Does enemy damage vary across the range of exotic plant species? Evidence from two coastal dune plant species in eastern Australia

• Published in: Oecologia Vol. 186; no. 2; pp. 303 - 309
• Main Authors: Tabassum, Samiya, Leishman, Michelle R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Science + Business Media 01-02-2018; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Annual rainfall; Biomedical and Life Sciences; Climate change; Coastal environments; Damage; Distance; Dunes; Ecology; Flowers & plants; Herbivores; HIGHLIGHTED STUDENT RESEARCH; Hydrology/Water Resources; Indigenous species; Introduced plants; Introduced species; Invasive plants; Invasive species; Leaf area; Leaves; Life Sciences; Natural enemies; Plant Sciences; Plant species; Population density; Probability theory; Rain; Rainfall; Range extension; Species; Temperature; Australia; Range limits; Plant invasions; Enemy release; Leaf traits; Population density
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s00442-017-4008-z

Release from natural enemies is often cited as a key factor for understanding the success of invasive plant species in novel environments. However, with time invasive species will accumulate native enemies in their invaded range, with factors such as spread distance from the site of introduction, climate and leaf-level traits potentially affecting enemy acquisition rates. However, the influence of such factors is difficult to assess without examining enemy attack across the entire species’ range. We tested the significance of factors associated with range expansion (distance from source population and maximum population density), climatic variables (annual temperature and rainfall) and leaf-level traits [specific leaf area (SLA) and foliar nitrogen concentration] in explaining variation in enemy damage across multiple populations of two coastal invasive plants (Gladiolus gueinzii Kunze and Hydrocotyle bonariensis Lam.) along their entire introduced distribution in eastern Australia. We found that for H. bonariensis, amount of foliar damage increased with distance from source population. In contrast, for G. gueinzii, probability and amount of foliar damage decreased with decreasing temperature and increasing rainfall, respectively. Our results show that patterns of enemy attack across species’ranges are complex and cannot be generalised between species or even range edges.