Pitcher plant, www.istockphoto.com

Ecological studies typically have focused on a given habitat, such as the food web of “who eats whom” in a forest or coral reef. While this approach offers insights into how each ecosystem is organized, such singular datasets can't answer questions about how the structure, dynamics, and functioning of a given food web vary across changing conditions.

Now, advances in data handling that can examine hundreds of instances of particular types of food webs are providing a new way to study how species resist or adjust to changes in the ecological context. 

One such study examines the aquatic ecosystem within a pitcher plant – a carnivorous plant that lures insects to nectar at the bottom of a long, jug-like leaf and traps them. The pitcher plant food web includes detritus (dead insects), midges, mosquito and fly larvae, bacteria, mites, rotifers, and protozoa. A database of 780 pitcher plant food webs, sampled in clusters at sites along the eastern U.S. and Canadian coastline, reveals trends in how the communities within these plants change in relation to environmental factors.

“By understanding how these tiny ecosystems are structured, we can start to see how ecosystem organization changes, or doesn’t change, across latitude and climate,” explains Jennifer Dunne, SFI’s Chair of the Faculty and an expert in ecological network structure and dynamics.

In early March Dunne convened the first of two SFI working groups on “Gradient-based Ecological Network Research.” The meeting brought together ecosystem modelers with researchers who recently have compiled or initially analyzed databases for mangrove islets, intertidal communities, rock pools, and pitcher plants. Together they began to explore the richness of the data and how best to learn from them. 

“We make the most progress when we use data to develop and test theory, and use models and theory to shape new questions and find new ways forward in data collection,” Dunne says. “With this group of outstanding empiricists and theoreticians, we are asking questions like: How do trophic organization, species roles, and feeding motifs vary with changing conditions? Are these characteristics the same across time and space or do they shift – and if so, how, and why?”

More about the March “Gradient-based Ecological Network Research” working group