CHANGES IN PHENOLIC PRODUCTION IN THE HAY-SCENTED FERN (DENNSTAEDTIA-PUNCTILOBULA) IN RELATION TO RESOURCE AVAILABILITY

Field studies of hay-scented fern (Dennstaedtia punctilobula) were conducted to examine the relationships between environmental factors and levels of phenolics in leaves. Several predictions related to the carbon-nutrient balance hypothesis were examined. Light availability showed a significant positive correlation to total phenolics (R2=0.57; P<0.05). Although soil nitrogen was not significantly correlated with total phenolics, nitrogen in leaves was the most important factor in determining levels of phenolics. No single environmental factor significantly influenced levels of leaf nitrogen, indicating that a plant's integration of the combined availability of multiple resources determines the carbon-nitrogen balance in plant tissues, and consequently levels of chemical defense.