Forage availability is a key factor regulating large herbivore populations. Global changes in land use and climate may affect the spatiotemporal distribution of forage across the ranges of large herbivores, especially in mountain ecosystems. We test two synergistic hypotheses for how landscape and climate changes from 2001 to 2023 have affected forb and graminoid biomass at the peak of the growing season within and across ecor...

Homeothermy requires increased metabolic rates as temperatures decline below the thermoneutral zone, so homeotherms typically select microhabitats within or near their thermoneutral zones during periods of inactivity. However, many mammals and birds are heterotherms that relax internal controls on body temperature and go into torpor when maintaining a high, stable body temperature, which is energetically costly. Such heterothe...

Summary Two populations of the cyanobacterium Calothrix sp. found in Yellowstone thermal spring outflows differ greatly in their contents of scytonemin, a UV‐screening pigment, and in their photosynthetic carbon assimilation rates. Clonal isolates from both populations were used to investigate these phenotypic differences. Identical partial 16S rDNA sequences (∼900 bp) suggest a very close relationship between the two Calothri...

Summary Phenotypic acclimation to changing conditions is typically thought to be beneficial to organisms in the environment. UV radiation is an important parameter affecting photosynthetic organisms in natural environments. We measured the response of photosynthetic carbon fixation in populations of cyanobacteria inhabiting a hot spring following acclimation to different UV treatments. These two very closely related population...