Quantitative ethnobotany and Amazonian conservation

We use quantitative ethnobotanical data to compare the usefulness of six floristically distinct forest types to mestizo people at Tambopata, southeast Peru. We aim to evaluate which forest types are most useful, and why. Ethnobotanical data were collected with informants in inventory plots and analyzed using a new technique that uses a two-tier calculation process to derive an "informant indexed" estimate of each species' use value. Use values are estimated based on the degree of consistency between repeated interviews of each informant and between different informants. We show that (1) in 6.1 ha, 94% of woody stems are "useful" to mestizos. (2) Based on percentages of useful plants per plot, there is little difference between each forest type. (3) Simply calculating the percent of useful plants is misleading, however, because most species have minor uses, and only a few are exceptionally useful. (4) Using the informant indexing technique, we demonstrate significant differences between each forest type's utility. Mature forests of present and former floodplains are more useful than other forest types, mostly due to their importance as sources of construction materials and food. (5) Lower floodplain is more useful medicinally, swamp more important commercially, and terra firme sandy more important technologically; they are not easily substituted for some of these uses. (6) On average, 80% of the value of forest plant products to mestizos is subsistence value; only 20% is commercial. We conclude that (1) to maintain cultural autonomy, Amazonian people may need access to all local forest types, and (2) present and former floodplain forests in western Amazonia should be a conservation priority. We make these broad conclusions on the basis of evidence of: (1) ethnoecological similarities among mestizo cultures in Peruvian Amazonia; (2) the similarity of family-level floristic composition at Tambopata and elsewhere in western Amazonia; (3) rapid floodplain deforestation; and (4) floodplain resource overextraction. Conservationists should focus on helping communities gain control of floodplain resources.