STATE WE’RE IN: Ten reasons why a cool spring is cool

By Michele Byers, Special Writer
New Jersey’s climate in March was the coldest in 30 years and the 11th coldest since the first records of the late 1880s!
   Data isn’t in yet for April, but we all know it’s been cold — and forecasts call for continued cooler temperatures.
   While some folks can’t wait for hot weather, having winter leap straight into summer isn’t good for our flora and fauna. This year’s slow onset of spring has some cool ecological effects!
   Here are 10 great reasons to embrace a cool start to spring:
   • Trees won’t flower and leaf out before warblers and other insect-eating birds arrive from their tropical wintering grounds.
   Bird migrations are timed with day length, not temperature. Cool springs are better for migrating birds because early, warm springs cause the flush of insects associated with flowers and young leaves of deciduous trees to peak before the birds arrive.
   This year’s timing should be perfect, allowing huge numbers of migrant birds to linger in our forest canopies and fatten up on insects.
   • Blooming times of spring wildflowers will space out well into May instead of becoming compressed in a flurry of hot April weeks.
   This allows insect pollinators the time needed to visit flowers a few species at a time, which means successful pollination and seed set. In quick, hot springs with too many plants flowering at once, much pollen is wasted.
   But when each species’ flowering peaks in natural progression, bumblebees and other native insects can “trap-line” from flower to flower of the same species, resulting in excellent seed production.
   • A staggered bloom of native plants helps insect pollinators as well as plants.
   When spring comes too fast, there’s a gap between the end of spring flowers and the beginning of warm-season summer wildflowers.
   It’s already hard enough for pollinators to thrive in forests whose shrubs are reduced by deer browsing. With large gaps in food supply, regional insect populations can be lost for good!
   • Rare snakes of the Pine Barrens won’t be lured out of the safety of their winter dens by hot days.
   In the spring of 2012, unusually early 85- to 90-degree days caused northern pine snakes to venture too far from their dens. A cold front ended the heat wave, catching the snakes too far from safety. Their body temperatures dropped, and they froze to death during the cold nights.
   • Fruit trees won’t be fooled into early bloom by a series of hot days, only to have their tiny, developing fruits be damaged by a killing frost.
   A gradual onset of spring slows down flowering and, hopefully, the danger of frost will be past by the time flowering, pollination and fruit development occur.
   • Cool temperatures means water remains longer in the forest’s vernal ponds instead of being sucked up by trees or lost to evaporation.
   When vernal ponds hold water well into spring, frog tadpoles and larval salamanders have enough time to mature and leave the drying vernal pond as adults.
   • For a change, Shadbush — native forest trees and shrubs in the genus Amelanchier — are blooming at the correct time, accurately predicting the migration of American shad in the Delaware River.
   • Soil moisture is retained in our forests when spring comes late.
   Hot, sunny, windy days severely dry out soil not yet shaded by leaves, creating dangerous conditions that can lead to wildfires. There have been many wind-driven brush fires this spring, but their heat and destructive force has not been as intense as in hotter springs.
   • The levels of water supply reservoirs stay high well into spring when they’re not drawn down by watering.
   Instead of sprinkling, homeowners can sit back and enjoy their daffodils and forsythia bushes, whose flowers have lasted for what seems like forever!
   • Continued cool nights and slow plant growth force rodents to let down their guard when foraging as their stored winter food supplies have run out.
   You might want to explore the state climatologist website at http://climate.rutgers.edu/stateclim to compare what you remember from days-gone-by to actual data.
    Michele Byers is executive director of the New Jersey Conservation Foundation. For more information, contact her at info@njconservation.org or visit NJCF’s website at www.njconservation.org.