Monthly Archives: November 2016

How an effective drought reshapes an urban bird community (a thesis seminar)

A few years ago we began what we hoped would be a long-term study of how urban water policy and water use by people affects the diversity and distribution of other species that share the city’s habitats with us. The “city” in question is the Fresno-Clovis metro area in California’s Central Valley, and the “we” in question refers to the multidisciplinary team I pulled together to successfully compete for one of the Urban Long-Term Research Area (ULTRA) – Exploratory Award grants given by National Science Foundation and US Forest Service. That grant was how my research directly benefited from President Obama’s stimulus package in his first term, and the relatively small two-year award came with a great deal of (eventually dashed) hope that there would be money to actually grow it into a real long-term research network.

We had a unique opportunity in Fresno-Clovis to study how human water use in cities influences biodiversity in a “found experiment” since the City of Fresno had just begun installing water meters in this quite large arid southwestern city. We were able to survey the city for birds, plants, and human perceptions of water before water metering went into effect in 2013, and stretch our NSF grant dollars to continue studying them in the years after. It has been fascinating to watch this urban ecosystem change over these years, and grapple with the challenge of tracking how people’s choices have changed and how biodiversity is changing in response to what people do in their yards and throughout the city. Our challenge became further complicated by another unplanned perturbation of water in this system: the onset and deepening of the drought over California in these recent years. The NSF grant funded a number of graduate thesis projects (and undergraduate students helping with the research) at Fresno State, and their work has opened up new questions for us to pursue, even as we look for other ways to fund the work for the long-term.

Today I am back in Fresno (having recently moved to North Carolina State University to join a new interdisciplinary faculty cluster for Leadership in Public Science, in case you missed that news) for the culmination of another Masters thesis from this project. My student Stephanie Slonka will defend her thesis today, where she has conducted the first detailed analysis of how bird species diversity and abundance have changed in Fresno-Clovis over recent years by comparing data from bird census (from the Fresno Bird Count) and habitat surveys from several years before water metering went into effect and more recent post-metering years. The increased cost of metered water combined with the drought (and calls from the California Governor) has caused people to reduce the amount of water they poured into their yards, creating a more “effective drought” with much less water available in the landscape. Meanwhile, the bird community in Fresno has also changed significantly, showing lower number of species and smaller overall population in recent post-meter/drought years compared to the pre-metering period. What does this mean? If you want an answer to that, you can come to the Fresno State campus today to hear Stephanie defend her thesis where she explores these dynamics.

post-metering-model

 

A thesis defense is a landmark event both for the student and the advisor, and I am proud to see another student achieve this today. Stephanie’s thesis exit seminar will happen at 4:30PM today, in Science II, room 110. Here is her seminar flyer with further details if you wish to attend.