Impacts of Hay‐Scented Fern on Nutrition of Northern Red Oak Seedlings

Abstract

A greenhouse study was conducted to assess the impacts of hay‐scented fern (Dennstaedtia punctilobula [Michx.] Moore) on the nutrition of first‐year, northern red oak (Quercus rubra L.) seedlings. Four common forest soil types in Pennsylvania were chosen as growth media for the study—two nutritionally poor soils and two moderately nutritional soils. Oaks and ferns were grown separately and together. Total macronutrient content [phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg)] was positively and significantly related to biomass in red oak, but not in ferns. Oaks grown with ferns exhibited greater nutrient imbalances and diminished nutrient status compared to oaks grown alone on all four soils. When grown with ferns, oak foliage exhibited significantly lower concentrations of K on all four soils, lower nitrogen (N) on three of four soils and lower P on two of four soils when compared to oaks grown alone. Conversely, ferns grown with oaks had fronds with significantly higher concentrations of N and K on all four soils and higher P on three of four soils. Differential nutrient capture between hay‐scented fern versus oak seedlings was evident in this study and interspecific competition from hay‐scented fern was shown to alter the nutritional balance of red oak seedlings. Hay‐scented fern exhibited a competitive advantage over red oak in maintaining growth and acquiring nutrients and nutrient competition was identified as a specific mechanism of below ground interference by hay‐scented fern.