The Archaeology and Historical Ecology of Small Scale Economies

9. Forging Collaborations between Ecology and Historical Ecology

9 Forging Collaborations between Ecology and Historical Ecology Steven C. Pennings When I was a graduate student, my fellow ecologists and I looked down on “applied ecology” (studies addressing practical problems, such as environmental impacts) and sought to do research on “pristine” ecosystems. Today, these views seem naïve (Kidder, this volume). Modern society faces many problems that are ecological in nature, and ecologists are turning out in droves to develop solutions. At the same time, we have realized that humans have been affecting ecosystems for tens of thousands of years (Thomas 1956; Redman 1999). “Pristine” ecosystems, as they’re usually understood (free from human influence), may not exist (Denevan 1992). Instead, to understand how natural systems work, we must consider how humans affect them. Ecologists have gotten fairly good at elucidating current human impacts on the biosphere. When we see large buildings, cleared fields or fishing boats, we realize that these human artifacts are likely clues to human impacts on natural systems (Jackson et al. 2001; Worm et al. 2006). But we struggle to understand the nature and extent of human activities in the past, many of which (fire, hunting, species introductions) did not leave clues that are readily seen by the untrained observer today (Briggs et al. 2006; Dambrine et al. 2007; Bover and Alcover 2008; Rick and Erlandson 2008). Ecologists need to collaborate with historical ecologists to gain a more complete understanding of these past human effects on natural systems . By historical ecologists, I mean those scholars who seek to understand the long-term dynamics between human decisions and actions and ecosystems (Balée 2006). In many cases, archaeological studies, such as the ones found in this book, have led the way in such endeavors. In turn, ecolo- 168 · Steven C. Pennings gists can bring a variety of perspectives and tools to these collaborations that would enhance the rigor of our understanding of the past. Today, ecologists and historical ecologists study many of the same questions (Thompson, this volume). Humans and the environment affect each other, and affect other species, in complex ways (Rick, this volume)(figure 9.1). Modern ecologists seek to understand these complex interactions (Liu et al. 2007). Historical ecologists seek to understand the same issues in the past (Balée, this volume). Both could benefit from interacting with each other, so that ecologists could better understand how the past affects the present, and historical ecologists could access a range of approaches and ideas that would offer new insights into historical data. Both share the challenge of working with complex systems, in which multiple species and drivers can affect each other through multiple direct and indirect pathways (Milner, this volume). As a result, inferring the primary causal pathways driving variation is difficult, because many potential links exist . For example, if a particular plant used in herbal remedies has recently become rare, is this due to climate change, to humans overharvesting the plant, to humans suppressing fire, to humans suppressing a mutualist of the plant, to humans introducing an exotic consumer or competitor of the plant, or to humans suppressing an herbivore that eats a competitor of the plant’s? Ecologists and historical ecologists might consider the same list of alternative hypotheses in trying to explain an ecological pattern. Ecologists have some advantages in that they can monitor ongoing changes and conduct experiments to examine possible drivers of current changes. Historical ecologists cannot do experiments in the past; however, they have the advantage of being able to examine interactions over longer time periods, and thus, potentially, over a wider range of conditions than those existing in the present (Gilman et al., this volume). Moreover, since the questions that they ask overlap heavily, and many of the species that they study overlap across time, there is the potential for collaborations between ecologists and historical ecologists to be mutually informative. This book and the broader field of historical ecology bear witness to the insights that can emerge when the fields of ecology and anthropology inform each other in cross-disciplinary studies of historical ecology (Balée and Erickson 2006; Briggs et al. 2006). But there is room for a more effective infusion of ecology into historical ecology and vice versa. In the following sections, I offer some thoughts about how each field can benefit from the other, and some practical steps toward better collaborations. Forging Collaborations between Ecology and Historical Ecology · 169 How Ecology Can...