Perennial vegetables: A neglected resource for biodiversity, carbon sequestration, and nutrition

RESEARCH ARTICLE Perennial vegetables: A neglected resource for biodiversity, carbon sequestration, and nutrition Eric ToensmeierID1*, Rafter FergusonID2, Mamta Mehra3 1 Perennial Agriculture Institute, Holyoke, Massachusetts, United States of America, 2 Union of Concerned Scientists, Washington, D.C., United States of America, 3 Perennial Agriculture Institute, Holyoke, Massachusetts, United States of America * toensmeier@gmail.com Abstract Perennial vegetables are a neglected and underutilized class of crops with potential to address 21st century challenges. They represent 33–56% of cultivated vegetable species, and occupy 6% of world vegetable cropland. Despite their distinct relevance to climate change mitigation and nutritional security, perennial vegetables receive little attention in the scientific literature. Compared to widely grown and marketed vegetable crops, many peren- nial vegetables show higher levels of key nutrients needed to address deficiencies. Trees with edible leaves are the group of vegetables with the highest levels of these key nutrients. Individual “multi-nutrient” species are identified with very high levels of multiple nutrients for addressing deficiencies. This paper reports on the synthesis and meta-analysis of a hereto- fore fragmented global literature on 613 cultivated perennial vegetables, representing 107 botanical families from every inhabited continent, in order to characterize the extent and potential of this class of crops. Carbon sequestration potential from new adoption of peren-

nial vegetables is estimated at 22.7–280.6 MMT CO2-eq/yr on 4.6–26.4 Mha by 2050. Introduction The perennialization of crop production has been proposed as a multifunctional approach to address environmental and other challenges in agriculture, due to the many benefits of peren- nial crops [1], but the perennialization of vegetable production has largely been ignored. Perennial vegetables (PVs) are a neglected and underutilized class of crops with potential to address crises of crop biodiversity, climate change, and nutrient deficiencies. While some indi- vidual species have been studied closely, as a class PVs have received little attention in peer- reviewed literature (for exceptions see [1–3]), though a body of grey literature has developed on the subject in recent decades [4, 5]. PVs are perennial plants cultivated for their edible vegetative growth (e.g., leaves) and/or reproductive structures (e.g., flowerbuds). They include some savory tree fruits that are used in cooked dishes, but not sweet or tart dessert fruits. Further definition is offered in the Meth- ods below. PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0234611 July 10, 2020 1 / 19 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Toensmeier E, Ferguson R, Mehra M (2020) Perennial vegetables: A neglected resource for biodiversity, carbon sequestration, and nutrition. PLoS ONE 15(7): e0234611. https://doi. org/10.1371/journal.pone.0234611 Editor: Birinchi Sarma, Banaras Hindu University, INDIA Received: September 16, 2019 Accepted: May 29, 2020

Published: July 10, 2020 Copyright: © 2020 Toensmeier et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the manuscript and its Supporting Information files. Funding: The authors received no specific funding for this work. Competing interests: The authors have declared that no competing interests exist.