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Conserving and restoring
America's native plants |
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CPC National Collection Plant Profile
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Arabis koehleri var. koehleri
| Family: |
Brassicaceae (Mustard or Crucifer Family) |
| Common Name: |
Koehler's rock cress |
| Author: |
Howell |
| Growth
Habit: |
Shrub |
| CPC
Number: |
180 |
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| Primary
custodian for this plant in the CPC National Collection of Endangered
Plants is: |
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| Edward Guerrant, Ph.D. contributed to this Plant Profile. |
Arabis koehleri var. koehleri
|
On a dry hill high above the rushing Umpqua River…precariously perched on a steep rocky outcrop …tucked into a small crack. That's where you will find the diminutive shrub, Arabis koehleri var. koehleri. Looking like something out of a Dr. Suess book, this tough, tufted member of the mustard family clings tenaciously to the rocky outcrops it calls home.
Koehler's rockcress has most likely always been a narrow endemic, whose overall range has probably not changed much since European settlement. While the range probably has not contracted much in the last 150 years, the number of populations and individuals has greatly decreased. Road construction, quarrying, livestock grazing, herbicide drift, and the construction of an electricity generating facility have all impacted populations.
To offset these losses, the Bureau of Land Management (BLM) and The Berry Botanic Garden are attempting a population augmentation. In 2001, researchers grew hundreds of plants in The Berry Botanic Garden greenhouse-using seeds collected by BLM staff from the wild. During the cool fall rains, researchers battled the slippery slopes and clung to the steep cliffs to place plants and directly sow seeds into appropriate habitat near existing Koehler's rockcress plants, carefully mapping and photographing their locations. Researchers collected data on the specific microhabitat that each plant or seed was placed in. Valuable knowledge about seed germination and plant growth in the wild as well as habitat and microhabitat requirements will be gained when researchers return in subsequent years and monitor the success of the introduced plants.
| Distribution
& Occurrence |
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State Range
Habitat
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Cracks and crevices on rocky bluffs and cliffs between approximately 730 and 1250 ft (225 and 280 m) in elevation. Found growing along with Phacelia sp., Sedum sp, and various mosses, selaginellas, and lycopodiums. |
Distribution
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Oregon: Umpqua River Valley, Douglas County |
Number Left
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9 occurrences (ONHP Data Base, 2000) with an unknown number of individuals. Only two sites are on federal land. Seven are on private property and are not protected (Holmes, pers comm.). |
State/Area
Protection
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State/Area |
Rank |
Status |
Date |
|
| |
Oregon |
S1 |
C |
2/1/2001 |
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| Conservation,
Ecology & Research |
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Ecological
Relationships
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Little is known about the ecology of this species. It grows on southwest- to northeast facing rock slopes, but most commonly on west-facing slopes (Holmes, pers. comm.). It is not known why the plant is a narrow endemic, inhabiting rock faces within only a short section of the Umpqua River Valley. |
Threats
| |
• Road construction (Holmes, pers. comm.).
• Railroad operations (Meinke 1982).
• Grazing by goats, cattle and other livestock (Holmes, pers. comm.).
• Herbicide drift (Meinke 1982).
• Rock quarry operations (Holmes, pers comm.).
• Fire (Holmes, pers. comm.).
• Noxious weeds (Holmes). |
Current Research Summary
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• Experimental population augmentation. Seeds and plants grown in the greenhouse from 9 different parent plants were planted in the wild in the fall of 2001. Researchers expect to gain valuable knowledge about seed germination and plant growth in the wild as well as habitat and microhabitat requirements. Ultimately, researchers hope to increase the population size and develop successful reintroduction methods (Berry Botanic Garden/BLM project).
• Germination trials conducted at The Berry Botanic Garden. A constant 68°F (20°C) temperature, with or without 8 weeks of cold stratification, yielded 100% germination (BBG File). |
Current Management Summary
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• Sites on BLM land are contained within the "North Bank Habitat Management Area." The area is managed for the continued survival and proliferation of Arabis koehleri var. koehleri. No management activity that would damage the population is allowed, including grazing, prescribed fire, and herbicide application (Holmes, pers. comm.).
• Seed from five populations is stored at the Berry Botanic Garden Seed Bank. |
Research Management Needs
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• Determine successful and practical reintroduction techniques (Holmes, pers. comm.).
• Augment existing populations. Reintroduce plants at historic sites (Holmes, pers. comm.).
• Analyze genetic variation within and between populations (Holmes pers. comm.).
• Study general ecology of this species, including: habitat requirements, life history, reproductive biology, etc. |
Ex Situ Needs
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• Collect and store seeds from all known populations. Keep maternal lines separate. |
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| Books (Single Authors)
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| Eastman, D.C. 1990. Rare and Endangered Plants of Oregon. Beautiful America Publishing Company. 194p. |
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| Meinke, R.J. 1982. Threatened and Endangered Vascular Plants of Oregon: An Illustrated Guide. Portland, Oregon: U.S. Fish & Wildlife Service, Region 1. 326p. |
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| ONHP. 2001. Rare, Threatened and Endangered Plants and Animals of Oregon. Portland, Oregon: Oregon Natural Heritage Program. 94p. |
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| Books (Sections)
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| Kartesz, J.T. 1999. A synonymized checklist of the vascular flora of the U.S., Canada, and Greenland. In: Kartesz, J.T.; Meacham, C.A., editors. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden. Chapel Hill, NC. |
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| Electronic Sources
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| ONHDB. (2000). Oregon Natural Heritage Program Database. Portland, Oregon. |
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| Journal Articles
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| 1897. (Original publication). Flora of North Western America. 44 |
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| Berge, G.; Nordal, I.; Hestmark, G. 1998. The effect of breeding systems and pollination vectors on the genetic variation of small plant populations within an agricultural landscape. Oikos. 81, 1: 17-29. |
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| Charlesworth, D.; Awadalla, P.; Mable, B.K. 2000. Population-level studies of multiallelic self-incompatibility loci, with particular reference to Brassicaceae. Annals of the Botanical Society of London. 85: 227-239. |
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| Koch, M.; Bishop, J.; Mitchell-Olds, T. 1999. Molecular systematics and evolution of Arabidopsis and Arabis. Plant Biology. 1, 5: 529-537. |
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| Kusaba, M.; Dwyer, K.; Hendershot, J. 2001. Self-incompatibility in the genus Arabidopsis: Characterization of the S locus in the outcrossing A. lyrata and its autogamous relative A. thaliana. Plant Cell. 13, 3: 627-643. |
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| Leeper, D.; Pavek, D.; Walsh, R.; Mitchellolds, T. 1992. Management of Arabis fecunda, a Threatened Plant. Northwest Environmental Journal. 8, 1: 200-201. |
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| Miyashita, N.T. 2001. DNA variation in the 5 ' upstream region of the Adh locus of the wild plants Arabidopsis thaliana and Arabis gemmifera. Molecular Biology and Evolution. 18, 2: 164-171. |
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| Roy, B.A. 1995. The Breeding Systems of 6 Species of Arabis (Brassicaceae). American Journal of Botany. 82, 7: 869-877. |
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| Ryser, P. 1993. Influences of neighboring plants on seedling establishment in limestone grassland. Journal of Vegetation Science. 4, 2: 195-202. |
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| Schwartz, A. Banking on Seeds to Avert Extinction. |
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| Personal Communications
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| Holmes, R. 2001. Botanist, Bureau of Land Management, Roseburg District, Roseburg, Oregon. Personal communication. |
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