Ecological thresholds and damage risk classification of the Manchurian zokor (Myospalax psilurus) in temperate meadow steppe

The ecological threshold of rodent damage is a crucial indicator that must be clearly defined for effective grassland rodent management. Ecological thresholds can vary considerably among different rodent species within the same grassland type, as well as for the same species across different grassland types. However, the threshold for the Manchurian zokor ( Myospalax psilurus ) in temperate meadow steppes remains undetermined, posing challenges for the development of targeted control strategies. To refine the control indicators for M. psilurus in temperate meadow steppe, we monitored fresh mound density and plant community characteristics in the Hulunbuir temperate meadow steppe, China, between 2014 and 2020. Generalized additive models were employed to determine the ecological thresholds of M. psilurus , while principal component analysis and cluster analysis were subsequently applied to establish a damage risk index (DRI) and classify damage levels based on these thresholds. The primary results were as follows: (1) The ecological thresholds were successfully identified as 255 fresh mounds/ha in spring and 434 fresh mounds/ha in autumn in the Hulunbuir meadow steppe. (2) A higher number of mounds may still be compatible with grassland ecosystem functioning than previously reported. (3) Based on the identified ecological thresholds, the DRI classified the damage caused by M. psilurus into light, moderate, and severe categories. These findings provide valuable guidance for the management of Manchurian zokors in temperate meadow steppes and highlight the importance of balancing species conservation with ecosystem functions. • Determined ecological thresholds of Manchurian zokor in spring and autumn (255 and 434 mounds/ha). • Thresholds exceed previous estimates, showing ecosystems tolerate higher mound densities. • Used PCA and cluster analysis to classify zokor damage as light, moderate, or severe.