With National Science Foundation support, Drs. Jennifer Kahn and Patrick Kirch, assisted by an international team of collaborators, will conduct archaeological and paleoecological fieldwork on three islands of French Polynesia. The team brings together U.S., Australian, New Zealand, and French specialists in archaeology, paleoethnobotany, paleoecology, and soil science. They will examine island ecosystems and cultural responses to ecosystem change which led to radically transformed landscapes and emergent sociopolitical formations (chiefdoms) in Polynesia. Using a comparative approach, the project will study the island ecosystems of Mangareva, Mo'orea, and Maupiti. These three islands exhibit critical contrasts in island geology and age, geomorphology, size, and climate and marine resources; they vary significantly in the degree of socio-political hierarchy and integration; and they have existing archaeological and paleoecological data upon which the research can build. Applying the concept of islands as model systems, the project seeks to understand both the vulnerability of island ecosystems and their resilience to long-term human interactions with the landscape. The team will also investigate how socio-political systems responded to, and were affected by, such processes. All Polynesian societies trace their origins back to a common Ancestral Polynesian culture, yet diverse social systems evolved through time with marked differences in population densities, productive systems, and political structures. Thus, comparative archaeological research in Polynesia offers an especially clear opportunity to understand the emergence of complex socio-political organizations such as chiefdoms. The study will contribute to understanding how dynamic interactions between island populations and island environments allowed some Polynesian cultures to develop substantial resilience, and led others into states of high instability and vulnerability.
The project will obtain basic data from former cultivation zones, monumental architecture sites, and coastal habitations with paleoecological records of island flora and fauna. These data will be used to understand: 1) interactions among human-induced landscape change; 2) shifts in settlement patterns; 3) changes in agricultural infrastructure and production; and, 4) levels of ideological control. The project will model how these variables influenced emerging social complexity, and how they affected long term adaptive cycles in island systems. The intellectual merit of the research includes testing models of how social complexity develops over time and examining how past societies adapted to challenges such as over-exploitation of resources and high population densities, two of the most contentious issues confronting contemporary archaeology and indeed, many current societies. The deeper understanding of interactions between island social systems, environments, and differential cultural responses to ecosystem change gained in this research will enhance current perspectives on sustainability and resilience.
The broader impacts of the study include education, outreach, fostering international research collaboration and integration of natural and social sciences. The project involves collaboration among scholars and students from multiple institutions in the U.S., Australia, New Zealand, and French Polynesia and of diverse cultural and ethnic backgrounds. The project team will offer critical training opportunities to students of Polynesian descent. The project emphasizes archaeology but is truly interdisciplinary, and will contribute more broadly to conceptual integration across the natural and social sciences.
This project (2011-2014) was designed to explore how decisions made by Polynesian cultures living in these islands led to landscape transformations and changes in their social and political systems. A major goal was to understand how resilient each society was to either external forces, such as climate change, or internal forces, such as environmental change caused by human activity. Using an archaeological approach in collaboration with several other natural sciences (soil science, botany, geology, palynology) our project investigated how some environmental conditions (such as island age and soil nutrient depletion) made island ecosystems inherently more vulnerable, as well as how human decisions allowed some societies to develop greater resilience. Inter-disciplinary data allowed for an understanding of how decisions made in different parts of social life-- including farming, fishing, household economies, and the construction and use of public spaces--affected long-term trajectories of population growth, the economy, and social relations. A further aim was to enhance research collaborations with French Polynesian institutions and organizations, and to support the inclusion of descendant Tahitian communities in scientific research. Using a comparative approach, we studied three islands in French Polynesia with differing sizes, ages, and natural resources: Mangareva, Mo‘orea, and Maupiti. On these islands we identified and investigated 11 archaeological sites occupied from 800 BP to 300 BP. Our results indicate that ancient East Polynesians were not inherently conservationist (often initially over-utilizing natural resources), but that they could learn to be so if their well-being depended on it. Archaeological and botanical data demonstrate how colonizing populations typically used easily accessible wild resources, such as birds, turtles, and shellfish, to feed their families. The most vulnerable of these animals, such as ground nesting birds, often went extinct as a consequence, while other animal populations became scarcer. This forced communities to change their food-procuring practices. Through time, island societies developed stocks of domesticated animals (pig, dog, chicken) and increased their cultivation of crop plants. However, these adaptations in turn caused further changes to island ecosystems, notably on the natural vegetation. Endemic forests were cleared for agricultural plots, in some locales leading to more limited plant biodiversity and massive slope erosion. These negative effects of human land use could be buffered, however, by choosing more sustainable and more productive farming practices, including terracing hillsides to reduce soil erosion, and sustainable multi-cropping in orchard gardens. Other effects were dampened by more severe choices, such as the deliberate elimination of pigs from the Mangareva production system. While pigs were a highly valued food animal, competition with humans for the same foods led to Mangarevan populations eliminating pigs from their island. The long-term history of East Polynesian populations, particularly their ability to adapt to a variety of environmental changes, some of their own doing, offers lessons for modern human populations facing unprecedented climate and landscape change. In order to be adaptive and to foster resilience, East Polynesian populations sometimes had to change how they lived in often dramatic ways, which holds lessons for modern responses to climate change. However, not all change was a direct consequence of human activity. Some transformations were linked to natural environmental shifts. For example, sea-level change 5-3,000 years ago transformed island coastlines on Mo‘orea and Maupiti. Other changes had multiple causes, such as the deforestation on Mangareva which involved dynamic interactions among humans, commensal rats, the island's vegetation communities, and populations of roosting and nesting seabirds. We also found that rates of environmental change differed in land-based contexts versus marine-based contexts. We tracked human-induced landscape change from colonization (c. 1,000 BP) to European Contact (c. 300 BP), utilizing terrestrial and marine data sets. In each island, human activities caused significant changes to land resources (particularly birds, insects, and landsnails), while marine resources-- the fish and shellfish collected from the lagoons, reef, and the far ocean-- were far more resilient. We privileged archaeology as the core discipline in this project, but our research has been truly multi-disciplinary, and has contributed more broadly to conceptual integration across the natural and social sciences; such multi-disciplinary integration is critical as we attempt to address the challenges our globe faces due to unprecedented climate change. Our findings highlight the complexity of relations among subsistence technology and land-use, local ecology, and socio-political factors, as manifest in material culture, the built environment, and the landscape. Our results underscore the need for millennial scale data provided by archaeology for understanding changes in island socioecosystems, particularly significant for contemporary interests in tropical biodiversity, sustainable development, resilience to climate change, and indigenous cultural heritage.
