We can no longer think of ecosystems as distinct entities. Much like human societies, the natural environment is connected through a wide range of transport and communication processes. Movement of energy and matter between ecosystems can modify food web interactions and nutrient cycling, as well as affect the number and diversity of plants, animals, and other organisms. Connectivity of ecosystems may be interrupted, however, by disruption in these transport processes through time. In our quest to understand complex ecological processes, we must explore the spatial and temporal variation (ecological topology) of such phenomena. For example, we need to ask how natural communities respond to changes in inputs of energy and nutrients through time. Coastal river otters (Lontra canadensis) transport nutrients from sea to land by feeding in the marine environment and scent-marking at latrine sites. This social communication of river otters creates "hotspots" where marine carbon (C), nitrogen (N), and phosphorus (P) are deposited along the coast. Sociality in otters is driven largely by the benefits of cooperative foraging on schooling fishes, such as salmon (Oncorhynchus spp.) and herring (Clupea pallasi). Therefore, any changes in the abundance and distribution of these fishes through global warming, pollution, or harvest, could change the transport of nutrients to otter latrines. This linking of marine and terrestrial systems through otter activity provides an excellent model system to explore the effects of spatial and temporal variation in inputs of marine nutrients on terrestrial plants and soil organisms. Using stable isotope analyses and genetic markers we will measure the variation in nutrient transport by river otters. We will then explore the effects of variation in otter fertilization on the diversity of the soil microbial community, nutrient cycling, plant uptake of marine nutrients, diversity of plants, plant growth, flowering and fruiting rates. Using isotopes measured in tree rings, we will also evaluate the time scale in which "hotspots" shift along the coast. After establishing these relations, we will develop a model that will simulate potential changes to the terrestrial landscape based on changing distributions of schooling fish, otter activity, and C, N, and P transport by river otters.
