Comparison Of Population Genetic Diversity,Habitat Suitability,nutritional Strategies And Gut Flora Of Siberian Roe Deer Between Two Types Of Habitat,Heilongjiang Province,China

The Siberian roe deer(Capreolus pygargus)is a typical forest-dwelling ungulate in northeast China.In the past,the area had experienced a series of human disturbance activities,such as large-scale forest cutting,deforestation and reclamation,road construction,as well as climate change,forest fire and pest infestation,which resulted in significant changes in the appearance and internal structure of forest vegetation in the habitat of Siberian roe deer.At the same time,the Siberian roe deer population had a series of responses in ecological adaptation and genetic composition.To this end,we selected two typical habitats of Siberian roe deer in Muling,Heilongjiang Province:(1)primary forest(PF)habitat,which is located inside the reserve and undisturbed by human activities,and(2)secondary forest(SF)habitat,which is outside the reserve and disturbed by human activities.We compared the genetic diversity,nutritional selection strategy and fecal gut flora of two Siberian roe deer populations by using molecular biology DNA genetic analysis,nutritional ecology and microbial metagenomics analysis techniques through field investigation and fecal samples.At the same time,we also predicted the suitable habitat distribution of Siberian roe deer in the study area,so as to explore how the different habitat types formed under the disturbance of human activities drive Siberian roe deer to produce adaptive strategies in terms of genetic structure,habitat suitability,nutritional strategy and gut microbiota structure and function.The main results are as follows:1.Genetic diversity of Siberian roe deer populationsAlthough there was a high gene flow between the Siberian roe deer populations in the two habitats,the genetic differentiation of the populations showed a trend due to geographical isolation and the difference of vegetation types between the two habitats.The results of mitochondrial marker detection and microsatellite marker analysis showed that the genetic diversity of the overall Siberian roe deer population in Muling forest was at a moderate level(PIC = 0.676 ～ 0.774),and the genetic diversity of the PF Siberian roe deer population was higher than that in SF.The evolutionary history of Siberian roe dee population in Muling forest area is complex,and no historical expansion event has been detected,but it may have experienced the process of gradual differentiation.Human activities and habitat types affected the genetic diversity and distribution of Siberian roe dee population in Muling forest.2.Prediction of suitable feeding habitat of Siberian roe deer in winterTwo habitats with different vegetation structure and composition were formed in the study area due to human disturbance and different protection intensity(P<0.05),which resulted in the obvious differentiation of edible plant distribution and suitable habitat distribution of the two Siberian roe deer populations(P<0.05).The distribution of edible plants and suitable habitat of Siberian roe deer in PF was higher than that in SF.Landscape energy distribution(composition of edible plants)had the greatest influence on the distribution pattern of suitable feeding habitat for Siberian roe deer in Muling Forest,followed by human disturbance variables(village,farmland)and vegetation structure.3.Food composition and nutrition strategy of Siberian roe deerThere were significant differences in the structure and composition of vegetation between two habitats,which resulted in significant differences in food composition and nutrient intake between the two Siberian roe deer populations(P<0.05).In terms of food composition,PF Siberian roe deer mainly fed on Corylus spp.and Acer spp.,while the Siberian roe deer in SF mainly ate Glycine spp.and Corylus spp.In terms of nutrient intake,the Siberian roe deer in PF had higher intake of crude protein,crude fat and soluble sugar,while the Siberian roe deer in SF took in more digestible fiber.In winter,the nutrients in edible plants of Siberian roe deer population were significantly different in plant category,plant species and genus level.At the plant level,shrub and deciduous tree species had higher carbohydrate content.The contents of crude protein,crude fat and soluble sugar in coniferous trees were higher,but tannin was also higher in coniferous trees.The contents of crude protein,crude fat,carbohydrate and tannin in deciduous trees were more balanced.The results of RMT model showed that the objective of Siberian roe deer in Muling forest was to achieve a certain balance among several major macronutrients.Although Siberian roe deer in the two habitats showed different nutritional strategies,they maintained the balance of macronutrients by adjusting the intake of different food groups.4.Structure and function of gut flora of Siberian roe deerHabitat differentiation resulted in significant differences in the diversity,structure and function of gut flora between the two Siberian roe deer populations in Muling forest(P<0.05).The gut microflora diversity of Siberian roe deer in PF was significantly higher than that in SF(P<0.05).At the functional level,gut flora in PF showed higher abundance in carbohydrate metabolism,while gut flora in SF showed higher abundance in fatty acid metabolism.5.The correlation of habitat type differences on suitable habitat distribution,nutritional strategy and gut flora of Siberian roe deerTwo distinct habitat types were formed due to human disturbance in Muling forest.In order to adapt to different habitat types,Siberian roe deer had a series of chain changes in the structure and function of gut flora and nutritional selection strategy.The composition,availability and quality of edible plants of Siberian roe deer were different with the plant community composition of habitat type,which resulted in the different uptake ratio and nutritional strategy of major nutrients by Siberian roe deer.In addition,due to the co-evolution of gut microbiota and host diet,differences in animal nutrition strategies are accompanied by differences in gut microbiota composition and expression of functional pathways related to the metabolism of corresponding nutrients.In summary,the results showed that the adjustment of nutrition strategy and the expression of gut flora structure and function could reflect the adaptability of Siberian roe deer population to different habitats.