On the study of phenology
In nature, timing is everything. If the alewives were to migrate into the lake before the algae begins to reproduce, the fish fry will starve soon after hatching. If the buds burst open only to freeze, the trees will have sunk valuable resources into growth, only to have them damaged before photosynthesis even begins. Phenology is the study of events in nature and how these events are impacted by seasonal changes and variations in climate.
At this time of year, changes are evident all around us: the buds begin to grow and change color; the pussy willows bloom; the sun feels warm on our backs; the rings of snow melt around the trees reach to the bare earth; the sap is running on warm days; skunk cabbage heats up the wet areas where it grows and prepares to bloom; barred and great-horned owls are busy bringing rodents to their owlets in the nests; skunks and turkeys and many other creatures have just finished their mating season and so the females are in search of extra nutrition and sites to give birth or lay their eggs.
All of these changes are related to each other and tie into far-flung, sometimes complicated relationships in nature. The new pollen and nectar in the pussy willows and skunk cabbage flowers provide sugars and protein to small birds and insects – this is a symbiotic relationship in which the flowers are pollinated while the animals receive nutrition. The insects attract beetles and spiders and other invertebrates, which in turn are welcome food for shrews, skunks and other small mammals seeking sustenance for their new litters of off-spring. The owls and other predators who are also raising their young at this time likewise benefit.
With climate change (or climate disruption as it is now sometimes called, to summon us out of complacency), many of these events are becoming misaligned, which can have far-reaching consequences. For example, if flowers bloom before their pollinators are present, or are delayed, this can mean their pollinators do not survive or are unable to reproduce. Birds and animals depending on those pollinators or their offspring are in turn affected – part of a cascade of cause and effect. Organisms that do survive disruptions in timing are susceptible to stress caused by changes in climate and weather patterns over time.
Before we know it, here in midcoast Maine, the vernal pools will be thawed and the wood frogs will begin to sing. The next time you come across a pool of water in the woods, look for the telltale masses of eggs below the surface. The wood frog offspring will soon be in a race against time to go through metamorphosis before their woodland pools dry out in midsummer – just one of the many interconnected lives, big and small, that depend on seasonal climate conditions to survive and thrive.
Photo of wood frog and wood frog eggs by Judy Gallagher.