College of Life and Environmental Science, Central South University of Forestry and Technology, Changsha 410004, Hunan, China; National Engineering Laboratory for Applied Technology of Forestry & Ecology in Southern China, Changsha 410004, Hunan, China; Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, China.
College of Life and Environmental Science, Central South University of Forestry and Technology, Changsha 410004, Hunan, China; National Engineering Laboratory for Applied Technology of Forestry & Ecology in Southern China, Changsha 410004, Hunan, China; Lutou National Station for Scientific Observation and Research of Forest Ecosystem in Hunan Province, Yueyang 414000, Hunan, China.
Sci Total Environ. 2024 Jul 20;935:173322. doi: 10.1016/j.scitotenv.2024.173322. Epub 2024 May 20.
The swift proliferation of forests converted into monoculture plantations has profound impacts on soil nutrients, microbial communities, and many ecological processes and functions. Nematodes are soil microfauna that play a pivotal role in biogeochemical cycling and in soil food web, whereas the response of soil nematode communities and energy flows to forest conversion remains unknown. Here, we assessed the community composition and the energy flows of the nematode food webs as a function of soil chemistry after conversion from natural forests (Forest) to four plantations (8-year-old): Amygdalus persica (Peach), Myrica rubra (Berry), Camellia oleifera (Oil), and Cunninghamia lanceolata (Fir). After forest conversion, soil organic carbon (SOC) and total nitrogen (TN) contents decreased by 65 % and 55 %, respectively. Forest conversion strongly reduced the abundance (particularly large-bodied omnivorous-predatory nematodes), diversity, maturity, and stability of the soil nematode community. The shifts in composition and structure of nematode communities after forest conversion are reflected in changes in the abundance of predominant genera and trophic taxa, especially bacterivorous, fungivorous, and omnivorous-predatory nematodes. Acrobeloides notably increased, whereas Plectus, Prismatolaimus, Tylencholaimus, and Tripyla decreased. Accordingly, the abundances of r-strategy nematodes (cp value = 1-2) increased, but that of the K-strategists (cp value = 3-5) declined. Additionally, the energy flow across the soil nematode food web was reduced by 36 % and flow uniformity declined by 24 % after forest conversion. These changes in nematode diversity and abundance were triggered by diminishing soil C and N contents, thereby affecting the energy flows via the nematode food webs. Thus, forest conversion affects soil biotas and multi-functions from the perspective of nematode food web structure and energy flows, and underlines the interconnections between ecosystem and energy dynamics across multi-trophic levels, which is crucial for sustainable forest management.
森林迅速转变为单一栽培种植园对土壤养分、微生物群落和许多生态过程和功能产生了深远的影响。线虫是土壤微小动物，它们在生物地球化学循环和土壤食物网中起着关键作用，而土壤线虫群落和能量流动对森林转化的反应尚不清楚。在这里，我们评估了社区组成和能量流动的线虫食物网作为功能的土壤化学后转换从天然林（森林）到四个种植园（8 岁）：扁桃（桃）、杨梅（浆果）、油茶（油）和杉木（冷杉）。森林转换后，土壤有机碳（SOC）和总氮（TN）含量分别下降了 65%和 55%。森林转换强烈降低了土壤线虫群落的丰度（特别是大型杂食性捕食线虫）、多样性、成熟度和稳定性。森林转换后线虫群落组成和结构的变化反映在优势属和营养类群丰度的变化上，特别是食细菌线虫、食真菌线虫和杂食性捕食线虫。阿克罗贝莱氏线虫（Acrobeloides）显著增加，而普勒克斯氏线虫（Plectus）、普拉氏线虫（Prismatolaimus）、泰利奇线虫（Tylencholaimus）和三带线虫（Tripyla）减少。因此，r 策略线虫（cp 值=1-2）的丰度增加，但 K 策略者（cp 值=3-5）的丰度减少。此外，森林转换后，土壤线虫食物网的能量流减少了 36%，流动均匀度下降了 24%。线虫多样性和丰度的这些变化是由土壤 C 和 N 含量的减少引起的，从而通过线虫食物网影响能量流动。因此，森林转换从线虫食物网结构和能量流动的角度影响土壤生物群和多功能性，并强调了多营养级生态系统和能量动态之间的相互联系，这对可持续森林管理至关重要。
