Ecological communities consist of species that interact with each other in many ways. An interaction in which both species benefit is called a "mutualistic" interaction. For example, in pollination plants receive pollen to produce seeds and the pollinators receive food. Some pollination partnerships may be unique and specialized, with each species depending on services that can be provided only by a single partner. Other pollination partnerships may be general and interchangeable, with many species providing the same services. If all partnerships are interchangeable, then communities may remain stable if their species change due to environmental stress. But if partnerships are unique and specialized, then communities may be very sensitive to stress. Thus, understanding how species interact in the way they do is a central question in ecology. This research will explore how different types of interactions (unique and specialized vs. interchangeable and generalized) affect how well plants and pollinators reproduce and how long their populations can persist in the face of environmental change. The study will focus on the plants and pollinators of the Madrean "sky islands", mountaintop meadows separated by lowland deserts in the southwestern United States. The study will help guide conservation and management of these unusual habitats and provide mentoring of students interested in ecological field work.
Network theory predicts that highly redundant and generalized networks of interactions maximize resistant to disturbance, whereas specialized, complementary networks maximize function. While such tradeoffs are assumed to be an inherent part of biological network organization, it is not known what ecological and evolutionary processes mediate them, preserving populations and maintaining network structure. Further, though interactions may be heterogeneous across both organismal (individual to species) and temporal scales (single interactions to multiple interactions across generations), the potential for this variability to drive both network structure and ecological function has not been systematically explored. This research will forge new ground by testing how mechanisms at different levels of biological organization simultaneously confer function and resistance within networks. By quantifying individual- and species-level networks, along with short- and long-term fitness outcomes, the researchers will examine the relationship between network structure, function and resistance, and their impact on plant and animal population dynamics across a biogeographic gradient.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
