The effect of ambient nitrogen levels on resource allocation in the purple pitcher plant, Sarracenia purpurea.

Abstract

An organism's fitness is determined by its strategy of resource allocation, i.e., the trade-off between current growth and reproduction. Nitrogen allocation in the pitcher plant, Sarracenia purpurea, was studied at four sites in northern Michigan. Water samples were analyzed for nitrate/nitrite concentrations, ammonia/ammonium concentrations and pH. These concentrations were then compared to the plants's flower to pitcher ratio (FP-ratio), which represents allocation of resources between current growth (pitchers) and reproduction (flowers). We found significant positive correlations between nitrate/nitrite levels and FP-ratio, pH levels and FP-ratio, nitrate/nitrite levels and pH levels, and number of pitchers and number of flowers across all sites. These correlations suggest that S. purpurea allocates nitrogen resources between flowers and pitchers and thereby maximizes fitness.