CHANGES IN FLORISTIC COMPOSITION IN THE STATE FORESTS IN WORCESTER COUNTY (MASSACHUSETTS) OVER 34 YEARS

ABSTRACT CHANGES IN FOREST DIVERSITY OF STATE FOREST IN WORCESTER COUNTY, MASSACHUSETTS, OVER 34 YEARS PERIOD The forest in Massachusetts has changed since the earliest colonial settlement and today the floristic composition is more homogeneous. This study investigates the potential change in the floristic composition over thirty years in Worcester County State Forests. Shannon, richness and evenness indices for two periods were compared, and Jaccard index was used to analyze similarity in composition between the periods. The possible influence of severe weather events was also analyzed. It was found Changes in the floristic composition, but the magnitude of the changes were not statistically significant. The Jaccard similarity index showed statistically significant differences between north and south. There was also, significant differences between plots that experienced insects’ attack or snow/ice damage compared to plots with no pest/ice damage. The implications of the research findings indicate that diversity of the State Forest did not present statistically significant change. Petersham presented the highest diversity, while the lower value was for North Brookfield. The similarity of the forest did not change through the time, but there is significant difference between the north and the south[fa1] . [fa1