Variation in soil and foliar nutrition status along a forest edge-interior gradient in sugar maple forest fragments

The consequences of forest fragmentation and edge effects on soil nutrient availability and nutrition of sugar maple (Acer saccharum Marsh.) forests remain understudied. We assessed soil chemistry (bulk pH, total carbon (C) and nitrogen (N), extractable phosphorus (P), exchangeable cations, and mineralizable N) and foliar nutrition (N, P, potassium (K), calcium (Ca), and magnesium (Mg)) of mature sugar maple forests along an edge-interior gradient (10, 20, 30, 50, 70, and 120 m from the forest edges) in seven sugar maple forest stands (three on sandstone and four on dolomite bedrock) that are embedded within an agricultural landscape in southern Quebec, Canada. We hypothesized that foliar nutritional imbalances of sugar maple forests would decline along this gradient. Foliar nutrition was analyzed using the diagnosis and recommendation integrated system (DRIS) and the compositional nutrient diagnosis with isometric log-ratio (CND-ilr) method. At the sandstone sites, rates of N mineralization and nitrification increased with increasing distance from the forest edge. Other soil chemical properties and all sugar maple foliar indices of nutritional diagnostics varied weakly along the edge-interior gradient. Assessment of sugar maple forest nutritional status through different nutritional indices revealed K and P deficiencies in all stands that were sampled and at all distances from the forest edge. Overall, we found weak forest-edge effects on soil chemical properties and sugar maple forest nutritional status.