A mast year is defined as a year in which multiple species of a wind-pollinated genus of plant produce more seed or nut than can be consumed by the wildlife the plants support. This phenomenon happens to many different genera of trees and a few shrubs. This would not seem unusual except that mast years appear to be synchronized; that is, when one species in a genus produces inordinate amounts of seed or nut, most all of the other species in that genus do the same regardless of the distance between the plants. The mast year occurrence happens most often in forests; however, I have noticed it in the serviceberry trees (Amelanchier spp.) growing in my neighborhood and in the demonstration gardens I steward. How do these plants work in concert? How do they discern that a particular year is a mast year when each plant can be separated by many miles?
Research has shown that the cause of masting is probably not a chemical signal produced by the plant telling its kin “now’s the time – do it!”; nor is it a signal carried in pollen from one plant to another and on down the line. Rather, it is most likely a plants’ response to environmental conditions, such as temperature fluctuations (and possibly water level in the soil) which affect an entire region, that alert plants to increase seed production. And then each plant in that species gets to the business at hand.
Plants are self-regulating. They respond appropriately to climatic conditions by processes we are just beginning to understand. Plants are finely attuned to their environment. For instance, we have learned that many plants share resources with their less hardy brethren and I will not be surprised to learn, years from now, that this is a common practice among all plants that has been occurring for eons. It is an easy leap to interpret this connectedness and interaction among plants as altruistic, but this interpretation is anthropomorphic and I am sure the real explanation will be far more majestic than we can imagine. At this time, however, I understand these phenomena as intrinsic to plants’ nature. It is just what they do. These processes are proven sound, and may be what will enable the plant world to survive our continued environmental onslaught.
Now, imagine if we humans decided to learn from plants and share our resources with those who have less. Imagine a mast year of kindness!