Our Garry oak paper made the cover of Environmental Management, although strangely the journal homepage still has last issues’ cover up, so just trust me on this one.
There’s a nice paper in the same issue about historical land use change in the Missouri River basin, using Missouri River Commission maps from the 1890s . We’ve (the PalEON team) been working with historic data from the upper Midwest with David Mladenoff from the Public Lands Survey (PLS). There seem to have been a number of methods for obtaining this data, and it’s certain that these historically based estimates of forest-cover are more accurate than model-derived estimates. Our own preliminary work in the upper Midwest shows strong differences between the prairie-forest boundary in Wisconsin based on PLS data versus those based on the standard Ramankutty and Foley (1999, raster here) estimates.
David Mladenoff has done extensive work with the PLS, culminating in this recent Ecological Monographs paper with Feng Liu and others (Liu et al, 2011). There is some debate about the quality of PLS data, and its utility, but, the ability to distinguish meso-scale features in landscape structure give it a clear benefit over other options that depend on either neo-ecological data sets, biased by anthropogenic landscape modification, or modeled landscapes, again dependent on the same neo-ecological datasets.
To make this point, I present a figure-in-progress (Figure 1) of some of the analysis I’ve been grinding through as part of the PalEON project. When we look at the model-based compositional information for the midwest we see that the Minnesota River has a significant impact on forest structure in the prairie regions of Minnesota. It’s actually really gratifying to see that, it means I’m not just banging my head against the wall!
It’s also interesting to note that Abrams and Nowacki (2008) cite a paper by Raup (1937; I haven’t read it though), indicating that the northern limit of oak is similar to the northern limit of agriculture in Native societies. The Abrams and Nowacki paper is generally pretty cool, I’m curious about the extent of Native agriculture in Minnesota and Wisconsin now. . .
There’s still a lot of work to be done, and I look forward to it! We’ve presented some of our work as a poster at AGU2011 in San Francisco, you can check it out here.
Listening to: Glen Campbell – Wichita Lineman