Fig. 1

Assembly method of different functional species in the phytotron experiment. Priority effects were created by manipulating plant order of arrival in the experiment: one plant species was sown four weeks before the two others and all plant species sown together at the same time (synchronous). The seeds of different species were spaced and sown symmetrically along the vertex of a hexagon, with each species sown in two sites. Different sizes of the same plants represent different sowing times: the larger plants represent the first sowing and the smaller plants represent the second sowing. Grass-first, grass was sown first in a mixed community; Legume-first, legume was sown first in mixed community; Forb-first, forb was sown first in mixed community. Dotted lines in pots represent nylon mesh isolation (mesh size 30 µm), incomplete isolation; Solid lines in pots represent plastic film isolation, total isolation. The first sowing plants were planted in the middle of the pot, and were removed in the corresponding treatment at the second sowing