高原鼠兔对高寒草甸冬季牧场中土壤C∶N∶P化学计量特征的影响

Effect of plateau pika disturbance on soil C:N:P stoi⁃ chiometrics of winter pasture in alpine meadow

摘要:

【目的】从小尺度的斑块状栖息地角度出发分析高原鼠兔干扰及不同干扰强度对植被覆盖区土壤有机碳（SOC）、全氮（STN）和全磷（STP）含量的影响，有助于全面理解小型食草动物对草地土壤化学计量特征的影响。【方法】以高原鼠兔为研究对象，测定高原鼠兔栖息地及栖息地不同植被覆盖区土壤的 SOC、STN、STP 含量及土壤 C∶N∶P 化学计量特征的变化。【结果】与未干扰植被覆盖区相比，高原鼠兔栖息地植被覆盖区的 STN 含量和 N∶P 显著下降（P＜0. 05），C∶N 显著增加（P＜0. 05），但 SOC 和 STP 含量及 C∶P 没有发生显著变化；STN 和 SOC 含量、C∶P 和 N∶P 在高原鼠兔干扰最大的核心区最低，干扰强度最小的边缘区最高；C∶N 在干扰强度适中的次核心区最高，边缘区最低；而 STP 含量在不同干扰强度的植被覆盖区没有显著差异。【结论】高原鼠兔干扰及干扰强度会对其领地内植被覆盖区的土壤化学计量特征产生影响。高原鼠兔斑块状栖息地中土壤化学计量特征的变化可能是影响植物丰富度的因素之一。

Abstract:

【Objective】 The effects of plateau pika disturbance and different disturbance intensity on soil organic carbon （SOC），total nitrogen （STN） and total phosphorus （STP） contents in vegetated areas were analyzed from the perspective of a small scale patchy habitat in order to comprehensively understand the effects of small herbivores on soil stoichiometric characteristics of grassland.【Method】 The contents of SOC，STN and STP of the vegetation covered areas in different regions of the plateau pika habitat were determined.【Result】 The results showed that com- pared with undisturbed areas，the STN content and N：P decreased significantly （P＜0. 05） in areas that plateau pikas inhabit. The C：N increased significantly （P＜0. 05），whereas SOC，STP content and C∶P showed no change. The STN and SOC content，C∶P and N∶P were the lowest in the central area where disturbance from the plateau pika was the highest，and the edge area with the least disturbance intensity was the highest. C∶N was the highest in the subcentral area that had a moderate level of disturbance，and the edge area was the lowest. However，the STP did not vary with the intensity of disturbance from plateau pikas.【Conclusion】 The above results indicate that the disturbance and intensity of the plateau pika have an impact on the C∶N∶P stoichiometrics in vegetated areas with pika territory. This suggests that changes in soil C∶N∶P stoichiometric in the patchy habitat of plateau pikas may be an important factor that could affect plant richness.