Community Ecology And Scientific Management Of Lawn Weeds Communities In Taiyuan

Based on the field investigation, the lawn communities were studied by using quantitative vegetation ecology method, including community composition, ecological relationship analysis between the weeds and turf grasses, the interspecific relationship of the dominant plant species, niche characteristics of dominant population.There were 70 weeds invasive in the autumn lawn, which belonged to 29 families,59 genera in the lawn of Taiyuan. Those species were mostly consisted of Composite and Grass Family. There were 37 weeds belonging to 18 families,32 genera in spring weeds and the Family possessing weeds most was Composite Family. Compared with spring weeds, the weeds species of autumn were more, and the coverage of weeds was larger.TWINSPAN and DCA were applied to the analysis of the lawn communities. The result showed that:1) TWINSPAN classified the 72 quadrats of autumn weeds into 14 associations, and classified the 66 quadrats of spring weeds into 8 associations, the species composition and quantities of weeds communities were affected by species characteristics of lawn grasses; 2) DCA ordination of autumn communities were consistent with the result of spring communities. The result indicated that the management levels of lawn were the dominant factors responsible for the weed distribution in lawn. The first axis of DCA indicated the soil moisture gradient among the communities, while the second axis expressed the level of weeding and mowing.The interspecific association and correlation of the dominant species of lawn vegetation were analyzed byχ2-test, Pearson's correlation coefficient and Spearman's rank correlation coefficient. The result of theχ2-test, Pearson's correlation coefficient and Spearman's rank correlation coefficient all showed that the most species-pairs were not correlative evidently and the ratios of positive and negative correlations were less than 1. That was to say competitiveness of the most species pairs was low and the community was unstable. According to biological features and the way of resource utilization, 25 dominant species of autumn were divided into 4 ecological groups and spring was one group less than autumn, because some weed species in spring did not sprout and grow.Niche breadths and niche overlaps of dominant species of the lawn plant communities were measured and analyzed using the indexes proposed by Shannon-Wiener and Pianka. The results indicated that:1) In autumn, the niche breadths of Digitaria sanguinalis(1.415), Setaria viridis(1.299) and Viola prioantha(1.181) were bigger than the others. The niche overlaps of the dominant species in Lepidium apetalum and Eleusine indica(0.483), Chenopodium glaucum and Amaranthus retroflexu(0.487) were big.2) In spring, Plantago asiatica(1.242), Lepidium apetalum(1.222), Taraxacum mongolicum(1.184) and Capsella bursa-pastoris (1.149) have bigger niche breadths. The niche overlap between Lepidium apetalum and Convolvulus arvensis (0.392), Trigonotis peduncularis and Plantago asiatica (0.381) were more than that of other species-pairs.According to the above research, some new strategies about the lawn scientific management were proposed.