Date of Defense
Richard Brewer, Biological Sciences
Stephen Malcolm, Biological Sciences
Alexander Enyedi, Biological Sciences
Phenology deals with the relations between changing seasons and biological phenomena including the life cycle phases or activities of plants and animals throughout the year. For this paper the spring phenology of the higher plant species in oak forests of the Allegan State Game Area were studied (Kenoyer 1929). Before settlement of Europeans, these uplands were dominated by white pine. Now, white and black oaks are the dominant species following logging of white pine and fire during the late 1800s. A description of spring plant activity, the roles of photoperiod are heat sum in scheduling events are considered. Photoperiod, the length of the daylight period, has little variation from year to year. Heat sum, expressed in degree days, is the accumulation of heat and can vary greatly from year to year. Proximate factors are those that act as an immediate stimulus for biological activity. A proximate factor that could apply to the forest area being studied is heat sum that accumulates to a certain point that triggers chemical reactions in the plant from which products may begin the plant's seasonal cycle. Photoperiod could initiate seasonal cycles in the same manner, thus it may also be considered a proximate factor.
McKenna, Allison, "The Role of Heat Sum in the Spring Phenology of the Southern Michigan Oak Forests" (1993). Honors Theses. 221.
Honors Thesis-Campus Only