain West (Amidon 1984; Van Hooser and and dimensional characteristics are essential if our wood Chojnacky 1983). Volume equations for western larch resources are to be fully utilized. And because utilization (Larix occidentalis Nutt.) have been developed using a standards are constantly being adjusted toward use of variety of bole form equations, but they did not account smaller stems, a bole form or taper function equation is for spacing effects (Plank and Snellgrove 1978). In this an important factor in tree volume calculations. paper, we describe a study designed to evaluate bole form differences between three spacing levels at four locations in western Montana. Girards and Absolute form quotients were used as measures of bole form.

Ward W. McCaughey is Research Forester and Wyman C. Schmidt is Project Leader and Research Silviculturist, Intermountain Research Sta­ tion, Forest Service, U.S. Department of Agriculture, Forestry Sciences METHODS Laboratory, Montana State University, Bozeman, MT 59717, U.S.A. Jack A. Schmidt is Forester, Intermountain Research Station, Forestry Sciences Laboratory, P.O. Box 8089, Missoula, MT 59807, U.S.A. This study complements a larger study on spacing effects on the growth and development of western larch 492 -- (Schmidt and Seidel 1988) and was initiated to evaluate DECILES OF the effects of three spacings on the bole form of "young" TOTAL HEIGHT western larch in western Montana. In 1961, four study areas were established in western Montana-two on the 10 ------Coram Experimental Forest and one each on the Flathead and Lolo National Forests. Each location contained ex­ tensive overstocked stands of young, 7- to 9-year-old, west­ 9 ------ern larch reproduction with minor components of Engel­ mann spruce (Picea engelmannii Parry ex Engelm.) and Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] t--~--- 4.9 m Franco). These young stands at each location were thinned in 1961 to a wide range of densities. From these, three initial stand densities of 704 (1740 TPA), 360 (890 TPA), and 146 (360 TPA) trees per hectare of pure western larch 7 ------1/2 total were selected for evaluating bole form. t-----1r-- height above After growing at these stand densities for 20 years, 1.37m the study plots were thinned again in early 1982 to wider spacings at the four locations, and felled trees were sam­ pled for this study (table 1). Ten thinned trees in each 0.04 ha plot were randomly selected for bole form meas­ urements. Sample trees were marked at 13 locations along the bole, and outside bark diameter and bark thickness 4 ------was measured and recorded (fig. 1). Outside bark diam­ eters were measured with a diameter tape to the nearest 0.25 cm. Bark thickness was measured with a Swedish bark gauge to the nearest 0.13 cm. Total height was also 3 ---- d.b.h. 1.37 m measured on sample trees and recorded to the nearest 0.3m. Outside bark diameter and bark thickness measure­ 2 ------ments were taken on each sample tree at the following locations along the bole: 1 ___ ...... -._. ___ ...... ____ 1. 1.37 m aboveground, diameter at breast heigh (d.b.h.) Figure 1-Location of bole form measurements 2. 4.9 m aboveground on young western larch. Measurements were 3. One-half total height above 1.37 m taken at base of each decile section. 4. Deciles of total height (base of each section) Inside bark diameters were calculated by subtracting twice the bark thickness from the outside bark diameter value at each measurement location. Decile measurements tree heights, outside bark diameters, Girards (GFQ), and were used to construct graphic representations of average Absolute (AFQ) form quotient. All significance tests were bole forms. Bole form quotients (Girards and Absolute) computed at the p S 0.05 level. Equations used to compute were computed and evaluated for their between-spacing GFQ and AFQ were: differences. Analysis of variance from the SAS computer Girards form quotient = d x 100 statistical package was used to analyze spacing effects on 1 ~

where d1 = diameter inside bark at 4.9 m Dl = diameter outside bark at breast height Table 1-Thinning schedule for 0.04 ha plots at two locations on the Absolute form quotient = d2 x 100 Coram Experimental Forest and one location each on the D2 Flathead and Lolo National Forests where d2 = diameter inside bark at Years of Spacing Trees per Number of D2 = at one-half total height thinning Interval hectare trees cut D2 = diameter inside bark at breast height m 1961 1.5 x 1.5 704 1981 2.4 x 2.4 275 106 RESULTS

1961 2.1 x 2.1 360 Mean tree heights and outside bark diameters generally 1981 3.4 x 3.4 146 53 increased as stand density decreased from 704 to 360 to 146 trees per hectare (TPH) (table 2). Outside bark diam­ 1961 3.4 x 3.4 146 eters at the 146 TPH stand density were always signifi- • 1981 4.6 x 4.6 81 16 cantly larger than the 704 and the 360 TPH stand densities.

493 Table 2-Mean total height and outside bark diameter at breast The 360 TPH stand density had significantly larger diam­ height (d.b.h.) of western larch grown under three eters than the 704 TPH stand density with the exception spacing levels at four locations in western Montana of Pinkham Creek, which still showed an absolute but not significant increase. Figure 2 demonstrates average bole Mean configuration for western larch trees growing at 146, 360, Outside and 704 TPH for all four study locations. An opposite re­ Area Spacing level Total height bark d.b.h. lationship exists between high and low values for GFQ Trees per ha m em and AFQ. A high GFQ value indicates a more buttressed Coram 1 704 7.5 A' S.9A tree form in comparison to a lower GFQ value, while a 360 9.2B 9.2 B high AFQ value indicates a less buttressed tree form in 146 12.6 B 14.6C comparison to a lower AFQ value. Coram 2 704 8.7 A 6.9A Results from analysis of variance for Girards form quo­ 360 9.4 A 9.0B tient (GFQ) for the four study locations showed that Cot­ 146 10.8 B 13.4C tonwood Lakes was significantly different from Coram 1, Cottonwood Lakes 704 4.1 A 4.1 A Coram 2, and Pinkham Creek. Stand density differences 360 6.6B 7.1 B using GFQ were analyzed separately for Cottonwood Lakes 146 6.6B 8.9C and pooled for the other three study locations. Girards Pinkham Creek 704 9.2A 7.8A form quotient could not be computed for the 704 TPH 360 9.0A 8.9A stand density at Cottonwood Lakes because sample trees 146 11 .4 B 13.6 B were less than 4.9 m tall. There was no significant differ­ ence in GFQ between the 360 (GFQ 34.6) and 146 (GFQ All areas combined 704 7.4A 6.2A 360 8.6 B 8.5 B 31.2) TPH stand density at Cottonwood Lakes. 146 10.3 C 12.6C The GFQ of 64.8 for the 146 TPH stand density was sig­ 'Different letters within a column, by individual area, denote significant nificantly greater than the GFQ of 57.5 for the 360 and differences at the p ~ 0.05 level. the GFQ of 50.2 for 146 TPH stand densities for the com­ bined data set of Coram 1, Coram 2, and Pinkham Creek. There was no significant difference in the GFQ between the 360 and 146 TPH stand densities for the three com­ bined areas. 11 - 146 The AFQ value for Coram 2 was significantly different Trees I hectare from Coram 1, Cottonwood Lakes, and Pinkham Creek, 10 _ which were not significantly different from each other. Density differences using AFQ were analyzed separately 360 for Coram 2 and pooled for the other three study loca­ 9- Trees I hectare tions. The AFQ of 56.3 for the 146 TPH stand density was significantly lower than the AFQ of61.3 for the 360 TPH and the AFQ of 59.7 for the 704 TPH stand densities at Coram 2. The AFQ values for the two denser spacings at Coram 2 did not differ significantly. There were no sig­ 7- nificant differences in AFQ values between the three den­ sities for the pooled areas. However, there was an abso­ lute increase in AFQ as stand densities changed from 704 (AFQ 56.5) to 360 (AFQ 57.5) to 146 (AFQ 58.6) TPH.

4- DISCUSSION AND CONCLUSIONS These bole form data describe the dimensions of trees 3- that could be used in thinning from below. Thinning from below is a practice commonly used in young western larch stands and best fits the biology of this highly shade­ 2- intolerant species. As a result, most trees removed in early thinnings, such as trees in this study, are poten­ 1 - tially those that would be used for small diameter wood products. J ) ) 0 \ \ ~ Only trees removed by thinning were sampled for this 16 ~ o ~ 1'0 : 16 5 tl 5 lb :1'0 5 0 ~ 110 study, and as with any thinning, they generally were the Radius (em) slowest growing trees. In spite of that, relative differences in bole form between stand densities are evident as shown Figure 2-Visual representation of bole configura­ by differences in visual appearance of bole form (fig. 3), tion for western larch trees growing at 146, 360, mean height and outside bark diameter measures (table 2), and 704 trees per hectare. All four study locations and in Girard and Absolute form quotients. Trees grow­ have been pooled and averaged. ing under a low stand density of 146 TPH, compared to

494 higher densities, are significantly taller, have larger out­ REFERENCES side bark diameters, and have GFQ and AFQ values con­ sistently larger or smaller, respectively. Amidon, Elliot L. 1984. A general taper function form The visual representation of bole form for the 146 TPH to predict bole volume for five mixed-conifer species stand density indicate that trees appear to be blocky with in California. Forest Science. 30(1): 166-171. more taper than trees growing under the 360 or 704 TPH Plank, Marlin E.; Snellgrove, Thomas A. 1978. An equa­ stand densities. This is due to less competition from other tion for estimating the value and volume of western trees, more growing space, and greater crown retention by larch trees. Res. Pap. PNW-231. Portland, OR: U.S. this highly shade-intolerant species. Crown development Department of Agriculture, Forest Service, Pacific was not a part of this supplemental study but will be eval­ Northwest Forest and Range Experiment Station. 29 p. uated in the main study on spacing effects on the growth Schmidt, Wyman C.; Seidel, Kenneth W. 1988. Western and development of western larch. larch and space: thinning to optimize growth. In: It appears that spacing affects bole form of "young" Schmidt, Wyman C., compiler. Proceedings-future western larch, and these differences should be considered forests of the Mountain West: a stand culture sympo­ when evaluating stands, from initial and subsequent in­ sium; 1986 September 29-0ctober 3; Missoula, MT. termediate thinnings, for potential wood products such as Gen. Tech. Rep. INT-243. Ogden, UT: U.S. Department posts and poles. Further study of crop trees is needed to of Agriculture, Forest Service, Intermountain Research evaluate bole form differences over a variety of age, site, Station: 165-174. and stand densities and for development of volume equa­ Van Hooser, Dwane D.; Chojnacky, David C. 1983. Whole tions specific to spacing levels. By using the full com­ tree volume estimates for the Rocky Mountain States. plement of trees in the stand, volume equations describ­ Resour. Bull. INT-29. Ogden, UT: U.S. Department of ing growth and bole form should be developed. Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 69 p.

Growth of 19 Larch Provenances in Croatia Steve Orlic and Marijan Ocvirek

Research of European larch provenances in Forest Re­ of the same provenance. These differences are sometimes sear£h Institute, Jastrebarsko, was started in 1965 (Dokus bigger than the ones between the provenances themselves. 1975). Seed samples were obtained from Czechoslovakia, Poland, Germany, and Croatia. The quantity of seed or was limited. Field trials were established on pilot MATERIALS AND METHODS plots in three ecologically characteristic regions of conti­ nental Croatia. Because of the limited quantity of plants, The research program included 18 European larch larch was planted with Weymouth pine in inter-rows. In provenances-13 provenances from Czechoslovakia, one addition to the 18 European larch provenances, the trial from Poland, two from Bavaria, Germany, and two from included one provenance of Japanese larch from southern Croatia-and 1 Japanese larch provenance from southern Korea. Korea. The 19 provenances were: The aim of the researchers was to determine the Euro­ Bruntal, Razova, Czechoslovakia pean larch variability, to define the provenance that would Albrehtice, Czechoslovakia be best for this environment, and to see what increment Sabinov, Brezovacka, Czechoslovakia could be expected from this economically interesting coni­ Liptovsky, Mikula, Czechoslovakia fer species. It is known that European larch has a wide Nizbor, Drevic, Czechoslovakia area of natural distribution in Europe, both horizontally Jeromerice, Czechoslovakia and vertically, and diverse edaphic and climatic conditions. Ruda, Raskov, Czechoslovakia Pintaric (1966) established international larch prove­ Rajec, Czechoslovakia nance trials on Igman in Bosnia in 1961. The research in­ Pozorice, Czechoslovakia cluded 11 provenances of European and one provenance of Jihlava, Hencov, Czechoslovakia Japanese larch. The trials were established in the region Blizyn, Svinia gora, Poland of sessile-flowered oak, in a common hornbeam commu­ Durdevac, Croatia nity, and a montane beech forest. During the first 5 years Vujnovic brdo, Gospic, Croatia the best was Krnov provenance from Czechoslovakia. Tanap, Visoka Tatri Czechoslovakia Pintaric (1966) points out big differences between trees Baden-Wtirtenberg, Germany Litovel, Usov, Czechoslovakia Ruda on Moravi, Czechoslovakia Steve Ortic and Marijan Ocvirek are with the Forest Research Institute. Amorbach, Kirchell, Germany Jastrebarsko, Croatia. Yongwol-kun, Southern Korea 495 Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald Old-Growth Western Larch Forests: Management Implications for Cavity­ Nesting Birds

B. Riley McClelland

Abstract-This paper discusses the role western larch plays in Considering its pathfinder role and need for large de­ the habitat requirements for cavity-nesting birds. The pileated caying trees, the pileated woodpecker is appropriately woodpecker's importance as a "pathfinder" species, the impor­ identified as a sensitive species, dependent on the old­ tance of old-growth western larch, and the need for management growth component in western larch forests. However, strategies that feature optimal ecological values are emphasized. the pileated woodpecker is not a meaningful management indicator for a diverse range of old-growth forests; the pileated woodpecker does not nest in all tree species (e.g., Engelmann spruce or subalpine fir) and it rarely nests in Characteristics of nest trees and surrounding habitats high elevation forests. Additionally, attributes of old were documented for more than 300 cavity nests used by growth are site specific. Use of a single bird species as 28 bird species in northwestern Montana between 1975 an indicator for a complex and diverse array of old growth and 1991. Study areas included the Coram Experimental is illogical. Forest and Glacier National Park. Forests of western larch (Larix occidentalis) and Douglas-fir (Pseudotsuga menziesii) were studied most intensively. BIOLOGICAL DIVERSITY There were more nests in western larch and fewer in Douglas-fir than expected, based on availability. Forest Where retention of biological diversity is important in stands characterized as old growth (with trees large and western larch forests, old growth is an essential compo­ old relative to species and site, large snags and logs, and nent. This will require subordinating maximum timber a high incidence of broken tops and heartwood decay) sup­ production on selected low elevation, productive sites and ported the highest density and diversity of cavity nesters. planning on a landscape scale-not simply one cutting proposal at a time. Heartrot, for example, may decrease timber production, but it is an indispensable process in A "PATHFINDER" SPECIES AND ITS cavity-nesting habitat. So called salvage and sanitation NESTS sales can destroy cavity-nesting habitat even while leav­ ing substantial volume on site. The study focused on the pileated woodpecker (Dryocopus Rather than focusing on minimum habitat standards pileatus), a "pathfinder" species that creates nesting, roost­ for cavity nesters (e.g., nest tree size and density of snags) ing, and feeding opportunities for many birds and small management strategies should emphasize optimum eco­ mammals incapable of excavating in the dense wood of logical values (Conner 1979). western larch. Fifty-three pileated woodpecker nests were Historically, extensive stands of old-growth western in western larch; only one was in Douglas-fir. Mean diam­ larch were shaped by lightning, wildfire, insects, disease, eter at breast height oflarch nest trees was 80 em; 72 per­ and decay. However, in recent decades the extent of old­ cent were snags. growth larch forests in northwestern Montana has been Nearly all larch nest trees had visible evidence of heart­ diminished primarily by logging. In the future, regardless wood decay: conks (primarily Phomitopsis officinalis) or of how eloquently "New Forestry" and biodiversity jargon white pocket rot in the wood chips from the cavity excava­ dominate forest planning rhetoric, the terms will be ca­ tion. Because undecayed larch wood is dense and difficult nards unless a biologically objective perception of diver­ to excavate, woodpeckers selected trees with heartwood sity is applied. The roles of all native flora and fauna in­ decay. Such trees usually were more than 200 years old. cluding insects, decay organisms, snags, old growth, and Western larch may have been preferred because the sap­ pathfinders need to be recognized and incorporated into wood is slow to decay, leaving a cylinder of relatively firm long-term management strategies for western larch forests. and protective sapwood surrounding a core of decaying heartwood. In Douglas-fir snags, the sapwood and heart­ wood decay nearly concurrently as the snag ages. REFERENCE Conner, R. N. 1979. Minimum standards and forest Paper presented at the Symposium on Ecology and Management of Larix Forests: A Look Ahead, Whitefish, MT, U.S.A, October 5-9, 1992. wildlife management. Wildlife Society Bulletin. 7(4): B. Riley McClelland, Ph.D., is a Profe880r at the School of Forestry, 293-296. University of Montana, Missoula, ¥T, U.S.A 59812.

376 Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald Ectomycorrhizal Relationships in Western Larch Ecosystems

Deborah Page-Dumroese Alan Harvey Martin Jurgensen Russell Graham

Ahstract- Ectomycorrhizae depend on soil organic materials for for nutrients, space, and water is keen. On droughty, successful colonization and activity in larch ecosystems of the nutrient-depleted, or stressful sites, only a brief period Intermountain West, U.S.A. Wea'tem larch (Larix occidentalis exists for favorable growth and, if a seedling fails to estab­ Nutt.) and three other conifer species were evaluated to assess lish during that time, survival is unlikely (Amaranthus the role of site disturbances and organic horizons on root growth and Perry 1987, 1989). Ectomycorrhizal root structures and ectomycorrhizal activity. All species use organic horizons help provide greater drought resistance than nonecto­ and principal growth substrates. Use of mineral horizons varies mycorrhizal roots (Parke and others 1983). Microbial by species. Soil types with the greatest organic matter supported populations shift in response to the loss of organic matter, the greatest fungal and root growth. nutrients, and decaying root systems (Kozlowski and Ahlgren 1974; Perry and Rose 1983). On harsh sites, these alterations may jeopardize reforestation (Pilz and Perry 1984), because without a living host, ectomycor­ Ectomycorrhizal fungi predominate in temperate forests rhizal fungi do not persist long (Amaranthus and Perry of the Intermountain West (Molina and Amaranthus 1991). 1987; Hacskaylo 1973). Total elimination of ectomycor­ Conifers in western larch (Larix occidentalis Nutt.) ecosys­ rhizal roots was reported 1 year after clearcutting a high­ tems form an obligate, usually mutually beneficial, rela­ elevation site in western Montana (Harvey and others tionship with ectomycorrhizae. Ectomycorrhizal fungi, in 1980). general, may allow trees to successfully compete with The effect of ectomycorrhizae on seedlings is not consis­ grasses and herbs for resources (Bowen 1980), and their tent (Kropp and Langlois 1990). Ectomycorrhizae are hyphae can connect plants of different species to facilitate generally thought to be crucial for acceptable growth and the transfer of carbon and nutrients (Bjorkman 1960; survival (Perry and others 1987), and failure of afforesta­ Francis and others 1986; Kropp and Langlois 1990). In tion efforts in absence of ectomycorrhizal inoculum return, the fungi receive simple sugar energy sources (Meyer 1973) demonstrates their importance. However, from host plant roots (Bjorkman 1962; Marx and others Harvey and others (1991) point out that the "cost" of 1977). Ectomycorrhizal associations depend on environ­ maintaining an active complement of these fungi may be ment, particularly soil fertility (Bjorkman 1962) and or­ high. Seedling growth responses vary according to soil ganic matter content (Harvey and others 1978), and play chemical and physical characteristics as well as the fun­ a critical role in soil development and plant nutrition. gal inoculum present (Danielson 1988; Marx and Cordell Ectomycorrhizal tip formation is dependent on rhizo­ 1988). sphere conditions such as moisture content, pH, tempera­ This paper discusses comparative root growth and ture (Slankis 1974), and the content and type of organic ectomycorrhizal colonization on four conifer species com­ matter (Bjorkman 1970; Harvey and others 1979). mon to western larch ecosystems of the Intermountain Harvey and others (1976, 1978, 1987) and Harvey (1982) West, U.S.A. have demonstrated that humus and brown cubical de­ cayed wood are major substrates for ectomycorrhizal root­ tip growth. Organic horizons also have a direct effect on METHODS tree root development (Coutts and Philipson 1977; Page­ Two studies of western larch ecosystems in the North­ Dumroese and others 1989). Organic soil horizons, such ern Rocky Mountains have been conducted to assess the as humus, decaying wood, and charcoal, are positively cor­ potential role of disturbance types and organic horizons related with root growth because of their high moisture on root growth and ectomycorrhizal formation and distri­ contents, high gas exchange, and low bulk densities. bution. This entailed (1) evaluation of natural conifer re­ Reforestation success depends on seedlings using site generation associated with undisturbed and harvested resources quickly. On relatively fertile sites, competition forests, and (2) the development of planted conifer regen­ eration associated with four postharvest site preparation Paper presented at the Symposium on Ecology and Management of treatments. Larix Forests: A Look Ahead, Whitefish, MT, USA, October 5-9, 1992. Deborah Page-Dumroese, Alan Harvey, and Russell Graham are, re­ spectively, Research Soil Scientist, Principal Plant Pathologist/Project Leader, and Research Forester, Intermountain Research Station, Forest The Natural Regeneration Study Service, U.s. Department of Agriculture, Moscow, ID 83843, USA. Martin Jurgensen is Professor of Forest Soils, School of Forestry and Wood Prod­ This study was conducted on 11 different sites (fig. 1). ucts, Michigan Technological University, Houghton, MI 49331, USA. Six sites were in northwestern Montana, three within the

342 complete block experiment was established at each site. Both sites were mechanically prepared in the summer of 1982 by concentrating the forest floor and mineral soil from the top 10 cm of a 1.5-m wide area and forming mounds. Treatments on these sites consisted of (1) mounded soil beds with competing vegetation left in place, (2) mounded soil beds with competing vegetation removed Montana manually in year 1, (3) a scalped area where the top 10 cm of organic matter and mineral topsoil were re­ moved, and (4) an area essentially undisturbed after har­ vesting. At the low-elevation site, there were four treat­ ments with four replications in one large block. A higher elevation, midslope site consisted of four treatments with three replications. Idaho In May 1983, the treatments were planted with locally adapted, 1+0 container-grown Douglas-fir, western white pine, and western larch on a 1- by 1-m spacing. Forty-five Douglas-fir and western white pine and five western larch seedlings were excavated from each treat­ Figure 1-Location of natural ment replication four times during the growing season for regeneration study sites. 2 consecutive years (1983 and 1984). Ectomycorrhizal root tips were counted on the entire seedling root system using a dissecting microscope. Seedling rooting depth and longest lateral roots were also measured. boundaries of the Coram Experimental Forest, one within An analysis of variance was conducted on the data, the Lubrecht Experimental Forest, and two on the Miller utilizing a randomized complete block design. The treat­ Creek Watershed. The other five sites were within the ment means were separated using Duncan's multiple Priest River Experimental Forest in northern Idaho. For range test. further information on site location and characteristics see Harvey and others (1976). Site treatments included un­ disturbed forests, clearcuts with broadcast burns, and RESULTS AND DISCUSSION underburned partial cuts. Tree species examined were Natural Regeneration Study western larch, Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco), western white pine (Pinus mon­ Species morphology and soil moisture were factors ex­ ticola Doug!. ex D.Don), and Engelmann spruce (Picea pected to influence ectomycorrhizal colonization of seed­ engelmannii Parry). ling roots, especially for natural regeneration (Harvey and Samples consisted of 10- by 30-cm soil cores (Jurgensen others 1980). Generally, those habitat types with the and others 1977) taken randomly, five from around each largest amounts of soil organic matter (from Harvey and plot center, 10 plot centers total, scattered evenly over others 1987) supported the greatest numbers of ecto­ 1 ha of uniform conditions on each study site. Samples mycorrhizae (table 1). In general, soil organic matter were taken during late spring and early summer over sev­ depth increased as precipitation and elevation increased. eral years (1978 to 1982) to obtain maximum seasonal ectomycorrhizal activity for each site (Harvey and others 1978). Roots were separated from soil cores and active Table 1-Total number of ectomycorrhizal root tips on naturally ectomycorrhizal tips counted with the aid of a dissecting regenerated seedlings growing on a variety of habitat microscope (10-50x). Each active tip was counted, even types (Cooper and others 1991) though in many cases it was part of a complex structure. From the core, total root length was also measured. Habitat Western Engelmann Western Douglas- Analysis of variance was used for testing the effects of type' white pine spruce larch fir site, soil component, ectomycorrhizae, and root length. If significant differences were found, Duncan's multiple range PSME/PHMA 240a 10b test was used to evaluate significance of differences be­ PSMElVAGL 93a 54a tween means. ABLNCLUN 2a 14b 14b ABLNXETE 17a 272a 14b 20b THPUPAMY 88a 27b 23b The Planted Regeneration Study TSHEICLUN 39b 13b 55a This study was conducted on two sites at different el­ 'PSMElPHMA = Pseudotsuga menziesiilPhysocarpus malvaceus PSMENAGL = Pseudotsuga menziesiiNaccinium globulare evations within the Priest River Experimental Forest. ABLAICLUN = Abies lasiocarpaiClintonia uniflora For more information about site characteristics and soil ABLAlXETE = Abies lasiocarpaiXerophyllum tenax THPUPAMY = Thuja plicataiPachistima myrsinites. chemical and physical properties from this study see TSHE/CLUN = Tsuga heterophyllaiClintonia uniflora. Page-Dumroese and others (1986,1989). A randomized 'Different letters indicate significant differences (P S 0.05) across habitat • types.

343 Harvey and others (1980) noted that the quantity of ecto­ Site treatments altered both location of seedling mycorrhizal root tips in random soil samples directly re­ ectomycorrhizae and greatest root length (tables 2 and 3). flect relative ecosystem productivity. In addition, each In undisturbed conditions, neither Engelmann spruce nor seedling species produced abundant ectomycorrhizae in western larch had longest roots or ectomycorrhizae in specific habitat types. For example, Engelmann spruce mineral or humus horizons. After a clearcut and burn, seedlings produced the greatest number of ectomycor­ all four species had lateral roots and ectomycorrhizae in rhizae in the ABLAICLUN habitat type, larch produced the mineral soil and decayed wood horizons. On the the most in the PSMENAGL habitat type and western burned sites, lower pH values may have made the min­ white pine was most prolific in the TSHEICLUN habitat eral soil more suitable for ectomycorrhizal activity. type. Douglas-fir appeared more of a generalist, produc­ In clearcut and burned sites, Douglas-fir used mostly ing about the same numbers of ectomycorrhizae in all decaying wood for ectomycorrhizal development. Western habitat types. white pine and larch, conversely, formed most of their

Table 2-Total number of ectomycorrhizae root tips on naturally regenerated seedlings as affected by site treatment and soil horizon. Values are averages across habitat types (n = 114)

Soli Western Engelmann Western Douglas- Treatment horizon white pine spruce larch fir

Undisturbed Mineral '43a 36a Humus 19b Decayed wood 23a 1Sa 13a 14b

Clearcut and bum Mineral 88a 39a 16a 19a Humus 7Sa 6a Decayed wood 66a 39a 10a 41a

Partial cut and underbum Mineral 98a 30a Humus 18a 64a Decayed wood 30a

'Different letters indicate significant differences (PS 0.05) across soil horizons within treatment.

Table 3-Total root length within random core samples as affected by site treatment and soil horizon. Values are averages across habitat types (n = 114)

Soli Western Engelmann Western Douglas­ Treatment horizon white pine spruce larch fir ------em ------••• ------• ---

Undisturbed Mineral '17.0a 11.7a Humus 12.8a Decayed wood 14.Sa 24.0a 18.4a 14.6a

Clearcut and bum Mineral 17.7a 16.2ab 14.1a 14.8a Humus 11.0b 11.Sa Decayed wood 19.1a 2S.Sa 19.5a 12.2a

Partial cut and underbum Mineral 12.Sa 13.Sa Humus 13.3a 11.1a Decayed wood S.Oa

'Different letters indicate significant differences (PS 0.05) across soil horizons within treatment.

344 Table 4-Root length in random soil cores as affected by soil (table 4). When humus horizons were present, western horizon. Values are averages across habitat types and larch was notably adept in exploiting them. treatment (n = 243) No specific attempts were made to identify particular ectomycorrhizal fungi associated with these seedlings. Soil Western Engelmann Western Douglas- However, Harvey and others (1976) noted that fruiting horizon white pine spruce larch fir structures of Russula brevipes Pk. and the distinctive mor­ ------em ------phology of Cenococcum graniforme (Sow.) Ferd. et Winge Mineral '17.7a 16.3a 13.3b 12.7b were often associated with Douglas-fir seedlings during Humus 2S.0a sampling. Douglas-fir is also host to Rhizopogon vinicolor Decayed wood 17.8a 13.7a 18.9ab 14.8a Smith, Laccaria laccata (Scop. ex Fr.) Berk and Br., and Charcoal 11.0a 13.3b 11.2c Hebeloma crustiliniforme (Bull ex St. Am.) Quel. (Perry and 'Different letters indicate significant differences (PS 0.05) across soil others 1987). Estimates indicate that Douglas-fir may form horizons. ectomycorrhizae with over 1,500 fungal species over its en­ tire range (Trappe and Strand 1969). Far fewer fungi are estimated to form ectomycorrhizae with western larch. Some that have been noted include: Suillus cavipes (Opat.) ectomycorrhizae in mineral soil. This may have been Smith et Thiers, Suillus grevellii (Kl..) Singer, Cenococcum because postharvest organic horizons depths were rela­ graniforme, Laccaria laccata, and Pisolithus tinctorious tively shallow (Harvey and others 1978). A partial cut (Pers.) Coker and Couch (Amaranthus 1992; Chakravarty with underburning seemed to be more detrimental to or­ and Chatarpaul1990; Harvey and others 1976). ganic horizons, as evidenced by high ectomycorrhizal de­ velopment in mineral horizons. The large volume, gen­ eral distribution, and high moisture content of decayed Planted Regeneration Study wood throughout the soil profile probably contributed to its ability to retain and support ectomycorrhizal activity Western larch seedlings planted in raised planting beds when compared to other soil components. Irrespective of formed fewer ectomycorrhizae than seedlings growing site treatment, organic horizons, and in particular de­ in scalped treatments (fig. 2a). Seedlings growing in cayed wood, were the locations of greatest root length treatments considered stressful (such as mounding with no competition control or scalping) formed most of their

10

CI) CO 8 .!::! .r...... 6 0 (.) >- E 4 0 (.) W- 2 1U 0 -t- O

25

E 20 -(.) -.r. C) 15 -c CI) ..J 10 0 -0 r::r: 5

0 Figures 2a and 21>-Total number of ecto­ Mounded Mound-herb. Scalped No site prep. mycorrhizae and length of longest lateral root Site Treatment of planted western larch as affected by site • IT! Organic soil 0 Mineral soil treatment.

345 ectomycorrhizae in the mineral horizons. Seedlings in the noted that both Douglas-fir and western white pine re­ mound with weed control and the no-site-'preparation sponded similarly in these treatments. There was signifi­ treatment formed most of their ectomycorrhizae in or­ cantly more ectomycorrhizal colonization in the scalped ganic soil horizons. These latter two treatments also had treatment than in the other three treatments. Despite the greatest height growth (see Graham and others, this high numbers of ectomycorrhizal short roots on these proceedings). There were few differences in western larch seedlings, growth was not improved after 3 years (Harvey root length among these treatments (fig. 2b). and others 1991; Page-Dumroese and others, in press). Western white pine and Douglas-fir seedlings exhibited Seedlings growing in more fertile environments tend to similar trends in ectomycorrhizal colonization in these have fewer ectomycorrhizae than those growing in treatments (figs. 3a and 4a). Seedlings in mounded, harsher conditions (Brainerd and Perry 1987; Page­ mounded with competition control, and scalped treat­ Dumroese and others 1990). Under fertile conditions, ments had more ectomycorrhizal tips in organic than min­ ectomycorrhizae may represent a carbohydrate cost to eral soil. However, the no-site-preparation treatment seedlings deficient in factors unimproved by colonization showed an opposite trend; more ectomycorrhizal tips in (Reid 1979) or perhaps unavailable in low organic matter mineral soil. This may be because the soil had intact soil soils (Harvey and others 1991). horizons after harvesting and only a shallow surface or­ ganic horizon. After three growing seasons, both species CONCLUSIONS growing in the mound-competition control treatment had the greatest biomass and height (Page-Dumroese and oth­ Ectomycorrhizae play an important role in maintaining ers, in press). healthy forest ecosystems in the Intermountain West. In Western white pine seedlings produced the longest lat­ most habitat types they are dependent on organic hori­ erals in organic soils for every treatment (figs. 3b and 4b). zons for successful colonization. Western larch is well Douglas-fir used the organic soil horizons more when com­ known for its ability to thrive in areas devoid of organic petition or compaction created unfavorable growing con­ matter. However, it and most other western conifers ditions elsewhere. benefit from intact organic horizons. The critical nature In this study, organic horizons were important for all of ectomycorrhizae and organic matter in these ecosys­ three of these western conifers. Harvey and others (1991) tems present many opportunities for land managers.

400

CD ftI .~ 300 ~...... o ~200 E o U W 100 S ~ o

14

E 12 -u 10 -~ C) -c 8 CD ..J 6 0 - 4 0 a:: 2

0 Mounded Mound-herb. Scalped No site prep. Figures 3a and 3b-Total number of ecto­ Site Treatment mycorrhizae and length of longest lateral root of planted western white pine as affected by t72I Organic soil D Mineral soil site treatment.

346 12 CDas N 10 :E .. 8 0 U >- E 6 0 u 4 W- a; 2 0 t-- O

140' E 120 -u -s:. 100 C) -c 80 CD -J 60 -0 0 a: 40 20

0 Mound-herb. Scalped No site prep. Figures 4a and 41>-Total number of Site Treatment ectomycorrhizae and length of longest lat­ eral root of planted Douglas-fir as affected [llJ Organic soil o Mineral soil by site treatment.

With careful management these soils can be protected or Bowen, G. D. 1980. Mycorrhizal roles in tropical plants even improved. Recognizing the importance of organic ho­ and ecosystems. In: Mikola, P., ed. Tropical mycorrhiza rizons and ectomycorrhizal colonization for seedling es­ research. Oxford, UK: Oxford University Press:165-190. tablishment and growth provides the basis for restoration Brainerd, R E.; Perry, D. A. 1987. Ectomycorrhizal for­ of damaged soils. mation in disturbed and undisturbed soil across a mois­ ture/elevation gradient in Oregon. In: Sylvia, D. M.; Hung, L. L.; Graham, J. H., eds. Mycorrhizae in the REFERENCES next decade-practical applications and research priori­ Amaranthus, M. P. 1992. [Personal communication). ties; 1987 May 3-8; Gainesville, FL. Gainesville, FL: September 11. Grants Pass, OR: U.S. Department of University of Florida: 145. Agriculture, Forest Service, Pacific Northwest Research Chakravarty, P.; Chatarpaul, L. 1990. Effect offertiliza­ Station. tion on seedling growth, ectomycorrhizal symbiosis, and Amaranthus, M. P.; Perry, D. A. 1987. Effect of soil trans­ nutrient uptake in . Canadian Journal of fer on ectomycorrhiza formation and the survival and Forest Research. 20: 245-248. growth of conifer seedlings on old, nonreforested clear­ Cooper, S. V.; Neiman, K. E.; Roberts, D. W. 1991. Forest cuts. Canadian Journal of Forest Research. 17: 994-950. habitat types of northern Idaho: a second approxima­ Amaranthus, M. P.; Perry, D. A. 1989. Interaction effects tion. Gen. Tech. Rep. INT-236. Ogden, UT: U.s. Depart­ of vegetation type and Pacific madrone soil inocula on ment of Agriculture, Forest Service, Intermountain Re­ survival, growth, and mycorrhiza formation of Douglas­ search Station. 143 p. fir. Canadian Journal of Forest Research. 19: 550-556. Coutts, M. P.; Philipson, J. J. 1977. The influence of min­ Bjorkman, E. 1960. Monotropa hypopitys. 1.: an epi­ eral nutrition on the root development of trees. Journal parasite on tree roots. Physiologia Plantarum. 134: 308. of Experimental Botany. 28: 1071-1075. Bjorkman, E. 1962. The influence of ectotrophic mycor­ Danielson, R M. 1988. Mycorrhizae in forestry: the state of rhiza on the development of forest tree plants after the art in land reclamation. In: Lalonde, M.; Piche, Y., planting. In: Proceedings of the 13th congress/meeting; eds. Proceedings of the Canadian workshop on mycor­ 1961. Part 2. Vol. 1. Sect. 24-1. International Union of rhizae in forestry; 1988 May 1-4. Sainte-Foy, PQ: Cen­ Forest Research Organizations. tre de recherche en biologie forestiere, Faculte de Bjorkman, E. 1970. Forest tree mycorrhizae-the condition foresterie et de geodesie, Universite Laval: 429-435. for its formation and the significance for tree growth Francis, R; Finlay, R D.; Read, D. J. 1986. Vesicular­ and afforestation. Plant and Soil. 32: 589-610. arbuscular mycorrhizae in natural vegetation systems. 347 IV. Transfer of nutrients in inter- and intra-specific forestry; 1988 May 1-4. Sainte-Foy, PQ: Centre de re­ combinations of host plants. New Phytology. 102: cherche en biologie forestiere, Faculte de foresterie et de 103-111. geodesie, Universite Laval: 167-176. Hackskaylo, E. 1973. Carbohydrate physiology of ecto­ Meyer, F. H. 1973. Distribution of ectomycorrhizae in na­ mycorrhizae. In: Marks, G. C.; Kozlowski, T. T., eds. tive and man-made forests. In: Marks, C. G.; Kozlowski, Ectomycorrhizae: their ecology and physiology. New T. T., eds. Ectomycorrhizae-their ecology and physiol­ York: Academic Press: 207-228. ogy. New York: Academic Press: 79-105. Harvey, A E. 1982. The importance of residual organic Molina, R; Amaranthus, M. P. 1991. Rhizosphere biology: debris in site preparation and amelioration for refores­ ecological linkages between soil processes, plant tation. In: Site preparation and fuels management on growth, and community dynamics. In: Harvey, A E.; steep terrain: symposium proceedings; 1982 February Neuenschwander, L. F., comps. Proceedings-manage­ 15-17; Spokane, WA Pullman, WA: Washington State ment and productivity of western-montane forest soils; University, Cooperative Extension: 75-85. 1990 April 10-12; Boise, ID. Gen. Tech. Rep. INT-280. Harvey, A E.; Jurgensen, M. F.; Larsen, M. J. 1978. Ogden, UT: U.S. Department of Agriculture, Forest Ser­ Seasonal distribution of ectomycorrhizae in a mature vice, Intermountain Research Station: 51-58. Douglas-firllarch forest soil in western Montana. Forest Page-Dumroese, D. S.; Jurgensen, M. F.; Graham, R T.; Science. 24: 203-208. Harvey, A E. 1986. Soil physical properties of raised Harvey, A E.; Jurgensen, M. F.; Larsen, M. J.; Graham, planting beds in a northern Idaho forest. Res. Pap. R T. 1987. Decaying organic materials and soil quality INT-360. Ogden, UT: U.S. Department of Agriculture, in the Inland Northwest: a management opportunity. Forest Service, Intermountain Research Station. 5 p. Gen. Tech. Rep. INT-225. Ogden, UT: U.S. Department Page-Dumroese, D. S.; Jurgensen, M. F.; Graham, R. T.; of Agriculture, Forest Service, Intermountain Research Harvey, A E. 1989. Soil chemical properties of raised Station. 15 p. planting beds in a northern Idaho forest. Res. Pap. Harvey, A E.; Larsen, M. J.; Jurgensen, M. F. 1976. Dis­ INT-419. Ogden, UT: U.S. Department of Agriculture, tribution of ectomycorrhizae in a mature Douglas-fir/ Forest Service, Intermountain Research Station. 7 p. larch forest soil in western Montana. Forest Science. 22: Page-Dumroese, D. S.; Jurgensen, M. F.; Harvey, A E.; 393-398. Graham, R T.; Tonn, J. [In press]. Tree seedling re­ Harvey, A .E.; Larsen, M. J.; Jurgensen, M. F. 1979. Com­ sponse and soil changes associated with site prepara­ parative distribution of ectomycorrhizae in soils of three tion in northern Idaho, U.S.A Canadian Journal ofFor­ western Montana forest habitat types. Forest Science. est Research. 25: 350-360. Page-Dumroese, D. S.; Loewenstein, H.; Graham, R T.; Harvey, A E.; Larsen, M. J .; Jurgensen, M. F. 1980. Par­ Harvey, A E. 1990. Soil source, seed source, and tial cut harvesting and ectomycorrhizae: early effects in organic-matter content effects on Douglas-fir seedling Douglas-firllarch forests of western Montana. Canadian growth. Soil Science Society of America Journal. 54: Journal of Forest Research. 10: 436-440. 229-233. Harvey, A E.; Page-Dumroese, D. S.; Graham, R T.; Parke, J. L; Linderman, R .G.; Black, C. H. 1983. The role Jurgensen, M. F. 1991. Ectomycorrhizal activity and co­ of ectomycorrhizae in drought tolerance of Douglas-fir nifer growth interactions in western-montane forest seedlings. New Phytology. 95: 83-95. soils. In: Harvey, A E.; Neuenschwander, L. F., comps. Perry, D. A; Molina, R; Amaranthus, M. P. 1987. Mycor­ Proceedings-management and productivity of western­ rhizae, mycorrhizospheres, and reforestation: current montane forest soils; 1990 April 10-12; Boise, ID. Gen. knowledge and research needs. Canadian Journal of Tech. Rep. INT-280. Ogden, UT: U.S. Department of Forest Research. 17: 929-940. Agriculture, Forest Service, Intermountain Research Perry, D. A; Rose, S. L. 1983. Soil biology and forest pro­ Station: 110-117. ductivity: opportunities and constraints. In: Ballard, R; Jurgensen, M. F.; Larsen, M. J.; Harvey, A E. 1977. A soil Gessel, S. P., eds. IUFRO symposium on forest site and sampler for steep, rocky sites. Res. Note INT-217. continuous productivity. Gen. Tech. Rep. PNW-163. Ogden, UT: U.S. Department of Agriculture, Forest Ser­ Portland, OR: U.S. Department of Agriculture, Forest vice, Intermountain Forest and Range Experiment Sta­ Service, Pacific Northw~st Research Station: 229-238. tion. 6 p. Pilz, D. P.; Perry, D. A 1984. Impact of clear-cutting and Kropp, B. R; Langlois, C.-G. 1990. Ectomycorrhizae in re­ slash burning on ectomycorrhizal associations of forestation. Canadian Journal of Forest Research. 20: Douglas-fir. Canadian Journal of Forest Research. 14: 438-451. 94-100. Kozlowski, T. T.; Ahlgren, C. E. 1974. Fire and ecosys­ Reid, C. P. P. 1979. Mycorrhizae: a root-soil interface in tems. New York: Academic Press: 475. plant nutrition. In: Todd, R L; Biddens, J. E.,eds. Marx, D. H.; Bryan, W. C.; Cordell, C. E. 1977. High soil Microbial-plant interactions. ASA Spec. Publ. 47. fertility decreases sucrose content and susceptibility of Madison, WI: American Society of Agronomy: 29-50. loblolly pine roots to ectomycorrhizal infection by Piso­ Slankis, V. 1974. Soil factors influencing formation of lithus tinctorius. Canadian Journal of Botany. 55: ectomycorrhizae. Annual Review of Phytopathology. 1569-1574. 12: 437-457. Marx, D. H.; Cordell, C. E. 1988. Specific ectomycorrhizae Trappe, J. M.; Strand, R F. 1969. Mycorrhizal deficiency improve reforestation and reclamation in the eastern in a Douglas-fir region nursery. Forest Science. 15: United States. In: Lalonde, M.; Piche, Y., eds. Proceed­ 381-389. ings of the Canadian workshop on mycorrhizae in

348 Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald Around the World with Larix: an Introduction Wyman C. Schmidt

Circling the globe at 60° N latitude, one is seldom out of conifers. Their light green hues in the spring and sum­ sight of Larix on the extended landmasses of Eurasia and mer, the gold in the fall, and the absence offoliage in the North America. Larch forests essentially encircle the North­ winter are but a part ofthe charm that this unique genus ern Hemisphere, stretching from eastern westward adds to its environs. across Eurasia (but presently absent in Scandinavia), re­ The 10 most commonly recognized larch species and their suming in eastern North America and westward across the general distribution are listed in table 1. In addition to United States and Canada to Alaska, where except for the these 10 species there are a large number of subspecies and Bering Sea, they essentially reach our starting point back hybrids where natural ranges of species overlap. Larch tax­ in Siberia (fig. 1). But along that approximate 20,000-km onomy has had little attention internationally. The last real (12,000-mile) path, larch splits into 10 species and numerous defmitive examination was over 60 years ago by Ostenfeld varieties and hybrids. These 10 species occupy a wide vari­ and Larsen (1930). This is reflected in the lack of total ety of ecological conditions and zones ranging from lowland agreement in the international literature about what consti­ boreal to upper montane to upper subalpine conditions and tutes a Larix species or a subspecies. It is the age-old tax­ extend south to 25° latitude at high elevations and north to onomy discussion between the "splitters and the lumpers." 75° latitude in the boreal lowlands. Splitting the species into subspecies often makes biological Larches have been in the same general area for a long sense at the local or regional level, but in the larger context time. Larch fossils recovered from sediments laid down in it makes generalizations difficult. For the purposes of this the Oligocene to the Holocene eras have been described in introduction, generalization to 10 species is in order, but for North America, Europe, and Asia. More species oflarch papers within this proceedings, breakdowns into subspecies have already gone extinct than the 10 presently surviving and hybrids are described that certainly prove helpful in species. Fossil larch have been found in northern Canada, relating to individual research activities around the world. Poland, , Japan, and Alaska, U.S.A. Lepage and To more readily illustrate the magnitude of and differences Basinger (1991) list many of the fossil species described in in Larix species distribution, I have divided the northern the world literature and describe in detail excellent fossil temperate zone into four geographic areas: North America, remains of Larix altoborealis found in the Canadian Arctic. Europe, Northern Asia, and Southern Asia (figs. 2, 3, 4, 5). AlllO larches are in the genus Larix, a needle­ Larix distributions shown here are only approximate and gymnosperm in the family . Although similar are based on adaptations made from maps and narratives in appearance, shade tolerance, and deciduous character, from several sources. Most ofthe descriptions in the litera­ larch species do differ substantially in growth, ability to ture are in at least partial, but usually not total, agreement. establish on different substrates, and ability to compete Good defmitive information on exact ranges of the species successfully with associated species. Larch's deciduous is just not available in some cases. characteristic clearly distinguishes the genus from ever­ Species boundaries in North America are relatively well green conifers with which it is almost always associated. defmed with practically no overlap between L. laricina, L. Larches are the exception in the characteristically ever­ occidentalis, and L. lyallii (fig. 2). Although L. occidentalis green world of the northern boreal and mountain subalpine and L. lyallii occur in much the same geographic area, they forests of the northern hemisphere. They possess morpho­ are usually elevationally separated by 300 to 500 m. Excep­ logical and physiological characteristics that distinguish tions to this are noted in this proceedings. them from their evergreen or deciduous counterparts and Larix laricina forests are by far the most extensive of the likely provide them with unique establishment and survival three species in North America, stretching from the east advantages. But they do well in spite oftheir differences, to the west of Canada and into Alaska, U.S.A. Its largely especially in adding the diversity that is advantageous to boreal habitat contrasts sharply with that of the upper associated flora and fauna. Aesthetically, Larix species have montane/subalpine habitat of L. occidentalis. no real match in the evergreen world of temperate forest Only one species of Larix occurs naturally in Europe. Larix decidua most commonly occurs in the subalpine habi­ tat of the Alps, but it also occurs in other areas of central Europe (fig. 3). Different subspecies and varieties are com­ monly recognized there and are described in this proceedings. Larix russica (often referred to as ) and L. Paper presented at the Symposium on Ecology and Management of gmelinii dominate the Siberian forest landscape in North­ Larix Forests: A Look Ahead, Whitefish, MT, U.S.A., October 5-9, 1992. ern Asia, with L. russica to the west and L. gmelinii to the Wyman C. Schmidt, Forestry Sciences Laboratory, Intermountain Re­ east (fig. 4). Their major boundary is contiguous in a gen­ search Station, Forest Service, U.S. Department of Agriculture, located at Montana State University, Bozeman, MT 59717-0278, U.S.A. erally north-south direction for thousands of kilometers,

6 WORLD DISTRIBUTION OF LARIX

Figure 1-Natural range of the genus Larix throughout the World (adapted from Krlissman 1985).

Table 1-The 10 commonly recognized species of larch with their general location and ecological situation.

Latin name Common name General location Ecological zones Larix occidentalis Western larch Rocky and Cascade Mountains of U.S. and Canada Upper montane to lower subalpine Larix Iyallii Alpine larch Rocky and Cascade Mountains of U.S. and Canada Upper subalpine to timberline ecotone Larix laricina Tamarack Northeastern and Lake States and Alaska in U.S. Mainly boreal and a wide belt completely across Canada Larix russica Siberian larch A wide belt in northern Russia and in Boreal to northern timberline Larix gmelinii Asian larch Eurasia east of the Siberian larch range Subalpine to (includes L. dahurica, northern olgensis, cajanderi, timberline other subspecies) Larix mastersiana Masters larch Mountain areas in south Upper montane to lower subalpine Larix griffithiana Sikkim larch Himalayas in Nepal, Bhutan, Tibet and south China High subalpine Larix potaninii Chinese larch Western China High subalpine Larix leptolepis Japanese larch Honshu,Japan Subalpine Larix decidua European larch Alps area in France, Switzerland, Austria, Italy, Subalpine Yugoslavia, Germany with scattered areas in Romania, Czechoslovakia, and Poland

7 NORTH AMERICA

_ Larix Iyallli

iii Larix occldentalis 200 400 600 100 1000 kilo.".., I I I I ! 111111111111 Larix larlclna Jo In Jx,maloI

Figure 2-Natural range of Larix species in North America (adapted from Johnston 1990; Arno 1990; Schmidt and Shearer 1990).

and where their boundaries overlap L. x czekanowski (=L. For at least 200 years people have carried seed from one russica xL. gmelinii) is often recognized. Within the wide continent to the other in hopes of fmding the perfect Larix range of L. gmelinii there are numerous regionally recog­ species for their area. As a result, plantations of introduced nized subspecies or varieties such as L. cajanderi in north­ Larix can be observed at many locations in the world, par­ eastern Siberia, L. olgensis on the east coast of Russia and ticularly in Europe and eastern North America (Kriissman down into Korea, L. principis-rupprechtii in northeast 1985). Genetics research, particularly with hybridization China, and L. kurilensis and L. kamtschatica on objectives, has been extensive. Some hybrids exhibit supe­ Island and Kamchatka. These are described in other pa­ rior growth and survival characteristics, and some of that pers within the proceedings. information is presented in this proceedings. Southern Asia accounts for a wide variety of Larix species, The value of Larix forests for wood products, animal ranging from the montane conditions of L. mastersiana in habitats, water production, aesthetics, and other resources southwestern China to the high elevation forests of L. grit­ is impressive, but the values vary tremendously by species fithiana in Nepal, Bhutan, and Tibet, and L. potaninii in and ecological zones. These forests harbor a wide comple­ southwestern China to the island environment of L. lep­ ment of fauna ranging from the moose to the mouse, the tolepis on Honshu in Japan (fig. 5). Larix mastersiana bear to the shrew, and the eagle to the hummingbird, not and L. leptolepis are unique, along with L. lyallii in North to mention the vast array of micro flora and fauna, as yet America, in having limited, but important, ranges. only generally comprehended. Many of these values and To the casual observer most Larix species look essentially ecological principles of this truly international genus are the same, but their cone and needle characteristics and par­ described in this proceedings. ticularly their ecological niches separate them. Some of these characteristics are illustrated in figure 6.

8 EUROPE

40" 50"

o 200 400 600 IlOO 1000 kilo I I!' I i I 200 A()() (:J:XJmllu

Larix decidua .0·

"\,.,\ ...... ~ ,.~ .~) Belorussia -;:-: ": :i,\ ······· .... :··,···.. ·t. Ukraine 50·

Figure 3-Natural range of Larix species 4"" 40· in Europe (adapted from Ostenfeld 1930; Gower and Richards 1990; Holtmeier, this proceedings).

Northern Asia

o "

_ larix gmelinil larix russlca 200 400 600 800 un} kilomokn iii::: ililllill larix leptolepis I I I I I I I I I russlcalgmelinii China o ax> 400 600 mil ..

Figure 4-Natural range of Larix species in Northern Asia (adapted from Ostenfeld and Larsen 1930; Gower and Richards 1990; Milyutin and Vishnevetskaia, this proceedings). The area shown as russicalgmelinii is often referred to as L. x czekanowski, and the area in northeast China shown as L. gmelinii is often referred to as L. principis-rupprechtii.

9 SOUTHERN ASIA

...... _ Larix gmellnii Ililllilll Larix leptolepls Ili ~~lliliii Larix potaninil _ Larix mastersiana 11111111111Larix griffithiana

.). -.,.,

.l; • • '

o 200 400 600 800 1000 kilometer• . I iii i o 200 400 600 milea

Figure 5-Natural range of Larix species in Southern Asia (adapted from Ostenfeld and Larsen 1930; Gower and Richards 1990; Wang, this proceedings). The area shown as russicalgmelinii is often re­ ferred to as L x czekanowski, and the area in northeast China shown as L gmelinii is often referred to as L principis-rupprechtii.

REFERENCES Lepage, Ben A; Basinger, James F. 1991. A new species of Larix (Pinaceae) from the early tertiary of Axel Heiberg Arno, Stephen F. 1990. Larix lyallii. In: Agriculture Hand­ Island, Arctic Canada. Review of Palaeobotany and Pa­ book 654. Washington, DC: U.S. Department of Agricul­ lynology, Elsevier Science Publisher B.V., Amsterdam. ture, Forest Service: 152-159. 70: 89-111. Gower, Stith T.; Richards, James H. 1990. Larches: Decidu­ Ostenfeld, C.H.; Larsen, C.S. 1930. The species of the ge­ ous conifers in an evergreen world. Bioscience. 40(11): nus Larix and their geographic distribution. Kongelige 818-826. Danske Videnskabemes Selskab Biologiske Meddelelser. Johnston, William F. 1990. Larix laricina. In: Agriculture 9: 1-106. Handbook 654. Washington, DC: U.S. Department of Schmidt, Wyman C.; Shearer, Raymond C. 1990. Larix Agriculture, Forest Service: 141-151. occidentalis. In: Agriculture Handbook 654. Washington, Krtissman, G. 1985. Manual of cultivated conifers. Timber DC: U.S. Department of Agriculture, Forest Service: Press, Portland, OR. pp. 157-163. 160-172.

10 Figure 6-This series of photos depicts some of the characteristics of the world's Larix species.

Larix occidentalis

L. occidentalis in a fall landscape scene in west­ em Montana, U.S.A. A 15-year old L. occidentalis in the spacing study on Coram Experimental Forest, Montana, U.S.A.

A 300-year old stand of L. occidentalis on Coram Experimental Forest, Montana, U.S.A. Large trees are about 40 m tall and nearly 1 m An ovulate cone of L. occidentalis in the in- diameter. early spring. 11 Larix /yallii

Ovulate cones and emerging foliage of L. Iyallii A late September view of L. Iyallii, Carlton Ridge, in early spring. Bitterroot Mountains, Montana, U.S.A.

A robust stand of L. Iyallii, Carlton Ridge, Bitterroot Mountains, Montana, U.S.A.

A planted L. Iya/lii seedling.

12 -Larix laricina

A stand of L. laricina during the October needle fall period on a lowland in Alberta, Canada.

Larix laricina provenance trial in Alberta, Canada.

13 Larix russica

A mixed species forest of larch, birch, and pine in the fall season near Lake Baikal in Russia.

A mature forest in the steppe area of Mongolia.

14 Larix gmelinii -

A fall scene in an intermediate-age stand of the sub­ species L. cajanderi, Yakutia, Russia.

A vigorous young forest of L. gmelinii in Korea.

A landscape showing an extensive forest of L. gmelinii in Korea.

15 A young vigorous stand of L. gmelinii in northeast China.

A stand of L. gmelinii adjoining an agricultural area in northeast China.

Establishing weather instruments in a forest of the A plantation of L. gmelinii, subspecies o/gensis in subspecies L. o/gensis in northeast China. northeast China.

16 Larix mastersiana -

A branchlet and cone of L. mastersiana in south­ A I~c~-~ike crown showing the drooping charac­ west China. teristiC In a southwest China forest.

Larix potaninii

Mature cones of L. potaninii in southwest China.

17 Larix leptolepis

A vigorous intermediate age stand in Japan. A thinned intermediate age stand with a heavy understory in Japan.

Larix decidua

Intermediate age L. decidua in a mixed­ species stand of spruce and pine near st. Moritz. Switzerland.

18 Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald Vegetation Responses to Silviculture and Woody Residue Treatments in a Western Larch Forest Wyman C. Schmidt Carl E. Fiedler Ward W. McCaughey

Editor's Note: This is an abstract of a paper that will be pub­ shrubs to as little as 3 percent of the preharvest volumes lished separately from this proceedings. Inquiries regarding the on the clearcut and burned treatments. The average for study and data may be made through the authors at the addresses all treatments 2 years after treatment, however, was about listed at the bottom of this column. 20 percent of preharvest level. Ten years after treatment, shrub volumes averaged 50 to 70 percent of preharvest levels with shrubs on the group selections and clearcuts responding the most and those in the shelterwoods the Western larch forests commonly have luxurious under­ least. Residues treatments, particularly prescribed fire story vegetation that protects the site and provides signifi­ and protected understory tree treatments, also affected cant habitat for various wildlife species. Knowing how var­ understory response. ious forest management practices affect the response of The two burning treatments reduced shrub volume the shrub, forb, and grass components of the understory was most, and the treatment that attempted to protect the under­ one of the subjects of a multidiscipline study in a larch­ story trees resulted in the least reduction in shrub volume. Douglas-fir forest. This report describes 10-year response Herb cover and volume generally increased to greater than to the harvest cutting treatments: (1) clearcut, (2) shelter­ preharvest levels during the first 4 years after treatments. wood, and (3) group selection and residues disposal treat­ After that these values generany declined. At about 10 years ments. The third group included: (1) moderate level of they had declined to near preharvest levels. Ten years af­ woody residues followed by broadcast burning, (2) heavy ter treatment the number of different species found on the amount of residues followed by broadcast burning, (3) in­ study plots exceeded that in the original mature forest. All tense removal of all residues, and (4) understory tree pro­ of the increases were in the herb component of the under­ tected with moderate removal of woody residues. story vegetation. Residues treatments were superimposed on the three Understory vegetation in larch-Douglas-fir forests is re­ harvest cutting treatments, resulting in 12 combinations. sponsive to various combinations of harvest cutting and There were two replications. Also included for comparison residues removal treatments. Vegetation responses are were identical understory vegetation measurements in rapid for the first 2 to 4 years. This is followed by a gradual adjacent virgin natural forests. approach toward the levels found in mature forests. Long­ Understory vegetation responded substantially in the term multidisciplinary studies such as this help derme the first 10 years following treatments. The initial harvest trajectory of the gradual changes in understory and the re­ cutting and residues treatments reduced volumes oflive lationship to other forest values and ecological processes.

Paper presented at the Symposium on Ecology and Management of Larix Forests: A Look Ahead, Whitefish, MT, U.S.A., October 5-9, 1992. At the time of the study, Wyman C. Schmidt (retired) was Proj~ Leader and Research Silviculturist, Intermountain Research StatIon, For­ eat Service. U.S. Department of Agriculture, located at the Forestry Sci­ ences Laboratory, Montana State University, Bozeman. MT 59717-0278, U.S.A Carl E. Fiedler is Research Silviculturist, Montana Forest and Conservation Experiment Station, University of Montana, Missoula, MT 59812, U.S.A Ward W. McCaughey is Research Forester, Intermountain Research Station. Forest Service, U.S. Department of Agriculture, For­ estry Sciences Laboratory, Montana State University. Bozeman, MT 59717-0278. U.S.A.

375 Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald Western Larch Growth and Perturbations in Stands Regulated for 30 Years Wyman C. Schmidt Ward W. McCaughey JackA. Schmidt

Editor's Note: This is an abstract of a paper that will be pub­ also related to stand density with the larch growing fastest lished separately from this proceedings. Inquiries regarding the in the less dense stands. However, height response on the study and data may be made through the authors at the addresses different densities was far less pronounced than diameter. listed at the bottom of this column. Three m~or problems occurred during the 30 years. About 5 years after the 9-year-old stand was thinned a ma­ jor storm of heavy wet snow in June flattened the young forest. Although crooks in the bole of the trees are still ap­ Western larch is one of the most rapidly growing coni­ parent in some trees 25 years later, overall the young forest fers in mountain forests of the Western United States and had practically no mortality from the extreme snowbend and Canada. Overstocking is a common problem that can sub­ recovered remarkably well. Western spruce budworm can stantially reduce the potential growth oflarch. It is one of sever the terminal and upper lateral stems oflarch. For sev­ the most significant problems in managing naturally regen­ eral years we experienced relatively severe damage to form erated forests. Thinning offers great silvicultural opportu­ quality and some reduction in height growth due to ­ nities in young larch forests. worm damage before budworm populations collapsed. Black We established a long-term, permanent plot study in 1961 bear can be a significant management problem in some ar­ to determine the effects of different levels of regulated stand eas, and this study helped identify the type and extent of densities on individual tree and stand growth. Also exam­ damage and its relationship to stand density. Bear feed ined was the relationship of these different stand densities on the inner bark of larch in the spring and often kill the to perturbations such as insect, animal, snow, and other tree by completely girdling it. Bear damage was most se­ types of damage to the trees. We now have 30 years of these vere where trees were largest and most vigorous in stands measurements and observations. with the fewest trees. Diameter growth of the shade-intolerant larch was very These results help define appropriate management strat­ responsive to stand density, with the greatest individual egies in young western larch forests. tree growth in the least dense stands. Height growth was

Paper presented at the Symposium on Ecology and Management of Larix Forests: A Look Ahead. Whitefish. MT. U.S.A .• October 5-9. 1992. At the time of the study. Wyman C. Schmidt (retired) was Project Leader and Research Silviculturist. Intermountain Research Station. For­ est Service. U.S. Department of Agriculture. located at the Forestry Sci­ ences Laboratory. Montana State University. Bozeman. MT 597~7-0278. U.S.A. Ward W. McCaughey is Research Forester. Intermountam Re­ search Station. Forest Service. U.S. Department of Agriculture. Forestry Sciences Laboratory. Montana State University. Bozeman. MT 59?17-0278. U.S.A. Jack A. Schmidt is Forester. Intermountain Research StatIOn. For­ est Service. U.S. Department of Agriculture. Forestry Sciences Laboratory. P.O. Box 8089. Missoula. MT 59807. U.S.A.

281 Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald Natural Regeneration Mter Harvest and Residue Treatment in a Western Larch Forest of Northwestern Montana, U.S.A. Raymond C. Shearer JackA. Schmidt

Editor's Note: This is an abstract of a paper that will be pub­ quickly resumed for Douglas-fir and more slowly for Engel­ lished separately from this proceedings. Inquiries regarding the mann spruce and subalpine fir. study and data may be made through the authors at the address Natural regeneration began in 1975; western larch regen­ listed at the bottom of this column. erated mostly on soil exposed during yarding of logs, and western hemlock on moist sites, especially near the bottom of the lower elevation units. By 1979, an average of 1,435 seedlings per ha were counted on all units: 808 larch, 571 Historically, major disturbance, usually wildfIre, pre­ Douglas-fir, 10 subalpine fir, 15 spruce, 21 hemlock, 5 west­ ceded regeneration of western larch (Larix occidentalis) ern redcedar (Thuja plicata), and 5 lodgepole pine (Pinus in the forests of the Northern Rocky Mountains. Obser­ contorta). Although the average number of seedlings ex­ vation and research show that establishment of western ploded to 16,494 per ha in 1992, the average number oflarch larch and other conifers is enhanced by coupling timber decreased to 649 seedlings. Quick recovery of shrubs and harvest with site preparation that exposes some mineral herbs virtually stopped establishment of new larch by the soil. But regeneration probability decreases, especially early 1980's. for shade-intolerant species such as western larch, when In contrast, Douglas-fir regenerated prolifically during there is little disturbance. This research tracked estab­ the 1980's and averaged 15,120 seedlings per ha in 1992. lishment of natural regeneration as influenced by harvest The number of subalpine fir and Engelmann spruce seed­ cutting method and forest residue reduction treatments, lings continued to increase slowly within all units: to 268 including light prescribed fIre, on the Coram Experimental subalpine fir per ha and to 175 spruce per ha in 1992. Also, Forest located in northwestern Montana, U.S.A. western hemlock and western redcedar increased in num­ In 1974, on an east-facing slope, a forest comprised bers to 160 and 36 seedlings per ha in 1992 mostly on the mostly of overstory Inland Douglas-fIr (Pseudotsuga men­ warmer, moister areas of the lower elevation units. Lodge­ ziesii) and western larch was harvested using three meth­ pole and western white pine (Pinus monticola) were occa­ ods of harvest cutting: a shelterwood, a clearcut, and a set sionally represented. of eight small group selection cuttings, within each of two Composition of natural regeneration in 1979 was, in elevational zones. The lower units lay between 1,195 and percentage: western larch 59, Douglas-fir 38, and all other 1,390 m and the upper units between 1,341 and 1,615 m. species 3. Percentage stocking of 0.0004 ha plots was 16 Each shelterwood, clearcut, and set of group selections re­ for western larch, 11 for Douglas-fir, and less than 1 for ceived four levels of timber and residue utilization. Moist other species. In 1992, 18 years after treatment, percentage fuels on about half of each area were prescribed burned in natural regeneration was composed mostly of Douglas-fir September 1975. at 92, western larch 4, and all other species 4. Percentage The interaction of poor site preparation, low cone pro­ stocking was 60 for Douglas-fir, 15 for larch, 6 each for duction, and high seed mortality initially limited natural spruce and subalpine fir, 4 for western hemlock, 2 for west­ regeneration. At the outset of this study in 1974, a serious ern white pine, and 1 each for western redcedar and lodge­ western spruce budworm (Choristoneura occidentalis) out­ pole pine. break was ongoing in the study area. Budworm larvae Without subsequent disturbance, the new forest will be killed most potential seed cones of subalpine fir (Abies lasi­ dominated by Douglas-fir both in the overstory and under­ ocarpa), Inland Douglas-fir, and Engelmann spruce (Picea story. Occasional groups or individual western larch will engelmannii) that year, but larch and western hemlock also occur in the overstory, mostly where soil was exposed (Tsuga heterophylla) disseminated considerable seed. The during logging or where prescribed fIre decreased the duff budworm population collapsed in 1975, and cone production layer. Subalpine fir and Engelmann spruce will slowly in­ crease in the understory throughout the units. Western hemlock and western redcedar will be limited to the warmer, moist areas on the lower elevation units. Occasional lodge­ pole pine will mature as an overstory tree and may provide a temporary seed source following a future disturbance, Paper presented at the Symposium on Ecology and Management of especially fire. Because of its greater shade tolerance, the Larix Forests: A Look Ahead, Whitefish, MT, U.S.A., October 5-9, 1992. Raymond C. Shearer is Research Forester and Jack A. Schmidt, For­ few western white pine will continue in this stand in the ester, Intermountain Research Station, Forest Service, U.s. Department overstory and understory unless killed by the white pine of Agriculture, located at the Forestry Sciences Laboratory, 800 East Beckwith Ave., Missoula, MT 59807-8089, U.S.A. blister rust (Cronartium ribicola).

169 Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald Appendix B: International Larix Arboretum, Coram Experimental Forest Headquarters, Hungry Horse, Montana, U.S.A. Raymond C. Shearer JackA. Schmidt Wyman C. Schmidt

The Larix Symposium provided the impetus to establish tion by attendees from North America, Europe, and Asia, an arboretum that features all Larix species of the world and by teachers and students from the nearby Hungry (figs. 1 and 2). This International Larix Arboretum, estab­ Horse elementary school (figs. 3 and 4). This symbol of lished on a 0.5 ha (1.2 acre) site next to the headquarters global cooperation will not only provide a visual demon­ of the Coram Experimental Forest and near the Hungry stration of larch internationale, but it is designed to pro­ Horse Ranger Station, was dedicated October 7,1992, with vide opportunities for species comparisons and genetics a tree-planting ceremony that had international participa- research.

Figure 1-Logo for the International Larix Arboretum at Coram Experimental Forest.

All authors are with the Intermountain Research Station, Forest Service, U.S. Department of Agriculture. For further information about this arboretum, contact Project Leader, Subalpine Silviculture Research Work Unit, Forestry Sciences Laboratory, Missoula, MT 59812.

518 Figure 2-An overview of the International Larix Arboretum, Coram Experimental For­ est, May 1993. Note the shade cards used to increase seedling survival.

Figure ~Attending the dedication of the International Larix Arboretum at Coram Experimental Forest, Montana, are: (from left to right) Klara Vishnevetskaia, from Moscow, Russia (currently a graduate stu­ dent at Toronto); Dr. Leonid I. Milyutin, from the Institute of Forests and Wood, Siberian Branch of Russian Academy of Science, Krasnoyarsk, Russia; and, Prof. Dr. Friedrich-Karl Holtmeier, Westfalische Wilhelms-Universitat, Munster, Germany.

- -,----

Figure 4-During dedication ceremonies of the International Larix Arboretum, Mrs. Sung-Cheon Hong, from Daegu, South Korea, helped plant a tree with Intermoun­ tain Station Forester Jack Schmidt, right, and a student from Hungry Horse, Montana, Elementary School.

519 The arboretum is divided into three equal-sized blocks, species, subspecies, and hybrids in each of the three blocks about 21.3 m x 70 m (70 ft x 230 ft). Within each block for a total of nearly 600 trees. The species, subspecies, Larix seedlings are randomly planted every 1 m (5 ft) in and hybrids that are (or will be) planted are: rows 3 m (10 ft) apart. The design calls for 12 trees of each

Common name Species name Comments Date planted Larix species European larch L. decidua Sept. 2,1992 Asian larch L. gmelinii Includes dahurica Sept. 3,1992 Sikkim larch L. griffithiana Not planted Tamarack L./aricina Sept. 2 and 8, 1992 Japanese larch L. /epto/epis Formerly kaempferi Sept. 3,1992 Alpine larch L./yallii Sept. 17, 1992 Masters larch L. mastersiana Sept. 15, 1993 Western larch L. occidentalis Sept. 17, 1992 Chinese larch L. potaninii Sept. 16, 1993 Siberian larch. L. russica Formerly siberica Sept. 3 and 8, 1992 Larix subspecies Polish larch L. decidua, ssp. p%nica Sept. 3,1992 Sudetic larch L. decidua, ssp. sudetica Sept. 3,1992 Olga Bay larch L. gmelinii, ssp. o/gensis Sept. 3,1992 Larix hybrids Dunkeld larch L. x euro/epis L. decidua [pollen] and L. /epto/epis Sept. 3 and 8, 1992 Bitterroot larch L. x occilyal L. occidentalis [pollen] and L. /yallii Sept. 17, 1992 Bitterroot larch L. x Iyalocci L. /yallii [pollen] and L. occidentalis Sept. 18, 1992

Source information for Larix species, subspecies, and hybrids in the International Larix Arboretum, Hungry Horse, Montana North East/West latitude longitude Common name Species name Provenance Degree Minute Degree Minute Elevation (m) Larix species European larch L. decidua 55 49 12 23E Asian larch L. gme/inii 47 00 127 ODE (includes dahurica) Sikkim larch L. griffithiana ------Not planted yet because no seed received------Tamarack L. /aricina Murray Twnshp 44 12 77 44W 120 Japanese larch L. /epto/epis ------Information not available ------(formerly kaempfefl) Alpine larch L. /yallii 46 42 114 11W 2,800 Masters larch L. mastersiana ------Information not available ------Western larch L. occidenta/is 46 56 113 42W 1,200 Chinese larch L. potaninii ------Information not available------Siberian larch L. russica Krasnoyarsk (formerly siberica) Larix subspecies Polish larch L. decidua, ssp. 46 00 77 25E 130 p%nica Sudetic larch L. decidua, ssp. ------Information not available ------sudetica Olga Bay larch L. gmelinii, ssp. Jilin 43 00 126 ODE o/gensis Larix hybrids Dunkeld larch L. x euro/epis ------Information not available ------370 (L. decidua [pollen] & L. /epto/epis) Bitterroot larch L. x occilyal 46 42 114 11W 2,800 (L. occidentalis [pollen] & L. /yal/i!) Bitterroot larch L. x Iyalocci 46 56 113 42W 1,200 (L. /yallii[pollen] & L. occidentalis)

520 CEREMONIAL PLANTING-INTERNATIONAL LARIX ARBORETUM, 7 OCTOBER 1992

A seedling of most of the larch species were planted along the north edge of the arboretum at its dedication. Those who planted these trees were:

Larix species Planter's name(s) City and country Affiliation

Larix leptolepis Fukio Takei Naganoken, Japan Nagano Prefectural Japanese larch Forestry Research Center Larix gmelinii Yeh-chu Wang Harbin, Peoples Ecological Research Asian larch Republic of China Group, Northeast Forestry University Larix russica Prof. Leonid I. Milyutin Krasnoyarsk, V.N. Sukachev Institute Siberian larch Russia of Forest, Siberian Branch, Russian Acad. of Science Larix decidua Friedrich-Karl Holtmeier Munster, Germany Landscape Ecology, European larch Westfalische-Wilhelms- Universitat Larix occidentalis Katrine Berg Hungry Horse, Student, Hungry Horse Western larch Montana, U.S.A. Elementary School AI Christophersen Columbia Falls, Ranger, Hungry Horse Montana, U.S.A. District, Flathead NF

Larix Iyallii Jack A. Schmidt Missoula, Montana Intermountain Research Alpine larch U.S.A. Station, FSL, Missoula, Montana, U.S.A. Larix laricina Joseph Fisher Hungry Horse, Student, Hungry Horse Eastern larch Montana, U.S.A. Elementary School or tamarack Don Fowler Fredericton, New Forestry Canada Brunswick, Canada Larix occidentalis Clinton E. Carlson Florence, Montana Intermountain Research x Iyallii U.S.A. Station, FSL, Western x Alpine Missoula, Montana, U.S.A. hybrid; WL pollen Larix eurolepis Claudette Berg-Rink Hungry Horse, Student, Hungry Horse European x Japan Montana, U.S.A. Elementary School hybrid; EL pollen Hans G. Schabel Stephens Point, WI University of Wisconsin Larix Iyallii Bob Muth Hungry Horse, Sixth Grade Teacher, x occidentalis Montana, U.S .A. Hungry Horse Alpine x Western Elementary School hybrid; AL pollen Larix gmelinii Gabe Buzzell Hungry Horse, Student, Hungry Horse spp. olgensis Montana, U.S.A. Elementary School Olga Bay larch Mrs. Sung-Cheon Hong Daegu, Republic of Kyungpook National South Korea University

Note: On September 17, 1993, Susan Colt planted Larix mastersiana and Jack A. Schmidt planted L. potaninii in the International

A paved road, a sidewalk, and a 1.5 m (5 ft) wide strip National Park Native Plant Nursery. The arboretum is planted with native shrubs form a border around the In­ enclosed by a 2.4 m (8 ft) high chain link fence that pro­ ternational Larix Arboretum. Shrubs planted in this strip tects the young larch from damage by large herbivores are mostly snowberry (Symphoricarpos albus), red-osier (deer, elk, moose) or by people driving vehicles or snow­ dogwood (Comus stolonifera), rose (Rosa woodsii), and mobiles across the area. chokecherry (Prunus virginiana), all from the Glacier

521 Ecology and Management of Larix Forests: A Look Ahead Proceedings of an International Symposium

Whitefish, Montana, U.S.A. October 5-9, 1992

Compilers:

Wyman C. Schmidt Kathy J. McDonald