Plant Communities And Their Relationship With Composition Of Food Items Of Rodents In Shallow Mountain Area, Jiyuan, China

To understand the relationship between plant communities and rodents and plant community dynamics, we investigated the plant communities in shallow mountain area, Jiyuan, China, from April to November, in the years 2009 and 2010. We did research on the composition of plant communities and their seasonal dynamics in the region as well as the seasonal dynamics of the aboveground biomass of plants in shrub-grass land. We also surveyed the spacial and temporal patterns of seed rain of Quercus variabilis. Results showed that:1. The composition of the plant communities was complex and stable. The plant communities could be classified into 3 types:i) Ass. Quercus variabilis-Vitex negundo var. heterophylla-Bothriochloa ischaemum; ii) Ass. Rose xanthina+Vitex negundo var. heterophylla+Cotinus coggygria+Artemisia sacrorum var. incana; iii) Ass. Artemisia sacrorum var. incana+Vitex negundo var. heterophylla.2. The abundance of the plant communities in shrub-grass land fluctuated among seasons in the whole year. It reached the largest point in spring and the lowest one in summer. The aboveground biomass of the plant communities rose from spring to autumn. There was a significant increase in aboveground biomass in summer. The density of rodents grew as time passing by. The aboveground biomass of the plant communities in shrub-grass land exerted positive influence on the density of rodents.3. The outputs of seed rain of Cork oak, Quercus variabilis, varied between years. The aborted and damaged rates of seeds of Quercus variabilis accounted for relatively higher percentages in seed rain. And this would decrease seed germination rate in some way. Meanwhile, individual Cork oak tree kept the same breeding pace as the population, though weak annual difference occurred.Seed rain of Quercus variabilis showed an apparent characteristic in the spacial distribution pattern, and total 80% of the seeds were found in the direction of southeast. The seed rain pattern under tree crown fitted quadratic distribution, and had high coefficients of determination. The density of seed rain increased with the increasing of distance from parent trees, and reached the peak at the edge under tree crown. From then on, the density negatively correlated to the distance.4. The dominant and frequent plants in the 3 habitats were mostly food sources for rodents. The food items of rodents had seasonal changes and there was no difference in food items of rodents in the same season among 3 habitats. Different plant communities supplied various food requirements to rodents in 3 habitats and seasons, which led to different numbers of rodents among different seasons and habitats.