Last year, on March 30, I wrote about spring on the prairie out in Doney Park, where we live. It came early last year, and I remember writing about the meadowlarks beginning to call in February and the prairie dogs coming out early. Last year, the USGS reported that spring bloom started 20 days earlier than normal in northern Arizona. This year spring may arrive even earlier. High temperatures in January averaged seven degrees above normal, and thus far in February temperatures are 13 degrees above normal. My horses, Scout and Kenosha, are having a difficult time with their thick winter coats. They've been spending their nights outside the barn, laying down in their paddocks trying to cool off, something I've never seen them do.

Two different phenomena happen at the same time in spring: it gets warmer, and the daylight lasts longer. Plant and animal species may react to both of these--or just one. This past weekend, as I was making the rounds before watering my plantings, I was shocked to see that the silver buffaloberry was blooming--and even more shocked to see tiny native bees feeding on the blossoms. These critters, so critical to native plant pollination, may not survive if we get a cold spell. (Unlike honey bees, native bees are generally solitary, nesting in the ground, crevices or hollow twigs.)

I watered for about an hour followed around by black and white leafcutter bees (Megachilidae spp.) looking for water, and began to see other effects of our warm winter. The currants and chokecherries are reddening and beginning to bud, and the daffodils (yes, I do plant non-natives) are peeking out from the soil. The Apache plume and junipers are starting to green.

Spring is indeed coming earlier every year, according to the National Phenological Network. (Phenology is the study of seasonal natural phenomena--when plants bloom, insects return, and animals give birth.) Across North America, spring has been arriving two to three days earlier every decade, and the last cold days occur earlier as well. Javelina and coatimundi have moved into northern Arizona, following the warming temperatures.

The irony of our early spring is that the last frost dates aren't changing that much. In essence, a "false spring," often occurs. A later cold spell can then kill frost-sensitive plants and insects, which in turn affects the animals that depend on them. This mismatch triggers a chilling domino effect, causing localized extinctions in some cases, or lower birth rates, as species contend with less forage or late cold snaps.

As I've been feeling sorry for the bees and hoping that a late frost doesn't kill any plants at the Arboretum, I've tried to figure out what I can do. Should I be putting out flowers for the bees? I already give them water. Are the birds going to mate early, and should I try to provide them with more protected places to build their nests? What should we do?

I've read countless articles about our warming temperatures, uneven weather patterns, and phenological changes, and none of them offers any suggestions, other than what we already know. We need to mitigate climate change, starting right now.

Lynne Nemeth, Executive Director of The Arboretum at Flagstaff, can be reached at Lynne.Nemeth@thearb.org.