“双碳”背景下,为提高生物质能开发利用率和综合能源系统(Integrated energy system,IES)运行能效,提出了一种考虑阶梯负碳交易的含生物质燃气和碳捕集电厂的综合能源系统优化调度模型。首先,构建含生物质燃气、电转气及碳捕集电厂耦...“双碳”背景下,为提高生物质能开发利用率和综合能源系统(Integrated energy system,IES)运行能效,提出了一种考虑阶梯负碳交易的含生物质燃气和碳捕集电厂的综合能源系统优化调度模型。首先,构建含生物质燃气、电转气及碳捕集电厂耦合运行的IES结构。其次,建立一种阶梯型负碳交易机制来弥补传统阶梯型碳交易机制的局限性。然后,将阶梯型负碳交易机制引入IES并构建以系统总成本最小为目标的函数进行求解。最后通过多个场景下算例结果进行对比,分析不同阶梯型负碳交易机制参数敏感性对IES经济性和低碳性的影响,验证了所提阶梯型负碳交易可以有效提高系统经济性,仿真结果也证实了所提模型的有效性。展开更多
The Loess Plateau in China is one of the most eroded areas in the world. Accordingly, vegetation restoration has been implemented in this area over the past two decades to remedy the soil degradation problem. Understa...The Loess Plateau in China is one of the most eroded areas in the world. Accordingly, vegetation restoration has been implemented in this area over the past two decades to remedy the soil degradation problem. Understanding the microbial community structure is essential for the sustainability of ecosystems and for the reclamation of degraded arable land. This study aimed to determine the effect of different vegetation types on microbial processes and community structure in rhizosphere soils in the Loess Plateau. The six vegetation types were as follows：two natural grassland （Artemisia capillaries and Heteropappus altaicus）, two artificial grassland （Astragalus adsurgens and Panicum virgatum）, and two artificial shrubland （Caragana korshinskii and Hippophae rhamnoides） species. The microbial community structure and functional diversity were examined by analyzing the phospholipid fatty acids （PLFAs） and community-level physiological profiles. The results showed that rhizosphere soil sampled from the H. altaicus and A. capillaries plots had the highest values of microbial biomass C, average well color development of carbon resources, Gram-negative （G-） bacterial PLFA, bacterial PLFA, total PLFA, Shannon richness, and Shannon evenness, as well as the lowest metabolic quotient. Soil sampled from the H. rhamnoides plots had the highest metabolic quotient and Gram-positive （G＋） bacterial PLFA, and soil sampled from the A. adsurgens and A. capillaries plots had the highest fungal PLFA and fungal：bacterial PLFA ratio. Correlation analysis indicated a signiifcant positive relationship among the microbial biomass C, G- bacterial PLFA, bacterial PLFA, and total PLFA. In conclusion, plant species under arid climatic conditions signiifcantly affected the microbial community structure in rhizosphere soil. Among the studied plants, natural grassland species generated the most favorable microbial conditions.展开更多
Stem density and size stratification of woody species are informative of vegetation conditions and its physiognomy in savannah whereas their variation influence woody population functioning. Current study endeavoured ...Stem density and size stratification of woody species are informative of vegetation conditions and its physiognomy in savannah whereas their variation influence woody population functioning. Current study endeavoured to evaluate the stand density and size variability of woody species related to aboveground biomass in a Sudanian savannah. Total height, stem diameter at breast height (dbh) ≥ 5 cm were measured in 30 plots of 50 m </span></span><span><span><span style="font-family:"">×<span> 20 m laid in respect to vegetation type as bowal, shrubland and woodland. Species diversity, stem density, height and basal area were calculated and compared across sites and variation in stem dbh classes evaluated. Total aboveground biomass was estimated and thereafter linear relationships were established between stand density and aboveground biomass</span></span></span></span><span><span><span style="font-family:"">,</span></span></span><span><span><span style="font-family:""> and basal area. Results revealed three different sites with an overall 58 species identified through vegetation type including liana species (4 stems in bowal) with 18 genera and 42 families. Fabaceae Combretaceae, Anacardiaceae and Rubiaceae were dominant families. Small sized trees represented 72% of total stem density considered in structure with significant higher basal area, while large sized trees as 28% were scarcely distributed. More than 70% variation in biomass w</span></span></span><span><span><span style="font-family:"">as </span></span></span><span><span><span style="font-family:"">due to stem density and basal area with a dominance of small trees. In conclusion increase size in tree community indicated increase in accumulated aboveground biomass as positive regeneration features. But, change in vegetation structure strongly influence negatively species ability to grow from lower to upper size class and later on, disrupt ecosystem functioning. Plant stem density and stratification could be considered as indicators of aboveground biomass fluctuating in regeneration monitoring.展开更多
文摘“双碳”背景下,为提高生物质能开发利用率和综合能源系统(Integrated energy system,IES)运行能效,提出了一种考虑阶梯负碳交易的含生物质燃气和碳捕集电厂的综合能源系统优化调度模型。首先,构建含生物质燃气、电转气及碳捕集电厂耦合运行的IES结构。其次,建立一种阶梯型负碳交易机制来弥补传统阶梯型碳交易机制的局限性。然后,将阶梯型负碳交易机制引入IES并构建以系统总成本最小为目标的函数进行求解。最后通过多个场景下算例结果进行对比,分析不同阶梯型负碳交易机制参数敏感性对IES经济性和低碳性的影响,验证了所提阶梯型负碳交易可以有效提高系统经济性,仿真结果也证实了所提模型的有效性。
基金supported by the Strategic Technology Project of Chinese Academy of Sciences(XDA05060300)the Science and Technology Research and Development Program of Shaanxi ProvinceChina(2011KJXX63)
文摘The Loess Plateau in China is one of the most eroded areas in the world. Accordingly, vegetation restoration has been implemented in this area over the past two decades to remedy the soil degradation problem. Understanding the microbial community structure is essential for the sustainability of ecosystems and for the reclamation of degraded arable land. This study aimed to determine the effect of different vegetation types on microbial processes and community structure in rhizosphere soils in the Loess Plateau. The six vegetation types were as follows：two natural grassland （Artemisia capillaries and Heteropappus altaicus）, two artificial grassland （Astragalus adsurgens and Panicum virgatum）, and two artificial shrubland （Caragana korshinskii and Hippophae rhamnoides） species. The microbial community structure and functional diversity were examined by analyzing the phospholipid fatty acids （PLFAs） and community-level physiological profiles. The results showed that rhizosphere soil sampled from the H. altaicus and A. capillaries plots had the highest values of microbial biomass C, average well color development of carbon resources, Gram-negative （G-） bacterial PLFA, bacterial PLFA, total PLFA, Shannon richness, and Shannon evenness, as well as the lowest metabolic quotient. Soil sampled from the H. rhamnoides plots had the highest metabolic quotient and Gram-positive （G＋） bacterial PLFA, and soil sampled from the A. adsurgens and A. capillaries plots had the highest fungal PLFA and fungal：bacterial PLFA ratio. Correlation analysis indicated a signiifcant positive relationship among the microbial biomass C, G- bacterial PLFA, bacterial PLFA, and total PLFA. In conclusion, plant species under arid climatic conditions signiifcantly affected the microbial community structure in rhizosphere soil. Among the studied plants, natural grassland species generated the most favorable microbial conditions.
文摘Stem density and size stratification of woody species are informative of vegetation conditions and its physiognomy in savannah whereas their variation influence woody population functioning. Current study endeavoured to evaluate the stand density and size variability of woody species related to aboveground biomass in a Sudanian savannah. Total height, stem diameter at breast height (dbh) ≥ 5 cm were measured in 30 plots of 50 m </span></span><span><span><span style="font-family:"">×<span> 20 m laid in respect to vegetation type as bowal, shrubland and woodland. Species diversity, stem density, height and basal area were calculated and compared across sites and variation in stem dbh classes evaluated. Total aboveground biomass was estimated and thereafter linear relationships were established between stand density and aboveground biomass</span></span></span></span><span><span><span style="font-family:"">,</span></span></span><span><span><span style="font-family:""> and basal area. Results revealed three different sites with an overall 58 species identified through vegetation type including liana species (4 stems in bowal) with 18 genera and 42 families. Fabaceae Combretaceae, Anacardiaceae and Rubiaceae were dominant families. Small sized trees represented 72% of total stem density considered in structure with significant higher basal area, while large sized trees as 28% were scarcely distributed. More than 70% variation in biomass w</span></span></span><span><span><span style="font-family:"">as </span></span></span><span><span><span style="font-family:"">due to stem density and basal area with a dominance of small trees. In conclusion increase size in tree community indicated increase in accumulated aboveground biomass as positive regeneration features. But, change in vegetation structure strongly influence negatively species ability to grow from lower to upper size class and later on, disrupt ecosystem functioning. Plant stem density and stratification could be considered as indicators of aboveground biomass fluctuating in regeneration monitoring.
