Effects of climate change on vegetation and snow cover area in Gilgit Baltistan using MODIS data.

The Hindukush-Karakoram-Himalaya (HKH) mountain ranges are the sources of Asia's most important river systems, which provide fresh water to 1.4 billion inhabitants in the region. Environmental and socioeconomic conditions are affected in many ways by climate change. Globally, climate change has received widespread attention, especially regarding seasonal and annual temperatures. Snow cover is vulnerable to climate warming, particularly temperature variations. By employing Moderate Resolution Imaging Spectroradiometer (MODIS) datasets and observed data, this study investigated the seasonal and interannual variability using snow cover, vegetation and land surface temperature (LST), and their spatial and temporal trend on different elevations from 2001 to 2020 in these variables in Gilgit Baltistan (GB), northern Pakistan. The study region was categorized into five elevation zones extending from < 2000 to > 7000 masl. Non-parametric Mann-Kendall trend tests and Sen's slope estimates indicate snow cover increases throughout the winter, but decreases significantly between June and July. In contrast, GB has an overall increasing annual LST trend. Pearson correlation coefficient (PCC) reveals a significant positive relationship between vegetation and LST (PCC = 0.73) and a significant negative relationship between LST and snow cover (PCC = - 0.74), and vegetation and snow cover (PCC = - 0.78). Observed temperature data and MODIS LST have a coefficient of determination greater than 0.59. Snow cover decreases at 3000-2000 masl elevations while increases at higher 5000 masl elevations.The vegetation in low and mid-elevation < 4000 masl zones decreases significantly annually. The temperature shows a sharply increasing trend at lower 2000-3000 masl elevations in the autumn, indicating the shifting of the winter seasons at this elevation zone. These findings better explain the spatiotemporal variations in snow cover, vegetation, and LST at various elevation zones and the interactions between these parameters at various elevations across the HKH region.

Effects of establishing cultivated grassland on soil organic carbon fractions in a degraded alpine meadow on the Tibetan Plateau.

Background: The degradation of alpine meadows has induced substantial losses of soil organic carbon (SOC) on the Tibetan Plateau. A commonly-used method for rehabilitating degraded alpine meadows in this region is establishing cultivated grasslands through sowing seed mixtures, but its impact on the biochemical stability of SOC has remained inadequately explored. Methods: In this study, a total of 20 composited 0-20 cm soil samples were collected from a heavily degraded alpine meadow (DM) and three adjacent cultivated grasslands established for 3 years (CG3), 12 years (CG12), and 17 years (CG17) on the eastern Tibetan Plateau, and the SOC pool was separated into labile C pool I (LOC I), labile C pool II (LOC II), and recalcitrant C pool (ROC) in order to investigate changes in contents of SOC fractions that have different biochemical stabilities after the establishment of cultivated grassland. Results: Although the establishment of cultivated grasslands led to increases in soil total organic C content, the increase was only significant in samples with 17 years of cultivation. We found that the contents of the three SOC fractions were higher at CG3 and CG12 compared with those in the DM, and the differences were only significant for soil LOC II. By comparison, 17 years of cultivation led to significant increases in all of the SOC fraction contents. The results implied that different cultivation years had distinct impacts on SOC fractions in cultivated grasslands, and longer cultivation years contributed to accumulated soil ROC. The recalcitrance index of SOC in the DM was higher than that at CG3 and CG12, but lower than that at CG17. This was possibly due to the generally low litter quality of cultivated grasslands, which led to a slow release of complex compounds to soils. Moreover, it was observed that soil C:N ratio was a potential indicator of SOC biochemical stability because of their close correlation. Conclusions: Our findings suggest that the long-term establishment of cultivated grasslands on DM is a promising solution to recovering both the quantity and stability of SOC on the Tibetan Plateau.

[Spatio-temporal characteristics of the matching degree of water, soil, and heat resources based on ecosystem services in Central Asia]. / åŸºäºŽç”Ÿæ€ç³»ç»ŸæœåŠ¡çš„ä¸­äºšæ°´åœŸçƒ­èµ„æºåŒ¹é åº¦æ—¶ç©ºå˜åŒ–ç‰¹å¾.

The status of matching degree among water, soil, and heat resources determines ecosystem stability and sustainability. Under the framework of ecosystem services related to human well-being, we constructed the matching index of water, soil, and heat resources in Central Asia by the vegetation net primary productivity (NPP) index method based on remote sensing data. We analyzed the spatio-temporal characteristics of the matching degree in Central Asia, and correlations between the matching degree and climatic factors, water use efficiency using trend analysis and the Hurst index. The results showed that the matching degree of water, soil, and heat resources was generally low in Central Asia with a mean value of 9.3. There were obvious differences in the mat-ching degree in different biomes, with the order of alpine forest region > alpine meadow region > typical steppe region > desert steppe region > lake > desert region. From 2000 to 2015, the matching degree of water, soil, and heat resources in each biome and in the whole Central Asia showed a fluctuating downward trend. However, the matching degree changed slightly, with relatively poor persistence. There was a large difference and misalignment of spatial variation in temperature and precipitation, which was the main cause of low matching degree of water, soil, and heat resources. The effect of precipitation on the matching degree of water, soil, and heat resources in Central Asia was stronger than that of the temperature. There was a strong correlation between the matching degree and water use efficiency in Central Asia.

Dietary guanidinoacetic acid improves the growth performance and skeletal muscle development of finishing pigs through changing myogenic gene expression and myofibre characteristics.

This study aimed to evaluate the effects of dietary guanidine acetic acid (GAA) supplementation on growth performance, carcass traits and the expression of muscle growth-related genes in finishing pigs. A total of 128 (81.03 ± 1.09 kg body weight) crossbred pigs (Duroc × Landrace ×Yorkshire) were blocked by body weight and allotted to 16 pens (eight pigs per pen), and pens were randomly assigned within blocks to one of five dietary treatments, with a basal diet (control group) or a basal diet supplemented with 0.03%, 0.06% and 0.09% GAA respectively. During the 60-day trial, GAA increased the average dairy gain (ADG) and average daily feed intake (ADFI) (p < .05). The back fat thickness of pigs fed 0.06% GAA was lower than other groups (p < .05). Pigs fed 0.06% GAA had improved lean meat percentage, loin muscle area, shear force and cross-sectional area of muscle fibre in comparison with control group (p < .05). The drop loss and the muscle fibre density in pigs fed 0.06% GAA were lower than control (p < .05). In addition, dietary GAA enhanced the expression of myosin heavy chain gene (MYH4), myogenic determination (Myod) and myogenic factor 5 (Myf5) in longissimus dorsi and carnitine palmitoyltransferase-1(CPT-1) in liver (p < .05). Meanwhile, GAA decreased the expression of Myostatin in longissimus dorsi and fatty acid synthase (FAS) in liver (p < .05). In conclusion, our results showed that appropriate dietary GAA supplementation (0.06%) promotes skeletal muscle development through changing myogenic gene expression and myofibre characteristics.

Estimating landslides vulnerability in Rwanda using analytic hierarchy process and geographic information system.

Landslides are among hazards that undermine the social, economic, and environmental well-being of the vulnerable community. Assessment of landslides vulnerability reveals the damages that could be recorded, estimates the severity of the impact, and increases the preparedness, response, recovery, and mitigation as well. This study aims to estimate landslides vulnerability for the western province of Rwanda. Field survey and secondary data sources identified 96 landslides used to prepare a landslides inventory map. Ten factors-altitude, slope angles, normalized difference vegetation index (NVDI), land use, distance to roads, soil texture, rainfall, lithology, population density, and possession rate of communication tools-were analyzed. The Analytical Hierarchy Process (AHP) model was used to weight and rank the vulnerability conditioning factors. Then the Weighted Linear Combination (WLC) in geographic information system (GIS) spatially estimated landslides vulnerability over the study area. The results indicated the altitude (19.7%), slope angles (16.1%), soil texture (14.3%), lithology (13.5%), and rainfall (12.2%) as the major vulnerability conditioning parameters. The produced landslides vulnerability map is divided into 5 classes: very low, low, moderate, high and very high. The proposed method is validated by using the relative landslides density index (R-index) method, which revealed that 35.4%, 25%, and 23.9% of past landslides are observed within moderate, high, and very high vulnerability zones, respectively. The consistency of validation indicates good performance of the methodology used and the vulnerability map prepared. The results can be used by policy makers to recognize hazard vulnerability lessening and future planning needs. Integr Environ Assess Manag 2019;00:000-000. © 2019 SETAC.

Impact of biochar application on yield-scaled greenhouse gas intensity: A meta-analysis.

The application of biochar to agricultural ecosystems is a potential solution to mitigate climate change and guarantee food security. However, the impacts of biochar on greenhouse gas emissions and crop yield are usually evaluated separately and the results are contradictory in individual studies. In this study, a meta-analysis was conducted based on data from 28 peer-reviewed studies to quantify the impacts of biochar application on greenhouse gas emissions and crop yield using yield-scaled greenhouse gas intensity (GHGI). Potential factors (experimental conditions and properties of soil and biochar) influencing the effect of biochar on yield-scaled GHGI were explored. The results showed that overall, biochar significantly reduced yield-scaled GHGI by 29%. The reductions in yield-scaled GHGI induced by biochar varied with different experimental conditions and properties of soil and biochar. However, the difference was only significant between the two cropping systems, with significantly greater reduction being observed in dry lands (-41%) than in paddy fields (-17%). Therefore, it is suggested that biochar amendment in dry lands may bring more environmental and agronomic benefits than that in paddy fields. The response of crop yield to biochar application further implied that biochar made from crop residue, biochar produced at low pyrolysis temperatures (≤400 °C), and biochar with high pH (>9.0) might contribute to save the production cost of biochar while promoting crop yield in agricultural ecosystems. Long-term field trials are required to elucidate the persistence of the impact of biochar on reducing yield-scaled GHGI and to clarify the underlying mechanisms. The balance between the price of biochar production and the benefits brought by biochar should also be focused in further studies.

Dynamics of soil carbon and nitrogen stocks after afforestation in arid and semi-arid regions: A meta-analysis.

Arid and semi-arid regions store approximately 27% of global soil organic carbon (SOC), thus playing an important role in the global carbon cycle. Although afforestation is widely used to achieve the goals of landscape protection and ecological restoration in these regions, its effects on the dynamics of SOC and total nitrogen (TN) stocks as well as the related controlling factors are still poorly understood. In this study, a meta-analysis was conducted by compiling results from published studies to evaluate the influences of afforestation on dynamics of SOC and TN stocks in mineral soils (0-30cm) in arid and semi-arid regions, and to examine whether the changes in SOC and TN stocks were influenced by prior land-use, planted tree species and plantation age. The results showed that overall, afforestation significantly increased SOC stock by 131% and TN stock by 88%. Prior land-use was found to be the most important factor that influenced the dynamics of SOC and TN stocks following afforestation. Significantly larger increases in SOC and TN stocks were observed after barren land afforestation in comparison to cropland and grassland afforestation. The accumulations in SOC and TN stocks after afforestation decreased in the following order: broadleaf deciduous forests>coniferous forests>broadleaf evergreen forests. However, significant differences in SOC and TN accumulations were only detected between broadleaf deciduous forests and broadleaf evergreen forests. Plantation age did not affect the dynamics of SOC and TN stocks after afforestation, mainly due to the rapid accumulations in SOC and TN after barren land afforestation. The results indicate that afforestation, especially on barren land with broadleaf deciduous species, provides substantial opportunities for SOC and TN sequestrations in arid and semi-arid regions.

Land-use impacts on profile distribution of labile and recalcitrant carbon in the Ili River Valley, northwest China.

There is a growing evidence that the decomposition of recalcitrant carbon (C) can be stimulated by environmental changes, such as fresh C supply and increased temperature. However, the effect of land-use on profile distribution of recalcitrant C content is still poorly understood. In this study, soil samples were collected to a depth of 100cm from pastures and four major croplands including maize field, wheat field, paddy and apple orchard in the Ili River Valley, northwest China, to investigate the effects of land-use on profile distribution of labile organic C (LOC), semi-labile organic C (SLOC), recalcitrant organic C (ROC) and their relative proportions in total organic C (TOC), and evaluate whether such effects can be different between topsoil (0-20cm) and subsoil (20-100cm). The results showed that soil ROC accounting for 49.4-66.3% of TOC for different land-uses, implying that ROC is the major form of soil organic C (SOC). Soil TOC contents of croplands were 20.4-85.2% lower than those of pastures along the soil profile, indicating that SOC pool may be decreased by agricultural land-uses. The lower contents of LOC, SLOC and ROC in croplands than in pastures suggested that the decreases in TOC content in croplands are not only due to the decreases in labile C pool but also the reductions in recalcitrant C pool. The differences in SOC fractions among land-uses were similar in topsoil and subsoil, while the proportions of each SOC fraction in TOC did not differ significantly between the two soil layers in most cases, indicating that each SOC fraction in subsoil can be also influenced by land-use types. Therefore, it is suggested that the ROC in subsoil, which plays a crucial role in C sequestration, should be taken into account when estimating the effect of land-use on SOC kinetic.

Response of N2O emissions to biochar amendment in a cultivated sandy loam soil during freeze-thaw cycles.

In the last decade, an increasing number of studies have reported that soil nitrous oxide (N2O) emissions can be reduced by adding biochar. However, the effect of biochar amendment on soil N2O emissions during freeze-thaw cycle (FTC) is still unknown. In this laboratory study, biochar (0%, 2% and 4%, w/w) was added into a cultivated sandy loam soil and then treated with 15 times of FTC (each FTC consisted of freeze at -5/-10 °C for 24 h and thaw at 5/10 °C for 24 h), to test whether biochar can mitigate soil N2O emissions during FTC, and estimate the relationships between N2O emissions and soil inorganic nitrogen contents/microbial biomass content/enzyme activities. The results showed that biochar amendment suppressed soil N2O emissions by 19.9-69.9% as compared to soils without biochar amendment during FTC. However, N2O emissions were only significantly correlated to soil nitrate nitrogen (NO3--N) contents, which decreased after biochar amendment, indicating that the decreased soil nitrification by adding biochar played an important role in mitigating N2O emissions during FTC. Further studies are needed to estimate the effectiveness of biochar amendment on reducing freeze-thaw induced N2O emissions from different soils under field conditions.

[Spatial distribution characteristics of the physical and chemical properties of water in the Kunes River after the supply of snowmelt during spring].

Eight physical and chemical indicators related to water quality were monitored from nineteen sampling sites along the Kunes River at the end of snowmelt season in spring. To investigate the spatial distribution characteristics of water physical and chemical properties, cluster analysis (CA), discriminant analysis (DA) and principal component analysis (PCA) are employed. The result of cluster analysis showed that the Kunes River could be divided into three reaches according to the similarities of water physical and chemical properties among sampling sites, representing the upstream, midstream and downstream of the river, respectively; The result of discriminant analysis demonstrated that the reliability of such a classification was high, and DO, Cl- and BOD5 were the significant indexes leading to this classification; Three principal components were extracted on the basis of the principal component analysis, in which accumulative variance contribution could reach 86.90%. The result of principal component analysis also indicated that water physical and chemical properties were mostly affected by EC, ORP, NO3(-) -N, NH4(+) -N, Cl- and BOD5. The sorted results of principal component scores in each sampling sites showed that the water quality was mainly influenced by DO in upstream, by pH in midstream, and by the rest of indicators in downstream. The order of comprehensive scores for principal components revealed that the water quality degraded from the upstream to downstream, i.e., the upstream had the best water quality, followed by the midstream, while the water quality at downstream was the worst. This result corresponded exactly to the three reaches classified using cluster analysis. Anthropogenic activity and the accumulation of pollutants along the river were probably the main reasons leading to this spatial difference.

A comparison of the potential health risk of aluminum and heavy metals in tea leaves and tea infusion of commercially available green tea in Jiangxi, China.

Heavy metals and Al in tea products are of increasing concern. In this study, contents of Al, Cd, Co, Cr, Cu, Ni, and Pb in commercially available green tea and its infusions were measured by ICP-MS and ICP-AES. Both target hazard quotient (THQ) and hazard index (HI) were employed to assess the potential health risk of studied metals in tea leaves and infusions to drinkers. Results showed that the average contents of Al, Cd, Co, Cr, Cu, Ni, and Pb in tea leaves were 487.57, 0.055, 0.29, 1.63, 17.04, 7.71, and 0.92 mg/kg, respectively. Except for Cu, metal contents were within their maximum limits (1, 5, 30, and 5 mg/kg for Cd, Cr, Cu, and Pb, respectively) of current standards for tea products. Concentrations of metals in tea infusions were all below their maximum limits (0.2, 0.005, 0.05, 1.0, 0.02, and 0.01 mg/L for Al, Cd, Cr(VI), Cu, Ni, and Pb, respectively) for drinking water, and decreased with the increase of infusion times. Pb, Cd, Cu, and Al mainly remained in tea leaves. The THQ from 2.33 × 10(-5) to 1.47 × 10(-1) and HI from1.41 × 10(-2) to 3.45 × 10(-1) values in tea infusions were all less than 1, suggesting that consumption of tea infusions would not cause significant health risks for consumers. More attention should be paid to monitor Co content in green tea. Both THQ and HI values decreased with the increase of infusion times. Results of this study suggest that tea drinkers should discard the first tea infusion and drink the following infusions.

Greenhouse gas emissions from cotton field under different irrigation methods and fertilization regimes in arid northwestern China.

Drip irrigation is broadly extended in order to save water in the arid cotton production region of China. Biochar is thought to be a useful soil amendment to reduce greenhouse gas (GHG) emissions. Here, a field study was conducted to compare the emissions of nitrous oxide (N2O) and methane (CH4) under different irrigation methods (drip irrigation (D) and furrow irrigation (F)) and fertilization regimes (conventional fertilization (C) and conventional fertilization + biochar (B)) during the cotton growth season. The accumulated N2O emissions were significantly lower with FB, DC, and DB than with FC by 28.8%, 36.1%, and 37.6%, while accumulated CH4 uptake was 264.5%, 226.7%, and 154.2% higher with DC, DB, and FC than that with FB, respectively. Irrigation methods showed a significant effect on total global warming potential (GWP) and yield-scaled GWP (P < 0.01). DC and DB showed higher cotton yield, water use efficiency (WUE), and lower yield-scaled GWP, as compared with FC and FB. This suggests that in northwestern China mulched-drip irrigation should be a better approach to increase cotton yield with depressed GHG. In addition, biochar addition increased CH4 emissions while it decreased N2O emissions.

A survey on the heavy metal contents in Chinese traditional egg products and their potential health risk assessment.

Pb, Zn and Cu were determined in 35 Preserved Egg (PE) samples, 25 Salted Egg (SE) samples and 40 Egg Preserved in Rice Wine (EPRW) samples collected from Jiangxi province by ICP-MS. The corresponding health risk for consumers was assessed by the target hazard quotients (THQ) and hazard index (HI). Average Pb, Zn and Cu content in all samples was 0.125 mg/kg, 10.939 mg/kg and 2.094 mg/kg, respectively. Average Pb content in PE was significantly higher than in SE and EPRW. THQ and HI values were less than 1, indicating that intake of heavy metals from PE, SE and EPRW will not pose a significant hazard risk to humans. However, more attention should be paid to control the ingestion by PE, which is the main source of Pb, Zn and Cu for consumers among these three egg products.

Impacts of nomad sedentarization on social and ecological systems at multiple scales in Xinjiang Uyghur autonomous region, China.

China's government is now promoting the Nomad Sedentarization Project (NSP) in large areas of grassland as a solution for ecological restoration and poverty alleviation. To examine the effects of this policy, we conducted in-depth interviews at two of the project's sites and examined the social and ecological systems at village, county, and catchment scales in Jinghe County of Xinjiang. We found that (1) the NSP in one village greatly improved the household standard of living and changed their resource utilization modes; (2) the success in this village can be attributed to resources imported from the social and ecological systems at larger scales, and could not be repeated in a second nearby village with different constraints; and (3) the NSP is poorly adapted to local ecosystem characteristics, and may therefore have negative impacts at larger scales. To avoid these problems, holistic assessments are necessary to judge the NSP's impacts on social and ecological systems at multiple scales, and the program must be implemented cautiously to account for the potential risks in ecologically vulnerable areas.

Dynamic analysis of QTLs on tiller number in rice (Oryza sativa L.) with single segment substitution lines.

Twelve single segment substitution lines (SSSLs) in rice, which contain quantitative trait loci (QTLs) for tiller number detected previously, were used to study dynamic expression of the QTLs in this study. These SSSLs and their recipient, Hua-Jing-Xian 74 (HJX74), were used to produce 78 crossing combinations first, and then these combinations and their parents were grown in two planting seasons with three cropping densities. Tiller number was measured at seven developmental stages. QTL effects including main effects (additive, dominance and epistasis), QTL × season and QTL × density interaction effects were analyzed at each measured stage. The additive, dominant and epistatic effects of the 12 QTLs as well as their interaction effects with the seasons and with the densities all display dynamic changes with the development. Eight QTLs are detected with significant additive effects and/or additive × season and/or additive × density interaction effects at least at one developmental stage, and all QTLs have significant dominant and epistatic effects and/or interaction effects involved in. For most of the QTLs dominant effects are much bigger than additive effects, showing overdominance. Each QTL interacts at least with eight other QTLs. Additive and dominant effects of these QTLs are mostly positive while epistatic effects are negative and minor. Most of the QTLs show significant interactions with planting seasons and cropping densities, but the additive effects of QTLs Tn3-1 and Tn3-2, the dominant effects of QTL Tn7 and Tn8, and the epistatic effects of 14 pairs of QTLs are stable across seasons and the dominant effect of QTL Tn3-3 and the epistatic effects of QTL pairs Tn2-1/Tn6-2, Tn2-1/Tn9 and Tn3-3/Tn6-3 are nearly consistent across cropping densities. This paper is the first report of dynamics on dominances and epistasis of QTLs for tiller number in rice and provides abundant information, which is useful to improve rice tiller number via heterosis and/or QTL pyramiding.

Effects of levofloxacin hydrochloride on photosystem II activity and heterogeneity of Synechocystis sp.

Effects of LH on photosynthesis of Synechocystis sp. were investigated by a variety of in vivo chlorophyll fluorescence. O2 evolution and the photosystem II (PSII) activity were clearly inhibited by LH. Exposure to LH increased the proportion of PSIIbeta and this weakened the connectivity between PSII units and hindered excitation energy-transfer between PSII units. LH decreased the density of the active photosynthetic reaction centers, inhibited electron transport, and increased the dissipated energy flux per reaction center. The inhibitory effect of LH on Q(A)(-) reoxidation process could be divided into several stages. LH first inhibited the electron transfer from Q(A)(-) to Q(B) by weakening the connectivity between Q(A)(-) and Q(B), and PQ binding began taking part in Q(A)(-) reoxidation. At the second stage, the connectivity between Q(A)(-) and PQ pool was broken and inhibition on PQ binding occurred. At this stage, some Q(A)(-) began to be oxidized by S2(Q(A)Q(B))(-). Finally, when the connectivity between Q(A)(-) and Q(B) and PQ was completely broken, all Q(A)(-) was oxidized through charge recombination.