CPC received a grant from the Institute for Museum and Library Services (IMLS) for a project entitled, “RNA integrity as a powerful metric of aging in preserved seed collections of wild rare plant species”, and as part of this grant The Arboretum at Flagstaff collected seeds for Purshia subintegra, or the Arizona Cliffrose. We collected 800 seeds bulked together in July of 2021. These fresh seeds will be compared to older seed we collected from the same population to find out how fast rare seeds are losing their viability in storage. The seed collecting conditions in 2021 were vastly superior to conditions in 2020, in which Northern Arizona experienced the worst drought in recorded history. Plants all across the ecosystem responded well to the shift back to a relatively normal amount of rainfall.

In 2021, CPC contracted the Arboretum at Flagstaff to recollect seed from a population currently held in long term orthodox seed storage as part of an IMLS-funded seed longevity experiment. The National Laboratory for Genetic Resources Preservation will evaluate how germination tested viability and RNA Integrity of seed lots decline over time in storage.

Our ongoing studies of Arizona cliffrose, Purshia subintegra, have concentrated on many aspects of understanding the biology of the species. Arizona cliffrose is known from 4 disjunct populations in central Arizona. The largest and healthiest population is found on state land in the Verde Valley, where new road construction will bisect the population, destroy approximately 10% of the plants in the population, and destroy available and potential habitat. This plant has extremely deep tap roots, making direct transplantation of threatened individuals to a new location away from the road construction is not possible. Therefore, in order to preserve these plants (with their potentially unique genes) it is necessary to cultivate them either from seeds or cuttings. Until a few yeas ago, this was not possible, as a drought kept the threatened individuals from producing seed, and cultivation from cuttings was considered difficult if not impossible to accomplish. From 1996-2000, the Arboretum at Flagstaff undertook a mitigation project that entailed learning how to cultivate Arizona cliffrose from cuttings of 65 plants that were threatened by the construction of one road. After a year of work, protocols were finally established for the successful cultivation of this species from cuttings. While not fast, (can take from 6 months to 1 year) this knowledge was key to saving the individuals in the population that were slated to be destroyed by the planned road. The next step of the process was determining the methods to successfully reintroduce this desert plant into its native habitat. To do this, The Arboretum at Flagstaff conducted 4 experimental reintroduction trials, and found that growing the cuttings in native soil, transplanting them to the reintroduction in February, and watering them for over 5 months resulted in the greatest survival. As of 2002, the results were somewhat promising, as some of the individuals in the reintroduced population were able to survive a second year of drought--the worst in recorded history in the area. (Maschinski 2000)

Our ongoing studies of Arizona cliffrose, Purshia subintegra, have concentrated on many aspects of understanding the biology of the species. Arizona cliffrose is known from 4 disjunct populations in central Arizona. The largest and healthiest population is found on state land in the Verde Valley, where new road construction will bisect the population, destroy approximately 10% of the plants in the population, and destroy available and potential habitat. This plant has extremely deep tap roots, making direct transplantation of threatened individuals to a new location away from the road construction is not possible. Therefore, in order to preserve these plants (with their potentially unique genes) it is necessary to cultivate them either from seeds or cuttings. Until a few yeas ago, this was not possible, as a drought kept the threatened individuals from producing seed, and cultivation from cuttings was considered difficult if not impossible to accomplish. From 1996-2000, the Arboretum at Flagstaff undertook a mitigation project that entailed learning how to cultivate Arizona cliffrose from cuttings of 65 plants that were threatened by the construction of one road. After a year of work, protocols were finally established for the successful cultivation of this species from cuttings. While not fast, (can take from 6 months to 1 year) this knowledge was key to saving the individuals in the population that were slated to be destroyed by the planned road. The next step of the process was determining the methods to successfully reintroduce this desert plant into its native habitat. To do this, The Arboretum at Flagstaff conducted 4 experimental reintroduction trials, and found that growing the cuttings in native soil, transplanting them to the reintroduction in February, and watering them for over 5 months resulted in the greatest survival. As of 2002, the results were somewhat promising, as some of the individuals in the reintroduced population were able to survive a second year of drought--the worst in recorded history in the area. (Maschinski 2000)

The acquisition of long-term datasets can represent decades of really hard work and thousands of dollars in exhausted resources. The standard model of monitoring these sites year after year is unsustainable for most organizations especially small organizations such as the Arboretum at Flagstaff. FLAG set out to address three different questions using a demography dataset of Purshia subintegra (Arizona cliffrose) spanning 22 years: (1) What is the long-term viability of the population? (2) What are the specific life stages that are potentially impeding population growth? (3) Is it possible to make modifications to the monitoring protocol to become more efficient and minimize resource use? This 22-year dataset of Purshia subintegra is based on the following criteria: (1) 3 plot types (random, high density, hybrid). (2) 10 m transects (40 m2 plot area); n=61 total plots. (3) Metrics: size, phenology, #flowers, #seeds, seedling count, damage, and mapping of new individuals. (4) 2 people x 5 days = 10 days of labor, plus travel (~100 mi RT x 5) to monitor all plots. Prior to making any procedure changes the question of the long-term viability of the population must be addressed. Therefore, based on the 100-Year Stochastic Projection for 24 Random Plots with results of 5000 Iterations and an initial population of 233 individuals - the probability of extinction or a significant high decrease of individuals is very high. Subsequently, the need to monitor still exists. Also based on the 21 years of demography data, it was noted that the number of reproductive mature adults was quite stable over time but the seedling recruitment into the next juvenile stage was abysmal. The next pertinent question was if there exists important correlations with different weather events. Further study of the Verde Valley which has a mean annual precipitation of 11.7 inches revealed that if the annual precipitation was the mean or less, the mean number of seedlings was less than 1 per plot. In years with even slightly more than the mean annual precipitation the number of seedlings jumped to 1 or greater per plot. This finding represents the crucial period for monitoring because these individuals represent recruitment into the next stage. (Haskins et al. 2018)

Based on findings of a long term population monitoring, low annual precipitation affects seedling recruitment into the next stage. (Haskins et al. 2018)

Based on findings, Arboretum at Flagstaff will implement the following:  (1) Reduce the number of plots to monitor, focusing on the 24 random plots.  (2) Track annual precipitation and monitor in years that expect seedling booms AND years in which high mortality is expected.  (3) These changes will capture important life history events and minimize labor and resource costs.  (Haskins et al. 2018)

The acquisition of long-term datasets can represent decades of really hard work and thousands of dollars in exhausted resources.  The standard model of monitoring these sites year after year is unsustainable for most organizations especially small organizations such as the Arboretum at Flagstaff.   FLAG set out to address three different questions using a demography dataset of Purshia subintegra (Arizona cliffrose) spanning 22 years: 
(1) What is the long-term viability of the population?  (2) What are the specific life stages that are potentially impeding population growth?  (3) Is it possible to make modifications to the monitoring protocol to become more efficient and minimize resource use?  This 22-year dataset of Purshia subintegra is based on the following criteria:  (1) 3 plot types (random, high density, hybrid).  (2) 10 m transects (40 m² plot area); n=61 total plots.  (3) Metrics: size, phenology, #flowers, #seeds, seedling count, damage, and mapping of new individuals.  (4) 2 people x 5 days = 10 days of labor, plus travel (~100 mi RT x 5) to monitor all plots.  Prior to making any procedure changes the question of the long-term viability of the population must be addressed.  Therefore, based on the 100-Year Stochastic Projection for 24 Random Plots with results of 5000 Iterations and an initial population of 233 individuals - the probability of extinction or a significant high decrease of individuals is very high.  Subsequently, the need to monitor still exists.  Also based on the 21 years of demography data, it was noted that the number of reproductive mature adults was quite stable over time but the seedling recruitment into the next juvenile stage was abysmal.  The next pertinent question was if there exists important correlations with different weather events.  Further study of the Verde Valley which has a mean annual precipitation of 11.7 inches revealed that if the annual precipitation was the mean or less, the mean number of seedlings was less than 1 per plot.  In years with even slightly more than the mean annual precipitation the number of seedlings jumped to 1 or greater per plot.  This finding represents the crucial period for monitoring because these individuals represent recruitment into the next stage.  (Haskins et al. 2018)

Narrowly restricted to infertile, white, calcareous deposits in central Arizona. Five populations are known and each is threatened to varying degrees by cattle and burro grazing, mineral exploration and development, urbanization, road construction, off-road vehicle traffic, and pesticide use.

Threats include: urbanization mining overuse by cattle and burros road construction off-road vehicle traffic extended drought (USFWS 1995)

This species is found in four localities in central Arizona below the Mogollon Rim. The most northern of these four locations contains the healthiest individuals, but these are threatened by road construction.

Our ongoing studies of Arizona cliffrose, Purshia subintegra, have concentrated on many aspects of understanding the biology of the species. Arizona cliffrose is known from 4 disjunct populations in central Arizona. The largest and healthiest population is found on state land in the Verde Valley, where new road construction will bisect the population, destroy approximately 10% of the plants in the population, and destroy available and potential habitat. This plant has extremely deep tap roots, making direct transplantation of threatened individuals to a new location away from the road construction is not possible. Therefore, in order to preserve these plants (with their potentially unique genes) it is necessary to cultivate them either from seeds or cuttings. Until a few yeas ago, this was not possible, as a drought kept the threatened individuals from producing seed, and cultivation from cuttings was considered difficult if not impossible to accomplish. From 1996-2000, the Arboretum at Flagstaff undertook a mitigation project that entailed learning how to cultivate Arizona cliffrose from cuttings of 65 plants that were threatened by the construction of one road. After a year of work, protocols were finally established for the successful cultivation of this species from cuttings. While not fast, (can take from 6 months to 1 year) this knowledge was key to saving the individuals in the population that were slated to be destroyed by the planned road. The next step of the process was determining the methods to successfully reintroduce this desert plant into its native habitat. To do this, The Arboretum at Flagstaff conducted 4 experimental reintroduction trials, and found that growing the cuttings in native soil, transplanting them to the reintroduction in February, and watering them for over 5 months resulted in the greatest survival. As of 2002, the results were somewhat promising, as some of the individuals in the reintroduced population were able to survive a second year of drought--the worst in recorded history in the area. (Maschinski 2000)

A management plan is being developed for the USFS lands holding Purshia subintegra in the Verde Valley. There is a good chance that more Purshia habitat will be protected.

Research needs include continued genetic and demographic studies.

The Arboretum at Flagstaff will continue to collect the genotypes of individuals that will be destroyed from road work and use knowledge of cultivation protocols to eventually reintroduce these individuals to the newly protected habitat on federal land.