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Miscanthus × giganteus has attracted much attention and occupied a significant niche as a bioenergy crop to meet the world's energy demand and in the fight against climate change. In this study, a field experiment was conducted to evaluate the yield and biomass characteristics of M. × giganteus over a period of three years from 2013 to 2015 in Beijing, China. M. × giganteus plants showed higher tiller density and litter leaf weight in the third year, whereas no significant difference in plant height was observed among the years. In contrast, a larger number of nodes per plant were recorded in the first year. Biomass yield potential was the highest in the third year (42.3 t ha−1). In addition, plant height (r =.594, p =.042), tiller density (r =.854, p <.01), and number of nodes per plant (r = ‐.589, p =.044) were significantly correlated with biomass yield. Contents of cellulose and lignin were higher in stems, while that of hemicellulose and ash were higher in leaves. M. × giganteus biomass may be used for cellulosic ethanol conversion due to high cellulose and hemicellulose contents and low lignin content and for direct combustion and co‐combustion due to high calorific value (18.5 MJ kg−1). To conclude, our findings indicate that M. × giganteus can be cultivated in northern China as an excellent herbaceous bioenergy crop. Rational utilization of the agronomic characteristics would be helpful to screening and breeding bioenergy grass for promoting bioenergy production in China. Core ideas: Miscanthus × giganteus is suitable for cultivation in northern China.Agronomic traits were significantly correlated with biomass yield.Biomass yield of M. × giganteus increased over a period of three years.Biomass quality exhibited better suitability for ethanol production.High calorific value may be used for direct combustion and co‐combustion. [ABSTRACT FROM AUTHOR]

Miscanthus spp. are increasingly cultivated in cropland worldwide due to their bioenergy potential and multiple ecological services. Effects of long‐term cropland‐to‐Miscanthus conversion without N fertilizer on soil microbiome and N cycling largely remain unknown. We aimed to explore the effects of Miscanthus conversion on soil microbiome and N cycling over a 15‐year period. We analyzed diversity, composition, and abundance of bacterial and archaeal communities using 16S rRNA amplicon sequencing, and abundances of N‐cycling‐related genes using quantitative polymerase chain reaction of 0–10 cm soils collected from bare land, cropland, 10‐year Miscanthus × giganteus, and 15‐year Miscanthussacchriflorus land in Beijing. Conversion decreased soil sand and micro‐aggregate proportion, nitrate N (NiN), available phosphorus levels, conductivity, temperature, and pH, while increasing proportion of soil clay and macro‐aggregate (MAA), soil organic C (SOC), available N (AN), exchangeable Mg2+ (EMg2+), and available potassium (AK) contents as well as microbial C/N. Consequently, diversity, composition, and abundance of soil bacterial community exhibited larger changes than those values of archaeal community after conversion. Soil AP, EMg2+, AK, and SOC were key factors in shifting microbiome from the cropland to Miscanthus pattern. Moreover, abundances of bacterial and archaeal communities and the N fixer gene nifH increased, whereas that of the bacterial ammonia monooxygenase gene decreased. The copies of other N‐cycling‐related genes in the two Miscanthus lands seemed similar to those values of cropland. The nifH copies negatively correlated with soil NiN and positively correlated with AN, EMg2+, ECa2+, SOC, AK, and MAA. We conclude that changes in soil microbiome pattern induced by the variation of soil properties enhance microbial N fixation potential, maintaining stable N levels and robust N cycling with lower N leakage risk after conversion. These results should inspire farmers and governments to large‐scale use Miscanthus on marginal cropland in Northern China. [ABSTRACT FROM AUTHOR]

• Eight years study of green roof plants in Beijing (Dwa climate). • Precipitation pattern greatly influence the plant growth and the community dynamics. • Species with rootstocks or thickened fibrous roots performed better. • Only Phediums aizoon was alive at all four substrate depths at the end of this study. • Substrate moisture content was more vital for plant survival than substrate depth. The selection of plants on green roofs should be tailored to the local climate. However, little is known about the long-term performance of plants in a Dwa climate (in the Köppen climate classification). This study follows the performance of 10 Crassulacean species (four species of Phedimus and six of Sedum) grown at four substrate depths (5, 10, 15, and 20 cm) over eight years on an unirrigated roof in Beijing, China. We found that the climate in Beijing, particularly the specific distribution of precipitation, had a substantial influence on plant growth and the community dynamics on extensive green roofs, and the dry and cold winters were the main factors that affected the plant survival on unirrigated green roofs. In such a climate, species with rootstocks or thickened fibrous roots performed better than species with entirely fibrous roots. Although deeper levels of substrate promoted better plant survival and performance, the species richness at all four depths continued to decrease. By the end of this research, only Phedimus aizoon and Phedimus floriferus 'Weihenstephaner Gold' still survived, and Phedimus aizoon was the only species that was alive at all of the four substrate depths. This research emphasized the importance of long-term research. The results of this study also revealed that the substrate moisture content was a more important factor than the substrate depth on the survival of plants over winter. To increase the rate of survival of plants on extensive green roofs over winter in Beijing, we advise the provision of supplementary irrigation before winter in years when the plants have experienced a dry autumn. [ABSTRACT FROM AUTHOR]