| This study evaluated long-term succession, recruitment, historical dynamics, and dendroclimatic relationships in Pinus banksiana in northern lower Michigan. In 1979, long-term study plots were established to develop a model for early successional patterns in Pinus banksiana following disturbance. The original study identified divergent multiple successional pathways which were determined by the individualistic nature of the sites. That study also identified the potential for arrested and accelerated succession. In this study, I remeasured the original sites to identify midsuccessional pathways and add them to the existing model. The results from this study indicate that the multiple successional pathways identified in the original model are maintained and there is no evidence for mid-successional convergence. One of the seres that emerged in the mid-successional stage is a mixed hardwood-Pinus banksiana community. The importance of this sere is also seen in the recruitment patterns I identified at other sites. Many stands show an initial recruitment of Pinus banksiana followed by a second episode of recruitment containing Pinus banksiana, Pinus resinosa, Pinus strobus, Prunus pensylvanica, and Quercus ellipsoidalis. The examples of arrested succession identified in the original model are again witnessed in the new data. One of the sites remains arrested in the Carex-Yaccinium meadow stage 21 years after it was clearcut. The original study stressed the importance of individual site characteristics, such as soils and topography, in determining successional development in Pinus banksiana. By using Public Land Survey data, I was able to verify that these edaphic conditions have controlled Pinus banksiana dynamics for at least 150 years. I also determined that land-use history and local climate conditions contribute to the growth patterns. The Pinus banksiana stands in northern lower Michigan are very dynamic systems, which behave in an individualistic fashion depending on the environmental conditions. |
