Leaf trait association in relation to herbivore defense, drought resistance, and economics in a tropical invasive plant

• Published in: American journal of botany 2022-06, Vol.109 (6), p.910-921
• Main Authors: Li, Yang‐Ping, Feng, Yu‐Long, Li, Wei‐Tao, Tomlinson, Kyle, Liao, Zhi‐Yong, Zheng, Yu‐Long, Zhang, Jiao‐Lin
• Format: Article
• Language: English
• Subjects: Chromolaena odorata; climate gradients; Climatic conditions; Clines; Drought; Drought resistance; economic traits; Economics; Environmental changes; Environmental conditions; Evolution & development; herbivore defense; Herbivores; Introduced species; Invasive plants; Invasive species; Leaves; Photosynthesis; Planting density; Plants; Populations; Senescence; Shoots; trait covariation; trait variation
• ISSN: 0002-9122; 1537-2197
• DOI: 10.1002/ajb2.1858

Premise Exploring how functional traits vary and covary is important to understand plant responses to environmental change. However, we have limited understanding of the ways multiple functional traits vary and covary within invasive species. Methods We measured 12 leaf traits of an invasive plant Chromolaena odorata, associated with plant or leaf economics, herbivore defense, and drought resistance on 10 introduced populations from Asia and 12 native populations from South and Central America, selected across a broad range of climatic conditions, and grown in a common garden. Results Species' range and climatic conditions influenced leaf traits, but trait variation across climate space differed between the introduced and native ranges. Traits that confer defense against herbivores and drought resistance were associated with economic strategy, but the patterns differed by range. Plants from introduced populations that were at the fast‐return end of the spectrum (high photosynthetic capacity) had high physical defense traits (high trichome density), whereas plants from native populations that were at the fast‐return end of the spectrum had high drought escape traits (early leaf senescence and high percentage of withered shoots). Conclusions Our results indicate that invasive plants can rapidly adapt to novel environmental conditions. Chromolaena odorata showed multiple different functional trait covariation patterns and clines in the native and introduced ranges. Our results emphasize that interaction between multiple traits or functions should be considered when investigating the adaptive evolution of invasive plants.