Nematode Community Characteristics Indicate Soil Restoration under Different Revegetation Approaches in the Semiarid Area of the Chinese Loess Plateau

Abstract

Soil nematode communities can offer valuable indicators for monitoring the status of soil ecosystems. However, their potential for assessing soil restoration under revegetation has been neglected in temperate arid and semiarid areas. This study examined the characteristics of soil nematode communities and their relationships with soil physicochemical properties under five typical revegetation approaches in the semiarid Loess Plateau of China. The results showed that planting an artificial Caragana korshinskii forest led to the recovery of the soil food web, which significantly increased soil nematode abundance (138.10 ± 11.60 inds./100 g dry soil) and community diversity (Shannon-Wiener diversity: 2.48 ± 0.13; trophic diversity: 3.08 ± 0.02), associated with the high contents of SOC and NH4+-N. However, establishing an artificial Prunus sibirica forest improved neither soil properties nor nematode community characteristics, reflecting poor soil ecosystem restoration. After establishing an artificial Prunus davidiana forest (PD) and an artificial Medicago sativa grassland (MS), substantial increases in herbivorous and fungivorous nematodes were observed, respectively, likely due to the accumulation of particular genera that fed on roots (e.g., Pratylenchus) or their symbiotic fungi (e.g., Tylencholaimus), which might result in the deterioration (in MS) or restoration (in PD) of the soil food webs. Natural grassland restoration greatly improved soil properties (i.e., SOC, NH4+-N, microbial biomass carbon) but did not change the nematode community obviously, probably due to top-down predation in natural habitats. In conclusion, the characteristics of nematode communities can effectively indicate the restoration of soil food webs and identify their possible driving forces under revegetation, which have important implications for vegetation restoration in arid and semiarid regions.

Employing Plant Parasitic Nematodes as an Indicator for Assessing Advancements in Landfill Remediation

“…The landfill is situated on sloping terrain, which we divided into five distinct 1 m 2 environmental sections. Among these, two sections were positioned outside of rip ditches (1, 5), while the remaining three were situated within the rip ditch areas (2,3,4). Rip ditches play a critical role in the effective management and operation of landfills, helping to mitigate environmental risks associated with water infiltration and runoff while promoting the long-term stability and integrity of the landfill site.…”

“…The consistent and interconnected response of free-living nematodes to shifts in soil microbial functions is evident in nematode trophic group ratios and functional indices [3]. Huang et al [4] suggest their potential as superior indicators of soil food web health, quality, and fertility parameters. The presence and abundance of specific taxa are indicators of the complexity of the web at the trophic levels indicated by those taxa.…”