摘要：The interaction between vegetation and soil is important for vegetation restoration and reconstruction during the succession of abandoned farmland. We chose 4 kinds of abandoned farmlands with the time of 1 year, 6 years, 12 years, and 22 years to experiment in the Loess Plateau. Community composition, community biomass and soil nutrients of the 4 kinds of abandoned farmlands were studied by the method of temporal-spatial alternation, and the interaction effects among vegetation, biomass, soil nutrients and the abandonment time were analyzed. The results showed there were 33 species belonging to 13 families during the succession and 15 species of Gramineae and Compositae, accounting for 47% of the total community species. The succession trend of abandoned farmland was as follows: the vegetation was the weed community of Heteropappusal taicus Artemisia capillaris in the beginning abandonment stage and became the weed community of Tragus racemosus Enneapogon borealis after 6 years of abandonment. Then, Leymus secalinus became the dominant population in the community after 12 years of abandonment. When the succession lasted for 22 years, the vegetation became a common advantages community of Stipa breviflora and Cleistogenes songorica. Soil moisture (SM) was positively correlated with soil nutrients and negatively correlated with abandonment time and community biomass. Soil organic matter (SOM), soil total nitrogen (STN), and alkali hydrolyzable nitrogen (AHN) were the highest in 0-10cm soil layer, showing obvious surface accumulation. The three decreased with the soil layer and there was a positive correlation among them. The abandonment time had a positive effect on the above-ground biomass (AGB) and below-ground biomass (BGB), and negative effect on the SOM, STN, and AHN. The root/shoot ratio (R/S) was positively correlated with SOM and negatively correlated with abandonment time. With the progress of succession, the hierarchical differentiation of the community was gradually obvious, and the community structure was begun to complicate, the community could better adapt to the arid environment and towards the local top community succession.
关键词：Abandoned farmland; Community biomass; Loess plateau; root/shoot ratio; Soil nutrients
