Long-term shifts in the phenology of rare and endemic Rocky Mountain plants.
•


OBJECTIVE
Mountainous regions support high plant productivity, diversity, and endemism, yet are highly vulnerable to climate change. Historical records and model predictions show increasing temperatures across high elevation regions including the Southern Rocky Mountains, which can have a strong influence on the performance and distribution of montane plant species. Rare plant species can be particularly vulnerable to climate change because of their limited abundance and distribution.•


METHODS
We tracked the phenology of rare and endemic species, which are identified as imperiled, across three different habitat types with herbarium records to determine if flowering time has changed over the last century, and if phenological change was related to shifts in climate.•


RESULTS
We found that the flowering date of rare species has accelerated 3.1 d every decade (42 d total) since the late 1800s, with plants in sagebrush interbasins showing the strongest accelerations in phenology. High winter temperatures were associated with the acceleration of phenology in low elevation sagebrush and barren river habitats, whereas high spring temperatures explained accelerated phenology in the high elevation alpine habitat. In contrast, high spring temperatures delayed the phenology of plant species in the two low-elevation habitats and precipitation had mixed effects depending on the season.•


CONCLUSIONS
These results provide evidence for large shifts in the phenology of rare Rocky Mountain plants related to climate, which can have strong effects on plant fitness, the abundance of associated wildlife, and the future of plant conservation in mountainous regions.
U.S. Geological Survey, Southwest Biological Science Center, 2255 N. Gemini Dr., Flagstaff, Arizona 86001 USA.
Seth M
SM
Munson
University of Denver, Department of Biological Sciences, 2190 E. Illif Ave., Denver, Colorado 80208 USA.
Anna A
AA
Sher
D057231:Climate Change; D003120:Colorado; D017753:Ecosystem; D056727:Endangered Species; D019684:Magnoliopsida / Q000502:physiology*; D063148:Plant Dispersal; D012098:Reproduction; D012621:Seasons; D013045:Species Specificity; D013696:Temperature
Colorado; climate change; endangered and imperiled species; flowering date; herbarium specimens; warming