Responses of microbial activities and soil physical-chemical properties to the successional process of biological soil crusts in the Gurbantunggut Desert,Xinjiang

Biological soil crusts （BSCs） are capable of modifying nutrient availability to favor the establishment of biogeochemical cycles. Microbial activities serve as critical roles for both carbon and nutrient transformation in BSCs. However, little is known about microbial activities and physical-chemical properties of BSCs in the Gurbantunggut Desert, Xinjiang, China. In the present research, a sampling line with 1-m wide and 20-m long was set up in each of five typical interdune areas selected randomly in the Gurbantunggut Desert. Within each sampling line, samples of bare sand sheet, algal crusts, lichen crusts and moss crusts were randomly collected at the depth of 0-2 cm. Varia- tions of microalgal biomass, microbial biomass, enzyme activities and soil physical-chemical properties in different succession of BSCs were analyzed. The relationships between microalgal biomass, microbial biomass, enzymatic activities and soil physical-chemical properties were explored by stepwise regression. Our results indicate that micro- algal biomass, microbial biomass and most of enzyme activities increased as the BSCs developed and their highest values occurred in lichen or moss crusts. Except for total K, the contents of most soil nutrients （organic C, total N, total P, available N, available P and available K） were the lowest in the bare sand sheet and significantly increased with the BSCs development, reaching their highest values in moss crusts. However, pH values significantly decreased as the BSCs developed. Significant and positive correlations were observed between chlorophyll a and microbial biomass C. Total P and N were positively associated with chlorophyll a and microbial biomass C, whereas there was a significant and negative correlation between microbial biomass and available P. The growth of cyanobacteria and microorganism contributed C and N in the soil, which offered substrates for enzyme activities thus increasing enzyme activities. Probably, improvement in enzyme activities increased soil fertility and promoted the growth of cyanobacteria, eukary- otic algae and heterotrophic microorganism, with the accelerating succession of BSCs. The present research found that microalgal-microbial biomass and enzyme activities played important roles on the contents of nutrients in the successional stages of BSCs and helped us to understand developmental mechanism in the succession of BSCs.

Alien invasive species in Siberia:current status and problem

Although alien and invasive plant species have been researched extensively in the European part of Russia,the situation in Siberia is another matter.Hitherto,alien and invasive species in Siberia have not received much attention because this problem was not especially acute in Siberia.The lack of attention on alien and invasive species in Siberia is attributed to three major reasons：1） Low vegetative productivity and sparse human populations in the Siberian territory have limited botanical research interest in the area.2） Severe Siberian climate likely prevents many alien and invasive species from increasing their distribution into Siberia.3） Most Siberian plant communities have not been human-transformed and thus may be resistant to newcomers.Nevertheless,recent increased economic activities have resulted in increasing plant migration to Siberia,and this process should be monitored.Furthermore,global environmental changes may also have made Siberia more favorable for more alien and invasive species.Currently,research on alien and invasive species has begun in the Altai-Sayan region（Western Siberia） and the Magadan region （Northeastern Asia）.

Chemical composition and phytotoxic activity of the volatile oil of invasive Xanthium italicum Moretti from Xinjiang,China

Aerial parts of Xanthium italicum in an air tight container greatly inhibited root elongation of radish, implying that this invasive plant could release biologically active volatile organic compounds （VOCs） into the environment to affect other plants＇ growth. This phenomenon was further studied by evaluating the phytotoxic effects of X. italicum essential oil against two dicot plants, amaranth （Amaranthus mangostanus L.） and lettuce （Lectuca sativa L.）, and two monocot plants, wheat （Triticum aestivum Linn） and ryegrass （Lolium multiforum）, and analyzing the chemical composition of the oil. Among the 4 test species, amaranth was the most sensitive plant, 0.5μl/mL essential oil application resulted in a 50% reduction on root elongation, and 2.5 μl/mL essential oil almost completely inhibited its seedling growth. Wheat was the least sensitive species, whose root growth was reduced to 36% of control by 5 μl/mL essential oil. The essential oil exerted moderate inhibitory effect on both lettuce and ryegrass. Compared to a commercial herbicide-Harness, X. italicum oil exhibited stronger phytotoxicity on amaranth, lettuce and wheat, but weaker activity on ryegrass. The chemical composition of the essential oil isolated by hydrodistillation from the aerial parts of X. italicum Moretti was analyzed by GC/MS. Thirty two compounds were identified, representing 94.89% of total oil, which was found to be rich in monoterpene hydrocarbons （60.71%）. The main constituents of the oil were limonene （51.61%）, germacrene B （6.98%）, 6-cadinol （5.94%）, β-pinene （5.23%）, α-caryophyllene （5.1%） and bornyl acetate （3.15%）. Bioassay revealed the dominant constituent-limonene, was unlikely the responsible phytotoxic compound due to its low biological activity; rather, there might be other oil constituent（s） that either act alone, or work together, and possibly assisted by synergistic effect, to display the phytotoxic activity. Our results suggested that X. italicum might produce allelopathic VOCs to facilitate its invasion success. This is the first report on the phytotoxic activity and the chemical composition of the essential oil of X. itaficum Moretti from China.

The improved FASTmrEMMA and GCIM algorithms for genome-wide association and linkage studies in large mapping populations

Owing to high power and accuracy and low false positive rate in our multi-locus approaches for genome-wide association studies and linkage analyses,these approaches have attracted considerable attention in plant and animal genetics.In large mapping population,however,fast multi-locus random-SNP-effect efficient mixed model association(FASTmrEMMA)and genome-wide composite interval mapping(GCIM)run a relatively long time.To address this issue,we proposed the improved FASTmrEMMA and GCIM algorithms in this study.In the new algorithms,some matrix identities,such as the Woodbury matrix identity,were used.In scanning each marker on the entire genome,in other words,the improved algorithms effectively replace the expensive eigenvector solutions in(restricted)maximum likelihood estimations in original algorithms with two(one)updated inner products and one updated vector-matrix-vector multiplication.Simulated and real data analyses showed that their computational efficiencies are increased sharply in large mapping population,although there are no mapping result differences between original and improved algorithms.In addition,the related software packages(mrMLM.GUI and QTL.gCIMapping.GUI)can be downloaded from the R and BioCode websites.

Metastable-phaseβ-Fe_(2)O_(3) photoanodes for solar water splitting with durability exceeding 100 h

Planar films of pure and Ti^(4+)-dopedβ-Fe_(2)O_(3)were prepared by a spray pyrolysis method.X-ray diffraction patterns and Raman spectra of the metastableβ-Fe_(2)O_(3)film showed that its thermal stability was significantly improved because of covalent bonds in the interfaces between the film and substrate,while only weak Van der Waals bonds existed at the interfaces within the particle-assembledβ-Fe_(2)O_(3)film prepared by electrophoretic deposition.The as-prepared planar films were thus able to withstand higher annealing temperature and stronger laser irradiation power in comparison with theβ-Fe_(2)O_(3)particle-assembly.Ti^(4+)doping was used to increase the concentration of carriers in the metastableβ-Fe_(2)O_(3)film.Compared with pureβ-Fe_(2)O_(3)photoanodes,the highest saturated photocurrent for water splitting over the Ti^(4+)-dopedβ-Fe_(2)O_(3)photoanode was increased by a factor of approximately three.Theβ-Fe_(2)O_(3)photoanode exhibited photochemical stability for water splitting for a duration exceeding 100 h,which indicates its important potential application in solar energy conversion.

Characteristics and utilization of plant diversity and resources in Central Asia

The geographical region of Central Asia comprises Kazakhstan,Kyrgyzstan,Tajikistan,Uzbekistan,Turkmenistan,and the Xinjiang Uygur Autonomous Region of China.Central Asia’s temperate forests,steppes,and sandy deserts,including riparian tugai forests,have been identified by the World Wide Fund for Nature as Global 200 ecoregions,and the Mountains of Central Asia are considered biodiversity hotspots.Here,we describe and analyze the diverse characteristics and utilization of plant diversity and resources of the region.We confirm that there are 9520 species of higher plants,20%of which are endemic species,belonging to 138 families and 1176 genera.The vegetation geography of Central Asia can be divided into 5 provinces and 33 districts,and more than 65%species have a Central Asian geographical distribution pattern.Plant resource utilization can be grouped into 5 categories and 31 subcategories,including food,medicine,industry,environmental protection,construction,and plant germplasm.In this review,we also discuss the principal threats to plant biodiversity in Central Asia posed by global climate change and offer recommendations for conservation strategies.

Diaspore characteristics and ecological adaptation of Bromus tectorum L.from different distribution regions

The invasion of nonnative plants is considered one of the main threats to the structure and function of North American ecosystems. Moreover, they can alter ecosystem processes and reduce biodiversity. In arid and semi-arid region of North America, the species of European annual grass Bromus tectorum L. is an outstanding example of these problems, which not only increase the fire density and change the fire regime, but replace native communities. Therefore, there are amount of researches on B. tectorum, including resource acquisition, water use efficiency and growth. Whereas the relevant research on the morphology of diaspore is scare. Diaspores have a fundamental role in seed germination and seedling establishment. Besides, as an important link between different generations, diaspores have a vital significance on individual reproduction and population extension. Hence, dias- pores under selection for studying have an important implication. This study compares differences in seed mor- phology for Bromus tectorum collected from the United States, Kazakhstan, and Xinjiang of China. The following indices of B. tectorum diaspores were analyzed： size, thickness of covering layers, and micromorphological char- acteristics of the base, middle and transition area of diaspores as well as of the awn. Micromorphology of the lemma and the cross-section of the diaspore were observed by scanning electron microscopy. Results showed that thick- ness of the lemma and the palea of diaspores from B. tectorum-infested grasslands in the United States were re- duced （P〈0.05）, likely because of environmental influences. This reduction facilitated the germination of diaspores and lowered the resistance of B. tectorum to adverse environmental conditions. The length of the awn also in- creased significantly （P〈0.05）, which helped in dispersal and anchoring of diaspores. Therefore, B. tectorum adapted ecologically to its new environment in the United States by strengthening its establishment ability. However, the defense capability of B. tectorum decreased. These results fit the evolution of increased competitive ability hy- pothesis （EICA） of invasive species. Analysis of various cells on the lemma revealed that prickle densities and col- lapsed, long epidermal cells were easily influenced by environmental factors such as temperature and moisture because of the physiologic function of these structures on silicon accumulation. However, the form and the position of silica cells, which were not greatly influenced by environmental factors, might be genetically controlled. Studying these structures at the microscopic level helps define the relationship between the diaspore and its environment. This study has a reference value for future studies on B. tectorum.

Selecting flagship species to solve a biodiversity conservation conundrum

The difficulty of effectively monitoring and managing the environment to conserve biodiversity is as yet an unsolved conundrum.A project of the Chinese Academy of Sciences has concluded that progress can be made through the use of flagship species selected using criteria drawn from conservation biology,ecosystem function,socio-economics,and cultural importance.Inclusion of the latter three criteria will help attract and maintain the commitment of the public to play full parts in carrying out any conservation measures needed.A system is proposed for scoring species to select those that are most suitable as flagships.This method can be used regardless of the size of the area chosen for attention,whether it is a region,a country,or a particular protected area.

Preparation of Kenaf Biochar and Its Adsorption Properties for Methylene Blue

The toxic dyestuff's from printing and dyeing wastewater have caused serious damages to the ecological environ-ment,thus exploring effective methods to remove them having become a key topic.Here,a series of biochar sam-ples were synthesized form kenaf to adsorb methylene blue(MB),which was acted as the dye representative for the test of adsorption capacity due to the presence of abundant double bond and aroma tic heterocyclic ring.By tuning the raw materials and pyrolysis temperature,a super adsorption capacity about 164.21 mg·g^(-1) was obtained over the biochar that pyrolyzed at 700℃ with the kenaf fiber as raw material Through the physical adsorption,elemental analysis,FTIR spectra and NH_(3)-TPD,it was found the high surface area and pore volume of biochar played a key role in the adsorption of MB,and the acidic sites would also assist the adsorption process.Besides,the adsorption kinetic model was ftted and calculated,implying the MB physically adsorbed on the bio-char rapidly and then occurred chemical adsorption on the acidic sites.In addition,through KBC700 recycling experiments,it was found that kenaf biochar had a good binding force to MB,which effectively avoided secondary pollution.This work provides important insights for the adsorption mechanism of MB by biochar,also offers some guidance for the further synthesis of biochar from various biomass.

西北荒漠区土壤氮素组分沿干旱梯度的空间变化

旱区面积占比大,对全球气候变化响应敏感。氮素通常被认为是荒漠生态系统的第二大限制资源,存在不同的形态,然而目前尚不清楚干旱程度如何影响土壤氮素的空间分布。本研究基于中国西北荒漠区54个样点的无机氮、有机氮和全氮数据,结合气候环境数据,探究不同干旱程度下,西北旱区氮素组分的空间变化及驱动要素。结果表明:土壤氮素沿干旱梯度的空间变化存在明显的干旱阈值(0.87),土壤氮素组分的空间变化对干旱程度的响应呈现突变特征;在阈值附近,土壤全氮、有机氮含量和有机无机氮比例急速上升,而硝态氮含量快速下降;干旱阈值前后的全氮和有机氮含量均随干旱增加而显著下降;0~10 cm土层内,土壤全氮和有机氮含量随土层的加深而逐渐增加。干旱程度会直接或通过土壤含水率、电导率和pH间接影响氮素组分的空间变化。

The extremotolerant desert moss Syntrichia caninervis is a promising pioneer plant for colonizing extraterrestrial environments

Many plans to establish human settlements on other planets focus on adapting crops to growth in controlled environments.However,these settlements will also require pioneer plants that can grow in the soils and harsh conditions found in extraterrestrial environments,such as those on Mars.Here,we report the extraordinary environmental resilience of Syntrichia caninervis,a desert moss that thrives in various extreme environments.S.caninervis has remarkable desiccation tolerance;even after losing>98%of its cellular water content,it can recover photosynthetic and physiological activities within seconds after rehydration.Intact plants can tolerate ultra-low temperatures and regenerate even after being stored in a freezer at80C for 5 years or in liquid nitrogen for 1 month.S.caninervis also has super-resistance to gamma irradiation and can survive and maintain vitality in simulated Mars conditions;i.e.,when simultaneously exposed to an anoxic atmosphere,extreme desiccation,low temperatures,and intense UV radiation.Our study shows that S.caninervis is among the most stress tolerant organisms.This work provides fundamental insights into the multi-stress tolerance of the desert moss S.caninervis,a promising candidate pioneer plant for colonizing extraterrestrial environments,laying the foundation for building biologically sustainable human habitats beyond Earth.

齿肋赤藓的亲缘地理结构显示其在冰期出现扩张

青藏高原的快速隆升和干旱化对该地区植物的分布和群落结构产生了显著影响。然而,大部分的研究都集中在维管植物上,苔藓植物作为单倍体植物,在第四纪剧烈的地质和气候环境变化中是否与其他维管植物具有相似的种群动态历史尚不清楚。本研究以齿肋赤藓(Syntrichia caninervis)为研究对象,利用2个叶绿体片段和19个核卫星位点对27个齿肋赤藓种群进行了基因分型,并模拟其在末次间冰期潜在分布区,以期揭示齿肋赤藓的遗传变异、分化和种群动态历史。研究结果表明,齿肋赤藓种群在青藏高原、帕米尔高原-天山和中亚的遗传特征一致,其遗传变异主要发生在种群内和特定区域的种群内,但不同区域间存在明显的基因交流。生态位模型预测结果显示齿肋赤藓可能在冰期扩张,在间冰期收缩。这为第四纪冰期和间冰期耐旱苔藓植物应对环境变化的种群动态历史提供了新的证据。

西北温带荒漠典型短生植物对积雪变化的响应

温带荒漠生态系统积雪变化影响植物的多样性、丰富度及其分布。这些生态系统中草本植物的生长和分布与积雪深度密切相关,积雪由于旱季缺水而成为生长期最重要的水资源。然而,温带荒漠植物对冬季积雪变化的响应仍不清楚。本研究旨在探讨积雪变化对草本植物根系生长的影响。以古尔班通古特沙漠为研究对象,研究了冬季4种积雪深度处理下荒漠典型短生植物尖喙牻牛儿苗(Erodium oxyrhinchum)的生长情况。4种积雪深度处理分别是:移除积雪(−S)、自然降雪、加2倍深度积雪(+S)和加3倍深度积雪(+2S)。研究结果显示,积雪深度的增加提高了草本植物的丰度和生长速度,同时也提高了这些植物的生物量(包括总生物量和个体生物量)。雪的添加显著增加了尖喙牻牛儿苗的叶面积,而叶干物质含量则对雪的添加呈现相反的响应。这些结果表明,该植物的地上部分比地下部分对积雪变化更敏感。积雪深度的变化也影响根系形态。积雪移除使侧根增多,增加积雪深度促进主根伸长,有助于其吸收更多的水分和养分。这些结果解释了冬季积雪深度的变化如何改变温带沙漠生态系统生长期间的植物生长、群落结构和生态系统功能。

新型冠状病毒肺炎(COVID-19)疫情持续中的治愈率/病死率估计

由新型冠状病毒SARS-CoV-2引起的疫情,已成为全球关注的紧急公共卫生事件.然而,由于疫情持续中的数据不断变化,对于疫情的治愈率和病死率尚无较为科学的计算方法.本研究提出了一种估计COVID-19治愈率和病死率的方法,以给定日累计出院人数与给定日累计出院人数和j日前累计死亡人数之和的比值来估计治愈率,此外,病死亡率也可以据此估计.当j=9时,新型冠状病毒肺炎全国的治愈率估计值为95.8%左右,而新型冠状病毒肺炎全国的病死率估计值为4.2%左右,这比2003年SARS疫情中国大陆的病死率6.6%低;武汉市的治愈率估计值为94.5%左右,而新型冠状病毒肺炎武汉市的病死率估计值则在5.5%左右.这种估计治愈率的方法可用于评价不同医疗方案和不同地区的治疗效果,对疫情的决策具有重要的参考价值和意义.

A highly durable catalyst based on CoxMn3-xO4 nanosheets for low-temperature formaldehyde oxidation

Cost-effective catalysts for the oxidation of volatile organic compounds （VOCs） are critical to energy conversion applications and environmental protection. The main bottleneck of this process is the development of an efficient, stable, and cost-effective catalyst that can oxidize HCHO at low temperature. Here, an advanced material consisting of manganese cobalt oxide nanosheet arrays uniformly covered on a carbon textile is successfully fabricated by a simple anodic electrodeposition method combined with post annealing treatment, and can be directly applied as a high-performance catalytic material for HCHO elimination. Benefiting from the increased surface oxygen species and improved redox properties, the as-prepared manganese cobalt oxide nanosheets showed substantially higher catalytic activity for HCHO oxidation. The catalyst completely converted HCHO to CO2 at temperatures as low as 100 ℃, and exhibited excellent catalytic stability. Such impressive results are rarely achieved by non-precious metal-based catalysts at such low temperatures.

“保护生物多样性,共建干旱区生命共同体”宣言

中国科学院新疆生态与地理研究所联合"一带一路"国际科学组织联盟,于2021年12月16-17日共同举办了"干旱区生物多样性保护与可持续发展国际研讨会",会议主题是"保护生物多样性,共建干旱区生命共同体"。来自中国生态环境部、联合国环境规划署、生物多样性公约秘书处、联合国防治荒漠化公约秘书处、联合国开发计划署、联合国教科文组织驻华代表处、"一带一路"国际科学组织联盟等机构的相关部门负责人及代表.

The influence of biological soil crusts on ^(15)N translocation in soil and vascular plant in a temperate desert of northwestern China

Aims Desert ecosystems are often characterized by patchy distribution of vascular plants,with biological soil crusts(BSC)covering interplant spaces.However,few studies have comprehensively examined the linkage between BSC and vascular plants through nitrogen(N)or element translocation.the objective of this study was to evaluate the ecological roles of BSC on N translocation from soil to the domi-nant herb Erodium oxyrrhynchum bieb.(geraniaceae)in a temper-ate desert in China.Methods Isotopes(including 15N-glu,15N-NH4Cl and 15N-NaNo3)were used as a tracer to detect translocation of N in two types of desert soil(BSC covered;bare)to the dominant herb E.oxyrrhynchum.three different forms of 15N-enriched N compounds were applied as a point source to small patches of BSC and to bare soil.and we measured isotopes(14N and 15N)and obtained the concentration of labeled-15N in both vascular plants and soils at different distances from substrate application Important Findings Plants of E.oxyrrhynchum growing in BSC-covered plots accumulated moreδ15N than those growing in the bare soil.similarly,soil from b Ccovered plots showed a higher concentration of labeled-N irrespective of form of isotope,than did the bare soil.the concentration of dissolved organic N(15N-glu)in E.oxyrrhynchum was higher than that of dis-solved inorganic N(15N-NH4Cl and 15N-NaNo3).soil covered by BSC also accumulated considerably more dissolved organic N than bare soil,whereas the dominant form of 15N concentrated in bare soil was dissolved inorganic N.Correlation analysis showed that the concentra-tion of labeled-N in plants was positively related to the concentration of labeled-N in soils and the N%recorded in E.oxyrrhynchum.our study supports the hypothesis that BSC facilitates ^(15)N translocation in soils and vascular plants in a temperate desert of northwestern China.

Enhanced removal of organic pollutant by separable and recyclable rGH-PANI/BiOI photocatalyst via the synergism of adsorption and photocatalytic degradation under visible light

A novel three-dimension separable and recyclable r GH-PANI/BiOI photocatalyst with the synergism of adsorption-enrichment and photocatalytic-degradation was successfully prepared via a facile three-step hydrothermal method.The three-dimension reduced graphene oxide hydrogel(rGH)in with flower-like BiOI photocatalyst uniformly distributed not only possesses excellent adsorption and electron transport properties,but also is easy to be separated from water for recycling.In addition,polyphenylamine(PANI)provides superior hole transport ability due to its delocalizedл-лconjugate structure.The cooperation of rGH and PANI greatly enhances the separation efficiency of photogenerated carriers,and finally improves the photocatalytic degradation behaviors.The removal rates of Rhodamine B(RhB)by rGH-PANI/BiOI-70%composite under visible light respectively reach 100%and 50.13%in static and dynamic systems,which are 12.85 and 3.58 times of BiOI,respectively.The removal rate does not show decrease after 5 recycles indicating the excellent separable and recyclable property of rGH-PANI/BiOI photocatalyst.The work provides an essential reference for designing and constructing hydrogel-based ternary composite photocatalysts with excellent synergism of adsorption and photocatalysis,which shows great potential in the treatment of water pollution.

Progress in the study of algae and mosses in biological soil crusts

Algae and mosses are not only two of the familiar communities in the process of desert vegetational succession,but also have the highest biomass in biological soil crusts.Meanwhile,being the pioneer plants,algae and mosses are involved in the establishment of biological soil crusts,which have great importance in arid environments and play a major role in desert ecosystems,such as being the indicator of the vegetation type,soil-holding,preventing erosion by water and wind,and sand fixation.This paper reviews the advances in the study of algae and mosses in arid and semi-arid areas.It mainly describes the ecological functions of algae and mosses including their influences on water cycle,circulation of substances,and community succession.In addition,the relationships between algae and mosses are discussed.Finally,some suggestions are proposed for the research orientations of algae and mosses in biological soil crusts.Ecologically,algae and mosses have significant ecological importance in arid areas,especially in those areas where environmental problems are becoming increasingly serious.

Challenges and possible solutions to creating an achievable and effective Post-2020 Global Biodiversity Framework

Global biodiversity is in crisis as a result of human activity.This biodiversity crisis has been well documented by scientists,recognized by world leaders,politicians,businesses,and citizens.Both the biodiversity and climate crises need to be addressed now.2020 was when this change was supposed to start,with the 15th Conference of Parties(COP15)of the Convention on Biodiversity(CBD)meeting in Kunming,and the 26th Conference of Parties(COP26)of the UN Framework Convention on Climate Change meeting in Glasgow,but both meetings were postponed.COP26 was held a year late(November 2021),while COP15 was split into two,with the first part held in Kunming in October 2021,and the second part scheduled for Montreal in December 2022.This meeting in Montreal-arguably the most important in the CBDs history-must agree on the Post-2020 Global Biodiversity Framework(GBF),to reverse biodiversity loss.Failure to reach agreement in Montreal would ultimately be a failure of us all,with irreversible consequences for life on earth.Yet,with three months before the final deadline only 20%of text and two targets are agreed.This paper reviews the factors hindering progress on the agreement and suggests possible solutions.