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The decomposition of abnormal litter caused by extreme weather events might play an increasingly important role in carbon and nutrient cycling in forest ecosystems under climate change scenarios, which needs to be fully investigated. In August 2020, the abnormal foliar litter of the goldenrain tree (Koelreuteria bipinnata var. Integrifoliola), the camphor tree (Cinnamomum camphora), and the weeping willow (Salix babylonica) after Typhoon Hagupit disturbance were collected and incubated on the soil surface at the Plant Ecology Research Base at Taizhou University, which is located on the eastern coast of China. Simultaneously, the physiological foliar litter of these three trees collected in the spring litter peak was incubated at the same site. The abnormal litter had higher concentrations of carbon (C), nitrogen (N), and phosphorus (P) and lower concentrations of lignin and cellulose than the physiological litter. The accumulative mass loss rates of abnormal litter in the goldenrain tree, the camphor tree, and the weeping willow during the incubation period increased by 7.72%, 29.78%, and 21.76% in comparison with physiological litter, and the corresponding carbon release increased by 9.10%, 24.15% and 19.55%, respectively. The autumn litter peak period and plum-rain season had higher rates of litter mass loss and carbon release, while the winter nongrowing season had lower rates. Accumulative mass loss, accumulative carbon release, daily mass loss and the daily carbon release of foliar litter were significantly and positively correlated with temperature and initial P concentrations, and significantly and negatively correlated with the initial C/P ratio, lignin/N ratio, and lignin/P ratio (p < 0.05). Compared with the physiological litter, abnormal litter had higher initial substrate quality, which may be the most important factor contributing to their high rates of mass loss and carbon release. The results imply that increasing tropical cyclones under climate change scenarios will facilitate carbon cycling in coastal urban forest ecosystems.

Background As a structurally and functionally important component in forest ecosystems, plant debris plays a crucial role in the global carbon cycle. Although it is well known that plant debris stocks vary greatly with tree species composition, forest type, forest origin, and stand age, simultaneous investigation on the changes in woody and non-woody debris biomass and their carbon stock with forest succession has not been reported. Therefore, woody and non-woody debris and carbon stocks were investigated across a subalpine forest successional gradient in Wanglang National Nature Reserve on the eastern Qinghai-Tibet Plateau. Results Plant debris ranged from 25.19 to 82.89 Mg∙ha− 1 and showed a global increasing tendency across the subalpine forest successional series except for decreasing at the S4 successional stage. Accordingly, the ratios of woody to non-woody debris stocks ranged from 26.58 to 208.89, and the highest and lowest ratios of woody to non-woody debris stocks were respectively observed in mid-successional coniferous forest and shrub forest, implying that woody debris dominates the plant debris. In particular, the ratios of coarse to fine woody debris stocks varied greatly with the successional stage, and the highest and lowest ratios were found in later and earlier successional subalpine forests, respectively. Furthermore, the woody debris stock varied greatly with diameter size, and larger diameter woody debris dominated the plant debris. Correspondingly, the carbon stock of plant debris ranged from 10.30 to 38.87 Mg∙ha− 1 across the successional series, and the highest and lowest values were observed in the mid-coniferous stage and shrub forest stage, respectively. Most importantly, the carbon stored in coarse woody debris in later successional forests was four times higher than in earlier successional forests. Conclusions The stock and role of woody debris, particularly coarse woody debris, varied greatly with the forest successional stage and dominated the carbon cycle in the subalpine forest ecosystem. Thus, preserving coarse woody debris is a critical strategy for sustainable forest management.

Aims: Soil fungi are crucial drivers of log decomposition in forest ecosystems. The objective of this study was thus to assess the conservation roles of decaying logs on soil fungi.Methods: Five classes of decaying Minjiang fir (Abies faxoniana) logs were incubated on the forest floor in a subalpine coniferous forest on the eastern Qinghai-Tibet Plateau, China, and the fungal communities compositions of the soil under decaying logs were assessed using high-throughput sequencing. Results: A total of 4321 operational taxonomic units (OTUs) were detected by Illumina MiSeq sequencing analysis. Basidiomycota and Ascomycota were dominant phyla regardless of log decay classes. With the log decomposition, the proportion of arbuscular mycorrhiza, wood saprotroph and saprotroph increased, but that of ectomycorrhiza decreased. Moreover, the diversity of soil fungal communities also increased along the decomposing process of logs. The decaying logs significantly altered soil fungal community composition by affecting biochemical properties (e.g. pH and concentrations of microbial biomass nitrogen and total phosphorus) and environmental factors (e.g. soil water content). Conclusion: Different decay classes of logs favor special fungal species, implying that the logs conservation with different decay classes in the forest ecosystem is of great significance for improving the diversity of soil fungi.

Idiopathic pulmonary fibrosis (IPF) is a highly fatal disease that lacks appropriate treatments and highly effective drugs. Many reported indicated that the TGF-β1/Smad3 signaling pathway played a pivotal role in development of IPF. In this case, it was hypothesized that discovery novel compounds to block the TGF-β1/Smad3 signaling pathway might be useful for treatment of IPF. Therefore, a high-throughput screening system based on stably transfected CAGA-NIH3T3 cells was established for discovering lead compounds which could validly suppress the TGF-β1/Smad3 signal path. In this study, a series of novel Pleuromutilin derivatives were prepared and quickly evaluated by high-throughput assay. The lead compound 32 was discovered to be able to remarkably suppress the TGF-β1/Smad3 pathway in vitro. Further biological evaluation revealed that compound 32 could remarkably decrease the myofibroblast stimulation and extracellular matrix (ECM) deposition. More importantly, compound 32 could remarkably mitigate bleomycin (BLM)-triggered lung fibrosis in mice models. Additionally, the lead compound possess excellent pharmacokinetics properties, good oral availability and low toxicity. In general, our study has demonstrated the potency of a novel Pleuromutilin derivative (compound 32), which might be a prospective candidate for developing anti-IPF medicines by suppress the TGF-β1/Smad3 signal pathway.

Knowledge regarding changes in soil microbial communities with forest succession is vital to understand soil microbial community shifts under global change scenarios. The composition and diversity of soil microbial communities across a subalpine forest successional series were therefore investigated in the Wanglang National Nature Reserve on the eastern Qinghai-Tibet Plateau, China. The calculated diversity indices of soil bacteria (8.598 to 9.791 for Shannon-Wiener, 0.997 to 0.974 for Simpson, 4131 to 4974 for abundance-based coverage estimator (ACE) and 3007 to 3511 for Species richness indices), and ACE (1323 to 921) and Species richness (1251 to 879) indices of soil fungi decreased from initial to terminal succession stages, but Shannon-Wiener and Simpson of soil fungi indices varied slightly with forest succession. Meanwhile, the composition and structure of soil microbial communities varied markedly with forest succession. The relative abundance of the dominant bacterial phyla (Acidobacteria, Firmicutes and Actinobacteria) and fungal taxa (Mortierellomycota, Rozellomycota and unassigned phylum clade GS01) varied considerably with forest succession. However, regardless of successional stage, Proteobacteria and Acidobacteria dominated soil bacterial communities and Ascomycota and Basidiomycota dominated soil fungal communities. Moreover, the changes in soil microbial diversity with forest succession were significantly affected by soil pH, soil organic carbon, soil temperature, altitude, and non-woody debris stock. Importantly, soil pH was the dominant driver of soil microbial community shift with forest succession. In conclusion, the forests at different succession stages not only conserve same microbial populations, but also nurse unique microbial diversity across the forest succession series; and the biodiversity of soil bacterial and fungal communities has differential responses to forest succession.

The three-dimensional zonality of soil organic carbon (SOC) density (C storage per unit area) is a scientific basis for estimating the potential of regional forest carbon sequestration on a large scale. To understand the three-dimensional zonality of forest SOC density in China and the effect of plantations on these zonal patterns, data on China’s forest SOC density were collected from 231 published studies. The average forest SOC density was 122.72 Mg ha−1, and SOC density in natural forests was significantly higher than that in plantations in China. In addition, forest SOC density significantly increased with increasing latitude (r2 = 0.04, P