NSF Biocomplexity Project Summary

Criterion One- Intellectual Merit: The importance of road and river network intersections in determining dynamic changes to landscapes will be tested using individual/agent-based simulation modeling that integrates field-based physical, biological and social sub-models. We focus on the road-river linkages because river ecosystems are vulnerable to anthropogenic perturbations that are related to road access (e.g., invasion by non-native species and over-harvesting). Our basic premises are that:

1. flows of energy through river and road networks, as well as food webs, have some fundamental similarities related to network topology;
2. a hierarchy of physical processes is altered by distinct thresholds of human access and use of rivers;
3. different locations within the spatial hierarchy of a drainage network alter access and intensities of land use as well as species diversity;
4. aquatic food webs respond to selective harvest of topo-trophic level consumer species and cumulative additions of non-native species.

Using this approach we will test four hypotheses regarding individual usage and landscape responses to changes in the road network in four watersheds that vary in land use, road density, and access by people. We expect that simultaneous modeling of physical, hydrological and social networks within an individual/agent-based framework will result in reduced error variance relative to isolated subsystem models. The project will also develop the use of network theory in enhancing communication and insight across disciplines.

Criterion Two- Broader Impacts: Our proposed research has several integrated educational and policy components. In terms of education, three high school teacher workshops will demonstrate the use of web based GIS models to actively engage high school seniors (and their teachers) in Puerto Rico and Colorado in biocomplexity research.

Undergraduate research assistants and development of inter-university graduate seminars In biocomplexity. These inter-university, multi-year seminars will directly engage students, CO-PI.s, and managers in the implementation and integration of interdisciplinary research. Graduate students at University of Puerto Rico will obtain field data on ecological and economic values of rivers in Puerto Rico . Our results will also provide information on the consequences of building new roads and closing existing roads. The results of this integrated model will be shared with planners and stakeholders in a series of workshops. Our findings regarding how individual/agent-based models are effective in integrating and visualizing feedback from physical, biological and social network interactions will be disseminated to the scientific community by an organized symposium at a national or international professional meeting. The methodology developed will have broad applicability to coastal-montane ecosystems ranging from North America to New Zealand.