Central Park today welcomes the first crocuses emerging from the melting snow and the deep green water-loving buttercups (Ranunculus ficaria) cover the entire ground by patches of mud and melt-water streams in the North Wood. Indian straw-berries have made their appearance and the spring onions are ready for salad, amongst many more species. Spring flowers get a head start on growth in the cavities between the moist earth and snow-blanket above so that they may photosynthesize on the first day of sun-light. The temperature is 55 degrees and sunny and these flowers have taken a gamble to appear green and succulent on this first big show-day with expected freezing snows coming next week.
Tiny red blossoms of a witch hazel (Hamamelis x intermedia) in the North Woods, photograph taken by Ken Chaya on 2/23/14.
The groundhogs and flowers are part of an entire ecosystem’s effort in the detection and signaling of coming spring. Little is known about how plants and animals anticipate spring. Some of the most important forecasts of spring come from organisms that live in total darkness and constant climatic conditions: plants and animals that live in the subnivian zone, a layer of cavities and space between the moist warm earth below and the blanket of snow above. Winter World, by Bernt Heindrich, includes a great story of the organisms that live in this subnivian zone as well as other adaptations that animals have to winters in the Maine woods. Many organisms have internal clocks that signal when to engage in a certain activity. A famous example is a species of bamboo that occurs globally and flowers synchronously once every several hundred years. A species of Cicada, famous to New York, spends seventeen years developing underground and then emerges synchronously to mate, lay eggs and die within a few days.
The study of periodic plant and animal life cycle events and the relationship between these events and seasonality is called phenology. Some information is known about how climate change is influencing the seasonal activities of plants and animals. In New York, our growing season, the period of time where most plant growth occurs, has extended over a week. Henry David Thoreau took painstaking efforts to document the flowering dates of dozens of different plants by Walden Pond in the 1850s. Scientists have found that the same species at Walden are now blossoming between two days and two weeks earlier than they were in Thoreau’s time and that those plants that exhibit the most plasticity are surviving the best.
The impact of climate change on global biodiversity is a major crisis, and it is valuable to examine this problem on local, regional, and global levels. Young people and students across New York City, as well as myself, are getting involved in phenology as a citizen science effort to track the dates when particular species of trees first bud, when species of flowers first bloom and when monarch butterflies first arrive on their migration. These studies have important implications regarding how our climate is changing and how our flora and fauna are adapting to climate change. You may wish to learn more about phenology and if you are a teacher or a student, you may wish to get involved in citizen science here: http://www.globe.gov/web/scrc/overview
Amidst the spring flowers, I walked the North Woods with the New York Mycological Society on a search for the buried gems of this year and years past. As a group of naturalists, children and students, we found twenty species including many edibles, medicinals, and several unknowns. This is part of an ongoing effort to inventory the fungi of Central Park.
Gary Lincoff, mycology expedition leader, holds mushrooms found on the first day of spring, 2/22/14.