Experimental addition of marine-derived nutrients affects wildflower traits in a coastal meta-ecosystem

Organismal movement can bring individuals, resources, and novel interactions across ecosystem boundaries and into recipient habitats, thereby forming meta-ecosystems. For example, Pacific salmon ecosystems receive large marine-derived nitrogen subsidies during annual spawning events, which can have a wide range of effects on aquatic and terrestrial plant species and communities. In this study, we evaluate the effects of cross-ecosystem nutrient subsidies on terrestrial plant growth and reproduction. We conducted a large-scale field experiment with four treatments: (1) addition of a pink salmon (Oncorhynchus gorbuscha) carcass, (2) addition of the drift seaweed rockweed (Fucus distichus), (3) addition of both salmon + rockweed, and (4) a control. We examined treatment effects on leaf nitrogen and fitness-associated floral traits in four common estuarine wildflower species. We found elevated leaf ∂15N in all plant species and all sampling years in treatments with salmon carcass additions ..., ,