雷州半岛红树林湿地鸟类多样性

从2000年5月-2003年11月,调查了雷州半岛红树林湿地鸟类.共记录鸟类133种,水鸟和迁徙鸟分别占总记录鸟类数量的81.7%和70.4%.分别有9种、2种、16种和12种鸟被列为中国红皮书保护种、IUCN保护种、CITES保护种和中国国家Ⅱ级保护种;还有63种被列为中日候鸟协定保护种、32种被列为中澳候鸟协定保护种.不同调查地点,鸟类的种类和数量相差较大,高桥鸟类最丰富,记录到83种鸟;五里鸟类种类最少,仅记录到40种鸟,各地鸟类种的相似性很低.环颈鸻(Charadrius alexandrinus)、白腰杓鹬(Numenius arquata)和红嘴鸥(Larus ridibundus)在雷州半岛的种群数量达到国际重要湿地的标准.雷州半岛鸟类种的丰度和多度季节变化明显,冬季种类多、数量丰富,夏季种类少、数量贫乏.冬季和夏季总的鸟类数量(P=0.043)和水鸟数量(P=0.001)差异明显.保护整个沿海红树林湿地是保护雷州半岛红树林湿地鸟类多样性的关键.     

长江中下游湿地大型水鸟种群动态和幼鸟比例研究

迁徙水鸟保护对生物多样性保护具有重要意义。开展水鸟种群数量和幼鸟比例监测,对科学评估其种群变化趋势、制定长期保护策略具有重要价值。长江中下游湿地是东亚-澳大利西亚迁徙路线上重要的水鸟越冬区之一。本研究采用野外同步调查等方法对该区域87个湿地的亟需保护和具有代表性的10种大型越冬水鸟,其中雁形目6种,分别是鸿雁Anser cygnoides、豆雁A.fabalis、灰雁A.grus、白额雁A.albifrons、小白额雁A.erythropus和小天鹅Cygnus columbianus;鹤形目4种,分别是白鹤Leucogeranus leucogeranus、白枕鹤Antigone vipio、灰鹤Grus grus和白头鹤G.monacha,进行了长期监测(2003—2019年冬季),并结合相关文献,评估其种群变化趋势、幼鸟比例和死亡率。研究结果如下：(1)2005—2019年3种水鸟(豆雁、灰雁和灰鹤)的种群数量呈上升趋势,7种水鸟(鸿雁、白额雁、小白额雁、小天鹅、白鹤、白枕鹤和白头鹤)种群数量呈下降趋势;(2)种群趋势下降组(N=7)和上升组(N=3)的幼鸟比例均值在2016—2...     

滹沱河湿地石家庄段水鸟群落结构及多样性

2003年3月～2006年4月,对滹沱河湿地石家庄段水鸟进行了调查。共记录水鸟80种,隶属于7目16科。其中候鸟73种(夏候鸟、冬候鸟和旅鸟),留鸟7种;古北种62种,东洋种11种,广布种7种;国家Ⅰ、Ⅱ级重点保护鸟类11种。鸻形目和雁形目鸟类占优势,各占水鸟种数的35.00%和30.00%。水鸟种类和数量高峰出现在4月和11月,低谷在1月和2月。多样性分析表明,冶河-黄壁庄水库和滹沱河-岗南水库Shannon-Weiner指数和G-F指数均高于石板水库,这与湿地面积和生境的多样性有关。滹沱河湿地石家庄段作为许多水鸟,尤其是黑鹳的重要栖息地,需进一步加强监测和保护。     

鄱阳湖南矶湿地国家级自然保护区越冬水鸟监测

2013—2018年,每年12月20日—翌年1月10日采用样区直数法对鄱阳湖南矶湿地国家级自然保护区13个样区的水鸟多样性进行1次监测。结果表明:共记录水鸟7目12科45种129633只,每年总数量在11604～33053只;其中,国家I级重点保护鸟类有白鹤(Grus leucogeranus)、白头鹤(Grus monacha)和东方白鹳(Ciconia boyciana),国家II级保护鸟类5种。本次共记录优势种9种,以雁鸭类和鹬科鸟类为主; 2013—2014年和2017—2018年优势种种类较多,2015—2016年每年优势种只有2种;大部分水鸟类群的数量变化趋势类似,提示合适的水位可为多种水鸟生态类群提供适宜的湿地复合体;??类数量高峰期正好是大部分水鸟数量较低或低谷期,提示水位对水鸟多样性的维持极其重要;不同样区的水鸟相似性指数为0.51～0.91;该保护区物种数和个体数总体呈上升趋势,这与绿翅鸭(Anas crecca)、红头潜鸭(Aythya ferina)、反嘴鹬(Recurvirostra avosetta)等在2016—2018年数量和遇见率较高有关;多样性和均匀度指数在2015—2016年明显下降,这与鸿雁(Anser cygnoid)或反嘴鹬占绝对优势有关;该地区鸟类资源丰富,东方白鹳和白琵鹭(Platalea leucorodia)种群数量大而稳定,鹤类几乎每年都有记录;南矶湿地保护区在鄱阳湖水鸟多样性维持和濒危水鸟特别是东方白鹳的保护上发挥着重要作用。本次监测持续年限较长,初步掌握了湖区优势鸟类及国家重点保护鸟类的种群动态规律,为该保护区的水鸟保护和栖息地管理提供了重要的科学依据。     

陕西省水鸟种群和地理分布研究

水鸟是湿地野生动物中最具代表性的类群,是湿地生态系统的重要组成部分,灵敏并深刻地反映着湿地环境的变迁.2002年以来,省林业厅鸟类调查组对我省的鸟类资源及分布进行了全面系统的调查,结果表明陕西省湿地水鸟有10目20科113种.本文阐明了我省水鸟的种类、地理分布及保护价值,并讨论了陕西湿地水鸟种群现状、面临的威胁和相应的保护对策.     

海南岛红树林湿地的水鸟多样性

从2015年10月至2016年6月,调查了海南岛17个沿海红树林湿地春、夏、秋、冬四季的湿地鸟类。共记录水鸟74种,隶属5目12科,其中,翘鼻麻鸭（Tadorna tadorna）为海南鸟类分布新记录种。位于海南省儋州市白马井镇洋浦湾的新英作为黑脸琵鹭（Platalea minor）新的越冬点被发现。全岛水鸟数量较多的地点在万宁小海、海口东寨港和乐东莺歌海,种类较多的地点在东寨港、东方四更和莺歌海。Jaccard指数分析表明,栖息地具有相似适合度的地方,水鸟种类相似性更高,人工湿地之间的水鸟相似性高,人工湿地与天然湿地之间的水鸟相似性低。海南岛沿海红树林湿地的鸟类种类和数量随季节变化,秋、冬季种类多、数量丰富,春、夏季的种类和数量均较少。鸻鹬类在春、冬季种类和数量占比均为最大,秋、夏季数量最多的为鹭类。Shannon-Wiener指数、Pielou均匀度指数分析得出东寨港的多样性指数最高,东寨港和莺歌海的均匀度指数表现较高。研究表明,海南岛的沿海红树林湿地是很多水鸟的重要栖息地,保护红树林是保护湿地水鸟多样性的关键。     

四川省东部和西南部冬季水鸟调查

2012年12月中旬至2013年1月中旬,对四川省东部8个中型水库和1条自然河段、西南部3个湖泊的冬季水鸟进行了调查,记录到水鸟41种,隶属7目10科。四川东部地区有23种,其中有国家Ⅱ级重点保护鸟类鸳鸯Aix galericulata 1种,东部冬季水鸟群落物种数不多,种群数量也不大,种群数量最多的是绿头鸭Anas platyrhynchos、绿翅鸭A.crecca和斑嘴鸭A.poecilorhyncha。四川西南部地区记录到33种,其中国家Ⅰ级重点保护鸟类中华秋沙鸭Mergus squamatus 1种,国家Ⅱ级重点保护鸟类鸳鸯1种,西南部冬季水鸟的群落物种数较多,种群数量也较大,种群数量最多的是骨顶鸡Fulica atra、凤头潜鸭A.fuligula和赤嘴潜鸭Netta rufina。天然湖泊和自然河段的冬季水鸟种类和数量都多于人工湖泊。除二滩水库外,湖泊(库塘)面积与水鸟种类和数量呈正相关。旅游、行船和偷猎是水鸟越冬地面临的主要干扰和威胁。需加强湿地保护和对偷猎行为的大力打击。     

安徽沿江两个浅水型湖泊越冬水鸟的季节动态(英文)

安徽沿江浅水型通江湖泊湿地是东亚-澳大利亚迁徙水鸟的重要越冬地和停歇地。近年来,高强度的渔业养殖使湿地严重退化,对越冬水鸟构成威胁。为了解湿地变化对越冬迁徙水鸟的影响,2007年11-2008年4月和2008年11月-2009年4月,对安徽菜子湖和升金湖11个样带内越冬水鸟的种类、数量及空间分布进行了调查,并分析了湖泊渔业模式对水鸟分布的影响。两个湖泊共统计到越冬水鸟7目12科43种。其中,菜子湖群38种,密度为8.2ind./hm2;升金湖42种,密度为3.5ind./hm2,优势种为鸿雁(Anser cygnoides)、豆雁(Anser fabalis)、小天鹅(Cygnus columbianus)和黑腹滨鹬(Calidris alpina)。越冬水鸟种类和数量在12月底-次年1月上旬达到最大值,但不同类型越冬群最大数量出现的具体时期有所不同。根据水鸟组成的聚类分析,可将水鸟栖息地分为三组。水鸟的分布与渔业模式有关,在自然捕捞区,鹤类、雁鸭类和鸻鹬类密度较大,在围网养殖区密度较小,而鹭类的密度在各湖区变化都较小。本研究结果提示,发展可持续渔业对于长江中下游浅水湖泊湿地越冬水鸟资源的保护具有重要意义。     

环渤海滨海湿地鸻鹬类水鸟多样性及其环境影响因子

环渤海湿地是水鸟南北迁徙的重要驿站,尤其对于该线路上的鸻鹬鸟类具有非常重要的意义。以环渤海地区12处典型滨海湿地为研究对象,于2016-2020年每年春季开展水鸟调查,明确了鸻鹬类水鸟群落组成及其时空变化,采用结构方程模型 （Structural Equation Modeling,SEM）分析了鸻鹬类水鸟多样性与环境因子的响应关系,评估了各环境因子的影响强度。结果表明：（1）共记录到鸻鹬类水鸟7科51种,几乎全部为旅鸟。全球极危物种1种,濒危物种3种,近危物种9种。国家一级保护鸟类2种,国家二级保护鸟类8种。黑腹滨鹬（Calidris alpina）、大滨鹬（Calidris tenuirostris）、黑尾塍鹬（Limosa limosa）、灰鸻（Pluvialis squatarola）、斑尾塍鹬（Limosa lapponica）个体数量最多。（2）山东黄河三角洲、辽宁辽河口、天津北大港等河口湿地,水鸟种类多,单位面积水鸟数量较少。（3）河北沧州沿海、山东滨州贝壳堤岛及其周边区域为环渤海地区湿地集中区,水鸟种类较多。（4）综合影响强度为保护强度>食物>气候,建立自然保护地是保护水鸟多样性的最有效措施。（5）建议将河北南大港湿地和鸟类省级自然保护区提升至国家级,扩大滨州贝壳堤岛与湿地国家级自然保护区面积,对山东黄河三角洲、辽宁辽河口覆盖的各级各类自然保护地进行优化整合。研究结果能为环渤海地区鸻鹬类水鸟保护策略的制定提供相关依据。     

天津地区水鸟区系组成及多样性分析

1997年10月－2000年12月间,作者对天津地区的20处湿地的水鸟进行了调查,共记录到水鸟107种,分属7目14科39属。其中候鸟103种,占总数的96.2%。Xing形目和雁形目无论在种类上还是在数量上都占绝对优势,分别占水鸟群落种类组成的41.1%和31.1%。记录到包括东方白鹳（Ciconia boyciana)、黑鹳（Ciconia nigra)、丹顶鹤（Grus japonensis)、白鹤（Grus leucogeranus)、大鸨（Otis tarda)及遗鸥（Larus relictus)在内的国家Ⅰ级保护物种6种。记录到国家Ⅱ级保护物种8种,分别为白枕鹤（Grus vipio)、蓑羽鹤（Anthropoides virgo)、灰鹤（Grus grus)、海鸬鹚（Phalacrocorax pelagicus)、大天鹅（Cygnus cygnus)、小天鹅（C.columbianus)、疣鼻天鹅（C.olor)、白额雁（Anser albifrons)。对包括北大港水库、团泊洼水库、七里海水库及尔王庄水库在内的4个重点调查区域进行水鸟多样性分析表明,北大港水库的物种多样性及科、属多样性均较高,且有众多的珍稀物种,是一个重要的水鸟停歇地,应加强对该区域的保护。此外,本文提出在分析生物群落多样性时,应将分类因素与物种的数量因素综合起来考虑,因而同时使用G－F指数与Shannon-Wiener指数,可更为全面地评价某一地区的群落多样性。     

Ectogenesis and the case against the right to the death of the foetus

Ectogenesis, or the use of an artificial womb to allow a foetus to develop, will likely become a reality within a few decades, and could significantly affect the abortion debate. We first examine the implications for Judith Jarvis Thomson’s violinist analogy, which argues for a woman’s right to withdraw life support from the foetus and so terminate her pregnancy, even if the foetus is granted full moral status. We show that on Thomson’s reasoning, there is no right to the death of the foetus, and abortion is not permissible if ectogenesis is available, provided it is safe and inexpensive. This raises the question of whether there are persuasive reasons for the right to the death of the foetus that could be exercised in the context of ectogenesis. Eric Mathison and Jeremy Davis have examined several arguments for this right, doubting that it exists, while Joona Räsänen has recently criticized their reasoning. We respond to Räsänen’s analysis, concluding that his arguments are unsuccessful, and that there is no right to the death of the foetus in these circumstances.     

On the diversity of the Cladocera in the tropics

The mythical concept of an impoverished tropical cladoceran fauna is refuted. On a planetary scale, around half of the cladoceran species presently known occur exclusively in the tropics-subtropics, often with considerable restriction to particular geographical subzones. On a regional (political) scale, the situation is often unclear because of the continued fragmentary nature of studies, and because political units are not a good basis for biogeographical comparisons. At the finest level of resolution (lake-perlake comparisons), there appears to be an upper limit of c. 50 cladoceran species per individual lake. No significant difference between lakes in the temperate zone and in the tropics could be established here. Daphnia is largely absent from the tropics, but is replaced by more Sidids, Moinids, and Bosminids, such that the average cladoceran community in the limnetic zone of a tropical lake is not characterized by less species but rather by lower population densities. This, in turn, is considered a consequence of higher prevalent predation levels in the tropics.     

Tubular networks in the terminal endings of the visual receptor cells in the human,the monkey,the cat and the dog

Summary A tubular network was found in the terminal endings of the visual receptor cells in the human, the monkey (Macaca mulatta), the cat and the dog. These tubules are arranged in close groups in the vicinity of the synaptic lamellae and the invaginated dendrites. According to the form, diameter, density of the tubules and to the consistence of the network formed by them one can distinguish at these places an initial type (type I), a transitory (type II) and a vesicular one (type III). In the the type III branching, bizarre forms are frequent. The diameter of all the tubules reaches 500–600 Å, their density and walls being the same as in the synaptic vesicles.Similar networks also occur in the axons of the visual receptor cells of the monkey.

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Zusammenfassung In den Endigungen der Photorezeptorzellen von Mensch, Affe (Macaca mulatta), Katze und Hund kommen aus Tubuli bestehende Komplexe vor. Organellenartig in geschlossenen Gruppen angeordnet, liegen sie in Nähe der synaptischen Lamellen und der invaginierten Dendriten. An diesen Stellen kann man nach Form, Durchmesser, Dichte und Konsistenz der von den Tubuli gebildeten Komplexe drei Typen unterscheiden: 1. einen initialen (Typus I), 2. einen Übergangstypus (Typus II) und 3. einen vesiculären Typus (Typus III). In letzterem kommen häufig verzweigte, bizarre Formen vor. Der Durchmesser sämtlicher Tubuli erreicht 500–600 Å. Ihre Dichte und ihre Wand gleicht denen der synaptischen Vesikel.Ähnliche Komplexe fanden wir auch in den Axonen der Photorezeptorzellen vom Affen.

     

Assessing the Physiological State of the Fucoids from the Barents Sea Littoral by the End of the Polar Night

Methods of amperometry and potentiometric titration were used to follow dark respiration (DR) and apparent photosynthesis (AP) in the fucoids Ascophyllum nodosum (L.) Le Jol, Fucus vesiculosus L., and F. serratus L. from the Barents Sea littoral by the end of the 40-day-long polar night. The macroalgae were shown to manifest species-specific low rates of photosynthesis and respiration. However, in spite of their low photosynthetic status due to the effects of subzero temperature and prolonged low or zero illumination, the macroalgae have been able to restore DR and AP to the initial level already by the day 9; the ability to restore AP depended on the level of illumination. The study of the changes in the carbonate–bicarbonate system in the light and darkness demonstrated that the macroalgae grown in darkness, in contrast to those grown in twilight, could absorb bicarbonate in darkness; however, they lost this capacity after two-day-long illumination at an irradiance of 7 mol/(m² s). Bicarbonate uptake in darkness and the capacity to restore the systems of photosynthesis and respiration in fucoid cells are discussed in the context of algal energy metabolism under the polar night conditions.     

Arranging the elements of the potassium channel: the T1 domain occludes the cytoplasmic face of the channel

The voltage-gated potassium channel is currently one of the few membrane proteins where functional roles have been mapped onto specific segments of sequence. Although high-resolution structures of the transmembrane portions of three bacterial potassium channels, the tetramerization domain and the cytoplasmic ball are available, their relative spatial arrangement in mammalian channels remains a matter of ongoing debate. Cryo-electron microscopic images of the six transmembrane voltage-gated Kv channel have been reconstructed at up to 18 Å resolution, revealing that the T1 domain tetramerizes and is suspended below the transmembrane segments. However, the resolution of these images is insufficient to reveal the location of the third piece of the puzzle, the inactivating ball domain. We have used the aberrant interactions observed in a series of chimæric channels to establish that an assembled T1 domain restricts access to the cytoplasmic face of the channel, suggesting that the N-terminal ball and chain may be confined in the space between the T1 domain and the transmembrane portion of the channel.     

Feeding the vertebrate retina from the Cambrian to the Tertiary

The retina of the vertebrate eye is metabolically active and requires nutritive support. During the last 540 million years it has evolved into forms as complicated and nutritionally demanding as those found in avian or primate eyes. Diffusion from the choroid is generally able to supply the metabolic needs of thin retinae. However, when the thickness exceeds the limits of diffusion, structures are needed to supplement the vascular supply from the choroid. These supplemental nutritive devices include the choroidal gland, the falciform process and preretinal vascular plexus of fish, the conus papillaris of lizards, the pecten oculi of birds, the intraretinal vessels of mammals and a few novel systems that remain difficult to classify. These vascular systems are among the most variable features of the vertebrate eye. Here, we review classical and recent findings regarding such retinal nutrition systems, propose a three category classification for them based on histologic origins and speculate on the evolutionary forces which drove their development.     

Observations on the permeability of the choriocapillaris of the eye

Summary The choriocapillaris is a fenestrated capillary bed located posterior to the retinal pigment epithelium. It serves as the main source of supply to the photoreceptors, retinal pigment epithelium, and other cells of the outer retina. The permeability of these capillaries to intravenously injected ferritin (MW — approx. 480,000; mol. diam. 11 nm) was examined in the mouse, rabbit, and guinea pig, each of which is characterized by a different type of retinal vascularization. In all three species, the bulk of the ferritin remained in the capillary lumina, where it appeared to be blocked at the level of the diaphragmed fenestrae. Some ferritin was present in endothelial cell vacuoles. The results confirm previous work on the rat choriocapillaris and indicate that the barrier function of the choriocapillary endothelium is present even among species in which the retinal circulation differs significantly.Supported by NIH grant EY03418     

Separation of the pineal vesicle from the wall of the third ventricle during the post-hatching development of the chicken

Summary According to light- and electron-microscopic observations the pineal organ of the 3-day-old chicken consists of a prominent end vesicle and a tapering parenchymal stalk. During this stage the pineal lumen is in open communication with the third ventricle. However, in the 40-day-old chicken, which still possesses a well-developed end vesicle, the proximal portion of the pineal stalk displays regressive changes leading to local fragmentation. At this stage the pineal stalk is reduced, and the pineal lumen is missing. In 1-year-old chickens the parenchyma of the proximal portion of the stalk is further diminished, and in 3-year-old domestic fowl is completely displaced by bundles of collagenous fibers, only some nerve fibers being present. This post-hatching pineal development may reflect the sequence of changes leading from pineal sense organs to pineal glands.This work was supported by a grant-in-aid for Scientific Research from the Ministry of Education, Science and Culture of Japan