Lytle Lab research

HOME PEOPLE RESEARCH PUBLICATIONS OPPORTUNITIES

Disturbance regimes and life history evolution

Disturbance events such as flood, drought, fire, and disease outbreaks are powerful forces that can shape both the ecology and evolution of organisms. Flash floods are an extreme example of disturbance – in some desert streams flash floods remove over 95% of aquatic insect larvae. The giant water bug Abedus herberti has evolved a strategy for escaping flash floods: they sense the rainfall that often precedes floods and use this as a cue to temporarily abandon streams. Using mtDNA sequences, we have identified over 30 distinct populations of Abedus herberti across the Madrean Sky Islands of Arizona and Sonora. These populations occupy streams with flood regimes that range from mild (flash floods never occur) to severe (several scouring floods per year). Funded by NSF and based out of the  AMNH Southwestern Research Station, Portal, AZ, we're using this as a model system to determine how populations adapt to local flood regimes, and whether enough genetic variation is present for populations to adapt to altered flood regimes due to climate change, dams, and other factors.

Insect identification using pattern recognition technology

Insects are overwhelmingly diverse. While the need to identify insects (for environmental monitoring, agricultural needs, biodiversity surveys) is on the increase, the prohibitive amount of time and expertise required to identify insect samples is the bottleneck that limits data collection. As part of an NSF-funded collaboration among computer scientists, engineers, and entomologists at OSU, we are developing pattern recognition algorithms for computer-aided insect identification. Using stoneflies and soil mites as test cases, we are building a digital image library from known specimens. Statistical algorithms will use this image library to identify new specimens. Rather than replace the need for traditional insect taxonomy, these methods should facilitate the use of insects for ecological monitoring.

Madrean Sky Island aquatic community biogeography

The Madrean Sky Islands Bioregion (MSI) of the southwestern United States and northwestern Mexico contains many fragmented stream habitats, isolated from one another by miles of dry desert.  Additionally the area is situated at the biogeographic confluence of the neotropical and temperate regions, and contain a fascinating mix of aquatic insect species from both regions.  Aquatic insect diversity is extremely high in these small, fragmented streams.  We are examining how habitat size and isolation is related to insect diversity and community composition and also how seasonal and annual variation in flow may help to support high aquatic insect diversity.

River management using prescribed flow regimes

Bill Williams River, Arizona