Seed Eaters Of China Armand Pine (Pinus Armandii) Within Animal-plant Mutualism Network In Southeast Tibet

The predation and dispersal of plant seeds by animals is the basis for studying the co-evolution relationship.Some plants and animals have evolved a stable mutualism relationship through long-term interactions.Therefore,the researches on the predation and dispersal process of plants,especially large seed plants,are helpful to clarify the mutualism network in the ecosystem and deepen the understanding of the co-evolution process of the ecosystem.From 2016 to 2018,field techniques including infrared camera,transect survey and cage trapping were used to investigate the animal diversity of China Armand pine forest in the southeast of Tibet and the characteristics of pine seed eaters.Meanwhile we analyzed the seed fate by placing labeled seeds experiment.The main results showed as follows:A total of 47 bird and mammal species were found in the China Armand pine forest of southeast Tibet,including 33 bird species of 6 orders and 12 families,and 15 mammal species of 6 orders and 11 families.The Shannon-wiener index of animals was 2.58,and the diversity of birds was higher than that of mammals.In the China Armand pine forest of southeast Tibet,brown-cheeked laughing thrush(Garrulax henrici)and yellow-billed chough(Pyrrhocorax graculus)were the dominant species of birds,while pika(Ochotona himalayana)and macaque(Macaca mulatta)are the dominant species of mammals.There were 4 species of China Armand pine seed eaters listed by occurrence frequencies from more to less:large-eared field mouse(Apodemus latronum),macaque,nutcracker(Nucifraga caryocatactes)and orange-bellied Himalayan squirrels(Dremomys lokriah).Nutcrackers only forged before seed release in the crown layer of pine trees and had scatter-hoarding behavior;other mammals ate seeds on the ground after seed release.Nutcracker,macaque,orange-bellied Himalayan squirrel were diurnal seed eaters,while large-eared field mouse were nocturnal seed eaters.There was no significant correlation between the visiting frequency of rodents and the fluctuation trend of seed rain density,indicating that the ground seed eaters had a weak dependence on China Armand pine seeds and did not form a specific mutualism relationship.Only 5%of the labeled seeds were left in situ after placing.Most of seeds were eaten,among which 10.33%were fed in situ and 61.06%were fed after flitting.Some seeds were discarded after flitting.Rats selected the habitats where they fed,and they preferred to cave and downed log as their feeding sites rather than the bare ground.It was found that there were only two caches with intact labeled seeds,and only one seed was found in each cache,indicating that ground rodents are main seed consumers,which disperse few seeds and have little effect on the dispersal of China Armand pine seeds.