Eighty-four per cent of all Amazonian arboreal plant individuals are useful to humans.

Sara D Coelho,Hans Ter Steege,Fernando O G Figueiredo,Fabrício B Baccaro,André Pinassi Antunes,Juliana Schietti,Carolina Levis,Marielos Peña-Claros,Charles R Clement,Narel Y Paniagua-Zambrana

doi:10.1371/journal.pone.0257875

Abstract

Plants have been used in Amazonian forests for millennia and some of these plants are disproportionally abundant (hyperdominant). At local scales, people generally use the most abundant plants, which may be abundant as the result of management of indigenous peoples and local communities. However, it is unknown whether plant use is also associated with abundance at larger scales. We used the population sizes of 4,454 arboreal species (trees and palms) estimated from 1946 forest plots and compiled information about uses from 29 Amazonian ethnobotany books and articles published between 1926 and 2013 to investigate the relationship between species usefulness and their population sizes, and how this relationship is influenced by the degree of domestication of arboreal species across Amazonia. We found that half of the arboreal species (2,253) are useful to humans, which represents 84% of the estimated individuals in Amazonian forests. Useful species have mean populations sizes six times larger than non-useful species, and their abundance is related with the probability of usefulness. Incipiently domesticated species are the most abundant. Population size was weakly related to specific uses, but strongly related with the multiplicity of uses. This study highlights the enormous usefulness of Amazonian arboreal species for local peoples. Our findings support the hypothesis that the most abundant plant species have a greater chance to be useful at both local and larger scales, and suggest that although people use the most abundant plants, indigenous people and local communities have contributed to plant abundance through long-term management.

Highlights

During at least 13,000 years, Amazonian indigenous peoples and local communities have harvested plant products from forests and cultivated numerous species in homegardens, swiddens and agroforests [1]
To understand if larger species population sizes are associated with broader spatial distributions across Amazonia, we evaluated the relationship between the population sizes of species and the number of plots in the Amazon Tree Diversity Network (ATDN) network where they occur across Amazonia using a linear model (LM) after log10 transformation to normalize both variables
We found that 51% of the arboreal species in the ATDN inventories (2,253 out 4,454) are reported as useful to humans in Amazonia, based on decades of compilations and ethnobotanical studies consulted in this study

Summary

Introduction

During at least 13,000 years, Amazonian indigenous peoples and local communities have harvested plant products from forests and cultivated numerous species in homegardens, swiddens and agroforests [1]. These plants are used in daily-life, such as food, ornament, poisons, cloths, basketry, medicines and many other uses [2], and some, such as rubber (Hevea brasiliensis), have entered national and international markets since European colonization [3]. Different plants have different abundances across landscapes; some tree and palm species (hereafter arboreal species) used by humans are rare [4, 5], while others represent the majority of individuals over large areas, the so-called hyperdominant species [6]. The in-depth knowledge people have about plant use, including which plants to choose and how to use and manage them, is the result of a history of reciprocal interactions among people and their environments [11], and leads to another hypothesis: people have increased the abundance of useful plant species through long-term management [12]

Methods

Results

Discussion

Conclusion