TABLE AND FIGURE LEGENDS
Table 1. Ecological characteristics . All variables are presented as an overall mean for all sites (MEAN), as well as the minimum (MIN) and maximum (MAX) values to show the variation across sites. Uncertainties show standard errors for all samples (MEAN, n=27), and per site (MIN, MAX, n=3). LAI: leaf area index, SLA: Specific leaf area. CT: Condensed tannins. Note that the insect deposits are in [mg m-2] while litter inputs are in [g m-2] Insect deposits are also presented in proportion to the total input with leaf litter plus herbivore deposits.
Table 2. Linear mixed effect modelling results for variables explaining variation in herbivory level (% of leaf area, sqrt transformed). Variables with significant predictive power are highlighted in bold. The coefficients (Coeff.) show the direction of change. CI: 95 % confidence intervals after 999 bootstrap simulations. Note that the elevation was transformed to Z-scores, partly to make the units more comparable to local elevation, and partly to make the variance more similar to the other variables.
Figure 1. The study site and design. Mean annual precipitation (a) and temperature (isolines in b) in the study area during the last normal period (1961-1990). The background colour scale in panel b is a digital elevation model of the area. The short black lines in panel a and b show the location and names of the 9 transects. Colours of the transect names correspond to Figure 3. The red dot on the inset in panel b shows the location of the study area in Sweden. Panel c shows a south-facing valley side in Vistasvagge, where transect N8 was located. The approximate relative positions of the three sites along this transect is shown in text. The black arrows in panel b shows the location and direction of where the picture in panel c was taken. The inset in panel c shows a typical site, with a person for scale. Data: SMHI and Lantmäteriet. Photos: Thomas Heister.
Figure 2. Elevational trend in background insect herbivory (a) and green leaf N content (b). Triangles represent gradients along south-facing slopes, while circles represent north-facing gradients. Each colour represents an individual elevational gradient (colours correspond to the transect names in Figure 1). Dashed lines show the trend lines for individual gradients. Note that these are not all significant, but are useful for showing the general trend along each gradient. Error bars show standard errors. In the insets, the dotted line show the approximated linear trend with regional scale elevation, while the solid line show the trend with local scale elevation (n=27).