New Harvard Forest Publication: Prey Availability and Its Effect On Carnivorous Plants

Former Harvard Forest Bullard Fellow Elizabeth Farnsworth and Harvard Forest Senior Ecologist Aaron Ellison examine scaling relationships among leaf traits of 10 species of pitcher plants (Sarracenia species) fed different quantities of insect prey. Increased prey availability increased photosystem efficiencey (as expressed by the ratio of Fv/Fm), chlorophyll content, and photosynthetic rate. It also led to a shift from P- to N-limitation in subsequently produced pitchers. Increased prey also shifted leaf-trait scaling relationships, bringing them more in line with those found for a wide range of non-carnivorous plant species. The results support a general hypothesis published in 2006 by Bill Shipley and his colleagues that suggested that observed scaling relationships amongst leaf traits derive from trade-offs in allocation to structural tissues versus liquid-phase (e.g., photosynthetic) processes. These trade-offs appear to be especially constraining for plants growing in extremely nutrient-poor habitats such as bogs and other wetlands.

Farnsworth, E. J., and A. M. Ellison. 2008. Prey availability directly affects physiology, growth, nutrient allocation, and scaling relationships among leaf traits in ten carnivorous plant species. Journal of Ecology 96: 213-221.