Hysteresis in a teapot: Organic enrichment and eutrophic collapse of the pitcher-plant foodweb

We conducted an ecosystem enrichment experiment using the aquatic microecosystem that develops naturally in the leaves of the northern pitcher plant Sarracenia purpurea. We enriched replicated pitchers with organic matter (bovine serum albumin), and monitored both organic matter and dissolved oxygen concentration during the enrichment and subsequent recovery phase. Depending on the enrichment rate, the system exhibits either classic hysteresis (low), environmental tracking (medium), or reverse hysteresis (high). These results suggest that variation in the rate of enrichment can generate a rich array of complex dynamic behavior in aquatic ecosystems.