WHAT’S NOT TO LIKE about the alpine? In the Rocky Mountains, alpine vistas showcase snow-speckled peaks above mixed coniferous forests and lush mountain meadows, and rarefied air offers a delightful relief from summer’s heat and humidity. Charismatic flora including sky blue alpine forget-me-nots (Eritrichium argenteum), blue and white columbines, (Aquilegia spp.) pink moss campion (Silene acaulis), and a host of yellow composites (Hymenoxys spp., Senecio spp., Tonestus spp.) dot rocky slopes, while adorable pikas call out from boulders before disappearing into their dens and camouflaged ptarmigan munch on willow buds, flowers, and berries.
Far below is the bustling metropolis of Denver. While often thought of as a mountain city, Denver is situated at the base of the Rockies in the western Great Plains. In the heart of the mile-high city, Denver Botanic Gardens, with its extensive living collections at three sites (York Street, Chatfield Farms, and Mt. Goliath), a large alpine collection, herbaria, research and conservation department, and educational outreach, offers visitors a taste of flora they will encounter high up in the Rockies. Founded in 1951, the Gardens has worked with the flora of Colorado including alpine species for decades. In fact, prior to its formal founding, Denver Botanic Gardens and the U.S. Forest Service partnered to preserve the flora, fauna, and ecosystems on a site above 11,540 feet (3517 m) on Mount Goliath, which is located 43 miles (69 km) west of Denver on the Mount Evans Scenic Byway. Today, visitors from around the world stroll the paths, learning about alpine floral diversity and the harsh but fragile life zone these plants call home.
Committed to the conservation of alpine flora, Denver Botanic Gardens partnered with Betty Ford Alpine Gardens in 2018 to build on foundational work done by Betty Ford. Since the publication of the Alpine Strategy in 2021, Denver Botanic Gardens’ staff and volunteers have focused on the following two targets as described in objective one of the Alpine Strategy: Understand and document alpine plant diversity.
Target One: Develop a working map of all North American alpine areas.
While it seems that a comprehensive map of alpine areas in North America should exist, a usable one has not been found. Rising to the challenge, a volunteer in the Research and Conservation department at Denver Botanic Gardens set out to generate a map delineating all alpine areas of the U.S. and Canada. Work to refine this map is ongoing.
Such a map is crucial to furthering the alpine strategy. First, as the strategy uses IUCN protection designation categories (Ia, Ib, II, III, IV, V, and VI), this map will allow partners to assess the protection level of each alpine area. For example, the map will highlight alpine areas with high levels of protection, such as wilderness areas, national parks, and habitat/species management areas, and those with less protection, including mining districts and ski resorts. Second, the map will include Important Plant Areas (IPAs), which have been designated by organizations such as the Colorado Natural Heritage Program as areas with exceptional botanical richness or that support rare, threatened, and endemic plants. This will allow partners to evaluate progress in our goal of protecting 50 percent of each IPA for alpine plants by 2030. Finally, this map will identify understudied alpine areas and where further botanical surveys are needed to provide more up-to-date species lists as well as habitat assessments.
Target two: Create a list of all known alpine plants of North America.
Staff, interns, and volunteers from Betty Ford Alpine Gardens and Denver Botanic Gardens are collaborating to compile a list of North American alpine taxa. This list draws from regional lists created by NARGS member Todd Boland of MUN Botanical Garden (Newfoundland and Labrador), Curtis Björk (western Canada and Alaska), Robert Fowler (Southern Rockies), regional floras including Flora of Colorado (Ackerfield, 2015), and various floristic surveys conducted in alpine areas. To date, the list includes around 2,500 taxa.
When complete, this list will be the most comprehensive list of North American alpine plants, enabling partners to meet other targets of the Alpine Strategy, specifically Target Six: Conserve at least 25% of all identified North American alpine flora in-situ; and Target Eight: Conserve at least 60% of all identified North American alpine flora ex-situ. Stored in BG-BASE, a database used by botanic gardens, arboreta, and similar institutions to document their collections, the taxa will be searchable by state/province, global and state conservation statuses, and endemism, which will inform which taxa to prioritize for field and conservation work. Ultimately, this list will be publicly available, allowing other stakeholders to benefit including botanists, land and resource managers, horticulturists, herbaria curators, university professors and students, natural heritage programs, citizen scientists, outdoor recreation groups, and even rock garden enthusiasts! For example, rock gardeners will be able to consult the alpine list to preview special plants they might encounter when visiting a specific area, and if these taxa have state or federal protection or are considered plentiful and secure. The list could also help highlight what noteworthy taxa rock gardeners are cultivating in their own gardens.
Objectives two, three, and four:
In addition to focusing on the above targets, Denver Botanic Gardens continues to contribute to other objectives of the Alpine Strategy. Specific to objective two (conserve alpine plants and their habitats), the Research & Conservation Department at Denver Botanic Gardens has a long history of plant conservation stretching back more than forty years. In the following article in this issue, Alex Segalis, the seed conservation research associate at the Gardens, outlines ex-situ and in-situ studies she is working on.
Also, while still early in the implementation of the strategy, Denver Botanic Gardens has used its international and national reach to address objective three: promote awareness of the alpine ecosystem and plant diversity through education and engage in outreach; and objective four: build capacity for the conservation of alpine plant species and associated habitats. Following the publication of the Strategy, Denver Botanic Gardens distributed it to other botanic gardens across the U.S. and Canada with notable alpine collections. The Gardens has also shared the strategy with local and regional forest service personnel. It will take many public gardens, land managers, and concerned members of the public to conduct outreach and build the capacity to conserve and safeguard alpine habitats.
Finally, for objectives three and four which deal with awareness and engaging partners and the public, few methods promote plant conservation like the plants themselves. Living plants are the panda bears and elephants that put a living representation of what is at stake in front of the audience we are hoping to inspire into action. The Gardens’ plant collections across three sites show visitors living representatives of the strategy and also allow us to work with alpine plants with different growing conditions. At the heart of the living collection is the Rock Alpine Garden. With over 4,000 plant taxa and covering one acre of Denver Botanic Gardens’ 23-acre (9.3-hectare) York Street location, this garden has been inspiring visitors since the early 1980s with the beauty and delicacy of high elevation flora from around the world. As the climate has continued to warm over the past decade, the Gardens have added interpretational signage to educate visitors on why these beautiful plants are in peril. Additional interpretation discusses specific alpine habitats replicated in the gardens and the importance of using microclimates to grow these plants at 5,300 feet (16,150 m) in elevation, where temperatures have reached 105°F (40°C) several times since 2004. Taxa that tolerate Denver’s warming climate may offer clues as to which taxa might weather climate change more successfully in-situ.
Finally, rock gardeners have also been inspired by the alpine life zone and its plants. Over the past several centuries, private rock gardens and troughs have brought a taste of alpine into our yards and neighborhoods. These beautiful gardens can educate and inspire our communities of the beauty, diversity, and fragility of alpine ecosystems. Please continue to share your enthusiasm for and knowledge of alpine plants. Also, stay tuned for opportunities to become involved with the Alpine Strategy itself. Specifically, we are looking for help refining state and province lists of alpine taxa. Emily Griffoul’s article in this issue has information about upcoming citizen science projects. Let’s use our combined knowledge and love of alpine plants to work together to help safeguard these plants and their precious habitats forever.
