Objective  This paper aims to clarify the composition structure and diversity characteristics of forest communities in Laoshan Mountain area of Shandong Province, eastern China and their relationship with environmental factors, so as to provide theoretical basis for forest management.

  Method  Using a cumulative species curve to verify the adequacy of sampling, according to the species importance matrix, the forest community was divided into different types. Relationship between the distribution of different community types and topographic and soil conditions was studied by canonical correspondence analysis (CCA). The relationship between species diversity and terrain and soil conditions was analyzed by Pearson correlation, and the regression curve was fitted by the local weighted regression distribution point smoothing method (LOWESS).

  Result  50 standard sample plots were adequate. The species composition of forest community in Laoshan Mountain was complex, and it could be divided into 10 community types by WARD clustering method according to the important value matrix of species. Altitude, slope position, slope direction and soil’s pH value were the main factors affecting community distribution, in which altitude factor had significant effect on the distribution of trees, shrubs and herbs as well. Among the 11 topographic and soil factors studied in this paper, altitude and soil available phosphorus content were significantly correlated with the overall species diversity of the community. With the increase of altitude, the Shannon-Wiener index of trees, shrubs and herbs increased at first and then decreased. The Pielou index of trees and shrubs increased slightly with the increase of altitude. When the content of available phosphorus reached 30 mg/kg, the Shannon-Wiener index and Pielou index decreased significantly, and then remained stable.

  Conclusion  Terrain and soil conditions had a certain influence on the distribution of Laoshan Mountain community types, which proves the role of habitat filtration. Altitude and soil available phosphorus content might be the most important limiting factors for species diversity in Laoshan Mountain forest community.