Soil, Climate, and Atmospheric Deposition Relationships with Elemental Concentrations in Annual Rings of Tuliptree

Abstract

AbstractThe objectives of this study were to investigate the relationships of contrasting soil properties, climate and atmospheric pollutant (especially S) deposition to elemental concentrations in tree rings. Concentrations of 12 elements were determined in annual rings of tuliptree (Liriodendron tulipifera L.) by proton‐induced x‐ray emission for the 50 even years from 1880 to 1980 within an urbanized‐industrial region in northeastern Ohio. Xylem concentrations of nine elements were consistently and significantly greater on Site 1 where soils were coarse textured and base status was low, than on Site 2 where soils were medium textured and base status was greater. Time series analysis detected high frequencies of elemental pulse interventions during periods of rising S emissions in the 1920s and mid‐1940s. Additionally, step changes in xylem S during these periods, and recently declining xylem S may also reflect changing S emissions. Significant climatic regressions [seasonal mean temperatures and total precipitation, plus annual basal area increment (BAI)] were obtained for 11 elements. Prior fall precipitation was the most consistent and important climate variable associated with xylem chemistry. A significant negative association of BAI with xylem Ca on Site 1, where soil Ca was low, suggested a growth dilution effect and the possibility that soil Ca may be near a critical limit. Soil properties influenced both the absolute concentrations of nearly all elements in xylem and relationships between xylem chemistry and climate. Variations in climate, in addition to soil, are therefore important considerations in spatial and temporal comparisons of xylem chemistry.