Hemispheric asymmetries in herbivory: do they exist?

: Kozlov MV, Klemola T

Publisher: WILEY

: 2017

: Journal of Ecology

: JOURNAL OF ECOLOGY

: J ECOL

: 105

: 6

: 1571

: 1574

: 4

: 0022-0477

: 1365-2745

DOI: https://doi.org/10.1111/1365-2745.12825

: http://onlinelibrary.wiley.com/doi/10.1111/1365-2745.12825/full

1. Latitudinal patterns in herbivory are widely debated. A recent publication (Zhang etal., Journal of Ecology, 104, 2016: 1089-1095) concluded that the absolute levels of herbivory (hypothesis 1), as well as latitudinal and climatic gradients in herbivory (hypothesis 2), differ between the hemispheres.2. Zhang etal. (2016), among others, used a measure of plant damage from Moles & Westoby (Oikos, 90, 2000: 517-524) that greatly overestimates insect herbivory, and they did not include the main effect of hemisphere in their linear model that explored the relationship between herbivory and latitude. After correction of the values extracted from Moles & Westoby (2000), none of several statistical models that tested both hypotheses simultaneously (i.e. including hemisphere, latitude/climate and their interaction) confirmed the existence of statistically significant differences in the patterns of insect herbivory between the hemispheres.3. Synthesis. The current level of knowledge does not provide grounds to conclude that hemispheric asymmetries exist either in the average levels of insect herbivory or in the relationships between herbivory and latitude or climate.