Agricultural systems offer substantial opportunities to integrate basic understanding of ecosystems and of human societies. Properties of ecosystems constrain the range of possible pathways for agricultural intensification, and the nature of agricultural production can influence aspects of human societies. At the same time, human societies create and develop specific systems of agricultural production that transform ecosystems, sometimes in dramatic ways. The Hawaiian Archipelago offers excellent opportunities to explore the nature and consequences of interactions among ecosystems, agricultural systems, and human societies as they played out over centuries prior to European contact. This collaborative research project will focus on intensive agriculture and society in Kohala, Hawai'i, where broad and well-defined environmental gradients encompass a large (60 km-square) and long-sustained rain-fed dryland agricultural system that was abandoned in the mid-19th century. With participation from local communities and schools, experimental gardens will be established across the range of the field system. This effort will draw on community input (traditional knowledge), archaeological observations, and ecosystem/soil analyses in addition to agricultural experimentation. Once in place, these gardens will be used to develop physiologically based agricultural crop models and to determine how the agricultural system was organized and integrated; how it was sustained for centuries prior to European contact; and how it interacted with nearby irrigated systems. This last effort will make use of strong differences in the abundances of multiple stable isotopes across the broad environmental gradient of Kohala.
The establishment of experimental gardens within the boundaries of the ancient and long-abandoned Kohala field system will serve several scientific and educational objectives. A well-validated crop model for dryland crops will allow much more detailed calculations of agricultural yields; these in turn will make existing models of past agricultural production and human demography across the Kohala landscape more realistic. Similarly, isotopic measurements of Hawaiian crops will support detailed interpretations of sources of food and other goods as these varied over space, time, and the social status of households in pre-contact Hawai'i. Together these efforts will make it possible to determine how this and other large, rain-fed agricultural systems functioned and how they interacted with nearby communities based on irrigated agriculture. The project therefore will contribute to understanding the evolution of complex societies. The gardens represent an extraordinary educational resource because they will make a step toward restoring an example of the main pre-contact agricultural system on the island of Hawai'i. School and community groups will make use of these gardens to learn science by conducting field experiments in a culturally meaningful setting. This project is supported by an award resulting from the NSF competition focusing on the Dynamics of Coupled Natural and Human Systems.
