Comparative Study On Red Deer Winter Nutritional Strategy In Heilongjiang Muling And Inner Mongolia Gaogesitai National Nature Reserve, Northeastern China

We collected faeces samples of red deer (Cervus elaphus xanthopygus) in winter of 2011, 2013 and 2015 in Gogestai National Nature Reserve of Inner Mongolia and winter of 2012, 2014 and 2015 in Muling Chinese Yew National Nature Reserve of Heilongjiang Province. Food component was calculated using proportation of plant species fragments faecal microhistological analysis by direct counting. Moreover, comparsion of food quality between different food types in the same plant community and same food types between different plant communities were performed. We determined content of crude protein, hemicellulose, cellulose, lignin, crude fat and combustion heat value of plants in different communities and compared the differences of plant nutritional composition between different food types in the same plant community and the same food types between the different plant communities. Then we integrated data on food component and food nutrients into response surface model to study nutritional strategies of red deer from the two plant communities. Then, we determined total tannins content, which is considered as the most widely studied and one of the most influencial plant secondary metabolites of protein absorbation, of all food species from two plant communities. Then we integrated tannin content as a non-nutritional variable for response surface model to analyze influence of tannins on red deer winter nutritional strategy in different communities. Results are as follows:1 The two red deer populations fed mainly on deciduous tree in both forest community and forest-grassland ecotone, though they distribute in communities that have significant different plant composition. Component of herbaceous plant did not vary a lot between communities. Red deer browse large mount of Chinese yew in Muling forestry community during sampling season. In contrast, almost no coniferous species was found in the diet of red deer population in forest-grassland ecotone, Inner Mongolia.2 Content of nitrogen, fat, cellulose, hemicellulose and lignin did not differ a lot among forbs, graminoids, coniferous and deciduous species. Combustion value of forbs was significantly lower than deciduous and other plant types in Muling forestry community. In forest-grassland ecotone, no significant difference was found among plant types as well. Combustion value and fat content of forbs were lower than the other plant types, while content of cellulose and hemicellulose were higer.3 Results from response surface model showed that red deer population in Muling national nature reserve prefer to browse foods with high energy, high protein and low fat. Red deer population in forest-grassland ecotone of Inner Mongolia prefers to browse the foods with high energy, high protein, high combustion value and low fat so that maximizing the intake of protein and carbohydrates.4 Content of total tannins of the taxus cuspidata was not as high as we expected, it even lower than some deciduous tree species.The condensed tannins of deciduous tree species in forest-grassland ecotone of Inner Mongolia were higher than gramineous plants and forbs. These results were consistent with the statement that the dicotyledonous woody plants contain higher condensed tannins. In Muling national nature reserve, tannins of the food largely changed the mathematical relationships between the food nutrients content of red deer and their demand for nutrients. In forest-grassland ecotone of Inner Mongolia, tannins of the plants have not effect the winter nutrition strategy of red deer population as Muling national nature reserve.Results of RSM demonstrated that red deer in Inner Mongolia prefer feeding on food with high protein, low carbohydrate, low fat and low tannins. And RSM gave suggestions of quantitative relationships between food component and nutrients and non-nutrtional components in two plant communities.