Seasonal Variation in Nutrients of Floodplain and Upland Forest Soils of Central Illinois

Abstract
Variation in nutrients was studied over a two‐year period in adjacent floodplain and upland forest soils in central Illinois. Nutrient pools of all elements except Na were greater in floodplain soils than in upland soils and were in the following order at both study sites: exchangeable Ca > exchangeable Mg > exchangeable K > available P. Seasonal variation in nutrient content of soils was the result of several environmental factors. Available P in floodplain soils was highly dependent on pH, which was in turn influenced by flooding, but there was no evidence of seasonal variation in available P for upland soils. Soil pH was positively correlated with the concentration of exchangeable bases in both soils, especially Ca and Mg in upland soils. Exchangeable Na was highly variable at both floodplain and upland sites and may have been influenced by leaching and variation in tree root exudation. The seasonal variation in nutrient pools of forest soils in this study has implications for tree growth, site evaluation, and nutrient cycling in forest stands.
Funding Information
  • McIntire-Stennis Project (55-309)