基于食物当量的中国居民食物消费变化

基于食物当量统一量化分析了1980年以来中国居民食物消费量和食物消费结构的演变趋势,结合Shannon-Wiener指数,分析探讨了居民食物消费种类的变化;通过进一步比较城乡居民恩格尔系数和不同收入阶层食物消费性支出,对比分析中国城乡居民及不同收入群体间的食物消费支出差异。研究发现,居民消费的食物质量不断提高,消费种类趋于多元化;居民直接粮食消费量逐年降低,动物性食物消费量持续增加,未来我国食物安全问题将转变为畜产品的生产和供给安全问题;我国居民肉类消费量与发达国家及饮食结构相似的地区相比仍有一定差距;参照《中国居民膳食指南（2016）》,目前居民谷类食物的摄入量已达到要求,肉类食物的摄入量略高于标准,但奶类的消费量还远远低于营养目标,食物消费结构还需进一步调整优化。     

论白鲢的食物问题

本文系作者结合自己的实践和国内外的文献资料,对白鲢食谱、食物的选择性和消化性等问题进行探讨,指出必须从新的角度来理解白鲢的食物问题和衡量养鱼池水的肥度。     

我国居民食物消费主要特征与问题分析

基于2013年全国2 000户家庭食物消费调研数据,从城乡、不同收入组和不同地区三个层次,深入分析当前食物消费结构快速转型时期居民食物消费与营养摄入现状与特征,从营养层面剖析当前居民食物消费中存在的问题,并就改善当前居民膳食营养状况提出政策建议。     

会议简讯

中国农学会食物与营养专业委员会第一届第一次委员会于1991年12月底在北京召开。中国农学会会长卢良恕主持会议并宣布了该会正式成立和委员及顾问名单。会议制订并通过了该会简则,主要内容包括贯彻食物结构为基本国策的指示精神,围绕食物与营养的问题,开展多学科、跨部门的综合调查研究和学术交流,为国家和有关部门提供决策咨询,普及食物与营养的知识,促进食物与营养工作的发展。 (中国科学院植物研究所印万芬)     

农田土壤食物网管理的原理与方法

土壤食物网在维持生态系统生产力和健康等方面起着重要作用,但现代农业中,化肥农药等外部投入已经改变或部分替代了土壤食物网的功能,由此也造成一系列的环境问题。为了协调作物高产与环境保护的利益,需要对土壤食物网进行管理,使土壤食物网符合作物生长的需要,即建立健康土壤食物网。管理土壤食物网有两种方式:(1)直接方式,即通过调节食物网各个功能群的组成来管理土壤食物网;(2)间接方式,即根据农田土壤食物网以自下而上调控方式为主、强调低营养阶层的资源限制的原理,通过调节碎屑的数量和质量来管理食物网。在这两种调控方式中,都需要对被管理的食物网进行监测,监测的方式也分两种,一种是直接测定食物网各功能群的数量和生物量,另外一种方式即以线虫为工具来反应土壤食物网的结构。     

食物网结构与功能: 理论进展与展望

食物网刻画了物种间通过捕食而形成的复杂网络关系。阐明食物网结构与功能之间的关系, 既是生态学的基本理论问题, 也是预测全球变化背景下生态系统响应的重要依据。早期关于食物网结构与功能的研究往往是分离的, 或是基于食物链等的简单网络模型, 而近期研究基于复杂食物网模型取得了重要理论进展。本文综述了食物网研究的理论方法和近期进展, 特别介绍了复杂食物网中的结构、多样性和功能的度量指标、结构-多样性-功能之间的关系以及全球变化对食物网结构与功能的影响。本文最后对未来的一些研究方向进行了展望, 包括与功能性状和化学计量学的整合、食物网与其他网络类型的整合以及拓展食物网研究的空间和时间尺度。     

田野工作在食物消费研究中的应用

田野工作作为一种经典研究手段和科学学术范式，通过参与式观察和深度访谈获取事实，探寻现象背后的逻辑和意义，特别适合对繁杂琐碎、难以系统表述的日常生活和行为事件，或缺乏客观表达能力的人群进行研究。田野工作研究有助于再现日常生活和行为的丰富细节和真实性，并且挖掘行为背后的意义。将田野工作用于食物消费研究中，有助于解决当前食物消费研究中数据获取成本高、准确性差的问题，弥补食物消费研究“重统计数据，轻生活实践”的不足，充分呈现食物消费的丰富内容和复杂层面，并挖掘其中的深层结构和意义。探讨应用田野调查工作方法研究中国居民食物消费问题，对于促进我国食物消费研究方法的多样化和理论进步具有重要现实意义。     

北京城市化进程中家庭食物碳消费动态

不可持续的家庭消费是造成全球环境问题的主要原因,食物碳消费研究是促进可持续家庭消费的重要内容。基于政府宏观统计数据,分析北京城市化进程中城市家庭食物碳消费的变化趋势和影响因素。结果表明,与1979年相比,1999年北京城市家庭人均及户均食物消费量分别减少了15.2%和38.6%,而食物碳消费总量增加了28.5%,食物碳消费结构由“以粮食为主”转变成“以粮食和肉类为主”。城市化进程中,以1993年为界,家庭食物人均及户均碳消费量均由明显减少趋势转变为明显增长趋势,变化的主要原因由“食物消费结构变化引起的人均谷物类碳消费量的减少”转变为“人均食物消费量增加引起的人均肉类碳消费量的增加”。北京城市家庭已基本完成食物消费结构的转变,人均食物消费量仍继续增加。GDP指数是影响人均食物碳消费量的主要经济因素,经济的继续增长可能带来人均食物碳消费量的增加,北京城市家庭食物碳消费尚未达到稳定状态。     

生物体负熵输入的针算(以蛋白质营养问题为例)

为了维持生物体经常的各种活动,需要不断的从外界得到能量供应,因此营养学中要计算食物中的能量含量。但这只是问题的一面,除去能量以外,要使生物体能够利用这些食物,还需要考虑食物的组成。正如Schrodinger指出生物体从食物中所获得的不是     

隐性饥饿的研究现状与应对策略

为了进一步系统研究隐性饥饿问题,对隐性饥饿的概念与危害及医学检验、食物强化、生物强化等方面的研究进展进行综述。提出面对隐性饥饿要强化系统理念,努力提高国家、地方和家庭经济水平,健全体检制度、丰富食物多样性、有针对性地开展食物强化与生物强化。     

姚江鱼类种群生态特点和鱼产力估量

本文根据1976-1977年的调查研究,讨论姚江鱼类种群生态特点,并参照对杭州青山水库的一些调查及中国科学院水生生物研究所对武昌东湖的研究,估量姚江的鱼产力,旨在为拟定增产措施提供科学根据。       

Study of the haemoglobin content of a single erythrocyte (M index) in various cultured fish species

Investigations of the erythrocyte count, haemoglobin content and M index of 7 fish species were performed under equivalent environmental conditions in the same period of the year. The species were: bighead Hypophthalmichthys nobilis (Richardson), carp Cyprinus carpio L., silver carp Hypophthalmichthys molitrix (Val.), grass carp Ctenopharyngodon idella (Val.), sheat-fish Silurus glanis L. , pike Esox Indus L., pike-perch Lucioperca lucioperca (L.). Bighead and carp are carnivorous and omnivorous, silver carp and grass carp are herbivorous and sheat-fish, pike and pike-perch are predatory. Significant differences were demonstrable between M values of fish living on different type of food, where the M index is: It is concluded that M index values are useful as one parameter differentiating between fish with distinctly different food habits.     

Effects of a filter-feeding fish [silver carp, Hypophthalmichthys molitrix (Val.)] on phyto- and zooplankton in a mesotrophic reservoir: results from an enclosure experiment

SUMMARY 1. Silver carp, Hypophthalmichthys molitrix (Val.), feeds on both phyto- and zooplankton and has been used in lake biomanipulation studies to suppress algal biomass. Because reports on the effects of silver carp on lake food webs have been contradictory, we conducted an enclosure experiment to test how a moderate biomass of the fish (10 g wet weight m⁻³) affects phytoplankton and crustacean zooplankton in a mesotrophic temperate reservoir.
2. Phytoplankton biomass <30 μm and particulate organic carbon (POC) <30 μm were significantly higher in enclosures with silver carp than in enclosures without fish, whereas Secchi depth was lower. Total copepod biomass declined strongly in both treatments during the experiment, but it was significantly higher in fish-free enclosures. Daphnid biomass was also consistently higher in enclosures without fish, although this effect was not significant. However, the presence of fish led to a fast and significant decrease in the size at maturity of Daphnia galeata Sars. Thus, the moderate biomass of silver carp had a stronger negative effect on cladoceran zooplankton than on phytoplankton.
3. Based on these results and those of previous studies, we conclude that silver carp should be used for biomanipulation only if the primary aim is to reduce nuisance blooms of large phytoplankton species (e.g. cyanobacteria) that cannot be effectively controlled by large herbivorous zooplankton. Therefore, stocking of silver carp appears to be most appropriate in tropical lakes that are highly productive and naturally lack large cladoceran zooplankton.     

Experimental study of the impacts of silver carp on plankton communities of eutrophic Villerest reservoir (France)

We examined the impact of five silver carp biomass levels (0, 8, 16, 20, and 32 g m⁻³) on plankton communities and water quality of Villerest eutrophic reservoir (France). We realized the experiments using outdoor mesocosms. The presence of silver carp led to changes in zooplankton and phytoplankton assemblages. High fish biomass strongly reduced cladoceran abundance (through predation). Silver carp inefficiently grazed down particles < 20 μm. More importantly, however, the suppression of herbivorous cladocerans resulted in the increase of small size algae which were relieved from grazing and benefit from high nutrient concentrations. In contrast, in mesocosms without fish, the dominance of cladocerans (mainly Daphnia) controlled small size algae and probably also larger size algae (colonial chlorophytes, cyanobacteria). Thus, the Secchi disc transparency increased markedly. Through cascade effects, the modification of grazers communities led to changes in the utilization patterns of the added nutrients by phytoplankton communities. In high fish biomass treatments, nutrients were more efficiently accumulated into particulate fractions compared with no-fish and low-fish biomass treatments that were characterized by higher dissolved nutrients concentrations. Zooplankton was an essential source of food for silver carp. The productivity of zooplankton sustained a moderate silver carp biomass (up to 16 g m⁻³). In the presence of the highest fish biomass, the productivity of zooplankton was not large enough and silver carps fed on additional phytoplankton. Although mesocosms with high fish biomass were characterized by a slight cyanobacteria development compared with other fish mesocosms, silver carp was not effective in reducing cyanobacteria dominance. This revised version was published online in August 2006 with corrections to the Cover Date.     

Structural conservation and food habit-related liver expression of uncoupling protein 2 gene in five major Chinese carps

The full-length cDNA of grass carp (Ctenopharyngodon idellus) and silver carp (Hypophthalmichthys molitrix) uncoupling protein 2 (UCP2) was obtained from liver. The grass carp UCP2 cDNA was determined to be 1152 bp in length with an open reading frame that encodes 310 amino acids. Five introns (Intron 3, 4, 5, 6 and 7) in the translated region, and partial sequence of Intron 2 in the untranslated region of grass carp UCP2 gene were also obtained. Gene structure comparison between grass carp and mammalian (human and mouse) UCP2 gene shows that, the UCP2 gene structure of grass carp is much similar to that of human and mouse. Partial UCP2 cDNA sequences of bighead carp (Aristichthys nobilis) and mud carp (Cirrhinus molitorella), were further determined. Together with the common carp (Cyprinus carpio) UCP2 sequence from GenBank (AJ243486), multiple alignment result shows that the nucleotide and amino acid sequences of the UCP2 gene, were highly conserved among the five major Chinese carps that belong to four subfamilies. Using beta-actin as control, the ratio UCP2/beta-actin mRNA (%) was determined to be 149.4 +/- 15.6 (common carp), 127.4 +/- 22.1(mud carp), 96.7 +/- 12.7 (silver carp), 94.1 +/- 26.8 (bighead carp) and 63.7 +/- 16.2 (grass carp). The relative liver UCP2 expression of the five major Chinese carps, shows a close relationship with their food habit: benthos and detritus-eating fish (common carp and mud carp) > planktivorious fish (silver carp and bighead carp) > herbivorous fish (grass carp). We suggest that liver UCP2 might be important for Chinese carps to detoxify cyanotoxins and bacteria in debris and plankton food.     

Seasonal variations in stable isotope ratios of two biomanipulation fishes and seston in a large pen culture in hypereutrophic Meiliang Bay, Lake Taihu

This paper reports on seasonal changes in stable carbon and nitrogen isotope ratios of seston and muscle tissue of silver carp and bighead carp during 2004 and 2005, focusing primarily on the carbon sources and trophic relationships among phytoplankton, zooplankton and silver carp and bighead carp in a large fish pen of Meiliang Bay (Lake Taihu, China). δ¹³C showed a minimal value in March 2005 and a maximal value in August 2005 in seston both inside and outside the pen, whereas δ¹⁵N of seston showed the minimum in winter and the maximum during algal blooms. A positive correlation between δ¹³C of silver carp and that of seston suggested that temporal variation of δ¹³C in seston was preserved in fish via the food chain. The differences of δ¹³C among seston, zooplankton and muscle tissue of silver carp and bighead carp ranged only 0.2–1.7%, indicating that plankton production was the primary food source of filter-feeding fishes. According to a mass balance model, we estimated that the contributions of zooplankton to the diets of silver carp and bighead carp were 45.7% and 54.3%, respectively, based on the δ¹⁵N values of zooplankton and planktivorous fishes.     

Evaluation of natural food for planktivorous fish in Lakes Phewa, Begnas, and Rupa in Pokhara Valley, Nepal

Six floating 4-m³ cages stocked with 40 silver carp per cage (three cages) and 40 bighead carp per cage (three cages) were placed in each of the three subtropical Lakes Phewa, Begnas, and Rupa. The fish were cultured, without supplying artificial feed, from August 1994 to December 1995. Fish growth was positively correlated with water temperature, and a slight loss in weight occurred in January when water temperature fell below 16°C in all the lakes. Fish growth was better in Lake Phewa than in Lakes Begnas and Rupa, where food might not have been sufficient or of a quality to sustain fish growth. The fish fed on mostly indigestible phytoplankton, Microcystis aeruginosa in Lake Begnas and on Tabellaria fenestrata and Microcystis aeruginosa in Lake Rupa, which can lead to poor fish growth. The maximum growth rate of silver carp (5.8 g day⁻¹) and bighead carp (4.7 g day⁻¹) occurred in Lake Phewa when Ceratium hirundinella and Peridinium spp. were abundant from August through October. The food particles found in the gut were mostly similar in silver and bighead carp, though Cladocerans (Bosmina longirostris) were observed sparsely in the gut contents of bighead carp only. Received: May 21, 1999 / Accepted: September 28, 1999     

保水渔业对千岛湖食物网结构及其相互作用的影响

为预防千岛湖连续暴发了2a(1998—1999)的蓝藻水华和改善千岛湖水质,于2000年起在千岛湖开展了以人工放养鲢鳙和控制凶猛鱼类为主要措施的保水渔业试验。作为试验的主要研究内容之一,通过构建1999和2000年千岛湖生态系统的Ecopath模型,比较分析了实施保水渔业对千岛湖生态系统食物网结构及其相互作用的影响。结果表明:实施保水渔业,使千岛湖中的银鱼和鲤生物量减少,而鲌类(主要是蒙古鲌)、鲴类和大眼华鳊等增加;使各种鱼类的捕食者和食饵生态位重叠指数下降;各主要鱼类的相互作用中,鲢、鳙对鳡、鲌的促进作用增强,鳡对鲌的抑制作用及鲌对虾类、银鱼和鲤等以及银鱼对浮游动物的抑制作用减弱,鳙对银鱼、大眼华鳊对鲤的抑制作用增强。这些影响,使千岛湖食物网结构更趋合理,如底层碎屑食性鱼类如鲴类等的增加,有利于营养物的再循环和再利用,从而增强了水体对营养物的净化作用。     

葛洲坝水利枢纽兴建后对青、草、鲢、鳙繁殖生态效应的研究

本文分析了葛洲坝枢纽截流后,大坝上、下游草、青、鲢、鳙的繁殖条件,产卵场位置,产卵规模,鱼卵、鱼苗成色以及4种鱼的群体组成等。指出除原宜昌产卵场发生变化外,其余产卵场基本存在,并在上游新发现了几处产卵场。讨论了大坝对4种鱼的影响程度和上游存在草鱼地方性群体,论证了4种鱼不必过坝产卵的理由。       

Trophic niche differences between coexisting omnivores silver carp and bighead carp in a pelagic food web

Understanding how omnivorous consumers are affected by their resources and how this is expressed through the food chain is a fundamental issue in ecology. We used stable isotope analysis of archived scales of two pelagic single-chain omnivorous fish species, bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix), to reconstruct historical trophic interactions patterns along a gradient of resources. We found that, although bighead carp and silver carp utilize the similar resources from the pelagic food chain, they can coexist and persist not only by regulating their trophic position and trophic dissimilarity, but also by regulating trophic niche width. Omnivorous fish often exhibit flexible foraging strategies, which is closely related to the availability of ecologic context. We found a positive relationship between trophic dissimilarity and zooplankton density, which may indicate that the competitive interactions induce strong top-down effects on zooplankton, and/or that high zooplankton availability release the between-population trophic interaction through bottom-up effect. The trophic niche width of bighead carp was positively related with zooplankton availability, probably reflecting that the niche of an omnivore at a higher trophic position is more sensitive to high quality resources. Our results indicate how different aspects of the trophic partitioning of coexisting omnivores may be regulated by different ecological contexts. These alternatives are not mutually exclusive and further theoretical work should include both these mechanisms to re-evaluate the effects of omnivory on food web properties.