Bayou-Diversity (18 February 2018) Spells of harsh winter weather occasionally disrupt the daily lives of people in Louisiana. Technological advancements in the last 100 years, however, minimize the impacts to a short period of inconvenience for most. Consider the differences now and during the Civil War era as described by a Confederate soldier. He wrote, “The last days of the year were rainy and disagreeable, and on the last night of 1863, the rain ceased, the wind blew almost a hurricane, turning the air most bitterly cold . . . There is not a man of the 18th who forgets the march on that New Year's day, up the river and thru Monroe. The wind came directly in their faces . . ., freezing so rapidly that the earth was frozen hard enough to bear up our heavy wagons . . . Many of the men had their fingers and feet frozen . . . many . . . were barefooted, some were without blankets, and others almost destitute of clothing . . . On the march to Bartholomew Bayou, the blood from the feet of the men was frequently to be seen upon the frozen ground . . . " This passage tends to put our weather-related privations in perspective. For better or worse, humans were much more in tune with the environment in those days.
For native plants and wildlife, though, little has changed. Cyclic weather extremes configured our natural ecosystems and continue to do so today. We can even predict with a degree of certainty some results of hard freezes based on past observations of similar events. For instance, south-central Arkansas tends to be about as far north as alligator populations can consistently thrive. Cold weather is a limiting factor, and many alligators in that area die in severe cold spells. Woodcocks are quail-size birds that spend the winter here and are adapted to feed on earthworms with their long probing bills. Large numbers have been known to starve when the ground freezes hard for several days. Waterfowl wintering in Louisiana stay busy trying to build fat reserves for the long flight back north to their breeding grounds. A stressful weather event can cause some, especially females, to arrive in less than optimum breeding condition, and thus have a negative impact on the number of young produced in the spring. In a recent year, oak trees produced a larger than average crop of acorns, but few germinated because a severe freeze killed the embryos inside. In contrast, some native species benefit when exotic invaders including fire ants, nutria, water hyacinth, and Chinese tallow are suppressed by cold weather.
Generally, isolated weather events have little long-term impact on native plant and wildlife populations. They contribute to nature’s complex system of checks and balances, which has evolved over thousands of years. The remarkable resiliency of our ecosystems is challenged only when humans with their technology overload the process. (Adapted from Bayou-Diversity: Nature & People in the Louisiana Bayou Country; LSU Press)