| There is only one reindeer population that domesticated by Ewenki herders for more than 300 years in Aoluguya, Inner Mongolia, China.The population is a rare small population that inhabits in the most south of northern hemisphere, and forms the unique life habit. In China, reindeer plays important roles on economic,ornamental and cultural research value, and is the strong ethnic characteristics and unique economic animal of Ewenki people.In recent years, the available habitat and food resources of reindeer is shrinked with the continuous development of forest resources in the Greater Khingan Mountains. Furthermore, the reindeer population exist obviously small population size, long-term inbreeding, extensive management, wild animal damaging, poaching and disease. For all those reasons, the reindeer population survival status is anxious.The population distribution of reindeer that semi-domesticated socially by the Ewenki herders has the typical regional limitation and distinctive ethnic characteristics, and has lost the migratory habits. It forms the characteristics of ecological species which are different from other large populations of reindeer in the arctic region.This research is focusing on the study of the present situation, food composition, nutritional carrying capacity and population viability analysis (PVA) of reindeer in Aoluguya, and provides the references for the population protection, restoration and development of reindeer in China.From 2011 to 2015, we tested and investigated the population quantity and age structure of reindeer and vegetation species consumed by reindeer that distributes in the forestry bureaus of Genhe city of Inner Mongolia, and collected fresh fecal samples of reindeer and plant specimens. The main results are as follows:Since 2012, the reindeer population had never exceeded 700 and been raised by 25 families consist of 8 tribes points and 1 tribal area distributing in Genhe, Jinhe and Alongshan forestry bureaus. The age structure of population is reasonable, and adult reindeer is the main body and accounts for about 40% of the entire population, larva and sub-adult are similar and those two account for about 50%, older individuals are fewest and less than 10%. But the sex ratio is unbalanced, and the ratio of female and male is 1.7:1.From 2011 to 2014,83 plant species (genus) and 2675 fresh feces were collected, and 240 composite feces samples were made. The annual food component of reindeer was studied with the fecal micro histological analysis. Reindeer consumed 73 plant species (genus) belonging to 40 families in the whole year, which consists of 10 families,18 species woody plant,18 families,40 species herbaceous plant,4 families,5 species pteridophyte,5 families,5 species bryophyte and 3 families,5 species lichen. The 12 families,15 species plants were foraged throughout the year. The Cladoniaceae (38.76%), Gramineae (4.58%), Cyperaceous (3.80%), Ericaceous (3.37%) and Hylocomiaceae (3.21%) plants constituted the main food in the whole year. And Cladina rangiferina and Cladina stellaris had higher RD in the diet composition and were most common and dominated foods for reindeer. The feeding proportion of Cladina rangiferina in spring, summer, autumn and winter were 18.13%,7.18%,21.05% and 37.56%, and that of Cladina stellaris were 15.41%,7.26%,16.49% and 21.65%, respectively.Regarding composition of foods, the tender branches and leaves of woody plants, and tender buds and leaves of herbaceous plant were foraged by reindeer, and making up 47.43% of diet composition of reindeer in spring. In summer,49.96% of diet composition was from the leaves of herbaceous plant. Lichens were foraged largely in autumn and winter, and the proportion were 42.06% and 68.03%, respectively. It showed that the food composition of reindeer has certain seasonal differences. On the diversity of feeding plants,59 plant species were identified through the micro histological analyses in summer, followed by the spring and autumn,51 and 33 species, respectively. In winter, there were only 28 species. Food diversity index, evenness indices and ecological niche width were highest in summer,3.57,0.87 and 28.30 respectively, and the lowest in the winter, only 2.17,0.65and 5.03, showed that winter is the most difficult season for reindeer.Cladina rangiferina, Cladina stellaris and Cladina pyxidata were the major food of reindeer, accounting for 63.97% of all the food in winter. From 2012 to 2015, the growth situation of Cladina rangiferina, Cladina stellaris and Cladina pyxidata where grow in Genhe, Jinhe, Alongshan and Mangui forestry bureaus was determined by locating 214,2.5-3km transects and 768,10m×10m plots. Cladina rangiferina is the dominant species in the Greater Khingan Mountains of Inner Mongolia, and its average coverage, height and dry matter biomass were 4.93%,14.1 mm and 44.90 kg/ha. The average coverage, height and dry matter biomass of Cladina stellaris and Cladina pyxidata were 2.72%,13.2 mm,23.25 kg/ha and 0.90%,10.0 mm and 5.93 kg/ha, respectively. The lichen of Mangui forestry bureaus where historic distribution area of reindeer had a better recovery of nearly 10 years and the dry matter biomass was the highest and reached 132.36kg/ha. Followed by Alongshan forestry bureau and Jinhe forestry bureau, dry matter biomass were 103.56 kg/ha and 49.91 kg/ha. The dry matter biomass of Genhe forestry bureau was the lowest as only 40.33 kg/ha. Geographically, the coverage and biomass of lichen of northern part is better than the south.Energy is the main nutrient that limits reindeer winter survival. Combining these data with lichen,we estimated the carrying capacity of Genhe, Jinhe, Alongshan and Mangui forestry bureaus for reindeer based on metabolism energy. The results indicated that these 4 forestry bureaus can sustain 759、926、1407 and 2078 reindeer in winter, respectively, and 8 tribe points can sustain 1468.Based on the biological characteristics, the special cultivation mode and management way adopted by Ewenki people, the real breeding areas where suitable for reindeer were very limited in vast forests of the Greater Khingan Mountains, and the actual carrying capacity of reindeer was much less than the estimated value. The diversified operations should be carried out in order to the sustainable development of reindeer. In Genhe and Jinhe forestry bureaus, the regional advantages should be fully taken to carry out the reindeer tourism with smaller population. The larger population breeding should be carried out through the growth advantage of lichen in Alongshan and Mangui forestry bureaus. It is urgent to create 1-2 nature reserves in each of the forestry bureaus and realize common development both natural environment protection and population increment of reindeer. In the process of reindeer breeding, the amount of each small population must be controlled according to the growth conditions of lichen plant and operating mode,and ensure the sustainable development of the reindeer population.In this study, we chose Vortex9.99 to simulate the dynamics of reindeer population. In ideal circumstances (no inbreeding and disaster), the population can grow quickly and maintain a level of carrying capacity. The intrinsic growth rate of heterogeneous populations was r=0.067, the periodic growth rate and net reproductive rate were 1.069 and 1.257, respectively. The average generation time of female and male reindeer were 3.57 years and 4.32 years, and the replacement of population genetic need 5.5 years or so every time. In natural conditions (inbreeding and disaster), the development of reindeer population was not optimistic, the intrinsic growth rate and periodic growth rate of heterogeneous populations were -0.071 and 0.929. All subpopulations had a negative growth except Maliya suo subpopulation and faced with very high risk of extinction, and their extinction probability were 4%-100%, which of Damala, Dawa, Yangshuanghu and Balajieyi subpopulations were 100% and extinction time were 21,39,21 and 17 years.Sensitivity analysis found that the wildlife damaging and poaching were the biggest factors affecting the development of reindeer population, directly related to the development direction of reindeer population. Followed by the mortality of infant reindeer, it related to the breeding stock and development speed of reindeer population.The development situation of reindeer population was not optimistic in China through a series of surveys of the present situation of reindeer population, available habitat, the growth and distribution of plants that were foraged by reindeer, and combining the study of the estimation of nutrient carrying capacity and future developments of reindeer population. We should take the effective measures to protect habitats, stop poaching, gathering illegally lichen and over-harvesting the forestry byproducts, and speed up the population rejuvenation of reindeer and strengthen the development and utilization of reindeer resources in China. |
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