Interactive effects on biomass production between nitrogen and water availabilities in boreal forests

Biomass production in boreal forests is mainly nitrogen (N) limited, so alleviating this limitation can improve productivity. As the climate warms, N limitation is expected to be reduced, which, in turn, could result in enhanced biomass productivity. However, empirical evidence from long-term studies is scarce. In addition, although water availability may constrain biomass production once N limitation has been partly or fully alleviated, little is known about the effect of the interaction between N and water availabilities on biomass production. In this research, I first examined the interactive effect on biomass production between N and water availabilities, based on field experiments in a Norway spruce forest and a Scots pine forest, supplementing these results with additional data from a literature survey. Nitrogen additions enhanced biomass production in both types of forest, while water availability only affected production in the pine forests in which N limitation had been partly or fully alleviated. In Scots pine forests, biomass production increased with increasing precipitation as the rate of N addition also increased. These forests are N limited, but the sigmoidal response to N additions indicates that even under moderate N supply, N availability meets their demand if precipitation is near average, and N limitation increases with increasing precipitation. Second, I examined the effect of soil warming on biomass production in the Norway spruce forest. The treatments comprised fertilization and soil warming (+5°C) at a plot scale of 100 m2 for 18 years. Increased biomass production in association with soil warming was only observed in the unfertilized plots, suggesting that the enhanced biomass production was mediated by increased N availability. However, the enhancement was ephemeral and, therefore, not of sufficiently long duration to significantly enhance biomass accumulation. Foliar nutrient analyses together with the findings from earlier studies of the same plots, suggest that soil warming shifted N uptake to deeper soil and may increase C stock in the mineral soil. Synthesizing the above results, I conclude that 1) biomass production of N limited boreal forests is strongly responsive to N additions following a sigmoidal curve, but the magnitude of response may depend on soil water availability, and 2) a warmer climate may not alleviate N limitation and thus will not increase biomass accumulation

No impact of nitrogen fertilization on carbon sequestration in a temperate Pinus densiflora forest

Carbon (C) sequestration capacity in forest ecosystems is generally constrained by soil nitrogen (N) availability. Consequently, N fertilization is seen as a promising tool for enhancing ecosystem-level C sequestration in N-limited forests. We examined the responses of ecosystem C (vegetation and soil) and soil N dynamics to 3 years of annual nitrogen-phosphorus-potassium (N3P4K1 = 11.3 g N, 15.0 g P, 3.7 g K m−2 year−1) or PK fertilization (P4K1), observed over 4 years in a 40-year-old Pinus densiflora forest with poor N nutrition in South Korea. PK fertilization without N was performed to test for PK limitation other than N. Neither tree growth nor soil C fluxes responded to annual NPK or PK fertilization despite an increase in soil mineral N fluxes following NPK fertilization. NPK fertilization increased the rate of N immobilization and 80% of the added N was recovered from mineral soil in the 0–5 cm layer, suggesting that relatively little of the added N was available to trees. These results indicate that N fertilization does not always enhance C sequestration even in forests with poor N nutrition and should therefore be applied with caution

A study of the anti-inflammatory effects of the ethyl acetate fraction of the methanol extract of Forsythiae fructus

Background: The dried fruit of Forsythia suspensa (Thunb.) Vahl. (Oleaceae) are better known by their herbal name Forsythiae Fructus, and have a bitter taste, slightly pungent smell, and cold habit. FF has been widely used to treat symptoms associated with the lung, heart, and small intestine. Recently, bioactive compounds isolated from hydrophobic solvent fractions of FF have been reported to have anti-oxidant, anti-bacterial, and anti-cancer effects. Traditionally, almost all herbal medicines are water extracts, and thus, extraction methods should be developed to optimize the practical efficacies of herbal medicines.Materials and Methods: In this study, the anti-inflammatory effects of the ethyl acetate fraction of the methanol extract of FF (FFE) were assessed by measuring NO and PGE2 production by and intracellular ROS and protein levels of iNOS and COX-2 in RAW 264.7 cells.Results: FFE inhibited COX-2 expression in LPS-stimulated RAW 264.7 cells.Conclusion: In summary, FFE effectively reduced intracellular ROS and NO levels and inhibited PGE2 production by downregulating COX-2 levels.Keywords: Forsythiae Fructus, herb, inflammation, efficacy

Large-scale assessment of artificially coated seeds for forest regeneration across Sweden

We report the results of two years' field performance of Scots pine (Pinus sylvestris) seedlings regenerated using artificially coated seeds. The coated seeds were used for regeneration on 12 clearcut sites, covering a 1000 km latitudinal gradient across Sweden. The coating was either combined with arginine-phosphate fertilizer (10 mg N per seed) or had no additions. Interactions with environmental variables associated with sites were also assessed. Coated seeds were deployed in May-June 2017 and surveyed in August-September of 2018 and 2019. After two years, the mean establishment rate of seedlings from coated seeds was 56 +/- 4% across the 12 sites. The fertilizer addition did not affect survival, and the biomass response to fertilizer varied significantly between sites. Maximum precipitation and wind speed during the first six weeks after deployment were correlated with seedling survival, regardless of fertilization treatment. Establishment increased with increasing precipitation and decreased with increasing wind speed. This highlights the importance of initial weather conditions for the seeds' establishment. Our data suggest that Scots pine regeneration using coated seeds can be practiced in boreal forests, but also that the method is sensitive to the weather conditions at the time of deployment of the seeds

Performance of a Distributed Simultaneous Strain and Temperature Sensor Based on a Fabry-Perot Laser Diode and a Dual-Stage FBG Optical Demultiplexer

A simultaneous strain and temperature measurement method using a Fabry-Perot laser diode (FP-LD) and a dual-stage fiber Bragg grating (FBG) optical demultiplexer was applied to a distributed sensor system based on Brillouin optical time domain reflectometry (BOTDR). By using a Kalman filter, we improved the performance of the FP-LD based OTDR, and decreased the noise using the dual-stage FBG optical demultiplexer. Applying the two developed components to the BOTDR system and using a temperature compensating algorithm, we successfully demonstrated the simultaneous measurement of strain and temperature distributions under various experimental conditions. The observed errors in the temperature and strain measured using the developed sensing system were 0.6 °C and 50 με, and the spatial resolution was 1 m, respectively

Quetiapine Misuse and Abuse: Is It an Atypical Paradigm of Drug Seeking Behavior?

Recent case reports in medical literatures suggest that more and more second-generation atypical antipsychotics (AAs) have been prescribed for off-label use; quetiapine (Brand name: Seroquel®) showed increase in its trend for off-label use. Little is known about the reasons behind this trend, although historical sedative and hypnotic prescription patterns suggest that despite relatively superior safety profiles of quetiapine (especially for movement disorders), it may be used for treating substance abuse disorder. In addition, recent studies have shown a strong potential for misuse and abuse (MUA) of quetiapine beyond Food and Drug Administration-approved indications. This includes drug-seeking behaviors, such as feigning symptoms, motivated by quetiapine and use of quetiapine in conjunction with alcohol. Quetiapine appears to be the most documented AA with street values bartered illicitly on the street. A recent report from the Drug Abuse Warning Network has shown a high prevalence of quetiapine-related emergency department visits involving MUA. Several other case studies have found that quetiapine causes seeking behaviors observed in substance use disorder. In fact, the majority of quetiapine MUA involved patients diagnosed with substance use disorder. In the absence of a definitive mechanism of action of quetiapine\u27s reinforcing properties, it is imperative to gather robust evidence to support or refute increasing off-label use of AAs