Spatial-temporal dynamics of plant-herbivore interactions and ecosystem processes in coastal tundra of the Yukon-Kuskokwim Delta in Western Alaska
This research will focus on how the spatial-temporal structure of feedbacks between vegetation and herbivore populations organizes ecosystem processes at local and regional scales. Understanding these feedbacks requires the coupling of both short-term and long-term impacts of herbivores on vegetation structure and nutrient cycling processes with the associated movement patterns and demographic parameters of herbivores. This project will build on a 14-year study of the demography of Black Brant geese, and on 7 years of research on vegetation/ecosystem response to herbivory. The investigators will mark 2,500 brant and record reproductive success for an additional 900 previously-marked adults to enable estimation of age- and time-specific breeding probability and survival, and fidelity to specific brood-rearing areas. The investigators will also continue a long-term investigation of spatial variation in growth. The project is leveraged by work planned by the USGS on the Mexico wintering grounds of the brant, allowing the PIs to study the impact of wintering location on reproductive performance and survival. In addition, the data collected in this year will enable the PIs to test hypotheses related to El Nino effects from the 1997-98 ENSO event.
