The Research On Nutritional Dynamics Of Moose Population In Winter In Geographic Gradient In Northeast China

In our study, according to the change of a latitudinal gradient, we chosen five sites in moose distribution area of the Greater Khingan and Lesser Khingan Mountains, including Mohe County, Shuanghe National Nature Reserve, Hanma National Nature Reserve, Nanweng River National Nature Reserve and Zhanhe District. We analysed nutritional status of moose population by locating503-km transects, surveyed43452-m×2-m subplots, tracked91footing chains and collected205fecal samples and plant samples fed by moose in winter in Northeast of china from December2011to December2012.1. We studied the diet composition of moose by using the fecal microscopic analysis method in winter. The results showed that the staple food of moose was aspen (Populus spp.), willow (Salix spp.), hazel (Corylus spp.) and brich (Betula spp.). The minor portion of food included linden (Tilia spp.), bilberry (Semen spp.), Mongolian oak (Quercus mongolica), northeast China ash (Fraxinus mandschurica), alder (Alnus spp.), spruce (Picea spp.) and Korean pine (Pinus koraiensis). In Zhanhe, the region with a lower latitude, aspen accounted for the largest proportion of the diet composition,while both willow and hazel were the two main diet compositions in Mohe,where the latitude is higher, and in the middle latitude in nan weng river, birch is the most important food source. Meanwhile, the composition of other minor food parts also showed geographic gradient distribution dynamic change.2. We analysed the proportion of food composition of moose and calculated Schoener’s index by field surveys of browsed vegetation and microhistological analysis of feces, meanwhile, seted up linear model for the proportion and coefficient of standard deviation(CV) by microhistological analysis of feces, field surveys and quadrat method (evaluate food abundance). The results showed that definite coherence of microhistological analysis of feces and field surveys, and the food abundance change impacted the proportion of moose diet.3. We seted up the linear models for the proportion of food composition of willow and latitude. The result of models showed that moose feeding of willow presented geographical gradient change as the change of latitude.4. We counted the food abundance and tested the cortisol content and nitrogen content of the fecal samples in5research sites. We analysed the correlation among them by Spearman’s Rank correlation analysis. The latitude was significantly negative correlated with food abundance and nitrogen content, showing that the shortage of food may impact the diet quality of moose along with the gradient habitat latitude.5. The significantly negative correlation between cortisol content and nitrogen content in the fecal samples showed that the decline in diet quality would lead to cortisol release increasingly. So, the shortage of food reduced diet quality of moose. In ordre to overcome the increase of nutrition stress, the moose may release more cortisol. And the size of this nutrient stress presented geographical gradient change as the change of latitude6. We found that moose in the high latitude Mohe county were in faced the greatest nutritional pressure, while the situation was obviously better in Zhanhe, and the habitat nutritional status did not remarkably impact the distribution of the southernmost moose population.