Chinese fir () is one of the most important economic tree species in Central South China. Several decades of successive rotation of monocultures have resulted in serious ecosystem degradation. Substantial efforts are underway to convert monocultures to mixed forests to restore ecosystem functions and services. However, it is unclear whether forest restoration will improve soil quality. Soil nematodes were employed as an ecological indicator of soil quality to assess soil food web structure and energy flow along a forest restoration chronosequence. The chronosequence of transformation stages include: (i) early stage monocultures aged 5, 10, and 20 years old; (ii) mid-stage conifer-broadleaf mixed forest aged over 20 years old; and (iii) late-stage broadleaf forest aged over 40 years old. Our results suggest that forest restoration changed soil nematode abundance, diversity, and community composition in both dry and wet seasons. Abundance of soil nematodes increased progressively along the restoration chronosequence, peaking in the conifer-broadleaf mixed forest. The relative abundance and energy flow of herbivorous nematodes decreased progressively by 25% and 82% with forest restoration stage, respectively. Forest restoration from to mixed forests increased energy flow from basal resources to fungivorous nematodes and from fungivorous to omnivorous-carnivorous nematodes by 58% and 52%, respectively. Our findings suggest that forest restoration from monocultures to mixed forests increases soil biodiversity and food web energy flows to trophic groups higher in the food chain. Therefore, converting plantations to mixed forests has potential to boost forest ecosystem services and promote sustainable forest management.

中文翻译：

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森林恢复增加了通过真菌通道的能量流，并减少了通过土壤微食物网中草食通道的能量流


杉木是中南地区最重要的经济树种之一。几十年来连续轮作的单一作物导致了严重的生态系统退化。目前正在进行大量努力，将单一栽培转变为混交林，以恢复生态系统功能和服务。然而，尚不清楚森林恢复是否会改善土壤质量。土壤线虫被用作土壤质量的生态指标，以评估土壤食物网结构和沿森林恢复时间顺序的能量流。转化阶段的时间顺序包括：（i）5年、10年和20年的早期单一栽培阶段； （二）树龄20年以上的中期针阔混交林； (iii) 树龄超过 40 年的晚期阔叶林。我们的结果表明，森林恢复改变了旱季和雨季土壤线虫的丰度、多样性和群落组成。土壤线虫的丰度沿着恢复时间顺序逐渐增加，在针阔叶混交林中达到顶峰。随着森林恢复阶段，草食性线虫的相对丰度和能量流分别递减25%和82%。从森林恢复到混交林，从基础资源到食真菌线虫和从食真菌到杂食肉食线虫的能量流分别增加了 58% 和 52%。我们的研究结果表明，从单一林地到混交林的森林恢复增加了土壤生物多样性和食物网能量流向食物链较高营养群体。因此，将人工林转变为混交林有可能增强森林生态系统服务并促进可持续森林管理。