关键词: 退耕还林, 优化模式, 机理分析, 黄土高原沟壑区

Abstract: A comparative study was conducted on the arthropod community diversity in the Citrus sinensis orchards under organic, conventional, and natural managements. After the conversion from conventional to organic management, the arthropods in the orchard increased 1 order, 24 families, and 130 species, and the individuals of pests decreased while those of natural enemies increased. The fluctuation ranges of the diversity index, evenness, and dominant concentration index of arthropod community in organic orchard within a year were between those in conventional and natural orchards. The species richness, diversity index, evenness, and dominant concentration index of arthropod community in organic orchard had no significant differences with those in natural orchard, but differed significantly with those in conventional orchard. Organic management could improve and restore the diversity of arthropod community in citrus orchard, and further, contribute to the ecological control of citrus pests.

Key words: Conversion of Farmland to Forests(CFF), Optimized model, Mechanism analysis, Hill-gully subregion of Loess Plateau