Dynamic mechanical characteristics of deep Jinping marble in complex stress environments

To reveal the dynamic mechanical characteristics of deep rocks,a series of impact tests under triaxial static stress states corresponding to depths of 300-2400 m were conducted.The results showed that both the strain rates and the stress environments in depth significantly affect the mechanical characteristics of rocks.The sensitivity of strain rate to the dynamic strength and deformation modulus shows a negative correlation with depth,indicating that producing penetrative cracks in deep environments is more difficult when damage occurs.The dynamic strength shows a tendency to decrease and then increase slightly,but decreases sharply finally.Transmissivity demonstrates a similar trend as that of strength,whereas reflectivity indicates the opposite trend.Furthermore,two critical depths with high dynamically induced hazard possibilities based on the China Jinping Underground Laboratory(CJPL)were proposed for deep engineering.The first critical depth is 600-900 m,beyond which the sensitivity of rock dynamic characteristics to the strain rate and restraint of circumferential stress decrease,causing instability of surrounding rocks under axial stress condition.The second one lies at 1500-1800 m,where the wave impedance and dynamic strength of deep surrounding rocks drop sharply,and the dissipation energy presents a negative value.It suggests that the dynamic instability of deep surrounding rocks can be divided into dynamic load dominant and dynamic load induced types,depending on the second critical depth.

Cloning of catalase gene and antioxidant genes in Scophthalmus maximus response to metalloprotease of Vibrio anguillarum stress

Metalloproteases represent a class of extracellular proteases found in Vibrio anguillarum that can generate toxic and pathogenic eff ects in turbot(Scophthalmus maximus).The toxicological eff ect partly results from oxidative damage due to the production of excessive reactive oxygen species(ROS).Catalase(CAT),superoxide dismutase(SOD),and glutathione peroxidase(GPx)are major antioxidant enzymes induced by various oxidative stresses and can scavenge peroxides generated in cells.To evaluate the eff ects of metalloprotease-induced ROS on the antioxidation defense mechanism of S.maximus head kidney cells,the cDNA of CAT gene(designated as SmCAT)was cloned and characterized.SmCAT comprises a 1584-bp coding sequence that encodes a protein containing 527 amino acids with a poly(A)tail.Bioinformatics analysis revealed an active site signature sequence,a heme-ligand signature sequence,and three catalytic amino acid residues.The deduced SmCAT amino acid sequence shares a sequence similarity of 66.1%-92.4%with those of other species.Phylogenetic analysis revealed that SmCAT is classifi ed with CAT of other fi shes.Quantitative real-time PCR analysis showed that SmCAT was extensively expressed in all tested tissues,especially in blood.The expression of SmCAT,SmMnSOD,and SmGPx were inhibited signifi cantly in head kidney cells treated with metalloprotease from 12 to 24 h.In 6 to 24 h metalloprotease-treated groups compared to that of the untreated group,it was found that the production of ROS was markedly increased,and the mitochondrial membrane potential was decreased considerably.Hoechst 33342 staining revealed the presence of apoptotic bodies when the cells were incubated with 8.0 or 40.0μg/mL metalloprotease for 12 and 24 h.Hence,the toxic eff ects of metalloprotease are associated with the down-regulation of antioxidant enzyme expression and increased ROS levels,which trigger the activation of apoptosis in the head kidney cells of turbot.Our fi ndings provide a better understanding on the mechanism of metalloprotease-induced apoptosis in fi sh.

中国特色、世界一流国家植物园的主要特征

2021年12月和2022年5月,国务院分别批复同意在北京设立国家植物园,在广州设立华南国家植物园。批复文件要求,国家植物园和华南国家植物园要建成中国特色、世界一流、万物和谐的国家植物园。国家植物园具有国家代表性、科学系统性和社会公益性。世界一流植物园应在植物迁地保护、科学研究、资源可持续利用、科普宣教和园林园艺展示等方面具有较强国际竞争力,且引领其他植物园发展。中国特色是指植物园在长期的实践中逐步形成的,具有中国特点的民族植物、传统文化、园林艺术、体制机制等。从植物园历史维度、功能维度和使命维度看,中国特色、世界一流的国家植物园的主要特征有:(1)具有一定的发展历史,在国家经济、社会发展和人民对美好生活需求的驱动下持续开展野生植物保护、研究与利用相关工作,在国内外植物园领域有一定的影响力;(2)在野生植物迁地保护、科学研究、资源可持续利用、科普宣教和园林园艺展示等5个功能领域,部分或全部处于国际领先水平;(3)服务国家重大战略,维护国家生态安全、生物安全、粮食安全,科技支撑国家或全球生物多样性保护、生态系统修复、气候变化应对和可持续发展。

Coastal blue carbon in China as a nature-based solution toward carbon neutrality

To achieve the Paris Agreement,China pledged to become“Carbon Neutral”by the 2060s.In addition to massive decarbonization,this would require significant changes in ecosystems toward negative CO_(2)emissions.The ability of coastal blue carbon ecosystems(BCEs),including mangrove,salt marsh,and seagrass meadows,to sequester large amounts of CO_(2)makes their conservation and restoration an important“nature-based solution(NbS)”for climate adaptation and mitigation.In this review,we examine how BCEs in China can contribute to climate mitigation.On the national scale,the BCEs in China store up to 118 Tg C across a total area of 1,440,377 ha,including over 75%as unvegetated tidal flats.The annual sedimental C burial of these BCEs reaches up to 2.06 Tg C year^(−1),of which most occurs in salt marshes and tidal flats.The lateral C flux of mangroves and salt marshes contributes to 1.17 Tg C year^(−1)along the Chinese coastline.Conservation and restoration of BCEs benefit climate change mitigation and provide other ecological services with a value of$32,000 ha^(−1)year^(−1).The potential practices and technologies that can be implemented in China to improve BCE C sequestration,including their constraints and feasibility,are also outlined.Future directions are suggested to improve blue carbon estimates on aerial extent,carbon stocks,sequestration,and mitigation potential.Restoring and preserving BCEs would be a cost-effective step to achieve Carbon Neutral by 2060 in China despite various barriers that should be removed.

National botanical gardens at the forefront of global plant conservation

Global changes in land use driven by demands on food,energy,and other resources in response to a rapidly increasing human population have collectively led to escalating environmental challenges,including biodiversity loss,global warming,environmental pollution,and ecosystem degradation.At present,biodiversity is seriously threatened at global,regional,and local scales,which,in turn,threatens our own survival.Biodiversity is a global asset of immense material and non-material value,providing us with food,medicine,building materials,fiber,and the ecological environment required for our well-being and health.

试论植物园功能变迁与中国国家植物园体系建设

植物资源是自然生态系统的基本组成部分,是经济社会可持续发展的重要物质来源,植物多样性是关系到国家生态安全和生物安全的战略资源。就地保护和迁地保护是植物多样性保护的两种主要方法,构建以国家公园为主体的自然保护地体系是就地保护的主要形式,构建以国家植物园为引领的植物园体系是迁地保护的主要形式,二者相辅相成,共同形成我国较为完整的植物多样性保护体系。通过建设国家植物园体系对我国植物多样性进行迁地保护,同时开展科学研究、园林展示、科普教育和资源开发利用,对深入推进生态文明建设和高质量发展具有重要意义。本文回顾了植物园的功能变迁、全球和中国植物园分布与数量以及植物迁地保护现状,讨论了植物园与植物迁地保护的关系,在此基础上,提出了我国国家植物园的定义及设立标准,进而讨论了建设国家植物园体系的意义、挑战、统筹迁地保护和就地保护等问题,最后提出了我国国家植物园体系的建设目标、管理体制、空间布局和认证等方面的建议,以期为我国的国家植物园体系建设提供参考。

南亚热带森林演替过程中土壤线虫群落结构变化

森林演替会通过改变植物群落组成和土壤环境影响土壤生物群落,反过来,土壤生物群落的变化也会对生态系统的演替产生反馈作用,但迄今南亚热带森林演替过程中土壤生物群落的变化特征尚不清晰。本研究以广东省鼎湖山的南亚热带森林演替序列(马尾松(Pinus massoniana)林–针阔叶混交林–季风常绿阔叶林)为对象,研究了森林演替过程中土壤线虫多样性和群落结构的动态变化及其影响因素。通过采集不同演替阶段的土壤样品,分析和比对了不同演替阶段土壤线虫的多度、多样性、群落组成、土壤线虫生态指数以及土壤理化性质的差异。结果表明:(1)在南亚热带森林演替过程中,针阔叶混交林和季风常绿阔叶林土壤线虫的α多样性显著高于马尾松林,但土壤线虫总数和各营养类群多度及其相对丰度并无显著变化;(2)针阔叶混交林中土壤线虫富集指数显著高于马尾松林,表明其土壤养分状况要好于马尾松林,而季风常绿阔叶林土壤线虫结构指数较高,表明其受干扰程度较低;(3)针阔叶混交林的土壤含水量和土壤理化性质(除土壤总磷含量)已达到季风常绿阔叶林的水平,但两者的土壤pH值均显著低于马尾松林,而土壤pH值和土壤含水量是影响土壤线虫群落动态变化的主要因素。综上所述,南亚热带森林中土壤线虫多度、多样性和群落结构对森林演替的响应略有不同,演替过程中土壤环境因素的趋同是导致针阔叶混交林和季风常绿阔叶林中土壤线虫多样性和群落特征相似的主要原因。

有害植物孪花蟛蜞菊扩张对西沙岛屿陆生软体动物的影响

有害植物孪花蟛蜞菊(Wedelia biflora)的扩张对我国西沙群岛原生植物群落结构和功能产生了深刻影响,但陆生软体动物如何响应该扩张却未见报道。本文调查了西沙群岛永兴岛孪花蟛蜞菊不同扩张程度下褐云玛瑙螺(Achatina fulica)、钻头螺科、坚齿螺科和拟阿勇蛞蝓科等主要陆生软体动物的残体分布情况,测定了残体的分布密度和壳高、壳宽、壳重等可量化性状指标,研究了孪花蟛蜞菊扩张对陆生软体动物种群的影响。结果表明:(1)随孪花蟛蜞菊扩张程度增加,钻头螺科和褐云玛瑙螺的种群密度增加,坚齿螺科种群密度减小,拟阿勇蛞蝓科种群密度出现先增加后减少的趋势;(2)陆生软体动物类群的体型分布频率随孪花蟛蜞菊扩张呈现不同的变化趋势,褐云玛瑙螺较小个体数量增加,其他陆生软体动物体型分布变化不明显或较大体型残体分布增加;(3)孪花蟛蜞菊扩张对褐云玛瑙螺体型特征产生抑制作用,褐云玛瑙螺主要采用r策略来响应有害植物扩张的影响。综上,有害植物孪花蟛蜞菊在热带珊瑚岛屿植被中的扩张改变了陆生软体动物的形态、密度与种群结构,不同的软体生物类群表现出不同响应策略,在海岛有害生物的综合防治过程中应该引起足够重视。

Pathways and Determinants of Early Spontaneous Vegetation Succession in Degraded Lowland of South China

Continuous and prolonged human disturbances have caused severe degradation of a large portion of lowland in South China, and how to restore such degraded ecosystems becomes an increasing concern. The process and mechanisms of spontaneous succession, which plays an important role in vegetation restoration, have not been adequately examined. To identify the pathways of early spontaneous vegetation succession, 41 plots representing plant communities abandoned over different times were established and investigated. The communities and indicator species of the vegetation were classified by analyzing the important values of plant species using multivariate analyses. The results indicated that the plant species could be classified into nine plant communities representing six succession stages. The pathway and species composition also changed in the process of succession. We also measured 13 environmental variables of microtopography, soil structure and soil nutrition in each plot to examine the driving forces of succession and the vegetation-environment relationships. Our results showed that the environmental variables changed in diverse directions, and that soil bulk density, soil water capacity and soil acidity were the most important factors.

Environmental remediation promotes the restoration of biodiversity in the Shenzhen Bay Estuary,South China

Background:Rapid urbanization has greatly changed land-use patterns in many estuarine areas around the world,including the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)resulting in serious water pollution and ecosystem degradation.Shenzhen City has conducted comprehensive ecological management and restoration in the Shenzhen Bay since 2007.The natural vegetation consisting of mangroves,semi-mangroves,wetland plants,and terrestrial plants were restored from the bund to the inner bank of the Fengtang River.Rain and sewage flow diversion systems were established.The non-point source and point-source sewage are now treated in municipal sewage treatment plants,then naturally flow through the constructed wetland,and then through a natural wetland,restored natural embankment,and finally through mangrove communities substantially improving water quality.Result:The restoration of the wetland has increased animal and microbial diversity and has supported the establishment of a complex and stable food web.With water purification and habitat restoration,the number of alien invasive plants in the estuarine ecosystem has decreased,and the diversity of native species of birds,fish,macrobenthos,amphibians,and reptiles has increased.Conclusion:These improvements indicate that human beings and nature can coexist in support of the sustainable development of Shenzhen City.

Conservation and reintroduction of the rare and endangered orchid Paphiopedilum armeniacum

Paphiopedilum armeniacum is a rare and endangered lady’s slipper orchid in China.It is distributed around the mid-elevations of the Nu Mountains in southwest China.Due to over-harvest,habitat loss,and degradation,wild populations of P.armeniacum has declined drastically.A combination of approaches involving biotechnology,habitat restoration,and interspecific relationship reconstruction was used to carry out the reintroduction of the species.Integrated conservation program for this species included in-situ protection,ex-situ conservation,and reintroduction,which helped to rebuild a harmonious relationship between local farmers and P.armeniacum.The sustainable utilization of native plant resources in poor areas can promote regional sustainable development which is compatible with species protection.