Title: | "Physical, but not chemical, antiherbivore defense expression is related to the clustered spatial distribution of tropical trees in an Amazonian forest" |
Author(s): | Cobo-Quinche J; Endara MJ; Valencia R; Munoz-Upegui D; Cardenas RE; |
Address: | "Herbario QCA, Laboratorio de Ecologia de Plantas, Escuela de Ciencias Biologicas, Facultad de Ciencias Exactas y Naturales Pontificia Universidad Catolica del Ecuador Quito Ecuador. Department of Biology University of Utah Salt Lake City Utah. Centro de Investigacion de la Biodiversidad y Cambio Climatico Universidad Tecnologica Indoamerica Quito Ecuador. Museo de Zoologia QCAZ, Laboratorio de Entomologia, Escuela de Ciencias Biologicas, Facultad de Ciencias Exactas y Naturales Pontificia Universidad Catolica del Ecuador Quito Ecuador" |
ISSN/ISBN: | 2045-7758 (Print) 2045-7758 (Electronic) 2045-7758 (Linking) |
Abstract: | "The conspecific negative density dependence hypothesis states that mortality of young trees (seedlings and saplings) is higher near conspecific adults due to mechanisms such as allelopathy, intraspecific competition, and pest facilitation, explaining why in the tropics, most of plant species tend to be rare and live dispersed. However, there are some tree species that defy this expectation and grow in large clusters of conspecific juveniles and adults. We hypothesize that conspecifics living in clusters show higher and/or more variable defensive profiles than conspecifics with dispersed distributions.We evaluated our hypothesis by assessing the expression of physical leaf traits (thickness, and the resistance to punch, tear and shear) and leaf chemical defenses for six clustered and six non-clustered tree species in Yasuni National Park, Ecuadorian Amazon. We ask ourselves whether (a) clustered species have leaves with higher physical resistance to damage and more chemical defenses variability than non-clustered species; (b) saplings of clustered species may show higher physical resistance to damage and higher variation on chemical leaf defenses than their conspecific adults, and (c) saplings of non-clustered species show lower resistance to physical damage and lower variation in chemical defenses compared to conspecific adults.Overall, our study did not support any of our hypotheses. Remarkably, we found that soluble metabolites were significantly species-specific.Our study suggests that plants physical but not chemical leaf antiherbivore defenses may be a crucial strategy for explaining survivorship of clustered species. Trees in Yasuni may also fall along a suite of tolerance/escape/defense strategies based on limitations of each species physiological constraints for survival and establishment. We conclude that other mechanisms, such as those related to indirect defenses, soil nutrient exploitation efficiency, volatile organic compounds, delayed leaf-greening, and seed dispersal mechanisms, shall be evaluated to understand conspecific coexistence in this forest" |
Keywords: | Ecuador Yasuni National Park conspecific negative density dependence damage leaf resistance metabolomics monodominance ontogeny physicochemical leaf traits; |
Notes: | "PubMed-not-MEDLINECobo-Quinche, Johanna Endara, Maria-Jose Valencia, Renato Munoz-Upegui, Dolly Cardenas, Rafael E eng England 2019/03/09 Ecol Evol. 2019 Jan 31; 9(4):1750-1763. doi: 10.1002/ece3.4859. eCollection 2019 Feb" |