Abstract: The population characteristics (number, density, area, distribution coefficient, sex ratio, biomass ratio, water distribution and the resistant traits of females and males) of Anaphalis lacteal were investigated in five different habitats: improved Elymus sibiricus grassland (A), improved Phalaris armdinacea grassland (B), natural grassland (C), natural meadow (D) and desertification grassland (E). The results showed that A. lacteal population characteristics varied with the different community properties found in the five habitats (such as the dominant species, density and coverage of the community, species saturation, height of the dominant species and the physical and chemical traits of soils). The order of effect by habitat community on A. lacteal population properties was area>density>sex ratio>age structure>number>distribution coefficient. The highest number and distribution coefficient of the A. lacteal population were in D, while the largest area and density were in C. Compared with E, the population numbers of C and D were 30.21% and 35.11% respectively, while the distribution coefficient of C was 36.04%. A. lacteal age structure, sex ratio, height, root number, leaf number and area, inflorescence and flowers, the number of males or females and the stem diameter and bracts layer of males were significantly different among the community types (P<0.05). The numbers of females varied between 2.22 and 7.03 times higher than males. Sex differences were found in height, stem diameter, root length, leaf number and area, florets number and the bracts layer (P<0.05). Significantly higher total biomass and flower distribution ratios but lower root distribution ratios were observed in males than females (P<0.05). The order of effects by community type on biomass distribution was flower>total biomass>leaf>root>stem for females and flower>stem>leaf>total biomass>root for males. The water contents of stem, leaf and flower were significantly higher in males than females. The order of effects by community type on water content was flower>stem>leaf>root for female, and leaf>stem>flower>root for males. H₂O₂ and malondialdehyde (MDA) contents were the lowest in A and B and total antioxidant capacity activity was the lowest in D. The E. sibiricus community composition had highly significant effects on H₂O₂ and MDA contents and on the T-AOC activity of males and females. MDA content was higher in males than females, but H₂O₂ content and T-AOC activity was higher in females (P<0.05). These results indicate that male and female individuals of A. lacteal can develop different growth strategies across habitats based on component characteristics, biomass ratio, water distribution and resistance physiology. These strategies may produce advantages in habitat adaptation, life history and population fitness.

Key words: Anaphalis lacteal, dioecious strain, population characteristics, morphological plasticity, growth strategy