The net primary productivity, carbon (C) stocks and turnover rates (i.e. C dynamics) of tropical forests are an important aspect of the global C cycle. These variables have been investigated in ...lowland tropical forests, but they have rarely been studied in tropical montane forests (TMFs). This study examines spatial patterns of above‐ and belowground C dynamics along a transect ranging from lowland Amazonia to the high Andes in SE Peru. Fine root biomass values increased from 1.50 Mg C ha⁻¹ at 194 m to 4.95 ± 0.62 Mg C ha⁻¹ at 3020 m, reaching a maximum of 6.83 ± 1.13 Mg C ha⁻¹ at the 2020 m elevation site. Aboveground biomass values decreased from 123.50 Mg C ha⁻¹ at 194 m to 47.03 Mg C ha⁻¹ at 3020 m. Mean annual belowground productivity was highest in the most fertile lowland plots (7.40 ± 1.00 Mg C ha⁻¹ yr⁻¹) and ranged between 3.43 ± 0.73 and 1.48 ± 0.40 Mg C ha⁻¹ yr⁻¹ in the premontane and montane plots. Mean annual aboveground productivity was estimated to vary between 9.50 ± 1.08 Mg C ha⁻¹ yr⁻¹ (210 m) and 2.59 ± 0.40 Mg C ha⁻¹ yr⁻¹ (2020 m), with consistently lower values observed in the cloud immersion zone of the montane forest. Fine root C residence time increased from 0.31 years in lowland Amazonia to 3.78 ± 0.81 years at 3020 m and stem C residence time remained constant along the elevational transect, with a mean of 54 ± 4 years. The ratio of fine root biomass to stem biomass increased significantly with increasing elevation, whereas the allocation of net primary productivity above‐ and belowground remained approximately constant at all elevations. Although net primary productivity declined in the TMF, the partitioning of productivity between the ecosystem subcomponents remained the same in lowland, premontane and montane forests.
The aims of this study were: to determine the incidence of Severe Acute Respiratory Syndrome Coronavirus‐2 (SARS‐CoV‐2) infection among vaccinated healthcare workers (HCWs), assess risk factors ...associated with the vaccine breakthrough (BT), and compare the effectiveness of vaccine manufacturers against SARS‐CoV‐2 variant of concern among HCWs in Duhok governorate. It is a multicenter retrospective cohort study, which enrolled 944 HCWs through March 2022. COVID‐19 vaccinated HCWs aging 18 and above were included. A random sampling process was performed by asking the participants to fill out a standardized questionnaire by means of interviews or participant‐completed surveys. Fully vaccinated HCWs with positive polymerase chain reaction tests were considered to have vaccine BT infection. Two hundred and eighty‐four (30.1%) out of 944 vaccinated HCWs had SARS‐CoV‐2 infection postvaccination, of whom 241 (84.9%) were fully vaccinated, concluding that the incidence of BT infection is 25.5%. There were 422 (44.7%) males and 522 (55.3%) females. Most vaccine BT infections had developed in SARS‐CoV‐2 Omicron variant (53.5%). The majority of BT infections were mild to moderate (95.5%). Occupation, namely dentist was a significant risk factor, with a p value of 0.001. HCWs with a history of SARS‐CoV‐2 infection prevaccination were more prone to a vaccine BT infection (p value =0.002). Pfizer vaccine manufacturers revealed the highest effectiveness against BT infection (p value =0.0001). Paramedics showed a significant association with the disease severity (p value =0.02). The three available vaccine manufacturers in the Duhok governorate are effective against COVID‐19 BT infections. Dentists and paramedics were significantly associated with poor COVID‐19 outcomes.
We present the results from a litter translocation experiment along a 2800-m elevation gradient in Peruvian tropical forests. The understanding of the environmental factors controlling litter ...decomposition is important in the description of the carbon and nutrient cycles of tropical ecosystems, and in predicting their response to long-term increases in temperature. Samples of litter from 15 species were transplanted across all five sites in the study, and decomposition was tracked over 448 d. Species' type had a large influence on the decomposition rate (k), most probably through its influence on leaf quality and morphology. When samples were pooled across species and elevations, soil temperature explained 95% of the variation in the decomposition rate, but no direct relationship was observed with either soil moisture or rainfall. The sensitivity of the decay rate to temperature (𝒦 T ) varied seven-fold across species, between 0.024 and 0.169°C⁻¹, with a mean value of 0.118 ± 0.009°C⁻¹ (SE). This is equivalent to a temperature sensitivity parameter (Q₁₀) for litter decay of 3.06 ± 0.28, higher than that frequently assumed for heterotrophic processes. Our results suggest that the warming of approx. 0.9°C experienced in the region in recent decades may have increased decomposition and nutrient mineralization rates by c. 10%.
The net primary productivity (NPP) of tropical forests is one of the most important and least quantified components of the global carbon cycle. Most relevant studies have focused particularly on the ...quantification of the above-ground coarse wood productivity, and little is known about the carbon fluxes involved in other elements of the NPP, the partitioning of total NPP between its above- and below-ground components and the main environmental drivers of these patterns. In this study we quantify the above- and below-ground NPP of ten Amazonian forests to address two questions: (1) How do Amazonian forests allocate productivity among its above- and below-ground components? (2) How do soil and leaf nutrient status and soil texture affect the productivity of Amazonian forests? Using a standardized methodology to measure the major elements of productivity, we show that NPP varies between 9.3±1.3 Mg C ha−1 yr−1 (mean±standard error), at a white sand plot, and 17.0±1.4 Mg C ha−1 yr−1 at a very fertile Terra Preta site, with an overall average of 12.8±0.9 Mg C ha−1 yr−1. The studied forests allocate on average 64±3% and 36±3% of the total NPP to the above- and below-ground components, respectively. The ratio of above-ground and below-ground NPP is almost invariant with total NPP. Litterfall and fine root production both increase with total NPP, while stem production shows no overall trend. Total NPP tends to increase with soil phosphorus and leaf nitrogen status. However, allocation of NPP to below-ground shows no relationship to soil fertility, but appears to decrease with the increase of soil clay content.
The consumption of products with high nutritional value and antioxidant capacity has increased notably in recent years. Due to health problems such as triglycerides and cardiovascular problems, its ...use is becoming reduced. So that, chia (Salvia hispánica) and sachatomate (Cyphomandra betacea) have gained interest as an alternative to develop nutraceutical products, compared to conventional products. The objective of the study was to determine the effect of the partial substitution of mango (Mangifera indica) and ground chia (Salvia hispánica) on the antioxidant capacity in the elaboration of nectar based on Sachatomate. The physicochemical characteristics were determined where sample 11 complies with the established parameters: 13.4° Brix, pH 4.323, 0.354 of C6-H8-O7 and viscosity 3967.3 mPas, according to the NTP 203.110 standard. Regarding the antioxidant capacity, sample 12 was the most optimal, according to the DPPH method, it has been determined 104.3 micromoles Trolox equivalents; according to the ABTS method, it was determined with an antioxidant content of 187.4 micromoles Trolox equivalents. Regarding the proximal chemical evaluation, sample 12 was determined to be the most suitable with a moisture percentage of 87.45%, ash 0.32%, crude fiber 0.09%, fat 0.10%, protein 0.45% and carbohydrates 11.59%. Concluding that substituting sachatomate and ground chia significantly influences the antioxidant capacity, increasing to 104.3 and 187.4 micromoles Trolox equivalents, determined by both methods, indicates that nectar consumption can be used to improve the health of consumers.
The production of poly-3-hydroxybutyrate (PHB) on an industrial scale remains a major challenge due to its higher production cost compared to petroleum-based plastics. As a result, it is necessary to ...develop efficient fermentative processes using low-cost substrates and identify high-value-added applications where biodegradability and biocompatibility properties are of fundamental importance. In this study, grape residues, mainly grape skins, were used as the sole carbon source in Azotobacter vinelandii OP cultures for PHB production and subsequent nanoparticle synthesis based on the extracted polymer. The grape residue pretreatment showed a high rate of conversion into reducing sugars (fructose and glucose), achieving up to 43.3 % w w−1 without the use of acid or external heat. The cultures were grown in shake flasks, obtaining a biomass concentration of 2.9 g L−1 and a PHB accumulation of up to 37.7 % w w−1. PHB was characterized using techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The formation of emulsified PHB nanoparticles showed high stability, with a particle size between 210 and 240 nm and a zeta potential between −12 and − 15 mV over 72 h. Owing to these properties, the produced PHB nanoparticles hold significant potential for applications in drug delivery.
The purpose of the present investigation was to determine the effect of rhizobium and gibberellin on the production of hydroponic green forage from red clover (Trifolium pratense L.) variety ...quiñequeli, four variables were measured: plant height, biomass weight, grass weight and root weight. The treatments were T0: 0%, T1: 10%, T2: 20%, T3: 30% and T4: 40% of Rhizobium before germination and Gibberellin T0: 0g, T1: 2.4g; T2: 3.3g; T3: 4.3 and T4: 5.3g each treatment with 6 repetitions, three applications on days 5, 10, 15 and 20 of growth. Data were analyzed with DCA, ANOVA and DUNCAN's multiple comparisons test; the results obtained were: first measurement with rhizobium without gibberellin there were no statistical differences, second and third measurement with Gibberellin application did not present statistical differences and the fourth measurement presented statistical difference (α=0.05), average height of the plant with a mean of 12.82 cm, T4 was higher, in biomass a statistical difference was obtained with a mean of 3.056 kg, T3 was higher, weight of grass and root did not present statistical differences; concluding that the use of rhizobium and gibberellin could be a usable alternative in the production of hydroponic green fodder, to alleviate the problems of fodder scarcity in dry season, its use being recommended in high Andean livestock.
Integrated nutrient management is a promising way to avoid plant nutrient shortages because of the positive relationship between the bioavailability of nutrients and greater economic interest in ...their application through organic amendments and microbial application. To examine how compost, charcoal, and rhizobium influence maize development, an experiment was set up in a container. In addition to the appropriate amounts of nitrogen, phosphorous, and potassium, the soil in the allotted pots was treated with 50 ml of rhizobium, 5 tonnes of compost, and 2.5 tonnes of biochar before maize seeds were planted. A total of nine treatments (with three replicates each) were arranged in a completely randomized design for this experiment. Various agronomic, chemical, and physiological data were measured and recorded after the crop was harvested 110 days after sowing. The results showed that when biochar, compost, and rhizobium were applied together, the root fresh biomass rose by 43.4%, the root dry biomass increased by 38.3%, and the shoot length increased by 61.7%, compared to the control treatment. Chlorophyll content (41.3% higher), photosynthetic rate (58.5% higher), transpiration rate (64.4% higher), quantum yield (32.6% higher), and stomatal conductivity (25.3% higher) were all significantly improved compared to the control. Soil levels of nitrogen, phosphorus, and potassium were also improved with this treatment compared to the control. The combined use of biochar, compost, and rhizobium was more successful than any of the components used individually in boosting maize yields. Based on the findings of our study, the integration of rhizobium, biochar, and compost within a unified treatment shown a substantial enhancement in both the growth and yield of maize.
Key message
We have identified 19 QTLs for rachis architecture, a key and complex trait for grapevine production. Fifty out of 1,173 genes underlying these QTLs are candidates to be further explored.
...In the table grape industry, the rachis architecture has economic and management implications. Therefore, understanding the genetics of this trait is key for its breeding. The aim of this work was to identify genetic determinants of traits associated with the cluster architecture. Characterisations of eight traits was performed on a ‘Ruby Seedless’ × ‘Sultanina’ crossing (F
1
:
n
= 137) during three seasons, with and without gibberellic acid (GA
3
) applications. The genotypic effects and the genotype × GA
3
interactions were significant for several traits. Rachis length (
rl
), lateral shoulder length and node number along the central axis were the most prominent traits. On average, the heritability of these traits was ~71 %, with heritability of
rl
being 76 % as estimated under different seasons. Quantitative trait loci (QTLs) analyses showed that linkage group 5 (LG
5
) and LG
18
harboured the largest number of QTLs for these traits. According to the variance explained, the main QTL (corresponding to
rl
) was found on LG
9
. These QTLs were supported mainly by a paternal additive effect and revealed possible pleiotropic effects. Based on the grapevine reference genome, we identified 1,173 genes located under these QTL confidence intervals. Fifty of the 891 annotated genes of this list were selected for their further characterisation because of their possible participation in the rachis architecture. In conclusion, the QTLs detected indicate that these traits and their GA
3
responsiveness have a clear genetic basis. Due to the percentage of the total variance explained, they are good candidates to participate in the genetic determination of the cluster architecture.
The key role of tropical forest belowground carbon stocks and fluxes is well recognised as one of the main components of the terrestrial ecosystem carbon cycle. This study presents the first detailed ...investigation of spatial and temporal patterns of fine root stocks and fluxes in tropical forests along an elevational gradient, ranging from the Peruvian Andes (3020 m) to lowland Amazonia (194 m), with mean annual temperatures of 11.8°C to 26.4 °C and annual rainfall values of 1900 to 1560 mm yr‐1, respectively. Specifically, we analyse abiotic parameters controlling fine root dynamics, fine root growth characteristics, and seasonality of net primary productivity along the elevation gradient. Root and soil carbon stocks were measured by means of soil cores, and fine root productivity was recorded using rhizotron chambers and ingrowth cores. We find that mean annual fine root below ground net primary productivity in the montane forests (0–30 cm depth) ranged between 4.27±0.56 Mg C ha‐1 yr‐1 (1855 m) and 1.72±0.87 Mg C ha‐1 yr‐1 (3020 m). These values include a correction for finest roots (<0.6 mm diameter), which we suspect are under sampled, resulting in an underestimation of fine roots by up to 31% in current ingrowth core counting methods. We investigate the spatial and seasonal variation of fine root dynamics using soil depth profiles and an analysis of seasonal amplitude along the elevation gradient. We report a stronger seasonality of NPPFineRoot within the cloud immersion zone, most likely synchronised to seasonality of solar radiation. Finally, we provide the first insights into root growth characteristics along a tropical elevation transect: fine root area and fine root length increase significantly in the montane cloud forest. These insights into belowground carbon dynamics of tropical lowland and montane forests have significant implications for our understanding of the global tropical forest carbon cycle.
Key pointsIncrease of NPPFine Root seasonality in cloud forestChange in fine root growth characteristics in montane forestPossible sampling bias of finest roots ( < 6mm) in IC data collection
PDF
