Agricultural production structure,market conditions and farmers’nutritional intake in rural China

Nutrition poverty alleviation is an effective measure to improve the nutritional status of economically disadvantaged individuals,fundamentally improving their health and reducing poverty.Based on the Entitlement Theory and using the China Health and Nutrition Survey(CHNS)data,this paper examines the relationship between farmers’nutritional intake,production structure and regional market conditions.Results show that farmers with diversified production have better nutritional intake than those who specialize.Furthermore,the correlation between regional market conditions and nutritional intake varies between economically disadvantaged and non-economically disadvantaged households.Market conditions significantly influence the carbohydrate and fat intake of economically disadvantaged households and are positively associated with the dietary structure and nutritional intake of non-economically disadvantaged ones.Moreover,income is positively correlated with the nutritional intake of non-economically disadvantaged households but not with economically disadvantaged ones.

Species Composition, Richness and Aboveground Biomass of Natural Grassland in Hilly-Gully Regions of the Loess Plateau, China

In order to study the characteristics of species composition, richness and aboveground biomass of natural grasslands, and then ifnd out the relations between species richness and aboveground productivity of the communities and possible mechanisms to form the relations, four typical grassland communities （Artemisia capillaries （AC）, Thymus quinquecostatus （TQ）, Stipa bungeana （SB） and Stipa grandis （SG）） along with a succession sequence in hilly-gully regions of the Loess Plateau, China, were investigated by ifeld survey and laboratory analysis. The results were summarized as follows：Different succession stages had different species compositions as well as different proportions of plant life forms and photosynthetic types, and Asteraceae, Poaceae and Leguminosae were their dominant species as well as their dominant perennial herb species;and different succession stages had signiifcantly different species richness and aboveground biomasses. There were many relation patterns （linear positive correlation, unrelated relations and unimodal relations） between the species richness and aboveground biomass in different succession stages and a signiifcant unimodal relation between the species richness and aboveground biomass in all the grassland communities and the highest species diversity appeared at a moderate level of productivity. The results suggest the unimodal relations in all the grassland communities are accumulative results of the relations in each succession stage.

Recent advances in metal-organic frameworks for catalytic CO_(2) hydrogenation to diverse products

Selective hydrogenation of CO_(2) to high value-added chemicals,not only gives an effective way to reduce the concentration of CO_(2),but also provides the precursors to advance the industrial manufacturing of chemicals and fuels.With the well-defined reticular frameworks and flexible modifiability,metal-organic frameworks(MOFs)can be the ideal platform to construct the enabled catalysts for CO_(2) hydrogenation,because they have shown the great potential for the enhancement of catalytic activity,the precise control of selectivity,and the excellent stability.In this review,we systematically summarize the recent advances in MOFs based catalysts for CO_(2) hydrogenation towards diverse products.Firstly,synthesis strategies for different kinds of MOFs based catalysts are described.Secondly,selective hydrogenation of CO_(2) towards CO and methane is discussed over various metal nanoparticles/MOFs composites.Thirdly,heterogenization and isolation of molecular catalysts by MOFs are elaborated for producing formic acid.Fourthly,selective hydrogenation of CO_(2) toward methanol is discussed in terms of interface structures of Cu,Zn,and metal nodes of MOFs,the synergy between auxiliary sites and noble metal,and tandem catalytic systems of molecular catalysts and Lewis acid sites.Subsequently,the integration of multiple metal sites,promoters,and cocatalysts into MOFs is described for the selective hydrogenation of CO_(2) to C2+products.After those,the key issue about the stability of MOFs based catalysts for CO_(2) hydrogenation reaction is discussed.Finally,the summary and perspective about MOFs based catalysts for selective CO_(2) hydrogenation and mechanism research are proposed.

Dominance by an obligate annual affects the morphological characteristics and biomass production of a planted wetland macrophyte community

Aims Biodiversity-ecosystem function experiments can test for causal relationships between planting diversity and community productivity.Planting diversity is routinely introduced as a design element in created wetlands,yet substantive support for the finding that early diversity positively affects ecosystem functioning is lacking for wetlands.We conducted a 2-year diversity-productivity experiment using freshwater wetland mesocosms to investigate community biomass production as affected by planted macrophyte functional richness.Methods A richness gradient of macrophytes in four emergent wetland plant functional groups was established in freshwater mesocosms for two consecutive years.Species-specific aboveground morphological traits of plant size were measured at peak growth in both years;rooting depth was measured for each species in the second year.Aboveground biomass(AGB)and belowground biomass(BGB)were harvested after peak growth in the second year;first year AGB was estimated from morphological traits in constructed regression equations.Net richness effects(i.e.both complementarity effects and selection effects)were calculated using an additive partitioning method.Important Findings Species richness had a positive effect on community AGB relative to monocultures in the first year.In the second year,mean AGB was significantly reduced by competition in the most species-rich mixtures and all mixtures underyielded relative to the average monoculture.Competition for soil resources was weaker belowground,whereby root distribution at depths>20cm was reduced at the highest richness levels but overall BGB production was not affected.Changes in species biomass were strongly reflected by variation in species morphological traits,and species above and belowground performances were highly correlated.The obligate annual(Eleocharis obtusa),a dominant competitor,significantly contributed to the depression of perennial species’growth in the second growing season.To foster primary productivity with macrophyte richness in early successional communities of created wetlands where ruderal strategies are favored and competition may be stronger than species complementarity,unsystematic planting designs such as clustering the same or similar species could provide protection for some individuals.Additionally,engineering design elements fostering spatial or temporal environmental variability(e.g.microtopography)in newly created wetlands helps diversify the responses of wetland macrophyte species to their environment and could allow for greater complementarity in biomass production.