Sunday, April 1, 2012

Spring for a Day

male and female alder catkins
Male (bottom) and female (top) alder catkins
What a difference a little sunshine makes. The lake's still frozen over and snowdrifts still abound, but the sky spills snow and rain in equal parts now. And after one warm and sunny day, it feels like spring is ready to blow in at any time.

Yesterday I heard the first Sandhill Cranes of the year, saw three micro-moths flitting about, and heard a rumor of a couple of butterflies working nearby. And the still-leafless alders were getting ready to dust the neighborhood in yellow pollen.

Alders are soft-wooded tree/shrub members of the birch family. They grow well in wet areas and, like flycatchers, there are a handful of alder species that all look very similar to me. Most alders are wind pollinated, therefore they produce early spring flowers before leafing out. And being monoecious, they have male and female flowers on the same plant, often on the same twig.

Alder flowers grow in small clusters of elongated catkins. The male catkins are starting to swell up and go to work around the lakeshore. A gentle thumping produces small puffs of pollen from a few of them already. As spring fades, and their job is done, they'll break apart and fall to the ground.

Female catkins are smaller, sturdier, and look sort of like miniature pine cones. New female catkins will be fertilized in the spring and slowly mature over the summer. By fall each brown and woody female catkin will contain 50-100 seeds. They'll persist on alder branches for a year or more.

Alders provide food for lots of native animals throughout the year. In early spring, Ruffed Grouse eat the male catkins, and bees emerging from winter rely on the early pollen to rebuild their colonies. In summer, the caterpillars of several dozen moth and butterfly species eat the leaves. Lots of bird species eat the mature seeds in fall and winter, including Redpolls, Crossbills and Pine Siskins. Deer and elk nibble at the smaller twigs year round, and beavers chew the bark off the larger stems that also double as dam-building material.

Yesterday's sunshine has slipped back into today's rain and snow mix. But the local alders are almost ready, and when the sunshine returns they'll blossom into small, yellow clouds of reproduction. Then, finally, spring will be in the air - literally.