A Study On Nutritional Niche Of Plateau Zokor And White Yak In The East Of Qilian Mountain Based On Stable Isotope Techniques

Animal nutrition niche refers to the function and status of organisms in their communities,emphasizing the nutritional relationship between species and other species.Dietary and food competition are the key elements of the study of nutritional niche of the same trophic levels animal.Due to the unique underground inhabitation characteristics of subterranean rodents,it is difficult for traditional diet research methods to comprehensively and objectively reflect their food habits,resulting in slow progress in the research on diet and its nutritional niche.In recent years,with the extensive application of stable isotope analysis in animal feeding research,it has provided great technical means for the study of nutritional niches of subterranea rodents.The plateau zokor?M.baileyi?is an indigenous species on the Tibetan Plateau.It is a primary consumer of the alpine meadow ecosystem and a competitor to grazing animals.Because of this special nutritional niche,the plateau zokor is considered to be grassland pest which need to control.However,what is the relationship between the food habits of the plateau zokor and grazing animals in different seasons?There are only a few articles at home and abroad that use traditional methods to study their food habits,and no studies have been reported on long-term scales.Therefore,understanding the nutritional niche relationship between the plateau zokor and herbivorous animals has a great significance for correctly understanding the function and location of plateau zokor in grassland ecosystems and scientifically defining its harm.In this study,the plateau zokor and white yak that were symbiotic in the alpine meadows of the eastern Qilian Mountains were selected.The stable isotope techniques were used to study the stable isotope characteristics of plateau zokor food(plants,the dietary characteristics of plateau zokor and white yak in different seasons and the nutritional niche competition relationship between plateau zokor and white yak.The main results were followed:1.There are 24 species of plants in the study area,belonging to 21 genera and 13families,all of which are C3 plants.The content of?¹³C in the aerial parts of plants was the lowest in Salicaceae,the highest in Liliaceae?P<0.05?,the?¹³C content in the underground part of plants,the highest in Polygonidae,and the lowest in gentian?P<0.05?.The content of?15N in aerial parts of plants was the lowest in Liliaceae,the highest in Thiolidae?P<0.05?,the?¹⁵N content in underground parts of plants,the lowest in Salicaceae,and the highest in Thiolidae?P<0.05?.The contents of?¹³C in the above-ground and underground parts of the annual plant species were the lowest?P<0.05?.The?¹⁵N in the ground parts of the ground bud plant was the highest?P<0.05?.The?¹³C and the underground part of the above-ground bud plant?¹⁵N were The highest and the lowest?P<0.05?,the highest?¹⁵N in the upper parts of the high bud plant?P<0.05?,the highest in the underground part of the annual plant?¹⁵N?P<0.05?2.Plateau moths are predatory.The above-ground foods in September were mainly Equisetum arvense,Kobresia humilis and Leymus racemosus,underground food line Kobresia capillifolia and Poa annua.In August,the above ground food was dominated by P.anserina and E.arvense,and the underground food was mainly P.anserina;in June,the above ground food was P.anserina and E.arvense are dominant,and underground food is mainly P.anserina and K.humilis.3.There is a seasonal nutritional niche differentiation between plateau zokor and white yak.In August of the vigorous growth of forage grass,Kobresia humilis and Leymus racemosus both contributed to the food of the two animals,but the contribution to the yak was significantly higher than that of the plateau zokor?P<0.05?.The two plants P.anserina and E.arvense,which have the highest contribution to the plateau zokor food,were not found in the white yak recipe.In June after the returning green period,the plateau zokor mainly feed on E.arvense and P.anserina,while the white yak mainly eats C.carvi and R.Japonicus and Gramineae and Cyperaceae.The above results indicated that the two animals had smaller nutritional niche overlap during the Shengcao period?August?,and they completely differentiated after the returning green period?June?.