Changes in Soil Temperature Associated with Reforestation in Central New York State

Abstract

Central New York State has experienced extensive reforestation during the past hundred years, significantly altering many natural systems. In order to begin to assess the impact of reforestation on soil organic carbon, soil temperature was measured within four different land cover types representing various stages of secondary succession following agricultural abandonment. Over forty thousand soil temperature observations were summarized by pedothermic period in order to characterize seasonal differences between cover types and to determine how mean annual temperature changes during reforestation. Forested sites were cooler during the spring and summer, and slightly warmer in the fall. During the winter field locations were significantly warmer that the forested sites, perhaps due to more complete snow cover, which acts to insulate the soil from cold winter air. In addition, soil temperature variability and vegetation were negatively correlated; as vegetation cover increased, variability in soil temperature decreased. Overall, results suggest that as succession proceeds average annual soil temperatures will decrease. Therefore, the succeeding forests will act as a carbon sink by both absorbing carbon directly from the atmosphere, thus increasing standing biomass, and decreasing soil temperature, which should increase the capacity of the soil landscape to store carbon.

Keywords:

• soil temperature
• organic carbon
• secondary succession
• New York