What Can a Mild Winter Do to the Environment?
Snowfall in the nation’s snowiest large city - Syracuse, N.Y. - has added up to less than half of its average mid-January total and temperatures in the usually wintry Northeast are expected to rise into the 50s again before January is over. As portions of the United States experience an unusually mild start to the winter, with higher-than-normal temperatures and less-than-average snowfall, questions are raised about the weather’s effect on the environment.
Scientists and researchers at the SUNY College of Environmental Science and Forestry (ESF) are available to discuss several aspects of this issue:
Aquatic insects and fish: Some aquatic insects, such as mayflies, might emerge earlier this spring. Winter stoneflies might appear earlier and they might grow faster as larvae. Fall-spawning fishes such as brown trout could have higher survival rates this year. Submerged aquatic vegetation is likely to be affected by not having been covered by ice. From an angler’s standpoint, the lack of ice fishing opportunities could mean increased survival of some game species such as northern pike.
Plants and trees: The warmer-than-usual winter could result in injury to plants, especially trees, that have not hardened (become freeze tolerant) because of the lack of persistently cold temperatures. These trees can be severely damaged by hard freezes when they finally occur. Lack of snow also means that soils are not insulated from freezing weather, which can damage shallow roots thus affecting many shallow-rooted trees in urban environments and in wetlands, riparian zones and other poorly drained areas.
Amphibians and reptiles: If warm temperatures continue throughout the winter they will emerge earlier and have a longer breeding season, which benefits them in northern climates with short growing seasons. But if there is a cold snap and no snow, the lack of insulation normally provided by snow will enable the freezing to penetrate deep into the ground and into wetlands where these animals are hibernating; that could kill many of them. Another danger could be presented by a lack of snow pack in the spring to sustain vernal pools, keep stream levels high and keep the ground moist into summer. A dry environment is dangerous for these animals.
Insects: Snow pack provides both protection from predators and insulation for insects that overwinter in the duff; without it they can die. Snowmelt provides perfect habitat for the development of black fly larvae in the spring. Without it, their numbers can be reduced.
Oranmental plants: Plants that are native to warmer climates could be affected without snow cover. They are more likely to break buds if temperatures get warm again because many have had their cold requirements met by now. Any flowers or leaves that emerge from buds before temperatures are consistently above freezing can be damaged; severely damaged flower buds won't produce flowers or fruit. Severely damaged leaf buds won't produce leaves; many species can't readily put out new leaves.