Status of soil nematode communities during natural regeneration of a subtropical forest in southwestern China

Abstract

Forest recovery has been extensively evaluated using plant communities but fewer studies have been conducted on soil fauna. This study reports the status of soil nematode communities during natural re-establishment after deforestation in a subtropical forest in southwestern China. Soil nematode communities of two secondary succession stages, shrub-grassland and secondary forest, were compared with those of virgin forest. Shrub-grassland had higher herbivore relative abundance but lower fungivore and bacterivore relative abundance than forests. Between secondary and virgin forest, the latter had higher abundance of bacterivores. Shrub-grassland had lower nematode diversity, generic richness, maturity index and trophic diversity index than virgin forest, whereas there were no differences in these indices between secondary forest and virgin forest. The small differences in nematode community structures between secondary forest and virgin forest suggest that soil nematode communities recovered to a level close to that of the undisturbed forest after up to 50 years of natural succession.

Changes in soil and litter properties differentially influence soil nematode communities across three successional stages in two contrasting forests

“…Total nematode abundance did not differ significantly during forest succession in both the forests (Figure 2). This is consistent with some previous findings, namely nematode abundance can quickly recover to the level of late stage at early stage of forest succession (Li et al, 2015; Wang et al, 2022). Interestingly, previous studies have found that nematode abundance at grassland or shrub stage is difficult to recover to the level of forest stage due to the limitation of soil nutrients during succession (Lei et al, 2015; Liu et al, 2022; Pate et al, 2000).…”

“…They are also sensitive to environmental changes (Fiscus & Neher, 2002) and can be used as indicators of soil food web structure and function (Bongers & Ferris, 1999). Previous studies have clearly recognized that the secondary succession from the abandoned farmland stage or grassland stage to forest stage gradually changes nematode community composition and improves its abundance and diversity (Li et al, 2015; Liu et al, 2022; Pate et al, 2000; Wu et al, 2021). Currently, forest secondary succession after disturbance is one of the most important restoration strategies for recovering plant community and improving ecosystem function (Teixeira et al, 2020), soil nematode abundance and diversity play a positive role in improving the ecosystem function during forest secondary succession (Shi et al, 2021).…”

Distinct community structures of soil nematodes from three ecologically different sites revealed by high-throughput amplicon sequencing of four 18S ribosomal RNA gene regions

“…There have been several reports of taxonomic analyses of nematodes in forest [ 33 , 58 , 60 – 71 ] and agricultural field [ 11 , 13 , 15 – 17 , 19 – 22 , 30 , 72 ] soils. Studies on forest soils have shown that bacteria, plant, and fungus feeders occupy significant fractions of the nematode communities despite varied proportions by the sampling sites, periods, and environmental status of forests [ 33 , 62 , 68 , 70 ]. Omnivores and predators were found in relatively minor fractions except for in natural subtropical forests [ 58 , 67 ] and coastal pine forests [ 70 ].…”

Taxonomic profiling of individual nematodes isolated from copse soils using deep amplicon sequencing of four distinct regions of the 18S ribosomal RNA gene

“…Pothula and colleagues have examined the impact of agricultural intensification and urbanization on soil nematode communities using 111 published articles and examined the richness and abundance of 5 trophic groups in 5 different environmental soils including forest [50], indicating that the order of abundance was herbivores (plant feeders) > bacterivores > fungivores and omnivores > predators despite high variation. So far, several taxonomic studies on soil nematode communities in forest soils have been known and were performed using morphogenic and sequence-based approaches over the world (Brazil [51], Canada [52], China [53][54][55][56], Germany [57], Japan [58,59], Slovakia [60], Sweden [61], USA [62]). These studies have shown that bacterial feeders, plant feeders, and fungivores often occupied significant fractions of the nematode communities in forest soils.…”

“…These studies have shown that bacterial feeders, plant feeders, and fungivores often occupied significant fractions of the nematode communities in forest soils. A relatively high abundance of bacterial feeders has been commonly found; however, their proportions varied by the sampling sites and periods [58,62], age [56], and environmental status of the forests [25,52,55] or treatments such as clear-cut harvesting and fertilization [61,63]. Omnivores and predators were found in relatively minor fractions of soil nematodes in forest soils except in natural re-establishing subtropical forest [54] and coastal fir and pine forests [51,58].…”