Abstract:

The distribution data of Pomatosace filicula (Primulaceae) , a second−class protected monotypic plant specied endemic to the Qinghai−Tibet Plateau, were investigated using MaxEnt (Maximum Entropy) ecological niche model and ArcGIS 10.7 software. 30 environmental variables, including climate, elevation, soil conditions and human activities were selected based on the species’ growth and distribution characteristics. The species’ potential distribution patterns and its responses to key environmental factors were simulated both with and without human activity impacts. The relationships between potential suitable distribution patterns and environmental factors were examined, and changes in potentially suitable distribution areas under human influence were analyzed. The following results were obtained: (1) the potential suitable areas for Pomatosace filicula in Qinghai province were primarily concentrated in the Three−river source region of southeastern Qinghai and the Qilian mountains in the northeast. Highly suitable areas, accounting for 14.2% of the province's total area, were mainly distributed across Chenduo, Maduo, Maqin, Gande, Dari, Jiuzhi, Henan and Zeku counties. Moderately suitable areas, comprising 15.4% of the provincial area, were predominantly found in Zhiduo, Zaduo, Qumalai, Tianjun, and Qilian counties. (2) When human activities were considered, the potential distribution area was found to be contracted and fragmented, displaying a strip−like pattern along plateau valleys. The total potential suitable area in Qinghai province was reduced by 35.6%, with highly suitable areas decreased by 9.96×10⁴ km² and moderately suitable areas reduced by 10.97×10⁴ km². (3) Without considering human influence, the primary environmental variables affecting Pomatosace filicula distribution were determined to be annual precipitation, elevation and precipitation in the driest season, with contribution rates of 27.7%, 14.5%, and 12.4%, respectively. When human activities were included, the main influencing factors were identified as the human footprint index, elevation and annual temperature range, with contribution rates of 57.6%, 11.6%, and 10.1%, respectively.

Key words: Pomatosace filicula (Primulaceae), MaxEnt model, Human activities, Potential distribution pattern