Yujie Zhao1, Shengyu Wang1, Zhiyong Liao2, Madalin Parepa3, Lei Zhang1, Peipei Cao1, Jingwen Bi1, Yaolin Guo1, Oliver Bossdorf3, Christina L. Richards3,4, Jihua Wu1,5, Bo Li1,6, Rui-Ting Ju1
1 Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Institute of Biodiversity Science and Institute of Eco-Chongming, School of Life Sciences, Fudan University, Shanghai, China
2 CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China
3 Plant Evolutionary Ecology, Institute of Evolution and Ecology, University of Tübingen, Tübingen, Germany
4 Department of Integrative Biology, University of South Florida, Tampa, FL, USA
5 State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
6 Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Centre for Invasion Biology, Institute of Biodiversity, Yunnan University, Kunming, China
Abstract
Like alien plant invasion, range expansion of native plants may threaten biodiversity and economies, rendering them native invaders. Abiotic and biotic conditions across a large geographic scale greatly affects plant traits and interactions with herbivores of native invaders, which is interesting yet mostly unexplored. We used a common garden experiment to compare defensive/nutritional traits and palatability to generalist herbivores of 20 native- and introduced-range populations of Reynoutria japonica, a typical native invader following expansion in China. We analysed the relationships among herbivore pressure, climate, plant chloroplast haplotypes, leaf traits and herbivore performance. Of the 16 variables tested, we observed range differences in 11 variables and latitudinal clines in 13 variables. Overall, herbivores performed better on introduced versus native plants and better on high-latitude versus low-latitude plants within the introduced populations. Leaf thickness, leaf-specific mass, and C:N ratio determined plant palatability, and they were significantly associated with temperature and/or precipitation of origin and plant haplotypes but not with herbivore pressure.Our results revealed a causality from environmental and genetic factors to plant quality and palatability in R. japonica. These findings suggest a rapid evolution of R. japonica, which may partly explain the colonization success of this important native, but invasive plant.
Keywords: biological invasions, biotic interaction, generalist, knotweed, latitudinal cline, palatability, plant introduction, range expansion
Status: submitted
Fig. 1 Collecting sites of Reynoutria japonica populations in the eastern mainland of China. The map projection used is Lambert.