The following Participating Institutions are custodians for this species in the CPC National Collection:
Rae Selling Berry Seed Bank & Plant Conservation Programs
The conservation of Calochortus umpquaensis is fully sponsored.
Edward Guerrant, Ph.D. contributed to this Plant Profile.
As its name suggests, Calochortus umpquaensis is only found along the Umpqua River in southwestern Oregon. It is restricted to serpentine soils, which characteristically have high concentrations of heavy, toxic metals. Despite its narrow range and specific soil requirements, this rare lily occurs within a broad continuum of habitats: from closed canopy coniferous forests to open grass-forb meadow.
On Aril 4, 1996, a conservation agreement was signed and implemented by the Bureau of Land Management (BLM), the Forest Service (USFS) and the Fish and Wildlife Service (USFWS). This agreement addressed the effects of timber harvest and cattle grazing on BLM lands. Already, the impact of this initiative is apparent. In the early 1990s 120,000 to 140,000 Umpqua mariposa lily individuals were estimated. By end of the 1990s, populations were estimated to total between 400,000 and 800,000 individuals on BLM lands alone. Based on this information, the Fish and Wildlife Service removed it from the list of Candidate for Endangered status in 1999 (USFWS 2000). It remains listed as endangered by the state of Oregon.
Distribution & Occurrence
Predominantly in grassland-forest ecotones on serpentine-derived soils (Fredricks 1989)
Serpentine soils (Fredricks 1992)
Broad range of habitats: from closed canopy coniferous forests to open grass-forb meadows. Predominantly in the ecotone (transition zone between the forest and meadow) (Fredricks 1992).
|2000: 14 populations (4 on BLM land), estimated 400,000 to 800,000 individuals on BLM land (USFWS 2000).|
Conservation, Ecology & Research
Even though it has a restricted range, C. umpquaensis is locally abundant and occurs within a rather broad continuum of habitats, from closed canopy coniferous forests to open grass-forb meadow. It is especially abundant in the transitional zone (ecotone) between the forest and meadows (Fredricks 1992).
In the coniferous forest, the overstory is composed of Pinus jeffreyi, Pseudotsuga menziessi, Calocedrus deccurrens and Arbutus menziesii. Meadows are species rich and dominated by grasses and herbaceous perennials. Within the meadow habitat, vegetation cover is patchy, with litter, bare soil, rock and moss openings of varying sizes (Fredricks 1992).
Since C. umpquaensis occurs across a wide range of habitats, Fredricks (1992) had an unusual opportunity to compare reproductive success, recruitment, and survival among a gradient of light, moisture, pollen vector and nutrient resource. Individuals were densest, produced more buds, and were on average larger in the ecotone habitat. The higher density did not seem to result from direct competition, since vegetative cover was highest in the ecotone. Rather, it is plausible that decreased light levels in the forest and low moisture in the meadow limited growth. C. umpquaensis may be more successful in ecotonal habitats because this area contains a combination of adequate moisture necessary for seedling survival and adequate light required for adult reproductive success. A high level of capsule abortion in forested habitats indicates that pollinators may also be less active in this cooler, shaded area (Fredricks 1992).
In demographic studies, there was a positive correlation between February through May precipitation and flower production. Correlations between precipitation, recruitment and mortality warrant further exploration (Fredricks 1992). Microhabitats strongly influence seedling establishment. Plants rarely establish in close proximity to other vegetation. In the forested habitat, the distribution of plants closely corresponds to the availability of leaf litter microsites. In the meadow, where desiccation posses a great threat, plants are found in mossy microsites. Litter is the preferred substrate for ecotonal plants (Fredricks 1992).
C. umpquaensis is restricted to serpentine-derived soils, but despite the rare occurrence of these soils, a considerable amount of apparently suitable habitat is unoccupied (Fredricks 1989b in Fredricks 1992). Most of these populations are small, but one located on public (BLM) land is extensive and conservation of this population is critical for the viability of the species (Fredricks 1992).
Reproductive output varies considerably across habitats. In general, the Calochortus life history is typical of long-lived herbaceous perennials: individual survival makes the largest contribution to growth rate, reproduction and mortality appear episodic, and reproductive success and seedling establishment appear to limit populations to certain habitats (Feidler et al. 1998).
Morphological differences among the widely separated populations indicate that the species may be diverging genetically, making it even more important to protect these distinct races (Fredricks 1992).
Logging and road construction (Fredricks 1989)
Bulb digging by collectors (Fredricks 1989)
Nickel mining (Fredricks 1989)
Competition from non-native vegetation
Seed biology studies and germination trials indicate that germination is stimulated by a long (12-14 week) period of cold, moist, dark stratification. This ensures that seeds only germinate in the spring, following the cold winter (Florance 1994).
Germination trials at The Berry Botanic Garden obtained 100% germination after 8 weeks of cold stratification followed by a constant 68F (20C) or alternating 50F/68F (10/20C) environment (BBG File).
In a three-year comparative demographic study, permanent plots were monitored at five sites comprising three different habitat types for C. umpquaensis and at two sites for C. coxii. Bud production was highest and plants were most dense and larger on average in the ecotone habitat (area between grassland and forest). Individual growth rates were higher among C. umpquaensis than among C. coxii, and it was less habitat-specific, suggesting that it is able to colonize. Transition matrix models indicated that the populations studied are projected to be stable rather than increasing or decreasing (Fredricks 1992).
Demographic comparisons using matrix models were made between eight closely related species from the Calochortus genus. Results indicated that matrix models do not give a complete picture of population dynamics. Population distribution (proportion of seedlings, juveniles, and reproductive adults) were highly variable between population, habitats, and years. For most species, including C. umpquaensis, there was a lower proportion of juvenile plants than the model predicted. Reproduction was most limiting to population growth and more variable, and perhaps less predictable than was mortality. Reproductive output varied considerably across habitats (Feidler et al. 1998).
In 1999, between 400,000 and 800,000 C. umpquaensis individuals were estimated to occur on BLM land. These numbers are significantly higher than the 120,000 to 140,000 individuals estimated in the early 1990s. Subsequently, the Fish and Wildlife Service removed it from the list of Candidate for Endangered status. (USFWS 2000)
Seed from 4 locations stored at The Berry Botanic Garden.
Study factors influencing limited distribution (Fredricks 1989)
US Forest Service is working with landowners to adjust seasonal livestock use and fences
Continued monitoring (Fredricks 1992).
Determine propagation and re-introduction protocols.