Low Moisture Levels Research Articles

Semar Sandy-app: monitoring system for sandy soil irrigation based on android application

Indonesia’s population increase leads to increase in food needs. The increasing need for food requires national food security. However the country faces the problem of agricultural land diminishing. Sandy soil is one of the suboptimal land that can be used for agricultural cultivation. Sandy soil leads to problems such as low water-holding capacity that will result in low levels of soil moisture. Soil moisture content is a very important factor in plant growth. Accordingly, we need an alternative solution to solve the problem. One of technology used in agriculture is an irrigation system. Therefore, the author proposes an idea in forms of Semar Sandy-App. Semar Sandy-App is a monitoring system as well as a system that provides direct supply water in the plant root zone. The system uses subsurface drip irrigation with perforated pipes then water comes out of the hole to wet the soil. This system can be a solution to optimize sandy soil through efficiency and effectiveness in providing water. The system can control and monitor the plant water requirements through the use of microcontroller that is connected directly to the android system, so it will increase agricultural productivity to support the availability of food for the community.

Entomopathogenic nematode management of small hive beetles (Aethina tumida) in three native Alabama soils under low moisture conditions.

The goal was to determine the efficacy of entomopathogenic nematodes (EPNs) on Aethina tumida small hive beetle (SHB) in Alabama soils. The objectives were to (i) determine the pupation success of SHB wandering larvae; (ii) determine the efficacy of EPNs on SHB wandering larvae in natural and autoclaved soil; and (iii) determine the efficacy of EPNs on SHB wandering larvae in three Alabama soil types at typical low moisture levels. The Alabama soils were Kalmia loamy sand (KLS), Benndale fine sandy loam (BFSL), and Decatur silt loam (DSL). Heterorhabditis bacteriophora, H. indica, Steinernema carpocapsae, S. feltiae, S. kraussei, and S. riobrave were tested at population densities of 5, 10, 20, 40, and 80 third-stage infective EPN juveniles (IJ3) per 130 cm3 soil. Pupation success in SHB population densities of 5, 10, and 20 wandering larvae per Petri dish were similar. Of the six EPN species, S. carpocapsae achieved the highest efficacy across all EPN population densities in both natural and autoclaved soil. Steinernema riobrave and H. indica achieved the next highest efficacies; however, they were significantly less effective than S. carpocapsae. Steinernema carpocapsae parasitized 87% SHB wandering larvae across all population densities tested. Steinernema carpocapsae achieved the best efficacy colonizing 94% of the SHB in the KLS soil, 80% in the BFSL soil, and 47% in the DSL soil. In conclusions, S. carpocapsae is be a promising biological control EPN to implement into a management system on SHB.

Lateglacial and Holocene climate change in the NE Tibetan Plateau: Reconciling divergent proxies of Asian summer monsoon variability

The nature of Holocene Asian summer monsoon (ASM) evolution documented by diverse natural archives remains controversial, with a contentious issue being whether or not a strong Asian summer monsoon prevailed during the early Holocene. Here we present sequences of multiple proxies measured in sediment cores from Genggahai Lake in the NE Tibetan Plateau (NETP). The results suggest that a higher lake level and relatively lower terrestrial vegetation cover occurred synchronously during the early Holocene (11.3–8.6kyrcalBP), compared with the period from 8.6 to 6.9 kyrcalBP. This finding clearly reflects the existence of different hydroclimatic conditions between the lake and its catchment due to diverse driving mechanisms. The early Holocene high stand of the lake, as demonstrated by the stratigraphic variability of the remains of aquatic biota, may have responded to the strengthened ASM and increased monsoonal precipitation; the relatively low vegetation cover in the marginal region of the Asian monsoon during the early Holocene, and the coeval widespread active sand dune mobility in both the NE Tibetan Plateau and NE China, most likely resulted from a low level of effective moisture due to high evaporation, and hence they cannot be interpreted as evidence of a weak ASM. Our results potentially reconcile the current divergent interpretations of various proxy climate records from the region. Our findings suggest that the ASM evolution was characterized by a consistent pattern across the monsoonal regions, as indicated by the oxygen isotope record of Chinese speleothems.

Drought legacy affects microbial community trait distributions related to moisture along a savannah grassland precipitation gradient

Abstract Ecosystem models commonly use stable‐state assumptions to predict responses of soil microbial functions to environmental change. However, past climatic conditions can shape microbial functional responses resulting in a ‘legacy effect’. For instance, exposure to drier conditions in the field may shape how soil microbial communities respond to subsequent drought and drying and rewetting (DRW) events. We investigated microbial tolerance to low moisture levels (‘resistance’) and ability to recover after a DRW perturbation (‘resilience’) across a steep precipitation gradient in Texas, USA. Although differences in precipitation regime did not result in differences in resistance and resilience of soil microbes, microbial communities appeared to be generally resilient and resistant across the gradient, suggesting that frequent exposure to drought had characterised the trait distributions of microbial communities. Moreover, microbial communities from historically drier sites used carbon more efficiently during a DRW perturbation suggesting that long‐term drought history leaves a legacy effect on microbial functions. This may have been due to an indirect effect of drought caused via precipitation‐induced differences in primary productivity, influencing the availability of soil organic matter to microbes. Alternatively, different exposures to drought might have shaped the microbial ‘readiness’ to cope with the DRW disturbance. Microbial community composition was also linked to drought history, but was unrelated to variation in function. Synthesis. Exposure to drought can have both direct and indirect effects on soil microbial communities, which can result in lasting legacy effects on the functions they control.

Effect of Mineral N on C and N Dynamics of Rice and Wheat Residues under Different Moisture Levels

Crop residue mineralization affects soil carbon (C) and nitrogen (N) dynamics during crop residue management in crop production. C and N mineralization dynamics of rice and wheat residues incorporated with and without mineral N under two moisture conditions were evaluated under laboratory conditions. Mineral N was applied @ 0.015 g/Kg (»30 Kg/ha), whereas soil moisture was maintained at high (» – 15 KPa, near field capacity) and at low (» – 500 KPa)moisture levels during course of study.Periodic determinations on CO2 – C and N mineralized were performed over a period of 120 days. The highest peaks for CO2 – C occurred during first week of the study which then reduced gradually until it attained an equilibrium. High moisture level enhanced CO2 – C flux by 14% than low moisture level. Combined application of crop residues and mineral N released 17% more CO2 – C than crop residue treatments without mineral N.In residue applied treatments, immobilization was 40% higher at high moisture level than that at low moisture level. Application of rice and wheat residues in combination with mineral N caused both immobilizations followed by mineralization phases at both moisture levels. At high moisture level, maximum immobilization occurred during initial 15 days, while at low moisture level it continued till about 30 days. After day15, mineralization started which continued to increase during remaining period of study at high moisture and at low moisture mineralization initiated from day 60 onward. Mineralization in rice residue was faster than that in wheat residues. Immobilization of N continued progressively in residue alone treated soils at both moisture levels during study period. In residue treated soils, increase in soil moisture increased soil organic carbon (SOC) and soil water stable aggregates (WSA) significantly by 14% and 55% over control respectively.Combined application of crop residues and mineral N increased SOC by 43% and WSA by 59%. This study indicated that incorporation of crop residues along with addition of mineral N in the presence of optimum moisture promoted its faster decomposition with a quicker mineral N release, more organic matter build up and soil structure improvement than crop residues incorporated without mineral N.

Comprehensive Chemical Characterisation of Durio Zibethinus

This study investigated the chemical properties of Durio zibethinus (Durian) in Malaysia. The cultivars included in the present study were D101, D197, and Kampung. A wide range of chemical properties such as proximate nutritional content, minerals, total phenolic content was analysed using established analytical methods. The antioxidant capacity in term of free radical scavenging activity was determined using colorimetric assay, whereas metabolite profiles of samples were analysed by hyphenated high throughput tool like GC-MS. The results showed that D197 durian had the highest content of ash, protein, fat, and carbohydrate, but the lowest moisture level. Potassium was found to be the highest mineral (8.68–11.36 mg g–1), followed by sodium (3.2–7.6 mg g–1), magnesium (0.86–1.88 mg g–1), and calcium (2.74–3.80 mg g–1) in the tested cultivars. The major sulphur containing compounds (% relative peak area) such as hydrogen sulphide (5.0–8.3%), methanethiol (0.5–1.0%), ethanethiol (20.7–35.0%), 1-propanethiol (2.7– 9.5%), and diethyl disulphide (0.6–1.9%), and esters, especially ethyl 2-methylbutanoate (10.0–15.0%), methyl 2-methylbutanoate (1.0%), and propyl 2-methylbutanoate (1.5%) were detected when fresh samples were heated in headspace GC-MS. However, those compounds evaporated during ultrasound assisted extraction and oven drying even at 40 °C.

Effects of Microbial Inoculants on the Fermentation and Preservation of Triticale Silages at High and Low Moisture Levels

In the current study, Lactobacillus rhamnosus (KCC-51) and Lactobacillus paracasei (KCC-52) were isolated and investigated for their biological potential including antibacterial activity, probiotic potential, nutritional changes, fermentation ability, and microbial population in experimental silages at high moisture (HM) and low moisture (LM) conditions. These strains showed significant antibacterial activity and probiotic activities. There are no significant changes in the dry matter content (DM) and nutritional profiles of control, KCC-51, and KCC-52 treated silages. High lactic acid (LA) and low butyric acid (BA) levels were noted in the HM (LA: 4.82 ± 0.34 and 5.5 ± 0.03, BA: 0.01 ± 0.01 and 0.008 ± 0.001, %DM) and LM (LA: 2.27 ± 0.32 and 2.61 ± 0.2, BA: 0.017 ± 0.001 vs. 0.006 ± 0.05, %DM) silages treated with KCC-51 and KCC-52 respectively, compared to non-inoculated silages. KCC-51 and KCC-52 treatment increased acceptable range of acetic acid (AA) in HM (0.33 ± 0.02 and 0.24 ± 0.007, %DM) and LM (0.22 ± 0.007 and 0.35 ± 0.02, %DM) silages compared to non-inoculated silages (0.22 ± 0.03 and 0.17 ± 0.05, %DM). Rich LAB and low yeast counts were noted in the silages treated with KCC-51 and KCC-52, it indicated that the addition of these inoculants strongly dominated the enterobacterial growth and preserved the silage quality with essential metabolites. It suggests that L. rhamnosus and the L. paracasei could be used as potent inoculants for the silage production with enriched nutrients.

Proximate Composition and Amino Acids Contents in Selected Legumes and Hura crepitans seed in Wukari Taraba State

The study evaluated the proximate composition and amino acid contents of selected legumes and Hura crepitans seed in Wukari,Taraba State, Nigeria. The Sand box seeds were collected from its tree in Wukari town, while black eyed pea and red kidney beans were purchased from Wukari market. The samples were processed into powder for proximate composition and amino profile. In all the samples, 18 amino acids were determined with higher values for aspartic acid, glutamic acid, leucine and phenylalanine while cysteine (0.43-0.79g/ 100g) had the lowest value in the samples analysed. Levels of amino acid ranged as: Sandbox seed had 0.79 ± 0.02 to 10.44 ± 0.02 g/100g, Black eyed pea seed had 0.51 ± 0.12 to 8.53 ± 0.03 g/100g, red kidney bean had 0.43 ± 0.02 to 7.93 ± 0.02 g/100g. The sand box seed had the highest protein content (33.71± 0.02 %), followed by red kidney bean (29.21 ± 0.02%). Nitrogen free extract had the highest value in black eyed pea (63.29±0.01%). The sand box seed had the highest crude fat (7.27 ± 0.02%). All the three crop samples had low safe moisture levels for storage. The study revealed the variation in the nutrients composition of the crop samples. However, sand box seeds had the highest protein content, coupled with high levels of amino acids detected, but the seed is yet to be consumed by humans. Hence, the need for further research on Hura crepitans with the view of reducing the deleterious effects of its antinutrients.

Effects of seed moisture content and Epichloe endophyte on germination and physiology of Achnatherum inebrians

Vertically transmitted Epichloe endophyte can be beneficial to host grasses. In order to achieve high seed and endophyte viability under storage, knowledge of optimal seed moisture content and germination behavior of endophyte-infected grass seed is required. In the current research project, Achnatherum inebrians seeds were adjusted to different moisture contents to investigate effects on germination and viability of the endophyte, E. gansuensis, after six months of storage. To explore mechanism of the effect of moisture content and endophyte on seed germination, a number of physiological and biochemical indicators were determined, including electrical conductivity (EC), contents of proline (Pro), malondialdehyde (MDA) and total soluble sugar; activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and hydrogen peroxide (H2O2). The results showed that the viability of the endophyte at 5.5% and 9.5% seed moisture was significantly (p<0.05) higher than with other seed moisture treatments. Furthermore, the infection rate was higher than the corresponding germination percentage at each seed moisture content. The endophyte significantly (p<0.05) improved the seed germination percentage, germination index, and vigor index at the seed moisture contents of 5.5% and 9.5%. A value of 5.5% was found to be the optimal seed moisture content under storage. This moisture level enhanced the activity of antioxidant enzymes and reduced lipid peroxidation of cell membranes, which is likely to be responsible for the slowing of which is likely to be responsible for the slowing of the decline in viability of Achnatherum inebrians seeds. Compared to the seed with endophyte, uninfected seeds had lower soluble sugar and proline contents. We conclude that the presence of the endophyte can improve vigor of A. inebrians seed after prolonged storage at low and intermediate moisture levels.

Sensitivity of spinach seed germination to moisture is driven by oxygen availability and influenced by seed size and pericarp

Uniform seedling emergence is crucial for economically viable spinach (Spinacia oleracea) leaf production. However, non-uniform seed germination occurs due to variation in moisture sensitivity between and within spinach seed lots. To test moisture sensitivity, we developed a floating germination system with fixed distances between germination papers and the water table, so that moisture levels could be standardised. We tested germination performance of different cultivar seed lots, with one seed lot fractioned in different seed sizes, and of seeds with an intact, open or removed pericarp. At a high moisture level, smaller seeds germinated better than larger seeds, and seeds without a pericarp or with an open pericarp germinated better than intact seeds. Further, the pericarp of smaller seeds was thinner than the pericarp of larger seeds. A lower temperature or increased oxygen level resulted in higher germination rates for differently-sized seeds at high moisture levels. In conclusion, the sensitivity of spinach seed germination to moisture is influenced by seed size, hence pericarp thickness and intactness, and is driven by the oxygen availability to the seed embryo. To determine the full germination potential of spinach seed lots, we recommend a standardised low moisture level in addition to a temperature of 15 or 20°C.

Process Monitoring of Moisture Content and Mass Transfer Rate in a Fluidised Bed with a Low Cost Inline MEMS NIR Sensor

PurposeThe current trend for continuous drug product manufacturing requires new, affordable process analytical techniques (PAT) to ensure control of processing. This work evaluates whether property models based on spectral data from recent Fabry–Pérot Interferometer based NIR sensors can generate a high-resolution moisture signal suitable for process control.MethodsSpectral data and offline moisture content were recorded for 14 fluid bed dryer batches of pharmaceutical granules. A PLS moisture model was constructed resulting in a high resolution moisture signal, used to demonstrate (i) endpoint determination and (ii) evaluation of mass transfer performance.ResultsThe sensors appear robust with respect to vibration and ambient temperature changes, and the accuracy of water content predictions (±13 % ) is similar to those reported for high specification NIR sensors. Fusion of temperature and moisture content signal allowed monitoring of water transport rates in the fluidised bed and highlighted the importance water transport within the solid phase at low moisture levels. The NIR data was also successfully used with PCA-based MSPC models for endpoint detection.ConclusionsThe spectral quality of the small form factor NIR sensor and its robustness is clearly sufficient for the construction and application of PLS models as well as PCA-based MSPC moisture models. The resulting high resolution moisture content signal was successfully used for endpoint detection and monitoring the mass transfer rate.

Effects of Muscle and Finishing Diets Containing Distillers Grains with Low Moisture Levels on Fatty Acid Deposition in Two Novel Value-added Beef Cuts.

This study evaluated the effects of muscle and dietary treatments including CORN, dry distillers grains (DDGS), and modified distillers grains (MDGS) on fatty acid (FA) deposition in two novel value-added beef cuts (Petite Tender - M. teres major - TM, and Flat Iron – M. infraspinatus - INF). Crossbred steers were randomly assigned to one of three dietary treatments (CORN, 40% of DDGS with 8%–12% of moisture, and 40% of MDGS with 45%–55% of moisture - DM basis) and fed for 190 days. The TM muscle had higher concentrations of ω6 FAs and polyunsaturated fatty acids (PUFA) when compared to INF. Beef fed CORN showed greater C16:0 and lower C18:0 values when compared to beef fed distillers grains (DGS). Beef fed DDGS had higher concentrations of ω6 FAs when compared to MDGS. Different moisture levels only affected FAs containing 14, 16, and 17 carbons. Different muscles, diets, and moisture levels of DGS affected the deposition of FAs in the lean.

Effects of precipitation intermittency on vegetation patterns in semi-arid landscapes

Patterns of vegetation are a characteristic feature of many semi-arid regions. The limiting resource in these ecosystems is water, which is added to the system through short and intense rainfall events that cause a pulse of biological processes such as plant growth and seed dispersal. We propose an impulsive model based on the Klausmeier reaction–advection–diffusion system, analytically investigate the effects of rainfall intermittency on the onset of patterns, and augment our results by numerical simulations of model extensions. Our investigation focuses on the parameter region in which a transition between uniform and patterned vegetation occurs. Results show that decay-type processes associated with a low frequency of precipitation pulses inhibit the onset of patterns and that under intermittent rainfall regimes, a spatially uniform solution is sustained at lower total precipitation volumes than under continuous rainfall, if plant species are unable to efficiently use low soil moisture levels. Unlike in the classical setting of a reaction–diffusion model, patterns are not caused by a diffusion-driven instability but by a combination of sufficiently long periods of droughts between precipitation pulses and water diffusion. Our results further indicate that the introduction of pulse-type seed dispersal weakens the effects of changes to width and shape of the plant dispersal kernel on the onset of patterns.

Comparison of selected local honey with Manuka honey based on their nutritional and antioxidant properties

This study aimed to determine and compare the proximate composition, sugars content and antioxidant properties of selected Malaysian raw honey (Tualang, Gelam, Kelulut, Wild, and Pineapple) with Manuka honey. Proximate analysis (energy, carbohydrate, protein, fat, ash, moisture and total dietary fibre), sugar analysis (fructose, sucrose, glucose and maltose), total phenolic content (TPC) and antioxidant analysis (DPPH radical scavenging activity and linoleic acid oxidation assay) were conducted on the honey samples. The proximate analysis and sugar analysis results for all honeys were within Codex Alimentarius Commission guidelines. In general, Malaysian honeys exhibited lower level of carbohydrates (80.27% to 82.32%), energy (324.18 kcal/100 g to 331.20 kcal/100 g), ash (0.17% to 0.28%) and protein (0.24% to 0.26%, except for Gelam 0.45%) but higher in moisture (17.07% to 19.08%) and fat (0.10% to 0.36%) contents compared to Manuka honey. No significance differences (P&gt;0.05) was detected in total sugar among the honey samples. Overall, among the selected honeys, Kelulut honey has the highest energy content, lowest moisture level, fat content and fructose level. Meanwhile, Wild honey showed the highest phenolic content and antioxidant activities.

Characterization of electroosmotic drainage: application to mine tailings and solid residues from leaching

Mining is the most important economic activity in Chile, which is the largest copper exporter in the world. However, mining has significant environmental impacts, such as generating large amounts of solid waste. Due to the high moisture content of solid waste, physical stabilization problems can arise at disposal sites as a result of aqueous solutions trapped in solids not draining by gravity. Electroosmotic drainage has been proposed as a technique to reduce moisture and thus increase the stability of disposal sites. However, the question arises whether the volume of drained solution depends on the percentage of fine matter in the solid matrix. The experimental work reported here, based on an experimental factorial design, was carried out to address this question. The first part consists of an experimental design with synthetic solid matrices. The percentage of fine particles and the initial moisture level were defined as factors with three levels. The volume of drained liquid was defined as the response variable. The results showed that electroosmotic drainage was more efficient than gravitational drainage when the moisture content and the percentage of fine material were at their highest levels. The effect of the factors and their interaction was corroborated by an ANOVA. An equation was developed to describe the relationship between the response variables and the factors. Finally, considering the application of the technique in mining, tests were conducted on tailing samples and solid leaching residues. The tests showed that the technique is effective with tailings due to the high content of fine material and the initial moisture level. However, it was not effective with leaching residues due to the low initial moisture level and the low fine particle content.

Probiotic Characteristics and Antifungal Activity of Lactobacillus plantarum and Its Impact on Fermentation of Italian Ryegrass at Low Moisture

The study aimed to investigate probiotic characteristics, and low moisture silage fermentation capability of selected lactic acid bacteria (LAB) isolated from Alfalfa (Medicago sativa L). Morphological and physiological properties, carbohydrates fermentation, enzymes, and organic acids production, anti-fungal activity, antibiotic sensitivity patterns, and probiotic characteristics (acidic and bile salt tolerances, hydrophobicity and aggregations natures) of LAB were examined. 16SrRNA sequencing was carried out to identify isolated strains. The identified strains Lactobacillus plantarum (KCC-37) and Lactobacillus plantarum (KCC-38) showed intense antifungal activity, survival tolerant in acidic and bile salt environments, cell surface and auto aggregations ability, enzymes and organic acids productions. At ensiled condition, KCC-37 and KCC-38 enhanced acidification of Italian ryegrass silages by producing a higher amount of lactic acid, a key acid for indicating silage quality with less extent to acetic acid and succinic acid at low moisture level than non-inoculated silages. Notably, the addition of mixed strains of KCC-37 and KCC-38 more potentially enhanced acidification of silage and organic acid productions than the single-culture inoculation. The overall data suggested that these strains could be used as an additive for improving the quality of the fermentation process in low moisture silage with significant probiotic characteristics.

Response of Soil Respiration and Microbial Biomass to Soil Salinity under Different Water Content in the Coastal Areas of Eastern China

Knowledge concerning the response of soil carbon transformation to soil moisture and salinity is essential for saline soil improvements and utilization. An incubation experiment with three moisture levels (50, 75 and 100% of field capacity) and six salinity levels (soil electrical conductivity of 1 : 5 soil suspension as 0.25, 1.01, 2.02, 3.21, 4.92 and 6.17 dS m–1 for S1, S2, S3, S4, S5 and S6 treatment) was conducted with the purpose to investigate the effect of moisture and salinity on soil respiration (SR) and soil microbial biomass carbon (SMBC). Both soil salinity and soil moisture significantly impact SR and SMBC, yet the interaction effect between them was not significant either for SR, or SMBC. SR and SMBC were found to positively correlate with soil moisture but increased first and then decreased along with increasing soil salinity with the maximum values observed at S3 and S2 salinity levels, respectively. It was found significantly higher at S1 or S2 than at S5 or S6 salinity levels. Furthermore, soil moisture was found to be the predominant factor with significant higher effect than soil salinity levels in determining the variation of SR and SMBC. The results suggested that both the active and total soil microbial communities slightly increased when soil salinity was low (0.25 to 1.01 or 2.02 dS m–1), while they were adversely affected by higher salinity (4.92 and 6.17 dS m–1). In addition, the reduction in SR at high salinity and low moisture levels is mostly caused by reduction in SMBC as it was found significantly correlated to SR.

Monitored conditions in wooden wall plates in relation to mold and wood decaying fungi

In historic masonry buildings, wood can be embedded in the walls as storey partition beams, or as supportive wall plates. Half-timbered masonry constructions, or wooden frames, e.g. combined with internal insulation, are other examples of wooden elements. Wood decaying fungi can cause serious damage to wood, which may lose mass and strength, ultimately yielding the risk of collapse. In addition, some fungal species may even be hazardous for occupants. All wood decaying fungi depend on favorable moisture and temperature conditions, although the threshold conditions may vary with various fungal species and types, and state of the wood. To predict the risk of occurrence of wood rot, several models have been developed, however most of these are based on a limited number of experiments, or very specific cases. For these reasons, the applicability of the models to other scenarios (fungal species, wood species) may not be appropriate. Furthermore, another failure mode for wood and moisture, is mold growth, which is initiated at lower moisture levels. An indication of risk of mold growth would indicate problems or risks before the initiation of wood rot. Mold growth does not deteriorate the wood, but is usually equally undesired due to health concerns of occupants. For this reason, there might be places where some mold growth would be acceptable, e.g. embedded beam ends if there is no transfer of air from the moldy area to the indoor air. Therefore, risk of rot could be important. The paper investigates models for mass loss due to wood decay and mold growth based on exposure time to favorable hygrothermal conditions. The investigation is based on inspection of wood samples (wall plates) from a full-scale experimental setup of masonry with embedded wood and monitored conditions, to which the prediction models will be applied. Monitored hygrothermal conditions were implemented in mold and wood decay models, and samples were removed from the test setup. The implemented models yielded high mold index and mass loss, whereas neither mold nor decay was observed in the physical samples. Results indicate that the implemented models, in these cases appear to overestimate the risks of mold and rot in the supportive lath behind the insulation.

Change in species composition of vegetation on various-aged set-aside lands of the Volga Delta

The object of the present research is set-aside lands of various ages. The study was aimed to identify the main biological groups of weed growing on set-aside lands of the Volga Delta, which were removed from production in different years. Within the study, species composition of set-aside lands’ vegetation was defined, which amounted to 28 species and 16 families. The plant community of set-aside lands includes such large families as Asteraceae (5 species), Poaceae (4 species), Brassicaceae (3 species). It was observed that quantitative species composition of set-aside lands’ flora has been changing depending on its age: the older a set-aside land is, the less species grow there. In spring and summer seasons, ephemeral, annual and biennial weeds prevailed, while in autumn perennial plants did: the latter were estimated of 75-80%, their wet weight amounted up to 70-92% of total weight due to the plentiful growth and development of a perennial rhizome plant named Phragmites australis (Cav.) Trin. ex Steudel. The research has lasted for 10 years and allowed observing a 14-32% increase in a number of plants belonging to a xerophyte group on longstanding set-aside lands with low level of soil moisture. Agro-ecosystems of various-aged set-aside lands hosted the development of flora having different vegetative weight that is capable of accumulating solar energy. Significant amount of accumulated energy reduced the entropy of the environment and improved its ecological state. On an old-aged set-aside land, corps of perennial plants vegetating for a long time have been maximally accumulating energy and gained 25712.42 MJ/ha.

Nine years of in situ soil warming and topography impact the temperature sensitivity and basal respiration rate of the forest floor in a Canadian boreal forest.

The forest floor of boreal forest stores large amounts of organic C that may react to a warming climate and increased N deposition. It is therefore crucial to assess the impact of these factors on the temperature sensitivity of this C pool to help predict future soil CO2 emissions from boreal forest soils to the atmosphere. In this study, soil warming (+2-4°C) and canopy N addition (CNA; +0.30-0.35 kg·N·ha-1·yr-1) were replicated along a topographic gradient (upper, back and lower slope) in a boreal forest in Quebec, Canada. After nine years of treatment, the forest floor was collected in each plot, and its organic C composition was characterized through solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Forest floor samples were incubated at four temperatures (16, 24, 32 and 40°C) and respiration rates (RR) measured to assess the temperature sensitivity of forest floor RR (Q10 = e10k) and basal RR (B). Both soil warming and CNA had no significant effect on forest floor chemistry (e.g., C, N, Ca and Mg content, amount of soil organic matter, pH, chemical functional groups). The NMR analyses did not show evidence of significant changes in the forest floor organic C quality. Nonetheless, a significant effect of soil warming on both the Q10 of RR and B was observed. On average, B was 72% lower and Q10 45% higher in the warmed, versus the control plots. This result implies that forest floor respiration will more strongly react to changes in soil temperature in a future warmer climate. CNA had no significant effect on the measured soil and respiration parameters, and no interaction effects with warming. In contrast, slope position had a significant effect on forest floor organic C quality. Upper slope plots had higher soil alkyl C:O-alkyl C ratios and lower B values than those in the lower slope, across all different treatments. This result likely resulted from a relative decrease in the labile C fraction in the upper slope, characterized by lower moisture levels. Our results point towards higher temperature sensitivity of RR under warmer conditions, accompanied by an overall down-regulation of RR at low temperatures (lower B). Since soil C quantity and quality were unaffected by the nine years of warming, the observed patterns could result from microbial adaptations to warming.