Abstract: To clarify the influence of topographic factors on population density of pests in alpine meadows, we combined field surveys and geographic information technology to analyze the population characteristics of primary pests in alpine meadows in Guoluo Prefecture, Qinghai Province. These pests included Eospalax baileyi, Ochotona curzoniae, Gynaephora qinghaiensis, and Ligularia virgaurea. Using geographical detector analysis, we examined the impact of topographic factors on the population density of major pests in alpine meadows. Results showed that population densities of O. curzoniae, E. baileyi, and G. qinghaiensis exhibited a trend of initial increasing and then decreasing with elevation, with the highest densities observed at 4360-4470, 3980-4080, and 3950-3990 m, respectively. The population density of L. virgaure increased along the elevation gradient, peaking at 4070-4110 and 4280-4620 m. The densities of O. curzoniae and G. qinghaiensis on slopes above 6° were significantly higher than that on 0°-5° gentle slopes, while E. baileyi density was highest on 0°-5° slopes. The L. virgaurea population showed peak density on slopes of 0°-5° and 16°-25°. There was no significant difference in pest population density across different aspects. Geographic detector analysis indicated that elevation had the greatest influence on population densities of O. curzoniae (0.0674) and E. baileyi (0.2052), while slope had the greatest impact on G. qinghaiensis (0.2362) and L. virgaure (0.0776). The interactions between any two topographic factors primarily showed dual enhancement and nonlinear enhancement, with elevation and aspect exhibiting the highest interacting interpretability for O. curzoniae, and elevation and slope showing the highest interacting interpretability for E. baileyi, G. qinghaiensis, and L. virgaure. In summary, the population density of different pests has different responses to topographic factors in alpine meadows. O. curzoniae and E. baileyi show significant responses to altitude, while G. qinghaiensis and L. virgaure are more sensitive to slope gradients.

Key words: grassland pests, terrain, geographic detector, population density