Besides a high risk of fire, what do dry conditions in Colorado mean to Rocky Mountain National Park ecosystems? A mild winter combined with very low precipitation, especially snowfall, results in exceptionally dry conditions. While this has a dramatic effect on fire danger, it also has an effect on how ecosystems function in the park as well.
In the park's meadows, many species of wildflowers bloom poorly or not at all. As one example, the Rocky Mountain iris (Iris missouriensis), a species that needs a bit more moisture, makes a very poor showing in drought years. On the other hand, dry adapted species such as the mountain ball cactus (Pediocactus simpsonii) bloom very well. Most alpine tundra species bloomed about a month earlier than usual.
Because certain groups of wildflowers do not bloom as well as usual or at atypical times, some groups of pollinators are also not seen in the usual numbers. Butterfly numbers go down in many places in the park and blue butterflies are virtually absent.
In small ponds and wet areas around the park, researchers observe breeding of amphibians occurring at a low rate, and survival appears poor. At treeline, rangers report more trees than normal losing branches.
Most species that inhabit the park are adapted to some variation in the climate, so dry conditions should not cause permanent harm to any healthy populations. Microclimates around waterfalls and streams, in steep valleys, and in protected locations provide places for some plants and animals to "weather out" such difficult times, provided the conditions do not persist for long periods. Other species, such as butterflies, are more mobile and can move to areas of better conditions. Nevertheless, the effects of a Colorado dry summer can be clearly read in the ecosystems in Rocky Mountain National Park.