Temperature alters reproductive life history patterns in Batrachochytrium dendrobatidis,a lethal pathogen associated with the global loss of amphibians

Understanding how pathogens respond to changing environmental conditions is a central challenge in disease ecology. The environmentally sensitive fungal pathogen Batrachochytrium dendrobatidis (Bd), which causes the amphibian disease chytridiomycosis, has spread globally causing amphibian extirpations in a wide variety of climatic regions. To gain an in‐depth understanding of Bd's responses to temperature, we used an integrative approach, combining empirical laboratory experiments with mathematical modeling. First, we selected a single Bd isolate and serially propagated two lineages of the isolate for multiple generations in two stable thermal conditions: 4°C (cold‐adapted lineage) and 23°C (warm‐adapted lineage). We quantified the production of infectious zoospores (fecundity), the timing of zoospore release, and zoospore activity in reciprocal temperature transplant experiments in which both Bd lineages were grown in either high or low temperature conditions. We then developed population growth models for the Bd lineages under each set of temperature conditions. We found that Bd had lower population growth rates, but longer periods of zoospore activity in the low temperature treatment (4°C) compared to the high temperature treatment (23°C). This effect was more pronounced in Bd lineages that were propagated in the low temperature treatment (4°C), suggesting a shift in Bd's response to low temperature conditions. Our results provide novel insights into the mechanisms by which Bd can thrive in a wide variety of temperature conditions, potentially altering the dynamics of chytridiomycosis and thus, the propensity for Bd to cause amphibian population collapse. We also suggest that the adaptive responses of Bd to thermal conditions warrant further investigation, especially in the face of global climate change.     

Partitioning the net effect of host diversity on an emerging amphibian pathogen

The ‘dilution effect’ (DE) hypothesis predicts that diverse host communities will show reduced disease. The underlying causes of pathogen dilution are complex, because they involve non-additive (driven by host interactions and differential habitat use) and additive (controlled by host species composition) mechanisms. Here, we used measures of complementarity and selection traditionally employed in the field of biodiversity–ecosystem function (BEF) to quantify the net effect of host diversity on disease dynamics of the amphibian-killing fungus Batrachochytrium dendrobatidis (Bd). Complementarity occurs when average infection load in diverse host assemblages departs from that of each component species in uniform populations. Selection measures the disproportionate impact of a particular species in diverse assemblages compared with its performance in uniform populations, and therefore has strong additive and non-additive properties. We experimentally infected tropical amphibian species of varying life histories, in single- and multi-host treatments, and measured individual Bd infection loads. Host diversity reduced Bd infection in amphibians through a mechanism analogous to complementarity (sensu BEF), potentially by reducing shared habitat use and transmission among hosts. Additionally, the selection component indicated that one particular terrestrial species showed reduced infection loads in diverse assemblages at the expense of neighbouring aquatic hosts becoming heavily infected. By partitioning components of diversity, our findings underscore the importance of additive and non-additive mechanisms underlying the DE.     

长江河口浮游动物的种类组成、群落结构及多样性

于1999年枯水期(2—3月份)、丰水期(8月份)、2000年枯水期(2—3月份)对长江河口浮游动物采样调查,研究了长江河口浮游动物的种类组成、群落结构及多样性并初步探讨了三峡工程对长江河口浮游动物的影响及长江河口水环境的生物监测。调查共发现浮游动物87种,甲壳动物占绝对优势,共59种。在所有浮游动物中挠足类31种。其次为水母类,有9种,此外,枝角类、毛颚类各8种。3次采样浮游动物的优势种主要有河口半咸水种和近岸低盐种类如华哲水蚤(Sinocalanus sinensis)、火腿许水蚤(Schmackeria poplesia)、虫肢歪水蚤(Tortanus vermiculus),真刺唇角水蚤(Labidocera euchaeta)等,还有长江径流带到河口的淡水种如近领剑水蚤（Cyclops vicinus vicinus)、英勇剑水蚤（Cyclops strenuus）、透明溞（Daphnia hyalina)等。一些浮游动物可作为水系指示种,其分布、数量反映了不同水系分布变化,长江河口浮游动物有;类水系指示种。通过对长江河口浮游动物群落聚类分析发现。1999、2000年枯水期浮游动物群落结构相似。可分为河口类群、近岸类群和近外海类群。1999年丰水期只形成近岸和近外海类群。浮游动物种类数由口门内向口门外方向有逐渐增加的趋势。浮游动物种类数由北向南变化趋势一致。大潮与小潮、涨憩与落强等潮汐作用对浮游动物影响往往因采样时间与区域等的不同而不同。对长江河口3次采样的物种多样性指数和均匀度指数进行了计算,结果表明：浮游动物多样性指数1999年枯水期最低,1999年丰水期最高。     

洞庭湖浮游生物群落DNA指纹拓扑结构与物种组成对应关系

对东洞庭湖7个采样站点的浮游生物群落进行了DNA多态性的RAPD指纹分析和物种组成的分类鉴定,并通过聚类分析探讨了DNA指纹拓扑结构与物种组成对应关系。结果如下:(1)筛选出的11条随机引物共获得148条长度在180~2000bp的谱带,多态率为98.6%,各引物扩增谱带数在11~16不等;各站点平均有57.6条谱带,其中站最多(70条),站最少(45条),而站的特有带最多(7条),站最少(2条);(2)共观察到54种/类浮游生物,其中站出现的最多(27),其它各站点在7~13不等,分布概率在85%以上的只有直链硅藻(Melosirasp.)。相似性聚类分析表明:7个站点的浮游生物群落可以划分为两大类——站作为单独的一类而明显有别于其它6站;并且,RAPD分析在此基础上将、、站和、、站进一步分作两小类。因此,研究说明浮游生物群落DNA指纹拓扑结构与物种组成是密切相关的,这类资料的积累将会为生态系统功能、机理的解释或阐明提供一些启示。     

Importance of intermediate disturbances for the species composition and diversity of phytoplankton in two very different Berlin lakes

Species composition and diversity of phytoplankton were studied for several years in two lakes which differ with respect to mixing conditions and nutrient limitation: Schlachtensee regularly stratifies very stably. In contrast, size and wind-exposure predispose Lake Tegel to deeper mixing; additionally, stratification is artificially destabilized by aeration. As the duration of aeration was varied, the study period includes interannual changes in mixing conditions. For both lakes, it also covers trophic change due to restoration; this was especially pronounced in Schlachtensee.Results show that mixing conditions affect species composition on two levels: on a superordinate level, lake morphology or hydrology govern stability of stratification and susceptibility to perturbation, and hence the extent to which motile species can develop. In Schlachtensee, species with some means of actively seeking preferred depths usually dominated during summer stratification: Planktothrix agardhii during the hypertrophic phase, and flagellates since restoration. In contrast, in Lake Tegel deeper mixing as a generally prevailing condition favored non-motile species. Their seasonal pattern was remarkably constant from year to year. Although changes in the extent of mixing were pronounced during the four years studied (1987–1990), these were within a range that affected species composition only slightly: in summer, cyanobacteria and diatoms represented climax species whose dominance was not offset by additional, weather-induced increases of turbulence.On a subordinate level, and within the constraints set by nutrient limitation as well as by grazing pressure, small-scale changes in mixing conditions caused by meteorological cycles were shown to strongly affect species composition and in consequence diversity: Results for the fouryear post-restoration study period at Schlachtensee show that considerable interannual variations of species composition and diversity can be attributed to variations in the frequency of meteorological changes. In accordance with the intermediate disturbance hypothesis (IDH), diversity was lowest during 1989, the year with the longest and most pronounced cycles of fair weather (14 to 27 fair days on end). However, the mechanism for this was rarely a decline of diversity caused by competitive exclusion within single long phases of stable conditions, as conceived by the intermediate disturbance hypothesis. Instead, diversity responded to changes in mixing conditions with a variety of patterns — often with low values during phases of increased mixing and with high values under quiescent conditions, especially during the first calm days just after increased mixing. Thus, not disturbance as such, but rather the rate of change between phases of disturbance and quiescence appears to determine the frequency of high diversity indices.In Lake Tegel, high diversity indices were somewhat more frequent in 1989, the year during which thermal stratification was most stable. For species adapted to frequent or continuous mixing, interjected calm phases with unusually high stability of thermal stratification may represent a disturbance of accustomed conditions. Thus, in turbulent Lake Tegel, meteorological cycles appear to act in reversal to the IDH, in a sense which may be termed intermediate quiescence hypothesis.Phosphorus limitation due to successful restoration was found to decrease winter and vernal diversity in Schlachtensee. Presumably, without nutrient constraints, new populations could grow more rapidly in response to the rapid changes of physical parameters during this season. In contrast, restoration has increased summer diversity, as phosphorus concentrations no longer allow the virtual monocultures of Planktothrix agardhii which prevailed previously. In Lake Tegel, the reduction of phosphorus concentration down to 60 µg/l P in 1989 limited biomass, but this level was still too high to significantly alter species composition or diversity.     

亚热带不同树种组成森林中土壤甲螨群落结构特征: 以江西新岗山为例

在全球环境变化的大背景下, 生物多样性丧失日益加剧。土壤动物作为生物多样性重要组成之一, 受到广泛的关注。位于我国江西省新岗山的亚热带森林生物多样性与生态系统功能实验样地(BEF-China)是全世界25个森林生物多样性控制实验样地之一。本研究自2019年9月至2022年4月在BEF-China两个不同树种组成的样地(A样地和B样地)内采样, 共获得甲螨23,704头, 隶属于34科50属61种。本文分析和对比了两个样地内甲螨群落结构的差异, 及其多度、物种丰富度、Shannon多样性指数的季节性差异; 通过Pearson检验探讨了甲螨多度与环境因子的关系。结果表明: 在A、B两个不同树种组成的森林生态系统内, 土壤甲螨群落结构及其季节动态具有显著差异。具体表现在: A样地奥甲螨科、罗甲螨科、若甲螨科和尖棱甲螨科的相对多度高于B样地; B样地菌甲螨科、盖头甲螨科和礼服甲螨科的相对多度高于A样地。A样地中夏季和秋季甲螨多度、物种丰富度和Shannon多样性指数显著低于春季和冬季; 而B样地中秋季甲螨多度和物种丰富度与春季差异不显著。Pearson检验结果显示, 凋落物木质素含量与单翼甲螨科和菌甲螨科多度呈负相关关系, 而与奥甲螨科多度呈正相关关系。菌甲螨科多度与土壤和凋落物同一理化因子的相关性基本相同(碳氮比除外), 但与凋落物碳氮比呈正相关关系而与土壤碳氮比呈负相关关系。     

流溪河水库敞水区轮虫多样性与群落的动态特征

流溪河水库是位于北回归线上的大型峡谷型供水水库,于2013—2014年对该水库敞水区轮虫群落及其环境因子进行观测,分析敞水区轮虫多样性与群落动态特征。流溪河水库介于贫营养到中营养水平之间,丰水期(5月—9月)的总磷、透明度均高于枯水期(10月—4月),两年的总磷的平均值为0.019mg/L,透明度为2.55m。两年共检出轮虫40种,单月检出物种数波动范围为8—19种,月均检出轮虫13种。螺形龟甲轮虫、真翅多肢轮虫、沟痕泡轮虫和胶鞘轮虫是主要优势轮虫。2013、2014年轮虫年均总丰度分别为68.9、66.9个/L,两年物种丰富度在丰水期大于枯水期,但枯水期轮虫群落Simpson多样性指数均大于丰水期。采用Bray-Curtis距离测度群落之间的相异性,计算表明两年的枯水期轮虫群落之间的平均距离均大于丰水期,即丰水期时轮虫群落相似性较高,枯水期时轮虫群落变异较大。丰水期的水温和水质参数的变化相对稳定,种类的优势度更为明显,导致丰水期群落之间更为相似。主成分分析表明,无柄轮属、胶鞘轮属、多肢轮属、异尾轮属、泡轮属、晶囊轮属和皱甲轮属的主要种类的全年分布有较大的差异,而其余多数轮虫种类全年分布差异较小,反映了我国南亚热带地区水温全年变幅小,可维持较多的全年性种类共存。群落的方差解析与RDA分析表明,相对于生物与化学变量,物理环境变量主导了流溪河水库敞水区轮虫群落的变异,就单个变量而言,水温和食物是影响流溪河水库敞水区轮虫群落结构的重要因素,降雨则是影响轮虫群落结构变异的宏观因素。绝大多数轮虫为滤食性的,处于食物链底端,个体小、生活史短,轮虫群落在对环境因子变化的响应上与浮游植物具有相似性。     

Spatial patterns of invertebrate species richness in a river: the relationship between riffles and microhabitats

This study describes the pattern of invertebrate species richness in a river reach with large differences in habitat complexity at two, hierarchically nested, spatial scales. The aim was to determine whether the mass effect was likely to be increasing invertebrate species richness in epilithic microhabitats in this river. The mass effect is the process by which the species richness of a patch is increased when it acts as a ‘sink’ for species generated by ‘source’ patches. Microhabitat patch types in Mountain River, Tasmania, were distinguished on the basis of physical structure and orientation on the river bed. They were nested within two types of riffle with contrasting structural complexity: bedrock and boulder-cobble riffles. It was hypothesized that microhabitats with high species richness would act as source patches, contributing species to other microhabitats (sinks) and thereby increasing their species richness. Microhabitat sampling was carried out in four consecutive seasons and rarefaction was used to estimate riffle-scale species richness. Analysis of variance ( ANOVA ) was used to compare the identical microhabitats present in the contrasting riffle types, to detect evidence of the mass effect in either riffle type. The more structurally complex boulder-cobble riffles had higher species richness than did bedrock riffles. Amongst the microhabitats, the spaces beneath the cobbles had the most species. Microhabitats accounted for a higher percentage of the variation in species richness than did differences between riffles of the same type. No evidence was found for the operation of the mass effect in either riffle type. The majority of species found only in boulder-cobble riffles were unique to the beneath-cobble microhabitat and appeared to be unable to colonize other microhabitats, even as transients. In Mountain River, small-scale habitat characteristics appeared to be more important than larger-scale effects in determining microhabitat species richness.     

International Biodiversity Observation Year in Western-Pacific and Asian regions (DIWPA-IBOY): a case report on species rarity and spatio-temporal variability of species composition in Lepidoptera and Coleoptera communities from a temperate forest of northern Japan

An international project, DIWPA-IBOY, took place for simultaneously observing biodiversity throughout the Western-Pacific and Asian regions in 2001–2003, as one of the core projects for International Biodiversity Observation Year, a crosscutting network activity of DIVERSITAS (an international programme of biodiversity science). DIWPA-IBOY provides extensive data on species diversity obtained by the standardized method. Under this project, 51,742 individuals of Lepidoptera and 11,633 of Coleoptera were collected by light traps from the Tomakomai Experimental Forest of Hokkaido University, one of the core DIWPA-IBOY sites, in the cool-temperate region of northern Japan. Based on these data, this study examined the relative abundance distribution (RAD) to evaluate the amount of rare species in the Lepidoptera and Coleoptera communities. The beta diversities between sampling seasons, forest strata, and trap sites were also assessed to evaluate the spatio-temporal variability of species composition in these communities. In the analysis of the RAD, the best-fit model was selected from the log-Normal, Zipf–Mandelbrot, and Zipf models differing in the tail length of the RAD, i.e., the proportion of rare species. To explore the beta diversity between samples, the abundance-based Jaccard index with an unseen species estimator was calculated, and then a hierarchical clustering analysis was conducted. As a result of RAD analysis, the Coleoptera community was regarded as containing a larger proportion of rare species than the Lepidoptera community. The seasonal compartmentalization of the community, deduced from the beta-diversity analysis, was finer in Lepidoptera (seven assemblages recognized) than in Coleoptera (three assemblages). The spatial (vertical and horizontal) compartmentalization was negligible in both communities. The coincidence of the larger proportion of rare species and the lower beta diversity between seasons in the Coleoptera community was explained by the longer life spans of beetles compared to moths, based on the assumption that the length of life span acts as a temporal agent for mass effect on the analogy of the migration rate as a spatial agent for mass effect.     

富营养化对小型湖泊浮游甲壳动物群落结构及多样性的影响

2017年3月到2018年2月研究了临涣湖浮游甲壳动物群落结构的季节变化。临涣湖共记录浮游甲壳动物13种,其中枝角类8属8种,桡足类5属5种。短尾秀体溞(Diaphanosoma brachyurum)、广布中剑水蚤(Mesocyclops leuckarti)和象鼻溞(Bosmina sp.)等小型富营养种类是温暖季节的优势种,而近邻剑水蚤(Cyclops vicinus)是冬季的优势种。盔形溞(Daphnia galeata)等大型种类仅在少数月份中被观察到。临涣湖浮游甲壳动物的年平均密度和生物量分别为28.3个/L和0.33 mg/L。营养状态指数(TSI_M)的年平均值为62.6。浮游甲壳动物的Shannon指数、Pielou指数和Simpson指数的年平均值分别为0.86、0.74和0.49,且3种多样性指数均具有显著的季节差异。营养盐水平、营养状态指数和物种多样性指数均表明,临涣湖水体处于富营养化状态。冗余分析结果表明,水温、总磷浓度和叶绿素a浓度是影响临涣湖浮游甲壳动物群落结构变化的上行效应因子。鲢、鳙鱼的捕食压力是临涣湖浮游甲壳动物群落结构小型化的下...     

长山列岛邻近海域鱼类群落种类组成和多样性时空变化

为了解黄、渤海生态系统交错带长山列岛邻近水域鱼类群落种类组成和多样性,根据2016年10月,2017年1月、5月及8月进行的鱼类资源底拖网调查数据,应用相对重要性指数、物种多样性指数、k优势度曲线等方法,研究了长山列岛邻近海域鱼类群落种类组成、物种多样性时空变化及其与环境因子的关系。结果表明: 该海域共计捕获鱼类77种,以温水性、底层、洄游性鱼类为主,优势种组成季节变化明显,春季、冬季主要优势种为黄鮟鱇,夏季以日本鲭、鳀等中上层鱼类为主。全年共计出现洄游性鱼类46种,季节间物种迁移指数均在100以上,其中秋季物种迁移指数最大。鱼类群落物种丰富度指数在春季最高、Shannon多样性指数和均匀度指数在秋季最高。夏季物种丰富度指数与表层水温呈显著负相关;冬季物种丰富度指数与水深、底层水温呈极显著正相关,Shannon多样性指数与底层水温呈极显著正相关。长山列岛邻近海域作为黄、渤海两大生态系统的交错带,鱼类群落表现出高物种多样性、洄游种多以及明显的时空异质性。     

Differing assemblage composition and dynamics in T4‐like myophages of two neighbouring sub‐alpine lakes

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Changes in vegetation structure and composition of a lowland mire over a sixty‐five‐year interval

1. Mires are characterized by plant communities of high conservation and societal value, which have experienced a major decline in area in many parts of the world, particularly Europe. Evidence suggests that they may be particularly vulnerable to changes in climate and nutrient addition. Although they have been the focus of extensive paleoecological research, few attempts have been made to examine the dynamics of mire vegetation during the current era of anthropogenic environmental change.
2. To assess long‐term change in the spatial structure and composition of a lowland mire community, in 2016 we resurveyed plots first surveyed in 1951. Measures of species richness and composition were compared between the two surveys, and changes in community composition were related to plant traits.
3. Overall, mean species richness declined by 26%. The area of occupancy declined in 37% of species, which were primarily oligotrophic species typical of nutrient‐poor bog communities. Conversely, occupancy increased in 21% of species, especially those that were more tolerant of higher nutrient availability. These changes were associated with variation in plant functional traits, as indicated by an increase mean Ellenberg trait values for nitrogen and mean temperature, and a decline in values for precipitation. These results suggest that eutrophication and climate change have been key drivers of floristic change on this site.
4. Synthesis. This investigation provides a rare assessment of the dynamics of a mire community over a multi‐decadal interval. Results indicate that substantial change has occurred in the composition of the community, and the distribution of species within it. The investigation provides evidence of the impact of environmental change on the composition and structure of a lowland mire community, and highlights challenges for its future conservation.

     

三疣梭子蟹两种养殖模式浮游动物调查

于2012年6-12月,在宁波市象山县东盛水产养殖有限公司对主养三疣梭子蟹池塘两种混养模式（模式Ⅰ：三疣梭子蟹与日本对虾、黑鲷、菲律宾蛤仔混养;模式Ⅱ：三疣梭子蟹与日本对虾、黑鲷混养）浮游动物进行了调查与比较。结果显示：共检出浮游动物13属19种,其中,原生动物3属3种;轮虫2属5种;枝角类2属3种;桡足类6属8种。浮游动物平均密度模式Ⅰ（370 ind./L）〉模式Ⅱ（209 ind./L）;平均生物量模式Ⅰ（17.974 mg/L）〈模式Ⅱ（18.102 mg/L）。Margalef指数为0.22~0.81;Shannon-Wiener指数为1.28~3.03;Pielou均匀度指数为0.54~0.96,均值都是模式Ⅰ〉模式Ⅱ。     

渤海东部海域秋季底层游泳动物种类组成及群落多样性

根据2014年9月在渤海东部海域(37°40'—38°20'N、120°00'—121°20'E)进行的游泳动物底拖网调查数据,应用相对重要性指数、生物多样性指数、群落结构多元统计分析等方法对该海域游泳动物种类组成及群落多样性特征进行了分析。结果表明:调查海域共捕获游泳动物54种,以头足类枪乌贼(Loliolus spp.)为绝对优势种;游泳动物资源密度为28.82kg/h和5166尾/h。游泳动物种类Margalef丰富度指数(D)的变化范围为1.99—3.67,Shannon-Wiener多样性指数(H')变化范围为0.89—2.28,Pielou均匀度指数(J')变化范围为0.29—0.69。群落结构多元统计分析表明,渤海东部海域游泳动物群落结构以60%的相似性可划分为3个组群:长岛群岛海域组群(A组群)、龙口海域组群(B组群)和蓬莱海域组群(C组群);ANOSIM分析表明,组群之间差异极显著,两两之间差异亦极显著。受增殖放流影响,C组群资源密度和种类多样性均保持较高的水平,而A、B组群人为活动频繁,过度捕捞严重,对海域生态环境和渔业资源整体结构的破坏较大。     

丛枝菌根真菌形态结构、物种多样性和群落组成对氮沉降响应研究进展

工业革命以来,人类活动输入到生态系统中的氮迅速增加,已突破地球所能承受的氮循环阈值。过量氮沉降会造成生物多样性丧失等一系列危害,严重影响生态系统结构和功能。丛枝菌根(AM)真菌能够与大约70%-80%的陆地植物种类形成共生关系,在宿主植物养分吸收、抵抗外界不良环境压力、群落动态和物种共存、生物地球化学循环等方面具有重要的作用。探究AM真菌对氮沉降的响应对认识和把握菌根真菌缓解氮沉降的负面后果,维持生态系统的结构和功能具有重要意义。本文综述了AM真菌的形态结构、物种多样性和群落组成等对氮沉降的响应机制。前人研究表明氮沉降通常降低AM真菌的根系定殖率,减少根外菌丝密度和土壤孢子密度,改变菌丝生长的时间动态;降低AM真菌多样性,改变AM真菌群落组成。氮沉降主要通过缓解植物氮限制、降低植物对菌根的依赖性、减少植物对菌根的碳分配、改变根系和土壤中菌根生物量比率、在植物根内维持稳定的菌根真菌组成作为应对未来扰动的“保险”、改变土壤资源有效性及土壤酸度等直接和间接途径影响AM真菌结构和功能。我们建议在未来研究中整合多组学手段、开展学科交叉,聚焦复杂的生物互作体系对氮沉降的响应机制,以及AM真菌对氮沉降响应的生态后果。     

气候变化对冬季东海外海中下层游泳动物群落结构及重要经济种类的影响

以全球气候变暖为主要特征的全球气候变化对海洋生物和海洋生态系统造成的影响已引起国际学者的高度关注。根据中国14家国营渔业公司底拖网渔业生产和渔业资源大面定点调查获得的17种中下层渔业数据,结合1960—2011年东海北部水域海表温度的变化情况,利用Fox模型移除捕捞效应产生的趋势变化后,分析了气候变化对中、下层游泳动物群落结构及几种重要经济种类的影响。通过气候跃变检验分析发现,海表温度在整体变暖的趋势上叠加有年代际波动,研究水域分别在1982/1983年发生了从寒冷期(1960—1982年)向升温期(1983—1998)、经由1998/1999年再到温暖期(1999—2011年)的跃变。群落结构变化特征显示:相比于寒冷期,温暖期间底层类和大型捕食类资源指数降低,中层类和无脊椎类升高;暖水种资源指数升高,暖温种降低;生物多样性指数略有增加。移除捕捞效应后,对不同生态属性种类CPUE与海表温度距平进行相关分析显示:底层类、中层类和无脊椎类残差与海表温度距平均呈正相关关系,其中中层类与海表温度距平显著正相关,而大型捕食类则呈负相关关系;暖水种残差与海表温度距平呈正相关,而暖温种则呈负相关关系。中层类中的黄鲫(Setipinna taty)、银鲳(Pampus argenteus)的CPUE残差均与海表温度距平呈显著正相关关系,近底层类中的带鱼(Trichiurus japonicus)和头足类(Squid)的CPUE残差均与海表温度距平呈正相关关系,而底层类小黄鱼(Larimichthys polyactis)和对虾(Shrimp)则呈负相关关系。在气候变化的大背景下,需加强其对海洋生态系统结构和功能影响的研究,查明渔业资源对气候变化的响应机制和机理,制定科学有效的渔业管理制度,实现渔业资源的可持续发展。     

胶州湾近岸浅水区鱼类群落结构及多样性

根据2009年3月-2010年2月在胶州湾西北部近岸浅水区进行的鱼类逐月定置网调查数据,采用生态多样性指数和多元统计分析等方法研究了该海域的鱼类群落结构及多样性特征.结果表明:调查共鉴定出44种鱼类,其中海洋性27种,河口性鱼类17种.鱼类种类组成与底层水温和盐度有密切关系.胶州湾近岸浅水区鱼类群落Margalef种类丰富度指数(R)变化范围为0.33-3.50,Shannon-Wiener多样性指数(H’)为0.42-2.25,Pielou均匀度指数(J’)为0.23-0.93.聚类分析(CLUSTER)和多维标度排序(MDS)分析表明,不同鱼类种类组成的各月份样品可划分为3个组分:水温较低的冬季组G1(12月-翌年4月)、水温次高的春秋季组G2(5-6月、10-11月)和水温最高的夏季组G3(7-9月).其中G1的典型种主要为尖海龙(Syngnathus acus)、方氏云鳚(Enedrias fangi)和玉筋鱼(Ammodytes personatus)等冷温性常栖类群种类,G2的主要典型种为鳀鱼(Engraulis japonicus)和尖海龙,G3的主要典型种为鲐鱼(Scomber japonicus)、细条天竺鱼(Apogonichthys lineatus)和普氏缰虾虎鱼(Amoya pflaumi)等洄游性鱼类.单因子相似性分析(ANOSIM)表明,3个月份组间鱼类群落结构差异显著,不同月份组间两两差异均显著.生物-环境分析(BIOENV)表明,底层水温是影响胶州湾近岸浅水区鱼类群落结构时间变化的主要环境因子.在胶州湾内近岸浅水区发现40余种幼鱼,但占优势的主要为低值鱼类,表明胶州湾的产卵、肥育场功能有所下降,应加强胶州湾近岸水域生态环境和渔业资源的保护及修复.     

Predicting the Distribution of the Amphibian Pathogen Batrachochytrium dendrobatidis in the New World1

One application of ecological niche modeling is predicting suitable areas for the establishment of invasive species. Herein, I model the fundamental niche of the chytrid fungus Batrachochytrium dendrobatidis, a pathogen linked to amphibian declines on several continents. Niche models were generated with the Genetic Algorithm of Rule‐Set Prediction using point distribution data of the pathogen and digital maps of environmental variables integrated in a GIS environment. The distribution of regions suitable for B. dendrobatidis in the New World is extensive and includes significant portions of: (1) Sierra Madre Occidental pine‐oak forest; (2) Sonoran and Sinaloan dry forest; (3) Veracruz moist forest; (4) Central America east from the Isthmus of Tehuantepec; (5) Caribbean Islands; (6) temperate forest in Chile and western Argentina south of latitude 30°S; (7) Andes above 1000 m of altitude in Venezuela, Colombia, and Ecuador; (8) eastern slopes of the Andes in Peru and Bolivia; (9) Brazilian Atlantic forest; (10) Uruguay, Paraguay, and northeastern Argentina; (11) southwestern and Madeira‐Tapajós Amazonian tropical rainforests. The regions with the highest suitability for B. dendrobatidis include habitats that contain the world's most diverse amphibian faunas. Models were built with New World localities, but also showed strong predictability for B. dendrobatidis localities in the Old World. Out of a total of 59 reported Old World localities for B. dendrobatidis, 56 occurred within regions with high predicted suitability. I also present analyses of the environmental envelope of B. dendrobatidis and discuss the implications of the results for the conservation of amphibians in the neotropics.