Analysis On The Structure Of Mutualism Network For Mistletoe Seed Dispersal

Co-evolution between plants and animals has always been a hot topic in ecological research.After long-term interaction between plants and animals,a certain mutual benefit relationship has been formed.The mutualism relationship network is formed due to the complexity of the interaction between animals and plants and the variety of their connections.In the mutualism network,animals play an important role in the seed dispersal,especially the birds,which has important ecological significance for the succession of forest ecosystem.The seed dispersal of fruit-eating birds is a key indicator affecting the contribution of plant population regeneration,which determines the survival of plant population and affects the maintenance of community biodiversity.In this study,field line transect method and quadrats method were conducted in Shengli Farm of Raohe County and Maoer mountain to analyze the composition and structure of the reciprocal network of mistletoe seed dispersal.Through bird cage feeding experiment,fruit nutrient composition determination,mistletoe seed germination experiment,to understand the bird's choice of five fleshy fruits and the contribution of waxwing bird to the effectiveness of mistletoe seed dissemination.The main results showed as follows:(1)In the eastern mountains of Heilongjiang Province,the main populations in the mutualism network of mistletoe seed dispersal were waxwings and Aspen,and the network had the characteristics of dispersion and asymmetry structure.(2)Among the six species of birds for feeding,bullfinches(Pyrrhula pyrrhula)an d white-waisted rosebird(Acanthis flammea)refused to eat fleshy fruit,North the linnet(Carpodacus roseus)and Tin mouth bird(Coccothrausles coccothraustes)peck at the f ruit when they are hungry,waxwings(Bombycilla garrulus)and Japanese waxwing(Bo mbycilla japonica)swallowed the fruit whole.The waxwing chose the five fruits that Dwarf apple(Malushaccata)>Sorbus(Sorbuspohuashanensis)>honeysuckle(Lonicera ma-ackii>Mistletoe(Viscum coloratum)>Viburnum of chicken(Viburnum opulus).The Japa-nese waxwing chose the five fruits that Dwarf apple>honeysuckle>Sorbus>Mistletoe>Vi-burnum of chicken.In December.the fruits of rowans and honeysuckle will anhydratio-n.The waxwings preference for each of the five fruits has been changed,preferring m-istletoe earlier.(3)There were differences in nutrient contents among the five fruits.The fruit of Dwarf apple is large and heavy,and the water and fat content low.The fruit of Honeysuckle had the highest protein content.Viburnum of chicken had the highest tannin content.Sorbus had the lowest protein content.Mistletoe had the highest polysaccharide content and low cellulose and tannin content.(4)The average passage time of mistletoe seeds from the gut of waxwings is 1238.06±28.90s,from the gut of Japanese waxwing is 1313.10±28.04s.There was no difference in seed germination days among different gut passage time.The germination rate of gut-passed seeds of birds(58.62%)was higher than that of manually extracted seeds(32.5%),and there was no difference in germination days.There was no difference in seed germination days under three different culture temperatures of 1 5?,20? and 25?,and the seed germination days increased with the increase of culture temperature.