Management Recommendations
for
Threeleaflet goldthread (Coptis trifolia (L.) Salisb.)

v. 2.0

by

M. Stein

December 1998

TABLE OF CONTENTS

EXECUTIVE SUMMARY

Species: Coptis trifolia (L.) Salisb. (Threeleaflet goldthread)

Taxonomic Group: Vascular Plants

ROD Components: 1, 2

Other Management Status: R6 Regional Forester's Sensitive Species List, Bureau of Land Management Assessment Species, Oregon Natural Heritage Program List 2; species that are threatened, endangered, or possibly extirpated from Oregon, but are more common or stable elsewhere.

Range: Coptis trifolia follows a circumboreal range from Greenland to Alaska and eastern Asia south to North Carolina, Iowa, Idaho, and Oregon. Within the range of the northern spotted owl, the species is known from 3 sites in Clackamas and Wasco Counties, Oregon. The 2 Clackamas County sites are located on federal lands managed by the Mt. Hood National Forest. The 1 site in Wasco County is located on Confederated Tribes of the Warm Springs land.

Specific Habitat: In Oregon the species inhabits the margins of boggy, wet, seepage areas within mature coniferous forests in the Western Hemlock and Silver Fir Zones at an elevation of 1000 to 1170 meters (3280 to 3800 ft.) above sea level. Plants typically grow on organic substrates, including decayed wood. Habitat within the main portion of the species' range appears to be similar to that in Oregon with the exception of a tree component that may be lacking farther north in muskeg habitat.

Threats: Activities that alter Coptis trifolia habitat or directly impact individual plants may threaten population viability. These actions include changes to hydrologic function, a loss of down wood recruitment, soil disturbance, or any action that results in mechanical damage to plants.

Management Recommendations:

1. Maintain habitat conditions at all known sites including inputs of down wood 18 inches in diameter and greater, hydrologic function, light levels, and undisturbed soils.
2. To provide for down wood inputs of 18 inches in diameter and greater, a mature tree component needs to be maintained at each site. To assure future inputs, no salvage of dead, dying, diseased or insect infested trees should take place within or adjacent to Coptis sites.
3. Hydrologic function, as a consideration for Coptis trifolia, equates to maintaining the water table at its current level. Activities that could alter flows, including road construction, culvert placement, and the manipulation of vegetation should be avoided.
4. Canopy closures between 25 to 60 percent should be maintained at each site to provide for proper light levels. This is the level currently found at known sites.
5. Coptis trifolia occurs in a narrow band of habitat immediately above the zone of saturated soil during the growing season. It is, therefore, likely to be shallow-rooted and prone to be adversely affected by soil disturbance. Avoid any activities that may lead to soil disturbance or mechanical damage and trampling of plants.

Information Needs:

• Current population trends of known sites.
• Ecological requirements of the species.
• Genetic relationships between known Oregon sites and populations within the main portion of the species' range.
• Pollination and seed dispersal mechanisms.

I. NATURAL HISTORY

A. Taxonomic/Nomenclatural History

Coptis trifolia was first described as Helleborus trifolius by Linnaeus in 1753. The current epithet was published in 1807. Helleborus pumilus is the only other synonym used (Hitchcock et al. 1964). Various authorities have segregated eastern and western races based on sepal and seed shape as well as other minor characteristics. Based on these distinctions, the races have, at various times, been assigned the rank of both species and subspecies. Oregon plants are now placed under the subspecies trifolia, along with other populations from the Pacific coast of North America and Asia. Plants of eastern North America and Greenland are placed in the subspecies groenlandica (Fern.) Hult. (Calder et al. 1968; Hulten 1968; Kartesz 1994).

B. Species Description (Hitchcock et al. 1964; Pojar and MacKinnon 1994; Hulten 1968.)

1. Morphology

Coptis trifolia is an evergreen, perennial herb from 4-10 cm (1.6-4.0 inches) tall. The leaves are shiny and dark above, paler below, and basally attached. Each leave is divided into 3 subsessile, toothed leaflets. The leaf blade measures 1-2 cm (0.4-0.8 inches) in length (Figure 1). Plants form small, compact mats due to its rhizomatous habit. The rhizomes are bright yellow in color, a characteristic common to all species in the genus, which accounts for the common name, goldthread.

Each plant may produce one flower, which has 5 whitish sepals 5-10 mm (0.2-0.4 inches) long and 5 hollow, fleshy, club-shaped orange petals, that produce nectar at the tip. The petals are about half as long as the sepals. Flowering generally occurs in June.

Fruits are a follicle measuring 5-10 mm (0.2-0.4 inches) long and are cup-shaped with a suture on the upper surface.

Coptis trifolia most closely resembles Coptis occidentalis (western goldthread), which does not occur within the range of the northern spotted owl. Within the known range of Coptis trifolia in Oregon, Coptis laciniata (cut-leaf goldthread) is sympatric and differs by having leaflets that are deeply lobed as opposed to leaflets that are not appreciably lobed.

2. Reproductive Biology

No published information could be found on the reproductive biology of Coptis trifolia. Casual observation of Oregon populations suggests that the species reproduces both vegetatively from rhizomes and from seed. Contrary to some references about the paucity of flowering, Oregon sites were found to be flowering in profusion when visited in 1992 and 1996. The nectiferous petals appear to be attractive to solitary bees and hover flies (family Syrphidae).

Figure 1. Coptis trifolia (line drawing from Hitchcock et al. 1964).

Reprinted by permission of the University of Washington Press

3. Ecology

Little is known of the ecology of Coptis trifolia. A study of the species Coptis aspleniifolia, (Tappeiner and Alaback 1988) may be used to infer a strategy for Coptis trifolia. The study, which looked at seed germination, seedling establishment, and clonal growth development, took place in various age stands of Tsuga heterophylla-Picea sitchenensis forest in Alaska. The study concluded that the species' slow growth rate, low rate of fruit production, evergreen leaves, and clonal growth habit appear to make it well suited as an understory species in old forests. These same characteristics result in slow establishment in young forest stands.

C. Range, Known Sites

Coptis trifolia has a circumboreal distribution extending from Greenland across North America to Alaska and into northeast Asia, south to northern Japan, British Columbia, Saskatchewan, Iowa, and North Carolina. The 3 known sites in Oregon (Figure 2) are disjunct some 450 kilometers (280 miles) south of the primary range in British Columbia (Madrono 1991). Subspecies trifolia includes those populations in Oregon, coastal British Columbia, Alaska, and Asia.

Two of the Oregon sites occur within Clackamas County, both on lands managed by the Mt. Hood National Forest. One Wasco County site is located on the Confederated

Tribes of the Warm Springs lands (USDA-USDI Appendix J2 1994, Oregon Natural Heritage Program 1995). All three known sites occur within a six mile radius.

Figure 2 - Distribution of Coptis trifolia in Oregon

D. Habitat Characteristics and Species Abundance

Coptis trifolia is described as inhabiting boggy, wet seepage areas (Pojar and MacKinnon 1994), sphagnum hummocks (Calder and Taylor 1968), muskegs to deep woods (Hitchcock et al. 1964), and mossy places (Hulten 1968). Known sites in Oregon are located within the western Hemlock Zone (Halverson et al. 1986) and Pacific Silver Fir Zone (Hemstrom et al. 1982) at an elevation of 1000-1170 meters (3280-3800 feet) above sea level. Precipitation ranges from 1500-2000 mm (60-90 inches) per year.

Oregon sites are associated with small wetland areas within mature coniferous forest. Soils are poorly drained histosols. This habitat is not uniformly wet, but a mosaic of small stream channels and boggy depressions interspersed with slightly higher, drier hummocks. The hummocks are the remains of large downed wood and the root masses of windthrown trees, while the depressions are likely the holes left by the displaced root masses. Typically, Coptis trifolia is found on the hummocks immediately above the level of saturated soil. This habitat often forms a narrow zone approximately 10-40 centimeters (4-16 inches) in width. Plants may be growing in either mineral soil or organic substrates, including decomposing wood. The three Oregon populations contain a total of approximately 5,000 stems of Coptis trifolia, covering an area of one half hectare (1.25 acres).

Canopy closure of the overstory tree component varies from 25 to 60 percent. Perhaps due to the high water table, snags and live trees with broken tops or sparse crowns are often present. Herbaceous vascular plants, mosses, and liverworts provide a ground cover of between 80 and 100 percent. Associated species include Tsuga heterophylla (western hemlock), Thuja plicata (red cedar), Pinus monticola (white pine), Pinus contorta (lodgepole pine), Abies amabilis (Pacific silver fir), Picea engelmannii (Engelmann spruce), Rhododendron macrophyllum (Pacific rhododendron), Menziesia ferruginea (Fool's huckleberry), Alnus incana (mountain alder), Taxus brevifolia (Pacific yew), Vaccinium ovalifolium (oval-leaf huckleberry), Gaultheria ovatifolia (slender wintergreen), Kalmia occidentalis (Western swamp laurel), Cornus canadensis (bunchberry), Caltha biflora (marshmarigold), Linnaea borealis (twinflower), Senecio triangularis (arrowleaf groundsel), Listera cordata (heart-leaf twayblade), Lysichitum americanum (skunk cabbage), Mitella pentandra (alpine mitrewort), and Sanguisorba occidentale (western burnet). Moss species associated with these sites include Pleurozium schreberi, Rhytidiadelphus loreus, Rhytidiadelphus triquetrus, Philonotis fontana, Eurhynchium praelongum, Dicranium fuscescens, Rhytidiopsis robusta, Hylocomnium splendens, Sphagnum sp., and the liverwort, Scapania americana.

II. CURRENT SPECIES SITUATION

A. Why Species is Listed Under Survey and Manage Standards and Guidelines

Coptis trifolia was rated 20-30-50-0 for Outcomes A, B, C, and D, respectively, under Option 9 (USDA-USDI FEMAT 1994) with the greatest probability given to Outcome C (50%), where the species is restricted to refugia with strong limitations on interactions among local populations. Oregon Coptis trifolia populations are disjunct 450 kilometers (280 miles), a significant extension from the southern edge of its range in British Columbia. The species requires small wetlands within mature or old-growth forest, with a component of down wood. Inventory data is lacking for this species, perhaps due to its diminutive stature, but it is assumed that more populations will be located in the future (USDA-USDI Appendix J2 1994). Species within the genus Coptis are collected for medicinal purposes but this does not appear to be a concern for Coptis trifolia at this time.

B. Major Habitat and Viability Considerations

Major considerations for maintaining the viability and habitat of Coptis trifolia include future inputs of down wood, hydrologic function, light levels, and undisturbed soils.

Oregon plants are most often found on low hummocks resulting from down wood and decomposed root wads. The maintenance of a mature forest component will provide for down wood 18 inches and greater in diameter.

Coptis trifolia sites in Oregon are all located within forested wetlands. Plants are found growing a few centimeters above the zone of saturated soil. It is, therefore, important to maintain the water level and hydrologic function at these sites.

Light levels are a consideration for habitat maintenance. Known sites in Oregon have canopy closures which range from 25 to 60 percent.

Soil disturbances may also be an important factor to consider. Individual plants occur just above the level where soils are saturated and the effective rooting zone may be very shallow for this species. Any action that damages this soil layer may adversely affect individual plants.

C. Threats to the Species

Due to the small number of populations occurring on federal lands, any loss of individuals should be considered a threat to the viability of this species within the range of the northern spotted owl. A loss of individuals may result from changes in habitat including altered hydrologic function, loss of the large tree component and corresponding loss of future down wood inputs, or mechanical damage to plants or soils. Asian species of Coptis are traditionally used as medicinal plants and collected for this purpose. This is not seen as a threat to Coptis trifolia at this time.

D. Distribution Relative to Land Allocations

The 2 known populations of Coptis trifolia on federal lands both occur within Riparian Reserves located in a Matrix allocation. The population on the Warm Springs Reservation is located approximately 6 meters (20 feet) from the Mt. Hood National Forest boundary. Land on the National Forest side of the boundary is within Matrix.

III. MANAGEMENT GOALS AND OBJECTIVES

A. Management Goals for the Taxon

The management goal for Coptis trifolia is to assist in maintaining species viability within the range of the northern spotted owl.

B. Specific Objectives

Until more information is gained on the ecological requirements of Coptis trifolia, specific management goals and objectives should be to maintain current hydrologic function, large woody inputs, a mature conifer overstory, and protect soils from disturbance at each known site.

IV. HABITAT MANAGEMENT

A. Lessons from History

It is not known to what extent, if any, populations have been affected by past actions.

B. Identification of Habitat Areas for Management

All known sites of Coptis trifolia should be managed to maintain population viability. Due to the close proximity of the Warm Springs Reservation population to National Forest System lands, actions on the National Forest side of the boundary should be assessed for affects to the Warm Springs Coptis trifolia site.

C. Management Within Habitat Areas

1. Maintain habitat conditions at all known sites including inputs of large down wood 18 inches in diameter and greater, hydrologic function, light levels, and undisturbed soils.
2. To provide for down wood inputs of 18 inches in diameter and greater, a mature tree component needs to be maintained at each site. To assure future inputs, no salvage of dead, dying, diseased or insect infested trees should take place within or adjacent to Coptis sites.
3. Hydrologic function, as a consideration for Coptis trifolia, equates to maintaining the water table at its current level. Activities that could alter flows, including road construction, culvert placement, and the manipulation of vegetation should be avoided.
4. Canopy closures between 25 to 60 percent should be maintained at each site to provide for proper light levels. This is the level currently found at known sites.
5. Coptis trifolia occurs in a narrow band of habitat immediately above the zone of saturated soil during the growing season. It is, therefore, likely to be shallow-rooted and prone to be adversely affected by soil disturbance. Avoid any activities that may lead to soil disturbance or mechanical damage and trampling of plants.

D. Other Management Issues and Considerations

Both Coptis trifolia sites on federal lands occur within Riparian Reserve Areas. As a component of the Aquatic Conservation Strategy (ACS), the objectives for the Reserves are to maintain and restore the distribution, diversity, and complexity of features to which riparian dependent species are adapted. These objectives are compatible with management of Coptis trifolia habitat.

The mechanisms that provide for down wood, such as insect and fungi pathogens, should also be considered a necessary function of habitat maintenance.

V. RESEARCH, INVENTORY, AND MONITORING NEEDS

The objective of this section is to identify opportunities for additional information which could contribute to more effective species management. The content of this section has not been prioritized or reviewed as to how important the particular items are for species management. While the inventory, research, and monitoring identified below are not required, these recommendations should be addressed by a regional coordinating body at the Northwest Forest Plan level.

A. Data Gaps and Information Needs

Coptis trifolia is an inconspicuous plant which has only been known from Oregon since 1991 and is easily overlooked. Additional inventory work is needed within areas of potential habitat to determine the extent of its range in Oregon and Washington. In particular, there should be a focus on the area between the Oregon sites and the species' primary range in British Columbia.

Very little information exists for Coptis trifolia. Any opportunity to gain knowledge on the ecology, demographics, genetics, or reproductive biology of this species should be pursued.

B. Research Questions

What are the genetic relationships between disjunct populations of Coptis trifolia in Oregon and plants within the main range of the species?

What are the dispersal mechanisms for Coptis trifolia?

What are the demographics of Coptis trifolia?

What is the pollination biology of Coptis trifolia?

C. Monitoring Needs and Recommendations

Basic monitoring information is needed to determine population trends at known sites.

VI. REFERENCES

Calder, J. A. and R. L. Taylor. 1968. Flora of the Queen Charlotte Islands Part 1. Agriculture, Research Branch. Monograph No. 4 part 1. Ottawa, Ontario.

Halverson, N. M., C. Topik, and R. Van Vickle. 1986. Plant Association and Management Guide for the Western Hemlock Zone. Mt. Hood National Forest. USDA Forest Service, Pacific Northwest Region, Portland, Oregon. R6-ECOL-232A-1986. 111 pp.

Hemstrom, M. A., W. H. Emmingham, N. M. Halverson, S. E. Logan, and C. Topik. 1982. Plant Association and Management Guide for the Pacific Silver Fir Zone, Mt. Hood and Willamette National Forests. USDA Forest Service, Pacific Northwest Region, Portland, Oregon. R6-ECOL-100-1982a. 104 p.

Hitchcock, C. L., A. Cronquist, M. Ownbey, and J. W. Thompson. 1964. Vascular Plants of the Pacific Northwest. Part 2: Salicaceae to Saxifragaceae. University of Washington Press, Seattle. 597 pp.

Hulten, E. 1968. Flora of Alaska and Neighboring Territories. A Manual of Vascular Plants. Stanford University Press. Stanford, California. 1008 pp.

Kartesz, J. T. 1994. A Synonymized Checklist of the Vascular Flora of the United States, Canada and Greenland. Volume 1. Timber Press. Portland, Oregon.

Madrono. 1991. Noteworthy Collections - Oregon. Madrono, Vol.38, No. 3, pp. 204-205.

Oregon Natural Heritage Program. 1995. Rare, Threatened and Endangered Plants and Animals of Oregon. Oregon Natural Heritage Program, Portland, Oregon. 84 pp.

Pojar, J. and A. MacKinnon. 1994. Plants of the Pacific Northwest Coast. B.C. Ministry of Forests and Lone Pine Publishing. Redmond, Washington. 527 pp.

Tappeiner, C. and P. B. Alaback. 1988. Early Establishment and Vegetative Growth of Understory Species in the Western Hemlock - Sitka Spruce Forests of Southeast Alaska. Can. J. Bot. 67: 318-326.

USDA, Forest Service, and USDI, Department of the Interior, Bureau of Land Management. 1994. Record of Decision for Amendments to Forest Service and Bureau of Land Management Planning Documents within the Range of the Northern Spotted Owl and Standards and Guidelines for Management of Habitat for Late-Successional and Old-Growth Related Species within the Range of the Northern Spotted Owl. Portland, OR.

USDA Forest Service and US Department of the Interior Bureau of Land Management. 1994. Final Supplemental Environmental Impact Statement on Management of Habitat for Late-Successional and Old-Growth Related Species Within the Range of the Northern Spotted Owl. Appendix A, Forest Ecosystem Management: An Ecological, Economic, and Social Assessment. Portland, OR.

USDA Forest Service and US Department of the Interior Bureau of Land Management. 1994. Final Supplemental Environmental Impact Statement on Management of Habitat for Late-Successional and Old-Growth Related Species Within the Range of the Northern Spotted Owl, Appendix J2, Results of Additional Species Analysis. Portland, OR.