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Aims Increased nitrification risks accelerating soil acidification under land-use change from tropical forest to cropland or plantation, but acidity might be neutralized by net mineralization of soil organic matter (SOM) that has accumulated under the former fallow vegetation. We aim to analyze key drivers of soil acidification and acid neutralization under different crops and fallow vegetation. Methods We compared 30 year changes in soil C stocks, pH, and exchangeable Al under different land-uses (primary dipterocarp forest, Macaranga forest, Imperata grassland, Imperata grassland converted to Acacia plantation, Imperata grassland converted to oil palm plantation) in Indonesia and identified the major drivers of acidification using proton budgets in soil. Results Nitrification is major driver of acidification in soil profiles under N-fixing Acacia or fertilized oil palm plantation. Protons generated by product removal and nitrification in oil palm plantation are neutralized partly by fertilizer and mineralization of the native SOM that has formerly accumulated under grassland. The remaining acidity results in accumulation of soil exchangeable Al. The SOM storage under short-term (< 10 yr) grass or long-term (> 10 yr) Macaranga forest increases without intensive acidification, while long-term Acacia plantation maximizes both SOM storage and acidification. Conclusion Magnitude of soil acidification is regulated largely by the balance between proton generation by nitrification of fertilized N and biologically-fixed N and proton consumption by net mineralization of the native SOM that has formerly accumulated under grass fallow. SOM accumulation under Imperata grassland or Macaranga forest could mitigate soil acidification in Acacia or oil palm plantation.

The scaling of respiratory metabolism with body mass is one of the most pervasive phenomena in biology. Using a single allometric equation to characterize empirical scaling relationships and to evaluate alternative hypotheses about mechanisms has been controversial. We developed a method to directly measure respiration of 271 whole plants, spanning nine orders of magnitude in body mass, from small seedlings to large trees, and from tropical to boreal ecosystems. Our measurements include the roots, which have often been ignored. Rather than a single power-law relationship, our data are fit by a biphasic, mixed-power function. The allometric exponent varies continuously from 1 in the smallest plants to 3/4 in larger saplings and Jtrees. Therefore, our findings support the recent findings of Reich et al. [Reich PB, Tjoelker MG, Machado JL, Oleksyn J (2006) Universal scaling of respiratory metabolism, size, and nitrogen in plants. Nature 439: 457-461] and West, Brown, and Enquist [West GB, Brown JH, Enquist BJ (1997) A general model for the origin of allometric scaling laws in biology. Science 276: 122 -126.]. The transition from linear to 3/4-power scaling may indicate fundamental physical and physiological constraints on the allocation of plant biomass between photosynthetic and nonphotosynthetic organs over the course of ontogenetic plant growth.

COVID-19 mRNA vaccines induce protective adaptive immunity against SARS-CoV-2 in most individuals, but there is wide variation in levels of vaccine-induced antibody and T-cell responses. However, the mechanisms underlying this inter-individual variation remain unclear. Here, using a systems biology approach based on multi-omics analyses of human blood and stool samples, we identified several factors that are associated with COVID-19 vaccine-induced adaptive immune responses. BNT162b2-induced T cell response is positively associated with late monocyte responses and inversely associated with baseline mRNA expression of activation protein 1 (AP-1) transcription factors. Interestingly, the gut microbial fucose/rhamnose degradation pathway is positively correlated with mRNA expression of AP-1, as well as a gene encoding an enzyme producing prostaglandin E2 (PGE2), which promotes AP-1 expression, and inversely correlated with BNT162b2-induced T-cell responses. These results suggest that baseline AP-1 expression, which is affected by commensal microbial activity, is a negative correlate of BNT162b2-induced T-cell responses. Multi-omics analyses of human blood and stool samples reveal that baseline AP-1 expression, which is affected by commensal microbial activity, is negatively associated with BNT162b2-induced T-cell responses.

The use of forest land under dipterocarp for agroforestry is hindered by the problem of low fertility, necessitating the application of fertilization from organic materials, such as manure, compost, or biochar. These materials provide essential nutrients, including nitrogen, carbon, phosphorus, and potassium, increase cation exchange capacity (CEC), neutralize the pH, and enhance soil texture and water retention. This study aims to determine the effect of fertilization on the growth of Porang in the dipterocarp forest in PT Utama Damai Indah Timber East Kalimantan. It was conducted from August 2021 to July 2022. A completely randomized design (CRD) was used with three replications at five treatment levels: manure 1000 g/plant (P1), compost 1000 g/plant (P2), biochar + manure 1000 g/plant (P3), biochar + compost 1000 g/plant (P4), and control without fertilization (P0).  Data analysis was performed using ANOVA, followed by the Duncan test at a 10% level. The results showed that applying organic fertilizer enhanced soil's physical and chemical properties significantly. The combination of biochar and manure, at 1000 g/plant, proved to be the most effective treatment for increasing the height and yield of Porang compared to the control and other treatments.

Biomass of a mature man-made forest in West Java, Indonesia, was estimated to evaluate the carbon sequestration potential of plantation forest in the humid tropics. Twenty plots, each 0.25ha in area and containing one to six planted species over 40 years of age and with closed canopies, were selected. Trunk dry mass was estimated from trunk diameter, tree height, and bulk density. Maximum trunk diameter (122cm) was observed in a 46-year-old Khaya grandifoliola C. DC. tree, and the tallest tree (51m) was a 46-year-old Shorea selanica (DC.) Blume. The largest trunk biomass (911Mgha -1 ) was achieved in the plot composed of two Khaya spp. Among the plots composed of indigeneous Dipterocarpaceae species, the largest trunk biomass was 635Mgha -1 . These trunk biomasses were larger than those reported from primary rainforests in Southeast Asia (e.g., 403Mgha -1 in East Kalimantan, 522 and 368Mgha -1 in Peninsular Malaysia). The large biomass in this forest suggests that, given favorable conditions, man-made forests can accumulate the quantities of atmospheric carbon that were lost by the logging of primary forests in the humid tropics.

The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter productivity measurements), their associate canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positively to precipitation when rainfall is < 2000 mm.yr.sup.−1 (water-limited forests) and to radiation otherwise (light-limited forests); on the other hand, independent of climate limitations, wood productivity and litterfall are driven by seasonal variation in precipitation and evapotranspiration respectively. Consequently, light-limited forests present an asynchronism between canopy photosynthetic capacity and wood productivity. Precipitation first-order control indicates an overall decrease in tropical forest productivity in a drier climate.

Between 1988 and 2000, changes in the above-ground biomass (AGB) of trees in an East Kalimantan lowland forest, damaged by fires in 1982-83 and 1998, were estimated using allometric functions and an annual inventory of stem diameter. The original vegetation of the study site was lowland dipterocarp forest which has since been affected by selective logging and wild fires. The 1982-83 fire killed large trees of primary species and the opened sites became dominated by a few pioneer species. Between 1988 to 1997, a few pioneer tree species, namely Macaranga spp., dominated a heavily disturbed stand (HDS). Primary tree species that survived the 1982-83 fire dominated a lightly disturbed stand (LDS). A moderately disturbed stand (MDS) contained vegetation intermediate between the HDS and the LDS. In 1997, there were 553, 499 and 356 trees ha-1 in the HDS, MDS and LDS, respectively. Macaranga trees accounted for 70%, 40% and 11% of the number of total trees in the HDS, MDS, and LDS, respectively. In 1997, the AGB of trees in the HDS, MDS, and LDS was 117, 280, and 315 Mg ha-1, respectively. The proportion of biomass accounted for by Macaranga trees for the HDS, MDS, and LDS was 34%, 8% and 1%, respectively. The pioneer trees did not compensate for the loss of aboveground biomass resulting from the death of large primary trees. The fire in 1998 again decreased AGB of the stands. In 2000, the AGB of trees in the HDS, MDS, and LDS was 27, 106, and 219 Mg ha-1, respectively. The sites opened up by the 1998 fire were covered with the pioneer seedlings and seemingly dominated by the pioneer trees with more number of stems per ha, but lower biomass as compared to the original forest (> 400 Mg ha-1).

The AP-1 transcription factor JunB is essential for the differentiation of pathogenic T helper 17 (Th17) cells, which are key mediators of autoimmune diseases such as multiple sclerosis and colitis. While the importance of JunB during Th17 polarization is known, its role in mature Th17 cells-critical therapeutic targets in these diseases-remains unclear. In this study, we employed the dTAG system, a targeted protein degradation approach, to deplete JunB in Th17 cells generated both in vitro and in vivo. During pathogenic Th17 cell differentiation, JunB degradation replicated known effects of JunB deficiency, including reduced expression of interleukin (IL)-17A and the genes encoding RORγt (Rorc) and the IL-23 receptor (Il23r). In contrast, in mature pathogenic Th17 cells, JunB degradation downregulated Il23r without affecting IL-17A or Rorc expression. Furthermore, JunB degradation compromised the viability of mature pathogenic Th17 cells. Transcriptomic analyses revealed that JunB regulates distinct gene sets during Th17 polarization compared to mature Th17 cells. The gene Inhba, which encodes activin A, was identified as a JunB target in both stages. Supplementation with activin A restored IL-17A and Rorc expression during pathogenic Th17 cell differentiation. These findings demonstrate that JunB maintains mature pathogenic Th17 cell phenotypes, including IL-23 receptor expression, and supports pathogenic Th17 cell survival. As IL-23 signaling is crucial for sustaining pathogenic Th17 cells, targeting JunB may offer a therapeutic strategy to limit Th17-driven autoimmune inflammation.Competing Interest StatementThe authors have declared no competing interest.