My research career began with parallel interests in forests and wildlife, but my interests have wandered over the years. You can trace that history—and see more papers on these and other topics—in my CV. Here is a bit of a tasting menu, on a few favorite topics.
Scaling and scaling. Scale is a fundamental concept in landscape ecology: what ecology means depends on how finely you resolve things and the spatial extent over which you view the system. My interest in this begins with my first paper (Urban et al. 1987), includes a few methodological efforts (Smith and Urban 1988, Urban et al. 2005, Keitt and Urban 2005), and finishes with a bit of a reminiscence (Urban 2014).
Of these, my favorites are the first and last, as they bookend a favorite topic and remind me how far I’ve come.
Forests, climate, and fire. I participated for many years in the National Park Service’s (later, the US Geological Survey’s) Global Change Research Program, working in Sequoia-Kings Canyon and Yosemite. As part of this, we developed a model of the physical template of that landscape (temperature and soil moisture along an elevation gradient), along with tree species sorting along that gradient (Urban et al. 2000). We then layered on the fire regime (Miller and Urban 1999a), and used the model to explore climate change scenarios (Miller and Urban 1999b).
I like this set of papers because the model covers the main agents of landscape pattern–the biophysical template, biological processes, and disturbance–and how they interact.
Habitat connectivity and large-scale conservation. I have been interested in forest birds for a long while, beginning with field studies for my Master’s thesis. I took that into the world of simulation, coupling models to field studies. This included work on microhabitats (e.g., Urban and Smith 1989) but soon expanded to look at habitat connectivity (Urban and Shugart 1986 [in my CV]). That work underwent a seismic shift when I adopted network models of habitat connectivity based in graph theory. That work began in collaboration with Tim Keitt (Keitt et al. 1997, Urban and Keitt 2001) and continued with various graduate students (Bunn et al. 2000, Minor and Urban 2008, Urban et al. 2009).
I find this work especially gratifying in retrospect, as network models have become the norm and are the basis of connectivity conservation. It was exciting to get in early.
Urban landscapes. I have spent a lot of time working in my own back yard, the Triangle region of North Carolina.
Urban biodiversity. Plant communities in urban landscapes are shaped by dispersal and this is especially true of invasive species (weeds) (McDonald and Urban 2006a). More generally, urban plant communities are filtered by the biophysical environment, habitat conversion and fragmentation, and direct actions by people; parsing the relative importance of these is a challenge (Lopez et al. 2018). Forest bird communities in urban settings reveal a strong gradient of the intensity of urban influences, from rural to higher-density developed settings (Minor and Urban 2010).
The urban stream syndrome. Small headwater streams are compelling units of study because streams perfectly integrate everything that happens in their catchments. Urban streams share a host of symptoms related to their altered hydrology—the urban stream syndrome. Working with Emily Bernhardt (Duke Biology), we have used urban streams as mesocosms in which to study the effects of landscape pattern on ecological processes (e.g., Somers et al. 2013, Blaszczak et al. 2019).
Land cover change. The Triangle region of NC is a heterogeneous and dynamic place. We have emphasized the heterogeneity of development patterns using novel modeling approaches (McDonald and Urban 2006b), and captured the long-term trends using models that can be extrapolated both backward and forward in time (Sexton et al. 2013).
What I like about all these examples is that all of these students were doing highly innovative work. It was fun to be a part of that.
