Estimating spatial variation in the effects of climate change on the net primary production of Japanese cedar plantations based on modeled carbon dynamics

Spatiotemporal prediction of the response of planted forests to a changing climate is increasingly important for the sustainable management of forest ecosystems. In this study, we present a methodology for estimating spatially varying productivity in a planted forest and changes in productivity with a changing climate in Japan, with a focus on Japanese cedar (Cryptomeria japonica D. Don) as a representative tree species of this region. The process-based model Biome-BGC was parameterized using a plant trait database for Japanese cedar and a Bayesian optimization scheme. To compare productivity under historical (1996–2000) and future (2096–2100) climatic conditions, the climate scenarios of two representative concentration pathways (i.e., RCP2.6 and RCP8.5) were used in five global climate models (GCMs) with approximately 1-km resolution. The seasonality of modeled fluxes, namely gross primary production, ecosystem respiration, net ecosystem exchange, and soil respiration, improved after two steps of parameterization. The estimated net primary production (NPP) of stands aged 36–40 years under the historical climatic conditions of the five GCMs was 0.77 ± 0.10 kgC m-2 year-1 (mean ± standard deviation), in accordance with the geographical distribution of forest NPP estimated in previous studies. Under the RCP2.6 and RCP8.5 scenarios, the mean NPP of the five GCMs increased by 0.04 ± 0.07 and 0.14 ± 0.11 kgC m-2 year-1, respectively. The increases in annual NPP were small in the southwestern region because of the decreases in summer NPP and the small increases in winter NPP under the RCP2.6 and RCP8.5 scenarios, respectively. Under the RCP2.6 scenario, Japanese cedar was at risk in the southwestern region, in accordance with previous studies, and monitoring and silvicultural practices should be modified accordingly

Ecological Impact on Nitrogen and Phosphorus Cycling of a Widespread Fast-growing Leguminous Tropical Forest Plantation Tree Species, Acacia mangium

Symbiotic nitrogen fixation is one of the major pathways of N input to forest ecosystems, enriching N availability, particularly in lowland tropics. Recently there is growing concern regarding the wide areas of fast-growing leguminous plantations that could alter global N2O emissions. Here, we highlight substantially different N and phosphorus utilization and cycling at a plantation of Acacia mangium, which is N2-fixing and one of the major plantation species in tropical/subtropical Asia. The litterfall, fresh leaf quality and fine-root ingrowth of A. mangium were compared to those of non-N2-fixing Swietenia macrophylla and coniferous Araucaria cunninghamii in wet tropical climates in Borneo, Malaysia. The N and P concentrations of the A. mangium fresh leaves were higher than those of the other two species, whereas the P concentration in the leaf-litterfall of A. mangium was less than half that of the others; in contrast the N concentration was higher. The N:P ratio in the A. mangium leaf was markedly increased from fresh-leaf (29) to leaf-litterfall (81). Although the N flux in the total litterfall at the A. mangium plantation was large, the fine-root ingrowth of A. mangium significantly increased by applying both N and P. In conclusion, large quantities of N were accumulated and returned to the forest floor in A. mangium plantation, while its P resorption capacity was efficient. Such large N cycling and restricted P cycling in wide areas of monoculture A. mangium plantations may alter N and P cycling and their balance in the organic layer and soil on a stand level

Carnitine insufficiency is associated with fatigue during lenvatinib treatment in patients with hepatocellular carcinoma.

BACKGROUND:Fatigue is a common adverse event during lenvatinib treatment in patients with hepatocellular carcinoma. One mechanism contributing to development of fatigue might involve abnormal adenosine triphosphate synthesis that is caused by carnitine deficiency. To address this possibility, we examined the relationship between carnitine levels and fatigue during lenvatinib treatment. METHODS:This prospective study evaluated 20 patients with hepatocellular carcinoma who underwent lenvatinib treatment. Both blood and urine samples were collected from the patients before starting lenvatinib therapy (day 0), and on days 3, 7, 14, and 28 thereafter. Plasma and urine concentrations of free and acyl carnitine (AC) were assessed at each time point. The changes in daily fatigue were evaluated using the Brief Fatigue Inventory (BFI). RESULTS:Plasma levels of free carnitine (FC) at days 3 and 7 were significantly higher compared with baseline (p = 0.005, p = 0.005, respectively). The urine FC level at day 3 was significantly higher compared with baseline (p = 0.030) and that of day 7 tended to be higher compared with baseline (p = 0.057). The plasma AC concentration at days 14 and 28 was significantly higher compared with that of baseline (p = 0.002, p = 0.005, respectively). The plasma AC-to-FC (AC/FC) ratio on days 14 and 28 was significantly higher compared with baseline (p = 0.001, p = 0.003, respectively). There were significant correlations between the plasma AC/FC ratio and the change in the BFI score at days 14 and 28 (r = 0.461, p = 0.041; r = 0.770, p = 0.002, respectively). CONCLUSIONS:Longitudinal assessments of carnitine and fatigue in patients with hepatocellular carcinoma suggest that lenvatinib affects the carnitine system in patients undergoing lenvatinib therapy and that carnitine insufficiency increases fatigue. The occurrence of carnitine insufficiency may be a common cause of fatigue during the treatment

Simultaneous enzymatic saccharification and comminution for the valorization of lignocellulosic biomass toward natural products

Abstract Background Large-scale processing of lignocellulosics for glucose production generally relies on high temperature and acidic or alkaline conditions. However, extreme conditions produce chemical contaminants that complicate downstream processing. A method that mainly rely on mechanical and enzymatic reaction completely averts such problem and generates unmodified lignin. Products from this process could find novel applications in the chemicals, feed and food industry. But a large-scale system suitable for this purpose is yet to be developed. In this study we applied simultaneous enzymatic saccharification and communition (SESC) for the pre-treatment of a representative lignocellulosic biomass, cedar softwood, under both laboratory and large-scale conditions. Results Laboratory-scale comminution achieved a maximum saccharification efficiency of 80% at the optimum pH of 6. It was possible to recycle the supernatant to concentrate the glucose without affecting the efficiency. During the direct alcohol fermentation of SESC slurry, a high yield of ethanol was attained. The mild reaction conditions prevented the generation of undesired chemical inhibitors. Large-scale SESC treatment using a commercial beads mill system achieved a saccharification efficiency of 60% at an energy consumption of 50 MJ/kg biomass. Conclusion SESC is very promising for the mild and clean processing of lignocellulose to generate glucose and unmodified lignin in a large scale. Economic feasibility is highly dependent on its potential to generate high value natural products for energy, specialty chemicals, feed and food application

High potential for increase in CO2_{2} flux from forest soil surface due to global warming in cooler areas of Japan

The CO$_{2}$ fluxes from the forest floor were measured using a closed chamber method at 26 sites from 26° N Lat. to 44° N Lat. in Japan. Seasonal fluctuation in CO$_{2}$ flux was found to correlate exponentially with seasonal fluctuation in soil temperature at each site. Estimate of annual carbon emission from the forest floor ranged from 3.1 to 10.6 Mg C ha$^{-1}$. The emission rate of soil-organic-carbon-derived CO$_{2}$, obtained by incubation of intact soil samples, correlated closely with the carboxymethylcellulase (CMCase) activity in the soil. The sum of cool-water soluble polysaccharides, hot-water soluble polysaccharides, hemicellulose, and cellulose content in the soil was greater at the sites with low CMCase activity than that at the sites with high CMCase activity. Because the sites in cooler-climate sites had a high content of easily decomposable soil organic carbon and organic litter, the potential increase in CO$_{2}$ efflux from forest floor with increasing soil temperature would be greater in cooler-climate sites.Fort potentiel d'accroissement de flux de CO$_{2}$ issu de la surface du sol forestier en relation avec le réchauffement global dans les régions fraîches du Japon. Le flux de CO$_2$ issu du sol forestier a été mesuré dans 26 sites, allant du 26° au 44° de latitude Nord dans l'archipel japonais, en utilisant la méthode des chambres fermées. Il a pu être mis en évidence que la fluctuation saisonnière du flux de CO$_2$ était corrélée de façon exponentielle avec celle de la température du sol de chacun des sites étudiés. L'estimation annelle de l'émission de carbone venant du sol variait de 3,1 à 10,6 Mg C ha$^{-1}$. Le taux d'émission de CO$_2$ obtenu par incubation d'échantillons intacts de sol est corrélé positivement avec l'activité de la carboxyméthacellulase (CMCase), dans le sol. La somme totale des polysaccharides solubles dans l'eau froide, des polysaccharides solubles dans l'eau chaude, des hémicelluloses et de la cellulose contenus dans le sol était plus grande dans les sites caractérisés par une faible activité CMCase que dans les sites avec une forte activité CMCase. Du fait que les sites en climat frais ont un contenu élevé en carbone organique du sol facilement décomposable et une litière organique, le potentiel d'accroissement du flux de CO$_{2}$ avec l'accroissement de la température du sol devrait être plus grand dans les sites à climat frais