Abstract: [Objective] The objectives of this study were to investigate and evaluate the influences of shrub plantation on the ground-dwelling arthropod diversity and their functional structure. With the adjacent exclosure grassland as a control, the effectiveness of afforested shrub plantation on the mobile sand land fixation was examined in terms of ground-dwelling diversity and trophic structure.[Method] In the desertified grassland of Yanchi County of Ningxia, the mobile sand land, and 6-, 15-, 36-years-old shrub plantations, as well as the adjacent exclosure grassland were selected as the experimental sites. The ground-dwelling arthropods and their functional structure were investigated by pitfall trapping method.[Result] 1) It was found that the Labiduridae, Tenebrionidae, and Melolonthidae families were the dominant groups, accounting for 78.84% of the total individuals. There were seven common groups, accounting for 15.23% of the total individuals. The other 26 taxon belonged to the rare groups, accounting for 5.93% of the total individuals. Meantime, there was marked different distribution of arthropod individuals between the microhabitats. For example, the Phalangidae, Lycosidae, Sphecidae families dominated the microhabitats beneath the shrub cover, whereas the Carabidae family dominated the mobile sand land. 2) Abundance of total ground-dwelling arthropods and the abundance of predators and herbivores decreased markedly (P<0.05) after the establishment of shrub afforestation for 6 years in the previous mobile sand land, whereas a reverse pattern was observed in the taxa richness and the Shannon index, as well as taxa richness of predators and herbivores. The total individuals of ground-dwelling arthropods in 6-, 15-, and 36-years-old shrub plantations and the exclosure grassland, and the individual number of predators and herbivores decreased by 79%-95%, 83%-95% and 72%-95%, respectively, whereas the taxa richness, Shannon index, and the richness of predators and herbivores increased by 0.6-1.4, 1.0-2.0, 0.2-1.0, 1.0-2.0, respectively, in comparison to the mobile sand land. 3) During the process of the stabilization, the total abundances and the abundance of both functional groups were found no significant (P>0.05) changes between the afforested shrubland and the exclosure grassland, whereas the taxa richness and Shannon index increased markedly (P<0.05). Taxa richness in 15-years-old shrubland was found to be close to that in the exclosure grassland, whereas the Shannon index in 36-years-old shrubland was found to be close to that in the exclosure grassland. 4) During the process of the stabilization, the taxa richness of predators and herbivores increased (P<0.05) markedly, with 6-years-old shrubland being close to the exclosure grassland, whereas the taxa richness of herbivores reached the peak before those of predators did, with the former in 15-years-old shrubland and the latter in 36-years-old shrubland. The interaction between predators and herbivores was impacted more by the land cover changes from mobile sand land to afforested shrubland, whereas little effect of shrub age was found. The herbivore groups quantitatively contributed much more to the trophic relationship in comparison to the predator ones.[Conclusion] It was suggested that the afforested shrubland could facilitate the fast recovery of taxon richness and diversity of ground-dwelling arthropods. After the establishment of shrub plantation, the relative stability of taxonomic and throphic structure of ground-dwelling arthropods could be maintained. During the process of shrub plantation development, the herbivores groups recovered before the predators groups did, which is beneficial to the maintenance of trophic structure stability and restoration of ecosystem functions. The shrub plantation had better effectiveness on recovery of ground-dwelling arthropods biodiversity conservation than the exclosure grassland.

Key words: ground-dwelling arthropod, afforested shrub, biodiversity recovery, functional group, desertification control