December 2012 Number 1 - Utah Native Plant Society

Utah Native Plant Society
earlier, however, the physiological limits of most species
are unknown and may not be exceeded. Or species
may be able to adapt at a pace commensurate with the
rate of climate change. Alternatively, climate change
may facilitate the migration of competitors into the specialized
habitats of these species. Many uncertainties
remain not only about the parameters of climate change
itself, but also about its potential effects on rare plant
species.
Conservation Strategies
We cannot predict with any certainty which of these
33 plant taxa, or for that matter the roughly 150 additional
G2 taxa (those with fewer than 20 known occurrences),
will be most affected by climate change. Nevertheless,
several conservation actions can be identified to
better ensure the long-term conservation of plant diversity
in the Great Basin. Julius and others (2008) identified
adaptation options with an overall goal of maximizing
resilience to climate change and noted that establishing
current baselines, identifying thresholds, and monitoring
for changes will be essential elements of any adaptation
approach.
Clearly, inventory and monitoring are critical elements
of a conservation strategy for these rare plants
Yet only 23 percent of the 167 reported populations of
the 33 rarest taxa have even been visited in the past decade,
and population estimates are available for fewer
than half of these populations (USFWS, unpublished
data). Quantitative monitoring programs are in place, or
in progress, for only five of the taxa. Without a concerted
effort to establish baselines and a commitment to
long-term monitoring, many populations could vanish
without our knowledge, potentially compromising the
long-term viability of species and certainly resulting in a
loss of genetic resources.
To inventory and monitoring, we can add ex situ approaches
as an, admittedly less than ideal, but necessary
element at least for genetic conservation. Ex situ conservation
has long been regarded as an option of last resort
among plant conservationists, in part, because of concern
that it might be viewed as an acceptable alternative
to the conservation of wild habitats. In the face of climate
change, however, many botanists now recognize
that ex situ conservation has a place among a portfolio
of scientifically based techniques that support the primary
objective of retaining plant diversity in the wild.
Such techniques are requisite for restoration and relocation
actions, especially when integrated with regional
conservation for both ecosystems and suites of species
(Guerrant and Pavlik 1997; Maunder et al. 2004; Pavlik
1996).
Fortunately, both the infrastructure and successful
models for comprehensive and integrated approaches
for ex situ conservation of plant genetic resources exist.
The Center for Plant Conservation (CPC; www.center
for plantconservation.org), is dedicated solely to preventing
the extinction of America’s imperiled native
flora. Hosted at the Missouri Botanical Garden in St.
Louis, Missouri, CPC coordinates a network of 33 participating
institutions throughout the country which
maintain plant material (seeds, cuttings, etc.) of the most
imperiled plant species in their region as part of the National
Collection of Endangered Plants, totaling some
700 species.
Representation of the rarest plants of the Great Basin
in the National Collection, however, is poor. Seeds of
only two of the 33 taxa in this study, Eriogonum argophyllum
and Eriogonum ovalifolium var. williamsiae,
are in long-term conservation storage at participating
institutions at the Red Butte Garden in Salt Lake City,
Utah, and the Berry Botanical Garden in Portland, Oregon,
respectively. Among the 11 participating institutions
in the western United States, the Berry Botanical
Garden has the most comprehensive collection with 53
taxa conserved, although only a few of these are from
the Great Basin, as delineated here, and it is uncertain
how representative these samples are of the full range of
genetic diversity among these few taxa. The Red Butte
Garden, the designated primary seed repository for the
Great Basin has 22 taxa conserved, most of which are
plants endemic to Utah.
Seed collection and long-term storage is also coordinated
by the Bureau of Land Management’s Seeds of
Success project established in 2001 in partnership with
the Royal Botanic Gardens, Kew (http://www.nps.gov/
plants/sos/) to collect, conserve, and develop native
plant materials for stabilizing, rehabilitating and restoring
lands in the United States. This partnership has now
grown to include many partners who have collected
over 6,689 seed accessions. While the focus of Seeds of
Success is on common species, it nevertheless provides
a useful model for a comprehensive, landscape-based
program of targeted seed collection.
CONCLUSIONS
While climate change poses ecosystemic challenges
to many species, narrowly distributed and highly specialized
taxa are particularly at risk. Among the rarest
plants in Great Basin of Nevada, the majority of those
likely to be at greatest risk are restricted to azonal edaphic
habitats in the valleys. A comprehensive and integrated
program of adaptation options is essential to
maximize the resilience of their ecosystems to change.
In particular, inventory, monitoring, and ex situ conservation
are needed to ensure that baseline data are available
against which demographic changes in these taxa
can be evaluated and to ensure that genetic resources
representative of the diversity within these taxa are conserved.
Conservation of the full range of genetic diver-
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