基于稳定同位素技术的高寒草甸高原鼢鼠营养生态位特征

Study on trophic niche characteristics of plateau zokor (Eospalax baileyi) in Alpine Meadows based on stable isotope technique

摘要:

【目的】分析啮齿动物营养生态位特征，了解动物所占据的营养层，揭示啮齿动物在不同时间尺度上的食物资源利用变化。【方法】以祁连山东段高寒草甸栖息的高原鼢鼠（Eospalax baileyi）为研究对象，采用贝叶斯碳氮稳定同位素质量平衡混合模型，分析高原鼢鼠不同组织的食性信息及其营养生态位特征。【结果】高原鼢鼠不同组织中同化的食物种类基本一致，但在食谱中的贡献率各有差异。地上部分蒲公英（Taraxacum mongolicum）在血液（24. 33%）、肌肉（19. 63%）和毛发（14. 00%）组织中的贡献率均最高；地下部分鹅绒委陵菜（Potentilla anserina）在不同组织中的贡献率均最高，分别为 66. 01%，17. 79% 和 10. 72%。不同组织中同化食物种类和营养生态位宽度变化一致，在植物地上部分表现为血液（8 种，1. 742）＜肌肉（10 种，2. 049）＜毛发（13 种，2. 227）组织，植物地下部分为血液（5 种，1. 100）＜肌肉（14 种，2. 370）＜毛发（15 种，2. 469）组织，且地上和地下植物在高原鼢鼠血液组织 （1. 100）中的生态位重叠度远低于肌肉（0. 447）和毛发（0. 566）组织。【结论】高原鼢鼠各组织代表的不同时间尺度的食性信息中，短期食性（血液组织）中同化物种数较少，生态位宽度较小。而在长期食谱 （肌肉和毛发组织）中食物种类广泛，生态位宽度变大。且地上和地下植物在高原鼢鼠短期食性中生态位重叠度远低于长期食性。鉴于高原鼢鼠的采食习性，建议在高原鼢鼠危害严重区域，可以通过补播禾本科等优良牧草，降低高原鼢鼠优质食物在其栖息地植物群落中的比例，达到防治高原鼢鼠危害的目的。

Abstract:

【Objective】 The analysis of the characteristics of rodent nutritional niche can not only help us to understand the nutrient layer occupied by animals，but also reveal the changes of rodent food resources utilization at different time scales.【Method】 In this study，the plateau zokor （Eospalax baileyi） inhabiting the alpine meadow in the eastern part of Qilian Mountain was selected，and the stable isotope mass balance mixed model was used to analyze the foraging information and nutritional niche characteristics of plateau zokor at different time scales.【Result】 The results showed that the main food intake of plateau zokor was the same in different tissues，but the contribution rate in diet was different. Among them，the aboveground part of Taraxacum mongolicum had the highest contribution rate in blood （24. 33%），muscle （19. 63%） and hair （14. 00%），while the underground part of Potentilla anserina had the highest contribution rate in different tissues，which were 66. 01%，17. 79% and 10. 72%，respectively. In different tissues，the changes of food intake and nutritional niche width were the same. In the aboveground part of plants，the results were as follows： blood （8 species，1. 742） ＜ muscle （10 species，2. 049） ＜ hair （13 species，2. 227） tissue. In the underground part of plants： blood （5 species，1. 100） ＜ muscle （14 species，2. 370） ＜ hair （15 species，2. 469）. The niche overlap of aboveground and underground plants in the blood tissue of plateau zokor （1. 100） was much lower than that in muscle （0. 447） and hair （0. 566）.【Conclusion】 The above results show that among the foraging information of different time scales represented by each tissue of plateau zokor，the number of ingested species in short ‐term eating habits （blood tissue） is less and the niche width is smaller. On the other hand，in the long ‐term diet （muscle and hair tissue），there are a wide variety of foods and a wider niche width. And the niche overlap of aboveground and underground plants in the shortterm foraging habits of plateau zokor is much lower than that of longterm foraging habits. In view of the foraging habits of plateau zokor，we suggest that for the areas with serious damage to plateau zokor， the proportion of high quality food in the plant community of plateau zokor shall be reduced by sowing Gramineae and eliminating forbs，so as to achieve the purpose of preventing and controlling the harm of plateau zokor.