Land management using suitable thinning intensities can promote the yield of Moso bamboo (Phyllostachys edulis) forests and alter the nutrient content and stoichiometric characteristics within the soil. However, the effects of different thinning intensities on soil carbon (C), nitrogen (N), and phosphorus (P) stoichiometry of P. edulis forests have not been comprehensively studied. Here, we evaluated the effects of three thinning intensities—no thinning control (NT), moderate thinning (annual removal of 15% of mature bamboo, MT), and heavy thinning (annual removal of 33% of mature bamboo, IT)—on the soil organic C (SOC), total N (TN), and total P (TP) stocks and their stoichiometry characteristics of a P. edulis forest located in the subtropical zone. The results showed that SOC, TN, and TP stocks decreased with increasing soil depth after three years of thinning. The SOC, TN, and TP stocks and the ecological stoichiometry ratios were varied with the change of thinning intensity and SOC stocks declining with the increased thinning intensity, but TN and TP stocks for the MT treatment were enhanced. The order of TN and TP stocks was MT > NT > IT. In comparison to CK, TN and TP stocks for MT increased significantly by 18.8 and 37.3%, while SOC, TN, and TP stocks for IT decreased by 31.0%, 7.2%, and 21.4%, respectively. The C:N and C:P ratios of MT decreased by 32.8% and 39.0%, and those of IT decreased by 26.5% and 15.6%, respectively. In summary, we conclude that the MT is an effective management strategy to promote soil nutrient cycling and provides a reference for formulating management strategies in subtropical Moso bamboo forests.

The NAC (NAM, ATAF1/2 and CUC2) gene family is one of the largest plant-specific transcription factor families, functioning as crucial regulators in diverse biological processes such as plant growth and development as well as biotic and abiotic stress responses. Although it has been widely characterized in many plants, the significance of the NAC family in Dendrobium officinale remained elusive up to now. In this study, a genome-wide search method was conducted to identify NAC genes in Dendrobium officinale (DoNACs) and a total of 110 putative DoNACs were obtained. Phylogenetic analysis classified them into 15 subfamilies according to the nomenclature in Arabidopsis and rice. The members in the subfamilies shared more similar gene structures and conversed protein domain compositions. Furthermore, the expression profiles of these DoNACs were investigated in diverse tissues and under cold stress by RNA-seq data. Then, a total of five up-regulated and five down-regulated, cold-responsive DoNACs were validated through QRT-PCR analysis, demonstrating they were involved in regulating cold stress response. Additionally, the subcellular localization of two down-regulated candidates (DoNAC39 and DoNAC58) was demonstrated to be localized in the nuclei. This study reported the genomic organization, protein domain compositions and expression patterns of the NAC family in Dendrobium officinale, which provided targets for further functional studies of DoNACs and also contributed to the dissection of the role of NAC in regulating cold tolerance in Dendrobium officinale.

Nitrogen (N), an indispensable mineral nutrient element for plant growth and development, is a major limiting source of productivity in many terrestrial ecosystems. Soil organic nitrogen (SON) is a crucial form of nitrogen (N) in the N cycle within terrestrial ecosystems, acting as either a “source” or a “sink” for environmental N release. In order to illustrate the research trends, evolution process and hotspots of SON, a bibliometric analysis was used to analyze 906 documents based on the ISI (Institute of Scientific Information) Web of Science (WoS) database. The results indicated that (1) the number of published papers on SON research showed a wavy growth from 2000 to 2022 and the research has entered a mature development period; China has been increasing its number of publications and has long been in the lead; (2) the most productive institutions and authors in this subject area are in the USA and China, with the Chinese Academy of Sciences being the key institution performing such research; (3) in the sample, Soil Biology and Biochemistry, Science of the Total Environment, and Biogeochemistry are the leading international journals that have played a key role in the evolution of the field and have laid a solid foundation for future research; (4) the characteristics and maintenance of SON in farmland and SON migration in small watersheds under forest conversion have become research hotspots. Through the in-depth analysis of SON research, this paper provides a better understanding of the development trends of SON over the past 20 years, which can also provide reference for future research.