Aquatic food webs, succession, and top-down control in an intermittent stream in Pinnacles National Park
Albert Ruhi Vidal, Professor
Environmental Science, Policy and Management
Applications for Spring 2024 are closed for this project.
Intermittent streams, or those that temporarily cease to flow or dry completely, are subject to summer droughts which can vary in timing and intensity from year to year. Fish and invertebrates in these ecosystems posses drought-response mechanisms that are broadly categorized into resistance and resilience strategies. Resistant strategists persist locally through drying, while resilient strategists survive in perennially wetted habitats and recolonize after flow resumption. Due to these different strategies, the recovery trajectories of individual species can vary greatly across a community. For example, fish generally recover more slowly from drying as they rely on longitudinal connectivity to disperse. These differences in the order and timing of species arrivals, or priority effects, can influence food web structure. For example, if a fish predator takes longer to recolonize than its insect prey, prey could bounce back via top-down release.
This project examines the successional trajectory during the rewetting phase of Chalone Creek, Pinnacles National Park. We address two questions: (1) How does the timing of fish and invertebrate predator arrival influence the recovery trajectory of prey? and (2) Are successional patterns synchronized across the stream network?
Role: Students will primarily assist in sorting and identifying macroinvertebrates. If interested, students will have opportunities to perform fieldwork in Pinnacles National Park to sample invertebrates.
Qualifications: No prior experience is required, but skills or coursework in aquatic ecology, entomology, plant ecophysiology, hydrology, or field research techniques are advantageous. Students will be trained in macroinvertebrate sorting and identification at the beginning of the semester.
Day-to-day supervisor for this project: Rose Mohammadi, Graduate Student
Hours: 6-8 hrs
Related website: https://nature.berkeley.edu/ruhilab/
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