Fig 1.
Schema of the experimental design.
Distribution of the populations of Salvia nubicola along the altitudinal gradient used in the study. Populations in open habitats are indicated by “sun” symbols and in forest habitats by “tree” symbols. The population numbers correspond with codes in Table 1.
Table 1.
List of the 12 studied Salvia nubicola populations in the Annapurna Conservation Area, Nepal.
Table 2.
Factors affecting herbivore damage recorded for individual plants of Salvia nubicola.
Fig 2.
Relationship between plant size and leaf herbivore damage in four locality types of Salvia nubicola.
Plant size was expressed as the logarithm of the product of length of the longest stem and the number of stems per plant. See Table 2 for details of the test results.
Fig 3.
Differences in leaf herbivore damage among four locality types of Salvia nubicola.
Altitude, openness and altitude × openness indicate the effect of altitude (low vs. high), habitat openness (open vs. forest) and their interaction. See Table 2 for details of the test results. * P < 0.05; ** P < 0.001; n.s. non-significant.
Table 3.
Effects of plant size, altitude, habitat openness and herbivore damage on Salvia nubicola vital rates.
Fig 4.
Relationship among plant size, herbivore damage and vital rates in four locality types of Salvia nubicola.
Logistic regression was used for predictions of survival and flowering, ordinary least squares regression for growth, and Poisson regression for the number of flowering stems. Shading represents 95% confidence intervals of the predictions. Plant size was expressed as the logarithm of the product of the length of the longest stem and the number of stems per plant.
Fig 5.
Effect of leaf herbivore damage on the population growth rate of Salvia nubicola populations.
Open and filled circles and triangles represent values of mean insect herbivory that plants of all stages experienced at the respective locality types. Lines sharing the same letter are not significantly different from each other (P > 0.05).
Fig 6.
Elasticities in the four locality types of Salvia nubicola under increasing herbivore damage.
Elasticity values indicate how different transitions between plants at time t and t+1 contribute to changes in the population growth rate. The lowest row within each panel shows the transitions between adult plants at time t and seedlings at time t+1 (seedling establishment). The first column within each panel shows the transitions between seedlings at time t and larger plants at time t+1 (seedling growth to larger plants). Plant size was expressed as the logarithm of the product of the length of the longest stem and the number of stems per plant. The dark blue colour indicates the lowest elasticity values, and dark red indicates the highest elasticity values.