| Title: | Herbivore resistance in congeneric and sympatric Nothofagus species is not related to leaf habit |
| Author(s): | Piper FI; Gundale MJ; Fuenzalida T; Fajardo A; |
| Address: | "Centro de Investigacion en Ecosistemas de la Patagonia (CIEP), Moraleda 16, Coyhaique, 5951601, Chile. Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umea, Sweden. Plant Science Division, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia" |
| ISSN/ISBN: | 1537-2197 (Electronic) 0002-9122 (Linking) |
| Abstract: | "PREMISE: Two fundamental hypotheses on herbivore resistance and leaf habit are the resource availability hypothesis (RAH) and the carbon-nutrient balance hypothesis (CNBH). The RAH predicts higher constitutive resistance by evergreens, and the CNBH predicts higher induced resistance by deciduous species. Although support for these hypotheses is mixed, they have rarely been examined in congeneric species. METHODS: We compared leaf constitutive and induced resistance (as leaf polyphenol and tannin concentrations, and as damage level in non-choice experiments) and leaf traits associated with herbivory of coexisting Nothofagus species using (1) a defoliation experiment and (2) natural defoliation caused by an outbreak of a common defoliator of Nothofagus species. RESULTS: In the defoliation experiment, polyphenol and tannin concentrations were similar between deciduous and evergreen species; regardless of leaf habit, polyphenols increased in response to defoliation. In the natural defoliation survey, N. pumilio (deciduous) had significantly higher herbivory, lower carbon/nitrogen ratio and leaf mass per area, and higher nitrogen and phosphorus concentrations than N. betuloides (evergreen); N. antarctica (deciduous) had intermediate values. Polyphenol concentrations and herbivore resistance indicated by the non-choice experiment were lower in N. pumilio than in N. antarctica and N. betuloides, which had similar values. CONCLUSIONS: Higher herbivory in N. pumilio was associated with a higher nutritional value and a lower level of leaf carbon-based defenses compared to both the evergreen and the other deciduous species, indicating that herbivore resistance in Nothofagus species cannot be attributed to only leaf habit as predicted by the RAH or CNBH" |
| Keywords: | *Antibiosis Fagales/*physiology *Herbivory Plant Leaves/*physiology Species Specificity Sympatry/*physiology Ormiscodes amphimone Patagonia carbon-based defenses defoliation leaf traits outbreaks polyphenols secondary metabolites tannins; |
| Notes: | "MedlinePiper, Frida I Gundale, Michael J Fuenzalida, Tomas Fajardo, Alex eng DID S-2010-67/Direccion de Investigacion/International 11121175/Fondecyt/International 1160330/Fondecyt/International 1160329/Fondecyt/International Research Support, Non-U.S. Gov't 2019/05/28 Am J Bot. 2019 Jun; 106(6):788-797. doi: 10.1002/ajb2.1293. Epub 2019 May 26" |
