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Sample records for abundance species composition

  1. Fish species composition, diversity and abundance of the lower New ...

    African Journals Online (AJOL)

    A thirteen-week investigation to determine the fish species composition, diversity and abundance of the Lower New Calabar River, in Rivers State, aimed at providing information on the fish stock and their status for documentation, knowledge improvement, and development of conservation and management strategies was ...

  2. The distribution, composition and abundance of fish species in two ...

    African Journals Online (AJOL)

    Fish composition and abundance of two Gold mine reservoir were investigated between May, 2008 and May, 2009. Seven fish families comprising of twelve species of fish were caught during the period of study. The families of fish caught included Anabantidae, Channidae, Clariidae, Cichlidae, Melanopluridae, Mormyridae ...

  3. Fish species composition and abundance on a subtropical, artificial ...

    African Journals Online (AJOL)

    The composition and abundance of fish species on a derelict rocky pier on the Durban beachfront, KwaZulu-. Natal, South Africa, were assessed by means of underwater visual census, using transects. A total of 74 spe- cies were recorded on the reef, with convict surgeons (Acanthurus triostegus), sash damsels ...

  4. Species Composition, Relative Abundance and Distribution of the ...

    African Journals Online (AJOL)

    Species Composition, Relative Abundance and Distribution of the Avian Fauna of Entoto Natural Park and Escarpment, Addis Ababa. ... Eucalyptus plantation, soil erosion, deforestation, habitat fragmentation, settlement and land degradation were the main threats for the distribution of birds in the present study area.

  5. Abundance, distribution and species composition of fish larvae in ...

    African Journals Online (AJOL)

    improving our knowledge of the abundance, distribution and species diversity ... banks as well as in the mid-channel, thus eliminating any bias that might have .... cond method (Table 2) may bias the importance of a single species due to one, ...

  6. Species composition, abundance and distribution of hydromedusae from Dharamtar estuarine system, adjoining Bombay Harbour

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.; Tiwari, L.R.; Nair, V.R.

    Species composition, abundance and distribution of hydromedusae from Dharamtar estuarine system, adjoining Bombay Harbour, Maharashtra, India were investigated during 1984-1985. Twenty six species belonging to 19 genera were obtained from this area...

  7. Long-Term Changes in Species Composition and Relative Abundances of Sharks at a Provisioning Site

    OpenAIRE

    Brunnschweiler, Juerg M.; Abrantes, Kátya G.; Barnett, Adam

    2014-01-01

    Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today's recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-...

  8. Sponge species composition, abundance, and cover in marine lakes and coastal mangroves in Berau, Indonesia

    NARCIS (Netherlands)

    Becking, L.E.; Cleary, D.F.R.; Voogd, de N.J.

    2013-01-01

    We compared the species composition, abundance, and cover of sponges in 2 marine lakes (Kakaban Lake and Haji Buang Lake) and adjacent coastal mangroves on the islands of Kakaban and Maratua in the Berau region of Indonesia. We recorded a total of 115 sponge species, 33 of which were restricted to

  9. Long-term changes in species composition and relative abundances of sharks at a provisioning site.

    Science.gov (United States)

    Brunnschweiler, Juerg M; Abrantes, Kátya G; Barnett, Adam

    2014-01-01

    Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today's recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-species shark feeding site in Fiji. Using direct observation sampling methods, eight species of sharks (bull shark Carcharhinus leucas, grey reef shark Carcharhinus amblyrhynchos, whitetip reef shark Triaenodon obesus, blacktip reef shark Carcharhinus melanopterus, tawny nurse shark Nebrius ferrugineus, silvertip shark Carcharhinus albimarginatus, sicklefin lemon shark Negaprion acutidens, and tiger shark Galeocerdo cuvier) displayed inter-annual site fidelity between 2003 and 2012. Encounter rates and/or relative abundances of some species changed over time, overall resulting in more individuals (mostly C. leucas) of fewer species being encountered on average on shark feeding dives at the end of the study period. Differences in shark community composition between the years 2004-2006 and 2007-2012 were evident, mostly because N. ferrugineus, C. albimarginatus and N. acutidens were much more abundant in 2004-2006 and very rare in the period of 2007-2012. Two explanations are offered for the observed changes in relative abundances over time, namely inter-specific interactions and operator-specific feeding protocols. Both, possibly in combination, are suggested to be important determinants of species composition and encounter rates, and relative abundances at this shark provisioning site in Fiji. This study, which includes the most species from a spatially confined shark provisioning site to date, suggests that long-term provisioning may result in competitive exclusion among shark

  10. Long-term changes in species composition and relative abundances of sharks at a provisioning site.

    Directory of Open Access Journals (Sweden)

    Juerg M Brunnschweiler

    Full Text Available Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today's recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-species shark feeding site in Fiji. Using direct observation sampling methods, eight species of sharks (bull shark Carcharhinus leucas, grey reef shark Carcharhinus amblyrhynchos, whitetip reef shark Triaenodon obesus, blacktip reef shark Carcharhinus melanopterus, tawny nurse shark Nebrius ferrugineus, silvertip shark Carcharhinus albimarginatus, sicklefin lemon shark Negaprion acutidens, and tiger shark Galeocerdo cuvier displayed inter-annual site fidelity between 2003 and 2012. Encounter rates and/or relative abundances of some species changed over time, overall resulting in more individuals (mostly C. leucas of fewer species being encountered on average on shark feeding dives at the end of the study period. Differences in shark community composition between the years 2004-2006 and 2007-2012 were evident, mostly because N. ferrugineus, C. albimarginatus and N. acutidens were much more abundant in 2004-2006 and very rare in the period of 2007-2012. Two explanations are offered for the observed changes in relative abundances over time, namely inter-specific interactions and operator-specific feeding protocols. Both, possibly in combination, are suggested to be important determinants of species composition and encounter rates, and relative abundances at this shark provisioning site in Fiji. This study, which includes the most species from a spatially confined shark provisioning site to date, suggests that long-term provisioning may result in competitive

  11. Species composition and abundance of Brevipalpus spp. on different citrus species in Mexican orchards.

    Science.gov (United States)

    Salinas-Vargas, D; Santillán-Galicia, M T; Valdez-Carrasco, J; Mora-Aguilera, G; Atanacio-Serrano, Y; Romero-Pescador, P

    2013-08-01

    We studied the abundance of Brevipalpus spp. in citrus orchards in the Mexican states of Yucatan, Quintana Roo and Campeche. Mites were collected from 100 trees containing a mixture of citrus species where sweet orange was always the main species. Eight collections were made at each location from February 2010 to February 2011. Mites from the genus Brevipalpus were separated from other mites surveyed and their abundance and relationships with the different citrus species were quantified throughout the collection period. A subsample of 25% of the total Brevipalpus mites collected were identified to species level and the interaction of mite species and citrus species were described. Brevipalpus spp. were present on all collection dates and their relative abundance was similar on all citrus species studies. The smallest number of mites collected was during the rainy season. Brevipalpus phoenicis (Geijskes) and Brevipalpus californicus (Banks) were the only two species present and they were found in all locations except Campeche, where only B. phoenicis was present. Yucatan and Campeche are at greater risk of leprosis virus transmission than Quintana Roo because the main vector, B. phoenicis, was more abundant than B. californicus. The implications of our results for the design of more accurate sampling and control methods for Brevipalpus spp. are discussed.

  12. Tree species composition affects the abundance of rowan (Sorbus aucuparia L.) in urban forests in Finland.

    Science.gov (United States)

    Hamberg, Leena; Lehvävirta, Susanna; Kotze, D Johan; Heikkinen, Juha

    2015-03-15

    Recent studies have shown a considerable increase in the abundance of rowan (Sorbus aucuparia) saplings in urban forests in Finland, yet the reasons for this increase are not well understood. Here we investigated whether canopy cover or tree species composition, i.e., the basal areas of different tree species in Norway spruce dominated urban forests, affects the abundances of rowan seedlings, saplings and trees. Altogether 24 urban forest patches were investigated. We sampled the number of rowan and other saplings, and calculated the basal areas of trees. We showed that rowan abundance was affected by tree species composition. The basal area of rowan trees (≥ 5 cm in diameter at breast height, dbh) decreased with increasing basal area of Norway spruce, while the cover of rowan seedlings increased with an increase in Norway spruce basal area. However, a decrease in the abundance of birch (Betula pendula) and an increase in the broad-leaved tree group (Acer platanoides, Alnus glutinosa, Alnus incana, Amelanchier spicata, Prunus padus, Quercus robur, Rhamnus frangula and Salix caprea) coincided with a decreasing number of rowans. Furthermore, rowan saplings were scarce in the vicinity of mature rowan trees. Although it seems that tree species composition has an effect on rowan, the relationship between rowan saplings and mature trees is complex, and therefore we conclude that regulating tree species composition is not an easy way to keep rowan thickets under control in urban forests in Finland. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Earthworm abundance and species composition in abandoned tropical croplands: comparisons of tree plantations and secondary forests.

    Science.gov (United States)

    G. Gonzalez; X. Zou; S. Borges

    1996-01-01

    We compared patterns of earthworms abundance and species composition in tree plantation and secondary forest of Puerto Rico. Tree plantations included pine (Pinus caribea Morelet) and mahogany (Swietenia macrophylla King) established in the 1930's; 1960's; and 1970's; secondary forests were naturally regenerated in areas adjacent to these plantations. We...

  14. Intercropping With Fruit Trees Increases Population Abundance and Alters Species Composition of Spider Mites on Cotton.

    Science.gov (United States)

    Li, Haiqiang; Pan, Hongsheng; Wang, Dongmei; Liu, Bing; Liu, Jian; Zhang, Jianping; Lu, Yanhui

    2018-05-05

    With the recent increase in planting of fruit trees in southern Xinjiang, the intercropping of fruit trees and cotton has been widely adopted. From 2014 to 2016, a large-scale study was conducted in Aksu, an important agricultural area in southern Xinjiang, to compare the abundance and species composition of spider mites in cotton fields under jujube-cotton, apple-cotton, and cotton monocrop systems. The abundance of spider mites in cotton fields under both intercropping systems was generally higher than in the cotton monocrop. The species composition of spider mites also differed greatly between cotton intercropped with apple or jujube compared to the cotton monocrop. The relative proportion of Tetranychus truncates Ehara (Acari: Tetranychidae) in the species complex generally increased while that of another spider mite, Tetranychus dunhuangensis Wang (Acari: Tetranychidae), decreased under fruit tree-cotton systems. More attention should be paid to the monitoring and management of spider mites, especially T. truncates in this important region of China.

  15. [Distribution and changes in species composition and abundance of ichthyoplankton in the Yangtze estuary].

    Science.gov (United States)

    Zhang, Heng; Yang, Sheng-Long; Meng, Hai-Xing

    2012-06-01

    Based on four surveys of eggs and larvae in the Yangtze estuary in 2005 (April and November) and 2006 (April and September), combined with the historical data of the wetland in 1990 (September) and 1991 (March), we analyzed seasonal changes in fish species composition and quantity of ichthyoplankton. Thirty-six species of egg and larvae were collected and marine fish species were the highest represented ecological guild. Average fish species and average abundance in spring were lower than in autumn for every survey. The total number of eggs in brackish water was higher than in fresh water, but the total number of larvae and juveniles in brackish water was lower. The abundance of eggs and larvae during from 2005 to 2006 in both spring and autumn was higher compared to those from 1990 to 1991. Obvious differences in species composition in September between 1990 and 2006 were found, especially for Erythroculter ilishaeformis and Neosalanx taihuensis. Fish species composition and quantity within the ichthyoplankton community has obviously changed in the Yangtze estuary over the last 20 years.

  16. Tree species, spatial heterogeneity, and seasonality drive soil fungal abundance, richness, and composition in Neotropical rainforests.

    Science.gov (United States)

    Kivlin, Stephanie N; Hawkes, Christine V

    2016-12-01

    Tropical ecosystems remain poorly understood and this is particularly true for belowground soil fungi. Soil fungi may respond to plant identity when, for example, plants differentially allocate resources belowground. However, spatial and temporal heterogeneity in factors such as plant inputs, moisture, or nutrients can also affect fungal communities and obscure our ability to detect plant effects in single time point studies or within diverse forests. To address this, we sampled replicated monocultures of four tree species and secondary forest controls sampled in the drier and wetter seasons over 2 years. Fungal community composition was primarily related to vegetation type and spatial heterogeneity in the effects of vegetation type, with increasing divergence partly reflecting greater differences in soil pH and soil moisture. Across wetter versus drier dates, fungi were 7% less diverse, but up to four-fold more abundant. The combined effects of tree species and seasonality suggest that predicted losses of tropical tree diversity and intensification of drought have the potential to cascade belowground to affect both diversity and abundance of tropical soil fungi. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. Zooplankton abundance, species composition and ecology of tropical high-mountain crater lake Wonchi, Ethiopia

    Directory of Open Access Journals (Sweden)

    Fasil Degefu

    2014-11-01

    Full Text Available The highlands of Ethiopia represent some of the remnants of undisturbed aquatic ecosystems; they are however highly threatened by significant socio–economic developments and associated anthropogenic impacts. Lake Wonchi is one of the few remaining fairly pristine high–mountain crater lakes in the central highlands and has never been investigated in detail. We present a first study on zooplankton taxa composition, abundance and biomass conducted over more than one year including the underlying environmental drivers. The lake is basic (pH 7.9-8.9, dilute (specific conductivity 185-245 µS cm-1 and oligotrophic with mean trophic status index of 36. The zooplankton community composition showed low species richness comprising a total of fourteen taxa with six cladocerans, one copepod and seven rotifers. Simpson´s index of diversity with values between 0.6 and 0.8 pointed towards a homogenous taxa occurrence within the single sample units. The overall mean (±SD standing biomass of zooplankton was 62.02±25.76 mg dry mass m-3,which is low compared to other highland and rift valley lakes in Ethiopia. Cyclopoid copepods, in particular Thermocyclops ethiopiensis were the most abundant group and contributed 50% to the total zooplankton abundance followed by cladocerans (38% and rotifers (12%. Non-metric multi-dimensional scaling resulted in a 3-dimensional model, which revealed similar community composition on successive sampling dates except in December/January and May. Temperature, alkalinity, conductivity and nitrate-N had significant influence on this seasonal pattern. A weak, but significant positive correlation (r=0.482, N=20, P=0.037 between Chlorophyll a and zooplankton biomass mirrors a bottom-up effect of phytoplankton biomass on zooplankton dynamics. The zooplankton of Lake Wonchi displayed some degree of segregation along the epi– and metalimnion during this study, but diel vertical migration was not observed. The results show that fish

  18. Species composition and seasonal abundance of sandflies (Diptera: Psychodidae: Phlebotominae in coffee agroecosystems

    Directory of Open Access Journals (Sweden)

    Jeanneth Perez

    2014-02-01

    Full Text Available The composition and seasonal occurrence of sandflies were investigated in coffee agroecosystems in the Soconusco region of Chiapas, Mexico. Insect sampling was performed on three plantations located at different altitudes: Finca Guadalupe Zajú [1,000 m above sea level (a.s.l.], Finca Argovia (613 m a.s.l. and Teotihuacán del Valle (429 m a.s.l.. Sandflies were sampled monthly from August 2007-July 2008 using three sampling methods: Shannon traps, CDC miniature light traps and Disney traps. Sampling was conducted for 3 h during three consecutive nights, beginning at sunset. A total of 4,387 sandflies were collected during the course of the study: 2,718 individuals in Finca Guadalupe Zajú, 605 in Finca Argovia and 1,064 in Teotihuacán del Valle. The Shannon traps captured 94.3% of the total sandflies, while the CDC light traps and Disney traps captured 4.9% and 0.8%, respectively. More females than males were collected at all sites. While the number of sandflies captured was positively correlated with temperature and relative humidity, a negative correlation was observed between sandfly numbers and rainfall. Five species of sandflies were captured: Lutzomyia cruciata , Lutzomyia texana , Lutzomyia ovallesi , Lutzomyia cratifer / undulata and Brumptomyia sp. Lu. cruciata , constituting 98.8% of the total, was the most abundant species. None of the captured sandflies was infected with Leishmania spp.

  19. Species composition and seasonal abundance of sandflies (Diptera: Psychodidae: Phlebotominae) in coffee agroecosystems

    Science.gov (United States)

    Pérez, Jeanneth; Virgen, Armando; Rojas, Julio Cesar; Rebollar-Téllez, Eduardo Alfonso; Alfredo, Castillo; Infante, Francisco; Mikery, Oscar; Marina, Carlos Felix; Ibáñez-Bernal, Sergio

    2013-01-01

    The composition and seasonal occurrence of sandflies were investigated in coffee agroecosystems in the Soconusco region of Chiapas, Mexico. Insect sampling was performed on three plantations located at different altitudes: Finca Guadalupe Zajú [1,000 m above sea level (a.s.l.)], Finca Argovia (613 m a.s.l.) and Teotihuacán del Valle (429 m a.s.l.). Sandflies were sampled monthly from August 2007-July 2008 using three sampling methods: Shannon traps, CDC miniature light traps and Disney traps. Sampling was conducted for 3 h during three consecutive nights, beginning at sunset. A total of 4,387 sandflies were collected during the course of the study: 2,718 individuals in Finca Guadalupe Zajú, 605 in Finca Argovia and 1,064 in Teotihuacán del Valle. The Shannon traps captured 94.3% of the total sandflies, while the CDC light traps and Disney traps captured 4.9% and 0.8%, respectively. More females than males were collected at all sites. While the number of sandflies captured was positively correlated with temperature and relative humidity, a negative correlation was observed between sandfly numbers and rainfall. Five species of sandflies were captured: Lutzomyia cruciata , Lutzomyia texana , Lutzomyia ovallesi , Lutzomyia cratifer / undulata and Brumptomyia sp. Lu. cruciata , constituting 98.8% of the total, was the most abundant species. None of the captured sandflies was infected with Leishmania spp. PMID:24271002

  20. Species composition, distribution and abundance of chaetodontidae along reef transects in the Flores Sea

    Science.gov (United States)

    Adrim, Mohammad; Hutomo, Malikusworo

    Observations on chaetodontid fishes were made by applying a visual census technique at 13 coral reef locations in the Flores Sea region in October and November 1984. These observations were made along 50 m transect lines, parallel to the shore or the reef edge at depths between 3 to 12 m. Twenty-three species of Chaetodontidae were observed, representing three genera: Chaetodon (20 species), Heniochus (2 species) and Forcipiger (1 species). Chaetodon kleini, C. trifasciatus, C. melannotus and C. baronessa proved to be the most abundant species, and among them C. kleini and C. trifasciatus were the most widely distributed ones. Chaetodon semeion and C. mertensi were the rarest species. The greatest number of individuals (77) was counted at station 4.268 near Tanjung Burung, Sumbawa, while the greatest number of species (14) was observed at station 4.257, north of Komodo. The lowest number of individuals (17) was counted at station 4.175 near P. Bahuluang, Salayer, while station 4.251 near Teluk Slawi, Komodo, was inhabited by the smallest numbver of species (2). Numerical classification by using the Bray Curtis dissimilarity index resulted in three groups of entities. The first group was characterized by predomination of C. kleini and the second by predomination of C. melannotus. The third one was a loose group not characterized by any predominant species. The analyses indicated that the similarities of the chaetodontid communities between locations are not related to the distance between them, but rather to habitat conditions. For example predomination of C. melannotus is strongly related to the predomination of soft coral. Compared to other areas of Indonesia, e.g. Bali, Seribu Islands, Batam, Sunda Strait, and Ambon Bay, the Flores Sea reefs have a more abundant and more diverse chaetodontid fauna.

  1. Multi-sensor data fusion for estimating forest species composition and abundance in northern Minnesota

    Science.gov (United States)

    Peter P. Wolter; Phillip A. Townsend

    2011-01-01

    The magnitude, duration, and frequency of forest disturbance caused by the spruce budworm and forest tent caterpillar in northern Minnesota and neighboring Ontario, Canada have increased over the last century due to a shift in forest species composition linked to historical fire suppression, forest management, and pesticide application that has fostered increased...

  2. Tree hole mosquito species composition and relative abundances differ between urban and adjacent forest habitats in northwestern Argentina.

    Science.gov (United States)

    Mangudo, C; Aparicio, J P; Rossi, G C; Gleiser, R M

    2018-04-01

    Water-holding tree holes are main larval habitats for many pathogen vectors, especially mosquitoes (Diptera: Culicidae). Along 3 years, the diversity and composition of mosquito species in tree holes of two neighbouring but completely different environments, a city and its adjacent forest, were compared using generalized linear mixed models, PERMANOVA, SIMPER and species association indexes. The city area (Northwest Argentina) is highly relevant epidemiologically due to the presence of Aedes aegypti L. (main dengue vector) and occurrence of dengue outbreaks; the Yungas rainforests are highly biologically diverse. In total seven mosquito species were recorded, in descending order of abundance: Ae. aegypti, Haemagogus spegazzinii Brèthes, Sabethes purpureus (Theobald), Toxorhynchites guadeloupensis Dyar and Knab, Aedes terrens Walker, Haemagogus leucocelaenus Dyar & Shannon and Sabethes petrocchiae (Shannon and Del Ponte). The seven mosquito species were recorded in both city sites and forested areas; however, their mosquito communities significantly diverged because of marked differences in the frequency and relative abundance of some species: Tx. guadeloupensis and Ae. aegypti were significantly more abundant in forest and urban areas, respectively. Positive significant associations were detected between Ae. aegypti, Hg. spegazzinii and Hg. leucocelaenus. The combined presence of Ae. aegypti, Haemagogus and Sabethes in the area also highlight a potential risk of yellow fever epidemics. Overall results show an impoverished tree hole mosquito fauna in urban environments, reflecting negative effects of urbanization on mosquito diversity.

  3. A database of marine phytoplankton abundance, biomass and species composition in Australian waters

    Science.gov (United States)

    Davies, Claire H.; Coughlan, Alex; Hallegraeff, Gustaaf; Ajani, Penelope; Armbrecht, Linda; Atkins, Natalia; Bonham, Prudence; Brett, Steve; Brinkman, Richard; Burford, Michele; Clementson, Lesley; Coad, Peter; Coman, Frank; Davies, Diana; Dela-Cruz, Jocelyn; Devlin, Michelle; Edgar, Steven; Eriksen, Ruth; Furnas, Miles; Hassler, Christel; Hill, David; Holmes, Michael; Ingleton, Tim; Jameson, Ian; Leterme, Sophie C.; Lønborg, Christian; McLaughlin, James; McEnnulty, Felicity; McKinnon, A. David; Miller, Margaret; Murray, Shauna; Nayar, Sasi; Patten, Renee; Pritchard, Tim; Proctor, Roger; Purcell-Meyerink, Diane; Raes, Eric; Rissik, David; Ruszczyk, Jason; Slotwinski, Anita; Swadling, Kerrie M.; Tattersall, Katherine; Thompson, Peter; Thomson, Paul; Tonks, Mark; Trull, Thomas W.; Uribe-Palomino, Julian; Waite, Anya M.; Yauwenas, Rouna; Zammit, Anthony; Richardson, Anthony J.

    2016-06-01

    There have been many individual phytoplankton datasets collected across Australia since the mid 1900s, but most are unavailable to the research community. We have searched archives, contacted researchers, and scanned the primary and grey literature to collate 3,621,847 records of marine phytoplankton species from Australian waters from 1844 to the present. Many of these are small datasets collected for local questions, but combined they provide over 170 years of data on phytoplankton communities in Australian waters. Units and taxonomy have been standardised, obviously erroneous data removed, and all metadata included. We have lodged this dataset with the Australian Ocean Data Network (http://portal.aodn.org.au/) allowing public access. The Australian Phytoplankton Database will be invaluable for global change studies, as it allows analysis of ecological indicators of climate change and eutrophication (e.g., changes in distribution; diatom:dinoflagellate ratios). In addition, the standardised conversion of abundance records to biomass provides modellers with quantifiable data to initialise and validate ecosystem models of lower marine trophic levels.

  4. The shark assemblage at French Frigate Shoals atoll, Hawai'i: species composition, abundance and habitat use.

    Science.gov (United States)

    Dale, Jonathan J; Stankus, Austin M; Burns, Michael S; Meyer, Carl G

    2011-02-10

    Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao M(h) ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289-1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling.

  5. Landscape composition influences abundance patterns and habitat use of three ungulate species in fragmented secondary deciduous tropical forests, Mexico

    Directory of Open Access Journals (Sweden)

    G. García-Marmolejo

    2015-01-01

    Full Text Available Secondary forests are extensive in the tropics. Currently, these plant communities are the available habitats for wildlife and in the future they will possibly be some of the most wide-spread ecosystems world-wide. To understand the potential role of secondary forests for wildlife conservation, three ungulate species were studied: Mazama temama, Odocoileus virginianus and Pecari tajacu. We analyzed their relative abundance and habitat use at two spatial scales: (1 Local, where three different successional stages of tropical deciduous forest were compared, and (2 Landscape, where available habitats were compared in terms of landscape composition (proportion of forests, pastures and croplands within 113 ha. To determine the most important habitat-related environmental factors influencing the Sign Encounter Rate (SER of the three ungulate species, 11 physical, anthropogenic and vegetation variables were simultaneously analyzed through model selection using Akaike’s Information Criterion. We found, that P. tajacu and O. virginianus mainly used early successional stages, while M. temama used all successional stages in similar proportions. The latter species, however, used early vegetation stages only when they were located in landscapes mainly covered by forest (97%. P. tajacu and O. virginianus also selected landscapes covered essentially by forests, although they required smaller percentages of forest (86%. All ungulate species avoided landscape fragments covered by pastures. For all three species, landscape composition and human activities were the variables that best explained SER. We concluded that landscape is the fundamental scale for ungulate management, and that secondary forests are potentially important landscape elements for ungulate conservation.

  6. Bird Surveys at DARHT Before and During Operations: Comparison of Species Abundance and Composition and Trace Element Uptake

    Energy Technology Data Exchange (ETDEWEB)

    P. R. Fresquez, D. C. Keller, C. D. Hathcock

    2007-11-30

    The Dual-Axis Radiographic Hydrodynamic Test (DARHT) Facility Mitigation Action Plan specifies the comparison of baseline conditions in biotic and abiotic media with those collected after operations have started. Operations at DARHT at Los Alamos National Laboratory started in 2000. In this study, the abundance and composition of birds collected near the DARHT facility from 2003 through 2006 were determined and compared to a preoperational period (1999). In addition, the levels of radionuclides and other inorganic chemicals in birds were compared to regional statistical reference levels (RSRLs). The number and diversity of bird species generally increased over preoperational levels with the greatest number of birds (412) and species (46) occurring in 2005. The most common bird species collected regardless of time periods were the chipping sparrow (Spizella passerina), the Virginia's warbler (Vermivora virginiae), the western bluebird (Sialia mexicana), the broad-tailed hummingbird (Selasphorus platycercus), the sage sparrow (Amphispiza belli), and the western tanager (Piranga ludoviciana). Most radionuclides, with the exception of uranium-234 and uranium-238, in (whole body) birds collected after operations began were either not detected or below RSRLs. Uranium-234 and uranium-238 concentrations in a few samples were far below screening levels and do not pose a potential unacceptable dose to the birds. In contrast, many inorganic chemicals, particularly arsenic and silver, in birds collected before and after operations began were in higher concentrations than RSRLs. Because birds (skin plus feathers) collected in the years before operations began contained higher levels of arsenic and silver than RSRLs and because there was no evidence of these metals in soil and sediment directly around the DARHT facility, the elevated levels of these metals in birds during early operations are probably not related to DARHT operations. Arsenic and silver in birds, however

  7. Seasonal variations of species composition and abundance of zooplankton in Ehoma Lake, a floodplain lake in Nigeria

    Directory of Open Access Journals (Sweden)

    Okechukwu. I Okogwu

    2010-03-01

    Full Text Available Ehoma Lake is among the important breeding sites of the major fishes in the Mid-Cross River, Nigeria. The juveniles of these fishes are solely dependent on zooplankton, which has not been studied previously. I studied monthly the lake’s physico-chemical variables and zooplankton composition in three stations (littoral, sub-littoral and pelagic from March 2005 to August 2006. Sixty-seven zooplankton species (42 rotifers, 19 cladocerans and 6 copepods were identified. Daphnia obtusa Kurz, Keratella valga Ehrenberg, Keratella ticinensis Callerrio, Keratella hiemalis Carlin, Brachionus dimidiatus Bryce and Lecane candida Hauer and Murray are new records for Nigeria. The dominant zooplankters were Diaphanosoma excisum Kurz and Moina micrura Kurz. There was an inverse relationship between species richness and abundance. Richness was highest in the dry season while peak zooplankton abundance was recorded in the rainy season. Zooplankton abundance and species richness decreased progressively from the littoral to the pelagic station while the Shannon-Weaver diversity index varied from 0.68 to 1.28 without a clear seasonal trend. There is a succession pattern: rotifers that are dominant in the dry season are replaced by cladocerans in the rainy season. This succession was greatly influenced by seasonal flooding of the lake. As no previous information on the zooplankton of the lake is available, this study provides baseline data on the lake`s zooplankton. Rev. Biol. Trop. 58 (1: 171-182. Epub 2010 March 01.El lago Ehoma, situado en la mitad del río Cross, es uno de los lugares de reproducción de las principales especies de peces del río. Los juveniles de estos peces dependen exclusivamente del zooplancton, sin embargo poco se sabe sobre este recurso en el lago. En este estudio, las variables físico-químicas y del zooplancton del lago fueron estudiadas mensualmente en tres estaciones (litoral, sub-litoral y pelágica, de marzo de 2005 a agosto de

  8. Species composition, diversity and relative abundance of amphibians in forests and non-forest habitats on Langkawi Island, Peninsular Malaysia

    Science.gov (United States)

    Nur Johana, J.; Muzzneena, A. M.; Grismer, L. L.; Norhayati, A.

    2016-11-01

    Anurans on Langkawi Island, Peninsular Malaysia exhibit variation in their habits and forms, ranging from small (SVL 150 mm), and occupy a range of habitats, such as riverine forests, agricultural fields, peat swamps, and lowland and upland dipterocarp forests. These variations provide a platform to explore species diversity, distribution, abundance, microhabitat, and other ecological parameters to understand the distribution patterns and to facilitate conservation and management of sensitive or important species and areas. The objective of this study was to evaluate the diversity and distribution of anuran species in different types of habitat on Langkawi Island. Specimens were collected based on active sampling using the Visual Encounter Survey (VES) method. We surveyed anuran species inhabiting seven types of habitat, namely agriculture (AG), coastal (CL), forest (FT), pond (PD), mangrove (MG), riparian forest (RF) and river (RV). A total of 775 individuals were sampled from all localities, representing 23 species from 12 genera and included all six families of frogs in Malaysia. FT and RF showed high values of Shannon Index, H', 2.60 and 2.38, respectively, followed by the other types of habitat, CL (1.82), RV (1.71), MG (1.56), PD (1.54), and AG (1.53). AG had the highest abundance (156 individuals) compared to other habitat types. Based on Cluster Analysis by using Jaccard coefficient (UPGMA), two groups can be clearly seen and assigned as forested species group (FT and RF) and species associating with human activity (AG, CL, PD, MG and RV). Forest species group is more diverse compared to non-forest group. Nevertheless, non-forest species are found in abundance, highlighting the relevance of these disturbed habitats in supporting the amphibians.

  9. Algal growth and species composition under experimental control of herbivory, phosphorus and coral abundance in Glovers Reef, Belize.

    Science.gov (United States)

    McClanahan, T R; Cokos, B A; Sala, E

    2002-06-01

    The proliferation of algae on disturbed coral reefs has often been attributed to (1) a loss of large-bodied herbivorous fishes, (2) increases in sea water nutrient concentrations, particularly phosphorus, and (3) a loss of hard coral cover or a combination of these and other factors. We performed replicated small-scale caging experiments in the offshore lagoon of Glovers Reef atoll, Belize where three treatments had closed-top (no large-bodied herbivores) and one treatment had open-top cages (grazing by large-bodied herbivores). Closed-top treatments simulated a reduced-herbivory situation, excluding large fishes but including small herbivorous fishes such as damselfishes and small parrotfishes. Treatments in the closed-top cages included the addition of high phosphorus fertilizer, live branches of Acropora cervicornis and a third unmanipulated control treatment. Colonization, algal biomass and species composition on dead A. palmata "plates" were studied weekly for 50 days in each of the four treatments. Fertilization doubled the concentration of phosphorus from 0.35 to 0.77 microM. Closed-top cages, particularly the fertilizer and A. cervicornis additions, attracted more small-bodied parrotfish and damselfish than the open-top cages such that there was moderate levels of herbivory in closed-top cages. The open-top cages did, however, have a higher abundance of the chemically and morphologically defended erect algal species including Caulerpa cupressoides, Laurencia obtusa, Dictyota menstrualis and Lobophora variegata. The most herbivore-resistant calcareous green algae (i.e. Halimeda) were, however, uncommon in all treatments. Algal biomass increased and fluctuated simultaneously in all treatments over time, but algal biomass, as measured by wet, dry and decalcified weight, did not differ greatly between the treatments with only marginally higher biomass (p reefs except for creating space. In contrast, A. cervicornis appears to attract aggressive damselfish that

  10. Effects of landscape composition and wetland fragmentation on frog and toad abundance and species richness in Iowa and Wisconsin, USA

    Science.gov (United States)

    Knutson, M.G.; Sauer, J.R.; Olsen, D.A.; Mossman, M.J.; Hemesath, L.M.; Lannoo, M.J.

    1999-01-01

    Management of amphibian populations to reverse recent declines will require defining high-quality habitat for individual species or groups of species, followed by efforts to retain or restore these habitats on the landscape. We examined landscape-level habitat relationships for frogs and toads by measuring associations between relative abundance and species richness based on survey data derived from anuran calls and features of land-cover maps for Iowa and Wisconsin. The most consistent result across all anuran guilds was a negative association with the presence of urban land. Upland and wetland forests and emergent wetlands tended to be positively associated with anurans. Landscape metrics that represent edges and patch diversity also had generally positive associations, indicating that anurans benefit from a complex of habitats that include wetlands. In Iowa the most significant associations with relative abundance were the length of the edge between wetland and forest (positive) and the presence of urban land (negative). In Wisconsin the two most significant associations with relative abundance were forest area and agricultural area (both positive). Anurans had positive associations with agriculture in Wisconsin but not in Iowa. Remnant forest patches in agricultural landscapes may be providing refuges for some anuran species. Differences in anuran associations with deep water and permanent wetlands between the two states suggest opportunities for management action. Large-scale maps can contribute to predictive models of amphibian habitat use, but water quality and vegetation information collected from individual wetlands will likely be needed to strengthen those predictions. Landscape habitat analyses provide a framework for future experimental and intensive research on specific factors affecting the health of anurans.

  11. Mosquitoes of the rice agroecosystem of Malaysia: species composition and their abundance in relation to rice farming

    International Nuclear Information System (INIS)

    Abu Hassan Ahmad; Che Salmah Md Rawi

    2002-01-01

    Mosquito abundance in relation to rice farming was studied in the Muda and the Kerian Irrigation Schemes. Mosquito larvae were collected using dippers for several growing seasons. Adult mosquitoes were collected by using human bait and cow bait and net trap at nights. Culex, Mansonia and Anopheles were the three genera of mosquito found in the rice agroecosystem. Four species of Mansonia were found biting on human bait. Culex mosquitoes were caught biting on human and cow baits. Culex tritaeniorhynchus, C pseudovishnui, C vishnui, C gelidus and C bitaeniorhynchus were the most common Culex mosquitoes found. Anoheles sinensis and A. peditaeniatus were the most dominant panopheline mosquitoes. High abundance of larvae and adult mosquitoes were observed during ploughing, planting, and tillering stages of rice farming. (Author)

  12. Fine-scale distribution of zooplankton is linked to phytoplankton species composition and abundance in a North Norwegian fjord system

    Science.gov (United States)

    Norrbin, F.; Priou, P. D.; Varela, A. P.

    2016-02-01

    We studied the influence of dense layers of phytoplankton and aggregates on shaping the vertical distribution of zooplankton in a North Norwegian fjord using a Video Plankton Recorder (VPR). This instrument provided fine-scale vertical distribution (cm-m scale) of planktonic organisms as well as aggregates of marine snow in relation to environmental conditions. At the height - later stage of the spring phytoplankton bloom in May, the outer part of the fjord was dominated by Phaeocystis pouchetii, while diatoms (Chaetoceros spp.) were dominating in the innermost basin. Small copepods species like Pseudocalanus spp., Microsetella norvegica, and Oithona spp. prevailed over larger copepod species in the inner part of the fjord whereas the outer part was dominated by large copepods like Calanus finmarchicus. While the zooplankton where spread out over the water column during the early stage of the bloom, in May they were linked to the phytoplankton vertical distribution and in the winter situation they were found in deeper waters. Herbivorous zooplankton species were affected by phytoplankton species composition; C. finmarchicus and Pseudocalanus spp. avoided the dense layer of P. pouchetii while herbivorous zooplankton matched the distribution of the diatom-dominated bloom. Small, omnivorous copepod species like Microsetella sp., Oithona sp. and Pseudocalanus sp. were often associated with dense layers of snow aggregates. This distribution may provide a shelter from predators as well as a food source. Natural or anthropogenic-induced changes in phytoplankton composition and aggregate distribution may thus influence food-web interactions.

  13. Temporal Patterns in the Abundance and Species Composition of Spiders on Host Plants of the Invasive Moth Epiphyas postvittana (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Hogg, Brian N; Mills, Nicholas J; Daane, Kent M

    2017-06-01

    Generalist predators such as spiders may help mitigate the spread and impact of exotic herbivores. The lack of prey specificity and long generation times of spiders may allow them to persist when pests are scarce, and to limit the growth of pest populations before they reach damaging levels. We examined whether resident spiders are likely to play a role in maintaining populations of the invasive light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), below outbreak levels in California. We surveyed the spider community on two E. postvittana host plants, the ornamental Australian tea tree, Leptospermum laevigatum, and the weed French broom, Genista monspessulana, to characterize spider and larval E. postvittana abundance and spider species composition throughout the year. Spider densities and species composition showed slight seasonal changes. Spiders were present during periods of high and low E. postvittana abundance. Anyphaenid hunting spiders, Anyphaena aperta Banks in Australian tea tree and Anyphaena pacifica Banks in French broom, dominated spider species composition at four of five sampled sites, and underwent only slight seasonal variation in abundance. Adult A. aperta were rare at all times of the year, suggesting that high mortality among juvenile A. aperta limits the potential of this species as a predator of E. postvittana. Nevertheless, the continued presence of spiders throughout the year indicates that the resident spider community is likely to play a key role in reducing E. postvittana populations in California. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

  14. Species composition and relative abundance of sand flies of the genus Lutzomyia (Diptera: Psychodidae) at an endemic focus of visceral leishmaniasis in Colombia.

    Science.gov (United States)

    Ferro, C; Morrison, A C; Torres, M; Pardo, R; Wilson, M L; Tesh, R B

    1995-07-01

    Ecological studies on the sand fly Lutzomyia longipalpis (Lutz & Neiva) were conducted during 1990-1993 at a small rural community in Colombia where American visceral leishmaniasis is endemic. Weekly sand fly collections were made from pigpens, houses, and natural resting sites, using hand-held aspirators, sticky (oiled) paper traps, and opossum-baited Disney traps. In total, 263,094 sand flies were collected; L. longipalpis predominated (86.1%), followed by L. trinidadensis (11.0%), L. cayennensis (2.7%), and 8 other Lutzomyia species. The species composition and sex ratio of these sand flies varied among sites and by collection method. L. longipalpis were captured most efficiently by direct aspiration from animal bait. Conversely, sticky paper traps, especially inside houses and at rock resting sites, collected a greater diversity of species, but a lower relative abundance of L. longipalpis.

  15. Population abundance and species composition of chaetognaths in the Bombay harbour-Thana and Bassein creek estuarine complex

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, Neelam; Nair, V.R.

    and tolerant of them. Total absence of S. eflata in the interior stations receiving large quantities of sewage and industrial effluents signifies a highly sensitive nature of this species. The present study shows a general decrease in the species diversity...

  16. Impact of culturing conditions on the abundance and composition of long chain alkyl diols in species of the genus

    NARCIS (Netherlands)

    Balzano, S.; Villanueva, L.; de Bar, M.; Sinninghe Damsté, J.S.; Schouten, S.

    2017-01-01

    Long chain alkyl diols (LCDs) are widespread in sediments and are synthesized, among others, by microalgae of the genus Nannochloropsis. The factors regulating the synthesis of LCDs and their biological function are, however, unclear. We investigated the changes in abundance of free + ester-bound

  17. Species composition, abundance and distribution of zooplankton in a tropical eutrophic lake: Lake Catemaco, México

    Directory of Open Access Journals (Sweden)

    Roberto E. Torres-Orozco B.

    1998-06-01

    Full Text Available From April 1992 to May 1993, zooplankton samples were collected monthly by means of horizontal tows in nine sites of the lake. Prior to the towing, temperature of surface water, transparency (Secchi, pH and dissolved oxygen were evaluated. A total of 31 zooplankton forms, including 14 species of rotifers, three copepods, five cladocerans and one ostracod, as well as protozoans (mainly vorticellids and ciliates, were detected. Rotifers were the dominant organisms, mainly Brachionus havanaensis (27.6 ind l-¹, B. angularis (6.9 ind l-¹, Keratella cochlearis (4.9 ind l-¹, Conochilus unicornis (10.8 ind l-¹ and C. dossuarius (3.1 ind l-¹. Within crustaceans, higher densities were shown by larvae (nauplii and copepodites of calanoid (16.8 ind l-¹ and cyclopoid (15.6 ind l-¹ copepods, as well as Arctodiaptomus dorsalis (2 ind l-¹, Mesocyclops edax (0.5 ind l-¹, and the cladocerans Bosmina longirostris (1.6 ind l-¹ and Diaphanosoma brachyurum (0.5 ind l-¹. Densities were low, probably because of a high predation pressure imposed by fishes. A gradual increase in total zooplankton density related with a progressive diminution of transparency was observed throughout the sampling period. Zooplankton densities in the stations located at the central part of the lake were higher when compared with those at a more peripheral position. Time variation in rotifer's relative abundance was directly related to temperature fluctuations. The low density and diversity values, the small size of the zooplankters, the presence of an important number of indicator species, and the calanoid copepods: other planktonic crustaceans low ratio, are all indicators of eutrophy. Evidences suggest that the eutrophication process of Lake Catemaco is still progressing rapidly.Entre abril de 1992 y mayo de 1993, se realizaron mensualmente recolectas subsuperficiales de zooplancton, con red, en nueve localidades del lago, en donde también se determinaron la temperatura

  18. Phytoplankton species composition, abundance and distribution in Fishing area 58 of Indian Ocean sector of Southern Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Rathod, V.

    in Nitzschia, Pseudonitzschia group of species. South of Polar Front Nitzschia "nana" (Cells of both N. cylindrus and N. pseudonana) and Dactyliosolen tenuijunctus dominate. Diatoms viz. Fragilariopsis kerguelensis and Thalassionema nitzschioides ; were...

  19. Composition, distribution and abundance of ichthyoplankton in the ...

    African Journals Online (AJOL)

    1989-06-29

    Jun 29, 1989 ... The species composition, distribution and seasonal abundance of ichthyoplankton in the Sundays River estuary was ... The importance of southern African estuaries as nursery areas for juvenile ... 1990,25(3) the mid-channel.

  20. Species composition, abundance and distribution of zooplankton in a tropical eutrophic lake: Lake Catemaco, México

    OpenAIRE

    Roberto E. Torres-Orozco B.; Sandra A. Zanatta

    1998-01-01

    From April 1992 to May 1993, zooplankton samples were collected monthly by means of horizontal tows in nine sites of the lake. Prior to the towing, temperature of surface water, transparency (Secchi), pH and dissolved oxygen were evaluated. A total of 31 zooplankton forms, including 14 species of rotifers, three copepods, five cladocerans and one ostracod, as well as protozoans (mainly vorticellids and ciliates), were detected. Rotifers were the dominant organisms, mainly Brachionus havanaens...

  1. Determining Lamprey Species Composition, Larval Distribution and Adult Abundance in the Deschutes River Subbasin, Oregon ; 2007 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Matt; Graham, Jennifer C. [Department of Natural Resources, Confederated Tribes of the Warm Springs Reservation, Oregon

    2009-06-26

    We will report results of an ongoing project in the Deschutes River Subbasin to describe Pacific lamprey (Lampetra tridentata) life history. Project objectives were to determine adult lamprey escapement from Sherars Falls located at Rkm 70.4 and determine lamprey focal spawning areas, spawn timing and habitat through radio telemetry. A mark-recapture study and tribal creel was conducted to determine adult escapement. Lamprey were radio tagged and are currently being mobile, aerial and fixed site tracked to describe spawning. Adult lamprey were collected at Sherars Falls using a long-handled dip net from June-September 2007. The fate of lamprey collected at Sherars Falls was determined based on girth measurements. Fish measuring less than 10.5 cm received two markings for the mark-recapture estimation while those measuring 10.5 cm or greater were implanted with radio transmitters. Two-hundred and nine lamprey were marked during first event sampling, 2,501 lamprey inspected for marks and 64 recaptured during second event sampling. We estimate lamprey abundance to be 8,083 (6,352-10,279) with a relative precision of 19.8. Tribal harvest was 2,303 +/- 88. Escapement was estimated at 5,780 adult lamprey. Thirty-six lamprey received radio transmitters. Lamprey were transported upstream 6.3 Rkm for surgery, held to recover from anesthesia and released. Mobile tracking efforts started mid-July 2007 and are on-going. To date 35 of the 36 lamprey have been detected. Upon release, extensive ground-based tracking was conducted until fish became dormant in mid-October. Since, fixed site downloading and tracking have occurred weekly on the mainstem Deschutes River. Majority of lamprey (88%) are holding in the mainstem Deschutes River. Three lamprey moved upstream more than 70 Rkms into westside tributaries from August-December. Three moved approximately 18 Rkms downstream of the release site. Tracking will continue through the spawning season when redd characteristics will be

  2. Bracken: estimating species abundance in metagenomics data

    Directory of Open Access Journals (Sweden)

    Jennifer Lu

    2017-01-01

    Full Text Available Metagenomic experiments attempt to characterize microbial communities using high-throughput DNA sequencing. Identification of the microorganisms in a sample provides information about the genetic profile, population structure, and role of microorganisms within an environment. Until recently, most metagenomics studies focused on high-level characterization at the level of phyla, or alternatively sequenced the 16S ribosomal RNA gene that is present in bacterial species. As the cost of sequencing has fallen, though, metagenomics experiments have increasingly used unbiased shotgun sequencing to capture all the organisms in a sample. This approach requires a method for estimating abundance directly from the raw read data. Here we describe a fast, accurate new method that computes the abundance at the species level using the reads collected in a metagenomics experiment. Bracken (Bayesian Reestimation of Abundance after Classification with KrakEN uses the taxonomic assignments made by Kraken, a very fast read-level classifier, along with information about the genomes themselves to estimate abundance at the species level, the genus level, or above. We demonstrate that Bracken can produce accurate species- and genus-level abundance estimates even when a sample contains multiple near-identical species.

  3. Clonal growth and plant species abundance.

    Science.gov (United States)

    Herben, Tomáš; Nováková, Zuzana; Klimešová, Jitka

    2014-08-01

    Both regional and local plant abundances are driven by species' dispersal capacities and their abilities to exploit new habitats and persist there. These processes are affected by clonal growth, which is difficult to evaluate and compare across large numbers of species. This study assessed the influence of clonal reproduction on local and regional abundances of a large set of species and compared the predictive power of morphologically defined traits of clonal growth with data on actual clonal growth from a botanical garden. The role of clonal growth was compared with the effects of seed reproduction, habitat requirements and growth, proxied both by LHS (leaf-height-seed) traits and by actual performance in the botanical garden. Morphological parameters of clonal growth, actual clonal reproduction in the garden and LHS traits (leaf-specific area - height - seed mass) were used as predictors of species abundance, both regional (number of species records in the Czech Republic) and local (mean species cover in vegetation records) for 836 perennial herbaceous species. Species differences in habitat requirements were accounted for by classifying the dataset by habitat type and also by using Ellenberg indicator values as covariates. After habitat differences were accounted for, clonal growth parameters explained an important part of variation in species abundance, both at regional and at local levels. At both levels, both greater vegetative growth in cultivation and greater lateral expansion trait values were correlated with higher abundance. Seed reproduction had weaker effects, being positive at the regional level and negative at the local level. Morphologically defined traits are predictive of species abundance, and it is concluded that simultaneous investigation of several such traits can help develop hypotheses on specific processes (e.g. avoidance of self-competition, support of offspring) potentially underlying clonal growth effects on abundance. Garden

  4. Attenuation of species abundance distributions by sampling

    Science.gov (United States)

    Shimadzu, Hideyasu; Darnell, Ross

    2015-01-01

    Quantifying biodiversity aspects such as species presence/ absence, richness and abundance is an important challenge to answer scientific and resource management questions. In practice, biodiversity can only be assessed from biological material taken by surveys, a difficult task given limited time and resources. A type of random sampling, or often called sub-sampling, is a commonly used technique to reduce the amount of time and effort for investigating large quantities of biological samples. However, it is not immediately clear how (sub-)sampling affects the estimate of biodiversity aspects from a quantitative perspective. This paper specifies the effect of (sub-)sampling as attenuation of the species abundance distribution (SAD), and articulates how the sampling bias is induced to the SAD by random sampling. The framework presented also reveals some confusion in previous theoretical studies. PMID:26064626

  5. Composition and abundance of tree regeneration

    Science.gov (United States)

    Todd F. Hutchinson; Elaine Kennedy Sutherland; Charles T. Scott

    2003-01-01

    The composition and abundance of tree seedlings and saplings in the four study areas in southern Ohio were related to soil moisture via a GIS-derived integrated moisture index and to soil texture and fertility. For seedlings, the total abundance of small stems (less than 30 cm tall) was significantly greater on xeric plots (81,987/ha) than on intermediate (54,531/ha)...

  6. A global database of ant species abundances

    Science.gov (United States)

    Gibb, Heloise; Dunn, Rob R.; Sanders, Nathan J.; Grossman, Blair F.; Photakis, Manoli; Abril, Silvia; Agosti, Donat; Andersen, Alan N.; Angulo, Elena; Armbrecht, Ingre; Arnan, Xavier; Baccaro, Fabricio B.; Bishop, Tom R.; Boulay, Raphael; Bruhl, Carsten; Castracani, Cristina; Cerda, Xim; Del Toro, Israel; Delsinne, Thibaut; Diaz, Mireia; Donoso, David A.; Ellison, Aaron M.; Enriquez, Martha L.; Fayle, Tom M.; Feener Jr., Donald H.; Fisher, Brian L.; Fisher, Robert N.; Fitpatrick, Matthew C.; Gomez, Cristanto; Gotelli, Nicholas J.; Gove, Aaron; Grasso, Donato A.; Groc, Sarah; Guenard, Benoit; Gunawardene, Nihara; Heterick, Brian; Hoffmann, Benjamin; Janda, Milan; Jenkins, Clinton; Kaspari, Michael; Klimes, Petr; Lach, Lori; Laeger, Thomas; Lattke, John; Leponce, Maurice; Lessard, Jean-Philippe; Longino, John; Lucky, Andrea; Luke, Sarah H.; Majer, Jonathan; McGlynn, Terrence P.; Menke, Sean; Mezger, Dirk; Mori, Alessandra; Moses, Jimmy; Munyai, Thinandavha Caswell; Pacheco, Renata; Paknia, Omid; Pearce-Duvet, Jessica; Pfeiffer, Martin; Philpott, Stacy M.; Resasco, Julian; Retana, Javier; Silva, Rogerio R.; Sorger, Magdalena D.; Souza, Jorge; Suarez, Andrew V.; Tista, Melanie; Vasconcelos, Heraldo L.; Vonshak, Merav; Weiser, Michael D.; Yates, Michelle; Parr, Catherine L.

    2017-01-01

    What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51,388 ant abundance and occurrence records of more than 2693 species and 7953 morphospecies from local assemblages collected at 4212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo-referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type and degree of disturbance. The aim of compiling this dataset was to provide comprehensive species abundance data in order to test relationships between assemblage structure and environmental and biogeographic factors. Data were collected using a variety of standardised methods, such as pitfall and Winkler traps, and will be valuable for studies investigating large-scale forces structuring local assemblages. Understanding such relationships is particularly critical under current rates of global change. We encourage authors holding additional data on systematically collected ant assemblages, especially those in dry and cold, and remote areas, to contact us and contribute their data to this growing dataset.

  7. Forms and genesis of species abundance distributions

    Directory of Open Access Journals (Sweden)

    Evans O. Ochiaga

    2015-12-01

    Full Text Available Species abundance distribution (SAD is one of the most important metrics in community ecology. SAD curves take a hollow or hyperbolic shape in a histogram plot with many rare species and only a few common species. In general, the shape of SAD is largely log-normally distributed, although the mechanism behind this particular SAD shape still remains elusive. Here, we aim to review four major parametric forms of SAD and three contending mechanisms that could potentially explain this highly skewed form of SAD. The parametric forms reviewed here include log series, negative binomial, lognormal and geometric distributions. The mechanisms reviewed here include the maximum entropy theory of ecology, neutral theory and the theory of proportionate effect.

  8. A biogeographical perspective on species abundance distributions

    DEFF Research Database (Denmark)

    Matthews, Thomas J.; Borges, Paulo A. V.; de Azevedo, Eduardo Brito

    2017-01-01

    It has become increasingly recognized that multiple processes can generate similar shapes of species abundance distributions (SADs), with the result that the fit of a given SAD model cannot unambiguously provide evidence in support of a given theory or model. An alternative approach to comparing...... the fit of different SAD models to data from a single site is to collect abundance data from a variety of sites, and then build models to analyse how different SAD properties (e.g. form, skewness) vary with different predictor variables. Such a biogeographical approach to SAD research is potentially very...... revealing, yet there has been a general lack of interest in SADs in the biogeographical literature. In this Perspective, we address this issue by highlighting findings of recent analyses of SADs that we consider to be of intrinsic biogeographical interest. We use arthropod data drawn from the Azorean...

  9. Abundance of introduced species at home predicts abundance away in herbaceous communities

    Science.gov (United States)

    Firn, Jennifer; Moore, Joslin L.; MacDougall, Andrew S.; Borer, Elizabeth T.; Seabloom, Eric W.; HilleRisLambers, Janneke; Harpole, W. Stanley; Cleland, Elsa E.; Brown, Cynthia S.; Knops, Johannes M.H.; Prober, Suzanne M.; Pyke, David A.; Farrell, Kelly A.; Bakker, John D.; O'Halloran, Lydia R.; Adler, Peter B.; Collins, Scott L.; D'Antonio, Carla M.; Crawley, Michael J.; Wolkovich, Elizabeth M.; La Pierre, Kimberly J.; Melbourne, Brett A.; Hautier, Yann; Morgan, John W.; Leakey, Andrew D.B.; Kay, Adam; McCulley, Rebecca; Davies, Kendi F.; Stevens, Carly J.; Chu, Cheng-Jin; Holl, Karen D.; Klein, Julia A.; Fay, Phillip A.; Hagenah, Nicole; Kirkman, Kevin P.; Buckley, Yvonne M.

    2011-01-01

    Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countries, revealed that species abundances were similar at native (home) and introduced (away) sites - grass species were generally abundant home and away, while forbs were low in abundance, but more abundant at home. Sites with six or more of these species had similar community abundance hierarchies, suggesting that suites of introduced species are assembling similarly on different continents. Overall, we found that substantial changes to populations are not necessarily a pre-condition for invasion success and that increases in species abundance are unusual. Instead, abundance at home predicts abundance away, a potentially useful additional criterion for biosecurity programmes.

  10. Marine litter in an EBSA (Ecologically or Biologically Significant Area) of the central Mediterranean Sea: Abundance, composition, impact on benthic species and basis for monitoring entanglement.

    Science.gov (United States)

    Consoli, Pierpaolo; Andaloro, Franco; Altobelli, Chiara; Battaglia, Pietro; Campagnuolo, Silvana; Canese, Simonepietro; Castriota, Luca; Cillari, Tiziana; Falautano, Manuela; Pedà, Cristina; Perzia, Patrizia; Sinopoli, Mauro; Vivona, Pietro; Scotti, Gianfranco; Esposito, Valentina; Galgani, Francois; Romeo, Teresa

    2018-05-01

    Marine litter is commonly observed everywhere in the ocean. In this study, we analyzed 17 km of video footage, collected by a Remotely Operated Vehicle (ROV) at depths ranging between 20 and 220 m, during 19 transects performed on the rocky banks of the Straits of Sicily. Recently, the Contracting Parties of the Convention on Biological Diversity (CBD) recognized this site as an Ecologically or Biologically Significant Area (EBSA). The research aim was to quantify the abundance of marine litter and its impact on benthic fauna. Litter density ranged from 0 items/100 m 2 to 14.02 items/100 m 2 with a mean (±standard error) of 2.13 (±0.84) items/100 m 2 . The observed average density was higher (5.2 items/100 m 2 ) at depths >100 m than at shallower depths (fishing lines contributed to 98.07% of the overall litter density, then representing the dominant source of marine debris. Litter interactions with fauna were frequently observed, with 30% of litter causing "entanglement/coverage" and 15% causing damage to sessile fauna. A total of 16 species showed interaction (entanglement/coverage or damage) with litter items and 12 of these are species of conservation concern according to international directives and agreements (CITES, Berne Convention, Habitat Directive, SPA/BD Protocol, IUCN Red List); we also observed 7 priority habitats of the SPA/BD Protocol. This research will support the implementation of monitoring "Harm" as recommended by the UN Environment/MAP Regional Plan on Marine Litter Management in the Mediterranean, and the Marine Strategy Framework Directive (MSFD). The institution of a SPAMI in the investigated area could represent a good management action for the protection of this hotspot of biodiversity and to achieve a Good Environmental Status (GES) for the marine environment by 2020, under the MSFD. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Geographical range and local abundance of tree species in China.

    Directory of Open Access Journals (Sweden)

    Haibao Ren

    Full Text Available Most studies on the geographical distribution of species have utilized a few well-known taxa in Europe and North America, with little research in China and its wide range of climate and forest types. We assembled large datasets to quantify the geographic ranges of tree species in China and to test several biogeographic hypotheses: 1 whether locally abundant species tend to be geographically widespread; 2 whether species are more abundant towards their range-centers; and 3 how abundances are correlated between sites. Local abundances of 651 species were derived from four tree plots of 20-25 ha where all individuals ≥1 cm in stem diameter were mapped and identified taxonomically. Range sizes of these species across China were then estimated from over 460,000 geo-referenced records; a Bayesian approach was used, allowing careful measures of error of each range estimate. The log-transformed range sizes had a bell-shaped distribution with a median of 703,000 km(2, and >90% of 651 species had ranges >10(5 km(2. There was no relationship between local abundance and range size, and no evidence for species being more abundant towards their range-centers. Finally, species' abundances were positively correlated between sites. The widespread nature of most tree species in China suggests few are vulnerable to global extinction, and there is no indication of the double-peril that would result if rare species also had narrow ranges.

  12. Species identification, distribution and abundance of Gerreidae ...

    African Journals Online (AJOL)

    the distribution and abundance of Gerres in estuaries wa'S collected from July 1978 to ..... the channel area between the W.L.R. and the mouth (not the tidal basin) during ..... overwhelming importance in the kelp beds of Britain. Recently Blaber ...

  13. Use of abundance of one species as a surrogate for abundance of others

    Science.gov (United States)

    Samuel A. Cushman; Kevin S. McKelvey; Barry R. Noon; Kevin McGarigal

    2010-01-01

    Indicator species concepts have a long history in conservation biology. Arguments in favor of these approaches generally stress expediency and assume efficacy. We tested the premise that the abundance patterns of one species can be used to infer those of other species. Our data consisted of 72,495 bird observations on 55 species across 1046 plots distributed across 30...

  14. The implicit assumption of symmetry and the species abundance distribution

    NARCIS (Netherlands)

    Alonso, D.; Ostling, A.; Etienne, R.S.

    2008-01-01

    Species abundance distributions (SADs) have played a historical role in the development of community ecology. They summarize information about the number and the relative abundance of the species encountered in a sample from a given community. For years ecologists have developed theory to

  15. The implicit assumption of symmetry and the species abundance distribution

    NARCIS (Netherlands)

    Alonso, David; Ostling, Annette; Etienne, Rampal S.

    Species abundance distributions (SADs) have played a historical role in the development of community ecology. They summarize information about the number and the relative abundance of the species encountered in a sample from a given community. For years ecologists have developed theory to

  16. A global database of ant species abundances

    Czech Academy of Sciences Publication Activity Database

    Gibb, H.; Dunn, R. R.; Sanders, N. J.; Grossman, B. F.; Photakis, M.; Abril, S.; Agosti, D.; Andersen, A. N.; Angulo, E.; Armbrecht, I.; Arnan, X.; Baccaro, F. B.; Bishop, T. R.; Boulay, R.; Brühl, C.; Castracani, C.; Cerdá, X.; Del Toro, I.; Delsinne, T.; Diaz, M.; Donoso, D. A.; Ellison, A. M.; Enríquez, M. L.; Fayle, Tom Maurice; Feener, D. H.; Fisher, B. L.; Fisher, R. N.; Fitzpatrick, M. C.; Gómez, C.; Gotelli, N. J.; Gove, A.; Grasso, D. A.; Groc, S.; Guenard, B.; Gunawardene, N.; Heterick, B.; Hoffmann, B.; Janda, Milan; Jenkins, C.; Kaspari, M.; Klimeš, Petr; Lach, L.; Laeger, T.; Lattke, J.; Leponce, M.; Lessard, J.-P.; Longino, J.; Lucky, A.; Luke, S. H.; Majer, J.; McGlynn, T. P.; Menke, S.; Mezger, D.; Mori, A.; Moses, Jimmy; Munyai, T. C.; Pacheco, R.; Paknia, O.; Pearce-Duvet, J.; Pfeiffer, M.; Philpott, S. M.; Resasco, J.; Retana, J.; Silva, R. R.; Sorger, M. D.; Souza, J.; Suarez, A.; Tista, M.; Vasconcelos, H. L.; Vonshak, M.; Weisser, M. D.; Yates, M.; Parr, C. L.

    2017-01-01

    Roč. 98, č. 3 (2017), s. 883-884 ISSN 0012-9658 R&D Projects: GA ČR GB14-36098G; GA ČR GAP505/12/2467; GA ČR GPP505/12/P875 Institutional support: RVO:60077344 Keywords : abundance * ants * database Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 4.809, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/ecy.1682/abstract

  17. Why abundant tropical tree species are phylogenetically old.

    Science.gov (United States)

    Wang, Shaopeng; Chen, Anping; Fang, Jingyun; Pacala, Stephen W

    2013-10-01

    Neutral models of species diversity predict patterns of abundance for communities in which all individuals are ecologically equivalent. These models were originally developed for Panamanian trees and successfully reproduce observed distributions of abundance. Neutral models also make macroevolutionary predictions that have rarely been evaluated or tested. Here we show that neutral models predict a humped or flat relationship between species age and population size. In contrast, ages and abundances of tree species in the Panamanian Canal watershed are found to be positively correlated, which falsifies the models. Speciation rates vary among phylogenetic lineages and are partially heritable from mother to daughter species. Variable speciation rates in an otherwise neutral model lead to a demographic advantage for species with low speciation rate. This demographic advantage results in a positive correlation between species age and abundance, as found in the Panamanian tropical forest community.

  18. Diversity, composition and abundance of macroinvertebrates ...

    African Journals Online (AJOL)

    user

    these genera were found at all sampling stations as shown in Table 2. Out of the orders sampled, Hemiptera, Pulmonata and. Coleoptera had the highest number of genera with 5, 4 and 4, respectively. In terms of relative abundance, dipterans and Pulmonata were the most abundant while. Hydracarina (water mites) were ...

  19. Composition, Abundance and Distribution of Brachyuran Larvae in ...

    African Journals Online (AJOL)

    ... Ocypodidae, Grapsidae and Xanthidae. Abundance of brachyuran larvae was significantly positively correlated with total zooplankton abundance (r2 = 0.8) and salinity (r2 = 0.71). Keywords: Brachyuran larvae, abundance, composition, Mida creek, Kenya West Indian Ocean Journal of Marine Science Vol. 3 (2) 2004: pp.

  20. Species composition and abundance of solpugids (Arachnida: Solifugae in ecotopes of the transitional coastal desert of Chile Composición de especies y abundancia de solífugos (Arachnida: Solifugae en ecotopos del desierto costero transicional de Chile

    Directory of Open Access Journals (Sweden)

    Daniel Eugenio Valdivia

    2011-12-01

    Full Text Available Using pitfall traps, the species composition and abundance of solpugids were studied in several ecotopes of Chile's transitional coastal desert. The study was conducted in the area around Punta de Choros (29°15'S, 71°26'W and in Los Choros Archipelago (29°32'S, 67°61'W, in 2005 and 2006. Five species were recorded: Procleobis sp.; Sedna pirata Muma, 1971 (Ammotrechidae; Mummucia sp.; Mummucia variegata (Gervais, 1849 (Mummuciidae; and Ammotrechelis goetschi Roewer, 1934 (Daesiidae. Solpugid abundance was higher on the continent (65% than on the islands (35%. The ANOSIM used to evaluate any difference in species richness between ecotopes revealed no significant differences (R= 0.097, p= 0.13. The similarity dendrogram obtained from the Bray-Curtis matrix indicates that there are 3 groups of ecotopes: steppe, dune, and a miscellaneous group. From the data it is inferred that the diversity and abundance of solpugids in the ecotopes studied may be related to plant structure and to the pedological conditions of the habitat.Mediante trampas de intercepción se estudió la composición específica y la abundancia de solífugos en diversos ecotopos del desierto costero transicional de Chile. El trabajo se llevó a cabo tanto en el sector de Punta de Choros (29°15'S, 71°26'O como en el archipiélago de Los Choros (29°32'S, 67°61'O, durante los años 2005 y 2006. Se registró la presencia de 5 especies: Procleobis sp.; Sedna pirata Muma, 1971 (Ammotrechidae, Mummucia sp.; Mummucia variegata (Gervais, 1849 (Mummuciidae y Ammotrechelis goetschi Roewer, 1934 (Daesiidae. En el sector continental se observó mayor abundancia que en el sector insular (65% y 35%, respectivamente. El ANOSIM aplicado para evaluar la diferencia en la riqueza especifica entre ecotopos, no mostró diferencias significativas (R= 0.097; p= 0.13. El dendrograma de similitud generado a partir de la matriz Bray-Curtis mostró 3 agrupaciones de ecotopos: estepario, dunario y

  1. Abundance of introduced species at home predicts abundance away in herbaceous communities

    Science.gov (United States)

    J. Firn; J.L. Moore; A.S. MacDougall; E.T. Borer; E.W. Seabloom; J. HilleRisLambers; S. Harpole; E.E. Cleland; C.S. Brown; J.M.H. Knops; S.M. Prober; D.A. Pyke; K.A. Farrell; J.D. Bakker; L.R. O’Halloran; P.B. Adler; S.L. Collins; C.M. D’Antonio; M.J. Crawley; E.M. Wolkovich; K.J. La Pierre; B.A. Melbourne; Y. Hautier; J.W. Morgan; A.D.B. Leakey; A.D. Kay; R.L. McCulley; K.F. Davies; C.J. Stevens; C.J. Chu

    2011-01-01

    Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at...

  2. Book review: A new view on the species abundance distribution

    Science.gov (United States)

    DeAngelis, Donald L.

    2018-01-01

    The sampled relative abundances of species of a taxonomic group, whether birds, trees, or moths, in a natural community at a particular place vary in a way that suggests a consistent underlying pattern, referred to as the species abundance distribution (SAD). Preston [1] conjectured that the numbers of species, plotted as a histogram of logarithmic abundance classes called octaves, seemed to fit a lognormal distribution; that is, the histograms look like normal distributions, although truncated on the left-hand, or low-species-abundance, end. Although other specific curves for the SAD have been proposed in the literature, Preston’s lognormal distribution is widely cited in textbooks and has stimulated attempts at explanation. An important aspect of Preston’s lognormal distribution is the ‘veil line’, a vertical line drawn exactly at the point of the left-hand truncation in the distribution, to the left of which would be species missing from the sample. Dewdney rejects the lognormal conjecture. Instead, starting with the long-recognized fact that the number of species sampled from a community, when plotted as histograms against population abundance, resembles an inverted J, he presents a mathematical description of an alternative that he calls the ‘J distribution’, a hyperbolic density function truncated at both ends. When multiplied by species richness, R, it becomes the SAD of the sample.

  3. Dispersal ability determines the scaling properties of species abundance distributions

    DEFF Research Database (Denmark)

    Borda-De-Água, Luís; Whittaker, Robert James; Cardoso, Pedro

    2017-01-01

    with computer simulations, low dispersal ability species generate a hump for intermediate abundance classes earlier than the distributions of high dispersal ability species. Importantly, when plotted as function of sample size, the raw moments of the SADs of arthropods have a power law pattern similar...

  4. Abundance, composition and distribution of simple sequence ...

    Indian Academy of Sciences (India)

    δ∗(W-29, W-70) = 1.25; δ∗(W-93, W-70 = 0.75)) even though they originate from different geographical regions. We can, therefore, infer that the WSSV sequences are closely related by ancestry. Table 3. Dinucleotide relative abundance in the ...

  5. species composition, relative abundance and distribution

    African Journals Online (AJOL)

    Preferred Customer

    College of Natural Sciences, Addis Ababa University, 2011. ISSN: 0379– ... distribution at Entoto Natural Park and escarpment was carried out during July 2009 - March 2010. The study ..... University Press, Princeton and Oxford, 496 pp. 20.

  6. Relating species abundance distributions to species-area curves in two Mediterranean-type shrublands

    Science.gov (United States)

    Keeley, Jon E.

    2003-01-01

    Based on both theoretical and empirical studies there is evidence that different species abundance distributions underlie different species-area relationships. Here I show that Australian and Californian shrubland communities (at the scale from 1 to 1000 m2) exhibit different species-area relationships and different species abundance patterns. The species-area relationship in Australian heathlands best fits an exponential model and species abundance (based on both density and cover) follows a narrow log normal distribution. In contrast, the species-area relationship in Californian shrublands is best fit with the power model and, although species abundance appears to fit a log normal distribution, the distribution is much broader than in Australian heathlands. I hypothesize that the primary driver of these differences is the abundance of small-stature annual species in California and the lack of annuals in Australian heathlands. Species-area is best fit by an exponential model in Australian heathlands because the bulk of the species are common and thus the species-area curves initially rise rapidly between 1 and 100 m2. Annuals in Californian shrublands generate very broad species abundance distributions with many uncommon or rare species. The power function is a better model in these communities because richness increases slowly from 1 to 100 m2 but more rapidly between 100 and 1000 m2due to the abundance of rare or uncommon species that are more likely to be encountered at coarser spatial scales. The implications of this study are that both the exponential and power function models are legitimate representations of species-area relationships in different plant communities. Also, structural differences in community organization, arising from different species abundance distributions, may lead to different species-area curves, and this may be tied to patterns of life form distribution.

  7. Bird species richness and abundance in different forest types at ...

    African Journals Online (AJOL)

    The avifauna of differently disturbed forest types of Kakamega Afrotropical forest were compared from December 2004 to May 2005. A total of 11 220 individual birds comprising of 129 bird species were recorded. Significant differences in abundance of birds among Psidium guajava, Bischoffia javanica, mixed indigenous, ...

  8. Relative abundance of mosquito species in Katsina Metropolis ...

    African Journals Online (AJOL)

    A study was conducted on the relative abundance of mosquito species, around selected areas of Katsina metropolis, Katsina State, Nigeria during the months of January, February, April and June 2010. Mosquitoes were collected from five sampling sites: Kofar Durbi, Kofar Kaura, Kofar Marusa, GRA and Layout. These were ...

  9. Measuring β-diversity with species abundance data.

    Science.gov (United States)

    Barwell, Louise J; Isaac, Nick J B; Kunin, William E

    2015-07-01

    In 2003, 24 presence-absence β-diversity metrics were reviewed and a number of trade-offs and redundancies identified. We present a parallel investigation into the performance of abundance-based metrics of β-diversity. β-diversity is a multi-faceted concept, central to spatial ecology. There are multiple metrics available to quantify it: the choice of metric is an important decision. We test 16 conceptual properties and two sampling properties of a β-diversity metric: metrics should be 1) independent of α-diversity and 2) cumulative along a gradient of species turnover. Similarity should be 3) probabilistic when assemblages are independently and identically distributed. Metrics should have 4) a minimum of zero and increase monotonically with the degree of 5) species turnover, 6) decoupling of species ranks and 7) evenness differences. However, complete species turnover should always generate greater values of β than extreme 8) rank shifts or 9) evenness differences. Metrics should 10) have a fixed upper limit, 11) symmetry (βA,B  = βB,A ), 12) double-zero asymmetry for double absences and double presences and 13) not decrease in a series of nested assemblages. Additionally, metrics should be independent of 14) species replication 15) the units of abundance and 16) differences in total abundance between sampling units. When samples are used to infer β-diversity, metrics should be 1) independent of sample sizes and 2) independent of unequal sample sizes. We test 29 metrics for these properties and five 'personality' properties. Thirteen metrics were outperformed or equalled across all conceptual and sampling properties. Differences in sensitivity to species' abundance lead to a performance trade-off between sample size bias and the ability to detect turnover among rare species. In general, abundance-based metrics are substantially less biased in the face of undersampling, although the presence-absence metric, βsim , performed well overall. Only

  10. Upscaling species richness and abundances in tropical forests.

    Science.gov (United States)

    Tovo, Anna; Suweis, Samir; Formentin, Marco; Favretti, Marco; Volkov, Igor; Banavar, Jayanth R; Azaele, Sandro; Maritan, Amos

    2017-10-01

    The quantification of tropical tree biodiversity worldwide remains an open and challenging problem. More than two-fifths of the number of worldwide trees can be found either in tropical or in subtropical forests, but only ≈0.000067% of species identities are known. We introduce an analytical framework that provides robust and accurate estimates of species richness and abundances in biodiversity-rich ecosystems, as confirmed by tests performed on both in silico-generated and real forests. Our analysis shows that the approach outperforms other methods. In particular, we find that upscaling methods based on the log-series species distribution systematically overestimate the number of species and abundances of the rare species. We finally apply our new framework on 15 empirical tropical forest plots and quantify the minimum percentage cover that should be sampled to achieve a given average confidence interval in the upscaled estimate of biodiversity. Our theoretical framework confirms that the forests studied are comprised of a large number of rare or hyper-rare species. This is a signature of critical-like behavior of species-rich ecosystems and can provide a buffer against extinction.

  11. Inferring invasive species abundance using removal data from management actions

    Science.gov (United States)

    Davis, Amy J.; Hooten, Mevin B.; Miller, Ryan S.; Farnsworth, Matthew L.; Lewis, Jesse S.; Moxcey, Michael; Pepin, Kim M.

    2016-01-01

    Evaluation of the progress of management programs for invasive species is crucial for demonstrating impacts to stakeholders and strategic planning of resource allocation. Estimates of abundance before and after management activities can serve as a useful metric of population management programs. However, many methods of estimating population size are too labor intensive and costly to implement, posing restrictive levels of burden on operational programs. Removal models are a reliable method for estimating abundance before and after management using data from the removal activities exclusively, thus requiring no work in addition to management. We developed a Bayesian hierarchical model to estimate abundance from removal data accounting for varying levels of effort, and used simulations to assess the conditions under which reliable population estimates are obtained. We applied this model to estimate site-specific abundance of an invasive species, feral swine (Sus scrofa), using removal data from aerial gunning in 59 site/time-frame combinations (480–19,600 acres) throughout Oklahoma and Texas, USA. Simulations showed that abundance estimates were generally accurate when effective removal rates (removal rate accounting for total effort) were above 0.40. However, when abundances were small (<50) the effective removal rate needed to accurately estimates abundances was considerably higher (0.70). Based on our post-validation method, 78% of our site/time frame estimates were accurate. To use this modeling framework it is important to have multiple removals (more than three) within a time frame during which demographic changes are minimized (i.e., a closed population; ≤3 months for feral swine). Our results show that the probability of accurately estimating abundance from this model improves with increased sampling effort (8+ flight hours across the 3-month window is best) and increased removal rate. Based on the inverse relationship between inaccurate abundances and

  12. Inferring invasive species abundance using removal data from management actions.

    Science.gov (United States)

    Davis, Amy J; Hooten, Mevin B; Miller, Ryan S; Farnsworth, Matthew L; Lewis, Jesse; Moxcey, Michael; Pepin, Kim M

    2016-10-01

    Evaluation of the progress of management programs for invasive species is crucial for demonstrating impacts to stakeholders and strategic planning of resource allocation. Estimates of abundance before and after management activities can serve as a useful metric of population management programs. However, many methods of estimating population size are too labor intensive and costly to implement, posing restrictive levels of burden on operational programs. Removal models are a reliable method for estimating abundance before and after management using data from the removal activities exclusively, thus requiring no work in addition to management. We developed a Bayesian hierarchical model to estimate abundance from removal data accounting for varying levels of effort, and used simulations to assess the conditions under which reliable population estimates are obtained. We applied this model to estimate site-specific abundance of an invasive species, feral swine (Sus scrofa), using removal data from aerial gunning in 59 site/time-frame combinations (480-19,600 acres) throughout Oklahoma and Texas, USA. Simulations showed that abundance estimates were generally accurate when effective removal rates (removal rate accounting for total effort) were above 0.40. However, when abundances were small (removal rate needed to accurately estimates abundances was considerably higher (0.70). Based on our post-validation method, 78% of our site/time frame estimates were accurate. To use this modeling framework it is important to have multiple removals (more than three) within a time frame during which demographic changes are minimized (i.e., a closed population; ≤3 months for feral swine). Our results show that the probability of accurately estimating abundance from this model improves with increased sampling effort (8+ flight hours across the 3-month window is best) and increased removal rate. Based on the inverse relationship between inaccurate abundances and inaccurate removal

  13. Should Ecosystem Management Involve Active Control of Species Abundances?

    Directory of Open Access Journals (Sweden)

    Robert B. Lessard

    2005-12-01

    Full Text Available We review four case studies in which there is a risk of extinction or severe reduction in highly valued species if we ignore either, or both, of two ecosystem control options. "Symptomatic control" implies direct control of extinction risk through direct harvesting or culling of competitors and predators. "Systemic control" implies treating the causes of the problem that led to an unnaturally high abundance in the first place. We demonstrate, with a discussion of historically observed population trends, how surprising trophic interactions can emerge as a result of alterations to a system. Simulation models were developed for two of the case studies as aids to adaptive policy design, to expose possible abundance changes caused by trophic interactions and to highlight key uncertainties about possible responses to ecosystem management policies involving active intervention to control abundances. With reasonable parameter values, these models predict a wide range of possible responses given available data, but do indicate a good chance that active control would reverse declines and reverse extinction risks. We find that controlling seal (Phoca vitulina populations in the Georgia Strait increases juvenile survival rates of commercial salmon (Oncorhynchus spp. species, but that commensurate increases in hake populations from decreased seal predation could be a compensatory source of predation on juvenile salmon. We also show that wolf (Canis lupus control and moose (Alces alces harvest bring about a recovery in caribou (Rangifer tarandus caribou populations, where simple habitat protection policies fail to recover caribou before wolf predation causes severe declines. The results help address a common problem in disturbed ecosystems, where controlling extinction risks can mean choosing between active control of species abundance or establishing policies of protection, and allowing threatened species to recover naturally.

  14. A new species of Trichoderma hypoxylon harbours abundant secondary metabolites.

    Science.gov (United States)

    Sun, Jingzu; Pei, Yunfei; Li, Erwei; Li, Wei; Hyde, Kevin D; Yin, Wen-Bing; Liu, Xingzhong

    2016-11-21

    Some species of Trichoderma are fungicolous on fungi and have been extensively studied and commercialized as biocontrol agents. Multigene analyses coupled with morphology, resulted in the discovery of T. hypoxylon sp. nov., which was isolated from surface of the stroma of Hypoxylon anthochroum. The new taxon produces Trichoderma- to Verticillium-like conidiophores and hyaline conidia. Phylogenetic analyses based on combined ITS, TEF1-α and RPB2 sequence data indicated that T. hypoxylon is a well-distinguished species with strong bootstrap support in the polysporum group. Chemical assessment of this species reveals a richness of secondary metabolites with trichothecenes and epipolythiodiketopiperazines as the major compounds. The fungicolous life style of T. hypoxylon and the production of abundant metabolites are indicative of the important ecological roles of this species in nature.

  15. Boolean analysis reveals systematic interactions among low-abundance species in the human gut microbiome.

    Directory of Open Access Journals (Sweden)

    Jens Christian Claussen

    2017-06-01

    Full Text Available The analysis of microbiome compositions in the human gut has gained increasing interest due to the broader availability of data and functional databases and substantial progress in data analysis methods, but also due to the high relevance of the microbiome in human health and disease. While most analyses infer interactions among highly abundant species, the large number of low-abundance species has received less attention. Here we present a novel analysis method based on Boolean operations applied to microbial co-occurrence patterns. We calibrate our approach with simulated data based on a dynamical Boolean network model from which we interpret the statistics of attractor states as a theoretical proxy for microbiome composition. We show that for given fractions of synergistic and competitive interactions in the model our Boolean abundance analysis can reliably detect these interactions. Analyzing a novel data set of 822 microbiome compositions of the human gut, we find a large number of highly significant synergistic interactions among these low-abundance species, forming a connected network, and a few isolated competitive interactions.

  16. Abundance modelling of invasive and indigenous Culicoides species in Spain

    Directory of Open Access Journals (Sweden)

    Els Ducheyne

    2013-11-01

    Full Text Available In this paper we present a novel methodology applied in Spain to model spatial abundance patterns of potential vectors of disease at a medium spatial resolution of 5 x 5 km using a countrywide database with abundance data for five Culicoides species, random regression Forest modelling and a spatial dataset of ground measured and remotely sensed eco-climatic and environmental predictor variables. First the probability of occurrence was computed. In a second step a direct regression between the probability of occurrence and trap abundance was established to verify the linearity of the relationship. Finally the probability of occurrence was used in combination with the set of predictor variables to model abundance. In each case the variable importance of the predictors was used to biologically interpret results and to compare both model outputs, and model performance was assessed using four different accuracy measures. Results are shown for C. imicola, C. newsteadii, C. pulicaris group, C. punctatus and C. obsoletus group. In each case the probability of occurrence is a good predictor of abundance at the used spatial resolution of 5 x 5 km. In addition, the C. imicola and C. obsoletus group are highly driven by summer rainfall. The spatial pattern is inverse between the two species, indicating that the lower and upper thresholds are different. C. pulicaris group is mainly driven by temperature. The patterns for C. newsteadii and C. punctatus are less clear. It is concluded that the proposed methodology can be used as an input to transmission-infection-recovery (TIR models and R0 models. The methodology will become available to the general public as part of the VECMAPTM software.

  17. Human land use promotes the abundance and diversity of exotic species on caribbean islands.

    Science.gov (United States)

    Jesse, Wendy A M; Behm, Jocelyn E; Helmus, Matthew R; Ellers, Jacintha

    2018-05-31

    Human land use causes major changes in species abundance and composition, yet native and exotic species can exhibit different responses to land use change. Native populations generally decline in human-impacted habitats while exotic species often benefit. In this study, we assessed the effects of human land use on exotic and native reptile diversity, including functional diversity, which relates to the range of habitat use strategies in biotic communities. We surveyed 114 reptile communities from localities that varied in habitat structure and human impact level on two Caribbean islands, and calculated species richness, overall abundance and evenness for every plot. Functional diversity indices were calculated using published trait data, which enabled us to detect signs of trait filtering associated with impacted habitats. Our results show that environmental variation among sampling plots was explained by two PCA ordination axes related to habitat structure (i.e. forest or non-forest) and human impact level (i.e. addition of man-made constructions such as roads and buildings). Several diversity indices were significantly correlated with the two PCA axes, but exotic and native species showed opposing responses. Native species reached the highest abundance in forests, while exotic species were absent in this habitat. Human impact was associated with an increase in exotic abundance and species richness, while native species showed no significant associations. Functional diversity was highest in non-forested environments on both islands, and further increased on St. Martin with the establishment of functionally unique exotic species in non-forested habitat. Habitat structure, rather than human impact, proved to be an important agent for environmental filtering of traits, causing divergent functional trait values across forested and non-forested environments. Our results illustrate the importance of considering various elements of land use when studying its impact on

  18. Fish community composition, seasonality and abundance in Fortaleza Lagoon, cidreira

    Directory of Open Access Journals (Sweden)

    Lúcia Cabral Schifino

    2004-09-01

    Full Text Available The Fortaleza Lagoon belongs to the Southern Tramandaí subsystem, formed by lagoons disposed linearly on the north-south direction (30º 08’S, 50º 13’W. The objective of this study was to describe some aspects related to the composition of the fish community of Fortaleza Lagoon. Samples were collected monthly from November 1998 to October 1999. The specimens were captured at four previously determined points in the lagoon, and classified in five orders, 12 families and 22 species. Cyphocharax voga, Hyphessobrycon luetkenii, Oligosarcus jenynsii, Oligosarcus robustus and Loricariichthys anus were more abundant species. Amongst the sampled species only two could not be characterised as freshwater species: Centropomus sp (marine and Lycengraulius grossidens (estuarine. The ichthyofauna of the lagoon was predominantly composed by constant species.A Planície Costeira do Rio Grande do Sul é formada por uma série de corpos d’água, dispostos em seqüência ao longo da costa. A lagoa da Fortaleza pertence ao subsistema lagunar Tramandaí-Sul que é composto por lagoas, dispostas linearmente no sentido norte-sul. O do presente estudo teve como objetivo descrever alguns aspectos relacionados à composição da comunidade de peixes da Lagoa da Fortaleza. As amostragens foram realizadas, mensalmente, no período de novembro de 1998 a outubro de 1999. Os exemplares foram capturados em 4 pontos da lagoa previamente determinados e classificados em 5 ordens, 11 famílias e 22 espécies. As espécies Cyphocharax voga, Hyphessobrycon luetkenii, Oligosarcus jenynsii, Oligosarcus robustus e Loricariichthys anus mostraram-se as mais abundantes. Entre as espécies coletadas apenas duas não caracterizam espécies de água doce: Centropomus sp (marinha and Lycengraulius grossidens (estuarina. A ictiofauna da lagoa caracterizou-se por uma predominância de espécies constantes.

  19. Abundance, composition and natural infection of Anopheles mosquitoes from two malaria-endemic regions of Colombia

    OpenAIRE

    Carolina Montoya; Priscila Bascuñán; Julián Rodríguez-Zabala; Margarita M. Correa

    2017-01-01

    Introduction: In Colombia there are three Anopheles species implicated in malaria transmission as primary vectors; however, the local role of some Anopheles species must still be defined. Objective: To determine the abundance, composition and natural infection rates for Anopheles mosquitoes with Plasmodium spp. in two malaria-endemic regions of Colombia. Materials and methods: Anopheles mosquitoes were collected using the human-landing catches and while resting in livestock corrals in n...

  20. Plant species richness and abundance in residential yards across a tropical watershed: implications for urban sustainability

    Directory of Open Access Journals (Sweden)

    Cristina P. Vila-Ruiz

    2014-09-01

    Full Text Available Green spaces within residential areas provide important contributions to the sustainability of urban systems. Therefore, studying the characteristics of these areas has become a research priority in cities worldwide. This project evaluated various aspects of the plant biodiversity of residential yards (i.e., front yards and back yards within the Río Piedras watershed in the San Juan metropolitan area of Puerto Rico. Our work included gathering information on vegetation composition and abundance of woody species (i.e., trees, shrubs, palms, ferns and large herbs (>2 m height, species origin (native vs. introduced, and species uses (ornamental, food, and medicinal plants. A total of 424 yards were surveyed within an area of 187,191 m². We found 383 woody species, with shrubs being the most abundant plant habitat. As expected, residential yards hosted a disproportionate amount of introduced species (69.5%. The most common shrub species were all non-native ornamentals, whereas the most common tree species included food trees as well as ornamental plants and two native species. Front yards hosted more ornamental species per unit area than backyards, while the latter had more food plants. The high amount of introduced species may present a challenge in terms of implementation of plant conservation initiatives if there is no clear definition of urban conservation goals. On the other hand, the high frequency of yards containing food plants may facilitate the development of residential initiatives that could provide future adaptive capacity to food shortages.

  1. Recent Changes in Tree Species Abundance: Patterns, Trends, and Drivers Across Northeastern US Forests

    Science.gov (United States)

    Gudex-Cross, D.; Pontius, J.; Adams, A.

    2017-12-01

    Monitoring trends in the abundance and distribution of tree species is essential to understanding potential impacts of climate change on forested ecosystems. Related studies to date have largely focused on modeling distributional shifts according to future climate scenarios or used field inventory data to examine compositional changes across broader landscapes. Here, we leverage a novel remote sensing technique that utilizes field data, multitemporal Landsat imagery, and spectral unmixing to model regional changes in the abundance (percent basal area) of key northeastern US species over a 30-year period (1985-2015). We examine patterns in how species abundance has changed, as well as their relationship with climate, landscape, and soil characteristics using spatial regression models. Results show significant declines in overall abundance for sugar maple ( 8.6% 30-yr loss), eastern hemlock ( 7.8% 30-yr loss), balsam fir ( 5.0% 30-yr loss), and red spruce ( 3.8% total 30-yr loss). Species that saw significant increasing abundance include American beech ( 7.0% 30-yr gain) and red maple ( 2.5% 30-yr gain). However, these changes were not consistent across the landscape. For example, red spruce is increasing at upper elevations with concurrent losses in balsam fir and birch species. Similarly, sugar maple decreases are concentrated at lower elevations, likely due to increases in American beech. Various abiotic factors were significantly associated with changes in species composition including landscape position (e.g. longitude, elevation, and heat load index) and ecologically-relevant climate variables (e.g. growing season precipitation and annual temperature range). Interestingly, there was a stronger relationship in abundance changes across longitudes, rather than latitudes or elevations as predicted in modeled species migration scenarios.These results indicate that the dominant composition of northeastern forests is changing in ways that run counter to accepted

  2. Grasshopper species composition shifts following a severe rangeland grasshopper outbreak

    Science.gov (United States)

    Little is known about how grasshopper species abundances shift during and following severe outbreaks, as sampling efforts usually end when outbreaks subside. Grasshopper densities, species composition and vegetation have infrequently been sampled during and after a severe outbreak in the western U.S...

  3. Fishing elevates variability in the abundance of exploited species.

    Science.gov (United States)

    Hsieh, Chih-Hao; Reiss, Christian S; Hunter, John R; Beddington, John R; May, Robert M; Sugihara, George

    2006-10-19

    The separation of the effects of environmental variability from the impacts of fishing has been elusive, but is essential for sound fisheries management. We distinguish environmental effects from fishing effects by comparing the temporal variability of exploited versus unexploited fish stocks living in the same environments. Using the unique suite of 50-year-long larval fish surveys from the California Cooperative Oceanic Fisheries Investigations we analyse fishing as a treatment effect in a long-term ecological experiment. Here we present evidence from the marine environment that exploited species exhibit higher temporal variability in abundance than unexploited species. This remains true after accounting for life-history effects, abundance, ecological traits and phylogeny. The increased variability of exploited populations is probably caused by fishery-induced truncation of the age structure, which reduces the capacity of populations to buffer environmental events. Therefore, to avoid collapse, fisheries must be managed not only to sustain the total viable biomass but also to prevent the significant truncation of age structure. The double jeopardy of fishing to potentially deplete stock sizes and, more immediately, to amplify the peaks and valleys of population variability, calls for a precautionary management approach.

  4. Analyzing fractal property of species abundance distribution and diversity indexes.

    Science.gov (United States)

    Su, Qiang

    2016-03-07

    Community diversity is usually characterized by numerical indexes; however it indeed depends on the species abundance distribution (SAD). Diversity indexes and SAD are based on the same information but treating as separate themes. Ranking species abundance from largest to smallest, the decreasing pattern can give the information about the SAD. Frontier proposed such SAD might be a fractal structure, and first applied the Zipf-Mandelbrot model to the SAD study. However, this model fails to include the Zipf model, and also fails to ensure an integer rank. In this study, a fractal model of SAD was reconstructed, and tested with 104 community samples from 8 taxonomic groups. The results show that there was a good fit of the presented model. Fractal parameter (p) determines the SAD of a community. The ecological significance of p relates to the "dominance" of a community. The correlation between p and classical diversity indexes show that Shannon index decreases and Simpson index increases as p increases. The main purpose of this paper is not to compare with other SADs models; it simply provides a new interpretation of SAD model construction, and preliminarily integrates diversity indexes and SAD model into a broader perspective of community diversity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. On the statistical mechanics of species abundance distributions.

    Science.gov (United States)

    Bowler, Michael G; Kelly, Colleen K

    2012-09-01

    A central issue in ecology is that of the factors determining the relative abundance of species within a natural community. The proper application of the principles of statistical physics to species abundance distributions (SADs) shows that simple ecological properties could account for the near universal features observed. These properties are (i) a limit on the number of individuals in an ecological guild and (ii) per capita birth and death rates. They underpin the neutral theory of Hubbell (2001), the master equation approach of Volkov et al. (2003, 2005) and the idiosyncratic (extreme niche) theory of Pueyo et al. (2007); they result in an underlying log series SAD, regardless of neutral or niche dynamics. The success of statistical mechanics in this application implies that communities are in dynamic equilibrium and hence that niches must be flexible and that temporal fluctuations on all sorts of scales are likely to be important in community structure. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. A robust and accurate binning algorithm for metagenomic sequences with arbitrary species abundance ratio.

    Science.gov (United States)

    Leung, Henry C M; Yiu, S M; Yang, Bin; Peng, Yu; Wang, Yi; Liu, Zhihua; Chen, Jingchi; Qin, Junjie; Li, Ruiqiang; Chin, Francis Y L

    2011-06-01

    With the rapid development of next-generation sequencing techniques, metagenomics, also known as environmental genomics, has emerged as an exciting research area that enables us to analyze the microbial environment in which we live. An important step for metagenomic data analysis is the identification and taxonomic characterization of DNA fragments (reads or contigs) resulting from sequencing a sample of mixed species. This step is referred to as 'binning'. Binning algorithms that are based on sequence similarity and sequence composition markers rely heavily on the reference genomes of known microorganisms or phylogenetic markers. Due to the limited availability of reference genomes and the bias and low availability of markers, these algorithms may not be applicable in all cases. Unsupervised binning algorithms which can handle fragments from unknown species provide an alternative approach. However, existing unsupervised binning algorithms only work on datasets either with balanced species abundance ratios or rather different abundance ratios, but not both. In this article, we present MetaCluster 3.0, an integrated binning method based on the unsupervised top--down separation and bottom--up merging strategy, which can bin metagenomic fragments of species with very balanced abundance ratios (say 1:1) to very different abundance ratios (e.g. 1:24) with consistently higher accuracy than existing methods. MetaCluster 3.0 can be downloaded at http://i.cs.hku.hk/~alse/MetaCluster/.

  7. Impacts of non-native Norway spruce plantation on abundance and species richness of ground beetles (Coleoptera: Carabidae

    Directory of Open Access Journals (Sweden)

    Z. Elek

    2001-06-01

    Full Text Available The impacts of non-native Norway spruce plantation on the abundance and species richness of carabids were studied in the Bükk National Park in Hungary, central Europe. Pitfall catches from recently established (5 yr old, young (15 yr after planting, middle-aged (30 yr after planting, old Norway spruce Picea abies plantation (50 yr after planting, and a native submontane beech forest (Fagetum sylvaticae as a control stand were compared.

    Our results showed that deciduous forest species decreased significantly in abundance in the plantations, and appeared in high abundance only in the native beech forest. Furthermore, open habitat species increased remarkably in abundance in the recently established plantation. Carabids were significantly more abundant and species rich in the native forest than in the plantations, while differences were not significant among the plantations. Multiple regression between the abundance and species richness of carabids and twelve environmental measurements showed that pH of the soil, herb cover and density of the carabids’ prey had a significant effect in determining abundance and species richness.

    Our results showed that plantation of non-native Norway spruce species had a detrimental effect on the composition of carabid communities and no regeneration could be observed during the growth of plantations even 50 yr after the establishment. This emphasises the importance of an active nature management practice to facilitate the recolonization of the native species.

  8. Asymptotic size determines species abundance in the marine size spectrum

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Beyer, Jan

    2006-01-01

    The majority of higher organisms in the marine environment display indeterminate growth; that is, they continue to grow throughout their life, limited by an asymptotic size. We derive the abundance of species as a function of their asymptotic size. The derivation is based on size-spectrum theory......, where population structure is derived from physiology and simple arguments regarding the predator-prey interaction. Using a hypothesis of constant satiation, which states that the average degree of satiation is independent of the size of an organism, the number of individuals with a given size is found...... to be proportional to the weight raised to the power -2.05, independent of the predator/prey size ratio. This is the first time the spectrum exponent has been derived solely on the basis of processes at the individual level. The theory furthermore predicts that the parameters in the von Bertalanffy growth function...

  9. From Leaf Synthesis to Senescence: n-Alkyl Lipid Abundance and D/H Composition Among Plant Species in a Temperate Deciduous Forest at Brown's Lake Bog, Ohio, USA

    Science.gov (United States)

    Freimuth, E. J.; Diefendorf, A. F.; Lowell, T. V.

    2014-12-01

    The hydrogen isotope composition (D/H, δD) of terrestrial plant leaf waxes is a promising paleohydrology proxy because meteoric water (e.g., precipitation) is the primary hydrogen source for wax synthesis. However, secondary environmental and biological factors modify the net apparent fractionation between precipitation δD and leaf wax δD, limiting quantitative reconstruction of paleohydrology. These secondary factors include soil evaporation, leaf transpiration, biosynthetic fractionation, and the seasonal timing of lipid synthesis. Here, we investigate the influence of each of these factors on n-alkyl lipid δD in five dominant deciduous angiosperm tree species as well as shrubs, ferns and grasses in the watershed surrounding Brown's Lake Bog, Ohio, USA. We quantified n-alkane and n-alkanoic acid concentrations and δD in replicate individuals of each species at weekly to monthly intervals from March to October 2014 to assess inter- and intraspecific isotope variability throughout the growing season. We present soil, xylem and leaf water δD from each individual, and precipitation and atmospheric water vapor δD throughout the season to directly examine the relationship between source water and lipid isotope composition. These data allow us to assess the relative influence of soil evaporation and leaf transpiration among plant types, within species, and along a soil moisture gradient throughout the catchment. We use leaf water δD to approximate biosynthetic fractionation for each individual and test whether this is a species-specific and seasonal constant, and to evaluate variation among plant types with identical growth conditions. Our high frequency sampling approach provides new insights into the seasonal timing of n-alkane and n-alkanoic acid synthesis and subsequent fluctuations in concentration and δD in a temperate deciduous forest. These results will advance understanding of the magnitude and timing of secondary influences on the modern leaf wax

  10. Seasonal variation in composition and abundance of harmful dinoflagellates in Yemeni waters, southern Red Sea.

    Science.gov (United States)

    Alkawri, Abdulsalam

    2016-11-15

    General abundance and species composition of a dinoflagellate community in Yemeni coastal waters of Al Salif (southern Red Sea) were studied with a view to understand the annual variations in particular the toxic species. Dinoflagellates were more abundant among phytoplankton. Thirty five dinoflagellate taxa were identified, among which 12 were reported as potentially toxic species. A significant change in seasonal abundance was recorded with the maximum (2.27∗10 6 cellsl -1 ) in May, and the minimum (2.50∗10 2 cellsl -1 ) recorded in January. Kryptoperidinium foliaceum, which was reported for the first time from the Red Sea, was the most abundant species with a maximum in May 2013 (2.26∗10 6 cellsl -1 ). Spearman's rank correlation analysis indicates that, total harmful dinoflagellate cells, K. foliaceum, Prorocentrum gracile and Prorocentrum micans were significantly correlated with temperature. This study suggests that Yemeni waters should be monitored to investigate harmful species and to identify areas and seasons at higher risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Daughter Species Abundances in Comet C/2014 Q2 (Lovejoy)

    Science.gov (United States)

    McKay, Adam; Cochran, Anita; Dello Russo, Neil; Kelley, Michael

    2015-11-01

    We present analysis of high spectral resolution optical spectra of C/2014 Q2 (Lovejoy) acquired with the Tull Coude spectrometer on the 2.7-meter Harlan J. Smith Telescope at McDonald Observatory and the ARCES spectrometer mounted on the 3.5-meter Astrophysical Research Consortium Telescope at Apache Point Observatory. Both Tull Coude and ARCES provide high spectral resolution (R=30,000-60,000) and a large spectral range of approximately 3500-10000 Angstroms. We obtained two observation epochs, one in February 2015 at a heliocentric distance of 1.3 AU, and another in May 2015 at a heliocentric distance of 1.9 AU. Another epoch in late August 2015 at a heliocentric distance of 3.0 AU is scheduled. We will present production rates of the daughter species CN, C3, CH, C2, and NH2. We will also present H2O production rates derived from the [OI]6300 emission, as well as measurements of the flux ratio of the [OI]5577 Angstrom line to the sum of the [OI]6300 and [OI]6364 Angstrom lines (sometimes referred to as the oxygen line ratio). This ratio is indicative of the CO2 abundance of the comet. As we have observations at several heliocentric distances, we will examine how production rates and mixing ratios of the various species change with heliocentric distance. We will compare our oxygen line measurements to observations of CO2 made with Spitzer, as well as our other daughter species observations to those of candidate parent molecules made at IR wavelengths.

  12. Effect of land use on the composition, diversity and abundance of insects drifting in neotropical streams

    Directory of Open Access Journals (Sweden)

    B. C. G. Gimenez

    Full Text Available Abstract Streams may exhibit differences in community structure of invertebrate drift, which may be a reflex of variation in environmental factors, able to change in conditions of anthropogenic interventions. The aim of this study was to analyze the composition, diversity and abundance of insects drifting in two neotropical streams under different land use and to identify the environmental factors involved in determining such patterns. 54 taxa of aquatic insects were identified in urban and rural streams. The results indicated significant differences in species composition due to the replacement of specialist species by generalist species in the urban stream. Higher diversity of taxa was recorded in the rural stream, with high levels of dissolved oxygen and high water flow, which favored the occurrence of sensitive groups to environmental disturbances, such as Ephemeroptera, Plecoptera, Trichoptera and Coleoptera taxa, that living mainly in clean and well oxygenated waters. On the other hand, a higher density of insects drifting, especially Chironomidae, was observed in the urban stream, where high values of pH, electrical conductivity and nitrogen were observed. These larvae are able to explore a wide range of environmental conditions, owing to their great capacity for physiological adaptation. Despite observing the expected patterns, there were no significant differences between streams for the diversity and abundance of species. Thus, the species composition can be considered as the best predictor of impacts on the drifting insect community.

  13. The relative importance of pollinator abundance and species richness for the temporal variance of pollination services.

    Science.gov (United States)

    Genung, Mark A; Fox, Jeremy; Williams, Neal M; Kremen, Claire; Ascher, John; Gibbs, Jason; Winfree, Rachael

    2017-07-01

    The relationship between biodiversity and the stability of ecosystem function is a fundamental question in community ecology, and hundreds of experiments have shown a positive relationship between species richness and the stability of ecosystem function. However, these experiments have rarely accounted for common ecological patterns, most notably skewed species abundance distributions and non-random extinction risks, making it difficult to know whether experimental results can be scaled up to larger, less manipulated systems. In contrast with the prolific body of experimental research, few studies have examined how species richness affects the stability of ecosystem services at more realistic, landscape scales. The paucity of these studies is due in part to a lack of analytical methods that are suitable for the correlative structure of ecological data. A recently developed method, based on the Price equation from evolutionary biology, helps resolve this knowledge gap by partitioning the effect of biodiversity into three components: richness, composition, and abundance. Here, we build on previous work and present the first derivation of the Price equation suitable for analyzing temporal variance of ecosystem services. We applied our new derivation to understand the temporal variance of crop pollination services in two study systems (watermelon and blueberry) in the mid-Atlantic United States. In both systems, but especially in the watermelon system, the stronger driver of temporal variance of ecosystem services was fluctuations in the abundance of common bee species, which were present at nearly all sites regardless of species richness. In contrast, temporal variance of ecosystem services was less affected by differences in species richness, because lost and gained species were rare. Thus, the findings from our more realistic landscapes differ qualitatively from the findings of biodiversity-stability experiments. © 2017 by the Ecological Society of America.

  14. Species are not most abundant in the centre of their geographic range or climatic niche.

    Science.gov (United States)

    Dallas, Tad; Decker, Robin R; Hastings, Alan

    2017-12-01

    The pervasive idea that species should be most abundant in the centre of their geographic range or centre of their climatic niche is a key assumption in many existing ecological hypotheses and has been declared a general macroecological rule. However, empirical support for decreasing population abundance with increasing distance from geographic range or climatic niche centre (distance-abundance relationships) remains fairly weak. We examine over 1400 bird, mammal, fish and tree species to provide a thorough test of distance-abundance relationships, and their associations with species traits and phylogenetic relationships. We failed to detect consistent distance-abundance relationships, and found no association between distance-abundance slope and species traits or phylogenetic relatedness. Together, our analyses suggest that distance-abundance relationships may be rare, difficult to detect, or are an oversimplification of the complex biogeographical forces that determine species spatial abundance patterns. © 2017 John Wiley & Sons Ltd/CNRS.

  15. Vegetation composition and structure influences bird species ...

    African Journals Online (AJOL)

    Vegetation composition and structure influences bird species community ... variables on bird species diversity and richness of respective foraging guilds, and ... of the species assessed: (1) increasing closed cover due to woody plant density, ...

  16. Local and Landscape Drivers of Parasitoid Abundance, Richness, and Composition in Urban Gardens.

    Science.gov (United States)

    Burks, Julia M; Philpott, Stacy M

    2017-04-01

    Urbanization negatively affects biodiversity, yet some urban habitat features can support diversity. Parasitoid wasps, an abundant and highly diverse group of arthropods, can inhabit urban areas and do well in areas with higher host abundance, floral resources, or local or landscape complexity. Parasitoids provide biological control services in many agricultural habitats, yet few studies have examined diversity and abundance of parasitoids in urban agroecosystems to understand how to promote conservation and function. We examined the local habitat and landscape drivers of parasitoid abundance, superfamily and family richness, and parasitoid composition in urban gardens in the California central coast. Local factors included garden size, ground cover type, herbaceous plant species, and number of trees and shrubs. Landscape characteristics included land cover and landscape diversity around gardens. We found that garden size, mulch cover, and urban cover within 500 m of gardens predicted increases in parasitoid abundance within gardens. The height of herbaceous vegetation and tree and shrub richness predicted increases in superfamily and family richness whereas increases in urban cover resulted in declines in parasitoid richness. Abundance of individual superfamilies and families responded to a wide array of local and landscape factors, sometimes in opposite ways. Composition of parasitoid communities responded to changes in garden size, herbaceous plant cover, and number of flowers. Thus, both local scale management and landscape planning may impact the abundance, diversity, and community composition of parasitoids in urban gardens, and may result in differences in the effectiveness of parasitoids in biological control. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. RELATIONSHIPS OF ALIEN PLANT SPECIES ABUNDANCE TO RIPARIAN VEGETATION, ENVIRONMENT, AND DISTURBANCE

    Science.gov (United States)

    Riparian ecosystems are often invaded by alien species. We evaluated vegetation, environment, and disturbance conditions and their interrelationships with alien species abundance along reaches of 29 streams in eastern Oregon, USA. Using flexible-BETA clustering, indicator species...

  18. Plant trait-species abundance relationships vary with environmental properties in subtropical forests in eastern china.

    Directory of Open Access Journals (Sweden)

    En-Rong Yan

    Full Text Available Understanding how plant trait-species abundance relationships change with a range of single and multivariate environmental properties is crucial for explaining species abundance and rarity. In this study, the abundance of 94 woody plant species was examined and related to 15 plant leaf and wood traits at both local and landscape scales involving 31 plots in subtropical forests in eastern China. Further, plant trait-species abundance relationships were related to a range of single and multivariate (PCA axes environmental properties such as air humidity, soil moisture content, soil temperature, soil pH, and soil organic matter, nitrogen (N and phosphorus (P contents. At the landscape scale, plant maximum height, and twig and stem wood densities were positively correlated, whereas mean leaf area (MLA, leaf N concentration (LN, and total leaf area per twig size (TLA were negatively correlated with species abundance. At the plot scale, plant maximum height, leaf and twig dry matter contents, twig and stem wood densities were positively correlated, but MLA, specific leaf area, LN, leaf P concentration and TLA were negatively correlated with species abundance. Plant trait-species abundance relationships shifted over the range of seven single environmental properties and along multivariate environmental axes in a similar way. In conclusion, strong relationships between plant traits and species abundance existed among and within communities. Significant shifts in plant trait-species abundance relationships in a range of environmental properties suggest strong environmental filtering processes that influence species abundance and rarity in the studied subtropical forests.

  19. Relative abundance and species richness of cerambycid beetles in partial cut and uncut bottomland hardwood forests

    Science.gov (United States)

    Newell, P.; King, S.

    2009-01-01

    Partial cutting techniques are increasingly advocated and used to create habitat for priority wildlife. However, partial cutting may or may not benefit species dependent on deadwood; harvesting can supplement coarse woody debris in the form of logging slash, but standing dead trees may be targeted for removal. We sampled cerambycid beetles during the spring and summer of 2006 and 2007 with canopy malaise traps in 1- and 2-year-old partial cut and uncut bottomland hardwood forests of Louisiana. We captured a total of 4195 cerambycid beetles representing 65 species. Relative abundance was higher in recent partial cuts than in uncut controls and with more dead trees in a plot. Total species richness and species composition were not different between treatments. The results suggest partial cuts with logging slash left on site increase the abundance of cerambycid beetles in the first few years after partial cutting and that both partial cuts and uncut forest should be included in the bottomland hardwood forest landscape.

  20. The fish fauna of Anambra river basin, Nigeria: species abundance and morphometry

    Directory of Open Access Journals (Sweden)

    Gregory Ejikeme Odo

    2009-06-01

    Full Text Available The fish yields of most Nigeria inland waters are generally on the decline for causes that may range from inadequate management of the fisheries to degradation of the water bodies. Sustainable exploitation requires knowledge of the ichthyofaunal composition in the water bodies. We did a survey of fish species in Anambra river basin for 22 months. Fish samples were collected using four different gears -hook and line of size 13, caste nets, gill nets, and cages of mesh sizes of 50mm, 75mm, and 100mm each. We recorded 52 fish species belonging to 17 families: 171, 236, and 169 individuals at Ogurugu, Otuocha, and Nsugbe stations respectively. Two families, Characidae, 19.5 %, and Mochokidae, 11.8%, constituted the dominant fish families in the river. The dominant fish species were Citherinus citherius, 9.02%, and Alestes nurse, 7.1%. Other fish species with significant abundance were Synodontis clarias 6.9%, Macrolepidotus curvier 5.7%, Labeo coubie 5.4%, Distichodus rostrtus 4.9%, and Schilbe mystus 4.5%. The meristic features of the two most abundant fish species caught are as follows: Citharinus citharius dorsal fins 20, anal fins 30, caudal fins 21, pectoral fins, 9 and 8 ventral fins, and Alestes nurse 10 dorsal fins, 14 anal fins, 31 caudal fins, 7 pectoral fins and 6 ventral fins. The morphometric features of the two most abundant fish species are Citharinus citharius total length 300mm, standard length 231mm, head length 69mm, body length 101mm, body girth 176 mm, body weight 900mg. Alestes nurse total length 200, standard length 140mm, head length 60mm, body length 80mm, body girth120mm, body weight 400mg. The most abundant animal utilizing the basin was Ardea cinerea(D3 with 22.2% occurrence (D4 and this was followed by Caprini with 13.51%, and Varanus niloticus, 10.04%. The least abundant animals utilizing basin were Chephalophus rufilatus, and Erythrocebus patas, with 0.58% each of occurrence. Rev. Biol. Trop. 57 (1-2: 177-186. Epub

  1. Fish and phytoplankton exhibit contrasting temporal species abundance patterns in a dynamic north temperate lake.

    Directory of Open Access Journals (Sweden)

    Gretchen J A Hansen

    Full Text Available Temporal patterns of species abundance, although less well-studied than spatial patterns, provide valuable insight to the processes governing community assembly. We compared temporal abundance distributions of two communities, phytoplankton and fish, in a north temperate lake. We used both 17 years of observed relative abundance data as well as resampled data from Monte Carlo simulations to account for the possible effects of non-detection of rare species. Similar to what has been found in other communities, phytoplankton and fish species that appeared more frequently were generally more abundant than rare species. However, neither community exhibited two distinct groups of "core" (common occurrence and high abundance and "occasional" (rare occurrence and low abundance species. Both observed and resampled data show that the phytoplankton community was dominated by occasional species appearing in only one year that exhibited large variation in their abundances, while the fish community was dominated by core species occurring in all 17 years at high abundances. We hypothesize that the life-history traits that enable phytoplankton to persist in highly dynamic environments may result in communities dominated by occasional species capable of reaching high abundances when conditions allow. Conversely, longer turnover times and broad environmental tolerances of fish may result in communities dominated by core species structured primarily by competitive interactions.

  2. Fish and Phytoplankton Exhibit Contrasting Temporal Species Abundance Patterns in a Dynamic North Temperate Lake

    Science.gov (United States)

    Hansen, Gretchen J. A.; Carey, Cayelan C.

    2015-01-01

    Temporal patterns of species abundance, although less well-studied than spatial patterns, provide valuable insight to the processes governing community assembly. We compared temporal abundance distributions of two communities, phytoplankton and fish, in a north temperate lake. We used both 17 years of observed relative abundance data as well as resampled data from Monte Carlo simulations to account for the possible effects of non-detection of rare species. Similar to what has been found in other communities, phytoplankton and fish species that appeared more frequently were generally more abundant than rare species. However, neither community exhibited two distinct groups of “core” (common occurrence and high abundance) and “occasional” (rare occurrence and low abundance) species. Both observed and resampled data show that the phytoplankton community was dominated by occasional species appearing in only one year that exhibited large variation in their abundances, while the fish community was dominated by core species occurring in all 17 years at high abundances. We hypothesize that the life-history traits that enable phytoplankton to persist in highly dynamic environments may result in communities dominated by occasional species capable of reaching high abundances when conditions allow. Conversely, longer turnover times and broad environmental tolerances of fish may result in communities dominated by core species structured primarily by competitive interactions. PMID:25651399

  3. Composição, abundância e notas sobre a ecologia de espécies de larvas de lepidópteros associadas a cinco espécies de plantas hospedeiras no Parque Nacional da Restinga de Jurubatiba, RJ Composition, abundance and notes on ecology of lepidopteran larvae associated with five plant species in Parque Nacional da Restinga de Jurubatiba, RJ

    Directory of Open Access Journals (Sweden)

    Ricardo F. Monteiro

    2007-12-01

    Full Text Available Com o objetivo de descrever a composição, ocorrência temporal e aspectos ecológicos das espécies de larvas de Lepidoptera associadas a cinco espécies de plantas: Erythroxylum ovalifolium e E. subsessile (Erythroxylaceae, Manilkara subsericea (Sapotaceae, Protium icicariba e P. heptaphyllum (Burseraceae, 1.455 plantas foram vistoriadas durante o período de Julho de 2003 a Agosto de 2005 no Parque Nacional da Restinga de Jurubatiba (PNRJ. Foram encontradas 32 espécies de Lepidoptera associadas a essas cinco espécies de plantas hospedeiras, sendo que as quatro espécies mais abundantes pertenciam à família Elachistidae. Manilkara subsericea apresentou o maior número de espécies de Lepidoptera associadas, 14 espécies, seguida por E. ovalifolium, com 10 espécies, P. icicariba, com sete, E. subsessile com seis e P. heptaphyllum com duas espécies de Lepidoptera associadas. Apenas uma das 32 espécies de Lepidoptera criadas apresentava hábito gregário e 56% utilizavam algum tipo de abrigo para alimentação e/ou defesa. Seis espécies de Lepidoptera identificadas (27% eram polífagas, três (14% oligófagas e 13 (59% tiveram apenas uma única espécie de planta hospedeira registrada. As espécies mais abundantes de mariposas apresentaram dois períodos reprodutivos no ano, predominantemente, no inverno e outono. Fatores abióticos, como a forte insolação na primavera e verão na formação aberta de restinga, podem ser importantes determinando esse padrão temporal de reprodução dos insetos, mas não podemos descartar também fatores bióticos como a pressão de inimigos naturais.In order to describe the species composition, temporal occurrence and ecological aspects of larvae associated with five plant species: Erythroxylum ovalifolium and E. subsessile (Erythroxylaceae, Manilkara subsericea (Sapotaceae, Protium icicariba and P. heptaphyllum (Burseraceae, 1.680 plants were bimonthly surveyed from July of 2003 to August of 2005 in

  4. Abundance, diversity and community composition of free-living protozoa on vegetable sprouts.

    Science.gov (United States)

    Chavatte, N; Lambrecht, E; Van Damme, I; Sabbe, K; Houf, K

    2016-05-01

    Interactions with free-living protozoa (FLP) have been implicated in the persistence of pathogenic bacteria on food products. In order to assess the potential involvement of FLP in this contamination, detailed knowledge on their occurrence, abundance and diversity on food products is required. In the present study, enrichment and cultivation methods were used to inventory and quantify FLP on eight types of commercial vegetable sprouts (alfalfa, beetroot, cress, green pea, leek, mung bean, red cabbage and rosabi). In parallel, total aerobic bacteria and Escherichia coli counts were performed. The vegetable sprouts harbored diverse communities of FLP, with Tetrahymena (ciliate), Bodo saltans and cercomonads (flagellates), and Acanthamoeba and Vannella (amoebae) as the dominant taxa. Protozoan community composition and abundance significantly differed between the sprout types. Beetroot harbored the most abundant and diverse FLP communities, with many unique species such as Korotnevella sp., Vannella sp., Chilodonella sp., Podophrya sp. and Sphaerophrya sp. In contrast, mung bean sprouts were species-poor and had low FLP numbers. Sampling month and company had no significant influence, suggesting that seasonal and local factors are of minor importance. Likewise, no significant relationship between protozoan community composition and bacterial load was observed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Snow cover and extreme winter warming events control flower abundance of some, but not all species in high arctic Svalbard

    DEFF Research Database (Denmark)

    Semenchuk, Philipp R.; Elberling, Bo; Cooper, Elisabeth J.

    2013-01-01

    octopetala. However, the affected species were resilient and individuals did not experience any long term effects. In the case of short or cold summers, a subset of species suffered reduced reproductive success, which may affect future plant composition through possible cascading competition effects. Extreme...... winter warming events were shown to expose the canopy to cold winter air. The following summer most of the overwintering flower buds could not produce flowers. Thus reproductive success is reduced if this occurs in subsequent years. We conclude that snow depth influences flower abundance by altering...... events, while Stellaria crassipes responded partly. Snow pack thickness determined whether winter warming events had an effect on flower abundance of some species. Warming events clearly reduced flower abundance in shallow but not in deep snow regimes of Cassiope tetragona, but only marginally for Dryas...

  6. Composition and abundance of small mammal communities in forest fragments and vegetation corridors in Southern Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Andréa O. Mesquita

    2012-09-01

    Full Text Available Habitat fragmentation leads to isolation and reduce habitat areas, in addition to a series of negative effects on natural populations, affecting richness, abundance and distribution of animal species. In such a text, habitat corridors serve as an alternative for connectivity in fragmented landscapes, minimizing the effects of structural isolation of different habitat areas. This study evaluated the richness, composition and abundance of small mammal communities in forest fragments and in the relevant vegetation corridors that connect these fragments, located in Southern Minas Gerais, Southeastern Brazil. Ten sites were sampled (five forest fragments and five vegetation corridors using the capture-mark-recapture method, from April 2007-March 2008. A total sampling effort of 6 300 trapnights resulted in 656 captures of 249 individuals. Across the 10 sites sampled, 11 small mammal species were recorded. Multidimensional scaling (MDS ordinations and ANOSIM based on the composition of small mammal communities within the corridor and fragment revealed a qualitative difference between the two environments. Regarding abundance, there was no significant difference between corridors and fragments. In comparing mean values of abundance per species in each environment, only Cerradomys subflavus showed a significant difference, being more abundant in the corridor environment. Results suggest that the presence of several small mammal species in the corridor environment, in relatively high abundances, could indicate corridors use as habitat, though they might also facilitate and/or allow the movement of individuals using different habitat patches (fragments.

  7. On the dependence of speciation rates on species abundance and ...

    Indian Academy of Sciences (India)

    Unknown

    abundance largely determines the rate of generation of intraspecific endogenous genetic variation, the result obtained ... population size together with generation time emerge as important ...... wind and wave mixing of the ocean, any prolonged exis- tence of ..... epipelagic plankton size structure in high latitude oceans; J.

  8. Restinga forests of the Brazilian coast: richness and abundance of tree species on different soils.

    Science.gov (United States)

    Magnago, Luiz F S; Martins, Sebastião V; Schaefer, Carlos E G R; Neri, Andreza V

    2012-09-01

    The aim of this study was to determine changes in composition, abundance and richness of species along a forest gradient with varying soils and flood regimes. The forests are located on the left bank of the lower Jucu River, in Jacarenema Natural Municipal Park, Espírito Santo. A survey of shrub/tree species was done in 80 plots, 5x25 m, equally distributed among the forests studied. We included in the sampling all individuals with >3.2 cm diameter at breast height (1.30 m). Soil samples were collected from the surface layer (0-10 cm) in each plot for chemical and physical analysis. The results indicate that a significant pedological gradient occurs, which is influenced by varying seasonal groundwater levels. Restinga forest formations showed significant differences in species richness, except for Non-flooded Forest and Non-flooded Forest Transition. The Canonical Correlation Analysis (CCA) showed that some species are distributed along the gradient under the combined influence of drainage, nutrient concentration and physical characteristics of the soil. Regarding the variables tested, flooding seems to be a more limiting factor for the establishment of plant species in Restinga forests than basic soil fertility attributes.

  9. MESSENGER Searches for Less Abundant or Weakly Emitting Species in Mercury's Exosphere

    Science.gov (United States)

    Vervack, Ronald J., Jr.; McClintock, William E.; Killen, Rosemary M.; Sprague, Ann L.; Burger, Matthew H.; Merkel, Aimee W.; Sarantos, Menelaos

    2011-01-01

    Mercury's exosphere is composed of material that originates at the planet's surface, whether that material is native or delivered by the solar wind and micrometeoroids. Many exospheric species have been detected by remote sensing, including H and He by Mariner 10, Na, K, and Ca by ground-based observations, and H, Na, Ca, Mg, and Ca+ by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. Other exospheric species, including Fe, AI, Si, 0, S, Mn, CI, Ti, OH, and their ions, are expected to be present on the basis of MESSENGER surface measurements and models of Mercury's surface chemistry. Here we report on searches for these species made with the Ultraviolet and Visible Spectrometer (UVVS) channel of the Mercury Atmospheric and Surface Composition Spectrometer (MASCS). No obvious signatures of the listed species have yet been observed in Mercury's exosphere by the UVVS as of this writing. It is possible that detections are elusive because the optimum regions of the exosphere have not been sampled. The Sun-avoidance constraints on MESSENGER place tight limits on instrument boresight directions, and some regions are probed infrequently. If there are strong spatial gradients in the distribution of weakly emitting species, a high-resolution sampling of specific regions may be required to detect them. Summing spectra over time will also aid in the ability to detect weaker emission. Observations to date nonetheless permit strong upper limits to be placed on the abundances of many undetected species, in some cases as functions of time and space. As those limits are lowered with time, the absence of detections can provide insight into surface composition and the potential source mechanisms of exospheric material.

  10. Physical factors affecting the abundance and species richness of fishes in the shallow waters of the southern Bothnian Sea (Sweden)

    Science.gov (United States)

    Thorman, Staffan

    1986-03-01

    The relationship between the composition of the fish assemblages and the abiotic environment in seven shallow areas within the same geographical range in the southern Bothnian Sea were studied in May, July, September and November 1982. Eighteen species were found in the areas and the major species were Pungitius pungitius (L.), Pomatoschistus minutus (Pallas), Gasterosteus aculeatus (L.), Phoxinus phoxinus (L.), Pomatoschistus microps (Krøyer) and Gobius niger L. The main purpose of the study was to examine the possible effects of exposure, organic contents in sediments and habitat heterogeneity on species richness and abundance of the assemblages. There was a negative correlation between the organic contents of the sediment and exposure. There were no significant correlations between exposure, organic contents, size of the areas and species numbers but habitat heterogeneity was positively correlated with species number. There were no correlations between fish abundance and heterogeneity of the areas. Negative correlations occurred between the exposure of the areas and fish abundance. The amounts of the pooled benthic fauna were negatively correlated to the exposure. The species/area hypothesis finds no support in the results, because there was no correlation between habitat heterogeneity of an area and its size. The effective fetch combined with the heterogeneity measurement of the areas seemed to be useful indicators of the species composition and fish abundance. Habitat heterogeneity and exposure were the most important structuring factors of these shallow water fish assemblages during the ice-free period and within the local geographical range. The assemblages consist of a mixture of species with marine or limnic origin and they have probably not evolved in the Bothnian Sea or together. They are most likely regulated by their physiological plasticity and not by interactions with other species.

  11. 1 Species Diversity and Relative Abundance.cdr

    African Journals Online (AJOL)

    Administrator

    from beach seine landings along the central coast during the study period. Landing sites were Winneba, Saltpond and Cape Coast. (Fig. 1). Fish identification was done in the laboratory using manuals (Schneider, 1990;. Kwei & Ofori-Adu, 2005). The identifications were to the family and species levels. Various fish species ...

  12. The effects of coastal development on sponge abundance, diversity, and community composition on Jamaican coral reefs.

    Science.gov (United States)

    Stubler, Amber D; Duckworth, Alan R; Peterson, Bradley J

    2015-07-15

    Over the past decade, development along the northern coast of Jamaica has accelerated, resulting in elevated levels of sedimentation on adjacent reefs. To understand the effects of this development on sponge community dynamics, we conducted surveys at three locations with varying degrees of adjacent coastal development to quantify species richness, abundance and diversity at two depths (8-10 m and 15-18 m). Sediment accumulation rate, total suspended solids and other water quality parameters were also quantified. The sponge community at the location with the least coastal development and anthropogenic influence was often significantly different from the other two locations, and exhibited higher sponge abundance, richness, and diversity. Sponge community composition and size distribution were statistically different among locations. This study provides correlative evidence that coastal development affects aspects of sponge community ecology, although the precise mechanisms are still unclear. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Parasites of mammals species abundance near zone Chernobyl

    International Nuclear Information System (INIS)

    Pen'kevich, V.A.

    2014-01-01

    In wildlife reserve parasitize various types of parasites: arachnids (mites) parasitic insects (horseflies, keds, mosquitoes, gnats, midges), helminths (trematodes, cestodes, nematodes and acanthocephalans) and parasitic protozoa. In quantity: 3 (beaver) to 25 species (wolf). (authors)

  14. [Composition, distribution and abundance of gastropod larvae in the South of Quintana Roo,Mexico and north of Belice].

    Science.gov (United States)

    Oliva Rivera, J; de Jesús Navarrete, A

    2000-12-01

    To know the composition, abundance and distribution of gastropod larvae, monthly samplings were carried out in the south of Quintana Roo, Mexico and north of Belize, from April to December, 1996. Collections were made in six sites at Chinchorro Bank, four in the South Coast and six at Hol-Chan, Belize, between the 10 and 20 hrs. At each station 2.5 m3 of seawater were pumped through a 202 microns mesh; 27 species were identified. The most abundant species were: South Coast, Rissoina sp. 1., Limacina sp. 1 and Natica sp. 1, Chinchorro Bank, Limacina sp. 1, Creseis acicula, Cerithiopsis hero and Rissoina sp. 1 and Hol-Chan, Limacina sp. 2, Alaba incerta and Rissoina sp. 1. The highest abundance was in rainy season. Apparently the presence of winds, coastal currents and food availability, control the distribution and abundance of larvae.

  15. Considerations on the biochemical composition of some freshwater zooplankton species.

    Directory of Open Access Journals (Sweden)

    Nicoletta RICCARDI

    1999-02-01

    Full Text Available The mean elemental (C, H, N and biochemical composition (lipids, carbohydrates and proteins of some abundant crustacean zooplankton species of Italian insubric lakes has been estimated by the analysis of samples collected at different seasons from various environments (Lake Maggiore, Lake Varese, Lake Comabbio, Lake Monate. From each sample an adequate number of specimens of each abundant species was sorted and analyzed by a CHN elemental analyzer. The percentage of lipids, carbohydrates and proteins and the calorific content were calculated from the elemental composition according to Gnaiger & Bitterlich (1984. Inter- and intraspecific variability of biochemical composition was quite high, while elemental composition and calorific content were less variable. An estimate of the mean elemental and biochemical composition of each species was obtained by pooling the data. These mean values have been used to estimate the pools of elements and compounds in the crustacean zooplankton of Lake Comabbio to provide an example of the importance of a multiple approach in zooplankton studies.

  16. Species Abundance in a Forest Community in South China: A Case of Poisson Lognormal Distribution

    Institute of Scientific and Technical Information of China (English)

    Zuo-Yun YIN; Hai REN; Qian-Mei ZHANG; Shao-Lin PENG; Qin-Feng GUO; Guo-Yi ZHOU

    2005-01-01

    Case studies on Poisson lognormal distribution of species abundance have been rare, especially in forest communities. We propose a numerical method to fit the Poisson lognormal to the species abundance data at an evergreen mixed forest in the Dinghushan Biosphere Reserve, South China. Plants in the tree, shrub and herb layers in 25 quadrats of 20 m×20 m, 5 m×5 m, and 1 m×1 m were surveyed. Results indicated that: (i) for each layer, the observed species abundance with a similarly small median, mode, and a variance larger than the mean was reverse J-shaped and followed well the zero-truncated Poisson lognormal;(ii) the coefficient of variation, skewness and kurtosis of abundance, and two Poisson lognormal parameters (σ andμ) for shrub layer were closer to those for the herb layer than those for the tree layer; and (iii) from the tree to the shrub to the herb layer, the σ and the coefficient of variation decreased, whereas diversity increased. We suggest that: (i) the species abundance distributions in the three layers reflects the overall community characteristics; (ii) the Poisson lognormal can describe the species abundance distribution in diverse communities with a few abundant species but many rare species; and (iii) 1/σ should be an alternative measure of diversity.

  17. Abundance and species richness of lombric macrofauna in a semi ...

    African Journals Online (AJOL)

    The importance of earthworms for soils has evolved over time. Our study was conducted in the forest of Ouled yagoub (North East Algerian). Sampling at three different altitudes resulted in a total of forty-nine individuals (49) and only three species were identified: Octodrilus complanatus, Allolobophora molleri and ...

  18. fish species and size distribution and abundance in different areas

    African Journals Online (AJOL)

    Larger individuals dominated in deep waters recording a mode at 45.5 cm TL. ... as a result of trophic interactions with introduced species ... sea level. The climate is equatorial with two wet seasons, one between October and. December, the ...

  19. Urbanization level and woodland size are major drivers of woodpecker species richness and abundance.

    Directory of Open Access Journals (Sweden)

    Lukasz Myczko

    Full Text Available Urbanization is a process globally responsible for loss of biodiversity and for biological homogenization. Urbanization may have a direct negative impact on species behaviour and indirect effects on species populations through alterations of their habitats, for example patch size and habitat quality. Woodpeckers are species potentially susceptible to urbanization. These birds are mostly forest specialists and the development of urban areas in former forests may be an important factor influencing their richness and abundance, but documented examples are rare. In this study we investigated how woodpeckers responded to changes in forest habitats as a consequence of urbanization, namely size and isolation of habitat patches, and other within-patch characteristics. We selected 42 woodland patches in a gradient from a semi-natural rural landscape to the city centre of Poznań (Western Poland in spring 2010. Both species richness and abundance of woodpeckers correlated positively to woodland patch area and negatively to increasing urbanization. Abundance of woodpeckers was also positively correlated with shrub cover and percentage of deciduous tree species. Furthermore, species richness and abundance of woodpeckers were highest at moderate values of canopy openness. Ordination analyses confirmed that urbanization level and woodland patch area were variables contributing most to species abundance in the woodpecker community. Similar results were obtained in presence-absence models for particular species. Thus, to sustain woodpecker species within cities it is important to keep woodland patches large, multi-layered and rich in deciduous tree species.

  20. Urbanization level and woodland size are major drivers of woodpecker species richness and abundance.

    Science.gov (United States)

    Myczko, Lukasz; Rosin, Zuzanna M; Skórka, Piotr; Tryjanowski, Piotr

    2014-01-01

    Urbanization is a process globally responsible for loss of biodiversity and for biological homogenization. Urbanization may have a direct negative impact on species behaviour and indirect effects on species populations through alterations of their habitats, for example patch size and habitat quality. Woodpeckers are species potentially susceptible to urbanization. These birds are mostly forest specialists and the development of urban areas in former forests may be an important factor influencing their richness and abundance, but documented examples are rare. In this study we investigated how woodpeckers responded to changes in forest habitats as a consequence of urbanization, namely size and isolation of habitat patches, and other within-patch characteristics. We selected 42 woodland patches in a gradient from a semi-natural rural landscape to the city centre of Poznań (Western Poland) in spring 2010. Both species richness and abundance of woodpeckers correlated positively to woodland patch area and negatively to increasing urbanization. Abundance of woodpeckers was also positively correlated with shrub cover and percentage of deciduous tree species. Furthermore, species richness and abundance of woodpeckers were highest at moderate values of canopy openness. Ordination analyses confirmed that urbanization level and woodland patch area were variables contributing most to species abundance in the woodpecker community. Similar results were obtained in presence-absence models for particular species. Thus, to sustain woodpecker species within cities it is important to keep woodland patches large, multi-layered and rich in deciduous tree species.

  1. Anthropogenic influence on the distribution, abundance and diversity of sandfly species (Diptera: Phlebotominae: Psychodidae, vectors of cutaneous leishmaniasis in Panama

    Directory of Open Access Journals (Sweden)

    Anayansi Valderrama

    2011-12-01

    Full Text Available In Panama, species of the genus Lutzomyia are vectors of American cutaneous leishmaniasis (ACL. There is no recent ecological information that may be used to develop tools for the control of this disease. Thus, the goal of this study was to determine the composition, distribution and diversity of Lutzomyia species that serve as vectors of ACL. Sandfly sampling was conducted in forests, fragmented forests and rural environments, in locations with records of ACL. Lutzomyia gomezi, Lutzomyia panamensis and Lutzomyia trapidoi were the most widely distributed and prevalent species. Analysis of each sampling point showed that the species abundance and diversity were greatest at points located in the fragmented forest landscape. However, when the samples were grouped according to the landscape characteristics of the locations, there was a greater diversity of species in the rural environment locations. The Kruskal Wallis analysis of species abundance found that Lu. gomezi and Lu. trapidoi were associated with fragmented environments, while Lu. panamensis, Lutzomyia olmeca bicolor and Lutzomyia ylephiletor were associated with forested environments. Therefore, we suggest that human activity influences the distribution, composition and diversity of the vector species responsible for leishmaniasis in Panama.

  2. Species abundance distributions : moving beyond single prediction theories to integration within an ecological framework

    NARCIS (Netherlands)

    McGill, Brian J.; Etienne, Rampal S.; Gray, John S.; Alonso, David; Anderson, Marti J.; Benecha, Habtamu Kassa; Dornelas, Maria; Enquist, Brian J.; Green, Jessica L.; He, Fangliang; Hurlbert, Allen H.; Magurran, Anne E.; Marquet, Pablo A.; Maurer, Brian A.; Ostling, Annette; Soykan, Candan U.; Ugland, Karl I.; White, Ethan P.

    2007-01-01

    Species abundance distributions (SADs) follow one of ecology's oldest and most universal laws - every community shows a hollow curve or hyperbolic shape on a histogram with many rare species and just a few common species. Here, we review theoretical, empirical and statistical developments in the

  3. Species abundance distributions: moving beyond single prediction theories to integration within an ecological framework

    NARCIS (Netherlands)

    McGill, B.J.; Etienne, R.S.; Gray, J.S.; Alonso, D.; Anderson, M.J.; Benecha, H.K.

    2007-01-01

    Species abundance distributions (SADs) follow one of ecology's oldest and most universal laws ¿ every community shows a hollow curve or hyperbolic shape on a histogram with many rare species and just a few common species. Here, we review theoretical, empirical and statistical developments in the

  4. Effect of Spent Lubricating Oil on the Composition and Abundance ...

    African Journals Online (AJOL)

    Journal of Applied Sciences and Environmental Management ... The Modified Berlese-Tullgren Funnel method was used for the extraction of soil arthropod fauna. ... Soil arthropod taxa and abundance were significantly lower (u(2) = 51, ...

  5. Distribution and abundance of diatom species from coastal waters of Karachi, Pakistan

    International Nuclear Information System (INIS)

    Khokhar, F. N.; Burhan, Z.; Iqbal, P.; Abbasi, J.; Siddiqui, P.

    2016-01-01

    This is the first comprehensive study on the distribution and abundance of diatom species from the coastal and nearshore waters of Karachi, Pakistan, bordering northern Arabian Sea. A total of 20 genera are recorded in high abundance (Cerataulina, Chaetoceros, Coscinodiscus, Cylindrotheca, Eucampia, Guinardia, Haslea, Hemiaulus, Lauderia, Lennoxia, Leptocylindrus, Navicula, Nitzschia, Trieres, Planktoniella, Pleurosigma, Pseudo-nitzschia, Rhizosolenia, Thalassionema and Thalassiosira). The most abundant genera were observed Guinardia, Chaetoceros, Leptocylindrus, Nitzschia and Lennoxia at all stations. Manora coastal station (MI-1) had high abundance corresponding with high Chlorophyll a (130 meu gL- l) values. Minimum abundance and low chlorophyll a value (0.05μgL-l) were observed at Mubarak Village coastal station (MV-1). Diatom abundance showed significant correlation with Chlorophyll a. In present study 12 centric and 8 pennate forms were recorded and similarly high diversity of centric taxa was observed compared to pennate forms. A total of 134 species are recorded of which 40 species were observed at four stations, 31species at three stations, 23 at two stations and 40 species only at one station. The total phytoplankton and diatom peak abundance was observed during NE monsoon (winter season) associated with nutrient loading through up-sloping of nutrient rich water upwelled off of Oman during South West monsoon. Overall higher diversity was observed at Manora coastal and nearshore stations (MI-1, MI-2) indicating the influence of organic pollution loading from Layari and Malir rivers. (author)

  6. Temporal Variations in the Abundance and Composition of Biofilm Communities Colonizing Drinking Water Distribution Pipes

    Science.gov (United States)

    Kelly, John J.; Minalt, Nicole; Culotti, Alessandro; Pryor, Marsha; Packman, Aaron

    2014-01-01

    Pipes that transport drinking water through municipal drinking water distribution systems (DWDS) are challenging habitats for microorganisms. Distribution networks are dark, oligotrophic and contain disinfectants; yet microbes frequently form biofilms attached to interior surfaces of DWDS pipes. Relatively little is known about the species composition and ecology of these biofilms due to challenges associated with sample acquisition from actual DWDS. We report the analysis of biofilms from five pipe samples collected from the same region of a DWDS in Florida, USA, over an 18 month period between February 2011 and August 2012. The bacterial abundance and composition of biofilm communities within the pipes were analyzed by heterotrophic plate counts and tag pyrosequencing of 16S rRNA genes, respectively. Bacterial numbers varied significantly based on sampling date and were positively correlated with water temperature and the concentration of nitrate. However, there was no significant relationship between the concentration of disinfectant in the drinking water (monochloramine) and the abundance of bacteria within the biofilms. Pyrosequencing analysis identified a total of 677 operational taxonomic units (OTUs) (3% distance) within the biofilms but indicated that community diversity was low and varied between sampling dates. Biofilms were dominated by a few taxa, specifically Methylomonas, Acinetobacter, Mycobacterium, and Xanthomonadaceae, and the dominant taxa within the biofilms varied dramatically between sampling times. The drinking water characteristics most strongly correlated with bacterial community composition were concentrations of nitrate, ammonium, total chlorine and monochloramine, as well as alkalinity and hardness. Biofilms from the sampling date with the highest nitrate concentration were the most abundant and diverse and were dominated by Acinetobacter. PMID:24858562

  7. Ecological pattern of lichen species abundance in mixed forests of Eastern Romania

    Directory of Open Access Journals (Sweden)

    Ioana Vicol

    2016-12-01

    Full Text Available The importance of this study consists in the knowledge of the ecological attributes characteristic to mixed forestry habitats and how they affect the structure of the lichen species abundances. The field activities were performed within five forest habitat types from Moldavia Province, characterised mainly by oak mixed forests, riparian mixed forests and mixed beech forests. The habitat variables, tree variables and the lichen species abundances were analysed to get informations on the structural disimilarities, on the one hand, and relationships on the other hand. Within this study no significant disimilarities were found out from abundance lichen species point of view. The lichen species abundances are a result of interactions between components of their microhabitat and macrohabitat. The correlation analysis pointed out the preferences of lichen species to their host trees, especially Quercus and Fraxinus, altitude and tree level variables as are aspect and mosses coverage. The regression analysis has highlighted that the changes in lichen species abundances are caused by macrohabitat level predictors such as host trees represented by Fraxinus. This study demonstrates that, structure of lichen species is influenced by attributes of mixed forest habitats; therefore maintaining the diversity of tree species and ensuring the continuous occurrence of forestry land is necessary for lichen and their habitat conservation.

  8. Assessing the sensitivity of avian species abundance to land cover and climate

    Science.gov (United States)

    LeBrun, Jaymi J.; Thogmartin, Wayne E.; Thompson, Frank R.; Dijak, William D.; Millspaugh, Joshua J.

    2016-01-01

    Climate projections for the Midwestern United States predict southerly climates to shift northward. These shifts in climate could alter distributions of species across North America through changes in climate (i.e., temperature and precipitation), or through climate-induced changes on land cover. Our objective was to determine the relative impacts of land cover and climate on the abundance of five bird species in the Central United States that have habitat requirements ranging from grassland and shrubland to forest. We substituted space for time to examine potential impacts of a changing climate by assessing climate and land cover relationships over a broad latitudinal gradient. We found positive and negative relationships of climate and land cover factors with avian abundances. Habitat variables drove patterns of abundance in migratory and resident species, although climate was also influential in predicting abundance for some species occupying more open habitat (i.e., prairie warbler, blue-winged warbler, and northern bobwhite). Abundance of northern bobwhite increased with winter temperature and was the species exhibiting the most significant effect of climate. Models for birds primarily occupying early successional habitats performed better with a combination of habitat and climate variables whereas models of species found in contiguous forest performed best with land cover alone. These varied species-specific responses present unique challenges to land managers trying to balance species conservation over a variety of land covers. Management activities focused on increasing forest cover may play a role in mitigating effects of future climate by providing habitat refugia to species vulnerable to projected changes. Conservation efforts would be best served focusing on areas with high species abundances and an array of habitats. Future work managing forests for resilience and resistance to climate change could benefit species already susceptible to climate impacts.

  9. Fatty acid composition of forage herb species

    DEFF Research Database (Denmark)

    Warner, D.; Jensen, Søren Krogh; Cone, J.W.

    2010-01-01

    The use of alternative forage species in grasslands for intensive livestock production is receiving renewed attention. Data on fatty acid composition of herbs are scarce, so four herbs (Plantago lanceolata, Achillea millefolium, Cichorium intybus, Pastinaca sativa) and one grass species (timothy......, Phleum pratense) were sown in a cutting trial. The chemical composition and concentration of fatty acids (FA) of individual species were determined during the growing season. Concentrations of crude protein and FA were generally higher in the herbs than in timothy. C. intybus had the highest nutritive...

  10. Fish larval composition, abundance and seasonality in a southern ...

    African Journals Online (AJOL)

    abundance was relatively low (38 larvae 100 m-3 ), possibly as a result of the extremely low phytoplankton productivity and poor ... hoveelheid visplankton is laag (38 larwes 100 m-3), heelwaarskynlik as gevolg van die baie lae fitoplankton- opbrengs en lae ..... depressed ichthyoplankton food resources. According to.

  11. Copepod composition, abundance and diversity in Makupa Creek ...

    African Journals Online (AJOL)

    Evenness (J) was, however, relatively constant (0.67 to 0.84) during the entire sampling period. These results point to suppressed copepod diversity and abundance in Makupa Creek, and possible reasons for this, which may include environmental degradation caused by pollution, are presented. Western Indian Ocean ...

  12. The taxonomic composition, distribution and abundance of the ...

    African Journals Online (AJOL)

    The study determined the abundance and distribution of phytoplankton flora of an impoundment in the Agricultural Teaching and Research Farm of ObafemiAwolowo University (O.A.U), Ile-Ife, Osun State, Nigeria. The study was carried out over an annual cycle from September 2006- August 2007, Phytoplankton and water ...

  13. Taxa Composition, Abundance, Distribution And Diversity Of The ...

    African Journals Online (AJOL)

    Forty-eight genera of plankton were recorded; nine of Cyanophyceae, thirteen each of Chlorophyceae and Bacillariophyceae, seven of Protozoa and three each of Rotifera and Crustacea. Members of Cyanophyceae dominated the assemblage accounting for 91.77% of the total plankton abundance. All the major plankton ...

  14. Estimating species occurrence, abundance, and detection probability using zero-inflated distributions.

    Science.gov (United States)

    Wenger, Seth J; Freeman, Mary C

    2008-10-01

    Researchers have developed methods to account for imperfect detection of species with either occupancy (presence absence) or count data using replicated sampling. We show how these approaches can be combined to simultaneously estimate occurrence, abundance, and detection probability by specifying a zero-inflated distribution for abundance. This approach may be particularly appropriate when patterns of occurrence and abundance arise from distinct processes operating at differing spatial or temporal scales. We apply the model to two data sets: (1) previously published data for a species of duck, Anas platyrhynchos, and (2) data for a stream fish species, Etheostoma scotti. We show that in these cases, an incomplete-detection zero-inflated modeling approach yields a superior fit to the data than other models. We propose that zero-inflated abundance models accounting for incomplete detection be considered when replicate count data are available.

  15. Arbovirus circulation, temporal distribution, and abundance of mosquito species in two Carolina bay habitats.

    Science.gov (United States)

    Ortiz, D I; Wozniak, A; Tolson, M W; Turner, P E

    2005-01-01

    Carolina bays, a type of geomorphic feature, may be important in the ecology of mosquito vectors in South Carolina. Their hydrology varies from wetland habitats with marked flooding/drying regimes to permanently flooded spring-fed lakes. Moreover, they possess characteristics that contribute to the support of a particularly abundant and diverse invertebrate fauna. Although it has been estimated that 2,700+ bays exist in South Carolina, approximately 97% have been altered; Heritage Preserve (SBHP) and Woods Bay State Park (WBSP), from June 1997 to July 1998 to determine mosquito temporal distribution, species composition, and the occurrence of arbovirus activity. The largest mosquito collection was obtained at WBSP (n = 31,172) representing 25 species followed by SBHP (n = 3,940) with 24 species. Anopheles crucians complex were the most common species encountered in both bays. Two virus isolates were obtained from SBHP in 1997: Keystone (KEY) virus from Ochlerotatus atlanticus-tormentor and Cache Valley (CV) virus from Oc. canadensis canadensis. Twenty-nine (29) arbovirus-positive pools were obtained from WBSP: 28 in 1997 and one in 1998. KEY virus was isolated from three pools of Oc. atlanticus-tormentor and Tensaw (TEN) virus was isolated from two pools of An. crucians complex; 10 isolates could not be identified with the sera available. Additionally, 14 pools of An. crucians complex tested positive for Eastern equine encephalitis (EEE) virus antigen. These represent the first record of KEY and CV viruses in South Carolina. Our data indicate the presence of high mosquito density and diversity in both Carolina bay habitats, which may be influenced, in part, by seasonal changes in their hydroperiods. The study of mosquito and arbovirus ecology in Carolina Bay habitats could provide more information on the transmission dynamics of arboviruses and its impact on human and animal arboviral disease occurrence in South Carolina.

  16. Temporal comparison and predictors of fish species abundance and richness on undisturbed coral reef patches

    Directory of Open Access Journals (Sweden)

    Elena L.E.S. Wagner

    2015-12-01

    Full Text Available Large disturbances can cause rapid degradation of coral reef communities, but what baseline changes in species assemblages occur on undisturbed reefs through time? We surveyed live coral cover, reef fish abundance and fish species richness in 1997 and again in 2007 on 47 fringing patch reefs of varying size and depth at Mersa Bareika, Ras Mohammed National Park, Egypt. No major human or natural disturbance event occurred between these two survey periods in this remote protected area. In the absence of large disturbances, we found that live coral cover, reef fish abundance and fish species richness did not differ in 1997 compared to 2007. Fish abundance and species richness on patches was largely related to the presence of shelters (caves and/or holes, live coral cover and patch size (volume. The presence of the ectoparasite-eating cleaner wrasse, Labroides dimidiatus, was also positively related to fish species richness. Our results underscore the importance of physical reef characteristics, such as patch size and shelter availability, in addition to biotic characteristics, such as live coral cover and cleaner wrasse abundance, in supporting reef fish species richness and abundance through time in a relatively undisturbed and understudied region.

  17. Where to nest? Ecological determinants of chimpanzee nest abundance and distribution at the habitat and tree species scale.

    Science.gov (United States)

    Carvalho, Joana S; Meyer, Christoph F J; Vicente, Luis; Marques, Tiago A

    2015-02-01

    Conversion of forests to anthropogenic land-uses increasingly subjects chimpanzee populations to habitat changes and concomitant alterations in the plant resources available to them for nesting and feeding. Based on nest count surveys conducted during the dry season, we investigated nest tree species selection and the effect of vegetation attributes on nest abundance of the western chimpanzee, Pan troglodytes verus, at Lagoas de Cufada Natural Park (LCNP), Guinea-Bissau, a forest-savannah mosaic widely disturbed by humans. Further, we assessed patterns of nest height distribution to determine support for the anti-predator hypothesis. A zero-altered generalized linear mixed model showed that nest abundance was negatively related to floristic diversity (exponential form of the Shannon index) and positively with the availability of smaller-sized trees, reflecting characteristics of dense-canopy forest. A positive correlation between nest abundance and floristic richness (number of plant species) and composition indicated that species-rich open habitats are also important in nest site selection. Restricting this analysis to feeding trees, nest abundance was again positively associated with the availability of smaller-sized trees, further supporting the preference for nesting in food tree species from dense forest. Nest tree species selection was non-random, and oil palms were used at a much lower proportion (10%) than previously reported from other study sites in forest-savannah mosaics. While this study suggests that human disturbance may underlie the exclusive arboreal nesting at LCNP, better quantitative data are needed to determine to what extent the construction of elevated nests is in fact a response to predators able to climb trees. Given the importance of LCNP as refuge for Pan t. verus our findings can improve conservation decisions for the management of this important umbrella species as well as its remaining suitable habitats. © 2014 Wiley Periodicals, Inc.

  18. Experimentally reducing species abundance indirectly affects food web structure and robustness.

    Science.gov (United States)

    Barbosa, Milton; Fernandes, G Wilson; Lewis, Owen T; Morris, Rebecca J

    2017-03-01

    Studies on the robustness of ecological communities suggest that the loss or reduction in abundance of individual species can lead to secondary and cascading extinctions. However, most such studies have been simulation-based analyses of the effect of primary extinction on food web structure. In a field experiment we tested the direct and indirect effects of reducing the abundance of a common species, focusing on the diverse and self-contained assemblage of arthropods associated with an abundant Brazilian shrub, Baccharis dracunculifolia D.C. (Asteraceae). Over a 5-month period we experimentally reduced the abundance of Baccharopelma dracunculifoliae (Sternorrhyncha: Psyllidae), the commonest galling species associated with B. dracunculifolia, in 15 replicate plots paired with 15 control plots. We investigated direct effects of the manipulation on parasitoids attacking B. dracunculifoliae, as well as indirect effects (mediated via a third species or through the environment) on 10 other galler species and 50 associated parasitoid species. The experimental manipulation significantly increased parasitism on B. dracunculifoliae in the treatment plots, but did not significantly alter either the species richness or abundance of other galler species. Compared to control plots, food webs in manipulated plots had significantly lower values of weighted connectance, interaction evenness and robustness (measured as simulated tolerance to secondary extinction), even when B. dracunculifoliae was excluded from calculations. Parasitoid species were almost entirely specialized to individual galler species, so the observed effects of the manipulation on food web structure could not have propagated via the documented trophic links. Instead, they must have spread either through trophic links not included in the webs (e.g. shared predators) or non-trophically (e.g. through changes in habitat availability). Our results highlight that the inclusion of both trophic and non

  19. Abundance, size composition and benthic assemblages of two Mediterranean echinoids off the

    Directory of Open Access Journals (Sweden)

    Elzahrae Elmasry

    2015-12-01

    Full Text Available This study is concerned with the variability in abundance, size composition and benthic assemblages of two echinoid species, the common sea urchin Paracentrotus lividus (Lamarck, 1816 and black urchin Arbacia lixula (Linnaeus, 1758 in the Southeastern Mediterranean (SEM along the coast of Alexandria, Egypt. Four seasonal trips were made during the years 2014–2015 covering 55 km of the shore with depths ranging between 3 and 9 m. The sea urchin species composition, density and size structure and distribution were compared. The associated macrobenthic invertebrates with prominent presence and biomass were observed as well as other benthic fauna and flora associations. The present results showed that P. lividus was the dominant echinoid spatially and temporally. A. lixula showed frequent occurrence in Sidi Bishr and Sidi Gaber stations in the spring season. The most dominant size class was the medium to large-sized classes for P. lividus and large-sized classes for A. lixula. The commercial size for the edible P. lividus represented 33% of the sampled population. Furthermore, the most dominant macrobenthic assemblages beside the echinoid population were primarily oysters, sea cucumbers, and mussels. Beside these, assemblage of seaweeds (red, green, brown and crustose algae, Porifera, Cnidaria, Crustacea, other Echinodermata, Bivalvia, Gastropoda, Tunicata, Bryozoa and Annelida were found. The present study shows that the investigated area represents stable habitats for the echinoid population with rich and diversified algal assemblages as well as other potential food resources.

  20. Early MESSENGER Results for Less Abundant or Weakly Emitting Species in Mercury's Exosphere

    Science.gov (United States)

    Vervack, Ronald J., Jr.; McClintock, William E.; Killen, Rosemary M.; Sprague, Ann L.; Burger, Matthew H.; Merkel, Aimee W.; Sarantos, Menelaos

    2011-01-01

    Now that the Messenger spacecraft is in orbit about Mercury, the extended observing time enables searches for exospheric species that are less abundant or weakly emitting compared with those for which emission has previously been detected. Many of these species cannot be observed from the ground because of terrestrial atmospheric absorption. We report here on the status of MESSENGER orbital-phase searches for additional species in Mercury's exosphere.

  1. Species composition, relative abundance and habitat association of ...

    African Journals Online (AJOL)

    The present study was carried out in Zegie Peninsula and Kibran Gebriel and Entos Iyesus Islands of Lake Tana from August 2006 to March 2007. Sampling sites were stratified based on the vegetation type and area cover. Point count technique and chi-square test were employed to see the association of birds with the ...

  2. Rainfall and Coconut Accession Explain the Composition and Abundance of the Community of Potential Auchenorrhyncha Phytoplasma Vectors in Brazil.

    Science.gov (United States)

    Silva, Flaviana G; Passos, Eliana M; Diniz, Leandro E C; Farias, Adriano P; Teodoro, Adenir V; Fernandes, Marcelo F; Dollet, Michel

    2018-04-05

    Coconut plantations are attacked by the lethal yellowing (LY), which is spreading rapidly with extremely destructive effects in several countries. The disease is caused by phytoplasmas that occur in the plant phloem and are transmitted by Haplaxius crudus (Van Duzee) (Auchenorrhyncha: Cixiidae). Owing to their phloem-sap feeding habit, other planthopper species possibly act as vectors. Here, we aimed at assessing the seasonal variation in the Auchenorrhyncha community in six dwarf coconut accessions. Also, we assessed the relative contribution of biotic (coconut accession) and abiotic (rainfall, temperature) in explaining Auchenorrhyncha composition and abundance. The Auchenorrhyncha community was monthly evaluated for 1 yr using yellow sticky traps. Among the most abundant species, Oecleus sp., Balclutha sp., Deltocephalinae sp.2, Deltocephalinae sp.3, Cenchreini sp., Omolicna nigripennis Caldwell (Derbidae), and Cedusa sp. are potential phytoplasma vectors. The composition of the Auchenorrhyncha community differed between dwarf coconut accessions and periods, namely, in March and April (transition from dry to rainy season) and August (transition from rainy to dry season). In these months, Oecleus sp. was predominantly found in the accessions Cameroon Red Dwarf, Malayan Red Dwarf, and Brazilian Red Dwarf Gramame, while Cenchreini sp. and Bolbonota sp. were dominant in the accessions Brazilian Yellow Dwarf Gramame, Malayan Yellow Dwarf, and Brazilian Green Dwarf Jequi. We conclude that dwarf coconut host several Auchenorrhyncha species potential phytoplasma vectors. Furthermore, coconut accessions could be exploited in breeding programs aiming at prevention of LY. However, rainfall followed by accessions mostly explained the composition and abundance of the Auchenorrhyncha community.

  3. Do abundance distributions and species aggregation correctly predict macroecological biodiversity patterns in tropical forests?

    Science.gov (United States)

    Wiegand, Thorsten; Lehmann, Sebastian; Huth, Andreas; Fortin, Marie‐Josée

    2016-01-01

    Abstract Aim It has been recently suggested that different ‘unified theories of biodiversity and biogeography’ can be characterized by three common ‘minimal sufficient rules’: (1) species abundance distributions follow a hollow curve, (2) species show intraspecific aggregation, and (3) species are independently placed with respect to other species. Here, we translate these qualitative rules into a quantitative framework and assess if these minimal rules are indeed sufficient to predict multiple macroecological biodiversity patterns simultaneously. Location Tropical forest plots in Barro Colorado Island (BCI), Panama, and in Sinharaja, Sri Lanka. Methods We assess the predictive power of the three rules using dynamic and spatial simulation models in combination with census data from the two forest plots. We use two different versions of the model: (1) a neutral model and (2) an extended model that allowed for species differences in dispersal distances. In a first step we derive model parameterizations that correctly represent the three minimal rules (i.e. the model quantitatively matches the observed species abundance distribution and the distribution of intraspecific aggregation). In a second step we applied the parameterized models to predict four additional spatial biodiversity patterns. Results Species‐specific dispersal was needed to quantitatively fulfil the three minimal rules. The model with species‐specific dispersal correctly predicted the species–area relationship, but failed to predict the distance decay, the relationship between species abundances and aggregations, and the distribution of a spatial co‐occurrence index of all abundant species pairs. These results were consistent over the two forest plots. Main conclusions The three ‘minimal sufficient’ rules only provide an incomplete approximation of the stochastic spatial geometry of biodiversity in tropical forests. The assumption of independent interspecific placements is most

  4. Acoustical Scattering, Propagation, and Attenuation Caused by Two Abundant Pacific Schooling Species: Humboldt Squid and Hake

    Science.gov (United States)

    2015-09-30

    an area important for acoustical testing and tactical exercises, the most abundant species by biomass is Pacific hake, Merluccius productus, a fish...scattering characteristics of the animal especially if the animal has eaten hard- shelled mollusc prey. Figure 7. A dorsal scan (similar to an x-ray) of a...kHz echogram. 11 In order to generate abundance and biomass estimates for organisms using active acoustics, one assumption that can be made is

  5. Composition and abundance of the zooplankton community in the ...

    African Journals Online (AJOL)

    The taxonomic composition of the zooplankton community of the Bitter Lakes, Egypt, was examined in 2003–2004 in relation to the spatial and temporal distribution of environmental factors. Copepoda were dominant, forming 49% of the zooplankton, followed by Protista at 37%. During the autumn, zooplankton in Small ...

  6. Evolutionary patterns of range size, abundance and species richness in Amazonian angiosperm trees

    Directory of Open Access Journals (Sweden)

    Kyle Dexter

    2016-09-01

    Full Text Available Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. The drivers of this variation are not well understood. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to contribute to explaining the variation. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics; closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species. Our results suggest that phylogenetically correlated intrinsic factors, namely traits of the genera themselves, shape among lineage variation in range size, abundance and species richness. We postulate that tree stature may be one particularly relevant trait. However, other traits may also be relevant, and our study reinforces the need for ambitious compilations of trait data for Amazonian trees. In the meantime, our study shows how large-scale phylogenies can help to elucidate, and contribute to explaining, macroecological and macroevolutionary patterns in hyperdiverse, yet poorly understood regions like the Amazon Basin.

  7. Composition, abundance and seasonality of fish larvae in the mouth ...

    African Journals Online (AJOL)

    In all, 28 species dependent on estuaries at some stage in their life cycle ... Temperature and salinity accounted for 31% of the variation in larval ... also on ebb tides, suggesting that selective tidal stream transport is a recruitment mechanism ...

  8. Using species abundance distribution models and diversity indices for biogeographical analyses

    Science.gov (United States)

    Fattorini, Simone; Rigal, François; Cardoso, Pedro; Borges, Paulo A. V.

    2016-01-01

    We examine whether Species Abundance Distribution models (SADs) and diversity indices can describe how species colonization status influences species community assembly on oceanic islands. Our hypothesis is that, because of the lack of source-sink dynamics at the archipelago scale, Single Island Endemics (SIEs), i.e. endemic species restricted to only one island, should be represented by few rare species and consequently have abundance patterns that differ from those of more widespread species. To test our hypothesis, we used arthropod data from the Azorean archipelago (North Atlantic). We divided the species into three colonization categories: SIEs, archipelagic endemics (AZEs, present in at least two islands) and native non-endemics (NATs). For each category, we modelled rank-abundance plots using both the geometric series and the Gambin model, a measure of distributional amplitude. We also calculated Shannon entropy and Buzas and Gibson's evenness. We show that the slopes of the regression lines modelling SADs were significantly higher for SIEs, which indicates a relative predominance of a few highly abundant species and a lack of rare species, which also depresses diversity indices. This may be a consequence of two factors: (i) some forest specialist SIEs may be at advantage over other, less adapted species; (ii) the entire populations of SIEs are by definition concentrated on a single island, without possibility for inter-island source-sink dynamics; hence all populations must have a minimum number of individuals to survive natural, often unpredictable, fluctuations. These findings are supported by higher values of the α parameter of the Gambin mode for SIEs. In contrast, AZEs and NATs had lower regression slopes, lower α but higher diversity indices, resulting from their widespread distribution over several islands. We conclude that these differences in the SAD models and diversity indices demonstrate that the study of these metrics is useful for

  9. Estimating Lion Abundance using N-mixture Models for Social Species.

    Science.gov (United States)

    Belant, Jerrold L; Bled, Florent; Wilton, Clay M; Fyumagwa, Robert; Mwampeta, Stanslaus B; Beyer, Dean E

    2016-10-27

    Declining populations of large carnivores worldwide, and the complexities of managing human-carnivore conflicts, require accurate population estimates of large carnivores to promote their long-term persistence through well-informed management We used N-mixture models to estimate lion (Panthera leo) abundance from call-in and track surveys in southeastern Serengeti National Park, Tanzania. Because of potential habituation to broadcasted calls and social behavior, we developed a hierarchical observation process within the N-mixture model conditioning lion detectability on their group response to call-ins and individual detection probabilities. We estimated 270 lions (95% credible interval = 170-551) using call-ins but were unable to estimate lion abundance from track data. We found a weak negative relationship between predicted track density and predicted lion abundance from the call-in surveys. Luminosity was negatively correlated with individual detection probability during call-in surveys. Lion abundance and track density were influenced by landcover, but direction of the corresponding effects were undetermined. N-mixture models allowed us to incorporate multiple parameters (e.g., landcover, luminosity, observer effect) influencing lion abundance and probability of detection directly into abundance estimates. We suggest that N-mixture models employing a hierarchical observation process can be used to estimate abundance of other social, herding, and grouping species.

  10. Some peculiarities of fish abundance, species and sizes distribution, and spacing

    International Nuclear Information System (INIS)

    Astrauskas, A.; Bernotas, E.; Jovaisha, R.

    1995-01-01

    During the construction and exploitation process of Ignalina NPP the abundance of fishes has dropped, and especially stenothermic species (smelt and vendace). The general increase of fish abundance is observed in recent years (1992-1994). This is linked with changes of fish species and their adaptation to the new environmental conditions. Now the partial renovation of vendace abundance is observed, too. It is a result of free feeding recess coming out as the smelt dramatically decreased. Before now the ecosystem of the lake is greatly disbalanced due to antropogenetic impact of the NPP. It's partial stabilisation (but on the essentially high level) is possible only in some generations of fish living in the lake. (author). 18 refs., 1 tab., 11 figs

  11. Dramatic changes in ectomycorrhizal community composition, root tip abundance and mycelial production along a stand-scale nitrogen deposition gradient

    DEFF Research Database (Denmark)

    Kjøller, Rasmus; Nilsson, Lars Ola; Hansen, Karin

    2012-01-01

    • Nitrogen (N) availability is known to influence ectomycorrhizal fungal components, such as fungal community composition, biomass of root tips and production of mycelia, but effects have never been demonstrated within the same forest. • We measured concurrently the abundance of ectomycorrhizal...... root tips and the production of external mycelia, and explored the changes in the ectomycorrhizal community composition, across a stand-scale N deposition gradient (from 27 to 43 kg N ha¿¹ yr¿¹) at the edge of a spruce forest. The N status was affected along the gradient as shown by a range of N...... availability indices. • Ectomycorrhizal root tip abundance and mycelial production decreased five and 10-fold, respectively, with increasing N deposition. In addition, the ectomycorrhizal fungal community changed and the species richness decreased. The changes were correlated with the measured indices of N...

  12. Landscape and Local Correlates of Bee Abundance and Species Richness in Urban Gardens.

    Science.gov (United States)

    Quistberg, Robyn D; Bichier, Peter; Philpott, Stacy M

    2016-03-31

    Urban gardens may preserve biodiversity as urban population densities increase, but this strongly depends on the characteristics of the gardens and the landscapes in which they are embedded. We investigated whether local and landscape characteristics are important correlates of bee (Hymenoptera: Apiformes) abundance and species richness in urban community gardens. We worked in 19 gardens in the California central coast and sampled bees with aerial nets and pan traps. We measured local characteristics (i.e., vegetation and ground cover) and used the USGS National Land Cover Database to classify the landscape surrounding our garden study sites at 2 km scales. We classified bees according to nesting type (i.e., cavity, ground) and body size and determined which local and landscape characteristics correlate with bee community characteristics. We found 55 bee species. One landscape and several local factors correlated with differences in bee abundance and richness for all bees, cavity-nesting bees, ground-nesting bees, and different sized bees. Generally, bees were more abundant and species rich in bigger gardens, in gardens with higher floral abundance, less mulch cover, more bare ground, and with more grass. Medium bees were less abundant in sites surrounded by more medium intensity developed land within 2 km. The fact that local factors were generally more important drivers of bee abundance and richness indicates a potential for gardeners to promote bee conservation by altering local management practices. In particular, increasing floral abundance, decreasing use of mulch, and providing bare ground may promote bees in urban gardens. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Linking nitrogen partitioning and species abundance to invasion resistance in the Great Basin

    Science.gov (United States)

    J. J. James; K. W. Davies; R. L. Sheley; Z. T. Aanderud

    2008-01-01

    Resource partitioning has been suggested as an important mechanism of invasion resistance. The relative importance of resource partitioning for invasion resistance, however, may depend on how species abundance is distributed in the plant community. This study had two objectives. First, we quantified the degree to which one resource, nitrogen (N), is partitioned by time...

  14. Marine litter in the Nordic Seas: Distribution composition and abundance.

    Science.gov (United States)

    Buhl-Mortensen, Lene; Buhl-Mortensen, Pål

    2017-12-15

    Litter has been found in all marine environments and is accumulating in seabirds and mammals in the Nordic Seas. These ecosystems are under pressure from climatic change and fisheries while the human population is small. The marine landscapes in the area range from shallow fishing banks to deep-sea canyons. We present density, distribution and composition of litter from the first large-scale mapping of sea bed litter in arctic and subarctic waters. Litter was registered from 1778 video transects, of which 27% contained litter. The background density of litter in the Barents Sea and Norwegian Sea is 202 and 279 items/km 2 respectively, and highest densities were found close to coast and in canyons. Most of the litter originated from the fishing industry and plastic was the second most common litter. Background levels were comparable to European records and areas with most littering had higher densities than in Europe. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Species abundance distributions in neutral models with immigration or mutation and general lifetimes.

    Science.gov (United States)

    Lambert, Amaury

    2011-07-01

    We consider a general, neutral, dynamical model of biodiversity. Individuals have i.i.d. lifetime durations, which are not necessarily exponentially distributed, and each individual gives birth independently at constant rate λ. Thus, the population size is a homogeneous, binary Crump-Mode-Jagers process (which is not necessarily a Markov process). We assume that types are clonally inherited. We consider two classes of speciation models in this setting. In the immigration model, new individuals of an entirely new species singly enter the population at constant rate μ (e.g., from the mainland into the island). In the mutation model, each individual independently experiences point mutations in its germ line, at constant rate θ. We are interested in the species abundance distribution, i.e., in the numbers, denoted I(n)(k) in the immigration model and A(n)(k) in the mutation model, of species represented by k individuals, k = 1, 2, . . . , n, when there are n individuals in the total population. In the immigration model, we prove that the numbers (I(t)(k); k ≥ 1) of species represented by k individuals at time t, are independent Poisson variables with parameters as in Fisher's log-series. When conditioning on the total size of the population to equal n, this results in species abundance distributions given by Ewens' sampling formula. In particular, I(n)(k) converges as n → ∞ to a Poisson r.v. with mean γ/k, where γ : = μ/λ. In the mutation model, as n → ∞, we obtain the almost sure convergence of n (-1) A(n)(k) to a nonrandom explicit constant. In the case of a critical, linear birth-death process, this constant is given by Fisher's log-series, namely n(-1) A(n)(k) converges to α(k)/k, where α : = λ/(λ + θ). In both models, the abundances of the most abundant species are briefly discussed.

  16. Weed-Species Abundance and Diversity Indices in Relation to Tillage Systems and Fertilization

    Directory of Open Access Journals (Sweden)

    Ilias S. Travlos

    2018-04-01

    Full Text Available Weeds pose a major threat to world agriculture by reducing detrimentally crop yield and quality. However, at the same time, weeds are major interacting components of the agroecosystems. Abundance and diversity of weeds vary significantly among the several communities. In order to evaluate each community's structure and the interactions among them, several population indices are used as key tools. In parallel, various cultivation and land management strategies, such as tillage and fertilization, are commonly used in terms of integrated weed management. Estimating the response of weed species on those practices is crucial for both biodiversity maintenance and alternative weed control methods. Many experiments have confirmed the fundamental role of tillage intensity and nutrition supply in weed species' abundance and diversity. For instance, in some studies, the abundance of perennial weeds was doubled under reduced tillage intensity. In addition, higher values of Shannon-Weiner and Pielou indices were reported in the PK fertilization treatment compared to the control and NK fertilization treatments. The objective of this paper is to provide a brief overview of the key results of these experiments and summarize the part of the literature related to the effect of tillage systems and fertilization on weed species abundance and diversity. Such knowledge could contribute to the sound design and implementation of integrated weed management programs which in turn may lead to a decrease in the density of serious and noxious weeds and an increase in the overall balance of agroecosystems.

  17. Species composition and bathymetric distribution of gorgonians (Anthozoa: Octocorallia on the Southern Mexican Pacific coast

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    Rosalinda Abeytia

    2013-09-01

    Full Text Available Gorgonians are important components of coastal ecosystems, as they provide niches, natural compounds with medical applications and are used as bioindicators. Species composition and assemblage structure of gorgonians (Anthozoa: Octocorallia were studied along a bathymetric profile in the Southern Mexican Pacific coast. Species composition was based on specimens collected within a depth range of 0-70m in 15 sites. The relative abundance of species was determined in six sites at four depths (5, 10, 20 and 25m using three 10m2 transects at each depth level. Twenty-seven species of gorgonians belonging to six genera and three families were registered. The species composition varied with depth: 11 species were distributed between 0-25m depth, while 17 species were found between 40-70m depth interval. The shallow zone is characterized by a relatively large abundance of gorgonians, dominated by colonies of Leptogorgia cuspidata and L. ena. In contrast, the deepest zone was characterized by relatively low abundance of gorgonians, dominated by L. alba, the only species observed in both depth intervals. The similarity analysis showed differences in the composition and abundance of species by depth and site, suggesting that the main factor in determining the assemblage structure is depth. Results of this study suggest that the highest richness of gorgonian species in the study area may be located at depths of 40-70m, whereas the highest abundances are found between 5 and 10m depth. This study represents a contribution to the poorly known eastern Pacific gorgonian biota.

  18. External Morphology of Adult Citrus Butterfly, Papilio memnon (Linnaeus, 1758) and Seasonal Abundance of the Species

    International Nuclear Information System (INIS)

    Ni Ni Win

    2005-10-01

    Sexual dimorphism is obvious in Papilio memnon. The female adult resembles that of Papilio polytes another citrus butterfly species. However, marked difference is observed in the size and red spots on the base of the forewing. The adult male P. memnon is blue black in colour and red spots are present on the base of the underside of both for and hind wings. The win span of sexes ranges from 120mm to 150mm. The breeding season is from end of June to early part of January, the peak being in the month of November. The recorded diagnostic external features of this studied species are described supported by scaled photographs. Seasonal abundance of this species is also mentioned. It is learnt through the internet that a mounted specimen of this species fetched $2.95 in Malaysia. It is therefore concluded that successful rearing of this species in captivity could be of benefit to the country.

  19. The effect of peatland drainage and restoration on Odonata species richness and abundance.

    Science.gov (United States)

    Elo, Merja; Penttinen, Jouni; Kotiaho, Janne S

    2015-04-09

    Restoration aims at reversing the trend of habitat degradation, the major threat to biodiversity. In Finland, more than half of the original peatland area has been drained, and during recent years, restoration of some of the drained peatlands has been accomplished. Short-term effects of the restoration on peatland hydrology, chemistry and vegetation are promising but little is known about how other species groups apart from vascular plants and bryophytes respond to restoration efforts. Here, we studied how abundance and species richness of Odonata (dragonflies and damselflies) respond to restoration. We sampled larvae in three sites (restored, drained, pristine) on each of 12 different study areas. We sampled Odonata larvae before restoration (n = 12), during the first (n = 10) and the third (n = 7) year after restoration and used generalized linear mixed models to analyze the effect of restoration. Drained sites had lower abundance and species richness than pristine sites. During the third year after restoration both abundance and species richness had risen in restored sites. Our results show that Odonata suffer from drainage, but seem to benefit from peatland restoration and are able to colonize newly formed water pools already within three years after restoration.

  20. Diversity of sand flies in domiciliary environment of Santarém, state of Pará, Brazil: species composition and abundance patterns in rural and urban areas Diversidade de flebotomíneos no ambiente domiciliar de Santarém, estado do Pará, Brazil: composição de espécies e padrões de abundância em áreas urbanas e rurais

    Directory of Open Access Journals (Sweden)

    Marlisson Augusto Costa Feitosa

    2012-01-01

    Full Text Available This paper aimed to evaluate the richness, abundance and frequency of sand fly occurrence in rural and urban areas American visceral Leishmaniasis -AVL is endemic in the study area of Santarém municipality, Pará state. Sand flies were collected during 1995-2000, using CDC light traps placed in neighborhoods and rural areas of the municipality. A total of 53.454 individuals and 26 species of sand flies were collected. The most abundant species in both urban and rural environments was Lutzomyia longipalpis, vector of AVL in the area. The highest species richness by capture was in rural area. In all years sampled, the largest number of species of sand fly collected was always in rural areas. The species of sand flies in urban and rural area were similar in 11 species. In the rural area other 11 species were found, a total of 22 species. Shannon-Wiener index ranged from 0.12 to 0.84 at rural areas and 0.08 to 0.34 at urban ones. In general, rural localities showed higher diversity (H' of phlebotomines than urban ones. Individual-based rarefaction curves for each area demonstrated that urban localities had the lowest expected number of phlebotomine species and the richest rural ones reach higher expected values with lower amount of individuals than urban sites. The most frequent species were Lutzomyia longipalpis, Evandromyia carmelinoi and Bichromomyia flaviscutellata.Com o objetivo de comparar a riqueza, abundância e freqüência de ocorrência de flebotomíneos em sítios rurais e urbanos numa área endêmica de leishmaniose visceral no município de Santarém (PA foi realizado no período entre 1995-2000, capturas de flebotomíneos por meio de armadilhas luminosas CDC montadas no ambiente domiciliar em diferentes bairros e localidades rurais do município. Foram capturados 53.454 indivíduos, de 26 espécies e dentre elas, a mais abundante, tanto em ambiente urbano e rural, foi Lutzomyia longipalpis, vetor da leishmaniose visceral americana na

  1. Estimating species – area relationships by modeling abundance and frequency subject to incomplete sampling

    Science.gov (United States)

    Yamaura, Yuichi; Connor, Edward F.; Royle, Andy; Itoh, Katsuo; Sato, Kiyoshi; Taki, Hisatomo; Mishima, Yoshio

    2016-01-01

    Models and data used to describe species–area relationships confound sampling with ecological process as they fail to acknowledge that estimates of species richness arise due to sampling. This compromises our ability to make ecological inferences from and about species–area relationships. We develop and illustrate hierarchical community models of abundance and frequency to estimate species richness. The models we propose separate sampling from ecological processes by explicitly accounting for the fact that sampled patches are seldom completely covered by sampling plots and that individuals present in the sampling plots are imperfectly detected. We propose a multispecies abundance model in which community assembly is treated as the summation of an ensemble of species-level Poisson processes and estimate patch-level species richness as a derived parameter. We use sampling process models appropriate for specific survey methods. We propose a multispecies frequency model that treats the number of plots in which a species occurs as a binomial process. We illustrate these models using data collected in surveys of early-successional bird species and plants in young forest plantation patches. Results indicate that only mature forest plant species deviated from the constant density hypothesis, but the null model suggested that the deviations were too small to alter the form of species–area relationships. Nevertheless, results from simulations clearly show that the aggregate pattern of individual species density–area relationships and occurrence probability–area relationships can alter the form of species–area relationships. The plant community model estimated that only half of the species present in the regional species pool were encountered during the survey. The modeling framework we propose explicitly accounts for sampling processes so that ecological processes can be examined free of sampling artefacts. Our modeling approach is extensible and could be applied

  2. The impact of land abandonment on species richness and abundance in the Mediterranean Basin

    DEFF Research Database (Denmark)

    Plieninger, Tobias; Hui, Cang; Gaertner, Mirijam

    2014-01-01

    species richness and abundance in agroforestry, arable land, pastures, and permanent crops of the Mediterranean Basin. In particular, we investigated (1) which taxonomic groups (arthropods, birds, lichen, vascular plants) are more affected by land abandonment; (2) at which spatial and temporal scales.......0001) plant and animal species richness and abundance overall, though results were heterogeneous, with differences in effect size between taxa, spatial-temporal scales, land uses, landforms, and climate. In conclusion, there is no "one-size-fits-all" conservation approach that applies to the diverse contexts......Land abandonment is common in the Mediterranean Basin, a global biodiversity hotspot, but little is known about its impacts on biodiversity. To upscale existing case-study insights to the Pan-Mediterranean level, we conducted a metaanalysis of the effects of land abandonment on plant and animal...

  3. Relationships between water transparency and abundance of Cynodontidae species in the Bananal floodplain, Mato Grosso, Brazil

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    Cesar Enrique de Melo

    Full Text Available The Cerrado in the Central Brazil is currently one of the most threatened ecosystems in the world. As a result, the aquatic habitats in this biome also undergo great impacts. Alterations related to land-use change increase sediment loadings in rivers, streams and lakes, resulting in sedimentation and decrease in water transparency. Water transparency determines underwater visibility conditions, and as a consequence fish assemblages respond to spatial and temporal changes in this variable. This work aimed to examine the influence of transparency on the abundance and distribution of Cynodontidae species, a visually oriented predatory fish group. Fish sampling was conducted in 15 sites located between Mortes and Araguaia rivers in the Bananal floodplain, Mato Grosso State. Regression analysis between relative abundance of Cynodontidae (in number of individuals and biomass and water transparency showed a positive and highly significant correlation, indicating that this group shows species-specific habitat affinities for clearer waters. These results suggest that the increase in water turbidity in this region can affect the patterns of abundance and distribution of the Cynodontidae species, as well as other visually oriented fishes.

  4. Microbial abundance in rhizosphere of medicinal and aromatic plant species in conventional and organic growing systems

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    Adamović Dušan

    2015-01-01

    Full Text Available This study was aimed at comparing the abundance of microorganisms in the rhizosphere of four different medicinal and aromatic plant species (basil, mint, dill and marigold grown under both conventional and organic management on the chernozem soil at the experimental field of Bački Petrovac (Institute of Field and Vegetable Crops, Novi Sad, Serbia. Two sampling terms (June 1 and July 18, 2012 were performed to collect samples for microbiological analyses. The microbial abundance was higher in organic than in conventional system while at the same time significant differences were obtained only with dill rhizosphere. The differences in number of microorganisms belonging to different groups relied upon both plant species and sampling term. Thus, in mint, the recorded number of azotobacters and fungi was significantly higher whereas the number of ammonifiers was significantly lower. The present results indicate that organic growing system affected the abundance of microorganisms in rhizosphere of species investigated, especially in the second term of sampling.

  5. Sampling designs matching species biology produce accurate and affordable abundance indices.

    Science.gov (United States)

    Harris, Grant; Farley, Sean; Russell, Gareth J; Butler, Matthew J; Selinger, Jeff

    2013-01-01

    Wildlife biologists often use grid-based designs to sample animals and generate abundance estimates. Although sampling in grids is theoretically sound, in application, the method can be logistically difficult and expensive when sampling elusive species inhabiting extensive areas. These factors make it challenging to sample animals and meet the statistical assumption of all individuals having an equal probability of capture. Violating this assumption biases results. Does an alternative exist? Perhaps by sampling only where resources attract animals (i.e., targeted sampling), it would provide accurate abundance estimates more efficiently and affordably. However, biases from this approach would also arise if individuals have an unequal probability of capture, especially if some failed to visit the sampling area. Since most biological programs are resource limited, and acquiring abundance data drives many conservation and management applications, it becomes imperative to identify economical and informative sampling designs. Therefore, we evaluated abundance estimates generated from grid and targeted sampling designs using simulations based on geographic positioning system (GPS) data from 42 Alaskan brown bears (Ursus arctos). Migratory salmon drew brown bears from the wider landscape, concentrating them at anadromous streams. This provided a scenario for testing the targeted approach. Grid and targeted sampling varied by trap amount, location (traps placed randomly, systematically or by expert opinion), and traps stationary or moved between capture sessions. We began by identifying when to sample, and if bears had equal probability of capture. We compared abundance estimates against seven criteria: bias, precision, accuracy, effort, plus encounter rates, and probabilities of capture and recapture. One grid (49 km(2) cells) and one targeted configuration provided the most accurate results. Both placed traps by expert opinion and moved traps between capture sessions

  6. Sampling designs matching species biology produce accurate and affordable abundance indices

    Directory of Open Access Journals (Sweden)

    Grant Harris

    2013-12-01

    Full Text Available Wildlife biologists often use grid-based designs to sample animals and generate abundance estimates. Although sampling in grids is theoretically sound, in application, the method can be logistically difficult and expensive when sampling elusive species inhabiting extensive areas. These factors make it challenging to sample animals and meet the statistical assumption of all individuals having an equal probability of capture. Violating this assumption biases results. Does an alternative exist? Perhaps by sampling only where resources attract animals (i.e., targeted sampling, it would provide accurate abundance estimates more efficiently and affordably. However, biases from this approach would also arise if individuals have an unequal probability of capture, especially if some failed to visit the sampling area. Since most biological programs are resource limited, and acquiring abundance data drives many conservation and management applications, it becomes imperative to identify economical and informative sampling designs. Therefore, we evaluated abundance estimates generated from grid and targeted sampling designs using simulations based on geographic positioning system (GPS data from 42 Alaskan brown bears (Ursus arctos. Migratory salmon drew brown bears from the wider landscape, concentrating them at anadromous streams. This provided a scenario for testing the targeted approach. Grid and targeted sampling varied by trap amount, location (traps placed randomly, systematically or by expert opinion, and traps stationary or moved between capture sessions. We began by identifying when to sample, and if bears had equal probability of capture. We compared abundance estimates against seven criteria: bias, precision, accuracy, effort, plus encounter rates, and probabilities of capture and recapture. One grid (49 km2 cells and one targeted configuration provided the most accurate results. Both placed traps by expert opinion and moved traps between capture

  7. Sampling designs matching species biology produce accurate and affordable abundance indices

    Science.gov (United States)

    Farley, Sean; Russell, Gareth J.; Butler, Matthew J.; Selinger, Jeff

    2013-01-01

    Wildlife biologists often use grid-based designs to sample animals and generate abundance estimates. Although sampling in grids is theoretically sound, in application, the method can be logistically difficult and expensive when sampling elusive species inhabiting extensive areas. These factors make it challenging to sample animals and meet the statistical assumption of all individuals having an equal probability of capture. Violating this assumption biases results. Does an alternative exist? Perhaps by sampling only where resources attract animals (i.e., targeted sampling), it would provide accurate abundance estimates more efficiently and affordably. However, biases from this approach would also arise if individuals have an unequal probability of capture, especially if some failed to visit the sampling area. Since most biological programs are resource limited, and acquiring abundance data drives many conservation and management applications, it becomes imperative to identify economical and informative sampling designs. Therefore, we evaluated abundance estimates generated from grid and targeted sampling designs using simulations based on geographic positioning system (GPS) data from 42 Alaskan brown bears (Ursus arctos). Migratory salmon drew brown bears from the wider landscape, concentrating them at anadromous streams. This provided a scenario for testing the targeted approach. Grid and targeted sampling varied by trap amount, location (traps placed randomly, systematically or by expert opinion), and traps stationary or moved between capture sessions. We began by identifying when to sample, and if bears had equal probability of capture. We compared abundance estimates against seven criteria: bias, precision, accuracy, effort, plus encounter rates, and probabilities of capture and recapture. One grid (49 km2 cells) and one targeted configuration provided the most accurate results. Both placed traps by expert opinion and moved traps between capture sessions, which

  8. Fatty acids composition of 10 microalgal species

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    Thidarat Noiraksar

    2005-11-01

    Full Text Available Fatty acids composition of 10 species of microalgae was determined at the exponential phase and the stationary phase. The microalgae consist of two species of diatoms, Bacillariophyceae, (Nitzschia cf. ovalis, Thalassiosira sp. five species of green microalgae, Prasinophyceae (Tetraselmis sp. and Chlorophyceae, (Dictyosphaerium pulchellum, Stichococcus sp., Chlorella sp., Scenedesmus falcatus and three species of blue green microalgae, Cyanophyceae (Anacystis sp., Synechococcus sp., Synechocystis sp..Medium for culture diatoms and green microalgae was F/2, and BG-11 media was used for Cyanophyceae. The microalgae were cultured beneath light intensity 143 μEm-2s-1, light: dark illustration 12:12 hrs., temperature 28ºC, and salinities 8-30 psu. The microalgae were harvested for analyzing fatty acid by centrivugal machine at 3500 rpm. for 5 min. at temperature 20ºC and stored at -80ºC prior to analysis.Fatty acids composition of microalgae differed from species to species. The majority fatty acids composition of diatoms at the exponential phase and the stationary phase were C16:1n-7 (17.12-31.47% and 28.22-42.02%, C16:0 (13.25-19.61% and 18.83-20.67%, C20:5 n-3 (16.65-26.67% and 11.32-23.68% respectively. The principle fatty acids composition of green microalgae, Prasinophyceae, Tetraselmis sp. were C18:3n-3 (16.17-16.67%, C16:0 (15.33-17.45%, C18:1n-9 (12.25-15.43%, C18:2n-6 (9.66-19.97%. The fatty acids composition of green microalgae, Chlorophyceae, were C18:3 n-3 (20.02-26.49% and 15.35- 30.63%, C16:0 (5.76-17.61% and 11.41-20.03%, C18:2n-6 (4.67-17.54% and 7.48-20.61% respectively. The major amounts of fatty acids content of blue green microalgae were C16:1n-7 (9.28-34.91% and 34.48- 35.04%, C14:0 (13.34-25.96% and 26.69-28.24%, C16:0 (5.89-29.15% and 5.70-16.81% except for Anacystis sp.which had a high amount of C18:3 n-3 (23.18-27.98% but low amount of C14:0 (3.66-4.98%.Bacillariophyceae contained the highest amount of highly unsaturated

  9. Species richness and relative abundance of birds in natural and anthropogenic fragments of Brazilian Atlantic forest

    Directory of Open Access Journals (Sweden)

    Luiz dos Anjos

    2004-06-01

    Full Text Available Bird communities were studied in two types of fragmented habitat of Atlantic forest in the State of Paraná, southern Brazil; one consisted of forest fragments that were created as a result of human activities (forest remnants, the other consisted of a set of naturally occurring forest fragments (forest patches. Using quantitative data obtained by the point counts method in 3 forest patches and 3 forest remnants during one year, species richness and relative abundance were compared in those habitats, considering species groups according to their general feeding habits. Insectivores, omnivores, and frugivores presented similar general tendencies in both habitats (decrease of species number with decreasing size and increasing isolation of forest fragment. However, these tendencies were different, when considering the relative abundance data: the trunk insectivores presented the highest value in the smallest patch while the lowest relative abundance was in the smallest remnant. In the naturally fragmented landscape, time permitted that the loss of some species of trunk insectivores be compensated for the increase in abundance of other species. In contrast, the remnants essentially represented newly formed islands that are not yet at equilibrium and where future species losses would make them similar to the patches.Comunidades de aves foram estudadas em duas regiões fragmentadas de floresta Atlântica no Estado do Paraná, sul do Brasil; uma região é constituída de fragmentos florestais que foram criados como resultado de atividades humanas (remanescentes florestais e a outra de um conjunto de fragmentos florestais naturais (manchas de floresta. Usando dados quantitativos (o método de contagens pontuais previamente obtidos em 3 manchas de floresta e em 3 remanescentes florestais durante um ano, a riqueza e a abundância relativa de aves foram comparadas naqueles habitats considerando as espécies pelos seus hábitos alimentares. Inset

  10. Diatom species abundance and morphologically-based dissolution proxies in coastal Southern Ocean assemblages

    Science.gov (United States)

    Warnock, Jonathan P.; Scherer, Reed P.

    2015-07-01

    Taphonomic processes alter diatom assemblages in sediments, thus potentially negatively impacting paleoclimate records at various rates across space, time, and taxa. However, quantitative taphonomic data is rarely included in diatom-based paleoenvironmental reconstructions and no objective standard exists for comparing diatom dissolution in sediments recovered from marine depositional settings, including the Southern Ocean's opal belt. Furthermore, identifying changes to diatom dissolution through time can provide insight into the efficiency of both upper water column nutrient recycling and the biological pump. This is significant in that reactive metal proxies (e.g. Al, Ti) in the sediments only account for post-depositional dissolution, not the water column where the majority of dissolution occurs. In order to assess the range of variability of responses to dissolution in a typical Southern Ocean diatom community and provide a quantitative guideline for assessing taphonomic variability in diatoms recovered from core material, a sediment trap sample was subjected to controlled, serial dissolution. By evaluating dissolution-induced changes to diatom species' relative abundance, three preservational categories of diatoms have been identified: gracile, intermediate, and robust. The relative abundances of these categories can be used to establish a preservation grade for diatom assemblages. However, changes to the relative abundances of diatom species in sediment samples may reflect taphonomic or ecological factors. In order to address this complication, relative abundance changes have been tied to dissolution-induced morphological change to the areolae of Fragilariopsis curta, a significant sea-ice indicator in Southern Ocean sediments. This correlation allows differentiation between gracile species loss to dissolution versus ecological factors or sediment winnowing. These results mirror a similar morphological dissolution index from a parallel study utilizing

  11. Facilitation influences patterns of perennial species abundance and richness in a subtropical dune system.

    Science.gov (United States)

    Dalotto, Cecilia E S; Sühs, Rafael B; Dechoum, Michele S; Pugnaire, Francisco I; Peroni, Nivaldo; Castellani, Tânia T

    2018-04-01

    Positive interactions in plant communities are under-reported in subtropical systems most likely because they are not identified as stressful environments. However, environmental factors or disturbance can limit plant growth in any system and lead to stressful conditions. For instance, salinity and low nutrient and water availability generate a gradient of stressful conditions in coastal systems depending on distance to shore. In a tropical coastal system in SE Brazil, we aimed to assess whether Guapira opposita , a shrub common in restinga environments, acted as nurse involved in ecological succession and which factors influenced its facilitation process. We sampled perennial species above 10 cm in height under the canopy of 35 G. opposita individuals and in neighbouring open areas. Shrub height, canopy area and distance to freshwater bodies were measured in the field, and distance to the ocean was obtained from aerial images. In addition, we measured the distance to the closest forest patch as a potential source of seeds. Plant abundance and species richness were higher under the canopy of G. opposita than in open areas. Facilitation by G. opposita was mainly determined by shrub height, which had a positive relationship with woody and bromeliads abundance and species richness while there was no relationship with the other factors. Overall, our data evidence that tropical environments may be highly stressful for plants and that nurse species play a key role in the regeneration of restinga environments, where their presence is critical to maintain ecosystem diversity and function.

  12. Epidemic disease decimates amphibian abundance, species diversity, and evolutionary history in the highlands of central Panama.

    Science.gov (United States)

    Crawford, Andrew J; Lips, Karen R; Bermingham, Eldredge

    2010-08-03

    Amphibian populations around the world are experiencing unprecedented declines attributed to a chytrid fungal pathogen, Batrachochytrium dendrobatidis. Despite the severity of the crisis, quantitative analyses of the effects of the epidemic on amphibian abundance and diversity have been unavailable as a result of the lack of equivalent data collected before and following disease outbreak. We present a community-level assessment combining long-term field surveys and DNA barcode data describing changes in abundance and evolutionary diversity within the amphibian community of El Copé, Panama, following a disease epidemic and mass-mortality event. The epidemic reduced taxonomic, lineage, and phylogenetic diversity similarly. We discovered that 30 species were lost, including five undescribed species, representing 41% of total amphibian lineage diversity in El Copé. These extirpations represented 33% of the evolutionary history of amphibians within the community, and variation in the degree of population loss and decline among species was random with respect to the community phylogeny. Our approach provides a fast, economical, and informative analysis of loss in a community whether measured by species or phylogenetic diversity.

  13. Facilitation influences patterns of perennial species abundance and richness in a subtropical dune system

    Science.gov (United States)

    Dalotto, Cecilia E S; Sühs, Rafael B; Dechoum, Michele S; Pugnaire, Francisco I; Peroni, Nivaldo; Castellani, Tânia T

    2018-01-01

    Abstract Positive interactions in plant communities are under-reported in subtropical systems most likely because they are not identified as stressful environments. However, environmental factors or disturbance can limit plant growth in any system and lead to stressful conditions. For instance, salinity and low nutrient and water availability generate a gradient of stressful conditions in coastal systems depending on distance to shore. In a tropical coastal system in SE Brazil, we aimed to assess whether Guapira opposita, a shrub common in restinga environments, acted as nurse involved in ecological succession and which factors influenced its facilitation process. We sampled perennial species above 10 cm in height under the canopy of 35 G. opposita individuals and in neighbouring open areas. Shrub height, canopy area and distance to freshwater bodies were measured in the field, and distance to the ocean was obtained from aerial images. In addition, we measured the distance to the closest forest patch as a potential source of seeds. Plant abundance and species richness were higher under the canopy of G. opposita than in open areas. Facilitation by G. opposita was mainly determined by shrub height, which had a positive relationship with woody and bromeliads abundance and species richness while there was no relationship with the other factors. Overall, our data evidence that tropical environments may be highly stressful for plants and that nurse species play a key role in the regeneration of restinga environments, where their presence is critical to maintain ecosystem diversity and function. PMID:29644027

  14. Parametric scaling from species relative abundances to absolute abundances in the computation of biological diversity: a first proposal using Shannon's entropy.

    Science.gov (United States)

    Ricotta, Carlo

    2003-01-01

    Traditional diversity measures such as the Shannon entropy are generally computed from the species' relative abundance vector of a given community to the exclusion of species' absolute abundances. In this paper, I first mention some examples where the total information content associated with a given community may be more adequate than Shannon's average information content for a better understanding of ecosystem functioning. Next, I propose a parametric measure of statistical information that contains both Shannon's entropy and total information content as special cases of this more general function.

  15. Variation in Population Synchrony in a Multi-Species Seabird Community: Response to Changes in Predator Abundance.

    Directory of Open Access Journals (Sweden)

    Gail S Robertson

    Full Text Available Ecologically similar sympatric species, subject to typical environmental conditions, may be expected to exhibit synchronous temporal fluctuations in demographic parameters, while populations of dissimilar species might be expected to show less synchrony. Previous studies have tested for synchrony in different populations of single species, and those including data from more than one species have compared fluctuations in only one demographic parameter. We tested for synchrony in inter-annual changes in breeding population abundance and productivity among four tern species on Coquet Island, northeast England. We also examined how manipulation of one independent environmental variable (predator abundance influenced temporal changes in ecologically similar and dissimilar tern species. Changes in breeding abundance and productivity of ecologically similar species (Arctic Sterna paradisaea, Common S. hirundo and Roseate Terns S. dougallii were synchronous with one another over time, but not with a species with different foraging and breeding behaviour (Sandwich Terns Thalasseus sandvicensis. With respect to changes in predator abundance, there was no clear pattern. Roseate Tern abundance was negatively correlated with that of large gulls breeding on the island from 1975 to 2013, while Common Tern abundance was positively correlated with number of large gulls, and no significant correlations were found between large gull and Arctic and Sandwich Tern populations. Large gull abundance was negatively correlated with productivity of Arctic and Common Terns two years later, possibly due to predation risk after fledging, while no correlation with Roseate Tern productivity was found. The varying effect of predator abundance is most likely due to specific differences in the behaviour and ecology of even these closely-related species. Examining synchrony in multi-species assemblages improves our understanding of how whole communities react to long-term changes

  16. Species Distribution Modelling: Contrasting presence-only models with plot abundance data.

    Science.gov (United States)

    Gomes, Vitor H F; IJff, Stéphanie D; Raes, Niels; Amaral, Iêda Leão; Salomão, Rafael P; de Souza Coelho, Luiz; de Almeida Matos, Francisca Dionízia; Castilho, Carolina V; de Andrade Lima Filho, Diogenes; López, Dairon Cárdenas; Guevara, Juan Ernesto; Magnusson, William E; Phillips, Oliver L; Wittmann, Florian; de Jesus Veiga Carim, Marcelo; Martins, Maria Pires; Irume, Mariana Victória; Sabatier, Daniel; Molino, Jean-François; Bánki, Olaf S; da Silva Guimarães, José Renan; Pitman, Nigel C A; Piedade, Maria Teresa Fernandez; Mendoza, Abel Monteagudo; Luize, Bruno Garcia; Venticinque, Eduardo Martins; de Leão Novo, Evlyn Márcia Moraes; Vargas, Percy Núñez; Silva, Thiago Sanna Freire; Manzatto, Angelo Gilberto; Terborgh, John; Reis, Neidiane Farias Costa; Montero, Juan Carlos; Casula, Katia Regina; Marimon, Beatriz S; Marimon, Ben-Hur; Coronado, Euridice N Honorio; Feldpausch, Ted R; Duque, Alvaro; Zartman, Charles Eugene; Arboleda, Nicolás Castaño; Killeen, Timothy J; Mostacedo, Bonifacio; Vasquez, Rodolfo; Schöngart, Jochen; Assis, Rafael L; Medeiros, Marcelo Brilhante; Simon, Marcelo Fragomeni; Andrade, Ana; Laurance, William F; Camargo, José Luís; Demarchi, Layon O; Laurance, Susan G W; de Sousa Farias, Emanuelle; Nascimento, Henrique Eduardo Mendonça; Revilla, Juan David Cardenas; Quaresma, Adriano; Costa, Flavia R C; Vieira, Ima Célia Guimarães; Cintra, Bruno Barçante Ladvocat; Castellanos, Hernán; Brienen, Roel; Stevenson, Pablo R; Feitosa, Yuri; Duivenvoorden, Joost F; Aymard C, Gerardo A; Mogollón, Hugo F; Targhetta, Natalia; Comiskey, James A; Vicentini, Alberto; Lopes, Aline; Damasco, Gabriel; Dávila, Nállarett; García-Villacorta, Roosevelt; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Emilio, Thaise; Alonso, Alfonso; Neill, David; Dallmeier, Francisco; Ferreira, Leandro Valle; Araujo-Murakami, Alejandro; Praia, Daniel; do Amaral, Dário Dantas; Carvalho, Fernanda Antunes; de Souza, Fernanda Coelho; Feeley, Kenneth; Arroyo, Luzmila; Pansonato, Marcelo Petratti; Gribel, Rogerio; Villa, Boris; Licona, Juan Carlos; Fine, Paul V A; Cerón, Carlos; Baraloto, Chris; Jimenez, Eliana M; Stropp, Juliana; Engel, Julien; Silveira, Marcos; Mora, Maria Cristina Peñuela; Petronelli, Pascal; Maas, Paul; Thomas-Caesar, Raquel; Henkel, Terry W; Daly, Doug; Paredes, Marcos Ríos; Baker, Tim R; Fuentes, Alfredo; Peres, Carlos A; Chave, Jerome; Pena, Jose Luis Marcelo; Dexter, Kyle G; Silman, Miles R; Jørgensen, Peter Møller; Pennington, Toby; Di Fiore, Anthony; Valverde, Fernando Cornejo; Phillips, Juan Fernando; Rivas-Torres, Gonzalo; von Hildebrand, Patricio; van Andel, Tinde R; Ruschel, Ademir R; Prieto, Adriana; Rudas, Agustín; Hoffman, Bruce; Vela, César I A; Barbosa, Edelcilio Marques; Zent, Egleé L; Gonzales, George Pepe Gallardo; Doza, Hilda Paulette Dávila; de Andrade Miranda, Ires Paula; Guillaumet, Jean-Louis; Pinto, Linder Felipe Mozombite; de Matos Bonates, Luiz Carlos; Silva, Natalino; Gómez, Ricardo Zárate; Zent, Stanford; Gonzales, Therany; Vos, Vincent A; Malhi, Yadvinder; Oliveira, Alexandre A; Cano, Angela; Albuquerque, Bianca Weiss; Vriesendorp, Corine; Correa, Diego Felipe; Torre, Emilio Vilanova; van der Heijden, Geertje; Ramirez-Angulo, Hirma; Ramos, José Ferreira; Young, Kenneth R; Rocha, Maira; Nascimento, Marcelo Trindade; Medina, Maria Natalia Umaña; Tirado, Milton; Wang, Ophelia; Sierra, Rodrigo; Torres-Lezama, Armando; Mendoza, Casimiro; Ferreira, Cid; Baider, Cláudia; Villarroel, Daniel; Balslev, Henrik; Mesones, Italo; Giraldo, Ligia Estela Urrego; Casas, Luisa Fernanda; Reategui, Manuel Augusto Ahuite; Linares-Palomino, Reynaldo; Zagt, Roderick; Cárdenas, Sasha; Farfan-Rios, William; Sampaio, Adeilza Felipe; Pauletto, Daniela; Sandoval, Elvis H Valderrama; Arevalo, Freddy Ramirez; Huamantupa-Chuquimaco, Isau; Garcia-Cabrera, Karina; Hernandez, Lionel; Gamarra, Luis Valenzuela; Alexiades, Miguel N; Pansini, Susamar; Cuenca, Walter Palacios; Milliken, William; Ricardo, Joana; Lopez-Gonzalez, Gabriela; Pos, Edwin; Ter Steege, Hans

    2018-01-17

    Species distribution models (SDMs) are widely used in ecology and conservation. Presence-only SDMs such as MaxEnt frequently use natural history collections (NHCs) as occurrence data, given their huge numbers and accessibility. NHCs are often spatially biased which may generate inaccuracies in SDMs. Here, we test how the distribution of NHCs and MaxEnt predictions relates to a spatial abundance model, based on a large plot dataset for Amazonian tree species, using inverse distance weighting (IDW). We also propose a new pipeline to deal with inconsistencies in NHCs and to limit the area of occupancy of the species. We found a significant but weak positive relationship between the distribution of NHCs and IDW for 66% of the species. The relationship between SDMs and IDW was also significant but weakly positive for 95% of the species, and sensitivity for both analyses was high. Furthermore, the pipeline removed half of the NHCs records. Presence-only SDM applications should consider this limitation, especially for large biodiversity assessments projects, when they are automatically generated without subsequent checking. Our pipeline provides a conservative estimate of a species' area of occupancy, within an area slightly larger than its extent of occurrence, compatible to e.g. IUCN red list assessments.

  17. Does mechanical disturbance affect the performance and species composition of submerged macrophyte communities?

    Science.gov (United States)

    Zhang, Qian; Xu, Ying-Shou; Huang, Lin; Xue, Wei; Sun, Gong-Qi; Zhang, Ming-Xiang; Yu, Fei-Hai

    2014-05-01

    Submerged macrophyte communities are frequently subjected to disturbance of various frequency and strength. However, there is still little experimental evidence on how mechanical disturbance affects the performance and species composition of such plant communities. In a greenhouse experiment, we constructed wetland communities consisting of five co-occurring clonal submerged macrophyte species (Hydrilla verticillata, Elodea canadensis, Ceratophyllum demersum, Chara fragilis, and Myriophyllum spicatum) and subjected these communities to three mechanical disturbance regimes (no, moderate and strong disturbance). Strong mechanical disturbance greatly decreased overall biomass, number of shoot nodes and total shoot length, and increased species diversity (evenness) of the total community. It also substantially decreased the growth of the most abundant species (H. verticillata), but did not affect growth of the other four species. Our data reveal that strong disturbance can have different effects on different submerged macrophyte species and thus alters the performance and species composition of submerged macrophyte communities.

  18. Microbial Distribution and Abundance in the Digestive System of Five Shipworm Species (Bivalvia: Teredinidae)

    Science.gov (United States)

    Betcher, Meghan A.; Fung, Jennifer M.; Han, Andrew W.; O’Connor, Roberta; Seronay, Romell; Concepcion, Gisela P.; Distel, Daniel L.; Haygood, Margo G.

    2012-01-01

    Marine bivalves of the family Teredinidae (shipworms) are voracious consumers of wood in marine environments. In several shipworm species, dense communities of intracellular bacterial endosymbionts have been observed within specialized cells (bacteriocytes) of the gills (ctenidia). These bacteria are proposed to contribute to digestion of wood by the host. While the microbes of shipworm gills have been studied extensively in several species, the abundance and distribution of microbes in the digestive system have not been adequately addressed. Here we use Fluorescence In-Situ Hybridization (FISH) and laser scanning confocal microscopy with 16S rRNA directed oligonucleotide probes targeting all domains, domains Bacteria and Archaea, and other taxonomic groups to examine the digestive microbiota of 17 specimens from 5 shipworm species (Bankia setacea, Lyrodus pedicellatus, Lyrodus massa, Lyrodus sp. and Teredo aff. triangularis). These data reveal that the caecum, a large sac-like appendage of the stomach that typically contains large quantities of wood particles and is considered the primary site of wood digestion, harbors only very sparse microbial populations. However, a significant number of bacterial cells were observed in fecal pellets within the intestines. These results suggest that due to low abundance, bacteria in the caecum may contribute little to lignocellulose degradation. In contrast, the comparatively high population density of bacteria in the intestine suggests a possible role for intestinal bacteria in the degradation of lignocellulose. PMID:23028923

  19. Monitoring species richness and abundance of shorebirds in the western Great Basin

    Science.gov (United States)

    Warnock, Nils; Haig, Susan M.; Oring, Lewis W.

    1998-01-01

    Broad-scale avian surveys have been attempted within North America with mixed results. Arid regions, such as the Great Basin, are often poorly sampled because of the vastness of the region, inaccessibility of sites, and few ornithologists. In addition, extreme variability in wetland habitat conditions present special problems for conducting censuses of species inhabiting these areas. We examined these issues in assessing multi-scale shorebird (order: Charadriiformes) censuses conducted in the western Great Basin from 1992-1997. On ground surveys, we recorded 31 species of shorebirds, but were unable to accurately estimate population size. Conversely, on aerial surveys we were able to estimate regional abundance of some shorebirds, but were unable to determine species diversity. Aerial surveys of three large alkali lakes in Oregon (Goose, Summer, and Abert Lakes) revealed > 300,000 shorebirds in one year of this study, of which 67% were American Avocets (Recurvirostra americana) and 30% phalaropes (Phalaropus spp.). These lakes clearly meet Western Hemisphere Shorebird Reserve Network guidelines for designation as important shorebird sites. Based upon simulations of our monitoring effort and the magnitude and variation of numbers of American Avocets, detection of S-10% negative declines in populations of these birds would take a minimum of 7-23 years of comparable effort. We conclude that a combination of ground and aerial surveys must be conducted at multiple sites and years and over a large region to obtain an accurate picture of the diversity, abundance, and trends of shorebirds in the western Great Basin.

  20. Macroinvertebrate abundance, water chemistry, and wetland characteristics affect use of wetlands by avian species in Maine

    Science.gov (United States)

    Longcore, J.R.; McAuley, D.G.; Pendelton, G.W.; Bennatti, C.R.; Mingo, T.M.; Stromborg, K.L.

    2006-01-01

    Our objective was to determine use by avian species (e.g., piscivores, marsh birds, waterfowl, selected passerines) of 29 wetlands in areas with low (chemistry, basin characteristics, and avian use of different wetland types. Shallow, beaver (Castor canadensis)-created wetlands with the highest phosphorus levels and abundant and varied macrophyte assemblages supported greater densities of macroinvertebrates and numbers of duck broods (88.3% of all broods) in contrast to deep, glacial type wetlands with sparse vegetation and lower invertebrate densities that supported fewer broods (11.7%). Low pH may have affected some acid-intolerant invertebrate taxa (i.e., Ephemeroptera), but high mean numbers of Insecta per wetland were recorded from wetlands with a pH of 5.51. Other Classes and Orders of invertebrates were more abundant on wetlands with pH > 5.51. All years combined use of wetlands by broods was greater on wetlands with pH ≤ 5.51 (77.4%) in contract to wetlands with pH > 5.51 that supported 21.8% of the broods. High mean brood density was associated with mean number of Insecta per wetland. For lentic wetlands created by beaver, those habitats contained vegetative structure and nutrients necessary to provide cover to support invertebrate populations that are prey of omnivore and insectivore species. The fishless status of a few wetlands may have affected use by some waterfowl species and obligate piscivores.

  1. Assessing landscape constraints on species abundance: Does the neighborhood limit species response to local habitat conservation programs?

    Science.gov (United States)

    Jorgensen, Christopher F.; Powell, Larkin A.; Lusk, Jeffrey J.; Bishop, Andrew A.; Fontaine, Joseph J.

    2014-01-01

    Landscapes in agricultural systems continue to undergo significant change, and the loss of biodiversity is an ever-increasing threat. Although habitat restoration is beneficial, management actions do not always result in the desired outcome. Managers must understand why management actions fail; yet, past studies have focused on assessing habitat attributes at a single spatial scale, and often fail to consider the importance of ecological mechanisms that act across spatial scales. We located survey sites across southern Nebraska, USA and conducted point counts to estimate Ring-necked Pheasant abundance, an economically important species to the region, while simultaneously quantifying landscape effects using a geographic information system. To identify suitable areas for allocating limited management resources, we assessed land cover relationships to our counts using a Bayesian binomial-Poisson hierarchical model to construct predictive Species Distribution Models of relative abundance. Our results indicated that landscape scale land cover variables severely constrained or, alternatively, facilitated the positive effects of local land management for Ring-necked Pheasants.

  2. CHEMICAL COMPOSITION OF CAATINGA POTENTIAL FORAGES SPECIES

    Directory of Open Access Journals (Sweden)

    Dynara Layza de Souza da Silva

    2015-12-01

    Full Text Available Chemical composition of some potential forages species, natives from Caatinga region, were evaluated. Samples of Macroptilium heterophyllum, Stylosanthes humilis, Rhynchosia mínima, Desmodium tortuosum Sw. Dc, Merremia aegyptia, Mimosa tenuiflora Wild, Bauhinia cheilantha and as well Macroptilium lathyroides, Caesalpinia pyramidalis and Mimosa tenuiflora hays were collected in Rio Grande do Norte Stated, during 2011 rainy season. The analyses: dry matter (DM, crude protein (CP mineral matter (MM ether extract  (EE neutral detergent fiber (NDF, acid detergent fiber (ADF, lignin (LIG, insoluble neutral detergent nitrogen, (INDN insoluble acid detergent nitrogen, (ADIN, total phenol (TF and total tannin (TT were done at Embrapa Caprinos e Ovinos in Ceará State. Plants analyzed, as expected, for tropical species, exhibited high level of cell wall constituents, high lignifications rate and revealed substantial presence of anti nutritional compounds. However, regardless of this data, the main problem, for grazing animals, is due to its xerophytes characteristics. Most of the shrubs and trees are deciduous, losing its leaves during the dry season. In addition, herbaceous presents a very rapid lifetime cycle, germinating and senescing during the brief wet season.

  3. Evaluating functional diversity: Missing trait data and the importance of species abundance structure and data transformation

    Czech Academy of Sciences Publication Activity Database

    Májeková, M.; Paal, T.; Plowman, Nichola S.; Bryndová, Michala; Kasari, L.; Norberg, A.; Weiss, Matthias; Bishop, T. R.; Luke, S. H.; Sam, Kateřina; Le Bagousse-Pinguet, Y.; Lepš, Jan; Götzenberger, Lars; de Bello, Francesco

    2016-01-01

    Roč. 11, č. 2 (2016), č. článku e0149270. E-ISSN 1932-6203 R&D Projects: GA ČR GB14-36098G; GA ČR(CZ) GP14-32024P; GA ČR GAP505/12/1296 Grant - others:GA JU(CZ) 156/2013/P Institutional support: RVO:60077344 ; RVO:67985939 Keywords : data incompleteness * functional diversity * species abundance Subject RIV: EH - Ecology, Behaviour; EH - Ecology, Behaviour (BU-J) Impact factor: 2.806, year: 2016 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0149270

  4. Fish assemblage in a semi-arid Neotropical reservoir: composition, structure and patterns of diversity and abundance.

    Science.gov (United States)

    Novaes, J L C; Moreira, S I L; Freire, C E C; Sousa, M M O; Costa, R S

    2014-05-01

    The aim of this study was to analyse the composition, structure and spatial and temporal patterns of diversity and abundance of the ichthyofauna of the Santa Cruz Reservoir in semi-arid Brazil. Data were collected quarterly at eight sampling locations on the reservoir between February 2010 and November 2011 using gillnets from 12- to 70-mm mesh that were left in the water for 12h00min during the night. We evaluated the composition, structure and assemblage descriptors (Shannon-Wiener diversity index and equitability, respectively) and catch per unit effort by the number (CPUEn) and biomass (CPUEb) of the ichthyofauna. The 6,047 individuals (399,211.6 g) captured represented three orders, ten families and 20 species, of which four belonged to introduced species. The family Characidae was the most abundant with a total of 2,772 (45.8%) individuals captured. The species-abundance curve fit the log-normal model. In the spatial analysis of diversity, there were significant differences between sampling sites in the lacustrine and fluvial regions, and the highest values were found in the lacustrine region. In the temporal analysis of diversity, significant differences were also observed between the rainy and dry seasons, and the higher values were found during the dry season. Equitability followed the same spatiotemporal pattern as diversity. The Spearman correlation was significantly negative between diversity and rainfall. A cluster analysis spatially separated the ichthyofauna into two groups: one group formed by sampling sites in the fluvial region and another group formed by the remainder of the points in the lacustrine region. Both the CPUEn and CPUEb values were higher at point 8 (fluvial region) and during the rainy season. A two-way ANOVA showed that the CPUEn and CPUEb values were spatially and temporally significant. We conclude that the spatial and temporal trends of diversity in the Santa Cruz reservoir differ from those of other Brazilian reservoirs but that

  5. Influence of species, size and relative abundance on the outcomes of competitive interactions between brook trout and juvenile coho salmon

    Science.gov (United States)

    Thornton, Emily J; Duda, Jeff; Quinn, Thomas P.

    2016-01-01

    Resource competition between animals is influenced by a number of factors including the species, size and relative abundance of competing individuals. Stream-dwelling animals often experience variably available food resources, and some employ territorial behaviors to increase their access to food. We investigated the factors that affect dominance between resident, non-native brook trout and recolonizing juvenile coho salmon in the Elwha River, WA, USA, to see if brook trout are likely to disrupt coho salmon recolonization via interference competition. During dyadic laboratory feeding trials, we hypothesized that fish size, not species, would determine which individuals consumed the most food items, and that species would have no effect. We found that species, not size, played a significant role in dominance; coho salmon won 95% of trials, even when only 52% the length of their brook trout competitors. As the pairs of competing fish spent more time together during a trial sequence, coho salmon began to consume more food, and brook trout began to lose more, suggesting that the results of early trials influenced fish performance later. In group trials, we hypothesized that group composition and species would not influence fish foraging success. In single species groups, coho salmon consumed more than brook trout, but the ranges overlapped. Brook trout consumption remained constant through all treatments, but coho salmon consumed more food in treatments with fewer coho salmon, suggesting that coho salmon experienced more intra- than inter-specific competition and that brook trout do not pose a substantial challenge. Based on our results, we think it is unlikely that competition from brook trout will disrupt Elwha River recolonization by coho salmon.

  6. Emergent macrophytes modify the abundance and community composition of ammonia oxidizers in their rhizosphere sediments.

    Science.gov (United States)

    Zhao, Dayong; He, Xiaowei; Huang, Rui; Yan, Wenming; Yu, Zhongbo

    2017-07-01

    Ammonia oxidation is a crucial process in global nitrogen cycling, which is catalyzed by the ammonia oxidizers. Emergent plants play important roles in the freshwater ecosystem. Therefore, it is meaningful to investigate the effects of emergent macrophytes on the abundance and community composition of ammonia oxidizers. In the present study, two commonly found emergent macrophytes (Zizania caduciflora and Phragmitas communis) were obtained from freshwater lakes and the abundance and community composition of the ammonia-oxidizing prokaryotes in the rhizosphere sediments of these emergent macrophytes were investigated. The abundance of the bacterial amoA gene was higher in the rhizosphere sediments of the emergent macrophytes than those of bulk sediments. Significant positive correlation was found between the potential nitrification rates (PNRs) and the abundance of bacterial amoA gene, suggesting that ammonia-oxidizing bacteria (AOB) might play an important role in the nitrification process of the rhizosphere sediments of emergent macrophytes. The Nitrosotalea cluster is the dominant ammonia-oxidizing archaea (AOA) group in all the sediment samples. Analysis of AOB group showed that the N. europaeal cluster dominated the rhizosphere sediments of Z. caduciflora and the bulk sediments, whereas the Nitrosospira cluster was the dominant AOB group in the rhizosphere sediments of P. communis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Impact of physicochemical parameters on phytoplankton compositions and abundances in Selameko Manmade Reservoir, Debre Tabor, South Gondar, Ethiopia

    Science.gov (United States)

    Wassie, Tilahun Adugna; Melese, Ayalew Wondie

    2017-07-01

    Impact of physicochemical parameters on 2 compositions and abundances in Selameko Reservoir, Debre Tabor, South Gondar from August 2009 to May 2010 was assessed. Water quality parameters, such as temperature, water transparency, water depth, dissolved oxygen, pH, total dissolved solids, phosphate, nitrate, and silicate were measured in situ from two sites (littoral and open water zone) of the reservoir. Phytoplankton compositions and abundances were analyzed in Tana fisheries and other aquatic organisms' research center. ANOVA result of the physicochemical parameters included chlorophyll-a showed the presence of significance difference among seasons and between sites ( P < 0.05). A total of seven families, 36 genera from three groups (Diatom, Blue green algae and Green algae) of phytoplankton were identified during the study period. From all groups, diatoms were the most abundant at both sites and Blue green algae were the least abundant. ANOVA of all phytoplankton showed highly significant difference among seasons and between sites ( P < 0.05). ANOVA of all phytoplankton showed highly significant difference among seasons and between sites ( P < 0.05). Based on the stepwise regression, a total number of phytoplanktons had positive correlation with some of the physicochemical parameters (R2 = 0.99, P < 0.001, N = 16). The study concluded that some of physicochemical parameters (NO3-N and PO4-P) indicated the presence of reservoir water pollution. This is supported by the presence of pollution-resistant phytoplankton species such as Melosira and Microcystis. The reservoir water was eutrophic (productive) throughout the year. To avoid such pollution, basin and reservoir management are recommended.

  8. Species composition of Bromeliaceae and their distribution at the Massambaba restinga in Arraial do Cabo, Rio de Janeiro, Brazil.

    Science.gov (United States)

    Rocha-Pessôa, T C; Nunes-Freitas, A F; Cogliatti-Carvalho, L; Rocha, C F D

    2008-05-01

    We studied some ecological parameters such as richness, abundance, density, biomass and variation in species composition in four vegetation zones and in a zone with anthropic disturbance in the Massambaba Restinga in Arraial do Cabo, Rio de Janeiro State. We sampled 100 plots of 100 m(2) (10 x 10 m) recording the bromeliad species and their abundance. We found a total of seven bromeliad species, with Vriesea neoglutinosa (5647 ramets) and Tillandsia stricta (1277 ramets) being the most abundant. The vegetation zone called Clusia shrubs had the highest richness (S = 5) and density (6360 ramets.ha(-1)) of bromeliads. The differences found in abundance and variation in species composition among vegetation zones seems to be related to the vegetation structure of each zone.

  9. Species composition of Bromeliaceae and their distribution at the Massambaba restinga in Arraial do Cabo, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    TC. Rocha-Pessôa

    Full Text Available We studied some ecological parameters such as richness, abundance, density, biomass and variation in species composition in four vegetation zones and in a zone with anthropic disturbance in the Massambaba Restinga in Arraial do Cabo, Rio de Janeiro State. We sampled 100 plots of 100 m² (10 x 10 m recording the bromeliad species and their abundance. We found a total of seven bromeliad species, with Vriesea neoglutinosa (5647 ramets and Tillandsia stricta (1277 ramets being the most abundant. The vegetation zone called Clusia shrubs had the highest richness (S = 5 and density (6360 ramets.ha-1 of bromeliads. The differences found in abundance and variation in species composition among vegetation zones seems to be related to the vegetation structure of each zone.

  10. Drivers of inter-annual variation and long-term change in High-Arctic spider species abundances

    DEFF Research Database (Denmark)

    Bowden, Joseph J.; Hansen, Oskar L. P.; Olsen, Kent

    2018-01-01

    Understanding how species abundances vary in space and time is a central theme in ecology, yet there are few long-term field studies of terrestrial invertebrate abundances and the determinants of their dynamics. This is particularly relevant in the context of rapid climate change occurring...... in the Arctic. Arthropods can serve as strong indicators of ecosystem change due to their sensitivity to increasing temperatures and other environmental variables. We used spider samples collected by pitfall trapping from three different habitats (fen, mesic and arid heath) in High-Arctic Greenland to assess...... interpretation of long-term trends. We used model selection to determine which climatic variables and/or previous years’ abundance best explained annual variation in species abundances over this period. We identified and used 28 566 adult spiders that comprised eight species. Most notably, the abundances of some...

  11. Composition, abundance and diversity of the Family Cichlidae in Oyan Dam, Ogun State, Nigeria

    Directory of Open Access Journals (Sweden)

    OLANIYI ALABA OLOPADE

    2014-10-01

    Full Text Available Olopade OA, Rufai OP. 2014. Composition, abundance and diversity of the Family Cichlidae in Oyan Dam, Ogun State, Nigeria. Biodiversitas 15: 195-199.This study was conducted to determine status of the family Cichlidae in Oyan Dam, Nigeria, during the wet and dry seasons of 2011. Samples were collected using multi-mesh gillnets ranging between 30 mm to 80 mm. Simpson's Diversity Index was used to determine the species richness, while dominance and evenness were given by Shannon's index. A total of 547 individuals were caught from Imala (S1 and Ibaro (S2 sites of the dam. Species collected include Sarotherodon galilaeus (42.60%, Oreochromis niloticus (17.92%, Tilapia zillii (25.41%, Hemichromis fasciatus (10.61% and Tilapia mariae (3.48%. Juveniles and sub-adults and adults were among the catch, the sizes were as big as 12.85±0.29cm SL, 109.22±6.00g BW in Tilapia zillii and small as 6.09±0.05cm SL and 8.07±0.15g BW in Hemichromis fasciatus. The diversity indexes showed that the diversity of Cichlids was lower in the two sites observed in Oyan Dam. The estimates of diversity indexes showed lower value for site 1 (0.284 than for site 2 (0.294; Simpson's diversity index was 0.716 for site 1 and 0.703 for site 2 while reciprocal indexes for site 1(3.521 was slightly lower than site 2 (3.367. Shannon-Wiener’s Index recorded in the site 1 (1.36 was slightly lower than site 2 (1.37. Pielou’s Index value recorded for site 1 was 0.845 and 0.852 for site 2. Sarotherodon galilaeus, Oreochromis niloticus, Tilapia zillii and Tilapia mariae exhibited a positive allometric growth pattern while only Hemichromis fasciatus showed a negative allometric growth.

  12. Abundance, composition and natural infection of Anopheles mosquitoes from two malaria-endemic regions of Colombia

    Directory of Open Access Journals (Sweden)

    Carolina Montoya

    2017-03-01

    Conclusions: Natural infection of A. darlingi and A. nuneztovari indicate that these malaria vectors continue to be effective carriers of Plasmodium in the localities under study in Valle del Cauca and Chocó. Additionally, the infected A. triannulatus s.l. collected in livestock corrals in the locality of the department of Córdoba suggests the need for further studies to define the epidemiological importance of this species given its abundance and opportunistic anthropophilic behavior.

  13. Connectivity and conditional models of access and abundance of species in stream networks.

    Science.gov (United States)

    Chelgren, Nathan D; Dunham, Jason B

    2015-07-01

    Barriers to passage of aquatic organisms at stream road crossings are a major cause of habitat fragmentation in stream networks. Accordingly, large investments have been made to restore passage at these crossings, but often without estimation of population-level benefits. Here, we describe a broad-scale approach to quantifying the effectiveness of passage restoration in terms interpretable at population levels, namely numbers of fish and length of stream gained through restoration, by sampling abundance in a study design that accounts for variable biogeographic species pools, variable stream and barrier configurations, and variable probabilities of capture and detectability for multiple species. We modified an existing zero-inflated negative-binomial model to estimate the probability of site access, abundance conditional on access, and capture probability of individual fish. Therein, we modeled probability of access as a function of gradient, stream road-crossing type, and downstream access by fish simultaneously with a predictive model for abundance at sites accessible to fish. Results indicated that replacement of barriers with new crossing designs intended to allow for greater movement was associated with dramatically higher probability of access for all fishes, including migratory Pacific salmon, trout, sculpin, and lamprey. Conversely, existing non-replaced crossings negatively impacted fish distributions. Assuming no downstream constraints on access, we estimated the potential length of stream restored by the program ranged between 7.33 (lamprey) and 15.28 km (small coastal cutthroat and rainbow trout). These contributions represented a fraction of the total length available upstream (187 km) of replaced crossings. When limited ranges of species were considered, the estimated contributions of culvert replacement were reduced (1.65-km range, for longnose dace to 12.31 km for small coastal cutthroat and rainbow trout). Numbers of fish contributed ranged from

  14. Community analysis of the abundance and diversity of biting midge species (Diptera: Ceratopogonidae) in three European countries at different latitudes.

    Science.gov (United States)

    Möhlmann, Tim W R; Wennergren, Uno; Tälle, Malin; Favia, Guido; Damiani, Claudia; Bracchetti, Luca; Takken, Willem; Koenraadt, Constantianus J M

    2018-03-27

    The outbreaks of bluetongue and Schmallenberg disease in Europe have increased efforts to understand the ecology of Culicoides biting midges and their role in pathogen transmission. However, most studies have focused on a specific habitat, region, or country. To facilitate wider comparisons, and to obtain a better understanding of the spread of disease through Europe, the present study focused on monitoring biting midge species diversity in three different habitat types and three countries across Europe. Biting midges were trapped using Onderstepoort Veterinary Institute light traps at a total of 27 locations in Sweden, the Netherlands and Italy, comprising farm, peri-urban and wetland habitats. From July 2014 to June 2015 all locations were sampled monthly, except for during the winter months. Trapped midges were counted and identified morphologically. Indices on species richness, evenness and diversity were calculated. Community compositions were analysed using non-metric multidimensional scaling (NMDS) techniques. A total of 50,085 female midges were trapped during 442 collection nights. More than 88% of these belonged to the Obsoletus group. The highest midge diversity was found in Sweden, while species richness was highest in the Netherlands, and most specimens were trapped in Italy. For habitats within countries, diversity of the trapped midges was lowest for farms in all countries. Differences in biting midge species communities were more distinct across the three countries than the three habitat types. A core midge community could be identified, in which the Obsoletus group was the most abundant. Variations in vector communities across countries imply different patterns of disease spread throughout Europe. How specific species and their associated communities affect disease risk is still unclear. Our results emphasize the importance of midge diversity data at community level, how this differs across large geographic range within Europe, and its implications

  15. Continuously Monocropped Jerusalem Artichoke Changed Soil Bacterial Community Composition and Ammonia-Oxidizing and Denitrifying Bacteria Abundances.

    Science.gov (United States)

    Zhou, Xingang; Wang, Zhilin; Jia, Huiting; Li, Li; Wu, Fengzhi

    2018-01-01

    Soil microbial communities have profound effects on the growth, nutrition and health of plants in agroecosystems. Understanding soil microbial dynamics in cropping systems can assist in determining how agricultural practices influence soil processes mediated by microorganisms. In this study, soil bacterial communities were monitored in a continuously monocropped Jerusalem artichoke (JA) system, in which JA was successively monocropped for 3 years in a wheat field. Soil bacterial community compositions were estimated by amplicon sequencing of the 16S rRNA gene. Abundances of ammonia-oxidizing and denitrifying bacteria were estimated by quantitative PCR analysis of the amoA , nirS , and nirK genes. Results showed that 1-2 years of monocropping of JA did not significantly impact the microbial alpha diversity, and the third cropping of JA decreased the microbial alpha diversity ( P < 0.05). Principal coordinates analysis and permutational multivariate analysis of variance analyses revealed that continuous monocropping of JA changed soil bacterial community structure and function profile ( P < 0.001). At the phylum level, the wheat field was characterized with higher relative abundances of Latescibacteria , Planctomycetes , and Cyanobacteria , the first cropping of JA with Actinobacteria , the second cropping of JA with Acidobacteria , Armatimonadetes , Gemmatimonadetes , and Proteobacteria . At the genus level, the first cropping of JA was enriched with bacterial species with pathogen-antagonistic and/or plant growth promoting potentials, while members of genera that included potential denitrifiers increased in the second and third cropping of JA. The first cropping of JA had higher relative abundances of KO terms related to lignocellulose degradation and phosphorus cycling, the second cropping of JA had higher relative abundances of KO terms nitrous-oxide reductase and nitric-oxide reductase, and the third cropping of JA had higher relative abundances of KO terms

  16. Continuously Monocropped Jerusalem Artichoke Changed Soil Bacterial Community Composition and Ammonia-Oxidizing and Denitrifying Bacteria Abundances

    Directory of Open Access Journals (Sweden)

    Xingang Zhou

    2018-04-01

    Full Text Available Soil microbial communities have profound effects on the growth, nutrition and health of plants in agroecosystems. Understanding soil microbial dynamics in cropping systems can assist in determining how agricultural practices influence soil processes mediated by microorganisms. In this study, soil bacterial communities were monitored in a continuously monocropped Jerusalem artichoke (JA system, in which JA was successively monocropped for 3 years in a wheat field. Soil bacterial community compositions were estimated by amplicon sequencing of the 16S rRNA gene. Abundances of ammonia-oxidizing and denitrifying bacteria were estimated by quantitative PCR analysis of the amoA, nirS, and nirK genes. Results showed that 1–2 years of monocropping of JA did not significantly impact the microbial alpha diversity, and the third cropping of JA decreased the microbial alpha diversity (P < 0.05. Principal coordinates analysis and permutational multivariate analysis of variance analyses revealed that continuous monocropping of JA changed soil bacterial community structure and function profile (P < 0.001. At the phylum level, the wheat field was characterized with higher relative abundances of Latescibacteria, Planctomycetes, and Cyanobacteria, the first cropping of JA with Actinobacteria, the second cropping of JA with Acidobacteria, Armatimonadetes, Gemmatimonadetes, and Proteobacteria. At the genus level, the first cropping of JA was enriched with bacterial species with pathogen-antagonistic and/or plant growth promoting potentials, while members of genera that included potential denitrifiers increased in the second and third cropping of JA. The first cropping of JA had higher relative abundances of KO terms related to lignocellulose degradation and phosphorus cycling, the second cropping of JA had higher relative abundances of KO terms nitrous-oxide reductase and nitric-oxide reductase, and the third cropping of JA had higher relative abundances of KO

  17. Atmospheric Composition of Weak G Band Stars: CNO and Li Abundances

    Science.gov (United States)

    Adamczak, Jens; Lambert, David L.

    2013-03-01

    We determined the chemical composition of a large sample of weak G band stars—a rare class of G and K giants of intermediate mass with unusual abundances of C, N, and Li. We have observed 24 weak G band stars with the 2.7 m Harlan J. Smith Telescope at the McDonald Observatory and derived spectroscopic abundances for C, N, O, and Li, as well as for selected elements from Na-Eu. The results show that the atmospheres of weak G band stars are highly contaminated with CN-cycle products. The C underabundance is about a factor of 20 larger than for normal giants and the 12C/13C ratio approaches the CN-cycle equilibrium value. In addition to the striking CN-cycle signature the strong N overabundance may indicate the presence of partially ON-cycled material in the atmospheres of the weak G band stars. The exact mechanism responsible for the transport of the elements to the surface has yet to be identified but could be induced by rapid rotation of the main sequence progenitors of the stars. The unusually high Li abundances in some of the stars are an indicator for Li production by the Cameron-Fowler mechanism. A quantitative prediction of a weak G band star's Li abundance is complicated by the strong temperature sensitivity of the mechanism and its participants. In addition to the unusual abundances of CN-cycle elements and Li, we find an overabundance of Na that is in accordance with the NeNa chain running in parallel with the CN cycle. Apart from these peculiarities, the element abundances in a weak G band star's atmosphere are consistent with those of normal giants.

  18. ATMOSPHERIC COMPOSITION OF WEAK G BAND STARS: CNO AND Li ABUNDANCES

    International Nuclear Information System (INIS)

    Adamczak, Jens; Lambert, David L.

    2013-01-01

    We determined the chemical composition of a large sample of weak G band stars—a rare class of G and K giants of intermediate mass with unusual abundances of C, N, and Li. We have observed 24 weak G band stars with the 2.7 m Harlan J. Smith Telescope at the McDonald Observatory and derived spectroscopic abundances for C, N, O, and Li, as well as for selected elements from Na-Eu. The results show that the atmospheres of weak G band stars are highly contaminated with CN-cycle products. The C underabundance is about a factor of 20 larger than for normal giants and the 12 C/ 13 C ratio approaches the CN-cycle equilibrium value. In addition to the striking CN-cycle signature the strong N overabundance may indicate the presence of partially ON-cycled material in the atmospheres of the weak G band stars. The exact mechanism responsible for the transport of the elements to the surface has yet to be identified but could be induced by rapid rotation of the main sequence progenitors of the stars. The unusually high Li abundances in some of the stars are an indicator for Li production by the Cameron-Fowler mechanism. A quantitative prediction of a weak G band star's Li abundance is complicated by the strong temperature sensitivity of the mechanism and its participants. In addition to the unusual abundances of CN-cycle elements and Li, we find an overabundance of Na that is in accordance with the NeNa chain running in parallel with the CN cycle. Apart from these peculiarities, the element abundances in a weak G band star's atmosphere are consistent with those of normal giants.

  19. [Species-area and species-abundance relationships of arthropod community in various vegetation restoration areas in Zhifanggou watershed, Shaanxi province of Northwest China].

    Science.gov (United States)

    Zhang, Feng; Hong, Bo; Li, Ying-Mei; Chen, Zhi-Jie; Zhang, Shu-Lian; Zhao, Hui-Yan

    2013-02-01

    Taking the Zhifanggou watershed in Ansai, Shaanxi Province of Northwest China as a study unit, an investigation on the arthropods in 8 forest stands was conducted from 2006 to 2008, with the species-area and species-abundance relationships of the arthropods in these stands analyzed by various mathematical models. In these forest stands, the species-area relationship of the arthropods accorded with the formula S= CAm With the increase of investigation area, the species number approached to a constant, and the corresponding smallest investigation area was in the order of natural bush > natural forest > Populus davidiana+Robinia pseudoacacia forest > Hippaphae rhamnoides +Caragana mocrophylla forest> Periploca sepium forest > Hippaphae rhamnoides forest > Robinia pseudoacacia forest > Caragana mocrophylla forest, indicating that the more complex the stands, the larger the minimum area needed to be investigated. Based on sampling investigation, the species-abundance models of the arthropods in various stands were established. Lognormal distribution model (LN) was most suitable to fit the arthropod community in natural recovery stands, suggesting that in the arthropod community, there were more species with medial individual amount and fewer abundant species and rare species, and no obvious dominant species. LogCauchy distribution model (LC) was most suitable to fit the arthropod community in mixed and pure stands. As compared with natural recovery stand, mixed and pure stands had more abundant and rare species, and more dominant species.

  20. Aerial Survey as a Tool to Estimate Abundance and Describe Distribution of a Carcharhinid Species, the Lemon Shark, Negaprion brevirostris

    Directory of Open Access Journals (Sweden)

    S. T. Kessel

    2013-01-01

    Full Text Available Aerial survey provides an important tool to assess the abundance of both terrestrial and marine vertebrates. To date, limited work has tested the effectiveness of this technique to estimate the abundance of smaller shark species. In Bimini, Bahamas, the lemon shark (Negaprion brevirostris shows high site fidelity to a shallow sandy lagoon, providing an ideal test species to determine the effectiveness of localised aerial survey techniques for a Carcharhinid species in shallow subtropical waters. Between September 2007 and September 2008, visual surveys were conducted from light aircraft following defined transects ranging in length between 8.8 and 4.4 km. Count results were corrected for “availability”, “perception”, and “survey intensity” to provide unbiased abundance estimates. The abundance of lemon sharks was greatest in the central area of the lagoon during high tide, with a change in abundance distribution to the east and western regions of the lagoon with low tide. Mean abundance of sharks was estimated at 49 (±8.6 individuals, and monthly abundance was significantly positively correlated with mean water temperature. The successful implementation of the aerial survey technique highlighted the potential of further employment for shark abundance assessments in shallow coastal marine environments.

  1. Allometric Equations for Estimating Biomass of Euterpe precatoria, the Most Abundant Palm Species in the Amazon

    Directory of Open Access Journals (Sweden)

    Fernando Da Silva

    2015-02-01

    Full Text Available Allometric models to estimate biomass components such as stem mass Ms, foliage mass Ml, root mass Mr and aboveground mass Ma, were developed for the palm species Euterpe precatoria Mart., which is the most abundant tree species in the Amazon. We harvested twenty palms including above- and below-ground parts in an old growth Amazonian forest in Brazil. The diameter at breast height D ranged from 3.9–12.7 cm, and the stem height H ranged from 2.3–16.4 m. The D, diameter at ground basis D0, crown diameter CD, H, stem specific gravity ρ, and number of fronds Nf were considered as independent variables and incorporated into a power function model. The best predictors were D2Hρ for Ms and Ma, D2HNf for Ml, and D for Mr. Slender index (H/D ranged from 0.56–1.46 m·cm−1, and the D-H relationship suggested that the stem shape becomes more slender with increasing D. On the other hand, ρ increased with D implying a stiffening of stem tissue. The average root/shoot ratio was estimated as 0.29 which was higher than that reported for the non-palm tree species in the Amazon. Comparisons of several models to estimate Ma of different palm species, suggested that the variations of the D-H relationship and ρ should be considered to develop allometric models for estimating biomass in palm species. In particular the ρ largely varied depending on individual size, which should be important to consider, when developing the allometric models for palms.

  2. Factors associated with long-term species composition in dry tropical forests of Central India

    Science.gov (United States)

    Agarwala, M.; DeFries, R. S.; Qureshi, Q.; Jhala, Y. V.

    2016-10-01

    The long-term future of species composition in forests depends on regeneration. Many factors can affect regeneration, including human use, environmental conditions, and species’ traits. This study examines the influence of these factors in a tropical deciduous forest of Central India, which is heavily used by local, forest-dependent residents for livestock grazing, fuel-wood extraction, construction and other livelihood needs. We measure size-class proportions (the ratio of abundance of a species at a site in a higher size class to total abundance in both lower and higher size classes) for 39 tree species across 20 transects at different intensities of human use. The size-class proportions for medium to large trees and for small to medium-sized trees were negatively associated with species that are used for local construction, while size class proportions for saplings to small trees were positively associated with those species that are fire resistant and negatively associated with livestock density. Results indicate that grazing and fire prevent non-fire resistant species from reaching reproductive age, which can alter the long term composition and future availability of species that are important for local use and ecosystem services. Management efforts to reduce fire and forest grazing could reverse these impacts on long-term forest composition.

  3. Thorium abundances on the aristarchus plateau: Insights into the composition of the aristarchus pyroclastic glass deposits

    Science.gov (United States)

    Hagerty, Justin J.; Lawrence, D.J.; Hawke, B.R.; Gaddis, Lisa R.

    2009-01-01

    Thorium (Th) data from the Lunar Prospector gamma ray spectrometer (LP-GRS) are used to constrain the composition of lunar pyroclastic glass deposits on top of the Aristarchus plateau. Our goal is to use forward modeling of LP-GRS Th data to measure the Th abundances on the plateau and then to determine if the elevated Th abundances on the plateau are associated with the pyroclastic deposits or with thorium-rich ejecta from Aristarchus crater. We use a variety of remote sensing data to show that there is a large, homogenous portion of the pyroclastics on the plateau that has seen little or no contamination from the Th-rich ejecta of Aristarchus crater. Our results show that the uncontaminated pyroclastic glasses on Aristarchus plateau have an average Th content of 6.7 ppm and ???7 wt % TiO2. These Th and Ti values are consistent with Th-rich, intermediate-Ti yellow glasses from the lunar sample suite. On the basis of this information, we use petrologic equations and interelement correlations for the Moon to estimate the composition of the source region from which the Aristarchus glasses were derived. We find that the source region for the Aristarchus glasses contained high abundances of heat-producing elements, which most likely served as a thermal driver for the prolonged volcanic activity in this region of the Moon. Copyright 2009 by the American Geophysical Union.

  4. Chlamydia caviae infection alters abundance but not composition of the guinea pig vaginal microbiota.

    Science.gov (United States)

    Neuendorf, Elizabeth; Gajer, Pawel; Bowlin, Anne K; Marques, Patricia X; Ma, Bing; Yang, Hongqiu; Fu, Li; Humphrys, Michael S; Forney, Larry J; Myers, Garry S A; Bavoil, Patrik M; Rank, Roger G; Ravel, Jacques

    2015-06-01

    In humans, the vaginal microbiota is thought to be the first line of defense again pathogens including Chlamydia trachomatis. The guinea pig has been extensively used as a model to study chlamydial infection because it shares anatomical and physiological similarities with humans, such as a squamous vaginal epithelium as well as some of the long-term outcomes caused by chlamydial infection. In this study, we aimed to evaluate the guinea pig-C. caviae model of genital infection as a surrogate for studying the role of the vaginal microbiota in the early steps of C. trachomatis infection in humans. We used culture-independent molecular methods to characterize the relative and absolute abundance of bacterial phylotypes in the guinea pig vaginal microbiota in animals non-infected, mock-infected or infected by C. caviae. We showed that the guinea pig and human vaginal microbiotas are of different bacterial composition and abundance. Chlamydia caviae infection had a profound effect on the absolute abundance of bacterial phylotypes but not on the composition of the guinea pig vaginal microbiota. Our findings compromise the validity of the guinea pig-C. caviae model to study the role of the vaginal microbiota during the early steps of sexually transmitted infection. © FEMS 2015.

  5. Continuous gene flow contributes to low global species abundance and distribution of a marine model diatom

    KAUST Repository

    Rastogi, Achal

    2017-08-15

    Unlike terrestrial ecosystems where geographical isolation often leads to a restricted gene flow between species, genetic admixing in aquatic micro-eukaryotes is likely to be frequent. Diatoms inhabit marine ecosystems since the Mesozoic period and presently constitute one of the major primary producers in the world ocean. They are a highly diversified group of eukaryotic phytoplankton with estimates of up to 200,000 species. Since decades, Phaeodactylum tricornutum is used as a model diatom species to characterize the functional pathways, physiology and evolution of diatoms in general. In the current study, using whole genome sequencing of ten P. tricornutum strains, sampled at broad geospatial and temporal scales, we show a continuous dispersal and genetic admixing between geographically isolated strains. We also describe a very high level of heterozygosity and propose it to be a consequence of frequent ancestral admixture. Our finding that P. tricornutum sequences are plausibly detectable at low but broadly distributed levels in the world ocean further suggests that high admixing between geographically isolated strains may create a significant bottleneck, thus influencing their global abundance and distribution in nature. Finally, in an attempt to understand the functional implications of genetic diversity between different P. tricornutum ecotypes, we show the effects of domestication in inducing changes in the selection pressure on many genes and metabolic pathways. We propose these findings to have significant implications for understanding the genetic structure of diatom populations in nature and provide a framework to assess the genomic underpinnings of their ecological success.

  6. Continuous gene flow contributes to low global species abundance and distribution of a marine model diatom

    KAUST Repository

    Rastogi, Achal; Deton-Cabanillas, Anne-Flore; Rocha Jimenez Vieira, Fabio; Veluchamy, Alaguraj; Cantrel, Catherine; Wang, Gaohong; Vanormelingen, Pieter; Bowler, Chris; Piganeau, Gwenael; Tirichine, Leila; Hu, Hanhua

    2017-01-01

    Unlike terrestrial ecosystems where geographical isolation often leads to a restricted gene flow between species, genetic admixing in aquatic micro-eukaryotes is likely to be frequent. Diatoms inhabit marine ecosystems since the Mesozoic period and presently constitute one of the major primary producers in the world ocean. They are a highly diversified group of eukaryotic phytoplankton with estimates of up to 200,000 species. Since decades, Phaeodactylum tricornutum is used as a model diatom species to characterize the functional pathways, physiology and evolution of diatoms in general. In the current study, using whole genome sequencing of ten P. tricornutum strains, sampled at broad geospatial and temporal scales, we show a continuous dispersal and genetic admixing between geographically isolated strains. We also describe a very high level of heterozygosity and propose it to be a consequence of frequent ancestral admixture. Our finding that P. tricornutum sequences are plausibly detectable at low but broadly distributed levels in the world ocean further suggests that high admixing between geographically isolated strains may create a significant bottleneck, thus influencing their global abundance and distribution in nature. Finally, in an attempt to understand the functional implications of genetic diversity between different P. tricornutum ecotypes, we show the effects of domestication in inducing changes in the selection pressure on many genes and metabolic pathways. We propose these findings to have significant implications for understanding the genetic structure of diatom populations in nature and provide a framework to assess the genomic underpinnings of their ecological success.

  7. Predicting species distribution and abundance responses to climate change: why it is essential to include biotic interactions across trophic levels.

    Science.gov (United States)

    Van der Putten, Wim H; Macel, Mirka; Visser, Marcel E

    2010-07-12

    Current predictions on species responses to climate change strongly rely on projecting altered environmental conditions on species distributions. However, it is increasingly acknowledged that climate change also influences species interactions. We review and synthesize literature information on biotic interactions and use it to argue that the abundance of species and the direction of selection during climate change vary depending on how their trophic interactions become disrupted. Plant abundance can be controlled by aboveground and belowground multitrophic level interactions with herbivores, pathogens, symbionts and their enemies. We discuss how these interactions may alter during climate change and the resulting species range shifts. We suggest conceptual analogies between species responses to climate warming and exotic species introduced in new ranges. There are also important differences: the herbivores, pathogens and mutualistic symbionts of range-expanding species and their enemies may co-migrate, and the continuous gene flow under climate warming can make adaptation in the expansion zone of range expanders different from that of cross-continental exotic species. We conclude that under climate change, results of altered species interactions may vary, ranging from species becoming rare to disproportionately abundant. Taking these possibilities into account will provide a new perspective on predicting species distribution under climate change.

  8. Species richness and relative species abundance of Nymphalidae (Lepidoptera in three forests with different perturbations in the North-Central Caribbean of Costa Rica

    Directory of Open Access Journals (Sweden)

    Carolyn Stephen

    2014-09-01

    Full Text Available Measurements of species richness and species abundance can have important implications for regulations and conservation. This study investigated species richness and abundance of butterflies in the family Nymphalidae at undisturbed, and disturbed habitats in Tirimbina Biological Reserve and Nogal Private Reserve, Sarapiquí, Costa Rica. Traps baited with rotten banana were placed in the canopy and the understory of three habitats: within mature forest, at a river/forest border, and at a banana plantation/forest border. In total, 71 species and 487 individuals were caught and identified during May and June 2011 and May 2013. Species richness and species abundance were found to increase significantly at perturbed habitats (p<0.0001, p<0.0001, respectively. The edge effect, in which species richness and abundance increase due to greater complementary resources from different habitats, could be one possible explanation for increased species richness and abundance. Rev. Biol. Trop. 62 (3: 919-928. Epub 2014 September 01.

  9. Meta-analysis of carrying capacity and abundance-area relationships in marine fish species

    DEFF Research Database (Denmark)

    Mantzouni, Irene

    Knowledge on the carrying capacity and the abundance-area relationships of fish is critical to evaluate the impacts of exploitation and climate on the sustainability and also the recovery potential of the populations. Of particular interest is climate change, inducing major consequences for popul......Knowledge on the carrying capacity and the abundance-area relationships of fish is critical to evaluate the impacts of exploitation and climate on the sustainability and also the recovery potential of the populations. Of particular interest is climate change, inducing major consequences...... differences in the patterns were identified between stocks located in the upper and lower thermal range. In the latter, strong year-classes occurred mainly during warmer seasons and vice versa. For stocks located in the warmer waters, however, no significant patterns were obtained, suggesting that increased......, to incorporate the influence of ecosystem factors, mainly temperature and habitat size, on model parameters representing cod maximum reproductive rate and carrying capacity. The pattern of temperature effects on cod productivity at the species level were identified and SR model parameters were estimated...

  10. Meta-analysis of carrying capacity and abundance-area relationships in marine fish species

    DEFF Research Database (Denmark)

    Mantzouni, Irene

    investigated also across the north Atlantic distribution of haddock. The major motivations were first, to provide an evaluation of potential thermal effects on haddock recruitment productivity across its distribution, since the species is relatively less investigated on this regard compared to cod. In addition......Knowledge on the carrying capacity and the abundance-area relationships of fish is critical to evaluate the impacts of exploitation and climate on the sustainability and also the recovery potential of the populations. Of particular interest is climate change, inducing major consequences...... morhua), herring (Clupea harengus) and haddock (Melanogrammus aeglefinus), in order to identify the effects of temperature, habitat size and life-history on their productivity patterns. The first objective was to investigate how production and survival indices of cod recruitment (i.e. the number of new...

  11. Composition and abundance of small mammal communities in forest fragments and vegetation corridors in Southern Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Andréa O. Mesquita

    2012-09-01

    Full Text Available Habitat fragmentation leads to isolation and reduce habitat areas, in addition to a series of negative effects on natural populations, affecting richness, abundance and distribution of animal species. In such a text, habitat corridors serve as an alternative for connectivity in fragmented landscapes, minimizing the effects of structural isolation of different habitat areas. This study evaluated the richness, composition and abundance of small mammal communities in forest fragments and in the relevant vegetation corridors that connect these fragments, located in Southern Minas Gerais, Southeastern Brazil. Ten sites were sampled (five forest fragments and five vegetation corridors using the capture-mark-recapture method, from April 2007-March 2008. A total sampling effort of 6 300 trapnights resulted in 656 captures of 249 individuals. Across the 10 sites sampled, 11 small mammal species were recorded. Multidimensional scaling (MDS ordinations and ANOSIM based on the composition of small mammal communities within the corridor and fragment revealed a qualitative difference between the two environments. Regarding abundance, there was no significant difference between corridors and fragments. In comparing mean values of abundance per species in each environment, only Cerradomys subflavus showed a significant difference, being more abundant in the corridor environment. Results suggest that the presence of several small mammal species in the corridor environment, in relatively high abundances, could indicate corridors use as habitat, though they might also facilitate and/or allow the movement of individuals using different habitat patches (fragments.La fragmentación del hábitat conduce al aislamiento y la reducción de los hábitats, además provoca una serie de efectos negativos sobre las poblaciones naturales, afectando la riqueza, abundancia y distribución de las especies de animales. Dentro de este contexto, los corredores biológicos sirven

  12. Site and plant species are important determinants of the Methylobacterium community composition in the plant phyllosphere.

    Science.gov (United States)

    Knief, Claudia; Ramette, Alban; Frances, Lisa; Alonso-Blanco, Carlos; Vorholt, Julia A

    2010-06-01

    The plant phyllosphere constitutes a habitat for numerous microorganisms; among them are members of the genus Methylobacterium. Owing to the ubiquitous occurrence of methylobacteria on plant leaves, they represent a suitable target for studying plant colonization patterns. The influence of the factor site, host plant species, time and the presence of other phyllosphere bacteria on Methylobacterium community composition and population size were evaluated in this study. Leaf samples were collected from Arabidopsis thaliana or Medicago truncatula plants and from the surrounding plant species at several sites. The abundance of cultivable Methylobacterium clearly correlated with the abundance of other phyllosphere bacteria, suggesting that methylobacteria constitute a considerable and rather stable fraction of the phyllosphere microbiota under varying environmental conditions. Automated ribosomal intergenic spacer analysis (ARISA) was applied to characterize the Methylobacterium community composition and showed the presence of similar communities on A. thaliana plants at most sites in 2 consecutive years of sampling. A substantial part of the observed variation in the community composition was explained by site and plant species, especially in the case of the plants collected at the Arabidopsis sites (50%). The dominating ARISA peaks that were detected on A. thaliana plants were found on other plant species grown at the same site, whereas some different peaks were detected on A. thaliana plants from other sites. This indicates that site-specific factors had a stronger impact on the Methylobacterium community composition than did plant-specific factors and that the Methylobacterium-plant association is not highly host plant species specific.

  13. Variation in local abundance and species richness of stream fishes in relation to dispersal barriers: Implications for management and conservation

    Science.gov (United States)

    Nislow, K.H.; Hudy, M.; Letcher, B.H.; Smith, E.P.

    2011-01-01

    1.Barriers to immigration, all else being equal, should in principle depress local abundance and reduce local species richness. These issues are particularly relevant to stream-dwelling species when improperly designed road crossings act as barriers to migration with potential impacts on the viability of upstream populations. However, because abundance and richness are highly spatially and temporally heterogeneous and the relative importance of immigration on demography is uncertain, population- and community-level effects can be difficult to detect. 2.In this study, we tested the effects of potential barriers to upstream movements on the local abundance and species richness of a diverse assemblage of resident stream fishes in the Monongahela National Forest, West Virginia, U.S.A. Fishes were sampled using simple standard techniques above- and below road crossings that were either likely or unlikely to be barriers to upstream fish movements (based on physical dimensions of the crossing). We predicted that abundance of resident fishes would be lower in the upstream sections of streams with predicted impassable barriers, that the strength of the effect would vary among species and that variable effects on abundance would translate into lower species richness. 3.Supporting these predictions, the statistical model that best accounted for variation in abundance and species richness included a significant interaction between location (upstream or downstream of crossing) and type (passable or impassable crossing). Stream sections located above predicated impassable culverts had fewer than half the number of species and less than half the total fish abundance, while stream sections above and below passable culverts had essentially equivalent richness and abundance. 4.Our results are consistent with the importance of immigration and population connectivity to local abundance and species richness of stream fishes. In turn, these results suggest that when measured at

  14. The Oxygen Isotopic Composition of MIL 090001: A CR2 Chondrite with Abundant Refractory Inclusions

    Science.gov (United States)

    Keller, Lindsay P.; McKeegan, K. D.; Sharp, Z. D.

    2012-01-01

    MIL 090001 is a large (>6 kg) carbonaceous chondrite that was classified as a member of the CV reduced subgroup (CVred) that was recovered during the 2009-2010 ANSMET field season [1]. Based on the abundance of refractory inclusions and the extent of aqueous alteration, Keller [2] suggested a CV2 classification. Here we report additional mineralogical and petrographic data for MIL 090001, its whole-rock oxygen isotopic composition and ion microprobe analyses of individual phases. The whole rock oxygen isotopic analyses show that MIL 090001 should be classified as a CR chondrite.

  15. Fitting and comparing competing models of the species abundance distribution: assessment and prospect

    Directory of Open Access Journals (Sweden)

    Thomas J Matthews

    2014-06-01

    Full Text Available A species abundance distribution (SAD characterises patterns in the commonness and rarity of all species within an ecological community. As such, the SAD provides the theoretical foundation for a number of other biogeographical and macroecological patterns, such as the species–area relationship, as well as being an interesting pattern in its own right. While there has been resurgence in the study of SADs in the last decade, less focus has been placed on methodology in SAD research, and few attempts have been made to synthesise the vast array of methods which have been employed in SAD model evaluation. As such, our review has two aims. First, we provide a general overview of SADs, including descriptions of the commonly used distributions, plotting methods and issues with evaluating SAD models. Second, we review a number of recent advances in SAD model fitting and comparison. We conclude by providing a list of recommendations for fitting and evaluating SAD models. We argue that it is time for SAD studies to move away from many of the traditional methods available for fitting and evaluating models, such as sole reliance on the visual examination of plots, and embrace statistically rigorous techniques. In particular, we recommend the use of both goodness-of-fit tests and model-comparison analyses because each provides unique information which one can use to draw inferences.

  16. Historical abundance and morphology of Didymosphenia species in Naknek Lake, Alaska

    Science.gov (United States)

    Pite, D.P.; Lane, K.A.; Hermann, A.K.; Spaulding, S.A.; Finney, B.P.

    2009-01-01

    Since the 1980s, nuisance blooms of Didymosphenia geminata (Lyngbye) M. Schmidt have been documented in sites that are warmer and more mesotrophic than historical records indicate. While the invasion of D. geminata in New Zealand is well documented, it is less clear whether nuisance blooms in North America are a new phenomenon. In order to test the hypothesis that D. geminata blooms have increased in recent years, we examined the historical record of this species in sediments of Naknek Lake, in Katmai National Park, Alaska. Chronological control was established by relating the presence of two ash layers to known volcanic eruptions. We identified two species of Didymosphenia within the sediment record: D. geminata and D. clavaherculis (Ehrenberg) Metzeltin et Lange-Bertalot. This is the first published record of D. clavaherculis in North America. We found no statistically significant change in the numerical presence of D. geminata or D. clavaherculis, as a group, in Naknek Lake between the years 1218 and 2003. While there has been no sudden, or recent, increase in abundance of Didymosphenia in Naknek Lake, morphological features of D. geminata populations in Naknek Lake are distinct compared to morphological features of D. geminata in streams containing nuisance blooms from sites in North America and New Zealand. Variance in the morphology of Didymosphenia cells may help determine relationships between distinct sub-populations and establish the history of habitat invasion.

  17. [Seasonal changes of fish species composition and diversity in mudflat wetlands of Hangzhou Bay].

    Science.gov (United States)

    Jia, Xing-huan; Zhang, Heng; Jiang, Ke-yi; Wu, Ming

    2010-12-01

    In order to understand the spatiotemporal variation of fish species composition and biodiversity in the mudflat wetlands of Hangzhou Bay, thirty six surveys were conducted in the mudflat area, inning area, and aquaculture area in the south bank of the Bay in. March (early spring), May (spring), July (summer), and October (autumn), 2009. A total of 41 species belonging to 9 orders and 16 families were observed, among which, Cyprinid had the largest species number (14 species, 33.3% of the total), followed by Gobiidae (8 species, 19.1%). According to the lifestyle of fish, these 41 species could be divided into five ecological types, i.e., freshwater type (21 species), brackish-water type (16 species), inshore type (2 species), anadromous type (Coilia ectenes), and catadromios type (Anguilla japonica). The fish abundance was the highest (54. 5 fish per net) in summer, followed by in spring and autumn, and the lowest (17.7 fish per net) in early spring. In the three habitats, mudflat area and inning area had the similar seasonal change of fish abundance, i.e., the lowest in early spring, the highest in summer, and then decreased in autumn. Only two or three species were the dominant species in different seasons. In mudflat area, the dominant species were Mugil cephalus and Liza carinatus; while in inning and aquaculture areas, the dominant species were Carassius auratus, Hemiculter leucisculus, and Pseudorasbora parva. The values of Margalef's richness index (D), Pielou's evenness index (J), and Shannon index (H) were lower in March than in other months, but had no significant differences among May, July, and October (P > 0.05). The H value ranged in 0. 27-2. 13, being the lowest in March and higher in May and October (1.66 and 1.63, respectively). Overall, the fish abundance and biodiversity in the mudflat wetlands of Hangzhou Bay had apparent seasonal changes.

  18. Evaluating Functional Diversity: Missing Trait Data and the Importance of Species Abundance Structure and Data Transformation

    Science.gov (United States)

    Bryndová, Michala; Kasari, Liis; Norberg, Anna; Weiss, Matthias; Bishop, Tom R.; Luke, Sarah H.; Sam, Katerina; Le Bagousse-Pinguet, Yoann; Lepš, Jan; Götzenberger, Lars; de Bello, Francesco

    2016-01-01

    Functional diversity (FD) is an important component of biodiversity that quantifies the difference in functional traits between organisms. However, FD studies are often limited by the availability of trait data and FD indices are sensitive to data gaps. The distribution of species abundance and trait data, and its transformation, may further affect the accuracy of indices when data is incomplete. Using an existing approach, we simulated the effects of missing trait data by gradually removing data from a plant, an ant and a bird community dataset (12, 59, and 8 plots containing 62, 297 and 238 species respectively). We ranked plots by FD values calculated from full datasets and then from our increasingly incomplete datasets and compared the ranking between the original and virtually reduced datasets to assess the accuracy of FD indices when used on datasets with increasingly missing data. Finally, we tested the accuracy of FD indices with and without data transformation, and the effect of missing trait data per plot or per the whole pool of species. FD indices became less accurate as the amount of missing data increased, with the loss of accuracy depending on the index. But, where transformation improved the normality of the trait data, FD values from incomplete datasets were more accurate than before transformation. The distribution of data and its transformation are therefore as important as data completeness and can even mitigate the effect of missing data. Since the effect of missing trait values pool-wise or plot-wise depends on the data distribution, the method should be decided case by case. Data distribution and data transformation should be given more careful consideration when designing, analysing and interpreting FD studies, especially where trait data are missing. To this end, we provide the R package “traitor” to facilitate assessments of missing trait data. PMID:26881747

  19. Seasonal composition, abundance and biomass of the subestuarine fish assemblage in Solís Chico (Río de la Plata estuary, Uruguay).

    Science.gov (United States)

    Plavan, A Acuña; Gurdek, R; Muñoz, N; Gutierrez, J M; Spósito, M; Correa, P; Caride, A

    2017-01-01

    The large estuaries can present long narrow branches called subestuaries or tidal creeks. These types of subsystems are distributed along the Uruguayan coast of the Río de la Plata estuary and are very important as nursery and refuge areas for fish. For the first time, the seasonal composition and abundance of the fish community of the Solís Chico subestuary was studied by using beach and gill nets. Fourteen species, mainly euryhaline (86%) presented a significant representation of juvenile stages. The fish community was dominated by Odontesthes argentinensis, Platanichthys platana, Mugil liza, Brevoortia aurea, Micropogonias furnieri and Paralichthys orbignyanus, similar to adjacent subestuaries. While Micropogonias furnieri and B. aurea were the most abundant species, some other species were rarely caught. A seasonal variation of the fish assemblage abundance was detected, with higher values in autumn showing a positive correlation with temperature. Species that complete their life cycle in the Río de la Plata estuary, some of which are relevant to fisheries (64% of the analyzed species) were captured in the Solís Chico subestuary. The importance of this environment as a transitional system for some estuarine fish species is advised.

  20. Tree Species Abundance Predictions in a Tropical Agricultural Landscape with a Supervised Classification Model and Imbalanced Data

    Directory of Open Access Journals (Sweden)

    Sarah J. Graves

    2016-02-01

    Full Text Available Mapping species through classification of imaging spectroscopy data is facilitating research to understand tree species distributions at increasingly greater spatial scales. Classification requires a dataset of field observations matched to the image, which will often reflect natural species distributions, resulting in an imbalanced dataset with many samples for common species and few samples for less common species. Despite the high prevalence of imbalanced datasets in multiclass species predictions, the effect on species prediction accuracy and landscape species abundance has not yet been quantified. First, we trained and assessed the accuracy of a support vector machine (SVM model with a highly imbalanced dataset of 20 tropical species and one mixed-species class of 24 species identified in a hyperspectral image mosaic (350–2500 nm of Panamanian farmland and secondary forest fragments. The model, with an overall accuracy of 62% ± 2.3% and F-score of 59% ± 2.7%, was applied to the full image mosaic (23,000 ha at a 2-m resolution to produce a species prediction map, which suggested that this tropical agricultural landscape is more diverse than what has been presented in field-based studies. Second, we quantified the effect of class imbalance on model accuracy. Model assessment showed a trend where species with more samples were consistently over predicted while species with fewer samples were under predicted. Standardizing sample size reduced model accuracy, but also reduced the level of species over- and under-prediction. This study advances operational species mapping of diverse tropical landscapes by detailing the effect of imbalanced data on classification accuracy and providing estimates of tree species abundance in an agricultural landscape. Species maps using data and methods presented here can be used in landscape analyses of species distributions to understand human or environmental effects, in addition to focusing conservation

  1. Preliminary observations on the species composition and ...

    African Journals Online (AJOL)

    Majority of the mushrooms appear during the rain season and are equally available during the short and long rains. This suggests that most species will grow well throughout the year whenever moisture level in the substrate is adequate irrespective of the season. Some of the species especially the Polypores (Ganoderma ...

  2. Macrobenthos composition, distribution and abundance within Sungai Pulai estuary, Johor, Malaysia

    Science.gov (United States)

    Shi, Guan Wan; Min, Lee Di; Ghaffar, Mazlan Abd; Ali, Masni Md; Cob, Zaidi Che

    2014-09-01

    Macrobenthos are very useful organisms for monitoring marine environmental and widely use in marine ecology research. They are able to monitor the difference phase in the recovery stage of disturbed sites by appear different species macrobenthos after the cessation of the impact. Univariate and multivariate methods were use to study the macrobenthos community within Sungai Pulai estuary, Johor, Malaysia. Five sub-samples were taken at each sampling sites by using 10 cm diameter corer. Crustaceans were the most abundant at Tanjung Adang (St. 1) and the station of non-seagrass area (St. 2) while polychaetes were the most abundant at Merambong Shoal (St. 3). Higher density of macrobenthos was found at St.3 followed by St. 1 and St. 2. The commonly used population indices such as diversity, richness, evenness and dominance were employed to determine the differences in diversity and abundance of macrobenthos. The diversity, richness and evenness index values showed slight increment from Station 1 to Station 3, while the dominance index decreasing trend from Station 1 to Station 3. A total 21 polychaete families were collected in Sungai Pulai estuary, which was dominated by the Spionidae, Capitellidae and Glyceridae. Cluster (Bray-Curtis similarities) analyses revealed that the Tanjung Adang and Merambong Shoal population were clearly separated from the station non-seagrass. For the time being factors that influence the pattern of distribution of the macrobenthos cannot be determined and subjected to further studies.

  3. Modern tree species composition reflects ancient Maya "forest gardens" in northwest Belize.

    Science.gov (United States)

    Ross, Nanci J

    2011-01-01

    Ecology and ethnobotany were integrated to assess the impact of ancient Maya tree-dominated home gardens (i.e., "forest gardens"), which contained a diversity of tree species used for daily household needs, on the modern tree species composition of a Mesoamerican forest. Researchers have argued that the ubiquity of these ancient gardens throughout Mesoamerica led to the dominance of species useful to Maya in the contemporary forest, but this pattern may be localized depending on ancient land use. The tested hypothesis was that species composition would be significantly different between areas of dense ancient residential structures (high density) and areas of little or no ancient settlement (low density). Sixty-three 400-m2 plots (31 high density and 32 low density) were censused around the El Pilar Archaeological Reserve in northwestern Belize. Species composition was significantly different, with higher abundances of commonly utilized "forest garden" species still persisting in high-density forest areas despite centuries of abandonment. Subsequent edaphic analyses only explained 5% of the species composition differences. This research provides data on the long-term impacts of Maya forests gardens for use in development of future conservation models. For Mesoamerican conservation programs to work, we must understand the complex ecological and social interactions within an ecosystem that developed in intimate association with humans.

  4. Temporal dynamics of abundance and composition of nitrogen-fixing communities across agricultural soils.

    Directory of Open Access Journals (Sweden)

    Michele C Pereira E Silva

    Full Text Available BACKGROUND: Despite the fact that the fixation of nitrogen is one of the most significant nutrient processes in the terrestrial ecosystem, a thorough study of the spatial and temporal patterns in the abundance and distribution of N-fixing communities has been missing so far. METHODOLOGY/PRINCIPAL FINDINGS: In order to understand the dynamics of diazotrophic communities and their resilience to external changes, we quantified the abundance and characterized the bacterial community structures based on the nifH gene, using real-time PCR, PCR-DGGE and 454-pyrosequencing, across four representative Dutch soils during one growing season. In general, higher nifH gene copy numbers were observed in soils with higher pH than in those with lower pH, but lower numbers were related to increased nitrate and ammonium levels. Results from nifH gene pyrosequencing confirmed the observed PCR-DGGE patterns, which indicated that the N fixers are highly dynamic across time, shifting around 60%. Forward selection on CCA analysis identified N availability as the main driver of these variations, as well as of the evenness of the communities, leading to very unequal communities. Moreover, deep sequencing of the nifH gene revealed that sandy soils (B and D had the lowest percentage of shared OTUs across time, compared with clayey soils (G and K, indicating the presence of a community under constant change. Cosmopolitan nifH species (present throughout the season were affiliated with Bradyrhizobium, Azospirillum and Methylocistis, whereas other species increased their abundances progressively over time, when appropriate conditions were met, as was notably the case for Paenibacilus and Burkholderia. CONCLUSIONS: Our study provides the first in-depth pyrosequencing analysis of the N-fixing community at both spatial and temporal scales, providing insights into the cosmopolitan and specific portions of the nitrogen fixing bacterial communities in soil.

  5. Semiparametric bivariate zero-inflated Poisson models with application to studies of abundance for multiple species

    Science.gov (United States)

    Arab, Ali; Holan, Scott H.; Wikle, Christopher K.; Wildhaber, Mark L.

    2012-01-01

    Ecological studies involving counts of abundance, presence–absence or occupancy rates often produce data having a substantial proportion of zeros. Furthermore, these types of processes are typically multivariate and only adequately described by complex nonlinear relationships involving externally measured covariates. Ignoring these aspects of the data and implementing standard approaches can lead to models that fail to provide adequate scientific understanding of the underlying ecological processes, possibly resulting in a loss of inferential power. One method of dealing with data having excess zeros is to consider the class of univariate zero-inflated generalized linear models. However, this class of models fails to address the multivariate and nonlinear aspects associated with the data usually encountered in practice. Therefore, we propose a semiparametric bivariate zero-inflated Poisson model that takes into account both of these data attributes. The general modeling framework is hierarchical Bayes and is suitable for a broad range of applications. We demonstrate the effectiveness of our model through a motivating example on modeling catch per unit area for multiple species using data from the Missouri River Benthic Fishes Study, implemented by the United States Geological Survey.

  6. Nutritional composition of five food trees species products used in ...

    African Journals Online (AJOL)

    Nutritional composition of five food trees species products used in human diet during food shortage period in Burkina Faso. Thiombiano Daniabla Natacha Edwige, Parkouda Charles, Lamien Nieyidouba, Sere Aminata, Castro-Euler Ana Margarida, Boussim Issaka Joseph ...

  7. Regional and Seasonal Differences in Species Composition and Trophic Groups for Tidepool Fishes of a Western Pacific Island – Taiwan

    Directory of Open Access Journals (Sweden)

    Colin K. C. Wen

    2018-03-01

    Full Text Available 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

  8. Wood Chemical Composition in Species of Cactaceae: The Relationship between Lignification and Stem Morphology

    Science.gov (United States)

    Canché-Escamilla, Gonzalo; Soto-Hernández, Marcos

    2015-01-01

    In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs) and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content) in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous) with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35%) of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level. PMID:25880223

  9. Wood chemical composition in species of Cactaceae: the relationship between lignification and stem morphology.

    Directory of Open Access Journals (Sweden)

    Jorge Reyes-Rivera

    Full Text Available In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35% of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level.

  10. Wood chemical composition in species of Cactaceae: the relationship between lignification and stem morphology.

    Science.gov (United States)

    Reyes-Rivera, Jorge; Canché-Escamilla, Gonzalo; Soto-Hernández, Marcos; Terrazas, Teresa

    2015-01-01

    In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs) and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content) in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous) with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35%) of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level.

  11. Impact of copper on the diazotroph abundance and community composition during swine manure composting.

    Science.gov (United States)

    Yin, Yanan; Gu, Jie; Wang, Xiaojuan; Zhang, Kaiyu; Hu, Ting; Ma, Jiyue; Wang, Qianzhi

    2018-05-01

    Biological nitrogen fixation is a major pathway in ecosystems. This study investigated the effects of adding Cu at different levels (0, 200, and 2000 mg kg -1 ) on the diazotroph community during swine manure composting. Quantitative PCR and high-throughput sequencing were used to analyze the abundances of diazotrophs and the community composition based on the nifH gene. The nifH gene copy number was relatively high in the early stage of composting and Cu had a significant inhibitory effect on the nifH copy number. Furthermore, Cu decreased the diversity of nifH and changed the microbial community structure in the early stage. The nifH genes from members of Firmicutes and Clostridium were most abundant. Co-occurrence ecological network analysis showed that the Cu treatments affected the co-occurrence patterns of diazotroph communities and reduced the associations between different diazotrophs. Interestingly, Cu may weaken symbiotic diazotrophic interactions and enhance the roles of free-living diazotrophs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Influence of culture medium composition on relative mRNA abundances in domestic cat embryos.

    Science.gov (United States)

    Hribal, R; Jewgenow, K; Braun, B C; Comizzoli, P

    2013-04-01

    Different culture conditions have been used to produce domestic cat embryos. As part of the in vitro procedures, the medium composition significantly affects the quality of the embryo development also. Quality assessments based on cleavage kinetics and blastomere symmetry are useful, but embryos also can differ in their relative gene expression patterns despite similar morphological characteristics. The aim of this study was to compare cat embryos produced with two different in vitro culture systems routinely used in two different laboratories [Smithsonian Conservation Biology Institute, Washington D.C., USA (SCBI) and Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany (IZW)]. Specifically, relative mRNA expression patterns of critical genes for pre-implantation embryo development were assessed in both conditions. Embryos were produced in parallel in both culture systems by IVF using frozen-thawed ejaculated semen in the United States and fresh epididymal sperm in Germany. Success of embryo development in vitro was recorded as well as relative mRNA abundances [DNA methyltransferases 1 and 3A (DNMT1, DNMT3A), gap junction protein alpha 1 (GJA1), octamer-binding transcription factor 4 [OCT4], insulin-like growth factors 1 and 2 receptors (IGF1R, IGF2R), beta-actin (ACTB)] in pools of days 4-5 morulae by semi-quantitative RT-PCR assay. Percentages of cleaved embryos were similar (p > 0.05) between both culture systems, regardless of the location. OCT4 mRNA abundance was higher (p culture system compared with those from the IZW system when epididymal sperm was used for IVF. No clear correlation between the expression pattern and the culture system could be found for all other genes. It is suggested that OCT4 expression might be affected by the media composition in some conditions and can be the indicator of a better embryo quality. © 2012 Blackwell Verlag GmbH.

  13. Factors affecting the species composition of arable field boundary vegetation

    NARCIS (Netherlands)

    Kleijn, D.; Verbeek, M.

    2000-01-01

    1. In recent decades the botanical diversity of arable field boundaries has declined drastically. To determine the most important factors related to the species composition of arable field boundaries, the vegetation composition of 105 herbaceous boundaries, 1-m wide, in the central and eastern

  14. Proximate and mineral composition of four edible mushroom species

    African Journals Online (AJOL)

    Owner

    Key words: Edible mushrooms; food composition. INTRODUCTION. Mushrooms are saprophytes. ... riboflavin, biotin and thiamine (Chang and Buswell,. 1996). Ogundana and Fagade (1981) indicated that ... Four edible mushroom species were analyzed for food composition according to the Association of Official Analytical ...

  15. Density is not Destiny: Characterizing Terrestrial Exoplanet Geology from Stellar Compositional Abundances

    Science.gov (United States)

    Unterborn, Cayman T.

    2018-01-01

    A planet’s mass-radius relationship alone is not a good indicator for its potential to be "Earth-like." While useful in coarse characterizations for distinguishing whether an exoplanet is water/atmosphere- or rock/iron-dominated, there is considerable degeneracy in using the mass-radius relation to determine the mineralogy and structure of a purely terrestrial planet like the Earth. The chemical link between host-stars and rocky planets and the utility of this connection in breaking the degeneracy in the mass-radius relationship is well documented. Given the breadth of observed stellar compositions, modeling the complex effects of these compositional variations on a terrestrial planet’s mineralogy, structure and temperature profile, and the potential pitfalls therein, falls within the purview of the geosciences.I will demonstrate here, the utility in adopting the composition of a terrestrial planet’s host star for contextualizing individual systems (e.g. TRAPPIST-1), as well as for the more general case of quantifying the geophysical consequences of stellar compositional diversity. This includes the potential for a host-star to produce planets able to undergo mantle convection, surface-to-interior degassing and long-term plate tectonics. As we search for truly “Earth-like” planets, we must move away from the simple density-driven definition of “Earth-like” and towards a more holistic view that includes both geochemistry and geophysics. Combining geophysical models and those of planetary formation with host-star abundance data, then, is of paramount importance. This will aid not only in our understanding of the mass-radius relationship but also provide foundational results necessary interpreting future atmospheric observations through the lens of surface-interior interactions (e.g. volcanism) and planetary evolution as a whole.

  16. Building essential biodiversity variables (EBVs) of species distribution and abundance at a global scale.

    Science.gov (United States)

    Kissling, W Daniel; Ahumada, Jorge A; Bowser, Anne; Fernandez, Miguel; Fernández, Néstor; García, Enrique Alonso; Guralnick, Robert P; Isaac, Nick J B; Kelling, Steve; Los, Wouter; McRae, Louise; Mihoub, Jean-Baptiste; Obst, Matthias; Santamaria, Monica; Skidmore, Andrew K; Williams, Kristen J; Agosti, Donat; Amariles, Daniel; Arvanitidis, Christos; Bastin, Lucy; De Leo, Francesca; Egloff, Willi; Elith, Jane; Hobern, Donald; Martin, David; Pereira, Henrique M; Pesole, Graziano; Peterseil, Johannes; Saarenmaa, Hannu; Schigel, Dmitry; Schmeller, Dirk S; Segata, Nicola; Turak, Eren; Uhlir, Paul F; Wee, Brian; Hardisty, Alex R

    2018-02-01

    Much biodiversity data is collected worldwide, but it remains challenging to assemble the scattered knowledge for assessing biodiversity status and trends. The concept of Essential Biodiversity Variables (EBVs) was introduced to structure biodiversity monitoring globally, and to harmonize and standardize biodiversity data from disparate sources to capture a minimum set of critical variables required to study, report and manage biodiversity change. Here, we assess the challenges of a 'Big Data' approach to building global EBV data products across taxa and spatiotemporal scales, focusing on species distribution and abundance. The majority of currently available data on species distributions derives from incidentally reported observations or from surveys where presence-only or presence-absence data are sampled repeatedly with standardized protocols. Most abundance data come from opportunistic population counts or from population time series using standardized protocols (e.g. repeated surveys of the same population from single or multiple sites). Enormous complexity exists in integrating these heterogeneous, multi-source data sets across space, time, taxa and different sampling methods. Integration of such data into global EBV data products requires correcting biases introduced by imperfect detection and varying sampling effort, dealing with different spatial resolution and extents, harmonizing measurement units from different data sources or sampling methods, applying statistical tools and models for spatial inter- or extrapolation, and quantifying sources of uncertainty and errors in data and models. To support the development of EBVs by the Group on Earth Observations Biodiversity Observation Network (GEO BON), we identify 11 key workflow steps that will operationalize the process of building EBV data products within and across research infrastructures worldwide. These workflow steps take multiple sequential activities into account, including identification and

  17. Density-dependent seedling mortality varies with light availability and species abundance in wet and dry Hawaiian forests

    Science.gov (United States)

    Faith Inman-Narahari; Rebecca Ostertag; Stephen P. Hubbell; Christian P. Giardina; Susan Cordell; Lawren Sack; Andrew MacDougall

    2016-01-01

    Conspecific density may contribute to patterns of species assembly through negative density dependence (NDD) as predicted by the Janzen-Connell hypothesis, or through facilitation (positive density dependence; PDD). Conspecific density effects are expected to be more negative in darker and wetter environments due to higher pathogen abundance and...

  18. Invertebrate composition and abundance associated with Didymosphenia geminata in a montane stream

    Science.gov (United States)

    James, Daniel A.; Ranney, Steven H.; Chipps, Steven R.; Spindler, Bryan D.

    2010-01-01

    Didymosphenia geminata, a relatively new aquatic nuisance species that can form extensive, mucilaginous mats on stream substrates, was reported from Rapid Creek, South Dakota in 2002. To examine the association between D. geminata and the invertebrate community in Rapid Creek, macroinvertebrates were quantified using three gear types in the fall of 2006. D. geminata was present at two of four sites sampled (range = 5.53 to 809.68 g m−2 dry mass). At each site, invertebrates were collected using dip nets, Surber samplers, and drift nets. The combined percentage of Ephemeroptera, Plecoptera, and Trichoptera in areas with D. geminata was lower (41%) than in areas without D. geminata (76%). Diptera abundance was higher at sites with D. geminata than in sites where D. geminata was absent.

  19. Dynamics of anopheline vector species composition and reported ...

    African Journals Online (AJOL)

    Indoor resting mosquitoes were collected between November 2013 and May 2014 using Pyrethrum spray collection (PSC). The mosquitoes were identified using morphological keys and species specific polymerase chain reaction (PCR) assays. The species composition of members of the An. gambiae complex and ...

  20. Tree species composition within Kano State University of science ...

    African Journals Online (AJOL)

    The study accessed the tree species composition within the Kano State University of Science and Technology Wudil, Kano State, Nigeria with the view of providing information that will help in the management and conservation of tree species within the campus. The study area was stratified into four (4) sections from which ...

  1. Factors affecting Archaeal Lipid Compositions of the Sulfolobus Species

    Science.gov (United States)

    He, L.; Han, J.; Wei, Y.; Lin, L.; Wei, Y.; Zhang, C.

    2010-12-01

    Temperature is the best known variable affecting the distribution of the archaeal glycerol dibiphytanyl glycerol tetraethers (GDGTs) in marine and freshwater systems. Other variables such as pH, ionic strength, or bicarbonate concentration may also affect archaeal GDGTs in terrestrial systems. Studies of pure cultures can help us pinpoint the specific effects these variables may have on archaeal lipid distribution in natural environments. In this study, three Sulfolobus species (HG4, HB5-2, HB9-6) isolated from Tengchong hot springs (pH 2-3, temperature 73-90°C) in China were used to investigate the effects of temperature, pH, substrate, and type of strain on the composition of GDGTs. Results showed that increase in temperature had negative effects on the relative contents of GDGT-0 (no cyclopentyl rings), GDGT-1 (one cyclopentyl ring), GDGT-2 and GDGT-3 but positive effects on GDGT-4, GDGT-4', GDGT-5 and GDGT-5'. Increase in pH, on the other hand, had negative effects on GDGT-0, GDGT-1, GDGT-4', GDGT-5 and GDGT-5', and positive effects on GDGT-3 and GDGT-4. GDGT-2 remained relatively constant with changing pH. When the HG4 was grown on different substrates, GDGT-5 was five time more abundant in sucrose-grown cultures than in yeast extract- or sulfur- grown cultures, suggesting that carbohydrates may stimulate the production of GDGT-5. For all three species, the ring index (average number of rings) of GDGTs correlated positively with incubation temperature. In HG4, ring index was much lower at optimal pH (3.5) than at other pH values. Ring index of HB5-2 or HB9-6 is higher than that of HG4, suggesting that speciation may affect the degree of cyclization of GDGT of the Sulfolobus. These results indicate that individual archaeal lipids respond differently to changes in environmental variables, which may be also species specific.

  2. Water Table Depth Reconstruction in Ombrotrophic Peatlands Using Biomarker Abundance Ratios and Compound-Specific Hydrogen Isotope Composition

    Science.gov (United States)

    Nichols, J. E.; Jackson, S. T.; Booth, R. K.; Pendall, E. G.; Huang, Y.

    2005-12-01

    Sediment cores from ombrotrophic peat bogs provide sensitive records of changes in precipitation/evaporation (P/E) balance. Various proxies have been developed to reconstruct surface moisture conditions in peat bogs, including testate amoebae, plant macrofossils, and peat humification. Studying species composition of testate amoeba assemblages is time consuming and requires specialized training. Humification index can be influenced by environmental factors other than moisture balance. The plant macrofossil proxy is less quantitative and cannot be performed on highly decomposed samples. We demonstrate that the ratio of C23 alkane to C29 alkane abundance may provide a simple alternative or complementary means of tracking peatland water-table depth. Data for this proxy can be collected quickly using a small sample (100 mg dry). Water-table depth decreases during drought, and abundance of Sphagnum, the dominant peat-forming genus, decreases as vascular plants increase. Sphagnum moss produces mainly medium chain-length alkanes (C21-C25) while vascular plants (grasses and shrubs) produce primarily longer chain-length alkanes (C27-C31). Therefore, C23:C29 n-alkane ratios quantitatively track the water table depth fluctuations in peat bogs. We compared C23:C29 n-alkane ratios in a core from Minden Bog (southeastern Michigan) with water table depth reconstructions based on testate-amoeba assemblages and humification. The 184-cm core spans the past ~3kyr of continuous peat deposition in the bog. Our results indicate that the alkane ratios closely track the water table depth variations, with C29 most abundant during droughts. We also explored the use of D/H ratios in Sphagnum biomarkers as a water-table depth proxy. Compound-specific hydrogen isotope ratio analyses were performed on Sphagnum biomarkers: C23 and C25 alkane and C24 acid. Dry periods are represented in these records by an enrichment of deuterium in these Sphagnum-specific compounds. These events also correlate

  3. Patrones de forrajeo en dos especies de peces intermareales herbívoros de las costas de Chile: Efecto de la abundancia y composición química del alimento Foraging patterns of two species of intertidal herbivorous fishes: Effect of food abundance and chemical composition

    Directory of Open Access Journals (Sweden)

    CRISTIAN W. CACERES

    2000-06-01

    in relation to fish herbivory are: i which are the factors that determine the selection or rejection of a given algal item? and ii are herbivorous fishes capable of extracting the nutrients and energy of a macroalgal diet? In this work, we studied in two species of herbivorous intertidal fishes, Scartichthys viridis and Girella laevifrons, the patterns of food selectivity in the field and in laboratory experiments, the assimilation efficiency for different dietary algal items, and the relationship between the observed patterns and the chemical composition of the algae. The results showed that more than 90% of the diet of these organisms consisted of benthic macroalgae. In the field both species present a non-selective trophic behavior in summer and selective one in winter, characterized by the consumption of green algae in the later season. Furthermore, in the experiments of food selection both species showed a similar pattern characterized by the preference of green and red algae. The results of the assimilation experiments, indicate that Girella laevifrons presents higher values of this parameter than Scartichthys viridis, being in the former the green algae Ulva and Enteromorpha, the items that present a higher efficiency of assimilation. Finally, the results obtained suggest in this herbivorous species a strong relationship among the patterns of food selection and the relationship between food composition and digestive characteristics

  4. Effects of copper on species composition of periphyton in a Sierra Nevada, California, stream

    Energy Technology Data Exchange (ETDEWEB)

    Leland, H.V.; Carter, J.L.

    1984-06-01

    Changes in species composition of the periphyton of an oliotrophic, Sierra Nevada stream continuously dosed for 1 year at three concentrations of copper (2.5, 5 and 10..mu..g 1/sup -1/ Cu/sub T/; approximately 12, 25 and 50 ng 1/sup -1/ Cu/sup 2 +/) were determined. The numerically most abundant taxa were Bacillariophyceae (Achnanthes minutissima, Cocconeis placentula, Cymbella microcephala, C. sinuata, Fragilaria construens, F. crotonensis, Navicula spp., Synedra acus and S. rumpens), and the Cyanophyta Lynbya spp., a co-dominant during spring and summer. Population densities of Lyngbya spp. were markedly reduced at all test concentrations of copper. Population densities of the principal Chlorophyta (Spirogyra spp. and Cladophora spp.) and the diatom Amphipleura pellucida were reduced at 5 ..mu..g 1/sup -1/ Cu/sub T/. Of the twenty-two most abundant taxa, sixteen were reduced in abundance by continuous exposure to 10 ..mu..g 1/sup -1/ Cu/sub T/. There was no commensurate reduction in standing crop (total number of individuals of all taxa). Achnanthes minutissima, a co-dominant in the control, was the primary replacement species. Other taxa that were more abundant at 5 ..mu..g 1/sup -1/ Cu/sub T/ than in the control were Ceratoneis arcus, Cocconeis placentula, Navicula spp. and Synedra rumpens. Only A. minutissima and Calothrix spp. were more abundant at l10 ..mu..g 1/sup -1/ than in the control. Three resemblance measures (Canberra metric, Bray-Curtis and Dice) and diversity (Brillouin's) were evaluated for detecting differences in species composition among experimental stream sections. The Canberra metric, an index sensitive to proportional rather than absolute differences, was the most informative of these indices.

  5. Effects of habitat-forming species richness, evenness, identity, and abundance on benthic intertidal community establishment and productivity.

    Directory of Open Access Journals (Sweden)

    Julie Lemieux

    Full Text Available In a context of reduced global biodiversity, the potential impacts from the loss of habitat-forming species (HFS on ecosystem structure and functioning must be established. These species are often the main community primary producers and have a major role in the establishment of organisms through facilitation processes. This study focuses on macroalgae and mussels as HFS within an intertidal zone along the St. Lawrence estuary (Quebec, Canada. Over a 16-week period, we manipulated the in situ diversity profile (richness, evenness, identity, and abundance of the dominant HFS (Fucus distichus edentatus, F. vesiculosus, and Mytilus spp. in order to define their role in both the establishment of associated species and community primary production. Contrary to expectation, no general change in HFS richness, evenness, abundance, or identity on associated species community establishment was observed. However, over the study period, the HFS diversity profile modified the structure within the trophic guilds, which may potentially affect further community functions. Also, our results showed that the low abundance of HFS had a negative impact on the primary productivity of the community. Our results suggest that HFS diversity profiles have a limited short-term role in our study habitat and may indicate that biological forcing in these intertidal communities is less important than environmental conditions. As such, there was an opportunistic establishment of species that ensured rapid colonization regardless of the absence, or the diversity profile, of facilitators such as HFS.

  6. Valuing the Recreational Benefits of Wetland Adaptation to Climate Change: A Trade-off Between Species' Abundance and Diversity

    Science.gov (United States)

    Faccioli, Michela; Riera Font, Antoni; Torres Figuerola, Catalina M.

    2015-03-01

    Climate change will further exacerbate wetland deterioration, especially in the Mediterranean region. On the one side, it will accelerate the decline in the populations and species of plants and animals, this resulting in an impoverishment of biological abundance. On the other one, it will also promote biotic homogenization, resulting in a loss of species' diversity. In this context, different climate change adaptation policies can be designed: those oriented to recovering species' abundance and those aimed at restoring species' diversity. Based on the awareness that knowledge about visitors' preferences is crucial to better inform policy makers and secure wetlands' public use and conservation, this paper assesses the recreational benefits of different adaptation options through a choice experiment study carried out in S'Albufera wetland (Mallorca). Results show that visitors display positive preferences for an increase in both species' abundance and diversity, although they assign a higher value to the latter, thus suggesting a higher social acceptability of policies pursuing wetlands' differentiation. This finding acquires special relevance not only for adaptation management in wetlands but also for tourism planning, as most visitors to S'Albufera are tourists. Thus, given the growing competition to attract visitors and the increasing demand for high environmental quality and unique experiences, promoting wetlands' differentiation could be a good strategy to gain competitive advantage over other wetland areas and tourism destinations.

  7. Composition, Diversity and Abundance of Gut Microbiome in Prediabetes and Type 2 Diabetes.

    Science.gov (United States)

    Lambeth, Stacey M; Carson, Trechelle; Lowe, Janae; Ramaraj, Thiruvarangan; Leff, Jonathan W; Luo, Li; Bell, Callum J; Shah, Vallabh O

    2015-12-26

    Association between type 2 diabetes (T2DM) and compositional changes in the gut micro biota is established, however little is known about the dysbiosis in early stages of Prediabetes (preDM). The purpose of this investigation is to elucidate the characteristics of the gut micro biome in preDM and T2DM, compared to Non-Diabetic (nonDM) subjects. Forty nine subjects were recruited for this study, 15 nonDM, 20 preDM and 14 T2DM. Bacterial community composition and diversity were investigated in fecal DNA samples using Illumina sequencing of the V4 region within the 16S rRNA gene. The five most abundant phyla identified were: Bacteroidetes, Firmicutes, Proteobacteria, Verrucomicrobia , and Actinobacteria . Class Chloracido bacteria was increased in preDM compared to T2DM (p = 0.04). An unknown genus from family Pseudonocardiaceae was significantly present in preDM group compared to the others (p = 0.04). Genus Collinsella , and an unknown genus belonging to family Enterobacteriaceae were both found to be significantly increased in T2DM compared to the other groups (Collinsella, and p = 0.03, Enterobacteriaceae genus p = 0.02). PERMANOVA and Mantel tests performed did not reveal a relationship between overall composition and diagnosis group or HbA1C level. This study identified dysbiosis associated with both preDM and T2DM, specifically at the class and genus levels suggesting that earlier treatment in preDM could possibly have an impact on the intestinal micro flora transitioning to T2DM.

  8. Species composition of grasshoppers (Orthoptera) in open plots and farmlands in calabar metropolis, southern Nigeria.

    Science.gov (United States)

    Oku, E E; Arong, G A; Bassey, D A

    2011-04-15

    The grasshoppers are strategic in the welfare of man and may constitute a major threat when its population is not checked. A study on the distribution of grasshoppers in open plots and farmlands was carried out within Calabar Metropolis between August to November, 2010. A total of 295 grasshoppers belonging to 11 species grouped under 3 families (Tettigoniidae, Acrididae and Pyrgomorphidae) were collected from 8 study locations. Grasshoppers were collected weekly from all study sites using sweep nets between 11 a.m. to 4 p.m. The collection was done using sweep nets between 11 a.m. to 4 p.m. when grasshoppers baked themselves under the sun. The percentage abundance of these species were Spathosterrium pygmaeum (16.27%), Tettigonia viridissima (11.86%), Catantops spissus (11.19%) Acridaturita sp. (10.17%), Gastrimargus acrididae (9.83%), Schistocerca nitens (9.49%), Tylopsis sp. (7.46%), Zonocerus variegatus (6.78%), Omocestus viridulus (6.10%), Scudderia mexicana (5.76%) and Zonocerus elegans (5.08%). Tettigonia viridissima and Acridaturita sp. were largely distributed as it occurred in 7 of 8 study sites while Scudderia mexicana was the least distributed, as it was reported in 3 sites only. The dominant grasshopper species in open plot was Spathosterrium pygmaeum (19%) in relative abundance and the least was Zonocerus variegatus (0.64%). Zonocerus variegatus was the dominant species in farmland (14%) in relative abundance and the least was Schistocerca nitens (4%). Chi-square test showed a high significant difference between the distribution of grasshoppers in open plots and farmlands (p grasshopper species composition were attributed to lizard predation and management practices such as grass cutting, fertilizer and pesticide applications. It was therefore concluded that species abundance and population of grasshoppers could be enhanced by minimizing human activities that interfere with land use.

  9. Generalized additive models used to predict species abundance in the Gulf of Mexico: an ecosystem modeling tool.

    Directory of Open Access Journals (Sweden)

    Michael Drexler

    Full Text Available Spatially explicit ecosystem models of all types require an initial allocation of biomass, often in areas where fisheries independent abundance estimates do not exist. A generalized additive modelling (GAM approach is used to describe the abundance of 40 species groups (i.e. functional groups across the Gulf of Mexico (GoM using a large fisheries independent data set (SEAMAP and climate scale oceanographic conditions. Predictor variables included in the model are chlorophyll a, sediment type, dissolved oxygen, temperature, and depth. Despite the presence of a large number of zeros in the data, a single GAM using a negative binomial distribution was suitable to make predictions of abundance for multiple functional groups. We present an example case study using pink shrimp (Farfantepenaeus duroarum and compare the results to known distributions. The model successfully predicts the known areas of high abundance in the GoM, including those areas where no data was inputted into the model fitting. Overall, the model reliably captures areas of high and low abundance for the large majority of functional groups observed in SEAMAP. The result of this method allows for the objective setting of spatial distributions for numerous functional groups across a modeling domain, even where abundance data may not exist.

  10. Interdependence of environmental parameters and sand dwelling benthic species abundance: a multivariate approach

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.; Parulekar, A.H.

    Multivariate analysis showed dependence of distribution and abundance of sand dwelling fauna on more than one ecologically significant environmental parameters rather than one ecological master factor. Salinity, grain size, beach gradient, dissolved...

  11. Combining counts and incidence data: an efficient approach for estimating the log-normal species abundance distribution and diversity indices.

    Science.gov (United States)

    Bellier, Edwige; Grøtan, Vidar; Engen, Steinar; Schartau, Ann Kristin; Diserud, Ola H; Finstad, Anders G

    2012-10-01

    Obtaining accurate estimates of diversity indices is difficult because the number of species encountered in a sample increases with sampling intensity. We introduce a novel method that requires that the presence of species in a sample to be assessed while the counts of the number of individuals per species are only required for just a small part of the sample. To account for species included as incidence data in the species abundance distribution, we modify the likelihood function of the classical Poisson log-normal distribution. Using simulated community assemblages, we contrast diversity estimates based on a community sample, a subsample randomly extracted from the community sample, and a mixture sample where incidence data are added to a subsample. We show that the mixture sampling approach provides more accurate estimates than the subsample and at little extra cost. Diversity indices estimated from a freshwater zooplankton community sampled using the mixture approach show the same pattern of results as the simulation study. Our method efficiently increases the accuracy of diversity estimates and comprehension of the left tail of the species abundance distribution. We show how to choose the scale of sample size needed for a compromise between information gained, accuracy of the estimates and cost expended when assessing biological diversity. The sample size estimates are obtained from key community characteristics, such as the expected number of species in the community, the expected number of individuals in a sample and the evenness of the community.

  12. Determining the Diversity and Species Abundance Patterns in Arctic Soils using Rational Methods for Exploring Microbial Diversity

    Science.gov (United States)

    Ovreas, L.; Quince, C.; Sloan, W.; Lanzen, A.; Davenport, R.; Green, J.; Coulson, S.; Curtis, T.

    2012-12-01

    Arctic microbial soil communities are intrinsically interesting and poorly characterised. We have inferred the diversity and species abundance distribution of 6 Arctic soils: new and mature soil at the foot of a receding glacier, Arctic Semi Desert, the foot of bird cliffs and soil underlying Arctic Tundra Heath: all near Ny-Ålesund, Spitsbergen. Diversity, distribution and sample sizes were estimated using the rational method of Quince et al., (Isme Journal 2 2008:997-1006) to determine the most plausible underlying species abundance distribution. A log-normal species abundance curve was found to give a slightly better fit than an inverse Gaussian curve if, and only if, sequencing error was removed. The median estimates of diversity of operational taxonomic units (at the 3% level) were 3600-5600 (lognormal assumed) and 2825-4100 (inverse Gaussian assumed). The nature and origins of species abundance distributions are poorly understood but may yet be grasped by observing and analysing such distributions in the microbial world. The sample size required to observe the distribution (by sequencing 90% of the taxa) varied between ~ 106 and ~105 for the lognormal and inverse Gaussian respectively. We infer that between 5 and 50 GB of sequencing would be required to capture 90% or the metagenome. Though a principle components analysis clearly divided the sites into three groups there was a high (20-45%) degree of overlap in between locations irrespective of geographical proximity. Interestingly, the nearest relatives of the most abundant taxa at a number of most sites were of alpine or polar origin. Samples plotted on first two principal components together with arbitrary discriminatory OTUs

  13. Seasonal trends in abundance and composition of marine debris in selected public beaches in Peninsular Malaysia

    Science.gov (United States)

    Mobilik, Julyus-Melvin; Ling, Teck-Yee; Husain, Mohd-Lokman Bin; Hassan, Ruhana

    2015-09-01

    The abundance and composition of marine debris were investigated at Saujana (in the state of Negeri Sembilan) and Batu Rakit (in the state of Terengganu) beaches during surveys conducted in December 2012 (northeast monsoon), May 2013 (intermediate monsoon) and July 2013 (southwest monsoon). A total of 4,682 items of debris weighing 231.4 kg were collected and sorted. Batu Rakit received substantially greater quantities of debris (815±717 items/km or 40.4±13.0 kg/km) compared to Saujana (745±444 items/km or 36.7±18.0 kg/km). Total debris item was more abundant during the southwest monsoon (SWM) (1,122±737 items/km) compared to the northeast monsoon (NEM) (825±593 items/ km) and the intermediate monsoon (IM) (394±4 items/km) seasons. Plastic category (88%) was the most numerous items collected and object items contributed 44.18% includes packaging, plastic fragments, cups, plastic shopping bags, plastic food wrapper, clear plastic bottles from the total debris items collected. Object items associated with common source (47%) were the highest debris accumulated, followed by terrestrial (30%) and marine (23%) sources. The high percentage of common and terrestrial sources during SWM season requires immediate action by marine environment stakeholders to develop and introduce strategies to reduce if not totally eliminates the marine debris in the marine environment. Awareness should be continued and focused on beach users and vessels' crew to alert them on the alarming accumulation rate of marine debris and its pathways into the marine environment.

  14. Abundance, composition and activity of ammonia oxidizer and denitrifier communities in metal polluted rice paddies from South China.

    Directory of Open Access Journals (Sweden)

    Yuan Liu

    Full Text Available While microbial nitrogen transformations in soils had been known to be affected by heavy metal pollution, changes in abundance and community structure of the mediating microbial populations had been not yet well characterized in polluted rice soils. Here, by using the prevailing molecular fingerprinting and enzyme activity assays and comparisons to adjacent non-polluted soils, we examined changes in the abundance and activity of ammonia oxidizing and denitrifying communities of rice paddies in two sites with different metal accumulation situation under long-term pollution from metal mining and smelter activities. Potential nitrifying activity was significantly reduced in polluted paddies in both sites while potential denitrifying activity reduced only in the soils with high Cu accumulation up to 1300 mg kg-1. Copy numbers of amoA (AOA and AOB genes were lower in both polluted paddies, following the trend with the enzyme assays, whereas that of nirK was not significantly affected. Analysis of the DGGE profiles revealed a shift in the community structure of AOA, and to a lesser extent, differences in the community structure of AOB and denitrifier between soils from the two sites with different pollution intensity and metal composition. All of the retrieved AOB sequences belonged to the genus Nitrosospira, among which species Cluster 4 appeared more sensitive to metal pollution. In contrast, nirK genes were widely distributed among different bacterial genera that were represented differentially between the polluted and unpolluted paddies. This could suggest either a possible non-specific target of the primers conventionally used in soil study or complex interactions between soil properties and metal contents on the observed community and activity changes, and thus on the N transformation in the polluted rice soils.

  15. Transcriptome discovery in non-model wild fish species for the development of quantitative transcript abundance assays

    Science.gov (United States)

    Hahn, Cassidy M.; Iwanowicz, Luke R.; Cornman, Robert S.; Mazik, Patricia M.; Blazer, Vicki S.

    2016-01-01

    Environmental studies increasingly identify the presence of both contaminants of emerging concern (CECs) and legacy contaminants in aquatic environments; however, the biological effects of these compounds on resident fishes remain largely unknown. High throughput methodologies were employed to establish partial transcriptomes for three wild-caught, non-model fish species; smallmouth bass (Micropterus dolomieu), white sucker (Catostomus commersonii) and brown bullhead (Ameiurus nebulosus). Sequences from these transcriptome databases were utilized in the development of a custom nCounter CodeSet that allowed for direct multiplexed measurement of 50 transcript abundance endpoints in liver tissue. Sequence information was also utilized in the development of quantitative real-time PCR (qPCR) primers. Cross-species hybridization allowed the smallmouth bass nCounter CodeSet to be used for quantitative transcript abundance analysis of an additional non-model species, largemouth bass (Micropterus salmoides). We validated the nCounter analysis data system with qPCR for a subset of genes and confirmed concordant results. Changes in transcript abundance biomarkers between sexes and seasons were evaluated to provide baseline data on transcript modulation for each species of interest.

  16. Empirical phylogenies and species abundance distributions are consistent with pre-equilibrium dynamics of neutral community models with gene flow

    KAUST Repository

    Bonnet-Lebrun, Anne-Sophie

    2017-03-17

    Community characteristics reflect past ecological and evolutionary dynamics. Here, we investigate whether it is possible to obtain realistically shaped modelled communities - i.e., with phylogenetic trees and species abundance distributions shaped similarly to typical empirical bird and mammal communities - from neutral community models. To test the effect of gene flow, we contrasted two spatially explicit individual-based neutral models: one with protracted speciation, delayed by gene flow, and one with point mutation speciation, unaffected by gene flow. The former produced more realistic communities (shape of phylogenetic tree and species-abundance distribution), consistent with gene flow being a key process in macro-evolutionary dynamics. Earlier models struggled to capture the empirically observed branching tempo in phylogenetic trees, as measured by the gamma statistic. We show that the low gamma values typical of empirical trees can be obtained in models with protracted speciation, in pre-equilibrium communities developing from an initially abundant and widespread species. This was even more so in communities sampled incompletely, particularly if the unknown species are the youngest. Overall, our results demonstrate that the characteristics of empirical communities that we have studied can, to a large extent, be explained through a purely neutral model under pre-equilibrium conditions. This article is protected by copyright. All rights reserved.

  17. Transcriptome discovery in non-model wild fish species for the development of quantitative transcript abundance assays.

    Science.gov (United States)

    Hahn, Cassidy M; Iwanowicz, Luke R; Cornman, Robert S; Mazik, Patricia M; Blazer, Vicki S

    2016-12-01

    Environmental studies increasingly identify the presence of both contaminants of emerging concern (CECs) and legacy contaminants in aquatic environments; however, the biological effects of these compounds on resident fishes remain largely unknown. High throughput methodologies were employed to establish partial transcriptomes for three wild-caught, non-model fish species; smallmouth bass (Micropterus dolomieu), white sucker (Catostomus commersonii) and brown bullhead (Ameiurus nebulosus). Sequences from these transcriptome databases were utilized in the development of a custom nCounter CodeSet that allowed for direct multiplexed measurement of 50 transcript abundance endpoints in liver tissue. Sequence information was also utilized in the development of quantitative real-time PCR (qPCR) primers. Cross-species hybridization allowed the smallmouth bass nCounter CodeSet to be used for quantitative transcript abundance analysis of an additional non-model species, largemouth bass (Micropterus salmoides). We validated the nCounter analysis data system with qPCR for a subset of genes and confirmed concordant results. Changes in transcript abundance biomarkers between sexes and seasons were evaluated to provide baseline data on transcript modulation for each species of interest. Published by Elsevier Inc.

  18. Empirical phylogenies and species abundance distributions are consistent with pre-equilibrium dynamics of neutral community models with gene flow

    KAUST Repository

    Bonnet-Lebrun, Anne-Sophie; Manica, Andrea; Eriksson, Anders; Rodrigues, Ana S.L.

    2017-01-01

    Community characteristics reflect past ecological and evolutionary dynamics. Here, we investigate whether it is possible to obtain realistically shaped modelled communities - i.e., with phylogenetic trees and species abundance distributions shaped similarly to typical empirical bird and mammal communities - from neutral community models. To test the effect of gene flow, we contrasted two spatially explicit individual-based neutral models: one with protracted speciation, delayed by gene flow, and one with point mutation speciation, unaffected by gene flow. The former produced more realistic communities (shape of phylogenetic tree and species-abundance distribution), consistent with gene flow being a key process in macro-evolutionary dynamics. Earlier models struggled to capture the empirically observed branching tempo in phylogenetic trees, as measured by the gamma statistic. We show that the low gamma values typical of empirical trees can be obtained in models with protracted speciation, in pre-equilibrium communities developing from an initially abundant and widespread species. This was even more so in communities sampled incompletely, particularly if the unknown species are the youngest. Overall, our results demonstrate that the characteristics of empirical communities that we have studied can, to a large extent, be explained through a purely neutral model under pre-equilibrium conditions. This article is protected by copyright. All rights reserved.

  19. Abundance, food habits, and breeding season of exotic T ilapia zillii and native O reochromis niloticus L. fish species in Lake Zwai , Ethiopia

    Directory of Open Access Journals (Sweden)

    Padanillay C. Prabu

    2008-05-01

    Full Text Available Relative abundance, diet and breeding season overlap in the reproduction of exotic Tilapia zillii and native Oreochromis niloticus in Lake Zwai were studied from samples collected over 12 months. Younger fish of both species collected were also evaluated for food composition.Food items from stomachs of both species were collected and analysed using the frequency of occurrence method. In terms of number, T. zillii dominated O. niloticus at the sampling sites. In both species, macrophytes, detritus, blue green algae, diatoms, green algae, Ceratium, Euglena,and Phacus constituted foods of plant origin, whereas chironomid larvae, Copepoda, Cladocera,Rotifera, Nematoda, fish eggs, and fish scales constituted foods of animal origin. Foods of the latter type such as Ephemeroptera and mollusks were also noted in the diet of adult T. zillii.Despite the extensive overlap in food habits of the two species, however, the food items were found in the diet of the species with different average percentage frequencies of occurrence. The level of gonad maturation and gonadosomatic index (GSI values showed that in Lake Zwai breeding was year-round for both T. zillii and O. niloticus, with a peak during April-September and February-August respectively, indicating extended breeding season overlap in reproduction. The two species were always found together in the catches from the sampling sites, which indicated some niche overlap between them.

  20. 454 pyrosequencing to describe microbial eukaryotic community composition, diversity and relative abundance: a test for marine haptophytes.

    Directory of Open Access Journals (Sweden)

    Elianne Egge

    Full Text Available Next generation sequencing of ribosomal DNA is increasingly used to assess the diversity and structure of microbial communities. Here we test the ability of 454 pyrosequencing to detect the number of species present, and assess the relative abundance in terms of cell numbers and biomass of protists in the phylum Haptophyta. We used a mock community consisting of equal number of cells of 11 haptophyte species and compared targeting DNA and RNA/cDNA, and two different V4 SSU rDNA haptophyte-biased primer pairs. Further, we tested four different bioinformatic filtering methods to reduce errors in the resulting sequence dataset. With sequencing depth of 11000-20000 reads and targeting cDNA with Haptophyta specific primers Hap454 we detected all 11 species. A rarefaction analysis of expected number of species recovered as a function of sampling depth suggested that minimum 1400 reads were required here to recover all species in the mock community. Relative read abundance did not correlate to relative cell numbers. Although the species represented with the largest biomass was also proportionally most abundant among the reads, there was generally a weak correlation between proportional read abundance and proportional biomass of the different species, both with DNA and cDNA as template. The 454 sequencing generated considerable spurious diversity, and more with cDNA than DNA as template. With initial filtering based only on match with barcode and primer we observed 100-fold more operational taxonomic units (OTUs at 99% similarity than the number of species present in the mock community. Filtering based on quality scores, or denoising with PyroNoise resulted in ten times more OTU99% than the number of species. Denoising with AmpliconNoise reduced the number of OTU99% to match the number of species present in the mock community. Based on our analyses, we propose a strategy to more accurately depict haptophyte diversity using 454 pyrosequencing.

  1. Patterns of species richness and abundance among cactus communities receiving different rainfall levels in the semiarid region of Brazil

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Monteiro Ferreira

    Full Text Available ABSTRACT This study examines the variation in cacti species richness and abundance among sites with different average rainfall and soil types. We assessed a total of 3,660 individuals of six species of Cactaceae: Cereus jamacaru, Melocactus zehntneri, Pilosocereus gounellei, Pilosocereus pachycladus, Tacinga inamoena, and Tacinga palmadora. The greatest species richness and abundance of cacti were at locations with low rainfall and more clayey soils. The species studied differed in multidimensional representation, with some species being more positively related to soils with a higher proportion of fine particles (M. zehntneri and P. gounellei, while others were negatively related to soils with a higher proportion of coarser particles (T. inamoena or positively related to areas with higher rainfall and vegetation cover (C. jamacaru and P. pachycladus. The differential responses of the species of Cactaceae studied in relation to the gradients analyzed demonstrates the need for more research into the relationship between cacti and environmental variables in semiarid ecosystems with high environmental heterogeneity.

  2. Species diversity and abundance of wild birds in Dagona-Waterfowl ...

    African Journals Online (AJOL)

    hope&shola

    The study of bird species diversity and richness in Dagona-Waterfowl sanctuary was carried out in early wet and late dry ... conservation of important species that rural inhabitants ... wetland of international importance on waterfowl habitat,.

  3. Wide prevalence of hybridization in two sympatric grasshopper species may be shaped by their relative abundances.

    Science.gov (United States)

    Rohde, Katja; Hau, Yvonne; Weyer, Jessica; Hochkirch, Axel

    2015-09-16

    Hybridization between species is of conservation concern as it might threaten the genetic integrity of species. Anthropogenic factors can alter hybridization dynamics by introducing new potentially hybridizing species or by diminishing barriers to hybridization. This may even affect sympatric species pairs through environmental change, which so far has received little attention. We studied hybridization prevalence and the underlying behavioral mechanisms in two sympatric grasshopper species, a rare specialist (Chorthippus montanus) and a common generalist (Chorthippus parallelus). We conducted a mate choice experiment with constant intraspecific density and varying heterospecific density, i.e. varying relative frequency of both species. Mate choice was frequency-dependent in both species with a higher risk of cross-mating with increasing heterospecific frequency, while conspecific mating increased linearly with increasing conspecific density. This illustrates that reproductive barriers could be altered by environmental change, if the relative frequency of species pairs is affected. Moreover, we performed a microsatellite analysis to detect hybridization in twelve syntopic populations (and four allotopic populations). Hybrids were detected in nearly all syntopic populations with hybridization rates reaching up to 8.9 %. Genetic diversity increased for both species when hybrids were included in the data set, but only in the common species a positive correlation between hybridization rate and genetic diversity was detected. Our study illustrates that the relative frequency of the two species strongly determines the effectiveness of reproductive barriers and that even the more choosy species (Ch. montanus) may face a higher risk of hybridization if population size decreases and its relative frequency becomes low compared to its sister species. The asymmetric mate preferences of both species may lead to quasi-unidirectional gene flow caused by unidirectional

  4. Greenhouse gas emissions from dung pats vary with dung beetle species and with assemblage composition.

    Directory of Open Access Journals (Sweden)

    Irene Piccini

    Full Text Available Cattle farming is a major source of greenhouse gases (GHGs. Recent research suggests that GHG fluxes from dung pats could be affected by biotic interactions involving dung beetles. Whether and how these effects vary among beetle species and with assemblage composition is yet to be established. To examine the link between GHGs and different dung beetle species assemblages, we used a closed chamber system to measure fluxes of carbon dioxide (CO2, methane (CH4 and nitrous oxide (N2O from cattle dung pats. Targeting a total of four dung beetle species (a pat-dwelling species, a roller of dung balls, a large and a small tunnelling species, we ran six experimental treatments (four monospecific and two mixed and two controls (one with dung but without beetles, and one with neither dung nor beetles. In this setting, the overall presence of beetles significantly affected the gas fluxes, but different species contributed unequally to GHG emissions. When compared to the control with dung, we detected an overall reduction in the total cumulative CO2 flux from all treatments with beetles and a reduction in N2O flux from the treatments with the three most abundant dung beetle species. These reductions can be seen as beneficial ecosystem services. Nonetheless, we also observed a disservice provided by the large tunneler, Copris lunaris, which significantly increased the CH4 flux-an effect potentially traceable to the species' nesting strategy involving the construction of large brood balls. When fluxes were summed into CO2-equivalents across individual GHG compounds, dung with beetles proved to emit less GHGs than did beetle-free dung, with the mix of the three most abundant species providing the highest reduction (-32%. As the mix of multiple species proved the most effective in reducing CO2-equivalents, the conservation of diverse assemblages of dung beetles emerges as a priority in agro-pastoral ecosystems.

  5. Predicting abundance of 80 tree species following climate change in the Eastern United States

    Science.gov (United States)

    Louis R. Iverson; Anantha M. Prasad; Anantha M. Prasad

    1998-01-01

    Projected climate warming will potentially have profound effects on the earth?s biota, including a large redistribution of tree species. We developed models to evaluate potential shifts for 80 individual tree species in the eastern United States. First, environmental factors associated with current ranges of tree species were assessed using geographic information...

  6. Abundance, composition and activity of denitrifier communities in metal polluted paddy soils

    Science.gov (United States)

    Liu, Yuan; Liu, Yongzhuo; Zhou, Huimin; Li, Lianqing; Zheng, Jinwei; Zhang, Xuhui; Zheng, Jufeng; Pan, Genxing

    2016-01-01

    Denitrification is one of the most important soil microbial processes leading to the production of nitrous oxide (N2O). The potential changes with metal pollution in soil microbial community for N2O production and reduction are not well addressed. In this study, topsoil samples were collected both from polluted and non-polluted rice paddy fields and denitrifier communities were characterized with molecular fingerprinting procedures. All the retrieved nirK sequences could be grouped into neither α- nor β- proteobacteria, while most of the nosZ sequences were affiliated with α-proteobacteria. The abundances of the nirK and nosZ genes were reduced significantly in the two polluted soils. Thus, metal pollution markedly affected composition of both nirK and nosZ denitrifiers. While the total denitrifying activity and N2O production rate were both reduced under heavy metal pollution of the two sites, the N2O reduction rate showed no significant change. These findings suggest that N2O production activity could be sensitive to heavy metal pollution, which could potentially lead to a decrease in N2O emission in polluted paddies. Therefore, metal pollution could have potential impacts on soil N transformation and thus on N2O emission from paddy soils. PMID:26739424

  7. Community Composition and Abundance of Anammox Bacteria in Cattail Rhizosphere Sediments at Three Phenological Stages.

    Science.gov (United States)

    Zhou, Xiaohong; Zhang, Jinping; Wen, Chunzi

    2017-11-01

    The distribution of anammox bacteria in rhizosphere sediments of cattail (Typha orientalis) at different phenological stages was investigated. Results showed that the number of 16S rRNA gene copies of the anammox bacteria was considerably higher in the rhizosphere sediment than in the nonrhizosphere sediment and control sediment. The abundances of the anammox bacteria exhibited striking temporal variations in the three different cattail phenological stages. In addition, the Chao1 and Shannon H indexes of the anammox bacteria in cattail rhizosphere sediments had evident spatial and temporal variations at different phenological stages. Four anammox genera (Brocadia, Kuenenia, Jettenia, and a new cluster) were detected and had proportions of 34.18, 45.57, 0.63, and 19.62%, respectively. The CCA analysis results indicated that Cu, TN, Pb, and Zn were pivotal factors that affect anammox bacteria composition. The PCoA analysis results indicated that the community structure at the rhizosphere and nonrhizosphere sediments collected on July was relatively specific and was different from sediments collected on other months, suggesting that cattail can influence the community structures of the anammox bacteria at the maturity stage.

  8. Species richness and abundance of hesperioidea and papilionoidea (lepidoptera) in Las Delicias natural reserve, Santa Marta, Magdalena, Colombia

    International Nuclear Information System (INIS)

    Vargas Zapata, Maria A; Martinez Hernandez, Neis Jose; Gutierrez Moreno, Luis C and others

    2011-01-01

    In the foothills of the Sierra Nevada de Santa Marta, Colombia, are formations of dry tropical secondary forest hosting a fauna representative of lepidoptera, which can be used as an indicator of group condition, because of their sensitivity to intervention and specificity in the use of resources; in the present study the changes in richness and abundance of butterflies hesperioidea papilionoidea in nature reserve Las Delicias were evaluated. Two sampling sites with different degrees of intervention were selected. The first site is located between 400- 550 over sea level, while the second at 200 m. We performed four samples, from April to July 2008; using two networks lepidopterist and 10 van someren rydon traps baited with macerated fruit and fish. We captured 432 individuals belonging to 66 species, distributed in 52 genera. Nymphalidae were the most rich family (42) and abundance (250); highlighting the species mechanitis lysimnia fabricius (41 specimens), typical in forest with very good coverage. Site 2, was the most diverse (48) and abundance (236), because in this place there was a greater stratification and tree coverage, and the presence of water resources during the sampling. With the arrival of rain in June and July, there was greater flowering and fruiting of vegetation in the area, increasing the availability of resources and therefore a greater richness and abundance of papilionoidea and hesperioidea in the study area.

  9. The effects of forest structure on occurrence and abundance of three owl species (Aves: Strigidae in the Central Amazon forest

    Directory of Open Access Journals (Sweden)

    Obed G. Barros

    2009-03-01

    Full Text Available We investigated how forest structure affects the occurrence and abundance of three owl species: the crested owl Lophostrix cristata Daudin, 1800, the Amazon pygmy owl Glaucidium hardyi Vielliard, 1990, and the tawny-bellied screech owl Megascops watsonii Cassin, 1849. We surveyed the owls mostly between 07:00 and 11:00 pm from July 2001 to April 2002, in eighteen 8 km transects along trails at the Ducke Reserve, Manaus, Central Amazon, Brazil. We staked out 50 x 50 m plots where the presence and absence of the owls were recorded. We compared some components of the forest structure between plots where owls were present and plots where they were absent. The spatial variation in these components were related to the occurrence and abundance of the owls using models of multiple logistic and multiple linear regressions analysis, respectively. Lophostrix cristata is rare in many other areas of the Amazon forest, but it was the most abundant in our study area. Lophostrix cristata and G. hardyi were more concentrated along the uplands (central plateau, which divide the reserve into two drainage water-basins. Megascops watsonii was distributed mainly in the southeastern part of the reserve. Glaucidium hardyi was more often found in areas with larger canopy openness. In areas with higher abundance of snags, there was significantly higher occurrence of L. cristata and M. watsonii. Megascops watsonii was also more abundant in areas with higher abundance of forest trees and in areas bearing shallower leaf litter on the forest floor. This study is the first to analyze at large spatial scale the effects of forest structure on neotropical forest top predator nocturnal birds. The results indicate that forest structure can affect the occurrence and abundance of owls in the Amazon forest.

  10. Preliminary data on nutritional value of abundant species in supraforestal Pyrenean pastures

    Directory of Open Access Journals (Sweden)

    Marinas, A.

    2006-12-01

    Full Text Available

    The alpine pastures of the Pyrenees have been used as summer ranges for centuries and continue to be an important forage resource for livestock husbandry to this day. Some studies attribute high nutritional values to alpine pastures, but recent surveys have revealed weight-loss in animals summering in Pyrenean pastures. There is virtually no information available with regard to the nutritional value of the species which constitute Pyrenean summer pastures. Twenty-three of the most common species were analysed chemically to determine their nutritional value and their capacity to meet livestock requirements. Monthly samplings of uneaten plants were performed from June to September in plots where species were abundant. These samples were analysed to determine neutral detergent fiber (NDF, lignin (ADL, crude protein (CP, P, K and Mg content. In vitro dry matter digestibility (IVDMD was calculated using the pepsin-cellulase method and metabolizable energy (ME was estimated from it. On average, graminoids presented higher levels of NDF and lower levels of the other nutrients when compared with forbs. Month effect was significant for ADL, CP, P and K. In these cases June was the month which differed significantly from other months. Crude protein, P and K contents diminished with maturity, whereas ADL and Ca levels increased. NDF, IVDMD and Mg values remained fairly constant throughout the summer in both botanical groups. This fact is noteworthy because it may provide a constant supply of ME for herbivores during the grazing period (July to September. Dicotyledoneous forbs meet livestock requirements of all the nutrients analysed except P during the grazing period. Graminoids are deficient in ME (mainly for sheep, P and Mg, and their CP content is slightly low for the requirements of sheep. When cattle and sheep diets

  11. Species composition and diversity of fish larvae in the Subtropical Convergence Zone of the Sargasso Sea from morphology and DNA barcoding

    DEFF Research Database (Denmark)

    Ayala, Daniel Jiro; Munk, Peter; Riemann, Lasse

    2016-01-01

    . In order to evaluate spatial variability of larval fish in the region, we examined species diversity, composition and abundances at eight stations in the Subtropical Convergence Zone (STCZ) using morphological identification and DNA barcoding. From a total of approximately 3500 specimens collected...... of the strong environmental gradients. Common eel species were concentrated between the fronts whereas common myctophids were of highest abundance at the outer edges of the fronts. The abundances of most species were generally enhanced in the vicinity of the fronts. The use of combined morphological and DNA-barcoding...

  12. Higher species richness and abundance of fish and benthic invertebrates around submarine groundwater discharge in Obama Bay, Japan

    OpenAIRE

    Tatsuya Utsunomiya; Masaki Hata; Ryo Sugimoto; Hisami Honda; Shiho Kobayashi; Yoji Miyata; Makoto Yamada; Osamu Tominaga; Jun Shoji; Makoto Taniguchi

    2017-01-01

    Study focus: There have been far more studies on how the variability in surface water discharge affects production of animal communities in aquatic ecosystems while less information has been accumulated on the mechanisms of how the groundwater supply works. Study region: Physical and biological surveys were conducted to test the hypothesis that high level of submarine ground water discharge enhances species richness, abundance and biomass of fishes and invertebrates in coastal waters of Ob...

  13. New records and detailed distribution and abundance of selected arthropod species collected between 1999 and 2011 in Azorean native forests

    DEFF Research Database (Denmark)

    Borges, Paulo A. V.; Gaspar, Clara; Crespo, Luís Carlos Fonseca

    2016-01-01

    Background In this contribution we present detailed distribution and abundance data for arthropod species identified during the BALA – Biodiversity of Arthropods from the Laurisilva of the Azores (1999-2004) and BALA2 projects (2010-2011) from 18 native forest fragments inseven of the nine Azorean...... islands (all excluding Graciosa and Corvo islands, which have no native forest left). New information Of the total 286 species identified, 81% were captured between 1999 and 2000, a period during which only 39% of all the samples were collected. On average, arthropod richness for each island increased...

  14. Species composition and diversity of non-forest woody vegetation along roads in the agricultural landscape

    Directory of Open Access Journals (Sweden)

    Tóth Attila

    2016-03-01

    Full Text Available Non-forest woody vegetation represents an important component of green infrastructure in the agricultural landscape, where natural and semi-natural forest cover has only a low land use proportion. This paper focuses on linear woody vegetation structures along roads in the agricultural landscape and analyses them in three study areas in the Nitra Region, Slovakia. We evaluate species composition and diversity, species occurrence frequency or spatial distribution, their structure according to relatively achievable age and origin. For the evaluation of occurrence frequency, a Frequency Factor was proposed and applied. This factor allows a better comparison of different study areas and results in more representative findings. The study areas were divided into sectors based on visual landscape features, which are easily identifiable in the field, such as intersections and curves in roads, and intersections of roads with other features, such as cadastral or land boundaries, watercourses, etc. Based on the species abundance, woody plants present within the sectors were categorised into 1 predominant, 2 complementary and 3 mixed-in species; and with regard to their origin into 1 autochthonous and 2 allochthonous. Further, trees were categorised into 1 long-lived, 2 medium-lived and 3 short-lived tree species. The main finding is that among trees, mainly allochthonous species dominated. Robinia pseudoacacia L. was the predominant tree species in all three study areas. It was up to 4 times more frequent than other predominant tree species. Introduced tree species prevailed also among complementary and mixed-in species. Among shrubs, mainly native species dominated, while non-native species had a significantly lower proportion and spatial distribution. Based on these findings, several measures have been proposed to improve the overall ecological stability, the proportion and spatial distribution of native woody plant species. The recommendations and

  15. Molecular species composition of plant cardiolipin determined by liquid chromatography mass spectrometry

    Science.gov (United States)

    Zhou, Yonghong; Peisker, Helga

    2016-01-01

    Cardiolipin (CL), an anionic phospholipid of the inner mitochondrial membrane, provides essential functions for stabilizing respiratory complexes and is involved in mitochondrial morphogenesis and programmed cell death in animals. The role of CL and its metabolism in plants are less well understood. The measurement of CL in plants, including its molecular species composition, is hampered by the fact that CL is of extremely low abundance, and that plants contain large amounts of interfering compounds including galactolipids, neutral lipids, and pigments. We used solid phase extraction by anion exchange chromatography to purify CL from crude plant lipid extracts. LC/MS was used to determine the content and molecular species composition of CL. Thus, up to 23 different molecular species of CL were detected in different plant species, including Arabidopsis, mung bean, spinach, barley, and tobacco. Similar to animals, plant CL is dominated by highly unsaturated species, mostly containing linoleic and linolenic acid. During phosphate deprivation or exposure to an extended dark period, the amount of CL decreased in Arabidopsis, accompanied with an increased degree in unsaturation. The mechanism of CL remodeling during stress, and the function of highly unsaturated CL molecular species, remains to be defined. PMID:27179363

  16. Presence and abundance of non-native plant species associated with recent energy development in the Williston Basin

    Science.gov (United States)

    Preston, Todd M.

    2015-01-01

    The Williston Basin, located in the Northern Great Plains, is experiencing rapid energy development with North Dakota and Montana being the epicenter of current and projected development in the USA. The average single-bore well pad is 5 acres with an estimated 58,485 wells in North Dakota alone. This landscape-level disturbance may provide a pathway for the establishment of non-native plants. To evaluate potential influences of energy development on the presence and abundance of non-native species, vegetation surveys were conducted at 30 oil well sites (14 ten-year-old and 16 five-year-old wells) and 14 control sites in native prairie environments across the Williston Basin. Non-native species richness and cover were recorded in four quadrats, located at equal distances, along four transects for a total of 16 quadrats per site. Non-natives were recorded at all 44 sites and ranged from 5 to 13 species, 7 to 15 species, and 2 to 8 species at the 10-year, 5-year, and control sites, respectively. Respective non-native cover ranged from 1 to 69, 16 to 76, and 2 to 82 %. Total, forb, and graminoid non-native species richness and non-native forb cover were significantly greater at oil well sites compared to control sites. At oil well sites, non-native species richness and forb cover were significantly greater adjacent to the well pads and decreased with distance to values similar to control sites. Finally, non-native species whose presence and/or abundance were significantly greater at oil well sites relative to control sites were identified to aid management efforts.

  17. Capture-recapture abundance and survival estimates of three cetacean species in Icelandic coastal waters using trained scientist-volunteers

    Science.gov (United States)

    Bertulli, Chiara G.; Guéry, Loreleï; McGinty, Niall; Suzuki, Ailie; Brannan, Naomi; Marques, Tania; Rasmussen, Marianne H.; Gimenez, Olivier

    2018-01-01

    Knowledge of abundance and survival of humpback whales, white-beaked dolphins and minke whales are essential to manage and conserve these species in Icelandic coastal shelf waters. Our main goal was to test the feasibility of employing inexpensive research methods (data collected by trained-scientist volunteers onboard opportunistic vessels) to assess abundance and apparent survival. No previous studies in Iceland have investigated these two demographic parameters in these three cetacean species using open capture-recapture models accounting for imperfect and possibly heterogeneous detection. A transient effect was accounted for whenever required to estimate the population of resident individuals. Identification photographs were collected by scientist-trained volunteers for 7 years (2006-2013) from onboard commercial whale-watching vessels in the coastal waters of Faxaflói (southwest coast, 4400 km2) and Skjálfandi (northeast coast, 1100 km2), Iceland. We estimated an average abundance of 83 humpback whales (Mn; 95% confidence interval: 54-130) in Skjálfandi; 238 white-beaked dolphins (La; [163-321]) in Faxaflói; and 67 minke whales (Ba; [53-82]) in Faxaflói and 24 (14-31) in Skjálfandi. We also found that apparent survival was constant for all three species (Mn: 0.52 [0.41-0.63], La: 0.79 [0.64-0.88], Ba-Faxaflói: 0.80 [0.67-0.88], Ba-Skjálfandi: 0.96 [0.60-0.99]). Our results showed inter-annual variation in abundance estimates which were small for all species, and the presence of transience for minke whales. A significant increase in abundance during the study period was solely found in minke whale data from Skjálfandi. Humpback whales and white-beaked dolphins showed lower apparent survival rates compared to similar baleen whale and dolphin populations. Our results show data collected by trained-scientist volunteers can produce viable estimates of abundance and survival although bias in the methods we employed exist and need to be addressed. With the

  18. Site-specific assessments of the abundance of three inshore dolphin species to inform conservation and management

    Directory of Open Access Journals (Sweden)

    Alexander Mark Brown

    2016-02-01

    Full Text Available Assessing the abundance of wildlife populations is essential to their effective conservation and management. Concerns have been raised over the vulnerability of tropical inshore dolphins in waters off northern Australia to anthropogenic impacts on local populations, yet a lack of abundance data precludes assessment of their conservation status and the management of threats. Using small vessels as cost-effective research platforms, photo-identification surveys and capture-recapture models were applied to provide the first quantitative abundance data for Australian snubfin (Orcaella heinsohni, Australian humpback (Sousa sahulensis, and Indo-Pacific bottlenose dolphins (Tursiops aduncus at five sites in the Kimberley region of north-western Australia. The abundance of each species was highly variable between different sites, likely reflecting species-specific habitat preferences. Within the c. 130 km2 study sites, the estimated abundance of most species was ≤ 60 individuals (excluding calves, and fewer than 20 humpback dolphins were identified at each site in any one 3-5 week sampling period. However, larger estimates of c. 130 snubfin and c. 160 bottlenose dolphins were obtained at two different sites. Several local populations showed evidence of site fidelity, particularly snubfin dolphins. By implementing a standardized, multi-site approach, data on local populations were provided within a broader, regional context, and indicated that each species is patchily distributed in the region. This highlights the need for site-specific baseline data collection using appropriate survey techniques to quantitatively assess the potential impacts of threatening activities to local populations. These findings further illustrate the need to gain a greater understanding of known and potential threats to inshore dolphin populations, their relative impacts, and to mitigate where necessary. In particular, the level of interactions with inshore gillnet fisheries

  19. Determining sample size for assessing species composition in ...

    African Journals Online (AJOL)

    Species composition is measured in grasslands for a variety of reasons. Commonly, observations are made using the wheel-point apparatus, but the problem of determining optimum sample size has not yet been satisfactorily resolved. In this study the wheel-point apparatus was used to record 2 000 observations in each of ...

  20. Development of an Integrated Moisture Index for predicting species composition

    Science.gov (United States)

    Louis R. Iverson; Charles T. Scott; Martin E. Dale; Anantha Prasad

    1996-01-01

    A geographic information system (GIS) approach was used to develop an Integrated Moisture Index (IMI), which was used to predict species composition for Ohio forests. Several landscape features (a slope-aspect shading index, cumulative flow of water downslope, curvature of the landscape, and the water-holding capacity of the soil) were derived from elevation and soils...

  1. Comparison of lignocellulose composition in four major species of ...

    African Journals Online (AJOL)

    By principal component analysis (PCA), the components ADF and cellulose were the PC1 that were considered the foremost for the evaluation and selection of resource in the four species. The conclusions show that lignocellulose composition contents of Miscanthus culms were different. M. floridulus was more fit to ethanol ...

  2. Sampling efficiency for species composition assessments using the ...

    African Journals Online (AJOL)

    A pilot survey to determine the sampling efficiency of the wheel-point method, using the nearest plant method, to assess species composition (using replicate similarity related to sampling intensity, and total sampling time) was conducted on three plot sizes (20 x 20m, 30 x 30m, 40 x 40m) at two sites in a semi-arid savanna.

  3. Regional variation in Caribbean dry forest tree species composition

    Science.gov (United States)

    Janet Franklin; Julie Ripplinger; Ethan H. Freid; Humfredo Marcano-Vega; David W. Steadman

    2015-01-01

    How does tree species composition vary in relation to geographical and environmental gradients in a globally rare tropical/subtropical broadleaf dry forest community in the Caribbean? We analyzed data from 153 Forest Inventory and Analysis (FIA) plots from Puerto Rico and the U.S. Virgin Islands (USVI), along with 42 plots that we sampled in the Bahamian Archipelago (...

  4. Species composition, plant cover and diversity of recently reforested ...

    African Journals Online (AJOL)

    SERVER

    2007-12-17

    Dec 17, 2007 ... Deforestation, over-cultivation and rural growth have severely ... over-cultivation, plant populations changed, and biolo- ... Restoring community structure (e.g. species composi-tion ... plant diversity at all spatial scales are the criteria that should ..... taxonomic groups in recovering and restored forests.

  5. Epidemic disease decimates amphibian abundance, species diversity, and evolutionary history in the highlands of central Panama

    OpenAIRE

    Crawford, Andrew J.; Lips, Karen R.; Bermingham, Eldredge

    2010-01-01

    Amphibian populations around the world are experiencing unprecedented declines attributed to a chytrid fungal pathogen, Batrachochytrium dendrobatidis. Despite the severity of the crisis, quantitative analyses of the effects of the epidemic on amphibian abundance and diversity have been unavailable as a result of the lack of equivalent data collected before and following disease outbreak. We present a community-level assessment combining long-term field surveys and DNA barcode data describing...

  6. The natural abundance of 15N in litter and soil profiles under six temperate tree species: N cycling depends on tree species traits and site fertility

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Nilsson, Lars Ola; Schmidt, Inger Kappel

    2013-01-01

    We investigated the influence of tree species on the natural 15N abundance in forest stands under elevated ambient N deposition.We analysed δ15N in litter, the forest floor and three mineral soil horizons along with ecosystem N status variables at six sites planted three decades ago with five Eur...... to nitrate leaching or other N transformation processes....... species leached more nitrate.The δ15N pattern reflected tree species related traits affecting the N cycling as well as site fertility and former land use, and possibly differences in N leaching. The tree species δ15N patterns reflected fractionation caused by uptake of N through mycorrhiza rather than due...

  7. Regional Variation in Parasite Species Richness and Abundance in the Introduced Range of the Invasive Lionfish, Pterois volitans.

    Science.gov (United States)

    Sellers, Andrew J; Ruiz, Gregory M; Leung, Brian; Torchin, Mark E

    2015-01-01

    Parasites can play an important role in biological invasions. While introduced species often lose parasites from their native range, they can also accumulate novel parasites in their new range. The accumulation of parasites by introduced species likely varies spatially, and more parasites may shift to new hosts where parasite diversity is high. Considering that parasitism and disease are generally more prevalent at lower latitudes, the accumulation of parasites by introduced hosts may be greater in tropical regions. The Indo-Pacific lionfish (Pterois volitans) has become widely distributed across the Western Atlantic. In this study, we compared parasitism across thirteen locations in four regions, spanning seventeen degrees of latitude in the lionfish's introduced range to examine potential spatial variation in parasitism. In addition, as an initial step to explore how indirect effects of parasitism might influence interactions between lionfish and ecologically similar native hosts, we also compared parasitism in lionfish and two co-occurring native fish species, the graysby grouper, Cephalopholis cruentata, and the lizardfish, Synodus intermedius, in the southernmost region, Panama. Our results show that accumulation of native parasites on lionfish varies across broad spatial scales, and that colonization by ectoparasites was highest in Panama, relative to the other study sites. Endoparasite richness and abundance, on the other hand, were highest in Belize where lionfish were infected by twice as many endoparasite species as lionfish in other regions. The prevalence of all but two parasite species infecting lionfish was below 25%, and we did not detect an association between parasite abundance and host condition, suggesting a limited direct effect of parasites on lionfish, even where parasitism was highest. Further, parasite species richness and abundance were significantly higher in both native fishes compared to lionfish, and parasite abundance was negatively

  8. Regional Variation in Parasite Species Richness and Abundance in the Introduced Range of the Invasive Lionfish, Pterois volitans.

    Directory of Open Access Journals (Sweden)

    Andrew J Sellers

    Full Text Available Parasites can play an important role in biological invasions. While introduced species often lose parasites from their native range, they can also accumulate novel parasites in their new range. The accumulation of parasites by introduced species likely varies spatially, and more parasites may shift to new hosts where parasite diversity is high. Considering that parasitism and disease are generally more prevalent at lower latitudes, the accumulation of parasites by introduced hosts may be greater in tropical regions. The Indo-Pacific lionfish (Pterois volitans has become widely distributed across the Western Atlantic. In this study, we compared parasitism across thirteen locations in four regions, spanning seventeen degrees of latitude in the lionfish's introduced range to examine potential spatial variation in parasitism. In addition, as an initial step to explore how indirect effects of parasitism might influence interactions between lionfish and ecologically similar native hosts, we also compared parasitism in lionfish and two co-occurring native fish species, the graysby grouper, Cephalopholis cruentata, and the lizardfish, Synodus intermedius, in the southernmost region, Panama. Our results show that accumulation of native parasites on lionfish varies across broad spatial scales, and that colonization by ectoparasites was highest in Panama, relative to the other study sites. Endoparasite richness and abundance, on the other hand, were highest in Belize where lionfish were infected by twice as many endoparasite species as lionfish in other regions. The prevalence of all but two parasite species infecting lionfish was below 25%, and we did not detect an association between parasite abundance and host condition, suggesting a limited direct effect of parasites on lionfish, even where parasitism was highest. Further, parasite species richness and abundance were significantly higher in both native fishes compared to lionfish, and parasite

  9. 1 diversity and abundance of fish species in gbedikere lake, bassa

    African Journals Online (AJOL)

    ADEYEMI, S. O. , AKOMBU, P. M. AND I. A. ADIKWU. 1. Department of ... State in particular and Nigeria in general is blessed with natural and ... was formed ) , revealed 10 species representing 7 ... MATERIALS AND METHODS. Study Area.

  10. Differences in ecological structure, function, and native species abundance between native and invaded Hawaiian streams

    Science.gov (United States)

    Tara Holitzki; Richard A. MacKenzie; Tracy N. Wiegner; Karla J. McDermid

    2013-01-01

    Poeciliids, one of the most invasive species worldwide, are found on almost every continent and have been identified as an ‘‘invasive species of concern’’ in the United States, New Zealand, and Australia. Despite their global prevalence, few studies have quantified their impacts on tropical stream ecosystem structure, function, and biodiversity. Utilizing Hawaiian...

  11. Essential Oil Composition and Volatile Profile of Seven Helichrysum Species Grown in Italy.

    Science.gov (United States)

    Giovanelli, Silvia; De Leo, Marinella; Cervelli, Claudio; Ruffoni, Barbara; Ciccarelli, Daniela; Pistelli, Luisa

    2018-03-06

    Helichrysum genus consists of about 600 species widespread throughout the world, especially in South Africa and in the Mediterranean area. In this study the aroma profile (HS-SPME) and the EO compositions of seven Helichrysum species (H. cymosum, H. odoratissimum, H. petiolare, H. fontanesii, H. saxatile, H. sanguineum, and H. tenax) were evaluated. All the plants were grown in Italy under the same growth conditions. The volatile constituents, particularly monoterpenes, depended by the plant's genotype and ecological adaptation. This study represents the first headspace evaluation on the selected plants and the results evidenced that monoterpenes represented the main class of constituents in five of the seven species analysed (from 59.2% to 95.0%). The higher content in sesquiterpene hydrocarbons was observed in the Mediterranean species of H. sanguineum (68.0%). Only H. saxatile showed relative similar abundance of monoterpenes and sesquiterpene hydrocarbons. The essential oil composition of the majority of examined species are characterised by high percentage of sesquiterpenes (especially β-caryophyllene and δ-cadinene) ranging from 51.3% to 92.0%, except for H. cymosum, H. tenax, and H. sanguineum leaves where monoterpenes predominated (from 51.7% to 74.7%). © 2018 Wiley-VHCA AG, Zurich, Switzerland.

  12. [Species composition and distribution of medical mollusca in Shanghai City].

    Science.gov (United States)

    Guo, Yun-hai; Lv, Shan; Gu, Wen-biao; Liu, He-xiang; Wu, Ying; Zhang, Yi

    2015-02-01

    To investigate the species diversity and distribution of medical mollusca in Shanghai City. From August 2012 to October 2013, all kinds of habitats in 8 districts and counties in Shanghai City, namely Jiading, Qingpu, Baoshan, Minhang, Songjiang, Jinshan, Chongming, Pudong, were selected for the field survey according to the distribution characteristics of the river system, and all the specimens of medical mollusca in the investigation sites were collected and classified by morphological identification. Meanwhile, the species composition, habitats as well as the fauna of the medical mollusca collected were analyzed. A total of 5,211 specimens were collected, which belonged to 2 classes, 14 families, 18 genera and 25 species, including Oncomelania hupensis hupensis, Pomacea canaliculata, Parafossarulus striatulus, Alocinma longicornis, Physa acuta, Galba pervia, Hippeutis cantori, etc. The species numbers of medical mollusca in Chongming, Jinshan, Pudong new area and Qingpu districts (counties) were 22, 22, 21 and 20, respectively, which were more than those of other areas. The habitat analysis suggested that the species numbers in the river and wetland were the most, both of which were 14 species. The main faunas of the medical mollusca in Shanghai were the cosmopolitan and oriental species. The freshwater gastropod species are paucity in Shanghai City, but almost of them can be served as the intermediate hosts of certain parasites to transmit snail-related parasitic diseases, so the surveillance of medical mollusca should be strengthened.

  13. Essential oil composition of four Artemisia species from Ethiopia

    Directory of Open Access Journals (Sweden)

    N. Asfaw

    2015-01-01

    Full Text Available The essential oil composition of four Artemisia species, namely A. schimperi Sch. Bip. ex Engl. A. abyssinica Sch. Bip. ex A. Rich., A. afra Jacq. ex Willd., and A. absinthium L. (previously called A. rehan from Ethiopia has been studied. The essential oil obtained from A. absinthium (seedling from Europe grown in two places in Ethiopia (Addis Ababa and Butajira was also analyzed for comparison. Morphological study on the leaves of A. absinthium L. from Ethiopia (previously called A. rehan and A. absinthium (from Europe was also conducted. The essential oils were obtained by hydrodistillation using a Clevenger apparatus and analyzed by capillary GC and GC/MS. Forty three compounds representing 76 to 94% of the oils were identified. The composition of the essential oils of A. schimperi, A. afra and A. abyssinica are mainly dominated by irregular monoterpenes: yogomi alcohol (13.5-37.6%, artemisyl acetate (12.7-35.5%, and artemisia ketone (2.3-13.2%. The composition of the oil of A. absinthium (previously A. rehan however, differs from the other three species in having camphor (21.2-28.3% and davanone (21.3-26.5% as major components. The composition of A. absinthum (Europe was found to have β-thujone (42.3-66.4% and chamazulene (11.3-24.2% as major components. The study indicated that the composition of the essential oil of A. absinthium (previously A. rehan is not only different from the other three species but also from A. absinthium from Europe and does not belong to any of the chemotypes described for the species in the literature. The morphological study on the leaves also showed that it differs from that of A. absinthium from Europe. DOI: http://dx.doi.org/10.4314/bcse.v29i1.11

  14. AMINOACID COMPOSITION OF SOME SPECIES FROM INULA GENUS

    Directory of Open Access Journals (Sweden)

    A. A. Kruglaya

    2016-01-01

    Full Text Available The majority of medicinal plants and medicinal plant raw materials are understudied pharmacgostically. These plants include species from Inula genus, which range in Russia amounts to up to 40 species. Rhizomes and roots of the Inula helenium L. are broadly applied in scientific and traditional medicine. They have expectorate, styptic, and anti-inflammatory properties.The purpose of the study was to determine the amino-acid composition of some species from Inula genus (Inula germanica, Inula ensifolia, Inula aspera, Inula orientalis, which grow in different regions if the North Caucasus.Methods. The studies were carried out using AAA 400 amino acid analyzer, highly specialized automatized liquid chromatographer with computer management. Aboveground parts of the plants, gathered in mass blossom phase from wild-growing plants and then dried out were the objects of the study.Results. For the first time the amino acid composition and raw protein of some species from Inula genus was determined (Inula germanica, Inula ensifolia, Inula aspera, Inula orientalis, 16 amino acids were discovered, 7 of which were essential, and raw proteins which substantival composition amounted to 16.19% in Inula germanica, 10.78% in Inula ensifolia, Inula aspera (11.15%, Inula orientalis (13.94%.Conclusion. The results of the studies conducted broaden the data about amino acids and protein composition and quantitative content in the species from Inula genus and can be used to develop methods of analysis of the drugs, obtained from these plants.

  15. Decapod larvae distribution and species composition off the southern Portuguese coast

    Science.gov (United States)

    Pochelon, Patricia N.; Pires, Rita F. T.; Dubert, Jesús; Nolasco, Rita; Santos, A. Miguel P.; Queiroga, Henrique; dos Santos, Antonina

    2017-12-01

    For decapod crustaceans, the larval phase is the main responsible for dispersal, given the direct emission from adult habitats into the water column. Circulation patterns and behavioural mechanisms control the dispersal distance and connectivity between different areas. Information on larval distribution and abundance is required to predict the size and location of breeding populations, and correctly manage marine resources. Spatial distribution and abundance data of decapod larvae, and environmental parameters were assessed in winter surveys off the southern Portuguese coast. To better understand the oceanic structures driving larval distribution patterns, in situ physical parameters were measured and a hydrodynamical model used. Inter-annual, cross-shore and alongshore differences on decapod larvae distribution were found. Brachyuran crabs dominated the samples and similar taxa composition was observed in the most dynamic areas. Coastal taxa dominated the nearshore survey and were almost absent in the more offshore one, that registered much lower abundances. An upwelling front allowed a clear cross-shore species separation, also evident in the abundance values and number of taxa. Hydrodynamical conditions and adult habitats were the main factors explaining the observed patterns. Important missing information to understand the distribution patterns of decapod larval communities and the mechanisms behind them is given for the region.

  16. Species interactions in an Andean bird–flowering plant network: phenology is more important than abundance or morphology

    Directory of Open Access Journals (Sweden)

    Oscar Gonzalez

    2016-12-01

    Full Text Available Biological constraints and neutral processes have been proposed to explain the properties of plant–pollinator networks. Using interactions between nectarivorous birds (hummingbirds and flowerpiercers and flowering plants in high elevation forests (i.e., “elfin” forests of the Andes, we explore the importance of biological constraints and neutral processes (random interactions to explain the observed species interactions and network metrics, such as connectance, specialization, nestedness and asymmetry. In cold environments of elfin forests, which are located at the top of the tropical montane forest zone, many plants are adapted for pollination by birds, making this an ideal system to study plant–pollinator networks. To build the network of interactions between birds and plants, we used direct field observations. We measured abundance of birds using mist-nets and flower abundance using transects, and phenology by scoring presence of birds and flowers over time. We compared the length of birds’ bills to flower length to identify “forbidden interactions”—those interactions that could not result in legitimate floral visits based on mis-match in morphology. Diglossa flowerpiercers, which are characterized as “illegitimate” flower visitors, were relatively abundant. We found that the elfin forest network was nested with phenology being the factor that best explained interaction frequencies and nestedness, providing support for biological constraints hypothesis. We did not find morphological constraints to be important in explaining observed interaction frequencies and network metrics. Other network metrics (connectance, evenness and asymmetry, however, were better predicted by abundance (neutral process models. Flowerpiercers, which cut holes and access flowers at their base and, consequently, facilitate nectar access for other hummingbirds, explain why morphological mis-matches were relatively unimportant in this system. Future

  17. Simulated geographic variations of plant species richness, evenness and abundance using climatic constraints on plant functional diversity

    International Nuclear Information System (INIS)

    Kleidon, Axel; Pavlick, Ryan; Reu, Bjoern; Adams, Jonathan

    2009-01-01

    Among the most pronounced large-scale geographic patterns of plant biodiversity are the increase in plant species richness towards the tropics, a more even distribution of the relative abundances of plant species in the tropics, and a nearly log-normal relative abundance distribution. Here we use an individual-based plant diversity model that relates climatic constraints to feasible plant growth strategies to show that all three basic diversity patterns can be predicted merely from the climatic constraints acting upon plant ecophysiological trade-offs. Our model predicts that towards objectively 'harsher' environments, the range of feasible growth strategies resulting in reproductive plants is reduced, thus resulting in lower functional plant species richness. The reduction of evenness is attributed to a more rapid decline in productivity from the most productive to less productive plant growth strategies since the particular setup of the strategy becomes more important in maintaining high productivity in harsher environments. This approach is also able to reproduce the increase in the deviation from a log-normal distribution towards more evenly distributed communities of the tropics. Our results imply that these general biodiversity relationships can be understood primarily by considering the climatic constraints on plant ecophysiological trade-offs.

  18. Molecular assessment of bacterial vaginosis by Lactobacillus abundance and species diversity

    NARCIS (Netherlands)

    J.A.M. Dols (Joke); D. Molenaar (Douwe); van der Helm, J.J. (Jannie J.); Caspers, M.P.M. (Martien P.M.); Angelino-Bart, A.K. (Alie de Kat); F.H.J. Schuren (Frank); Speksnijder, A.G.C.L. (Adrianus G.C.L.); Westerhoff, H.V. (Hans V.); J.H. Richardus (Jan Hendrik); Boon, M.E. (Mathilde E.); G. Reid (Gregor); de Vries, H.J.C. (Henry J.C.); R. Kort (Remco)

    2016-01-01

    markdownabstract__Background:__ To date, women are most often diagnosed with bacterial vaginosis (BV) using microscopy based Nugent scoring or Amsel criteria. However, the accuracy is less than optimal. The aim of the present study was to confirm the identity of known BV-associated composition

  19. The abundance of pink-pigmented facultative methylotrophs in the root zone of plant species in invaded coastal sage scrub habitat.

    Science.gov (United States)

    Irvine, Irina C; Brigham, Christy A; Suding, Katharine N; Martiny, Jennifer B H

    2012-01-01

    Pink-pigmented facultative methylotrophic bacteria (PPFMs) are associated with the roots, leaves and seeds of most terrestrial plants and utilize volatile C(1) compounds such as methanol generated by growing plants during cell division. PPFMs have been well studied in agricultural systems due to their importance in crop seed germination, yield, pathogen resistance and drought stress tolerance. In contrast, little is known about the PPFM abundance and diversity in natural ecosystems, let alone their interactions with non-crop species. Here we surveyed PPFM abundance in the root zone soil of 5 native and 5 invasive plant species along ten invasion gradients in Southern California coastal sage scrub habitat. PPFMs were present in every soil sample and ranged in abundance from 10(2) to 10(5) CFU/g dry soil. This abundance varied significantly among plant species. PPFM abundance was 50% higher in the root zones of annual or biennial species (many invasives) than perennial species (all natives). Further, PPFM abundance appears to be influenced by the plant community beyond the root zone; pure stands of either native or invasive species had 50% more PPFMs than mixed species stands. In sum, PPFM abundance in the root zone of coastal sage scrub plants is influenced by both the immediate and surrounding plant communities. The results also suggest that PPFMs are a good target for future work on plant-microorganism feedbacks in natural ecosystems.

  20. The abundance of pink-pigmented facultative methylotrophs in the root zone of plant species in invaded coastal sage scrub habitat.

    Directory of Open Access Journals (Sweden)

    Irina C Irvine

    Full Text Available Pink-pigmented facultative methylotrophic bacteria (PPFMs are associated with the roots, leaves and seeds of most terrestrial plants and utilize volatile C(1 compounds such as methanol generated by growing plants during cell division. PPFMs have been well studied in agricultural systems due to their importance in crop seed germination, yield, pathogen resistance and drought stress tolerance. In contrast, little is known about the PPFM abundance and diversity in natural ecosystems, let alone their interactions with non-crop species. Here we surveyed PPFM abundance in the root zone soil of 5 native and 5 invasive plant species along ten invasion gradients in Southern California coastal sage scrub habitat. PPFMs were present in every soil sample and ranged in abundance from 10(2 to 10(5 CFU/g dry soil. This abundance varied significantly among plant species. PPFM abundance was 50% higher in the root zones of annual or biennial species (many invasives than perennial species (all natives. Further, PPFM abundance appears to be influenced by the plant community beyond the root zone; pure stands of either native or invasive species had 50% more PPFMs than mixed species stands. In sum, PPFM abundance in the root zone of coastal sage scrub plants is influenced by both the immediate and surrounding plant communities. The results also suggest that PPFMs are a good target for future work on plant-microorganism feedbacks in natural ecosystems.

  1. Zooplankton species identities, zooplankton species number per sample, and zooplankton abundance collected using zooplankton net as part of the California Cooperative Fisheries Investigation (CALCOFI) project, for 1994-03-01 (NODC Accession 9700104)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton species identities, zooplankton species number per sample, and zooplankton abundance were collected from March 1, 1994 to March 1, 1994. Data were...

  2. Seasonal phenology and species composition of the aphid fauna in a northern crop production area.

    Directory of Open Access Journals (Sweden)

    Sascha M Kirchner

    Full Text Available BACKGROUND: The species diversity of aphids and seasonal timing of their flight activity can have significant impacts on crop production, as aphid species differ in their ability to transmit plant viruses and flight timing affects virus epidemiology. The aim of the study was to characterise the species composition and phenology of aphid fauna in Finland in one of the northernmost intensive crop production areas of the world (latitude 64°. METHODOLOGY/PRINCIPAL FINDINGS: Flight activity was monitored in four growing seasons (2007-010 using yellow pan traps (YPTs placed in 4-8 seed potato fields and a Rothamsted suction trap. A total of 58,528 winged aphids were obtained, identified to 83 taxa based on morphology, and 34 species were additionally characterised by DNA barcoding. Seasonal flight activity patterns analysed based on YPT catch fell into three main phenology clusters. Monoecious taxa showed early or middle-season flight activity and belonged to species living on shrubs/trees or herbaceous plants, respectively. Heteroecious taxa occurred over the entire potato growing season (ca. 90 days. Abundance of aphids followed a clear 3-year cycle based on suction trap data covering a decade. Rhopalosiphum padi occurring at the end of the potato growing season was the most abundant species. The flight activity of Aphis fabae, the main vector of Potato virus Y in the region, and Aphis gossypii peaked in the beginning of potato growing season. CONCLUSIONS/SIGNIFICANCE: Detailed information was obtained on phenology of a large number aphid species, of which many are agriculturally important pests acting as vectors of plant viruses. Aphis gossypii is known as a pest in greenhouses, but our study shows that it occurs also in the field, even far in the north. The novel information on aphid phenology and ecology has wide implications for prospective pest management, particularly in light of climate change.

  3. Nekton communities in Hawaiian coastal wetlands: The distribution and abundance of introduced fish species

    Science.gov (United States)

    Richard Ames MacKenzie; Gregory L. Bruland

    2012-01-01

    Nekton communities were sampled from 38 Hawaiian coastal wetlands from 2007 to 2009 using lift nets, seines, and throw nets in an attempt to increase our understanding of the nekton assemblages that utilize these poorly studied ecosystems. Nekton were dominated by exotic species, primarily poeciliids (Gambusia affinis, Poecilia...

  4. Bird Species Diversity and Abundance in the Abiriw Sacred Grove in ...

    African Journals Online (AJOL)

    L. Kangah-Kesse1 , D. Attuquayefio1*, E. Owusu2, F. Gbogbo1

    attributed to (i) rapid population growth and its attendant problems of urbanization, migration, and resettlement, (ii) .... Species from other vegetation zones such as coastal thickets made up .... Habitat: F = Forest, S = Savanna, FSB = Forest-savanna boundary, FC = Forest clearings, CT = Coastal thicket, CFZ. = Coastal forest ...

  5. Delta smelt: Life history and decline of a once abundant species in the San Francisco Estuary

    Science.gov (United States)

    Moyle, Peter B.; Brown, Larry R.; Durand, John R; Hobbs, James A.

    2016-01-01

    This paper reviews what has been learned about Delta Smelt and its status since the publication of The State of Bay-Delta Science, 2008 (Healey et al. 2008). The Delta Smelt is endemic to the upper San Francisco Estuary. Much of its historic habitat is no longer available and remaining habitat is increasingly unable to sustain the population. As a listed species living in the central node of California’s water supply system, Delta Smelt has been the focus of a large research effort to understand causes of decline and identify ways to recover the species. Since 2008, a remarkable record of innovative research on Delta Smelt has been achieved, which is summarized here. Unfortunately, research has not prevented the smelt’s continued decline, which is the result of multiple, interacting factors. A major driver of decline is change to the Delta ecosystem from water exports, resulting in reduced outflows and high levels of entrainment in the large pumps of the South Delta. Invasions of alien species, encouraged by environmental change, have also played a contributing role in the decline. Severe drought effects have pushed Delta Smelt to record low levels in 2014–2015. The rapid decline of the species and failure of recovery efforts demonstrate an inability to manage the Delta for the “co-equal goals” of maintaining a healthy ecosystem and providing a reliable water supply for Californians. Diverse and substantial management actions are needed to preserve Delta Smelt.

  6. Mapping host-species abundance of three major exotic forest pests

    Science.gov (United States)

    Randall S. Morin; Andrew M. Liebhold; Eugene R. Luzader; Andrew J. Lister; Kurt W. Gottschalk; Daniel B. Twardus

    2005-01-01

    Periodically over the last century, forests of the Eastern United States devastated by invasive pests. We used existing data to predict the geographical extent of future damage from beech bark disease (BBD), hemlock woolly adelgid (HWA), and gypsy moth. The distributions of host species of these alien pests were mapped in 1-km2 cells by interpolating host basal area/ha...

  7. Community analysis of the abundance and diversity of mosquito species (Diptera

    NARCIS (Netherlands)

    Mohlmann, Tim W.R.; Wennergren, Uno; Tälle, Malin; Favia, Guido; Damiani, Claudia; Bracchetti, Luca; Koenraadt, Constantianus J.M.

    2017-01-01

    Background: Studies on mosquito species diversity in Europe often focus on a specific habitat, region or country. Moreover, different trap types are used for these sampling studies, making it difficult to compare and validate results across Europe. To facilitate comparisons of trapping sites and

  8. Abundance patterns of six fish species in the shallow coastal zone in The Netherlands

    NARCIS (Netherlands)

    Glorius, S.T.; Wolfshaar, van de K.E.; Tulp, I.Y.M.

    2012-01-01

    Sand nourishment is an essential part of the long term flood defense strategy of the Dutch coast. A distinction can be made between beach nourishments and underwater nourishments. This report concerns underwater nourishments. Nourishments have ecological consequences that differ between species

  9. Species Distribution Modelling: Contrasting presence-only models with plot abundance data

    NARCIS (Netherlands)

    Gomes, Vitor H.F.; Ijff, Stéphanie D.; Raes, Niels; Amaral, Iêda Leão; Salomão, Rafael P.; Coelho, Luiz De Souza; Matos, Francisca Dionízia De Almeida; Castilho, Carolina V.; Filho, Diogenes De Andrade Lima; López, Dairon Cárdenas; Guevara, Juan Ernesto; Magnusson, William E.; Phillips, Oliver L.; Wittmann, Florian; Carim, Marcelo De Jesus Veiga; Martins, Maria Pires; Irume, Mariana Victória; Sabatier, Daniel; Molino, Jean François; Bánki, Olaf S.; Guimarães, José Renan Da Silva; Pitman, Nigel C.A.; Piedade, Maria Teresa Fernandez; Mendoza, Abel Monteagudo; Luize, Bruno Garcia; Venticinque, Eduardo Martins; Novo, Evlyn Márcia Moraes De Leão; Vargas, Percy Núñez; Silva, Thiago Sanna Freire; Manzatto, Angelo Gilberto; Terborgh, John; Reis, Neidiane Farias Costa; Montero, Juan Carlos; Casula, Katia Regina; Marimon, Beatriz S.; Marimon, Ben Hur; Coronado, Euridice N.Honorio; Feldpausch, Ted R.; Duque, Alvaro; Zartman, Charles Eugene; Arboleda, Nicolás Castaño; Killeen, Timothy J.; Mostacedo, Bonifacio; Vasquez, Rodolfo; Schöngart, Jochen; Assis, Rafael L.; Medeiros, Marcelo Brilhante; Simon, Marcelo Fragomeni; Andrade, Ana; Laurance, William F.; Camargo, José Luís; Demarchi, Layon O.; Laurance, Susan G.W.; Farias, Emanuelle De Sousa; Nascimento, Henrique Eduardo Mendonça; Revilla, Juan David Cardenas; Quaresma, Adriano; Costa, Flavia R.C.; Vieira, Ima Célia Guimarães; Cintra, Bruno Barçante Ladvocat; Castellanos, Hernán; Brienen, Roel; Stevenson, Pablo R.; Feitosa, Yuri; Duivenvoorden, Joost F.; Aymard, Gerardo A.C.; Mogollón, Hugo F.; Targhetta, Natalia; Comiskey, James A.; Vicentini, Alberto; Lopes, Aline; Damasco, Gabriel; Dávila, Nállarett; García-Villacorta, Roosevelt; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Emilio, Thaise; Alonso, Alfonso; Neill, David; Dallmeier, Francisco; Ferreira, Leandro Valle; Araujo-Murakami, Alejandro; Praia, Daniel; Do Amaral, Dário Dantas; Carvalho, Fernanda Antunes; De Souza, Fernanda Coelho; Feeley, Kenneth; Arroyo, Luzmila; Pansonato, Marcelo Petratti; Gribel, Rogerio; Villa, Boris; Licona, Juan Carlos; Fine, Paul V.A.; Cerón, Carlos; Baraloto, Chris; Jimenez, Eliana M.; Stropp, Juliana; Engel, Julien; Silveira, Marcos; Mora, Maria Cristina Peñuela; Petronelli, Pascal; Maas, Paul; Thomas-Caesar, Raquel; Henkel, Terry W.; Daly, Doug; Paredes, Marcos Ríos; Baker, Tim R.; Fuentes, Alfredo; Peres, Carlos A.; Chave, Jerome; Pena, Jose Luis Marcelo; Dexter, Kyle G.; Silman, Miles R.; Jørgensen, Peter Møller; Pennington, Toby; Di Fiore, Anthony; Valverde, Fernando Cornejo; Phillips, Juan Fernando; Rivas-Torres, Gonzalo; Von Hildebrand, Patricio; Van Andel, Tinde R.; Ruschel, Ademir R.; Prieto, Adriana; Rudas, Agustín; Hoffman, Bruce; Vela, César I.A.; Barbosa, Edelcilio Marques; Zent, Egleé L.; Gonzales, George Pepe Gallardo; Doza, Hilda Paulette Dávila; Miranda, Ires Paula De Andrade; Guillaumet, Jean Louis; Pinto, Linder Felipe Mozombite; Bonates, Luiz Carlos De Matos; Silva, Natalino; Gómez, Ricardo Zárate; Zent, Stanford; Gonzales, Therany; Vos, Vincent A.; Malhi, Yadvinder; Oliveira, Alexandre A.; Cano, Angela; Albuquerque, Bianca Weiss; Vriesendorp, Corine; Correa, Diego Felipe; Torre, Emilio Vilanova; Van Der Heijden, Geertje; Ramirez-Angulo, Hirma; Ramos, José Ferreira; Young, Kenneth R.; Rocha, Maira; Nascimento, Marcelo Trindade; Medina, Maria Natalia Umaña; Tirado, Milton; Wang, Ophelia; Sierra, Rodrigo; Torres-Lezama, Armando; Mendoza, Casimiro; Ferreira, Cid; Baider, Cláudia; Villarroel, Daniel; Balslev, Henrik; Mesones, Italo; Giraldo, Ligia Estela Urrego; Casas, Luisa Fernanda; Reategui, Manuel Augusto Ahuite; Linares-Palomino, Reynaldo; Zagt, Roderick; Cárdenas, Sasha; Farfan-Rios, William; Sampaio, Adeilza Felipe; Pauletto, Daniela; Sandoval, Elvis H.Valderrama; Arevalo, Freddy Ramirez; Huamantupa-Chuquimaco, Isau; Garcia-Cabrera, Karina; Hernandez, Lionel; Gamarra, Luis Valenzuela; Alexiades, Miguel N.; Pansini, Susamar; Cuenca, Walter Palacios; Milliken, William; Ricardo, Joana; Lopez-Gonzalez, Gabriela; Pos, Edwin; Ter Steege, Hans

    2018-01-01

    Species distribution models (SDMs) are widely used in ecology and conservation. Presence-only SDMs such as MaxEnt frequently use natural history collections (NHCs) as occurrence data, given their huge numbers and accessibility. NHCs are often spatially biased which may generate inaccuracies in SDMs.

  10. Effects of constant and stepwise changes in temperature on the species abundance dynamics of four cladocera species

    Directory of Open Access Journals (Sweden)

    Verbitsky V. B.

    2011-09-01

    Full Text Available Laboratory experiments with natural zooplankton communities were carried out to study the effects of two contrasting temperature regimes: constant temperature (15, 20, and 25 °C and graded changes in temperature. The graded regime consisted of repeated sustained (three weeks controlled stepwise temperature changes of 5 or 10 °C within 15–25 °C on the population dynamics of four dominant species of lake littoral zooplankton, Daphnia longispina (Müller, 1785, Diaphanosoma brachyurum (Lievin, 1848, Simocephalus vetulus (Müller, 1776 and Chydorus sphaericus (Müller, 1785. The results show that controlled stepwise changes (positive or negative in temperature within the ranges of 15–20, 20–25, and 15–25 °C can exert either stimulating or inhibitory effect (direct or delayed on the development of D. longispina and S. vetulus populations. The development of D. brachyurum and Ch. sphaericus, both more steno-thermophile, was only stimulated by a stable elevated temperature (25 °C. These results support the previously formulated hypothesis that, in determining the ecological temperature optimum of a species within a natural community, it is not enough to define its optimum from constant, cyclic or random temperature fluctuations, but also from unidirectional stepwise changes in temperature. These stepwise changes may also induce prolonged or delayed effects.

  11. Species richness and abundance of bats in fragments of the stational semidecidual forest, Upper Paraná River, southern Brazil

    Directory of Open Access Journals (Sweden)

    H. Ortêncio-Filho

    Full Text Available The Upper Paraná River floodplain is inserted in a region of the Mata Atlântica biome, which is a critical area to preserve. Due to the scarcity of researches about the chiropterofauna in this region, the present study investigated species richness and abundance of bats in remnants from the stational semidecidual forest of the Upper Paraná River, southern Brazil. Samplings were taken every month, from January to December 2006, using 32 mist nets with 8.0 x 2.5 m, resulting in 640 m²/h and totaling a capture effort of 87,040 m²/h. In order to estimate the species richness, the following estimators were employed Chao1 and Jack2. During the study, a total of 563 individuals belonging to 17 species (Artibeus planirostris, Artibeus lituratus, Carollia perspicillata, Platyrrhinus lineatus, Sturnira lilium, Artibeus fimbriatus, Myotis nigricans, Desmodus rotundus, Artibeus obscurus, Noctilio albiventris, Phylostomus discolor, Phylostomus hastatus, Chrotopterus auritus, Lasiurus ega, Chiroderma villosum, Pygoderma bilabiatum and Lasiurus blossevillii were captured. The estimated richness curves tended to stabilize, indicating that most of the species were sampled. Captured species represented 10% of the taxa recorded in Brazil and 28% in Paraná State, revealing the importance of this area for the diversity of bats. These findings indicate the need to determine actions aiming to restrict human activities in these forest fragments, in order to minimize anthropogenic impacts on the chiropterofauna.

  12. Marine litter in the upper São Vicente submarine canyon (SW Portugal): Abundance, distribution, composition and fauna interactions.

    Science.gov (United States)

    Oliveira, Frederico; Monteiro, Pedro; Bentes, Luis; Henriques, Nuno Sales; Aguilar, Ricardo; Gonçalves, Jorge M S

    2015-08-15

    Marine litter has become a worldwide environmental problem, tainting all ocean habitats. The abundance, distribution and composition of litter and its interactions with fauna were evaluated in the upper S. Vicente canyon using video images from 3 remote operated vehicle exploratory dives. Litter was present in all dives and the abundance was as high as 3.31 items100m(-1). Mean abundance of litter over rock bottom was higher than on soft substrate. Mean litter abundance was slightly higher than reported for other canyons on the Portuguese margin, but lower in comparison to more urbanized coastal areas of the world. Lost fishing gear was the prevalent type of litter, indicating that the majority of litter originates from maritime sources, mainly fishing activity. Physical contact with sessile fauna and entanglement of specimens were the major impacts of lost fishing gear. Based on the importance of this region for the local fishermen, litter abundance is expected to increase. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Do competitive interactions in dry heathlands explain plant abundance patterns and species coexistence?

    DEFF Research Database (Denmark)

    Ransijn, Johannes; Damgaard, Christian; Schmidt, Inger K

    2015-01-01

    Plant community patterns in space and time may be explained by the interactions between competing plant species. The presented study investigates this in a nutrient and species poor ecosystem. The study presents a methodology for inferring competitive interactions from yearly vegetation inventories...... to predict the community dynamics of C. vulgaris and D. flexuosa. This was compared with the observed plant community structure at 198 Danish dry heathland sites. Interspecific competition will most likely lead to competitive exclusion of D. flexuosa at the observed temporal and spatial scale...... and uses this to assess the outcome of competitive interactions and to predict community patterns and dynamics in a Northwest-European dry heathland. Inferred competitive interactions from five consecutive years of measurements in permanent vegetation frames at a single dry heathland site were used...

  14. Abundance and species richness of snakes along the Middle Rio Grande riparian forest in New Mexico

    Science.gov (United States)

    Heather L. Bateman; Alice Chung-MacCoubrey; Howard L. Snell; Deborah M. Finch

    2009-01-01

    To understand the effects of removal of non-native plants and fuels on wildlife in the riparian forest of the Middle Rio Grande in New Mexico, we monitored snakes from 2000 to 2006 using trap arrays of drift fences, pitfalls, and funnel traps. We recorded 158 captures of 13 species of snakes from 12 study sites. We captured more snakes in funnel traps than in pitfalls...

  15. Draft Genome Sequences of Three Novel Low-Abundance Species Strains Isolated from Kefir Grain.

    Science.gov (United States)

    Kim, Yongkyu; Blasche, Sonja; Patil, Kiran R

    2017-09-28

    We report here the genome sequences of three novel bacterial species strains- Bacillus kefirresidentii Opo, Rothia kefirresidentii KRP, and Streptococcus kefirresidentii YK-isolated from kefir grains collected in Germany. The draft genomes of these isolates were remarkably dissimilar (average nucleotide identities, 77.80%, 89.01%, and 92.10%, respectively) to those of the previously sequenced strains. Copyright © 2017 Kim et al.

  16. Historical abundance and morphology of Didymosphenia species in Naknek Lake, Alaska

    OpenAIRE

    Pite, Danielle P.; Lane, Kelly A.; Hermann, Anna K.; Spaulding, Sarah A.; Finney, Bruce P.

    2009-01-01

    Since the 1980s, nuisance blooms of Didymosphenia geminata (Lyngbye) M. Schmidt have been documented in sites that are warmer and more mesotrophic than historical records indicate. While the invasion of D. geminata in New Zealand is well documented, it is less clear whether nuisance blooms in North America are a new phenomenon. In order to test the hypothesis that D. geminata blooms have increased in recent years, we examined the historical record of this species in sediments of Naknek Lake, ...

  17. The effect of peatland drainage and restoration on Odonata species richness and abundance

    OpenAIRE

    Elo, Merja; Penttinen, Jouni; Kotiaho, Janne Sakari

    2015-01-01

    Background Restoration aims at reversing the trend of habitat degradation, the major threat to biodiversity. In Finland, more than half of the original peatland area has been drained, and during recent years, restoration of some of the drained peatlands has been accomplished. Short-term effects of the restoration on peatland hydrology, chemistry and vegetation are promising but little is known about how other species groups apart from vascular plants and bryophytes respond to restoration effo...

  18. Abundance and composition of near surface microplastics and plastic debris in the Stockholm Archipelago, Baltic Sea.

    Science.gov (United States)

    Gewert, Berit; Ogonowski, Martin; Barth, Andreas; MacLeod, Matthew

    2017-07-15

    We collected plastic debris in the Stockholm Archipelago using a manta trawl, and additionally along a transect in the Baltic Sea from the island of Gotland to Stockholm in a citizen science study. The samples were concentrated by filtration and organic material was digested using hydrogen peroxide. Suspected plastic material was isolated by visual sorting and 59 of these were selected to be characterized with Fourier transform infrared spectroscopy. Polypropylene and polyethylene were the most abundant plastics identified among the samples (53% and 24% respectively). We found nearly ten times higher abundance of plastics near central Stockholm than in offshore areas (4.2×10 5 plastics km -2 compared to 4.7×10 4 plastics km -2 ). The abundance of plastic debris near Stockholm was similar to urban areas in California, USA, and the overall abundance in the Stockholm Archipelago was similar to plastic abundance reported in the northwestern Mediterranean Sea. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. SPECIES COMPOSITION OF PSAMMOPHILIC CILIATES OF SUMGAIT CASPIAN COAST

    Directory of Open Access Journals (Sweden)

    I. Kh. Alekperov

    2014-01-01

    Full Text Available Abstract. Comparative data on the species composition and species saprobic indicators of the psammon ciliates from Sumgait coast of the Caspian Sea are given.Methods. “Alive” samples were collected using a small clean plastic wide mouth bottles. Further processing was carried out under laboratory conditions. Small quantities of soil were examined under a binocular microscope MBS-9 . Ciliates detected microvessel caught and fixed castors for further impregnation kinetoma silver nitrate (Chatton et Lwoff, 1930 or silver proteinate. To determine the keys for ciliates used Foyssner’s major publications (Foissner et al., 1991, 1992, 1999 and “Free-living ciliates Atlas” (Alekperov, 2005.Results. We observed 75 species of ciliates during the studies, which species composition and distribution of the collection points are shown in table 1. Diagrams with average data were made relations groups psammophilous ciliates indicators saprobity different zones for each of the sites investigated Sumgait coast.Main conclusions. Environmental analysis using benthic ciliates indicators saprobity different zones showed that as expected, the industrial zone of Sumgayit coast coast, despite the decline in recent years, the total amount of pollution that is still highly contaminated portion of the coastal zone of the Caspian Sea.

  20. Plant Species Rather Than Climate Greatly Alters the Temporal Pattern of Litter Chemical Composition During Long-Term Decomposition

    Science.gov (United States)

    Li, Yongfu; Chen, Na; Harmon, Mark E.; Li, Yuan; Cao, Xiaoyan; Chappell, Mark A.; Mao, Jingdong

    2015-10-01

    A feedback between decomposition and litter chemical composition occurs with decomposition altering composition that in turn influences the decomposition rate. Elucidating the temporal pattern of chemical composition is vital to understand this feedback, but the effects of plant species and climate on chemical changes remain poorly understood, especially over multiple years. In a 10-year decomposition experiment with litter of four species (Acer saccharum, Drypetes glauca, Pinus resinosa, and Thuja plicata) from four sites that range from the arctic to tropics, we determined the abundance of 11 litter chemical constituents that were grouped into waxes, carbohydrates, lignin/tannins, and proteins/peptides using advanced 13C solid-state NMR techniques. Decomposition generally led to an enrichment of waxes and a depletion of carbohydrates, whereas the changes of other chemical constituents were inconsistent. Inconsistent convergence in chemical compositions during decomposition was observed among different litter species across a range of site conditions, whereas one litter species converged under different climate conditions. Our data clearly demonstrate that plant species rather than climate greatly alters the temporal pattern of litter chemical composition, suggesting the decomposition-chemistry feedback varies among different plant species.

  1. Fatty Acid Compositions of Six Wild Edible Mushroom Species

    Science.gov (United States)

    Günç Ergönül, Pelin; Akata, Ilgaz; Kalyoncu, Fatih; Ergönül, Bülent

    2013-01-01

    The fatty acids of six wild edible mushroom species (Boletus reticulatus, Flammulina velutipes var. velutipes, Lactarius salmonicolor, Pleurotus ostreatus, Polyporus squamosus, and Russula anthracina) collected from different regions from Anatolia were determined. The fatty acids were identified and quantified by gas chromatography and studied using fruit bodies. Fatty acid composition varied among species. The dominant fatty acid in fruit bodies of all mushrooms was cis-linoleic acid (18 : 2). Percentage of cis-linoleic acid in species varied from 22.39% to 65.29%. The other major fatty acids were, respectively, cis-oleic, palmitic, and stearic acids. Fatty acids analysis of the mushrooms showed that the unsaturated fatty acids were at higher concentrations than saturated fatty acids. PMID:23844377

  2. Fatty Acid Compositions of Six Wild Edible Mushroom Species

    Directory of Open Access Journals (Sweden)

    Pelin Günç Ergönül

    2013-01-01

    Full Text Available The fatty acids of six wild edible mushroom species (Boletus reticulatus, Flammulina velutipes var. velutipes, Lactarius salmonicolor, Pleurotus ostreatus, Polyporus squamosus, and Russula anthracina collected from different regions from Anatolia were determined. The fatty acids were identified and quantified by gas chromatography and studied using fruit bodies. Fatty acid composition varied among species. The dominant fatty acid in fruit bodies of all mushrooms was cis-linoleic acid (18 : 2. Percentage of cis-linoleic acid in species varied from 22.39% to 65.29%. The other major fatty acids were, respectively, cis-oleic, palmitic, and stearic acids. Fatty acids analysis of the mushrooms showed that the unsaturated fatty acids were at higher concentrations than saturated fatty acids.

  3. Species composition of insects in contaminated areas of Apsheron

    International Nuclear Information System (INIS)

    Guseynzadeh, G.A; Mamedova, T.G; Atakishiyeva, A.M; Hajiyeva, S.A

    2010-01-01

    Full text:The main area of the Apsheron Peninsula, semi-complete urbanization area, where as a result of human impact, in particular oil production and processing large areas of once fertile land have been ruined. As a result, formed locally contaminated sites where the oil soaks into the soil to a depth of 1m or more, the mold is completely ruined. The aim of our research was to study the species composition of bugs, beetles, butterflies, bees in these locally contaminated areas of Absheron, their relationships and nutritive degree of occurrence. Expeditionary trips were made in the following areas: Karadag, Seaside, Bibi Geybatsky, Surakhani, Sabunchu Oil Gas Mining Management, Ramaninsky iodine plant. These areas are divided into three gradations of anthropogenic strain:1) The weak degree of load-zone relatively clean; 2) The average degree of load-space of moderate economic use; A strong degree of load-immediately adjacent to the locally-contaminated sites. According to the results of environmental monitoring of terrestrial invertebrates group found: bugs, 22 species, 10 species of beetles, butterflies, eight species of bee-25, found food and the degree of occurrence of communication. Identified several types of bee-bioindicators: Zholletes similes, Schylaeus variegate, Andrew Flavipes. Identification of these species will provide an opportunity to determine in advance the impact of background radiation in this ecosystem and to conduct cleaning, remediation work. On the basis of faunal material collected in Table 1 shows the species composition of the above insects, food relations and the degree of occurrence.

  4. Abundances and implications of volatile-bearing species from evolved gas analysis of the Rocknest aeolian deposit, Gale Crater, Mars

    Science.gov (United States)

    Archer, Paul Douglas; Franz, Heather B.; Sutter, Brad; Arevalo, Ricardo D.; Coll, Patrice; Eigenbrode, Jennifer L.; Glavin, Daniel P.; Jones, John J.; Leshin, Laurie A.; Mahaffy, Paul R.; McAdam, Amy C.; McKay, Christopher P.; Ming, Douglas W.; Morris, Richard V.; Navarro-González, Rafael; Niles, Paul B.; Pavlov, Alex; Squyres, Steven W.; Stern, Jennifer C.; Steele, Andrew; Wray, James J.

    2014-01-01

    The Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory (MSL) rover Curiosity detected evolved gases during thermal analysis of soil samples from the Rocknest aeolian deposit in Gale Crater. Major species detected (in order of decreasing molar abundance) were H2O, SO2, CO2, and O2, all at the µmol level, with HCl, H2S, NH3, NO, and HCN present at the tens to hundreds of nmol level. We compute weight % numbers for the major gases evolved by assuming a likely source and calculate abundances between 0.5 and 3 wt.%. The evolution of these gases implies the presence of both oxidized (perchlorates) and reduced (sulfides or H-bearing) species as well as minerals formed under alkaline (carbonates) and possibly acidic (sulfates) conditions. Possible source phases in the Rocknest material are hydrated amorphous material, minor clay minerals, and hydrated perchlorate salts (all potential H2O sources), carbonates (CO2), perchlorates (O2 and HCl), and potential N-bearing materials (e.g., Martian nitrates, terrestrial or Martian nitrogenated organics, ammonium salts) that evolve NH3, NO, and/or HCN. We conclude that Rocknest materials are a physical mixture in chemical disequilibrium, consistent with aeolian mixing, and that although weathering is not extensive, it may be ongoing even under current Martian surface conditions.

  5. Neutral theory and the species abundance distribution: recent developments and prospects for unifying niche and neutral perspectives

    Science.gov (United States)

    Matthews, Thomas J; Whittaker, Robert J

    2014-01-01

    Published in 2001, The Unified Neutral Theory of Biodiversity and Biogeography (UNTB) emphasizes the importance of stochastic processes in ecological community structure, and has challenged the traditional niche-based view of ecology. While neutral models have since been applied to a broad range of ecological and macroecological phenomena, the majority of research relating to neutral theory has focused exclusively on the species abundance distribution (SAD). Here, we synthesize the large body of work on neutral theory in the context of the species abundance distribution, with a particular focus on integrating ideas from neutral theory with traditional niche theory. First, we summarize the basic tenets of neutral theory; both in general and in the context of SADs. Second, we explore the issues associated with neutral theory and the SAD, such as complications with fitting and model comparison, the underlying assumptions of neutral models, and the difficultly of linking pattern to process. Third, we highlight the advances in understanding of SADs that have resulted from neutral theory and models. Finally, we focus consideration on recent developments aimed at unifying neutral- and niche-based approaches to ecology, with a particular emphasis on what this means for SAD theory, embracing, for instance, ideas of emergent neutrality and stochastic niche theory. We put forward the argument that the prospect of the unification of niche and neutral perspectives represents one of the most promising future avenues of neutral theory research. PMID:25360266

  6. Neutral theory and the species abundance distribution: recent developments and prospects for unifying niche and neutral perspectives.

    Science.gov (United States)

    Matthews, Thomas J; Whittaker, Robert J

    2014-06-01

    Published in 2001, The Unified Neutral Theory of Biodiversity and Biogeography (UNTB) emphasizes the importance of stochastic processes in ecological community structure, and has challenged the traditional niche-based view of ecology. While neutral models have since been applied to a broad range of ecological and macroecological phenomena, the majority of research relating to neutral theory has focused exclusively on the species abundance distribution (SAD). Here, we synthesize the large body of work on neutral theory in the context of the species abundance distribution, with a particular focus on integrating ideas from neutral theory with traditional niche theory. First, we summarize the basic tenets of neutral theory; both in general and in the context of SADs. Second, we explore the issues associated with neutral theory and the SAD, such as complications with fitting and model comparison, the underlying assumptions of neutral models, and the difficultly of linking pattern to process. Third, we highlight the advances in understanding of SADs that have resulted from neutral theory and models. Finally, we focus consideration on recent developments aimed at unifying neutral- and niche-based approaches to ecology, with a particular emphasis on what this means for SAD theory, embracing, for instance, ideas of emergent neutrality and stochastic niche theory. We put forward the argument that the prospect of the unification of niche and neutral perspectives represents one of the most promising future avenues of neutral theory research.

  7. Emergence of Algal Blooms: The Effects of Short-Term Variability in Water Quality on Phytoplankton Abundance, Diversity, and Community Composition in a Tidal Estuary

    Directory of Open Access Journals (Sweden)

    Todd A. Egerton

    2014-01-01

    Full Text Available Algal blooms are dynamic phenomena, often attributed to environmental parameters that vary on short timescales (e.g., hours to days. Phytoplankton monitoring programs are largely designed to examine long-term trends and interannual variability. In order to better understand and evaluate the relationships between water quality variables and the genesis of algal blooms, daily samples were collected over a 34 day period in the eutrophic Lafayette River, a tidal tributary within Chesapeake Bay’s estuarine complex, during spring 2006. During this period two distinct algal blooms occurred; the first was a cryptomonad bloom and this was followed by a bloom of the mixotrophic dinoflagellate, Gymnodinium instriatum. Chlorophyll a, nutrient concentrations, and physical and chemical parameters were measured daily along with phytoplankton abundance and community composition. While 65 phytoplankton species from eight major taxonomic groups were identified in samples and total micro- and nano-phytoplankton cell densities ranged from 5.8 × 106 to 7.8 × 107 cells L−1, during blooms, cryptomonads and G. instriatum were 91.6% and 99.0%, respectively, of the total phytoplankton biomass during blooms. The cryptomonad bloom developed following a period of rainfall and concomitant increases in inorganic nitrogen concentrations. Nitrate, nitrite and ammonium concentrations 0 to 5 days prior were positively lag-correlated with cryptomonad abundance. In contrast, the G. insriatum bloom developed during periods of low dissolved nitrogen concentrations and their abundance was negatively correlated with inorganic nitrogen concentrations.

  8. Hydrological and environmental variables outperform spatial factors in structuring species, trait composition, and beta diversity of pelagic algae.

    Science.gov (United States)

    Wu, Naicheng; Qu, Yueming; Guse, Björn; Makarevičiūtė, Kristė; To, Szewing; Riis, Tenna; Fohrer, Nicola

    2018-03-01

    There has been increasing interest in algae-based bioassessment, particularly, trait-based approaches are increasingly suggested. However, the main drivers, especially the contribution of hydrological variables, of species composition, trait composition, and beta diversity of algae communities are less studied. To link species and trait composition to multiple factors (i.e., hydrological variables, local environmental variables, and spatial factors) that potentially control species occurrence/abundance and to determine their relative roles in shaping species composition, trait composition, and beta diversities of pelagic algae communities, samples were collected from a German lowland catchment, where a well-proven ecohydrological modeling enabled to predict long-term discharges at each sampling site. Both trait and species composition showed significant correlations with hydrological, environmental, and spatial variables, and variation partitioning revealed that the hydrological and local environmental variables outperformed spatial variables. A higher variation of trait composition (57.0%) than species composition (37.5%) could be explained by abiotic factors. Mantel tests showed that both species and trait-based beta diversities were mostly related to hydrological and environmental heterogeneity with hydrological contributing more than environmental variables, while purely spatial impact was less important. Our findings revealed the relative importance of hydrological variables in shaping pelagic algae community and their spatial patterns of beta diversities, emphasizing the need to include hydrological variables in long-term biomonitoring campaigns and biodiversity conservation or restoration. A key implication for biodiversity conservation was that maintaining the instream flow regime and keeping various habitats among rivers are of vital importance. However, further investigations at multispatial and temporal scales are greatly needed.

  9. Abundance data acquired in support of invasive species distribution studies at ten macroalgal ecology and taxonomic assessment sites in Hawaii during 2001 (NODC Accession 0000879)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Abundance data represent estimates of percent cover of species type (coral or algal) in 10 randomly placed quadrats along two 50 meter transect lines of each site....

  10. 2001 Abundance Data Acquired in Support of Invasive Species Distribution Studies at 10 Macroalgal Ecology and Taxonomic Assessment Sites in Hawaii (NODC Accession 0000879)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Abundance data represent estimates of percent cover of species type (coral or algal) in 10 randomly placed quadrats along two 50 meter transect lines of each site....

  11. The overall and fat composition of milk of various species

    Directory of Open Access Journals (Sweden)

    Vesna Gantner

    2015-11-01

    Full Text Available Milk, an essential source of offspring nourishment, varies in it’s composition and properties significantly across species. In human nutrition, fresh milk and dairy products are valuable sources of protein, fat and energy, and are an important part of daily meals. Most of the world’s milk production (85 % comes from cows followed by buffaloes, goats, ewes, mares and donkeys. However milk related food allergies in infants may be a reason for health problems and may cause a decrease in milk. The objective of this paper was to give an overview of the overall composition of milk and fat from different species in comparison to women milk. Regarding the overall milk composition remarkable differences in energy content, fat, lactose, protein and ash of the various milks were found, but also some similarities among milk from ruminants and non-ruminants were detected. The structures of fat globule membranes were similar among non-ruminants and women milk, while the milk fat globule structure in ruminants differed significantly. The size of fat globules was significantly different between species and highly correlated to the milk fat content, regardless of the specie. The amount of triacylglycerols was notably higher, while the amount of free fatty acids and phospholipids was notably lower in milk from ruminants and women compared to milk from mares and donkeys. The triacylglycerol structure in women and non-ruminantsˈ was similar. The percentage of saturated and monounsaturated fatty acids was lower, while the unsaturated fatty acid content was higher in milk from non-ruminants, with a remarkably higher percentage of C-18:2 and C-18:3. The cholesterol content was similar in women and ruminantsˈ milk, but lower in that of non-ruminants. This review indicates that milk from non-ruminants could be more suitable for human nourishment than milk from ruminants.

  12. [Species and size composition of fishes in Barra de Navidad lagoon, Mexican central Pacific].

    Science.gov (United States)

    González-Sansón, Gaspar; Aguilar-Betancourt, Consuelo; Kosonoy-Aceves, Daniel; Lucano-Ramírez, Gabriela; Ruiz-Ramírez, Salvador; Flores-Ortega, Juan Ramón; Hinojosa-Larios, Angel; de Asís Silva-Bátiz, Francisco

    2014-03-01

    Coastal lagoons are considered important nursery areas for many coastal fishes. Barra de Navidad coastal lagoon (3.76km2) is important for local economy as it supports tourism development and artisanal fisheries. However, the role of this lagoon in the dynamics of coastal fish populations is scarcely known. Thus, the objectives of this research were: to characterize the water of the lagoon and related weather conditions, to develop a systematic list of the ichthyofauna, and to estimate the proportion of juveniles in the total number of individuals captured of most abundant species. Water and fish samples were collected between March 2011 and February 2012. Physical and chemical variables were measured in rainy and dry seasons. Several fishing gears were used including a cast net, beach purse seine and gillnets of four different mesh sizes. Our results showed that the lagoon is most of the time euhaline (salinity 30-40ups), although it can be mixopolyhaline (salinity 18-30ups) during short periods. Chlorophyll and nutrients concentrations suggested eutrophication in the lagoon. Mean water temperature changed seasonally from 24.9 degrees C (April, high tide) to 31.4 degrees C (October, low tide). Considering ichthyofauna species, a total of 36 448 individuals of 92 species were collected, 31 of them adding up to 95% of the total of individuals caught. Dominant species were Anchoa spp. (44.6%), Diapterus peruvianus (10.5%), Eucinostomus currani (8.1%), Cetengraulis mysticetus (7.8%), Mugil curema (5.2%) and Opisthonema libertate (4.5%). The lagoon is an important juvenile habitat for 22 of the 31 most abundant species. These included several species of commercial importance such as snappers (Lutjanus argentiventris, L. colorado and L. novemfasciatus), snook (Centropomus nigrescens) and white mullet (Mugil curema). Other four species seem to use the lagoon mainly as adults. This paper is the first contribution on the composition of estuarine ichthyofauna in Jalisco

  13. Meta-analysis of carrying capacity and abundance-area relationships in marine fish species

    DEFF Research Database (Denmark)

    Mantzouni, Irene

    , to incorporate the influence of ecosystem factors, mainly temperature and habitat size, on model parameters representing cod maximum reproductive rate and carrying capacity. The pattern of temperature effects on cod productivity at the species level were identified and SR model parameters were estimated...... on the environmental impacts on key population parameters, which is required for an ecosystem approach to cod management, particularly under ocean-warming scenarios. The commonly used SR models, Ricker and Beverton-Holt, were extended by applying hierarchical methods, mixed-effects models and Bayesian inference...... morhua), herring (Clupea harengus) and haddock (Melanogrammus aeglefinus), in order to identify the effects of temperature, habitat size and life-history on their productivity patterns. The first objective was to investigate how production and survival indices of cod recruitment (i.e. the number of new...

  14. Burrower bugs (Heteroptera: Cydnidae) in peanut: seasonal species abundance, tillage effects, grade reduction effects, insecticide efficacy, and management.

    Science.gov (United States)

    Chapin, Jay W; Thomas, James S

    2003-08-01

    Pitfall traps placed in South Carolina peanut, Arachis hypogaea (L.), fields collected three species of burrower bugs (Cydnidae): Cyrtomenus ciliatus (Palisot de Beauvois), Sehirus cinctus cinctus (Palisot de Beauvois), and Pangaeus bilineatus (Say). Cyrtomenus ciliatus was rarely collected. Sehirus cinctus produced a nymphal cohort in peanut during May and June, probably because of abundant henbit seeds, Lamium amplexicaule L., in strip-till production systems. No S. cinctus were present during peanut pod formation. Pangaeus bilineatus was the most abundant species collected and the only species associated with peanut kernel feeding injury. Overwintering P. bilineatus adults were present in a conservation tillage peanut field before planting and two to three subsequent generations were observed. Few nymphs were collected until the R6 (full seed) growth stage. Tillage and choice of cover crop affected P. bilineatus populations. Peanuts strip-tilled into corn or wheat residue had greater P. bilineatus populations and kernel-feeding than conventional tillage or strip-tillage into rye residue. Fall tillage before planting a wheat cover crop also reduced burrower bug feeding on peanut. At-pegging (early July) granular chlorpyrifos treatments were most consistent in suppressing kernel feeding. Kernels fed on by P. bilineatus were on average 10% lighter than unfed on kernels. Pangaeus bilineatus feeding reduced peanut grade by reducing individual kernel weight, and increasing the percentage damaged kernels. Each 10% increase in kernels fed on by P. bilineatus was associated with a 1.7% decrease in total sound mature kernels, and kernel feeding levels above 30% increase the risk of damaged kernel grade penalties.

  15. Multiscale change in reef coral species diversity and composition in the Tropical Eastern Pacific

    Science.gov (United States)

    Gomez, Catalina G.; Gonzalez, Andrew; Guzman, Hector M.

    2018-03-01

    Both natural and anthropogenic factors are changing coral-reef structure and function worldwide. Long-term monitoring has revealed declines in the local composition and species diversity of reefs. Here we report changes in coral-reef community structure over 12 yr (2000-2012) at 17 sites and three spatial scales (reef, gulf and country) in the Tropical Eastern Pacific (Panama). We found a significant 4% annual decline in species population sizes at the country and gulf scales, with significant declines ranging from 3 to 32% at all but one reef. No significant temporal change in expected richness was found at the country scale or in the Gulf of Chiriquí, but a 7% annual decline in expected species richness was found in the Gulf of Panama. There was a 2% increase in community evenness in the Gulf of Chiriquí, but no change in the Gulf of Panama. Significant temporal turnover was found at the country and gulf scales and at 29% of the reefs, a finding mostly explained by changes in species abundance, and losses and gains of rare species. Temporal trends in alpha and beta diversity metrics were explained by water temperature maxima, anomalies and variation that occurred even in the absence of a strong El Niño warming event.

  16. Effects of submerged macrophytes on the abundance and community composition of ammonia-oxidizing prokaryotes in a eutrophic lake.

    Science.gov (United States)

    Zhao, Da-yong; Luo, Juan; Zeng, Jin; Wang, Meng; Yan, Wen-ming; Huang, Rui; Wu, Qinglong L

    2014-01-01

    Abundances and community compositions of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in unvegetated sediment and the rhizosphere sediments of three submerged macrophytes (Ceratophyllum demersum, Vallisneria spinulosa, and Potamogeton crispus) were investigated in a large, eutrophic freshwater lake, Lake Taihu. Abundances of archaeal ammonia monooxygenase alpha-subunit (amoA) gene (from 6.56 × 10(6) copies to 1.06 × 10(7) copies per gram of dry sediment) were higher than those of bacterial amoA (from 6.13 × 10(5) to 3.21 × 10(6) copies per gram of dry sediment) in all samples. Submerged macrophytes exhibited no significant effect on the abundance and diversity of archaeal amoA gene. C. demersum and V. spinulosa increased the abundance and diversity of bacterial amoA gene in their rhizosphere sediment. However, the diversity of bacterial amoA gene in the rhizosphere sediments of P. crispus was decreased. The data obtained in this study would be helpful to elucidate the roles of submerged macrophytes involved in the nitrogen cycling of eutrophic lake ecosystems.

  17. Species composition of a soil invertebrate multi-species test system determines the level of ecotoxicity

    International Nuclear Information System (INIS)

    Sechi, Valentina; D'Annibale, Alessandra; Maraldo, Kristine; Johansen, Anders; Bossi, Rossana; Jensen, John; Krogh, Paul Henning

    2014-01-01

    A soil multi-species, SMS, experimental test system consisting of the natural microbial community, five collembolan species and a predatory mite along with either Enchytraeus crypticus or the earthworm Eisenia fetida were exposed to α-cypermethrin. A comparison of the performance of these two types of SMSs is given to aid the development of a standard test system. E. fetida had a positive effect on the majority of the species, reducing the negative insecticide effect. E. fetida affected the species sensitivity and decreased the degradation of the insecticide due to the organic matter incorporation of earthworm food. After 8 weeks, the EC50 was 0.76 mg kg −1 for enchytraeids and ranged between 2.7 and 18.9 mg kg −1 for collembolans, more sensitive than previously observed with single species. Changes observed in the community structure and function illustrates the strength of a multi-species test system as an ecotoxicological tool compared to single species tests. -- Highlights: • Degradation of alpha-cypermethrin was faster with enchytraeids than with earthworms. • Lumbricid castings and bioturbation explains bioavailability of α-cypermethrin. • Pesticide effects on soil arthropods alter with the community composition. • Multispecies test systems are feasible with either an enchytraeid or a lumbricid. • Collembolans are more sensitive to cypermethrin with enchytraeids than with earthworms. -- Soil ecotoxicological fate and effects in multispecies test systems are affected by earthworm activity

  18. Seed Carotenoid and Tocochromanol Composition of Wild Fabaceae Species Is Shaped by Phylogeny and Ecological Factors

    Science.gov (United States)

    Fernández-Marín, Beatriz; Míguez, Fátima; Méndez-Fernández, Leire; Agut, Agustí; Becerril, José M.; García-Plazaola, José I.; Kranner, Ilse; Colville, Louise

    2017-01-01

    Carotenoids distribution and function in seeds have been very scarcely studied, notwithstanding their pivotal roles in plants that include photosynthesis and phytohormone synthesis, pigmentation, membrane stabilization and antioxidant activity. Their relationship with tocochromanols, whose critical role in maintaining seed viability has already been evidenced, and with chlorophylls, whose retention in mature seed is thought to have negative effects on storability, remain also unexplored. Here, we aimed at elucidating seed carotenoids relationship with tocochromanols and chlorophylls with regard to phylogenetic and ecological traits and at understanding their changes during germination. The composition and distribution of carotenoids were investigated in seeds of a wide range of wild species across the Fabaceae (the second-most economically important family after the Poaceae). Photosynthetic pigments and tocochromanols were analyzed by HPLC in mature dry seeds of 50 species representative of 5 subfamilies within the Fabaceae (including taxa that represent all continents, biomes and life forms within the family) and at key timepoints during seedling establishment in three species representative of distinct clades. Total-carotenoids content positively correlated with tocopherols in the basal subfamilies Detarioideae, Cercidoideae, and Dialioideae, and with chlorophylls in the Papilionoideae. Papilionoideae lacked tocotrienols and had the highest total-carotenoids, chlorophyll and γ-tocopherol contents. Interestingly, lutein epoxide was present in 72% of the species including several herbs from different subfamilies. Overall, species original from temperate biomes presented higher carotenoids and lower tocochromanols levels than those from tropical biomes. Also shrub species showed higher carotenoids content than herbs and trees. During germination, total content of photosynthetic pigments increased in parallel to changes in relative abundance of carotenoids

  19. The effect of Ni on concentration of the most abundant essential cations in several Brassica species

    Directory of Open Access Journals (Sweden)

    Putnik-Delić Marina I.

    2014-01-01

    Full Text Available Some plants from the genus Brassica have the ability to tolerate excessive concentrations of heavy metals, including Ni. Considering the fact that Ni is a very toxic element for living beings we wanted to examine its influence on some species from genus Brassicaceae. The aim of this study was to investigate the effect of Ni on distribution and accumulation of essential macronutrients from the standpoint of food quality and phytoremediation potential. Experiments were performed using winter (W and spring (S varieties of rapeseed (Brassica napus, L., white mustard (Brassica alba, L., black mustard (Brassica nigra, L. and turnip (Brassica rapa, L.. The seeds were exposed to 10 μM Ni from the beginning of germination. Plants were grown in water cultures, in semi-controlled conditions of a greenhouse, on ½ strength Hoagland solution to which was added Ni in the same concentration as during germination. Concentrations and distribution of Ca, Mg, K in leaf and stem were altered in the presence of increased concentration of Ni. Significant differences were found between the control and Ni-treated plants as well as among the genotypes. [Projekat Ministarstva nauke Republike Srbije, br. TR 31036 i br. TR 31016

  20. Examining the patterns and dynamics of species abundance distributions in succession of forest communities by model selection

    Science.gov (United States)

    Luo, Shao-Ming; Chen, Ping; He, Xiao; Guo, Wei; Li, Bailian

    2018-01-01

    There are a few common species and many rare species in a biological community or a multi-species collection in given space and time. This hollow distribution curve is called species abundance distribution (SAD). Few studies have examined the patterns and dynamics of SADs during the succession of forest communities by model selection. This study explored whether the communities in different successional stages followed different SAD models and whether there existed a best SAD model to reveal their intrinsic quantitative features of structure and dynamics in succession. The abundance (the number of individuals) of each vascular plant was surveyed by quadrat sampling method from the tree, shrub and herb layers in two typical communities (i.e., the evergreen needle- and broad-leaved mixed forest and the monsoon evergreen broad-leaved forest) in southern subtropical Dinghushan Biosphere Reserve, South China. The sites of two forest communities in different successional stages are both 1 ha in area. We collected seven widely representative SAD models with obviously different function forms and transformed them into the same octave (log2) scale. These models are simultaneously confronted with eight datasets from four layers of two communities, and their goodness-of-fits to the data were evaluated by the chi-squared test, the adjusted coefficient of determination and the information criteria. The results indicated that: (1) the logCauchy model followed all the datasets and was the best among seven models; (2) the fitness of each model to the data was not directly related to the successional stage of forest community; (3) according to the SAD curves predicted by the best model (i.e., the logCauchy), the proportion of rare species decreased but that of common ones increased in the upper layers with succession, while the reverse was true in the lower layers; and (4) the difference of the SADs increased between the upper and the lower layers with succession. We concluded that

  1. Abundance of food plant species and food habits of Rhinoceros unicorns Linn. in Pobitora Wildlife Sanctuary, Assam, India

    Directory of Open Access Journals (Sweden)

    P. Konwar

    2009-09-01

    Full Text Available Food habits and abundance of food plant species of Rhinoceros unicornis in Pobitora Wildlife Sanctuary were studied from January 1999 through December 2001. Totally 32 numbers of Rhino food plants were identified, of which 15 were grasses, four shrubs, five aquatic hydrophytes and eight tree species (21 terrestrial and 11 aquatic. During the dry season, the Rhino feeds on almost 90% food items from Hemarthria compressa, Arundo donax, Phragmites karka, Cerex rubro-brumee etc. The other short grasses such as Cynodon dactylon, Andropogon ssp., Cenchrus ciliaris, Chrysopogon aciculatus and tender and young shoots and twigs of Schelristechya fuesche, Saccharum spontaneum, Lagerstroemia flosreginae etc. are consumed in limited portions. The rhino consumes 11 cultivated crops and vegetables, viz., Ricinus communis, Oryza sativa, Solanum melongena, Lycopersicon esculentum, Solanum tuberosum, Brassica nigra, Luffa cylindrica, Luffa acutangula, Cucurbita moschata, Cucumis sativus and Ipomoea batatas etc. Highest density of food plant species observed in the study area were Cynodon dactylon (167.5/m2, Hemarthria compressa (73.75/m2, Vetiveria zizanioides (56/m2, Saccharum ravannae (51.5/m2, Pharagmites karka (50.75/m2, Leersia hexandra (46.75/m2, Brachiarea pseudointerrupta (40/m2 and Eichhornia crassipes (35/m2.

  2. The overall and fat composition of milk of various species

    OpenAIRE

    Vesna Gantner; Pero Mijić; Mirjana Baban; Zoran Škrtić; Alka Turalija

    2015-01-01

    Milk, an essential source of offspring nourishment, varies in it’s composition and properties significantly across species. In human nutrition, fresh milk and dairy products are valuable sources of protein, fat and energy, and are an important part of daily meals. Most of the world’s milk production (85 %) comes from cows followed by buffaloes, goats, ewes, mares and donkeys. However milk related food allergies in infants may be a reason for health problems and may cause a decrease in milk. T...

  3. Species composition and geographical distribution of Saharan scorpion fauna, Morocco

    Directory of Open Access Journals (Sweden)

    Oulaid Touloun

    2016-11-01

    Full Text Available Objective: To describe the species composition of scorpions and to study its geographical distribution in Laayoune-Sakia El Hamra and Dakhla-Oued Ed Dahab regions in July 2014. Methods: To locate scorpions, the ground was examined through searching the places under the stones, rocks and in burrows. The nocturnal missions were also conducted using portable ultraviolet lamps. The scorpions were subsequently identified in the laboratory. Results: The results of the investigations in these regions showed the presence of five scorpion species, two of which Androctonus gonneti and Buthus bonito were endemic in Morocco. Conclusions: This work is allowed to complete the inventory of the studied scorpion fauna and provides some considerations on the distribution patterns in the study area.

  4. [Species composition, diversity and density of small fishes in two different habitats in Niushan Lake].

    Science.gov (United States)

    Ye, Shao-Wen; Li, Zhong-Jie; Cao, Wen-Xuan

    2007-07-01

    This paper studied the spatial distribution of small fishes in a shallow macrophytic lake, Niushan Lake in spring 2003, and its relations with habitat heterogeneity. Based on the macrophyte cover condition, distance from lake shore and water depth, two representative habitat types in the lake were selected. Habitat A was near the shore with dense submersed macrophyte, while habitat B was far from the shore with sparse submersed macrophyte. Small fishes were sampled quantitatively by block net (180 m2), and their densities within the net area were estimated by multiple mark-recapture or Zippin's removal method. The results showed that there were some differences in species composition, biodiversity measurement, and estimated density of small fishes between the two habitats: 1) the catches in habitat A consisted of 14 small fish species from 5 families, among which, benthopelagic species Rhodeus ocellatus, Paracheilognathus imberbis and Pseudorasbora parva were considered as dominant species, while those in habitat B consisted of 9 small fish species from 3 families, among which, bottom species Rhinogobius giurinus and Micropercops swinhonis were dominant; 2) the Bray-Curtis index between the two small fish communities was 0.222, reflecting their low structure similarity, and no significant difference was observed between their rank/ abundance distributions, both of which belonged to log series distribution; 3) the total density of 9 major species in habitat A was 8.71 ind x m(-2), while that of 5 major species in habitat B was only 3.54 ind x m(-2). The fact that the spatial distribution of the small fishes differed with habitats might be related to their habitat need for escaping predators, feeding, and breeding, and thus, aquatic macrophyte habitat should be of significance in the rational exploitation of small fish resources as well as the conservation of fish resource diversity.

  5. Wastewater treatment plant effluents change abundance and composition of ammonia-oxidizing microorganisms in mediterranean urban stream biofilms.

    Science.gov (United States)

    Merbt, Stephanie N; Auguet, Jean-Christophe; Blesa, Alba; Martí, Eugènia; Casamayor, Emilio O

    2015-01-01

    Streams affected by wastewater treatment plant (WWTP) effluents are hotspots of nitrification. We analyzed the influence of WWTP inputs on the abundance, distribution, and composition of epilithic ammonia-oxidizing (AO) assemblages in five Mediterranean urban streams by qPCR and amoA gene cloning and sequencing of both archaea (AOA) and bacteria (AOB). The effluents significantly modified stream chemical parameters, and changes in longitudinal profiles of both NH(4)(+) and NO(3)(-) indicated stimulated nitrification activity. WWTP effluents were an allocthonous source of both AOA, essentially from the Nitrosotalea cluster, and mostly of AOB, mainly Nitrosomonas oligotropha, Nitrosomonas communis, and Nitrosospira spp. changing the relative abundance and the natural composition of AO assemblages. Under natural conditions, Nitrososphaera and Nitrosopumilus AOA dominated AO assemblages, and AOB were barely detected. After the WWTP perturbation, epilithic AOB increased by orders of magnitude whereas AOA did not show quantitative changes but a shift in population composition to dominance of Nitrosotalea spp. The foraneous AOB successfully settled in downstream biofilms and probably carried out most of the nitrification activity. Nitrosotalea were only observed downstream and only in biofilms exposed to either darkness or low irradiance. In addition to other potential environmental limitations for AOA distribution, this result suggests in situ photosensitivity as previously reported for Nitrosotalea under laboratory conditions.

  6. The chemical composition of red giants in 47 Tucanae. I. Fundamental parameters and chemical abundance patterns

    Science.gov (United States)

    Thygesen, A. O.; Sbordone, L.; Andrievsky, S.; Korotin, S.; Yong, D.; Zaggia, S.; Ludwig, H.-G.; Collet, R.; Asplund, M.; Ventura, P.; D'Antona, F.; Meléndez, J.; D'Ercole, A.

    2014-12-01

    Context. The study of chemical abundance patterns in globular clusters is key importance to constraining the different candidates for intracluster pollution of light elements. Aims: We aim at deriving accurate abundances for a wide range of elements in the globular cluster 47 Tucanae (NGC 104) to add new constraints to the pollution scenarios for this particular cluster, expanding the range of previously derived element abundances. Methods: Using tailored 1D local thermodynamic equilibrium (LTE) atmospheric models, together with a combination of equivalent width measurements, LTE, and NLTE synthesis, we derive stellar parameters and element abundances from high-resolution, high signal-to-noise spectra of 13 red giant stars near the tip of the RGB. Results: We derive abundances of a total 27 elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ru, Ba, La, Ce, Pr, Nd, Eu, Dy). Departures from LTE were taken into account for Na, Al, and Ba. We find a mean [Fe/H] = -0.78 ± 0.07 and [ α/ Fe ] = 0.34 ± 0.03 in good agreement with previous studies. The remaining elements show good agreement with the literature, but including NLTE for Al has a significant impact on the behavior of this key element. Conclusions: We confirm the presence of an Na-O anti-correlation in 47 Tucanae found by several other works. Our NLTE analysis of Al shifts the [Al/Fe] to lower values, indicating that this may be overestimated in earlier works. No evidence of an intrinsic variation is found in any of the remaining elements. Based on observations made with the ESO Very Large Telescope at Paranal Observatory, Chile (Programmes 084.B-0810 and 086.B-0237).Full Tables 2, 5, and 9 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/572/A108Appendix A is available in electronic form at http://www.aanda.org

  7. Characterization of Antibiotic Resistance Gene Abundance and Microbiota Composition in Feces of Organic and Conventional Pigs from Four EU Countries.

    Science.gov (United States)

    Gerzova, Lenka; Babak, Vladimir; Sedlar, Karel; Faldynova, Marcela; Videnska, Petra; Cejkova, Darina; Jensen, Annette Nygaard; Denis, Martine; Kerouanton, Annaelle; Ricci, Antonia; Cibin, Veronica; Österberg, Julia; Rychlik, Ivan

    2015-01-01

    One of the recent trends in animal production is the revival of interest in organic farming. The increased consumer interest in organic animal farming is mainly due to concerns about animal welfare and the use of antibiotics in conventional farming. On the other hand, providing animals with a more natural lifestyle implies their increased exposure to environmental sources of different microorganisms including pathogens. To address these concerns, we determined the abundance of antibiotic resistance and diversity within fecal microbiota in pigs kept under conventional and organic farming systems in Sweden, Denmark, France and Italy. The abundance of sul1, sul2, strA, tet(A), tet(B) and cat antibiotic resistance genes was determined in 468 samples by real-time PCR and the fecal microbiota diversity was characterized in 48 selected samples by pyrosequencing of V3/V4 regions of 16S rRNA. Contrary to our expectations, there were no extensive differences between the abundance of tested antibiotic resistance genes in microbiota originating from organic or conventionally housed pigs within individual countries. There were also no differences in the microbiota composition of organic and conventional pigs. The only significant difference was the difference in the abundance of antibiotic resistance genes in the samples from different countries. Fecal microbiota in the samples originating from southern European countries (Italy, France) exhibited significantly higher antibiotic resistance gene abundance than those from northern parts of Europe (Denmark, Sweden). Therefore, the geographical location of the herd influenced the antibiotic resistance in the fecal microbiota more than farm's status as organic or conventional.

  8. Comparative composition, diversity, and abundance of oligosaccharides in early lactation milk from commercial dairy and beef cows

    Science.gov (United States)

    Sischo, William M.; Short, Diana M.; Geissler, Mareen; Bunyatratchata, Apichaya; Barile, Daniela

    2017-01-01

    Prebiotics are nondigestible dietary ingredients, usually oligosaccharides (OS), that provide a health benefit to the host by directly modulating the gut microbiota. Although there is some information describing OS content in dairy-source milk, no information is available to describe the OS content of beef-source milk. Given the different trait emphasis between dairy and beef for milk production and calf survivability, it is plausible that OS composition, diversity, and abundance differ between production types. The goal of this study was to compare OS in milk from commercial dairy and beef cows in early lactation. Early-lactation multiparous cows (5–12 d in milk) from 5 commercial Holstein dairy herds and 5 Angus or Angus hybrid beef herds were sampled once. Milk was obtained from each enrolled cow and frozen on the farm. Subsequently, each milk sample was assessed for total solids, pH, and OS content and relative abundance. Oligosaccharide diversity and abundance within and between samples was transformed through principal component analysis to reduce data complexity. Factors from principal component analysis were used to create similarity clusters, which were subsequently used in a multivariate logistic regression. In total, 30 OS were identified in early-lactation cow milk, including 21 distinct OS and 9 isomers with unique retention times. The majority of OS detected in the milk samples were present in all individual samples regardless of production type. Two clusters described distribution patterns of OS for the study sample; when median OS abundance was compared between the 2 clusters, we found that overall OS relative abundance was consistently greater in the cluster dominated by beef cows. For several of the structures, including those with known prebiotic effect, the difference in abundance was 2- to 4-fold greater in the beef-dominated cluster. Assuming that beef OS content in milk is the gold standard for cattle, it is likely that preweaning dairy

  9. [Species composition and diversity of soil mesofauna in the 'Holy Hills' fragmentary tropical rain forest of Xishuangbanna, China].

    Science.gov (United States)

    Yang, X; Sha, L

    2001-04-01

    The species composition and diversity of soil mesofauna were examined in fragmented dry tropical seasonal rainforest of tow 'Holy Hills' of Dai nationality, compared with the continuous moist tropical seasonal rain forest of Nature Reserve in Xishuangbanna area. 5 sample quadrats were selected along the diagonal of 20 m x 20 m sampling plot, and the samples of litterfall and 0-3 cm soil were collected from each 50 cm x 10 cm sample quadrat. Animals in soil sample were collected by using dry-funnel(Tullgren's), were identified to their groups according to the order. The H' index, D.G index and the pattern of relative abundance of species were used to compare the diversity of soil mesofauna. The results showed that the disturbance of vegetation and soil resulted by tropical rainforest fragmentation was the major factor affecting the diversity of soil mesofauna. Because the fragmented forest was intruded by some pioneer tree species and the "dry and warm" effect operated, this forest had more litterfall on the floor and more humus in the soil than the continuous moist rain forest. The soil condition with more soil organic matter, total N and P, higher pH value and lower soil bulk density became more favorable to the soil mesofauna. Therefore, the species richness, abundance and diversity of soil mesofauna in fragmented forests were higher than those in continuous forest, but the similarity of species composition in fragmented forest to the continuous forest was minimal. Soil mesofauna diversity in fragmented forests did not change with decreasing fragmented area, indicating that there was no species-area effect operation in this forest. The pattern of relative abundance of species in these forest soils was logarithmic series distribution.

  10. Chemical composition of some wild peanut species (Arachis L.) seeds.

    Science.gov (United States)

    Grosso, N R; Nepote, V; Guzmán, C A

    2000-03-01

    Oil, protein, ash, and carbohydrate contents, iodine value, and fatty acid and sterol compositions were studied in seeds of Arachis trinitensis, A. chiquitana, A. kempff-mercadoi, A. diogoi, A. benensis, A. appressipila, A. valida, A. kretschmeri, A. helodes, A. kuhlmannii, A. williamsii, A. sylvestris, A. matiensis, A. pintoi, A. hoehnei, A. villosa, and A. stenosperma. Oil content was greatest in A.stenosperma (mean value = 51.8%). The protein level was higher in A. sylvestris (30.1%) and A. villosa (29.5%). Mean value of oleic acid varied between 30.6% (A. matiensis) and 46.8% (Arachis villosa), and linoleic acid oscillated between 34.1% (A. villosa) and 47.4% (A. appressipila). The better oleic-to-linoleic (O/L) ratio was exhibited by A. villosa (1.38). Some species showed higher concentration of behenic acid. The greatest level of this fatty acid was found in A. matiensis (6.2%). Iodine value was lower in A. valida (99.2). The sterol composition in the different peanut species showed higher concentration of beta-sitosterol (mean values oscillated between 55.7 and 60.2%) followed by campesterol (12.4-16. 5%), stigmasterol (9.7-13.3%), and Delta(5)-avenasterol (9.7-13.4%). The chemical quality and stability of oils (iodine value and O/L ratio) from wild peanut studied in this work are not better than those of cultivated peanut.

  11. Species richness and trait composition of butterfly assemblages change along an altitudinal gradient.

    Science.gov (United States)

    Leingärtner, Annette; Krauss, Jochen; Steffan-Dewenter, Ingolf

    2014-06-01

    Species richness patterns along altitudinal gradients are well-documented ecological phenomena, yet very little data are available on how environmental filtering processes influence the composition and traits of butterfly assemblages at high altitudes. We have studied the diversity patterns of butterfly species at 34 sites along an altitudinal gradient ranging from 600 to 2,000 m a.s.l. in the National Park Berchtesgaden (Germany) and analysed traits of butterfly assemblages associated with dispersal capacity, reproductive strategies and developmental time from lowlands to highlands, including phylogenetic analyses. We found a linear decline in butterfly species richness along the altitudinal gradient, but the phylogenetic relatedness of the butterfly assemblages did not increase with altitude. Compared to butterfly assemblages at lower altitudes, those at higher altitudes were composed of species with larger wings (on average 9%) which laid an average of 68% more eggs. In contrast, egg maturation time in butterfly assemblages decreased by about 22% along the altitudinal gradient. Further, butterfly assemblages at higher altitudes were increasingly dominated by less widespread species. Based on our abundance data, but not on data in the literature, population density increased with altitude, suggesting a reversed density-distribution relationship, with higher population densities of habitat specialists in harsh environments. In conclusion, our data provide evidence for significant shifts in the composition of butterfly assemblages and for the dominance of different traits along the altitudinal gradient. In our study, these changes were mainly driven by environmental factors, whereas phylogenetic filtering played a minor role along the studied altitudinal range.

  12. Hunting billbug (Coleoptera: Curculionidae) life cycle and damaging life stage in North Carolina, with notes on other billbug species abundance.

    Science.gov (United States)

    Doskocil, J P; Brandenburg, R L

    2012-12-01

    In the southeastern United States, hunting billbug, Sphenophorus venatus vestitus Chittenden, adults are often observed in turfgrass, but our knowledge of their biology and ecology is limited. Field surveys and experiments were conducted to determine the species composition, life cycle, damaging life stage, and distribution of billbugs within the soil profile in turfgrass in North Carolina. Linear pitfall trapping revealed six species of billbug, with the hunting billbug making up 99.7% of all beetles collected. Data collected from turf plus soil sampling suggest that hunting billbugs have two overlapping generations per year in North Carolina and that they overwinter as both adults and larvae. Field experiments provided evidence that adult hunting billbugs are capable of damaging warm season turfgrasses.

  13. Fluctuations in the Composition and Abundance of Entomofauna in the Forest-Protected Agrocenoses

    Directory of Open Access Journals (Sweden)

    Belitskaya Mariya Nikolaevna

    2015-04-01

    Full Text Available The author investigates the influence of field-protective forest plantations on the diversity and quantity of pests and entomophages in interbelt cereal agrocenoses of the steppe and dry steppe natural zones. It is revealed that the protective forest plantations play important role in the biota and the food chains management within agrocenoses. It is identified that the forest belts have smoothing influence on the change in the abundance of insects belonging to the different trophic groups on the developped fields. The peaks in the number of harmful and useful insects coincide in these fields, whereas in treeless agrocenoses the rise in useful components density takes place only after a year of the mass reproduction of pests. The growth and development of cereal crops is accompanied by the increase in the number of insects in the stalks of the crops. At the same time, the abundance of different insect groups varies. This applies both to the inhabitants of the stalks and to the complex insects on the surface of the ground.

  14. Influence of galactic arm scale dynamics on the molecular composition of the cold and dense ISM. I. Observed abundance gradients in dense clouds

    Science.gov (United States)

    Ruaud, M.; Wakelam, V.; Gratier, P.; Bonnell, I. A.

    2018-04-01

    Aim. We study the effect of large scale dynamics on the molecular composition of the dense interstellar medium during the transition between diffuse to dense clouds. Methods: We followed the formation of dense clouds (on sub-parsec scales) through the dynamics of the interstellar medium at galactic scales. We used results from smoothed particle hydrodynamics (SPH) simulations from which we extracted physical parameters that are used as inputs for our full gas-grain chemical model. In these simulations, the evolution of the interstellar matter is followed for 50 Myr. The warm low-density interstellar medium gas flows into spiral arms where orbit crowding produces the shock formation of dense clouds, which are held together temporarily by the external pressure. Results: We show that depending on the physical history of each SPH particle, the molecular composition of the modeled dense clouds presents a high dispersion in the computed abundances even if the local physical properties are similar. We find that carbon chains are the most affected species and show that these differences are directly connected to differences in (1) the electronic fraction, (2) the C/O ratio, and (3) the local physical conditions. We argue that differences in the dynamical evolution of the gas that formed dense clouds could account for the molecular diversity observed between and within these clouds. Conclusions: This study shows the importance of past physical conditions in establishing the chemical composition of the dense medium.

  15. Diversity and composition of the copepod communities associated with megafauna around a cold seep in the Gulf of Mexico with remarks on species biogeography

    NARCIS (Netherlands)

    Plum, C.; Gollner, S.; Martinez Arbizu, P.; Bright, M.

    2015-01-01

    In order to characterize the copepod communitiesassociated with tubeworm and mussel aggregations around ahydrocarbon seep in the Green Canyon of the Gulf of Mexico,diversity, abundance, and community composition were analyzed.Also analyzed were species biogeography and the potentialconnectivity to

  16. Effects of green-tree retention on abundance and guild composition of corticolous arthropods

    Science.gov (United States)

    Juraj Halaj; Charles B. Halpern; Hoonbok Yi

    2009-01-01

    We studied the effects of varying levels and patterns of green-tree retention on the community composition of bark-dwelling arthropods. Arthropods were sampled with crawl traps installed on 280 live trees and 260 snags (all Douglas-fir) at three locations (experimental blocks) in the western Cascade Range of Oregon and Washington. Sampling coincided with the breeding...

  17. New records and detailed distribution and abundance of selected arthropod species collected between 1999 and 2011 in Azorean native forests

    Science.gov (United States)

    Gaspar, Clara; Crespo, Luís Carlos Fonseca; Rigal, François; Cardoso, Pedro; Pereira, Fernando; Rego, Carla; Amorim, Isabel R.; Melo, Catarina; Aguiar, Carlos; André, Genage; Mendonça, Enésima P.; Ribeiro, Sérvio; Hortal, Joaquín; Santos, Ana M.C.; Barcelos, Luís; Enghoff, Henrik; Mahnert, Volker; Pita, Margarida T.; Ribes, Jordi; Baz, Arturo; Sousa, António B.; Vieira, Virgílio; Wunderlich, Jörg; Parmakelis, Aristeidis; Whittaker, Robert J.; Quartau, José Alberto; Serrano, Artur R.M.; Triantis, Kostas A.

    2016-01-01

    Abstract Background In this contribution we present detailed distribution and abundance data for arthropod species identified during the BALA – Biodiversity of Arthropods from the Laurisilva of the Azores (1999-2004) and BALA2 projects (2010-2011) from 18 native forest fragments in seven of the nine Azorean islands (all excluding Graciosa and Corvo islands, which have no native forest left). New information Of the total 286 species identified, 81% were captured between 1999 and 2000, a period during which only 39% of all the samples were collected. On average, arthropod richness for each island increased by 10% during the time frame of these projects. The classes Arachnida, Chilopoda and Diplopoda represent the most remarkable cases of new island records, with more than 30% of the records being novelties. This study stresses the need to expand the approaches applied in these projects to other habitats in the Azores, and more importantly to other less surveyed taxonomic groups (e.g. Diptera and Hymenoptera). These steps are fundamental for getting a more accurate assessment of biodiversity in the archipelago. PMID:28174509

  18. Molecular size-dependent abundance and composition of dissolved organic matter in river, lake and sea waters.

    Science.gov (United States)

    Xu, Huacheng; Guo, Laodong

    2017-06-15

    Dissolved organic matter (DOM) is ubiquitous in natural waters. The ecological role and environmental fate of DOM are highly related to the chemical composition and size distribution. To evaluate size-dependent DOM quantity and quality, water samples were collected from river, lake, and coastal marine environments and size fractionated through a series of micro- and ultra-filtrations with different membranes having different pore-sizes/cutoffs, including 0.7, 0.4, and 0.2 μm and 100, 10, 3, and 1 kDa. Abundance of dissolved organic carbon, total carbohydrates, chromophoric and fluorescent components in the filtrates decreased consistently with decreasing filter/membrane cutoffs, but with a rapid decline when the filter cutoff reached 3 kDa, showing an evident size-dependent DOM abundance and composition. About 70% of carbohydrates and 90% of humic- and protein-like components were measured in the definition of DOM and its size continuum in quantity and quality in aquatic environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Three dimensional marine seismic survey has no measurable effect on species richness or abundance of a coral reef associated fish community

    International Nuclear Information System (INIS)

    Miller, Ian; Cripps, Edward

    2013-01-01

    Highlights: • A marine seismic survey was conducted at Scott Reef, North Western Australia. • Effects of the survey on demersal fish were gauged using underwater visual census. • There was no detectable impact of the seismic survey on species abundance. • There was no detectable impact of the seismic survey on species richness. -- Abstract: Underwater visual census was used to determine the effect of a three dimensional seismic survey on the shallow water coral reef slope associated fish community at Scott Reef. A census of the fish community was conducted on six locations at Scott Reef both before and after the survey. The census included small site attached demersal species belonging to the family Pomacentridae and larger roving demersal species belonging to the non-Pomacentridae families. These data were combined with a decade of historical data to assess the impact of the seismic survey. Taking into account spatial, temporal, spatio-temporal and observer variability, modelling showed no significant effect of the seismic survey on the overall abundance or species richness of Pomacentridae or non-Pomacentridae. The six most abundant species were also analysed individually. In all cases no detectable effect of the seismic survey was found on the abundance of these fish species at Scott Reef

  20. Influence of Trap Height and Bait Type on Abundance and Species Diversity of Cerambycid Beetles Captured in Forests of East-Central Illinois.

    Science.gov (United States)

    Schmeelk, Thomas C; Millar, Jocelyn G; Hanks, Lawrence M

    2016-08-01

    We assessed how height of panel traps above the forest floor, and the type of trap bait used, influenced the abundance and diversity of cerambycid beetles caught in forested areas of east-central Illinois. Panel traps were suspended from branches of hardwood trees at three heights above the ground: understory (∼1.5 m), lower canopy (∼6 m), and midcanopy (∼12 m). Traps were baited with either a multispecies blend of synthesized cerambycid pheromones or a fermenting bait mixture. Traps captured a total of 848 beetles of 50 species in the cerambycid subfamilies Cerambycinae, Lamiinae, Lepturinae, and Parandrinae, and one species in the closely related family Disteniidae. The species caught in highest numbers was the cerambycine Anelaphus pumilus (Newman), represented by 349 specimens. The 17 most abundant species (mean ± 1 SD: 45 ± 80 specimens per species) included 12 cerambycine and five lamiine species. Of these most abundant species, 13 (77%) were attracted to traps baited with the pheromone blend. Only the cerambycine Eburia quadrigeminata (Say) was attracted by the fermenting bait. Three species were captured primarily in understory traps, and another five species primarily in midcanopy traps. Variation among cerambycid species in their vertical distribution in forests accounted for similar overall abundances and species richness across trap height treatments. These findings suggest that trapping surveys of native communities of cerambycids, and quarantine surveillance for newly introduced exotic species, would be optimized by including a variety of trap baits and distributing traps across vertical strata of forests. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Oxygen-Vacancy Abundant Ultrafine Co3O4/Graphene Composites for High-Rate Supercapacitor Electrodes.

    Science.gov (United States)

    Yang, Shuhua; Liu, Yuanyue; Hao, Yufeng; Yang, Xiaopeng; Goddard, William A; Zhang, Xiao Li; Cao, Bingqiang

    2018-04-01

    The metal oxides/graphene composites are one of the most promising supercapacitors (SCs) electrode materials. However, rational synthesis of such electrode materials with controllable conductivity and electrochemical activity is the topical challenge for high-performance SCs. Here, the Co 3 O 4 /graphene composite is taken as a typical example and develops a novel/universal one-step laser irradiation method that overcomes all these challenges and obtains the oxygen-vacancy abundant ultrafine Co 3 O 4 nanoparticles/graphene (UCNG) composites with high SCs performance. First-principles calculations show that the surface oxygen vacancies can facilitate the electrochemical charge transfer by creating midgap electronic states. The specific capacitance of the UCNG electrode reaches 978.1 F g -1 (135.8 mA h g -1 ) at the current densities of 1 A g -1 and retains a high capacitance retention of 916.5 F g -1 (127.3 mA h g -1 ) even at current density up to 10 A g -1 , showing remarkable rate capability (more than 93.7% capacitance retention). Additionally, 99.3% of the initial capacitance is maintained after consecutive 20 000 cycles, demonstrating enhanced cycling stability. Moreover, this proposed laser-assisted growth strategy is demonstrated to be universal for other metal oxide/graphene composites with tuned electrical conductivity and electrochemical activity.

  2. Abundance and composition of indigenous bacterial communities in a multi-step biofiltration-based drinking water treatment plant.

    Science.gov (United States)

    Lautenschlager, Karin; Hwang, Chiachi; Ling, Fangqiong; Liu, Wen-Tso; Boon, Nico; Köster, Oliver; Egli, Thomas; Hammes, Frederik

    2014-10-01

    Indigenous bacterial communities are essential for biofiltration processes in drinking water treatment systems. In this study, we examined the microbial community composition and abundance of three different biofilter types (rapid sand, granular activated carbon, and slow sand filters) and their respective effluents in a full-scale, multi-step treatment plant (Zürich, CH). Detailed analysis of organic carbon degradation underpinned biodegradation as the primary function of the biofilter biomass. The biomass was present in concentrations ranging between 2-5 × 10(15) cells/m(3) in all filters but was phylogenetically, enzymatically and metabolically diverse. Based on 16S rRNA gene-based 454 pyrosequencing analysis for microbial community composition, similar microbial taxa (predominantly Proteobacteria, Planctomycetes, Acidobacteria, Bacteriodetes, Nitrospira and Chloroflexi) were present in all biofilters and in their respective effluents, but the ratio of microbial taxa was different in each filter type. This change was also reflected in the cluster analysis, which revealed a change of 50-60% in microbial community composition between the different filter types. This study documents the direct influence of the filter biomass on the microbial community composition of the final drinking water, particularly when the water is distributed without post-disinfection. The results provide new insights on the complexity of indigenous bacteria colonizing drinking water systems, especially in different biofilters of a multi-step treatment plant. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Like will to like: abundances of closely related species can predict susceptibility to intestinal colonization by pathogenic and commensal bacteria.

    Science.gov (United States)

    Stecher, Bärbel; Chaffron, Samuel; Käppeli, Rina; Hapfelmeier, Siegfried; Freedrich, Susanne; Weber, Thomas C; Kirundi, Jorum; Suar, Mrutyunjay; McCoy, Kathy D; von Mering, Christian; Macpherson, Andrew J; Hardt, Wolf-Dietrich

    2010-01-01

    The intestinal ecosystem is formed by a complex, yet highly characteristic microbial community. The parameters defining whether this community permits invasion of a new bacterial species are unclear. In particular, inhibition of enteropathogen infection by the gut microbiota ( = colonization resistance) is poorly understood. To analyze the mechanisms of microbiota-mediated protection from Salmonella enterica induced enterocolitis, we used a mouse infection model and large scale high-throughput pyrosequencing. In contrast to conventional mice (CON), mice with a gut microbiota of low complexity (LCM) were highly susceptible to S. enterica induced colonization and enterocolitis. Colonization resistance was partially restored in LCM-animals by co-housing with conventional mice for 21 days (LCM(con21)). 16S rRNA sequence analysis comparing LCM, LCM(con21) and CON gut microbiota revealed that gut microbiota complexity increased upon conventionalization and correlated with increased resistance to S. enterica infection. Comparative microbiota analysis of mice with varying degrees of colonization resistance allowed us to identify intestinal ecosystem characteristics associated with susceptibility to S. enterica infection. Moreover, this system enabled us to gain further insights into the general principles of gut ecosystem invasion by non-pathogenic, commensal bacteria. Mice harboring high commensal E. coli densities were more susceptible to S. enterica induced gut inflammation. Similarly, mice with high titers of Lactobacilli were more efficiently colonized by a commensal Lactobacillus reuteri(RR) strain after oral inoculation. Upon examination of 16S rRNA sequence data from 9 CON mice we found that closely related phylotypes generally display significantly correlated abundances (co-occurrence), more so than distantly related phylotypes. Thus, in essence, the presence of closely related species can increase the chance of invasion of newly incoming species into the gut

  4. Do abundance and proximity of the alien Impatiens glandulifera affect pollination and reproductive success of two sympatric co-flowering native species?

    Directory of Open Access Journals (Sweden)

    Anne-Laure Jacquemart

    2012-12-01

    Full Text Available In invasion ecology, potential impacts of aliens on native flora are still under debate. Our aim was to determine the pollinator mediated effects of both proximity and abundance of an alien species on the reproductive success of natives. We chose the highly invasive Impatiens glandulifera and two native species: Epilobium angustifolium and Aconitum napellus ssp. lusitanicum. These species share characteristics allowing for pollination interactions: similar biotopes, overlapping flowering periods and same main pollinators. The effects of abundance (5, 25 and 100 individuals and proximity (0 and 15 m of the alien on visitation rate, insect behaviour, pollen deposition and reproductive success of both natives were investigated during 2 flowering seasons. We used centred visitation rates as they can be directly interpreted as a positive or negative effect of the invasive.Both abundance and proximity of the alien increased bumblebee visitation rates to both natives. On the other hand, abundance of the exotic species had a slight negative effect on honeybee visits to natives while its proximity had no effect. The behaviour of bumblebees changed as visitors left significantly more often the native plants for I. glandulifera when its abundance increased. As a consequence of this “inconstancy”, bees deposited considerable quantities of alien pollen on native stigmas. Nevertheless, this interspecific pollen transfer did not decrease seed set in natives. Self-compatibility and high attractiveness of both native species probably alleviate the risk of altered pollinator services and reproductive success due to the invader in natural populations.

  5. Importance of species abundance for assessment of trait composition: an example based on pollinator communities

    Czech Academy of Sciences Publication Activity Database

    de Bello, F.; Lepš, Jan; Lavorel, S.; Moretti, M.

    2007-01-01

    Roč. 8, č. 2 (2007), s. 163-170 ISSN 1585-8553 R&D Projects: GA MŠk LC06073 Grant - others:VIth Framework Programme EU(BE) EU-036890 Institutional research plan: CEZ:AV0Z50070508 Source of funding: R - rámcový projekt EK Keywords : bee * biodiversity * community assembly Subject RIV: EH - Ecology, Behaviour Impact factor: 0.604, year: 2007

  6. Influence of species composition of biocorridors on the abundance of aphids in cereal fields

    Czech Academy of Sciences Publication Activity Database

    Ameixa, Olga; Dvořáková, R.; Šipoš, Jan; Kindlmann, Pavel

    2014-01-01

    Roč. 4, č. 1 (2014), s. 47-52 ISSN 1805-0174 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : biocorridors * Prunus padus * Rhopalosiphum padi * pest refuge * spatial distribution Subject RIV: EH - Ecology, Behaviour

  7. Effects of habitat and landscape characteristics on medium and large mammal species richness and composition in northern Uruguay

    Directory of Open Access Journals (Sweden)

    María José Andrade-Núñez

    2010-01-01

    Full Text Available The increasing world population and demand for food and other products has accelerated the conversion of natural habitats into agricultural lands, plantations and urban areas. Changes in habitat and landscape characteristics due to land-use change can have a significant effect on species presence, abundance, and distribution. Multi-scale approaches have been used to determine the proper spatial scales at which species and communities are responding to habitat transformation. In this context, we evaluated medium and large mammal species richness and composition in gallery forest (n = 10, grassland (n = 10, and exotic tree plantation (n = 10 in a region where grasslands have been converted into exotic tree plantations. We quantified mammal species richness and composition with camera traps and track surveys. The composition of the mammal community was related with local habitat variables, and landscape variables measured at seven spatial scales. We found 14 mammal species in forest, 11 species in plantation, and 7 mammal species in grassland. Two species are exotics, the wild boar Sus scrofa Linnaeus, 1758 and the European hare Lepus europaeus Pallas, 1778. The most common species are the crab-eating fox Cerdocyon thous Linnaeus, 1766, the nine-banded armadillo Dasypus novemcinctus Linnaeus, 1758 and the gray brocket deer Mazama gouazoubira G. Fischer, 1814 which are generalist species. Our results showed significant differences in mammal species richness and composition among the three habitat types. Plantations can have positive and negative effects on the presence of species restricted to grasslands. Positive effects are reflected in a wider local distribution of some forest species that rarely use grassland. The most important habitat and landscape variables that influenced mammal species richness and composition were vertical structure index, canopy cover, tree species diversity, percentage of grass, and the percentage of forest and grassland

  8. Chemical composition of late-type supergiants. IV. Homogeneous abundances and galactic metallicity trends

    International Nuclear Information System (INIS)

    Luck, R.E.

    1982-01-01

    In a recent series of papers by Luck and by Luck and Bond on the chemical composition of G and K lb supergiants, [Fe/H] ratios were determined from high-dispersion spectroscopic data for 54 stars. The main results were: (1) that supergiants in the solar neighborhood have about twice the iron content of the Sun ( = +0.3); and (2) that supergiants between 7.7 and 10.2 kpc from the galactic center show a steep radial metallicity gradient, d[Fe/H]/dR = -0.24 kpc -1

  9. Variability in chemical composition and abundance of the rare tertiary relict Pinus heldreichii in Serbia.

    Science.gov (United States)

    Bojović, Srdjan; Nikolić, Biljana; Ristić, Mihailo; Orlović, Saša; Veselinović, Milorad; Rakonjac, Ljubinko; Dražić, Dragana

    2011-09-01

    The particular significance of the whitebark pine (Pinus heldreichii Christ.) stems from the fact that it is a tertiary relict and Balkanic subendemite covering a very narrow and intermittent area in Serbia. A representative pool of 48 adult trees originating from three populations, one recently discovered natural (Population I) and two planted populations (Populations II and III) was investigated in order to evaluate the intra- and interpopulation variability of the essential oil of the complete fund of P. heldreichii in Serbia. In the pine-needle-terpene profile, 104 compounds were detected, 84 of which could be identified. Among the essential-oil constituents, monoterpenes and sesquiterpenes dominated, comprising ca. 90% of the essential oil. The terpenic profile of Population I was characterized by a predominance of monoterpenes (e.g., limonene (1), α-pinene, and Δ(3) -carene (4)), while sesquiterpenes (e.g., germacrene D (2) and β-caryophyllene (3)) obviously preponderated in the profile of Populations II and III. This study also demonstrated that the abundance of whitebark pines in Serbia had significantly changed over the last few decades. The number of individuals in the natural population had increased, while the number of individuals in the planted populations had decreased. Today, the whitebark pine fund in Serbia comprises less than 250 trees. 2011 Verlag Helvetica Chimica Acta AG, Zürich.

  10. Snow-borne nanosized particles: Abundance, distribution, composition, and significance in ice nucleation processes

    Science.gov (United States)

    Rangel-Alvarado, Rodrigo Benjamin; Nazarenko, Yevgen; Ariya, Parisa A.

    2015-11-01

    Physicochemical processes of nucleation constitute a major uncertainty in understanding aerosol-cloud interactions. To improve the knowledge of the ice nucleation process, we characterized physical, chemical, and biological properties of fresh snow using a suite of state-of-the-art techniques based on mass spectrometry, electron microscopy, chromatography, and optical particle sizing. Samples were collected at two North American Arctic sites, as part of international campaigns (2006 and 2009), and in the city of Montreal, Canada, over the last decade. Particle size distribution analyses, in the range of 3 nm to 10 µm, showed that nanosized particles are the most numerous (38-71%) in fresh snow, with a significant portion (11 to 19%) less than 100 nm in size. Particles with diameters less than 200 nm consistently exhibited relatively high ice-nucleating properties (on average ranged from -19.6 ± 2.4 to -8.1 ± 2.6°C). Chemical analysis of the nanosized fraction suggests that they contain bioorganic materials, such as amino acids, as well as inorganic compounds with similar characteristics to mineral dust. The implication of nanoparticle ubiquity and abundance in diverse snow ecosystems are discussed in the context of their importance in understanding atmospheric nucleation processes.

  11. Abundance, stable isotopic composition, and export fluxes of DOC, POC, and DIC from the Lower Mississippi River during 2006–2008

    Science.gov (United States)

    Cai, Yihua; Guo, Laodong; Wang, Xuri; Aiken, George R.

    2015-01-01

    Sources, abundance, isotopic compositions, and export fluxes of dissolved inorganic carbon (DIC), dissolved and colloidal organic carbon (DOC and COC), and particulate organic carbon (POC), and their response to hydrologic regimes were examined through monthly sampling from the Lower Mississippi River during 2006–2008. DIC was the most abundant carbon species, followed by POC and DOC. Concentration and δ13C of DIC decreased with increasing river discharge, while those of DOC remained fairly stable. COC comprised 61 ± 3% of the bulk DOC with similar δ13C abundances but higher percentages of hydrophobic organic acids than DOC, suggesting its aromatic and diagenetically younger status. POC showed peak concentrations during medium flooding events and at the rising limb of large flooding events. While δ13C-POC increased, δ15N of particulate nitrogen decreased with increasing discharge. Overall, the differences in δ13C between DOC or DIC and POC show an inverse correlation with river discharge. The higher input of soil organic matter and respired CO2 during wet seasons was likely the main driver for the convergence of δ13C between DIC and DOC or POC, whereas enhanced in situ primary production and respiration during dry seasons might be responsible for their isotopic divergence. Carbon export fluxes from the Mississippi River were estimated to be 13.6 Tg C yr−1 for DIC, 1.88 Tg C yr−1 for DOC, and 2.30 Tg C yr−1 for POC during 2006–2008. The discharge-normalized DIC yield decreased during wet seasons, while those of POC and DOC increased and remained constant, respectively, implying variable responses in carbon export to the increasing discharge.

  12. Variation in leaf litter production and resorption of nutrients in abundant tree species in Nyungwe tropical montane rainforest in Rwanda

    Science.gov (United States)

    Nyirambangutse, Brigitte; Mirindi Dusenge, Eric; Nsabimana, Donat; Bizuru, Elias; Pleijel, Håkan; Uddling, Johan; Wallin, Göran

    2014-05-01

    , phosphorus and other nutrients is being studied to analyse the nutrient saving efficiency of different species within the primary and secondary forest communities. This is made by analyzing the nutrient content within fresh and fallen leaves of most abundant pioneer and climax species. Results from litterfall patterns as well as foliar, litter and soil carbon and nutrients are currently being compiled and will be reported.

  13. Abundances of Volatile - Bearing Species from Evolved Gas Analysis of Samples from the Rocknest Aeolian Bedform in Gale Crater

    Science.gov (United States)

    Archer, P. D., Jr.; Franc, H. B.; Sutter, B.; McAdam, A.; Ming, D. W.; Morris, R. V.; Mahaffy, P. R.

    2013-01-01

    The Sample Analysis at Mars (SAM) instrument suite on board the Mars Science Laboratory (MSL) recently ran four samples from an aeolian bedform named Rocknest. SAM detected the evolution of H2O, CO2, O2, and SO2, indicative of the presence of multiple volatile bearing species (Fig 1). The Rocknest bedform is a windblown deposit selected as representative of both the windblown material in Gale crater as well as the globally-distributed martian dust. Four samples of Rocknest material were analyzed by SAM, all from the fifth scoop taken at this location. The material delivered to SAM passed through a 150 m sieve and is assumed to have been well mixed during the sample acquisition/preparation/handoff process. SAM heated the Rocknest samples to approx.835 C at a ramp rate of 35 C/min with a He carrier gas flow rate of apprx.1.5 standard cubic centimeters per minute and at an oven pressure of 30 mbar [1]. Evolved gases were detected by a quadrupole mass spectrometer (QMS). This abstract presents the molar abundances of H2O, CO2, O2, and SO2 as well as their concentration in rocknest samples using an estimated sample mass.

  14. The Composition of Comet C/2012 K1 (PanSTARRS) and the Distribution of Primary Volatile Abundances Among Comets

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Nathan X.; Gibb, Erika L. [Department of Physics and Astronomy, University of Missouri-St. Louis, 503 Benton Hall, One University Blvd., St. Louis, MO 63121 (United States); Bonev, Boncho P.; DiSanti, Michael A.; Mumma, Michael J.; Villanueva, Geronimo L.; Paganini, Lucas, E-mail: nxrq67@mail.umsl.edu [Goddard Center for Astrobiology, NASA Goddard Space Flight Center, Mail Stop 690, Greenbelt, MD 20771 (United States)

    2017-04-01

    On 2014 May 22 and 24 we characterized the volatile composition of the dynamically new Oort cloud comet C/2012 K1 (PanSTARRS) using the long-slit, high resolution ( λ /Δ λ  ≈ 25,000) near-infrared echelle spectrograph (NIRSPEC) at the 10 m Keck II telescope on Maunakea, Hawaii. We detected fluorescent emission from six primary volatiles (H{sub 2}O, HCN, CH{sub 4}, C{sub 2}H{sub 6}, CH{sub 3}OH, and CO). Upper limits were derived for C{sub 2}H{sub 2}, NH{sub 3}, and H{sub 2}CO. We report rotational temperatures, production rates, and mixing ratios (relative to water). Compared with median abundance ratios for primary volatiles in other sampled Oort cloud comets, trace gas abundance ratios in C/2012 K1 (PanSTARRS) for CO and HCN are consistent, but CH{sub 3}OH and C{sub 2}H{sub 6} are enriched while H{sub 2}CO, CH{sub 4}, and possibly C{sub 2}H{sub 2} are depleted. When placed in context with comets observed in the near-infrared to date, the data suggest a continuous distribution of abundances of some organic volatiles (HCN, C{sub 2}H{sub 6}, CH{sub 3}OH, CH{sub 4}) among the comet population. The level of “enrichment” or “depletion” in a given comet does not necessarily correlate across all molecules sampled, suggesting that chemical diversity among comets may be more complex than the simple organics-enriched, organics-normal, and organics-depleted framework.

  15. Targeting Abundant Fish Stocks while Avoiding Overfished Species: Video and Fishing Surveys to Inform Management after Long-Term Fishery Closures

    Science.gov (United States)

    2016-01-01

    Historically, it has been difficult to balance conservation goals and yield objectives when managing multispecies fisheries that include stocks with various vulnerabilities to fishing. As managers try to maximize yield in mixed-stock fisheries, exploitation rates can lead to less productive stocks becoming overfished. In the late 1990s, population declines of several U.S. West Coast groundfish species caused the U.S. Pacific Fishery Management Council to create coast-wide fishery closures, known as Rockfish Conservation Areas, to rebuild overfished species. The fishery closures and other management measures successfully reduced fishing mortality of these species, but constrained fishing opportunities on abundant stocks. Restrictive regulations also caused the unintended consequence of reducing fishery-dependent data available to assess population status of fished species. As stocks rebuild, managers are faced with the challenge of increasing fishing opportunities while minimizing fishing mortality on rebuilding species. We designed a camera system to evaluate fishes in coastal habitats and used experimental gear and fishing techniques paired with video surveys to determine if abundant species could be caught in rocky habitats with minimal catches of co-occurring rebuilding species. We fished a total of 58 days and completed 741 sets with vertical hook-and-line fishing gear. We also conducted 299 video surveys in the same locations where fishing occurred. Comparison of fishing and stereo-video surveys indicated that fishermen could fish with modified hook-and-line gear to catch abundant species while limiting bycatch of rebuilding species. As populations of overfished species continue to recover along the U.S. West Coast, it is important to improve data collection, and video and fishing surveys may be key to assessing species that occur in rocky habitats. PMID:28002499

  16. The influence of gap size on plant species diversity and composition in beech (Fagus orientalis forests, Ramsar, Mazandaran Province, North of Iran

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    MARZIEH BEGYOM-FAGHIR

    2013-10-01

    Full Text Available Pourbabaei H, Haddadi-Moghaddam H, Begyom-Faghir M, Abedi T. 2013. The influence of gap size on plant species diversity and composition in beech (Fagus orientalis forests, Ramsar, Mazandaran Province, North of Iran. Biodiversitas 14: 89-94.This study was conducted to investigate the influence of gap size on plant species diversity and composition in beech (Fagus orientalis Lipsky. forests, Ramsar, Mazandaran province. Fifteen gaps in small, medium, and large sizes were randomly selected. Abundance of tree saplings, shrubs and herbaceous species were counted on 4 m2 micro-plots within the gaps. Diversity indices including Shannon-Wiener, Simpson, Mc Arthur's N1, Hill's N2, species richness and Smith-Wilson’s evenness index were computed. The results revealed that there was significant difference among three gap categories in terms of diversity. The highest diversity values of tree and herbaceous species were obtained in the large gaps, while the highest diversity value of shrub species was in the medium gaps. Species composition of small gaps (28 species: 7 trees and 21 herbaceous, medium gaps (37 species: 7 trees, 5 shrubs and 25 herbaceous and large gaps (40 species: 7 trees, 4 shrubs and 29 herbaceous were recognized. Therefore, based on the results of this study, it is recommended that in order to maintain plant diversity and composition up to 400 m2 gap size cloud be used in this forests.

  17. Effect of water stress on seedling growth in two species with different abundances: the importance of Stress Resistance Syndrome in seasonally dry tropical forest

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    Wanessa Nepomuceno Ferreira

    2015-09-01

    Full Text Available ABSTRACTIn seasonally dry tropical forests, species carrying attributes of Stress Resistance Syndrome (SRS may have ecological advantages over species demanding high quantities of resources. In such forests, Poincianella bracteosa is abundant, while Libidibia ferrea has low abundance; therefore, we hypothesized that P. bracteosa has characteristics of low-resource species, while L. ferrea has characteristics of high-resource species. To test this hypothesis, we assessed morphological and physiological traits of seedlings of these species under different water regimes (100%, 70%, 40%, and 10% field capacity over 85 days. For most of the studied variables we observed significant decreases with increasing water stress, and these reductions were greater in L. ferrea. As expected, L. ferreamaximized their growth with increased water supply, while P. bracteosa maintained slower growth and had minor adjustments in biomass allocation, characteristics representative of low-resource species that are less sensitive to stress. We observed that specific leaf area, biomass allocation to roots, and root/shoot ratio were higher in L. ferrea, while biomass allocation to leaves and photosynthesis were higher in P. bracteosa. Results suggest that the attributes of SRS can facilitate high abundance of P. bracteosa in dry forest.

  18. The impact on orchid species abundance of gathering their edible tubers by HIV/AIDS orphans : a case of three villages in the Southern Highlands of Tanzania

    NARCIS (Netherlands)

    Challe, J.F.X.; Struik, P.C.

    2008-01-01

    This paper examines the gathering of wild orchids and its effect on orchid species diversity and abundance in rural communities with high prevalence of HIV/AIDS and high numbers of orphans. The study was conducted in three villages in the Makete District of Tanzania. The study used a triangulation

  19. COMPOSITIONAL PROPERTIES OF THREE FRESHWATER CARP SPECIES GROWN IN BRACKISH WATER

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    Muhammad Ismail Chughtai

    2015-06-01

    Full Text Available Three freshwater fish species viz. Labeo rohita, Cirrhinus mrigala and Gibelion catla, grown in brackish water ponds were analyzed for compositional properties to assess the potential of this habitat to produce nutritionally adequate fish for human consumption. Overall, the unsaturated fatty acids were lower in L. rohita (46.6% than saturated fatty acids; while in C. mrigala and G. catla, the unsaturated fatty acids were 50.4% and 58.2%, respectively. The most abundant saturated fatty acid in examined species was palmitic acid (C16:0, 23.7 to 34.1%; mono-unsaturated fatty acid was oleic acid (C18:1 19.6 to 31.7% and poly-unsaturated fatty acid linoleic acid (C18:2 9.46 to 13.3%. A reasonable amount of essential fatty acids ω-3 (5.80 to 9.26% and ω-6 (9.46 to 13.3% was also found in these species while growing in brackish water on salt tolerant forages like Leptochloa fusca, Brachiaria mutica and Kochia indica as supplemental feed. The ω-3/ω-6 ratio was calculated as 0.46, 0.80 and 0.69 in L. rohita, C. mrigala and G. catla, respectively. The maximum EPA (eicosapentaenoic acid, C20:5 was observed in C. mrigala (2.23%, followed by G. catla (1.62% and L. rohita (0.98%. While the DHA (docosahexanenoic acids, C22:6 was found maximum in G. catla (1.97% and minimum in C. mrigala (0.95%. The results of body composition indicated that L. rohita found maximum protein contents (19.2% with minimum total fats (1.28% while C. mrigala found maximum total fats (2.11% but minimum protein contents (18.3%. Overall results indicated that the Indian carps grown in brackish water have comparable chemical composition and nutritive value with the same species grown in freshwater medium.

  20. Volatile Metabolomic Composition of Vitex Species: Chemodiversity Insights and Acaricidal Activity

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    José G. de Sena Filho

    2017-11-01

    Full Text Available The Vitex genus (Lamiaceae produces a plethora of metabolites that include ecdysteroids and terpenoids, some of which have demonstrated insect repellent properties. The volatile composition of several members of this genus has not been chemically defined, as many taxa are endemic to remote ecosystems. In this study, leaves were collected from the northeast of Brazil from Vitex capitata, V. megapotamica, V. gardneriana, and V. rufescens plants and examined for their chemical profile via GC-MS/FID of essential oil extracts. The analyses showed a diversity of terpenoids. Of particular note were seven-member ring sesquiterpenes which were present in great abundance; a dendrogram showed clades separating by the production of bicyclogermacrene, aromadendrane and 5,10-cycloaromadendrane sesquiterpenoids for the four species. Comparison of volatile metabolite profiles to 13 other Vitex species showed strong similarities in the production of some monoterpenes, but varied by their production of larger terpenes, especially those with gem-dimethylcyclopropyl subunits on seven-member ring compounds. From this work, we suggest that the sesquiterpene skeleton with seven member rings is a good chemosystematic biomarker candidate for the Vitex genus. Separation using this biomarker was then validated using Inter-Simple Sequence Repeat profiling. Lastly, experiments examining the toxicity of these four oils against the coconut mite Aceria guerreronis showed that only the oil of V. gardneriana had strong acaricidal activity, with an LC50 of 0.85 mg/mL, thus demonstrating its potential for use as a natural pesticide.

  1. Species composition and assemblages of ichthyoplankton during summer in the East China Sea

    Science.gov (United States)

    Lin, Han-Yang; Chiu, Mei-Yun; Shih, Yu-Ming; Chen, I.-Shiung; Lee, Ming-An; Shao, Kwang-Tsao

    2016-09-01

    The East China Sea (ECS) is one of the most important fish spawning and nursery grounds in the north Pacific. Even though summer is an important spawning season for many fishes in the region, large-scale molecular identification studies on ichthyoplankton during this season are few. In this study, we sampled 8,933 fish eggs and 12,161 fish larvae from 25 stations during the summer of 2009. Using DNA barcoding, a number of the fish eggs and larvae were identified and classified into 45 and 124 taxa, respectively. Principal component analysis (PCA) categorized the inshore stations of the Changjiang Diluted Water area as having the hydrographic features of low sea surface temperature (SST), salinity (SSS) and high chlorophyll a (SSC) contents, whereas the continental shelf and offshore stations under the influence of the Kuroshio Current displayed the opposite results. Ichthyoplankton was more abundant at the inshore stations than the offshore stations, but species diversity was lower at the former locations. Species compositions of both fish eggs and fish larvae at the 25 stations were categorized into three different assemblages based on a non-metric multidimensional scaling analysis. Combining the assemblage patterns of ichthyoplankton with the results of the PCA and satellite images of SST and SSC showed that the assemblage patterns of fish eggs were correlated with water mass, while those of the fish larvae were not.

  2. Coccolithophore responses to environmental variability in the South China Sea: species composition and calcite content

    Science.gov (United States)

    Jin, Xiaobo; Liu, Chuanlian; Poulton, Alex J.; Dai, Minhan; Guo, Xianghui

    2016-08-01

    Coccolithophore contributions to the global marine carbon cycle are regulated by the calcite content of their scales (coccoliths) and the relative cellular levels of photosynthesis and calcification rates. All three of these factors vary between coccolithophore species and with response to the growth environment. Here, water samples were collected in the northern basin of the South China Sea (SCS) during summer 2014 in order to examine how environmental variability influenced species composition and cellular levels of calcite content. Average coccolithophore abundance and their calcite concentration in the water column were 11.82 cells mL-1 and 1508.3 pg C mL-1, respectively, during the cruise. Water samples can be divided into three floral groups according to their distinct coccolithophore communities. The vertical structure of the coccolithophore community in the water column was controlled by the trophic conditions, which were regulated by mesoscale eddies across the SCS basin. The evaluation of coccolithophore-based calcite in the surface ocean also showed that three key species in the SCS (Emiliania huxleyi, Gephyrocapsa oceanica, Florisphaera profunda) and other larger, numerically rare species made almost equal contributions to total coccolith-based calcite in the water column. For Emiliania huxleyi biometry measurements, coccolith size positively correlated with nutrients (nitrate, phosphate), and it is suggested that coccolith length is influenced by light and nutrients through the regulation of growth rates. Larger-sized coccoliths were also linked statistically to low pH and calcite saturation states; however, it is not a simple cause and effect relationship, as carbonate chemistry was strongly co-correlated with the other key environmental factors (nutrients, light).

  3. Abundance and survival rates of three leaf-litter frog species in fragments and continuous forest of the Mata Atlântica, Brazil

    Directory of Open Access Journals (Sweden)

    Henning Steinicke

    2018-04-01

    Full Text Available Habitat destruction and fragmentation alter the quality of habitats and put populations under the risk of extinction. Changes in population parameters can provide early warning signs of negative impacts. In tropical forests, where habitat loss and fragmentation are vast, such indicators are of high relevance for directing conservation efforts before effects are irreversible. Most of our knowledge from tropical ecosystems originates from community level surveys, whereas our understanding of the influence of habitat conversion on vital rates of species is limited. This study focused on the influence of anthropogenic habitat fragmentation on the survival probability and abundance of three leaf-litter frog species (Rhinella ornata, Ischnocnema guentheri and I. parva in forest patches of the Atlantic rainforest of South-east Brazil compared to a continuous forest. The species differ in their matrix tolerance: high for R. ornata and low for I. guentheri and I. parva and, thus, we examined whether their survival and abundance correspond to this classification. Ischnocnema guentheri showed highest abundances in all study sites and low mortality in the forest patches compared to the continuous forest; I. parva was encountered only in isolated fragments, with very low mortality in one isolated fragment; and the matrix tolerant species had generally low abundance and showed no clear pattern in terms of mortality in the different sites. Our counter-intuitive results show that even matrix sensitive amphibian species may show high abundance and low mortality in small forest patches. Therefore, these patches can be of high value for amphibian conservation regardless of their degree of matrix aversion. Landscape level conservation planning should not abandon small habitat patches, especially in highly fragmented tropical environments.

  4. Changes in Species Richness and Composition of Tiger Moths (Lepidoptera: Erebidae: Arctiinae) among Three Neotropical Ecoregions

    Science.gov (United States)

    Beccacece, Hernán Mario; Zeballos, Sebastián Rodolfo; Zapata, Adriana Inés

    2016-01-01

    Paraná, Yungas and Chaco Serrano ecoregions are among the most species-rich terrestrial habitats at higher latitude. However, the information for tiger moths, one of the most speciose groups of moths, is unknown in these ecoregions. In this study, we assess their species richness and composition in all three of these ecoregions. Also we investigated whether the species composition of tiger moths is influenced by climatic factors and altitude. Tiger moth species were obtained with samples from 71 sites using standardized protocols (21 sites were in Yungas, 19 in Paraná and 31 in Chaco Serrano). Rarefaction-extrapolation curves, non-parametric estimators for incidence and sample coverage indices were performed to assess species richness in the ecoregions studied. Non metric multidimensional scaling and adonis tests were performed to compare the species composition of tiger moths among ecoregions. Permutest analysis and Pearson correlation were used to evaluate the relationship among species composition and annual mean temperature, annual temperature range, annual precipitation, precipitation seasonality and altitude. Among ecoregions Paraná was the richest with 125 species, followed by Yungas with 63 species and Chaco Serrano with 24 species. Species composition differed among these ecoregions, although Yungas and Chaco Serrano were more similar than Paraná. Species composition was significantly influenced by climatic factors and altitude. This study showed that species richness and species composition of tiger moths differed among the three ecoregions assessed. Furthermore, not only climatic factors and altitude influence the species composition of tiger moths among ecoregions, but also climatic seasonality at higher latitude in Neotropical South America becomes an important factor. PMID:27681478

  5. Changes in Species Richness and Composition of Tiger Moths (Lepidoptera: Erebidae: Arctiinae among Three Neotropical Ecoregions.

    Directory of Open Access Journals (Sweden)

    Hernán Mario Beccacece

    Full Text Available Paraná, Yungas and Chaco Serrano ecoregions are among the most species-rich terrestrial habitats at higher latitude. However, the information for tiger moths, one of the most speciose groups of moths, is unknown in these ecoregions. In this study, we assess their species richness and composition in all three of these ecoregions. Also we investigated whether the species composition of tiger moths is influenced by climatic factors and altitude. Tiger moth species were obtained with samples from 71 sites using standardized protocols (21 sites were in Yungas, 19 in Paraná and 31 in Chaco Serrano. Rarefaction-extrapolation curves, non-parametric estimators for incidence and sample coverage indices were performed to assess species richness in the ecoregions studied. Non metric multidimensional scaling and adonis tests were performed to compare the species composition of tiger moths among ecoregions. Permutest analysis and Pearson correlation were used to evaluate the relationship among species composition and annual mean temperature, annual temperature range, annual precipitation, precipitation seasonality and altitude. Among ecoregions Paraná was the richest with 125 species, followed by Yungas with 63 species and Chaco Serrano with 24 species. Species composition differed among these ecoregions, although Yungas and Chaco Serrano were more similar than Paraná. Species composition was significantly influenced by climatic factors and altitude. This study showed that species richness and species composition of tiger moths differed among the three ecoregions assessed. Furthermore, not only climatic factors and altitude influence the species composition of tiger moths among ecoregions, but also climatic seasonality at higher latitude in Neotropical South America becomes an important factor.

  6. Can DNA-Based Ecosystem Assessments Quantify Species Abundance? Testing Primer Bias and Biomass--Sequence Relationships with an Innovative Metabarcoding Protocol.

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    Vasco Elbrecht

    Full Text Available Metabarcoding is an emerging genetic tool to rapidly assess biodiversity in ecosystems. It involves high-throughput sequencing of a standard gene from an environmental sample and comparison to a reference database. However, no consensus has emerged regarding laboratory pipelines to screen species diversity and infer species abundances from environmental samples. In particular, the effect of primer bias and the detection limit for specimens with a low biomass has not been systematically examined, when processing samples in bulk. We developed and tested a DNA metabarcoding protocol that utilises the standard cytochrome c oxidase subunit I (COI barcoding fragment to detect freshwater macroinvertebrate taxa. DNA was extracted in bulk, amplified in a single PCR step, and purified, and the libraries were directly sequenced in two independent MiSeq runs (300-bp paired-end reads. Specifically, we assessed the influence of specimen biomass on sequence read abundance by sequencing 31 specimens of a stonefly species with known haplotypes spanning three orders of magnitude in biomass (experiment I. Then, we tested the recovery of 52 different freshwater invertebrate taxa of similar biomass using the same standard barcoding primers (experiment II. Each experiment was replicated ten times to maximise statistical power. The results of both experiments were consistent across replicates. We found a distinct positive correlation between species biomass and resulting numbers of MiSeq reads. Furthermore, we reliably recovered 83% of the 52 taxa used to test primer bias. However, sequence abundance varied by four orders of magnitudes between taxa despite the use of similar amounts of biomass. Our metabarcoding approach yielded reliable results for high-throughput assessments. However, the results indicated that primer efficiency is highly species-specific, which would prevent straightforward assessments of species abundance and biomass in a sample. Thus, PCR

  7. Effects of weed cover composition on insect pest and natural enemy abundance in a field of Dracaena marginata (Asparagales: Asparagaceae) in Costa Rica.

    Science.gov (United States)

    Sadof, Clifford S; Linkimer, Mildred; Hidalgo, Eduardo; Casanoves, Fernando; Gibson, Kevin; Benjamin, Tamara J

    2014-04-01

    Weeds and their influence on pest and natural enemy populations were studied on a commercial ornamental farm during 2009 in the Atlantic Zone of Costa Rica. A baseline survey of the entire production plot was conducted in February, along a 5 by 5 m grid to characterize and map initial weed communities of plants, cicadellids, katydids, and armored scales. In total, 50 plant species from 21 families were found. Seven weed treatments were established to determine how weed manipulations would affect communities of our targeted pests and natural enemies. These treatments were selected based on reported effects of specific weed cover on herbivorous insects and natural enemies, or by their use by growers as a cover crop. Treatments ranged from weed-free to being completely covered with endemic species of weeds. Although some weed treatments changed pest abundances, responses differed among arthropod pests, with the strongest effects observed for Caldwelliola and Empoasca leafhoppers. Removal of all weeds increased the abundance of Empoasca, whereas leaving mostly cyperacaeous weeds increased the abundance of Caldwelliola. Weed manipulations had no effect on the abundance of katydid and scale populations. No weed treatment reduced the abundance of all three of the target pests. Differential responses of the two leafhopper species to the same weed treatments support hypotheses, suggesting that noncrop plants can alter the abundance of pests through their effects on arthropod host finding and acceptance, as well as their impacts on natural enemies.

  8. Can Airborne Laser Scanning (ALS and Forest Estimates Derived from Satellite Images Be Used to Predict Abundance and Species Richness of Birds and Beetles in Boreal Forest?

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    Eva Lindberg

    2015-04-01

    Full Text Available In managed landscapes, conservation planning requires effective methods to identify high-biodiversity areas. The objective of this study was to evaluate the potential of airborne laser scanning (ALS and forest estimates derived from satellite images extracted at two spatial scales for predicting the stand-scale abundance and species richness of birds and beetles in a managed boreal forest landscape. Multiple regression models based on forest data from a 50-m radius (i.e., corresponding to a homogenous forest stand had better explanatory power than those based on a 200-m radius (i.e., including also parts of adjacent stands. Bird abundance and species richness were best explained by the ALS variables “maximum vegetation height” and “vegetation cover between 0.5 and 3 m” (both positive. Flying beetle abundance and species richness, as well as epigaeic (i.e., ground-living beetle richness were best explained by a model including the ALS variable “maximum vegetation height” (positive and the satellite-derived variable “proportion of pine” (negative. Epigaeic beetle abundance was best explained by “maximum vegetation height” at 50 m (positive and “stem volume” at 200 m (positive. Our results show that forest estimates derived from satellite images and ALS data provide complementary information for explaining forest biodiversity patterns. We conclude that these types of remote sensing data may provide an efficient tool for conservation planning in managed boreal landscapes.

  9. Riqueza, abundância e sazonalidade de Sphingidae (Lepidoptera num fragmento de Mata Atlântica de Pernambuco, Brasil Species richness, abundance and seasonality of Sphingidae (Lepidoptera in a fragment of Atlantic Rainforest of Pernambuco, Brazil

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    José A. Duarte Júnior

    2005-09-01

    Full Text Available Na Mata Atlântica de Pernambuco, NE-Brasil (Reserva Biológica de Gurjaú, Cabo de Santo Agostinho foi realizado um levantamento de Sphingidae de dezembro de 2002 a novembro de 2003. Os esfingídeos foram coletados com luz de vapor de mercúrio durante duas noites consecutivas por mês, próximo ao novilúnio. Foram determinadas riqueza de espécies, abundância e sazonalidade. Oitenta e nove espécimes de 23 espécies em 13 gêneros foram registrados; 84% dos indivíduos foram machos. Muitas espécies foram raras e de 13 espécies foi coletado apenas um exemplar. Xylophanes loelia (Druce, 1878, X. libya (Druce, 1878, Hemeroplanes triptolemus (Cramer, 1779, Eumorpha anchemolus (Cramer, 1779, Manduca brasilensis (Jordan, 1911, M. hannibal (Cramer, 1779, Adhemarius gannascus (Stoll, 1790 e Protambulyx astygonus (Boisduval, [1875] foram registradas pela primeira vez no Nordeste do Brasil. A esfingofauna não mostrou nenhum padrão de sazonalidade, e riqueza e abundância de espécies de esfingídeos não se correlacionaram com precipitação mensal e temperatura.In the Atlantic Rainforest of Pernambuco, NE-Brazil (Reserva Biológica de Gurjaú, Cabo de Santo Agostinho a survey of Sphingidae was performed from December 2002 to November 2003. The hawkmoths were collected with vapor mercury light during two consecutive nights per months near new moon. Species richness, abundance and seasonality were determined. Eighty-nine specimens of 23 species in13 genera were recorded; 84% the individuals were males. Most species were rare and from 13 species only one exemplar was collected. Xylophanes loelia (Druce, 1878, X. libya (Druce, 1878, Hemeroplanes triptolemus (Cramer, 1779, Eumorpha anchemolus (Cramer, 1779, Manduca brasilensis (Jordan, 1911, M. hannibal (Cramer, 1779, Adhemarius gannascus (Stoll, 1790 e Protambulyx astygonus (Boisduval, [1875] were recorded for the first time in Northeastern Brazil. The sphingofauna showed no seasonal patterns and

  10. Roads may act as barriers to flying insects: species composition of bees and wasps differs on two sides of a large highway

    Directory of Open Access Journals (Sweden)

    Petter Andersson

    2017-07-01

    Full Text Available Roads may act as barriers to animal movements, but direct barrier effects on insects have rarely been studied. In this study we collected data on bees and wasps along two sides of a large road in Sweden using yellow pan traps. We then analyzed if the species composition differed between the two sides of the road; first for the whole community, and then only for the smallest species (which typically are poorer dispersers. As a complement, we analyzed if different vegetation variables differed between the two sides of the road, as this may also affect differences in species composition. Finally, we analyzed if species richness and abundance in general differed between the two sides and how these two response variables were explained by the vegetation variables. There was a significant difference in species composition between the eastern and the western side of the road when analyzing the whole community, and this relationship became even stronger when the largest species were excluded. The vegetation variables did not strongly differ between the two sides, and there was no difference in species richness and abundance of bees and wasps either. Abundance was, however, explained by the number of flowering plants in the surroundings of the trap. Even though using a rather limited data set, our results indicate that large roads may act as barriers on the movement of bees and wasps, especially for small species with poor dispersal ability. On the other hand, road verges may be important habitat for many species, which leads to a potential conflict that is important to consider in the planning of green infrastructure.

  11. EPICUTICULAR WAX COMPOSITION OF SOME EUROPEAN SEDUM SPECIES

    NARCIS (Netherlands)

    STEVENS, JF; THART, H; BOLCK, A; ZWAVING, JH; MALINGRE, TM

    Epicuticular waxes from 30 species of Sedum and 2 species of Sempervivoideae, i.e. Aeonium spathulatum and Sempervivum nevadense, have been analysed by GC and GC-MS. The Sedum taxa examined were S. acre, S. album, S. series Alpestria (13 species), S. anglicum, S. brevifolium, S. litoreum, S. lydium,

  12. Impacts of Human Activities on Tree Species Composition Along the Forest Savanna Boundary in Nigeria

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    Christiana Ndidi Egbinola

    2016-02-01

    Full Text Available The study investigated the tree species composition along the forest-savanna boundary in Oyo state of Nigeria with the aim of assessing the impact of human activities on the floristic composition. A transect was placed along the study area and species data was collected from quadrats placed in study plots within different study sites. Detrended Correspondence Analysis (DCA was used to determine vegetation assemblages, while both correlation and the analysis of variance (ANOVA were used to show the relationship between species in the different study sites. Results of the DCA revealed three species assemblages, an area with only forest species, another with only savanna species and a third with both forest/savanna species. ANOVA results further revealed that within the forest and savanna assemblages, species in mature and successional sites were alike. The study therefore revealed that human activities’ within the region is leading to the establishment of savanna species and an elimination of forest species.

  13. Bromeliaceae da restinga da Reserva Biológica Estadual da Praia do Sul: composição, abundância e similaridade da comunidade Bromeliaceae of the Praia do Sul State Biological Reserve restinga: community composition, abundance and similarity

    Directory of Open Access Journals (Sweden)

    André Felippe Nunes-Freitas

    2006-09-01

    Full Text Available A Reserva Biológica Estadual da Praia do Sul (Ilha Grande, RJ é um importante remanescente de restinga preservada do Rio de Janeiro. A vegetação das restingas não é homogênea, distribuindo-se em zonas de vegetação, e cada uma delas é caracterizada por sua topografia, fisionomia e florística distintas. Estudamos a comunidade de Bromeliaceae, analisando variações na riqueza, abundância, densidade e freqüência de ocorrência entre quatro zonas de vegetação. Nas quatro zonas, amostramos um total de 150 parcelas de 100 m² cada, onde contabilizamos as espécies e suas abundâncias, e medidas de estrutura da vegetação (altura e DAP das árvores e densidade de árvores e de arbustos do sub-bosque. Testamos diferenças entre zonas na abundância de rosetas e na estrutura da vegetação, e entre as abundâncias das espécies de bromélias através de ANOVA seguida do teste de Tukey. Encontramos 16 espécies de bromélias, com abundâncias e padrões de distribuição distintos entre as zonas, além de diferenças significativas entre as abundâncias das espécies. Os dados indicam que a elevada riqueza de espécies encontradas na RBEPS pode estar relacionada à heterogeneidade e à complexidade locais. As diferenças encontradas entre as zonas de vegetação podem ser devidas às diferenças na estrutura da vegetação de cada zona.The Praia do Sul State Biological Reserve (Ilha Grande, RJ is an important remnant of Restinga habitat in Rio de Janeiro State. Restinga vegetation is not homogeneous and it is distributed in different vegetation zones, each zone having different topography, physiognomy and flora. We analyzed ecological parameters of the bromeliad community such as richness, abundance, density, biomass and variation in species composition in four vegetation zones. We sampled 150 plots of 100 m² (10×10 m, distributed in the four vegetation zones, recording the bromeliad species and their abundance, and measuring the height

  14. Comparative study on composition and abundance of major planktons and physico-chemical characteristics among two ponds and Lake Tana, Ethiopia

    Directory of Open Access Journals (Sweden)

    Wondie Zelalem Amanu

    2015-11-01

    Full Text Available Objective: To evaluate the difference in physico-chemical characteristics, composition and abundance of plankton communities owing to the supplementary feed added in fish ponds as compared to Lake Tana. Methods: Physico-chemical and biological data of plankton were collected from 3 studied sites from November 2008 to October 2009. Data were compared using One-way ANOVA to see the difference among sites. Diversity indices such as Margalef's index, Shannon-Wiener index, and evenness index were employed to describe the distribution of plankton community among the studied sites. Results: The pH value was remarkably higher in ponds water. However, conductivity and total dissolved solids were the highest in lake water. Nitrate concentration was relatively high in ponds. Zooplankton species richness was higher in lake water than ponds. The lake also had the highest mean value of both Shannon-Wiener index and evenness index in phytoplankton. Conclusions: The results revealed that the supplementary feed added to each pond had influence on nutrient content which enhanced algal biomass and productivity of the ponds. However, the pond water has to be regularly refreshed to control eutrophication.

  15. Composition and abundance of fishes in the interface between open water and macrophyte banks, and the dynamics of this interface during morning and evening twilight, in lake Catalão, Amazonas, Brazil

    Directory of Open Access Journals (Sweden)

    Igor David da Costa

    2011-06-01

    Full Text Available This work studied the composition and abundance of the fishes that move between macrophyte banks and open water during the morning twilight (CM and afternoon twilight (CV. The collections were made using gillnets, along banks of Paspalum repens, at Catalão lake, in Amazonas, Brazil. A total of 222 individuals and 37 species were collected. Of these, 130 individuals were collected during the CM and 92 during the CV; 80 individuals were leaving during the CM and 40 individuals were leaving during the CV. Auchenipterus nuchalis, Pellona castelnaeana, Triportheus angulatus and T. albus were the most common and concentrated species collected in the CM and Pimelodus blochii was the most common species collected in the CV.

  16. The Effect of Landscape Composition on the Abundance of Laodelphax striatellus Fallén in Fragmented Agricultural Landscapes

    Directory of Open Access Journals (Sweden)

    Zhanyu Liu

    2016-10-01

    Full Text Available The spatial distribution of crop and non-crop habitats over segmented agricultural landscapes could be used as a means to reduce insect pest populations. Seven land cover categories such as wheat, rapeseed, vegetable, water, built-up, paved road, and unsurfaced road were extracted from GeoEye satellite images dating from late May to late June of 2010. Three diversity metrics and three evenness metrics were estimated from the abovementioned land cover categories for quantifying the effect of landscape composition on nymphal and adult Laodelphax striatellus Fallén. The degree of correlation between the proportion of crop cover and adjacent spatial scales (r: 0.651–0.983 was higher than the correlation between the proportion of crop cover and nonadjacent spatial scales (r: −0.255–0.896. While the degree of correlation between diversity indices and abundance of L. striatellus decreased gradually when the spatial scales varied from large (>100 m radius buffer to small (<100 m. Our study suggests that when using natural biological pest control and ecological engineering practices in the rural-urban fringes, the crop field’s width should be less than 200 m and increasing vegetation diversity within such a scale will be helpful to regulate the insect pests under a certain density.

  17. A comparison of multiple indicator kriging and area-to-point Poisson kriging for mapping patterns of herbivore species abundance in Kruger National Park, South Africa.

    Science.gov (United States)

    Kerry, Ruth; Goovaerts, Pierre; Smit, Izak P J; Ingram, Ben R

    Kruger National Park (KNP), South Africa, provides protected habitats for the unique animals of the African savannah. For the past 40 years, annual aerial surveys of herbivores have been conducted to aid management decisions based on (1) the spatial distribution of species throughout the park and (2) total species populations in a year. The surveys are extremely time consuming and costly. For many years, the whole park was surveyed, but in 1998 a transect survey approach was adopted. This is cheaper and less time consuming but leaves gaps in the data spatially. Also the distance method currently employed by the park only gives estimates of total species populations but not their spatial distribution. We compare the ability of multiple indicator kriging and area-to-point Poisson kriging to accurately map species distribution in the park. A leave-one-out cross-validation approach indicates that multiple indicator kriging makes poor estimates of the number of animals, particularly the few large counts, as the indicator variograms for such high thresholds are pure nugget. Poisson kriging was applied to the prediction of two types of abundance data: spatial density and proportion of a given species. Both Poisson approaches had standardized mean absolute errors (St. MAEs) of animal counts at least an order of magnitude lower than multiple indicator kriging. The spatial density, Poisson approach (1), gave the lowest St. MAEs for the most abundant species and the proportion, Poisson approach (2), did for the least abundant species. Incorporating environmental data into Poisson approach (2) further reduced St. MAEs.

  18. Trait-abundance relation in response to nutrient addition in a Tibetan alpine meadow: The importance of species trade-off in resource conservation and acquisition.

    Science.gov (United States)

    Liu, Huiying; Li, Ying; Ren, Fei; Lin, Li; Zhu, Wenyan; He, Jin-Sheng; Niu, Kechang

    2017-12-01

    In competition-dominated communities, traits promoting resource conservation and competitive ability are expected to have an important influence on species relative abundance (SRA). Yet, few studies have tested the trait-abundance relations in the line of species trade-off in resource conservation versus acquisition, indicating by multiple traits coordination. We measured SRA and key functional traits involving leaf economic spectrum (SLA, specific leaf area; LDMC, leaf dry matter content; LCC, leaf carbon concentration; LNC, leaf nitrogen concentration; LPC, leaf phosphorus concentration; Hs, mature height) for ten common species in all plots subjected to addition of nitrogen fertilizer (N), phosphorus fertilizer (P), or both of them (NP) in a Tibetan alpine meadow. We test whether SRA is positively related with traits promoting plant resource conservation, while negatively correlated with traits promoting plant growth and resource acquisition. We found that species were primarily differentiated along a trade-off axis involving traits promoting nutrient acquisition and fast growth (e.g., LPC and SLA) versus traits promoting resource conservation and competition ability (e.g., large LDMC). We further found that SRA was positively correlated with plant height, LDMC, and LCC, but negatively associated with SLA and leaf nutrient concentration irrespective of fertilization. A stronger positive height-SRA was found in NP-fertilized plots than in other plots, while negative correlations between SRA and SLA and LPC were found in N or P fertilized plots. The results indicate that species trade-off in nutrient acquisition and resource conservation was a key driver of SRA in competition-dominated communities following fertilization, with the linkage between SRA and traits depending on plant competition for specific soil nutrient and/or light availability. The results highlight the importance of competitive exclusion in plant community assembly following fertilization and

  19. Study on the species composition and ecology of anophelines in Addis Zemen, South Gondar, Ethiopia.

    Science.gov (United States)

    Kindu, Mizan; Aklilu, Esayas; Balkew, Meshesha; Gebre-Michael, Teshome

    2018-03-27

    Malaria is a public health problem in Ethiopia and its transmission is generally unstable and seasonal. For the selection of the most appropriate vector control measures, knowledge on the ecology of the vector is necessary at a local level. Therefore, the objectives of this study were to document the species composition, breeding habitat characteristics and occurrence of anopheline larva in Sheni stream and the vectorial role of the prevailing Anopheles in relation to malaria transmission in Addis Zemen, Ethiopia. Immature anophelines were sampled from breeding habitats and characteristics, such as water temperature, turbidity, water current, water pH and other variables, of the habitats were measured from October 2011 to February 2012. Adult anophelines were sampled inside human dwellings using space spray and Center for Disease Control light traps. Artificial pit shelters and clay pots were also used for outdoor adult collections. Anophelines collected were identified using morphological key. The enzyme-linked immunosorbent assay was applied to detect circumsporozoite proteins of Plasmodium and source of blood meals. A total of 6258 Anopheles larvae were collected and identified morphologically. Five anopheline species were found: An. gambiae (s.l.), An. cinereus, An. demeilloni, An. christi and An. pretoriensis. Anopheles gambiae (s.l.) existed in most of the habitats investigated. Only the former three species were captured in the adult collections. Sun-lit Sheni stream, rain pools, hoof prints, drainage and irrigation canals were found to be habitats of larvae. Anopheles gambiae (s.l.) larvae were most abundantly sampled from sand mining and natural sand pools of Sheni stream. Multiple regression analysis showed that clear, permanent and temporary habitats devoid of mats of algae were the best predictors of An. gambiae (s.l.) larval abundance. It is also the responsible malaria vector in the study area and exhibits anthropophilic and endophagic behaviour. The

  20. The dynamics of intraguild predation in Chrysomya albiceps Wied. (Diptera: Calliphoridae): interactions between instars and species under different abundances of food.

    Science.gov (United States)

    Rosa, Gisele S; de Carvalho, Lidia R; dos Reis, Sergio F; Godoy, Wesley A C

    2006-01-01

    The pattern of larval interaction in blowflies confined with Chrysomya albiceps Wied. and C. rufifacies Maquart can be changed in response to the predatory behaviour of the two species to a contest-type process instead of the scramble competition that usually occurs in blowflies. Facultative predation is a frequent behaviour in C. albiceps and C. rufifacies that occurs as an alternative food source during the larval stage. In this study, we investigated the dynamics of intraguild predation by C. albiceps on other fly species in order to analyse interspecific and intraspecific survival in C. albiceps, C. megacephala and C. macellaria Fabricius. The experimental design of the study allowed us to evaluate how factors such as species, density and abundance of food influenced the survival of the calliphorid species. When C. albiceps was confined with C. megacephala or C. macellaria, only adults of C. albiceps survived at different larval densities and abundance of food. In addition, the survival of C. albiceps was higher in two-species experiments when compared to single species experiments. The implications of these results for the dynamics of C. albiceps were discussed.

  1. Chemical composition and antioxidant activity of certain Morus species

    Science.gov (United States)

    Imran, Mohammad; Khan, Hamayun; Shah, Mohibullah; Khan, Rasool; Khan, Faridullah

    2010-01-01

    In the present work, the fruits of four Morus species, namely Morus alba (white mulberry), Morus nigra (black mulberry), Morus laevigata (large white fruit), and Morus laevigata (large black fruit), were analyzed for proximate composition, essential minerals, and antioxidant potentials. For this purpose, the ripe fruits were collected from the northern regions of Pakistan. The major nutritional components (moisture, ash, lipids, proteins, fibres, carbohydrates, and total sugar) were found to be in the suitable range along with good computed energy. Total dry weight, pH, and titratable acidity (percent citric acid) were (17.60±1.94)–(21.97±2.34) mg/100 g, (3.20±0.07)–(4.78±0.15), and (0.84±0.40)%–(2.00±0.08)%, respectively. Low riboflavin (vitamin B2) and niacin (vitamin B3) contents were recorded in all the fruits, while ascorbic acid (vitamin C) was in the range from (15.20±1.25) to (17.03±1.71) mg/100 g fresh weight (FW). The mulberry fruits were rich with regard to the total phenol and alkaloid contents, having values of (880±7.20)–(1650±12.25) mg/100 g FW and (390±.22)–(660±5.25) mg/100 g FW, respectively. Sufficient quantities of essential macro-(K, Ca, Mg, and Na) and micro-(Fe, Zn, and Ni) elements were found in all the fruits. K was the predominant element with concentration ranging from (1270±9.36) to (1731±11.50) mg/100 g, while Ca, Na, and Mg contents were (440±3.21)–(576±7.37), (260±3.86)–(280±3.50), and (24±3.51)–(360±4.20) mg/100 g, respectivly. The decreasing order of micro-minerals was Fe>Zn>Ni. The radical scavenging activity of methanolic extract of fruits was concentration-dependent and showed a correlation with total phenolic constituents of the respective fruits. Based on the results obtained, mulberry fruits were found to serve as a potential source of food diet and natural antioxidants. PMID:21121077

  2. Linking Compositional and Functional Predictions to Decipher the Biogeochemical Significance in DFAA Turnover of Abundant Bacterioplankton Lineages in the North Sea

    Directory of Open Access Journals (Sweden)

    Bernd Wemheuer

    2017-11-01

    Full Text Available Deciphering the ecological traits of abundant marine bacteria is a major challenge in marine microbial ecology. In the current study, we linked compositional and functional predictions to elucidate such traits for abundant bacterioplankton lineages in the North Sea. For this purpose, we investigated entire and active bacterioplankton composition along a transect ranging from the German Bight to the northern North Sea by pyrotag sequencing of bacterial 16S rRNA genes and transcripts. Functional profiles were inferred from 16S rRNA data using Tax4Fun. Bacterioplankton communities were dominated by well-known marine lineages including clusters/genera that are affiliated with the Roseobacter group and the Flavobacteria. Variations in community composition and function were significantly explained by measured environmental and microbial properties. Turnover of dissolved free amino acids (DFAA showed the strongest correlation to community composition and function. We applied multinomial models, which enabled us to identify bacterial lineages involved in DFAA turnover. For instance, the genus Planktomarina was more abundant at higher DFAA turnover rates, suggesting its vital role in amino acid degradation. Functional predictions further indicated that Planktomarina is involved in leucine and isoleucine degradation. Overall, our results provide novel insights into the biogeochemical significance of abundant bacterioplankton lineages in the North Sea.

  3. Linking Compositional and Functional Predictions to Decipher the Biogeochemical Significance in DFAA Turnover of Abundant Bacterioplankton Lineages in the North Sea.

    Science.gov (United States)

    Wemheuer, Bernd; Wemheuer, Franziska; Meier, Dimitri; Billerbeck, Sara; Giebel, Helge-Ansgar; Simon, Meinhard; Scherber, Christoph; Daniel, Rolf

    2017-11-05

    Deciphering the ecological traits of abundant marine bacteria is a major challenge in marine microbial ecology. In the current study, we linked compositional and functional predictions to elucidate such traits for abundant bacterioplankton lineages in the North Sea. For this purpose, we investigated entire and active bacterioplankton composition along a transect ranging from the German Bight to the northern North Sea by pyrotag sequencing of bacterial 16S rRNA genes and transcripts. Functional profiles were inferred from 16S rRNA data using Tax4Fun. Bacterioplankton communities were dominated by well-known marine lineages including clusters/genera that are affiliated with the Roseobacter group and the Flavobacteria . Variations in community composition and function were significantly explained by measured environmental and microbial properties. Turnover of dissolved free amino acids (DFAA) showed the strongest correlation to community composition and function. We applied multinomial models, which enabled us to identify bacterial lineages involved in DFAA turnover. For instance, the genus Planktomarina was more abundant at higher DFAA turnover rates, suggesting its vital role in amino acid degradation. Functional predictions further indicated that Planktomarina is involved in leucine and isoleucine degradation. Overall, our results provide novel insights into the biogeochemical significance of abundant bacterioplankton lineages in the North Sea.

  4. A Preliminary Survey of Species Composition of Termites (Insecta: Isoptera) in Samunsam Wildlife Sanctuary, Sarawak.

    Science.gov (United States)

    Jamil, Norsyarizan; Ismail, Wan Nurainie Wan; Abidin, Siti Shamimi; Amaran, Mazdan Ali; Hazali, Ratnawati

    2017-07-01

    A survey on termite species composition was conducted in Samunsam Wildlife Sanctuary, Sarawak in February 2015. Overall 19 species of termite belonging to 13 genera and 8 subfamilies was found in the sanctuary. It was recorded the subfamily of Termitinae had the highest number of species (6 species, equal to 31.58% of total species), followed by Nasutermitinae (3 species, 15.79%), Macrotermitinae, Amitermitinae, Rhinotermitinae, Coptotermitinae, (2 species, 10.53% respectively), and Heterotermitinae, Termitogetoninae (1 species, 5.26% respectively). Since this rapid survey is the first termite assemblage representation in Samunsam Wildlife Sanctuary, the preliminary result may serve as the baseline data for termite composition in the area. Therefore, a whole coverage for the area within this sanctuary would definitely increase the number of termite species found in the sanctuary.

  5. Composition and species diversity of pine-wiregrass savannas of the Green Swamp, North Carolina

    Science.gov (United States)

    Joan Walker; Robert K. Peet

    1983-01-01

    Fire-maintained, species-rich pines wiregrass savannas in the Green Swamp, North Carolina were sampled over their natural range of environmental conditions and fire frequencies. Species composition, species richness, diversity (Exp H', I/ C), and aboveground production were documented and fertilization experiments conducted to assess possible mechanisms for the...

  6. Composition of Mix Species Foraging Flocks of Birds in Riverstan of Montane Region, Sri Lanka

    Directory of Open Access Journals (Sweden)

    W.G.D.D.M. Shermila

    2013-04-01

    Full Text Available Montane zone mixed-species bird flock system is distinct from that of low-land wet zone of SriLanka, although some species are present in both systems. The present study identified the mixed speciesflocks of birds in Riverstan at Knuckles Region, Sri Lanka. Monthly transect counts and opportunisticobservations were made between January and May, 2012. A total of 78 flocks and 27 bird species wereencountered at Riverstan during the study period. The flock size varied between 2 to 13 species and 4 to58 individuals. The mean number of species per flock was 6.03 ± 2.25 and the mean number ofindividuals in a flock was 18.41±9.87. The flock size was positively correlated with the number of speciespresent (r = 0.756, P <0.05. Grey-headed Canary Flycatcher was the most abundant species (mean2.68±1.02 birds per flocks while Sri Lanka White-eye was the most frequent species (mean 5.69±3.92birds per flocks. Grey-headed Canary Flycatcher and Sri Lanka Scimitar-babbler were the nuclear speciesin Riverstan. The leading species were Sri Lanka white-eye and Sri Lanka Yellow-eared Bulbul. Differentbird species used different heights within flocks.Keywords: Mixed-species flock, Nuclear species, Abundance, Foraging flocks

  7. Relationship between species composition and homegarden size in ...

    African Journals Online (AJOL)

    Taxa such as Musa species, Vernonia amygdalina, Citrus species, Psidium guajava and Terminalia catappa were found to be the common food/medicinal plants as evidenced by their densities in the study sites. The household members cited most of the plants as food; others as medicinal and ornamentals. Miscellaneous ...

  8. Effects of fishing technique on assessing species composition in aquatic systems in semi-arid Brazil

    Directory of Open Access Journals (Sweden)

    ESF Medeiros

    Full Text Available In most ecological field research, appropriate sampling is critical for the understanding of processes underlying fish populations and communities, and is even more important in heterogeneous environments such as the aquatic systems of the semi-arid region of Brazil. This study intends to make a contribution to the development of sampling programs and gear selection in aquatic systems of semi-arid Brazil by evaluating the effects of different fishing techniques on the assessment of richness and composition of the fish fauna in selected aquatic environments. Six sites were selected to represent typical artificial (reservoirs and natural (intermittent streams environments and four different types of sampling gear were applied to each site during four occasions. The present study shows that when selecting sampling techniques to be used in aquatic systems in semi-arid Brazil, one must consider the objectives of the study, e.g. ecological or taxonomic, in order to decide on inclusion of rare species in the sampling population. Also, the effect of the sampling gear on natural abundances of fish must be considered given that some sampling techniques are highly detrimental to fish population numbers.

  9. Flow regime in a restored wetland determines trophic links and species composition in the aquatic macroinvertebrate community.

    Science.gov (United States)

    González-Ortegón, E; Walton, M E M; Moghaddam, B; Vilas, C; Prieto, A; Kennedy, H A; Pedro Cañavate, J; Le Vay, L

    2015-01-15

    In a restored wetland (South of Spain), where different flow regimes control water exchange with the adjacent Guadalquivir estuary, the native Palaemon varians coexists with an exotic counterpart species Palaemon macrodactylus. This controlled m\\acrocosm offers an excellent opportunity to investigate how the effects of water management, through different flow regimes, and the presence of a non-native species affect the aquatic community and the trophic niche (by gut contents and C-N isotopic composition) of the native shrimp Palaemon varians. We found that increased water exchange rate (5% day(-1) in mixed ponds vs. 0.1% day(-1) in extensive ponds) modified the aquatic community of this wetland; while extensive ponds are dominated by isopods and amphipods with low presence of P. macrodactylus, mixed ponds presented high biomass of mysids, corixids, copepods and both shrimp species. An estuarine origin of nutrients and primary production might explain seasonal and spatial differences found among ponds of this wetland. A combined analysis of gut contents and isotopic composition of the native and the exotic species showed that: (1) native P. varians is mainly omnivorous (2) while the non-native P. macrodactylus is more zooplanktivorous and (3) a dietary overlap occurred when both species coexist at mixed ponds where a higher water exchange and high abundance of mysids and copepods diversifies the native species' diet. Thus differences in the trophic ecology of both species are clearly explained by water management. This experimental study is a valuable tool for integrated management between river basin and wetlands since it allows quantification of wetland community changes in response to the flow regime. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Spatial statistics for modeling of abundance and distribution of wildlife species in the Masai Mara ecosystem, Kenya

    NARCIS (Netherlands)

    Khaemba, W.M.; Stein, A.

    2001-01-01

    This study illustrates the use of modern statistical procedures for better wildlife management by addressing three key issues: determination of abundance, modeling of animal distributions and variability of diversity in space and time. Prior information in Markov Chain Monte Carlo (MCMC) methods is

  11. The source, discharge, and chemical characteristics of selected springs, and the abundance and health of associated endemic anuran species in the Mojave network parks

    Science.gov (United States)

    Schroeder, Roy A.; Smith, Gregory A.; Martin, Peter; Flint, Alan L.; Gallegos, Elizabeth; Fisher, Robert N.; Martin, Peter; Schroeder, Roy A.

    2015-01-01

    Hydrological and biological investigations were done during 2005 and 2006 in cooperation with the U.S. National Park Service to investigate the source, discharge, and chemical characteristics of selected springs and the abundance and health of endemic anuran (frog and toad) species at Darwin Falls in Death Valley National Park, Piute Spring in Mojave National Preserve, and Fortynine Palms Oasis in Joshua Tree National Park. Discharge from the springs at these sites sustains isolated riparian habitats in the normally dry Mojave Desert. Data were collected on water quantity (discharge) and quality, air and water temperature, and abundance and health of endemic anuran species. In addition, a single survey of the abundance and health of endemic anuran species was completed at Rattlesnake Canyon in Joshua Tree National Park. Results from this study were compared to limited historical data, where they exist, and can provide a baseline for future hydrological and biological investigations to evaluate the health and sustainability of the resource and its response to changing climate and increasing human use.

  12. Seasonal variations in biomass and species composition of ...

    Indian Academy of Sciences (India)

    of seaweeds along the northern coasts of Persian Gulf. (Bushehr ... Keywords. Seaweed; biomass; composition; Bushehr; Persian Gulf. ...... tosynthesis at increasing dim and turbid waters. .... rock jetty in the Northwest Gulf of Mexico; Bot. Mar.

  13. Macronutrient composition of three cucurbit species cultivated for ...

    African Journals Online (AJOL)

    .) Matsum. & Nakai., Cucumeropsis mannii Naudin, and Cucumis melo var. agrestis L.] largely cultivated in Côte d'Ivoire and consumed as sauce thickeners were analyzed for their proximate composition and compared to a local landrace of ...

  14. The Diversity of Chemical Composition: The Impact of Stellar Abundances on the Evolution of Stars and Habitable Zones

    Science.gov (United States)

    Truitt, Amanda R.; Young, Patrick A.

    2018-01-01

    I have investigated how stars of different mass and composition evolve, and how stellar evolution impacts the location of the habitable zone around a star. Current research into habitability of exoplanets focuses mostly on the concept of a “classical” HZ, the range of distances from a star over which liquid water could exist on a planet's surface. This is determined by the host star's luminosity and spectral characteristics; in order to gauge the habitability potential of a given system, both the evolutionary history and the detailed chemical characterization of the host star must be considered. With the ever-accelerating discovery of new exoplanets, it is imperative to develop a better understanding of what factors play a role in creating “habitable” conditions of a planet. I will discuss how stellar evolution is integral to how we define the HZ, and how this work will apply to the search for Earth-like planets in the future.I have developed a catalog of stellar evolution models for Sun-like stars with variable compositions; masses range from 0.1-1.2 Msol (spectral types M4-F4) at scaled metallicities (Z) of 0.1-1.5 Zsol, and O/Fe, C/Fe, and Mg/Fe values of 0.44-2.28, 0.58-1.72, and 0.54-1.84, respectively. I use a spread in abundance values based on observations of variability in nearby stars. It is important to understand how specific elements, not just total Z, impacts stellar lifetime. Time-dependent HZ boundaries are calculated for each track. I have also created a grid of M-dwarfs, and I am currently working to estimate stellar activity vs. age for each model.This catalog is meant to characterize potential host stars of interest. I have explored how to use existing observational data (i.e. Hypatia Catalog) for a more robust comparison to my grid of theoretical models, and I will discuss a new statistical analysis of the catalog to further refine our definition of “continuous” habitability. This work is an important step to assess whether a planet

  15. X ray microanalysis of leaf and seed elemental composition among four species of living fossil gymnosperm

    International Nuclear Information System (INIS)

    Chang Chongyan; Li Yongliang; Chen Xiaoduan; Liu Jinying; Zhou Yunlong

    2002-01-01

    The leaf and seed elemental composition and average mass fraction are analysed or four species of living fossil gymnosperm: Ginkgo biloba L., Cathaya argyrophylla Chun et Kuang, Glyptostrobus pensilis (D. Don) Koch and Metasequoia glyptostroboides Hu et Cheng by SEM X ray microanalysis method. The results show that the elemental composition is different and the elemental average mass fraction is evidently different between the seed and leaf for the same species. The elemental composition and average mass fraction between seed and seed wing is different in Cathaya argyrophylla and Metasequoia glyptostroboides. Among three type leaf of Glyptostrobus pensilis, the elemental composition is the same, but average mass fraction is very different

  16. The Human Release Hypothesis for biological invasions: human activity as a determinant of the abundance of invasive plant species [v1; ref status: indexed, http://f1000r.es/33c

    Directory of Open Access Journals (Sweden)

    Heike Zimmermann

    2014-05-01

    Full Text Available Research on biological invasions has increased rapidly over the past 30 years, generating numerous explanations of how species become invasive. While the mechanisms of invasive species establishment are well studied, the mechanisms driving abundance patterns (i.e. patterns of population density remain poorly understood. Invasive species typically have higher abundances in their new environments than in their native ranges, and patterns of invasive species abundance differ between invaded regions. To explain differences in invasive species abundance, we propose the Human Release Hypothesis. In parallel to the established Enemy Release Hypothesis, this hypothesis states that the abundance of invasive species may be partly explained by the level of human activity or landscape maintenance, with intermediate levels of human activity providing optimal conditions for high abundance. The Human Release Hypothesis does not negate other important drivers of species invasions, but rather should be considered as a potentially important additional or complementary mechanism. We illustrate the hypothesis via a case study on an invasive rose species, and hypothesize which locations globally may be most likely to support high abundances of invasive species. We propose that more extensive empirical work on the Human Release Hypothesis could be useful to test its general applicability.

  17. Temperature alters the relative abundance and population growth rates of species within the Dendroctonus frontalis (Coleoptera: Curculionidae) community.

    Science.gov (United States)

    L. Evans; Richard Hoffstetter; Matthew Ayres; Kier Klepzig

    2011-01-01

    Temperature has strong effects on metabolic processes ofindividuals and demographics of populations, but effects on ecological communities are not well known. Many economically and ecologically important pest species have obligate associations with other organisms; therefore, effects of temperature on these species might be mediated by strong interactions. The southern...

  18. Use of 15N Natural Abundance and N Species Concentrations to Assess N-Cycling in Constructed and Natural Coastal

    International Nuclear Information System (INIS)

    Aelion, W.C.M.; Engle, M.R.; Aelion, W.C.M.; Ma, H.

    2010-01-01

    Natural abundance of N stable isotopes used in combination with concentrations may be useful indicators of N-cycling in wetlands. Concentrations and 15 N signatures of NO 3 -, NH 4 and sediment organic nitrogen (SON) were measured in two impacted coastal golf course retention ponds and two natural marshes. Limited NO 3 was detected in natural site surface water or pore water, but both isotopic signature and concentrations of NO 3 - in surface water of impacted sites indicated anthropogenic inputs. In natural sites, NH 4 concentrations were greatest in deeper pore water and least in surface water, suggesting diffusion predominates. The natural sites had greater % SON, and 15 N indicated that the natural sites also had greater NH 4 + released from SON mineralization than impacted sites. In NO 3 --limited systems, neither concentrations nor 15 N natural abundance was able to provide information on N-cycling, while processes associated with NH 4 + were better elucidated by using both concentrations and 15 N natural abundance

  19. Use of N Natural Abundance and N Species Concentrations to Assess N-Cycling in Constructed and Natural Coastal Wetlands

    Directory of Open Access Journals (Sweden)

    C. Marjorie Aelion

    2010-01-01

    Full Text Available Natural abundance of N stable isotopes used in combination with concentrations may be useful indicators of N-cycling in wetlands. Concentrations and N signatures of NO3−, NH4+, and sediment organic nitrogen (SON were measured in two impacted coastal golf course retention ponds and two natural marshes. Limited NO3− was detected in natural site surface water or pore water, but both isotopic signature and concentrations of NO3− in surface water of impacted sites indicated anthropogenic inputs. In natural sites, NH4+ concentrations were greatest in deeper pore water and least in surface water, suggesting diffusion predominates. The natural sites had greater %SON, and N indicated that the natural sites also had greater NH4+ released from SON mineralization than impacted sites. In NO3−-limited systems, neither concentrations nor N natural abundance was able to provide information on N-cycling, while processes associated with NH4+ were better elucidated by using both concentrations and N natural abundance.

  20. A COMPARATIVE ANALYSIS OF SPECIES COMPOSITION OF GROUND BEETLES OF COASTAL AND ISLAND ECOSYSTEMS OF THE WESTERN CASPIAN

    Directory of Open Access Journals (Sweden)

    G. M. Abdurakhmanov

    2011-01-01

    Full Text Available For the first time studied the species composition of ground beetles of coastal and island ecosystems of the Western Caspian. The article provides a comparative analysis of species composition of ground beetles and adjacent areas.

  1. Landscape composition influences farm management effects on farmland birds in winter: A pan-European approach

    NARCIS (Netherlands)

    Geiger, F.; Snoo, de G.R.; Berendse, F.

    2010-01-01

    This study examined the effects of agricultural intensity, various farming practices, landscape composition and vegetation cover on the abundance and species richness of wintering farmland birds, assessed simultaneously across seven European regions. The abundance and species richness of wintering

  2. Essential Oil Composition of Two Grammosciadium DC Species, G ...

    African Journals Online (AJOL)

    Turk J Bot 2012; 36: 637-643. 7. Buchbauer G. The detailed analysis of essential oils leads to the understanding of their properties. Perfumer. & Flavourist 2000; 25: 64-67. 8. Tzakou O, Pitarokili D, Chinou IB, Harvala C. Composition and antimicrobial activity of the essential oil of Salvia ringens. Planta Med 2001; 67: 81-83.

  3. Plant species composition and structure of the Mana Angetu moist ...

    African Journals Online (AJOL)

    A floristic composition and structure study of the Mana Angetu Forest was carried out between July 2003 and June 2004 at four sites of the forest with an altitudinal range of 1533-2431 m. Three transects, 750 ... Analysis of Importance Value Index indicated that Vepris dainellii had the highest value (79). The population ...

  4. Seasonal species composition of invertebrates in several Oregon streams.

    Science.gov (United States)

    Pamela E. Porter; William R. Meehan

    1987-01-01

    The invertebrate communities ofeight Oregon streams were sampled seasonally from 1974 to 1976. Benthic, drift, and two types of aerial-trap samples were collected. Occurrence and percentage composition are summarized by sample type, season, and geographic area (coastal, Cascade, central, and eastern Oregon). Within 276 families, 426 taxa were identified; the 20...

  5. Species-abundance distribution patterns of soil fungi: contribution to the ecological understanding of their response to experimental fire in Mediterranean maquis (southern Italy).

    Science.gov (United States)

    Persiani, Anna Maria; Maggi, Oriana

    2013-01-01

    Experimental fires, of both low and high intensity, were lit during summer 2000 and the following 2 y in the Castel Volturno Nature Reserve, southern Italy. Soil samples were collected Jul 2000-Jul 2002 to analyze the soil fungal community dynamics. Species abundance distribution patterns (geometric, logarithmic, log normal, broken-stick) were compared. We plotted datasets with information both on species richness and abundance for total, xerotolerant and heat-stimulated soil microfungi. The xerotolerant fungi conformed to a broken-stick model for both the low- and high intensity fires at 7 and 84 d after the fire; their distribution subsequently followed logarithmic models in the 2 y following the fire. The distribution of the heat-stimulated fungi changed from broken-stick to logarithmic models and eventually to a log-normal model during the post-fire recovery. Xerotolerant and, to a far greater extent, heat-stimulated soil fungi acquire an important functional role following soil water stress and/or fire disturbance; these disturbances let them occupy unsaturated habitats and become increasingly abundant over time.

  6. Abundance, biting behaviour and parous rate of anopheline mosquito species in relation to malaria incidence in gold-mining areas of southern Venezuela.

    Science.gov (United States)

    Moreno, J E; Rubio-Palis, Y; Páez, E; Pérez, E; Sánchez, V

    2007-12-01

    A longitudinal entomological and epidemiological study was conducted in five localities of southern Venezuela between January 1999 and April 2000 to determine the abundance, biting behaviour and parity of anopheline mosquitoes (Diptera: Culicidae) in relation to climate variables and malaria incidence. A total of 3685 female anopheline mosquitoes, representing six species, were collected. The most abundant species were Anopheles marajoara Galvão & Damasceno (60.7%) and Anopheles darlingi Root (35.1%), which together represented 95.8% of the total anophelines collected. Abundance and species distribution varied by locality. Malaria prevalence varied from 12.5 to 21.4 cases per 1000 population. Transmission occurred throughout the year; the annual parasite index (API) for the study period was 813.0 cases per 1000 population, with a range of 71.6-2492 per 1000 population, depending on locality. Plasmodium vivax (Grassi & Feletti) (Coccidia: Plasmodiidae) accounted for 78.6% of cases, Plasmodium falciparum (Welch) for 21.4% and mixed infections (Pv+Pf) for 0.05) between mosquito abundance and rainfall. Correlations between malaria incidence by parasite species and mosquito abundance were not significant (P > 0.05). Monthly parous rates were similar for An. marajoara and An. darlingi throughout the year, with two peaks that coincided with the dry-rainy transition period and the period of less rain. Peaks in the incidence of malaria cases were observed 1 month after major peaks in biting rates of parous anophelines. Anopheles darlingi engages in biting activity throughout the night, with two minor peaks at 23.00-00.00 hours and 03.00-04.00 hours. Anopheles marajoara has a different pattern, with a biting peak at 19.00-21.00 hours and 76.6% of biting occurring before midnight. Although both vectors bite indoors and outdoors, they showed a highly significant (P < 0.01) degree of exophagic behaviour. The present study constitutes the first effort to characterize the

  7. composition and size class structure of tree species in ihang'ana

    African Journals Online (AJOL)

    nb

    Previous plant biodiversity studies in this ecosystem concentrated on large-sized Forest ... assess tree species composition, structure and diversity in Ihang'ana FR (2982 ha), one of the ..... Dombeya rotundifolia. (Hochst) ... Ficus lutea. Vahl.

  8. Abundance, Natural Infection with Trypanosomes, and Food Source of an Endemic Species of Triatomine, Panstrongylus howardi (Neiva 1911), on the Ecuadorian Central Coast

    Science.gov (United States)

    Villacís, Anita G.; Ocaña-Mayorga, Sofía; Lascano, Mauricio S.; Yumiseva, César A.; Baus, Esteban G.; Grijalva, Mario J.

    2015-01-01

    The elimination of domestic triatomines is the foundation of Chagas disease control. Regional initiatives are eliminating introduced triatomine species. In this scenario, endemic triatomines can occupy the ecological niches left open and become a threat to long-term Chagas disease control efforts. This study determined the abundance, colonization, and Trypanosoma cruzi infection rate of the endemic Panstrongylus howardi in 10 rural communities located in Ecuador's Manabí Province. In total, 518 individuals of P. howardi were collected. Infestation indices of 1.4% and 6.6% were found in the domestic and peridomestic environments, respectively. We determined a T. cruzi infection rate of 53.2% (N = 47) in this species. P. howardi has a high capacity to adapt to different habitats, especially in the peridomicile. This implies a considerable risk of transmission because of the frequency of intradomicile invasion. Therefore, this species needs to be taken into account in Chagas control and surveillance efforts in the region. PMID:25385867

  9. Seasonal variation in biomass and species composition of ...

    Indian Academy of Sciences (India)

    April 2005 showed an average biomass value of 3.10 kg fresh wt/m. 2. /month with maximum ... were based on the weed washed ashore. Mantri and Chaugule ..... and phenology of Sargassum species and its recruit- ment dynamics have ...

  10. Assessment of Soil Seedbank Composition of Woody Species in ...

    African Journals Online (AJOL)

    Bheema

    Momona Ethiopian Journal of Science (MEJS), V6(1):25-44,2014. ©CNCS ... In present work, soil seedbank assessment of woody plant species was made in .... 1995; Azene Bekele, 2007) and NDA (Natural Database for Africa) software. 2.3.

  11. Spatial distribution and species composition of small pelagic fishes in the Gulf of California

    Directory of Open Access Journals (Sweden)

    Edgar Lanz

    2008-06-01

    Full Text Available Traditional regionalization methods in fisheries based on provinces or major fishing areas, includes large and arbitrary grids in which basic statistics or inferences on distribution or abundance are made. We describe a method for regionalization and analysis of fishing activities for small pelagic fisheries in the Gulf of California based on spatial patterns of landing and catch data in a Geographic Information System (GIS environment. A fisheries database from logbooks with spatial attributes from October 2002 to June 2007 was analyzed. Landings and catching data were transformed to a Weighted Region Index (WRI by using fuzzy logic operators. The WRI revealed fishing action centers characterized by areas with the highest WRI values, and a hierarchy for the relative importance of the regions was established. Guaymas, Desemboque de Caborca, Isla Patos, and Bahía San Rafael they were the most prominent ones. An analysis of the relative frequency of species composition showed that the Pacific sardine had an over 80 % abundance in the midriff islands, and remained as the most important in the upper gulf regions, while in the central part of the gulf, relative abundances of Pacific sardine and Northern anchovy were more balanced. Relative abundance of mackerel was significantly larger around Isla Patos than in any other place. Guaymas had the largest relative composition of Northern anchovy and the lowest values for Pacific sardine. Desemboque de Caborca showed the largest homogeneity in species relative composition. It is important to highlight that this results come from in situ data, while the results previously reported come from landing statistics by port. Therefore, the present method acknowledges the spatial differences of species by regions, additional to the traditional time series analysis. Rev. Biol. Trop. 56 (2: 575-590. Epub 2008 June 30.Los métodos tradicionales de regionalización en pesquerías, basados en provincias o grandes

  12. Potential impacts of OCS oil and gas activities on fisheries. Volume 1. Annotated bibliography and database descriptions for target-species distribution and abundance studies. Section 1, Part 2. Final report

    International Nuclear Information System (INIS)

    Tear, L.M.

    1989-10-01

    The purpose of the volume is to present an annotated bibliography of unpublished and grey literature related to the distribution and abundance of select species of finfish and shellfish along the coasts of the United States. The volume also includes descriptions of databases that contain information related to target species' distribution and abundance. An index is provided at the end of each section to help the reader locate studies or databases related to a particular species

  13. Potential impacts of OCS oil and gas activities on fisheries. Volume 1. Annotated bibliography and database descriptions for target species distribution and abundance studies. Section 1, Part 1. Final report

    International Nuclear Information System (INIS)

    Tear, L.M.

    1989-10-01

    The purpose of the volume is to present an annotated bibliography of unpublished and grey literature related to the distribution and abundance of select species of finfish and shellfish along the coasts of the United States. The volume also includes descriptions of databases that contain information related to target species' distribution and abundance. An index is provided at the end of each section to help the reader locate studies or databases related to a particular species

  14. [Influences of long-term application of organic and inorganic fertilizers on the composition and abundance of nirS-type denitrifiers in black soil].

    Science.gov (United States)

    Yin, Chang; Fan, Fen-Liang; Li, Zhao-Jun; Song, A-Lin; Zhu, Ping; Peng, Chang; Liang, Yong-Chao

    2012-11-01

    The objectives of this study were to explore the effects of long-term organic and inorganic fertilizations on the composition and abundance of nirS-type denitrifiers in black soil. Soil samples were collected from 4 treatments (i. e. no fertilizer treatment, CK; organic manure treatment, OM; chemical fertilizer treatment (NPK) and combination of organic and chemical fertilizers treatment (MNPK)) in Gongzhuling Long-term Fertilization Experiment Station. Composition and abundance of nirS-type denitrifiers were analyzed with terminal restriction fragment length polymorphism (T-RFLP) and real-time quantitative PCR (Q-PCR), respectively. Denitrification enzyme activity (DEA) and soil properties were also measured. Application of organic fertilizers (OM and MNPK) significantly increased the DEAs of black soil, with the DEAs in OM and MNPK being 5.92 and 6.03 times higher than that in CK treatment, respectively, whereas there was no significant difference between NPK and CK. OM and MNPK treatments increased the abundances of nirS-type denitrifiers by 2.73 and 3.83 times relative to that of CK treatment, respectively. The abundance of nirS-type denitrifiers in NPK treatment was not significantly different from that of CK. The T-RFLP analysis of nirS genes showed significant differences in community composition between organic and inorganic treatments, with the emergence of a 79 bp T-RF, a significant decrease in relative abundance of the 84 bp T-RF and a loss of the 99 bp T-RF in all organic treatments. Phylogenetic analysis indicated that the airS-type denitrifiers in the black soil were mainly composed of alpha, beta and gamma-Proteobacteria. The 79 bp-type denitrifiers inhabiting exclusively in organic treatments (OM and MNPK) were affiliated to Pseudomonadaceae in gamma-Proteobacteria and Burkholderiales in beta-Proteobacteria. The 84 bp-types were related to Burkholderiales and Rhodocyclales. Correlation analysis indicated that pH, concentrations of total nitrogen

  15. Phytoplankton species composition of four ecological provinces in Yellow Sea, China

    Science.gov (United States)

    Li, Xiaoqian; Feng, Yuanyuan; Leng, Xiaoyun; Liu, Haijiao; Sun, Jun

    2017-12-01

    The ecological province based on phytoplankton species composition is important to understanding the interplay between environmental parameters and phytoplankton species composition. The aim of this study was to establish phytoplankton species composition ecological pattern thus elucidate the relationship between environmental factors and the phytoplankton species composition in the ecological provinces. Phytoplankton samples were collected from 31 stations in Yellow Sea (121.00°-125.00°E, 32.00°-39.22°N) in November 2014. The samples were enumerated and identified with the Utermöhl method under an optical inverted microscope-AE2000 with magnifications of 200 × or 400 ×. In the present study, a total of 141 taxa belonging to 60 genera of 4 phyla of phytoplankton were identified, among them 101 species of 45 genera were Bacillariophyta, 36 species of 11 genera were Dinophyta, 3 species of 3 genera were Chrysophyta and 1 species of 1 genera was Chlorophyta. The study area was divided into 4 ecological provinces according to an unsupervised cluster algorithm applied to the phytoplankton biomass. A T-S (Temperature-Salinity) scatter diagram depicted with data of water temperature and salinity defined by environmental provinces matched well with the ecological provinces. The results of Canonical Correspondence Analysis (CCA) indicated that the phytoplankton species composition was mainly correlated with temperature, salinity and silicate concentration in the studied area. A method of establishing ecological provinces is useful to further understanding the environmental effects on the marine phytoplankton species composition and the consequent marine biogeochemistry.

  16. Changes in the Abundance of Grassland Species in Monocultures versus Mixtures and Their Relation to Biodiversity Effects

    Science.gov (United States)

    Marquard, Elisabeth; Schmid, Bernhard; Roscher, Christiane; De Luca, Enrica; Nadrowski, Karin; Weisser, Wolfgang W.; Weigelt, Alexandra

    2013-01-01

    Numerous studies have reported positive effects of species richness on plant community productivity. Such biodiversity effects are usually quantified by comparing the performance of plant mixtures with reference monocultures. However, several mechanisms, such as the lack of resource complementarity and facilitation or the accumulation of detrimental agents, suggest that monocultures are more likely than mixtures to deteriorate over time. Increasing biodiversity effects over time could therefore result from declining monocultures instead of reflecting increases in the functioning of mixtures. Commonly, the latter is assumed when positive trends in biodiversity effects occur. Here, we analysed the performance of 60 grassland species growing in monocultures and mixtures over 9 years in a biodiversity experiment to clarify whether their temporal biomass dynamics differed and whether a potential decline of monocultures contributed significantly to the positive net biodiversity effect observed. Surprisingly, individual species’ populations produced, on average, significantly more biomass per unit area when growing in monoculture than when growing in mixture. Over time, productivity of species decreased at a rate that was, on average, slightly more negative in monocultures than in mixtures. The mean net biodiversity effect across all mixtures was continuously positive and ranged between 64–217 g per m2. Short-term increases in the mean net biodiversity effect were only partly due to deteriorating monocultures and were strongly affected by particular species gaining dominance in mixtures in the respective years. We conclude that our species performed, on average, comparably in monocultures and mixtures; monoculture populations being slightly more productive than mixture populations but this trend decreased over time. This suggested that negative feedbacks had not yet affected monocultures strongly but could potentially become more evident in the future. Positive

  17. Forecasting the impact of an invasive macrophyte species in the littoral zone through aquatic insect species composition

    Directory of Open Access Journals (Sweden)

    Hugo H. L. Saulino

    2017-11-01

    Full Text Available ABSTRACT Invasive macrophytes threaten freshwater ecosystem biodiversity. We analyzed the impact of the invasive white ginger lily (Hedychium coronarium J. König, Zingiberaceae on aquatic insect assemblages living in the littoral zone of a tropical reservoir. We took aquatic insect samples in the littoral zone on four main vegetal profile banks: white ginger monotypic bank, forest partially invaded, native macrophyte monotypic bank and riparian forest. At each vegetal bank, we measured abiotic variables such as dissolved oxygen, pH, water temperature and depth. We analyzed the aquatic insects through abundance, richness and Simpson diversity. We used the non-Metric Multidimensional Scaling (nMDS analysis to analyze the spatial distribution of each assemblage, and Analysis of similarities (ANOSIM to verify differences amongst dissimilarity distances. Additionally, we analyzed the main taxa associated with invasive macrophytes through indicator species analyses using IndVal index. We observed that the invasive macrophyte banks presented higher abundance of associated specimens, as well as lower dissimilarity of aquatic insect assemblages. Additionally, invasive macrophytes shifted the water pH and littoral depth of reservoir banks. The IndVal index indicated eight aquatic insects as indicator species. Labrundinia unicolor Silva, 2013, Ablabesmyia depaulai Neubern, 2013 and Diastatops Rambur, 1842 were indicator species on banks. We concluded that invasion of white ginger lily caused loss of shallow littoral habitat and altered the pH of the surrounding water probably by high decomposition rate and high production of plant biomass. We suggest the use of species of aquatic insects as indicator species to monitor white ginger lily impact in freshwater systems.

  18. Dinucleotide Composition in Animal RNA Viruses Is Shaped More by Virus Family than by Host Species.

    Science.gov (United States)

    Di Giallonardo, Francesca; Schlub, Timothy E; Shi, Mang; Holmes, Edward C

    2017-04-15

    Viruses use the cellular machinery of their hosts for replication. It has therefore been proposed that the nucleotide and dinucleotide compositions of viruses should match those of their host species. If this is upheld, it may then be possible to use dinucleotide composition to predict the true host species of viruses sampled in metagenomic surveys. However, it is also clear that different taxonomic groups of viruses tend to have distinctive patterns of dinucleotide composition that may be independent of host species. To determine the relative strength of the effect of host versus virus family in shaping dinucleotide composition, we performed a comparative analysis of 20 RNA virus families from 15 host groupings, spanning two animal phyla and more than 900 virus species. In particular, we determined the odds ratios for the 16 possible dinucleotides and performed a discriminant analysis to evaluate the capability of virus dinucleotide composition to predict the correct virus family or host taxon from which it was isolated. Notably, while 81% of the data analyzed here were predicted to the correct virus family, only 62% of these data were predicted to their correct subphylum/class host and a mere 32% to their correct mammalian order. Similarly, dinucleotide composition has a weak predictive power for different hosts within individual virus families. We therefore conclude that dinucleotide composition is generally uniform within a virus family but less well reflects that of its host species. This has obvious implications for attempts to accurately predict host species from virus genome sequences alone. IMPORTANCE Determining the processes that shape virus genomes is central to understanding virus evolution and emergence. One question of particular importance is why nucleotide and dinucleotide frequencies differ so markedly between viruses. In particular, it is currently unclear whether host species or virus family has the biggest impact on dinucleotide frequencies and

  19. The response of archaeal species to seasonal variables in a subtropical aerated soil: insight into the low abundant methanogens.

    Science.gov (United States)

    Xie, Wei; Jiao, Na; Ma, Cenling; Fang, Sa; Phelps, Tommy J; Zhu, Ruixin; Zhang, Chuanlun

    2017-08-01

    Archaea are cosmopolitan in aerated soils around the world. While the dominance of Thaumarchaeota has been reported in most soils, the methanogens are recently found to be ubiquitous but with low abundances in the aerated soil globally. However, the seasonal changes of Archaea community in the aerated soils are still in the mist. In this study, we investigated the change of Archaea in the context of environmental variables over a period of 12 months in a subtropical soil on the Chongming Island, China. The results showed that Nitrososphaera spp. were the dominant archaeal population while the methanogens were in low proportions but highly diverse (including five genera: Methanobacterium, Methanocella, Methanosaeta, Methanosarcina, and Methanomassiliicoccus) in the aerated soil samples determined by high throughput sequencing. A total of 126 LSA correlations were found in the dataset including all the 72 archaeal OTUs and 8 environmental factors. A significance index defined as the pagerank score of each OTU divided by its relative abundance was used to evaluate the significance of each OTU. The results showed that five out of 17 methanogen OTUs were significantly positively correlated with temperature, suggesting those methanogens might increase with temperature rather than being dormant in the aerated soils. Given the metabolic response of methanogens to temperature under aerated soil conditions, their contribution to the global methane cycle warrants evaluation.

  20. Assessing plant community composition fails to capture impacts of white-tailed deer on native and invasive plant species.

    Science.gov (United States)

    Nuzzo, Victoria; Dávalos, Andrea; Blossey, Bernd

    2017-07-01

    Excessive herbivory can have transformative effects on forest understory vegetation, converting diverse communities into depauperate ones, often with increased abundance of non-native plants. White-tailed deer are a problematic herbivore throughout much of eastern North America and alter forest understory community structure. Reducing (by culling) or eliminating (by fencing) deer herbivory is expected to return understory vegetation to a previously diverse condition. We examined this assumption from 1992 to 2006 at Fermilab (Batavia, IL) where a cull reduced white-tailed deer ( Odocoileus virginianus ) abundance in 1998/1999 by 90 % from 24.6 to 2.5/km 2 , and at West Point, NY, where we assessed interactive effects of deer, earthworms, and invasive plants using 30 × 30 m paired fenced and open plots in 12 different forests from 2009 to 2012. We recorded not only plant community responses (species presence and cover) within 1 m 2 quadrats, but also responses of select individual species (growth, reproduction). At Fermilab, introduced Alliaria petiolata abundance initially increased as deer density increased, but then declined after deer reduction. The understory community responded to the deer cull by increased cover, species richness and height, and community composition changed but was dominated by early successional native forbs. At West Point plant community composition was affected by introduced earthworm density but not deer exclusion. Native plant cover increased and non-native plant cover decreased in fenced plots, thus keeping overall plant cover similar. At both sites native forb cover increased in response to deer reduction, but the anticipated response of understory vegetation failed to materialize at the community level. Deer-favoured forbs ( Eurybia divaricata , Maianthemum racemosum , Polygonatum pubescens and Trillium recurvatum ) grew taller and flowering probability increased in the absence of deer. Plant community monitoring fails to capture

  1. Species composition of a soil invertebrate multi-species test system determines the level of ecotoxicity

    DEFF Research Database (Denmark)

    Sechi, Valentina; D'Annibale, Alessandra; Maraldo, Kristine

    2014-01-01

    A soil multi-species, SMS, experimental test system consisting of the natural microbial community, five collembolan species and a predatory mite along with either Enchytraeus crypticus or the earthworm Eisenia fetida were exposed to α-cypermethrin. A comparison of the performance of these two typ...

  2. BIOMETRY AND COMPOSITION OF FISH SPECIES IN OWENA RESERVOIR, ONDO STATE, NIGERIA

    Directory of Open Access Journals (Sweden)

    FAPOHUNDA Olawumi Oluwafunmilola

    2007-11-01

    Full Text Available A survey of fish species present in Owena reservoir was conducted between October 2004 and March 2005. Fish samples were taken from the catch of the fishermen operating in the reservoir. The results of the survey showed that 14 fish species belonging to seven families were recorded. Two families namely Characidae and Clariidae constituted the dominant fish families in the reservoir. Among the Characidae, Brycinus nurse (23.1% and among the Clariidae family, Clarias gariepinus (22.8% were dominant. Other fish species with significant abundance were Sarotherodon galilaeus (9.3%, Parachanna obscura (8.0%, Clarias anguillaris (7.7% and Oreochromis niloticus (6.4%. The meristic features of the two most abundant fish species caught are as follows: Brycinus nurse had two dorsal spines with eight dorsal fins, two anal spines with eleven anal fins, 25 caudal fins, one pectoral spine and 13 pectoral fins and two ventral spines with seven ventral fins. Clarias gariepinus had 75 dorsal fins, 31 anal fins, 10 caudal fins, six pectoral fins and five ventral fins. The morphometric features of the two most abundant fish species are: Brycinus nurse: total length: 312mm, standard length: 255mm, head length: 60mm, body length: 90mm and body girth: 190mm. Clarias gariepinus: total length: 265mm, standard length: 240mm, head length: 62mm, body length: 62mm and body girth: 130mm.

  3. Composição específica e abundância da ictiofauna do rio dos Padres, bacia do rio Iguaçu, Brasil = Specific composition and abundance of the ichthyofauna from Padres’ river, Iguaçu river basin, Brazil

    Directory of Open Access Journals (Sweden)

    Alessandro Gasparetto Bifi

    2006-07-01

    Full Text Available A composição e estrutura das comunidades de peixes podem ser consideradas como indicadores ecológicos e ambientais, constituindo-se desta forma como ferramenta para o manejo de bacias hidrográficas. O presente estudo objetivou levantar informaçõessobre a composição específica e abundância da ictiofauna do rio dos Padres. Foram realizadas amostragens trimestrais pelo método da pesca elétrica em dois pontos de coleta, um próximo à nascente e outro nas proximidades da foz. As coletas resultaram na captura de 7.026 exemplares pertencentes a 12 espécies distribuídas em sete famílias. A nascente apresentou uma alta densidade em número de indivíduos e menores valores de diversidade, eqüitabilidade e riqueza de espécies em relação à foz. O levantamento da composição específica e abundância da ictiofauna de um rio é de grande importância, por fornecer subsídio a futuros manejos e monitoramentos, tanto da comunidade aquática quanto do ambiente.The composition and structure of fish community can be considered ecological and environmental indicators. The present study aimed to survey information about the specific composition and abundance of theichthyofauna from Padres’ River. Quarterly samplings were accomplished by the method of the electrofishing in two sample sites, one close to the headwater and another in the proximities of the mouth. The collections resulted in the capture of 7026 specimens belonging to 12 species, which, in turn, fit in seven different families. The headwater presented a high density in number of individuals and smaller values of diversity, evenness and richness of species in relation to the mouth. The raising of the specific composition and abundance of the ichthyofauna of a river is of great importance for supplying subsidy to future managements and accompaniment, as much of the aquatic community as of the environment.

  4. [Species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China].

    Science.gov (United States)

    Zhang, Qian; Zhong, Jin-Xin

    2013-05-01

    Based on the related published papers, and by using Geographic Information System (ArcGIS 9.3), this paper analyzed the species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China. There were 83 threatened species living in the Province, belonging to 5 orders, 13 families, and 47 genera. Cypriniformes was absolutely dominant, with 64 species, followed by Siluriformes, with 16 species. Cyprinidae fishes had 51 species, accounting for 79.7% of Cypriniformes. The most species of Cyprinid fishes were of Barbinae (14 species), Cyprininae (10 species), and Cultrinae (10 species). The threatened fishes could be divided into two zoogeographical regions, i. e., Tibetan Plateau region and Oriental region, and their species composition and geographical distribution were resulted from the historical evolution adapted to the related environments. Whatever in rivers and in lakes, the Cyprinid fishes were both absolutely dominant, occupying 36.1% and 31.3% of the total, respectively. The Cyprinid fishes in rivers were mostly of endangered species, while those in lakes were mostly of vulnerable species. The factors affecting the threatened fishes in the Province were discussed from the two aspects of geodynamic evolution and present situation.

  5. Seed Density Significantly Affects Species Richness and Composition in Experimental Plant Communities

    Czech Academy of Sciences Publication Activity Database

    Münzbergová, Zuzana

    2012-01-01

    Roč. 7, č. 10 (2012), e46704 E-ISSN 1932-6203 R&D Projects: GA ČR GAP505/10/0593 Institutional support: RVO:67985939 Keywords : species richness * seed rain * species composition Subject RIV: EF - Botanics Impact factor: 3.730, year: 2012

  6. Large and abundant flowers increase indirect costs of corollas: a study of coflowering sympatric Mediterranean species of contrasting flower size.

    Science.gov (United States)

    Teixido, Alberto L; Valladares, Fernando

    2013-09-01

    Large floral displays receive more pollinator visits but involve higher production and maintenance costs. This can result in indirect costs which may negatively affect functions like reproductive output. In this study, we explored the relationship between floral display and indirect costs in two pairs of coflowering sympatric Mediterranean Cistus of contrasting flower size. We hypothesized that: (1) corolla production entails direct costs in dry mass, N and P, (2) corollas entail significant indirect costs in terms of fruit set and seed production, (3) indirect costs increase with floral display, (4) indirect costs are greater in larger-flowered sympatric species, and (5) local climatic conditions influence indirect costs. We compared fruit set and seed production of petal-removed flowers and unmanipulated control flowers and evaluated the influence of mean flower number and mean flower size on relative fruit and seed gain of petal-removed and control flowers. Fruit set and seed production were significantly higher in petal-removed flowers in all the studied species. A positive relationship was found between relative fruit gain and mean individual flower size within species. In one pair of species, fruit gain was higher in the large-flowered species, as was the correlation between fruit gain and mean number of open flowers. In the other pair, the correlation between fruit gain and mean flower size was also higher in the large-flowered species. These results reveal that Mediterranean environments impose significant constraints on floral display, counteracting advantages of large flowers from the pollination point of view with increased indirect costs of such flowers.

  7. ABUNDANCE AND ISOTOPIC COMPOSITION OF PLANKTONIC MICROCRUSTACEANS IN A CENTRAL AMAZON FLOODPLAIN LAKE: IMPLICATIONS FOR THE TROPHIC DYNAMICS OF THE PLANKTON COMMUNITY

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    Pedro Caraballo

    2016-01-01

    Full Text Available During the hydrological year from December 2007 to November 2008, monthly samplings in the pelagic, littoral and macrophytes zones were conducted in the Lago Catalão, a floodplain lake receiving a mixture of water from Negro and Solimões Rivers, in front of Manaus city. Taxonomic composition and their relative abundance of the planktonic microcrustaceans community was studied. Natural abundances of carbon (C and nitrogen (N stable isotopes were measured to indicate energy sources. Cladocerans were the most abundant, with a relative abundance of 60%, followed by the calanoid and cyclopoid copepods with relative abundances of 29% and 11%, respectively. Diaphanosoma spp. was the dominant cladoceran group during all the sampling periods. Cladocerans were also represented by Moina spp., Ceriodaphnia spp. and Daphnia gessneri. Three genera of calanoid copepods were found: Notodiaptomus spp, Rhacodiaptomus spp., and Argyrodiaptomus spp. The genus Mesocyclops spp. was identified among the cyclopoid copepods. Zooplankton δ13C values indicated that the aquatic macrophyte zone was distinct, with a mean of -27.31‰, which was more enriched than zooplankton in the pelagic and littoral zones, where they had mean δ13C values of -33.11 and -34.66‰, respectively. Overall, analysis of stable isotopes showed that regardless of the pathways, the initial source of carbon for the zooplankton was phytoplankton, with a minimal participation of heterotrophic bacteria.

  8. Testing the enemy release hypothesis: abundance and distribution patterns of helminth communities in grey mullets (Teleostei: Mugilidae) reveal the success of invasive species.

    Science.gov (United States)

    Sarabeev, Volodimir; Balbuena, Juan Antonio; Morand, Serge

    2017-09-01

    The abundance and aggregation patterns of helminth communities of two grey mullet hosts, Liza haematocheilus and Mugil cephalus, were studied across 14 localities in Atlantic and Pacific marine areas. The analysis matched parasite communities of (i) L. haematocheilus across its native and introduced populations (Sea of Japan and Sea of Azov, respectively) and (ii) the introduced population of L. haematocheilus with native populations of M. cephalus (Mediterranean, Azov-Black and Japan Seas). The total mean abundance (TMA), as a feature of the infection level in helminth communities, and slope b of the Taylor's power law, as a measure of parasite aggregation at the infra and component-community levels, were estimated and compared between host species and localities using ANOVA. The TMA of the whole helminth community in the introduced population of L. haematocheilus was over 15 times lower than that of the native population, but the difference was less pronounced for carried (monogeneans) than for acquired (adult and larval digeneans) parasite communities. Similar to the abundance pattern, the species distribution in communities from the invasive population of L. haematocheilus was less aggregated than from its native population for endoparasitic helminths, including adult and larval digeneans, while monogeneans showed a similar pattern of distribution in the compared populations of L. haematocheilus. The aggregation level of the whole helminth community, endoparasitic helminths, adult and larval digeneans was lower in the invasive host species in comparison with native ones as shown by differences in the slope b. An important theoretical implication from this study is that the pattern of parasite aggregation may explain the success of invasive species in ecosystems. Because the effects of parasites on host mortality are likely dose-dependent, the proportion of susceptible host individuals in invasive species is expected to be lower, as the helminth distribution in

  9. Pollination of pima pineapple cactus (Coryphantha sheeri var. robustispina): does pollen flow limit abundance of this endangered species?

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    Christopher J. McDonald; Guy R. McPherson

    2005-01-01

    Pima pineapple cactus (PPC) (Coryphantha sheeri var. robustispina), a federally listed endangered species, occurs throughout southeastern Arizona and has relatively low population densities. To determine whether pollination limits reproduction of PPC we used florescent dye to quantify pollen flow between individuals in a PPC...

  10. Preliminary Estimate of Earthworm Abundance and Species Richness in Spathodea campanulata Beauv. Forests in Northern Puerto Rico

    Science.gov (United States)

    ARIEL E. LUGO; OSCAR J. ABELLEIRA; SONIA BORGES; LAUREN J. COLÓN; SYNDI MELÉNDEZ; MARIELA A. RODRÍGUEZ

    2006-01-01

    The alien tree species Spathodea campanulata forms monodominant stands in abandoned agricultural lands in Puerto Rico. In July 2005, we excavated three replicate randomly located soil pits (25 by 25 by 30 cm) in each of six stands of Spathodea. Three of the stands were located in the moist alluvial geoclimatic zone and three were in the moist karst geoclimatic zone,...

  11. Landscape- vs gap-level controls on the abundance of a fire-sensitive, late-successional tree species.

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    Michael C. Wimberly; Thomas A. Spies

    2002-01-01

    Tsuga heterophylla (western hemlock), a fire-sensitive, late-successional tree species, is an important component of old-growth forests in the Pacific Northwest, USA. In the Oregon Coast Range, however, T. heterophylla occurs at low densities in or is completely absent from many conifer stands. We used a cellular automata-based...

  12. Algal composition and abundance in the neuston surface micro layer from a lake and pond in Virginia (U.S.A.

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    Harold G. MARSHALL

    2003-08-01

    Full Text Available A comparative study was conducted that characterized the algae within the neuston, ca 2 mm below the surface, and the algae in the water column from two freshwater habitats. There were significant differences in total algal abundance and the abundance of diatoms, cyanoprokaryotes, and chlorophytes between the neuston and water column algae of these two regions during each season and at both sites. The pond neuston was dominated by chlorophytes, with total algal abundance ranging seasonally from 0.6 to 59.6 × 10-3 cells ml-1 compared to water column algal concentrations of 4.1 to 40.4 × 10-3 cells ml-1. The lake was dystrophic, with diatoms the most common and abundant species, with the neuston algal abundance ranging from 0.09 to 1.31 × 10-3 cells ml-1, and the water column algae from 0.19 to 2.70 × 10-3 cells ml-1. Proximity to the variable nature of the surface layer was not a deterrent for neuston algal development, which frequently reached bloom status and contained a diverse assemblage of taxa.

  13. Organic, integrated and conventional management in apple orchards: effect on plant species composition, richness and diversity

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    Zdeňka Lososová

    2011-01-01

    Full Text Available The study was conducted to assess the effect of conventional, integrated and organic management on differences in plant species composition, richness and diversity. The plants were studied in triads of orchards situated in three regions of the Czech Republic. Data about species occurrences were collected on 15 permanent plots in the tree rows and 15 plots between tree rows in each of the apple orchards during 2009. A total of 201 vascular plant species (127 native species, 65 archaeophytes, and 9 neophytes were found. Management type and also different regional conditions had a significant effect on plant species composition and on diversity parameters of orchard spontaneous vegetation. Species richness and species pool was significantly higher in the organic orchards than in the differently managed orchards. Management type had significant effect on proportions of archaeophytes, and also neophytes in apple orchards. The results showed that a change from conventional to integrated and organic management in apple orchards lead to higher plant species diversity and to changes in plant species composition.

  14. DNA barcoding of shark meats identify species composition and CITES-listed species from the markets in Taiwan.

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    Shang-Yin Vanson Liu

    Full Text Available BACKGROUND: An increasing awareness of the vulnerability of sharks to exploitation by shark finning has contributed to a growing concern about an unsustainable shark fishery. Taiwan's fleet has the 4th largest shark catch in the world, accounting for almost 6% of the global figures. Revealing the diversity of sharks consumed by Taiwanese is important in designing conservation plans. However, fins make up less than 5% of the total body weight of a shark, and their bodies are sold as filets in the market, making it difficult or impossible to identify species using morphological traits. METHODS: In the present study, we adopted a DNA barcoding technique using a 391-bp fragment of the mitochondrial cytochrome oxidase I (COI gene to examine the diversity of shark filets and fins collected from markets and restaurants island-wide in Taiwan. RESULTS: Amongst the 548 tissue samples collected and sequenced, 20 major clusters were apparent by phylogenetic analyses, each of them containing individuals belonging to the same species (most with more than 95% bootstrap values, corresponding to 20 species of sharks. Additionally, Alopias pelagicus, Carcharhinus falciformis, Isurus oxyrinchus, and Prionace glauca consisted of 80% of the samples we collected, indicating that these species might be heavily consumed in Taiwan. Approximately 5% of the tissue samples used in this study were identified as species listed in CITES Appendix II, including two species of Sphyrna, C. longimanus and Carcharodon carcharias. CONCLUSION: DNA barcoding provides an alternative method for understanding shark species composition when species-specific data is unavailable. Considering the global population decline, stock assessments of Appendix II species and highly consumed species are needed to accomplish the ultimate goal of shark conservation.

  15. DNA barcoding of shark meats identify species composition and CITES-listed species from the markets in Taiwan.

    Science.gov (United States)

    Liu, Shang-Yin Vanson; Chan, Chia-Ling Carynn; Lin, Oceana; Hu, Chieh-Shen; Chen, Chaolun Allen

    2013-01-01

    An increasing awareness of the vulnerability of sharks to exploitation by shark finning has contributed to a growing concern about an unsustainable shark fishery. Taiwan's fleet has the 4th largest shark catch in the world, accounting for almost 6% of the global figures. Revealing the diversity of sharks consumed by Taiwanese is important in designing conservation plans. However, fins make up less than 5% of the total body weight of a shark, and their bodies are sold as filets in the market, making it difficult or impossible to identify species using morphological traits. In the present study, we adopted a DNA barcoding technique using a 391-bp fragment of the mitochondrial cytochrome oxidase I (COI) gene to examine the diversity of shark filets and fins collected from markets and restaurants island-wide in Taiwan. Amongst the 548 tissue samples collected and sequenced, 20 major clusters were apparent by phylogenetic analyses, each of them containing individuals belonging to the same species (most with more than 95% bootstrap values), corresponding to 20 species of sharks. Additionally, Alopias pelagicus, Carcharhinus falciformis, Isurus oxyrinchus, and Prionace glauca consisted of 80% of the samples we collected, indicating that these species might be heavily consumed in Taiwan. Approximately 5% of the tissue samples used in this study were identified as species listed in CITES Appendix II, including two species of Sphyrna, C. longimanus and Carcharodon carcharias. DNA barcoding provides an alternative method for understanding shark species composition when species-specific data is unavailable. Considering the global population decline, stock assessments of Appendix II species and highly consumed species are needed to accomplish the ultimate goal of shark conservation.

  16. Floristic composition, environmental variation and species distribution patterns in burned grassland in southern Brazil.

    Science.gov (United States)

    Overbeck, G E; Müller, S C; Pillar, V D; Pfadenhauer, J

    2006-11-01

    In regularly burned grassland on Morro Santana, Porto Alegre, RS, Brazil, we investigated differences in the floristic composition and their relation to soil properties, aspect and distance from the forest border. In 48 plots of 0.75 m2, we identified a total of 201 species from a local species pool of approximately 450 to 500 species. Most species occurred in low frequencies, showing clumpy distribution patterns in the studied area. Multivariate analysis showed that plots close to the forest edge clearly differed from plots in the open grassland concerning composition and structure. Plots exposed to the north differed from plots on the top of the hill both in the composition of species as well as in soil variables, mainly due to shallower soil in the former. No strong relation between soil properties and variation in vegetation composition could be detected at a finer scale. The studied grassland, as all grassland vegetation in southern Brazil, is very rich in species compared to other grassland formations worldwide. However, this high biodiversity and conservational value of Campos vegetation in general has so far not been recognized properly. Disturbance is essential to maintain this open vegetation type and its species richness. Fire should be considered as a management option in the absence of grazing.

  17. Species effects on ecosystem processes are modified by faunal responses to habitat composition.

    Science.gov (United States)

    Bulling, Mark T; Solan, Martin; Dyson, Kirstie E; Hernandez-Milian, Gema; Luque, Patricia; Pierce, Graham J; Raffaelli, Dave; Paterson, David M; White, Piran C L

    2008-12-01

    Heterogeneity is a well-recognized feature of natural environments, and the spatial distribution and movement of individual species is primarily driven by resource requirements. In laboratory experiments designed to explore how different species drive ecosystem processes, such as nutrient release, habitat heterogeneity is often seen as something which must be rigorously controlled for. Most small experimental systems are therefore spatially homogeneous, and the link between environmental heterogeneity and its effects on the redistribution of individuals and species, and on ecosystem processes, has not been fully explored. In this paper, we used a mesocosm system to investigate the relationship between habitat composition, species movement and sediment nutrient release for each of four functionally contrasting species of marine benthic invertebrate macrofauna. For each species, various habitat configurations were generated by selectively enriching patches of sediment with macroalgae, a natural source of spatial variability in intertidal mudflats. We found that the direction and extent of faunal movement between patches differs with species identity, density and habitat composition. Combinations of these factors lead to concomitant changes in nutrient release, such that habitat composition effects are modified by species identity (in the case of NH4-N) and by species density (in the case of PO4-P). It is clear that failure to accommodate natural patterns of spatial heterogeneity in such studies may result in an incomplete understanding of system behaviour. This will be particularly important for future experiments designed to explore the effects of species richness on ecosystem processes, where the complex interactions reported here for single species may be compounded when species are brought together in multi-species combinations.

  18. Composition of arthropod species assemblages in Bt-expressing and near isogenic eggplants in experimental fields.

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    Arpaia, Salvatore; Di Leo, Grazia M; Fiore, Maria C; Schmidt, Jörg E U; Scardi, Michele

    2007-02-01

    The environmental impact of genetically modified (GM) plants in experimental fields has been examined in several ways, in particular with respect to the dynamics of specific nontarget organisms. The approach of sampling for biodiversity in agroecosystems to compare complex patterns could also be useful in studying potential disruptions caused by GM crops. In this study, we set up replicated field plots of Bt-expressing eggplants and near isogenic untransformed eggplants as a control. We monitored the presence and abundance of herbivore and predator arthropods in weekly visual samplings of the plant canopy for three growing seasons (2001-2003). Insect species were pooled in organismal taxonomic units (OTUs); three multivariate methods were used to compare species assemblage as an estimate of insect biodiversity. This multistep statistical approach proved to be efficient in recognizing association patterns, as evidenced by the data for the target species Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae) clearly showing a significant association with the control plots. All the analyses indicate a comparable species assemblage between transgenic and near isogenic eggplant areas. Our results suggest that some taxa may warrant more specific study. For example, Alticinae beetles (Coleoptera: Chrysomelidae) were alternatively more abundant in either of the two treatments, and their overall abundance was significantly higher on transgenic eggplants. In light of these results and because of their taxonomic proximity to the target species, these herbivores may represent an important nontarget group to be further studied. Moreover, some sap feeders (e.g., Homoptera: Cicadellidae) were more abundant on Bt-expressing plants in some samples in all 3 yr.

  19. Remnant trees affect species composition but not structure of tropical second-growth forest.

    Science.gov (United States)

    Sandor, Manette E; Chazdon, Robin L

    2014-01-01

    Remnant trees, spared from cutting when tropical forests are cleared for agriculture or grazing, act as nuclei of forest regeneration following field abandonment. Previous studies on remnant trees were primarily conducted in active pasture or old fields abandoned in the previous 2-3 years, and focused on structure and species richness of regenerating forest, but not species composition. Our study is among the first to investigate the effects of remnant trees on neighborhood forest structure, biodiversity, and species composition 20 years post-abandonment. We compared the woody vegetation around individual remnant trees to nearby plots without remnant trees in the same second-growth forests ("control plots"). Forest structure beneath remnant trees did not differ significantly from control plots. Species richness and species diversity were significantly higher around remnant trees. The species composition around remnant trees differed significantly from control plots and more closely resembled the species composition of nearby old-growth forest. The proportion of old-growth specialists and generalists around remnant trees was significantly greater than in control plots. Although previous studies show that remnant trees may initially accelerate secondary forest growth, we found no evidence that they locally affect stem density, basal area, and seedling density at later stages of regrowth. Remnant trees do, however, have a clear effect on the species diversity, composition, and ecological groups of the surrounding woody vegetation, even after 20 years of forest regeneration. To accelerate the return of diversity and old-growth forest species into regrowing forest on abandoned land, landowners should be encouraged to retain remnant trees in agricultural or pastoral fields.

  20. Impact of habitat degradation on species diversity and nest abundance of five African stingless bee species in a tropical rainforest of Kenya

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    Kiatoko, Nkoba; Raina, Suresh Kumar; Langevelde, Van Frank

    2017-01-01

    Natural habitat degradation often involves the reduction or disappearance of bee species. In Africa, stingless bees are hunted for honey, which is used as food, for medicinal purposes, and for traditional rituals. Severe habitat degradation due to human settlement is hypothesized to have a negative

  1. Anthocyanins in the bracts of Curcuma species and relationship of the species based on anthocyanin composition.

    Science.gov (United States)

    Koshioka, Masaji; Umegaki, Naoko; Boontiang, Kriangsuk; Pornchuti, Witayaporn; Thammasiri, Kanchit; Yamaguchi, Satoshi; Tatsuzawa, Fumi; Nakayama, Masayoshi; Tateishi, Akira; Kubota, Satoshi

    2015-03-01

    Five anthocyanins, delphinidin 3-O-rutinoside, cyanidin 3-O-rutinoside, petunidin 3-O-rutinoside, malvidin 3-O-glucoside and malvidin 3-O-rutinoside, were identified. Three anthocyanins, delphinidin 3-O-glucoside, cyanidin 3-O-glucoside and pelargonidin 3-O-rutinoside, were putatively identified based on C18 HPLC retention time, absorption spectrum, including λmax, and comparisons with those of corresponding standard anthocyanins, as the compounds responsible for the pink to purple-red pigmentation of the bracts of Curcuma alismatifolia and five related species. Cluster analysis based on four major anthocyanins formed two clusters. One consisted of only one species, C. alismatifolia, and the other consisted of five. Each cluster further formed sub-clusters depending on either species or habitats.

  2. Effects of soil and space on the woody species composition and vegetation structure of three Cerrado phytophysiognomies in the Cerrado-Amazon transition.

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    Maracahipes-Santos, L; Lenza, E; Santos, J O; Mews, H A; Oliveira, B

    2017-11-01

    The Cerrado Biome is considered one of the world's biodiversity hotspots because of its rich biodiversity, the high level of endemism and the increasing threat. The Cerrado is composed by a mosaic of different vegetation types, including physiognomies that vary from grasslands (campo limpo) to savannas (typical cerrado or cerrado sensu stricto) and cerrado woodlands (cerradão). However, the factors that determine the composition of the Cerrado's flora and the structure of the physiognomies that compose this biome are still poorly understood. Here, we investigate the influence of the chemical and granulometric properties of the soil and the effect of geographic distance on the occurrence and abundance of woody species in three Cerrado phytophysiognomies - cerrado woodland (cerradão), dense cerrado savanna and typical cerrado savanna - in the Cerrado-Amazon transition. We tested the hypothesis that the edaphic characteristics and geographic space determine the species composition and the structure of the woody vegetation of these three phytophysiognomies. We demonstrate that the dissimilarities in the structure and composition of the three sites were determined more by space (13% of explanation) than edaphic properties (1%), but primarily by the interaction between these two factors (26%). We conclude that, in situations where the chemical and granulometric properties of the soil are relatively homogeneous, as we found in the present study, geographic distance between sites has a greater influence than variation in the substrate's properties on modelling the occurrence and abundance of the woody plant species in the Cerrado.

  3. Marine Microbial Gene Abundance and Community Composition in Response to Ocean Acidification and Elevated Temperature in Two Contrasting Coastal Marine Sediments

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    Ashleigh R. Currie

    2017-08-01

    Full Text Available Marine ecosystems are exposed to a range of human-induced climate stressors, in particular changing carbonate chemistry and elevated sea surface temperatures as a consequence of climate change. More research effort is needed to reduce uncertainties about the effects of global-scale warming and acidification for benthic microbial communities, which drive sedimentary biogeochemical cycles. In this research, mesocosm experiments were set up using muddy and sandy coastal sediments to investigate the independent and interactive effects of elevated carbon dioxide concentrations (750 ppm CO2 and elevated temperature (ambient +4°C on the abundance of taxonomic and functional microbial genes. Specific quantitative PCR primers were used to target archaeal, bacterial, and cyanobacterial/chloroplast 16S rRNA in both sediment types. Nitrogen cycling genes archaeal and bacterial ammonia monooxygenase (amoA and bacterial nitrite reductase (nirS were specifically targeted to identify changes in microbial gene abundance and potential impacts on nitrogen cycling. In muddy sediment, microbial gene abundance, including amoA and nirS genes, increased under elevated temperature and reduced under elevated CO2 after 28 days, accompanied by shifts in community composition. In contrast, the combined stressor treatment showed a non-additive effect with lower microbial gene abundance throughout the experiment. The response of microbial communities in the sandy sediment was less pronounced, with the most noticeable response seen in the archaeal gene abundances in response to environmental stressors over time. 16S rRNA genes (amoA and nirS were lower in abundance in the combined stressor treatments in sandy sediments. Our results indicated that marine benthic microorganisms, especially in muddy sediments, are susceptible to changes in ocean carbonate chemistry and seawater temperature, which ultimately may have an impact upon key benthic biogeochemical cycles.

  4. Culicoides species abundance and potential over-wintering of African horse sickness virus in the Onderstepoort area, Gauteng, South Africa

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    Gert J. Venter

    2014-11-01

    Full Text Available In South Africa, outbreaks of African horse sickness (AHS occur in summer; no cases are reported in winter, from July to September. The AHS virus (AHSV is transmitted almost exclusively by Culicoides midges (Diptera: Ceratopogonidae, of which Culicoides imicola is considered to be the most important vector. The over-wintering mechanism of AHSV is unknown. In this study, more than 500 000 Culicoides midges belonging to at least 26 species were collected in 88 light traps at weekly intervals between July 2010 and September 2011 near horses in the Onderstepoort area of South Africa. The dominant species was C. imicola. Despite relatively low temperatures and frost, at least 17 species, including C. imicola, were collected throughout winter (June–August. Although the mean number of midges per night fell from > 50 000 (March to < 100 (July and August, no midge-free periods were found. This study, using virus isolation on cell cultures and a reverse transcriptase polymerase chain reaction (RT-PCR assay, confirmed low infection prevalence in field midges and that the detection of virus correlated to high numbers. Although no virus was detected during this winter period, continuous adult activity indicated that transmission can potentially occur. The absence of AHSV in the midges during winter can be ascribed to the relatively low numbers collected coupled to low infection prevalence, low virus replication rates and low virus titres in the potentially infected midges. Cases of AHS in susceptible animals are likely to start as soon as Culicoides populations reach a critical level.

  5. Nectar production dynamics and sugar composition in two Mucuna species (Leguminosae, Faboideae) with different specialized pollinators

    Science.gov (United States)

    Agostini, Kayna; Sazima, Marlies; Galetto, Leonardo

    2011-11-01

    Nectar is secreted in particular rhythms throughout the lifespan of a flower, which allows determining the nectar production dynamics. This paper compares nectar features in Mucuna japira and Mucuna urens describing: dynamics of nectar production, floral response to nectar removal, resorption, nectar sugar composition, and variation in nectar sugar composition. M. japira inflorescence bears 12-21 yellow flowers, which are in anthesis for 7 days, whereas M. urens inflorescence bears 36-54 greenish flowers, but only 1-3 flowers are in anthesis simultaneously that last one night. Nectar volume and sugar concentration were measured, and the amount of sugar was estimated. Qualitative and quantitative nectar sugar composition was determined. Both species had a constant nectar sugar concentration (ca. 10% for M. japira and ca. 16% for M. urens) and secreted high volumes of nectar (ca. 340 μl per flower for M. japira and 310 μl per flower for M. urens), during 5 days for M. japira and 6 h for M. urens, but after the first removal, i.e., when flower opening mechanism is triggered, nectar production stops immediately. Nectar resorption occurred in both species. Nectar sugar composition showed some similarities between the species. Variation in nectar sugar composition occurred in both species. The Mucuna species are dependent on their pollinators to produce fruits and seeds, and they have different strategies to promote the necessary interaction with birds or bats, especially related to nectar and flower characteristics.

  6. Essential Oils Composition and Antioxidant Properties of Three Thymus Species

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    Hamzeh Amiri