A Comparative Study Of Trophic Niche Of Wapiti And Roe Deer Pre And Post The Heavy Snowfall In Eastern Wandashan Mountain

From January to April of 2007, we comparatively studied the trophic niche of wapiti (Cervus elaphus) and roe deer (Capreolus pygargus) in sympatry in eastern Wandashan mountain in winter, by using the fecal microhistological analysis technique, we calculated the trophic niche breadth and overlap between these two ungulates, and analyzed the die composition and niche parameter pre and post the heavy snowfall events, the results showed that:The diet composition of wapiti and roe deer were mainly woody plants, and had little in herbage and fern, which were even unshown in the diets of roe deer in this study. These two ungulates had similar foods during the study period, but the proportions of their diet compositions were different, the rank of the single forage species appeared differently. Both wapiti and roe deer mainly took Syringa reticulate and Euonymus pauciflorus as the main diet in winter, but there still had significant differences in the rank of their diet items, when the wapiti decreased the use of some food species like Aralia mandshurica , which were increased in the diet of roe deer, for instance, some species like Phellodendron amurense took higher rank in the diet composition of wapiti, but it was lower in the diet of roe deer, it suggested that niche differentiation appeared between wapiti and roe deer in this dimension, which might supply some important insights in the interspecies coexistence of them.The trophic niche breadth of wapiti and roe deer were 18.07 and 14.10 respectively pro the extreme snow events and 19.74 and 15.73 post the extreme snow events. Pre and post the extreme snow events, the niche overlap were 0.946 and 0.921 respectively, which were in high level and suggested that the potential competition between the two ungulates was still fierce. But the effect of extreme snow events to the evenness of diet composition between wapiti and roe deer was in contrary. Although the extreme snow events might decrease the competitive extent of them, the effect was not remarkable. No matter pre or post the extreme snow events, the difference of the diet composition between wapiti and roe deer was not significant (p>0.05), which suggested that the extreme snow events had no distinct effect to the diet composition of wapiti and roe deer in a shorter time scale.The effect of extreme snowfall to the trophic niche of wapiti and roe deer yielded less effect to the diet composition in fine time scales, but the changes of the forage ranks of ungulates to the different food species and the richness of which had important significances to the Cervids survival in a severe winter habitat with heavy snow cover. So, study of the short-term effect by the extreme snow events to the trophic niche of the Cervids still had important significance in theory and conservation management implications.