Ecological and evolutionary importance of plant reproductive responses to climate change.
Inouye, David*,1, 2, 1 University of Maryland, College Park, MD2 Rocky Mountain Biological Laboratory, Crested Butte, CO
ABSTRACT- The seasonal timing of flowering (flowering phenology) is a phenotypic trait with both ecological and evolutionary significance. Most temperate species rely on environmental cues for the development of floral buds and the timing of flowering. Precipitation is an important cue for some species (e.g., desert annuals), while temperature cues (often measured as growing degree days) are common for many others. In the montane area where I work in the Colorado Rocky Mountains the primary determinant of flowering time for almost all species is the date when the snow cover melts, signaling the beginning of the growing season. This phenological event is very variable across years, and likely to change in response to regional and global climate change. For example, ENSO and the North Pacific Oscillation (or PDO) are regional events that influence winter snowpack and therefore the timing of snowmelt, and global warming may also be influencing snowmelt through effects on precipitation and temperature. Plants that are dependent upon pollinators for reproduction must be in phenological synchrony with the time of pollinator activity. There is some evidence that plants and pollinators are responding differently to changes in the environment, in their phenology and their altitudinal and latitudinal distributions, which could result in reduced reproductive success on the parts of both plants and their pollinators, changes in the species with which a particular partner interacts, and the possibility of extinctions. Data from long-term studies of phenology at the Rocky Mountain Biological Laboratory will be used to illustrate some of these points.
Key words: phenology, flowering, montane meadows
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