Perils of Public Natural History

I have begun my historical research explorations with some research into a topic in California historical ecology: how did California grasslands come to be dominated by non-native annual grasses? The story I learned as a student was that prior to European settlement California grasslands were mainly dominated by perennial bunchgrasses, but the introduction of grazing livestock led to their replacement by the non-native grasses. This is what Davis botanist Glen Holstein called the “Bunchgrass Dominance Paradigm” in a paper in the journal Madroño in the year 2001. The first sentence of the sign in the photo (“Purple needlegrass (Stipa pulchra) once covered the Central Valley floor and surrounding foothills”) from the UC Davis Arboretum sums up this paradigm pretty well.

The sign clearly dates from no earlier than 2004, and the trouble is is that the paradigm was already falling out of favor in historical ecology by that date, due to the research of Holstein and others. (A more minor point is that Stipa pulchra had been renamed Nassella pulchra with the publication of The Jepson Manual (a comprehensive flora of California) in 1993.) I have used the phrase “public natural history” in the title to this post in an analogy to the field of public history, the professional discipline of interpretation of history for the general public, for example in writing the text for museum displays. Public history is a challenging discipline — how does one know which stories to tell to what publics? From this example from our Arboretum, it seems like there are similar challenges in presenting natural history — the science is always changing.