The Arboretum Host of the Third Rare and Endangered Plant Conference in 2000

Conference proceedings are available now, free of charge.  To order "Southwest Rare and Endangered Plants:  Proceedings of Third Conference," contact Richard Schneider.  Be sure to give this reference number when you order:  RMRS-P-23.

(970) 498-1392

rschneider@fs.fed.us

The Arboretum staff was pleased to host a very important conference addressing current research on rare plants and ecosystems in the Southwest and Colorado Plateau. The Third Rare and Endangered Plant Conference was held September 25-28, 2000 at the duBois Center on the Northern Arizona University campus. 

Topics covered included surveys and monitoring, population biology, demographic studies, reproductive and pollination biology, seed biology, distribution, genetics and systematics, preserving biodiversity, hybridization threats, reintroduction, recovery strategies, strategies for protection, and public involvement in plant conservation. 

Following the tradition of the first conference hosted by Robert Sivinski and Karen Lightfoot in Santa Fe in 1992, and the second conference hosted by Joyce Maschinski in Flagstaff in 1995, the third conference provided opportunities for information exchange and networking with plant conservation professionals and the general public. As was true of the first two conferences, the proceedings will be published and abstracts will be indexed with Cambridge Scientific Abstracts.  

Details of the program follow:

THIRD SOUTHWESTERN

Field Trips

8:00 a.m. – 12:00 p.m. Late Registration; du Bois Conference Center Ballroom.

                                                            PAPER SESSION II: Ecology

1:30 p.m. ¹Phillips, Arthur M., III and Barbara G. Phillips². ¹Botanical and Environmental Consulting, Flagstaff, AZ, and ²Coconino, Kaibab, and Prescott National Forests, Flagstaff, AZ. Spatial distribution of Pediocactus paradinei on the North Kaibab Ranger District, Kaibab National Forest, Arizona.

Aitken, M., D. W. Roberts and L. M. Shultz. Dept. of Forest Resources, Utah State University, Logan UT 84321. Predictive modeling of rare plant habitat in the eastern Great Basin. ORAL PRESENTATION

Across landscapes, the availability of suitable habitat limits the distribution of plant species. The distribution of rare plant species with small geographic range and/or narrow habitat specificity generally correlate with independent environmental variables. This study developed site- and landscape level predictive models for identification of potential rare plant habitat in the Great Basin, UT, USA. Four rare endemic plant species were chosen to include a range of environmental variability, community associations and elevations. In the first phase of this study, herbarium records were used to initially choose and map specific sample sites. Geographic coordinates, environmental attributes and associated species data collected at each site were used to develop two predictive models for each species: a field key and a probability of occurrence map. A tree-classification program was used to generate the dichotomous field keys and the maps of occurrence probabilities. The field key was developed from environmental attribute and associated species data collected at the sites and employed data only available in the field. Predictive maps were developed from the coordinate data recorded at each site by locating the position of each site in a geographic information system (GIS) containing slope, elevation, aspect, soils and geologic data. During the second phase, predictions from both models were field validated. Development of the models was an iterative process, where data collected during the field validation were incorporated into subsequent predictive models. The models suggested that potential habitat can be identified by combining elevation, slope, aspect, rock type and geologic process data, into habitat models for each species.

Allphin, L.¹, D. Wiens², N. Brian³, and P. Randall¹. ¹Botany and Range Science, BYU, Provo, UT, ²Department of Biology, University of Utah, SLC, UT, ³National Park Service, Grand Canyon Science Center, Grand Canyon, AZ. Reproductive success and genetic divergence among varieties of the rare and endangered Astragalus cremnophylax from Arizona, USA. ORAL PRESENTATION

Populations of Astragalus cremnophylax from Arizona and related A. humillimus from New Mexico were assessed for reproductive, genetic, and demographic differences. Results suggest that some of the taxa (i.e. A. cremnophylax var. cremnophylax and A. humillimus) are poor reproducers and environmental fluctuation is not a factor contributing to low fecundity in these species. Astragalus cremnophylax var. cremnophylax appears to have low fecundity due to inbreeding depression. Isozyme data from 12 loci show little within-population and taxon genetic variability. Variability is distributed among populations and taxa. Cape Final, a population of A. cremnophylax var. cremnophylax on the Grand Canyon (North Rim) is genetically different from typical materials of this taxon (South Rim) which are more closely related to other taxa within this species. Varieties of A. cremnophylax are more closely related to A. humillimus than the population at Cape Final, suggesting possible varietal status for Cape Final materials based on isozyme divergence.

Amos, B. B. and C. Vassiliou. Angelo State University, Department of Biology, San Angelo, TX 76909. Preliminary report on the reproductive biology of the threatened Chisos Mountain hedgehog cactus (Echinocereus chisoensis, Cactaceae). ORAL PRESENTATION.

The Chisos Mountain hedgehog cactus, Echinocereus chisoensis, is restricted to a few sites in Big Bend National Park in Brewster County, Texas. In 1987 it was added to the federal lists of endangered and threatened wildlife and plants as threatened because of its restricted distribution, the species' low numbers, vulnerability to private and commercial cactus collectors, and habitat disruption. A lack of basic scientific information about the species has hampered conservation efforts. During the spring of 1999 and 2000, field studies were conducted to gain knowledge of the reproductive biology of this rare taxon. Plants produce primarily self-incompatible flowers in a mast cycle from mid-March to mid-April; a flower typically lasts a single day. Floral rewards include nectar, although scanty, and pollen. The primary pollinator is the cactus oligoleg, Diadasia rinconis. Insect visitation is infrequent but adequate for high seed production. Fruit and seed dispersal mechanisms are currently under investigation.

Anderson, J. L. U.S. Bureau of Land Management, 2015 W. Deer Valley Rd, Phoenix, AZ 85027.  The white-margined penstemon (Penstemon albomarginata) and the Hualapai Mountains land exchange in Arizona. ORAL PRESENTATION

The white-margined penstemon (Penstemon albomarginatus Jones) is a rare Mohave Desert species with an unusual tripartite distribution with disjunct localities in Arizona, California, and Nevada. The Arizona population is the largest single population occurring with a range of fifteen miles by five miles in Dutch Flat near Yucca, Arizona in Mohave County. The land ownership pattern in Dutch Flat was a checkerboard of public and private land, a legacy of railroad lands. Although the Bureau of Land Management (BLM) designated the White-margined Penstemon Area of Critical Environmental Concern (ACEC) in 1993 for conservation of this Arizona BLM sensitive species, the checkerboard pattern of public and private lands within the ACEC made its conservation management difficult. Rural development was increasing impacts to the Dutch Flat area as the private land was being sold off in forty acre parcels. The Hualapai Mountains Land Exchange between the Santa Fe Pacific Railroad and the BLM provided a tool for consolidating a portion of the ACEC into a solid block of public land, thereby increasing its manageability for the conservation and survivability of the white-margined penstemon.

Gilia caespitosa Gray (Rabbit Valley gilia) is a rare species restricted to scattered occurrences from the northern Waterpocket Fold to Thousand Lakes Mountain and Rabbit Valley in Wayne County, Utah. This species is a very narrow endemic, known only from unstable and faulting soils of detrital Navajo and Wingate sandstones. Species occurrences are often found with limited numbers of plants and minimal potential for increasing. Available information regarding historic abundance, ecology, biology and demographics is limited. These factors contributed to the need to develop a Conservation Agreement and Strategy which provide the initial direction for conservation. Initial objectives of the strategy were to survey for additional occurrences and identify and establish management guidelines which would ensure overall long-term survival of the species. Through an interagency effort, most of the initial conservation measures have been achieved. Results from these efforts included greatly expanded numbers of known population occurrences, refined monitoring protocols and increased public awareness efforts.

Existence of the endangered shrub Purshia subintegra is believed to be threatened by hybridization with the more common P. stansburiana. Using discriminant function analysis, we found the parents and hybrids had detectable morphological differences that we could use to classify individuals. We then examined plant performance in a common garden experiment. To determine the performance of P. subintegra and it hybrids across a soil gradient, we collected stem cuttings from P. subintegra, P. stansburiana, and hybrids and transplanted rooted cuttings to pots containing one of each of the three parent soils. After 9 months, all plants had the greatest growth in the hybrid soils when compared to P. subintegra and P. stansburiana soils. We next examined the habitat of both parents and their hybrids in the Verde Valley. We found a significant difference between disturbed and undisturbed habitats in the distribution of P. subintegra, P. stansburiana, and hybrids. Washes and roadsides contained a greater proportion of hybrids than undisturbed habitat. Undisturbed habitat contained a greater proportion of P. subintegra. Increased road construction and human disturbance in the rare P. subintegra habitat may increase the invasion of hybrids and have implications for the management of this rare species.

Baggs, J.E. and J. Maschinski. The Arboretum at Flagstaff, 4001 S. Woody Mountain Rd. Flagstaff, AZ 86001 USA.  From the greenhouse to the field: cultivation requirements of Purshia subintegra, Arizona cliffrose. POSTER

Implementation of the habitat management plan for, Eriastrum densifolium ssp. sanctorum (Eds) (Polemoniaceae), in the Santa Ana River floodplain is in its 5th year. The PVA goals are to: a) avoid unnecessary habitat manipulation; b) to establish population transition matrices; c) predict the extinction of local populations; and d) compare demographic patterns of Eds in good and marginal habitats. The experimental management plots will; a) determine the most effective means of restoring viable habitat; and b) propose effective means of enhancing natural sand deposition in potential Eds habitats. Demography plots represent a continuum of habitat quality. Data acquired annually from 1996 through 2006 will be the basis for average matrices, that will be tested at 10 year intervals. Increasing populations have l values of 1.14,1.07, 1.33,1.35. The population projections for one study site are quite different in the three years for which we have data (l = 1.03 to 0.969). The oldest site, probably flooded last in 1939 or 1896 is at risk of extinction. The experimental treatments are uncleared (control), cleared only, diked, cut 20 cm, topped 10 cm washed sand, 20 cm washed sand, and 30 cm washed sand. Seedling mortality was greatest on sand deposition plots during drier winters and improved during wetter years. Cut and diked plots had the highest rates of establishment perhaps because they have greater clay and silt near the surface and therefore have greater water holding capacity.

This paper will document the author's field and herbarium studies covering several of the rare orchids in Arizona, New Mexico, and Texas. Each orchid will be discussed in terms of relative rarity within the study area, and absolute rarity throughout its range. Comparisons will be made between current and historic ranges. Population dynamics discussions will include estimates of number of sites, total number of plants, threats, and self recruitment. Results of ongoing demographic studies will be reported based on permanent monitoring plots. Orchids discussed will include: Spiranthes delitescens, Stenorrhynchos michuacana, Platanthera zothecina, Hexalectris warnockii, Hexalectris revoluta, Malaxis tenuis, Malaxis porphyrea, Malaxis corymbosa, and Schiedeella parasitica.

Penstemon harringtonii Penland (Scrophulariaceae) is a perennial species endemic to the open sagebrush communities of North-Central Colorado. The scattered populations occur in Eagle, Garfield, Grand, Pitkin, Routt, and Summit counties. It is designated a sensitive species by the U.S. Forest Service and the U.S. Bureau of Land Management, and was formerly a Category 2 Candidate for ESA listing. Throughout its range, fluctuating population numbers and increased land development have led to uncertainty about it current status. The goal of the study is to detect a biologically significant change in the population size by implementing a study that incorporates sample size and power analysis into the experimental design. In 1996, a pilot study was initiated to determine the appropriate sample size to detect a 20% change in the population. Annual census of the two macroplots (Above Eagle and Dry Lake) has documented differences between the two populations. Results of four years data indicate that the Above Eagle population is stable, while the Dry Lake population is experiencing statistically significant fluctuations in rosette number. The differences between these two populations may be related to the percent cover sagebrush, precipitation, or soil type. Our results indicate that a stable population occurs on sites with lower sagebrush cover. Ongoing analysis of these data may support this prediction.

Donovan, Jim. University of Arizona, P.O. Box 85487 Tucson AZ 85754. Pollination ecology of the Kearney's bluestar amsonia kearneyana (Apocynaceae): a rare and endemic species in Arizona. POSTER

I studied the pollination and reproductive ecology of the threatened and endangered Kearney's bluestar in a transplant population and a natural population. Current information reveals that the species is self-compatible but requires a pollen vector. Fruit production varied spatially and temporally in and between populations. The natural population had a higher diversity of floral visitors and higher fruit set compared to the transplant population. Insects, in particular bees, were the most common floral visitors in both populations. Hummingbirds and butterflies were also recorded visiting the flowers but were probably negligible contributors to pollination. Higher floral visitor diversity in the natural population compared to the transplant population is attributed to three factors: a) higher population number and density, b) the spatial arrangement of the population is more conducive for visitation by pollinators, c) pollinators nest among the individual plants.

Traditional approaches to the conservation of plant diversity have emphasized protection of existing populations and habitat. While this approach must continue to constitute the core of any reasonable strategy, it is no longer sufficient to meet the goal of protecting biodiversity. This is so primarily because human effects on the landscape and its biota show little sign of abating. Indeed, the pace of major anthropogenic impacts such as global climate change, habitat alteration, and fragmentation, are accelerating. Roads and air transport are making once-remote areas accessible for resource extraction, agriculture, recreation, and even habitation. In the US, the boundaries between protected areas and private lands have "hardened", compromising the integrity and natural variability of keystone ecological processes. Because most indigenous peoples are entirely dependent on the integrity of their ecosystems, worldwide cultural diversity is declining as rapidly as is biotic diversity.

In such a world, merely protecting extant populations is not a sustainable strategy, and is in fact a negative-sum game. To maintain biodiversity beyond a few decades into the future, additional measures are required. The essence of a strategy for the coming century must revolve around a major commitment to restoration. This would begin with buffer zones and corridors placed in relation to remaining natural areas and populations, and eventually expand to include the entire semi-natural matrix that constitutes 85% of the land area in most countries of the world. While a massive commitment to restoration of the ecological fabric may seem daunting, it is probably the only comprehensive strategy that can prevent Earth’s remaining biological and cultural diversity from eroding further.

Pediocactus paradinei has been quantitatively monitored since 1987. While the numbers of individuals on permanent plots has varied relatively stable, the future of the species is still in question. In the last several years we have added four new permanent plots to fill gaps in the distribution of plots across the geographic range of the species. Addition of these plots have allowed us to subdivide our plots into eight sites, each of which has at least one replicate plot. Replicate plots have allowed us to estimate variance components in population growth of the species. These components include demographic, metapopulation and environmental variability.

Fule’, Peter Z., Judith D. Springer, David W. Huffman, and W. Wallace Covington Ecological Restoration Institute, Northern Arizona University, P.O. Box 15018, Flagstaff AZ 86011. Tel (520) 523-1463, Fax (520) 523-1080. E-mail: Pete.Fule@nau.edu  Response of a rare endemic, Penstemon clutei, to burning and reduced below ground competition. ORAL PRESENTATION

Penstemon clutei, a rare perennial beardtongue endemic to the ponderosa pine forest of the Sunset Crater volcanic field of northern Arizona, presents an opportunity to test the hypothesis that restoration of historic ecosystem conditions may enhance the sustainability of a rare species. We tested small-scale burning and root trenching treatments as proxies for the surface fires and reduced tree densities characteristic of historic ponderosa pine ecosystems, in a study area at O'Leary Peak, part of the Sunset Crater volcanic field (Coconino National Forest, AZ). Prescribed burning killed many mature P. clutei plants and affected density for at least 3 years post-burn. In contrast, trenching to cut root competition of overstory trees led to a 1000% increase in P. clutei seedlings. Precipitation influenced the response. Seed germination experiments showed that P. clutei does not have innate dormancy. Germination rates in the lab ranged from 5-70% under a range of environmental and fire-related conditions (cold stratification, light, exposure to ash, NH4, etc.), but tested seedling establishment rates in situ were very low. These experiments suggest that the observed P. clutei population increase following the 1973 Burnt fire may have been due primarily to the removal of tree competition rather than to direct fire effects. Further experiments are suggested to develop ecological information for the thoughtful integration of ecosystem restoration with rare plant habitat needs.

The habitat associated with riparian, understory, rare and endangered plant populations of the Southwest includes rocky places in high altitude canyons, mostly along shady streams, pools, and dripping cliffs. The composition of these insular plant populations, separated by intervening desert, is influenced by several local environmental variables. One particular environmental component, the understory light environment, is influenced by canopy cover, is a key determinant of vegetation patterns, and varies spatially within and among populations. Light availability could directly affect individual fitness (e.g. via affecting photosynthetic and micro-climatic processes) and, subsequently, could indirectly affect plant population size and persistence. We quantified the effect of canopy cover and light availability in populations of herbaceous, perennial yellow columbines (genus Aquilegia) in the Southwest. Aquilegia populations exhibit many of the characteristics, particularly isolation and relatively small population size, associated with at-risk populations. This is exemplified by the conservation status of Aquilegia chaplinei, or Chapline's columbine, and its current protection under the New Mexico Endangered Plant Species Act. Canopy cover and understory light environment was quantified from the view each plant has of the sky as detected with photography of the canopy above each plant. Images were analyzed to determine percentages of sky versus canopy cover and, subsequently, the relationships among canopy cover and within- and among-population dynamics were investigated. Overall, these ecological assessments will help our understanding of the environmental influences on population dynamics, and are important to the conservation and recovery of rare and endangered plant populations.

Tetraneuris verdiensis was first published in 1996. It appears to be closely related to Tetraneuris scaposa Greene (including Hymenoxys acaulis var. arizonicus). The two are morphologically separated by the discoid condition of T. verdiensis. The closest known location of H. scaposa is approximately 7 miles west of the known T. verdiensis locations, which are five miles east of Camp Verde. T. verdiensis is significant in that no other entirely discoid populations, or series of populations, of Tetraneuris have been reported. T. verdiensis populations are consistently discoid and separate from T. scaposa. The type locality is on the top of a low hill of a gypsum strata of the Verde Formation. In 1999, the type locality population contained approximately 200 individuals. Denham and Turner state that additional populations occur on the tops of the adjacent small hills within this stratigraphic unit. A survey of all of the gypsum hills in this area east of Camp Verde and population sizes for each gypsum hill where this species occurs are presented. The morphological similarities and differences between T. verdiensis and T. scaposa will be discussed. The taxonomic status of T. verdiensis is addressed.

Hannon, D. Rancho Santa Ana Botanic Garden, 1500 N College Ave., Claremont, CA 91711. Rare plant projects at Rancho Santa Ana Botanic Garden. ORAL PRESENTATION

Of southern California's many rare plant taxa the two following, among others, are the subject of ongoing projects at Rancho Santa Ana Botanic Garden. The first project aims to increase ex situ seed holdings of Astragalus pycnostachyus var. lanosissimus. Additional work with this taxon may also augment the recently discovered and only known population. This population exists amidst complex and intense pressures in its coastal habitat in Ventura County. In the second project, propagation and cultivation protocols are being established for Eriogonum ovalifolium var. vineum in order to effect mitigation plantings at a cement mine site in San Bernardino County. This buckwheat occurs in scattered populations on carbonate limestone formations along the northern slopes of the San Bernardino Mts. at 1500-2100m.

Samples from three mutually isolated populations of the dwarf bear poppy, Arctomecon humilis (Coville), demonstrate that both flower pollination and seed set per fruit are suppressed as interplant distances increase. Those reproductive parameters are also impaired on plants that produce few flowers. Interplant distance and flower number per plant interact strongly with reproduction being most impaired on plants that produce few flowers and are far from other flowering individuals of the species. Such data warn that number of surviving individuals alone is not a safe criterion for evaluating the reproductive health of a population. Population density (number of individuals/ unit area) has a strong influence on reproductive success in plant populations.

Hreha, A.M. and T.B. Meyer. Red Butte Garden, University of Utah, Salt Lake City, Utah 84112.  Five year demographic monitoring study of the threatened Siler’s pincushion cactus (Pediocactus sileri) in Kane County, southern Utah. ORAL PRESENTATION

Platanthera zothecina (alcove bog orchid) is a recently described western member of this genus. The alcove bog orchid is in a group of species that have been placed in three different genera over time: Habenaria, Limnorchis, and Platanthera (Colorado Native Plant Society 1997). Welch et al. (1987) described and named it based on a specimen from Grand County, Utah. Before their description, it had been considered a variant of P. sparsiflora (Hevly 1961). This study was initiated by the National Park Service after the alcove bog orchid was identified in Arizona during a threatened and endangered species survey at Navajo National Monument (Drost 2000). Its status is listed as Category 2 (species of special concern) by the U.S. Fish and Wildlife Service, and Category 3 (likely to become endangered) by the Navajo Nation. Scientists from the Biological Resources Division of U.S. Geologic Service recommended the development of monitoring protocols to address number, distribution, and condition of these orchids. Because P. zothecina is a fairly new taxon, and little is known about its ecology, this study will document baseline information on the number, size and distribution of P. zothecina populations as well as flowering and fruit set rates for the first year.

Hughes, Lee E. Arizona Strip Field Office, BLM, 345 E. Riverside Dr., St. George, UT 84790.  Monitoring update on four listed plants from the Arizona Strip. ORAL PRESENTATION

Although related taxa occur throughout the western United States, Salvia dorrii ssp. mearnsii is known only from central Arizona. In part, its narrow distribution may be attributable to its limited seed production, seedling establishment, and germination requirements. Heavy herbivory pressures decreased fruit set in populations in two distinct vegetation zones, desert scrub (limestone-based soil) and chaparrral (sandstone-based soil). Seed viability and fruit set were higher in populations in desert scrub vegetation (limestone-based soil). In situ, little evidence of seedling establishment was observed during 3 field seasons. Greenhouse germination experiments were conducted in order to test the effects of watering level, soil type, light level, and scarification. Greenhouse results indicate that Salvia dorrii ssp. mearnsii has few restrictions for germination. Germination was independent of soil type except that seeds did not germinate at all in potting soil. Low watering levels and low light availability appear to be the most important factors for germination.

Although related taxa occur throughout the western United States, Salvia dorrii ssp. mearnsii is known only from central Arizona. In part, its narrow distribution may be attributable to prehistoric human influences. A spatial analysis was used to determine the spatial relationship of archaeological sites and populations of Salvia dorrii ssp. mearnsii. In the Verde Valley, Arizona approximately 89% of the plant populations were spatially related to archaeological sites. Plant populations from a different geographic area near Perkinsville, Arizona were also spatially related to known ruins, although only 75% of the time. Consultations with traditional scholars of three indigenous tribes, the Hopi, Paipai, and Kumiai, were conducted in order to better interpret the statistical results. The consultants indicated that plants in this group (Salvia dorrii var. dorrii, Salvia pachyphylla) are used in ceremony and as medicine. These plant/ruin associations may be the result of prehistoric plant husbandry systems including trade and dispersal of seeds via Native American clan travel.

Johnson, David W., Department of Science and Mathematics, and Margaret R. Johnson, Fogelson Library, The College of Santa Fe, 1600 St. Michael's Drive, Santa Fe, NM, 87501. History and value of collections made by Brother Gerfroy Arsène Brouard. POSTER

The herbarium at The College of Santa Fe houses plants collected by Brother Gerfroy Arsène Brouard in northern New Mexico from 1926 to 1938. The collection comprises several thousand bryophytes, liverworts, other non-flowering plants, and flowering plants from plains, woodlands, foothills, and mountains in the vicinity of Santa Fe and Las Vegas. Included are mosses that were the basis of Bartram's 1931 article, "Mosses of northern New Mexico collected by Bro. Arsène." Bro. Arsène is best known for his extensive collections of plants from Mexico and at least 24 species were named for him. More than 15,000 of his specimens are in herbaria in North America, Europe, and Africa. A brief history and description of The College of Santa Fe collection and its value will be presented.

Pollinator taxa and pollinator limitations of Eriastrum densifolium ssp densifolium (Eds), a rare and endangered riparian subshrub in the Polemoniaceae, were investigated. We studied breeding biology, pollinator constancy, male fertility, nectar volume, principal pollinator nesting sites, and pollen/ovule ratios. Two principal hypotheses were tested, 1) Eds is pollinator limited and 2) Pollinator efficiency varies among the dominant pollinators. Five study sites, on the Santa Ana River floodplain in San Bernardino County, California represent the range of habitats that support Eds. Major pollinators were identified in "dawn to dusk" in early, mid and late season in multiple three-day sequences of dawn to dusk observations. The most important pollinator visitors were bumblebees, hummingbirds, halictid bees and the giant flower-loving fly. Replicate inflorescences were emasculated in bud and bagged. Pollinator specimens of the important pollinators were used to simulate one or more visits by each pollinator. The fruit and seed set for visited flowers was determined and compared with controls. Halictid bees, Digger bees, and hummingbirds were important vectors throughout the blooming season. The Giant Flower-loving Fly, Rhaphiomidas acton, became a major pollinator in mid season. Fruit set (not significantly different than the controls) was accomplished by a single visit by any of the insects but multiple hummingbird visits were required. The three insect pollinators are all reasonably efficient and could effectively pollinate a flower of Eds with a single visit. There are sufficient pollinator taxa but numbers of individuals vary dramatically and cause dramatic reduction in fruit and seed.

Kass, Ronald J. Intermountain Ecosystems, 270 East 1230 North, Springville, Ut. 84663. Demographic monitoring of the Wright fishook cactus (Sclerocactus wrightiae) Benson. ORAL PRESENTATION.

Wright fishook cactus (Sclerocactus wrightiae) is a small barrel cactus endemic to the San Rafael Swell in south central Utah. It was listed as an Endangered Species in 1979 because of its small population size and threats of over-collecting and energy development. Demographic monitoring was initiated in 1993 with the following objectives: (1) establish permanent plots to monitor growth, fecundity, recruitment, and mortality for at least 10 years, (2) identify habitat factors positively associated with cacti, and (3) identify important insect visitors and predators. Three permanent plots (Hanksville, Giles & Mesa Butte) were distributed throughout the range of S. wrightiae and 93 individuals were followed since 1993. In general, diameter size classes were significantly different for all 3 plots. Size class three (adult) and four (older adult) produced the greatest amounts of reproductive structures. Size class three produced more structures by virtue of its larger numbers while size class four produced more structures by virtue of its larger size. At Giles, mortality exceeded recruitment; 22 cacti remain from the original 31, a 29% decrease. At Mesa Butte, recruitment equaled mortality but a rare recruitment event in 1999 added 17 new recruits, a 21% increase. At Hanksville, 21 cacti (68%) were recorded dead in 1994, and the remaining 10 individuals and 5 recruits were recorded dead in 1995. No new recruits have been recorded since 1995 at Hanksville. Ords kangaroo rats (Dipodomys ordii) and white-tailed antelope ground squirrels (Ammospermophilus leucurus) were the primary mortality sources at Hanksville, and the cactus-borer beetle (Moneilma semipunctatum) was the primary mortality source at Giles and Mesa Butte.

Landscape anomalies are regionally restricted habitats created by unusual geological, edaphic, or hydrological factors. Barrens, cliff faces, canyons, hanging gardens, and playas are all examples of landscape anomalies in the arid Southwest. Such sites often harbor an unusual and rich flora, including endemic, disjunct, or relictual plant species. Using examples from our studies on the chalk barrens and riparian canyons of SE Colorado, we show how regional diversity can be enriched by the biota of habitats which are small in extent but biologically distinctive. Landscape anomalies are relatively easily surveyed and monitored, provide opportunities for comparative studies, and can serve as flagship habitats for capturing public interest. Because of their small size, however, they may be easily destroyed by development or overlooked in regional planning. While coarse filter conservation approaches can be effective for protection of regional ecosystems, a focus on small landscape anomalies as specific conservation targets may also be desirable in order to protect biota with low prominence but high biogeographic significance.

Lepidospartum burgessii is designated a "species of concern" by the US Fish and Wildlife Service. This silvery-white, Asteraceae shrub is endemic to gypsum soils in north Culberson County, TX and southern Otero County, NM. In 1991/1992 the condition and numbers of plants in NM were examined but otherwise little is known about the ecology or biology of this species. Our objectives were to define its habitat characteristics and status. We found that L. burgessii colonizes more diverse habitats than previously thought. In NM the plants generally grew on stabilized, cryptogam-covered, gypsum soils with approximately 5% basal vegetation/litter cover. In TX, and at one site in NM, shrubs grew on mobile gypsum dunes with an average of 20% basal vegetation/litter cover. In 1997 plants were counted in seven colonies in NM. Approximately 15% of the individuals counted within those colonies in 1991/1992 were dead in 1997. The number of juvenile plants had also declined. Recruitment was only by clonal propagation. No seeds formed although there were abundant flowers. Genetic diversity appeared to exist between the TX and NM populations. Involucre length from plants in TX was longer than from those in NM. Two potential disease problems were identified. Corythuca marmorata, a known pathogen of some Asteraceae species, caused leaf loss and stem necrosis. Alternaria alternata, a potential pathogenic fungi, was observed within some flowers.

For rare plants, the question of whether and to what extent wild and domestic herbivory influences growth, reproduction, and survival can be critical to the species preservation. In two separate 3-year experiments, I investigated how timing and intensity of herbivory influenced two rare plants: the herbaceous understory plant, Clematis hirsutissima var. hirsutissima (formerly var. arizonica) and the riparian shrub, Arizona willow, Salix arizonica. Herbivory by wild and domestic ungulates had detrimental impacts on both species; neither species was able to compensate fully for tissue or seeds lost to herbivores, regardless of the timing and/or intensity of herbivory. In the case of Clematis, herbivory had the least impact on plant reproduction, growth, and survival when it occurred very late in the growing season, because most plants had already set and shed seed. While early-season herbivory had significant negative effects on reproduction, there were no detrimental effects of late-season herbivory detected in the years following clipping treatments. In contrast, Salix arizonica reproduction and growth was severely impacted by herbivory; herbivory restricted plant growth to < 10 cm tall, reduced flower production, and increased mortality. Recovery from one growing season to the next was minimal even when plants were protected from herbivores. These studies illustrate the serious impacts ungulate herbivores can have on rare plants and provide management alternatives for plant conservation.

Maschinski, J. The Arboretum at Flagstaff, 4001 S. Woody Mountain Rd. Flagstaff, AZ 86001.  The problem of being small: demographic and reproductive patterns of Ipomopsis sancti-spiritus. POSTER

Mast, J.C. and J.A. Souder. College of Ecosystem Science and Management, Box 15018, Northern Arizona University, Flagstaff, AZ 86011-5018. Economic benefits of wildflower viewing in Arizona. ORAL PRESENTATION.

We conducted a study using contingent valuation survey methods to determine how Arizona residents value wildflowers. This valuation is expressed by respondents' willingness-to-pay for additional densities of wildflowers in natural settings, and additional vegetation diversity along urban roadsides. Values for wildflower viewing were determined through a mail survey in which respondents were presented with hypothetical management programs whose effects were displayed with a set of digitally-altered photographs of the three different landscape scenes - mountain, desert and urban freeway - each of which showed four different levels of wild-flowers (or types of roadside vegetation). Additional questions asked for information on demographics, environmental attitudes, and preferred funding mechanisms.

Survey results show that Arizona residents highly value wildflowers, with broad support for programs that increase wildflowers on public lands in Arizona (67% of survey respondents, extrapolated to 26% of state residents). Using the most conservative interpretation, Arizona residents are willing to pay at least $1.9 million annually (over 20 years) for management programs in Arizona that double, $2.4 million annually to triple, and $4 million annually to quadruple wildflowers in natural settings and vegetation along urban freeways. Extrapolating from the survey results shows that Arizona residents place an estimated value in the range of $42 - $110 million for the low density, $66 - $167 million for the moderate density, and $88 - $177 million for the high density of wildflowers on public lands and vegetation along urban highways.

Morin, N.R. The Arboretum at Flagstaff, 4001 S. Woody Mountain Road, Flagstaff, AZ 86001.  Regional, national, and international plant conservation efforts—What do they mean for the southwest? ORAL PRESENTATION

There are many efforts underway to understand better the floras and habitats of the southwest, and at the same time this area is under tremendous threat from development, recreational uses, and recent land and resource management methods. The southwest has been identified as a high priority area for study and for resource conservation, and there are national programs that may be looked to for funding for work in our area. At the same time, a remarkable number of national and international initiatives are underway or have been established recently. These include The Global Strategy for Plant Conservation, the International Agenda for Plant Conservation in Botanical Gardens, the Species Survival Commission, the Plant Conservation Alliance, and the Center for Plant Conservation. How do the goals and priorities set by these initiatives fit in with what is happening in the southwest? Important regional strategies include regional task forces, regional exotic plant pest councils, and formal and informal networks. This talk will discuss what these various initiatives are, what their goals are, how southwestern plant conservationists and scientists can be helpful, and how these initiatives can be used to further the goal of conserving plants in the southwest.

Phillips, Arthur M., III (Botanical and Environmental Consulting, Flagstaff, AZ), and Barbara G. Phillips (Coconino, Kaibab, and Prescott National Forests, USDA Forest Service, Flagstaff, AZ).  Spatial distribution of Pediocactus paradinei on the North Kaibab Ranger District, Kaibab National Forest, Arizona. ORAL PRESENTATION.

Pediocactus paradinei B.W. Benson (Cactaceae), Paradine plains cactus (Kaibab plains cactus), is a rare cactus endemic to the eastern slopes of the Kaibab Plateau. It is managed under a Conservation Agreement signed in 1998 by US Fish & Wildlife Service, USDA Forest Service, and Bureau of Land Management, incorporating management direction and commitments in a Conservation Assessment and Strategy adopted in 1996. The species is found in pinyon-juniper woodland and shrub/grassland. The latter sites are either open, treeless areas along drainages within the woodland, or sites adjacent to and below the woodland. Distribution of the cactus in the shrub/grassland is usually clumped in clusters or colonies in openings within stands of big sagebrush. In the woodland, plants are more widely scattered, occurring as individuals in openings between trees. Observation indicates that they do not occur in thick litter under trees, but they may occur preferentially just outside the dripline at the edge of tree canopies. We examine the distribution of Pediocactus paradinei to find any patterns within the woodland, and to ascertain whether the plants overall are more abundant in shrub/grassland or woodland.

We examined the pollination ecology of Spiranthes diluvialis Sheviak, Ute ladies’-tresses, a federally listed, threatened orchid species known only from small, isolated populations in the western U.S. The pollinator composition, male and female reproductive success, and demography of S. diluvialis populations was examined in 1995, 1997, and 1999. Spiranthes diluvialis sets fruit only when visited by pollinators and observations indicate that native bees, predominantly bumblebees (Bombus spp.), are the most important pollinators. Comparisons of male and female reproductive success were made between populations and years. Significant declines in fruit production and pollinia removal occurred in 1999 in the Diamond Fork population and may be related to changes in pollinator composition. Significant increases in fruit production were recorded in the Brown's Park population, an area in which native pollinators were released in 1999. Management plans to conserve this threatened orchid must provide for the pollinators, their nesting habitat, and pollen-producing plants (S. diluvialis provides no pollen to pollinators). We identified important pollen sources for pollinators in the Diamond Fork population and supplied several types of semi-natural nesting materials to promote nesting in 1999. Successful preservation of this threatened orchid requires a community-level conservation plan.

DNA sequences of the chloroplast trnL-F region are used to infer population structure of Pediocactus winkleri and P. despainii. Two metapopulations are identified, based on inferred haplotype diversity and frequency at eight populations. The San Rafael and the Waterpocket Fold
metapopulations correspond well with geography but less so with morphology. The Waterpocket Fold metapopulation occurs within and east of Capitol Reef National Park, Utah, and would be referred to P. winkleri, based upon morphology. The San Rafael metapopulation is found north of Capitol Reef, within the San Rafael Swell and includes populations that would be identified as P. winkleri, P. despainii, or as intermediate forms. Consideration of the San Rafael metapopulation as equivalent to P. despainii is problematic because the morphological variation far exceeds the traditional circumscription of this species. Further, the treatment of the two at the species rank results in one (or both) species being paraphyletic, which is philosophically problematic for many systematists. Reducing the rank and treating P. winkleri and P. despainii as varieties or ubspecies of P. winkleri solves the problem of paraphyly (together they are monophyletic), but fails to deal with other issues (e.g., morphological variation in the San Rafael metapopulation and identification of the intermediate forms). Even so, reduction in rank seems the most appropriate strategy. Equating the metapopulations with taxonomic units is the best theoretical approach but may present challenges to management.

Imperiled plants are sometimes protected as endangered or threatened species at national and state levels. However, politically-defined geographic units fall short for conservation purposes. A conservation strategy that recognizes imperiled plants for various eco-regions or greater ecosystems is proposed. This would help a) safeguard plant populations of evolutionary significance; b) maintain ecological integrity of regionally distinct biotic communities; and c) preserve wild plant populations locally for various educational, recreational, medicinal and aesthetic reasons. A recent tally of imperiled plants of the San Juan Mountains and adjacent areas of Colorado and New Mexico, for example, showed that only 10 of 57 (18%) regionally imperiled species appear on federal or state endangered species lists. Yet populations of regionally at-risk plants such as alpine aster Aster alpinus var. vierhapperi and Parish's alkali grass Puccinellia parishii may have high ecological or evolutionary value, while others, like American spikenard Aralia racemosa and wood lily Lilium philadelphicum, are of special cultural interest. The proposed regional approach to imperiled species classification could also serve to focus conservation attention on rare endemics, such as skiff milkvetch Astragalus microcymbus and Pagosa gilia Ipomopsis polyantha, which fail to make federal or state endangered species lists.

The Lane Mountain milkvetch (Astragalus jaegerianus) is an endemic, Federally listed endangered plant of the central Mojave Desert. During recent surveys, we found over 840 plants, and we estimate that there are over 2600 plants within a total area of 5.4 km² that was systematically surveyed. Milkvetch occurs on specific habitats within the upper elevations of creosote bush scrub. These habitats differ from the surrounding sites by having thin soils composed of coarse, decomposed granite and granitic parent rock that is partially exposed or within 25 cm of the soil surface. Milkvetch site vegetation is characterized by lower cover and higher density of shrubs than that found on neighboring sites; and although most shrubby species occur on both sites, there are some species that are distinctive to only one of the habitats. Milkvetch is normally associated with a nurse plant but sometimes is found alone. Of the sixteen species found as nurse plants, both Ephedra nevadensis and Thamnosma montana are more and Eriogonum fasciculatum is less frequently associated with milkvetch than would be expected from their relative density or cover. The diversity of nurse plant species suggests that milkvetch benefits from many species. However, milkvetch probably survives longer when growing with a long-lived host of short stature and, perhaps, more open canopy. Nurse plants provide support for the viney growth of the milkvetch and protection from herbivory. In return, the milkvetch increases soil nitrogen, which benefits the nurse plant.

The National Forest Genetic Electrophoresis Laboratory (NFGEL) is a national Forest Service facility designed to assess and monitor genetic variation in plant species. We collect information on genetic diversity for a variety of forest plants that in turn is used to form management and conservation strategies. Services are provided to Forest Service managers and research scientists, other Federal and State Government agencies, and non-government organizations. NFGEL was established twelve years ago to serve as a link between science and management. Our work supports the conservation of plant species (especially threatened, endangered, and sensitive species), restoration efforts, and genetic improvement programs. We use both isozyme and DNA-based laboratory techniques to determine genetic structure, measure genetic diversity, clarify taxonomic relationships, study mating systems and genetic relatedness, and address issues of biodiversity and conservation. Ideally, management practices designed to preserve rare plant biodiversity are based in part on an understanding of the population genetics of the rare species. This poster will discuss our recent genetic studies of the rare plants, Sisyrinchium sarmentosum, Hackelia venusta, and Rorippa subumbellata.

Historically, Kusche's sandwort (Arenaria macradenia var. kuschei), a perennial member of the Caryophyllaceae, was known only from the holotype, a vague southern California collection from 1929. In 1994 this taxon was rediscovered on Liebre Mountain, in the Western Transverse Range, Los Angeles County. To date, seven populations of A. macradenia var. kuschei have been located on Liebre Mountain, all within the Angeles National Forest, resulting in the classification of this taxon as a Forest sensitive species. Arenaria macradenia var. arcuifolia also occurs on the Angeles National Forest, and is morphologically similar to var. kuschei. What primarily distinguishes var. kuschei from var. arcuifolia is the formers densely glandular-hairy inflorescence. Four of the populations of A. macradenia var. kuschei on Liebre Mountain co-occur with var. arcuifolia, exhibiting an east-west trend with the number of var. kuschei individuals decreasing and the number of var. arcuifolia individuals increasing towards the east. Seeds were collected from both varieties from six of the populations, germinated, and transplanted into one-gallon pots to observe the ratios of glandular versus nonglandular progeny from a single parental type from each population. Offspring resulting from a single parental type from a single population are exhibiting both glandular and nonglandular varieties, raising questions about taxonomic validity and management needs of Kusche's sandwort.

The yellow-flowered columbines (Aquilegia chrysantha Gray) are usually found in small, isolated populations near streams and pools in mountain ranges throughout the southwestern U.S. To study the long-term dynamics of these populations vulnerable to extinction, we have monitored the demography of a population in Fillmore Canyon in the Organ Mountains of southern New Mexico. Annual estimates of growth, survival, and reproduction were recorded from nearly 2,000 individuals in fifteen 1 meter square plots over a six year period. We estimated a seed bank survival rate from experimental plots and constructed annual size-structured transition matrices. Population growth rates varied widely between 0.55 and 1.50 and were strongly correlated with spring precipitation. We will utilize the relationship between population growth rate and precipitation to calculate a mean growth rate over all years with recorded climate data and project future growth rates under different climate conditions. These methods provide an additional approach to modeling population persistence and present a clearer understanding of the likelihood of extinction for a species dependent on mesic habitat in Fillmore Canyon.

Two endemic locoweeds of Washington Co., UT, Astragalus holmgreniorum and A. ampullarioides occur in only a few small populations surrounded by regions of increasing human activity. These locoweeds are rare and restricted in their habitat preference. Astragalus holmgreniorum is limited to one larger population and two, small, isolated populations on the eastern and western edge of it’s range. It is a short-lived perennial that grows on the Virgin Limestone member of the Moenkopi Formation. At known population sites, living cover averages less than 15 percent. Average density of A. holmgreniorum for all known sites is less than 2 plants per 4m². Astragalus ampullarioides occurs in four populations that fluctuate from a few dozen plants to nearly 300 plants from year to year. This locoweed is restricted to clay soils of the Chinle Formation, which has made demographic studies where individuals are marked and tracked from year to year quite challenging. These soils can shrink and swell as water conditions change. We have monitored populations of these locoweeds and report the status of each species. Associated species, soil characteristics and other descriptions of habitat are reported as well as a discussion of possible threats to the survival of these rare endemics. All known populations of these locoweeds are within 7 miles of St. George, Utah, an ever-expanding urban center surrounded by landscape that invites recreational activities that have radiated in every direction. Direct threats to these Astragalus populations include OHV use, road and structural construction, and population fragmentation. Indirect threats include continual disturbances that encourage aggressive introduced annual species such as Bromus rubens, Malcomia africans, and Erodium cicutarium. These three species are the most closely associated species to both locoweeds. Astragalus holmgreniorum and A. ampullarioides are perhaps 2 species most in danger of extinction in the state of Utah and formal rulings for protection are no in preparation by the U.S. Fish and Wildlife Service. Additional studies investigating seed bank and reproduction biology, as well as additional monitoring are needed to better understand these species and thereby effectively carry out appropriate measures to ensure their survival.

The San Fernando Valley spineflower, Chorizanthe parryi var. fernandina is an annual Coastal Sage Scrub species that had been presumed extirpated since the early 1930’s. In 1999 the plant was rediscovered on property slated for development of over 3,000 homes in the greater Los Angeles area. One component of a comprehensive conservation strategy to protect these highly endangered plant occurrences is through the establishment of an ex-situ (off-site) conservation germplasm collection. Using the spineflower as a model Mr. Wall will present information on considerations and limitations along with methods used at Rancho Santa Ana Botanic Garden in making conservation seed collections.

Shinner’s Tickle Tongue (Zanthoxylum parvum, Rutaceae) is an endemic species of the Trans-Pecos region of West Texas, that has been found in approximately eight locations within the Davis Mountains of Jeff Davis County and a single tentative location within Brewster County. Only the pistillate flowers of this dioecious species were described from the type specimen. The location of staminate as well as the first pistillate population to be found since the type locality in 1947 has allowed a more complete evaluation, including immature fruit and seed, of the reproductive biology of this species. The production of both staminate and pistillate flowers before leaves suggests the possibility of wind pollination. Presence of a vestigial gynoecium within staminate flowers and a general lack of a vestigial androecium in pistillate flowers may indicate that gynoecium suppression is a relatively recent event. Further, Zanthoxylum parvum may represent an evolutionary series of separation from hermaphroditic to gyno-dioecious to dioecious plants. Finally, limited reproductive success of pistillate plants, disruptive meiosis within staminate plants, rhizomes, and initial evidence of polyploidy, may suggest sexual reproduction suppression altogether or at least an apomictic alternative.

Please note the following guidelines for giving oral and poster presentations. Thirty minutes are scheduled for each oral presentation – 25 minutes for your talk and 5 minutes for questions. Because we have a full schedule, please adhere to this time limit. Please note that there will not be provisions for computer presentations. Please convert your presentations to slides. There will be slide projectors and overhead transparency projectors for your use. Please give your slides to the projectionist in the morning. Please check the conference program at www.thearb.org if you have any questions about the time of your presentation at the Third Southwest Rare and Endangered Plant conference.

Poster presentations are scheduled for Tuesday, September 26, from 4:00 to 5:00 p.m. Please set up your poster that morning. You may leave your poster up throughout the rest of the conference.

Please note that the conference will end at 11:30 a.m. on Thursday. There will be optional field trips available afterwards for interested parties. Details are given within the program section.

If you wish to have your paper published in the proceedings, please follow the following instructions to help us produce the proceedings in a timely manner.

Submit your complete manuscript in hardcopy and on disk to me at the conference.

The disk version of the manuscript should be saved as Rich Text Format. Please do not use autoformatting, as it gives our editor headaches.

Manuscripts are limited to 20 double-spaced pages of text.

Limit tables, figures, and illustrations to 8 maximum.

Submit figures as PMT’s or equivalent. If submitted electronically, files must be created in Adobe Illustrator, Correl Draw or Macromedia Freehand and include a hard copy. If your program can save files as EPS export files that is fine.

If none of the above options for figures will work for you, print your figure on good quality (the whiter the better) laser paper with a laser printer. Dot matrix and inkjet printed figures are not acceptable.

Submit photos as black and white glossy 8" x 10" prints. Have a human being print your photos to assure good quality. This was the stickiest problem with our publisher, particularly photos of gels.

The manuscript including literature citations should follow the format of papers in the journal Ecology or as in the Southwestern Rare and Endangered Plants: Proceedings of the Second Conference. Abstracts should be 200 words or less.

We will try to have manuscripts through an initial review by the end of January 2001. If revisions are necessary, we will send your manuscripts back to you. We certainly hope that you will consider publishing in the proceedings. Many from federal and state agencies have told us how valuable the first two proceedings have been. If you have any questions, please feel free to call me at (928) 774-1442 x114 or e-mail me at Joyce.Maschinski@nau.edu.

Sincerely,

Director of Research

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Last modified: Monday May 12, 2008