scholarly journals Cladocera of the Lençóis Maranhenses (NE - Brazil): faunal composition and a reappraisal of Sars' Method

2010 ◽  
Vol 70 (3 suppl) ◽  
pp. 755-779 ◽  
Author(s):  
K. Van Damme ◽  
HJ. Dumont

We studied the Cladocera of a group of ephemeral interdunal pools in the Lençóis Maranhenses, Maranhão State (NE - Brazil) and recorded 34 species. The fauna was overwhelmingly neotropical, with no evidence of invasive species. Species composition differed in Lagoa da Colher, an acid system. We provide notes on behaviour, morphology and taxonomy of some lesser-known anomopods, with emphasis on the Chydoridae. We figure male Oxyurella longicaudis, Chydorus eurynotus, Disparalona leptorhyncha, Alonella dadayi and A. clathratula. We provide notes on the "Sars' Method", hatching of freshwater crustaceans from dry mud, a simple technique that complements the information of hit-and-run surveys. About half of the total species number (44%) was revived through this method; 18% of species were additional to field-collected samples. The Sars' method also yielded abundant specimens of rare species, useful for identification and studies on behaviour.

2013 ◽  
Vol 807-809 ◽  
pp. 1695-1701 ◽  
Author(s):  
Gen Hai Zhu ◽  
Chun Sheng Wang ◽  
Zhen Sheng Liu ◽  
Shuji Ohtani

It was investigated and analyzed about the species composition of phytoplankton, and their relations to environmental factors sampled in spring, summer and autumn in 2001-2011 in Fuxian Lake (24o 21'~24o 38' N, 102o 49'12 "~102o 57'26"E). The phytoplankton from Fuxian lake included 78 species belong to 41 genera 25 family, 7 phyla. Chlorophyta was predominant, with consisted of 43.5% of total species number. Species number of phytoplankton appeared visible monthly variation. The main predominant phytoplankton species was Mougeotia bloodlei, which accounted for 42.94%~84.94% of total cell density of phytoplankton. The community structures of phytoplankton were consist of Mougeotia bloodlei, Chroococcus spp., Cyclotella spp., Ceratium hirundinella and Dinobryon sertularia.


2020 ◽  
Vol 20 (3) ◽  
pp. 267-276
Author(s):  
Dam Duc Tien ◽  
Nguyen Thi Mai Anh ◽  
Linh Manh Nguyen ◽  
Pham Thu Hue ◽  
Lawrence Liao

This paper exhibites species composition and distribution of marine seaweed at 10 sites of Co To and Thanh Lan islands in May 2019. The studies record 76 species of marine algae in the area, belonging to four divisions: Cyanophytes, Rhodophytes, Ochrophytes and Chlorophytes. Among them, five species are classified into Cyanophytes (comprising 6.6% of total species); thirty-four species into Rhodophytes (44.7%); twenty-one species into Ochrophytes/Phaeophytes (27.6%) and sixteen species into Chlorophytes (21.1%). The species composition of marine seaweeds in Co To and Thanh Lan shows significant differences as follows: 22 species (sites number 4 and 10) to 58 species (site number 2) and the average value is 38.7 species per site. Sørensen similarity coefficient fluctuates from 0.33 (sites number 5 and 10) to 0.84 (sites number 1 and 3) and the average value is 0.53. The current investigations show that four species of twenty-one species are collected in the littoral zone and forty-two species in the sub-littoral zone (in which there are thirteen species distributed in both littoral zone and sub-littoral zone). The algal flora in Co To and Thanh Lan is characterized by subtropics.


2018 ◽  
Vol 23 (1) ◽  
pp. 1 ◽  
Author(s):  
Colin K. C. Wen ◽  
Li-Shu Chen ◽  
Kwang-Tsao Shao

Spatial and temporal variations in the species composition of assemblages are common in many marine organisms, including fishes. Variations in the fish species composition of subtidal coral reefs have been well documented, however much less is known about such differences for intertidal fish assemblages. This is surprising, given that intertidal fishes are more vulnerable to terrestrial human disturbances. It is critical to evaluate the ecology and biology of intertidal fishes before they are severely impacted by coastal development, especially in developing countries such as those in the tropical western Pacific region where coastal development is rapidly increasing. In this study, we investigated the species composition, abundance, biomass and species number (richness) for intertidal fish assemblages in subtropical (northern) and tropical (southern) Taiwan across four seasons by collecting fishes from tidepools using clove oil. We also examined the gut contents of collected fishes to identify their trophic functional groups in order to investigate regional and seasonal variations for different trophic groups. We found significant differences in the species composition of tidepool fish assemblages between subtropical and tropical Taiwan. Bathygobius fuscus, Abudefduf vaigiensis and Istiblennius dussumieri were dominant species in subtropical Taiwan, whereas Bathygobius coalitus, Abudefduf septemfasciatus and Istiblennius lineatus were dominant in tropical Taiwan. Other species such as Bathygobius cocosensis, Abudefduf sordidus and Istiblennius edentulus were common in both regions. For trophic groups, omnivores and detritivores had or showed trends towards higher species numbers and abundances in the subtropical region, whereas herbivores, planktivores and general carnivores had or showed trends towards higher species numbers and biomass in the tropical region. Overall, many intertidal fish species and trophic groups showed differences in abundance, biomass and species number between subtropical and tropical Taiwan. Further studies on large scale geographical gradients in trophic groups and species compositions in the Indo-west Pacific region are encouraged to assist with ecosystem monitoring and assessment. Keywords: Intertidal fishes, spatio-temporal pattern, feeding guild, diet


1987 ◽  
Vol 82 (1) ◽  
pp. 119-124 ◽  
Author(s):  
M. Dora Feliciangeli

A study on the ecology of phlebotomine sandfly fauna in a restricted focus of cutaneous leishmaniasis in northern Venezuela was undertaken in order to investigate the species responsible for the transmission. The study area and catching methods for phlebotomine sandflies are described. A total of 9,061 females and 1,662 males were collected during a year-term study. 12 species of Lutzomya and 1 species of Brumptomya sp. were identified. Absolute and relative abundance and ocurrence for each species were determined. The rel ative occurrence allowed to distinguish the common species, viz. L. panamensis, L. ovallesi, L. gomezi, L. tinidadensis, L. atroclavata, L. cayennensis, L. shannoni and L. olmeca bicolor from the rare species vis., L. punctigeniculata, L. rangeliana, L. evansi and L. dubitans. General comments on the species composition of the sandfly fauna in this locality are made.


2021 ◽  
Vol 3 ◽  
Author(s):  
Aarti P. Mistry ◽  
Adam W. T. Steffeck ◽  
Mark J. Potosnak

Urban trees provide numerous benefits, such as cooling from transpiration, carbon sequestration, and street aesthetics. But volatile organic compound emissions from trees can combine with anthropogenic nitrogen oxide emissions to form ozone, a harmful air pollutant. The most commonly-emitted of these compounds, isoprene, negatively impacts air quality and hence is detrimental to human health. In addition to environmental controls such as light and temperature, the quantity of isoprene emitted from a leaf is a genus-specific trait. Leaf isoprene emission is enzymatically controlled, and species are typically classified as emitters or non-emitters (near-zero emission rates). Therefore, the species composition of urban forests affects whole-system isoprene production. The process of plant invasion alters species composition, and invasive tree species can be either emitters or non-emitters. If an invasive, isoprene-emitting tree species displaces native, non-emitting species, then isoprene emission rates from urban forests will increase, with a concomitant deterioration of air quality. We tested a hypothesis that invasive species have higher isoprene emission rates than native species. Using existing tree species inventory data for the Chicago region, leaf-level isoprene emission rates of the six most common invasive and native tree species were measured and compared. The difference was not statistically significant, but this could be due to the variability associated with making a sufficient number of measurements to quantify species isoprene emission rates. The most common invasive species European buckthorn (Rhamnus cathartica, L.) was an emitter. Because European buckthorn often invades the disturbed edges common in urban forests, we tested a second hypothesis that edge-effect isoprene emissions would significantly increase whole-system modeled isoprene emissions. Using Google Earth satellite imagery to estimate forested area and edge length in the LaBagh Woods Forest Preserve of Cook County (Chicago, IL, USA), edge isoprene emission contributed 8.1% compared to conventionally modeled forest emissions. Our results show that the invasion of European buckthorn has increased isoprene emissions from urban forests. This implies that ecological restoration efforts to remove European buckthorn have the additional benefit of improving air quality.


2018 ◽  
Vol 3 (1) ◽  
pp. 9-22 ◽  
Author(s):  
N. A. Boltacheva ◽  
M. V. Makarov ◽  
L. V. Bondarenko ◽  
M. A. Kovaleva

During 2015–2106 the macrozoobenthos under the clam farm located in the area of Sevastopol was investigated. The aim of the study is to consider species composition, density and biomass of macrozoobenthos in the area of the clam farm. The samples were taken using standard benthic techniques. Relatively low species diversity was observed, with 56 species of macrozoobenthos identified. The density was 500–975 ind. per m², the biomass varied from 0.8 to 381.1 g·m-2. The community of the bivalve mollusk Lucinella divaricata (Linnaeus, 1758) was found. Trophic structure of the community with high quantity of detritus feeders dominated by small polychaetes was determined. The dominating, typical and rare species were identified. Comparison with the data obtained in 1957 in Evpatoriya – Sevastopol area at the same depths and sediments was made.


2020 ◽  
pp. 142-147
Author(s):  
Shaswati Chakraborty ◽  
Dipalok Karmaker ◽  
Subroto Kumar Das ◽  
Riyad Hossen

Phytoplanktons, also called microalgae, are microscopic photosynthetic living organisms that generally found in aquatic environments. Although they are considered as the most important primary producers and bioindicators of aquatic ecosystems, there was no previous report found for Barishal City about these tiny organisms. Consequently, the present study selected 10 freshwater reservoirs from the city to investigate phytoplankton communities and listed 110 taxa under 4 phyla, 7 classes, 18 orders, 24 families and 49 genera. The distribution of Chlorophytes was abundant relatively in terms of species number (45 taxa) followed by Euglenophytes, Chlorophytes and Cyanophytes in this area. Only Euglenaceae possessed one-third of the total species of this report. Among all stations, the highest number of taxa was recorded from station 2 and according to nine biodiversity indices, the station 2 and 9 showed comparatively good results. All of the recorded taxa were previously mentioned by different authors from Bangladesh.


2002 ◽  
Vol 357 (1421) ◽  
pp. 667-681 ◽  
Author(s):  
Ricard V. Solé ◽  
David Alonso ◽  
Alan McKane

Why are some ecosystems so rich, yet contain so many rare species? High species diversity, together with rarity, is a general trend in neotropical forests and coral reefs. However, the origin of such diversity and the consequences of food web complexity in both species abundances and temporal fluctuations are not well understood. Several regularities are observed in complex, multispecies ecosystems that suggest that these ecologies might be organized close to points of instability. We explore, in greater depth, a recent stochastic model of population dynamics that is shown to reproduce: (i) the scaling law linking species number and connectivity; (ii) the observed distributions of species abundance reported from field studies (showing long tails and thus a predominance of rare species); (iii) the complex fluctuations displayed by natural communities (including chaotic dynamics); and (iv) the species–area relations displayed by rainforest plots. It is conjectured that the conflict between the natural tendency towards higher diversity due to immigration, and the ecosystem level constraints derived from an increasing number of links, leaves the system poised at a critical boundary separating stable from unstable communities, where large fluctuations are expected to occur. We suggest that the patterns displayed by species–rich communities, including rarity, would result from such a spontaneous tendency towards instability.


2021 ◽  
Vol 28 (1) ◽  
Author(s):  
IGOR GRICHANOV ◽  
MARIYA CHURSINA ◽  
MENGQING WANG

The dolichopodid fauna of continental Chinese and Russian regions belonging to the East Palaearctic have been selected for a comparative diversity investigation. We gathered information about 654 species of long-legged flies in the studied areas. Regarding the total species number, Primorsky Kray and Republic of Sakha in Russia, Henan and Shaanxi in China, as well as Mongolia are the top five regions, each with more than 100 species known. Cluster analysis of the dolichopodid genera composition allows us to divide all studied territories into two groups: Group A is mixed, since it includes both the Russian regions and the Chinese provinces; Group B includes only Russian regions. Generally, the mathematical analysis of the dolichopodid species supports the uniqueness of Primorsky Kray as the biodiversity center in East Asian Palaearctic. A decrease in the number of known species and biodiversity indices is observed northward, southward and westward of Primorsky Kray. One more possible center is located closely to the Oriental provinces of China (Henan and Shaanxi provinces).


Author(s):  
Е. Пещанская ◽  
В. Кожевников

Необходимость восстановления луговой степи центрального Ставрополья возникла ещё в середине прошлого столетия. Причиной тому послужило усиление воздействия антропогенных факторов на окружающую среду: распашка целины, промышленное и гражданское строительство, чрезмерный выпас скота, а также воздействие различного вида эрозий. В целях сохранения уникального природного комплекса степей с большим набором ценных и редких видов, а также в качестве опыта по восстановлению кормовых угодий в Ставропольском ботаническом саду в 1963 году были начаты исследования по интродукции дёрна. В период с 1963 по 1984 год на площади около 2 га были воссозданы фрагменты луговой степи. Изучение состояния искусственных ценозов, получение сравнительных данных в отношении видового состава, хозяйственно-ботанических групп, урожайности ценозов важнейшие компоненты исследования. В качестве эталонов обследовались территории естественных целинных степей (эталоны) (г. Бучинка, г. Стрижамент, урочище Новомарьевская поляна) с доминантами, сходными с доминантами изучаемых участков, восстановленных дёрном ( Бучинка , Стрижамент , Новомарьевская поляна ). Количество видов на эталонных участках составляет 6592, на восстановленных участках 83103. Видовой состав максимально представлен разнотравьем: от 44 до 72 видов. Во всех выборках проб преобладают злаки (31,9446,17) и разнотравье (29,4041,64), значительный удельный вес приходится на сухие остатки (старику) 7,6128,64. Масса бобовых колеблется в пределах от 0,85 до 11,01, осок от 0,1 до 13,83. Урожайность травостоя восстановленных ценозов сохраняется высокой 3,243,97 т/га. Показатели урожайности травостоя восстановленных формаций превышают показатели эталонов с разницей от 0,61 до 1,65 т/га. Restoration of grasslands became important in the Central Stavropol region in the middle of the last century. The reason was an increased anthropogenic effect: plowing, industrial and civil engineering, cattle grazing and erosion. Experiments on turf introduction got started at the Stavropol Botanical Garden in 1963 to preserve and restore the unique natural steppe area with a large number of valuable and rare species. Fragments of steppe were grown on 2 ha area from 1963 to 1984. The investigation focused on ecosystem conditions, species composition, botanical groups and yield. Natural steppes performed as controls (Buchinka, Strizhament, Novomaryevskaya Polyana) having similar dominant species as the trial areas. Control areas contained 6592 species, the restored ones 83103. There were 4472 different grass species grown. Proportions of gramineous averaged to 31.9446.17, grass mixtures 29.4041.64, grassland litter 7.6128.64. Contents of legumes varied within 0.8511.01, sedge 0.113.83. Grass productivity of the restored area was high 3.243.97 t ha-1. It exceeded the one of the natural areas by 0.611.65 t ha-1.


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