青海湖流域高原鼠兔(Ochotona curzoniae)粪花粉和真菌孢子组合及其生态指示意义

POLLEN AND FUNGAL SPORE ASSEMBLAGES IN THE PLATEAU PIKA(OCHOTONA CURZONIAE) DUNG AND THEIR ECOLOGICAL SIGNIFICANCE IN THE QINGHAI LAKE WATERSHED

高原鼠兔(Ochotona curzoniae)是青藏高原生态系统中的关键物种,是高寒草地生态系统演化过程中的重要组成部分,其对高寒生态系统的影响作用是广泛关注的热点科学问题。本研究采集了青藏高原东北部青海湖流域高寒草甸和温性草原植被群落中的27个高原鼠兔粪样品并开展花粉和真菌孢子分析。结果表明,高原鼠兔粪样品中花粉组合以蒿属、禾本科、莎草科、豆科、菊科、蔷薇科和龙胆科等为主,通过与研究区表土花粉组合对比发现,高原鼠兔的主要食物类型为禾本科和豆科植物,蒿属、莎草科、紫菀属、蔷薇科、蒲公英属和龙胆科等植物也是其少量采食的植物类型。高寒草甸和温性草原植被群落中高原鼠兔粪花粉组合存在一定的差异,表明植物群落组成对高原鼠兔食物的选择产生一定的影响;高原鼠兔粪便真菌孢子组合中荚孢腔菌属占显著优势,是监测高原鼠兔种群密度变化的潜在指示性属种。此外,粪壳菌属、条黑粉菌属、毛壳菌属、格孢腔菌属、Fungi type-1和Fungi type-10也是重要的粪生真菌孢子类型。鼠兔粪样品真菌孢子组合中球囊霉属百分含量较低,指示高原鼠兔对植物根系啃食程度较低。本研究对于深入理解高原鼠兔采食习性,以及对区域植被生态的影响研究提供了重要基础资料,为今后青藏高原草地资源管理、生态恢复治理和高原鼠兔防治策略的制定提供了科学依据。

The plateau pika(Ochotona curzoniae) is a key species in the ecosystem of the Qinghai-Tibet Plateau and plays an important role in the evolution of alpine grassland ecosystems. Its impact on alpine ecosystems remains a hot scientific issue at present. In this study, 27 plateau pika fecal samples were collected from the alpine meadow and temperate steppe vegetation communities in the Qinghai Lake watershed in the northeastern Qinghai-Tibet Plateau for the pollen and fungal spore analyses. The results show that the pollen assemblages from the plateau pika fecal samples are dominated by Artemisia, Poaceae, Cyperaceae, Fabaceae, Asteraceae, Rosaceae, Gentianaceae, etc. Comparison with the soil pollen assemblages in the study area implies that Poaceae and Fabaceae are the primary food sources for the plateau pika. Additionally, plant types including Artemisia, Cyperaceae, Aster-T, Rosaceae, Taraxacum, and Gentianaceae are also consumed in a small proportion. Pollen assemblages are different in the fecal samples from the alpine meadow and temperate steppe, suggesting the composition of the vegetational communities have influences on the plateau pika's food selection. Sporormiella is a predominant taxon in the fecal fungal spore assemblages of the plateau pika, and may be a potential indicator species for monitoring changes in the population density of the plateau pika. In addition, Sordaria, Urocystis, Chaetomium, Pleospora, Fungi type-1, and Fungi type-10 are also important coprophilous fungal spore types. The low percentage of Glomus in the fungal spore assemblage of the fecal samples indicates that the plateau pikas have a low degree of gnawing on the plant roots. This study provides an important basic information for understanding the feeding habits of the plateau pika and its impact on the regional ecosystems, which will be useful for the future management of the grassland resource, ecological restoration, and plateau pika control strategies on the Qinghai-Tibetan Plateau.