Low seed sets among irrigated, fertilized, greenhouse-grown, and hand-pollinated plants suggest that low seed set is not a result of water or macronutrient deficiency, but rather may be limited by intrinsic genetic factors, possibly inbreeding depression, or other resource limitations (USFWS 1997). Greenhouse experiments revealed that native soil inoculation was successful at facilitating abundant colonization of mycorrhizal fungi. Plants were grown in both non-inoculated and inoculated soil, and only those plants from the inoculation treatment survived (Barroetavena et al. 1998). Growth and survival of individuals grown under greenhouse conditions in six experimental soil treatments were compared: 1) field soil from natural habitat, 2) field soil subjected to heat sterilization (control treatment), 3) field soil treated with fungicide, 4) commercial grade Rhizobium inoculum, 5) commercial grade mycorrhizal (VAM) inoculum, and 6) mixture of commercial grade Rhizobium + VAM inoculate. Plants were not fertilized. Results from the trials clearly indicate that A. applegatei grew best under the field soil treatment. Astragalus applegatei grown under the field soil treated with fungicide treatment performed slightly better than the control and commercial inoculum treatment, but not nearly as well as the untreated field soil treatment (Gisler and Meinke 2001). Growth and survival of individuals grown with sterilized soil inoculated with a small amount of field soil were compared. Only one tablespoon of field soil was needed to promote healthy growth for each individual, posing little threat of depleting natural populations of their soil. Alternatively, a self-sustainable source of inoculum can be developed from a field soil inoculum starter in the greenhouse using other species of host plants (Gisler and Meinke 2001). Germination trials at The Berry Botanic Garden. For scarified seeds, all treatments (Either 8 weeks cold stratification or no cold stratification and either constant 68F (20C) or alternating 50/68F (10/20 C) treatments yielded between 40 and 60 % germination (BBG File).

Germination trials at The Berry Botanic Garden. For scarified seeds, all treatments (Either 8 weeks cold stratification or no cold stratification and either constant 68F (20C) or alternating 50/68F (10/20 C) treatments yielded between 40 and 60 % germination (BBG File).

As of 1998: 3 populations: One with 11,500 individuals (seven acres with the greatest number and density of plants is owned and managed by The Nature Conservancy, while the remainder is on private land). Another with fewer than 500 individuals (owned and managed by the Oregon Department of Fish and Wildlife). A third with only 3 plants (discovered in 1997) (USFWS 1998). 1,500 individuals were cultivated for introduction to the Klamath Wildlife Area. Seeds were collected from the Klamath Wildlife Area population being augmented. Monitoring at the site managed by The Nature Conservancy. At this site, recruitment is decreasing and seedlings have become rare within the macroplots that were established in 1988 for long term monitoring. This population initially showed an increase from 1988 to 1991, when it hit a high at nearly 30,000 estimated individuals. Since 1995, the population has been hovering at lowest record levels of abundance (between ~4,500 to ~10,000 individuals). Though poorly documented, distribution of Astragalus applegatei individuals outside the macroplot suggests that the population may be expanding westward. It is important to note that the suitability of habitat is this new area is questionable, and that slow dispersal rate may limit the extent of colonization (Borgias 2001). Seed from one population is stored at The Berry Botanic Garden.

Seed from one population is stored at The Berry Botanic Garden.

1,500 individuals were cultivated for introduction to the Klamath Wildlife Area. Seeds were collected from the Klamath Wildlife Area population being augmented.

Limited range with a small number of extant populations. Threatened from fragmentation and loss of habitat, potential development and road construction, elimination of the natural seasonal flooding regime along the floodplains supporting the species, suppression of fire, invasive exotic plants, and insect usage. Two sites are threatened by rabbit grazing.

Habitat conversion to fields and pasture (Meinke 1982 & USFWS, 1998). Commercial development on habitat of largest (and only genetically viable) population. Negotiations to lease the land from the owner were unsuccessful. The area is now an auto

As of 1998: 3 populations: One with 11,500 individuals (seven acres with the greatest number and density of plants is owned and managed by The Nature Conservancy, while the remainder is on private land). Another with fewer than 500 individuals (owned and managed by the Oregon Department of Fish and Wildlife). A third with only 3 plants (discovered in 1997) (USFWS 1998).

Low seed sets among irrigated, fertilized, greenhouse-grown, and hand-pollinated plants suggest that low seed set is not a result of water or macronutrient deficiency, but rather may be limited by intrinsic genetic factors, possibly inbreeding depression, or other resource limitations (USFWS 1997). Greenhouse experiments revealed that native soil inoculation was successful at facilitating abundant colonization of mycorrhizal fungi. Plants were grown in both non-inoculated and inoculated soil, and only those plants from the inoculation treatment survived (Barroetavena et al. 1998). Growth and survival of individuals grown under greenhouse conditions in six experimental soil treatments were compared: 1) field soil from natural habitat, 2) field soil subjected to heat sterilization (control treatment), 3) field soil treated with fungicide, 4) commercial grade Rhizobium inoculum, 5) commercial grade mycorrhizal (VAM) inoculum, and 6) mixture of commercial grade Rhizobium + VAM inoculate. Plants were not fertilized. Results from the trials clearly indicate that A. applegatei grew best under the field soil treatment. Astragalus applegatei grown under the field soil treated with fungicide treatment performed slightly better than the control and commercial inoculum treatment, but not nearly as well as the untreated field soil treatment (Gisler and Meinke 2001). Growth and survival of individuals grown with sterilized soil inoculated with a small amount of field soil were compared. Only one tablespoon of field soil was needed to promote healthy growth for each individual, posing little threat of depleting natural populations of their soil. Alternatively, a self-sustainable source of inoculum can be developed from a field soil inoculum starter in the greenhouse using other species of host plants (Gisler and Meinke 2001). Germination trials at The Berry Botanic Garden. For scarified seeds, all treatments (Either 8 weeks cold stratification or no cold stratification and either constant 68F (20C) or alternating 50/68F (10/20 C) treatments yielded between 40 and 60 % germination (BBG File).

Protection from grazing, vehicular traffic, development on site managed by Oregon Department of Fish and Wildlife (USFWS 1997). Grazing does occur at the Klamath Wildlife Area (Gisler and Meinke 1998). Experimental prescribed burning, herbicide application, and mowing at site managed by The Nature Conservancy to examine the influence of invasive species on Astragalus applegatei populations (USFWS 1997) Recovery plan finalized in 1998. 1,500 individuals were cultivated for introduction to the Klamath Wildlife Area. Seeds were collected from the Klamath Wildlife Area population being augmented. Despite consistently high (~ 90%) germination rates after scarification, the fungal root pathogen Fusarium oxysporum stunted growth and greatly reduced the number of plants available for outplanting. Fungicide, fertilization, and irrigation treatment failed to decrease infection. In all cases, only 12 and 14% of plants were usable, and even those plants available for outplanting were of questionable vigor. Of these plants, few survived one growing season (Gisler and Meinke 1998). Monitoring at the site managed by The Nature Conservancy. At this site, recruitment is decreasing and seedlings have become rare within the macroplots that were established in 1988 for long term monitoring. This population initially showed an increase from 1988 to 1991, when it hit a high at nearly 30,000 estimated individuals. Since 1995, the population has been hovering at lowest record levels of abundance (between ~4,500 to ~10,000 individuals). Though poorly documented, distribution of Astragalus applegatei individuals outside the macroplot suggests that the population may be expanding westward. It is important to note that the suitability of habitat is this new area is questionable, and that slow dispersal rate may limit the extent of colonization (Borgias 2001). Seed from one population is stored at The Berry Botanic Garden.

Study levels of seedling recruitment, natural rates of plant development, plant longevity, and minimum population sizes required for long term survival (USFWS 1997). Study outcrossing rates, and relative fitness between individuals resulting from self- and cross-pollinated seeds (USFWS 1997). Research impacts of competition from weeds and other plants. Explore whether the presence of other plants facilitate pollination by attracting pollinators or reduces pollination due to competition for pollinators (USFWS 1997). Investigate the benefits of controlled burning (USFWS 1997). Determine alkalinity tolerance, and to what degree soil specialization may prevent competitive exclusion by other less alkaline-tolerant native taxa (USFWS 1997). Study salinity and hydrological tolerances (Borgias 2001). Identify the abundance and geographic distribution of soil symbionts. In habitats lacking such symbionts, it may be possible to inoculate sites with field soil from natural populations to increase potential habitat for A. applegatei (Gisler and Meinke 2001). Further research on the extent, impacts, and possible control of herbivory and predation (USFWS 1997). Study age structure and levels of recruitment population dynamics in order to assess the long-term viability of population in terms of age/growth stage structure (USFWS 1997). Monitor the westward expansion of A. applegatei at the site managed by The Nature Conservancy (TNC) population (Borgias 2001). Determine the long term effect of quackgrass colonization on the TNC Astragalus applegatei population (Borgias 2001). Investigate whether appropriate soil microfauna in field soil samples can survive dry frozen storage.

Collect and store seed from all known populations. Collect a few seeds over a period of years to reduce the impact of seed removal on the population. If techniques can be developed, collect and store field soil samples containing appropriate soil microflora to aid in population establishment or reintroduction.