Search

The diurnal temperature range (DTR) has generally decreased at global scale according to the IPCC reports and previous publications. Here, we examined the change in DTR within the past four decades and found that DTR decreased in wet areas, but it increased in dry areas. This is because the daily minimum air temperature (Tmin) increased at a slower rate than the daily maximum air temperature (Tmax) in the dry areas, while it increased more rapidly in the wet areas. The changes in cloud cover, water vapour and moisture flux were observed to have contributed to the observed change in DTR. The change in moisture flux largely contributed to this change through the indirect effect on the change in water vapour across the aridity gradient. The significant impact of moisture flux is linked to the differential change in moisture flux between the dry and wet zones. [ABSTRACT FROM AUTHOR]

Climate change‐induced species range shift may pose severe challenges to species conservation. The Qinghai‐Tibet Plateau is the highest and biggest plateau, and also one of the most sensitive areas to global warming in the world, which provides important shelters for a unique assemblage of species. Here, ecological niche‐based model was employed to project the potential distributions of 59 key rare and endangered species under three climate change scenarios (RCP2.6, RCP4.5 and RCP8.5) in Qinghai Province. I assessed the potential impacts of climate change on these key species (habitats, species richness and turnover) and effectiveness of nature reserves (NRs) in protecting these species. The results revealed that that climate change would shrink the geographic ranges of about a third studied species and expand the habitats for two thirds of these species, which would thus alter the conservation value of some local areas and conservation effectiveness of some NRs in Qinghai Province. Some regions require special attention as they are expected to experience significant changes in species turnover, species richness or newly colonized species in the future, including Haidong, Haibei and Haixi junctions, the southwestern Yushu, Qinghai Nuomuhong Provincial NR, Qinghai Qaidam and Haloxylon Forest NR. The Haidong and the eastern part of Haibei, are projected to have high species richness and conservation value in both current and future, but they are currently not protected, and thus require extra protection in the future. The results could provide the first basis on the high latitude region to formulate biodiversity conservation strategies on climate change adaptation. In this manuscript, species distribution modeling based on ensemble forecasting was employed to project the potential distributions of 59 key rare and endangered species under three climate change scenarios in Qinghai Province. We assessed the potential impacts of climate change on species diversity (species richness and turnover) and effectiveness of NR network in protecting these species. The results could provide the first decision‐making basis on the high latitude region to formulate biodiversity conservation strategies on climate change adaptation. [ABSTRACT FROM AUTHOR]

Aim Conservation strategies must anticipate how climate change may alter the geographic distributions of limited food resources for highly specialized species. Here, we use bamboo as a case study to investigate climate change-induced changes in species diversity and discuss how to protect the critical food species for giant pandas. Location Giant panda habitats. Methods Using a niche-based model and the most updated climate projections, we projected the current and future distribution of 16 bamboo species under no and universal dispersal assumptions. We then assessed the impact of climate change on bamboo forests and their alpha and beta diversities in the giant panda habitats and reserves. Results Under both dispersal assumptions and three RCPs, six bamboo species are projected to vanish from panda habitats as climate change progresses, resulting in a great loss of the current bamboo forests. Although about half of the bamboo species may potentially colonize new climatically suitable areas under universal dispersal, the other species would experience significant habitat loss. Consequently, climate change would reduce both the alpha and beta diversity of bamboo species in panda habitats. Meanwhile, the proportion of single-species bamboo forests would significantly increase. The decline in bamboo forests and diversity would be most drastic in Qinling, Daxiangling and Qionglaishan Mountains, whereas those in the north-west of Minshan Mountains and Liangshan Mountains may increase. Main conclusions Climate change-induced decline in bamboo habitats and species diversity would pose a severe challenge to the food availability of giant pandas. We posit that human-assisted adaptation and increasing bamboo species diversity are critical to ensuring food security of the giant panda in a changing climate. Our results indicate that conservation planning should not only incorporate species range shifts but also diversity patterns in communities under climate change. [ABSTRACT FROM AUTHOR]

It is increasingly recognized that biotic interactions could play a significant role in species distribution modelling. To assess the conservation effectiveness of the giant panda ( Ailuropoda melanoleuca ) reserves in a changing climate, we combined both biotic variables (food availability) and abiotic (climatic and geographic) to project the potential changes of distribution and quality of giant panda habitats using the most recent IPCC-CMIP5 climate scenarios. Our results suggested that climate change would adversely affect giant pandas through habitat degradation, in that: (1) 52.9–71.3% of the current habitats could be lost; (2) the giant panda habitats could become more fragmented and isolated; and (3) both the quantity and quality of habitats in the current giant panda reserves could substantially contract, and approximately 20% of the reserves could lose all habitat representations in this century. Additionally, we found that climate change would make it increasingly necessary to translocate small populations of pandas from the southwestern to the northwestern part of the current distribution range to ensure population viability. Our results suggest the need for immediate change in current conservation policies and formulating adaptation plans for giant panda conservation in a changing climate. [ABSTRACT FROM AUTHOR]

Abstract: Species with distributions severely restricted and isolated by human-related factors are of a challenge to niche modelers. And for those species that have high dietary plasticity and tolerance to different climatic conditions, such as Yunnan snub-nosed monkey, Rhinopithecus bieti, possible impacts of climate change can be assessed by the species’ ecology and the presence of migration barriers surrounding the current ranges. This study demonstrates an integrative approach for assessing the potential impacts of climate change on the distribution of a species not suitable for common niche models and its implications on species conservation. We first developed vegetation models using regional vegetation cover, and a combination of climatic, geographic and disturbance-related variables. The vegetation cover was simulated referring to the A1B climate change scenario for year 2050 and 2100. We then analyzed migration pressure faced by R. bieti based on simulated vegetation changes and the species’ habitat preferences, and evaluated feasibility of range shift/expansion based on the presence of migration barriers around current group ranges. The results show that while the coverage of the most suitable habitat type (mixed forest) is expanding, regional forest cover is becoming increasingly fragmented. Four out of fifteen groups (G8–10, 12) of R. bieti are particularly vulnerable to climate change where habitat quality is reducing rapidly, while five of the groups (G8–12) have low adaptability to habitat change due to genetic isolation and limitations to range shift. This integrative approach offers a new and an important tool for evaluating potential impacts of climate change on highly adaptable but range-restricted species and is useful in guiding conservation practices. [Copyright &y& Elsevier]

Yunnan Province with numerous international rivers has huge impacts on downstream countries such as Burma, Laos and Vietnam. Agricultural expansion in Yunnan has conferred and continues to confer detrimental impacts on environments. In the past 43 years (1960-2003), the increase in crop yield was associated with a 99.1-fold increase in fertilizers, 2.0-fold in pesticides, and 0.4-fold in cultivated lands, respectively. Based on linear regression of the past trend, the next doubling of crop yield in the future would be accompanied by the increase in fertilizer application (from about 1.3×109 kg to 3.6×109 kg), and the increase in application of pesticides (from about 2.7×107kg to 9.6×107 kg). Similarly, the total amount of cultivated lands would increase from about 5.9×106 hato 9.3×106 ha. In the past decades, these changes have caused a series of environmental problems such as agricultural non-point source pollution (ANSP), deforestation, land degradation, and biodiversity loss. If the escalating status continues as our prediction, those problems would get worse and be tough to be dealt with. As for the situation in this region, some practices to minimize the impacts should be implemented in controlling population growth, protecting wetlands, developing tourism, and utilizing fertilizers and pesticides more rationally. [ABSTRACT FROM AUTHOR]

Abstract: After Sepharose 4B polymer beads were activated by using epichlorohydrin, hemin was binded with them to prepare an immobilized hemin affinity chromatography column. The coupling rate of this column was very high, more than 0.25mg hemin could be fixed by 1g of wet Sepharose 4B beads. The column equilibrated with deionized water and eluated with pH 3.0 NaAc–HAc buffer was applied to capture the proteins in human serum, earthworm body and Bacillus subtilis cells. Three polypeptides in human serum were captured, one of which was verified as serum albumin after comparison to the control. At least one polypeptide in earthworm body, two in Bacillus subtilis cells displayed the powerful binding specificity to hemin. Our experiments demonstrated that the immobilized hemin affinity chromatography was available as a probe for some proteins having potentiality to bind with heme. [Copyright &y& Elsevier]

Building ecological networks can effectively enhance the quality and stability of ecosystems and better conserve biodiversity. Previous studies mainly determined ecological corridors based on selecting ecological sources at a regional scale (e.g., an administrative area), without considering the bioclimatic heterogeneity within the study area. Here, we propose a novel integrating approach involving bioclimatic zoning and selecting ecological sources from various bioclimatic zones to design ecological corridors. Taking Xi'an City, China, as an example, key bioclimatic variables were first chosen, and we partitioned the study area based on its bioclimatic characteristics through a combination of K-means clustering and variance inflation factor (VIF). Ecological sources were then identified from the combination of ecosystem services and habitats of 36 endangered species. Subsequently, the minimum cumulative resistance (MCR) model was used to build ecological networks within different bioclimatic zones and across the entire region. We found the following: (1) In Xi'an city, a total of 49 source areas and 117 corridors were identified. The identified network can protect 97.77% of species, facilitating connectivity between 30.50% of ecosystems and 35.5% of species-rich areas. (2) The integrating approach protects 12.26% more species richness and 10.95% more ecosystem services than the average value of the regional and bioregional approaches. Compared to regional and bioregional methods, integrating approaches demonstrate greater advantages in preserving species richness and ecosystem services. This study introduces a novel approach to constructing regional ecological networks, which integrates the impact of bioclimatic zoning into the process of network construction to improve ecosystem services and protect species habitats. [ABSTRACT FROM AUTHOR]

While air quality in China has improved significantly in recent years, the population is becoming increasingly vulnerable to air pollution due to the aging population. In this study, we assessed premature deaths attributable to long- and short-term exposures to PM2.5 and O3, as well as their driving forces in Shandong from 2014 to 2060 based on county-level near-real-time air pollutant concentration datasets and projected concentrations of PM2.5 and O3. We found that the concentrations of PM2.5 and O3 in most districts and counties from Shandong are still higher than the corresponding concentration limit of Grade II. Premature mortality caused by long- and short-term exposures to PM2.5 decreased by 13,045 and 8092 in 2020 compared with those in 2014, respectively. Furthermore, premature mortality attributable to short-term exposure to O3 was 36.08% higher than that due to short-term exposure to PM2.5 in 2020. The results of the driving force analysis indicate that the health benefits brought about by the improvement in air quality have been offset by the changes in population age structure. In the future, the increase in O3 concentration and population aging are the top two driving forces having adverse effects on the health burden. This study provides support for controlling the health risks of PM2.5 and O3 pollution, especially for the development of dual-pollutant concentration targets and synergistic control strategies. [ABSTRACT FROM AUTHOR]

Chiral lactic acids and their ester derivatives are crucial building blocks and intermediates for the synthesis of a great variety of valuable functional materials and pharmaceuticals. Before our study, the reports about the enantioselective preparation of pure L-lactic acid and its ester derivatives through direct hydrolysis of racemic substrate were quite rare. Herein, we heterologously expressed and functionally characterized one novel microbial esterase WDEst9 from Dactylosporangium aurantiacum, which exhibited high resistance to diverse metal ions, organic solvents, surfactants, NaCl and KCl. We further utilized WDEst9 as a green biocatalyst in the kinetic resolution of (±)-methyl lactate through direct hydrolysis and generated L-methyl lactate with high enantiomeric excess (e.e. >99%) and high yield (>86%) after process optimization. Notably, the enantioselectivity of WDEst9 was opposite than that of two previously reported esterases PHE14 and BSE01701 that can generate D-methyl lactate though kinetic resolution of (±)-methyl lactate. Microbial esterase WDEst9 is a promising green biocatalyst in the preparation of valuable chiral chemicals and opens the door for the identification of useful industrial enzymes and biocatalysts from the genus Dactylosporangium. [ABSTRACT FROM AUTHOR]

Abstract Blueberry (Vaccinium corymbosum L.) is a deciduous flowering shrub, which originates from North America. In recent years, Blueberry has been introduced into subtropical China where featured with high temperature climates. Understanding the thermal endurance ability of different blueberry cultivars is necessary for heat-tolerant cultivars selection and plantation in subtropical China. We conducted a comparative study on six cultivars including 'Bluecrop', 'Duke', 'Brigitta', 'Gulfcoast', 'O'Neal', and 'Blue Ridge' at different temperatures of 25/20, 30/25, 35/30, or 40/35℃ (day/night) to examine the changes of growth, physiology, and biochemistry in blueberry plants. We found that the biomass of blueberry plants generally shared bell-shaped curves with increasing growth temperatures, indicating different optimal growth temperature for each cultivar. Meanwhile, the six blueberry cultivars also shared different heat endurance abilities that the appearances of 'Duke' and 'Blue Ridge' featured with wilted plants and defoliated leaves, but the other four cultivars ('Bluecrop', 'Brigitta', 'Gulfcoast', and 'O'Neal') present better appearances under high temperature stress. The good performances of the four heat tolerant cultivars in response to high temperature stress may benefit from the higher transpiration rates, which can dissipate much more heat through leaf transpiration than the two heat sensitive cultivars ('Duke' and 'Blue Ridge'). Thus, the heat tolerant cultivars suffered less from high temperature stress can be attributed to the higher efficiency of heat dispersion, which may be explained by the changes in the distribution pattern of stomata and the total stomatal aperture area per leaf area (SAAI) through altering the stomatal density as well as the aperture size and shape of individual stoma. These findings suggested that thermal tolerant cultivars may improve their heat dispersing efficiency through regulating stomatal traits to protect harmful impacts on chloroplast structure and function, and membrane thermostability from high temperature stress as evidenced by the intact chloroplasts as well as the higher F v / F m and electrolyte leakage than the two heat sensitive cultivars. [ABSTRACT FROM AUTHOR]

This paper designs an ellipsoidal tube‐based output feedback robust model predictive control approach for linear systems with bounded disturbances and noises subject to physical constraints. The ellipsoidal tube‐based output feedback robust model predictive control approach combines the off‐line optimization to compute controller parameters and deal with system uncertainties, and the on‐line optimization to stabilize the nominal system with time‐varying tightened constraints. In the off‐line optimization, the state observer gain, ancillary feedback controller gain, and tightened constraint sets on the nominal system are synthesized in one optimization. Then, an ellipsoidal terminal constraint set with terminal controller gain and terminal cost matrix, and tightened constraint sets related to different sizes of estimation error bounds are computed. In the on‐line model predictive control optimization with time‐varying tightened constraints, a sequence of nominal control inputs is receding horizon optimized to steer the nominal system state to the ellipsoidal terminal constraint set. When the current nominal system state is bounded within the ellipsoidal terminal constraint set, the nominal control inputs are switched to the feedbacks on the closed‐loop nominal system states. Recursive feasibility of the proposed algorithm and robust stability of the controlled system are guaranteed. [ABSTRACT FROM AUTHOR]

Water is a limiting factor for plant growth and vegetation dynamics in alpine sandy land of the Tibetan Plateau, especially with the increasing frequency of extreme precipitation events and drought caused by climate change. Therefore, a relatively stable water source from either deeper soil profiles or ground water is necessary for plant growth. Understanding the water use strategy of dominant species in the alpine sandy land ecosystem is important for vegetative rehabilitation and ecological restoration. The stable isotope methodology of δD, δ18O, and δ13C was used to determine main water source and long-term water use efficiency of Salix psammophila and S. cheilophila, two dominant shrubs on interdune of alpine sandy land in northeastern Tibetan Plateau. The root systems of two Salix shrubs were investigated to determine their distribution pattern. The results showed that S. psammophila and S. cheilophila absorbed soil water at different soil depths or ground water in different seasons, depending on water availability and water use strategy. Salix psammophila used ground water during the growing season and relied on shallow soil water recharged by rain in summer. Salix cheilophila used ground water in spring and summer, but relied on shallow soil water recharged by rain in spring and deep soil water recharged by ground water in fall. The two shrubs had dimorphic root systems, which is coincident with their water use strategy. Higher biomass of fine roots in S. psammophila and longer fine roots in S. cheilophila facilitated to absorb water in deeper soil layers. The long-term water use efficiency of two Salix shrubs increased during the dry season in spring. The long-term water use efficiency was higher in S. psammophila than in S. cheilophila, as the former species is better adapted to semiarid climate of alpine sandy land. [ABSTRACT FROM AUTHOR]

This study aims to investigate the level of soil microbial biomass (MB) and analyze the relationships between soil MB and edaphic, vegetational and climatic factors at high elevation sites (>3000 m). We collected soil samples from 0 to 10 cm soil depth in 259 plots at 55 sites across 6 biomes in Three-River Headwaters (TRH) region at 3280–5127 m elevation. Soil microbial biomass carbon and nitrogen (MBC and MBN) were measured with the chloroform fumigation–extraction method. Multivariate stepwise regression analyses were used to analyze the combined effects of edaphic, vegetational and climatic factors on soil MB. We found: (1) soil MBC and MBN had an average of 30.95 mmol C/kg dry soil and 5.84 mmol N/kg dry soil in TRH, respectively, and their values were found to be negatively correlated with elevation; (2) soil MB was found to be significantly different among different biomes, and this spatial variation could be explained by the levels of soil organic carbon and belowground plant biomass. Our results indicate that the MB at high elevation region might be very low, and the increasing trend of soil microbial biomass with elevation could reverse at higher elevations. [ABSTRACT FROM AUTHOR]

Quantifying forest carbon storage and its spatial distribution at regional scales is critical for the creation of greenhouse gases inventories, the evaluation of forest services and carbon-oriented forest management. The plot-based forest inventory (PBFI) and stand-based forest inventory (SBFI) collect extensive information on trees and stands respectively, and together, provide an opportunity to improve the regional estimates of forest carbon. In this study, we applied the SBFI to overcome the spatial extent limits of the PBFI in neighboring plots and improve the regional carbon estimation. We found that the forests in Sichuan Province reserved a total of 624.2 Tg C in biomass and featured a large spatial heterogeneity, with high values in natural forests and low values in plantations. We found that the solo use of PBFI derived a slightly higher (46.63 Mg C/ha) estimation on average compared with the integrated method (43.6 Mg C/ha). However, when considering the spatial distribution, the PBFI generated an overestimation of young forests located between 3000and 4000 m in elevation, and an underestimation in mature forests. The spatially explicit biomass carbon estimation could be helpful in guiding regional forest management and biodiversity conservation. [ABSTRACT FROM PUBLISHER]

Sodium sulfide (SS) was added to the non-detoxified wheat straw hydrolysate for ABE fermentation by Clostridium acetobutylicum CICC8012. Biochemical measurements demonstrated that supplementation with SS promoted earlier and enhanced conversion of acid to ABE and led to a 27.48% improvement in sugar consumption, a 20.48% improvement in the sugar-based ABE yield, a 47.63% improvement in the butanol titer, and a 53.50% improvement in the ABE concentration. The response of C. acetobutylicum CICC8012 at the mRNA level was examined by a transcriptional analysis performed with RNA sequencing. The expression of genes involved in the membrane transport of carbohydrates, glycolysis, and ABE formation increased following SS-supplemented fermentation, whereas the expression of genes encoding enzymes involved in acid formation decreased, which indicates that supplemental SS affected the central fermentative pathway, down-regulated the metabolic flux toward the acid formation branches, and up-regulated the metabolic flux toward the ABE formation branches. [ABSTRACT FROM AUTHOR]

Highlights: [•] The histones purified from pig liver tissue were immobilized onto Sepharose 4B to create a histone-Sepharose column. [•] Two isoforms of prion protein (PrPc) were obtained during the chromatography of cow milk casein by histone-Sepharose column. [•] The PrPc-Sepharose column was prepared and used to separate the histones. [•] H3 in the histones was convinced to interact with PrPc. [Copyright &y& Elsevier]

The Tibetan Plateau (TP) has a variety of vegetation types that range from alpine tundra to tropic evergreen forest, which play an important role in the global carbon (C) cycle and is extremely vulnerable to climate change. The vegetation C uptake is crucial to the ecosystem C sequestration. Moreover, net reduction in vegetation C uptake (NRVCU) will strongly affect the C balance of terrestrial ecosystem. Until now, there is limited knowledge on the recovery process of vegetation net C uptake and the spatial-temporal patterns of NRVCU after the disturbance that caused by climate change and human activities. Here, we used the MODIS-derived net primary production to characterize the spatial-temporal patterns of NRVCU. We further explored the influence factors of the net reduction rate in vegetation C uptake (NRRVCU) and recovery processes of vegetation net C uptake across a unique gradient zone on the TP. Results showed that the total net reduction amount of vegetation C uptake gradually decreased from 2000 to 2015 on the TP (Slope = −0.002, P < 0.05). Specifically, an increasing gradient zone of multi-year average of net reduction rate in vegetation carbon uptake (MYANRRVCU) from east to west was observed. In addition, we found that the recovery of vegetation net C uptake after the disturbance caused by climate change and anthropogenic disturbance in the gradient zone were primarily dominated by precipitation and temperature. The findings revealed that the effects of climate change on MYANRRVCU and vegetation net C uptake recovery differed significantly across geographical space and vegetation types. Our results highlight that the biogeographic characteristics of the TP should be considered for combating future climate change. • An increasing gradient zone of net reduction rate in vegetation C uptake from east to west on TP was observed. • Vegetation C uptake recovery differs significantly across geographical space and vegetation types. • The recovery time to normal levels of vegetation C uptake was differed between alpine steppes and meadows. • Restoration of alpine steppes and alpine meadows were primarily dominated by precipitation and temperature, respectively. [ABSTRACT FROM AUTHOR]