Effects of macrophyte species richness on wetland ecosystem functioning and services

Wetlands provide many important ecosystem services to human society, which may depend on how plant diversity influences biomass production and nutrient retention. Vascular aquatic plant diversity may not necessarily enhance wetland ecosystem functioning, however, because competition among these plant species can be strong, often resulting in the local dominance of a single species. Here we have manipulated the species richness of rooted, submerged aquatic plant (macrophyte) communities in experimental wetland mesocosms. We found higher algal and total plant (algal plus macrophyte) biomass, as well as lower loss of total phosphorus, in mesocosms with a greater richness of macrophyte species. Greater plant biomass resulted from a sampling effect; that is, the increased chance in species mixtures that algal production would be facilitated by the presence of a less competitive species-in this case, crisped pondweed. Lower losses of total phosphorus resulted from the greater chance in species mixtures of a high algal biomass and the presence of sago pondweed, which physically filter particulate phosphorus from the water. These indirect and direct effects of macrophyte species richness on algal production, total plant biomass and phosphorus loss suggest that management practices that maintain macrophyte diversity may enhance the functioning and associated services of wetland ecosystems.     

产分泌蛋白酶酵母菌株的筛选

用含有脱脂奶粉平板上点种培养的方法,从分属９３个属,４９２个种的２１２９０个酵母菌株中进行筛选,发现有分属２７个属,８７个种的１６５个酵母菌株可产一不同程度的分泌蛋白酶,并对其中３株产酶较高的菌株进行培养基对产酶量的研究。     

论大棚早春无公害番茄生产技术

文章分别从品种选择、培育壮苗、整地、施肥等方面论述了大棚早春无公害番茄生产技术。     

杂草繁殖方式的多样性及其对环境的适应

杂草是在人为和环境双重选择压力下演化而成的一类高度进化的植物类群，其繁殖方式多样，表现在种子产量、萌发、休眠、拟态、生命力、繁殖体传播方式等。作者以举例方式比较详细地论述了杂草多样的繁殖方式，并讨论其对人为干扰环境适应的意义。     

山西外来入侵植物的研究

经过调查和对大量文献资料的整理和分析，确定山西的外来入侵植物有41种，隶属19科35属，其中水生植物1种，陆生植物40种．美洲的植物种类最多，达26种，占总种数的63％；亚热带分布的最多，有18个属，大多为适宜于温凉气候条件的杂草种类;作为蔬菜、花卉和药用植物等有意引进的有32种，随人工引种带入或自然扩散无意引进的有9种;分布广、危害严重的植物有10种，它们的危害性主要体现在3个方面，即破坏生态系统的结构和功能、加快物种多样性的丧失和严重危害农林业生产．针对山西外来入侵植物的现状提出了一些相应的防治对策．     

食菌甲虫物种多样性及其与菌物的关系

食菌甲虫依赖大型真菌而生存,形成了紧密的协同进化关系和丰富的物种多样性.迄今全球已知食菌甲虫的种类多达3亚目16总科82科1 386属8 000余种,构成了复杂昆虫多样性的一个重要分支.食菌甲虫因取食而与自然界广泛的菌类建立起了复杂的依存关系,一些种类因危及蘑菇农业生产而与人类经济利益十分密切.为此,本文主要基于掌握的文献信息对该类甲虫国内外研究状况做一初步概述,以引起我国学术界对丰富食菌甲虫资源的关注.     

青冈属3个树种的种苗形态特征研究及引种栽培效果

通过对壳斗科青冈属的小叶青冈、云山青冈、毛果青冈3个树种的引种栽培，就这些树种的种子和苗木的生产技术做了细致的探索性的研究，并就其种子及幼苗进行观察、记载和绘制成图；经造林六年后评价引种成败。研究结果：可为研究壳斗科青冈属植物系统发育和亲缘关系方面提供理论依据；也可为用材林造林树种选择提供参考和对这3个树种继续引种栽培提供实践依据。     

Aerosol formation: atmospheric particles from organic vapours

Aerosol particles produced over forested areas may affect climate by acting as nuclei for cloud condensation, but their composition (and hence the chemical species that drive their production) remains an open question. Here we show, to our knowledge for the first time, that these newly formed particles (3-5 nm in diameter) are composed primarily of organic species, such as cis-pinonic acid and pinic acid, produced by oxidation of terpenes in organic vapours released from the canopy.     

Diversity and dispersal interactively affect predictability of ecosystem function

Theory and small-scale experiments predict that biodiversity losses can decrease the magnitude and stability of ecosystem services such as production and nutrient cycling. Most of this research, however, has been isolated from the immigration and emigration (dispersal) processes that create and maintain diversity in nature. As common anthropogenic drivers of biodiversity change--such as habitat fragmentation, species introductions and climate change--are mediated by these understudied processes, it is unclear how environmental degradation will affect ecosystem services. Here we tested the interactive effects of mobile grazer diversity and dispersal on the magnitude and stability of ecosystem properties in experimental seagrass communities that were either isolated or connected by dispersal corridors. We show that, contrary to theoretical predictions, increasing the number of mobile grazer species in these metacommunities increased the spatial and temporal variability of primary and secondary production. Moreover, allowing grazers to move among and select patches reduced diversity effects on production. Finally, effects of diversity on stability differed qualitatively between patch and metacommunity scales. Our results indicate that declining biodiversity and habitat fragmentation synergistically influence the predictability of ecosystem functioning.     

牛大力内生细菌的多样性及其促生特性研究

为研究牛大力Callerya speciose内生细菌多样性组成及其促生特性,从经表面消毒处理的牛大力根茎组织中分离内生细菌,采用16SrDNA序列分析法对内生细菌的多样性进行系统发育分析,并以固氮、溶磷性、产铁载体、产IAA能力等为指标,对内生细菌进行促生特性检测。从牛大力根和茎中共分离到59株内生细菌,包括16属20种,芽孢杆菌属是牛大力的优势菌群;在20种分离菌株中,分别有11,17,7株具有潜在的固氮、溶磷性、产铁载体能力,有13株菌可以合成IAA。其中RH17-2、RH17-5、GR2-1 3株菌同时具备固氮、溶磷性、产铁载体、产IAA 4种促生特性。从牛大力中分离得到的内生细菌具有丰富的物种多样性和促生特性,在未来的农业生产上具有潜在的应用价值。     

氧化淀粉粘合剂的研制

文章通过几种氧化剂的实验摸索，得到了有效的ＮａＣｌＯ氧化剂和相应有效的ＮｉＳＯ４催化剂的淀粉粘合剂的配方，并且提出一套生产新工艺，为工业化生产提供了理论依据。     

罗非鱼育种研究进展

罗非鱼是世界性的养殖鱼类,同时也是我国水产业重要养殖品种.我国罗非鱼产业发展迅速,罗非鱼养殖产量、产值和出口额均居世界第一位.但由于引种时间较长,我国罗非鱼繁殖也较普遍的存在种质退化的问题.针对罗非鱼育种研究,从选择育种、杂交育种、细胞工程育种及分子辅助育种几个方面对其育种的基本原理和应用技术进行了系统的阐述,希望较全面的反应国内外罗非鱼育种研究的进展和动态,并对今后科研工作者开展罗非鱼良种繁育工作提供参考.     

Partitioning selection and complementarity in biodiversity experiments.

The impact of biodiversity loss on the functioning of ecosystems and their ability to provide ecological services has become a central issue in ecology. Several experiments have provided evidence that reduced species diversity may impair ecosystem processes such as plant biomass production. The interpretation of these experiments, however, has been controversial because two types of mechanism may operate in combination. In the 'selection effect', dominance by species with particular traits affects ecosystem processes. In the 'complementarity effect', resource partitioning or positive interactions lead to increased total resource use. Here we present a new approach to separate the two effects on the basis of an additive partitioning analogous to the Price equation in evolutionary genetics. Applying this method to data from the pan-European BIODEPTH experiment reveals that the selection effect is zero on average and varies from negative to positive in different localities, depending on whether species with lower- or higher-than-average biomass dominate communities. In contrast, the complementarity effect is positive overall, supporting the hypothesis that plant diversity influences primary production in European grasslands through niche differentiation or facilitation.     

粮食种植环节存在的质量安全问题与对策

粮食作物的优质安全生产涉及种植、采收、收购、运输和加工等各个环节,而种植过程中的安全是无公害农产品、绿色和有机农产品生产最重要的环节.对粮食安全生产过程中涉及的品种选择、安全生产技术规程、安全生产标准、环境因子调控及安全等方面问题进行了概述.对策包括选用抗病虫品种;严格执行无公害生产技术标准和技术规程;加强温度、湿度、土壤等环境因子调控,综合运用生物、物理防治措施;严格生产和销售渠道,保证生产出无公害、绿色有机农产品.     

北工商海洋杆菌诱导戊糖片球菌产生细菌素及降黄酒生物胺功效研究

利用功能微生物控制杂菌污染,是黄酒生产中控制生物胺含量的有效途径。从黄酒麦曲中分离筛选出新菌种[北工商海洋杆菌(Pontibacter beigongshangensis)]和新菌株[戊糖片球菌(Pediococcus pentosaceus) M25]。北工商海洋杆菌能够诱导戊糖片球菌产生细菌素,对黄酒中产生物胺的腐生葡萄球菌(Staphylococcus saprophyticus)、阪崎肠杆菌(Cronobacter sakazakii)、乳酪短杆菌(Brevibacterium casei)、芽孢杆菌(Bacillus)和阴沟肠杆菌(Enterobacter cloacae)均具有抑制作用。北工商海洋杆菌和戊糖片球菌自身不产生物胺。添加北工商海洋杆菌和戊糖片球菌,制备强化功能曲,利用强化功能曲酿造黄酒,可使黄酒中的生物胺含量降低29.8%,而对黄酒的风味物质影响不明显。因此,未来北工商海洋杆菌和戊糖片球菌可以作为降生物胺功能菌株应用在黄酒酿造中。     

防止菌种退化的新途径

本文设计了一套新的菌种生产程序,繁殖周期短,系数大。在食用菌菌种生产过程中,使用该程序可有效地防止菌种退化。     

湖北省人体寄生虫种类及分布的初步研究

按分层整群随机抽样法,调查了湖北省３９个县（市、区）,５３２８４人,湖北省人体寄生虫平均感染率５２．０４％,确定的虫种６５种,分布于全省各县（市、区）的虫种１７种,驻见于少数地区极少数人群的少（罕）见虫种１３种,棘口科吸虫,横川后殖吸虫,猫后睾吸虫,异形异形吸虫,小杆线虫铁线虫、美丽筒线虫和缩小膜壳绦虫等系省内首次报道,寄生虫感染和分布与地理条件,气候,社会经济基础、卫生条件、人群职业,年龄,生活     

烟台海域基岩潮间带底栖红藻资源的空间分布格局

所调查的5月份烟台海域6基岩潮间带的红藻群落由21种红藻组成,养马岛的种类组成最为丰富(11种),金沟寨最为贫乏,仅有3种.潮间带红藻总生产量的排序为养马岛>月亮湾>芝罘岛>金沟寨>金沟寨砾石滩>龙须岛.烟台海域基岩潮间带红藻群落的优势种为仙菜和江蓠.红藻群落的物种丰富度依次为养马岛>芝罘岛>龙须岛>月亮湾>金沟寨>金沟寨砾石滩;物种多样性指数以养马岛为最高,金沟寨砾石滩最低,依次为养马岛>月亮湾>龙须岛>金沟寨>芝罘岛>金沟寨砾石滩;物种分布的均匀度指数依次为月亮湾>龙须岛>养马岛>金沟寨>芝罘岛>金沟寨砾石滩.     

水驱油藏微生物群落结构及影响因素

中国主力油田多已进入开采中后期,其开采难度进一步增大,微生物采油技术具有成本低、效益高、绿色环保等优点,在剩余油进一步提高采收率中具有广泛的应用前景。由于对油藏微生物群落结构认识不足、激活剂配方筛选周期长等问题,限制了微生物驱油技术的现场推广应用。通过分析油藏中群落结构差异及环境因子与优势菌种间的相互作用关系,为定向激活油藏微生物提供基础数据及理论指导。通过物种组成分析、物种多样性分析、主坐标分析(principal coordinate analysis, PCoA)以及冗余分析方法对油藏高通量测序数据进行分析,结果表明A油田注水井和生产井间的物种组成差异较大,L油田的注水井和生产井间的物种组成差异不明显;在物种丰度、物种均度以及物种多样性上,A油田和L油田均表现出差异不明显情况;但在基于属水平的注水井和生产井间的物种相似性上,A油田表现出较低的相似性,而L油田则表现出较高的相似性;环境因子分析中,L油田中的微生物群落与含盐量相关性显著,而A油田中的微生物群落组成则与温度、pH和SO₄^2-浓度显著相关。     

贵州毛莨科植物种类与分布补遗（Ⅰ）

本文对贵州毛莨科植物３１种变种１变型的产地进行了增补，其中金沙人字果Ｄｉｃｈｏｃａｒｐｕｍ ｄａｌｚｉｅｌｌｉｉ ｖａｒ．ｊｉｓｈａｅｎｓｅ Ｄ．Ｚ．ＦｕｅｔＳ．Ｚ．Ｈｅ为新变种，獐耳细辛属为新记录属，南川升麻、川鄂獐耳细辛、褐鞘毛莨为新记录种，类叶升麻属、升麻等为贵州植物志未记载的属、种和变种。