Variation in herbivory along a latitudinal gradient for native and exotic Asteraceae

Abstract

HOW TO CITE TSPACE ITEMSAlways cite the published version, so the author(s) will receive recognition through services that track citation counts, e.g. Scopus. If you need to cite the page number of the TSpace version (original manuscript or accepted manuscript) because you cannot access the published version, then cite the TSpace version in addition to the published version using the permanent URI (handle) found on the record page. ABSTRACTIt has long been hypothesized that biotic interactions, including herbivory, are most intense at lower latitudes.However, this generalization has recently been challenged with studies showing that latitudinal gradients in damage may be rarer than previously believed. Additionally, most studies have focused on herbivory of native species, so it remains unknown whether natives and exotics follow similar patterns. This study compares rates of aboveground herbivory of multiple native and non-native Asteraceae across a latitudinal gradient, with a more detailed investigation of a focal exotic, Cirsium arvense. Herbivory of multiple tissue types was quantified for all species across an 815 kilometre transect in Ontario, Canada. The native Asteraceae included in the survey typically experienced a decline in folivory with increasing latitude. Herbivory patterns for the exotic species were less clear; while most experienced high damage at the southernmost site, some also experienced high damage rates at midlatitudes. For the focal species Cirsium arvense, leaf and stem herbivory declined with increasing latitude, although seed damage showed strong regional variation across the invaded range. These results show that latitudinal variation in herbivory is highly dependent on the plant species being investigated, the tissue type being measured, and the type of herbivore(s) causing the damage. In some cases, populations in marginal areas might benefit from reduced damage by some groups of herbivores. In other cases, factors such as the availability of suitable habitat, the biology of specific enemies, and the origin of the host plant may override the influence of latitude on host performance.

Urbanization drives unique latitudinal patterns of insect herbivory and tree condition

“…However, the consistency of latitudeherbivory patterns is an area of active debate (Moles et al 2011, Anstett et al 2016. Some recent latitude-herbivory studies have yielded equivocal results, with some studies finding no, hump-shaped or positive latitude-herbivory patterns (Moreira et al 2015, Nunes et al 2016. One potential source of these contrasting patterns is the lack of consistent methodology (reviewed byAnstett et al 2016).…”

Pre‐dispersal seed predation and pollen limitation constrain population growth across the geographic distribution of Astragalus utahensis

“…pollen limitation: Feldman & Morris, 2011;Horvitz, Ehrlén, & Matlaga, 2010;Law et al, 2010;Parker, 1997;Price et al, 2008;herbivory: Kauffman & Maron, 2006;Kolb, Leimu, et al, 2007;Rose, Russell, & Louda, 2011;von Euler, Ågren, & Ehrlén, 2014). The per capita impacts of herbivory can also vary across broader elevational (Bruelheide & Scheidel, 1999;Miller, Louda, Rose, & Eckberg, 2009) or latitudinal gradients (Alexander, Price, Houser, Finch, & Tourtellot, 2007;Anstett, Naujokaitis-Lewis, & Johnson, 2014;Moreira, Abdala-Roberts, Parra-Tabla, & Mooney, 2015;Nunes, Cassin, & Kotanen, 2016;Pennings & Silliman, 2005). Yet, few studies have linked the individual-scale impact of pollinators or herbivores across sizable portions of the latitudinal range of a species to how these interactions influence population growth from the range centre to range edge.…”

Comparative impacts of aboveground and belowground enemies on an invasive thistle

“…However, the same principles may apply within the invaded range, as an exotic can experience reduced enemy pressure as it invades new locations and expands its latitudinal range. A decline in herbivory within marginal areas of the invaded range has been shown for some guilds of aboveground herbivores (Harvey, Nipperess, Britton, & Hughes, 2013;Kambo & Kotanen, 2014;Nunes, Cassin, & Kotanen, 2016) and has been shown cross-continentally for belowground herbivores and pathogens (Yang et al, 2013). The way in which the above-and belowground biota vary across large spatial scales will have important consequences for the direction and rate of spread of an invader to novel locations (van der Putten et al, 2009).…”