Chin J Plant Ecol ›› 2019, Vol. 43 ›› Issue (9): 834-842.DOI: 10.17521/cjpe.2018.0153

• Research Articles • Previous Articles    

Community assembly of herbaceous layer of the planted forests in the central Loess Plateau, China

SHI Jing-Jing1,2,ZHAO Ming-Fei1,2,WANG Yu-Hang1,2,XUE Feng1,2,KANG Mu-Yi3,1,JIANG Yuan1,2,3,*()   

  1. 1College of Resources Science & Technology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
    2Beijing Key Laboratory of Chinese Medicine Resource for Protection and Utilization, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
    3State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China
  • Received:2018-07-03 Accepted:2018-10-18 Online:2019-09-20 Published:2020-01-03
  • Contact: JIANG Yuan
  • Supported by:
    Supported by the National Basic Work of Science and Technology of China(2011FY110300);the National Natural Science Foundation of China(41630750);the National Natural Science Foundation of China(41271059)


Aims Many competing theories seek to identify the mechanisms behind the community assembly. Niche theory and neutral theory are among the two most competing mechanisms. Exploring factors controlling the patterns of β-diversity is an approach to reveal the underlying mechanisms of community assembly. In this paper, we aim to reveal the β-diversity pattern of understory in planted forests of the central Loess Plateau and to evaluate the relative influences of deterministic (environmental filtering) and stochastic (dispersal limitation) processes on the community assembly.
Methods We sampled in total 107 sites of planted forests spatially spreading over the central Loess Plateau. In each site, three plots (10 m × 10 m) were randomly designed each at a distance of about 50 m. The floristic composition, community structure, and environmental conditions were investigated in each plot. We calculated the dissimilarity (βsim) of species composition, geographic distance and environmental divergence for each of the 5 671 site pairs. We used random forest (RF) to quantify the influence of the selected factors on species composition, and distance-based multivariate regression method (MRM) to fit the relationship between dissimilarity, geographic distance and environmental divergence. To quantify how and in what extent the environmental filtering and the dispersal limitation influence the species composition among sites, we performed the principle coordinates of neighbor matrices (PCNM) and distance-based RDA (db-RDA) to select the pronounced independent variables. We then partitioned the variance into three parts, namely, 1) independent contributions of geographic distance; 2) independent contributions of environmental divergence; and 3) the joint contribution of both.
Important findings The community similarity declined with increasing geographical distance and environmental divergence. Geographical distance and environmental divergence together explained 47.8% of variance in the dissimilarity in species composition. The spatial variables accounted for 14.1%, while the environmental variables accounted for another 9.8% of the variance in dissimilarity of species composition. Annual precipitation and basal area of trees are the two most important environmental factors influencing the pattern of dissimilarity of species composition. These results implied that both environmental filtering and the dispersal limitation play important roles in shaping the community assembly of the herbaceous layers of planted forests in the central Loess Plateau.

Key words: community assembly, niche theory, neutral theory, environmental filtering, dispersal limitation, β diversity, understory community