Experimental Reintroduction of Lilium occidentale: A cooperative project involving the Berry Botanic Gardena and the Coos Bay District of the USDI Bureau of Land Management. Because the science of reintroducing endangered plants back into the wild from ex situ collections is still in its infancy, we are approaching this project as a controlled scientific experiment. We are asking four classes of questions. 1. Does propagule type used at planting time affect subsequent emergence of plants and/or plant size We used three classes of propagules at planting time: Yearling bulbs (about the size of half a grain of small rice), New Seeds (planted the year they were collected, 1996), and Old Seeds (seeds that had been collected either one or two years previously, and stored in the seed bank). 2. Another primary question is more practical or management oriented. Does removing the ground cover vegetation at the time of planting have an effect on emergence or plant size 3. Does source population have an effect on emergence or plant size We used four of the most local and ecologically similar populations as seed sources. 4. Finally, does maternal plant affect emergence or plant size A large number of families were used. Experimental Design We used a fully randomized split-plot design with 760 propagules (320 new seeds, 320 old seeds, and 120 bulbs) There are 20 replicate plots (38 propagules each). One-half of each plot was randomly selected for ground cover removal. Summary Results: Propagule type affected emergence and leaf area. Bulbs emerged at greater rates and produced larger plants than both new or old seeds. Ground cover treatment affected emergence (slightly more plants emerged in areas with ground cover intact), but not leaf area. Source population affect on emergence was strong initially but has diminished over time. The reverse is true for leaf area (source population effect increasing over time) Effects of maternal parent are complex. (Guerrant 2001).

Seed germination studies. A warm treatment of a few weeks induces the first bulblet to be produced. Several weeks of moist cold treatment followed by a few weeks at room temperature cause the cotyledons to emerge (Kierstead 1988). Mortality and dormancy studies revealed that floral dormancy occurs in order to conserve resources in response to competitive stress (Schultz 1989). Various propagation methods are described in Schultz (1989).

Based on an September 2020 extract of the California Plant Rescue Database, Rae Selling Berry Seed Bank & Plant Conservation Program holds 8 accessions of Lilium occidentale in orthodox seed collection. There are as many as 4811 seeds of this species in their collection - although some may have been used for curation testing or sent to back up.

Based on an August 2020 extract of the California Plant Rescue Database, Rae Selling Berry Seed Bank & Plant Conservation Program has collected 8 seed accessions of Lilium occidentale from 4 plant occurrences listed in the California Natural Diversity Database. These collections together emcompass 129 maternal plants

There are currently about 45-50 mostly small, widely separated populations along the coast of southern Oregon and northern California. (Although it was never widespread, the species may have had a more continuous distribution just after the last ice age, when bogs and coastal scrub were more extensive than today.) The species is now rapidly declining, and some populations are currently non-flowering, presumably due to environmental stresses. It is known or assumed to be extirpated from at least 8 historical sites due to coastal development, fire suppression and associated forest succession, conversion to cranberry farms, and grazing. Horticultural collection is also a concern. These factors continue to be severe threats to the species' existence throughout its narrow geographic range. A few sites are protected, and annual monitoring is recommended.

Known populations have been destroyed by: commercial cranberry bog development, ranch development, windfallen trees, the realignment of Highway 101, botanical competition, bulldozing for road construction and powerline right-of-ways, and housing and comm

As of 1998: Historically, 55 sites. 18 have been extirpated. 9 of the remaining 37 sites have not been able to be relocated in recent years, so it is not known if plants are still present. Of the 28 sites that have been surveyed, 4 have 1000 or more individuals, 3 have 100-300, 14 have between 10-100, while 7 have fewer than 10 individuals (USFWS 1998).

Extensive monitoring at various sites. Monitoring at Table Bluff Ecological Preserve for four years prior to the removal of cattle and annually since. The annual average number of flowering plants was less when grazed, but there was a decline in the total number of plants, esp. juveniles, following removal of cattle (Imper et al. 1988, Imper and Sawyer 1999b, and Imper and Sawyer 2000). Seed germination studies. A warm treatment of a few weeks induces the first bulblet to be produced. Several weeks of moist cold treatment followed by a few weeks at room temperature cause the cotyledons to emerge (Kierstead 1988). Mortality and dormancy studies revealed that floral dormancy occurs in order to conserve resources in response to competitive stress (Schultz 1989). Various propagation methods are described in Schultz (1989). Experimental Reintroduction of Lilium occidentale: A cooperative project involving the Berry Botanic Gardena and the Coos Bay District of the USDI Bureau of Land Management. Because the science of reintroducing endangered plants back into the wild from ex situ collections is still in its infancy, we are approaching this project as a controlled scientific experiment. We are asking four classes of questions. 1. Does propagule type used at planting time affect subsequent emergence of plants and/or plant size We used three classes of propagules at planting time: Yearling bulbs (about the size of half a grain of small rice), New Seeds (planted the year they were collected, 1996), and Old Seeds (seeds that had been collected either one or two years previously, and stored in the seed bank). 2. Another primary question is more practical or management oriented. Does removing the ground cover vegetation at the time of planting have an effect on emergence or plant size 3. Does source population have an effect on emergence or plant size We used four of the most local and ecologically similar populations as seed sources. 4. Finally, does maternal plant affect emergence or plant size A large number of families were used. Experimental Design We used a fully randomized split-plot design with 760 propagules (320 new seeds, 320 old seeds, and 120 bulbs) There are 20 replicate plots (38 propagules each). One-half of each plot was randomly selected for ground cover removal. Summary Results: Propagule type affected emergence and leaf area. Bulbs emerged at greater rates and produced larger plants than both new or old seeds. Ground cover treatment affected emergence (slightly more plants emerged in areas with ground cover intact), but not leaf area. Source population affect on emergence was strong initially but has diminished over time. The reverse is true for leaf area (source population effect increasing over time) Effects of maternal parent are complex. (Guerrant 2001).

Some sites are protected from development as Ecological reserves and Wildlife areas. Informal attempts at population augmentation by spreading seed and replanting bulb-scales (Imper et al. 1988). Seeds stored at The Berry Botanic Garden. Greenhouse propagation of a seedling bank. Seedlings used for reintroductions. As of 1999, more than 1000 bulbs had been grown for 1-5 years and were available for planting. A total of 150 plants had been established at 4 expansion colonies (CDFG 1999). Fencing placed around some populations to decrease grazing by cattle, deer, and small mammals (Schultz 1989 and Imper 1997). Seasonal introduction of cattle (Imper 1997) Experimental manual vegetation removal (Salzer 1994 in USFWS 1998, and Imper 1997) Mowing of grassland (Imper 1997) Listed Endangered by USFWS in 1994 (USFWS 1994). Recovery plan approved and implemented in 1998. Lilium occidentale can be downlisted to Threatened when there are at least 20 viable populations (defined as having at least 1,000 flowering plants and a population structure indicating stable or increasing numbers) distributed among the 6 recovery areas (USFWS 1998).

Controlled burning or girdling to remove competing shrubs and trees (Schultz 1989). Continued monitoring at all known sites, especially after habitat alterations (burns, storms, human intervention, etc) (Schultz 1989). Further research effect of clearing vegetation around lily plants (USFWS 1998). Further research on the effect of deer and cattle grazing (USFWS 1998). Browsing by deer and small mammals may result in a 50% or greater loss of reproductive output. However, complete removal of cattle may actually decrease lily survival by allowing other plants to flourish and compete with the lily. Limited, periodic grazing by cattle to reduce vegetation cover followed by a rest period to allow the lily to develop may be ideal (Imper and Sawyer 2000). Study breeding system. Determine whether Lilium occidentale is self-compatible or not (USFWS 1998). There are conflicting reports as to its self-compatibility (Imper et al. 1988). Determine the amount and patterns of genetic diversity within and among populations (USFWS 1998).

Collect and store seeds from all extant populations across the species' range (USFWS 1998). Determine most effective methods to reintroduce or augment populations.