Effects Of Rodent On Sympatric Tree Seeds In Secondary Forest Habitat

Many granivorous rodents are known to store large amounts of plant seeds in the field during seed-rich period in forest. They either transported seeds from source to nest (larder hoarding) or shallowly buried them in different localities (scatter hoarding). Rodents scatter hoarding behavior usually played a positive role on seed dispersal and plant recruitment because scatter-hoarded seeds were commonly buried in microhabitat with favorable temperature and moisture for seed germination. When storing seeds, rodents had to tradeoff among net energy income, nutrients, hoarding costs and predation risk. It has been revealed that seeds traits can influence animals’ selection and decision in eating or hoarding. However, this sympatric food resource always possessed great difference in edibility and nutritional value. Meanwhile, the selectivity of rodents to food variety and quality was very important to their survival and reproduction. It consequently exhibite implication and ecological significance on studying effects on fate of difference forest seeds from rodent in returning farmland to forest areas.In State-owned Yugong Forestry Farm of Jiyuan city, China, we studied food hoarding behavior of rodents and community characteristics and dynamic changes of rodents according to the field investigation experiment in secondary forest, shrub and rehabilitated land habitats. Meanwhile, we studied the differences in food hoarding behavior of sympatric tree seeds by rodents in secondary forest habitats. The main results and conclusions of this researchs are listed below:1) The dominant rodent species in the secondary forest habitat were Apodemus peninsulae, Sciurotamias davidianus and Niviventer confucianus; and Apodemus peninsula, Niviventer confucianus, Apodemus agrarius, Cricetulus triton were commonly found in the shrub habitat, with dominant species was Apodemus peninsula; the rodents included Apodemus peninsula, Niviventer confucianus, Sciurotamias davidianus in the rehabitated land, and the dominant species was Apodemus peninsula, Niviventer confucianus. The populations of rodents was significant different on the seasonal and inter-annual; rodent trapped rate of5.62%and3.62%respectively in2011and2012; the trapped rate of rodents were significant larger in autumn than in summer, and also, in summer than in spring in2011; the trapped rate of rodents were same in spring and in summer and significant larger in autumn respectively.2) In spring, wild apricot (Prunus armeniaca) were firstly dispersed, then seeds of wild peach (P. davidiana) and plums (P. salicind) and peach (P. persica), respectively; while little peach seeds (P. persicd) and plums (P. salicind) remained in situ, seed of P. salicina had lower removal rates but higher proportion of ate than others; wild apricots seeds were hoarded farthest from seed station, then plums seeds and then wild peach seeds, the peach seeds were hoarded nearest from seed station; the rodents that in scatter hoarding often formed single-seed caches and tended to cache seeds under shrubs, shrub edge and near tree base but only a small amount of seed cached in bare ground.3) In summer, wild apricot (P. armeniaca) were firstly dispersed, then seeds of wild peach (P. davidiana) and peach (P. persica), respectively; rodents tended to cached seeds; and with the increase in the thickness of the seed coat rodent feeding behavior gradually reduced; more than60%seeds of less than6.0m in diffusion distance; rodents tend to choose nder shrubs, shrub edge and near tree base dispersed storage wild peach and wild apricot seeds, only a small amount of seed cached in the bare ground; the rodents that in scatter hoarding often formed single-seed caches with bigger seeds and cache sites of smaller seeds comprised more than one seed. 4) Acorns of Cork oak(Quercus variabilis) were firstly dispersed, then seeds of wild apricot (Prunus armeniaca) and wild peach (Prunus davidiana), respectively; while almost all (99%) peach seeds (P. persica) remained in situ; rodents preferred to consume acorns while bury seeds of wild apricot and wild peach, but no peach seeds were eaten or buried; wild peach seeds were hoarded farthest from seed station, then wild apricots seeds and acorns; some cache sites of wild apricot comprised more than one seed, while the cache sites of acorn and wild peach usually contained only one seed; rodents tended to cache seeds under shrubs, shrub edge and near tree base but only a small amount of seed cached in bare ground.