大洲岛海杧果群落及其物种多样性特征

通过野外实地调查对海南省万宁市大洲岛的海杧果群落特征及其物种多样性进行研究,以期为海杧果的种质保护、海防林物种的合理搭配及红树林生态恢复提供参考。结果表明：调查样方内有维管束植物62种,隶属于37科58属。乔木层的优势种为海杧果,重要值为36.45%;灌木层的优势种为矮紫金牛,重要值为8.31%;草本层的优势种为观音草,重要值为25.53%。种子植物区系成分以热带成分占优势,泛热带分布的科属最多,分别为27科、17属。群落物种丰富度Margalef指数、Shannon-Wiener指数、均匀度Pielou指数排序均为灌木层>乔木层>草本层,优势度Simpson指数为灌木层>草本层>乔木层。本调查明确了大洲岛海杧果群落的伴生物种及该群落特征,可为红树林生态恢复及海防林建设提供参考。     

海南省新英湾红树林资源现状调查分析

采用实地样方方法,对海南省新英湾红树林的红树植物种类和群落进行了调查和分析,确定有真红树7科11种,半红树植物2科3种;群落类型有红海榄群落、红海榄＋桐花树＋白骨壤群落及桐花树＋白骨壤群落3种,红树林群落演替系列是桐花树＋白骨壤(前沿向海带)→红海榄群落。     

海南中部丘陵区热带次生林物种多样性及区系分析

为弥补海南中部热带雨林区到滨海台地区的过渡地带丘陵区次生林群落物种多样性及区系研究的空缺,为海南中部丘陵地区次生林种子植物区系组成和恢复该地区物种多样性及保育提供理论依据,采用典型抽样法选取海南屯昌丘陵区不同类型次生林,对植物群落的物种多样性、区系地理成分进行调查研究。结果显示调查样地内共有维管植物87科201属267种,其中,蕨类植物3科3属4种,裸子植物2科2属2种,被子植物82科196属261种。群落的优势科为大戟科、茜草科、豆科、蔷薇科、梧桐科及樟科等。分析结果表明,该区种子植物区系起源古老,地理成分复杂,87个科中,世界分布、热带分布、温带分布的科分别有20、59和8个,显示明显的热带性质特征。200个属中,世界分布、热带分布、温带分布的属分别有1、169和30个,种类组成的科、属地理成分热带成分分别为67.81%和84.50%(不包括世界广布的科属),温带成分分别为9.10%和15.00%,表明以热带分布为主。群落垂直结构分为乔木层、灌木层和草本层,物种多样性指数显示,Margalef指数表现出灌木层最大,其次是乔木层、草本层;Shannon-Wiener指数表现为灌木层最大,其次是草本层和乔木层;Simpson指数是灌木层最大,其次是草本层、乔木层;Pielou指数则表现出草本层最大,灌木层其次,乔木层最小。      

海南七仙岭裂苞省藤的群落特征研究

[目的]研究海南七仙岭裂苞省藤群落的物种组成以及群落特征。[方法]采用样方调查法,统计样方内乔木(胸径大于2 cm)的胸径、树高、种名,同时记录裂苞省藤的萌蘖数和长度;记录灌木(胸径小于2 cm且株高大于50 cm)的种名、株高和株数,以及草本植物(株高低于50 cm)的种名、盖度。[结果](1)在1 200 m2样方中,裂苞省藤密度为24.11%;共记录维管植物129种,隶属51科97属。(2)群落植物科以泛热带分布类型最为丰富,植物属以热带亚洲分布类型最为丰富;以大戟科、梧桐科、番荔枝科和樟科为优势科,野桐属、柿属和山矾属为优势属。(3)乔木层物种丰富度最大,多样性指数变化趋势为乔木层>草本层>灌木层,均匀性指数的变化趋势均表现为草本层>灌木层>乔木层。(4)裂苞省藤幼苗在该群落占较高的优势,具有较高的重要值,反映该藤种在群落处于发育的初级阶段。[结论]不仅为生物多样性研究提供物质基础,还为裂苞省藤资源保存提供针对不同种类和生长阶段的种源知识贮备,对天然藤林可持续经营具有重要意义。     

大岗山植物群落物种多样性与群落结构研究

物种多样性是生物多样性的基本层次，不仅体现生物种类的丰富程度，也表现物种演化的空间范围及对特定环境的生态适应性。群落结构是研究植物历史动态的基础，在认识明确物种间生长竞争关系的同时，反映着群落演替的趋势。本研究以江西省大岗山为研究区，基于62个样地，共计3.72 hm²面积调查结果，对大岗山植物群落的物种多样性和群落结构进行分析。结果表明：群落内共有植物486种，隶属于120科286属，其中单种属占总数的66.43%，杉木在群落中处于优势地位；大岗山处于亚热带地区，具有过渡带性质，种子植物属包括13个分布类型，其中包含9个中国特有属；香农-威纳(Shannon-Wiener)多样性指数、辛普森(Simpson)多样性指数、皮诺(Pielou)均匀度指数在各生长层的分布趋势基本一致，灌木层优势明显，草本层略高于乔木层。群落整体物种多样性指数较高，物种较丰富；按样带划分，2号样带物种最丰富，1号样带略低于其他样带。但1、2号样带群落相似性最高，3、4号样带物种多样性指数相差较小，但群落差异最大。     

广西猫儿山高山湿地植物区系特征与群落演替进程

采用样方调查法对广西猫儿山高山湿地湿生草本植物到木本植物阶段的群落类型、物种多样性、演替度和径级结构进行分析，探究植物区系特征与群落演替进程与趋势。结果共记录到维管植物136种，隶属于62科103属，单属科、单种属所占比例大。物种组成的地理成分较为复杂，属的地理分布兼具热带、亚热带和北温带的过渡特征，包含中国特有分布的3个属及特有树种铁杉，多样性程度较高。铁杉湿地很少见，该区域的铁杉湿地却保持得非常原始，保护意义重大。植物种类数量一般会随着演替进程先增加后减少，在演替中后期出现最大值，植物种类丰富度高低并不能很准确地衡量群落的演替程度。根据重要值划分植物群系，比较各演替度，推测出该区域湿生草本植物到木本植物阶段的演替顺序为笄石菖草丛→条穗薹草草丛→尾叶悬钩子灌丛→中华槭灌丛→华西箭竹灌丛→针阔混交林铁杉群落→常绿阔叶林褐叶青冈+山桂花群落→常绿落叶混交林吴茱萸五加林群落，为自然条件下的正向演替。演替的最终结果会形成顶级群落。分析乔木群落优势种的径级结构，在乔木群落阶段演替进程中，各优势种群落发展趋势为铁杉群落波动较大，褐叶青冈和山桂花为稳定群落，以吴茱萸五加为主要落叶树种的种群发展有衰...     

极小种群植物洛氏蝴蝶兰所处群落结构特征

洛氏蝴蝶兰（Phalaenopsis lobbii）野生资源珍贵,种群数量十分稀少,被列入我国优先拯救保护的极小种群野生植物。本研究对广西龙虎山自然保护区洛氏蝴蝶兰所在的群落1及广西大新县宝圩乡的海南风吹楠-凹脉金花茶的保护小区内所在的群落2进行了生境调查与样地调查,分析生境特征、物种组成、群落区系特点及群落结构。结果显示,调查群落1样地内共有维管束植物32科45属50种,群落生物多样性较为丰富,其中百合科为该群落的优势科;群落2样地内共有维管束植物26科35属38种,无优势科现象;所在群落属的地理成分中泛热带和热带亚洲成分占绝对优势,具有热带向亚热带过渡的性质;群落中均以高位芽植物为主,又以藤本植物的比例最大,林下郁闭度增大,表明洛氏蝴蝶兰对环境湿度和光照有一定的要求;洛氏蝴蝶兰在群落1、2草本层中重要值较低,仅作为伴生种,与常绿阔叶林群落植物共生。目前蝴蝶兰属野生植物资源的群落结构的野外调查与保育研究等方面的系统性研究较少,建议加强就地保护,结合迁地保护,研究濒危机理,通过人工栽培繁殖再进行引种回归野外,缓解洛氏蝴蝶兰野外濒危现状,并为合理开发利用提供技术支撑。     

文昌8个森林群落结构与物种多样性研究

以文昌航天发射缓冲区不同森林群落为研究对象,选择8个不同植被类型,分别设置1 hm2固定大样地,对森林植物群落的多样性、森林植物群落的物种均匀度、森林植物群落的物种优势度进行观测。结果表明：不同森林群落乔木层物种多样性差异显著,半红树林群落树种种类最高,物种多样性最高达到2.38,其次分别是天然次生林和人工混交林;不同森林群落中不同层次植物均匀度总体表现出草本层＞灌木层＞乔木层的规律,但天然次生林由于郁闭度较高,林下草本较灌木少,多样性和均匀度均小于灌木层;红树林物种优势度最小,各物种优势差异不显著。     

海南省花场湾红树林资源现状调查分析

采用实地样方方法,对海南省花场湾红树林自然保护区的红树植物种类和群落进行调查和分析,确定有真红树植物7科11种,半红树植物1科1种;群落类型有榄李群落、桐花树群落、桐花树＋秋茄群落及红海榄群落4种,红树林群落演替系列是桐花树＋秋茄、桐花树、榄李—红海榄群落。     

福建省连城县南方红豆杉古树群落特征

古树是自然和历史文化瑰宝，具有重要的生态、社会、经济、科研和人文价值，在维护生物多样性、生态平衡和环境保护等方面发挥着重要作用。为更好地对福建省连城县南方红豆杉古树群落进行保育，采用样地调查法对群落的物种组成和结构进行了分析。结果表明：群落内共有维管束植物41科66属74种，含单种属的科较多；蔷薇科、禾本科、金缕梅科和樟科是该群落含有物种数最多的4个科。群落属的分布区类型有12个，其中热带性质的属30个，温带性质的属29个，中国特有属1个；热带属与温带属的比值（T/R）为1.03，与群落所处地域相吻合。重要值结果显示，南方红豆杉、毛竹和杉木位列乔木层的前3，分别为50.76%、14.33%和6.61%；灌木层以连蕊茶、檵木和椤木石楠的重要值较大，分别为4.07%、3.91%和3.60%；草本层重要值以繁缕、铁芒萁、芒占有较大优势，分别为13.30%、10.33%和9.82%。该古树群落垂直结构明显，可分成乔木层、灌木层和草本层3个层次，层间植物较少；乔木最上层以南方红豆杉占有绝对优势。连城县南方红豆杉古树群落具有重要的保护价值，但由于受人为干扰、种间竞争等因素的制约，南方红豆杉幼树与幼...     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation,Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O₂^•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O₂^•− scavenging, (IC₅₀ = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC₂₅ = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC₅₀ = 863 µg/mL; elastase, IC₅₀ = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O₂^•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.     

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.     

Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).