Assessing the impacts and drivers of urban expansion on terrestrial carbon storage (TCS) is important for urban ecology and sustainability; however, a unified accounting standard for carbon intensity and research on the drivers and economic value of TCS changes are lacking. Here, urban expansion and TCS in the Yangtze River Delta were simulated based on Patch-generating Land Use Simulation and Integrated Valuation of Ecosystem Services and Trade-offs models; scenario simulation; Literature, Correction, Ratio, Verification carbon intensity measurement; and land use transfer matrix methods. The results showed that (1) from 2000 to 2020, urbanization and TCS loss accelerated, with 61.127% of TCS loss occurring in soil, and land conversion was prominent in riverine and coastal cities, mainly driven by the urban land occupation of cropland around suitable slopes, transportation arteries, and rivers. (2) From 2020 to 2030, urban land expansion and TCS loss varied under different scenarios; economic losses from the loss of the carbon sink value under cropland protection and ecological protection were USD 102.368 and 287.266 million lower, respectively, than under the baseline scenario. Even if urban expansion slows, the loss of TCS under global warming cannot be ignored. Considering the indirect impacts of urbanization, the failure to establish a regional development master plan based on ecosystem services may affect China’s carbon targets.
This study investigated the effects of dietary rumen‐protected lysine ( RPL ys) on milk yield and composition in lactating cows fed diets containing double‐low rapeseed meal. Twenty‐four cows were divided into three groups and fed one of three dietary treatments: 10% soya bean meal ( SBM ) diet (control), 15% double‐low rapeseed meal ( DLRSM ) diet and 15% DLRSM + 32 g/d RPL ys ( DLRSML ) diet. The results showed that no differences ( P > 0.05) were observed in milk yield, 4% fat correction milk ( FCM ), energy correction milk ( ECM ), protein yield, milk fat yield, milk fat, lactose yield and lactose between control and DLRSM . Supplementation with DLRSML increased ( P < 0.05) milk yield, 4% FCM , ECM , and protein yield compared with the SBM . The results indicated that DLRSM and DLRSML might be used to substitute for SBM as a protein source in lactating cows, and the latter might be more beneficial to improve the performance.
This study aimed at characterizing changes in rumen bacteria abundance and fermentation profiles by artificial saliva (AS) pH, and at evaluating the potential modulatory role of Aspergillus oryzae culture (AOC) in a rumen simulation technique (RUSITEC) system. The treatment included high AS pH (pH 6.8) or low AS pH (pH 5.5) according to the McDougall’s method, and low AS pH was sustained by changing the composition of the AS (NaHCO3 from 9.8 to 1.96 g/L, Na2HPO4 from 9.3 to 1.86 g/L). In low AS pH condition, the diets contained either 0% AOC, 1.25% AOC, or 2.5% AOC. Therefore, there are four treatments: (1) high AS pH, 0% AOC (HASP); (2) low AS pH, 0% AOC (AOC0); (3) low AS pH, 1.25% AOC (AOC1); (4) low AS pH, 2.5% AOC (AOC2), respectively. The experimental diets were supplemented with 16 g basic diets with the forage to concentrate ratio of 40:60. The experiments were conducted two independent 13 days, with 9 days adaption periods and 4 days sample collection. The results showed that low AS pH decreased the degradabilites of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) (p < 0.05), which occurred due to a decreased abundance of fibrolytic Ruminococcus albus (p < 0.001). The total concentration of volatile fatty acid (VFA) and proportion of propionate were decreased in the low AS pH (p = 0.026) and tended to increase the molar proportion of butyrate (p = 0.086) and the ratio of acetate to propionate (p = 0.088). The abundances of phylum Firmicutes (p = 0.065) and Proteobacteria (p = 0.063) tended to be greater in low AS pH group than high AS pH group. Low AS pH increased the abundance of phylum Actinobacteria (p = 0.002) compared to the high AS pH and decreased the abundances of phylum Spirochaetes (p = 0.032). Compared with the high AS pH, low AS pH increased the abundances of Prevotella (p = 0.003), Pseudoscardovia (p = 0.001), Mitsuokella (p = 0.005), and Dialister (p = 0.047), and decreased the abundances of Olivibacter (p = 0.026), Ruminobacter (p = 0.025), Treponema (p = 0.037), and Sphaerochaeta (p = 0.027) at genus level. Under a severe SARA in RUSITEC, supplementation of 2.5% AOC increased OM degradability, the copy numbers of Selenomonas ruminantium and Fibrobacter succinogenes. These findings indicate that the reduction AS pH at 5.5 caused a strong shift in bacterial composition in rumen. In addition, the addition of AOC in diets increased the growth rate of certain rumen bacteria that digest fiber or utilize lactate under SARA condition in RUSITEC system.
Brittle Culm 15 ( BC15 ) gene encodes a membrane-associated chitinase-like protein that participates in cellulose synthesis, and BC15 gene mutation affects cell wall composition in plant, such as cellulose or hemicellulose. The present study was designed to investigate the changes of carbohydrates composition in bc15 mutant straw, and the resulting consequence on rumen fermentation, methanogenesis, and microbial populations (qPCR) during in vitro ruminal fermentation process. Two substrates, bc15 mutant and wild-type (WT) rice straws, were selected for in vitro rumen batch culture. The first experiment was designed to investigate the kinetics of total gas and CH 4 production through 48-h in vitro ruminal fermentation, while the second experiment selected incubation time of 12 and 48 h to represent the early and late stage of in vitro ruminal incubation, respectively, and then investigated changes in biodegradation, fermentation end products, and selected representative microbial populations. The bc15 mutant straw had lower contents of cellulose, neutral detergent fiber (NDF) and acid detergent fiber (ADF), and higher contents of water-soluble carbohydrates, neutral detergent solubles (NDS) and monosaccharides. The bc15 mutant straw exhibited a distinct kinetics of 48-h total gas and CH 4 production with faster increases in early incubation when compared with WT straw. The bc15 mutant straw had higher DM degradation, NDF degradation and total volatile fatty acid concentration at 12 h of incubation, and lower NDF degradation and CH 4 production at 48 h of incubation, together with lower acetate to propionate ratio and ADF degradation and higher butyrate molar percentage and NDS degradation at both incubation times. Furthermore, the bc15 mutant straw resulted in greater 16S gene copies of F. succinogenes , with lower 18S gene copies of fungi at both incubation times. These results indicated that the BC15 gene mutation decreased fibrosis of cell wall of rice straw, enhanced degradation at the early stage of rumen fermentation, and shifts fermentation pattern from acetate to propionate and butyrate production, leading to the decreased volume and fractional rate of CH 4 production. However, BC15 gene mutation may enhance hardenability of cell wall structure of rice straw, which is more resistant for microbial colonization with decreased fiber degradation. Thus, this study modified rice straw by manipulating a cell wall biosynthesis gene and provides a potential strategy to alter degradation and CH 4 production during in vitro ruminal fermentation process.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The pelleted TMR pulverized the grass during processing, which may result in more solid attached microorganisms in the filtered rumen fluid. The objective of this study was evaluating the necessity of distinguishing physical phases of rumen contents for analysis of prokaryotes communities in rumen of lambs fed pelleted TMR, considering the dissimilarity of diversity and community of bacteria and archaea between fluid and mixed rumen contents. The yield of microbial DNA, bacterial diversity, abundances of fibrolytic bacteria of phylum Fibrobacterota and Spirochaetota, as well as genus Ruminococcus, Lachnospiraceae_NK3A20, Fibrobacter, and F082, and abundance of archaeal Methanimicrococcus in rumen fluid were lower than those in mixed phase of rumen contents (p ≤ 0.05). In conclusion, it is necessary to consider rumen content physical phases when studying the prokaryotic community in rumen of lambs fed pelleted TMR.
Background The Three Gorges project has caused many ecosystem problems. Ecological restoration using readily-available plants is an effective way of mitigating environmental impacts. Two perennial submergence-tolerant ecotypes of Calamagrostis arundinacea were planted in an experimental field in the drawdown zone. Responses of the two plant ecotypes to flooding stress in the drawdown zone were unknown. Methodology/Principal Findings Carbohydrate content and membrane stability, two key factors for survival of plants under flooding stress, of two ecotypes (designated "dwarf" and "green") of C. arundinacea growing at different elevations of the drawdown zone were investigated. Live stems (LS) and dead stems (DS) of the two plant ecotypes at eight elevations (175, 170, 162, 160, 158, 155, 152 m and 149 m) were sampled. Contents of soluble sugar, starch and malondialdehyde (MDA), as well as plasma membrane permeability of live stems were measured. The lowest elevations for survival of dwarf and green C. arundinacea were 160 m and 158 m, respectively. Soluble sugar content of live stems of both ecotypes decreased with elevation, with amounts from an elevation of 170 m being lower than from an elevation of 175 m. MDA content and plasma membrane permeability in live stems of green C. arundinacea did not increase with the decrease in elevation, while these measures in dwarf C. arundinacea from an elevation of 162 m were significantly higher than from an elevation of 175 m. Conclusions Carbohydrate content, especially soluble sugar content, in both ecotypes was more sensitive to flooding stress than membrane stability. Green C. arundinacea had a higher tolerance to submergence than dwarf C. arundinacea, and thus green C. arundinacea can be planted at lower elevations than dwarf C. arundinacea.
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