Effects of slope aspect on component traits, biomass structure and water distribution of Arthraxon hispidus

In the study, wild Arthraxon hispidus invaded into degraded lawn of three slope directions was used as the research object. Indexes including the quantitative and qualitative characters of leaves, stems and roots, the biomass accumulation and distribution ratio and water content of plants were measured. The effects of slope direction on component traits, biomass structure and water distribution ratio of A. hispidu was analyzed. The purpose was to study the growth strategy and coping ability of A. hispidu in the heterogeneous habitats. The results showed that: 1) Slope direction had significant effects on light intensity, soil water content and soil thickness (P < 0.05), which resulted in significant differences in the coverage of A. hispidu. 2) Slope direction had significant effect on the traits of leaf, stem and root (P < 0.05). By adjusting the number of leave, tiller and root, A. hispidu changed leaf area, plant height, internode length and root length, which could form components and shapes adapting to the slope habitat. 3) Slope direction had a significant effect on biomass accumulation (P < 0.05). The biomass per plant on sunny slope was significantly larger than that on shady and semi-shady slopes. The biomass on sunny slope was preferentially distributed to stems, while that on shady slope was distributed to the leaves. The adaptability and stress resistance of A. hispidu were increased by adjusting the distribution ratio of biomass. 4) Slope direction had a significant effect on water content of plant. Water content in sunny and shady slopes was greater than that in semi-shady slopes. Water in sunny slopes was preferentially distributed to stems, while that in shady slope was preferentially distributed to roots. In conclusion, the growth strategy of A. hispidu can be adjusted according to the habitat of slope direction. A. hispidu all could form dominant species in three slope directions, which was suitable for popularization and application in planting slope lawn.