.The Effect of Climate on White Oak Trees in Oxford Ohio
By: Shawn Seiler
The surface of the Earth is in constant change. One of the main driving forces behind this change is climate. Climate affects and shapes the land, plants and animals. Climate is not static; instead, it to is in constant change. The climate of one region today, may have been completely different than the climate of the past. To understand and interpret the paleoclimate of a region, scientists have invested a vast amount of research in this area. Dendrochronology is an important tool in order to understand the past, present and future climates of an area. Dendrochronolgy is the study of the chronological sequence of annual growth rings in trees (Stokes & Smiley, 1996). Trees exhibit certain annular growth patterns, depending on the species. These growth patterns, or rings, are influenced by age-related growth trend, climate, disturbance processes within the forest stand, disturbance processes from outside the forest stand, and random processes (Grissino-Mayer, 2000). It is difficult to decipher the disturbances within and outside a forest and to uncover the random processes that hindered or perpetuated the growth of a tree. Climate, however, is a factor that can be examined and linked to the extent of the growth of tree rings. Since trees are living they need certain factors in which to grow and survive. These factors need to be ideal in order for a tree to sustain vigorous growth. If one of the factors is unsuitable for the tree, that limiting factor will be seen in that tree's ring record. The ring record reflects favorable and unfavorable conditions in the life of the tree. It has been shown by numerous research ventures that climate affects tree growth in positive and harmful ways. To study the tree ring record, is to look back in time at the environmental stimuli, which affected that tree.
Oxford, Ohio is situated in a temperate climate zone. This means that the vegetation period lasts several months (approx. April 1-September 30) and there is ample rainfall for growth throughout the growing season (Schweingruber, 1987). The growing period for temperate climates lasts from around April to the end of September. The only factors that limit tree growth in temperate climates are lack of precipitation and excessively low temperatures during the growing season (Schweingruber, 1987). The purpose of this paper is to analyze a sample of the White Oak (Quercus alba) population in Oxford, Ohio and observe their response to changing climatic conditions over the last seventy years.
Being situated in a temperate climate, Oxford's White Oak (Quercus alba) will exhibit tree rings that will correlate with changing climatic conditions in the area. In growing periods where there is lower precipitation than normal and excessively low temperatures, tree growth will be diminished. Conversely, when there are ideal growing conditions, the tree growth will be enhanced.
Numerous processes on Earth exhibit rhythmic growth patterns. These patterns are found in both abiotic and biotic processes. For instance, sedimentation of a lake or ocean can display layers, which are indicative of a time series. Living organisms can also produce rhythmic growth patterns. However, the time series in both cases do not necessarily reflect astronomical patterns (days, years, etc.), which are called aperiodic growth (Schweingruber, 1987). The process of development of growth patterns is never continuous. There are interruptions in their development that will pause the growth. In many organisms, growth patterns develop due to the interrupted development. Clam shells add many layers to their shell each year in response to environmental changes. Tortoises have increment layers on their shell and elephants have layers in their tusks. Generally, the organisms that produce a periodic growth pattern do not survive more than a few years (Schweingruber, 1987). Trees are the major ex