title: Defense pattern of Chinese cork oak across latitudinal gradients: influences of ontogeny, herbivory, climate and soil nutrients.
abstract: Knowledge of latitudinal patterns in plant defense and herbivory is crucial for understanding the mechanisms that govern ecosystem functioning and for predicting their responses to climate change. Using a widely distributed species in East Asia, Quercus variabilis, we aim to reveal defense patterns of trees with respect to ontogeny along latitudinal gradients. Six leaf chemical (total phenolics and total condensed tannin concentrations) and physical (cellulose, hemicellulose, lignin and dry mass concentration) defensive traits as well as leaf herbivory (% leaf area loss) were investigated in natural Chinese cork oak (Q. variabilis) forests across two ontogenetic stages (juvenile and mature trees) along a ~14°-latitudinal gradient. Our results showed that juveniles had higher herbivory values and a higher concentration of leaf chemical defense substances compared with mature trees across the latitudinal gradient. In addition, chemical defense and herbivory in both ontogenetic stages decreased with increasing latitude, which supports the latitudinal herbivory-defense hypothesis and optimal defense theory. The identified trade-offs between chemical and physical defense were primarily determined by environmental variation associated with the latitudinal gradient, with the climatic factors (annual precipitation, minimum temperature of the coldest month) largely contributing to the latitudinal defense pattern in both juvenile and mature oak trees.
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
authors.forename: Wen-Qiang
authors.initials: WQ
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
authors.forename: Yun-Peng
authors.initials: YP
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Ni
authors.affiliation: The Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou 510520, China.
authors.forename: Yi-Hua
authors.initials: YH
authors.lastname: Xiao
authors.affiliation: College of Forestry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Feng-Feng
authors.initials: FF
authors.lastname: Kang
authors.affiliation: Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
authors.forename: Jing-Pin
authors.initials: JP
authors.lastname: Lei
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
authors.forename: Ze-Ping
authors.initials: ZP
authors.lastname: Jiang
mesh_terms: D002681:China; D057231:Climate Change; D017753:Ecosystem; D060434:Herbivory; D010636:Phenols / Q000032:analysis; D064209:Phytochemicals / Q000032:analysis; D018515:Plant Leaves / Q000737:chemistry; D029963:Quercus / Q000737:chemistry* / Q000254:growth & development*
chemical_list: D010636:Phenols; D064209:Phytochemicals