Phenotypic characteristics and biomass allocation of Cenchrus pauciflorus in four different habitats in Horqin Sandy Land

Cenchrus pauciflorus is one of the main invasive species in northern China, and Horqin Sandy Land is the most severely invaded region in the West Liaohe Plain of Inner Mongolia. It has had a steady spread trend in recent years and a profound impact on the development of local agriculture and animal husbandry. In this study, the phenotypic characteristics and biomass allocation of C. pauciflorus in different habitats of Horqin Sandy Land were explored. The phenotypic characteristics of C. pauciflorus in four habitats were analyzed and compared. In addition, the response of the phenotypic characteristics and material distribution of C. pauciflorus to these habitat were discussed to comprehensively elucidate the morphological and biological characteristics of C. pauciflorus in Horqin Sandy Land and reveal the scientific significance of the invasion mechanism of C. pauciflorus in Horqin Sandy Land. The results of this study can provide a theoretical basis for the research and development of the related ecological prevention and control technologies for C. pauciflorus. Our findings were as follows: 1) habitat had a significant effect on the selected phenotypic variables of C. pauciflorus, and the order of all the phenotypic variables in the four habitats from large to small was: field, sand dune, forestland and grassland, respectively. 2) The coefficient of variation of the same phenotype showed no significant differences among the four habitat populations; however, the same habitat showed significant differences among the different phenotypes. 3) The biomass allocation of C. pauciflorus was significantly affected by the habitat. In the farmland habitat, the ratio of stem to leaf of C. pauciflorus was significantly higher than that in other habitats; however, the ratio of root to shoot and the proportion of spiny burs to the whole plant were significantly lower than those in other habitats. 4) Habitat had no significant effect on the variation of root to shoot but had a significant effect on the variation of stem to leaf and spiny burs to the whole plant. Cenchrus pauciflorus adapts to different habitats by adjusting its phenotype and biomass allocation strategies, and its nutritional traits, clonal traits, reproductive traits, and biomass allocation have habitat plasticity. Stress, disturbance, and propagule quality differences may be the cause of the phenotypic difference and variation of C. pauciflorus in different habitats.