Bao G.S.,Qinghai Academy of Animal Science and Veterinary |
Wang H.S.,Qinghai Academy of Animal Science and Veterinary |
Zeng H.,Qinghai Academy of Animal Science and Veterinary |
Kai Z.C.R.,HenanCounty |
And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2016
Alpine grassland is an important andcharacteristic ecosystem of the Qinghai-Tibet Plateau, but about 30% has been severely degraded by the combined effects of climate change, human activity, overgrazing, and rodent damage.Plateau zokor (Myospalax baileyi) are endemic subterranean herbivores on the Qinghai-Tibet plateau and they exhibit several ecological characteristics that not only influence the succession of plant communities, but also cause soil moisture, organic carbon, and soil nutrient heterogeneity. However, few studies have investigated vertical soil nutrient allocation in plateau zokor mounds, something that this study addresses by investigating zokor mounds with different formation times. Total nitrogen, available nitrogen, total phosphorus, available phosphorus, available potassium, and the organic contents of different soil samples from a number ofzokor mounds, and a control sample where plateau zokor did not inhabit in this region, were measured. Our results showed that soil nutrients were highest in the one-year old mound and lowest in the control sample, and that the nutrient content found in the mounds did not change with soil depth. These results contrasted with those from the control sample, which recorded decreasing soil nutrients with increasing soil depth. The results for total nitrogen and available nitrogen showed that the one-year-old mound > three-year-old mound > five-year-old mound > control. Total nitrogen content was found to increase with soil depth in the one-year old mound, whereas total nitrogen levels decreased in the three- and five-year-old mounds. Available nitrogen content decreased in the 0-10cm and 10-20cm layers in the one-year-old mound, five-year-old mound and in the control. However, available nitrogen content rose as the profile depth increased. In the 0-10cm layer, the total phosphorus content increased as the mounds got older, i.e.five-year-old mound > three-year-old mound > one-year-old mound > control.The total phosphorus content in the five-year-old mound was significantly higher than the control (P < 0.05), and the total phosphorus content of this mound considerably decreased with increasing depth.Available phosphorus content in the 0-10cm layer of the mounds decreased as the age of the mound increased.The available potassium contents inthe five-year old mound and control were higher than the three-year old mound in the 0-10cm layer. In the 10-20 cm layer, the available potassium content was significantly higher than in the other layers of the mounds. The one-year old mound also contained more available potassium than the other mounds or the control. Our study has indicated that the burrowing activity of plateau zokor can change the physical and chemical properties of the soil, and that the zokor mounds can form a "fertile island" in a relatively short period. These mounds provide a suitable environment for seed germination and survival, and they are important as a soil seed bank. Therefore, plateau zokor play an important role as "ecosystem engineers"in the Tibetan plateau ecosystem. © 2016, Ecological Society of China. All rights reserved.