Qilian Mountains in Northwest China is a significant ecological security barrier due to its distinctive geographic setting,which has significant biological resource and gene pool.In order to assess the soil quality an...Qilian Mountains in Northwest China is a significant ecological security barrier due to its distinctive geographic setting,which has significant biological resource and gene pool.In order to assess the soil quality and ecosystem health in this area,we identified the structural characteristics and functional groups of soil microbial communities.This study focused on Amidongsuo,a typical watershed of the Qilian Mountains,and researched the vertical distribution and dominant populations of soil microorganisms in different habitats,and the relationship between soil microorganisms and environmental factors.Soil microorganisms from three grassland plots,five shrubland plots,and five forest plots in Amidongsuo were studied using high-throughput sequencing.The Venn diagram showed that the types of bacteria were fewer than those of fungi in Amidongsuo.Soil bacteria Acidobacteriota,Proteobacteria,and Methylomirabilota as well as fungi Basidiomycota,Ascomycota,and Mortierellomycota played dominant roles in Amidongsuo,according to the LEfSe(linear discriminant analysis(LDA)effect size)and community structure analyses.According to the ANOSIM(analysis of similarities)result,for both bacteria and fungi,R values of grassland and shrubland were small(R^(2)=0.045 and R^(2)=0.256,respectively),indicating little difference between these two ecosystems.RDA(redundancy analysis)showed a closer relationship between soil nutrients and fungi,and a gradually decreasing correlation between soil nutrients and microorganisms with increasing soil depth.Bacteria were mainly affected by pH,nitrogen(N),and potassium(K),while fungi were mainly affected by K.Overall,fungi had more effect on soil quality than bacteria.Therefore,adjustment of soil K content might improve the soil environment of Amidongsuo in the Qilian Mountains.展开更多
The hydrological regime in wetlands plays an important role in the process of wintering waterbird metacommunity assemblage.However,increasing frequency of extreme climate and the intensification of human activities,su...The hydrological regime in wetlands plays an important role in the process of wintering waterbird metacommunity assemblage.However,increasing frequency of extreme climate and the intensification of human activities,such as the construction of sluices and dams,have resulted in frequently abnormal hydrological regime in the middle and lower Yangtze River floodplain.In recent years,earlier flood recession has become one of the main hydrological problems faced in the shallow lakes,having a great impact on wetland biodiversity.It is necessary to understand the impact of earlier flood recession on waterbirds,an indicator of wetland biodiversity,and the metacommunity concept is helpful to elucidate the underlying mechanism involved in the processes of assemblage by waterbird communities.In this study,we surveyed the wintering waterbirds at three sub-lakes of Caizi Lakes during 2019-2020 and 2020-2021 and compared the richness,abundance,alpha and beta diversity of waterbirds in and among local metacommunities under earlier flood recession and normal hydrological regime.The results showed that the earlier flood recession reduced the species richness in the early stage and abundance in the late stage,it also reduced the Shannon-Wiener index in the early stage and increased the dissimilarity between and within waterbird metacommunities in the late stage.The partition of beta diversity showed that the turnover component played a major role in the process of waterbird metacommunity assemblage.It was found that the earlier flood recession reduced the richness,abundance in different stages of flood recession,which also increased the turnover of waterbirds.Metacommunities with high habitat heterogeneity had better resistance to abnormal hydrological regime,which resulted in high dissimilarity between and within metacommunities.The results of this study provide important information for waterbird conservation and water level management at shallow lakes in the middle and lower Yangtze River floodplain.展开更多
Dongtian Park is a forest park in Dongtian Lake Ecological Tourism Resort in Meizhou City,South China.Through investigation and analysis of sample methods of the forest community structure and plant diversity in this ...Dongtian Park is a forest park in Dongtian Lake Ecological Tourism Resort in Meizhou City,South China.Through investigation and analysis of sample methods of the forest community structure and plant diversity in this park,the results showed that there were 181 plant species,belonging to 138 genera in 76 families,including 48 trees,60 shrubs,36 herbs and 37 lianas.The flora is a subtropical evergreen broad-leaved forest with some distinct tropical properties,and evergreen trees accounted for 48.62%of total plant species.The dominant species in the tree layer were Schima superba,Pinus massoniana,Cinnamomum parthenoxylon,etc.,and those in the shrub layer were Bambusa textilis,Aidia cochinchinensis,Rhaphiolepis indica,etc.,and in herb layer were Carex baccans,Adiantum flabellulatum,Cibotium barometz,etc.,and the lianas mainly included Smilax hypoglauca,Callerya dielsiana,Trachelospermum jasminoides,etc.There were few adults of dominant species in the tree layer,S.superba and P.massoniana also lacked seedlings,they would still maintain their dominant position for a quite long period,but Cyclobalanopsis neglecta had sufficient seedling reserves and would be most likely to become a dominant species in future.The community had relatively rich species,many ferns and lianas and complex hierarchy.The evenness,Shannon-Wiener diversity,Pielou uniformity and Simpson index were higher in the shrub layer than in the tree and herb layer,and the Simpson index was the lowest(0.9280)in the herb layer and Shannon-Wiener diversity index was the highest(7.5853)in the liana layer.展开更多
The soil microorganisms at different depths play an important role in soil formation,ecosystem biogeochemistry,recycling of nutrients,and degradation of waste products.The aims of this study were to observe the microb...The soil microorganisms at different depths play an important role in soil formation,ecosystem biogeochemistry,recycling of nutrients,and degradation of waste products.The aims of this study were to observe the microbial diversity in the profile of an agricultural soil in northern China,and to research the correlation between soil microbes and geochemistry.First,the soil geochemistry of the profile was investigated through 25 chemical elements.Secondly,the various physiological groups of microorganisms w...展开更多
DNA sequence diversities of soil microbial communities in rhizosphere and non-rhizosphere of 1 - 6 years Panax ginseng were evaluated by random amplified polymorphic DNA (RAPD). Total genomic DNA of soil samples were ...DNA sequence diversities of soil microbial communities in rhizosphere and non-rhizosphere of 1 - 6 years Panax ginseng were evaluated by random amplified polymorphic DNA (RAPD). Total genomic DNA of soil samples were amplified by twenty-four out of two hundred random primers. The products were separated in agarose gel, and 359 and 181 reliable fragments were generated, of which, 324 and 123 were polymorphic. The gene diversity index, Shannon’s information index, and similarity coefficient were calculated, and results showed that, diversity of soil microbial community at DNA level was present. Furthermore, with the increasing of P. ginseng growing at one site, deference on soil microbial community DNA sequence between rhizosphere and non-rhizosphere tend to be more and more significant. In addition, RAPD technique was proved to be an effective tool to assess the diversity of soil microbial communities. From results we deduced that, the ecological function that performed by soil microbes may changed following the change of microbial community in rhizospheric and non-rhizospheric soils, and finally broke the balance of soil nutrition and energy cycle, soil spatial structure, microbial ecology etc.展开更多
An understanding of soil microbial communities is crucial in roadside soil environmental assessments.The 16S rRNA se quencing of a stressed microbial community in soil adjacent to the Qinghai-Tibet Highway(QTH)reveale...An understanding of soil microbial communities is crucial in roadside soil environmental assessments.The 16S rRNA se quencing of a stressed microbial community in soil adjacent to the Qinghai-Tibet Highway(QTH)revealed that the accu mulation of heavy metals(over about 10 years)has affected the diversity of bacterial abundance and microbial community structure.The proximity of a sampling site to the QTH/Qinghai-Tibet Railway(QTR),which is effectively a measure of the density of human engineering,was the dominant factor influencing bacterial community diversity.The diversity of bacterial communities shows that 16S rRNA gene abundance decreased in relation to proximity to the QTH and QTR in both alpine wetland and meadow areas.The dominant phyla across all samples were Actinobacteria and Proteobacteria.The concentration of Cr and Cd in the soil were positively correlated with proximity to the QTH and QTR(MC/WC sam pling sites),and Ni,Co,and V were positively correlated with proximity to the QTH and QTR(MA/WA sampling sites).The results presented in this study provide an insight into the relationships among heavy metals and soil microbial commu nities,and have important implications for assessing and predicting the impacts of human-induced activities from the QTH and QTR in such an extreme and fragile environment.展开更多
The sediment samples were collected from Maluku Strait at a depth of 1250 m, which is influenced by Mindanao Current and Indonesian Throughflow. Based on 16S rRNA clone libraries, the community structure and vertical ...The sediment samples were collected from Maluku Strait at a depth of 1250 m, which is influenced by Mindanao Current and Indonesian Throughflow. Based on 16S rRNA clone libraries, the community structure and vertical distribution of archaea and bacteria were studied in a columnar sediment of 2m in length. From the surface sediment, 16S sequences were derived from fourteen bacterial phyla (Gammaproteobacteria, Planctomycetes, Alphaproteobacteria, Deltproteobacteria were dominant), but were limited to two groups of archaea: Crenarchaeota (99%) and Euryarchaeota (1%). Besides, 90% of the archaea clones were ammonia oxidation-related which indicated that the ammonia-oxidizing archaea might make a significant contribution to the chemosynthesis in the surface sediment. Contrastively in the bottom sediment, six bacterial phylogenetic groups were obtained (Gammaproteobacteria and Firmicutes were absolutely dominant), however no archaea 16S rRNA was detected. The microbial diversity of surface sediment was much higher than the bottom and seven unique bacterial phyla were obtained from two sediment respectively. The geochemical elements analysis revealed that the content of C, TOC and S in the surface sediment was much higher than the bottom, but the content of P is contrary. The microbial communities might be in response to the geochemical substance transfer and deposit influenced by the ocean current and it deserves further study compared with the other sediment samples in this area.展开更多
The influencing factors of soil microbial community under conservation tillage system were summarized,the changes of soil microbial community under conservation tillage system and the general situation of soil microbi...The influencing factors of soil microbial community under conservation tillage system were summarized,the changes of soil microbial community under conservation tillage system and the general situation of soil microbial community research under rotation system were analyzed,and the contents of soil microbial community need to be future studied were prospected.展开更多
The status of fishery stocks in the coastal waters of China is far from ideal, mainly due to climate change and the impacts of human activities (e.g., pollution and overfishing). Thus, the restoration and protection o...The status of fishery stocks in the coastal waters of China is far from ideal, mainly due to climate change and the impacts of human activities (e.g., pollution and overfishing). Thus, the restoration and protection of fishery resources have become critical and complex. The stability and balanced structure of the fish community is a basic foundation for the protection of fishery resources. Based on data collected from bottom trawls by the R/V Beidou in continental shelf of the East China Sea in November 2006 and February 2007, changes in the composition and diversity of fish species and functional groups were analyzed. The research area was divided into offshore waters and inshore waters by the two-way indicator species analysis (TWIA). The results showed that the dominant species were different between offshore waters and inshore waters and also varied with the survey time. The most abundant family was Sciaenidae and Teraponidae in November 2006, Sciaenidae, Engraulidae and Triglidae were most abundant in February 2007. The species belonged mainly to mobile piscivores (G6), benthivores/piscivores (G4), benthivores (G3) and planktivores (G1), and the dominant species in November 2006 were commercial species (e.g. Larimichthys polyactis and Trichiurus japonicus), but small-sized species were dominant in February 2007 (e.g., Harpadon nehereus, Benthosema pterotum, Champsodon capensis, and Acropoma japonicum). The species diversity showed a similar trend as the functional group diversity. Stations with higher diversity were mainly distributed in inshore waters in February 2007, whereas higher diversity was found in offshore waters in November 2006. The highest biomass and species number were found in G6 group, followed by the G4, G5 and G1 groups. The distribution of the number of individuals of each functional group showed the opposite trend as that of the biomass distribution. In addition, the size spectra were mainly concentrated around 3-29 cm, and the individual number of fish species gradually decreased with the increase in body size, but the relative biomass showed a moderate fluctuation in each size class. These changes showed that species with faster growth rate and earlier maturity age became dominant in continental shelf of the East China Sea. So the variations in biological characteristics of fish should be fully considered in maintaining sustainable utilization of fishery resource.展开更多
Fermented foods play an important role in the daily life and diet of the populations in Congo. Among these fermented foods, there is Pilipili or fermented </span><span style="font-family:Verdana;"&g...Fermented foods play an important role in the daily life and diet of the populations in Congo. Among these fermented foods, there is Pilipili or fermented </span><span style="font-family:Verdana;">pepper which is consumed without prior cooking. The microorganisms</span><span style="font-family:Verdana;"> present are eaten alive. Few studies have been carried out on these microorganisms which may have beneficial effects on health. This study aimed to investing taxonomic diversity of bacterial communities in 3 samples of fermented peppers produced in 3 distinct areas of Brazzaville. To do this investigation, Illumina Miseq sequencing of 16S rRNA gene was used. The results showed that the number of identified operational taxonomic units (OTUs) ranged from 156 to 392. All OTUs belong to the domain of Bacteria and could be categorized into 21 Phyla, 36 Classes, 58 Orders, 100 Families and 171 genera. Firmicutes and Proteobacteria were the main dominant phyla of the total phyla present with a relative abundance of 89.12% and 8.08%, respectly. At the class level, Bacili were dominant in EB1 (99.50%), EB3 (85.32%) and EB2 (42.29%) while Clostridia in EB2 (40.10%). Lactobacillus, Clostridium sensu stricto and Frutobacillus were the dominant genera in the sample EB1, EB2 and EB3, respectively. The hierarchical classification showed that the samples EB1 and EB2 form the same group and EB3 is unique. Principal component analysis showed that the younger EB3 and EB2 samples were more diverse than the older EB1 sample. This study is a first in Congo on the diversity of fermented pepper using Illumina Miseq. It has shown that this food is very diverse and can be a source for the isolation of bacteria with biotechnological potential.展开更多
Glacial meltwater runoff is a dynamic ecosystem.On the one hand,nutrient concentration changes as it flows from upstream to downstream,and on the other hand,bacterial community structure changes due to its contact wit...Glacial meltwater runoff is a dynamic ecosystem.On the one hand,nutrient concentration changes as it flows from upstream to downstream,and on the other hand,bacterial community structure changes due to its contact with nearby soil during the flow process.We studied meltwater and soil in the Midre Lovénbreen glacier region,to explore changes in bacterial diversity as meltwater flows,and the relationship between meltwater and soil bacterial diversity.As glacial meltwater flows from upstream to downstream,the relative abundance of dominant bacterial groups changes.In addition,we found that during the flowing process,nutrient exchange and bacterial contact had occurred between the meltwater runoff and the soil.As a result,the distribution patterns of some bacteria in the meltwater are very similar to those in the soil.Finally,we combined distance-based redundancy analysis and weighted correlation network analysis to show that NO_(3)^(-)-N and NO_(2)^(-)-N are the most two significant factors affecting glacial meltwater and soil,respectively.Our results suggest that in such a close-knit ecosystem,the interaction of glacial meltwater with soil,as well as environmental factors,together determine bacterial community composition.展开更多
Timely removal of the flower is a key agricultural measure to ensure the concentrated supply of nutrients for the growth of underground bulbs and to increase the yield of lilies. Removing flowers and returning them to...Timely removal of the flower is a key agricultural measure to ensure the concentrated supply of nutrients for the growth of underground bulbs and to increase the yield of lilies. Removing flowers and returning them to the field is one of the tradi‐tional ways of treatment, and field litter is formed at this time. Previous study showed that the decomposition of litter changes the soil properties. In order to study the effects of lily litter decomposition on soil physical and chemical proper‐ties and microbial structure, three treatments were set up in reference to the Decomposition Bag Method: control (CK), Lanzhou lily flower treatment (LZF), and Zhongbai No.1 flower treatment (ZBF). The effects of lily decomposition on soil physical and chemical properties and microbial community composition were studied in order to provide a scientific basis and theoretical guidance for the planting process of Lanzhou lily. The results show that the decomposition of lily flowers significantly increased the contents of soil organic matter, soil total nitrogen, soil total phosphorus and soil avail‐able potassium, and decreased soil pH. RDA shows that soil available nutrients and pH were the driving factors for the change of the soil microbial community. A short-term change of soil microenvironment caused by the decomposed lily flower is beneficial to growing the Lanzhou lily. However, under the correlation analysis of environmental factors, the long-term effects of returning the Lanzhou lily flower to the field, such as the trend of soil acidification, need to be further studied.展开更多
Pandé is a Congolese fermented food produced from fruit pulps of raffia palm. The aim of this study was to explore the diversities in bacterial communities in the unfermented pulps (control) (PNFL) and fermented ...Pandé is a Congolese fermented food produced from fruit pulps of raffia palm. The aim of this study was to explore the diversities in bacterial communities in the unfermented pulps (control) (PNFL) and fermented pulps obtained from fruits using boiling (PMF) and purchased at markets in Brazzaville (PFL) and using Illumina MiSeq<sup>TM</sup> sequencing of 16S rRNA gene. A total number of 157,054 sequences was obtained and grouped into 737 operational taxonomic units (OTUs). These were classified into 13 phyla, 26 classes, 48 orders, 96 families and 176 genera. At the phylum level, the most frequent bacterial communities were: for PFM, Proteobacteria (38.94%) and Firmicutes (19.37%);for PFL, Firmicutes (69.10%) and Proteobacteria (30.89%);for PNFL, Firmicutes (84.92%) and Proteobacteria (14.22%). were the most frequent in PFL, while Acidobacteria (40.02%), Proteobacteria (38.94%) and Firmicutes (19.37%) were preponderant in PFM. Firmicutes (84.92%) and Proteobacteria (14.22%) were the most common in unfermented pulps (PNFL). Lactobacillus (47.70%) and Gluconobacter genera (15.33%) were the most represented in the PFL sample. Acidipila (35.56%) and Rhizomicrobium (11.41%) were preponderant genera in the PFM sample. Weissella genus was the most frequent in the PNFL sample. Hierarchical cluster indicated that the samples could be grouped into two groups of different origins. PCA showed that main genera were higher in the fermented samples. The diversity was higher in the fermented pulps or Pandé than in the unfermented pulps. Pandé can be a potential source for the isolation of bacteria with biotechnological potential.展开更多
In this study, effect of rice added to meju dough was evaluated based on the variation of nutritional ingredients and bacterial community diversity in finished doenjang. The ratio of rice added to meju dough (cooked a...In this study, effect of rice added to meju dough was evaluated based on the variation of nutritional ingredients and bacterial community diversity in finished doenjang. The ratio of rice added to meju dough (cooked and crushed soybean before fermentation) was 0, 0.2, and 0.4 based on dry weight. Free amino acids, minerals, polyphenol, and total phenolic compounds relatively decreased by addition of rice. However, 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) scavenging and ferric ion reduction activity was not influenced. Organic acids, which are fermentation metabolites, significantly increased in proportion to percentage balance of rice. Seven and four volatile compounds (VCs) were detected in doenjang prepared without and with rice, respectively, and contents of VCs were significantly lower in the rice-supplemented doenjang. Bacterial community diversity was significantly increased by addition of rice to meju dough. Rice alters chemical composition, fermentation products, and bacterial diversity, but does not downgrade the nature of doenjang.展开更多
Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest chang...Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest changed over a 15-year period.Specifically,renewal and death of common species was large,with the renewal of individuals mainly concentrated within a few populations,especially those of Aidia canthioides and Cryptocarya concinna.The numbers of individual deaths for common species were concentrated in the small and mid-diameter level.The spatial distribution of community species diversity fluctuated in each monitoring period,showing a more dispersed diversity after the 15-year study period,and the coefficient of variation on quadrats increased.In 2010,the death and renewal of the community and the spatial variation of species diversity were different compared to other survey years.Extreme weather may have affected species regeneration and community stability in our subtropical monsoon evergreen broad-leaved forests.Our findings suggest that strengthening the monitoring and management of the forest community will help better understand the long-and short-term causes of dynamic fluctuations of community structure and species diversity,and reveal the factors that drive changes in community structure.展开更多
Since 2015, community forests have been promoted in Togo as an alternative to protect areas from degradation and as a means of contributing to forest landscape restoration. The study focuses on the Nakpadjouak Communi...Since 2015, community forests have been promoted in Togo as an alternative to protect areas from degradation and as a means of contributing to forest landscape restoration. The study focuses on the Nakpadjouak Community Forest (NCF) in Tami (Togo, West Africa) which contributes to community forests sustainable management. It aims in (i) mapping forest ecosystems and analysing their dynamic and (ii) characterizing the floristic diversity of the NCF. The ecosystems were mapped and their dynamic was evaluated based on Google Earth images of 2014 and 2020. Floristic and forestry inventories were carried out using the transect technique in a sample of 20 plots of 50 m × 20 m. The NCF was made up mainly by wooded/shrub savannahs (95.37%) and croplands/fallow (4.63%) in 2014. These two land use types undergone changes over the 6 years prior to 2020. By 2020, the NCF had 3 land use types: wooded/shrub savannahs (77.59%), open forest/wooded savannahs (22.23%), and croplands/fallows (0.18%). A total of 89 plant species belonging to 70 genera and 28 families were recorded within the NCF. The dominant species are: Heteropogon contortus (L.) P.Beauv. and Combretum collinum Fresen. followed by Pteleopsissuberosa Engl. & Diels, Annona senegalensis Pers. The most common species are: Lannea acida A.Rich. s.l., A. senegalensis, Vitellaria paradoxa C.F.Gaertner subsp. paradoxa, C. collinum and Acacia dudgeonii Craib ex Holland. Due to its small area of just 40 hectares and its diverse plant life, this community forest of Savannahs Region is a significant biodiversity hotspot and warrants conservation efforts.展开更多
The nirS-type denitrifying bacterial community is the main drivers of the nitrogen loss process in drinking water reservoir ecosystems.The temporal patterns in nirS gene abundance and nirS-type denitrifying bacterial ...The nirS-type denitrifying bacterial community is the main drivers of the nitrogen loss process in drinking water reservoir ecosystems.The temporal patterns in nirS gene abundance and nirS-type denitrifying bacterial community harbored in aerobic water layers of drinking water reservoirs have not been studied well.In this study,quantitative polymerase chain reaction(qPCR)and Illumina Miseq sequencing were employed to explore the nirS gene abundance and denitrifying bacterial community structure in two drinking water reservoirs.The overall results showed that the water quality parameters in two reservoirs had obvious differences.The qPCR results suggested that nirS gene abundance ranged from(2.61±0.12)×10^(5) to(3.68±0.16)×10^(5) copies/mL and(3.01±0.12)×10^(5) to(5.36±0.31)×10^(5) copies/mL in Jinpen and Lijiahe reservoirs,respectively.The sequencing results revealed that Paracoccus sp.,Azoarcus sp.,Dechloromonas sp.and Thauera sp.were the dominant genera observed.At species level,Cupriavidus necator,Dechloromonas sp.R-28400,Paracoccus denitrificans and Pseudomonas stutzeri accounted for more proportions in two reservoirs.More importantly,the co-occurrence network analysis demonstrated that Paracoccus sp.R-24615 and Staphylococcus sp.N23 were the keystone species observed in Jinpen and Lijiahe reservoirs,respectively.Redundancy analysis indicated that water quality(particularly turbidity,water temperature,pH and Chlorophyll a)and sampling time had significant influence on the nirS-type denitrifying bacterial community in both reservoirs.These results will shed new lights on exploring the dynamics of nirS-type denitrifying bacteria in aerobic water layers of drinking water reservoirs.展开更多
A more resilient livelihood is increasingly recognized as an efficient way to improve vulnerable households’food security and optimize their dietary decisions.This study quantifies rural household resilience in weste...A more resilient livelihood is increasingly recognized as an efficient way to improve vulnerable households’food security and optimize their dietary decisions.This study quantifies rural household resilience in western China,identifies the three pillars(absorptive capacity,adaptive capacity,and transformative capacity)contribution to resilience,and then establishes the estimated Resilience Capacity Index(RCI)linked with food security and dietary diversity supported by the multiple indicator multiple cause(MIMIC)model.Results show that,despite geographical heterogeneity,the RCI consistently increased from 2015 to 2021.Households with a higher RCI inheriting better capacity to deal with risk and shocks are significantly and positively correlated with increasing food expenditure and diversifying food choices.It can be because resilient households will allocate more money to food expenditure instead of saving for livelihood uncertainty.Thus,policymakers can provide more incentives for rural households to adopt more dynamic and effective risk management strategies.This,in turn,could yield positive spillover effects by preventing human capital loss associated with dietary-related chronic diseases and mortality.展开更多
Access to off-farm employment has been expected to be a critical approach to ending hunger and all forms of malnutrition,two important targets of achieving Zero Hunger.This study aims to investigate the role of off-fa...Access to off-farm employment has been expected to be a critical approach to ending hunger and all forms of malnutrition,two important targets of achieving Zero Hunger.This study aims to investigate the role of off-farm employment in improving dietary diversity through substitution effect and complementary effect with agricultural production activities and income effect.This study adopts Poisson/Tobit/Probit/OLS regressions and the instrument variable method based on the primary survey data collected among 1,282 households at 12 sites in environmentally and economically vulnerable areas of China,Nepal,Cambodia,Thailand,and Myanmar in 2019.The results show that off-farm employment is positively associated with household dietary diversity and the consumption of flesh meat,fish and other aquatic animals,fruits,and milk and dairy products,which are rich in protein and micronutrients.The results of mechanism analysis show that off-farm employment contributes to household dietary diversity by improving crop diversity,especially for poor households,boosting the probability of livestock raising for households with the middle one-third disposal income,and increasing household income.The positive association between off-farm employment and household dietary diversity is much higher for households with the bottom one-third disposal income,low illiteracy,and from upper-middle income countries.These findings imply that off-farm employment does play a vital role in achieving multiple benefits of poverty alleviation,malnutrition reduction,and agrobiodiversity conservation in environmentally and economically vulnerable areas.However,it may enlarge the gaps in dietary diversity between households with low human capital and from low and lower-middle income countries and those with high human capital and from middle-high countries.展开更多
Lead(Pb)pollution is one of the most widespread and harmful environmental problems worldwide.Determination of changes in soil properties and microbial functional diversity due to land use is needed to establish a basi...Lead(Pb)pollution is one of the most widespread and harmful environmental problems worldwide.Determination of changes in soil properties and microbial functional diversity due to land use is needed to establish a basis for remediation of soil pollution.This study aimed to investigate soils contaminated by Pb from different sources and to analyze the functional diversity and metabolism of soil microbial communities using Biolog technology.Pb pollution(>300 mg kg-1)significantly influenced the diversity and metabolic functions of soil microbial communities.Specifically,Pb contamination significantly reduced soil microbial biomass carbon(C)and nitrogen(N)levels and catalase activity while increasing invertase activity.Furthermore,Biolog EcoPlate assays revealed that Pb pollution reduced the general activities of soil microorganisms,suppressing their ability to utilize C sources.In Pb-contaminated areas lacking vegetation cover,Shannon,Simpson,and McIntosh diversity indices of soil microorganisms were significantly reduced.The microbial diversity and biomass C and N levels were affected by land use and soil properties,respectively,whereas soil enzyme activity was primarily affected by the interaction between land use and soil properties.Our results provide a reference and a theoretical basis for developing soil quality evaluation and remediation strategies.展开更多
基金funded by the Qinghai Provincial Natural Science Foundation Project(2020-ZJ-725)the Wetland Protection and Restoration Project of the Second Batch of Forestry Reform and Development Funds in Qinghai Province,China(QHTX-2020-043-02).
文摘Qilian Mountains in Northwest China is a significant ecological security barrier due to its distinctive geographic setting,which has significant biological resource and gene pool.In order to assess the soil quality and ecosystem health in this area,we identified the structural characteristics and functional groups of soil microbial communities.This study focused on Amidongsuo,a typical watershed of the Qilian Mountains,and researched the vertical distribution and dominant populations of soil microorganisms in different habitats,and the relationship between soil microorganisms and environmental factors.Soil microorganisms from three grassland plots,five shrubland plots,and five forest plots in Amidongsuo were studied using high-throughput sequencing.The Venn diagram showed that the types of bacteria were fewer than those of fungi in Amidongsuo.Soil bacteria Acidobacteriota,Proteobacteria,and Methylomirabilota as well as fungi Basidiomycota,Ascomycota,and Mortierellomycota played dominant roles in Amidongsuo,according to the LEfSe(linear discriminant analysis(LDA)effect size)and community structure analyses.According to the ANOSIM(analysis of similarities)result,for both bacteria and fungi,R values of grassland and shrubland were small(R^(2)=0.045 and R^(2)=0.256,respectively),indicating little difference between these two ecosystems.RDA(redundancy analysis)showed a closer relationship between soil nutrients and fungi,and a gradually decreasing correlation between soil nutrients and microorganisms with increasing soil depth.Bacteria were mainly affected by pH,nitrogen(N),and potassium(K),while fungi were mainly affected by K.Overall,fungi had more effect on soil quality than bacteria.Therefore,adjustment of soil K content might improve the soil environment of Amidongsuo in the Qilian Mountains.
基金supported by the National Natural Science Foundation of China(32171530)the Scientific and Technology Project of the Anhui Provincial Group Limited for Yangtze-to-Huaihe Water Diversion(YJJH-ZT-ZX-20180404062)。
文摘The hydrological regime in wetlands plays an important role in the process of wintering waterbird metacommunity assemblage.However,increasing frequency of extreme climate and the intensification of human activities,such as the construction of sluices and dams,have resulted in frequently abnormal hydrological regime in the middle and lower Yangtze River floodplain.In recent years,earlier flood recession has become one of the main hydrological problems faced in the shallow lakes,having a great impact on wetland biodiversity.It is necessary to understand the impact of earlier flood recession on waterbirds,an indicator of wetland biodiversity,and the metacommunity concept is helpful to elucidate the underlying mechanism involved in the processes of assemblage by waterbird communities.In this study,we surveyed the wintering waterbirds at three sub-lakes of Caizi Lakes during 2019-2020 and 2020-2021 and compared the richness,abundance,alpha and beta diversity of waterbirds in and among local metacommunities under earlier flood recession and normal hydrological regime.The results showed that the earlier flood recession reduced the species richness in the early stage and abundance in the late stage,it also reduced the Shannon-Wiener index in the early stage and increased the dissimilarity between and within waterbird metacommunities in the late stage.The partition of beta diversity showed that the turnover component played a major role in the process of waterbird metacommunity assemblage.It was found that the earlier flood recession reduced the richness,abundance in different stages of flood recession,which also increased the turnover of waterbirds.Metacommunities with high habitat heterogeneity had better resistance to abnormal hydrological regime,which resulted in high dissimilarity between and within metacommunities.The results of this study provide important information for waterbird conservation and water level management at shallow lakes in the middle and lower Yangtze River floodplain.
基金Supported by Guangdong Provincial Science&Technology Innovation and Rural Revitalization Strategy in 2021(2021A0305)Guangdong Science and Technology Plan Project(2020B121201013)+2 种基金Guangdong Base Hakka Research Institute Bidding Project in 2020(20KYKT09)Characteristic Innovation Project of Guangdong General Universities in 2019(2019KTSCX171)Basic Education Research Project of Jiaying University in 2021(JCJY20211001)。
文摘Dongtian Park is a forest park in Dongtian Lake Ecological Tourism Resort in Meizhou City,South China.Through investigation and analysis of sample methods of the forest community structure and plant diversity in this park,the results showed that there were 181 plant species,belonging to 138 genera in 76 families,including 48 trees,60 shrubs,36 herbs and 37 lianas.The flora is a subtropical evergreen broad-leaved forest with some distinct tropical properties,and evergreen trees accounted for 48.62%of total plant species.The dominant species in the tree layer were Schima superba,Pinus massoniana,Cinnamomum parthenoxylon,etc.,and those in the shrub layer were Bambusa textilis,Aidia cochinchinensis,Rhaphiolepis indica,etc.,and in herb layer were Carex baccans,Adiantum flabellulatum,Cibotium barometz,etc.,and the lianas mainly included Smilax hypoglauca,Callerya dielsiana,Trachelospermum jasminoides,etc.There were few adults of dominant species in the tree layer,S.superba and P.massoniana also lacked seedlings,they would still maintain their dominant position for a quite long period,but Cyclobalanopsis neglecta had sufficient seedling reserves and would be most likely to become a dominant species in future.The community had relatively rich species,many ferns and lianas and complex hierarchy.The evenness,Shannon-Wiener diversity,Pielou uniformity and Simpson index were higher in the shrub layer than in the tree and herb layer,and the Simpson index was the lowest(0.9280)in the herb layer and Shannon-Wiener diversity index was the highest(7.5853)in the liana layer.
文摘The soil microorganisms at different depths play an important role in soil formation,ecosystem biogeochemistry,recycling of nutrients,and degradation of waste products.The aims of this study were to observe the microbial diversity in the profile of an agricultural soil in northern China,and to research the correlation between soil microbes and geochemistry.First,the soil geochemistry of the profile was investigated through 25 chemical elements.Secondly,the various physiological groups of microorganisms w...
文摘DNA sequence diversities of soil microbial communities in rhizosphere and non-rhizosphere of 1 - 6 years Panax ginseng were evaluated by random amplified polymorphic DNA (RAPD). Total genomic DNA of soil samples were amplified by twenty-four out of two hundred random primers. The products were separated in agarose gel, and 359 and 181 reliable fragments were generated, of which, 324 and 123 were polymorphic. The gene diversity index, Shannon’s information index, and similarity coefficient were calculated, and results showed that, diversity of soil microbial community at DNA level was present. Furthermore, with the increasing of P. ginseng growing at one site, deference on soil microbial community DNA sequence between rhizosphere and non-rhizosphere tend to be more and more significant. In addition, RAPD technique was proved to be an effective tool to assess the diversity of soil microbial communities. From results we deduced that, the ecological function that performed by soil microbes may changed following the change of microbial community in rhizospheric and non-rhizospheric soils, and finally broke the balance of soil nutrition and energy cycle, soil spatial structure, microbial ecology etc.
基金funded by a grant from the Cold and Arid Regions Environmental and the Engineering Research Institute of the Chinese Academy of Sciences Nos. HHS-TSS-STS-1505 and 55Y855Z11, CAS "Light of West China" Program, Frontier Science Research Program of Chineses Academy of Scienc No. QYZDJ- SSW_SMC011
文摘An understanding of soil microbial communities is crucial in roadside soil environmental assessments.The 16S rRNA se quencing of a stressed microbial community in soil adjacent to the Qinghai-Tibet Highway(QTH)revealed that the accu mulation of heavy metals(over about 10 years)has affected the diversity of bacterial abundance and microbial community structure.The proximity of a sampling site to the QTH/Qinghai-Tibet Railway(QTR),which is effectively a measure of the density of human engineering,was the dominant factor influencing bacterial community diversity.The diversity of bacterial communities shows that 16S rRNA gene abundance decreased in relation to proximity to the QTH and QTR in both alpine wetland and meadow areas.The dominant phyla across all samples were Actinobacteria and Proteobacteria.The concentration of Cr and Cd in the soil were positively correlated with proximity to the QTH and QTR(MC/WC sam pling sites),and Ni,Co,and V were positively correlated with proximity to the QTH and QTR(MA/WA sampling sites).The results presented in this study provide an insight into the relationships among heavy metals and soil microbial commu nities,and have important implications for assessing and predicting the impacts of human-induced activities from the QTH and QTR in such an extreme and fragile environment.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA11030404)the National High Technology Research and Development Program of China (2012AA092103)+3 种基金National Natural Science Foundation of China (31300365)the Knowledge Innovation Project of the Chinese Academy of Sciences (KZCX2-YWJC201)the Open Project Program of the Key Laboratory of Marine Bio-resources Sustainable Utilization, SCSIO,CAS (LMB121006)the Scientific and Technological Innovation Project financially supported by Qingdao National Laboratory for Marine Science and Technology (2015ASKJ02).
文摘The sediment samples were collected from Maluku Strait at a depth of 1250 m, which is influenced by Mindanao Current and Indonesian Throughflow. Based on 16S rRNA clone libraries, the community structure and vertical distribution of archaea and bacteria were studied in a columnar sediment of 2m in length. From the surface sediment, 16S sequences were derived from fourteen bacterial phyla (Gammaproteobacteria, Planctomycetes, Alphaproteobacteria, Deltproteobacteria were dominant), but were limited to two groups of archaea: Crenarchaeota (99%) and Euryarchaeota (1%). Besides, 90% of the archaea clones were ammonia oxidation-related which indicated that the ammonia-oxidizing archaea might make a significant contribution to the chemosynthesis in the surface sediment. Contrastively in the bottom sediment, six bacterial phylogenetic groups were obtained (Gammaproteobacteria and Firmicutes were absolutely dominant), however no archaea 16S rRNA was detected. The microbial diversity of surface sediment was much higher than the bottom and seven unique bacterial phyla were obtained from two sediment respectively. The geochemical elements analysis revealed that the content of C, TOC and S in the surface sediment was much higher than the bottom, but the content of P is contrary. The microbial communities might be in response to the geochemical substance transfer and deposit influenced by the ocean current and it deserves further study compared with the other sediment samples in this area.
基金Guiding Science and Technology Project of Daqing(zd-2019-78)Key Scientific Research Projects of Heilongjiang Farms and Land Reclamation Administration(No.HKKY190206-1)Doctoral Scientific Research Start-up Foundation of Heilongjiang Bayi Agricultural University of China(No.XYB2014-04).
文摘The influencing factors of soil microbial community under conservation tillage system were summarized,the changes of soil microbial community under conservation tillage system and the general situation of soil microbial community research under rotation system were analyzed,and the contents of soil microbial community need to be future studied were prospected.
基金Supported by the Key Project of National Natural Science Foundation of China(No.31061160187)the National Basic Research Program of China(973 Program)(No.2010CB951204)+1 种基金Taishan Scholar Program of Shandong ProvinceYellow & Bohai Sea Scientific Observation and Experiment Station for Fishery Resources and Environment,Ministry of Agriculture
文摘The status of fishery stocks in the coastal waters of China is far from ideal, mainly due to climate change and the impacts of human activities (e.g., pollution and overfishing). Thus, the restoration and protection of fishery resources have become critical and complex. The stability and balanced structure of the fish community is a basic foundation for the protection of fishery resources. Based on data collected from bottom trawls by the R/V Beidou in continental shelf of the East China Sea in November 2006 and February 2007, changes in the composition and diversity of fish species and functional groups were analyzed. The research area was divided into offshore waters and inshore waters by the two-way indicator species analysis (TWIA). The results showed that the dominant species were different between offshore waters and inshore waters and also varied with the survey time. The most abundant family was Sciaenidae and Teraponidae in November 2006, Sciaenidae, Engraulidae and Triglidae were most abundant in February 2007. The species belonged mainly to mobile piscivores (G6), benthivores/piscivores (G4), benthivores (G3) and planktivores (G1), and the dominant species in November 2006 were commercial species (e.g. Larimichthys polyactis and Trichiurus japonicus), but small-sized species were dominant in February 2007 (e.g., Harpadon nehereus, Benthosema pterotum, Champsodon capensis, and Acropoma japonicum). The species diversity showed a similar trend as the functional group diversity. Stations with higher diversity were mainly distributed in inshore waters in February 2007, whereas higher diversity was found in offshore waters in November 2006. The highest biomass and species number were found in G6 group, followed by the G4, G5 and G1 groups. The distribution of the number of individuals of each functional group showed the opposite trend as that of the biomass distribution. In addition, the size spectra were mainly concentrated around 3-29 cm, and the individual number of fish species gradually decreased with the increase in body size, but the relative biomass showed a moderate fluctuation in each size class. These changes showed that species with faster growth rate and earlier maturity age became dominant in continental shelf of the East China Sea. So the variations in biological characteristics of fish should be fully considered in maintaining sustainable utilization of fishery resource.
文摘Fermented foods play an important role in the daily life and diet of the populations in Congo. Among these fermented foods, there is Pilipili or fermented </span><span style="font-family:Verdana;">pepper which is consumed without prior cooking. The microorganisms</span><span style="font-family:Verdana;"> present are eaten alive. Few studies have been carried out on these microorganisms which may have beneficial effects on health. This study aimed to investing taxonomic diversity of bacterial communities in 3 samples of fermented peppers produced in 3 distinct areas of Brazzaville. To do this investigation, Illumina Miseq sequencing of 16S rRNA gene was used. The results showed that the number of identified operational taxonomic units (OTUs) ranged from 156 to 392. All OTUs belong to the domain of Bacteria and could be categorized into 21 Phyla, 36 Classes, 58 Orders, 100 Families and 171 genera. Firmicutes and Proteobacteria were the main dominant phyla of the total phyla present with a relative abundance of 89.12% and 8.08%, respectly. At the class level, Bacili were dominant in EB1 (99.50%), EB3 (85.32%) and EB2 (42.29%) while Clostridia in EB2 (40.10%). Lactobacillus, Clostridium sensu stricto and Frutobacillus were the dominant genera in the sample EB1, EB2 and EB3, respectively. The hierarchical classification showed that the samples EB1 and EB2 form the same group and EB3 is unique. Principal component analysis showed that the younger EB3 and EB2 samples were more diverse than the older EB1 sample. This study is a first in Congo on the diversity of fermented pepper using Illumina Miseq. It has shown that this food is very diverse and can be a source for the isolation of bacteria with biotechnological potential.
基金funded by the National Natural Science Foundation of China(Grant no.41776198)the Natural Science Foundation of Shandong Province,China(Grant no.ZR2020KC036)+1 种基金the Key R&D Program of China(Grant no.2018YFC1406700)Basic Scientific Fund for National Public Research Institutes of China(Grant no.GY0219Q10).
文摘Glacial meltwater runoff is a dynamic ecosystem.On the one hand,nutrient concentration changes as it flows from upstream to downstream,and on the other hand,bacterial community structure changes due to its contact with nearby soil during the flow process.We studied meltwater and soil in the Midre Lovénbreen glacier region,to explore changes in bacterial diversity as meltwater flows,and the relationship between meltwater and soil bacterial diversity.As glacial meltwater flows from upstream to downstream,the relative abundance of dominant bacterial groups changes.In addition,we found that during the flowing process,nutrient exchange and bacterial contact had occurred between the meltwater runoff and the soil.As a result,the distribution patterns of some bacteria in the meltwater are very similar to those in the soil.Finally,we combined distance-based redundancy analysis and weighted correlation network analysis to show that NO_(3)^(-)-N and NO_(2)^(-)-N are the most two significant factors affecting glacial meltwater and soil,respectively.Our results suggest that in such a close-knit ecosystem,the interaction of glacial meltwater with soil,as well as environmental factors,together determine bacterial community composition.
基金study was funded by Major Special Science & Technology Project of Gansu Province (Grant No. Y839C01001).
文摘Timely removal of the flower is a key agricultural measure to ensure the concentrated supply of nutrients for the growth of underground bulbs and to increase the yield of lilies. Removing flowers and returning them to the field is one of the tradi‐tional ways of treatment, and field litter is formed at this time. Previous study showed that the decomposition of litter changes the soil properties. In order to study the effects of lily litter decomposition on soil physical and chemical proper‐ties and microbial structure, three treatments were set up in reference to the Decomposition Bag Method: control (CK), Lanzhou lily flower treatment (LZF), and Zhongbai No.1 flower treatment (ZBF). The effects of lily decomposition on soil physical and chemical properties and microbial community composition were studied in order to provide a scientific basis and theoretical guidance for the planting process of Lanzhou lily. The results show that the decomposition of lily flowers significantly increased the contents of soil organic matter, soil total nitrogen, soil total phosphorus and soil avail‐able potassium, and decreased soil pH. RDA shows that soil available nutrients and pH were the driving factors for the change of the soil microbial community. A short-term change of soil microenvironment caused by the decomposed lily flower is beneficial to growing the Lanzhou lily. However, under the correlation analysis of environmental factors, the long-term effects of returning the Lanzhou lily flower to the field, such as the trend of soil acidification, need to be further studied.
文摘Pandé is a Congolese fermented food produced from fruit pulps of raffia palm. The aim of this study was to explore the diversities in bacterial communities in the unfermented pulps (control) (PNFL) and fermented pulps obtained from fruits using boiling (PMF) and purchased at markets in Brazzaville (PFL) and using Illumina MiSeq<sup>TM</sup> sequencing of 16S rRNA gene. A total number of 157,054 sequences was obtained and grouped into 737 operational taxonomic units (OTUs). These were classified into 13 phyla, 26 classes, 48 orders, 96 families and 176 genera. At the phylum level, the most frequent bacterial communities were: for PFM, Proteobacteria (38.94%) and Firmicutes (19.37%);for PFL, Firmicutes (69.10%) and Proteobacteria (30.89%);for PNFL, Firmicutes (84.92%) and Proteobacteria (14.22%). were the most frequent in PFL, while Acidobacteria (40.02%), Proteobacteria (38.94%) and Firmicutes (19.37%) were preponderant in PFM. Firmicutes (84.92%) and Proteobacteria (14.22%) were the most common in unfermented pulps (PNFL). Lactobacillus (47.70%) and Gluconobacter genera (15.33%) were the most represented in the PFL sample. Acidipila (35.56%) and Rhizomicrobium (11.41%) were preponderant genera in the PFM sample. Weissella genus was the most frequent in the PNFL sample. Hierarchical cluster indicated that the samples could be grouped into two groups of different origins. PCA showed that main genera were higher in the fermented samples. The diversity was higher in the fermented pulps or Pandé than in the unfermented pulps. Pandé can be a potential source for the isolation of bacteria with biotechnological potential.
文摘In this study, effect of rice added to meju dough was evaluated based on the variation of nutritional ingredients and bacterial community diversity in finished doenjang. The ratio of rice added to meju dough (cooked and crushed soybean before fermentation) was 0, 0.2, and 0.4 based on dry weight. Free amino acids, minerals, polyphenol, and total phenolic compounds relatively decreased by addition of rice. However, 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) scavenging and ferric ion reduction activity was not influenced. Organic acids, which are fermentation metabolites, significantly increased in proportion to percentage balance of rice. Seven and four volatile compounds (VCs) were detected in doenjang prepared without and with rice, respectively, and contents of VCs were significantly lower in the rice-supplemented doenjang. Bacterial community diversity was significantly increased by addition of rice to meju dough. Rice alters chemical composition, fermentation products, and bacterial diversity, but does not downgrade the nature of doenjang.
基金funded by the Guangxi Natural Science Foundation Program (2022GXNSFAA035583 and 2020GXNSFAA159108)National Natural Science Foundation of China (32060305)+2 种基金Foundation of Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University)Ministry of Education, China (ERESEP 2021Z06)Chinese Forest Biodiversity Monitoring Network
文摘Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest changed over a 15-year period.Specifically,renewal and death of common species was large,with the renewal of individuals mainly concentrated within a few populations,especially those of Aidia canthioides and Cryptocarya concinna.The numbers of individual deaths for common species were concentrated in the small and mid-diameter level.The spatial distribution of community species diversity fluctuated in each monitoring period,showing a more dispersed diversity after the 15-year study period,and the coefficient of variation on quadrats increased.In 2010,the death and renewal of the community and the spatial variation of species diversity were different compared to other survey years.Extreme weather may have affected species regeneration and community stability in our subtropical monsoon evergreen broad-leaved forests.Our findings suggest that strengthening the monitoring and management of the forest community will help better understand the long-and short-term causes of dynamic fluctuations of community structure and species diversity,and reveal the factors that drive changes in community structure.
文摘Since 2015, community forests have been promoted in Togo as an alternative to protect areas from degradation and as a means of contributing to forest landscape restoration. The study focuses on the Nakpadjouak Community Forest (NCF) in Tami (Togo, West Africa) which contributes to community forests sustainable management. It aims in (i) mapping forest ecosystems and analysing their dynamic and (ii) characterizing the floristic diversity of the NCF. The ecosystems were mapped and their dynamic was evaluated based on Google Earth images of 2014 and 2020. Floristic and forestry inventories were carried out using the transect technique in a sample of 20 plots of 50 m × 20 m. The NCF was made up mainly by wooded/shrub savannahs (95.37%) and croplands/fallow (4.63%) in 2014. These two land use types undergone changes over the 6 years prior to 2020. By 2020, the NCF had 3 land use types: wooded/shrub savannahs (77.59%), open forest/wooded savannahs (22.23%), and croplands/fallows (0.18%). A total of 89 plant species belonging to 70 genera and 28 families were recorded within the NCF. The dominant species are: Heteropogon contortus (L.) P.Beauv. and Combretum collinum Fresen. followed by Pteleopsissuberosa Engl. & Diels, Annona senegalensis Pers. The most common species are: Lannea acida A.Rich. s.l., A. senegalensis, Vitellaria paradoxa C.F.Gaertner subsp. paradoxa, C. collinum and Acacia dudgeonii Craib ex Holland. Due to its small area of just 40 hectares and its diverse plant life, this community forest of Savannahs Region is a significant biodiversity hotspot and warrants conservation efforts.
基金supported by the National Nature Science Foundation of China (Nos. 51979217, 51978561)grant from Youth Innovation Team of Shaanxi Universities in 2020 (PI: Dr. Haihan Zhang)
文摘The nirS-type denitrifying bacterial community is the main drivers of the nitrogen loss process in drinking water reservoir ecosystems.The temporal patterns in nirS gene abundance and nirS-type denitrifying bacterial community harbored in aerobic water layers of drinking water reservoirs have not been studied well.In this study,quantitative polymerase chain reaction(qPCR)and Illumina Miseq sequencing were employed to explore the nirS gene abundance and denitrifying bacterial community structure in two drinking water reservoirs.The overall results showed that the water quality parameters in two reservoirs had obvious differences.The qPCR results suggested that nirS gene abundance ranged from(2.61±0.12)×10^(5) to(3.68±0.16)×10^(5) copies/mL and(3.01±0.12)×10^(5) to(5.36±0.31)×10^(5) copies/mL in Jinpen and Lijiahe reservoirs,respectively.The sequencing results revealed that Paracoccus sp.,Azoarcus sp.,Dechloromonas sp.and Thauera sp.were the dominant genera observed.At species level,Cupriavidus necator,Dechloromonas sp.R-28400,Paracoccus denitrificans and Pseudomonas stutzeri accounted for more proportions in two reservoirs.More importantly,the co-occurrence network analysis demonstrated that Paracoccus sp.R-24615 and Staphylococcus sp.N23 were the keystone species observed in Jinpen and Lijiahe reservoirs,respectively.Redundancy analysis indicated that water quality(particularly turbidity,water temperature,pH and Chlorophyll a)and sampling time had significant influence on the nirS-type denitrifying bacterial community in both reservoirs.These results will shed new lights on exploring the dynamics of nirS-type denitrifying bacteria in aerobic water layers of drinking water reservoirs.
基金This paper was supported by the National Natural Science Foundation of China(NSFC)(71973138 and 72061137002)the Ministry of Science and Technology of China(2023YFE0105009).
文摘A more resilient livelihood is increasingly recognized as an efficient way to improve vulnerable households’food security and optimize their dietary decisions.This study quantifies rural household resilience in western China,identifies the three pillars(absorptive capacity,adaptive capacity,and transformative capacity)contribution to resilience,and then establishes the estimated Resilience Capacity Index(RCI)linked with food security and dietary diversity supported by the multiple indicator multiple cause(MIMIC)model.Results show that,despite geographical heterogeneity,the RCI consistently increased from 2015 to 2021.Households with a higher RCI inheriting better capacity to deal with risk and shocks are significantly and positively correlated with increasing food expenditure and diversifying food choices.It can be because resilient households will allocate more money to food expenditure instead of saving for livelihood uncertainty.Thus,policymakers can provide more incentives for rural households to adopt more dynamic and effective risk management strategies.This,in turn,could yield positive spillover effects by preventing human capital loss associated with dietary-related chronic diseases and mortality.
基金We acknowledge the financial support from the National Natural Science Foundation of China(72373140 and 42061144004)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20010303).
文摘Access to off-farm employment has been expected to be a critical approach to ending hunger and all forms of malnutrition,two important targets of achieving Zero Hunger.This study aims to investigate the role of off-farm employment in improving dietary diversity through substitution effect and complementary effect with agricultural production activities and income effect.This study adopts Poisson/Tobit/Probit/OLS regressions and the instrument variable method based on the primary survey data collected among 1,282 households at 12 sites in environmentally and economically vulnerable areas of China,Nepal,Cambodia,Thailand,and Myanmar in 2019.The results show that off-farm employment is positively associated with household dietary diversity and the consumption of flesh meat,fish and other aquatic animals,fruits,and milk and dairy products,which are rich in protein and micronutrients.The results of mechanism analysis show that off-farm employment contributes to household dietary diversity by improving crop diversity,especially for poor households,boosting the probability of livestock raising for households with the middle one-third disposal income,and increasing household income.The positive association between off-farm employment and household dietary diversity is much higher for households with the bottom one-third disposal income,low illiteracy,and from upper-middle income countries.These findings imply that off-farm employment does play a vital role in achieving multiple benefits of poverty alleviation,malnutrition reduction,and agrobiodiversity conservation in environmentally and economically vulnerable areas.However,it may enlarge the gaps in dietary diversity between households with low human capital and from low and lower-middle income countries and those with high human capital and from middle-high countries.
基金supported by the Major Basic Research Projects of Natural Science Foundation of Shandong(Grant No.ZR2018ZC2363).
文摘Lead(Pb)pollution is one of the most widespread and harmful environmental problems worldwide.Determination of changes in soil properties and microbial functional diversity due to land use is needed to establish a basis for remediation of soil pollution.This study aimed to investigate soils contaminated by Pb from different sources and to analyze the functional diversity and metabolism of soil microbial communities using Biolog technology.Pb pollution(>300 mg kg-1)significantly influenced the diversity and metabolic functions of soil microbial communities.Specifically,Pb contamination significantly reduced soil microbial biomass carbon(C)and nitrogen(N)levels and catalase activity while increasing invertase activity.Furthermore,Biolog EcoPlate assays revealed that Pb pollution reduced the general activities of soil microorganisms,suppressing their ability to utilize C sources.In Pb-contaminated areas lacking vegetation cover,Shannon,Simpson,and McIntosh diversity indices of soil microorganisms were significantly reduced.The microbial diversity and biomass C and N levels were affected by land use and soil properties,respectively,whereas soil enzyme activity was primarily affected by the interaction between land use and soil properties.Our results provide a reference and a theoretical basis for developing soil quality evaluation and remediation strategies.
