Influence of the density of burrow entrances of plateau pika on the concentration of soil nutrients in a Kobresia pygmaea meadow

Disturbance in the population of the plateau pika, Ochotona curzoniae, often induces changes in the concentration of soil nutrients in alpine meadows. The effects of disturbance in the population of plateau pika on the concentration of the primary soil nutrients in a Kobresia pygmaea meadow was investigated to examine the relationships between the density of total burrow entrances and active burrow entrances of plateau pika and the concentration of the primary soil nutrients. Our results showed that the disturbance significantly increased the concentration of organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), soil ammonium nitrogen (NH4+-N), and nitrate nitrogen (NO3--N) in the soil, but there was a decrease in available phosphorus (AP) concentration in the 0-20 cm soil layer. As the densities of total burrow entrances and active burrow entrances increased, the total nutrient concentration in the 0-20 cm soil layer (SOC, TN, and TP) initially increased but then decreased. The nutrient concentration for NH4+-N, NO3--N, and AP initially decreased then increased, indicating the relationship between the density of total burrow entrances and the concentration of soil nutrients are consistent with the density of active burrow entrances of plateau pika and the concentration of soil nutrients. Therefore, when determining the effects of plateau pika disturbances on the concentration of soil nutrients, the density of active burrow entrances can be replaced with the density of total burrow entrances.