A Study On Dynamics Of Rodent Community Patterns In Forests Of Zhangguangcai Moutain,Heilongjiang Province,China

Trap-day method was applied to study the rodents fauna composition,population dynamics,community distribution characteristics and diversity in Zhangguangcai mountains from 2011 to 2016.Stomach content analysis and Quadrat Sampling method were used to study the diets of the forest rodents and the perniciousness to forest.The outcomes were compared with the results of Mr.Ruyong Sun in 1959 in the same area.The results are showing as follow.1.28 species of rodents and insectivorous animals were recorded in this survey,belonging to 3 orders,8 families and 17 generas.Palaeoarctic was the main fauna composition.The rodents population had significant seasonal and annual difference.The seasonal dynamic curve of the rodent population was unimodal type.The capture rate were low in March,April and November,but high in July and August.There wasn't an periodic interannual variation in the six investigated years.The Myodes rufocanus and Apodemus peninsulae were dominant species in these area.Their populations were significantly positively related to seasonal fluctuations.The diversity and evenness of rodents in different habitats were different.The broad-leaved forest and the forest meadow had more diversity.The forest meadow and the coniferous forest had better evenness.The rodents diversity and evenness were stable in different years,but varied in different months.There was more variation in March,and showed a tendency of decling between March and October,and rose in November.2.The distribution of rodents in different habitats in Chaihe Forest Farm were different.The Myodes rufocanus and Apodemus peninsulae were dominant species in mixed broadleaf-conifer forest and broadleaf forest,and the former with a high proportion of Myodes rufocanus,the latter with more Apodemus peninsulae.There were more species in meadow and Myodes rufocanus had a higher proportion.The rodents richness in different habitats was meadow>farmland>mixed broadleaf-conifer forest>broadleaf forest.The rodents evenness in different habitats was meadow>broadleaf forest>farmland>mixed broadleaf-conifer forest.Compared with the results of Mr.Ruyong sun in 1959 in the same area:(1)The rodents capture rate declined and the number of species was reduced in mixed broadleaf-conifer forest.The rodents capture rate rised and the number of the species was reduced in broadleaf forest.With the Myodes rufocanus' and Apodemus peninsulae's capture rates rising,the capture rates of other species declined and the number of species multiplied in marshland.Species replacement rate was the highest in mixed broadleaf-conifer forest.The Sorenson index of similarity in different habitats was marshland>broadleaf forest>mixed broadleaf-conifer forest.The Whittaker index of similarity in different habitats was mixed broadleaf-conifer forest>broadleaf forest>marshland.(2)The rodents richness declined sharply in mixed broadleaf-conifer forest and broadleaf forest,but rose in marshland.The rodents diversity declined sharply in mixed broadleaf-conifer forest,but rose in marshland and was stable in broadleaf forest.The rodent evenness rose in all habitats.(3)The biomass of rodents declined in habitats with low interference,but rose in habitat with more interference.3.Six species' diet were investigated.Their diets were different:Myodes rufocanus,Eutamias siviricus and Sciurus vulgaris lived on nuts like red pine nuts;Eutamias siviricus,Myodes rufocanus and Apodemus peninsulaea also consumed fruits,stems and leaves of plants;Cricetulus triton and Apodemus Agrarius lived on the seeds of crops;Apodemus Agrarius and Apodemus peninsulae lived on the seeds of plants.The interannual variation,distribution,type and quantity of food resources were closely related to the dynamics of rodents community.4.In the eastern mountainous area of Heilongjiang province,Myodes rufocanus,Apodemus peninsulae,Apodemus agrarius and Sciurus vulgaris were the main species damaging the forest.Conifer species and planted species were the main tree species victims.The degree of damage by rodent varied in different habitats,but the damage situation was similar.Forest rodents damage was associated with rodent community structure characteristics.Dominant species and their distribution were related to forest rodent damage.The seasonal variation trend of the forest rodents population was negatively related to the forest rodent damage.