Stable isotope mixing models demonstrate the role of an invasive plant in wetland songbird food webs.

Premise: Invasive plants in wetlands are often ecosystem engineers, mediating changes in ecosystem functions like trophic support. We documented the impacts of , an invasive plant, on the food web of omnivorous birds (Suisun song sparrows, ) in a tidal wetland of northern California, USA.

Methods: We used analysis of natural abundance stable isotopes of C and N in song sparrow blood, invertebrate food sources, seeds, and other marsh plant seeds to inform Bayesian, concentration-dependent mixing models that predicted average song sparrow diets.

Nutrients mitigate the impacts of extreme drought on plant invasions.

Extreme climate events, such as drought, are becoming increasingly important drivers of plant community change, yet little is known about their impacts on invasive plants. Further, drought impacts may be altered by other anthropogenic stressors, such as eutrophication. We found drought dramatically reduced density of invasive Lepidium latifolium in salt marshes, and this die-back was mitigated by nutrient addition.