Species turnover from climate change
Climate change reshuffles ecological assemblages. As communities experience turnover, existing interactions are lost and new interactions form. Although assemblages display predictable shifts, individual species are much less predictable: a cohesive pattern emerges from unpredictable components.
Species that fail to track climate change
Most species show strong patterns of shifting their distributions in response to rising temperatures. However, traits of species and environments can sometimes prohibit climate tracking. Some fish species are not tracking their shifting thermal requirements because of natural and anthropogenic barriers and unsuitable geomorphic conditions.
Ecological recovery following the Clean Water Act
Environmental conditions have improved in many American rivers as stricter standards for water quality have been implemented. How have these changes affected fish populations? Often, we lack sufficient empirical data to compare the status of contemporary assemblages to those several decades ago. A standardized, six-decade fish monitoring program shows a dramatic recovery of fish populations after the Clean Water Act.
Detection in monitoring programs
Ecologists increasingly use larger datasets and more extensive monitoring data to infer meaningful changes in populations and ecosystems. Such inferences can be sensitive to the detection probability of species across time and space. Monitoring program with data sufficient to estimate detection probability and the influence of environmental conditions provide ways to better understand what monitoring data can reveal and its limitations.
The rise and fall of invasions
Invasive species can increase exponentially, yet they can also collapse. In the Illinois River, different invasive species are show both extremes of these responses. What causes some abundant invasive populations to crash, and is there demographic information that predicts these events?
Climate change creates rapid turnover in montane communities. Ecology & Evolution. Open access.
Inconsistent range shifts within species highlight idiosyncratic responses to climate warming. PLOS ONE. Open access.
Natural and anthropogenic barriers to climate tracking along a mountains-plains transition zone. Accepted. Diversity and Distributions. Email me for a draft copy.
Ecological recovery of a large river following the Clean Water Act. In review. Email me for a draft copy.
Estimating the effects of environmental variables and gear type on the detection and occupancy of large river fishes in a standardized monitoring program. 2016. North American Journal of Fisheries Management. Available through journal or email me for a draft copy.
Development and assessment of a new method for combining catch per unit effort data from different fish sampling gears. 2017.Canadian Journal of Fisheries and Aquatic Sciences. Open access.
Widespread and enduring collapse of invasive common carp in the Upper Mississippi River System. Accepted. Biological Invasions. Email me for a draft copy.
Strong reductions in size at age accompany increasing population densities. In review. Email me for a draft copy.