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Sample records for alaska species composition

  1. Bumble bees (Hymenoptera: Apidae: Bombus spp.) of interior Alaska: Species composition, distribution, seasonal biology, and parasites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite the ecological and agricultural significance of bumble bees in Alaska, very little is known and published about this important group at the regional level. The objectives of this study were to provide baseline data on species composition, distribution, seasonal biology, and parasites of the ...

  2. Bumble Bees (Hymenoptera: Apidae: Bombus spp.) of Interior Alaska: Species Composition, Distribution, Seasonal Biology, and Parasites

    PubMed Central

    Pampell, Rehanon; Pantoja, Alberto; Holloway, Patricia; Knight, Charles; Ranft, Richard

    2015-01-01

    Abstract Background Despite the ecological and agricultural significance of bumble bees in Alaska, very little is known and published about this important group at the regional level. The objectives of this study were to provide baseline data on species composition, distribution, seasonal biology, and parasites of the genus Bombus at three major agricultural locations within Alaska: Fairbanks, Delta Junction, and Palmer, to lay the groundwork for future research on bumble bee pollination in Alaska. New information A total of 8,250 bumble bees representing 18 species was collected from agricultural settings near Delta Junction, Fairbanks, and Palmer, Alaska in 2009 and 2010. Of the 8,250 specimens, 51% were queens, 32.7% were workers, and 16.2% were males. The species composition and relative abundances varied among sites and years. Delta Junction had the highest relative abundance of bumble bees, representing 51.6% of the specimens collected; the other two locations, Fairbanks and Palmer represented 26.5% and 21.8% of the overall catch respectively. The species collected were: Bombus bohemicus Seidl 1837 (= B. ashtoni (Cresson 1864)), B. balteatus Dahlbom 1832, B. bifarius Cresson 1878, B. centralis Cresson 1864, B. cryptarum (Fabricius 1775) (=B. moderatus Cresson 1863), B. distinguendus Morawitz 1869, B. flavidus Eversmann 1852 (=B. fernaldae Franklin 1911), B. flavifrons Cresson 1863, B. frigidus Smith 1854, B. insularis (Smith 1861), B. jonellus (Kirby 1802), B. melanopygus Nylander 1848, B. mixtus Cresson 1878, B. neoboreus Sladen 1919, B. occidentalis Greene 1858, B. perplexus Cresson 1863, B. rufocinctus Cresson 1863, and B. sylvicola Kirby 1837. Overall, the most common bumble bees near agricultural lands were B. centralis, B. frigidus, B. jonellus, B. melanopygus, B. mixtus, and B. occidentalis. Species' relative population densities and local diversity were highly variable from year to year. Bombus occidentalis, believed to be in decline in the Pacific

  3. Proximate composition and fatty acid signatures of selected forage fish species in Prince William Sound, Alaska. Exxon Valdez Oil Spill Restoration Project 95121. Final report

    SciTech Connect

    Worth, G.A.J.; Miculka, T.A.

    1997-12-31

    The proximate composition and fatty acid signatures of several prey species, which are important for sea birds and marine mammals in Prince William Sound, Alaska, were determined. Fish were collected as part of the SEA cruises in the fall of 1995 and were frozen immediately and then shipped to Galveston for analysis. Fatty acid signatures of herring, pollock, and tomcod were consistent with previously reported data, Three different species of sole (English, rock, and flathead) were also consistent with previously reported data for yellowfin sole. Detailed analyses of individual rock fish suggest that this species may exhibit trends in some specific fatty acids (20:5 n-3, 22:6 n-3) which differ from herring or pollock.

  4. Mercury in fishes of Alaska, with emphasis on subsistence species.

    PubMed

    Jewett, Stephen C; Duffy, Lawrence K

    2007-11-15

    In the north, the presence of mercury (Hg) in food leading to chronic exposure is a scientific, economic and political issue. Guidelines have been established for the safe consumption of fish containing Hg, however, adherence to these guidelines must be weighed against the health benefits of consuming fish, such as from the omega-3 polyunsaturated fatty acids, vitamins and minerals. Alaskan Natives generally consume much more fish than the national average. This review summarizes and synthesizes the significant amount of data that has been generated on Hg in Alaska fish, particularly those consumed by Alaskans. Also included are a review of the benefits of eating fish, human health concerns relating to Hg toxicity and various risk assessment guidelines for food consumption. Emphasis was placed on methylmercury (MeHg), the most toxic form to humans. Hg concentrations were examined in 17 freshwater fish species and 24 anadromous and marine fish species, for a total of 2,692 specimens. For freshwater fish the greatest database was on northern pike (Esox lucius). For anadromous and marine fish the greatest database was on Pacific halibut (Hippoglossus stenolepis) and the five species of Pacific salmon (Oncorhynchus spp.). Overall, most fish had muscle Hg concentrations of < or =1 mg kg(-1) (wet wt.), within the USFDA's Action Level and Alaska's guideline for safe concentrations of MeHg in edible fish. Pacific salmon, the most commonly consumed fish group, had exceptionally low (< or =0.1 mg kg(-1)) Hg concentrations. Pacific halibut muscle Hg content was less than 0.3 mg kg(-1). Northern pike, a piscivorous (fish-eating) and long-lived fish, contained the highest muscle Hg values, often exceeding the state's guidelines for food consumption. A discussion of the safe consumption level for pike is included. PMID:17825359

  5. Species List of Alaskan Birds, Mammals, Fish, Amphibians, Reptiles, and Invertebrates. Alaska Region Report Number 82.

    ERIC Educational Resources Information Center

    Taylor, Tamra Faris

    This publication contains a detailed list of the birds, mammals, fish, amphibians, reptiles, and invertebrates found in Alaska. Part I lists the species by geographical regions. Part II lists the species by the ecological regions of the state. (CO)

  6. Plant community composition and vegetation height, Barrow, Alaska, Ver. 1

    DOE Data Explorer

    Sloan, Victoria; Norby, Richard; Siegrist, Julia; Iversen, Colleen; Brooks, Jonathan; Liebig, Jennifer; Wood, Sarah

    2014-04-25

    This dataset contains i) the results of field surveys of plant community composition and vegetation height made between 17th and 29th July 2012 in 48, 1 x 1 m plots located in areas A-D of Intensive Site 1 at the Next-Generation Ecosystem Experiments (NGEE) Arctic site near Barrow, Alaska and ii) results of a mapping exercise undertaken in August 2013 using two perpendicular transects across each polygon containing vegetation plots to determine the boundaries of vegetation communities described in 2012.

  7. 75 FR 56017 - Fisheries of the Exclusive Economic Zone Off Alaska; Shallow-Water Species by Vessels Using Trawl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-15

    ... under Sec. 679.21(d)(7)(i) on September 3, 2010 (75 FR 54290, September 7, 2010). NMFS has determined... Economic Zone Off Alaska; Shallow- Water Species by Vessels Using Trawl Gear in the Gulf of Alaska AGENCY...-water species by vessels using trawl gear in the Gulf of Alaska (GOA). This action is necessary to...

  8. 77 FR 46338 - Fisheries of the Economic Exclusive Zone Off Alaska; Deep-Water Species Fishery by Vessels Using...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-03

    ... groundfish of the GOA (77 FR 15194, March 14, 2012), for the period 1200 hrs, A.l.t., July 1, 2012, through... Exclusive Zone Off Alaska; Deep-Water Species Fishery by Vessels Using Trawl Gear in the Gulf of Alaska... comprise the deep-water species fishery by vessels using trawl gear in the Gulf of Alaska (GOA)....

  9. Estimation of avian population sizes and species richness across a boreal landscape in Alaska

    USGS Publications Warehouse

    Handel, C.M.; Swanson, S.A.; Nigro, Debora A.; Matsuoka, S.M.

    2009-01-01

    We studied the distribution of birds breeding within five ecological landforms in Yukon-Charley Rivers National Preserve, a 10,194-km2 roadless conservation unit on the Alaska-Canada border in the boreal forest zone. Passerines dominated the avifauna numerically, comprising 97% of individuals surveyed but less than half of the 115 species recorded in the Preserve. We used distance-sampling and discrete-removal models to estimate detection probabilities, densities, and population sizes across the Preserve for 23 species of migrant passerines and five species of resident passerines. Yellow-rumped Warblers (Dendroica coronata) and Dark-eyed Juncos (Junco hyemalis) were the most abundant species, together accounting for 41% of the migrant passerine populations estimated. White-winged Crossbills (Loxia leucoptera), Boreal Chickadees (Poecile hudsonica), and Gray Jays (Perisoreus canadensis) were the most abundant residents. Species richness was greatest in the Floodplain/Terrace landform flanking the Yukon River but densities were highest in the Subalpine landform. Species composition was related to past glacial history and current physiography of the region and differed notably from other areas of the northwestern boreal forest. Point-transect surveys, augmented with auxiliary observations, were well suited to sampling the largely passerine avifauna across this rugged landscape and could be used across the boreal forest region to monitor changes in northern bird distribution and abundance. ?? 2009 The Wilson Ornithological Society.

  10. Changes in Species, Areal Cover, and Production of Moss across a Fire Chronosequence in Interior Alaska

    USGS Publications Warehouse

    Harden, J.W.; Munster, J.; Manies, K.L.; Mack, M.C.; Bubier, J.L.

    2009-01-01

    In an effort to characterize the species and production rates of various upland mosses and their relationship to both site drainage and time since fire, annual net primary production of six common moss species was measured. Several stands located near Delta Junction, interior Alaska, were located. These stands ranged from one to 116 years since fire in well-drained (dry) and moderately to somewhat poorly drained (wet) black spruce (Picea mariana)-feathermoss systems. Moss species composition varied greatly during the fire cycle, with Ceratodon purpureus dominating the earliest years after a fire, Aulacomnium palustre dominating the transitional and older stages, and Hylocomium splendens dominating the oldest, mature sites. Polytrichum spp. was found at all sites. Average moss cover ranged from <10 percent in the youngest sites to almost 90 percent in the mature sites. Species from the genus Polytrichum were the most productive and contributed up to 30 g m2 of organic matter in one growing season. Least productive was Rhytidium rugosum, which contributed about 1.5 g m2 of organic matter in mature stands. Recovery of moss productivity after fire was not significantly different for wet and dry sites.

  11. Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Though it's not quite spring, waters in the Gulf of Alaska (right) appear to be blooming with plant life in this true-color MODIS image from March 4, 2002. East of the Alaska Peninsula (bottom center), blue-green swirls surround Kodiak Island. These colors are the result of light reflecting off chlorophyll and other pigments in tiny marine plants called phytoplankton. The bloom extends southward and clear dividing line can be seen west to east, where the bloom disappears over the deeper waters of the Aleutian Trench. North in Cook Inlet, large amounts of red clay sediment are turning the water brown. To the east, more colorful swirls stretch out from Prince William Sound, and may be a mixture of clay sediment from the Copper River and phytoplankton. Arcing across the top left of the image, the snow-covered Brooks Range towers over Alaska's North Slope. Frozen rivers trace white ribbons across the winter landscape. The mighty Yukon River traverses the entire state, beginning at the right edge of the image (a little way down from the top) running all the way over to the Bering Sea, still locked in ice. In the high-resolution image, the circular, snow-filled calderas of two volcanoes are apparent along the Alaska Peninsula. In Bristol Bay (to the west of the Peninsula) and in a couple of the semi-clear areas in the Bering Sea, it appears that there may be an ice algae bloom along the sharp ice edge (see high resolution image for better details). Ground-based observations from the area have revealed that an under-ice bloom often starts as early as February in this region and then seeds the more typical spring bloom later in the season.

  12. 76 FR 39790 - Fisheries of the Economic Exclusive Zone Off Alaska; Deep-Water Species Fishery by Catcher...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... GOA (76 FR 11111, March 1, 2011). In accordance with Sec. 679.82(d)(9)(i)(B), the Administrator... Exclusive Zone Off Alaska; Deep-Water Species Fishery by Catcher Vessels in the Gulf of Alaska AGENCY... the deep-water species fishery for catcher vessels subject to sideboard limits established under...

  13. Critical fishery species in Alaska offshore oil and gas lease areas

    SciTech Connect

    Arbegast, J.; Allen, M.

    1980-11-01

    Offshore oil and gas development in Alaska is governed through sales of lease blocks in designated areas. USBLM manages these sales and prepares the necessary environmental impact statement prior to each sale. Collected fishery data are tabulated, linking critical crustacean and fishery species with their associated lease areas. Listed are critical species, organized by taxonomic name, associated common name, and taxonomic code numbers. Each critical species is linked to one or more of the lease area numbers, derived from USBLM planning units.

  14. Moose as a vector for non-indigenous plant species in Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White sweetclover and narrowleaf hawksbeard are non-indigenous invasive plant species in Alaska that are rapidly spreading, including into areas that are otherwise free of non-indigenous plants. There has been concern that native moose could be dispersing viable seed from these plants after ingestio...

  15. Four new species of Haplosclerida (Porifera, Demospongiae) from the Aleutian Islands, Alaska.

    PubMed

    Lehnert, Helmut; Stone, Robert P

    2013-01-01

    Four new species of Haplosclerida are described from the Aleutian Islands, Alaska: Callyspongia mucosa n.sp., Cladocroce infundibulum n. sp., Cladocroce attu n. sp. and Cladocroce kiska n. sp. The new species are described and compared to congeners of the region. This is the northernmost record of the genus Callyspongia and the first record of the subgenus Callyspongia from the North Pacific Ocean. To accommodate Cladocroce kiska in its genus the definition has to be broadened to allow sigmas.

  16. Plant Community Composition and Nitrogen Stocks across Complex Polygonal Landscapes on the North Slope of Alaska

    NASA Astrophysics Data System (ADS)

    Wullschleger, S. D.; Sloan, V. L.; Norby, R. J.; Iversen, C. M.; Childs, J.

    2013-12-01

    A reorganization of Arctic plant communities due to regional warming and changes to permafrost stability will drive important land-atmosphere feedbacks to climate. Quantifying key processes that link plant community structure to soil moisture, nutrient availability, thaw depth, and microtopography across tundra ecosystems is thus required if vegetation patterns are to be represented in models that operate at regional and global scales. The heterogeneity of Arctic landscapes, particularly those dominated by ice-rich polygons on the North Slope of Alaska and their characteristic geomorphic subunits, makes this a challenging endeavor. Here, we quantify plant community composition in relation to centers, ridges, and troughs across a gradient from low-centered to high-centered polygons at the Next-Generation Ecosystems Experiments (NGEE Arctic) field site on the Barrow Environmental Observatory (BEO) outside Barrow, Alaska. Plant communities were surveyed in 1 x 1 m plots across four polygon types. Destructive harvests were conducted to characterize leaf area index, above- and below-ground biomass, and plant carbon and nitrogen stocks. The site was dominated by Carex aquatilis, which comprised 54% of aboveground plant biomass and 59% of aboveground plant nitrogen. Foliar nitrogen concentration in Carex was uniform across the site, averaging 2.6%. The biomass-weighted average foliar nitrogen of the plant community across the land surface was 2.4%, but it was distinctly less (1.5%) in the dry centers of high-centered polygons, reflecting the presence of the evergreen shrub Vaccinium vitis-idaea, which had lower foliar nitrogen concentration than other species (1.0%). Vegetation nitrogen on a land area basis was well predicted by leaf area index (LAI), regardless of plant community composition, and supports the use of LAI as a scalar for plant productivity across this landscape. Overall, improving understanding of the links between plant community composition and

  17. Composition of Heads and Livers of Yelloweye Rockfish (Sebastes ruberrimus) Harvested in Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to their large size and fillet quality, yelloweye rockfish (YER) are a highly prized species in both commercial and recreational Alaska fisheries. Processing yields for YER are relatively low, thus by-product volume is significant at up to 77% of whole fish weight (WFW). The objective of this re...

  18. Chemical composition of the snowpack during the OASIS spring campaign 2009 at Barrow, Alaska

    NASA Astrophysics Data System (ADS)

    Jacobi, H. W.; Voisin, D.; Jaffrezo, J. L.; Cozic, J.; Douglas, T. A.

    2012-07-01

    The chemical composition of the seasonal snowpack was determined close to Barrow, an Arctic coastal location in northern Alaska. One hundred and twelve samples of different snow types including fresh snow, surface hoar, diamond dust, blowing snow, rounded snow grains, and depth hoar were collected and analyzed for major sea salt components, bromide, and nitrate. Sodium, chloride, sulfate, and potassium are mainly introduced into the snowpack by the deposition of sea salt, while magnesium and calcium result from a combination of sea salt and dust. Sulfate was strongly depleted in most samples compared to other sea salt components. This is attributed to the precipitation of mirabilite in newly formed sea ice and frost flowers that leads to an efficient fractionation of sulfate. Uptake of volatile but soluble species from the gas phase also contributed to the observed chloride, sulfate, and nitrate in the snow. However, for chloride and sulfate the input from the marine sources was overwhelming and the uptake from the gas phase was only visible in the samples with low concentrations like fresh snow, diamond dust, and surface hoar. Nitrate concentrations in the snowpack were less variable and for aged snow nitrate was related to the specific surface area of the snow indicating the adsorption of nitric acid can be an important nitrate source in the aged snow. Bromide was also introduced into the snowpack from marine sources, but due to its high reactivity it was partly transferred back to the atmosphere in the form of reactive species. The result of these processes was evident in bromide concentrations, which were both enriched and depleted at the snowpack surface while deeper layers were mostly depleted. Blowing snow also exhibited a depleted bromide composition. For all compounds except nitrate, many depth hoar samples exhibited the greatest concentrations, probably as a result of higher input earlier in the season as well as increases due to the sublimation of water

  19. Soluble, light-absorbing species in snow at Barrow, Alaska

    NASA Astrophysics Data System (ADS)

    Beine, Harry; Anastasio, Cort; Esposito, Giulio; Patten, Kelley; Wilkening, Elizabeth; Domine, Florent; Voisin, Didier; Barret, Manuel; Houdier, Stephan; Hall, Sam

    2011-07-01

    As part of the international multidisciplinary Ocean - Atmosphere - Sea Ice - Snowpack (OASIS) program we analyzed more than 500 terrestrial (melted) snow samples near Barrow, AK between February and April 2009 for light absorption, as well as H2O2 and inorganic anion concentrations. For light absorption in the photochemically active region (300-450 nm) of surface snows, H2O2 and NO3- make minor contributions (combined < 9% typically), while HUmic LIke Substances (HULIS) and unknown chromophores each account for approximately half of the total absorption. We have identified four main sources for our residual chromophores (i.e., species other than H2O2 or NO3-): (1) vegetation and organic debris impact mostly the lowest 20 cm of the snowpack, (2) marine inputs, which are identified by high Cl- and SO42- contents, (3) deposition of diamond dust to surface snow, and (4) gas-phase exchange between the atmosphere and surface snow layers. The snow surfaces, and accompanying chromophore concentrations, are strongly modulated by winds and snowfall at Barrow. However, even with these physical controls on light absorption, we see an overall decline of light absorption in near-surface snow during the 7 weeks of our campaign, likely due to photo-bleaching of chromophores. While HULIS and unknown chromophores dominate light absorption by soluble species in Barrow snow, we know little about the photochemistry of these species, and thus we as a community are probably overlooking many snowpack photochemical reactions.

  20. Serum antibody prevalence of malignant catarrhal fever viruses in seven wildlife species from Alaska.

    PubMed

    Zarnke, Randall L; Li, Hong; Crawford, Timothy B

    2002-07-01

    Blood samples were collected from seven species of free-ranging ungulates in Alaska. Sera were tested for evidence of exposure to malignant catarrhal fever viruses (MCFV) by means of a competitive enzyme-linked immunosorbent assay. Antibody prevalences were as follows: muskox (Ovibos moschatus) 100 positive samples of 104 tested (96%); Dall sheep (Ovis dalli) 212 of 222 (95%); elk (Cervus elaphus) 14 of 51 (27%); bison (Bison bison) 34 of 197 (17%); caribou (Rangifer tarandus) nine of 232 (4%); Sitka black-tailed deer (Odocoileus hemionus sitkensis) one of 49 (2%); and moose (Alces alces) three of 219 (1%). Antibody prevalence in a bison population from the Interior was stable over a 5 yr period. These results indicate that at least one virus in the MCF group is enzootic in Dall sheep and muskox in Alaska. Lower antibody prevalences in the other species in this survey suggest that MCFV are latent or subclinical in these free-ranging ruminants. Whole blood samples were collected from 14 Dall sheep and subjected to a polymerase chain reaction assay. Fragments of ovine herpesvirus-2 DNA were detected in six of the samples. The significance of these findings for the health of free-ranging ungulates in Alaska is unknown.

  1. Serum antibody prevalence of malignant catarrhal fever viruses in seven wildlife species from Alaska.

    PubMed

    Zarnke, Randall L; Li, Hong; Crawford, Timothy B

    2002-07-01

    Blood samples were collected from seven species of free-ranging ungulates in Alaska. Sera were tested for evidence of exposure to malignant catarrhal fever viruses (MCFV) by means of a competitive enzyme-linked immunosorbent assay. Antibody prevalences were as follows: muskox (Ovibos moschatus) 100 positive samples of 104 tested (96%); Dall sheep (Ovis dalli) 212 of 222 (95%); elk (Cervus elaphus) 14 of 51 (27%); bison (Bison bison) 34 of 197 (17%); caribou (Rangifer tarandus) nine of 232 (4%); Sitka black-tailed deer (Odocoileus hemionus sitkensis) one of 49 (2%); and moose (Alces alces) three of 219 (1%). Antibody prevalence in a bison population from the Interior was stable over a 5 yr period. These results indicate that at least one virus in the MCF group is enzootic in Dall sheep and muskox in Alaska. Lower antibody prevalences in the other species in this survey suggest that MCFV are latent or subclinical in these free-ranging ruminants. Whole blood samples were collected from 14 Dall sheep and subjected to a polymerase chain reaction assay. Fragments of ovine herpesvirus-2 DNA were detected in six of the samples. The significance of these findings for the health of free-ranging ungulates in Alaska is unknown. PMID:12238366

  2. Description of Caurinus tlagu, new species, from Prince of Wales Island, Alaska (Mecoptera, Boreidae, Caurininae)

    PubMed Central

    Sikes, Derek S.; Stockbridge, Jill

    2013-01-01

    Abstract A new species of the cryptic, minute, wingless, and enigmatic taxon Caurinus, and the second for the subfamily Caurininae,is described from Prince of Wales Island in the Alexander Archipelago, Alaska. It is distinguished from its only congener, Caurinus dectes Russell, 1979b, which occurs 1,059 km southeast in Oregon and Washington, based on external morphology and sequences of the mitochondrial gene cytochrome oxidase II. These two species are probably evolutionary relicts – the only known members of a clade dating to the Late Jurassic or older. PMID:23878513

  3. Tree Species Linked to Large Differences in Ecosystem Carbon Distribution in the Boreal Forest of Alaska

    NASA Astrophysics Data System (ADS)

    Melvin, A. M.; Mack, M. C.; Johnstone, J. F.; Schuur, E. A. G.; Genet, H.; McGuire, A. D.

    2014-12-01

    In the boreal forest of Alaska, increased fire severity associated with climate change is altering plant-soil-microbial feedbacks and ecosystem carbon (C) dynamics. The boreal landscape has historically been dominated by black spruce (Picea mariana), a tree species associated with slow C turnover and large soil organic matter (SOM) accumulation. Historically, low severity fires have led to black spruce regeneration post-fire, thereby maintaining slow C cycling rates and large SOM pools. In recent decades however, an increase in high severity fires has led to greater consumption of the soil organic layer (SOL) during fire and subsequent establishment of deciduous tree species in areas previously dominated by black spruce. This shift to a more deciduous dominated landscape has many implications for ecosystem structure and function, as well as feedbacks to global C cycling. To improve our understanding of how boreal tree species affect C cycling, we quantified above- and belowground C stocks and fluxes in adjacent, mid-successional stands of black spruce and Alaska paper birch (Betula neoalaskana) that established following a 1958 fire near Fairbanks, Alaska. Although total ecosystem C pools (aboveground live tree biomass + dead wood + SOL + top 10 cm of mineral soil) were similar for the two stand types, the distribution of C among pools was markedly different. In black spruce, 78% of measured C was found in soil pools, primarily in the SOL, where spruce contained twice the C stored in paper birch (4.8 ± 0.3 vs. 2.4 ± 0.1 kg C m-2). In contrast, aboveground biomass dominated ecosystem C pools in birch forest (6.0 ± 0.3 vs. 2.5 ± 0.2 kg C m-2 in birch and spruce, respectively). Our findings suggest that tree species exert a strong influence over plant-soil-microbial feedbacks and may have long-term effects on ecosystem C sequestration and storage that feedback to the climate system.

  4. New species of sponges (Porifera, Demospongiae) from the Aleutian Islands and Gulf of Alaska.

    PubMed

    Lehnert, Helmut; Stone, Robert P

    2015-10-27

    Ten new species of demosponges, assigned to the orders Poecilosclerida, Axinellida and Dictyoceratida, discovered in the Gulf of Alaska and along the Aleutian Island Archipelago are described and compared to relevant congeners. Poecilosclerida include Cornulum globosum n. sp., Megaciella lobata n. sp., M. triangulata n. sp., Artemisina clavata n. sp., A. flabellata n. sp., Coelosphaera (Histodermion) kigushimkada n. sp., Stelodoryx mucosa n. sp. and S. siphofuscus n. sp. Axinellida is represented by Raspailia (Hymeraphiopsis) fruticosa n. sp. and Dictyoceratida is represented by Dysidea kenkriegeri n. sp. The genus Cornulum is modified to allow for smooth tylotes. We report several noteworthy biogeographical observations. We describe only the third species within the subgenus Histodermion and the first from the Indo-Pacific Region. Additionally, the subgenus Hymerhaphiopsis was previously represented by only a single species from Antarctica. We also report the first record of a dictyoceratid species from Alaska. The new collections further highlight the richness of the sponge fauna from the region, particularly for the Poecilosclerida.

  5. New species of sponges (Porifera, Demospongiae) from the Aleutian Islands and Gulf of Alaska.

    PubMed

    Lehnert, Helmut; Stone, Robert P

    2015-01-01

    Ten new species of demosponges, assigned to the orders Poecilosclerida, Axinellida and Dictyoceratida, discovered in the Gulf of Alaska and along the Aleutian Island Archipelago are described and compared to relevant congeners. Poecilosclerida include Cornulum globosum n. sp., Megaciella lobata n. sp., M. triangulata n. sp., Artemisina clavata n. sp., A. flabellata n. sp., Coelosphaera (Histodermion) kigushimkada n. sp., Stelodoryx mucosa n. sp. and S. siphofuscus n. sp. Axinellida is represented by Raspailia (Hymeraphiopsis) fruticosa n. sp. and Dictyoceratida is represented by Dysidea kenkriegeri n. sp. The genus Cornulum is modified to allow for smooth tylotes. We report several noteworthy biogeographical observations. We describe only the third species within the subgenus Histodermion and the first from the Indo-Pacific Region. Additionally, the subgenus Hymerhaphiopsis was previously represented by only a single species from Antarctica. We also report the first record of a dictyoceratid species from Alaska. The new collections further highlight the richness of the sponge fauna from the region, particularly for the Poecilosclerida. PMID:26624419

  6. Combining High Temporal Resolution Gas Composition and Seismic Data to Identify Subsurface Fluid Movement within the Katmai Volcanic Complex, Alaska

    NASA Astrophysics Data System (ADS)

    Lopez, T. M.; West, M. E.; Aiuppa, A.; Holtkamp, S. G.; Giudice, G.; Whittaker, S.; Capecchiacci, F.; Ketner, D. M.; Tassi, F.; Paskievitch, J.; Chiodini, G.; Fiebig, J.; Rizzo, A. L.; Caliro, S.

    2015-12-01

    Volcano seismicity is often attributed to subsurface fluid movement; however the type of fluid (i.e. magma, volatiles, or hydrothermal waters) cannot be uniquely identified using seismic data alone. The chemical composition of volcanic gases released from active volcanoes can be used to distinguish magmatic from hydrothermal degassing, and to identify magma recharge from depth. In this project we use complementary geochemical and seismic datasets from three hydrothermally and seismically active volcanoes within the Katmai Volcanic Cluster, Alaska, in an effort to constrain seismic signatures of subsurface fluid movement. We combine new data collected in July and August 2013 from Mount Martin Volcano, with previously presented gas and seismic data from the nearby volcanoes of Mount Mageik and Trident. High temporal resolution (~1 Hz) major-species (e.g. H2O, CO2, SO2, H2S) gas composition measurements were collected over four ~30 minute sample periods each day for 2-4 week periods from the target volcanoes using campaign MultiGas instruments located adjacent to the primary degassing sources. These instruments were complemented by co-located broadband seismometers on the crater rims of Mount Martin and Mount Mageik, as well as by the Alaska Volcano Observatory Katmai seismic network, which consists of nine short-period and two broadband seismometers located within 30 km of the target volcanoes. Here we apply template-matching techniques to identify repeating earthquakes, and compare changes in shallow seismicity with changes in gas composition. Preliminary results from Trident suggest a potential link between an ~5 day SO2 gas pulse, presumed to reflect magma degassing, and shallow repeating earthquakes. In this study, we present analysis of ~4 weeks of new gas and seismic data from Mount Martin and expand on the analyses at Trident in an effort to provide robust correlations between potential geochemical and geophysical signals of subsurface fluid movement.

  7. The Post-Glacial Species Velocity of Picea glauca following the Last Glacial Maximum in Alaska.

    NASA Astrophysics Data System (ADS)

    Morrison, B. D.; Napier, J.; Kelly, R.; Li, B.; Heath, K.; Hug, B.; Hu, F.; Greenberg, J. A.

    2015-12-01

    Anthropogenic climate change is leading to dramatic fluctuations to Earth's biodiversity that has not been observed since past interglacial periods. There is rising concern that Earth's warming climate will have significant impacts to current species ranges and the ability of a species to persist in a rapidly changing environment. The paleorecord provides information on past species distributions in relation to climate change, which can illuminate the patterns of potential future distributions of species. Particularly in areas where there are multiple potential limiting factors on a species' range, e.g. temperature, radiation, and evaporative demand, the spatial patterns of species migrations may be particularly complex. In this study, we assessed the change in the distributions of white spruce (Picea glauca) from the Last Glacial Maxima (LGM) to present-day for the entire state of Alaska. To accomplish this, we created species distribution models (SDMs) calibrated from modern vegetation data and high-resolution, downscaled climate surfaces at 60m. These SDMs were applied to downscaled modern and paleoclimate surfaces to produce estimated ranges of white spruce during the LGM and today. From this, we assessed the "species velocity", the rate at which white spruce would need to migrate to keep pace with climate change, with the goal of determining whether the expansion from the LGM to today originated from microclimate refugia. Higher species velocities indicate locations where climate changed drastically and white spruce would have needed to migrate rapidly to persist and avoid local extinction. Conversely, lower species velocities indicated locations where the local climate was changing less rapidly or was within the center of the range of white spruce, and indicated locations where white spruce distributions were unlikely to have changed significantly. Our results indicate the importance of topographic complexity in buffering the effects of climate change

  8. Stratigraphic and compositional complexities of the late Quaternary Lethe tephra in South-central Alaska

    USGS Publications Warehouse

    Riehle, J.R.; Ager, T.A.; Reger, R.D.; Pinney, D.S.; Kaufman, D.S.

    2008-01-01

    Recently discovered Lethe tephra has been proposed as a latest Pleistocene marker bed in Bristol Bay lowland NE to the Cook Inlet region, Alaska, on the basis of correlations involving a single "Lethe average" glass composition. Type deposits in the Valley of Ten Thousand Smokes, however, are chemically heterogeneous-individual lapilli as well as aggregate ash deposits have glass compositions that range from the average mode to much higher SiO2 and K2O. Moreover, a lake-sediment core from the Cook Inlet region contains one ash deposit similar to "Lethe average" and other, closely underlying deposits that resemble a mixture of the average mode and high-Si high-K mode of proximal deposits. Synthesis of previously published radiocarbon ages indicates a major eruption mainly of "Lethe average" mode about 13,000 14C yr BP. As many as six deposits in the Cook Inlet region-five chiefly "Lethe average" mode-range from about 13,000 to 15-16,000 14C yr BP, and an early Holocene deposit in the Bristol Bay lowland extends the minimum age range of Lethe tephra throughout this region to 8000 14C yr BP. Because of the appearance of "Lethe average" composition in multiple deposits spanning thousands of years, we urge caution when using a Lethe-like composition as a basis for inferring a latest Pleistocene age of a tephra deposit in south-central Alaska. Linear variation plots suggest that magma mixing caused the Lethe heterogeneity; multiple magmas were involved as well in other large pyroclastic eruptions such as Katmai (Alaska) and Rotorua (New Zealand). Lethe is an example of a heterogeneous tephra that may be better compared with other tephras by use of plots of individual analytical points rather than by calculating similarity coefficients based on edited data. ?? 2006 Elsevier Ltd and INQUA.

  9. Compositional Analysis of Fine Particulate Matter in Fairbanks, Alaska

    NASA Astrophysics Data System (ADS)

    Nattinger, K.; Simpson, W. R.; Huff, D.

    2015-12-01

    Fairbanks, AK experiences extreme pollution episodes that result in winter violations of the fine particulate matter (PM2.5) National Ambient Air Quality Standards. This poses a significant health risk for the inhabitants of the area. These high levels result from trapping of pollution in a very shallow boundary layer due to local meteorology, but the role of primary (direct emission) of particulate matter versus secondary production (in the atmosphere) of particulate matter is not understood. Analysis of the PM2.5 composition is being conducted to provide insight into sources, trends, and chemistry. Methods are developed to convert carbon data from IMPROVE (post-2009 analysis method) to NIOSH (pre-2009 method) utilizing blank subtraction, sampler bias adjustment, and inter-method correlations from co-located samples. By converting all carbon measurements to a consistent basis, long-term trends can be analyzed. The approach shows excellent mass closure between PM2.5 mass reconstructed from constituents and gravimetric-analyzed mass. This approach could be utilized in other US locations where the carbon analysis methods also changed. Results include organic and inorganic fractional mass percentages, analyzed over an eight-year period for two testing sites in Fairbanks and two in the nearby city of North Pole. We focus on the wintertime (Nov—Feb) period when most air quality violations occur and find that the particles consist primarily of organic carbon, with smaller percentages of sulfate, elemental carbon, ammonium, and nitrate. The Fairbanks area PM2.5 organic carbon / elemental carbon partitioning matches the source profile of wood smoke. North Pole and Fairbanks PM2.5 have significant compositional differences, with North Pole having a larger percentage of organic matter. Mass loadings in SO42-, NO3-, and total PM2.5 mass correlate with temperature. Multi-year temporal trends show little if any change with a strong effect from temperature. Insights from this

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

    USGS Publications Warehouse

    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.

  11. A comprehensive inventory of the Gulf of Alaska sponge fauna with the description of two new species and geographic range extensions.

    PubMed

    Lehnert, Helmut; Stone, Robert P

    2016-01-01

    Two new species, Hamacantha (Vomerula) cassanoi n. sp. and Prosuberites salgadoi n. sp., are described from the eastern Gulf of Alaska in the North Pacific Ocean. These are the first records of the genera Hamacantha and Prosuberites from Alaska. We also report two geographic range extensions for the region. Geodia japonica Sollas, 1888 was previously known only from Japan and is now recorded from the Gulf of Alaska. We also document the first record of Rhizaxinella cervicornis Thiele, 1898 from the Gulf of Alaska. Our comprehensive inventory of the sponge fauna of the Gulf of Alaska confirms the presence of 52 taxa with an additional 38 taxa suspected of occurring in the region. This is a much lower number of species than that recorded from neighbouring regions like the Aleutian Islands and British Columbia. PMID:27470862

  12. Storage and interaction of compositionally heterogeneous magmas from the 1986 eruption of Augustine Volcano, Alaska

    USGS Publications Warehouse

    Roman, D.C.; Cashman, K.V.; Gardner, C.A.; Wallace, P.J.; Donovan, J.J.

    2006-01-01

    Compositional heterogeneity (56-64 wt% SiO2 whole-rock) in samples of tephra and lava from the 1986 eruption of Augustine Volcano, Alaska, raises questions about the physical nature of magma storage and interaction beneath this young and frequently active volcano. To determine conditions of magma storage and evolutionary histories of compositionally distinct magmas, we investigate physical and chemical characteristics of andesitic and dacitic magmas feeding the 1986 eruption. We calculate equilibrium temperatures and oxygen fugacities from Fe-Ti oxide compositions and find a continuous range in temperature from 877 to 947??C and high oxygen fugacities (??NNO=1-2) for all magmas. Melt inclusions in pyroxene phenocrysts analyzed by Fourier-transform infrared spectroscopy and electron probe microanalysis are dacitic to rhyolitic and have water contents ranging from <1 to ???7 wt%. Matrix glass compositions are rhyolitic and remarkably similar (???75.9-76.6 wt% SiO2) in all samples. All samples have ???25% phenocrysts, but lower-silica samples have much higher microlite contents than higher-silica samples. Continuous ranges in temperature and whole-rock composition, as well as linear trends in Harker diagrams and disequilibrium mineral textures, indicate that the 1986 magmas are the product of mixing between dacitic magma and a hotter, more mafic magma. The dacitic endmember is probably residual magma from the previous (1976) eruption of Augustine, and we interpret the mafic endmember to have been intruded from depth. Mixing appears to have continued as magmas ascended towards the vent. We suggest that the physical structure of the magma storage system beneath Augustine contributed to the sustained compositional heterogeneity of this eruption, which is best explained by magma storage and interaction in a vertically extensive system of interconnected dikes rather than a single coherent magma chamber and/or conduit. The typically short repose period (???10 years) between

  13. A new genus and species of Thyasiridae (Mollusca, Bivalvia) from deep-water, Beaufort Sea, northern Alaska.

    PubMed

    Valentich-Scott, Paul; Powell, Charles L; Ii; Lorenson, Thomas D; Edwards, Brian E

    2014-01-01

    Bivalve mollusk shells were collected in 2350 m depth in the Beaufort Sea, Arctic Ocean off northern Alaska. Initial identification suggested the specimens were a member of the bivalve family Thyasiridae, but no known eastern Pacific or Arctic living or fossil thyasirid resembled these deep-water specimens. Comparisons were made with the type of the genera Maorithyas Fleming, 1950, Spinaxinus Oliver & Holmes, 2006, Axinus Sowerby, 1821, and Parathyasira Iredale, 1930. We determined the Beaufort Sea species represents a new genus, herein described as Wallerconcha. These specimens also represent a new species, herein named Wallerconchasarae. These new taxa are compared with known modern and fossil genera and species of thyasirds.

  14. Petrology, composition, and age of intrusive rocks associated with the Quartz Hill molybdenite deposit, southeastern Alaska.

    USGS Publications Warehouse

    Hudson, T.; Smith, James G.; Elliott, R.L.

    1979-01-01

    A large porphyry molybdenum deposit (Quartz Hill deposit) was recently discovered in the heart of the Coast Range batholithic complex about 70 km E of Ketchikan, SE Alaska. Intrusive rocks associated with the mineral deposit form two composite epizonal to hypabyssal stocks and many dikes in country rocks. All observed metallization and alteration is within the Quartz Hill stock. Molybdenite forms fracture coatings and occurs in veins with quartz. Alteration is widespread and includes development of secondary quartz, pyrite, K-feldspar, biotite, white mica, chlorite, and zeolite. Field relations indicate that the stocks were emplaced after regional uplift and erosion of the Coast Range batholithic complex, and K-Ar data show that intrusion and alteration took place in late Oligocene time, about 27 to 30 Ma ago. Data from the Ketchikan quadrangle indicate that porphyry molybdenum metallization in the Coast Range batholithic complex is associated with regionally extensive but spotty, middle Tertiary or younger, felsic magmatism. -from Authors

  15. Acanthocephalans in northern fur seals (Callorhinus ursinus) and a harbor seal (Phoca vitulina) on St. Paul Island, Alaska: species, prevalence, and biodiversity in four fur seal subpopulations.

    PubMed

    Kuzmina, T A; Lisitsyna, O I; Lyons, E T; Spraker, T R; Tolliver, S C

    2012-09-01

    Monitoring studies of acanthocephalans in northern fur seals (Callorhinus ursinus Linnaeus, 1758) (NFSs) and a harbor seal (Phoca vitulina Linnaeus, 1758) were performed on St. Paul Island, Alaska, in July-August 2011. Gastrointestinal tracts of 105 humanely harvested NFS subadult males (SAMs) (3-4 years old) were collected during the annual Aleut subsistence harvest at four haul-out areas (HOAS): Lukanin (n = 26 NFSs), Polovina (n = 28), Gorbatch (n = 30), and Morzhovyi (n = 21). One gastrointestinal tract collected from a harbor seal (about 3-4 years old) found dead at Morzhovyi HOAS was also examined. The total prevalence of infection in NFSs with acanthocephalans was 29.52 % with variations from 7.69 % to 47.62 % between the four different HOAS. Eight acanthocephalan species of two genera-Corynosoma Lühe, 1904 (Corynosoma strumosum, Corynosoma alaskensis, Corynosoma cameroni, Corynosoma semerme, Corynosoma similis, Corynosoma validum, and Corynosoma villosum), and Bolbosoma Porta, 1908 (Bolbosoma nipponicum)-were found in the NFSs and a harbor seal. This is a new record of C. alaskensis for the NFSs. Short biological notes of the species found are presented. Differences in species composition as well as in prevalence of acanthocephalans parasitizing NFSs were observed in subpopulations from four different HOAS on St. Paul Island. The highest biodiversity of acanthocephalans and infection were found in subpopulations on Polovina and Morzhovyj HOAS, the lowest was on Lukanin HOAS. From 3.2 % (for C. validum) to 19.4 % (for C. villosum) of NFSs were infected by one acanthocephalan species; two species were found in 22.6 %; three in 9.7 %; and four in 3.2 %. Further studies of NFS parasites are necessary to follow the trends in parasitic infection rates and diversity in NFS population on the Pribilov Islands and for monitoring the influence of various ecological factors on NFS populations in Alaska.

  16. Examining mechanisms in the final stages of the elimination of boreal tree species on vulnerable sites in boreal Alaska

    NASA Astrophysics Data System (ADS)

    Juday, G. P.; Jess, R.; Alix, C. M.; Verbyla, D.

    2015-12-01

    The boreal forest of Alaska and western Canada exist in a complex mosaic of environments determined by elevation, aspect of exposure, and longitudinal and latitudinal gradients of change from warm, dry continental to maritime-influenced conditions. This forest region is largely made up of trees with two growth responses to temperature increases. Trees that decrease in growth are termed negative responders, and occupy warm, dry sites at low elevations. Trees that increase in radial growth are termed positive responders, and are largely in western Alaska, and at high elevation of the Brooks and Alaska Ranges. Since the Pacific climate regime shift of the 1970s, mature trees at low elevation sites have experienced increasing climate stress in several quasi-decadal cycles of intensifying drought stress. NDVI trends and tree ring records demonstrating radial growth decline are coherent. Phenological monitoring of spruce height growth also indicates that depletion of spring soil moisture is a critical process driven by the interaction of early warm season temperatures and precipitation. Novel biotic disturbance agents including spruce budworm, outbreaks of which are triggered by warm temperature anomalies related to its biology, and aspen leaf miner are depressing realized growth below climatically predicted levels, suggesting a pathway by which tree death is likely to occur before absolute temperature limits. As a result, insect outbreaks are degrading the otherwise strong long-term climate signal in Alaska boreal trees. However, young tree (> 40 yrs.) regeneration generally does not yet display the symptoms of acute high temperature stress. Overall, on these vulnerable sites, if temperature increases similar to the past 40 years continue, long term survival prospects are questionable because the climate conditions would be outside the limits that have historically defined the species ranges of aspen, Alaska birch, and black and white spruce.

  17. Composition of the Haines and Klukwan zoned ultramafic complexes, southeastern Alaska

    SciTech Connect

    Burns, L.E. ); Newberry, R.J. . Dept. Geology)

    1993-04-01

    Zoned ultramafic complexes in southeastern Alaska have particular compositional characteristics, both major and mineral composition, that allows differentiation of these ultramafic rocks from ophiolitic rocks. The Haines and Klukwan ultramafic bodies fit these distinctive compositional trends. Major oxide differentiation between suites is based on TiO[sub 2], Al[sub 2]O[sub 3], CaO, and MgO. Mineral compositions can be distinguished by Al[sub 2]O[sub 3]-MgO contents of cpx. Haines and Klukwan bodies are fairly evolved for zoned complexes and consist of clinopyroxenite, magnetite clinopyroxenite, and hornblendite. Cpx compositions show that the rocks fit the same trend as the ultramafic sills adjacent to the Treadwell Au mine near Juneau. The Haines and Klukwan bodies consist of multiple generations of dikes and metasomatic veining. Due to the abundant diking by hornblende gabbro, fine-grained clinopyroxenite, and hornblendite, only remnants of the early-formed, coarse-grained clinopyroxenites are exposed in the Haines body. Klukwan contains more coarse-grained clinopyroxenites. Haines and Klukwan also differ in that Klukwan contains abundant magnetite, while Haines contains more biotite. The analyses suggest that the rocks intruded at moderate pressure, possibly from an alkalic magma, and that at least part of the Haines ultramafic is slightly more differentiated, and probably more alkalic/lower fO[sub 2] than the Klukwan body. Roof pendants 1 km sq of ultramafic rocks in younger plutons north of Klukwan indicate many more small bodies associated with zoned ultramafic complexes are probably present in southeast. The authors that these bodies are sills or laccoliths above Duke Island type bodies.

  18. Calibration, Compositing, and Classification of Landsat Datasets and High-Resolution Imagery in Arctic Alaska

    NASA Astrophysics Data System (ADS)

    Macander, M. J.; Frost, G. V., Jr.

    2014-12-01

    Providing calibrated, cloud-free, and phenologically consistent satellite basemaps at moderate (~30 m) and high resolution (≤2 m) is critical to the mapping of arctic tundra vegetation and landscape attributes across large study areas. We obtained ground cover (n = 107) and field spectra (n = 28) data for tundra vegetation across a network of field plots in a ~100,000 km2 study area spanning the foothills and coastal plain ecoregions of Alaska's North Slope. Calibration and atmospheric correction of Landsat TM, ETM+ and OLI, WorldView-2, and GeoEye-1 imagery were performed and we compared results across sensors and with ground spectra. For the Landsat imagery, we produced consistent basemaps using compositing approaches that focused on capturing central tendencies from multiple years of imagery within narrow phenological windows (e.g., green-up, peak growth, fall senescence). We leveraged information from the full 1985-2014 time series to optimize compositing year ranges to prevent bias due to directional changes (e.g., shrubification), and "step-changes" (e.g., tundra fire, lake drainage, ice-wedge degradation) in vegetation and landscape characteristics over the Landsat era. Finally, we explored automated classification of the calibrated Landsat and high-resolution imagery using the spectral rule-based classifier Satellite Image Automatic Mapper (SIAM).

  19. The Composition of Individual Aerosol Particles over the North Slope of Alaska during ISDAC

    NASA Astrophysics Data System (ADS)

    Zelenyuk, A.; Imre, D.; Liu, P.; MacDonald, A.; Leaitch, R.

    2008-12-01

    During the month of April 2008 a single particle mass spectrometer, SPLAT II, was deployed on board the Canadian National Research Council Convair 580 aircraft for participation in the Indirect and Semi-Direct Aerosol Campaign (ISDAC). ISDAC's main scientific objective was to improve our understanding of the relationship between the properties of aerosol particles over the North Pole and their impact on the regional climate. During ISDAC SPLAT II participated in all 27 flights that lasted slightly over 100 hrs. It measured the size of more than 10 million particles and characterized the composition of over 3 million of them. When sampling in clear air SPLAT II measured a wide range of particle compositions, including sulfates mixed with organics, nitrates mixed with organic, processed and freshly emitted sea-salt, a few dust particles, and a significant number of biomass burning particles. Many of these particle types appeared in aerosol layers that had horizontal and vertical filamentous structures. Biomass burning particles, many of which were transported from Asia, were rather prevalent over the North Slope of Alaska during the campaign. Since one of the main goals of this campaign was to characterize cloud properties, large fraction of the data was collected through the CVI inlet. The ice-clouds sampled in ISDAC had typically very low ice crystal concentrations; correspondingly, when sampled through the CVI inlet the number of characterized particles drops precipitously. Despite the low number concentrations SPLAT was able to measure the size and composition of thousands of ice-nuclei. Since the CVI inlet transmits, in addition to ice crystals, liquid droplets, SPLAT was able to characterize a large number of particles that served as cloud condensation nuclei as well. We will present a preliminary analysis of the single particle data collected during this campaign.

  20. Seasonal variability in the composition of dissolved organic matter in the Yukon River, Alaska

    NASA Astrophysics Data System (ADS)

    Aiken, G.; Cao, X.; Mao, J.; Stubbins, A.; Schmidt-Rohr, K.; Spencer, R. G.

    2015-12-01

    Modern analytical approaches allow for detailed characterization of the composition of dissolved organic matter (DOM) in aquatic systems. The utility of advanced FTICR-MS and 13C-NMR approaches is presented for assessing the seasonal variability in DOM composition for samples collected across the hydrograph (2008 and 2009) from the Yukon River at Pilot Station, Alaska. FTICR-MS analyses were obtained on whole water samples while one- and two-dimensional solid-state NMR analyses were performed on the hydrophobic organic acid (HPOA) and transphilic organic acid (TPIA) fractions obtained using XAD resins (accounting for 64-74% of the DOM). Both approaches indicated that lignin-derived and carboxyl-rich alicyclic molecules (CRAM) were major fractions of all samples collected throughout the year, and that contributions from black carbon were minor. Each approach also provided unique information. FTICR-MS indicated the presence in spring of compounds containing sulfur that previously were identified to be atmospherically deposited combustion products in glacial meltwaters. These likely were deposited with snowfall. NMR analyses indicated that HPOA isolates from the spring period were characterized by greater contributions from lignin residues and carbohydrate-like materials than those from summer-autumn and winter. In addition, the spring TPIA samples had a predominance of carbohydrate, which was much less evident in the structures of summer-autumn and winter TPIA isolates. Spring DOM, therefore, was representative of inputs from freshly leached plant materials. These relatively fresh organic materials were depleted in summer-fall and winter samples, indicating that summer-fall and especially winter DOM was associated with more extensively degraded DOM and older DOM pools. These results provide chemical evidence supporting observations that spring freshet DOM in Arctic rivers is more biolabile than DOM exported at other times of the year.

  1. A new genus and species of Thyasiridae (Mollusca, Bivalvia) from deep-water, Beaufort Sea, northern Alaska

    PubMed Central

    Valentich-Scott, Paul; Powell, Charles L.; II; Lorenson, Thomas D.; Edwards, Brian E.

    2014-01-01

    Abstract Bivalve mollusk shells were collected in 2350 m depth in the Beaufort Sea, Arctic Ocean off northern Alaska. Initial identification suggested the specimens were a member of the bivalve family Thyasiridae, but no known eastern Pacific or Arctic living or fossil thyasirid resembled these deep-water specimens. Comparisons were made with the type of the genera Maorithyas Fleming, 1950, Spinaxinus Oliver & Holmes, 2006, Axinus Sowerby, 1821, and Parathyasira Iredale, 1930. We determined the Beaufort Sea species represents a new genus, herein described as Wallerconcha. These specimens also represent a new species, herein named Wallerconcha sarae. These new taxa are compared with known modern and fossil genera and species of thyasirds. PMID:25589851

  2. Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America - Alaska Species and Ecoregions

    USGS Publications Warehouse

    Thompson, Robert S.; Anderson, Katherine H.; Strickland, Laura E.; Shafer, Sarah L.; Pelltier, Richard T.; Bartlein, Patrick J.

    2006-01-01

    Climate is the primary factor in controlling the continental-scale distribution of plant species, although the relations between climatic parameters and species' ranges is only now beginning to be quantified. Preceding volumes of this atlas explored the continental-scale relations between climatic parameters and the distributions of woody plant species across all of the continent of North America. This volume presents similar information for important woody species, groups of species, and ecoregions in more detail for the State of Alaska. For these analyses, we constructed a 25-kilometer equal-area grid of modern climatic and bioclimatic parameters for North America from instrumental weather records. We obtained a digital representation of the geographic distribution of each species or ecoregion, either from a published source or by digitizing the published distributions ourselves. The presence or absence of each species or ecoregion was then determined for each point on the 25-kilometer grid, thus providing a basis for comparison of the climatic data with the geographic distribution of each species or ecoregion. The relations between climate and these distributions are presented in graphical and tabular form.

  3. Early life history pelagic exposure profiles of selected commercially important fish species in the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Doyle, Miriam J.; Mier, Kathryn L.

    2016-10-01

    A synthesis of nearly four decades of ichthyoplankton survey data from the Gulf of Alaska was undertaken to provide the most comprehensive information available on the early life history ecology of five focal species: Pacific Cod (Gadus macrocephalus), Walleye Pollock (Gadus chalcogrammus), Pacific Ocean Perch (Sebastes alutus), Sablefish (Anoplopoma fimbria), and Arrowtooth Flounder (Atheresthes stomias). This analysis of historical data, along with information from published studies, is presented here in the form of ecological reviews of the species during their planktonic phase. The reviews include descriptions of temporal and spatial patterns of exposure to the environment, and interpretation regarding associated sensitivities to environmental forcing. On a temporal scale, patterns in abundance of eggs and larvae are synthesized that characterize seasonal exposure to the pelagic environment, and interannual variation that is presumed to incorporate responses to long-term environmental forcing. Spatial patterns are synthesized to identify horizontal and vertical extent of egg and larval distributions, delineate areas of primary larval habitat, and illuminate egg and larval drift pathways. The observed patterns are discussed with respect to characterizing species early life history strategies, identifying long-term adaptations to the Gulf of Alaska environment, and associated resilience and vulnerability factors that may modulate early life responses to environmental forcing in this region. For each species, gaps in knowledge are identified and are concerned primarily with the period of transition between the larval and juvenile stage, and feeding habits and ecology across seasons, habitats and sub-intervals of early ontogeny. These early life history reviews advance our ecological understanding of the pelagic phase, and fine-tune our focus for the investigation of potential response mechanisms to environmental forcing at appropriate, species-specific temporal

  4. Unexpectedly high diversity of Monoporella (Bryozoa: Cheilostomata) in the Aleutian Islands, Alaska: taxonomy and distribution of six new species.

    PubMed

    Dick, Matthew H

    2008-01-01

    The cheilostome bryozoan genus Monoporella is poorly resolved taxonomically; only four Recent species have been formally described, though several undescribed species have been reported in the literature. The literature indicates no more than five species in the genus occurring in any local region of the world, with one to three species in most regions where the genus has been reported. I examined bryozoans from 52 trawl catches in the western and western-central Aleutian Islands, Alaska, and found specimens of Monoporella in 12 of these samples. Study of these specimens by scanning electron microscopy (SEM) revealed six new species that are described herein: M. flexibila, M. elongata, M. gigantea, M. ellefsoni, M. seastormi, and M. aleutica. Two of the species have erect colony morphologies, a condition not previously reported in Monoporella. The species diversity of Monoporella appears to be greater in the Aleutians than in any other part of the world adequately surveyed. I discuss whether this apparent high diversity is an artifact due to insufficient sampling in the deep shelf zone, and present two hypotheses to explain this high diversity should it prove not to be an artifact: 1) the present high local diversity represents a relict of past high diversity occurring broadly around the North Pacific rim; and 2) a local radiation of Monoporella occurred in the Aleutian archipelago.

  5. Interannual variability in species composition explained as seasonally entrained chaos

    PubMed Central

    Dakos, Vasilis; Benincà, Elisa; van Nes, Egbert H.; Philippart, Catharina J. M.; Scheffer, Marten; Huisman, Jef

    2009-01-01

    The species composition of plankton, insect and annual plant communities may vary markedly from year to year. Such interannual variability is usually thought to be driven by year-to-year variation in weather conditions. Here we examine an alternative explanation. We studied the effects of regular seasonal forcing on a multi-species predator–prey model consisting of phytoplankton and zooplankton species. The model predicts that interannual variability in species composition can easily arise without interannual variability in external conditions. Seasonal forcing increased the probability of chaos in our model communities, but squeezed these irregular species dynamics within the seasonal cycle. As a result, the population dynamics had a peculiar character. Consistent with long-term time series of natural plankton communities, seasonal variation led to a distinct seasonal succession of species, yet the species composition varied from year to year in an irregular fashion. Our results suggest that interannual variability in species composition is an intrinsic property of multi-species communities in seasonal environments. PMID:19474038

  6. Critical fishery species in Alaska offshore oil and gas lease areas

    SciTech Connect

    Arbegast, J.; Allen, M.

    1980-11-01

    Offshore oil and gas development in Alaska is governed through sales of lease blocks within a designated lease area. The Department of the Interior through the Bureau of Land Management (BLM) manages these sales and prepares the necessary Environmental Impact Statement prior to each sale. BLM and the National Oceanic and Atmospheric Administration (NOAA) are involved in the Outer Continental Shelf Environmental Assessment Program (OCSEAP). OCSEAP was initiated by BLM to help assess the impact of outer continental shelf oil and gas development on the environment.

  7. Comparative fatty acid composition of four Sargassum species (Fucales, Phaeophyta)

    NASA Astrophysics Data System (ADS)

    Wu, Xiang-Chun; Lu, Bao-Ren; Tseng, C. K.

    1995-12-01

    Fatty acid composition of four Sargassum species from Qingdao and Shidao, Shandong Province was investigated. 16:0 (palmitic acid) was the major saturated fatty acid. C18 and C20 were the main polyunsaturated fatty acids (PUFAs). Arachidonic acid and eicosapentaenoic acid predominated among polyenoic acids in all the algal species examined, except for Sargassum sp. which had low concentration of eicosapentaenoic acid.

  8. Chemical composition of various Ephedra species

    PubMed Central

    Ibragic, Saida; Sofić, Emin

    2015-01-01

    The medicinal significance of Ephedra is based on the sympathomimetic properties of ephedrine (E) alkaloids. Pharmacological effects depend on the phytocomposition of individual Ephedra species. The aim of this study was to measure the total alkaloids content (TAC), total phenolics content (TPC), and total flavonoids content (TFC) and determine their relationship in dry herb of Ephedra major, Ephedra distachya subsp. helvetica, Ephedra monosperma, Ephedra fragilis, Ephedra foeminea, Ephedra alata, Ephedra altissima and Ephedra foliata. Nowadays, medicinal use of Ephedrae herba is limited, but the abuse of its psychostimulants is rising. In this study, TAC, TPC and TFC were determined using spectrophotometric methods. For the first time, ultra-performance liquid chromatography with ultraviolet detection (UPLC-UV) was used for separation and quantification of E-type alkaloids of various Ephedra species. The highest TPC and TFC were found in E. alata (53.3 ± 0.1 mg Gallic acid equivalents/g dry weight, 2.8 mg quercetin equivalents/g dry weight, respectively). The total content of E and pseudoephedrine determined by UPLC-UV varied between 20.8 mg/g dry weight (E. distachya subsp. helvetica) and 34.7 mg/g dry weight (E. monosperma). The variable content and ratio between secondary metabolites determined in different Ephedra species reflects their metabolic activities. Utilization of UPLC-UV unveiled that this technique is sensitive, selective, and useful for separation and quantification of different alkaloids in complex biological matrixes. The limit of detection was 5 ng. Application of UPLC-UV can be recommended in quick analyses of E-type alkaloids in forensic medicine and quality control of pharmaceutical preparations. PMID:26295290

  9. Occurrence and genotypic analysis of Trichinella species in Alaska marine-associated mammals of the Bering and Chukchi seas.

    PubMed

    Seymour, J; Horstmann-Dehn, L; Rosa, C; Lopez, J A

    2014-02-24

    The zoonotic parasite Trichinella is the causative agent of trichinellosis outbreaks in the circumpolar Arctic. Subsistence communities are particularly prone to trichinellosis due to traditional meat preparation methods and regional presence of a freeze-tolerant Trichinella species (Trichinella nativa). This study is the first application of a validated artificial digestion method in determining incidence of Trichinella sp. in Alaskan mammals. Infection incidence in pinniped species (Erignathus barbatus, Eumetopias jubatus, Odobenus rosmarus divergens, and Pusa hispida) was low, with only 1/57 ringed seals infected. Polymerase Chain Reaction assays indicate T. nativa as the only species present in northern Alaska. Analysis of an archived polar bear (Ursus maritimus) muscle sample shows freeze-tolerance and longevity for T. nativa to -20°C for 10 years and short-term freeze resistance to -80°C when morphology was used to determine presence of live larvae. However, larval motility suggests 0% survival. An approach that combines artificial digestion with PCR based species identification has excellent potential for Trichinella sp. detection and identification of archived tissues. Overall, Trichinella in Alaskan mammals, particularly marine mammals of subsistence importance, appears to be a minor problem. These modern diagnostic techniques provide accurate insight into the presence of Trichinella in the Alaskan marine environment. PMID:24373515

  10. Estimating Forest Species Composition Using a Multi-Sensor Approach

    NASA Astrophysics Data System (ADS)

    Wolter, P. T.

    2009-12-01

    The magnitude, duration, and frequency of forest disturbance caused by the spruce budworm and forest tent caterpillar has 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 the increase in dominance of host tree species. Modeling approaches are currently being used to understand and forecast potential management effects in changing insect disturbance trends. However, detailed forest composition data needed for these efforts is often lacking. Here, we used partial least squares (PLS) regression to integrate satellite sensor data from Landsat, Radarsat-1, and PALSAR, as well as pixel-wise forest structure information derived from SPOT-5 sensor data (Wolter et al. 2009), to estimate species-level forest composition of 12 species required for modeling efforts. C-band Radarsat-1 data and L-band PALSAR data were frequently among the strongest predictors of forest composition. Pixel-level forest structure data were more important for estimating conifer rather than hardwood forest composition. The coefficients of determination for species relative basal area (RBA) ranged from 0.57 (white cedar) to 0.94 (maple) with RMSE of 8.88 to 6.44 % RBA, respectively. Receiver operating characteristic (ROC) curves were used to determine the effective lower limits of usefulness of species RBA estimates which ranged from 5.94 % (jack pine) to 39.41 % (black ash). These estimates were then used to produce a dominant forest species map for the study region with an overall accuracy of 78 %. Most notably, this approach facilitated discrimination of aspen from birch as well as spruce and fir from other conifer species which is crucial for the study of forest tent caterpillar and spruce budworm dynamics, respectively, in the Upper Midwest. Thus, use of PLS regression as a data fusion strategy has proven to be an effective tool for regional characterization of forest

  11. Brucella species survey in polar bears (ursus maritimus) of northern Alaska.

    PubMed

    O'Hara, Todd M; Holcomb, Darce; Elzer, Philip; Estepp, Jessica; Perry, Quinesha; Hagius, Sue; Kirk, Cassandra

    2010-07-01

    We report on the presence of specific antibodies to Brucella spp. and Yersinia enterocolitica in polar bears (Ursus maritimus) from northern Alaska (southern Beaufort Sea) during 2003-2006. Based on numerous known stressors (e.g., climate change and loss of sea ice habitat, contaminants), there is increased concern regarding the status of polar bears. Considering these changes, it is important to assess exposure to potentially pathogenic organisms and to improve understanding of transmission pathways. Brucella or specific antibodies to Brucella spp. has been reported in marine mammals. Various assays were used to elucidate the pathway or source of exposure (e.g., "marine" vs. "terrestrial" Brucella spp.) of northern Alaska polar bears to Brucella spp. The standard plate test (SPT) and the buffered Brucella antigen card test (BBA) were used for initial screening for antibodies specific to Brucella. We then evaluated positive reactors (presence of serum antibody specific for Brucella spp.) using immunoblots and competitive enzyme-linked immunosorbent assay (cELISA; based on pinniped-derived Brucella spp. antigen). Annual prevalence of antibody (BBA and SPT) for Brucella spp. ranged from 6.8% to 18.5% over 2003-2006, with an overall prevalence of 10.2%. Prevalence of Brucella spp. antibody did vary by age class. Western blot analyses indicated 17 samples were positive for Brucella spp. antibody; of these, 13 were negative by marine (pinniped) derived Brucella antigen cELISA and four were positive by marine cELISA. Of the four samples positive for Brucella antibody by marine cELISA, three cross-reacted with Y. enterocolitica and Brucella spp. (one sample was Brucella negative and Y. enterocolitica positive). It appears the polar bear antibody does not react with the antigens used on the marine cELISA assay, potentially indicating a terrestrial (nonpinniped) source of Brucella spp.

  12. Limited effects of a keystone species: Trends of sea otters and kelp forests at the Semichi Islands, Alaska

    USGS Publications Warehouse

    Konar, B.

    2000-01-01

    Sea otters are well known as a keystone species because of their ability to transform sea urchin-dominated communities into kelp-dominated communities by preying on sea urchins and thus reducing the intensity of herbivory. After being locally extinct for more than a century, sea otters re-colonized the Semichi Islands in the Aleutian Archipelago, Alaska in the early 1990s. Here, otter populations increased to about 400 individuals by 1994, but rapidly declined to about 100 by 1997. Roughly 7 yr after initial otter re-colonization, there were only marginal changes in sea urchin biomass, mean maximum test size, and kelp density. These small changes may be the first steps in the cascading effects on community structure typically found with the invasion of a keystone species. However, no wholesale change in community structure occurred following re-colonization and growth of the sea otter population. Instead, this study describes a transition state and identifies factors such as keystone species density and residence time that can be important in dictating the degree to which otter effects are manifested.

  13. Assessment of resource selection models to predict occurrence of five juvenile flatfish species (Pleuronectidae) over the continental shelf in the western Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Wilson, Matthew T.; Mier, Kathryn L.; Cooper, Dan W.

    2016-05-01

    According to the nursery size hypothesis, flatfish recruitment is constrained by nursery area. Thus, if resource selection models can be shown to accurately predict the location and geographic extent of flatfish nursery areas, they will become important tools in the management and study of flatfish population dynamics. We demonstrate that some resource selection models derived previously to predict the presence and absence of juvenile flatfishes near shore were applicable to the broader continental shelf. For other age-species groups, derivation of new models for the continental shelf was necessary. Our study was conducted in the western Gulf of Alaska (GoA) during October 2011 on four groups of age-0 juvenile flatfishes: Pacific halibut (Hippoglossus stenolepis), arrowtooth flounder (Atheresthes stomias), northern rock sole (Lepidopsetta polyxystra), and flathead sole (Hippoglossoides elassodon); and three groups of age-1 juvenile flatfishes: northern rock sole, flathead sole, and yellowfin sole (Limanda aspera). Sampling occurred at 33 sites across the continental shelf. Fish were collected using a 3-m beam trawl, and a midwater trawl. Environmental data were collected on sediment composition and water temperature and depth. Many of the age-species groups co-occurred in the Shumagin and Barnabus sea valleys; however, age-0 arrowtooth flounder occurred at more locations than other juveniles, perhaps due to a relatively broad tolerance of environmental conditions and to the utilization of midwater habitat. Thus, the large nursery area of arrowtooth flounder may be one reason why they are currently the most abundant GoA flatfish. In fact, among all species, mean recruitment at age 3 increased with the percent occurrence of age-0 juveniles at the 33 sites, a proxy for relative nursery area, in accordance with the nursery size hypothesis, suggesting that mean recruitment among GoA flatfishes is structured by nursery size.

  14. Conservation tillage affects species composition but not species diversity: a comparative study in Northern Italy.

    PubMed

    Boscutti, Francesco; Sigura, Maurizia; Gambon, Nadia; Lagazio, Corrado; Krüsi, Bertil O; Bonfanti, Pierluigi

    2015-02-01

    Conservation tillage (CT) is widely considered to be a practice aimed at preserving several ecosystem functions. In the literature, however, there seems to be no clear pattern with regard to its benefits on species diversity and species composition. In Northern Italy, we compared species composition and diversity of both vascular plants and Carabids under two contrasting tillage systems, i.e., CT and conventional tillage, respectively. We hypothesized a significant positive impact of CT on both species diversity and composition. We also considered the potential influence of crop type. The tillage systems were studied under open field conditions with three types of annual crops (i.e., maize, soybean, and winter cereals), using a split-plot design on pairs of adjacent fields. Linear mixed models were applied to test tillage system, crop, and interaction effects on diversity indices. Plant and Carabids communities were analyzed by multivariate methods (CCA). On the whole, 136 plant and 51 carabid taxa were recorded. The two tillage systems studied did not differ in floristic or carabid diversity. Species composition, by contrast, proved to be characteristic for each combination of tillage system and crop type. In particular, CT fields were characterized by nutrient demanding weeds and the associated Carabids. The differences were especially pronounced in fields with winter cereals. The same was true for the flora and Carabids along the field boundaries. For studying the effects of CT practices on the sustainability of agro-ecosystems, therefore, the focus should be on species composition rather than on diversity measures.

  15. Conservation Tillage Affects Species Composition But Not Species Diversity: A Comparative Study in Northern Italy

    NASA Astrophysics Data System (ADS)

    Boscutti, Francesco; Sigura, Maurizia; Gambon, Nadia; Lagazio, Corrado; Krüsi, Bertil O.; Bonfanti, Pierluigi

    2015-02-01

    Conservation tillage (CT) is widely considered to be a practice aimed at preserving several ecosystem functions. In the literature, however, there seems to be no clear pattern with regard to its benefits on species diversity and species composition. In Northern Italy, we compared species composition and diversity of both vascular plants and Carabids under two contrasting tillage systems, i.e., CT and conventional tillage, respectively. We hypothesized a significant positive impact of CT on both species diversity and composition. We also considered the potential influence of crop type. The tillage systems were studied under open field conditions with three types of annual crops (i.e., maize, soybean, and winter cereals), using a split-plot design on pairs of adjacent fields. Linear mixed models were applied to test tillage system, crop, and interaction effects on diversity indices. Plant and Carabids communities were analyzed by multivariate methods (CCA). On the whole, 136 plant and 51 carabid taxa were recorded. The two tillage systems studied did not differ in floristic or carabid diversity. Species composition, by contrast, proved to be characteristic for each combination of tillage system and crop type. In particular, CT fields were characterized by nutrient demanding weeds and the associated Carabids. The differences were especially pronounced in fields with winter cereals. The same was true for the flora and Carabids along the field boundaries. For studying the effects of CT practices on the sustainability of agro-ecosystems, therefore, the focus should be on species composition rather than on diversity measures.

  16. Using the Landscape Reconstruction Algorithm (LRA) to estimate Holocene regional and local vegetation composition in the Boreal Forests of Alaska

    NASA Astrophysics Data System (ADS)

    Hopla, Emma-Jayne; Edwards, Mary; Langdon, Pete

    2016-04-01

    Vegetation is already responding to increasing global temperatures, with shrubs expanding northwards in the Arctic in a process called "greening". Lakes are important features within these changing landscapes, and lake ecosystems are affected by the vegetation in their catchments. Use of dated sediment archives can reveal how lake ecosystems responded to past changes over timescales relevant to vegetation dynamics (decades to centuries). Holocene vegetation changes have been reconstructed for small lake catchments in Alaska to help understand the long-term interactions between vegetation and within lake processes. A quantitative estimate of vegetation cover around these small lakes clarifies the catchment drivers of lake ecosystem processes. Pollen productivity is one of the major parameters used to make quantitative estimates of land cover from palaeodata. Based on extensive fieldwork, we obtained first Pollen Productivity Estimates (PPEs) for the main arboreal taxa in interior Alaska. We used the model REVEALS to estimate the regional vegetation abundance from existing pollen data from large lakes in the region based on Alaskan and European pollen productivity estimates (PPEs). Quantitative estimates of vegetation cover differ from those based on pollen percentages alone. The model LOVE will then be applied to smaller lake basins that are the subject of detailed palaeoliminological investigations in order to estimate the local composition at these sites.

  17. Selected marine mammals of Alaska: species accounts with research and management recommendations

    SciTech Connect

    Lentfer, J.W.

    1988-01-01

    This book is the result of a need seen by the Marine Mammal Commission for a current summary of the biology and status of ten species of Alaskan marine mammals, including recommendations for research and management. Its purpose is to serve as a reference and working document as conservation and management plans are developed and implemented for the ten species.

  18. Polyphenol composition and antioxidant capacity of Epilobium species.

    PubMed

    Hevesi Tóth, Barbara; Blazics, Balázs; Kéry, Agnes

    2009-01-15

    Epilobium species (Onagraceae) are commonly used herbal remedies in traditional, adjuvant therapy of benignus prostate hyperplasia (BPH), however the pharmacological and clinical standardization of commercially available Epilobii herba (willow-herb) remains difficult. Willow-herb products usually consist of mixtures from various species, with different phenoloid content, often only partially identified. The present study reports comprehensive LC-MS/MS investigation on the polyphenol composition of the most common Epilobium species, emphasizing the pharmaceutical importance of a uniform standardization protocol in case of their products. The antioxidant capacity of species was evaluated by a simple spectrophotometric method, using ABTS(+) (2,2'azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)). High ratio of macrocyclic tannins, mainly oenothein B was identified in all Epilobium species examined. Flavonoid composition of Epilobium extracts showed several differences, especially comparing E. angustifolium to other species. Myricetin, quercetin, kaempferol and their various glycosides were dominant in samples, but their combination and ratio were distinctive in all cases. Epilobium extracts showed high radical-scavenger activity, comparable to that of well-known antioxidants, Trolox and ascorbic acid. Among species examined, extract of Epilobium parviflorum possessed the highest antioxidant capacity (EC(50)=1.71+/-0.05 microg/ml). PMID:19013046

  19. Effectiveness of mosquito traps in measuring species abundance and composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosquito species abundance and composition estimates provided by trapping devices are commonly used to guide control efforts, but knowledge of trap biases is necessary for accurately interpreting results. We compared the Mosquito Magnet – Pro, the Mosquito Magnet – X and the CDC Miniature Light Trap...

  20. Organic Nutrients and Contaminants In Subsistence Species of Alaska: Concentrations and Relationship To Food Preparation Method

    PubMed Central

    Moses, Sara K.; Whiting, Alex V.; Muir, Derek C.G.; Wang, Xiaowa; O'Hara, Todd M.

    2009-01-01

    Objectives To determine nutrient and contaminant concentrations, document concentration changes related to common preparation methods and provide a basic risk-benefit analysis for select subsistence foods consumed by residents of Kotzebue, Alaska. Study design Eleven organic nutrients and 156 persistent organic pollutants (POPs) were measured in foods derived from spotted seals and sheefish. Methods Nutrients in foodstuffs were compared to Daily Recommended Intake criteria. POPs were compared to Tolerable Daily Intake Limits (TDIL). Results Cooking, as well as absence/presence of skin during sheefish processing, altered nutrient and contaminant concentrations in seals and fish. Sheefish muscle and seal blubber were particularly rich in omega-3 fatty acids and seal liver in vitamin A. Seal liver exceeded the recommended upper limit for vitamin A. POP contribution to TDIL was <25% in all tissues except blubber, in which 4 POPs were present at >25% TDIL. No POPs exceeded TDIL in a serving of any tissue studied. The most prominent concerns identified were levels of vitamin A in spotted seal liver and certain POPs in blubber, warranting consideration when determining how much and how often these foods should be consumed. Conclusions Preparation methods altering tissues from their raw state significantly affect nutrient and contaminant concentrations, thus direct evaluation of actual food items is highly recommended to determine risk-benefits ratios of traditional diets. Traditional foods provide essential nutrients with very limited risk from contaminants. We encourage the consumption of traditional foods and urge public health agencies to develop applicable models to assess overall food safety and quality. PMID:19917188

  1. Structural geology and kinematics associated with the collision of the Wrangellia composite terrane and North America, south-central Alaska

    NASA Astrophysics Data System (ADS)

    Bier, Sara Elizabeth

    The collision of the Insular superterrane, and thus, the Wrangellia composite terrane (WCT), with the Mesozoic margin of North America is one of the most important, yet enigmatic events in the tectonic history of North American cordillera. The location and therefore the nature of the collision of the Insular superterrane with North America remains controversial. In southern Alaska, the suture zone between the WCT and North America consists of the Kahiltna assemblage, Jurassic-Cretaceous submarine fan deposits. Structural investigation of the Kahiltna assemblage provides additional data on the kinematics of the collision and suggests an oblique collision with a significant component of right-lateral shearing. The first study of the dissertation presents the results across a transect at the northern end of Broad Pass where the depositional and deformational history of three tectonostratigraphic units enables determination of the tectonic evolution of the suture zone. The Reindeer Hills exposes melange units that include oceanic lithologies and represent a remnant of an accretionary complex that formed during subduction prior to the collision of the WCT. Structures within the Kahiltna assemblage in the Talkeetna Mountains indicate oblique northwest-directed thrusting and right-lateral shear during the collision of the WCT. The Jack River conglomerate, a fluvial clast-supported conglomerate unconformably overlies the Reindeers Hills melange and represents uplift, erosion, and deposition late in the collision. The second study is on the other side of Broad Pass, in the southern Alaska Range, and consists of a composite transect across the Peters and Dutch Hills and Chelatna Lake. Horizontal stretching lineations and steeply-dipping foliation indicate that deformation occurred during transpression as a result of an oblique collision. Strain analysis of pressure shadows indicate a counterclockwise rotation of the extension direction and thus, right-lateral shearing during

  2. Chemical composition of the giant red sea cucumber, Parastichopus californicus, commercially harvested in Alaska

    PubMed Central

    Bechtel, Peter J; Oliveira, Alexandra CM; Demir, Necla; Smiley, Scott

    2013-01-01

    Giant red sea cucumbers, Parastichopus californicus, are commercially harvested in the U.S. Pacific Northwest; however, the nutritional and chemical properties of its edible muscle bands and body wall have not been fully elucidated. In particular are the fatty acid profiles of P. californicus tissues, which have not been documented. Sea cucumbers were delivered live and muscle bands and body wall freeze dried, vacuum packed, and stored at –30°C until analyzed. Proximate composition of freeze-dried tissues varied greatly with muscle bands being composed of 68% protein, 12% ash, 9% carbohydrate, and 5% lipids, while the body wall was composed of 47% protein, 26% ash, 15% carbohydrate, and 8% lipids. The hydroxyproline, proline, and glycine contents of the body wall were much higher than those in muscle bands, consistent with the larger amount of connective tissue. Calcium, magnesium, sodium, and iron contents were higher in the body wall than those in muscle bands, whereas the opposite was observed for zinc content. Total long-chain n-3 fatty acid contents were 19% and 32% of total fatty acids in body wall and muscle bands, respectively. Muscle bands had higher content of eicosapentaenoic acid (20:5n-3) than body wall at 22.6% and 12.3%, respectively. High content of arachidonic acid (20:4n-6) was recorded in both body wall (7.1%) and muscle bands (9.9%). Overall, the fatty acid profiles of body wall and muscle bands of P. californicus resemble those described for other species; however, the distribution and occurrence of certain fatty acids is unique to P. californicus, being representative of the fatty acid composition of temperate-polar marine organisms. The chemical characterization of freeze-dried edible tissues from P. californicus demonstrated that these products have valuable nutritional properties. The body wall, a food product of lower market value than muscle bands, could be better utilized for nutraceutical and pharmaceutical applications. PMID

  3. Twig and foliar biomass estimation equations for major plant species in the Tanana River basin of interior Alaska. Forest Service research paper

    SciTech Connect

    Yarie, J.; Mead, B.R.

    1988-09-01

    Equations are presented for estimating the twig, foliage, and combined biomass for 58 plant species in interior Alaska. The equations can be used for estimating biomass from percentage of the foliar cover of 10-centimeter layers in a vertical profile from 0 to 6 meters. Few differences were found in regressions of the same species between layers except when the ratio of foliar-to-twig biomass changed drastically between layers, for example, Rosa acicularis Lindl. Eighteen species were tested for regression differences between years. Thirteen showed no significant differences, five were different. Of these five, three were feather mosses for which live and dead biomass are easily confused when measured.

  4. Effects of ozone on species composition in an upland grassland.

    PubMed

    Wedlich, Kerstin V; Rintoul, Naomi; Peacock, Simon; Cape, J Neil; Coyle, Mhairi; Toet, Sylvia; Barnes, Jeremy; Ashmore, Mike

    2012-04-01

    Northern hemispheric background concentrations of ozone are increasing, but few studies have assessed the ecological significance of these changes for grasslands of high conservation value under field conditions. We carried out a 3-year field experiment in which ozone was released at a controlled rate over three experimental transects to produce concentration gradients over the field site, an upland mesotrophic grassland located in the UK. We measured individual species biomass in an annual hay cut in plots receiving ambient ozone, and ambient ozone elevated by mean concentrations of approximately 4 ppb and 10 ppb in the growing seasons of 2008 and 2009. There was a significant negative effect of ozone exposure on herb biomass, but not total grass or legume biomass, in 2008 and 2009. Within the herb fraction, ozone exposure significantly decreased the biomass of Ranunculus species and that of the hemi-parasitic species Rhinanthus minor. Multivariate analysis of species composition, taking into account spatial variation in soil conditions and ozone exposure, showed no significant ozone effect on the grass component. In contrast, by 2009, ozone had become the dominant factor influencing species composition within the combined herb and legume component. Our results suggest that elevated ozone concentrations may be a significant barrier to achieving increased species diversity in managed grasslands.

  5. Species loss on spatial patterns and composition of zoonotic parasites.

    PubMed

    Harris, Nyeema C; Dunn, Robert R

    2013-11-22

    Species loss can result in the subsequent loss of affiliate species. Though largely ignored to date, these coextinctions can pose threats to human health by altering the composition, quantity and distribution of zoonotic parasites. We simulated host extinctions from more than 1300 host-parasite associations for 29 North American carnivores to investigate changes in parasite composition and species richness. We also explored the geography of zoonotic parasite richness under three carnivore composition scenarios and examined corresponding levels of human exposure. We found that changes in parasite assemblages differed among parasite groups. Because viruses tend to be generalists, the proportion of parasites that are viruses increased as more carnivores went extinct. Coextinction of carnivore parasites is unlikely to be common, given that few specialist parasites exploit hosts of conservation concern. However, local extirpations of widespread carnivore hosts can reduce overall zoonotic richness and shift distributions of parasite-rich areas. How biodiversity influences disease risks remains the subject of debate. Our results make clear that hosts vary in their contribution to human health risks. As a consequence, so too does the loss (or gain) of particular hosts. Anticipating changes in host composition in future environments may help inform parasite conservation and disease mitigation efforts.

  6. Species of coccidia (Apicomplexa: Eimeriidae) in shrews from Alaska, U.S.A., and northeastern Siberia, Russia, with description of two new species.

    PubMed

    Lynch, A J; Duszynski, D W

    2008-08-01

    Fecal samples (n = 636) from 10 species of shrews collected in Alaska (n = 540) and northeastern Siberia (n = 96) were examined for the presence of coccidia (Apicomplexa: Eimeriidae). Five distinct oocyst morphotypes were observed. Three types were consistent with oocysts of previously recognized coccidia species from other shrew hosts. These were Eimeria inyoni, E. vagrantis, and Isospora brevicauda, originally described from the inyo shrew (Sorex tenellus), dusky shrew (S. monticolus), and northern short-tailed shrew (Blarina brevicauda), respectively. We found 5 new host records for E. inyoni, 3 for E. vagrantis, and 3 for I. brevicauda. The 2 additional oocyst morphotypes, both from the tundra shrew (Sorex tundrensis), are putative new species. Sporulated oocysts of Eimeria beringiacea n. sp. are subspheroidal, 17.7 x 15.6 microm (14-24 x 13-20 microm) with a length (L)/width (W) ratio of 1.1 (1.0-1.4); these lack a micropyle (M), an oocyst residuum (OR), and a polar granule (PG). Sporocysts are ellipsoidal, 10.3 x 6.1 microm (7-14 x 4-8 microm), with a L/W ratio of 1.7 (1.3-2.3) and have a Stieda body (SB), Substieda body (SSB), and sporocyst residuum (SR). Oocysts of Eimeria tundraensis n. sp. are spheroidal to subspheroidal, 24.8 x 23.5 microm (23-26 x 22-25 microm), with a L/W ratio of 1.1 (1.0-1.2); these lack a M and OR, but a single PG is present. Sporocysts are elongate ellipsoidal, 15.4 x 8.3 microm (13-17 x 7-9 microm), with a L/W ratio of 1.9 (1.4-2.1) and have a SB, SSB, and SR. PMID:18576829

  7. Time of day of ovulation by three duck species in subarctic Alaska

    USGS Publications Warehouse

    Esler, Daniel

    1999-01-01

    I examined variation in ovulation times of Northern Pintails (Anas acuta), American Wigeon (A. americana), and Lesser Scaup (Aythya affinis) breeding in subarctic Alaskan wetlands. Ovulation times and, by extension, egg-laying times were highly variable in all three species, with ovulations occurring during all hours of the day. Only Lesser Scaup demonstrated a morning peak in ovulations, within a broad range of ovulation times. Lack of a distinct time of day of ovulation suggests that fitness is not related to egg-laying time for these species, particularly at subarctic latitudes with nearly perpetual daylight. Egg-laying interval may have more adaptive significance than egg-laying time for these species. Ovulation intervals were estimated to be approximately 24 hr, which is short relative to the range of intervals documented in birds, despite high energetic and nutritional costs of egg formation in these species. Evidence of approximately 24-hr ovulation intervals, particularly in the absence of a distinct time of day for egg laying, supports hypotheses that a shortened period of egg production in waterfowl may have selective advantage due to reduction in the period of nest exposure to predation, earlier hatch dates, reduced hatch asynchrony, or improved viability of early-laid eggs.

  8. Spatial variability in plant species composition and peatland carbon exchange

    NASA Astrophysics Data System (ADS)

    Goud, E.; Moore, T. R.; Roulet, N. T.

    2015-12-01

    Plant species shifts in response to global change will have significant impacts on ecosystem carbon (C) exchange and storage arising from changes in hydrology. Spatial variation in peatland C fluxes have largely been attributed to the spatial distribution of microhabitats that arise from variation in surface topography and water table depth, but little is known about how plant species composition impacts peatland C cycling or how these impacts will be influenced by changing environmental conditions. We quantified the effect of species composition and environmental variables on carbon dioxide (CO2) and methane (CH4) fluxes over 2 years in a temperate peatland for four plant communities situated along a water table gradient from ombrotrophic bog to beaver pond. We hypothesized that (i) spatial heterogeneity in species composition would drive predictable spatial heterogeneity in C fluxes due to variation in plant traits and ecological tolerances, and (ii) increases in peat temperature would increase C fluxes. Species had different effects on C fluxes primarily due to differences in leaf traits. Differences in ecological tolerances among communities resulted in different rates of CO2 exchange in response to changes in water table depth. There was an overall reduction in ecosystem respiration (ER), gross primary productivity (GPP) and CH4 flux in response to colder peat temperatures in the second year, and the additive effects of a deeper water table in the bog margin and pond sites further reduced flux rates in these areas. These results demonstrate that different plant species can increase or decrease the flux of C into and out of peatlands based on differences in leaf traits and ecological tolerances, and that CO2 and CH4 fluxes are sensitive to changes in soil temperature, especially when coupled with changes in moisture availability.

  9. Molecular composition of sugars in atmospheric particulate matter from interior Alaska

    NASA Astrophysics Data System (ADS)

    Haque, Md. Mozammel; Kawamura, Kimitaka; Kim, Yongwon

    2015-04-01

    Sugars can account for 0.5-8% of carbon in atmospheric particulate matter, affecting the earth climate, air quality and public health. Total of 33 total suspended particle (TSP) samples were collected from Fairbanks, Alaska in June 2008 to June 2009 using a low volume air sampler. Here, we report the molecular characteristics of anhydro-sugars (levoglucosan, galactosan and mannosan), primary saccharides (xylose, fructose, glucose, sucrose and trehalose) and sugar alcohols (erythritol, arabitol, mannitol and inositol). The average contribution of sugars to the organic carbon (OC) was also determined to be 0.92%. Sugar compounds were measured using solvent extraction/TMS-derivatization technique followed by gas chromatography-mass spectrometry (GC-MS) determination. The concentrations of total quantified sugar compounds ranged from 2.3 to 453 ng m-3 (average 145 ng m-3). The highest concentration was recorded for levoglucosan in summer, with a maximum concentration of 790 ng m-3 (average 108 ng m-3). Levoglucosan, which is specifically formed by a pyrolysis of cellulose, has been used as an excellent tracer of biomass burning. The highest level of levoglucosan indicates a significant contribution of biomass burning in ambient aerosols. Galactosan (average 20 ng m-3) and mannosan (average 27 ng m-3), which are also formed through the pyrolysis of cellulose/hemicelluloses, were identified in all samples. The average concentrations of arabitol, mannitol, glucose and sucrose were also found 14.7, 14.6, 14.1 and 16.8 ng m-3, respectively. They have been proposed as tracers for resuspension of surface soil and unpaved road dust, which contain biological materials including fungi and bacteria. These results suggest that there is some impact of bioaerosols on climate over Interior Alaska. We will also measure water-soluble organic carbon (WSOC) and inorganic ions for all samples.

  10. Nutritional compositions and bioactivities of Dacryodes species: a review.

    PubMed

    Tee, Lee Hong; Yang, Bao; Nagendra, Krishnamurthy Prasad; Ramanan, Ramakrishnan Nagasundara; Sun, Jian; Chan, Eng-Seng; Tey, Beng Ti; Azlan, Azrina; Ismail, Amin; Lau, Cheng Yuon; Jiang, Yueming

    2014-12-15

    Dacryodes species are evergreen, perennial trees with fleshy fruits and belong to the family Buseraseae. Many Dacryodes species are underutilized but are widely applied in traditional folk medicine to treat malaria, fever and skin diseases. The nutritional compositions, phytochemicals and biological activities of Dacryodes edulis, Dacryodes rostrata, Dacryodes buettneri, Dacryodes klaineana and Dacryodes hexandra are presented. The edible fruits of D. edulis are rich in lipids, proteins, vitamins, fatty acids and amino acids. Its extracts (leaf, fruit and resin) exhibit antioxidant, anti-microbial, anti-carcinogenic and other bioactivities. D. rostrata fruit has significant nutrient content, and is rich in proteins, lipids and minerals. These fruits are also highly rich in polyphenols, anthocyanins and antioxidant activities. This comprehensive review will assist the reader in understanding the nutritional benefits of Dacryodes species and in identifying current research needs. PMID:25038673

  11. Fire effects on soil organic matter content, composition, and nutrients in boreal interior Alaska

    USGS Publications Warehouse

    Neff, J.C.; Harden, J.W.; Gleixner, G.

    2005-01-01

    Boreal ecosystems contain a substantial fraction of the earth's soil carbon stores and are prone to frequent and severe wildfires. In this study, we examine changes in element and organic matter stocks due to a 1999 wildfire in Alaska. One year after the wildfire, burned soils contained between 1071 and 1420 g/m2 less carbon than unburned soils. Burned soils had lower nitrogen than unburned soils, higher calcium, and nearly unchanged potassium, magnesium, and phosphorus stocks. Burned surface soils tended to have higher concentrations of noncombustible elements such as calcium, potassium, magnesium, and phosphorus compared with unburned soils. Combustion losses of carbon were mostly limited to surface dead moss and fibric horizons, with no change in the underlying mineral horizons. Burning caused significant changes in soil organic matter structure, with a 12% higher ratio of carbon to combustible organic matter in surface burned horizons compared with unburned horizons. Pyrolysis gas chromatography - mass spectroscopy also shows preferential volatilization of polysaccharide-derived organic matter and enrichment of lignin-and lipid-derived compounds in surface soils. The chemistry of deeper soil layers in burned and unburned sites was similar, suggesting that immediate fire impacts were restricted to the surface soil horizon. ?? 2005 NRC.

  12. Mosquitoes of Zika Forest, Uganda: species composition and relative abundance.

    PubMed

    Kaddumukasa, M A; Mutebi, J-P; Lutwama, J J; Masembe, C; Akol, A M

    2014-01-01

    Mosquito collections were conducted in Zika Forest near Entebbe, Uganda, from July 2009 through June 2010 using CO2-baited light traps, ovitraps, and human-baited catches. In total, 163,790 adult mosquitoes belonging to 12 genera and 58 species were captured. Of these, 22 species (38%) were captured in Zika Forest for the first time. All the new records found in the forest in this study had previously been captured in other regions of Uganda, implying that they are native to the country and do not represent new introductions. More than 20 species previously collected in Zika Forest were not detected in our collections, and this may suggest a change in the mosquito fauna during the past 40 yr or variation in species composition from year to year. Arboviruses of public health importance have previously been isolated from >50% of the 58 mosquito species captured in Zika Forest, which suggests ahigh potential for transmission and maintenance of a wide range of arboviruses in Zika Forest.

  13. Coccolithophore Dynamics In Alfonso Basin: Seasonal Variation And Species Composition

    NASA Astrophysics Data System (ADS)

    Cortés, M. Y.; Urcádiz-Cázares, F. J.; Silverberg, N.; Aguirre-Bahena, F.; Bollmann, J.

    2007-05-01

    The production of organic and inorganic carbon by coccolithophores is considered to play a significant role in the global carbon cycle. Therefore, detailed knowledge of their vertical flux is needed. Here we present a time-series record of coccolithophore standing stock and vertical coccolith flux from Alfonso Basin, southwest coast of the Gulf of California. This location is of particular interest as it is very sensitive to changes in environmental conditions and these may be preserved in laminated underlying sediments. Coccolithophore standing stock and assemblage composition were obtained from plankton samples taken at 3- month intervals during 2002-2003. Furthermore, coccolith flux and species composition were determined in samples from a time-series sediment trap (sampling intervals 7-14 days) deployed at 350 m depth from January 2002 to October 2003. The coccolithophore standing stock and coccolith flux varied considerably between sampling periods but, in general, a seasonal pattern was apparent, with low fluxes in spring-summer and maximal values in autumn- winter. During 2002, fluxes ranged from 0.02x108 coccoliths m-2 d-1 in summer to 64.7x108 coccoliths m-2 d-1 in autumn. Values increased considerably during 2003: registering 52.4 x108 coccoliths m-2 d-1 in spring to the highest (128.8x108 coccoliths m-2 d-1) in late summer/autumn. The latter are related to hurricanes that occurred during the sampling period. In total 47 taxa were identified but only three species, Gephyrocapsa oceanica (43.6%), Emiliania huxleyi (28%) and Florisphera profunda (15.7%), constituted 88 percent of the total coccolith flux. This corresponds to the species composition observed in the water column. G. oceanica was always present and its flux pattern followed that of the total flux. The flux of E. huxleyi remained almost constant during the observed time period whereas F. profunda showed peak fluxes in autumn. Although the cosmopolitan species E. huxleyi has been considered the

  14. Using dissolved organic matter age and composition to detect permafrost thaw in boreal watersheds of interior Alaska

    USGS Publications Warehouse

    O'Donnell, Jonathan A.; Aiken, George R.; Walvoord, Michelle Ann; Raymond, Peter A.; Butler, Kenna; Dornblaser, Mark M.; Heckman, Katherine

    2014-01-01

    Recent warming at high latitudes has accelerated permafrost thaw, which can modify soil carbon dynamics and watershed hydrology. The flux and composition of dissolved organic matter (DOM) from soils to rivers are sensitive to permafrost configuration and its impact on subsurface hydrology and groundwater discharge. Here, we evaluate the utility of DOM composition and age as a tool for detecting permafrost thaw in three rivers (Beaver, Birch, and Hess Creeks) within the discontinuous permafrost zone of interior Alaska. We observed strong temporal controls on Δ14C content of hydrophobic acid isolates (Δ14C-HPOA) across all rivers, with the most enriched values occurring during spring snowmelt (75 ± 8‰) and most depleted during winter flow (−21 ± 8‰). Radiocarbon ages of winter flow samples ranged from 35 to 445 yr BP, closely tracking estimated median base flow travel times for this region (335 years). During spring snowmelt, young DOM was composed of highly aromatic, high molecular-weight compounds, whereas older DOM of winter flow had lower aromaticity and molecular weight. We observed a significant correlation between Δ14C-HPOA and UV absorbance coefficient at 254 nm (α254) across all study rivers. Usingα254 as an optical indicator for Δ14C-HPOA, we also observed a long-term decline in α254 during maximum annual thaw depth over the last decade at the Hess Creek study site. These findings suggest a shift in watershed hydrology associated with increasing active layer thickness. Further development of DOM optical indicators may serve as a novel and inexpensive tool for detecting permafrost degradation in northern watersheds.

  15. Differences in the volatile compositions of ginseng species (Panax sp.).

    PubMed

    Cho, In Hee; Lee, Hyun Jeong; Kim, Young-Suk

    2012-08-01

    The volatile compositions in dried white ginseng according to species (Panax ginseng, Panax notoginseng, and Panax quinquefolius) were analyzed and compared by applying multivariate statistical techniques to gas chromatography-mass spectrometry data sets. Main volatile compounds of ginseng species in the present study were sesquiterpenes, such as bicyclogermacrene, (E)-β-farnesene, β-panasinsene, calarene, α-humulene, β-elemene, etc. In particular, α-selinene, α-terpinolene, β-bisabolene, β-phellandrene, β-sesquiphellandrene, zingiberene, germacrene D, limonene, α-gurjunene, (E)-caryophyllene, δ-cadinene, (E)-β-farnesene, α-humulene, bicyclogermacrene, longiborn-8-ene, β-neoclovene, and (+)-spathulenol were mainly associated with the difference between P. ginseng and P. notoginseng versus P. quinquefolius species. On the other hand, the discrimination between P. ginseng and P. notoginseng could be constructed by hexanal, 2-pyrrolidinone, (E)-2-heptenal, (E)-2-octenal, heptanal, isospathulenol, (E,E)-2,4-decadienal, 3-octen-2-one, benzaldehyde, 2-pentylfuran, and (E)-2-nonenal.

  16. The occurrence and composition of thrips (Thysanoptera) species on leek.

    PubMed

    Pobozniak, M; Bujak, P; Rataj, S

    2006-01-01

    The aim of the present research work was to investigate the population density and species composition of thrips infesting crops of leek in south Poland. The flight activity of thrips was monitored using blue sticky traps and plant samples were taken to record the number of adult and larvae of thrips on leek. In 2004, the thrips were caught into blue sticky traps from the middle of June to the end of second decade of October. The first peak flight activity was noticed on the beginning of the third decade of July. The next peak flight activity was recorded in the middle and at the end of August. In 2004 the rapid growth of the numerousness of adult thrips was recorded at the third decade of September. The evident growth of the number of the adult thrips was continued until the third decade of October. Thrips larvae were observed from the second decade of September to the third decade of October. In 2005 the highest number of adult thrips on both cultivars was noticed at the third decade of July and this corresponded to a period of intensive flight activity. 2004, the most numerous species was Thrips tabaci Lindeman, which amounted to the 98.5% of the total number of collected thrips. The second most numerous species was Frankliniella intonsa Trybom (1.1%). In 2005, the most dominant was Frankliniella intonsa (Trybom) (78.3%). The percentage participation of Thrips tabaci Lindeman was 9.8%.

  17. Factors affecting Culicoides species composition and abundance in avian nests.

    PubMed

    Martínez-de la Puente, J; Merino, S; Tomás, G; Moreno, J; Morales, J; Lobato, E; Talavera, S; Sarto I Monteys, V

    2009-08-01

    Mechanisms affecting patterns of vector distribution among host individuals may influence the population and evolutionary dynamics of vectors, hosts and the parasites transmitted. We studied the role of different factors affecting the species composition and abundance of Culicoides found in nests of the blue tit (Cyanistes caeruleus). We identified 1531 females and 2 males of 7 different Culicoides species in nests, with C. simulator being the most abundant species, followed by C. kibunensis, C. festivipennis, C. segnis, C. truncorum, C. pictipennis and C. circumscriptus. We conducted a medicationxfumigation experiment randomly assigning bird's nests to different treatments, thereby generating groups of medicated and control pairs breeding in fumigated and control nests. Medicated pairs were injected with the anti-malarial drug Primaquine diluted in saline solution while control pairs were injected with saline solution. The fumigation treatment was carried out using insecticide solution or water for fumigated and control nests respectively. Brood size was the main factor associated with the abundance of biting midges probably because more nestlings may produce higher quantities of vector attractants. In addition, birds medicated against haemoparasites breeding in non-fumigated nests supported a higher abundance of C. festivipennis than the rest of the groups. Also, we found that the fumigation treatment reduced the abundance of engorged Culicoides in both medicated and control nests, thus indicating a reduction of feeding success produced by the insecticide. These results represent the first evidence for the role of different factors in affecting the Culicoides infracommunity in wild avian nests.

  18. The nature of the crust in the Yukon-Koyukuk province as inferred from the chemical and isotopic composition of five Late Cretaceous to Early Tertiary volcanic fields in western Alaska

    USGS Publications Warehouse

    Moll-Stalcup, E.; Arth, Joseph G.

    1989-01-01

    Late Cretaceous and early Tertiary volcanic and plutonic rocks in western Alaska comprise a vast magmatic province extending from the Alaska Range north to the Arctic Circle, south to Bristol Bay, and west to the Bering Sea Shelf. The chemical and isotopic composition of five of these Late Cretaceous to early Tertiary volcanic fields in the north central part of this province were studied to determine if Paleozoic or older continental crust underlies the Yukon-Koyukuk province. -from Authors

  19. Coupled long-term summer warming and deeper snow alters species composition and stimulates gross primary productivity in tussock tundra.

    PubMed

    Leffler, A Joshua; Klein, Eric S; Oberbauer, Steven F; Welker, Jeffrey M

    2016-05-01

    Climate change is expected to increase summer temperature and winter precipitation throughout the Arctic. The long-term implications of these changes for plant species composition, plant function, and ecosystem processes are difficult to predict. We report on the influence of enhanced snow depth and warmer summer temperature following 20 years of an ITEX experimental manipulation at Toolik Lake, Alaska. Winter snow depth was increased using snow fences and warming was accomplished during summer using passive open-top chambers. One of the most important consequences of these experimental treatments was an increase in active layer depth and rate of thaw, which has led to deeper drainage and lower soil moisture content. Vegetation concomitantly shifted from a relatively wet system with high cover of the sedge Eriophorum vaginatum to a drier system, dominated by deciduous shrubs including Betula nana and Salix pulchra. At the individual plant level, we observed higher leaf nitrogen concentration associated with warmer temperatures and increased snow in S. pulchra and B. nana, but high leaf nitrogen concentration did not lead to higher rates of net photosynthesis. At the ecosystem level, we observed higher GPP and NEE in response to summer warming. Our results suggest that deeper snow has a cascading set of biophysical consequences that include a deeper active layer that leads to altered species composition, greater leaf nitrogen concentration, and higher ecosystem-level carbon uptake.

  20. Coupled long-term summer warming and deeper snow alters species composition and stimulates gross primary productivity in tussock tundra.

    PubMed

    Leffler, A Joshua; Klein, Eric S; Oberbauer, Steven F; Welker, Jeffrey M

    2016-05-01

    Climate change is expected to increase summer temperature and winter precipitation throughout the Arctic. The long-term implications of these changes for plant species composition, plant function, and ecosystem processes are difficult to predict. We report on the influence of enhanced snow depth and warmer summer temperature following 20 years of an ITEX experimental manipulation at Toolik Lake, Alaska. Winter snow depth was increased using snow fences and warming was accomplished during summer using passive open-top chambers. One of the most important consequences of these experimental treatments was an increase in active layer depth and rate of thaw, which has led to deeper drainage and lower soil moisture content. Vegetation concomitantly shifted from a relatively wet system with high cover of the sedge Eriophorum vaginatum to a drier system, dominated by deciduous shrubs including Betula nana and Salix pulchra. At the individual plant level, we observed higher leaf nitrogen concentration associated with warmer temperatures and increased snow in S. pulchra and B. nana, but high leaf nitrogen concentration did not lead to higher rates of net photosynthesis. At the ecosystem level, we observed higher GPP and NEE in response to summer warming. Our results suggest that deeper snow has a cascading set of biophysical consequences that include a deeper active layer that leads to altered species composition, greater leaf nitrogen concentration, and higher ecosystem-level carbon uptake. PMID:26747269

  1. The occurrence and species composition of thrips (Thysanoptera) on onion.

    PubMed

    Pobozniak, Maria; Palacz, Anna; Rataj, Agnieszka

    2007-01-01

    The aim of the present research work was to investigate the population density and species composition of thrips infesting crops of onion in South Poland. The flight activity of thrips was monitored using blue sticky traps and plant samples were taken to record the number of adult and Larvae of thrips on onion. In 2004 the thrips were caught into blue sticky traps from the start of June to the end of the first decade of September. The peak flight activity was noticed in the middle of July. In 2004 the significant growth of the numerousness of adult thrips on onion grown from seeds was recorded in the middle and in the third decade of August, whereas on onion grown from sets in the first decade of August. Thrips larvae were not observed during the whole vegetation season. In 2005, the thrips were caught into blue sticky traps form the half of June to the first decade of September. The peak flight activity was noticed in the first decade of August. In 2005 the rapid growth of the numerousness of adult thrips on onion grown from seeds was recorded in the third decade of July. The highest number of adult thrips on onion grown from sets was noticed at the beginning of August. Thrips larvae were observed on onion grown from seeds in the third decade of July and at the end of the second decade of August. In both years of observations the most numerous species was Frankliniella intonsa Tryb. The second most numerous species was Thrips tabaci Lindeman. In 2004, the most numerous species was predacious Aeolothrips intermedius Bagnall.

  2. Viable Compositional Analysis of an Eleven Species Oral Polymicrobial Biofilm

    PubMed Central

    Sherry, Leighann; Lappin, Gillian; O'Donnell, Lindsay E.; Millhouse, Emma; Millington, Owain R.; Bradshaw, David J.; Axe, Alyson S.; Williams, Craig; Nile, Christopher J.; Ramage, Gordon

    2016-01-01

    Purpose: Polymicrobial biofilms are abundant in clinical disease, particularly within the oral cavity. Creating complex biofilm models that recapitulate the polymicrobiality of oral disease are important in the development of new chemotherapeutic agents. In order to do this accurately we require the ability to undertake compositional analysis, in addition to determine individual cell viability, which is difficult using conventional microbiology. The aim of this study was to develop a defined multispecies denture biofilm model in vitro, and to assess viable compositional analysis following defined oral hygiene regimens. Methods: An in vitro multispecies denture biofilm containing various oral commensal and pathogenic bacteria and yeast was created on poly (methyl methacrylate) (PMMA). Denture hygiene regimens tested against the biofilm model included brushing only, denture cleansing only and combinational brushing and denture cleansing. Biofilm composition and viability were assessed by culture (CFU) and molecular (qPCR) methodologies. Scanning electron microscopy and confocal laser scanning microscopy were also employed to visualize changes in denture biofilms following treatment. Results: Combinational treatment of brushing and denture cleansing had the greatest impact on multispecies denture biofilms, reducing the number of live cells by more than 2 logs, and altering the overall composition in favor of streptococci. This was even more evident during the sequential testing, whereby daily sequential treatment reduced the total and live number of bacteria and yeast more than those treated intermittently. Bacteria and yeast remaining following treatment tended to aggregate in the pores of the PMMA, proving more difficult to fully eradicate the biofilm. Conclusions: Overall, we are the first to develop a method to enable viable compositional analysis of an 11 species denture biofilm following chemotherapeutic challenge. We were able to demonstrate viable cell

  3. Phylogeography above the species level for perennial species in a composite genus

    PubMed Central

    Tremetsberger, Karin; Ortiz, María Ángeles; Terrab, Anass; Balao, Francisco; Casimiro-Soriguer, Ramón; Talavera, María; Talavera, Salvador

    2016-01-01

    In phylogeography, DNA sequence and fingerprint data at the population level are used to infer evolutionary histories of species. Phylogeography above the species level is concerned with the genealogical aspects of divergent lineages. Here, we present a phylogeographic study to examine the evolutionary history of a western Mediterranean composite, focusing on the perennial species of Helminthotheca (Asteraceae, Cichorieae). We used molecular markers (amplified fragment length polymorphism (AFLP), internal transcribed spacer and plastid DNA sequences) to infer relationships among populations throughout the distributional range of the group. Interpretation is aided by biogeographic and molecular clock analyses. Four coherent entities are revealed by Bayesian mixture clustering of AFLP data, which correspond to taxa previously recognized at the rank of subspecies. The origin of the group was in western North Africa, from where it expanded across the Strait of Gibraltar to the Iberian Peninsula and across the Strait of Sicily to Sicily. Pleistocene lineage divergence is inferred within western North Africa as well as within the western Iberian region. The existence of the four entities as discrete evolutionary lineages suggests that they should be elevated to the rank of species, yielding H. aculeata, H. comosa, H. maroccana and H. spinosa, whereby the latter two necessitate new combinations. PMID:26644340

  4. Phylogeography above the species level for perennial species in a composite genus.

    PubMed

    Tremetsberger, Karin; Ortiz, María Ángeles; Terrab, Anass; Balao, Francisco; Casimiro-Soriguer, Ramón; Talavera, María; Talavera, Salvador

    2015-01-01

    In phylogeography, DNA sequence and fingerprint data at the population level are used to infer evolutionary histories of species. Phylogeography above the species level is concerned with the genealogical aspects of divergent lineages. Here, we present a phylogeographic study to examine the evolutionary history of a western Mediterranean composite, focusing on the perennial species of Helminthotheca (Asteraceae, Cichorieae). We used molecular markers (amplified fragment length polymorphism (AFLP), internal transcribed spacer and plastid DNA sequences) to infer relationships among populations throughout the distributional range of the group. Interpretation is aided by biogeographic and molecular clock analyses. Four coherent entities are revealed by Bayesian mixture clustering of AFLP data, which correspond to taxa previously recognized at the rank of subspecies. The origin of the group was in western North Africa, from where it expanded across the Strait of Gibraltar to the Iberian Peninsula and across the Strait of Sicily to Sicily. Pleistocene lineage divergence is inferred within western North Africa as well as within the western Iberian region. The existence of the four entities as discrete evolutionary lineages suggests that they should be elevated to the rank of species, yielding H. aculeata, H. comosa, H. maroccana and H. spinosa, whereby the latter two necessitate new combinations. PMID:26644340

  5. Phylogeny and assemblage composition of Frankia in Alnus tenuifolia nodules across a primary successional sere in interior Alaska.

    PubMed

    Anderson, M D; Taylor, D L; Ruess, R W

    2013-07-01

    In nitrogen (N) fixing symbioses, host-symbiont specificity, genetic variation in bacterial symbionts and environmental variation represent fundamental constraints on the ecology, evolution and practical uses of these interactions, but detailed information is lacking for many naturally occurring N-fixers. This study examined phylogenetic host specificity of Frankia in field-collected nodules of two Alnus species (A. tenuifolia and A. viridis) in interior Alaska and, for A. tenuifolia, distribution, diversity, spatial autocorrelation and correlation with specific soil factors of Frankia genotypes in nodules collected from replicated habitats representing endpoints of a primary sere. Frankia genotypes most commonly associated with each host belonged to different clades within the Alnus-infective Frankia clade, and for A. tenuifolia, were divergent from previously described Frankia. A. tenuifolia nodules from early and late succession habitats harboured distinct Frankia assemblages. In early succession, a single genotype inhabited 71% of nodules with no discernable autocorrelation at any scale, while late succession Frankia were more diverse, differed widely among plants within a site and were significantly autocorrelated within and among plants. Early succession Frankia genotype occurrence was strongly correlated with carbon/nitrogen ratio in the mineral soil fraction, while in late succession, the most common genotypes were correlated with different soil variables. Our results suggest that phylogenetic specificity is a significant factor in the A. tenuifolia-Frankia interaction and that significant habitat-based differentiation may exist among A. tenuifolia-infective genotypes. This is consistent with our hypothesis that A. tenuifolia selects specific Frankia genotypes from early succession soils and that this choice is attenuated in late succession. PMID:23731390

  6. Phylogeny and assemblage composition of Frankia in Alnus tenuifolia nodules across a primary successional sere in interior Alaska.

    PubMed

    Anderson, M D; Taylor, D L; Ruess, R W

    2013-07-01

    In nitrogen (N) fixing symbioses, host-symbiont specificity, genetic variation in bacterial symbionts and environmental variation represent fundamental constraints on the ecology, evolution and practical uses of these interactions, but detailed information is lacking for many naturally occurring N-fixers. This study examined phylogenetic host specificity of Frankia in field-collected nodules of two Alnus species (A. tenuifolia and A. viridis) in interior Alaska and, for A. tenuifolia, distribution, diversity, spatial autocorrelation and correlation with specific soil factors of Frankia genotypes in nodules collected from replicated habitats representing endpoints of a primary sere. Frankia genotypes most commonly associated with each host belonged to different clades within the Alnus-infective Frankia clade, and for A. tenuifolia, were divergent from previously described Frankia. A. tenuifolia nodules from early and late succession habitats harboured distinct Frankia assemblages. In early succession, a single genotype inhabited 71% of nodules with no discernable autocorrelation at any scale, while late succession Frankia were more diverse, differed widely among plants within a site and were significantly autocorrelated within and among plants. Early succession Frankia genotype occurrence was strongly correlated with carbon/nitrogen ratio in the mineral soil fraction, while in late succession, the most common genotypes were correlated with different soil variables. Our results suggest that phylogenetic specificity is a significant factor in the A. tenuifolia-Frankia interaction and that significant habitat-based differentiation may exist among A. tenuifolia-infective genotypes. This is consistent with our hypothesis that A. tenuifolia selects specific Frankia genotypes from early succession soils and that this choice is attenuated in late succession.

  7. 78 FR 57106 - Fisheries of the Exclusive Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-17

    ... Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment 95 to the Fishery Management Plan for... implement Amendment 95 to the Fishery Management Plan for Groundfish of the Gulf of Alaska (FMP). This proposed action would modify halibut prohibited species catch (PSC) management in the Gulf of Alaska...

  8. Bryophytes from Tuxedni Wilderness area, Alaska

    USGS Publications Warehouse

    Schofield, W.B.; Talbot, S. S.; Talbot, S.L.

    2002-01-01

    The bryoflora of two small maritime islands, Chisik and Duck Island (2,302 ha), comprising Tuxedni Wilderness in western lower Cook Inlet, Alaska, was examined to determine species composition in an area where no previous collections had been reported. The field study was conducted from sites selected to represent the totality of environmental variation within Tuxedni Wilderness. Data were analyzed using published reports to compare the bryophyte distribution patterns at three levels, the Northern Hemisphere, North America, and Alaska. A total of 286 bryophytes were identified: 230 mosses and 56 liverworts. Bryum miniatum, Dichodontium olympicum, and Orthotrichum pollens are new to Alaska. The annotated list of species for Tuxedni Wilderness expands the known range for many species and fills distribution gaps within Hulte??n's Central Pacific Coast district. Compared with bryophyte distribution in the Northern Hemisphere, the bryoflora of Tuxedni Wilderness primarily includes taxa of boreal (61%), montane (13%), temperate (11%), arctic-alpine (7%), cosmopolitan (7%), distribution; 4% of the total moss flora are North America endemics. A brief summary of the botanical exploration of the general area is provided, as is a description of the bryophytes present in the vegetation and habitat types of Chisik and Duck Islands.

  9. The Influences of Canopy Species and Topographic Variables on Understory Species Diversity and Composition in Coniferous Forests

    PubMed Central

    Huo, Hong; Feng, Qi; Su, Yong-hong

    2014-01-01

    Understanding the factors that influence the distribution of understory vegetation is important for biological conservation and forest management. We compared understory species composition by multi-response permutation procedure and indicator species analysis between plots dominated by Qinghai spruce (Picea crassifolia Kom.) and Qilian juniper (Sabina przewalskii Kom.) in coniferous forests of the Qilian Mountains, northwestern China. Understory species composition differed markedly between the forest types. Many heliophilous species were significantly associated with juniper forest, while only one species was indicative of spruce forest. Using constrained ordination and the variation partitioning model, we quantitatively assessed the relative effects of two sets of explanatory variables on understory species composition. The results showed that topographic variables had higher explanatory power than did site conditions for understory plant distributions. However, a large amount of the variation in understory species composition remained unexplained. Forward selection revealed that understory species distributions were primarily affected by elevation and aspect. Juniper forest had higher species richness and α-diversity and lower β-diversity in the herb layer of the understory plant community than spruce forest, suggesting that the former may be more important in maintaining understory biodiversity and community stability in alpine coniferous forest ecosystems. PMID:25097871

  10. Factors affecting Archaeal Lipid Compositions of the Sulfolobus Species

    NASA Astrophysics Data System (ADS)

    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.

  11. DNA nucleoside composition and methylation in several species of microalgae

    SciTech Connect

    Jarvis, E.E.; Dunahay, T.G.; Brown, L.M. )

    1992-06-01

    Total DNA was isolated from 10 species of microalgae, including representatives of the Chlorophyceae (Chlorella ellipsoidea, Chlamydomonas reinhardtii, and Monoraphidium minutum), Bacillariophyceae (Cyclotella cryptica, Navicula saprophila, Nitzschia pusilla, and Phaeodactylum tricornutum), Charophyceae (Stichococcus sp.), Dinophyceae (Crypthecodinium cohnii), and Prasinophyceae (Tetraselmis suecica). Control samples of Escherichia coli and calf thymus DNA were also analyzed. The nucleoside base composition of each DNA sample was determined by reversed-phase high performance liquid chromatography. All samples contained 5-methyldeoxycytidine, although at widely varying levels. In M. minutum, about one-third of the cytidine residues were methylated. Restriction analysis supported this high degree of methylation in M. minutum and suggested that methylation is biased toward 5[prime]-CG dinucleotides. The guanosine + cytosine (GC) contents of the green algae were, with the exception of Stichococcus sp., consistently higher than those of the diatoms. Monoraphidium minutum exhibited an extremely high GC content of 71%. Such a value is rare among eukaryotic organisms and might indicate an unusual codon usage. This work is important for developing strategies for transformation and gene cloning in these algae. 46 refs., 1 fig., 2 tabs.

  12. Composition and sources of atmospheric dusts in snow at 3200 meters in the St. Elias Range, southeastern Alaska, USA

    USGS Publications Warehouse

    Hinkley, T.K.

    1994-01-01

    Dusts in snow from the accumulation zone in the St. Elias Range appear from their chemical compositions to have come from terranes of rocks of ferromagnesian composition. These dusts, with respect to their composition and to the moderate degree of variation that occurs through a depositional year, are similar those deposited in Greenland. The high portion of the St. Elias Range is isolated from dominance by any local dust source terranes, because of altitude and the extent of the surrounding glacierized and snow-covered region. In Greenland the altitude is typically lower, but local sources are even less likely to dominate the character of the dusts deposited into the ice record there. The similar compositions and moderate compositional variations of dusts from these two places bear on the question of whether the dusts that are transported over long distances by the atmosphere under modern and glacial-period conditions are uniform and representative of a broad regional or even hemispheric background dust. The dusts in the snow were measured by means of a suite of major, minor, and trace rock-forming metals chosen to give information about rock types, their constituent minerals, degree of degradation (weathering), and energies of atmospheric uptake from source. The variations in amounts of rock dust through the year in the St. Elias Range snowpack have no time-stratigraphic correspondence to the also large variations in concentrations of other species that are not constituents of rock-derived dusts, such the anions chloride, sulfate, and nitrate; the highs and lows of the two types of materials are apparently completely independent. The structure revealed by the moderately fine-scale sampling of the present study (??? 10 increments/y) serves as a background for the interpretation of analysis of ice core samples, in which annual layers may be too compressed to permit analysis of sub-annual samples. ?? 1994.

  13. Composition and sources of atmospheric dusts in snow at 3200 meters in the St. Elias Range, southeastern Alaska, USA

    NASA Astrophysics Data System (ADS)

    Hinkley, Todd K.

    1994-08-01

    Dusts in snow from the accumulation zone in the St. Elias Range appear from their chemical compositions to have come from terranes of rocks of ferromagnesian composition. These dusts, with respect to their composition and to the moderate degree of variation that occurs through a depositional year, are similar those deposited in Greenland. The high portion of the St. Elias Range is isolated from dominance by any local dust source terranes, because of altitude and the extent of the surrounding glacierized and snow-covered region. In Greenland the altitude is typically lower, but local sources are even less likely to dominate the character of the dusts deposited into the ice record there. The similar compositions and moderate compositional variations of dusts from these two places bear on the question of whether the dusts that are transported over long distances by the atmosphere under modern and glacial-period conditions are uniform and representative of a broad regional or even hemispheric background dust. The dusts in the snow were measured by means of a suite of major, minor, and trace rock-forming metals chosen to give information about rock types, their constituent minerals, degree of degradation (weathering), and energies of atmospheric uptake from source. The variations in amounts of rock dust through the year in the St. Elias Range snowpack have no time-stratigraphic correspondence to the also large variations in concentrations of other species that are not constituents of rock-derived dusts, such the anions chloride, sulfate, and nitrate; the highs and lows of the two types of materials are apparently completely independent. The structure revealed by the moderately fine-scale sampling of the present study (≈ 10 increments/y) serves as a background for the interpretation of analysis of ice core samples, in which annual layers may be too compressed to permit analysis of sub-annual samples.

  14. UNIT, ALASKA.

    ERIC Educational Resources Information Center

    Louisiana Arts and Science Center, Baton Rouge.

    THE UNIT DESCRIBED IN THIS BOOKLET DEALS WITH THE GEOGRAPHY OF ALASKA. THE UNIT IS PRESENTED IN OUTLINE FORM. THE FIRST SECTION DEALS PRINCIPALLY WITH THE PHYSICAL GEOGRAPHY OF ALASKA. DISCUSSED ARE (1) THE SIZE, (2) THE MAJOR LAND REGIONS, (3) THE MOUNTAINS, VOLCANOES, GLACIERS, AND RIVERS, (4) THE NATURAL RESOURCES, AND (5) THE CLIMATE. THE…

  15. Temporal and Spatial Dynamics of Tree Species Composition in Temperate Mountains of South Korea

    NASA Astrophysics Data System (ADS)

    Lee, Boknam; Park, Juhan; Cho, Sungsik; Ryu, Daun; Zaw Wynn, Khine; Park, Minji; Cho, Sunhee; Yoon, Jongguk; Park, Jongyoung; Kim, Hyun Seok

    2015-04-01

    Long term studies on vegetation dynamics are important to identify changes of ecosystem-level responses to climate change. To learn how tree species composition and stand structure change across temperate mountains, the temporal and spatial variations in tree species diversity and structure were investigated using the species composition and DBH size collected over the fourteen-year period across 134 sites in Jiri and Baekoon Mountains, South Korea. The overall temporal changes over fourteen years showed significant increase in stand density, species diversity and evenness according to the indices of Shannon-Weiner diversity, Bray-Curtis dissimilarity, and Pielou's evenness, contributing to the increase of basal area and biomass growth. The change of tree species composition could be categorized into five species communities, representing gradual increase or decrease, establishment, extinction, fluctuation of species population. However, in general, the change in species composition appeared to have consistent and directional patterns of increase in the annual rate of change in the mean species traits including species richness, pole growth rate, adult growth rate, and adult stature with five common dominant species (Quercus mongolica, Quercus variabilis, Quercus serrata, Carpinus laxiflora, and Styrax japonicus). The spatial patterns of species composition appeared to have a higher stand density and species diversity along with the low latitude and high slope ecosystem. The climate change was another main driver to vary the distribution of species abundance. Overall, both temporal and spatial changes of composition in tree species community was clear and further analysis to clarify the reasons for such fast and species-specific changes is underway especially to separate the effect of successional change and climate change. Keywords species composition; climate change; temporal and spatial variation ; forest structure; temperate forest

  16. A seasonal survey of click beetles in two potato production areas of Interior Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wireworms are becoming more of a problem in potato [Solanum tuberosum (L.)] producing areas, especially where potatoes are seasonally rotated with grasses, like in interior Alaska. The objective of this research was to study the species composition and seasonal biology of adult elaterids (Coleoptera...

  17. Detection of viruses and virus-like particles in four species of wild and farmed bivalve molluscs in Alaska, U.S.A., from 1987 to 2009.

    PubMed

    Meyers, Theodore R; Burton, Tamara; Evans, Wally; Starkey, Norman

    2009-12-22

    The U.S. Alaska Department of Fish and Game has regulatory oversight of the mariculture industry that is partially administered through a statewide shellfish health policy. Possession and transport of bivalve molluscs require development of indigenous pathogen histories from diagnostic examinations of wild and farmed populations. These examinations have resulted in the detection of various infectious agents and parasites including viruses: an aquareovirus and aquabirna-like virus isolated by fish cell culture, and papilloma- or polyoma- and herpes-like virus particles within bivalve cell intranuclear inclusion bodies observed by electron microscopy. This study summarizes these results in samples examined from 1987 to 2009 and is the first description of poikilothermic viruses from Alaskan waters isolated from or observed within the tissues of 4 species of bivalve molluscs: geoduck clam Panope abrupta, native littleneck clam Protothaca staminea, purple-hinged rock scallop Crassadoma gigantea and Pacific oyster Crassostrea gigas.

  18. Detection of viruses and virus-like particles in four species of wild and farmed bivalve molluscs in Alaska, U.S.A., from 1987 to 2009.

    PubMed

    Meyers, Theodore R; Burton, Tamara; Evans, Wally; Starkey, Norman

    2009-12-22

    The U.S. Alaska Department of Fish and Game has regulatory oversight of the mariculture industry that is partially administered through a statewide shellfish health policy. Possession and transport of bivalve molluscs require development of indigenous pathogen histories from diagnostic examinations of wild and farmed populations. These examinations have resulted in the detection of various infectious agents and parasites including viruses: an aquareovirus and aquabirna-like virus isolated by fish cell culture, and papilloma- or polyoma- and herpes-like virus particles within bivalve cell intranuclear inclusion bodies observed by electron microscopy. This study summarizes these results in samples examined from 1987 to 2009 and is the first description of poikilothermic viruses from Alaskan waters isolated from or observed within the tissues of 4 species of bivalve molluscs: geoduck clam Panope abrupta, native littleneck clam Protothaca staminea, purple-hinged rock scallop Crassadoma gigantea and Pacific oyster Crassostrea gigas. PMID:20183960

  19. Changes in Species Richness and Composition of Tiger Moths (Lepidoptera: Erebidae: Arctiinae) among Three Neotropical Ecoregions

    PubMed Central

    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

  20. Species composition of Black Sea marine planktonic copepods

    NASA Astrophysics Data System (ADS)

    Gubanova, A.; Altukhov, D.; Stefanova, K.; Arashkevich, E.; Kamburska, L.; Prusova, I.; Svetlichny, L.; Timofte, F.; Uysal, Z.

    2014-07-01

    This paper reviews the changes in the marine planktonic copepods of the Black Sea species' list from the beginning of taxonomic research to the present day. The study was based on the SESAME biological database, unpublished data, literature and data obtained during the course of the SESAME project. Comparisons were made with the Guidebook for Marine Fauna of the Black Sea and the Sea of Azov, which revealed changes both in the taxonomic status of some species and in the structure of the copepod community. The taxonomic status of two species (Acartia clausi small form and Centropages kroyeri pontica) and the nomenclature of two species (Oihona minuta and Calanus helgolandicus) have been changed. Three native species (Acartia margalefi, Oithona nana, and Paracartia latisetosa) have disappeared. Two non-indigenous copepods (Acartia tonsa and Oithona davisae) became established in the Black Sea ecosystem in the 1970s and 2000s, respectively. The success of their establishment was determined by biological features of the species and vulnerability of the native copepod community to invasions. It is highly probable that both species were introduced to the Black Sea by vessel ballast water. The hypothesis of "mediterranization" of the Black Sea fauna does not appear to hold true for zooplankton. Numerous claims of alien copepod species in the Black Sea remain largely unverified due to insufficient information. Data on newly discovered species of the Acartia genus are not authenticated. An updated list of marine planktonic copepods of the Black Sea is hereby presented.

  1. Representative Bulk Composition of Oil Types for the 2002 U.S. Geological Survey Resource Assessment of National Petroleum Reserve in Alaska

    USGS Publications Warehouse

    Lillis, Paul G.

    2004-01-01

    Bulk oil composition is an important economic consideration of a petroleum resource assessment. Geological and geochemical interpretations from previous North Slope studies combined with recently acquired geochemical data are used to predict representative oil gravity (?API) and sulfur content (wt.% S) of the oil types for the 2002 U.S. Geological Survey resource assessment of the National Petroleum Reserve of Alaska (NPRA). The oil types are named after their respective source rock units and include Kuna-Lisburne, Shublik-Otuk, Kingak-Blankenship, and Pebble-GRZ-Torok. The composition of the oil (24?API, 1.6 wt.% S) in the South Barrow 12 well was selected as representative of Kuna-Lisburne oil. The average gravity and sulfur values (23?API and 1.6 wt.% S, respectively) of the Kuparuk field were selected to be representative of Shublik-Otuk oil type. The composition of the oil (39?API, 0.3 wt.% S) from the Alpine field discovery well (ARCO Bergschrund 1) was selected to be representative of Kingak-Blankenship oil. The oil composition (37?API, 0.1 wt.% S) of Tarn field was considered representative of the Pebble-GRZ-Torok oil type in NPRA.

  2. AIRS Remote Sensing of Ammonia Species Preceding the Alaska Fire of 2004 Compared to Ground Monitoring in New York City

    NASA Astrophysics Data System (ADS)

    Padilla, D.; Steiner, J.; Menzel, P.

    2008-05-01

    Ammonia and ammonium sulfate are common industrial and agricultural byproducts. A widespread pollution event recorded by the Environmental Protection Agency July 2004 in the northeastern United States was overprinted and replaced in New York City by a down-trending of a smoke-laden aerosol tracked from the 2004 Alaska fire. Background subtraction of the absorption bands for ammonia (A) using the AIRS band at 966 cm-1 identifies a possible ammonia-rich plume that followed a westerly transect from the Midwest to New York City. The transition from ammonium sulfate (AS)-dominated to organic-derived carbon is documented at CCNY/NYC using x-ray diffraction (XRD) analysis of ribbons from an Environmental Beta Attenuation Monitor. XRD peaks are consistent with crystalline PM2.5 AS increasing dramatically over the interval July 17-21, being replaced by smoke particulates on July 22. Scanning electron microscope and energy dispersive analysis (SEM/EDS) of the smoke particulates show significant potassium and calcium enrichment in the complex ash, as do analysis of fractions of the ribbon analyzed by induced coupled plasma emission (ICP). This conforms to laboratory investigation of the byproducts of the combustion of pine and fir that show similar K- and Ca-enrichment. The laboratory data and the AIRS remote sensing measurements are combined with the MODIS Aerosol Optical Depth product to develop a method for monitoring industrial and agricultural ammonia-concentrated air masses for climate modeling.

  3. Biomarkers of PAH exposure in an intertidal fish species from Prince William Sound, Alaska: 2004-2005.

    PubMed

    Huggett, Robert J; Neff, Jerry M; Stegeman, John J; Woodin, Bruce; Parker, Keith R; Brown, John S

    2006-10-15

    Polycyclic aromatic hydrocarbon (PAH) exposure biomarkers were measured in high cockscomb prickleback (Anoplarchus purpurescens) fish collected from both previously oiled and unoiled shore in Prince William Sound (PWS), Alaska, to test the hypothesis that fish living in the nearshore environment of the sound were no longer being exposed to PAH from the Exxon Valdez oil spill. Pricklebacks spend their entire lives in the intertidal zone of rocky shores with short-term movements during feeding and breeding restricted to an area of about 15 meters in diameter. Fish were assayed for the PAH exposure biomarkers, bile fluorescent aromatic compounds (FAC), and liver ethoxyresorufin O-deethylase (EROD) activity (a measure of cytochrome P450 1A (CYP1A) monooxygenase activity). Bile FAC concentrations and EROD activities were low and not significantly different in fish from previously oiled and unoiled sites. The similar low EROD activity and bile FAC concentrations in fish from oiled and unoiled shores, supports the hypothesis that these low-level biomarker responses were not caused by exposure of the fish to residues of the spilled oil. PMID:17120588

  4. Use of community-composition data to predict the fecundity and abundance of species.

    PubMed

    Elmendorf, Sarah C; Moore, Kara A

    2008-12-01

    Species distribution models are critical tools for the prediction of invasive species spread and conservation of biodiversity. The majority of species distribution models have been built with environmental data. Community ecology theory suggests that species co-occurrence data could also be used to predict current and potential distributions of species. Species assemblages are the products of biotic and environmental constraints on the distribution of individual species and as a result may contain valuable information for niche modeling. We compared the predictive ability of distribution models of annual grassland plants derived from either environmental or community-composition data. Composition-based models were built with the presence or absence of species at a site as predictors of site quality, whereas environment-based models were built with soil chemistry, moisture content, above-ground biomass, and solar radiation as predictors. The reproductive output of experimentally seeded individuals of 4 species and the abundance of 100 species were used to evaluate the resulting models. Community-composition data were the best predictors of both the site-specific reproductive output of sown individuals and the site-specific abundance of existing populations. Successful community-based models were robust to omission of data on the occurrence of rare species, which suggests that even very basic survey data on the occurrence of common species may be adequate for generating such models. Our results highlight the need for increased public availability of ecological survey data to facilitate community-based modeling at scales relevant to conservation. PMID:18847440

  5. Seabirds in Alaska

    USGS Publications Warehouse

    Hatch, Scott A.; Piatt, John F.

    1995-01-01

    Techniques for monitoring seabird populations vary according to habitat types and the breeding behavior of individual species (Hatch and Hatch 1978, 1989; Byrd et al. 1983). An affordable monitoring program can include but a few of the 1,300 seabird colonies identified in Alaska, and since the mid-1970's, monitoring effotrts have emphasized a small selection of surface-feeding and diving species, primarily kittiwakes (Rissa spp.) and murres (Uria spp.). Little or no information on trends is available for other seabirds (Hatch 1993a). The existing monitoring program occurs largely on sites within the Alaska Maritime National Wildlife Refuge, which was established primarily for the conservation of marine birds. Data are collected by refuge staff, other state and federal agencies, private organizations, university faculty, and students.

  6. [Species composition of food-spoiling mycelial fungi].

    PubMed

    Feofilova, E P; Kuznetsova, L S; Sergeeva, Ia E; Galanina, L A

    2009-01-01

    We investigated the composition of the microflora that spoils foodstuffs (the surface of hard cheeses and sausages) at agribusiness factories. Mycelial fungi, mostly ascomycetes of the order Eurotiales belonging to the genus Penicillium play the main role in spoiling food. Most representatives of these fungi are mesophiles and possess the capacity for utilizing nutrient substrates in surface and submerged cultures.

  7. 75 FR 38938 - Fisheries of the Economic Exclusive Zone Off Alaska; Shallow-Water Species Fishery by Catcher...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-07

    ... for groundfish of the GOA (75 FR 11749, March 12, 2010), and as posted as the Catcher/Processor... species fishery for the sideboard limit are shallow-water flatfish and flathead sole. After the...

  8. 75 FR 38937 - Fisheries of the Economic Exclusive Zone Off Alaska; Deep-Water Species Fishery by Catcher...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-07

    ... GOA (75 FR 11749, March 12, 2010). In accordance with Sec. 679.82(d)(9)(i)(B), the Administrator... comprise the deep-water species fishery for the sideboard limit include deep-water flatfish, rex sole,...

  9. 76 FR 57679 - Fisheries of the Exclusive Economic Zone Off Alaska; Shallow-Water Species by Vessels Using Trawl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-16

    ... FR 55726, September 7, 2011). As of September 12, 2011, NMFS has determined that approximately 149... comprise the shallow-water species fishery are pollock, Pacific cod, shallow-water flatfish, flathead...

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

    PubMed

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

    2014-01-01

    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.

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

    PubMed Central

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

    2014-01-01

    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. PMID:24811826

  12. Large woody debris and salmonid habitat in the Anchor River basin, Alaska, following an extensive spruce beetle (Dendroctonus rufipennis) outbreak

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A widespread and intense spruce beetle outbreak has killed most of the mature white spruce trees across many watersheds in south-central Alaska. To investigate the potential habitat impacts in a salmon stream, we characterized the current abundance and species composition of large woody debris (LWD...

  13. High latitude meteoric δ18O compositions: Paleosol siderite in the Middle Cretaceous Nanushuk Formation, North Slope, Alaska

    USGS Publications Warehouse

    Ufnar, David F.; Ludvigson, Greg A.; Gonzalez, Luis A.; Brenner, Richard L.; Witzke, Brian J.

    2004-01-01

    Siderite-bearing pedogenic horizons of the Nanushuk Formation of the North Slope, Alaska, provide a critical high paleolatitude oxygen isotopic proxy record of paleoprecipitation, supplying important empirical data needed for paleoclimatic reconstructions and models of "greenhouse-world" precipitation rates. Siderite ??18O values were determined from four paleosol horizons in the National Petroleum Reserve Alaska (NPR-A) Grandstand # 1 Core, and the values range between -17.6??? and -14.3??? Peedee belemnite (PDB) with standard deviations generally less than 0.6??? within individual horizons. The ??13C values are much more variable, ranging from -4.6??? to +10.8??? PDB. A covariant ??18O versus ??13C trend in one horizon probably resulted from mixing between modified marine and meteoric phreatic fluids during siderite precipitation. Groundwater values calculated from siderite oxygen isotopic values and paleobotanical temperature estimates range from -23.0??? to -19.5??? standard mean ocean water (SMOW). Minor element analyses show that the siderites are impure, having enrichments in Ca, Mg, Mn, and Sr. Minor element substitutions and Mg/Fe and Mg/ (Ca + Mg) ratios also suggest the influence of marine fluids upon siderite precipitation. The pedogenic horizons are characterized by gleyed colors, rare root traces, abundant siderite, abundant organic matter, rare clay and silty clay coatings and infillings, some preservation of primary sedimentary stratification, and a lack of ferruginous oxides and mottles. The pedogenic features suggest that these were poorly drained, reducing, hydromorphic soils that developed in coal-bearing delta plain facies and are similar to modern Inceptisols. Model-derived estimates of precipitation rates for the Late Albian of the North Slope, Alaska (485-626 mm/yr), are consistent with precipitation rates necessary to maintain modern peat-forming environments. This information reinforces the mutual consistency between empirical

  14. Results of elemental and stable isotopic measurements, and dietary composition of Arctic grayling (Thymallus arcticus) collected in 2000 and 2001 from the Fortymile River Watershed, Alaska

    USGS Publications Warehouse

    Crock, J.G.; Seal, R.R.; Gough, L.P.; Weber-Scannell, P.

    2003-01-01

    We report the results of the elemental and stable isotopic analyses, as well as the composition of stomach contents, of Arctic grayling (Thymallus arcticus), an ecologically important resident freshwater sport and subsistence fish in the Fortymile River Mining District of the Interior Highlands Ecoregion in eastern Alaska. These data are presented here as a data compilation with minimal interpretation or discussion. Further analyses of the data will be presented elsewhere. The study area has been mined for placer gold for over a century and is currently experiencing renewed mineral exploration activity. The results for the analysis of 40 inorganic elements are reported for grayling muscle (fillet) tissue, liver tissue, and stomach contents from 34 individuals caught at 11 sites within the watershed. The 11 sites were classified as occurring within the following lithologies: metavolcanic (7 sites), metasedimentary (3 sites), and granitic intrusion (1 site). This information (along with fish tissue stable isotope data) is critical in the assessment of the influence of regional lithology on the fish chemical composition, especially the trace metal content. We report the nitrogen, carbon, and sulfur stable isotope composition of muscle samples. Nitrogen isotopes appear homogeneous (d15N = 7.6 to 9.7 permil) whereas carbon and sulfur isotope compositions of the same samples span a range from d 13C = ?33.1 to ?25.8 permil, and d 34S = ?8.4 to 8.2 permil. Stomach content material was examined for the occurrence and frequency of macroinvertebrate composition and diversity in three individual fish. Results showed a high degree of diversity with 9 to 15 invertebrate taxa; both aquatic and terrestrial forms were represented.

  15. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  16. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  17. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  18. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  19. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

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

    PubMed

    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. PMID:23949863

  1. Species composition and biomasses of fishes in tropical seagrasses at Groote Eylandt, northern Australia

    NASA Astrophysics Data System (ADS)

    Blaber, S. J. M.; Brewer, D. T.; Salini, J. P.; Kerr, J. D.; Conacher, C.

    1992-12-01

    The species composition and biomasses of fishes in the tropical seagrasses of Groote Eylandt, northern Australia, were studied in 1989 and 1990. A total of 156 species was recorded. Tall dense seagrass, short seagrass and control (no seagrass) sites in different depths were compared. Shallow (<1 m) sites were dominated by small resident species and juveniles of non-resident species, while deeper waters (to 7 m) were dominated by larger species. Species composition was not significantly different between sites, but species diversity ( H) and evenness ( E) were higher in non-vegetated areas. In slightly deeper water (<2 m) species composition was different between habitats and species diversity was highest in tall seagrass and least in open areas. Most species were more abundant in tall seagrass and least abundant in open areas. Most of the larger fishes, including 11 species of sharks, are piscivores, and most move into shallow sea-grass areas at night, irrespective of tide height. Only five species showed abundance patterns related to tide height and there were no significant seasonal patterns of abundance in any of the communities. The biomasses for all sites and sampling methods were mostly from 1 to 2 g m -2, which is low relative to other inshore tropical areas. The possible causes—the characteristics of adjacent habitats (coral reefs and mangroves) and the role of seagrasses in the life cycle of fishes are discussed. It is suggested that habitat structure is a major determinant of the species composition of fish in tropical seagrass areas, primarily because it affects food availability, both for small residents and juveniles, and for visiting predators.

  2. Species composition of Malassezia yeasts in dogs in Slovakia.

    PubMed

    Sihelská, Zuzana; Váczi, Peter; Conková, Eva

    2016-01-01

    Malassezia (M.) pachydermatis is the lipophilic yeast, which is normally present on the skin and in the ear canal of dogs but under certain conditions it may cause dermatitis and otitis. There is less known about the occurrence of lipid-dependent Malassezia species in dogs. The aim of this study was to detect whether lipid-dependent yeasts are part of the normal microflora in dogs. Two groups of animals were selected for comparison. The group of healthy dogs contained samples of 118 individuals and the group of dogs with cutaneous lesions or otitis externa comprised 328 dogs. The isolates of Malassezia were identified by using genotypic methods that allow the precise identification. M. pachydermatis was the most frequently isolated species in this study (121 isolates). Only four isolates were identified as M. furfur and one isolate was identified as M. nana. PMID:27529998

  3. Species composition of Malassezia yeasts in dogs in Slovakia.

    PubMed

    Sihelská, Zuzana; Váczi, Peter; Conková, Eva

    2016-01-01

    Malassezia (M.) pachydermatis is the lipophilic yeast, which is normally present on the skin and in the ear canal of dogs but under certain conditions it may cause dermatitis and otitis. There is less known about the occurrence of lipid-dependent Malassezia species in dogs. The aim of this study was to detect whether lipid-dependent yeasts are part of the normal microflora in dogs. Two groups of animals were selected for comparison. The group of healthy dogs contained samples of 118 individuals and the group of dogs with cutaneous lesions or otitis externa comprised 328 dogs. The isolates of Malassezia were identified by using genotypic methods that allow the precise identification. M. pachydermatis was the most frequently isolated species in this study (121 isolates). Only four isolates were identified as M. furfur and one isolate was identified as M. nana.

  4. [Species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China].

    PubMed

    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. The megaepifauna of the Dogger Bank (North Sea): species composition and faunal characteristics 1991-2008

    NASA Astrophysics Data System (ADS)

    Sonnewald, Moritz; Türkay, Michael

    2012-03-01

    During a long-term study in the summer months of the years 1991-2008, 176 megaepifaunal species were recorded through a series of beam trawl surveys on a grid of fixed stations on the Dogger Bank (central North Sea). This paper gives a qualitative overview on species composition throughout the research period, determined from samples collected during 15 cruises. In recent years, a number of species with more oceanic distribution patterns (e.g. species from SW British coasts) has been collected. In spite of these newcomers, there was a slight decrease in total species numbers during the research period.

  6. Landscape- and decadal-scale changes in the composition and structure of plant communities in the northern foothills of the Brooks Range of Arctic Alaska

    NASA Astrophysics Data System (ADS)

    Mercado-Díaz, J. A.; Gould, W. A.

    2010-12-01

    Scientists have predicted an increase in vascular plant cover in some tundra ecosystems as a result of global climate change. In Arctic Alaska, observational studies have documented increases in shrub cover for some regions; however, only a few studies have provided detailed quantitative evidence supporting the existence such changes. To address these shortcomings, we analyzed plant community data from 156 1m2 vegetation plots located at two 1km2 grids in Toolik Lake, Alaska. This data covered the time period from 1989-2008. After 18 years, we found that the relative abundance of vascular vegetation have increased by 16%, while the relative abundance of nonvascular vegetation decreased by 19%. Mean plant canopy height has experienced an increase from 4.4 cm in 1990 to 6.5 cm in 2008 and the extent and complexity of the canopy have increased over time from about 60% to 80%. Species diversity was also significantly reduced. While major vegetation changes in other tundra regions have been attributed to gradual increases in surface air temperature, changes documented in this study were apparently promoted by increasing soil moisture conditions that resulted from increased summer rainfall in our region. These results support the idea that tundra ecosystems in this region of the Alaskan Arctic are experiencing significant increases in aboveground standing crop and a shift in carbon allocation to vascular plants vs. bryophytes. These changes will likely affect important ecosystem processes like snow re-deposition, winter biological activities, nutrient cycling and could ultimately result in significant feedbacks to climate.

  7. Host species composition influences infection severity among amphibians in the absence of spillover transmission

    PubMed Central

    Han, Barbara A; Kerby, Jacob L; Searle, Catherine L; Storfer, Andrew; Blaustein, Andrew R

    2015-01-01

    Wildlife epidemiological outcomes can depend strongly on the composition of an ecological community, particularly when multiple host species are affected by the same pathogen. However, the relationship between host species richness and disease risk can vary with community context and with the degree of spillover transmission that occurs among co-occurring host species. We examined the degree to which host species composition influences infection by Batrachochytrium dendrobatidis (Bd), a widespread fungal pathogen associated with amphibian population declines around the world, and whether transmission occurs from one highly susceptible host species to other co-occurring host species. By manipulating larval assemblages of three sympatric amphibian species in the laboratory, we characterized the relationship between host species richness and infection severity, whether infection mediates growth and survivorship differently across various combinations of host species, and whether Bd is transmitted from experimentally inoculated tadpoles to uninfected tadpoles. We found evidence of a dilution effect where Bd infection severity was dramatically reduced in the most susceptible of the three host species (Anaxyrus boreas). Infection also mediated survival and growth of all three host species such that the presence of multiple host species had both positive (e.g., infection reduction) and negative (e.g., mortality) effects on focal species. However, we found no evidence that Bd infection is transmitted by this species. While these results demonstrate that host species richness as well as species identity underpin infection dynamics in this system, dilution is not the product of reduced transmission via fewer infectious individuals of a susceptible host species. We discuss various mechanisms, including encounter reduction and antagonistic interactions such as competition and opportunistic cannibalism that may act in concert to mediate patterns of infection severity, growth

  8. Influences of forest structure, climate and species composition on tree mortality across the eastern US.

    PubMed

    Lines, Emily R; Coomes, David A; Purves, Drew W

    2010-10-13

    Few studies have quantified regional variation in tree mortality, or explored whether species compositional changes or within-species variation are responsible for regional patterns, despite the fact that mortality has direct effects on the dynamics of woody biomass, species composition, stand structure, wood production and forest response to climate change. Using bayesian analysis of over 430,000 tree records from a large eastern US forest database we characterised tree mortality as a function of climate, soils, species and size (stem diameter). We found (1) mortality is U-shaped vs. stem diameter for all 21 species examined; (2) mortality is hump-shaped vs. plot basal area for most species; (3) geographical variation in mortality is substantial, and correlated with several environmental factors; and (4) individual species vary substantially from the combined average in the nature and magnitude of their mortality responses to environmental variation. Regional variation in mortality is therefore the product of variation in species composition combined with highly varied mortality-environment correlations within species. The results imply that variation in mortality is a crucial part of variation in the forest carbon cycle, such that including this variation in models of the global carbon cycle could significantly narrow uncertainty in climate change predictions.

  9. The lipid composition of a halotolerant species of Staphylococcus epidermidis.

    PubMed

    Komaratat, P; Kates, M

    1975-09-19

    Studies were carried out on the lipid composition of a halotolerant Staphylococcus epidermidis isolated in pure culture from a growth medium for extreme halophiles containing 25% NaCl. The four major polar lipid components in this bacterium were found to be: (a) glycerophosphoryl diglucosyl diglyceride (10% by weight) with structure 3(1)-O-(-sn-glycerol-1-phosphoryl-6'-O=(beta-D glucopyranosyl-(1 leads to 6)- O-beta-D-glucopyranosyl)-1(3),2-diacyl-sn-glycerol; (b) diglucosyl diglyceride (15% by weight) with structure 3(1)-O-(beta-D-glucopyranosyl (1 leads to 6)-O-beta-D-glucopyranosyl)-1(3),2-diacyl-sn-glycerol; (c) monoglucosyl diglyceride (3% by weight) with structure 3(1)-O-(beta-D-glucopyranosyl)-1(3),2-diacyl-sn-glycerol, and (d) phosphatidylglycerol (60% by weight) with structure 1,2 diacyl-sn-glycero-3-phosphoryl-1'-sn-glycerol. Phosphatidic acid, cardiolipin, lysophosphatidylglycerol and three unidentified phospholipids were also detected in small amounts. Each lipid component had essentially the same fatty acid composition namely, anteiso-15:0 (60-75%), anteiso-17:0 (18-24%), iso-17:0 (8--10%), and small amounts of palmitic and stearic acids (2-5%). The fatty acids were non-randomly distributed in phosphatidylglycerol, the shorter chain anteiso 15:0 fatty acid being exclusively esterified to the 2-position and the longer chain anteiso- and iso-17:0 fatty acids at the 1-position. The fatty acid composition was not affected by increaseing NaCl content in the medium in the rande 0--15% but the proportion of anteiso-15:0 increased greatly when the salt concentration was increased to 25%. The proportions of ionic polar lipids were modified to give an increased net negative charge per mol ionic lipids when NaCl in the medium was increased from 15 to 25%, but the proportions of neutral glycolipids remained fairly constant.

  10. The lipid composition of a halotolerant species of Staphylococcus epidermidis.

    PubMed

    Komaratat, P; Kates, M

    1975-09-19

    Studies were carried out on the lipid composition of a halotolerant Staphylococcus epidermidis isolated in pure culture from a growth medium for extreme halophiles containing 25% NaCl. The four major polar lipid components in this bacterium were found to be: (a) glycerophosphoryl diglucosyl diglyceride (10% by weight) with structure 3(1)-O-(-sn-glycerol-1-phosphoryl-6'-O=(beta-D glucopyranosyl-(1 leads to 6)- O-beta-D-glucopyranosyl)-1(3),2-diacyl-sn-glycerol; (b) diglucosyl diglyceride (15% by weight) with structure 3(1)-O-(beta-D-glucopyranosyl (1 leads to 6)-O-beta-D-glucopyranosyl)-1(3),2-diacyl-sn-glycerol; (c) monoglucosyl diglyceride (3% by weight) with structure 3(1)-O-(beta-D-glucopyranosyl)-1(3),2-diacyl-sn-glycerol, and (d) phosphatidylglycerol (60% by weight) with structure 1,2 diacyl-sn-glycero-3-phosphoryl-1'-sn-glycerol. Phosphatidic acid, cardiolipin, lysophosphatidylglycerol and three unidentified phospholipids were also detected in small amounts. Each lipid component had essentially the same fatty acid composition namely, anteiso-15:0 (60-75%), anteiso-17:0 (18-24%), iso-17:0 (8--10%), and small amounts of palmitic and stearic acids (2-5%). The fatty acids were non-randomly distributed in phosphatidylglycerol, the shorter chain anteiso 15:0 fatty acid being exclusively esterified to the 2-position and the longer chain anteiso- and iso-17:0 fatty acids at the 1-position. The fatty acid composition was not affected by increaseing NaCl content in the medium in the rande 0--15% but the proportion of anteiso-15:0 increased greatly when the salt concentration was increased to 25%. The proportions of ionic polar lipids were modified to give an increased net negative charge per mol ionic lipids when NaCl in the medium was increased from 15 to 25%, but the proportions of neutral glycolipids remained fairly constant. PMID:1174526

  11. Biochemical composition of three species of unionid mussels after emersion

    USGS Publications Warehouse

    Greseth, Shari L.; Cope, W.G.; Rada, R.G.; Waller, D.L.; Bartsch, M.R.

    2003-01-01

    Freshwater mussels are emersed (exposed to air) during conservation activities such as surveys and relocations. Success of these activities depends upon the ability of mussels to survive emersion and to re-burrow in the substratum. We evaluated the acute sublethal effects of emersion on three species of unionid mussels [pocketbook, Lampsilis cardium (Rafinesque, 1820); pimpleback, Quadrula pustulosa pustulosa (I. Lea, 1831); spike, Elliptio dilatata (Rafinesque, 1820)] by measuring three biochemicals (carbohydrate, lipid, protein) indicative of biochemical function and energy storage. Mussels were acclimated in water at 25??C and exposed to five air temperatures (15, 20, 25, 35 and 45??C) for 15, 30 and 60 min. After emersion, mussels were returned to water at 25??C and observed for 14 days. Samples of mantle tissue were taken after the 14-day postexposure period and analysed for carbohydrate, lipid and protein. Three-way analysis of variance (ANOVA) did not reveal consistent trends in carbohydrate, lipid or protein concentrations due to sex of mussels, duration of emersion, air temperature or their interaction terms that indicated biological compensation to stress. Overall mean carbohydrate concentrations were greatest (range 447-615 mg/g dry wt) among the species, followed by protein (179-289 mg/g dry wt) and lipids (26.7-38.1 mg/g dry wt). These results have positive implications for conducting conservation activities, because emersion over the range of temperatures (15-35??C) and durations (15-60 min) examined did not appear acutely harmful to mussels.

  12. DNA Barcoding of Shark Meats Identify Species Composition and CITES-Listed Species from the Markets in Taiwan

    PubMed Central

    Liu, Shang-Yin Vanson; Chan, Chia-Ling Carynn; Lin, Oceana; Hu, Chieh-Shen; Chen, Chaolun Allen

    2013-01-01

    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. PMID:24260209

  13. Floristic composition, environmental variation and species distribution patterns in burned grassland in southern Brazil.

    PubMed

    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. PMID:17299944

  14. Explaining the effects of floral density on flower visitor species composition

    PubMed Central

    Essenberg, Carla J.

    2013-01-01

    Floral density often influences the species composition of flower visitors. This variation in visitor species composition could have significant effects on pollination success and plant fitness but is poorly understood, especially in the many pollination guilds dominated by non-territorial species. This paper presents a foraging model that explores how flower visitors with diverse traits should distribute themselves across resource patches differing in floral density. The model predicts that species with low flower search speeds and low flower handling costs compared to competitors will usually dominate dense flower patches. In addition, amongst flower visitors that have lower energy expenditure rates while handling flowers than while traveling, species maximizing energetic efficiency are typically associated with dense flower patches whereas those maximizing net rate of energy intake are associated with sparse patches. The model is able to predict some key aspects of a previously-observed effect of floral density on species composition of flower visitors to the yellowflower tarweed (Holocarpha virgata). By providing insights into how flower visitors’ traits shape the effects of floral density on the species composition of flower visitors, this study makes an important step towards understanding how pollinator diversity influences relationships between plant density and plant fitness. PMID:23448884

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

    PubMed

    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.

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

    PubMed Central

    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

  17. Species richness effects on ecosystem multifunctionality depend on evenness, composition and spatial pattern

    USGS Publications Warehouse

    Maestre, F.T.; Castillo-Monroy, A. P.; Bowker, M.A.; Ochoa-Hueso, R.

    2012-01-01

    1. Recent studies have suggested that the simultaneous maintenance of multiple ecosystem functions (multifunctionality) is positively supported by species richness. However, little is known regarding the relative importance of other community attributes (e.g. spatial pattern, species evenness) as drivers of multifunctionality. 2. We conducted two microcosm experiments using model biological soil crust communities dominated by lichens to: (i) evaluate the joint effects and relative importance of changes in species composition, spatial pattern (clumped and random distribution of lichens), evenness (maximal and low evenness) and richness (from two to eight species) on soil functions related to nutrient cycling (β-glucosidase, urease and acid phosphatase enzymes, in situ N availability, total N, organic C, and N fixation), and (ii) assess how these community attributes affect multifunctionality. 3. Species richness, composition and spatial pattern affected multiple ecosystem functions (e.g. organic C, total N, N availability, β-glucosidase activity), albeit the magnitude and direction of their effects varied with the particular function, experiment and soil depth considered. Changes in species composition had effects on organic C, total N and the activity of β-glucosidase. Significant species richness × evenness and spatial pattern × evenness interactions were found when analysing functions such as organic C, total N and the activity of phosphatase. 4. The probability of sustaining multiple ecosystem functions increased with species richness, but this effect was largely modulated by attributes such as species evenness, composition and spatial pattern. Overall, we found that model communities with high species richness, random spatial pattern and low evenness increased multifunctionality. 5. Synthesis. Our results illustrate how different community attributes have a diverse impact on ecosystem functions related to nutrient cycling, and provide new

  18. Species effects on ecosystem processes are modified by faunal responses to habitat composition.

    PubMed

    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.

  19. Biochemical composition of three species of unionid mussels after emersion

    USGS Publications Warehouse

    Greseth, Shari L.; Cope, W.G.; Rada, R.G.; Waller, D.L.; Bartsch, M.R.

    2003-01-01

    Freshwater mussels are emersed (exposed to air) during conservation activities such as surveys and relocations. Success of these activities depends upon the ability of mussels to survive emersion and to re-burrow in the substratum. We evaluated the acute sublethal effects of emersion on three species of unionid mussels [pocketbook, Lampsilis cardium (Rafinesque, 1820); pimpleback, Quadrula pustulosa pustulosa (I. Lea, 1831); spike, Elliptio dilatata (Rafinesque, 1820)] by measuring three biochemicals (carbohydrate, lipid, protein) indicative of biochemical function and energy storage. Mussels were acclimated in water at 25A?C and exposed to five air temperatures (15, 20, 25, 35 and 45A?C) for 15, 30 and 60 min. After emersion, mussels were returned to water at 25A?C and observed for 14 days. Samples of mantle tissue were taken after the 14-day postexposure period and analysed for carbohydrate, lipid and protein. Three-way analysis of variance (ANOVA) did not reveal consistent trends in carbohydrate, lipid or protein concentrations due to sex of mussels, duration of emersion, air temperature or their interaction terms that indicated biological compensation to stress. Overall mean carbohydrate concentrations were greatest (range 447a??615 mg/g dry wt) among the species, followed by protein (179a??289 mg/g dry wt) and lipids (26.7a??38.1 mg/g dry wt). These results have positive implications for conducting conservation activities, because emersion over the range of temperatures (15a??35A?C) and durations (15a??60 min) examined did not appear acutely harmful to mussels.

  20. Evidence for multiple mechanisms of crustal contamination of magma from compositionally zoned plutons and associated ultramafic intrusions of the Alaska Range

    USGS Publications Warehouse

    Reiners, P.W.; Nelson, B.K.; Nelson, S.W.

    1996-01-01

    Models of continental crustal magmagenesis commonly invoke the interaction of mafic mantle-derived magma and continental crust to explain geochemical and petrologic characteristics of crustal volcanic and plutonic rocks. This interaction and the specific mechanisms of crustal contamination associated with it are poorly understood. An excellent opportunity to study the progressive effects of crustal contamination is offered by the composite plutons of the Alaska Range, a series of nine early Tertiary, multiply intruded, compositionally zoned (peridotite to granite) plutons. Large initial Sr and Nd isotopic contrasts between the crustal country rock and likely parental magmas allow evaluation of the mechanisms and extents of crustal contamination that accompanied the crystallization of these ultramafic through granitic rocks. Three contamination processes are distinguished in these plutons. The most obvious of these is assimilation of crustal country rock concurrent with magmatic fractional crystallization (AFC), as indicated by a general trend toward crustal-like isotopic signatures with increasing differentiation. Second, many ultramafic and mafic rocks have late-stage phenocryst reaction and orthocumulate textures that suggest interaction with felsic melt. These rocks also have variable and enriched isotopic compositions that suggest that this felsic melt was isotopically enriched and probably derived from crustal country rock. Partial melt from the flysch country rock may have reacted with and contaminated these partly crystalline magmas following the precipitation and accumulation of the cumulus phenocrysts but before complete solidification of the magma. This suggests that in magmatic mush (especially of ultramafic composition) crystallizing in continental crust, a second distinct process of crustal contamination may be super-imposed on AFC or magma mixing involving the main magma body. Finally, nearly all rocks, including mafic and ultramafic rocks, have (87Sr

  1. Remnant Trees Affect Species Composition but Not Structure of Tropical Second-Growth Forest

    PubMed Central

    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. PMID:24454700

  2. Remnant trees affect species composition but not structure of tropical second-growth forest.

    PubMed

    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.

  3. Anthocyanins in the bracts of Curcuma species and relationship of the species based on anthocyanin composition.

    PubMed

    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.

  4. Species and life-history affects the utility of otolith chemical composition to determine natal stream-of-origin in Pacific salmon

    USGS Publications Warehouse

    Zimmerman, Christian E.; Swanson, Heidi K.; Volk, Eric C.; Kent, Adam J.R.

    2013-01-01

    To test the utility of otolith chemical composition as a tool for determining the natal stream of origin for salmon, we examined water chemistry and otoliths of juvenile and adult Chum Salmon Oncorhynchus keta and Coho Salmon O. kisutch from three watersheds (five rivers) in the Norton Sound region of Alaska. The two species are characterized by different life histories: Coho Salmon rear in freshwater for up to 3 years, whereas Chum Salmon emigrate from freshwater shortly after emergence. We used laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry (MS) to quantify element: Ca ratios for Mg, Mn, Zn, Sr, and Ba, and we used multicollector LA-ICP-MS to determine 87Sr:86Sr ratios in otolith regions corresponding to the period of freshwater residence. Significant differences existed in both water and otolith elemental composition, suggesting that otolith composition could be used to discriminate the natal origin of Coho Salmon and Chum Salmon but only when 87Sr:86Sr ratios were included in the discriminant function analyses. The best discriminant model included 87Sr:86Sr ratios, and without 87Sr:86Sr ratios it was difficult to discriminate among watersheds and rivers. Classification accuracy was 80% for Coho Salmon and 68% for Chum Salmon, indicating that this method does not provide sufficient sensitivity to estimate straying rates of Pacific salmon at the scale we studied.

  5. Species composition and feeding success of mosquitoes attracted to caged dogs in Indiana.

    PubMed

    Pinger, R R

    1985-06-01

    A field study using caged dogs in mosquito bait traps was conducted in eastcentral Indiana to determine the species composition of mosquitoes coming to feed. Fourteen species of mosquitoes from 5 genera were collected; Aedes trivittatus predominated. Feeding success rates were measured as the percentage of mosquitoes collected that had a fresh blood meal. The species having the highest rates were: Culex erraticus, Aedes stimulans and Ae. trivittatus. Aedes vexans and Cx. pipiens/restuans had markedly lower feeding success rates. A New Jersey light trap operated at the same site each year yielded a different species composition. Because of its propensity for feeding on dogs, Ae. trivittatus may be considered as a major potential vector of heartworm disease in dogs, even where it is one of several possible vector species present in abundance.

  6. Nutrient and antinutrient composition of three varieties of Piper species.

    PubMed

    Isong, E U; Essien, I B

    1996-02-01

    The proximate composition of three varieties of Piper guineense (Odusa-Ibibio/Efik) viz. 'Uyat Odusa' (cultivated and peppery), 'Eting-keni Ikot' (wild forest variety) and 'Eting-keni mben inyang' (wild, riverine variety), were determined using available standard methods. Also determined were mineral, antinutrient and ascorbate levels. The cultivated pepperic variety had the highest content of crude protein and moisture (18.9% and 97% respectively) while the wild, riverine variety had the highest content of ether extract, carbohydrate and calories (7.79%, 63.38% and 398 cals respectively). The cultivated variety had appreciable amounts of phosphorus (1.12 mg/100 g), potassium (1.2 mg/100 g), sodium (0.24 mg/100 g), zinc (0.18 mg/100 g), and copper (0.18 mg/100 g) while the forest variety contained more of calcium (12.38 mg/100 g), magnesium (1.21 mg/100 g) and iron (0.85 mg/100 g). The wild riverine variety appeared to have the least mineral content but had the highest ascorbate level of 173.4 mg/100 g. Of four antinutrients assayed, the cultivated pepperic one had the least quantities while the forest variety was highest in hydrocyanic acid (85.8 mg/100 g) and glucosinolates (0.20 mg/100 g). The wild riverine variety had the highest level of total oxalate (165.0 mg/100 g). These quantities are however far below documented toxic levels. PMID:8811726

  7. Floral scent composition predicts bee pollination system in five butterfly bush (Buddleja, Scrophulariaceae) species.

    PubMed

    Gong, W-C; Chen, G; Vereecken, N J; Dunn, B L; Ma, Y-P; Sun, W-B

    2015-01-01

    Traditionally, plant-pollinator interactions have been interpreted as pollination syndrome. However, the validity of pollination syndrome has been widely doubted in modern studies of pollination ecology. The pollination ecology of five Asian Buddleja species, B. asiatica, B. crispa, B. forrestii, B. macrostachya and B. myriantha, in the Sino-Himalayan region in Asia, flowering in different local seasons, with scented inflorescences were investigated during 2011 and 2012. These five species exhibited diverse floral traits, with narrow and long corolla tubes and concealed nectar. According to their floral morphology, larger bees and Lepidoptera were expected to be the major pollinators. However, field observations showed that only larger bees (honeybee/bumblebee) were the primary pollinators, ranging from 77.95% to 97.90% of total visits. In this study, floral scents of each species were also analysed using coupled gas chromatography and mass spectrometry (GC-MS). Although the five Buddleja species emitted differentiated floral scent compositions, our results showed that floral scents of the five species are dominated by substances that can serve as attractive signals to bees, including species-specific scent compounds and principal compounds with larger relative amounts. This suggests that floral scent compositions are closely associated with the principal pollinator assemblages in these five species. Therefore, we conclude that floral scent compositions rather than floral morphology traits should be used to interpret plant-pollinator interactions in these Asian Buddleja species.

  8. Effects of Previous Land-Use on Plant Species Composition and Diversity in Mediterranean Forests.

    PubMed

    Kouba, Yacine; Martínez-García, Felipe; de Frutos, Ángel; Alados, Concepción L

    2015-01-01

    At some point in their history, most forests in the Mediterranean Basin have been subjected to intensive management or converted to agriculture land. Knowing how forest plant communities recovered after the abandonment of forest-management or agricultural practices (including livestock grazing) provides a basis for investigating how previous land management have affected plant species diversity and composition in forest ecosystems. Our study investigated the consequences of historical "land management" practices on present-day Mediterranean forests by comparing species assemblages and the diversity of (i) all plant species and (ii) each ecological group defined by species' habitat preferences and successional status (i.e., early-, mid-, and late-successional species). We compared forest stands that differed both in land-use history and in successional stage. In addition, we evaluated the value of those stands for biodiversity conservation. The study revealed significant compositional differentiation among stands that was due to among-stand variations in the diversity (namely, species richness and evenness) of early-, intermediate-, and late-successional species. Historical land management has led to an increase in compositional divergences among forest stands and the loss of late-successional forest species. PMID:26397707

  9. The effect of AMF suppression on plant species composition in a nutrient-poor dry grassland.

    PubMed

    Dostálek, Tomáš; Pánková, Hana; Münzbergová, Zuzana; Rydlová, Jana

    2013-01-01

    Arbuscular mycorrhizal fungi (AMF) are expected to be one of the key drivers determining the diversity of natural plant communities, especially in nutrient-poor and dry habitats. Several previous studies have explored the importance of AMF for the composition of plant communities in various types of habitats. Surprisingly, studies of the role of AMF in nutrient-poor dry grassland communities dominated by less mycotrophic plant species are still relatively rare. We present the results of a 3-year study in which a plant community in a species-rich dry grassland was subjected to the fungicide carbendazim to suppress AMF colonization. We tested the effect of the fungicide on the following parameters: the plant species composition; the number of plant species; the cover of the rare, highly mycorrhiza-dependent species Aster amellus; the cover of the dominant, less mycorrhiza-dependent species Brachypodium pinnatum; and the cover of graminoids and perennial forbs. In addition, we examined the mycorrhizal inoculation potential of the soil. We found that the suppression of AMF with fungicide resulted in substantial changes in plant species composition and significant decrease in species richness, the cover of A. amellus and the cover of perennial forbs. In contrast the species increasing their cover after fungicide application were graminoids--the C3 grasses B. pinnatum and Bromus erectus and the sedge Carex flacca. These species appear to be less mycorrhiza dependent. Moreover, due to their clonal growth and efficient nutrient usage, they are, most likely, better competitors than perennial forbs under fungicide application. Our results thus suggest that AMF are an essential part of the soil communities supporting a high diversity of plant species in species-rich dry grasslands in nutrient-poor habitats. The AMF are especially important for the maintenance of the populations of perennial forbs, many of which are rare and endangered in the area.

  10. The Effect of AMF Suppression on Plant Species Composition in a Nutrient-Poor Dry Grassland

    PubMed Central

    Dostálek, Tomáš; Pánková, Hana; Münzbergová, Zuzana; Rydlová, Jana

    2013-01-01

    Arbuscular mycorrhizal fungi (AMF) are expected to be one of the key drivers determining the diversity of natural plant communities, especially in nutrient-poor and dry habitats. Several previous studies have explored the importance of AMF for the composition of plant communities in various types of habitats. Surprisingly, studies of the role of AMF in nutrient-poor dry grassland communities dominated by less mycotrophic plant species are still relatively rare. We present the results of a 3-year study in which a plant community in a species-rich dry grassland was subjected to the fungicide carbendazim to suppress AMF colonization. We tested the effect of the fungicide on the following parameters: the plant species composition; the number of plant species; the cover of the rare, highly mycorrhiza-dependent species Aster amellus; the cover of the dominant, less mycorrhiza-dependent species Brachypodium pinnatum; and the cover of graminoids and perennial forbs. In addition, we examined the mycorrhizal inoculation potential of the soil. We found that the suppression of AMF with fungicide resulted in substantial changes in plant species composition and significant decrease in species richness, the cover of A. amellus and the cover of perennial forbs. In contrast the species increasing their cover after fungicide application were graminoids—the C3 grasses B. pinnatum and Bromus erectus and the sedge Carex flacca. These species appear to be less mycorrhiza dependent. Moreover, due to their clonal growth and efficient nutrient usage, they are, most likely, better competitors than perennial forbs under fungicide application. Our results thus suggest that AMF are an essential part of the soil communities supporting a high diversity of plant species in species-rich dry grasslands in nutrient-poor habitats. The AMF are especially important for the maintenance of the populations of perennial forbs, many of which are rare and endangered in the area. PMID:24265829

  11. The effect of AMF suppression on plant species composition in a nutrient-poor dry grassland.

    PubMed

    Dostálek, Tomáš; Pánková, Hana; Münzbergová, Zuzana; Rydlová, Jana

    2013-01-01

    Arbuscular mycorrhizal fungi (AMF) are expected to be one of the key drivers determining the diversity of natural plant communities, especially in nutrient-poor and dry habitats. Several previous studies have explored the importance of AMF for the composition of plant communities in various types of habitats. Surprisingly, studies of the role of AMF in nutrient-poor dry grassland communities dominated by less mycotrophic plant species are still relatively rare. We present the results of a 3-year study in which a plant community in a species-rich dry grassland was subjected to the fungicide carbendazim to suppress AMF colonization. We tested the effect of the fungicide on the following parameters: the plant species composition; the number of plant species; the cover of the rare, highly mycorrhiza-dependent species Aster amellus; the cover of the dominant, less mycorrhiza-dependent species Brachypodium pinnatum; and the cover of graminoids and perennial forbs. In addition, we examined the mycorrhizal inoculation potential of the soil. We found that the suppression of AMF with fungicide resulted in substantial changes in plant species composition and significant decrease in species richness, the cover of A. amellus and the cover of perennial forbs. In contrast the species increasing their cover after fungicide application were graminoids--the C3 grasses B. pinnatum and Bromus erectus and the sedge Carex flacca. These species appear to be less mycorrhiza dependent. Moreover, due to their clonal growth and efficient nutrient usage, they are, most likely, better competitors than perennial forbs under fungicide application. Our results thus suggest that AMF are an essential part of the soil communities supporting a high diversity of plant species in species-rich dry grasslands in nutrient-poor habitats. The AMF are especially important for the maintenance of the populations of perennial forbs, many of which are rare and endangered in the area. PMID:24265829

  12. Nectar production dynamics and sugar composition in two Mucuna species (Leguminosae, Faboideae) with different specialized pollinators.

    PubMed

    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.

  13. Nectar production dynamics and sugar composition in two Mucuna species (Leguminosae, Faboideae) with different specialized pollinators

    NASA Astrophysics Data System (ADS)

    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.

  14. Nectar production dynamics and sugar composition in two Mucuna species (Leguminosae, Faboideae) with different specialized pollinators.

    PubMed

    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. PMID:21928066

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

    PubMed

    Abeytia, Rosalinda; Guzmán, Hector M; Breedy, Odalisca

    2013-09-01

    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 0-70 m in 15 sites. The relative abundance of species was determined in six sites at four depths (5, 10, 20 and 25 m) using three 10 m2 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 40-70 m 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 40-70 m, whereas the highest abundances are found between 5 and 10 m depth. This study represents a contribution to the poorly known eastern Pacific gorgonian biota.

  16. Correlating Permafrost Organic Matter Composition and Characteristics with Methane Production Potentials in a First Generation Thermokarst Lake and Its Underlying Permafrost Near Fairbanks, Alaska, USA

    NASA Astrophysics Data System (ADS)

    Heslop, J.; Walter Anthony, K. M.; Sepulveda-Jauregui, A.; Martinez-Cruz, K. C.

    2014-12-01

    Thermokarst lakes, formed in permafrost-thaw depressions, are known sources of atmospheric methane (CH4) and carbon dioxide (CO2). The organic carbon (OC) utilized in the production of these greenhouse gases originates from microbial decomposition of aquatic and terrestrial organic matter (OM) sources, including soils of the lakes' watersheds and permafrost thaw beneath the lakes. OM derived from permafrost thaw is particularly important given the thickness of permafrost soils underlying some lakes (typically 10-30 m in yedoma permafrost); however, OM heterogeneity remains a significant uncertainty in estimating how microbial decomposition responds to permafrost thaw. This study correlates OM and water-extractable OC (WEOC) composition with CH4 production potentials determined from anaerobic laboratory incubations. Samples were collected from 21 depths along a 5.9-m deep thermokarst-lake sediment core and 17 depths along an adjacent 40-m deep undisturbed yedoma permafrost profile near Vault Creek, Alaska. The Vault Lake core, collected in the center of a 3230 m2 first generation thermokarst lake, includes surface lake sediments, the talik (thaw bulb), and permafrost actively thawing beneath the lake. Soil OM composition was characterized using pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) and the most prevalent compounds were grouped into six indices based on their likely origin. WEOC was characterized using fluorescence spectrometry. Using stepwise multiple linear regression analyses, we found that CH4 production was negatively correlated with WEOC aromaticity (p = 0.018) and fulvic acids (p = 0.027). CH4 production was positively correlated with lipids and carboxylic acids (p < 0.001), polysaccharides (p = 0.036) and the degree of WEOC humification (p = 0.013). Results suggest OM and WEOC composition can be correlated with CH4 production, indicating potential for model building to better predict greenhouse gas release from permafrost thaw.

  17. Xylem sap protein composition is conserved among different plant species.

    PubMed

    Buhtz, Anja; Kolasa, Anna; Arlt, Kathleen; Walz, Christina; Kehr, Julia

    2004-08-01

    Xylem sap from broccoli (Brassica oleracea L. cv. Calabrais), rape (Brassica napus L. cv. Drakkar), pumpkin (Cucurbita maxima Duch. cv. gelber Zentner) and cucumber (Cucumis sativus L. cv. Hoffmanns Giganta) was collected by root pressure exudation from the surface of cut stems of healthy, adult plants. Total protein concentrations were in the range of 100 microg ml(-1). One-dimensional gel electrophoresis (SDS-PAGE) resulted in 10-20 visible protein bands in a molecular mass range from 10 to 100 kDa. The main bands were cut out, digested with trypsin, and analysed using tandem mass spectrometry. Fifty bands resulted in amino acid sequence information that was used to perform database similarity searches. Sequences from 30 bands showed high homology to proteins present in databases. Among them, we found mostly peroxidases, but could also identify the lectin-like xylem protein XSP30, a glycine-rich protein, serine proteases, an aspartyl protease family protein, chitinases, and a lipid transfer protein-like polypeptide. Sequence analysis predicted apoplastic secretion signals for all database entries similar to the partial xylem protein sequences. This and the lack of cross-reactivity with phloem protein-specific antibodies suggest that the proteins really originate from the xylem and do not result from phloem contamination. Most of the highly similar proteins probably function in repair and defence reactions. Some of the most abundant proteins (peroxidases, chitinases, serine proteases) were present in xylem exudate of all species analysed, often in more than one band. This indicates an important basic role of these proteins in maintaining xylem function. PMID:15064951

  18. Species Composition at the Sub-Meter Level in Discontinuous Permafrost in Subarctic Sweden

    NASA Astrophysics Data System (ADS)

    Anderson, S. M.; Palace, M. W.; Layne, M.; Varner, R. K.; Crill, P. M.

    2013-12-01

    Northern latitudes are experiencing rapid warming. Wetlands underlain by permafrost are particularly vulnerable to warming which results in changes in vegetative cover. Specific species have been associated with greenhouse gas emissions therefore knowledge of species compositional shift allows for the systematic change and quantification of emissions and changes in such emissions. Species composition varies on the sub-meter scale based on topography and other microsite environmental parameters. This complexity and the need to scale vegetation to the landscape level proves vital in our estimation of carbon dioxide (CO2) and methane (CH4) emissions and dynamics. Stordalen Mire (68°21'N, 18°49'E) in Abisko and is located at the edge of discontinuous permafrost zone. This provides a unique opportunity to analyze multiple vegetation communities in a close proximity. To do this, we randomly selected 25 1x1 meter plots that were representative of five major cover types: Semi-wet, wet, hummock, tall graminoid, and tall shrub. We used a quadrat with 64 sub plots and measured areal percent cover for 24 species. We collected ground based remote sensing (RS) at each plot to determine species composition using an ADC-lite (near infrared, red, green) and GoPro (red, blue, green). We normalized each image based on a Teflon white chip placed in each image. Textural analysis was conducted on each image for entropy, angular second momentum, and lacunarity. A logistic regression was developed to examine vegetation cover types and remote sensing parameters. We used a multiple linear regression using forwards stepwise variable selection. We found statistical difference in species composition and diversity indices between vegetation cover types. In addition, we were able to build regression model to significantly estimate vegetation cover type as well as percent cover for specific key vegetative species. This ground-based remote sensing allows for quick quantification of vegetation

  19. Explicitly correlated composite thermochemistry of transition metal species

    NASA Astrophysics Data System (ADS)

    Bross, David H.; Hill, J. Grant; Werner, H.-J.; Peterson, Kirk A.

    2013-09-01

    Atomization energies were calculated using explicitly correlated coupled cluster methods with correlation consistent basis sets for a series of 19 small molecules containing 3d transition metal atoms. The atomization energies were calculated using a modified Feller-Peterson-Dixon approach in which CCSD(T) complete basis set (CBS) limits were obtained using extrapolations of aVTZ/aVQZ CCSD(T)-F12b correlation energies, and then a series of additive contributions for relativity, core correlation, higher order correlation, and zero-point vibrations were included. The frozen-core CBS limits calculated with F12 methods closely matched the more computational expensive conventional awCVQZ/awCV5Z CBS extrapolations, with a mean unsigned deviation of just 0.1 kcal/mol. In particular, the CCSD(T*)-F12b/aVDZ and aVTZ atomization energies were more accurate on average than the conventional CCSD(T)/aVQZ and aV5Z results, respectively. In several cases the effects of higher order correlation beyond CCSD(T), as judged by CCSDT and CCSDT(Q)Λ calculations, were greater than 1 kcal/mol, reaching 4.5 kcal/mol for CrO3. For the 16 molecules of this study with experimental uncertainties of ˜3.5 kcal/mol or less, the final composite heats of formation have a mean unsigned deviation (MUD) from experiment of just 1.3 kcal/mol, which is slightly smaller than the average of the experimental uncertainties, 1.8 kcal/mol. The root mean square deviation (RMS) is only slightly larger at 1.7 kcal/mol. Without the contributions due to higher order correlation effects, the MUD and RMS rise to 2.1 and 2.8 kcal/mol, respectively. To facilitate the F12 calculations, new (aug-)cc-pVnZ/MP2Fit (n = Q, 5) and (aug-)cc-pwCVTZ/MP2Fit auxiliary basis sets were also developed for the transition metal atoms.

  20. Mycorrhizal Fungal Diversity and Community Composition in Two Closely Related Platanthera (Orchidaceae) Species

    PubMed Central

    Esposito, Fabiana; Jacquemyn, Hans; Waud, Michael; Tyteca, Daniel

    2016-01-01

    While it is generally acknowledged that orchid species rely on mycorrhizal fungi for completion of their life cycle, little is yet known about how mycorrhizal fungal diversity and community composition vary within and between closely related orchid taxa. In this study, we used 454 amplicon pyrosequencing to investigate variation in mycorrhizal communities between pure (allopatric) and mixed (sympatric) populations of two closely related Platanthera species (Platanthera bifolia and P. chlorantha) and putative hybrids. Consistent with previous research, the two species primarily associated primarily with members of the Ceratobasidiaceae and, to a lesser extent, with members of the Sebacinales and Tulasnellaceae. In addition, a large number of ectomycorrhizal fungi belonging to various families were observed. Although a considerable number of mycorrhizal fungi were common to both species, the fungal communities were significantly different between the two species. Individuals with intermediate morphology showed communities similar to P. bifolia, confirming previous results based on the genetic architecture and fragrance composition that putative hybrids essentially belonged to one of the parental species (P. bifolia). Differences in mycorrhizal communities between species were smaller in mixed populations than between pure populations, suggesting that variation in mycorrhizal communities was largely controlled by local environmental conditions. The small differences in mycorrhizal communities in mixed populations suggests that mycorrhizal fungi are most likely not directly involved in maintaining species boundaries between the two Platanthera species. However, seed germination experiments are needed to unambiguously assess the contribution of mycorrhizal divergence to reproductive isolation. PMID:27695108

  1. Effects of Previous Land-Use on Plant Species Composition and Diversity in Mediterranean Forests

    PubMed Central

    Kouba, Yacine; Martínez-García, Felipe; de Frutos, Ángel; Alados, Concepción L.

    2015-01-01

    At some point in their history, most forests in the Mediterranean Basin have been subjected to intensive management or converted to agriculture land. Knowing how forest plant communities recovered after the abandonment of forest-management or agricultural practices (including livestock grazing) provides a basis for investigating how previous land management have affected plant species diversity and composition in forest ecosystems. Our study investigated the consequences of historical “land management” practices on present-day Mediterranean forests by comparing species assemblages and the diversity of (i) all plant species and (ii) each ecological group defined by species’ habitat preferences and successional status (i.e., early-, mid-, and late-successional species). We compared forest stands that differed both in land-use history and in successional stage. In addition, we evaluated the value of those stands for biodiversity conservation. The study revealed significant compositional differentiation among stands that was due to among-stand variations in the diversity (namely, species richness and evenness) of early-, intermediate-, and late-successional species. Historical land management has led to an increase in compositional divergences among forest stands and the loss of late-successional forest species. PMID:26397707

  2. Global pattern of phylogenetic species composition of shark and its conservation priority.

    PubMed

    Chen, Hungyen; Kishino, Hirohisa

    2015-10-01

    The diversity of marine communities is in striking contrast with the diversity of terrestrial communities. In all oceans, species richness is low in tropical areas and high at latitudes between 20 and 40°. While species richness is a primary metric used in conservation and management strategies, it is important to take into account the complex phylogenetic patterns of species compositions within communities. We measured the phylogenetic skew and diversity of shark communities throughout the world. We found that shark communities in tropical seas were highly phylogenetically skewed, whereas temperate sea communities had phylogenetically diversified species compositions. Interestingly, although geographically distant from one another, tropical sea communities were all highly skewed toward requiem sharks (Carcharhinidae), hammerhead sharks (Sphyrnidae), and whale sharks (Rhincodon typus). Worldwide, the greatest phylogenetic evenness in terms of clades was found in the North Sea and coastal regions of countries in temperate zones, such as the United Kingdom, Ireland, southern Australia, and Chile. This study is the first to examine patterns of phylogenetic diversity of shark communities on a global scale. Our findings suggest that when establishing conservation activities, it is important to take full account of phylogenetic patterns of species composition and not solely use species richness as a target. Protecting areas of high phylogenetic diversity in sharks, which were identified in this study, could form a broader strategy for protecting other threatened marine species. PMID:26819704

  3. Global pattern of phylogenetic species composition of shark and its conservation priority.

    PubMed

    Chen, Hungyen; Kishino, Hirohisa

    2015-10-01

    The diversity of marine communities is in striking contrast with the diversity of terrestrial communities. In all oceans, species richness is low in tropical areas and high at latitudes between 20 and 40°. While species richness is a primary metric used in conservation and management strategies, it is important to take into account the complex phylogenetic patterns of species compositions within communities. We measured the phylogenetic skew and diversity of shark communities throughout the world. We found that shark communities in tropical seas were highly phylogenetically skewed, whereas temperate sea communities had phylogenetically diversified species compositions. Interestingly, although geographically distant from one another, tropical sea communities were all highly skewed toward requiem sharks (Carcharhinidae), hammerhead sharks (Sphyrnidae), and whale sharks (Rhincodon typus). Worldwide, the greatest phylogenetic evenness in terms of clades was found in the North Sea and coastal regions of countries in temperate zones, such as the United Kingdom, Ireland, southern Australia, and Chile. This study is the first to examine patterns of phylogenetic diversity of shark communities on a global scale. Our findings suggest that when establishing conservation activities, it is important to take full account of phylogenetic patterns of species composition and not solely use species richness as a target. Protecting areas of high phylogenetic diversity in sharks, which were identified in this study, could form a broader strategy for protecting other threatened marine species.

  4. BOREAS TGB-3 Plant Species Composition Data over the NSA Fen

    NASA Technical Reports Server (NTRS)

    Bubier, Jill L.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Trace Gas Biogeochemistry (BOREAS TGB-3) team collected several data sets that contributed to understanding the measured trace gas fluxes over sites in the Northern Study Area (NSA). This data set contains information about the composition of plant species that were within the collars used to measure Net Ecosystem Exchange of CO2 (NEE). The species composition was identified to understand the differences in NEE among the various plant communities in the NSA fen. The data were collected in July of 1994 and 1996. The data are contained in comma-delimited, ASCII files.

  5. Use of multivariate dispersion to assess water quality based on species composition data.

    PubMed

    Jiang, Yong; Xu, Guangjian; Xu, Henglong

    2016-02-01

    Multivariate dispersion is a powerful approach to determine the variability in species composition of a fauna or a flora and has been considered as a broad β-diversity in global ecological research. To explore the availability of the dispersions based on species composition data for assessing water quality, a dataset of ciliated protozoa in a basin ecosystem, northern China, was studied. Samples were collected from five sampling stations, within a significant heterogeneity of environmental stress. The homogeneity of multivariate dispersions in species composition of the ciliate assemblages represented a clear spatial pattern in response to the environmental stress. Multivariate analysis demonstrated that the spatial variation in species composition of the ciliate was significantly correlated with the changes of environmental variables, especially the nutrients, in combination with the salinity and pH, or alone. Furthermore, the dispersion measure was found to be significantly related to the nutrient. Based on our data, we suggest that multivariate dispersion measures based on species presence/absence data might be used as a potential bioindicator of water quality in marine ecosystems.

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

    PubMed

    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. PMID:25588119

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

    PubMed

    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.

  8. Estimating size and composition of biological communities by modeling the occurrence of species

    USGS Publications Warehouse

    Dorazio, R.M.; Royle, J. Andrew

    2005-01-01

    We develop a model that uses repeated observations of a biological community to estimate the number and composition of species in the community. Estimators of community-level attributes are constructed from model-based estimators of occurrence of individual species that incorporate imperfect detection of individuals. Data from the North American Breeding Bird Survey are analyzed to illustrate the variety of ecologically important quantities that are easily constructed and estimated using our model-based estimators of species occurrence. In particular, we compute site-specific estimates of species richness that honor classical notions of species-area relationships. We suggest extensions of our model to estimate maps of occurrence of individual species and to compute inferences related to the temporal and spatial dynamics of biological communities.

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

    PubMed Central

    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

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

    PubMed

    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

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

    PubMed

    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

  12. Alaska Resource Data File, Noatak Quadrangle, Alaska

    USGS Publications Warehouse

    Grybeck, Donald J.; Dumoulin, Julie A.

    2006-01-01

    This report gives descriptions of the mineral occurrences in the Noatak 1:250,000-scale quadrangle, Alaska. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  13. Species composition of larvae cultured after anthelmintic treatment indicates reduced moxidectin susceptibility of immature Cylicocyclus species in horses.

    PubMed

    Kooyman, F N J; van Doorn, D C K; Geurden, T; Mughini-Gras, L; Ploeger, H W; Wagenaar, J A

    2016-08-30

    For the control of cyathostomins in horses, the macrocyclic lactones (MLs), moxidectin (MOX) and ivermectin (IVM) are the most commonly used anthelmintics. However, reduced activity, observed as shortening of the egg reappearance period (ERP) has been described. Shortening of the ERP may be caused by a decreased susceptibility of immature worms for MLs. Alternatively, immature worms may develop faster into egg producing adults as a result of repeated ML treatments. The species composition of the larval cultures obtained shortly after ML and pyrantel (PYR) treatment can confirm the hypothesis of decreased ML susceptibility, as this is often class-specific, whereas faster development would also occur after treatment with anthelmintics with a different mode of action. From 3 farms with a known history of shortened ERP, 8 horses per farm were selected and divided into 2 groups. The MOX-PYR-MOX group was treated twice with MOX (day 0 and 126) and once with PYR (day 84) and the IVM-PYR-IVM group was treated twice with IVM (day 0 and 98) and once with PYR (day 56). Cultured infective larvae (L3s) were counted and differentiated with the reverse line blot on pooled samples. Per cyathostomin species, the number of larvae per gram was calculated. The efficacy of all ML treatments was 100% and a shortened ERP was found on all 3 farms. The species composition of the larval cultures after ML treatment did not differ significantly from that after PYR treatment in the IVM-PYR-IVM group, but it did differ in the MOX-PYR-MOX group. The larval cultures obtained after MOX treatment consisted mostly of Cylicocyclus nassatus, while after PYR treatment Cylicostephanus longibursatus was the most abundant species. In the cultures from 42days after MOX treatment 6 cyathostomin species from 3 genera were found on the farm with the lowest activity (farm 1), while on the farm with the highest activity (farm 3) only 3 species from one genus were found in the same number of examined L3s. The

  14. Plankton studies in San Francisco Bay; IV, Phytoplankton abundance and species composition, January 1980 - February 1981

    USGS Publications Warehouse

    Wong, R.L.; Cloern, J.E.

    1982-01-01

    Data are presented on the phytoplankton species composition and abundance in San Francisco Bay from January 1980 through February 1981. Phytoplankton were identified and enumerated in surface samples collected approximately every two weeks at selected stations in the main channel of the Bay, and at shoal stations in the central portion of South San Francisco Bay, San Pablo Bay, and Suisun Bay. Also reported are separate species lists for microphytoplankton (< 60 micrometers) and macrophytoplankton (> 60 micrometers). (Author 's abstract)

  15. The ghosts of trees past: savanna trees create enduring legacies in plant species composition.

    PubMed

    Stahlheber, Karen A; Crispin, Kimberly L; Anton, Cassidy; D'Antonio, Carla M

    2015-09-01

    Isolated trees in savannas worldwide are known to modify their local environment and interact directly with neighboring plants. Less is known about how related tree species differ in their impacts on surrounding communities, how the effects of trees vary between years, and how composition might change following loss of the tree. To address these knowledge gaps, we explored the following questions: How do savanna trees influence the surrounding composition of herbaceous plants? Is the influence of trees consistent across different species and years? How does this change following the death of the tree? We surveyed herbaceous species composition and environmental attributes surrounding living and dead evergreen and deciduous Quercus trees in California (USA) savannas across several years that differed in their total precipitation. Oak trees of all species created distinct, homogenous understory communities dominated by exotic grasses across several sites. The composition of the low-diversity understory communities showed less interannual variation than open grassland, despite a two-fold difference in precipitation between the driest and wettest year. Vegetation composition was correlated with variation in soil properties, which were strongly affected by trees. Oaks also influenced the communities beyond the edge of the crown, but this depended on site and oak species. Low-diversity understory communities persisted up to 43 years following the death of the tree. A gradual decline in the effect of trees on the physical, environment following death did not result in vegetation becoming more similar to open grassland over time. The presence of long-lasting legacies of past tree crowns highlights the difficulty of assigning control of the current distribution of herbaceous species in grassland to their contemporary environment.

  16. The ghosts of trees past: savanna trees create enduring legacies in plant species composition.

    PubMed

    Stahlheber, Karen A; Crispin, Kimberly L; Anton, Cassidy; D'Antonio, Carla M

    2015-09-01

    Isolated trees in savannas worldwide are known to modify their local environment and interact directly with neighboring plants. Less is known about how related tree species differ in their impacts on surrounding communities, how the effects of trees vary between years, and how composition might change following loss of the tree. To address these knowledge gaps, we explored the following questions: How do savanna trees influence the surrounding composition of herbaceous plants? Is the influence of trees consistent across different species and years? How does this change following the death of the tree? We surveyed herbaceous species composition and environmental attributes surrounding living and dead evergreen and deciduous Quercus trees in California (USA) savannas across several years that differed in their total precipitation. Oak trees of all species created distinct, homogenous understory communities dominated by exotic grasses across several sites. The composition of the low-diversity understory communities showed less interannual variation than open grassland, despite a two-fold difference in precipitation between the driest and wettest year. Vegetation composition was correlated with variation in soil properties, which were strongly affected by trees. Oaks also influenced the communities beyond the edge of the crown, but this depended on site and oak species. Low-diversity understory communities persisted up to 43 years following the death of the tree. A gradual decline in the effect of trees on the physical, environment following death did not result in vegetation becoming more similar to open grassland over time. The presence of long-lasting legacies of past tree crowns highlights the difficulty of assigning control of the current distribution of herbaceous species in grassland to their contemporary environment. PMID:26594707

  17. Vegetation in Bangalore's Slums: Composition, Species Distribution, Density, Diversity, and History

    NASA Astrophysics Data System (ADS)

    Gopal, Divya; Nagendra, Harini; Manthey, Michael

    2015-06-01

    There is widespread acknowledgement of the need for biodiversity and greening to be part of urban sustainability efforts. Yet we know little about greenery in the context of urban poverty, particularly in slums, which constitute a significant challenge for inclusive development in many rapidly growing cities. We assessed the composition, density, diversity, and species distribution of vegetation in 44 slums of Bangalore, India, comparing these to published studies on vegetation diversity in other land-use categories. Most trees were native to the region, as compared to other land-use categories such as parks and streets which are dominated by introduced species. Of the most frequently encountered tree species, Moringa oleifera and Cocos nucifera are important for food, while Ficus religiosa plays a critical cultural and religious role. Tree density and diversity were much lower in slums compared to richer residential neighborhoods. There are also differences in species preferences, with most plant (herb, shrub and vines) species in slums having economic, food, medicinal, or cultural use, while the species planted in richer residential areas are largely ornamental. Historic development has had an impact on species distribution, with older slums having larger sized tree species, while recent slums were dominated by smaller sized tree species with greater economic and food use. Extensive focus on planting trees and plant species with utility value is required in these congested neighborhoods, to provide livelihood support.

  18. Species composition of fish communities in northern Wisconsin lakes: Relation to pH

    USGS Publications Warehouse

    Wiener, J.G.; Rago, P.J.; Eilers, J.M.; Hendrey, G.R.

    1984-01-01

    Fish communities in circumneutral Wisconsin lakes contained significantly more species than did those in acidic lakes (pH 5.1-6.0). Common, as well as rare, species occurred with lower frequency in acidic lakes than in circumneutral lakes. Certain taxa, such as minnows and darters, were either absent or rare in the acidic lakes, probably because of pH-related stress. The differences in species composition and richness of fish communities between acidic and circumneutral lakes did not appear to be related to differences in physical habitat characteristics, past fish migrations or productivity between the two lake groups.

  19. Compositional shifts in Costa Rican forests due to climate-driven species migrations.

    PubMed

    Feeley, Kenneth J; Hurtado, Johanna; Saatchi, Sassan; Silman, Miles R; Clark, David B

    2013-11-01

    Species are predicted to shift their distributions upslope or poleward in response to global warming. This prediction is supported by a growing number of studies documenting species migrations in temperate systems but remains poorly tested for tropical species, and especially for tropical plant species. We analyzed changes in tree species composition in a network of 10 annually censused 1-ha plots spanning an altitudinal gradient of 70-2800 m elevation in Costa Rica. Specifically, we combined plot data with herbarium records (accessed through GBIF) to test if the plots' community temperature scores (CTS, average thermal mean of constituent species weighted by basal area) have increased over the past decade as is predicted by climate-driven species migrations. In addition, we quantified the contributions of stem growth, recruitment, and mortality to the observed patterns. Supporting our a priori hypothesis of upward species migrations, we found that there have been consistent directional shifts in the composition of the plots, such that the relative abundance of lowland species, and hence CTS, increased in 90% of plots. The rate of the observed compositional shifts corresponds to a mean thermal migration rate (TMR) of 0.0065 °C yr(-1) (95% CI = 0.0005-0.0132 °C yr(-1) ). While the overall TMR is slower than predicted based on concurrent regional warming of 0.0167 °C yr(-1) , migrations were on pace with warming in 4 of the 10 plots. The observed shifts in composition were driven primarily by mortality events (i.e., the disproportionate death of highland vs. lowland species), suggesting that individuals of many tropical tree species will not be able to tolerate future warming and thus their persistence in the face of climate change will depend on successful migrations. Unfortunately, in Costa Rica and elsewhere, land area inevitably decreases at higher elevations; hence, even species that are able to migrate successfully will face heightened risks of

  20. Changes in seagrass species composition in northwestern Gulf of Mexico estuaries: effects on associated seagrass fauna.

    PubMed

    Ray, Brandon R; Johnson, Matthew W; Cammarata, Kirk; Smee, Delbert L

    2014-01-01

    The objective of this study was to measure the communities associated with different seagrass species to predict how shifts in seagrass species composition may affect associated fauna. In the northwestern Gulf of Mexico, coverage of the historically dominant shoal grass (Halodule wrightii) is decreasing, while coverage of manatee grass (Syringodium filiforme) and turtle grass (Thalassia testudinum) is increasing. We conducted a survey of fishes, crabs, and shrimp in monospecific beds of shoal, manatee, and turtle grass habitats of South Texas, USA to assess how changes in sea grass species composition would affect associated fauna. We measured seagrass parameters including shoot density, above ground biomass, epiphyte type, and epiphyte abundance to investigate relationships between faunal abundance and these seagrass parameters. We observed significant differences in communities among three seagrass species, even though these organisms are highly motile and could easily travel among the different seagrasses. Results showed species specific relationships among several different characteristics of the seagrass community and individual species abundance. More work is needed to discern the drivers of the complex relationships between individual seagrass species and their associated fauna. PMID:25229897

  1. Changes in Seagrass Species Composition in Northwestern Gulf of Mexico Estuaries: Effects on Associated Seagrass Fauna

    PubMed Central

    Ray, Brandon R.; Johnson, Matthew W.; Cammarata, Kirk; Smee, Delbert L.

    2014-01-01

    The objective of this study was to measure the communities associated with different seagrass species to predict how shifts in seagrass species composition may affect associated fauna. In the northwestern Gulf of Mexico, coverage of the historically dominant shoal grass (Halodule wrightii) is decreasing, while coverage of manatee grass (Syringodium filiforme) and turtle grass (Thalassia testudinum) is increasing. We conducted a survey of fishes, crabs, and shrimp in monospecific beds of shoal, manatee, and turtle grass habitats of South Texas, USA to assess how changes in sea grass species composition would affect associated fauna. We measured seagrass parameters including shoot density, above ground biomass, epiphyte type, and epiphyte abundance to investigate relationships between faunal abundance and these seagrass parameters. We observed significant differences in communities among three seagrass species, even though these organisms are highly motile and could easily travel among the different seagrasses. Results showed species specific relationships among several different characteristics of the seagrass community and individual species abundance. More work is needed to discern the drivers of the complex relationships between individual seagrass species and their associated fauna. PMID:25229897

  2. Changes in seagrass species composition in northwestern Gulf of Mexico estuaries: effects on associated seagrass fauna.

    PubMed

    Ray, Brandon R; Johnson, Matthew W; Cammarata, Kirk; Smee, Delbert L

    2014-01-01

    The objective of this study was to measure the communities associated with different seagrass species to predict how shifts in seagrass species composition may affect associated fauna. In the northwestern Gulf of Mexico, coverage of the historically dominant shoal grass (Halodule wrightii) is decreasing, while coverage of manatee grass (Syringodium filiforme) and turtle grass (Thalassia testudinum) is increasing. We conducted a survey of fishes, crabs, and shrimp in monospecific beds of shoal, manatee, and turtle grass habitats of South Texas, USA to assess how changes in sea grass species composition would affect associated fauna. We measured seagrass parameters including shoot density, above ground biomass, epiphyte type, and epiphyte abundance to investigate relationships between faunal abundance and these seagrass parameters. We observed significant differences in communities among three seagrass species, even though these organisms are highly motile and could easily travel among the different seagrasses. Results showed species specific relationships among several different characteristics of the seagrass community and individual species abundance. More work is needed to discern the drivers of the complex relationships between individual seagrass species and their associated fauna.

  3. A decade of predatory control of zooplankton species composition of Lake Michigan

    USGS Publications Warehouse

    Makarewicz, Joseph C.; Bertram, Paul; Lewis, Theodore; Brown, Edward H.

    1995-01-01

    From 1983 to 1992, 71 species representing 38 genera from the Calanoida, Cladocera, Cyclopoida, Mysidacea, Rotifera, Mollusca and Harpacticoida comprised the offshore zooplankton community of Lake Michigan. Our data demonstrate that the composition and abundance of the calanoid community after 1983 is not unlike that of 1960s and that species diversity of the calanoid community is more diverse than the cladoceran community in the 1990s as compared to the early 1980s. Even though the relative biomass of the cladocerans has remained similar over the 1983-1993 period, the species diversity and evenness of the Cladocera community in the early 1990s is unlike anything that has been previously reported for Lake Michigan. Cladocera dominance is centered in one species, Daphnia galeata mendotae, and only three species of Cladocera were observed in the pelagic region of the lake in 1991 and 1992. Nutrient levels, phytoplankton biomass, and the abundance of planktivorous alewife and bloater chub and Bythotrephes are examined as possible causes of these changes in zooplankton species composition. The increase in Rotifera biomass, but not Crustacea, was correlated with an increase in relative biomass of unicellular algae. Food web models suggest Bythotrephes will cause Lake Michigan's plankton to return to a community similar to that of the 1970s; that is Diaptomus dominated. Such a change has occurred. However, correlational analysis suggest that alewife and bloater chubs (especially juveniles) are affecting size and biomass of larger species of zooplankton as well as Bythotrephes.

  4. Influence of Tree Species Composition and Community Structure on Carbon Density in a Subtropical Forest

    PubMed Central

    Hu, Yanqiu; Su, Zhiyao; Li, Wenbin; Li, Jingpeng; Ke, Xiandong

    2015-01-01

    We assessed the impact of species composition and stand structure on the spatial variation of forest carbon density using data collected from a 4-ha plot in a subtropical forest in southern China. We found that 1) forest biomass carbon density significantly differed among communities, reflecting a significant effect of community structure and species composition on carbon accumulation; 2) soil organic carbon density increased whereas stand biomass carbon density decreased across communities, indicating that different mechanisms might account for the accumulation of stand biomass carbon and soil organic carbon in the subtropical forest; and 3) a small number of tree individuals of the medium- and large-diameter class contributed predominantly to biomass carbon accumulation in the community, whereas a large number of seedlings and saplings were responsible for a small proportion of the total forest carbon stock. These findings demonstrate that both biomass carbon and soil carbon density in the subtropical forest are sensitive to species composition and community structure, and that heterogeneity in species composition and stand structure should be taken into account to ensure accurate forest carbon accounting. PMID:26317523

  5. Proximate composition and mineral content of two edible species of Cnidoscolus (tree spinach).

    PubMed

    Kuti, J O; Kuti, H O

    1999-01-01

    Proximate composition and mineral content of raw and cooked leaves of two edible tree spinach species (Cnidoscolus chayamansa and C. aconitifolius), known locally as 'chaya', were determined and compared with that of a traditional green vegetable, spinach (Spinicia oleraceae). Results of the study indicated that the edible leafy parts of the two chaya species contained significantly (p<0.05) greater amounts of crude protein, crude fiber, Ca, K, Fe, ascorbic acid and beta-carotene than the spinach leaf. However, no significant (p>0.05) differences were found in nutritional composition and mineral content between the chaya species, except minor differences in the relative composition of fatty acids, protein and amino acids. Cooking of chaya leaves slightly reduced nutritional composition of both chaya species. Cooking is essential prior to consumption to inactivate the toxic hydrocyanic glycosides present in chaya leaves. Based on the results of this study, the edible chaya leaves may be good dietary sources of minerals (Ca, K and Fe) and vitamins (ascorbic acid and beta-carotene). PMID:10540979

  6. Comparison of the chemical compositions and nutritive values of various pumpkin (Cucurbitaceae) species and parts

    PubMed Central

    Kim, Mi Young; Kim, Eun Jin; Kim, Young-Nam; Choi, Changsun

    2012-01-01

    Pumpkins have considerable variation in nutrient contents depending on the cultivation environment, species, or part. In this study, the general chemical compositions and some bioactive components, such as tocopherols, carotenoids, and β-sitosterol, were analyzed in three major species of pumpkin (Cucurbitaceae pepo, C. moschata, and C. maxima) grown in Korea and also in three parts (peel, flesh, and seed) of each pumpkin species. C. maxima had significantly more carbohydrate, protein, fat, and fiber than C. pepo or C. moschata (P < 0.05). The moisture content as well as the amino acid and arginine contents in all parts of the pumpkin was highest in C. pepo. The major fatty acids in the seeds were palmitic, stearic, oleic, and linoleic acids. C. pepo and C. moschata seeds had significantly more γ-tocopherol than C. maxima, whose seeds had the highest β-carotene content. C. pepo seeds had significantly more β-sitosterol than the others. Nutrient compositions differed considerably among the pumpkin species and parts. These results will be useful in updating the nutrient compositions of pumpkin in the Korean food composition database. Additional analyses of various pumpkins grown in different years and in different areas of Korea are needed. PMID:22413037

  7. Comparison of the Essential Oil Composition of Selected Impatiens Species and Its Antioxidant Activities.

    PubMed

    Szewczyk, Katarzyna; Kalemba, Danuta; Komsta, Łukasz; Nowak, Renata

    2016-01-01

    The present paper describes the chemical composition of the essential oils obtained by hydrodistillation from four Impatiens species, Impatiens glandulifera Royle, I. parviflora DC., I. balsamina L. and I. noli-tangere L. The GC and GC-MS methods resulted in identification of 226 volatile compounds comprising from 61.7%-88.2% of the total amount. The essential oils differed significantly in their composition. Fifteen compounds were shared among the essential oils of all investigated Impatiens species. The majority of these constituents was linalool (0.7%-15.1%), hexanal (0.2%-5.3%) and benzaldehyde (0.1%-10.2%). Moreover, the antioxidant activity of the essential oils was investigated using different methods. The chemical composition of the essential oils and its antioxidant evaluation are reported for the first time from the investigated taxon. PMID:27598111

  8. Correlational patterns between invertebrate species composition and the presence of an invasive plant

    NASA Astrophysics Data System (ADS)

    Palmer, Miquel; Linde, Marta; Pons, Guillem X.

    2004-12-01

    It is widely assumed that the presence of invasive exotic plants causes a negative impact on native biotas. Here, we analyse the correlational patterns between the presence of one of these invasive plants, the South African Hottentot fig, Carpobrotus acinaciformis (L.) L. Bolus (Aizoaceae), and the terrestrial invertebrate species composition of a Mediterranean rocky shore. Variations in invertebrate community were estimated by determining the presence-absence of 94 species in 30 plots along a 2.5 km shoreline. Canonical correspondence analyses revealed that three environmental variables showed significant correlation with the invertebrate presence-absence matrix. Namely, distance to the nearest urban area, soil type, and vegetation type. Presence-absence of the invasive plant was correlated with these environmental variables, but no additional effect on the invertebrate community specifically attributable to the presence of the invasive plant was detected. These facts exemplify the uncertainties in linking the presence of an invasive species with its putative outcomes because they are consistent with the hypothesis that a general gradient of anthropic influence affects the invertebrate species composition, and that the supposed effects of C. acinaciformis on the invertebrate species composition are correlated with (and therefore, indiscernible from) those derived from the existence of such general gradient of anthropic influence.

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

    PubMed

    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.

  10. Big plants — Do they affect neighbourhood species richness and composition in herbaceous vegetation?

    NASA Astrophysics Data System (ADS)

    Aarssen, Lonnie W.; Schamp, Brandon S.; Wight, Stephanie

    2014-02-01

    According to traditional theory, success in competition between plant species generally involves a 'size-advantage'. We predicted therefore that plants with larger body size should impose greater limits on the number of species — especially relatively small ones — that can reside within their immediate neighbourhoods. Species composition was compared within local neighbourhoods surrounding target plants of different sizes belonging to one of the largest herbaceous species found within old-field vegetation in eastern Ontario Canada — Centaurea jacea. Resident species density was generally greater within immediate 'inner' target neighbourhoods than within adjacent circular 'outer' neighbourhoods, and mean body size of resident neighbour species was unrelated to increases in target plant size. As target plant size increased, the proportion of resident neighbour species that were reproductive increased. Relatively big plants of C. jacea do not limit the number or the proportion of reproductive species that can coexist within their immediate neighbourhoods, nor do they cause local exclusion of relatively small species from these neighbourhoods. These results fail to support the 'size-advantage' hypothesis and are more consistent with the 'reproductive economy advantage' hypothesis: success under intense competition is promoted by capacity to recruit offspring that — despite severe suppression — are able to reach their minimum body size needed for reproduction, and hence produce grand-offspring for the next generation. The latter is facilitated by a relatively small minimum reproductive threshold size, which is generally negatively correlated with a relatively large maximum potential body size.

  11. Species Composition and Abundance of Stink Bugs (Hemiptera: Heteroptera: Pentatomidae) in Minnesota Field Corn.

    PubMed

    Koch, Robert L; Pahs, Tiffany

    2015-04-01

    In response to concerns of increasing significance of stink bugs (Hemiptera: Heteroptera: Pentatomidae) in northern states, a survey was conducted over 2 yr in Minnesota to characterize the Pentatomidae associated with field corn, Zea mays L. Halyomorpha halys (Stål), an exotic species, was not detected in this survey, despite continued detection of this species as an invader of human-made structures in Minnesota. Five species of Pentatomidae (four herbivorous; one predatory) were collected from corn. Across years, Euschistus variolarius (Palisot de Beauvois) and Euschistus servus euschistoides (Vollenhoven) had the greatest relative abundances and frequencies of detection. In 2012, the abundance of herbivorous species exceeded 25 nymphs and adults per 100 plants (i.e., an economic threshold) in 0.48% of fields. However, the abundance of herbivorous species did not reach economic levels in any fields sampled in 2013. The frequency of detection of herbivorous species and ratio of nymphs to adults was highest during reproductive growth stages of corn. The predator species, Podisus maculiventris (Say), was detected in 0 to 0.32% of fields. These results provide baseline information on the species composition and abundance of Pentatomidae in Minnesota field corn, which will be necessary for documentation of changes to this fauna as a result of the invasion of H. halys and to determine if some native species continue to increase in abundance in field crops.

  12. Species Composition and Abundance of Stink Bugs (Hemiptera: Heteroptera: Pentatomidae) in Minnesota Field Corn.

    PubMed

    Koch, Robert L; Pahs, Tiffany

    2015-04-01

    In response to concerns of increasing significance of stink bugs (Hemiptera: Heteroptera: Pentatomidae) in northern states, a survey was conducted over 2 yr in Minnesota to characterize the Pentatomidae associated with field corn, Zea mays L. Halyomorpha halys (Stål), an exotic species, was not detected in this survey, despite continued detection of this species as an invader of human-made structures in Minnesota. Five species of Pentatomidae (four herbivorous; one predatory) were collected from corn. Across years, Euschistus variolarius (Palisot de Beauvois) and Euschistus servus euschistoides (Vollenhoven) had the greatest relative abundances and frequencies of detection. In 2012, the abundance of herbivorous species exceeded 25 nymphs and adults per 100 plants (i.e., an economic threshold) in 0.48% of fields. However, the abundance of herbivorous species did not reach economic levels in any fields sampled in 2013. The frequency of detection of herbivorous species and ratio of nymphs to adults was highest during reproductive growth stages of corn. The predator species, Podisus maculiventris (Say), was detected in 0 to 0.32% of fields. These results provide baseline information on the species composition and abundance of Pentatomidae in Minnesota field corn, which will be necessary for documentation of changes to this fauna as a result of the invasion of H. halys and to determine if some native species continue to increase in abundance in field crops. PMID:26313176

  13. Plasticity in plant functional traits is shaped by variability in neighbourhood species composition.

    PubMed

    Abakumova, Maria; Zobel, Kristjan; Lepik, Anu; Semchenko, Marina

    2016-07-01

    Plant functional traits can vary widely as a result of phenotypic plasticity to abiotic conditions. Trait variation may also reflect responses to the identity of neighbours, although not all species are equally responsive to their biotic surroundings. We hypothesized that responses to neighbours are shaped by spatial community patterns and resulting variability in neighbour composition. More precisely, we tested the theoretical prediction that plasticity is most likely to evolve if alternative environments (in this case, different neighbour species) are common and encountered at similar frequencies. We estimated the frequencies of encountering different neighbour species in the field for 27 grassland species and measured the aboveground morphological responses of each species to conspecific vs heterospecific neighbours in a common garden. Responses to neighbour identity were dependent on how frequently the experimental neighbours were encountered by the focal species in their home community, with the greatest plasticity observed in species that encountered both neighbours (conspecific and heterospecific) with high and even frequency. Biotic interactions with neighbouring species can impose selection on plasticity in functional traits, which may feed back through trait divergence and niche differentiation to influence species coexistence and community structure.

  14. Northern Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Seasonal ice in the Beaufort Sea off Alaska's North Slope has begun its spring retreat. This true color MODIS image from March 18, 2002, shows the pack ice in the Chuckchi Sea (left) and Beaufort Sea (top) backing away from its winter position snug up against Alaska's coasts, beginning its retreat into the Arctic Ocean. While not as pronounced in the Beaufort and Chukchi Seas as other part of the Arctic, scientists studying Arctic sea ice over the course of the century have documented dramatic changes in the extent of Arctic sea ice. It retreats farther in the summer and does not advance as far in the winter than it did a half-century ago. Both global warming and natural variation in regional weather systems have been proposed as causes. Along the coastal plain of the North Slope, gray-brown tracks (see high-resolution image) hint at melting rivers. South of the North Slope, the rugged mountains of the Brooks Range make a coast-to-coast arc across the state. Coming in at the lower right of the image, the Yukon River traces a frozen white path westward across half the image before veering south and out of view. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

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

    PubMed

    Zhou, Yonghong; Peisker, Helga; Dörmann, Peter

    2016-07-01

    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. CO2 and CH4 Surface Flux, Soil Profile Concentrations, and Stable Isotope Composition, Barrow, Alaska, 2012-2013

    DOE Data Explorer

    Curtis, J.B.; Vaughn, L.S.; Torn, M.S.; Conrad, M.S.; Chafe, O.; Bill, M.

    2015-12-31

    In August-October 2012 and June-October 2013, co-located measurements were made of surface CH4 and CO2 flux, soil pore space concentrations and stable isotope compositions of CH4 and CO2, and subsurface temperature and soil moisture. Measurements were made in intensive study site 1 areas A, B, and C, and from the site 0 and AB transects, from high-centered, flat-centered, and low-centered polygons, from the center, edge, and trough of each polygon.

  17. Species composition and seasonal abundance of Chaetognatha in the subtropical coastal waters of Hong Kong

    NASA Astrophysics Data System (ADS)

    Tse, P.; Hui, S. Y.; Wong, C. K.

    2007-06-01

    Species composition, species diversity and seasonal abundance of chaetognaths were studied in Tolo Harbour and the coastal waters of eastern Hong Kong. Tolo Harbour is a semi-enclosed and poorly flushed bay with a long history of eutrophication. It opens into the eastern coast of Hong Kong which is fully exposed to water currents from the South China Sea. Zooplankton samples were collected monthly from July 2003 to July 2005 at six stations. Twenty species of chaetognaths were identified. They included six species of the genus Aidanosagitta ( Aidanosagitta neglecta, Aidanosagitta delicata, Aidanosagitta johorensis, Aidanosagitta regularis, Aidanosagitta bedfordii and Aidanosagitta crassa), four species of the genus Zonosagitta ( Zonosagitta nagae, Zonosagitta bedoti, Zonosagitta bruuni and Zonosagitta pulchra), three species of the genus Ferosagitta ( Ferosagitta ferox, Ferosagitta tokiokai and Ferosagitta robusta) and one species each from the genera Serratosagitta ( Serratosagitta pacifica), Decipisagitta ( Decipisagitta decipiens), Flaccisagitta ( Flaccisagitta enflata), Krohnitta ( Krohnitta pacifica), Mesosagitta ( Mesosagitta minima), Pterosagitta ( Pterosagitta draco) and Sagitta ( Sagitta bipunctata). The most abundant species were Flaccisagitta enflata, A. neglecta and A. delicata. Averaged over the entire study period, the densities of Flaccisagitta enflata, A. neglecta and A. delicata were 9.3, 6.6 and 5.2 ind. m -3, respectively. Overall, these species constituted 39.7%, 28.2% and 22.0% of all chaetognaths collected in the study. Averaged over the entire study, the density of most of the low abundance species was <0.6 ind. m -3. Flaccisagitta enflata occurred throughout the year at all sampling stations. Aidanosagitta neglecta occurred at all sampling stations, but was most common in summer. Aidanosagitta delicata was most common in Tolo Harbour during summer. Tolo Harbour supported larger populations, but fewer species of chaetognaths than the

  18. Measuring size and composition of species pools: a comparison of dark diversity estimates.

    PubMed

    de Bello, Francesco; Fibich, Pavel; Zelený, David; Kopecký, Martin; Mudrák, Ondřej; Chytrý, Milan; Pyšek, Petr; Wild, Jan; Michalcová, Dana; Sádlo, Jiří; Šmilauer, Petr; Lepš, Jan; Pärtel, Meelis

    2016-06-01

    Ecological theory and biodiversity conservation have traditionally relied on the number of species recorded at a site, but it is agreed that site richness represents only a portion of the species that can inhabit particular ecological conditions, that is, the habitat-specific species pool. Knowledge of the species pool at different sites enables meaningful comparisons of biodiversity and provides insights into processes of biodiversity formation. Empirical studies, however, are limited due to conceptual and methodological difficulties in determining both the size and composition of the absent part of species pools, the so-called dark diversity. We used >50,000 vegetation plots from 18 types of habitats throughout the Czech Republic, most of which served as a training dataset and 1083 as a subset of test sites. These data were used to compare predicted results from three quantitative methods with those of previously published expert estimates based on species habitat preferences: (1) species co-occurrence based on Beals' smoothing approach; (2) species ecological requirements, with envelopes around community mean Ellenberg values; and (3) species distribution models, using species environmental niches modeled by Biomod software. Dark diversity estimates were compared at both plot and habitat levels, and each method was applied in different configurations. While there were some differences in the results obtained by different methods, particularly at the plot level, there was a clear convergence, especially at the habitat level. The better convergence at the habitat level reflects less variation in local environmental conditions, whereas variation at the plot level is an effect of each particular method. The co-occurrence agreed closest the expert estimate, followed by the method based on species ecological requirements. We conclude that several analytical methods can estimate species pools of given habitats. However, the strengths and weaknesses of different methods

  19. Environmental Gradients Explain Species Richness and Community Composition of Coastal Breeding Birds in the Baltic Sea

    PubMed Central

    Nord, Maria; Forslund, Pär

    2015-01-01

    Scientifically-based systematic conservation planning for reserve design requires knowledge of species richness patterns and how these are related to environmental gradients. In this study, we explore a large inventory of coastal breeding birds, in total 48 species, sampled in 4646 1 km2 squares which covered a large archipelago in the Baltic Sea on the east coast of Sweden. We analysed how species richness (α diversity) and community composition (β diversity) of two groups of coastal breeding birds (specialists, i.e. obligate coastal breeders; generalists, i.e. facultative coastal breeders) were affected by distance to open sea, land area, shoreline length and archipelago width. The total number of species per square increased with increasing shoreline length, but increasing land area counteracted this effect in specialists. The number of specialist bird species per square increased with decreasing distance to open sea, while the opposite was true for the generalists. Differences in community composition between squares were associated with differences in land area and distance to open sea, both when considering all species pooled and each group separately. Fourteen species were nationally red-listed, and showed similar relationships to the environmental gradients as did all species, specialists and generalists. We suggest that availability of suitable breeding habitats, and probably also proximity to feeding areas, explain much of the observed spatial distributions of coastal birds in this study. Our findings have important implications for systematic conservation planning of coastal breeding birds. In particular, we provide information on where coastal breeding birds occur and which environments they seem to prefer. Small land areas with long shorelines are highly valuable both in general and for red-listed species. Thus, such areas should be prioritized for protection against human disturbance and used by management in reserve selection. PMID:25714432

  20. Environmental gradients explain species richness and community composition of coastal breeding birds in the Baltic Sea.

    PubMed

    Nord, Maria; Forslund, Pär

    2015-01-01

    Scientifically-based systematic conservation planning for reserve design requires knowledge of species richness patterns and how these are related to environmental gradients. In this study, we explore a large inventory of coastal breeding birds, in total 48 species, sampled in 4646 1 km2 squares which covered a large archipelago in the Baltic Sea on the east coast of Sweden. We analysed how species richness (α diversity) and community composition (β diversity) of two groups of coastal breeding birds (specialists, i.e. obligate coastal breeders; generalists, i.e. facultative coastal breeders) were affected by distance to open sea, land area, shoreline length and archipelago width. The total number of species per square increased with increasing shoreline length, but increasing land area counteracted this effect in specialists. The number of specialist bird species per square increased with decreasing distance to open sea, while the opposite was true for the generalists. Differences in community composition between squares were associated with differences in land area and distance to open sea, both when considering all species pooled and each group separately. Fourteen species were nationally red-listed, and showed similar relationships to the environmental gradients as did all species, specialists and generalists. We suggest that availability of suitable breeding habitats, and probably also proximity to feeding areas, explain much of the observed spatial distributions of coastal birds in this study. Our findings have important implications for systematic conservation planning of coastal breeding birds. In particular, we provide information on where coastal breeding birds occur and which environments they seem to prefer. Small land areas with long shorelines are highly valuable both in general and for red-listed species. Thus, such areas should be prioritized for protection against human disturbance and used by management in reserve selection.

  1. Environmental gradients explain species richness and community composition of coastal breeding birds in the Baltic Sea.

    PubMed

    Nord, Maria; Forslund, Pär

    2015-01-01

    Scientifically-based systematic conservation planning for reserve design requires knowledge of species richness patterns and how these are related to environmental gradients. In this study, we explore a large inventory of coastal breeding birds, in total 48 species, sampled in 4646 1 km2 squares which covered a large archipelago in the Baltic Sea on the east coast of Sweden. We analysed how species richness (α diversity) and community composition (β diversity) of two groups of coastal breeding birds (specialists, i.e. obligate coastal breeders; generalists, i.e. facultative coastal breeders) were affected by distance to open sea, land area, shoreline length and archipelago width. The total number of species per square increased with increasing shoreline length, but increasing land area counteracted this effect in specialists. The number of specialist bird species per square increased with decreasing distance to open sea, while the opposite was true for the generalists. Differences in community composition between squares were associated with differences in land area and distance to open sea, both when considering all species pooled and each group separately. Fourteen species were nationally red-listed, and showed similar relationships to the environmental gradients as did all species, specialists and generalists. We suggest that availability of suitable breeding habitats, and probably also proximity to feeding areas, explain much of the observed spatial distributions of coastal birds in this study. Our findings have important implications for systematic conservation planning of coastal breeding birds. In particular, we provide information on where coastal breeding birds occur and which environments they seem to prefer. Small land areas with long shorelines are highly valuable both in general and for red-listed species. Thus, such areas should be prioritized for protection against human disturbance and used by management in reserve selection. PMID:25714432

  2. [Species composition and spatial structure of plants in urban parks of Beijing].

    PubMed

    Zhao, Juan-Juan; Ouyang, Zhi-Yun; Zheng, Hua; Xu, Wei-Hua; Wang, Xiao-Ke

    2009-02-01

    By the method of stratified random sampling, the species composition and spatial structure of the plants in 53 parks in Beijing urban area were investigated, aimed to provide basic information for the protection of plant diversity in the parks and the management of the parks. A total of 492 plant species belong to 96 families and 283 genera were recorded. Based on the data of 21 investigation items about the trees, shrubs, and grasses in the study area and related statistical analyses, the plant structural patterns commonly seen in the green space of the parks of Beijing urban area were introduced. Among the plants in the parks, native species occupied 53.86% of the total. The chorological composition of the genera embraced broad kinds of geographical elements in China, and the predominance of dominant plants was remarkable. In most green patches of the parks, herbaceous species were more abundant and had higher coverage, shrubs had relatively low coverage and were less beneath tree canopy, and trees and shrubs had lower species richness and density. The canopy breadth and the diameter of breast height of trees as well as the breadth of shrubs and the heights of trees and shrubs were basically at the second grade, but the canopy structure of the trees were better, with good conditions of sunlight and growth. The crown missing of the shrubs was relatively low. It was suggested from correlation analyses and document survey of Beijing parks construction history that park landscape design, alien species introduction; and cultivation management were the main factors affecting the species composition and spatial structure of the plants in Beijing urban parks. PMID:19459367

  3. The Eocene Arctic Azolla phenomenon: species composition, temporal range and geographic extent.

    NASA Astrophysics Data System (ADS)

    Collinson, Margaret; Barke, Judith; van der Burgh, Johan; van Konijnenburg-van Cittert, Johanna; Pearce, Martin; Bujak, Jonathan; Brinkhuis, Henk

    2010-05-01

    Azolla is a free-floating freshwater fern that is renowned for its rapid vegetative spread and invasive biology, being one of the world's fastest growing aquatic macrophytes. Two species of this plant have been shown to have bloomed and reproduced in enormous numbers in the latest Early to earliest Middle Eocene of the Arctic Ocean and North Sea based on samples from IODP cores from the Lomonosov Ridge (Arctic) and from outcrops in Denmark (Collinson et al 2009 a,b Review of Palaeobotany and Palynology 155,1-14; and doi:10.1016/j.revpalbo.2009.12.001). To determine the geographic and temporal extent of this Azolla phenomenon, and the spatial distribution of the different species, we have examined samples from 15 additional sites using material from ODP cores and commercial exploration wells. The sites range from the Sub-Arctic (Northern Alaska and Canadian Beaufort Mackenzie Basin) to the Nordic Seas (Norwegian-Greenland Sea and North Sea Basin). Our data show that the Azolla phenomenon involved at least three species. These are distinguished by characters of the megaspore apparatus (e.g. megaspore wall, floats, filosum) and the microspore massulae (e.g. glochidia fluke tips). The Lomonosov Ridge (Arctic) and Danish occurrences are monotypic but in other sites more than one species co-existed. The attachment to one another and the co-occurrence of megaspore apparatus and microspore massulae, combined with evidence that these spores were shed at the fully mature stage of their life cycle, shows that the Azolla remains were not transported over long distances, a fact which could not be assumed from isolated massula fragments alone. Our evidence, therefore, shows that Azolla plants grew on the ocean surfaces for approximately 1.2 million years (from 49.3 to 48.1 Ma) and that the Azolla phenomenon covered the area from Denmark northwards across the North Sea Basin and the whole of the Arctic and Nordic seas. Apparently, early Middle Eocene Northern Hemisphere middle

  4. Phospholipid composition of plasma and erythrocyte membranes in animal species by 31P NMR.

    PubMed

    Ferlazzo, Alida Maria; Bruschetta, Giuseppe; Di Pietro, Patrizia; Medica, Pietro; Notti, Anna; Rotondo, Enrico

    2011-12-01

    The aim of this study was to provide basal values of phospholipid (PL) composition in different animal species by 31P NMR analysis using detergents. This fast and accurate method allowed a quantitative analysis of PLs without any previous separation. Plasma and erythrocyte membrane PLs were investigated in mammals (pig, cow, horse). Moreover, for the first time, the composition of plasma PLs in avian (chicken and ostrich) was performed by 31P NMR. Significant qualitative and quantitative interspecies differences in plasma PL levels were found. Phosphatidilcholine (PC) and sphingomyelin (SPH) levels were significantly higher (P < 0.001) in chicken plasma than all the other species tested. In erythrocytes, cow PC and phosphatidylcholine diarachidoyl were significantly lower (P < 0.001) than for pigs and horses, whereas pig PC presented intermediate values among cows and horses. Inorganic phosphate and 2,3-diphosphoglycerate levels were also significantly different between the species under investigation. The [SPH/total PLs] molar ratios in erythrocytes confirmed interspecies differences in phospholipid composition while the PC/SPH molar ratios could be related to a distinct erythrocyte flexibility and aggregability. Diet and nutrition may contribute primarily to the interspecies differences in plasma PL amounts detected. Significant differences between chicken plasma PC and SPH levels and those of the other animal species could be ascribed to a fat metabolism specific to egg production.

  5. Assembling an ignimbrite: Compositionally defined eruptive packages in the 1912 Valley of Ten Thousand Smokes ignimbrite, Alaska

    USGS Publications Warehouse

    Fierstein, J.; Wilson, C.J.N.

    2005-01-01

    The 1912 Valley of Ten Thousand Smokes (VTTS) ignimbrite was constructed from 9 compositionally distinct, sequentially emplaced packages, each with distinct proportions of rhyolite (R), dacite (D), and andesite (A) pumices that permit us to map package boundaries and flow paths from vent to distal extents. Changing pumice proportions and interbedding relationships link ignimbrite formation to coeval fall deposition during the first ???16 h (Episode I) of the eruption. Pumice compositional proportions in the ignimbrite were estimated by counts on ???100 lapilli at multiple levels in vertical sections wherever accessible and more widely over most of the ignimbrite surface in the VTTS. The initial, 100% rhyolite ignimbrite package (equivalent to regional fall Layer A and occupying ???3.5 h) was followed by packages with increasing proportions of andesite, then dacite, emplaced over ???12.5 h and equivalent to regional fall Layers B1-B3. Coeval fall deposits are locally intercalated with the ignimbrite and show parallel changes in R:D (rhyolite:dacite) proportions, but lack significant amounts of andesite. Andesite was thus dominantly a low-fountaining component in the eruption column and is preferentially represented in packages filling the VTTS north of the vent. The most extensive packages (3 and 4) occur in B1 and early B2 times where flow mobility and volume were optimized; earlier all-rhyolite flows (Package 1) were highly energetic but less voluminous, while later packages (5-9) were both less voluminous and emplaced at lower velocities. Package boundaries are expressed as one or more of the following: sharp color changes corresponding to compositional variations; persistent finer-grained basal parts of flow units; compaction swales filled by later packages; erosional channels cut by the flows that fill them; lobate accumulations of one package; and (mostly south of the vent) intercalated fall deposit layers. Clear flow-unit boundaries are best developed between

  6. Comparison of phylogeny, venom composition and neutralization by antivenom in diverse species of bothrops complex.

    PubMed

    Sousa, Leijiane F; Nicolau, Carolina A; Peixoto, Pedro S; Bernardoni, Juliana L; Oliveira, Sâmella S; Portes-Junior, José Antonio; Mourão, Rosa Helena V; Lima-dos-Santos, Isa; Sano-Martins, Ida S; Chalkidis, Hipócrates M; Valente, Richard H; Moura-da-Silva, Ana M

    2013-01-01

    In Latin America, Bothrops snakes account for most snake bites in humans, and the recommended treatment is administration of multispecific Bothrops antivenom (SAB--soro antibotrópico). However, Bothrops snakes are very diverse with regard to their venom composition, which raises the issue of which venoms should be used as immunizing antigens for the production of pan-specific Bothrops antivenoms. In this study, we simultaneously compared the composition and reactivity with SAB of venoms collected from six species of snakes, distributed in pairs from three distinct phylogenetic clades: Bothrops, Bothropoides and Rhinocerophis. We also evaluated the neutralization of Bothrops atrox venom, which is the species responsible for most snake bites in the Amazon region, but not included in the immunization antigen mixture used to produce SAB. Using mass spectrometric and chromatographic approaches, we observed a lack of similarity in protein composition between the venoms from closely related snakes and a high similarity between the venoms of phylogenetically more distant snakes, suggesting little connection between taxonomic position and venom composition. P-III snake venom metalloproteinases (SVMPs) are the most antigenic toxins in the venoms of snakes from the Bothrops complex, whereas class P-I SVMPs, snake venom serine proteinases and phospholipases A2 reacted with antibodies in lower levels. Low molecular size toxins, such as disintegrins and bradykinin-potentiating peptides, were poorly antigenic. Toxins from the same protein family showed antigenic cross-reactivity among venoms from different species; SAB was efficient in neutralizing the B. atrox venom major toxins. Thus, we suggest that it is possible to obtain pan-specific effective antivenoms for Bothrops envenomations through immunization with venoms from only a few species of snakes, if these venoms contain protein classes that are representative of all species to which the antivenom is targeted. PMID

  7. Comparison of Phylogeny, Venom Composition and Neutralization by Antivenom in Diverse Species of Bothrops Complex

    PubMed Central

    Peixoto, Pedro S.; Bernardoni, Juliana L.; Oliveira, Sâmella S.; Portes-Junior, José Antonio; Mourão, Rosa Helena V.; Lima-dos-Santos, Isa; Sano-Martins, Ida S.; Chalkidis, Hipócrates M.; Valente, Richard H.; Moura-da-Silva, Ana M.

    2013-01-01

    In Latin America, Bothrops snakes account for most snake bites in humans, and the recommended treatment is administration of multispecific Bothrops antivenom (SAB – soro antibotrópico). However, Bothrops snakes are very diverse with regard to their venom composition, which raises the issue of which venoms should be used as immunizing antigens for the production of pan-specific Bothrops antivenoms. In this study, we simultaneously compared the composition and reactivity with SAB of venoms collected from six species of snakes, distributed in pairs from three distinct phylogenetic clades: Bothrops, Bothropoides and Rhinocerophis. We also evaluated the neutralization of Bothrops atrox venom, which is the species responsible for most snake bites in the Amazon region, but not included in the immunization antigen mixture used to produce SAB. Using mass spectrometric and chromatographic approaches, we observed a lack of similarity in protein composition between the venoms from closely related snakes and a high similarity between the venoms of phylogenetically more distant snakes, suggesting little connection between taxonomic position and venom composition. P-III snake venom metalloproteinases (SVMPs) are the most antigenic toxins in the venoms of snakes from the Bothrops complex, whereas class P-I SVMPs, snake venom serine proteinases and phospholipases A2 reacted with antibodies in lower levels. Low molecular size toxins, such as disintegrins and bradykinin-potentiating peptides, were poorly antigenic. Toxins from the same protein family showed antigenic cross-reactivity among venoms from different species; SAB was efficient in neutralizing the B. atrox venom major toxins. Thus, we suggest that it is possible to obtain pan-specific effective antivenoms for Bothrops envenomations through immunization with venoms from only a few species of snakes, if these venoms contain protein classes that are representative of all species to which the antivenom is targeted. PMID

  8. Degradation in the Dentin-Composite Interface Subjected to Multi-Species Biofilm Challenges

    PubMed Central

    Li, Yuping; Carrera, Carola; Chen, Ruoqiong; Li, Jianying; Patricia, Lenton; Rudney, Joel. D.; Jones, Robert S.; Aparicio, Conrado; Fok, Alex

    2013-01-01

    Oral biofilms can degrade the components in dental resin-based composite restorations, thus compromising marginal integrity and leading to secondary caries. In this study, we investigated the mechanical integrity of the dentin-composite interface challenged with multi-species oral biofilms. While most studies used single-species biofilms, we used a more realistic, diverse biofilm model produced directly from plaques collected from donors with a history of early childhood caries. Dentin–composite disks were made using bovine incisor roots filled with Z100™ or Filtek™ LS (3M ESPE). The disks were incubated for 72hr in paired CDC biofilm reactors, using a previously published protocol. One reactor was pulsed with sucrose, and the other was not. A sterile saliva-only control group was run with sucrose pulsing. The disks were fractured under diametral compression to evaluate their interfacial bond strength. Surface deformation of the disks was mapped using digital image correlation (DIC) to ascertain fracture origin. Fracture surfaces were examined using SEM/EDS to assess demineralization and interfacial degradation. Dentin demineralization was greater under sucrose-pulsed biofilms, as the pH dropped below 5.5 during pulsing, with LS and Z100 specimens suffering similar degrees of surface mineral loss. Biofilm growth with sucrose pulsing also caused preferential degradation of the composite-dentin interface, depending on the composite/adhesive system used. Specifically, Z100 specimens showed greater bond strength reduction and more frequent cohesive failure in the adhesive layer. This was attributed to the inferior dentin coverage by Z100 adhesive which possibly led to a higher level of chemical and enzymatic degradation. The results suggested that factors other than dentin demineralization were also responsible for interfacial degradation. We have thus developed a clinically relevant in vitro biofilm model which would allow us to effectively assess the

  9. Degradation in the dentin-composite interface subjected to multi-species biofilm challenges.

    PubMed

    Li, Y; Carrera, C; Chen, R; Li, J; Lenton, P; Rudney, J D; Jones, R S; Aparicio, C; Fok, A

    2014-01-01

    Oral biofilms can degrade the components in dental resin-based composite restorations, thus compromising marginal integrity and leading to secondary caries. This study investigates the mechanical integrity of the dentin-composite interface challenged with multi-species oral biofilms. While most studies used single-species biofilms, the present study used a more realistic, diverse biofilm model produced directly from plaques collected from donors with a history of early childhood caries. Dentin-composite disks were made using bovine incisor roots filled with Z100(TM) or Filtek(TM) LS (3M ESPE). The disks were incubated for 72 h in paired CDC biofilm reactors, using a previously published protocol. One reactor was pulsed with sucrose, and the other was not. A sterile saliva-only control group was run with sucrose pulsing. The disks were fractured under diametral compression to evaluate their interfacial bond strength. The surface deformation of the disks was mapped using digital image correlation to ascertain the fracture origin. Fracture surfaces were examined using scanning electron microscopy/energy-dispersive X-ray spectroscopy to assess demineralization and interfacial degradation. Dentin demineralization was greater under sucrose-pulsed biofilms, as the pH dropped <5.5 during pulsing, with LS and Z100 specimens suffering similar degrees of surface mineral loss. Biofilm growth with sucrose pulsing also caused preferential degradation of the composite-dentin interface, depending on the composite/adhesive system used. Specifically, Z100 specimens showed greater bond strength reduction and more frequent cohesive failure in the adhesive layer. This was attributed to the inferior dentin coverage by Z100 adhesive, which possibly led to a higher level of chemical and enzymatic degradation. The results suggested that factors other than dentin demineralization were also responsible for interfacial degradation. A clinically relevant in vitro biofilm model was therefore

  10. Ecological Significance of a Geomorphic Stream Classification: Species and Functional Group Composition of Riparian Plant Communities

    NASA Astrophysics Data System (ADS)

    Shaw, J. R.; Cooper, D. J.

    2014-12-01

    We tested the ecological significance of a geomorphic classification of Sonoran Desert ephemeral stream channels based on channel plan-form, degree of lateral confinement, and boundary material composition. This typology has been shown to discriminate among channel geometry and hydraulic characteristics for bedrock, bedrock with alluvium, incised alluvium, braided, and piedmont headwater channels. We examined stream reach-scale relationships of geomorphic stream types to the relative cover and density of perennial plant species and functional groups, and identified the dominant fluvial drivers, within riparian communities at 101 ephemeral stream reaches on the U.S. Army Yuma Proving Ground and Barry M. Goldwater Air Force Range in southwestern Arizona, USA. Nonparametric multivariate analysis of variance showed that species and functional group composition differed significantly among geomorphic stream types, both in terms of relative cover and density. Partitioning of among-site multivariate dissimilarity revealed that species compositional differences between stream types were caused largely by variation in the cover and density of the most common members of the regional flora. Distinctive functional group composition among reach types resulted from differences in the cover and density of drought-deciduous shrubs and subshrubs, evergreen trees and shrubs, and photosynthetic-stemmed trees. Comparison of environmental and biotic dissimilarity matrices highlighted the role of channel gradient as the dominant abiotic driver of riparian plant community composition, with stream channel elevation and width:depth providing additional explanatory power. Distinctive riparian plant community composition among the geomorphic stream types demonstrates the ecological significance of this a priori channel classification, and indicates its potential utility in understanding spatial patterns of ecological dynamics, sample stratification for process-based studies, and reference

  11. Evolutionary Divergences in Root Exudate Composition among Ecologically-Contrasting Helianthus Species

    PubMed Central

    Bowsher, Alan W.; Ali, Rifhat; Harding, Scott A.; Tsai, Chung-Jui; Donovan, Lisa A.

    2016-01-01

    Plant roots exude numerous metabolites into the soil that influence nutrient availability. Although root exudate composition is hypothesized to be under selection in low fertility soils, few studies have tested this hypothesis in a phylogenetic framework. In this study, we examined root exudates of three pairs of Helianthus species chosen as phylogenetically-independent contrasts with respect to native soil nutrient availability. Under controlled environmental conditions, seedlings were grown to the three-leaf-pair stage, then transferred to either high or low nutrient treatments. After five days of nutrient treatments, we used gas chromatography-mass spectrometry for analysis of root exudates, and detected 37 metabolites across species. When compared in the high nutrient treatment, species native to low nutrient soils exhibited overall higher exudation than their sister species native to high nutrient soils in all three species pairs, providing support for repeated evolutionary shifts in response to native soil fertility. Species native to low nutrient soils and those native to high nutrient soils responded similarly to low nutrient treatments with increased exudation of organic acids (fumaric, citric, malic acids) and glucose, potentially as a mechanism to enhance nutrition acquisition. However, species native to low nutrient soils also responded to low nutrient treatments with a larger decrease in exudation of amino acids than species native to high nutrient soils in all three species pairs. This indicates that species native to low nutrient soils have evolved a unique sensitivity to changes in nutrient availability for some, but not all, root exudates. Overall, these repeated evolutionary divergences between species native to low nutrient soils and those native to high nutrient soils provide evidence for the adaptive value of root exudation, and its plasticity, in contrasting soil environments. PMID:26824236

  12. Evolutionary Divergences in Root Exudate Composition among Ecologically-Contrasting Helianthus Species.

    PubMed

    Bowsher, Alan W; Ali, Rifhat; Harding, Scott A; Tsai, Chung-Jui; Donovan, Lisa A

    2016-01-01

    Plant roots exude numerous metabolites into the soil that influence nutrient availability. Although root exudate composition is hypothesized to be under selection in low fertility soils, few studies have tested this hypothesis in a phylogenetic framework. In this study, we examined root exudates of three pairs of Helianthus species chosen as phylogenetically-independent contrasts with respect to native soil nutrient availability. Under controlled environmental conditions, seedlings were grown to the three-leaf-pair stage, then transferred to either high or low nutrient treatments. After five days of nutrient treatments, we used gas chromatography-mass spectrometry for analysis of root exudates, and detected 37 metabolites across species. When compared in the high nutrient treatment, species native to low nutrient soils exhibited overall higher exudation than their sister species native to high nutrient soils in all three species pairs, providing support for repeated evolutionary shifts in response to native soil fertility. Species native to low nutrient soils and those native to high nutrient soils responded similarly to low nutrient treatments with increased exudation of organic acids (fumaric, citric, malic acids) and glucose, potentially as a mechanism to enhance nutrition acquisition. However, species native to low nutrient soils also responded to low nutrient treatments with a larger decrease in exudation of amino acids than species native to high nutrient soils in all three species pairs. This indicates that species native to low nutrient soils have evolved a unique sensitivity to changes in nutrient availability for some, but not all, root exudates. Overall, these repeated evolutionary divergences between species native to low nutrient soils and those native to high nutrient soils provide evidence for the adaptive value of root exudation, and its plasticity, in contrasting soil environments. PMID:26824236

  13. Evolutionary Divergences in Root Exudate Composition among Ecologically-Contrasting Helianthus Species.

    PubMed

    Bowsher, Alan W; Ali, Rifhat; Harding, Scott A; Tsai, Chung-Jui; Donovan, Lisa A

    2016-01-01

    Plant roots exude numerous metabolites into the soil that influence nutrient availability. Although root exudate composition is hypothesized to be under selection in low fertility soils, few studies have tested this hypothesis in a phylogenetic framework. In this study, we examined root exudates of three pairs of Helianthus species chosen as phylogenetically-independent contrasts with respect to native soil nutrient availability. Under controlled environmental conditions, seedlings were grown to the three-leaf-pair stage, then transferred to either high or low nutrient treatments. After five days of nutrient treatments, we used gas chromatography-mass spectrometry for analysis of root exudates, and detected 37 metabolites across species. When compared in the high nutrient treatment, species native to low nutrient soils exhibited overall higher exudation than their sister species native to high nutrient soils in all three species pairs, providing support for repeated evolutionary shifts in response to native soil fertility. Species native to low nutrient soils and those native to high nutrient soils responded similarly to low nutrient treatments with increased exudation of organic acids (fumaric, citric, malic acids) and glucose, potentially as a mechanism to enhance nutrition acquisition. However, species native to low nutrient soils also responded to low nutrient treatments with a larger decrease in exudation of amino acids than species native to high nutrient soils in all three species pairs. This indicates that species native to low nutrient soils have evolved a unique sensitivity to changes in nutrient availability for some, but not all, root exudates. Overall, these repeated evolutionary divergences between species native to low nutrient soils and those native to high nutrient soils provide evidence for the adaptive value of root exudation, and its plasticity, in contrasting soil environments.

  14. Fatty acid composition of seeds of some species of Nepeta L.

    PubMed

    Kiliç, Turgut; Dirmenci, Tuncay; Gören, Ahmet C

    2007-05-01

    The fatty acid compositions of Nepeta viscida, N. cilicica, N. crinita, N. nuda ssp. glandulifera and N. aristata were analyzed by GC/MS. The main free fatty acids were found as linolenic acid (49.8-58.5%), linoleic acid (10.9-23.5%), oleic acid (11.5-19.2%), palmitic acid (5.2-6.8%) and stearic acid (2.0-3.7%) and, total fatty acid compositions of species were analyzed and results were found as 36.2-49.8%, 17.1-25.8%, 15.4-25.8%, 6.4-7.8%, and 2.7-4.1%, respectively.

  15. Changes in plant species composition of coastal dune habitats over a 20-year period.

    PubMed

    Del Vecchio, Silvia; Prisco, Irene; Acosta, Alicia T R; Stanisci, Angela

    2015-01-01

    Coastal sandy ecosystems are increasingly being threatened by human pressure, causing loss of biodiversity, habitat degradation and landscape modifications. However, there are still very few detailed studies focussing on compositional changes in coastal dune plant communities over time. In this work, we investigated how coastal dune European Union (EU) habitats (from pioneer annual beach communities to Mediterranean scrubs on the landward fixed dunes) have changed during the last 20 years. Using phytosociological relevés conducted in 1989-90 and in 2010-12, we investigated changes in floristic composition over time. We then compared plant cover and the proportion of ruderal, alien and habitat diagnostic species ('focal species') in the two periods. Finally, we used Ellenberg indicator values to define the 'preferences' of the plant species for temperature and moisture. We found that only fore dune habitats showed significant differences in species cover between the two time periods, with higher plant cover in the more recent relevés and a significant increase in thermophilic species. Although previous studies have demonstrated consistent habitat loss in this area, we observed that all coastal dune plant communities remain well represented, after a 20-year period. However, fore dunes have been experiencing significant compositional changes. Although we cannot confirm whether the observed changes are strictly related to climatic changes, to human pressure or to both, we hypothesize that a moderate increment in average yearly temperature may have promoted the increase in plant cover and the spread of thermophilic species. Thus, even though human activities are major driving forces of change in coastal dune vegetation, at the community scale climatic factors may also play important roles. Our study draws on re-visitation studies which appear to constitute a powerful tool for the assessment of the conservation status of EU habitats. PMID:25750408

  16. Assessing spider species richness and composition in Mediterranean cork oak forests

    NASA Astrophysics Data System (ADS)

    Cardoso, Pedro; Gaspar, Clara; Pereira, Luis C.; Silva, Israel; Henriques, Sérgio S.; da Silva, Ricardo R.; Sousa, Pedro

    2008-01-01

    Semi-quantitative sampling protocols have been proposed as the most cost-effective and comprehensive way of sampling spiders in many regions of the world. In the present study, a balanced sampling design with the same number of samples per day, time of day, collector and method, was used to assess the species richness and composition of a Quercus suber woodland in Central Portugal. A total of 475 samples, each corresponding to one hour of effective fieldwork, were taken. One hundred sixty eight species were captured, of which 150 were recorded inside a delimited one-hectare plot; this number corresponds to around 90% of the estimated species richness. We tested the effect of applying different sampling approaches (sampling day, time of day, collector experience and method) on species richness, abundance, and composition. Most sampling approaches were found to influence the species measures, of which method, time of day and the respective interaction had the strongest influence. The data indicated that fauna depletion of the sampled area possibly occurred and that the inventory was reaching a plateau by the end of the sampling process. We advocate the use of the Chao estimators as best for intensive protocols limited in space and time and the use of the asymptotic properties of the Michaelis-Menten curve as a stopping or reliability rule, as it allows the investigator to know when a close-to-complete inventory has been obtained and when reliable non-parametric estimators have been achieved.

  17. Rear-arc vs. arc-front volcanoes in the Katmai reach of the Alaska Peninsula: A critical appraisal of across-arc compositional variation

    USGS Publications Warehouse

    Hildreth, W.; Fierstein, J.; Siems, D.F.; Budahn, J.R.; Ruiz, J.

    2004-01-01

    Physical and compositional data and K-Ar ages are reported for 14 rear-arc volcanoes that lic 11-22 km behind the narrowly linear volcanic front defined by the Mount Katmai-to-Devils Desk chain on the Alaska Peninsula. One is a 30-km3 stratocone (Mount Griggs; 51-63% SiO2) active intermittently from 292 ka to Holocene. The others are monogenetic cones, domes, lava flows, plugs, and maars, of which 12 were previously unnamed and unstudied; they include seven basalts (48-52% SiO2), four mafic andesites (53-55% SiO2), and three andesite-dacite units. Six erupted in the interval 500-88 ka, one historically in 1977, and five in the interval 3-2 Ma. No migration of the volcanic front is discernible since the late Miocene, so even the older units erupted well behind the front. Discussion explores the significance of the volcanic front and the processes that influence compositional overlaps and differences among mafic products of the rear-arc volcanoes and of the several arc-front edifices nearby. The latter have together erupted a magma volume of about 200 km3, at least four times that of all rear-arc products combined. Correlation of Sr-isotope ratios with indices of fractionation indicates crustal contributions in volcanic-front magmas (0.7033-0.7038), but lack of such trends among the rear-arc units (0.70298-0.70356) suggests weaker and less systematic crustal influence. Slab contributions and mantle partial-melt fractions both appear to decline behind the front, but neither trend is crisp and unambiguous. No intraplate mantle contribution is recognized nor is any systematic across-arc difference in intrinsic mantle-wedge source fertility discerned. Both rear-arc and arc-front basalts apparently issued from fluxing of typically fertile NMORB-source mantle beneath the Peninsular terrane, which docked here in the Mesozoic. ?? Springer-Verlag 2004.

  18. Plankton studies in San Francisco Bay; II, Phytoplankton abundance and species composition, July 1977-December 1979

    USGS Publications Warehouse

    Wong, Raymond L. J.; Cloern, James E.

    1981-01-01

    Data are presented on the phytoplankton species composition and abundance in San Francisco Bay from July 1977 through December 1979. Phytoplankton identification and enumerations were made at selected stations. Sample collections were made at selected stations in the main channel of the Bay from Rio Vista on the Sacramento River to Calaveras Point in South San Francisco Bay, and at shoal stations in the central portion of South San Francisco Bay, San Pablo Bay, and Suisun Bay. Also reported, from October 1978 through December 1979, are the calculated phytoplankton carbon and percent nondiatom carbon, and the species list. This study is one component of an ongoing interdisciplinary study of San Francisco Bay. (USGS)

  19. The compositionally zoned eruption of 1912 in the Valley of Ten Thousand Smokes, Katmai National Park, Alaska

    USGS Publications Warehouse

    Hildreth, W.

    1983-01-01

    On June 6-8, 1912, ??? 15 km3 of magma erupted from the Novarupta caldera at the head of the Valley of Ten Thousand Smokes (VTTS), producing ??? 20 km3 of air-fall tephra and 11-15 km3 of ash-flow tuff within ??? 60 hours. Three discrete periods of ash-fall at Kodiak correlate, respectively, with Plinian tephra layers designated A, CD, and FG by Curtis (1968) in the VTTS. The ash-flow sequence overlapped with but outlasted pumice fall A, terminating within 20 hours of the initial outbreak and prior to pumice fall C. Layers E and H consist mostly of vitric dust that settled during lulls, and Layer B is the feather edge of the ash flow. The fall units filled and obscured the caldera, but arcuate and radial fissures outline a 6-km2 depression. The Novarupta lava dome and its ejecta ring were emplaced later within the depression. At Mt. Katmai, 10 km east of the 1912 vent, a 600-m-deep caldera of similar area also collapsed at about this time, probably owing to hydraulic connection with the venting magma system; but all known ejecta are thought to have erupted at Novarupta. Mingling of three distinctive magmas during the eruption produced an abundance of banded pumice, and mechanical mixing of chilled ejecta resulted in deposits with a wide range of bulk composition. Pumice in the initial fall unit (A) is 100% rhyolite, but fall units atop the ash flow are > 98% dacite; black andesitic scoria is common only in the ash flows and in near-vent air-fall tephra. Pumice counts show the first half of the ash-flow deposit to be 91-98% rhyolite, but progressive increases of dacite and andesite eventually reduced the rhyolitic component to 20 km to the lowermost VTTS, and deposited 1-8 m of debris there. Rhyolitic ejecta contain only 1-2% phenocrysts but andesite and dacite have 30-45%. Quartz is present and augite absent only in the rhyolite, but all ejecta contain plagioclase, orthopyroxene, titanomagnetite, ilmenite, apatite, and pyrrhotite; rare olivine occurs in the

  20. Fatty-Acid Composition of Seeds and Chemotaxonomic Evaluation of Sixteen Sapindaceae Species.

    PubMed

    Coutinho, Diogenes J Gusmão; Barbosa, Mariana O; Silva, Rejane M; da Silva, Suzene I; de Oliveira, Antonio Fernando M

    2015-08-01

    Circumscriptions for the Sapindaceae family and its infrafamilial relationships have been widely discussed. Certain groups are highly morphologically similar; thus, it is difficult to identify certain taxa. DNA Analyses have also indicated complex phylogenetic relationships, and it is difficult to relate such analyses to morphological data. Given the above concerns, this study aimed to investigate the fatty-acid profiles of the seed oils of 16 Sapindaceae species belonging to five tribes and to evaluate their potential chemotaxonomic significance. In total, eleven fatty acids were identified, and eicosenoic acid predominated in nine species. Multivariate analyses (principal component and cluster analyses) of the fatty-acid profiles of the seed oils allowed to separate them in two major clusters. The first cluster, characterized by oils with high eicosenoic acid levels, included all species belonging to the Paullinieae tribe (Cardiospermum, Paullinia, and Serjania species). In the second main cluster, the chemical similarity of the oils was lower, and the species belonged to different tribes. Nevertheless, the tree investigated Allophylus species (Thouinieae tribe) constituted a separate subcluster. Thus, the results showed that the fatty-acid composition of the seed oils of Sapindaceae species provide chemotaxonomic support for the separation of the Paullinieae tribe from the other tribes studied. PMID:26265579

  1. Rapid plant evolution in the presence of an introduced species alters community composition.

    PubMed

    Smith, David Solance; Lau, Matthew K; Jacobs, Ryan; Monroy, Jenna A; Shuster, Stephen M; Whitham, Thomas G

    2015-10-01

    Because introduced species may strongly interact with native species and thus affect their fitness, it is important to examine how these interactions can cascade to have ecological and evolutionary consequences for whole communities. Here, we examine the interactions among introduced Rocky Mountain elk, Cervus canadensis nelsoni, a common native plant, Solidago velutina, and the diverse plant-associated community of arthropods. While introduced species are recognized as one of the biggest threats to native ecosystems, relatively few studies have investigated an evolutionary mechanism by which introduced species alter native communities. Here, we use a common garden design that addresses and supports two hypotheses. First, native S. velutina has rapidly evolved in the presence of introduced elk. We found that plants originating from sites with introduced elk flowered nearly 3 weeks before plants originating from sites without elk. Second, evolution of S. velutina results in a change to the plant-associated arthropod community. We found that plants originating from sites with introduced elk supported an arthropod community that had ~35 % fewer total individuals and a different species composition. Our results show that the impacts of introduced species can have both ecological and evolutionary consequences for strongly interacting species that subsequently cascade to affect a much larger community. Such evolutionary consequences are likely to be long-term and difficult to remediate.

  2. Rapid plant evolution in the presence of an introduced species alters community composition.

    PubMed

    Smith, David Solance; Lau, Matthew K; Jacobs, Ryan; Monroy, Jenna A; Shuster, Stephen M; Whitham, Thomas G

    2015-10-01

    Because introduced species may strongly interact with native species and thus affect their fitness, it is important to examine how these interactions can cascade to have ecological and evolutionary consequences for whole communities. Here, we examine the interactions among introduced Rocky Mountain elk, Cervus canadensis nelsoni, a common native plant, Solidago velutina, and the diverse plant-associated community of arthropods. While introduced species are recognized as one of the biggest threats to native ecosystems, relatively few studies have investigated an evolutionary mechanism by which introduced species alter native communities. Here, we use a common garden design that addresses and supports two hypotheses. First, native S. velutina has rapidly evolved in the presence of introduced elk. We found that plants originating from sites with introduced elk flowered nearly 3 weeks before plants originating from sites without elk. Second, evolution of S. velutina results in a change to the plant-associated arthropod community. We found that plants originating from sites with introduced elk supported an arthropod community that had ~35 % fewer total individuals and a different species composition. Our results show that the impacts of introduced species can have both ecological and evolutionary consequences for strongly interacting species that subsequently cascade to affect a much larger community. Such evolutionary consequences are likely to be long-term and difficult to remediate. PMID:26062439

  3. The compositionally zoned eruption of 1912 in the Valley of Ten Thousand Smokes, Katmai National Park, Alaska

    NASA Astrophysics Data System (ADS)

    Hildreth, Wes

    1983-10-01

    On June 6-8, 1912, ˜ 15 km 3 of magma erupted from the Novarupta caldera at the head of the Valley of Ten Thousand Smokes (VTTS), producing ˜ 20 km 3 of air-fall tephra and 11-15 km 3 of ash-flow tuff within ˜ 60 hours. Three discrete periods of ash-fall at Kodiak correlate, respectively, with Plinian tephra layers designated A, CD, and FG by Curtis (1968) in the VTTS. The ash-flow sequence overlapped with but outlasted pumice fall A, terminating within 20 hours of the initial outbreak and prior to pumice fall C. Layers E and H consist mostly of vitric dust that settled during lulls, and Layer B is the feather edge of the ash flow. The fall units filled and obscured the caldera, but arcuate and radial fissures outline a 6-km 2 depression. The Novarupta lava dome and its ejecta ring were emplaced later within the depression. At Mt. Katmai, 10 km east of the 1912 vent, a 600-m-deep caldera of similar area also collapsed at about this time, probably owing to hydraulic connection with the venting magma system; but all known ejecta are thought to have erupted at Novarupta. Mingling of three distinctive magmas during the eruption produced an abundance of banded pumice, and mechanical mixing of chilled ejecta resulted in deposits with a wide range of bulk composition. Pumice in the initial fall unit (A) is 100% rhyolite, but fall units atop the ash flow are > 98% dacite; black andesitic scoria is common only in the ash flows and in near-vent air-fall tephra. Pumice counts show the first half of the ash-flow deposit to be 91-98% rhyolite, but progressive increases of dacite and andesite eventually reduced the rhyolitic component to < 2%. The later, rhyolite-poor flows were hotter, less mobile, and widely produced partially welded tuff and vapor-indurated sillar. The main ash flow was too deflated and sluggish 16 km from the vent to surmount a 25-m-high moraine in its path but was diverted around it and continued 5 km down-valley, engulfing and charring trees but

  4. Walker Branch Throughfall Displacement Experiment Data Report: Site Characterization, System Performance, Weather, Species Composition, and Growth

    SciTech Connect

    Hanson, P.J.

    2001-09-04

    This numeric data package provides data sets, and accompanying documentation, on site characterization, system performance, weather, species composition, and growth for the Throughfall Displacement Experiment, which was established in the Walker Branch Watershed of East Tennessee to provide data on the responses of forests to altered precipitation regimes. The specific data sets include soil water content and potential, coarse fraction of the soil profile, litter layer temperature, soil temperature, monthly weather, daily weather, hourly weather, species composition of trees and saplings, mature tree and sapling annual growth, and relative leaf area index. Fortran and SAS{trademark} access codes are provided to read the ASCII data files. The data files and this documentation are available without charge on a variety of media and via the Internet from the Carbon Dioxide Information Analysis Center (CDIAC).

  5. Army ants in four forests: geographic variation in raid rates and species composition.

    PubMed

    O'Donnell, Sean; Lattke, John; Powell, Scott; Kaspari, Michael

    2007-05-01

    1. The New World army ants are top predators in the litter of tropical forest, but no comprehensive studies exist on variation in assemblage-wide activity and species composition. We used standardized protocols to estimate foraging raid rates and species composition of army ant communities in four Neotropical forests. The study sites spanned approximately 10 degrees latitude, with two sites each in Central and South America. 2. We recorded a total of 22 species of army ants. The four sites varied in observed and estimated species richness. Species overlap was highest between the Central American sites, and lowest between the South American sites. 3. Raid activity varied significantly among sites. Raid activity per kilometre of trail walks was over four times higher at the most active site (Sta. Maria, Venezuela) than at the least active site (Barro Colorado Island, Panama). Furthermore, each site showed a different diel pattern of activity. For example, raid activity was higher during daylight hours in Costa Rica, and higher at night in Venezuela. Raid activity relationships with ambient temperature also varied significantly among sites. 4. The overall rate of army ant raids passing through 1 m(2) plots was 0.73 raids per day, but varied among sites, from 0 raids per day (Panama) to 1.2 raids per day (Venezuela). 5. Primarily subterranean species were significantly more abundant in Venezuela, and above-ground foragers that form large swarm fronts were least abundant in Panama. The site heterogeneity in species abundance and diel activity patterns has implications for army ant symbionts, including ant-following birds, and for the animals hunted by these top predators. PMID:17439474

  6. Copepod abundance and species composition in the Eastern subtropical/tropical Atlantic

    NASA Astrophysics Data System (ADS)

    Schnack-Schiel, Sigrid B.; Mizdalski, Elke; Cornils, Astrid

    2010-12-01

    Abundance and species composition of copepods were studied during the expedition ANT XXI/1 on a latitudinal transect in the eastern Atlantic from 34°49.5'N to 27°28.1'S between 2-20 November 2002. Stratified zooplankton tows were carried out at 19 stations with a multiple opening-closing net between 300 m water depth and the surface. Cyclopoid and calanoid copepods showed similar patterns of distribution and abundance. Oithona was the most abundant cyclopoid genus, followed by Oncaea. A total of 149 calanoid copepod species were identified. Clausocalanus was by far the most abundant genus, comprising on average about 45% of all calanoids, followed by Calocalanus (13%), Delibus (9%), Paracalanus (6%), and Pleuromamma (5%). All other genera comprised on average less than 5% each, with 40 genera less than 1%. The calanoid copepod communities were distinguished broadly in accordance with sea surface temperature, separating the subtropical from the tropical stations, and were largely determined by variation in species composition and species abundance. Nine Clausocalanus species were identified. The most numerous Clausocalanus species was C. furcatus, which on average comprised half of all adult of this genus. C. pergens, C. paululus, and C. jobei, contributed an average of 19%, 9%, and 9%, respectively. The Clausocalanus species differed markedly in their horizontal and vertical distributions: C. furcatus, C. jobei, and C. mastigophorus had widespread distributions and inhabited the upper water layers. Major differences between the species were found in abundance. C. paululus and C. arcuicornis were biantitropical and were absent or occurred in very low numbers in the equatorial zone. C. parapergens was found at all stations and showed a bimodal distribution pattern with maxima in the subtropics. C. pergens occurred in higher numbers only at the southern stations, where it replaced C. furcatus in dominance. In contrast to the widespread species, the bulk of the C

  7. Modified oleic cottonseeds show altered content, composition and tissue-specific distribution of triacylglycerol molecular species.

    PubMed

    Horn, Patrick J; Sturtevant, Drew; Chapman, Kent D

    2014-01-01

    Targeted increases in monounsaturated (oleic acid) fatty acid content of refined cottonseed oil could support improved human nutrition and cardiovascular health. Genetic modifications of cottonseed fatty acid composition have been accomplished using several different molecular strategies. Modification of oleic acid content in cottonseed embryos using a dominant-negative protein approach, while successful in effecting change in the desired fatty acid composition, resulted in reduced oil content and seed viability. Here these changes in fatty acid composition were associated with changes in dominant molecular species of triacylglycerols (TAGs) and their spatial distributions within embryo tissues. A combination of mass spectrometry (MS)-based lipidomics approaches, including MS imaging of seed cryo-sections, revealed that cotton embryos expressing a non-functional allele of a Brassica napus delta-12 desaturase showed altered accumulation of TAG species, especially within cotyledonary tissues. While lipid analysis of seed extracts could demonstrate detailed quantitative changes in TAG species in transgenics, the spatial contribution of metabolite compartmentation could only be visualized by MS imaging. Our results suggest tissue-specific differences in TAG biosynthetic pathways within cotton embryos, and indicate the importance of considering the location of metabolites in tissues in addition to their identification and quantification when developing a detailed view of cellular metabolism.

  8. Assessing variation in bacterial composition between the rhizospheres of two mangrove tree species

    NASA Astrophysics Data System (ADS)

    Gomes, Newton C. M.; Cleary, Daniel F. R.; Pires, Ana C. C.; Almeida, Adelaide; Cunha, Angela; Mendonça-Hagler, Leda C. S.; Smalla, Kornelia

    2014-02-01

    This study aimed to determine to what extent roots from the common mangrove tree species Avicennia schaueriana and Laguncularia racemosa are able to impose a selective force on the composition of sediment bacterial communities in mangrove intertidal sediments using barcoded pyrosequencing analysis of 16S rRNA gene fragments (V4 hyper-variable region). The novel results showed that root systems of A. schaueriana and L. racemosa are associated with increased bacterial dominance, lower richness and compositional shifts of sediment bacterial communities. The proportion of OTUs (operational taxonomc units) belonging to the orders Rhizobiales and Vibrionales were enriched in rhizosphere samples from both plant species and sulphur-reducing bacteria (SRB) belonging to the order Desulfobacterales and Desulfuromonadales were enriched in the rhizosphere of A. schaueriana. In addition, Clostridium and Vibrio populations were more abundant in different mangrove rhizospheres. A. schaueriana and L. racemosa roots appear to be able to impose a selective force on the composition of mangrove sediment bacterial communities and this phenomenon appears to be plant species specific. Our findings provide new insights into the potential ecological roles of bacterial guilds in plant-microbe interactions and may aid rhizoengineering approaches for replanting impacted mangrove areas.

  9. Chemical composition of the essential oil from Croton kimosorum, an endemic species to Madagascar.

    PubMed

    Rabehaja, Delphin J R; Ihandriharison, Harilala; Ramanoelina, Panja A R; Benja, Rakotonirina; Ratsimamanga-Urverg, Suzanne; Bighelli, Ange; Casanova, Joseph; Tomi, Félix

    2014-01-01

    Croton kimosorum Leandri is an endemic species to Madagascar. The chemical composition of aerial parts, leaf and stem oils is reported for the first time. Analysis was carried out by combination of chromatographic (CC, GC), spectroscopic and spectrometric (MS, 13C NMR) techniques. In total, 76 compounds have been identified. Essential oil isolated from aerial parts contained mainly linalool (21.6%), sabinene (10.4%), 1,8-cineole (6.3%), beta-pinene (6.2%), (E)-beta-caryophyllene (5.9%), terpinen-4-ol (4.8%), geraniol (4,5%) and germacrene D (2.3%). In comparison with the first sample, the composition of leaf and stem oils varied slightly, while essential oil isolated by vapor distillation from a semi-industrial still exhibited similar composition.

  10. Chemical composition of black rockfish (Sebastes melanops) fillets and byproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Black rockfish are important in the near shore fishery of Southeast Alaska. They are the only species among the pelagic shelf rockfishes for which there is a directed fishery in state waters. The purpose of this study was to determine the composition black rockfish fillets and its major processing b...

  11. The Costs of Evaluating Species Densities and Composition of Snakes to Assess Development Impacts in Amazonia

    PubMed Central

    de Fraga, Rafael; Stow, Adam J.; Magnusson, William E.; Lima, Albertina P.

    2014-01-01

    Studies leading to decision-making for environmental licensing often fail to provide accurate estimates of diversity. Measures of snake diversity are regularly obtained to assess development impacts in the rainforests of the Amazon Basin, but this taxonomic group may be subject to poor detection probabilities. Recently, the Brazilian government tried to standardize sampling designs by the implementation of a system (RAPELD) to quantify biological diversity using spatially-standardized sampling units. Consistency in sampling design allows the detection probabilities to be compared among taxa, and sampling effort and associated cost to be evaluated. The cost effectiveness of detecting snakes has received no attention in Amazonia. Here we tested the effects of reducing sampling effort on estimates of species densities and assemblage composition. We identified snakes in seven plot systems, each standardised with 14 plots. The 250 m long centre line of each plot followed an altitudinal contour. Surveys were repeated four times in each plot and detection probabilities were estimated for the 41 species encountered. Reducing the number of observations, or the size of the sampling modules, caused significant loss of information on species densities and local patterns of variation in assemblage composition. We estimated the cost to find a snake as $ 120 U.S., but general linear models indicated the possibility of identifying differences in assemblage composition for half the overall survey costs. Decisions to reduce sampling effort depend on the importance of lost information to target-issues, and may not be the preferred option if there is the potential for identifying individual snake species requiring specific conservation actions. However, in most studies of human disturbance on species assemblages, it is likely to be more cost-effective to focus on other groups of organisms with higher detection probabilities. PMID:25147930

  12. Diet composition and resource partitioning in two small flatfish species in the German Bight

    NASA Astrophysics Data System (ADS)

    Schückel, S.; Sell, A.; Kröncke, I.; Reiss, H.

    2011-10-01

    Since the late 1980s, the small-sized non-commercial flatfish species solenette ( Buglossidium luteum) and scaldfish ( Arnoglossus laterna) have increased in abundance in the southern North Sea. Because these species are considered as possible competitors for prey of commercial flatfish, this study aimed at advancing knowledge of their feeding ecology. Between January 2009 and January 2010 stomach contents of solenette and scaldfish and benthic infauna were sampled seasonally in a study area in the German Bight. The objectives were to investigate the seasonal variability of feeding activity and diet composition of both flatfish species related to benthic prey availability. For both flatfish, the highest feeding activity was found in summer, at the same time that the highest prey densities occurred in the study area. A reduced feeding activity was observed during the winter of 2010, but not in the winter of 2009, probably related to higher 2009 water temperatures. In all seasons, diet composition of solenette was dominated by meiofauna, mainly harpacticoid copepods. Macrofauna prey species, namely juveniles of bivalves and echinoderms became important in spring. An increase in amphipods and cumaceans was found in the stomach contents during summer and autumn, simultaneously with their increased abundance in the benthic infauna. In contrast, polychaetes were rarely found in the diet, but dominated the infauna during all seasons. Diet composition of scaldfish was dominated by larger and mobile prey, and, during all seasons, was mainly comprised of crustaceans. Amphipods characterised the diet in both winters, while decapods such as Crangon spp. and Liocarcinus spp. were the dominant prey from spring to autumn. Additionally, juveniles of flatfish (Pleuronectids) and bivalves were found in the scaldfish diet in spring, replaced by cumaceans in summer. No dietary overlap between both flatfish species was found across seasons, indicating partitioning of prey resources

  13. The costs of evaluating species densities and composition of snakes to assess development impacts in amazonia.

    PubMed

    Fraga, Rafael de; Stow, Adam J; Magnusson, William E; Lima, Albertina P

    2014-01-01

    Studies leading to decision-making for environmental licensing often fail to provide accurate estimates of diversity. Measures of snake diversity are regularly obtained to assess development impacts in the rainforests of the Amazon Basin, but this taxonomic group may be subject to poor detection probabilities. Recently, the Brazilian government tried to standardize sampling designs by the implementation of a system (RAPELD) to quantify biological diversity using spatially-standardized sampling units. Consistency in sampling design allows the detection probabilities to be compared among taxa, and sampling effort and associated cost to be evaluated. The cost effectiveness of detecting snakes has received no attention in Amazonia. Here we tested the effects of reducing sampling effort on estimates of species densities and assemblage composition. We identified snakes in seven plot systems, each standardised with 14 plots. The 250 m long centre line of each plot followed an altitudinal contour. Surveys were repeated four times in each plot and detection probabilities were estimated for the 41 species encountered. Reducing the number of observations, or the size of the sampling modules, caused significant loss of information on species densities and local patterns of variation in assemblage composition. We estimated the cost to find a snake as $ 120 U.S., but general linear models indicated the possibility of identifying differences in assemblage composition for half the overall survey costs. Decisions to reduce sampling effort depend on the importance of lost information to target-issues, and may not be the preferred option if there is the potential for identifying individual snake species requiring specific conservation actions. However, in most studies of human disturbance on species assemblages, it is likely to be more cost-effective to focus on other groups of organisms with higher detection probabilities. PMID:25147930

  14. Grazing effects on species composition in different vegetation types (La Palma, Canary Islands)

    NASA Astrophysics Data System (ADS)

    Arévalo, J. R.; de Nascimento, L.; Fernández-Lugo, S.; Mata, J.; Bermejo, L.

    2011-05-01

    Grazing management is probably one of the most extensive land uses, but its effects on plant communities have in many cases been revealed to be contradictory. Some authors have related these contradictions to the stochastic character of grazing systems. Because of that, it is necessary to implement specific analyses of grazing effects on each community, especially in natural protected areas, in order to provide the best information to managers. We studied the effects of grazing on the species composition of the main vegetation types where it takes place (grasslands, shrublands and pine forests) on the island of La Palma, Canary Islands. We used the point-quadrat intersect method to study the species composition of grazed and ungrazed areas, which also were characterized by their altitude, distance to farms, distance to settlements, year of sampling, herbaceous aboveground biomass and soil organic matter. The variables organic matter, productivity and species richness were not significantly affected by grazing. The species composition of the analyzed plant communities was affected more by variables such as altitude or distance to farms than by extensive grazing that has been traditionally carried out on the island of La Palma involving certain practices such as continuous monitoring of animals by goat keepers, medium stocking rates adjusted to the availability of natural pastures, supplementation during the dry season using local forage shrubs or mown pastures and rotating animals within grazing areas Although some studies have shown a negative effect of grazing on endangered plant species, these results cannot be freely extrapolated to the traditional grazing systems that exert a low pressure on plant communities (as has been found in this study). We consider extensive grazing as a viable way of ensuring sustainable management of the studied ecosystems.

  15. Changes in plant species composition of coastal dune habitats over a 20-year period

    PubMed Central

    Del Vecchio, Silvia; Prisco, Irene; Acosta, Alicia T. R.; Stanisci, Angela

    2015-01-01

    Coastal sandy ecosystems are increasingly being threatened by human pressure, causing loss of biodiversity, habitat degradation and landscape modifications. However, there are still very few detailed studies focussing on compositional changes in coastal dune plant communities over time. In this work, we investigated how coastal dune European Union (EU) habitats (from pioneer annual beach communities to Mediterranean scrubs on the landward fixed dunes) have changed during the last 20 years. Using phytosociological relevés conducted in 1989–90 and in 2010–12, we investigated changes in floristic composition over time. We then compared plant cover and the proportion of ruderal, alien and habitat diagnostic species (‘focal species’) in the two periods. Finally, we used Ellenberg indicator values to define the ‘preferences’ of the plant species for temperature and moisture. We found that only fore dune habitats showed significant differences in species cover between the two time periods, with higher plant cover in the more recent relevés and a significant increase in thermophilic species. Although previous studies have demonstrated consistent habitat loss in this area, we observed that all coastal dune plant communities remain well represented, after a 20-year period. However, fore dunes have been experiencing significant compositional changes. Although we cannot confirm whether the observed changes are strictly related to climatic changes, to human pressure or to both, we hypothesize that a moderate increment in average yearly temperature may have promoted the increase in plant cover and the spread of thermophilic species. Thus, even though human activities are major driving forces of change in coastal dune vegetation, at the community scale climatic factors may also play important roles. Our study draws on re-visitation studies which appear to constitute a powerful tool for the assessment of the conservation status of EU habitats. PMID:25750408

  16. Whole-rock chemical composition of some samples from two drill hole cores in the Capps coal field, Beluga coal area, south-central Alaska

    USGS Publications Warehouse

    Hinkley, T.K.; Smith, K.S.; Peard, J.L.; Tompkins, M.L.

    1982-01-01

    Whole-rock chemical analysis was done on samples from drill cores of rocks lying atop and between coal beds in the Beluga coal area, south-central Alaska. The samples were classified as sandstone, siltstone or claystone at time of hand specimen description. Chemical data were compared to those from corresponding rocks from other sites in the conterminous United States. The study supports the following conclusions: 1. The sample suites from the two cored Alaska holes, about 1 km apart, contrast sharply in their degree of lithologic differentiation, one having relatively purer sandstones and claystones, the other having more mixed rock types. This suggests that considerable variation occurs in depositional environments and, possibly, in rock chemistry over small distances in the Beluga coal area. 2. Hand specimen inspection is a reasonably reliable way of assigning names denoting the lithologic type of Alaska rocks, and thereby making broad predictions of their whole-rock chemistry.

  17. Dynamics of Tree Species Composition in Temperate Mountains of South Korea over Fourteen Years using 880 Permanent Plots

    NASA Astrophysics Data System (ADS)

    Lee, B.; Kim, H. S.; Park, J.; Moon, M.; Cho, S.; Ryu, D.; Wynn, K. Z.; Park, J.

    2014-12-01

    The structure of forest and diversity of tree species in temperate mountains have been influenced by changing climate conditions as well as successional changes. To understand how tree species composition and stand structure change across temperate mountains, the species composition, size, and environmental information were collected over the past fourteen years in 880 quadrats of 20 m x 50 m of woodland communities distributed across Jiri and Baekoon Mountains, South Korea. The preliminary investigation on variations of tree species revealed that overall composition of tree species increased in terms of both diversity and biomass growth of tree species, reflecting fast and wide changes in temperate forests of Korea. Among dominant trees, the Quercus mongolica, Styrax japonicu, and Acer pseudosieboldianum recorded the highest increase in stand density, implying the most prosperous species under current conditions, while the species of Quercus variabilis and Fraxinus mandshurica appeared as fast declining species in the number. In terms of biomass growth of dominant species, the Stewartia pseudocamellia showed the largest increase of biomass, followed by Quercus serrata and Quercus mongolica., while the Fraxinus mandshurica appeared to have a rapid decline, followed by Alnus japonica and Quercus dentata. Overall, the fast change of composition in tree species is clear and further analysis to clarify the reasons for such fast and species-specific changes is underway especially to separate the effect of successional change and climate change.

  18. Response of soil microbial community composition to afforestation with pure and mixed tree species

    NASA Astrophysics Data System (ADS)

    Gunina, Anna; Smith, Andrew; Godbold, Douglas; Kuzyakov, Yakov; Jones, Davey

    2016-04-01

    Afforestation of agricultural land affects soil ecosystem functions by inducing carbon (C) and nitrogen (N) sequestration and promoting shifts in microbial community structure. Soil C and N stocks undergo progressive changes over several decades after forest establishment, particularly in successional forests. In contrast, microbial community structure can be shifted already in the first decade and thus, direct effect of tree species can be revealed. Thus, the aim of this study was to determine how soil microbial community composition is altered by afforestation with either one, two or three species mixtures of trees, which possess strongly contrasting functional traits. The study was conducted at the BangorDIVERSE temperate forest experiment established in 2004 on a former arable soil. Soil samples were collected under single, two and three species mixtures of alder, birch, beech and oak, while contiguous field was chosen as a control. Soil samples were analysed for key quality indicators (total C and N, pH, nitrate and ammonium), and microbial community structure was determined by phospholipid fatty acids (PLFAs) analysis. Ten years after afforestation, total soil C, N and C/N ratios were not strongly affected, with the highest positive changes (up to 20%) for the birch, alder+oak and birch+beech plots. Decrease of C and N contents were observed for the pure beech plot. pH decreased by 1-1.2 units for all forest plots compare to the control soil. Total PLFAs content (370-630 nmol g‑1 soil) increased in comparison to the control (315 nmol g‑1 soil), resulting in the changes in total PLFAs content from 20 to 100%. Thus, changes of chemical properties (C, N) occur slower than changes of microbial biomarkers at the early stage of afforestation. Bacterial PLFA content was shifted by 20-120%, whereas fungal PLFAs were changed by 50-300%, reflecting stronger impact of afforestation on the recovery of fungal communities than on bacterial. Principal component analysis

  19. Response of soil microbial community composition to afforestation with pure and mixed tree species

    NASA Astrophysics Data System (ADS)

    Gunina, Anna; Smith, Andrew; Godbold, Douglas; Kuzyakov, Yakov; Jones, Davey

    2016-04-01

    Afforestation of agricultural land affects soil ecosystem functions by inducing carbon (C) and nitrogen (N) sequestration and promoting shifts in microbial community structure. Soil C and N stocks undergo progressive changes over several decades after forest establishment, particularly in successional forests. In contrast, microbial community structure can be shifted already in the first decade and thus, direct effect of tree species can be revealed. Thus, the aim of this study was to determine how soil microbial community composition is altered by afforestation with either one, two or three species mixtures of trees, which possess strongly contrasting functional traits. The study was conducted at the BangorDIVERSE temperate forest experiment established in 2004 on a former arable soil. Soil samples were collected under single, two and three species mixtures of alder, birch, beech and oak, while contiguous field was chosen as a control. Soil samples were analysed for key quality indicators (total C and N, pH, nitrate and ammonium), and microbial community structure was determined by phospholipid fatty acids (PLFAs) analysis. Ten years after afforestation, total soil C, N and C/N ratios were not strongly affected, with the highest positive changes (up to 20%) for the birch, alder+oak and birch+beech plots. Decrease of C and N contents were observed for the pure beech plot. pH decreased by 1-1.2 units for all forest plots compare to the control soil. Total PLFAs content (370-630 nmol g-1 soil) increased in comparison to the control (315 nmol g-1 soil), resulting in the changes in total PLFAs content from 20 to 100%. Thus, changes of chemical properties (C, N) occur slower than changes of microbial biomarkers at the early stage of afforestation. Bacterial PLFA content was shifted by 20-120%, whereas fungal PLFAs were changed by 50-300%, reflecting stronger impact of afforestation on the recovery of fungal communities than on bacterial. Principal component analysis of

  20. STUDIES ON THE SPECIES COMPOSITION AND RELATIVE ABUNDANCE OF MOSQUITOES OF MPIGI DISTRICT, CENTRAL UGANDA

    PubMed Central

    Mayanja, Martin; Mutebi, John-Paul; Crabtree, Mary B.; Ssenfuka, Fred; Muwawu, Teddy; Lutwama, Julius J.

    2015-01-01

    Prediction of arboviral disease outbreaks and planning for appropriate control interventions require knowledge of the mosquito vectors involved. Although mosquito surveys have been conducted in different regions of Uganda since the mid 30’s such studies have not been carried out in Mpigi District. In October 2011, we conducted mosquito collections in Mpigi district to determine species composition and relative abundance of the different species. The survey was conducted in four villages, Njeru, Ddela, Kiwumu and Nsumbain Kammengo sub-county, Mpigi district, Uganda. CDC light traps baited with dry ice (carbon dioxide) were used to capture adult mosquitoes. A total of 54,878 mosquitoes comprising 46 species from eight genera were collected. The dominant species at all sites was Coquilletidia (Coquilletidia) fuscopennata Theobald (n=38,059, 69%), followed by Coquillettidia (Coquillettidia) metallica Theobald (n=4,265, 7.8%). The number of species collected varied from 17 in the genus Culex to 1 in the genus Lutzia. Of the 46 species identified, arboviruses had previously been isolated from 28 (60.9%) suggesting a high potential for arboviral transmission and/or maintenance in Mpigi District. PMID:26346305

  1. Positional-Species Composition of Diacylglycerol Acetates from Mature Euonymus Seeds.

    PubMed

    Sidorov, Roman A; Pchelkin, Vasily P; Zhukov, Anatoly V; Tsydendambaev, Vladimir D

    2016-06-01

    The positional-species composition (PSC) of 3-acetyl-1,2-diacyl-sn-glycerols (AcDAGs) from the seeds of mature fruits of 14 species of the genus Euonymus L. was established. The residues of six major fatty acids (FAs), palmitic (P), stearic (St), hexadecenoic (H), octadecenoic (O), linoleic (L), and linolenic (Ln), were present in the AcDAGs. Here, we demonstrated that the profile of PSC of AcDAGs could serve as chemotaxonomic factor to divide euonymus species studied here into groups which completely correlate with the present day systematic of the genus. In particular, the Euonymus section greatly exceeded other sections of the Euonymus subgenus as well as the Kalonymus one in the total levels of AcDAGs positional species having one and two O residues and was characterized by significantly lesser concentrations of species with one and two L residues. Moreover, in seed, AcDAGs of almost all Euonymus species EFL values were slightly higher than EFO ones, but all EFL and EFO values were higher than 1.0, and therefore, it can be concluded that both FAs mainly esterified sn-2-position of the glycerol moiety and saturated FAs residues were always virtually absent in the sn-2 position of Euonymus seed AcDAGs, as it is also the case in nearly all TAGs molecules of plant origin.

  2. Positional-Species Composition of Diacylglycerol Acetates from Mature Euonymus Seeds.

    PubMed

    Sidorov, Roman A; Pchelkin, Vasily P; Zhukov, Anatoly V; Tsydendambaev, Vladimir D

    2016-06-01

    The positional-species composition (PSC) of 3-acetyl-1,2-diacyl-sn-glycerols (AcDAGs) from the seeds of mature fruits of 14 species of the genus Euonymus L. was established. The residues of six major fatty acids (FAs), palmitic (P), stearic (St), hexadecenoic (H), octadecenoic (O), linoleic (L), and linolenic (Ln), were present in the AcDAGs. Here, we demonstrated that the profile of PSC of AcDAGs could serve as chemotaxonomic factor to divide euonymus species studied here into groups which completely correlate with the present day systematic of the genus. In particular, the Euonymus section greatly exceeded other sections of the Euonymus subgenus as well as the Kalonymus one in the total levels of AcDAGs positional species having one and two O residues and was characterized by significantly lesser concentrations of species with one and two L residues. Moreover, in seed, AcDAGs of almost all Euonymus species EFL values were slightly higher than EFO ones, but all EFL and EFO values were higher than 1.0, and therefore, it can be concluded that both FAs mainly esterified sn-2-position of the glycerol moiety and saturated FAs residues were always virtually absent in the sn-2 position of Euonymus seed AcDAGs, as it is also the case in nearly all TAGs molecules of plant origin. PMID:27151557

  3. The Prevalence and Species Composition of Malassezia yeasts in Patients with Clinically Suspected Onychomycosis

    PubMed Central

    Prohic, Asja; Kuskunovic-Vlahovljak, Suada; Sadikovic, Tamara Jovovic; Cavaljuga, Semra

    2015-01-01

    Introduction: There are limited numbers of studies which focused on the identification of Malassezia yeasts to a species level in onychomycosis. Therefore, the aim of our study was to determine the prevalence and species composition of Malassezia yeasts in patients with clinically suspected onychomycosis and to examine if the range of species varies with patient gender, age, site of involvement and clinical pattern of onychomycosis. Methods: Specimens were taken from 785 patients presenting signs of onychomycosis and then incubated on Sabouraud dextrose agar and modified Dixon agar. The yeasts isolated were identified according to their macroscopic and microscopic features and physiological characteristics. Results: Malassezia species were diagnosed both by microscopy and culture in fourteen (1.8%) patients. M. globosa was the predominant, if not only, species identified from nail samples. Mixed cultures were observed in five cases: in 4 cases Malassezia was co-isolated with Candida albicans and in one case with dermatophyte. Fingernails were affected more frequently than toenails (85.7%) and distolateral subungual onychomycosis was the most common clinical type (78.6%). Conclusion: No significant differences were found in the distribution of Malassezia species isolated according to demographic parameters. PMID:26005253

  4. Hydrocarbon composition and toxicity of sediments following the Exxon Valdez oil spill in Prince William Sound, Alaska, USA.

    PubMed

    Page, David S; Boehm, Paul D; Stubblefield, William A; Parker, Keith R; Gilfillan, Edward S; Neff, Jerry M; Maki, Alan W

    2002-07-01

    An 1-year study of the 1989 Exxon Valdez oil spill found that spill residues on the oiled shorelines rapidly lost toxicity through weathering. After 1990, toxicity of sediments remained at only a few heavily oiled, isolated locations in Prince William Sound (AK, USA), as measured by a standard amphipod bioassay using Rhepoxynius abronius. Data from 648 sediment samples taken during the 1990 to 1993 period were statistically analyzed to determine the relationship between the total concentration of 39 parent and methyl-substituted polycyclic aromatic hydrocarbons (defined as total polycyclic aromatic hydrocarbons [TPAH]) and amphipod mortality and the effect of oil weathering on toxicity. A logistic regression model yielded estimates of the lower threshold, LC10 (lethal concentration to 10% of the population), and LC50 (median lethal concentration) values of 2,600, 4,100, and 10,750 ng/g TPAH (dry wt), respectively. Estimates of the threshold and LC50 values in this field study relate well to corresponding sediment quality guideline (SQG) values reported in the literature. For sediment TPAH concentrations >2,600 ng/g, samples with high mortality values (>90%) had relatively high fractions of naphthalenes and those with low mortality (<20%) had relatively high fractions of chrysenes. By 1999, the median sediment TPAH concentration of 117 ng/g for the post-1989 worst-case sites studied were well below the 2,600 ng/g toxicity threshold value, confirming the lack of potential for long-term toxic effects. Analysis of biological community structure parameters for sediment samples taken concurrently found that species richness and Shannon diversity decreased with increasing TPAH above the 2,600 ng/g threshold, demonstrating a correspondence between sediment bioassay results and biological community effects in the field. The low probability of exposure to toxic concentrations of weathered spill residues at the worst-case sites sampled in this study is consistent with the

  5. Hydrocarbon composition and toxicity of sediments following the Exxon Valdez oil spill in Prince William Sound, Alaska, USA.

    PubMed

    Page, David S; Boehm, Paul D; Stubblefield, William A; Parker, Keith R; Gilfillan, Edward S; Neff, Jerry M; Maki, Alan W

    2002-07-01

    An 1-year study of the 1989 Exxon Valdez oil spill found that spill residues on the oiled shorelines rapidly lost toxicity through weathering. After 1990, toxicity of sediments remained at only a few heavily oiled, isolated locations in Prince William Sound (AK, USA), as measured by a standard amphipod bioassay using Rhepoxynius abronius. Data from 648 sediment samples taken during the 1990 to 1993 period were statistically analyzed to determine the relationship between the total concentration of 39 parent and methyl-substituted polycyclic aromatic hydrocarbons (defined as total polycyclic aromatic hydrocarbons [TPAH]) and amphipod mortality and the effect of oil weathering on toxicity. A logistic regression model yielded estimates of the lower threshold, LC10 (lethal concentration to 10% of the population), and LC50 (median lethal concentration) values of 2,600, 4,100, and 10,750 ng/g TPAH (dry wt), respectively. Estimates of the threshold and LC50 values in this field study relate well to corresponding sediment quality guideline (SQG) values reported in the literature. For sediment TPAH concentrations >2,600 ng/g, samples with high mortality values (>90%) had relatively high fractions of naphthalenes and those with low mortality (<20%) had relatively high fractions of chrysenes. By 1999, the median sediment TPAH concentration of 117 ng/g for the post-1989 worst-case sites studied were well below the 2,600 ng/g toxicity threshold value, confirming the lack of potential for long-term toxic effects. Analysis of biological community structure parameters for sediment samples taken concurrently found that species richness and Shannon diversity decreased with increasing TPAH above the 2,600 ng/g threshold, demonstrating a correspondence between sediment bioassay results and biological community effects in the field. The low probability of exposure to toxic concentrations of weathered spill residues at the worst-case sites sampled in this study is consistent with the

  6. Species composition, abundance, and seasonal dynamics of stink bugs (Hemiptera: Pentatomidae) in Minnesota soybean fields.

    PubMed

    Koch, Robert L; Pahs, Tiffany

    2014-08-01

    Stink bugs (Hemiptera: Pentatomidae) have historically not been pests of soybean in Minnesota. In response to the invasion of Halyomorpha halys (Stål) and reports of increasing abundance of species native to North America, a state-wide survey of soybean was conducted over 3 yr in Minnesota to determine species composition, abundance, and seasonal dynamics of Pentatomidae associated with soybean. Fourteen species of Pentatomidae (12 herbivorous and two predatory) were collected from soybean. H. halys was not detected in this survey. Among the herbivorous species found, adults of Euschistus variolarius (Palisot de Beauvois) had the greatest relative abundance (60.51%) and frequency of detection (18.44%), followed by Euschistus servus euschistoides (Say) (19.37 and 3.04%, respectively) and Chinavia hilaris (Say) (5.50 and 1.69%, respectively). Abundance of herbivorous nymphs and adults exceeded an economic threshold (20 nymphs and adults per 100 sweeps) in 0.82% of fields in 2012 but not in 2011 or 2013. The frequency of detection of herbivorous species and ratio of nymphs to adults increased with increasing reproductive growth stage of soybean. In two of three years, herbivorous adults were more abundant in the edge compared with interior of fields. Two predatory Pentatomidae, Podisus maculiventris (Say) and Podisus placidus Uhler, comprised 5.95 and 1.62% of the pentatomid adults. Though the species composition of Pentatomidae in Minnesota soybean differs from that in eastern and southern states, the spatial (i.e., greater abundance near field edge) and seasonal dynamics (i.e., increasing abundance and reproduction with increasing reproductive maturity of soybean) in soybean appear similar.

  7. Relationships between pigment composition variation and reflectance for plant species from a coastal savannah in California

    NASA Technical Reports Server (NTRS)

    Ustin, Susan L.; Sanderson, Eric W.; Grossman, Yaffa; Hart, Quinn J.

    1993-01-01

    Advances in imaging spectroscopy have indicated that remotely sensed reflectance measurements of the plant canopy may be used to identify and qualify some classes of canopy biochemicals; however, the manner in which differences in biochemical compositions translate into differences is not well understood. Most frequently, multiple linear regression routines have been used to correlate narrow band reflectance values with measured biochemical concentrations. Although some success has been achieved with such methods for given data sets, the bands selected by multiple regression are not consistent between data sets, nor is it always clear what physical or biological basis underlies the correlation. To examine the relationship between biochemical concentration and leaf reflectance signal we chose to focus on the visible spectrum where the primary biochemical absorbances are due to photosynthetic pigments. Pigments provide a range of absorbance features, occur over a range of concentrations in natural samples, and are ecophysiologically important. Concentrations of chlorophyll, for example, have been strongly correlated to foliar nitrogen levels within a species and to photosynthetic capacity across many species. In addition pigments effectively absorb most of the photosynthetically active radiation between 400-700 nm, a spectral region for which silicon detectors have good signal/noise characteristics. Our strategy has been to sample a variety of naturally occurring species to measure leaf reflectance and pigment compositions. We hope to extend our understanding of pigment reflectance effects to interpret small overlapping absorbances of other biochemicals in the infrared region. For this reason, selected samples were also tested to determine total nitrogen, crude protein, cellulose, and lignin levels. Leaf reflectance spectra measured with AVIRIS bandwidths and wavelengths were compared between species and within species and for differences between seasons, for changes

  8. Microphytobenthic biomass and species composition in intertidal flats of the Nakdong River estuary, Korea

    NASA Astrophysics Data System (ADS)

    Du, GuoYing; Son, Moonho; Yun, Misun; An, Soonmo; Chung, Ik Kyo

    2009-05-01

    Intertidal microphytobenthos (MPB) were investigated monthly from August 2006 to March 2008 at four different sites in the sand flats of Nakdong River estuary, Korea. Samples of surface sediment (ca. 1 cm) were collected, and chlorophyll a was extracted as biomass estimation. Species identification and enumeration were carried out by light microscopy, assisted where necessary by scanning electronic microscopy. Biomass varied between 0.47 and 16.58 μg cm -3, abundance changed from 5.25 to 414.75 × 10 3 cells cm -3, while the Shannon diversity indexes ranged between 0.69 and 2.35 H'. Thirty-nine MPB taxa were identified, primarily composed of epipelic diatoms, among which Amphora and Navicula were the most abundant genera. Based on the biomass, abundance, species composition and their dynamics, MPB assemblages of sampling sites were grouped into three distinct communities corresponding to their sediment composition characteristics. Multivariate correlation analysis revealed that biomass was positively related to mud and very fine sand, negatively related to fine and medium sand, but not significantly related to environmental factors such as pore water nutrients, light intensity and salinity, which fluctuated rapidly during emersion period. Cluster analysis corroborated the division of MPB communities according to site types on seasonal scales, and also showed seasonality between sites by cluster of all summer groups. Principal component analysis identified that variability in species composition was significantly affected by mud, very fine sand, fine sand, light intensity, and sediment temperature. This study suggests that sediment composition plays an important role in the functioning of intertidal MPB communities in estuarine ecosystems.

  9. Alaska's Children, 1997.

    ERIC Educational Resources Information Center

    Douglas, Dorothy, Ed.

    1997-01-01

    These four issues of the "Alaska's Children" provide information on the activities of the Alaska Head Start State Collaboration Project and other Head Start activities. Legal and policy changes affecting the education of young children in Alaska are also discussed. The Spring 1997 issue includes articles on brain development and the "I Am Your…

  10. Alaska's Economy: What's Ahead?

    ERIC Educational Resources Information Center

    Alaska Review of Social and Economic Conditions, 1987

    1987-01-01

    This review describes Alaska's economic boom of the early 1980s, the current recession, and economic projections for the 1990s. Alaska's economy is largely influenced by oil prices, since petroleum revenues make up 80% of the state government's unrestricted general fund revenues. Expansive state spending was responsible for most of Alaska's…

  11. Alaska Natives & the Land.

    ERIC Educational Resources Information Center

    Arnold, Robert D.; And Others

    Pursuant to the Native land claims within Alaska, this compilation of background data and interpretive materials relevant to a fair resolution of the Alaska Native problem seeks to record data and information on the Native peoples; the land and resources of Alaska and their uses by the people in the past and present; land ownership; and future…

  12. Alaska Women: A Databook.

    ERIC Educational Resources Information Center

    White, Karen; Baker, Barbara

    This data book uses survey and census information to record social and economic changes of the past three decades and their effects upon the role of Alaska women in society. Results show Alaska women comprise 47% of the state population, an increase of 9% since 1950. Marriage continues as the predominant living arrangement for Alaska women,…

  13. Temporal Decay in Timber Species Composition and Value in Amazonian Logging Concessions.

    PubMed

    Richardson, Vanessa A; Peres, Carlos A

    2016-01-01

    Throughout human history, slow-renewal biological resource populations have been predictably overexploited, often to the point of economic extinction. We assess whether and how this has occurred with timber resources in the Brazilian Amazon. The asynchronous advance of industrial-scale logging frontiers has left regional-scale forest landscapes with varying histories of logging. Initial harvests in unlogged forests can be highly selective, targeting slow-growing, high-grade, shade-tolerant hardwood species, while later harvests tend to focus on fast-growing, light-wooded, long-lived pioneer trees. Brazil accounts for 85% of all native neotropical forest roundlog production, and the State of Pará for almost half of all timber production in Brazilian Amazonia, the largest old-growth tropical timber reserve controlled by any country. Yet the degree to which timber harvests beyond the first-cut can be financially profitable or demographically sustainable remains poorly understood. Here, we use data on legally planned logging of ~17.3 million cubic meters of timber across 314 species extracted from 824 authorized harvest areas in private and community-owned forests, 446 of which reported volumetric composition data by timber species. We document patterns of timber extraction by volume, species composition, and monetary value along aging eastern Amazonian logging frontiers, which are then explained on the basis of historical and environmental variables. Generalized linear models indicate that relatively recent logging operations farthest from heavy-traffic roads are the most selective, concentrating gross revenues on few high-value species. We find no evidence that the post-logging timber species composition and total value of forest stands recovers beyond the first-cut, suggesting that the commercially most valuable timber species become predictably rare or economically extinct in old logging frontiers. In avoiding even more destructive land-use patterns, managing

  14. Temporal Decay in Timber Species Composition and Value in Amazonian Logging Concessions

    PubMed Central

    Peres, Carlos A.

    2016-01-01

    Throughout human history, slow-renewal biological resource populations have been predictably overexploited, often to the point of economic extinction. We assess whether and how this has occurred with timber resources in the Brazilian Amazon. The asynchronous advance of industrial-scale logging frontiers has left regional-scale forest landscapes with varying histories of logging. Initial harvests in unlogged forests can be highly selective, targeting slow-growing, high-grade, shade-tolerant hardwood species, while later harvests tend to focus on fast-growing, light-wooded, long-lived pioneer trees. Brazil accounts for 85% of all native neotropical forest roundlog production, and the State of Pará for almost half of all timber production in Brazilian Amazonia, the largest old-growth tropical timber reserve controlled by any country. Yet the degree to which timber harvests beyond the first-cut can be financially profitable or demographically sustainable remains poorly understood. Here, we use data on legally planned logging of ~17.3 million cubic meters of timber across 314 species extracted from 824 authorized harvest areas in private and community-owned forests, 446 of which reported volumetric composition data by timber species. We document patterns of timber extraction by volume, species composition, and monetary value along aging eastern Amazonian logging frontiers, which are then explained on the basis of historical and environmental variables. Generalized linear models indicate that relatively recent logging operations farthest from heavy-traffic roads are the most selective, concentrating gross revenues on few high-value species. We find no evidence that the post-logging timber species composition and total value of forest stands recovers beyond the first-cut, suggesting that the commercially most valuable timber species become predictably rare or economically extinct in old logging frontiers. In avoiding even more destructive land-use patterns, managing

  15. Tularemia in Alaska, 1938 - 2010

    PubMed Central

    2011-01-01

    Tularemia is a serious, potentially life threatening zoonotic disease. The causative agent, Francisella tularensis, is ubiquitous in the Northern hemisphere, including Alaska, where it was first isolated from a rabbit tick (Haemophysalis leporis-palustris) in 1938. Since then, F. tularensis has been isolated from wildlife and humans throughout the state. Serologic surveys have found measurable antibodies with prevalence ranging from < 1% to 50% and 4% to 18% for selected populations of wildlife species and humans, respectively. We reviewed and summarized known literature on tularemia surveillance in Alaska and summarized the epidemiological information on human cases reported to public health officials. Additionally, available F. tularensis isolates from Alaska were analyzed using canonical SNPs and a multi-locus variable-number tandem repeats (VNTR) analysis (MLVA) system. The results show that both F. t. tularensis and F. t. holarctica are present in Alaska and that subtype A.I, the most virulent type, is responsible for most recently reported human clinical cases in the state. PMID:22099502

  16. Tularemia in Alaska, 1938 - 2010.

    PubMed

    Hansen, Cristina M; Vogler, Amy J; Keim, Paul; Wagner, David M; Hueffer, Karsten

    2011-01-01

    Tularemia is a serious, potentially life threatening zoonotic disease. The causative agent, Francisella tularensis, is ubiquitous in the Northern hemisphere, including Alaska, where it was first isolated from a rabbit tick (Haemophysalis leporis-palustris) in 1938. Since then, F. tularensis has been isolated from wildlife and humans throughout the state. Serologic surveys have found measurable antibodies with prevalence ranging from < 1% to 50% and 4% to 18% for selected populations of wildlife species and humans, respectively. We reviewed and summarized known literature on tularemia surveillance in Alaska and summarized the epidemiological information on human cases reported to public health officials. Additionally, available F. tularensis isolates from Alaska were analyzed using canonical SNPs and a multi-locus variable-number tandem repeats (VNTR) analysis (MLVA) system. The results show that both F. t. tularensis and F. t. holarctica are present in Alaska and that subtype A.I, the most virulent type, is responsible for most recently reported human clinical cases in the state. PMID:22099502

  17. Microclimate, Water Potential, Transpiration, and Bole Dielectric Constant of Coniferous and Deciduous Tree Species in the Continental Boreal Ecotone of Central Alaska

    NASA Technical Reports Server (NTRS)

    Zimmermann, R.; McDonald, K.; Way, J.; Oren, R.

    1994-01-01

    Tree canopy microclimate, xylem water flux and xylem dielectric constant have been monitored in situ since June 1993 in two adjacent natural forest stands in central Alaska. The deciduous stand represents a mature balsam poplar site on the Tanana River floodplain, while the coniferous stand consists of mature white spruce with some black spruce mixed in. During solstice in June and later in summer, diurnal changes of xylem water potential were measured to investigate the occurrence and magnitude of tree transpiration and dielectric constant changes in stems.

  18. Comparison of species composition and richness of fish assemblages in altered and unaltered littoral habitats

    USGS Publications Warehouse

    Poe, T.P.; Hatcher, C.O.; Brown, C.L.; Schloesser, D.W.

    1986-01-01

    Species composition and richness of fish assemblages in altered and unaltered littoral habitats in Lake St. Clair, Michigan, differed between areas. A percid-cyprinid-cyprinodontid assemblage dominated in the unaltered area, Muscamoot Bay, which has a natural shoreline (with almost no alteration due to dredging or bulkheading), high water quality, and high species richness of aquatic macrophytes. A centrarchid assemblage dominated in the altered area, Belvidere Bay, which has a bulkheaded shoreline, many dredged areas, reduced water quality due to inputs of nutrients from a nearby river, and relatively low species richness of aquatic macrophytes. Habitat factors, species richness and abundance of aquatic macrophytes, had the most influence on fish community structure in both areas. The percid-cyprinid-cyprinodontid assemblage was significantly correlated with six species of macrophytes whereas the centrarchid assemblage was significantly correlated with only four. These patterns suggest that preference for diverse habitats was higher, and tolerance to habitat alteration lower, in percid-cyprinid-cyprinodontid assemblages than in centrarchid assemblages.

  19. Use of DNA barcoding to reveal species composition of convenience seafood.

    PubMed

    Huxley-Jones, Elizabeth; Shaw, Jennifer L A; Fletcher, Carly; Parnell, Juliette; Watts, Phillip C

    2012-04-01

    Increased education of consumers can be an effective tool for conservation of commercially harvested marine species when product labeling is accurate and allows an informed choice. However, generic labeling (e.g., as white fish or surimi) and mislabeling of seafood prevents this and may erode consumer confidence in seafood product labels in general. We used DNA barcoding to identify the species composition of two types of convenience seafood (i.e., products processed for ease of consumption): fish fingers (long pieces of fish covered with bread crumbs or batter, n = 241) and seafood sticks (long pieces of cooked fish, n = 30). In products labeled as either white fish or surimi, four teleost species were present. Less than 1.5% of fish fingers with species-specific information were mislabeled. Results of other studies show substantially more mislabeling (e.g., >25%) of teleost products, which likely reflects the lower economic gains associated with mislabeling of convenience seafood compared with whole fillets. In addition to species identification, seafood product labels should be required to contain information about, for example, harvesting practices, and our data indicate that consumers can have reasonable confidence in the accuracy of the labels of convenience seafood and thus select brands on the basis of information about current fisheries practice.

  20. Effect of growth phase on the fatty acid compositions of four species of marine diatoms

    NASA Astrophysics Data System (ADS)

    Liang, Ying; Mai, Kangsen

    2005-04-01

    The fatty acid compositions of four species of marine diatoms ( Chaetoceros gracilis MACC/B13, Cylindrotheca fusiformis MACC/B211, Phaeodactylum tricornutum MACC/B221 and Nitzschia closterium MACC/B222), cultivated at 22°C±1°C with the salinity of 28 in f/2 medium and harvested in the exponential growth phase, the early stationary phase and the late stationary phase, were determined. The results showed that growth phase has significant effect on most fatty acid contents in the four species of marine diatoms. The proportions of 16:0 and 16:1n-7 fatty acids increased while those of 16:3n-4 and eicosapentaenoic acid (EPA) decreased with increasing culture age in all species studied. The subtotal of saturated fatty acids (SFA) increased with the increasing culture age in all species with the exception of B13. The subtotal of monounsaturated fatty acids (MUFA) increased while that of polyunsaturated fatty acids (PUFA) decreased with culture age in the four species of marine diatoms. MUFA reached their lowest value in the exponential growth phase, whereas PUFA reached their highest value in the same phase.

  1. Species Composition and Distribution of Adult Anopheles (Diptera: Culicidae) in Panama

    PubMed Central

    LOAIZA, J. R.; BERMINGHAM, E.; SCOTT, M. E.; ROVIRA, J. R.; CONN, J. E.

    2010-01-01

    Anopheles (Diptera: Culicidae) species composition and distribution were studied using human landing catch data over a 35-yr period in Panama. Mosquitoes were collected from 77 sites during 228 field trips carried out by members of the National Malaria Eradication Service. Fourteen Anopheles species were identified. The highest average human biting rates were recorded from Anopheles (Nyssorhynchus) albimanus (Wiedemann) (9.8 bites/person/night) and Anopheles (Anopheles) punctimacula (Dyar and Knab) (6.2 bites/person/night). These two species were also the most common, present in 99.1 and 74.9%, respectively, of the sites. Anopheles (Nyssorhynchus) aquasalis (Curry) was encountered mostly in the indigenous Kuna Yala Comarca along the eastern Atlantic coast, where malaria case history and average human biting rate (9.3 bites/person/night) suggest a local role in malaria transmission. An. albimanus, An. punctimacula, and Anopheles (Anopheles) vestitipennis (Dyar and Knab) were more abundant during the rainy season (May–December), whereas An. aquasalis was more abundant in the dry season (January–April). Other vector species collected in this study were Anopheles (Kerteszia) neivai (Howard, Dyar, and Knab) and Anopheles (Anopheles) pseudopunctipennis s.l. (Theobald). High diversity of Anopheles species and six confirmed malaria vectors in endemic areas of Panama emphasize the need for more detailed studies to better understand malaria transmission dynamics. PMID:18826025

  2. Interactive effects of disturbance and dispersal directionality on species richness and composition in metacommunities.

    PubMed

    Altermatt, Florian; Schreiber, Sebastian; Holyoak, Marcel

    2011-04-01

    Dispersal among ecological communities is usually assumed to be random in direction, or to vary in distance or frequency among species. However, a variety of natural systems and types of organisms may experience dispersal that is biased by directional currents or by gravity on hillslopes. We developed a general model for competing species in metacommunities to evaluate the role of directionally biased dispersal on species diversity, abundance, and traits. In parallel, we tested the role of directionally biased dispersal on communities in a microcosm experiment with protists and rotifers. Both the model and experiment independently demonstrated that diversity in local communities was reduced by directionally biased dispersal, especially dispersal that was biased away from disturbed patches. Abundance of species (and composition) in local communities was a product of disturbance intensity but not dispersal directionality. High disturbance selected for species with high intrinsic growth rates and low competitive abilities. Overall, our conclusions about the key role of dispersal directionality in (meta)communities seem robust and general, since they were supported both by the model, which was set in a general framework and not parameterized to fit to a specific system, and by a specific experimental test with microcosms.

  3. Mapping Forest Species Composition Using Imaging Spectrometry and Airborne Laser Scanner Data

    NASA Astrophysics Data System (ADS)

    Torabzadeh, H.; Morsdorf, F.; Leiterer, R.; Schaepman, M. E.

    2013-09-01

    Accurate mapping of forest species composition is an important aspect of monitoring and management planning related to ecosystem functions and services associated with water refinement, carbon sequestration, biodiversity, and wildlife habitats. Although different vegetation species often have unique spectral signatures, mapping based on spectral reflectance properties alone is often an ill-posed problem, since the spectral signature is as well influenced by age, canopy gaps, shadows and background characteristics. Thus, reducing the unknown variation by knowing the structural parameters of different species should improve determination procedures. In this study we combine imaging spectrometry (IS) and airborne laser scanning (ALS) data of a mixed needle and broadleaf forest to differentiate tree species more accurately as single-instrument data could do. Since forest inventory data in dense forests involve uncertainties, we tried to refine them by using individual tree crowns (ITC) position and shape, which derived from ALS data. Comparison of the extracted spectra from original field data and the modified one shows how ALS-derived shape and position of ITCs can improve separablity of the different species. The spatially explicit information layers containing both the spectral and structural components from the IS and ALS datasets were then combined by using a non-parametric support vector machine (SVM) classifier.

  4. Phytotoxic Activity and Chemical Composition of Aqueous Volatile Fractions from Eucalyptus Species

    PubMed Central

    Zhang, Jinbiao; An, Min; Wu, Hanwen; Liu, De Li; Stanton, Rex

    2014-01-01

    The essential oils from four Eucalyptus species (E. spathulata, E. salubris, E. brockwayii and E. dundasii) have been previously confirmed to have stronger inhibitory effects on germination and seedling growth of silverleaf nightshade (Solanum elaeagnifolium Cav.). The aqueous volatile fractions (AVFs) were the water soluble volatile fractions produced together with the essential oils (water insoluble fractions) during the steam distillation process. The aim of this study was to further assess the phytotoxicity of AVFs from the four Eucalyptus species and their chemical composition. The fresh leaves of the four Eucalyptus species were used for the extraction of AVFs. The AVFs were tested for their phytotoxic effects on the perennial weed, silverleaf nightshade under laboratory conditions. The chemical compositions of the AVFs were determined by gas chromatograph–mass spectrometry (GC-MS). Our results showed that the AVFs had strong inhibition on the germination and seedling growth of silverleaf nightshade. The inhibition index increased with the increasing concentrations of AVFs. The inhibitory effects of the AVFs varied between different Eucalyptus species. The AVF from E. salubris demonstrated the highest inhibitory activity on the weed tested, with complete inhibition on germination and seedling growth at a concentration of 75%. The GC-MS analysis revealed that 1,8-cineole, isopentyl isovalerate, isomenthol, pinocarvone, trans-pinocarveol, alpha-terpineol and globulol were the main compounds in the AVFs. These results indicated that all AVFs tested had differential inhibition on the germination and seedling growth of silverleaf nightshade, which could be due to the joint effects of compounds present in the AVFs as these compounds were present in different quantities and ratio between Eucalyptus species. PMID:24681490

  5. Species richness and trait composition of butterfly assemblages change along an altitudinal gradient.

    PubMed

    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. PMID:24668013

  6. Species richness and trait composition of butterfly assemblages change along an altitudinal gradient.

    PubMed

    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.

  7. Culicoides species composition and environmental factors influencing African horse sickness distribution at three sites in Namibia.

    PubMed

    Liebenberg, Danica; Piketh, Stuart; Labuschagne, Karien; Venter, Gert; Greyling, Telane; Mienie, Charlotte; de Waal, Tania; van Hamburg, Huib

    2016-11-01

    African horse sickness (AHS) is one of the most lethal infectious, non-contagious, vector-borne disease of equids. The causative agent, African horse sickness virus (AHSV) is transmitted via Culicoides midges (Diptera: Ceratopogonidae). AHS is endemic to Namibia but detailed studies of Culicoides communities and influencing environmental parameters are limited. This study aims to determine the Culicoides species composition at three different sites and to assess environmental parameters influencing the geographical distribution of AHS in Namibia. Weekly collections of Culicoides were made during the AHS peak season from January to May for 2013 and 2014 using the Onderstepoort 220V UV-light trap. Out of 397 collections made, 124 collections (3287 Culicoides) were analysed for AHSV presence with RT-qPCR. A total of 295 collections were analysed for total Culicoides (all collected Culicoides individuals) and in 75% of these collections the Culicoides were identified to species level. C. imicola was the dominant species with proportional representation of 29.9%. C. subschultzei, C. exspectator and C. ravus each contribute more than 10% to the species composition. The lowest number of Culicoides was collected at Aus 9980, a total of 21819 at Windhoek and the highest number at Okahandja 47343. AHSV was present at all three sites during 2013 but only in Windhoek and Okahandja during 2014. Multivariate analyses of data from the two year survey indicate the environmental parameters in order of importance for the distribution of AHS in Namibia as precipitation>temperature>clay>relative humidity>NDVI. The implication of these findings is that any precipitation event increases Culicoides numbers significantly. Together with these results the high number of species found of which little is known regarding their vector competence, add to the complexity of the distribution of AHS in Namibia. PMID:27491343

  8. Plant compartment and biogeography affect microbiome composition in cultivated and native Agave species.

    PubMed

    Coleman-Derr, Devin; Desgarennes, Damaris; Fonseca-Garcia, Citlali; Gross, Stephen; Clingenpeel, Scott; Woyke, Tanja; North, Gretchen; Visel, Axel; Partida-Martinez, Laila P; Tringe, Susannah G

    2016-01-01

    Desert plants are hypothesized to survive the environmental stress inherent to these regions in part thanks to symbioses with microorganisms, and yet these microbial species, the communities they form, and the forces that influence them are poorly understood. Here we report the first comprehensive investigation of the microbial communities associated with species of Agave, which are native to semiarid and arid regions of Central and North America and are emerging as biofuel feedstocks. We examined prokaryotic and fungal communities in the rhizosphere, phyllosphere, leaf and root endosphere, as well as proximal and distal soil samples from cultivated and native agaves, through Illumina amplicon sequencing. Phylogenetic profiling revealed that the composition of prokaryotic communities was primarily determined by the plant compartment, whereas the composition of fungal communities was mainly influenced by the biogeography of the host species. Cultivated A. tequilana exhibited lower levels of prokaryotic diversity compared with native agaves, although no differences in microbial diversity were found in the endosphere. Agaves shared core prokaryotic and fungal taxa known to promote plant growth and confer tolerance to abiotic stress, which suggests common principles underpinning Agave-microbe interactions.

  9. Arbuscular mycorrhizal community composition associated with two plant species in a grassland ecosystem.

    PubMed

    Vandenkoornhuyse, P; Husband, R; Daniell, T J; Watson, I J; Duck, J M; Fitter, A H; Young, J P W

    2002-08-01

    Arbuscular mycorrhizal (AM) fungi are biotrophic symbionts colonizing about two-thirds of land plant species and found in all ecosystems. They are of major importance in plant nutrient supply and their diversity is suggested to be an important determinant of plant community composition. The diversity of the AM fungal community composition in the roots of two plant species (Agrostis capillaris and Trifolium repens) that co-occurred in the same grassland ecosystem was characterized using molecular techniques. We analysed the small subunit (SSU) ribosomal RNA gene amplified from a total root DNA extract using AM fungal-specific primers. A total of 2001 cloned fragments from 47 root samples obtained on four dates were analysed by restriction fragment length polymorphism, and 121 of them were sequenced. The diversity found was high: a total of 24 different phylotypes (groups of phylogenetically related sequences) colonized the roots of the two host species. Phylogenetic analyses demonstrate that 19 of these phylotypes belonged to the Glomaceae, three to the Acaulosporaceae and two to the Gigasporaceae. Our study reveals clearly that the AM fungal community colonizing T. repens differed from that colonizing A. capillaris, providing evidence for AM fungal host preference. In addition, our results reveal dynamic changes in the AM fungal community through time.

  10. Annual cycle of zooplankton abundance and species composition in Izmit Bay (the northeastern Marmara Sea)

    NASA Astrophysics Data System (ADS)

    Isinibilir, Melek; Kideys, Ahmet E.; Tarkan, Ahmet N.; Yilmaz, I. Noyan

    2008-07-01

    The monthly abundance, biomass and taxonomic composition of zooplankton of Izmit Bay (the northeastern Marmara Sea) were studied from October 2001 to September 2002. Most species within the zooplankton community displayed a clear pattern of succession throughout the year. Generally copepods and cladocerans were the most abundant groups, while the contribution of meroplankton increased at inner-most stations and dominated the zooplankton. Both species number ( S) and diversity ( H') were positively influenced by the increase in salinity of upper layers ( r = 0.30 and r = 0.31, p < 0.001, respectively), while chlorophyll a was negatively affected ( r = -0.36, p < 0.001). Even though Noctiluca scintillans had a significant seasonality ( F11,120 = 8.45, p < 0.001, ANOVA), abundance was not related to fluctuations in temperature and only chlorophyll a was adversely correlated ( r = -0.35, p < 0.001). In general, there are some minor differences in zooplankton assemblages of upper and lower layers. A comparison of the species composition and abundance of Izmit Bay with other Black Sea bays reveals a high similarity between them.

  11. Plant compartment and biogeography affect microbiome composition in cultivated and native Agave species.

    PubMed

    Coleman-Derr, Devin; Desgarennes, Damaris; Fonseca-Garcia, Citlali; Gross, Stephen; Clingenpeel, Scott; Woyke, Tanja; North, Gretchen; Visel, Axel; Partida-Martinez, Laila P; Tringe, Susannah G

    2016-01-01

    Desert plants are hypothesized to survive the environmental stress inherent to these regions in part thanks to symbioses with microorganisms, and yet these microbial species, the communities they form, and the forces that influence them are poorly understood. Here we report the first comprehensive investigation of the microbial communities associated with species of Agave, which are native to semiarid and arid regions of Central and North America and are emerging as biofuel feedstocks. We examined prokaryotic and fungal communities in the rhizosphere, phyllosphere, leaf and root endosphere, as well as proximal and distal soil samples from cultivated and native agaves, through Illumina amplicon sequencing. Phylogenetic profiling revealed that the composition of prokaryotic communities was primarily determined by the plant compartment, whereas the composition of fungal communities was mainly influenced by the biogeography of the host species. Cultivated A. tequilana exhibited lower levels of prokaryotic diversity compared with native agaves, although no differences in microbial diversity were found in the endosphere. Agaves shared core prokaryotic and fungal taxa known to promote plant growth and confer tolerance to abiotic stress, which suggests common principles underpinning Agave-microbe interactions. PMID:26467257

  12. [Species and size composition of fishes in Barra de Navidad lagoon, Mexican central Pacific].

    PubMed

    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. Abundance, species composition of microzooplankton from the coastal waters of Port Blair, South Andaman Island

    PubMed Central

    2012-01-01

    Background Microzooplankton consisting of protists and metazoa <200 μm. It displays unique feeding mechanisms and behaviours that allow them to graze cells up to five times their own volume. They can grow at rates which equal or exceed prey growth and can serve as a viable food source for metazoans. Moreover, they are individually inconspicuous, their recognition as significant consumers of oceanic primary production. The microzooplankton can be the dominant consumers of phytoplankton production in both oligo- and eutrophic regions of the ocean and are capable of consuming >100% of primary production. Results The microzooplankton of the South Andaman Sea were investigated during September 2011 to January 2012. A total of 44 species belong to 19 genera were recorded in this study. Tintinnids made larger contribution to the total abundance (34%) followed in order by dinoflagellates (24%), ciliates (20%) and copepod nauplii (18%). Foraminifera were numerically less (4%). Tintinnids were represented by 20 species belong to 13 genera, Heterotrophic dinoflagellates were represented by 17 species belong to 3 genera and Ciliates comprised 5 species belong to 3 genera. Eutintinus tineus, Tintinnopsis cylindrical, T. incertum, Protoperidinium divergens, Lomaniella oviformes, Strombidium minimum were the most prevalent microzooplankton. Standing stock of tintinnids ranged from 30–80 cells.L-1 and showed a reverse distribution with the distribution of chlorophyll a relatively higher species diversity and equitability was found in polluted harbour areas. Conclusions The change of environmental variability affects the species composition and abundance of microzooplankton varied spatially and temporarily. The observations clearly demonstrated that the harbor area differed considerably from other area in terms of species present and phytoplankton biomass. Further, the phytoplankton abundance is showed to be strongly influenced by tintinnid with respect to the relationship of

  14. Species composition, richness and nestedness of lizard assemblages from Restinga habitats along the brazilian coast.

    PubMed

    Rocha, C F D; Vrcibradic, D; Kiefer, M C; Menezes, V A; Fontes, A F; Hatano, F H; Galdino, C A B; Bergallo, H G; Van Sluys, M

    2014-05-01

    Habitat fragmentation is well known to adversely affect species living in the remaining, relatively isolated, habitat patches, especially for those having small range size and low density. This negative effect has been critical in coastal resting habitats. We analysed the lizard composition and richness of restinga habitats in 16 restinga habitats encompassing three Brazilian states (Rio de Janeiro, Espírito Santo and Bahia) and more than 1500km of the Brazilian coast in order to evaluate if the loss of lizard species following habitat reduction occur in a nested pattern or at random, using the "Nestedness Temperature Calculator" to analyse the distribution pattern of lizard species among the restingas studied. We also estimated the potential capacity that each restinga has to maintain lizard species. Eleven lizard species were recorded in the restingas, although not all species occurred in all areas. The restinga with the richest lizard fauna was Guriri (eight species) whereas the restinga with the lowest richness was Praia do Sul (located at Ilha Grande, a large coastal island). Among the restingas analysed, Jurubatiba, Guriri, Maricá and Praia das Neves, were the most hospitable for lizards. The matrix community temperature of the lizard assemblages was 20.49° (= P <0.00001; 5000 randomisations; randomisation temperature = 51.45° ± 7.18° SD), indicating that lizard assemblages in the coastal restingas exhibited a considerable nested structure. The degree in which an area is hospitable for different assemblages could be used to suggest those with greater value of conservation. We concluded that lizard assemblages in coastal restingas occur at a considerable level of ordination in restinga habitats and that some restinga areas such as Jurubatiba, Guriri, Maricá and Praia das Neves are quite important to preserve lizard diversity of restinga environments.

  15. Bryophytes from Simeonof Island in the Shumagin Islands, southwestern Alaska

    USGS Publications Warehouse

    Schofield, W.B.; Talbot, S. S.; Talbot, S.L.

    2004-01-01

    Simeonof Island is located south of the Alaska Peninsula in the hyperoceanic sector of the middle boreal subzone. We examined the bryoflora of Simeonof Island to determine species composition in an area where no previous collections had been reported. This field study was conducted in sites selected to represent the spectrum of environmental variation within Simeonof Island. Data were analyzed using published reports to compare bryophyte distribution patterns at three levels, the Northern Hemisphere, North America, and Alaska. A total of 271 bryophytes were identified: 202 mosses and 69 liverworts. The annotated list of species for Simeonof Island expands the known range for many species and fills distribution gaps within Hulte??n's Western Pacific Coast district. Maps and notes on the distribution of 14 significant distribution records are presented. Compared with bryophyte distribution in the Northern Hemisphere, the bryoflora of Simeonof Island primarily includes taxa of boreal (55%), temperate (20%), arctic (10%), and cosmopolitan (8%) distribution; 6% of the moss flora are western North America endemics. A description of the bryophytes present in the vegetation and habitat types is provided as is a quantitative analysis of the most frequently occurring bryophytes in crowberry heath.

  16. Effects of habitat composition and landscape structure on worker foraging distances of five bumble bee species.

    PubMed

    Redhead, John W; Dreier, Stephanie; Bourke, Andrew F G; Heard, Matthew S; Jordan, William C; Sumner, Seirian; Wang, Jinliang; Carvell, Claire

    2016-04-01

    Bumble bees (Bombus spp.) are important pollinators of both crops and wildflowers. Their contribution to this essential ecosystem service has been threatened over recent decades by changes in land use, which have led to declines in their populations. In order to design effective conservation measures, it is important to understand the effects of variation in landscape composition and structure on the foraging activities of worker bumble bees. This is because the viability of individual colonies is likely to be affected by the trade-off between the energetic costs of foraging over greater distances and the potential gains from access to additional resources. We used field surveys, molecular genetics, and fine resolution remote sensing to estimate the locations of wild bumble bee nests and to infer foraging distances across a 20-km² agricultural landscape in southern England, UK. We investigated five species, including the rare B. ruderatus and ecologically similar but widespread B. hortorum. We compared worker foraging distances between species and examined how variation in landscape composition and structure affected foraging distances at the colony level. Mean worker foraging distances differed significantly between species. Bombus terrestris, B. lapidarius, and B. ruderatus exhibited significantly greater mean foraging distances (551, 536, and 501 m, respectively) than B. hortorum and B. pascuorum (336 and 272 m, respectively). There was wide variation in worker foraging distances between colonies of the same species, which was in turn strongly influenced by the amount and spatial configuration of available foraging habitats. Shorter foraging distances were found for colonies where the local landscape had high coverage and low fragmentation of semi-natural vegetation, including managed agri-environmental field margins. The strength of relationships between different landscape variables and foraging distance varied between species, for example the strongest

  17. Effects of habitat composition and landscape structure on worker foraging distances of five bumble bee species.

    PubMed

    Redhead, John W; Dreier, Stephanie; Bourke, Andrew F G; Heard, Matthew S; Jordan, William C; Sumner, Seirian; Wang, Jinliang; Carvell, Claire

    2016-04-01

    Bumble bees (Bombus spp.) are important pollinators of both crops and wildflowers. Their contribution to this essential ecosystem service has been threatened over recent decades by changes in land use, which have led to declines in their populations. In order to design effective conservation measures, it is important to understand the effects of variation in landscape composition and structure on the foraging activities of worker bumble bees. This is because the viability of individual colonies is likely to be affected by the trade-off between the energetic costs of foraging over greater distances and the potential gains from access to additional resources. We used field surveys, molecular genetics, and fine resolution remote sensing to estimate the locations of wild bumble bee nests and to infer foraging distances across a 20-km² agricultural landscape in southern England, UK. We investigated five species, including the rare B. ruderatus and ecologically similar but widespread B. hortorum. We compared worker foraging distances between species and examined how variation in landscape composition and structure affected foraging distances at the colony level. Mean worker foraging distances differed significantly between species. Bombus terrestris, B. lapidarius, and B. ruderatus exhibited significantly greater mean foraging distances (551, 536, and 501 m, respectively) than B. hortorum and B. pascuorum (336 and 272 m, respectively). There was wide variation in worker foraging distances between colonies of the same species, which was in turn strongly influenced by the amount and spatial configuration of available foraging habitats. Shorter foraging distances were found for colonies where the local landscape had high coverage and low fragmentation of semi-natural vegetation, including managed agri-environmental field margins. The strength of relationships between different landscape variables and foraging distance varied between species, for example the strongest

  18. Semi-volatile inorganic species: importance for atmospheric chemical composition on diurnal and seasonal timescales

    NASA Astrophysics Data System (ADS)

    Pearce, Hana; Mann, Graham; Arnold, Stephen; O'Connor, Fiona; Benduhn, Francois; Rumbold, Steven; Pringle, Kirsty

    2016-04-01

    Nitrate aerosol has become an important driver of reduced European air quality and climate forcing, following reductions in sulphate precursor emissions since the 1980s, and is expected to be more influential in future decades. Measurements from the European Integrated Project on Aerosol and Cloud Climate Air Quality Interactions (EUCAARI) field campaign have shown that semi-volatile aerosol species such as ammonium nitrate can comprise a major component of the sub-micron particulate matter, particularly in high pollution episodes. This presentation will assess the contribution of semi-volatile inorganic aerosol to diurnal and seasonal cycles in atmospheric chemical composition over Europe. We use the UM-UKCA composition-climate model, including the GLOMAP interactive aerosol microphysics module and a recently developed 'hybrid' dissolution solver (HyDis) to accurately represent size-resolved partitioning of ammonia and nitric acid to the particle phase. In particular, we evaluate simulated size-resolved composition variations over Europe through the diurnal cycle, comparing hourly model output to Aerosol Mass Spectrometer observations at several sites during 2008. We will present the results of this composition analysis, in addition to model evaluation from comparisons with European Monitoring for Environmental Protection (EMEP) network and EUCAARI field campaign observations.

  19. ISOB: A Database of Indigenous Snake Species of Bangladesh with respective known venom composition

    PubMed Central

    Roly, Zahida Yesmin; Hakim, Md Abdul; Zahan, ASM Shahriar; Hossain, M Monzur; Reza, Md Abu

    2015-01-01

    At present there is no well structured database available for the venomous snakes and venom composition of snakes in the world although venom has immense importance in biomedical research. Searching for a specific venom component from NCBI, PDB or public databases is troublesome, because they contain huge amount of data entries. Therefore, we created a database named “ISOB” which is a web accessible unique secondary database that represents the first online available bioinformatics resource showing venom composition of snakes. This database provides a comprehensive overview of seventy-eight indigenous snake species covering description of snakes supplemented with structural information of the relevant individual available venom proteins. We strongly believe that this database will contribute significantly in the field of bioinformatics, environmental research, proteomics, drug development and rationale drug designing. Availability The database is freely available at http://www.snakebd.com/ PMID:25848172

  20. Leptospirosis risk increases with changes in species composition of rat populations

    NASA Astrophysics Data System (ADS)

    Theuerkauf, Jörn; Perez, Julie; Taugamoa, Alefosio; Niutoua, Iasinito; Labrousse, Didier; Gula, Roman; Bogdanowicz, Wieslaw; Jourdan, Hervé; Goarant, Cyrille

    2013-04-01

    Rats are major reservoirs of leptospirosis and considered as a main threat to biodiversity. A recent introduction of Rattus rattus to the island of Futuna (Western Polynesia) provided the opportunity to test if a possible change in species composition of rat populations would increase the risk of leptospirosis to humans. We trapped rodents on Wallis and Futuna and assessed Leptospira carriage in 357 rodents ( Rattus norvegicus, R. rattus, Rattus exulans, and Mus domesticus) from 2008 to 2012. While Leptospira prevalence in rodents and the composition of rat populations on Futuna fluctuated with rainfall, the biomass of Leptospira-carrying rodents has been continuously rising from 2008 to 2012. Our results suggest that the introduction of R. rattus increases the risk to humans being infected with leptospirosis by rats.

  1. Chemical composition and variability of the volatile components from inflorescences of Cirsium species.

    PubMed

    Kozyra, Małgorzata; Mardarowicz, Marek; Kochmańska, Joanna

    2015-01-01

    The present study aimed to investigate the chemical composition of the essential oils of inflorescences Cirsium spp. (Asteraceae) by GC/MS method. Essential oils were extracted from the inflorescences of Cirsium pannonicum (Link), Cirsium ligulare Boiss., Cirsium heterophyllum (L.) Hill., Cirsium acaule (L.) Scop., Cirsium oleraceum (L.) Scop., Cirsium dissectum (L.) Hill., Cirsium decussatum (Janka) and Cirsium eriophorum (L.) Scop., using the steam distillation method. A gas chromatography-mass spectrometry method was employed for the analysis of essential oils. Our study shows the differences in chemical composition of volatile oils in the inflorescences of Cirsium spp. The main components of the essential oil were ketones and aldehydes with a long carbon side-chain. Volatile oils also contained small amounts of terpenes: thymol, β-linalool, eugenol, carvacrol and fatty acids with odd number of carbon atoms-waxes. The compounds in the essential oils obtained from inflorescences Cirsium L. species have been identified for the first time. PMID:25674834

  2. Process for derivatizing carbon nanotubes with diazonium species and compositions thereof

    NASA Technical Reports Server (NTRS)

    Tour, James M. (Inventor); Bahr, Jeffrey L. (Inventor); Yang, Jiping (Inventor)

    2011-01-01

    Methods for the chemical modification of carbon nanotubes involve the derivatization of multi- and single-wall carbon nanotubes, including small diameter (ca. 0.7 nm) single-wall carbon nanotubes, with diazonium species. The method allows the chemical attachment of a variety of organic compounds to the side and ends of carbon nanotubes. These chemically modified nanotubes have applications in polymer composite materials, molecular electronic applications, and sensor devices. The methods of derivatization include electrochemical induced reactions, thermally induced reactions, and photochemically induced reactions. Moreover, when modified with suitable chemical groups, the derivatized nanotubes are chemically compatible with a polymer matrix, allowing transfer of the properties of the nanotubes (such as, mechanical strength or electrical conductivity) to the properties of the composite material as a whole. Furthermore, when modified with suitable chemical groups, the groups can be polymerized to form a polymer that includes carbon nanotubes.

  3. The biological activities and chemical composition of Pereskia species (Cactaceae)--a review.

    PubMed

    Pinto, Nícolas de Castro Campos; Scio, Elita

    2014-09-01

    The exploration of nature as a source of sustainable, novel bioactive substances continues to grow as natural products play a significant role in the search for new therapeutic and agricultural agents. In this context, plants of the genus Pereskia (Cactaceae) have been studied for their biological activities, and are evolving as an interesting subject in the search for new, bioactive compounds. These species are commonly used as human foodstuffs and in traditional medicine to treat a variety of diseases. This review focuses on the bioactivity and chemical composition of the genus Pereskia, and aims to stimulate further studies on the chemistry and biological potential of the genus.

  4. Chemical compositions and larvicidal activities of leaf essential oils from two eucalyptus species.

    PubMed

    Cheng, Sen-Sung; Huang, Chin-Gi; Chen, Ying-Ju; Yu, Jane-Jane; Chen, Wei-June; Chang, Shang-Tzen

    2009-01-01

    In the current study, the mosquito larvicidal activity of leaf essential oils and their constituents from two eucalyptus species (Eucalyptus camaldulensis and Eucalyptus urophylla) against two mosquito species, Aedes aegypti and Aedes albopictus, was investigated. In addition, the chemical compositions of the leaf essential oils were analyzed using gas chromatography-mass spectrometry. Results from the larvicidal tests revealed that essential oil from the leaves of E. camaldulensis had an excellent inhibitory effect against both A. aegypti and A. albopictus larvae. The 12 pure constituents extracted from the two eucalyptus leaf essential oils were also tested individually against two mosquito larvae. Among the six effective constituents, alpha-terpinene exhibits the best larvicidal effect against both A. aegypti and A. albopictus larvae. Results of this study show that the leaf essential oil of E. camaldulensis and its effective constituents might be considered as a potent source for the production of fine natural larvicides. PMID:18396398

  5. Effects of ‘Target’ Plant Species Body Size on Neighbourhood Species Richness and Composition in Old-Field Vegetation

    PubMed Central

    Schamp, Brandon S.; Aarssen, Lonnie W.; Wight, Stephanie

    2013-01-01

    Competition is generally regarded as an important force in organizing the structure of vegetation, and evidence from several experimental studies of species mixtures suggests that larger mature plant size elicits a competitive advantage. However, these findings are at odds with the fact that large and small plant species generally coexist, and relatively smaller species are more common in virtually all plant communities. Here, we use replicates of ten relatively large old-field plant species to explore the competitive impact of target individual size on their surrounding neighbourhoods compared to nearby neighbourhoods of the same size that are not centred by a large target individual. While target individuals of the largest of our test species, Centaurea jacea L., had a strong impact on neighbouring species, in general, target species size was a weak predictor of the number of other resident species growing within its immediate neighbourhood, as well as the number of resident species that were reproductive. Thus, the presence of a large competitor did not restrict the ability of neighbouring species to reproduce. Lastly, target species size did not have any impact on the species size structure of neighbouring species; i.e. they did not restrict smaller, supposedly poorer competitors, from growing and reproducing close by. Taken together, these results provide no support for a size-advantage in competition restricting local species richness or the ability of small species to coexist and successfully reproduce in the immediate neighbourhood of a large species. PMID:24349177

  6. Species composition and diversity of macrobenthos in the intertidal zone of Xiangshan bay, China

    NASA Astrophysics Data System (ADS)

    Jiao, Haifeng; Zheng, Dan; You, Zhongjie; Xu, Nianjun; Lou, Dan; Huang, Chengwei

    2015-04-01

    Xiangshan bay is a narrow semi-closed bay and situated on the northwestern coast of the East China Sea. Over past decades, it has become to a major bay with intensive human activities, dense urbanized area, and poor water quality. The aim of this paper was to reveal the ecological status through the elucidation of the species composition, abundance, biomass and diversity of macrobenthos in this bay. Six intertidal sections were surveyed from January 2007 to November 2008 quarterly. Sections TG, HD and XH are located in the three inner bays, sections QJ and WS are located near the thermal power plants, and section XX is located at the outer part of Xiangshan Bay. Great variations in macrobenthos community were indentified, and the species composition of the community in the present study showed the dominance in the order of molluscs (bivalves and gastropods), crustaceans and others, and only few Polychaeta were recorded. Only three dominant species, Littorina brevicula, Ilyplax tansuiensis, and Cerithidea cingulata were collected in all the sections, and a total of 19 dominant species were recorded only in one section. Two-way ANOVA analyses of abundance indicated that there were significant differences among sections or seasons. Shannon-Wiener diversity index ( H') had its maximum (2.45) in section QJ, and minimum (1.76) in section TG. Multiple irregular k-dominance plots clearly showed that the study area was polluted and the macrobenthos community was under stress. We conclude that the macrobenthos of Xiangshan Bay have been disturbed by human activities, especially at the interior bay.

  7. Different Assembly Processes Drive Shifts in Species and Functional Composition in Experimental Grasslands Varying in Sown Diversity and Community History

    PubMed Central

    Roscher, Christiane; Schumacher, Jens; Gerighausen, Uta; Schmid, Bernhard

    2014-01-01

    Background The prevalence of different biotic processes (limiting similarity, weaker competitor exclusion) and historical contingency due to priority effects are in the focus of ongoing discussions about community assembly and non-random functional trait distributions. Methodology/Principal Findings We experimentally manipulated assembly history in a grassland biodiversity experiment (Jena Experiment) by applying two factorially crossed split-plot treatments to all communities: (i) duration of weeding (never weeded since sowing or cessation of weeding after 3 or 6 years); (ii) seed addition (control vs. seed addition 4 years after sowing). Spontaneous colonization of new species in the control treatment without seed addition increased realized species richness and functional richness (FRic), indicating continuously denser packing of niches. Seed addition resulted in forced colonization and increased realized species richness, FRic, functional evenness (FEve) and functional divergence (FDiv), i.e. higher abundances of species with extreme trait values. Furthermore, the colonization of new species led to a decline in FEve through time, suggesting that weaker competitors were reduced in abundance or excluded. Communities with higher initial species richness or with longer time since cessation of weeding were more restricted in the entry of new species and showed smaller increases in FRic after seed addition than other communities. The two assembly-history treatments caused a divergence of species compositions within communities originally established with the same species. Communities originally established with different species converged in species richness and functional trait composition over time, but remained more distinct in species composition. Conclusions/Significance Contrasting biotic processes (limiting similarity, weaker competitor exclusion) increase functional convergence between communities initially established with different species. Historical

  8. Expected shifts in Fusarium species' composition on cereal grain in Northern Europe due to climatic change.

    PubMed

    Parikka, P; Hakala, K; Tiilikkala, K

    2012-01-01

    In Northern Europe, changes in climate may result in better growing conditions for many crops. However, the expected warmer and more humid conditions are favourable for Fusarium head blight infections on cereals. The Fusarium species prevalent in Nordic areas to date are the same as in Central Europe: F. avenaceum, F. culmorum, F. graminearum and F. poae. The prevalence of F. graminearum in cereal grain has already increased in Central Europe and is likely to increase in the North due to the expected changes in weather conditions, reduced tillage and the predicted increase in maize cultivation in Nordic countries. The possible weather extremes predispose cereals to Fusarium infections by increasing the populations of insect pests injuring plants. Adverse conditions may even create conditions suitable for F. subglutinans or F. verticilloides to infect maize and possibly other cereals in rotation in southern parts of Scandinavia. The importance of the species that infect in relatively dry conditions, F. langsethiae and F. poae, may also increase on winter cereals which are predicted to be more prevalent in future farming. If the number of crop species cultivated will increase and non-cereal crops are included in rotations effects of reduced tillage on Fusarium infections in grain could be limited. The predicted changes in climate towards 2050 are expected to slightly change Fusarium species composition in Northern Europe. An increase in F. graminearum and possibly the invasion of northern parts of Central Europe and Denmark by fumonisin producers is expected.

  9. Does host plant influence parasitism and parasitoid species composition in Lygus rugulipennis? A molecular approach.

    PubMed

    Gariepy, T D; Kuhlmann, U; Gillott, C; Erlandson, M

    2008-06-01

    Lygus Hahn plant bugs (Hemiptera: Miridae) are serious pests of a wide variety of economically important crops in North America. European Peristenus digoneutis Loan and P. relictus Ruthe (Hymenoptera: Braconidae) are being considered for release in Canada as part of a classical biological control program for Lygus. The attractiveness of different host plants to European Peristenus has not been addressed, but may be an important consideration prior to parasitoid release. Lygus rugulipennis Poppius nymphs were collected in the Northern Temperate Atlantic (NTA) ecoregion on red clover (Trifolium pratense L.; Fabaceae) and chamomile (Matricaria recutita L.; Asteraceae), and in the Western European Broadleaf Forest (WEBF) ecoregion on red clover and alfalfa (Medicago sativa L.; Fabaceae). Parasitism levels and parasitoid species were determined using a multiplex PCR assay for P. digoneutis, P. relictus, and P. pallipes Curtis. Mean parasitism levels in L. rugulipennis were 45-49% in the NTA ecoregion and 25-32% in the WEBF ecoregion. However, in neither ecoregion were parasitism levels and parasitoid species compositions significantly different in nymphs from different host plant species. Furthermore, multiparasitism was low despite the fact that P. digoneutis and P. relictus share the same host species. PMID:18439339

  10. Anopheles species composition explains differences in Plasmodium transmission in La Guajira, northern Colombia

    PubMed Central

    Herrera-Varela, Manuela; Orjuela, Lorena I; Peñalver, Cilia; Conn, Jan E; Quiñones, Martha L

    2014-01-01

    Malaria in La Guajira, the most northern state of Colombia, shows two different epidemiological patterns. Malaria is endemic in the municipality of Dibulla whereas in Riohacha it is characterised by sporadic outbreaks. This study aimed to establish whether differences in transmission patterns could be attributed to different vector species. The most abundant adult female species were Anopheles aquasalis, exclusive to Riohacha, and Anopheles darlingi, restricted to Dibulla. Anopheles mosquitoes were identified using morphology and the molecular markers internal transcribed spacer 2 and cytochrome c oxidase I. All specimens (n = 1,393) were tested by ELISA to determine natural infection rates with Plasmodium falciparum and Plasmodium vivax. An. darlingi was positive for P. vivax 210, with an infection rate of 0.355% and an entomological inoculation rate of 15.87 infective bites/person/year. Anopheles albimanus larvae were the most common species in Riohacha, found in temporary swamps; in contrast, in Dibulla An. darlingi were detected mainly in permanent streams. Distinctive species composition and larval habitats in each municipality may explain the differences in Plasmodium transmission and suggest different local strategies should be used for vector control.

  11. Anthropophilic Anopheles species composition and malaria in Tierradentro, Córdoba, Colombia

    PubMed Central

    Schiemann, David Joachim; Pinzón, Martha Lucía Quiñones; Hankeln, Thomas

    2014-01-01

    Malaria is still a primary health problem in Colombia. The locality of Tierradentro is situated in the municipality of Montelíbano, Córdoba, in the northwest of Colombia, and has one of the highest annual parasite index of malaria nationwide. However, the vectors involved in malaria transmission in this locality have not yet been identified. In this study, the local anthropophilic Anopheles composition and natural infectivity with Plasmodium were investigated. In August 2009, 927 female Anopheles mosquitoes were collected in eight localities using the human landing catch method and identified based on their morphology. Cryptic species were determined by restriction fragment length polymorphism-internal transcribed spacer (ITS)2 molecular analysis. Eight species [Anopheles nuneztovari s.l. (92.8%), Anopheles darlingi (5.1%), Anopheles triannulatus s.l. (1.8%), Anopheles pseudopunctipennis s.l. (0.2%), Anopheles punctimacula s.l. (0.2%), Anopheles apicimacula (0.1%), Anopheles albimanus (0.1%) and Anopheles rangeli (0.1%)] were identified and species identity was confirmed by ITS2 sequencing. This is the first report of An. albimanus, An. rangeli and An. apicimacula in Tierradentro. Natural infectivity with Plasmodium was determined by ELISA. None of the mosquitoes was infectious for Plasmodium. An. nuneztovari s.l. was the predominant species and is considered the primary malaria vector; An. darlingi and An. triannulatus s.l. could serve as secondary vectors.

  12. Prospects for quantifying structure, floristic composition and species richness of tropical forests

    USGS Publications Warehouse

    Gillespie, T.W.; Brock, J.; Wright, C.W.

    2004-01-01

    Airborne spectral and light detection and ranging (lidar) sensors have been used to quantify biophysical characteristics of tropical forests. Lidar sensors have provided high-resolution data on forest height, canopy topography, volume, and gap size; and provided estimates on number of strata in a forest, successional status of forests, and above-ground biomass. Spectral sensors have provided data on vegetation types, foliar biochemistry content of forest canopies, tree and canopy phenology, and spectral signatures for selected tree species. A number of advances are theoretically possible with individual and combined spectral and lidar sensors for the study of forest structure, floristic composition and species richness. Delineating individual canopies of over-storey trees with small footprint lidar and discrimination of tree architectural types with waveform distributions is possible and would provide scientists with a new method to study tropical forest structure. Combined spectral and lidar data can be used to identify selected tree species and identify the successional status of tropical forest fragments in order to rank forest patches by levels of species richness. It should be possible in the near future to quantify selected patterns of tropical forests at a higher resolution than can currently be undertaken in the field or from space. ?? 2004 Taylor and Francis Ltd.

  13. Anopheles species composition explains differences in Plasmodium transmission in La Guajira, northern Colombia.

    PubMed

    Herrera-Varela, Manuela; Orjuela, Lorena I; Peñalver, Cilia; Conn, Jan E; Quiñones, Martha L

    2014-11-01

    Malaria in La Guajira, the most northern state of Colombia, shows two different epidemiological patterns. Malaria is endemic in the municipality of Dibulla whereas in Riohacha it is characterised by sporadic outbreaks. This study aimed to establish whether differences in transmission patterns could be attributed to different vector species. The most abundant adult female species were Anopheles aquasalis, exclusive to Riohacha, and Anopheles darlingi, restricted to Dibulla. Anopheles mosquitoes were identified using morphology and the molecular markers internal transcribed spacer 2 and cytochrome c oxidase I. All specimens (n = 1,393) were tested by ELISA to determine natural infection rates with Plasmodium falciparum and Plasmodium vivax. An. darlingi was positive for P. vivax 210, with an infection rate of 0.355% and an entomological inoculation rate of 15.87 infective bites/person/year. Anopheles albimanus larvae were the most common species in Riohacha, found in temporary swamps; in contrast, in Dibulla An. darlingi were detected mainly in permanent streams. Distinctive species composition and larval habitats in each municipality may explain the differences in Plasmodium transmission and suggest different local strategies should be used for vector control.

  14. [Distribution and species composition of hyporheic macroinvertebrates in a mountain stream].

    PubMed

    Zhang, Yue-wei; Yuan, Xing-zhong; Liu, Hong; Ren, Hai-qing; Deng, Wei; Wang, Xiao-feng

    2015-09-01

    Hyporheic macroinvertebrates are an important component of stream ecosystem. The composition and distribution of the hyporheic macroinvertebrates were investigated using artificial substrates in the upper reaches of Heishuitan River in August, December 2013 and April 2014. The results indicated that a total of 27 microinvertbrate species were identified in all three seasons. In summer, 22 species were identified, accounting for 81.8% of aquatic insects. 16 species were identified both in winter and spring, accounting for 75.0% and 62.5% of aquatic insects, respectively. The density of macroinvertebrate assemblage was significantly lower in summer than in winter and spring, and was the highest in spring. The biomass of macroinvertebrate assemblage was significantly higher in winter than in summer and spring, and was the lowest in summer. Species richness, Shannon index and Pielou index all had no significant difference among the three seasons. The density and richness of macroinvertebrates decreased with bed depth, and the maximum invertebrate density was found within the top 20 cm of the stream bed. Collector-filterer and collector-gatherer were the dominant functional feeding group in all three seasons. The community structure and temporal-spatial distribution of macroinvertebrates were determined by interactions and life history strategy of macroinvertebrates, and physical-chemical factors of hyporheic zone. PMID:26785569

  15. [Distribution and species composition of hyporheic macroinvertebrates in a mountain stream].

    PubMed

    Zhang, Yue-wei; Yuan, Xing-zhong; Liu, Hong; Ren, Hai-qing; Deng, Wei; Wang, Xiao-feng

    2015-09-01

    Hyporheic macroinvertebrates are an important component of stream ecosystem. The composition and distribution of the hyporheic macroinvertebrates were investigated using artificial substrates in the upper reaches of Heishuitan River in August, December 2013 and April 2014. The results indicated that a total of 27 microinvertbrate species were identified in all three seasons. In summer, 22 species were identified, accounting for 81.8% of aquatic insects. 16 species were identified both in winter and spring, accounting for 75.0% and 62.5% of aquatic insects, respectively. The density of macroinvertebrate assemblage was significantly lower in summer than in winter and spring, and was the highest in spring. The biomass of macroinvertebrate assemblage was significantly higher in winter than in summer and spring, and was the lowest in summer. Species richness, Shannon index and Pielou index all had no significant difference among the three seasons. The density and richness of macroinvertebrates decreased with bed depth, and the maximum invertebrate density was found within the top 20 cm of the stream bed. Collector-filterer and collector-gatherer were the dominant functional feeding group in all three seasons. The community structure and temporal-spatial distribution of macroinvertebrates were determined by interactions and life history strategy of macroinvertebrates, and physical-chemical factors of hyporheic zone.

  16. The influence of habitat structure on bird species composition in lowland malaysian rain forests.

    PubMed

    Mansor, Mohammad Saiful; Sah, Shahrul Anuar Mohd

    2012-05-01

    Bird surveys were conducted in the Bukit Kepala Gajah limestone area in Lenggong, Perak from July 2010 to January 2011. The study area was divided into three zones: forest edge, forest intermediate and forest interior. A point-count distance sampling method was used in the bird surveys. The study recorded 7789 detections, representing 100 bird species belonging to 28 families. Pycnonotidae, Timaliidae and Nectariniidae were the dominant families overall and showed the highest number of observations recorded in the study area whereas Motacillidae showed the fewest observations. The bird species were grouped into three feeding guilds: insectivores, frugivores and others (omnivores, carnivores, nectarivores and granivores). The species richness of insectivorous birds differed significantly among the forest zones sampled (Kruskal-Wallis: α=0.05, H=10.979, d.f.=2, p=0.004), with more insectivorous birds occurring in the forest interior. No significant differences were found among the zones in the species richness of either the frugivore guild or the composite others guild.

  17. [Polypore species diversity, floral composition, and distribution characteristics in Changbai Mountains, Northeast China].

    PubMed

    Wei, Yu-lian

    2011-10-01

    Polypore is an important group of wood-rotting fungi, which can decompose wood cellulose, semi-cellulose, and lignin into nutrients to be utilized by itself and other organisms, and accordingly, can promote the material cycling in forest ecosystem. Based on more than 10 years investigation and collection, it was found that the polypore in Changbai Mountains was rich in species diversity, with the Shannon diversity index being 5.06. In the Mountains, a total of 246 polypore species were recorded, occupying 40.7% of the total in China. The polypore species recorded belonged to 80 genera, 11 families, and 6 orders, among which, Polyporaceae was the dominant family. The most important bio-geographical elements of the polypore in Changbai Mountains were north temperate element and cosmopolitan element, other elements also included, showing a distinct north temperate character in floral composition. Pinus was the main host of polypore, supporting 41.5% of the polypore in Changbai Mountains. Most of the polypore was saprophytic, and its quantity had a significant correlation with the decaying degree of substrates, implying its important role in the material cycling in forest ecosystem in Changbai Mountains. There were 18 threatened polypore species in the Mountains, accounting for 37.5% of total in China. Besides their important ecological functions, many of the polypore also had higher economic value. On the premise of complete protection on them, these fungal resources should be exploited reasonably.

  18. The Influence of Habitat Structure on Bird Species Composition in Lowland Malaysian Rain Forests

    PubMed Central

    Mansor, Mohammad Saiful; Sah, Shahrul Anuar Mohd

    2012-01-01

    Bird surveys were conducted in the Bukit Kepala Gajah limestone area in Lenggong, Perak from July 2010 to January 2011. The study area was divided into three zones: forest edge, forest intermediate and forest interior. A point-count distance sampling method was used in the bird surveys. The study recorded 7789 detections, representing 100 bird species belonging to 28 families. Pycnonotidae, Timaliidae and Nectariniidae were the dominant families overall and showed the highest number of observations recorded in the study area whereas Motacillidae showed the fewest observations. The bird species were grouped into three feeding guilds: insectivores, frugivores and others (omnivores, carnivores, nectarivores and granivores). The species richness of insectivorous birds differed significantly among the forest zones sampled (Kruskal-Wallis: α=0.05, H=10.979, d.f.=2, p=0.004), with more insectivorous birds occurring in the forest interior. No significant differences were found among the zones in the species richness of either the frugivore guild or the composite others guild. PMID:24575221

  19. Fruit composition diversity in land races and modern pepino (Solanum muricatum) varieties and wild related species.

    PubMed

    Herraiz, Franscisco J; Raigón, María D; Vilanova, Santiago; García-Martínez, María D; Gramazio, Pietro; Plazas, Mariola; Rodríguez-Burruezo, Adrián; Prohens, Jaime

    2016-07-15

    Pepino (Solanum muricatum) fruits from 15 accessions of cultivated pepino as well as six accessions from wild relatives were evaluated for contents in dry matter, protein, β-carotene, chlorophylls and seven minerals. Several-fold differences among accessions were found for most traits. Average values obtained were similar to those of melon and cucumber, but the phenolic contents were much higher. Wild species had significantly higher average contents for all traits vs. the cultivated pepino accessions. And, the comparisons among the cultivated pepino varieties showed that the modern varieties were more uniform in composition, and they possessed significantly lower concentrations of protein, P, K, and Zn than local land races. Most of the significant correlations among composition traits were positive. Our studies show that regular consumption of pepino fruits could make a significant contribution to the recommended daily intake of P, K, Fe and Cu as well as to the average daily intake of phenolics. Furthermore, the higher values for most nutrients measured in the wild species and in the local land races indicate that new pepino varieties with improved fruit contents in nutrient and bioactive compounds can be developed. PMID:26948588

  20. Fruit composition diversity in land races and modern pepino (Solanum muricatum) varieties and wild related species.

    PubMed

    Herraiz, Franscisco J; Raigón, María D; Vilanova, Santiago; García-Martínez, María D; Gramazio, Pietro; Plazas, Mariola; Rodríguez-Burruezo, Adrián; Prohens, Jaime

    2016-07-15

    Pepino (Solanum muricatum) fruits from 15 accessions of cultivated pepino as well as six accessions from wild relatives were evaluated for contents in dry matter, protein, β-carotene, chlorophylls and seven minerals. Several-fold differences among accessions were found for most traits. Average values obtained were similar to those of melon and cucumber, but the phenolic contents were much higher. Wild species had significantly higher average contents for all traits vs. the cultivated pepino accessions. And, the comparisons among the cultivated pepino varieties showed that the modern varieties were more uniform in composition, and they possessed significantly lower concentrations of protein, P, K, and Zn than local land races. Most of the significant correlations among composition traits were positive. Our studies show that regular consumption of pepino fruits could make a significant contribution to the recommended daily intake of P, K, Fe and Cu as well as to the average daily intake of phenolics. Furthermore, the higher values for most nutrients measured in the wild species and in the local land races indicate that new pepino varieties with improved fruit contents in nutrient and bioactive compounds can be developed.

  1. Retention of Anionic Species on Granite: Influence of Granite Composition - 12129

    SciTech Connect

    Videnska, Katerina; Havlova, Vaclava

    2012-07-01

    Technetium (Tc-99, T{sub 1/2} = 2.1.10{sup 5} yrs) and selenium (Se-79, T{sub 1/2} = 6.5.10{sup 4} yrs) belong among fission products, being produced by fission of nuclear fuel. Both elements can significantly contribute to risk due to their complicated chemistry, long life times, high mobility and prevailing anionic character. Therefore, knowledge of migration behaviour under different conditions can significantly improve input into performance and safety assessment models. Granite is considered as a potential host rock for deep geological disposal of radioactive waste in many countries. Granitic rocks consist usually of quartz, feldspar, plagioclase (main components), mica, chlorite, kaolinite (minor components). The main feature of the rock is advection governed transport in fractures, complemented with diffusion process from fracture towards undisturbed rock matrix. The presented work is focused on interaction of anionic species (TcO{sub 4}{sup -}, SeO{sub 4}{sup 2-}, SeO{sub 3}{sup 2-}) with granitic rock. Furthermore, the importance of mineral composition on sorption of anionic species was also studied. The batch sorption experiments were conducted on the crushed granite from Bohemian Massive. Five fractions with defined grain size were used for static batch method. Mineral composition of each granitic fraction was evaluated using X-ray diffraction. The results showed differences in composition of granitic fractions, even though originating from one homogenized material. Sorption experiments showed influence of granite composition on adsorption of both TcO4{sup -} and SeO3{sup 2-} on granitic rock. Generally, Se(IV) showed higher retention than Tc(VII). Se(VI) was not almost sorbed at all. Fe containing minerals are pronounced as a selective Se and Tc sorbent, being reduced on their surface. As micas in granite are usually enriched in Fe, increased sorption of anionic species onto mica enriched fractions can be explained by this reason. On the other hand

  2. Assessment of fish abundance and species composition at selected sites in South Dakota: an overview

    USGS Publications Warehouse

    Harwood, Alison

    2010-01-01

    The U.S. Geological Survey (USGS) conducted surveys of streams throughout the State of South Dakota during 2008-09 as part of the U.S. Environmental Protection Agency?s (USEPA) National Rivers and Streams Assessment (NRSA) Program. During 2008-09, as part of the stream assessment, the USGS completed surveys of fish populations and species composition at 64 sites. Fish were inventoried at 60 of the 64 sites, but not at four of the sites because water was too low to sustain fish or specific conductivity was too high to electroshock effectively. Four of the sites were surveyed in 2000-04 during the USEPA's Environmental Monitoring and Assessment Program-West (EMAP-West) project. Two wadeable sites and two boatable sites were revisited for quality-assurance/quality-control requirements. During the study, both wadeable and boatable streams were sampled using electrofishing equipment and methods. Of the 64 sites, 62 were wadeable and 2 were boatable. Procedures for sampling wadeable streams differed slightly from procedures for boatable streams. Backpack electrofishing equipment was used for wadeable streams, whereas boat electrofishing equipment was used for boatable streams. Wadeable streams also were fished in an opposite direction than boatable streams. Several species of fish were collected during the NRSA. Species diversity ranged from 0-11 species in wadeable streams and from 6-26 species in boatable streams. Many common species were sampled during the study. The most frequently sampled fish was the sand shiner (Notropis stramineus), with 609 individuals sampled. In contrast, only one heritage species, the skipjack herring (Alosa chrysochloris), was identified during 2008-09. Common anomalies found in fish caught were parasitic lesions, "black spot disease," and tumors. When comparing the fish sampling results for the four sites visited in both 2000-04 and in 2008-09, more individuals and species were collected during 2008-09 than in 2000-04 at two sites, whereas

  3. Changes in Phlebotomine Sand Fly Species Composition Following Insecticide Thermal Fogging in a Rural Setting of Western Panamá

    PubMed Central

    Calzada, Jose E.; Saldaña, Azael; Rigg, Chystrie; Valderrama, Anayansi; Romero, Luz; Chaves, Luis Fernando

    2013-01-01

    American Cutaneous Leishmaniasis, ACL, is a zoonotic disease with a large richness of co-occurring vector species in transmission foci. Here, we describe changes in patterns of phlebotomine sand fly (Diptera: Psychodidae: Phlebotominae) species composition at the village of Trinidad de Las Minas, Capira, Panamá, a hyperendemic focus of ACL transmission, subjected to a vector control intervention with insecticide thermal fogging (ITF). Our study setting consisted of 24 houses, 12 subjected to two rounds of ITF and 12 kept as control. During 15 months (April 2010– June 2011) we monitored sand fly species composition and abundance with modified HP light traps inside (domicile) and outside (peridomicile) the studied houses. From 5628 sand flies collected, we were able to identify 5617 of the samples into 24 species, a number of species close to 25±1.6, the estimate from the Chao2 Index. The most abundant species were Lutzomya trapidoi (20%), Lu. gomezi (20%) and Lu. triramula (20%). Cluster analyses showed that most of the 24 houses had high similarity in relative abundance patterns of the six most common species, with only few peripheral houses not following the main cluster pattern. We also found that species richness was decreased to 22 species in the fogged houses, of which only 19 were found in the domiciliary environment. Changes in species richness were especially notorious at the end of the wet season. Our results suggest that species richness can decrease following ITF in domiciliary environments, primarily affecting the less common species. PMID:23536748

  4. Accretion tectonics and crustal structure in Alaska

    USGS Publications Warehouse

    Coney, P.J.; Jones, D.L.

    1985-01-01

    The entire width of the North American Cordillera in Alaska is made up of "suspect terranes". Pre-Late Cretaceous paleogeography is poorly constrained and the ultimate origins of the many fragments which make up the state are unclear. The Prince William and Chugach terranes accreted since Late Cretaceous time and represent the collapse of much of the northeast Pacific Ocean swept into what today is southern Alaska. Greater Wrangellia, a composite terrane now dispersed into fragments scattered from Idaho to southern Alaska, apparently accreted into Alaska in Late Cretaceous time crushing an enormous deep-marine flysch basin on its inboard side. Most of interior eastern Alaska is the Yukon Tanana terrane, a very large entirely fault-bounded metamorphic-plutonic assemblage covering thousands of square kilometers in Canada as well as Alaska. The original stratigraphy and relationship to North America of the Yukon-Tanana terrane are both obscure. A collapsed Mesozoic flysch basin, similar to the one inboard of Wrangellia, lies along the northern margin. Much of Arctic Alaska was apparently a vast expanse of upper Paleozoic to Early Mesozoic deep marine sediments and mafic volcanic and plutonic rocks now scattered widely as large telescoped sheets and Klippen thrust over the Ruby geanticline and the Brooks Range, and probably underlying the Yukon-Koyukuk basin and the Yukon flats. The Brooks Range itself is a stack of north vergent nappes, the telescoping of which began in Early Cretaceous time. Despite compelling evidence for thousands of kilometers of relative displacement between the accreted terranes, and large amounts of telescoping, translation, and rotation since accretion, the resulting new continental crust added to North America in Alaska carries few obvious signatures that allow application of currently popular simple plate tectonic models. Intraplate telescoping and strike-slip translations, delamination at mid-crustal levels, and large-scale lithospheric

  5. Acceleration and novelty: community restoration speeds recovery and transforms species composition in Andean cloud forest.

    PubMed

    Wilson, Sarah Jane; Rhemtulla, Jeanine M

    2016-01-01

    Community-based tropical forest restoration projects, often promoted as a win-win solution for local communities and the environment, have increased dramatically in number in the past decade. Many such projects are underway in Andean cloud forests, which, given their extremely high biodiversity and history of extensive clearing, are understudied. This study investigates the efficacy of community-based tree-planting projects to accelerate cloud forest recovery, as compared to unassisted natural regeneration. This study takes place in northwest Andean Ecuador, where the majority of the original, highly diverse cloud forests have been cleared, in five communities that initiated tree-planting projects to restore forests in 2003. In 2011, we identified tree species along transects in planted forests (n = 5), naturally regenerating forests (n = 5), and primary forests (n = 5). We also surveyed 120 households about their restoration methods, tree preferences, and forest uses. We found that tree diversity was higher in planted than in unplanted secondary forest, but both were less diverse than primary forests. Ordination analysis showed that all three forests had distinct species compositions, although planted forests shared more species with primary forests than did unplanted forests. Planted forests also contained more animal-dispersed species in both the planted canopy and in the unplanted, regenerating understory than unplanted forests, and contained the highest proportion of species with use value for local people. While restoring forest increased biodiversity and accelerated forest recovery, restored forests may also represent novel ecosystems that are distinct from the region's previous ecosystems and, given their usefulness to people, are likely to be more common in the future.

  6. Acceleration and novelty: community restoration speeds recovery and transforms species composition in Andean cloud forest.

    PubMed

    Wilson, Sarah Jane; Rhemtulla, Jeanine M

    2016-01-01

    Community-based tropical forest restoration projects, often promoted as a win-win solution for local communities and the environment, have increased dramatically in number in the past decade. Many such projects are underway in Andean cloud forests, which, given their extremely high biodiversity and history of extensive clearing, are understudied. This study investigates the efficacy of community-based tree-planting projects to accelerate cloud forest recovery, as compared to unassisted natural regeneration. This study takes place in northwest Andean Ecuador, where the majority of the original, highly diverse cloud forests have been cleared, in five communities that initiated tree-planting projects to restore forests in 2003. In 2011, we identified tree species along transects in planted forests (n = 5), naturally regenerating forests (n = 5), and primary forests (n = 5). We also surveyed 120 households about their restoration methods, tree preferences, and forest uses. We found that tree diversity was higher in planted than in unplanted secondary forest, but both were less diverse than primary forests. Ordination analysis showed that all three forests had distinct species compositions, although planted forests shared more species with primary forests than did unplanted forests. Planted forests also contained more animal-dispersed species in both the planted canopy and in the unplanted, regenerating understory than unplanted forests, and contained the highest proportion of species with use value for local people. While restoring forest increased biodiversity and accelerated forest recovery, restored forests may also represent novel ecosystems that are distinct from the region's previous ecosystems and, given their usefulness to people, are likely to be more common in the future. PMID:27039520

  7. Biochemical composition of three algal species proposed as food for captive freshwater mussels

    USGS Publications Warehouse

    Gatenby, C.M.; Orcutt, D.M.; Kreeger, D.A.; Parker, B.C.; Jones, V.A.; Neves, R.J.

    2003-01-01

    To identify potential diets for rearing captive freshwater mussels, the protein, carbohydrate (CHO), and lipid contents of two green algae, Neochloris oleoabundans, Bracteacoccus grandis, and one diatom, Phaeodactylum tricornutum, were compared at different growth stages. The fatty acid and sterol composition were also identified. Protein was greatest (55-70%) for all species at late log growth stage (LL), and declined in late stationary (LS) growth. CHO was greatest at LS stage for all species (33.9-56.4% dry wt). No significant change in lipid levels occurred with growth stage, but tended to increase in N. oleoabundans. Mean lipid content differed significantly in the order: N. oleoabundans > P. tricornutum > B. grandis. Total fatty acids (TFA) were higher at LS stage compared to other stages in the two green algae, and stationary stage in the diatom. Mean unsaturated fatty acids (UFA) as %TFA was significantly higher in N. oleoabundans than the other species. The green algae contained high percentages of C-18 polyunsaturated fatty acids (PUFAs), while the diatom was abundant in C-16 saturated and mono-unsaturated fatty acids and C-20 PUFA fatty acids. Growth stage had no effect on sterol concentration of any species. B. grandis showed significantly higher sterol levels than the other species except P. tricornutum at S stage. B. grandis was characterized by predominantly ??5, C-29 sterols, while N. oleoabundans synthesized ??5,7, ??5,7,22, and ??7, C-28 sterols. P. tricornutum produced primarily a ??5,22, C-28 sterol, and a small amount of a ??7,22, C-28 sterol.

  8. Bryophyte Species Richness and Composition along an Altitudinal Gradient in Gongga Mountain, China

    PubMed Central

    Sun, Shou-Qin; Wu, Yan-Hong; Wang, Gen-Xu; Zhou, Jun; Yu, Dong; Bing, Hai-Jian; Luo, Ji

    2013-01-01

    An investigation of terrestrial bryophyte species diversity and community structure along an altitudinal gradient from 2,001 to 4,221 m a.s.l. in Gongga Mountain in Sichuan, China was carried out in June 2010. Factors which might affect bryophyte species composition and diversity, including climate, elevation, slope, depth of litter, vegetation type, soil pH and soil Eh, were examined to understand the altitudinal feature of bryophyte distribution. A total of 14 representative elevations were chosen along an altitudinal gradient, with study sites at each elevation chosen according to habitat type (forests, grasslands) and accessibility. At each elevation, three 100 m × 2 m transects that are 50 m apart were set along the contour line, and three 50 cm × 50 cm quadrats were set along each transect at an interval of 30 m. Species diversity, cover, biomass, and thickness of terrestrial bryophytes were examined. A total of 165 species, including 42 liverworts and 123 mosses, are recorded in Gongga mountain. Ground bryophyte species richness does not show any clear elevation trend. The terrestrial bryophyte cover increases with elevation. The terrestrial bryophyte biomass and thickness display a clear humped relationship with the elevation, with the maximum around 3,758 m. At this altitude, biomass is 700.3 g m−2 and the maximum thickness is 8 cm. Bryophyte distribution is primarily associated with the depth of litter, the air temperature and the precipitation. Further studies are necessary to include other epiphytes types and vascular vegetation in a larger altitudinal range. PMID:23472146

  9. Effects of past burning frequency on plant species structure and composition in dry dipterocarp forest

    NASA Astrophysics Data System (ADS)

    Wanthongchai, Dr.; Bauhus, Prof.; Goldammer, Prof.

    2009-04-01

    Anthropogenic burning in dry dipterocarp forests (DDF) has become a common phenomenon throughout Thailand. It is feared that too frequent fires may affect vegetation structure and composition and thus impact on ecosystem productivity. The aim of this study was to quantify the effects of prescribed fires on sites with different past burning regimes on vegetation structure and composition in the Huay Kha Khaeng Wildlife Sanctuary (HKK), Thailand. Fire frequency was determined from satellite images and ranged from frequent, infrequent, rare and unburned with fire occurrences of 7, 2, 1 and 0 out of the past 10 years, respectively. The pre-burn fuel loads, the overstorey and understorey vegetation structure and composition were determined to investigate the effects of the contrasting past burning regimes. The burning experiment was carried out, applying a three-strip head-fire burning technique. The vegetation structure and composition were sampled again one year after the fire to assess the fire impacts. Aboveground fine fuel loads increased with the length of fire-free interval. The woody plant structures of the frequently burned stand differed from those of the other less frequently burned stands. The species composition of the overstorey on the frequently burned site, in particular that of small sized trees (4.5-10 cm dbh), also differed significantly from that of the other sites. Whilst the ground vegetation including shrubs and herbs did not differ between the past burning regimes, frequent burning obviously promoted the proliferation of graminoid vegetation. There was no clear evidence showing that the prescribed fires affected the mortality of trees (dbh> 4.5 cm) on the sites of the different past burning regimes. The effects of prescribed burning on the understorey vegetation structures varied between the past burning regimes and the understorey vegetation type. Therefore, it is recommended that the DDF at HKK should be subjected to a prescribed fire frequency

  10. Scale-dependent shifts in the species composition of flower visitors with changing floral density.

    PubMed

    Essenberg, Carla J

    2013-01-01

    Responses of flower-visiting animals to floral density can alter interactions between plants, influencing a variety of biological processes, including plant population dynamics and the evolution of flowering phenology. Many studies have found effects of floral or plant density on pollinator visitation rates at patch scales, but little is known about responses of flower visitors to floral densities at larger scales. Here, I present data from an observational field study in which I measured the effects of floral density on visitation to the annual composite Holocarpha virgata at both patch (4 m(2)) and site (12.6 ha) spatial scales. The species composition of flower visitors changed with floral density, and did so in different ways at the two scales. At the site scale, average floral density within patches of H. virgata or within patches of all summer-flowering species combined had a significant positive effect on per-flowerhead visitation by the long-horned bee Melissodes lupina and no significant effects on visitation by any other taxa. At the patch scale, per-flowerhead visitation by honeybees significantly increased whereas visitation by M. lupina often decreased with increasing floral density. For both species, responses to patch-scale floral density were strongest when site-scale floral density was high. The scale-dependence of flower visitor responses to floral density and the interactions between site- and patch-scale effects of floral density observed in this study underscore the importance of improving our understanding of pollinators' responses to floral density at population scales.

  11. Assessing Historical Fish Community Composition Using Surveys, Historical Collection Data, and Species Distribution Models

    PubMed Central

    Labay, Ben; Cohen, Adam E.; Sissel, Blake; Hendrickson, Dean A.; Martin, F. Douglas; Sarkar, Sahotra

    2011-01-01

    Accurate establishment of baseline conditions is critical to successful management and habitat restoration. We demonstrate the ability to robustly estimate historical fish community composition and assess the current status of the urbanized Barton Creek watershed in central Texas, U.S.A. Fish species were surveyed in 2008 and the resulting data compared to three sources of fish occurrence information: (i) historical records from a museum specimen database and literature searches; (ii) a nearly identical survey conducted 15 years earlier; and (iii) a modeled historical community constructed with species distribution models (SDMs). This holistic approach, and especially the application of SDMs, allowed us to discover that the fish community in Barton Creek was more diverse than the historical data and survey methods alone indicated. Sixteen native species with high modeled probability of occurrence within the watershed were not found in the 2008 survey, seven of these were not found in either survey or in any of the historical collection records. Our approach allowed us to more rigorously establish the true baseline for the pre-development fish fauna and then to more accurately assess trends and develop hypotheses regarding factors driving current fish community composition to better inform management decisions and future restoration efforts. Smaller, urbanized freshwater systems, like Barton Creek, typically have a relatively poor historical biodiversity inventory coupled with long histories of alteration, and thus there is a propensity for land managers and researchers to apply inaccurate baseline standards. Our methods provide a way around that limitation by using SDMs derived from larger and richer biodiversity databases of a broader geographic scope. Broadly applied, we propose that this technique has potential to overcome limitations of popular bioassessment metrics (e.g., IBI) to become a versatile and robust management tool for determining status of

  12. Lipid Content and Composition of Oocytes from Five Coral Species: Potential Implications for Future Cryopreservation Efforts

    PubMed Central

    Lin, Chiahsin; Wang, Li-Hsueh; Meng, Pei-Jie; Chen, Chii-Shiarng; Tsai, Sujune

    2013-01-01

    Given the previously documented importance of lipid concentration and composition in the successful cryopreservation of gorgonian corals, these parameters were assessed in oocytes of five species of scleractinian coral; Platygyra daedalea, Echinopora gemmacea, Echinophyllia aspera, Oxypora lacera and Astreopora expansa. Wax esters, phosphatidylethanolamine, phosphatidylcholine, and fatty acids were all measured at detectable levels, and the latter were produced at significantly elevated quantities in E. gemmacea, E. aspera, and O. lacera. On the other hand, phosphatidylethanolamine, phosphatidylcholine, and wax ester were found at significantly higher concentrations in A. expansa oocytes. Triacylglycerol was not present in any species. Interestingly, the total lipid content of oocytes from all five scleractinians was significantly lower than that of oocytes of two gorgonian species, Junceella juncea and Junceella fragilis. As higher total lipid concentrations may be correlated with greater degrees of cellular membrane fluidity at lower temperatures, it stands to reason that gorgonian coral oocytes may be more likely to survive the cryopreservation process than oocytes of scleractinian corals. PMID:23469074

  13. Zooplankton community structure and copepod species composition in the northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Ortner, Peter B.; Hill, Leonard C.; Cummings, Shailer R.

    1989-04-01

    Zooplankton community structure and copepod species composition are analysed in samples obtained during spring and winter from three areas of the northern Gulf of Mexico: near the Mississippi River outflow, off Cape San Blas, and in the central Gulf of Mexico. Samples from different regions were distinguishable in correspondence analysis of dominant species and/or functional groups. The near-surface communities of the Mississippi and central Gulf were particularly distinct while Cape San Blas was intermediate in both structure and specific character. Saltier waters directly beneath the Mississippi Plume yielded samples similar to those from near-surface waters well offshore. At the same time near-surface waters off the Mississippi and off Cape San Blass to the west were distinguishable even during spring when the outflow from the Mississippi was at its annual peak. These differences are consistent with the discharge and flow patterns of the Mississippi River plume and the northern Gulf and with systematic differences in such parameters as temperature, salinity and chlorophyll concentration. The implications of these observations upon the feeding environments of the larvae of commercially significant fish species are addressed since both zooplankton prey and larval predators appear to be particularly abundant in the Mississippi River plume environs.

  14. Distribution, species composition and relative abundances of sandflies in North Waziristan Agency, Pakistan.

    PubMed

    Ali, N; Ullah, A; Wahid, S; Khisroon, M; Rasheed, S B

    2016-03-01

    This study was conducted to investigate the diversity of sandflies (Psychodidae: Phlebotominae) and the incidence of leishmaniasis in three villages of North Waziristan Agency, Pakistan. Sandflies were sampled monthly during 2012, at dusk and dawn, in selected indoor habitats including both bedrooms and animal sheds using a knock-down spray catch method. A total of 3687 sandflies were collected, including 1444 individuals in Drezanda, 1193 in Damdil and 1050 in Dattakhel. This study revealed 14 species of two genera, Phlebotomus (Phlebotomus sergenti, Phlebotomus papatasi, Phlebotomus caucasicus, Phlebotomus kazeruni, Phlebotomus alexandri and Phlebotomus salehi) and Sergentomyia (Sergentomyia dentate, Sergentomyia baghdadis, Sergentomyia babu, Sergentomyia theodori, Sergentomyia sumbarica, Sergentomyia dreyfussitur kestanica, Sergentomyia hogsoni pawlowskyi and Sergentomyia fallax afghanica) (both: Diptera: Psychodidae). Phlebotomus sergenti was the most abundant species (42.1%), followed by S. dentata (17.7%) and S. baghdadis (17.4%). The number of males collected represented about twice that of female flies, and the maximum number was collected in July, followed by August. The determination of the species composition of sandfly populations, seasonal variations, relative abundances and estimations of infection in the vector population may provide information about the dynamics of leishmaniasis transmission that is useful in planning vector control activities.

  15. Species composition and cyanotoxin production in periphyton mats from three lakes of varying trophic status.

    PubMed

    Wood, Susie A; Kuhajek, Jeannie M; de Winton, Mary; Phillips, Ngaire R

    2012-02-01

    In lakes, benthic micro-algae and cyanobacteria (periphyton) can contribute significantly to total primary productivity and provide important food sources for benthic invertebrates. Despite recognition of their importance, few studies have explored the diversity of the algal and cyanobacterial composition of periphyton mats in temperate lakes. In this study, we sampled periphyton from three New Zealand lakes: Tikitapu (oligotrophic), Ōkāreka (mesotrophic) and Rotoiti (eutrophic). Statistical analysis of morphological data showed a clear delineation in community structure among lakes and highlighted the importance of cyanobacteria. Automated rRNA intergenic spacer analysis (ARISA) and 16S rRNA gene clone libraries were used to investigate cyanobacterial diversity. Despite the close geographic proximity of the lakes, cyanobacterial species differed markedly. The 16S rRNA gene sequence analysis identified eight cyanobacterial OTUs. A comparison with other known cyanobacterial sequences in GenBank showed relatively low similarities (91-97%). Cyanotoxin analysis identified nodularin in all mats from Lake Tikitapu. ndaF gene sequences from these samples had very low (≤ 89%) homology to sequences in other known nodularin producers. To our knowledge, this is the first detection of nodularin in a freshwater environment in the absence of Nodularia. Six cyanobacteria species were isolated from Lake Tikitapu mats. None were found to produce nodularin. Five of the species shared low (< 97%) 16S rRNA gene sequence similarities with other cultured cyanobacteria.

  16. Carotenoid composition and its chemotaxonomic significance in leaves of ten species of the genus Ceratozamia (Cycads).

    PubMed

    Cardinif, Franco; Bonzi, Laura Morassi

    2005-05-01

    The qualitative composition and localization of carotenoids in leaflets of ten species of the genus Ceratozamia (Cycads) was investigated, and the distributions of 16 of these carotenoids, which were isolated and differently located in the chloroplast, are discussed. Eight classic carotenoids are located in the thylakoidal membranes of the chloroplasts of all ten of the species examined. In contrast, eight red keto-carotenoids are unusually located in several plastoglobules present in the stroma of nine species Ceratozamia mexicana Brongn. excluded. The characteristic red-brown transitory coloration shown by the newly formed leaflets during the first stages of development is due to this latter keto mixture. It is constituted of three very rare keto-carotenoids, which were, in our case, identified for the first time from the photosynthetic tissues (semi-beta-carotenone, triphasiaxanthin, and beta-carotenone). It is also constituted of four others, which are completely novel (ceratoxanthin, ceratozamiaxanthin, kuesteriaxanthin, and ceratoxanthone). Some hypotheses about their presence and function are presented.

  17. Development of in-situ imaging tools to quantify vegetation stress, plant mortality, and species composition

    NASA Astrophysics Data System (ADS)

    Goulden, M.

    2014-12-01

    We have developed and deployed an imaging system at an eddy covariance site in a Southern California Pinyon-Juniper woodland; our goals are to quantify the species-level patterns of stress and mortality over time, and also to learn how to better interpret the Landsat record. Our imaging system combines a four channel spectrometer with cameras that are sensitive to Visible, Near Infrared (NIR), Shortwave Infrared (SWIR), and Thermal radiation; these cameras include filters that mimic the spectral sensitivity of several Landsat bands. The cameras and spectrometer foreoptic are positioned on a pan-tilt mount on the tower that scans a 300o x 90o area every hour and allows us to collect images of hundreds of distinct plants. The imaging system is being used to test several approaches that have been proposed to detect vegetation stress, mortality, and species composition. We are exploring the potential to detect stomatal closure and stress by: a) increased canopy temperature with decreased evaporative cooling, b) Photochemical Reflectance Index (PRI), c) Fraunhofer line fluorescence, and d) water band indices. Similarly, we are exploring the potential to detect plant mortality by: a) NIR reflectance, b) SWIR reflectance, and c) radiance temperature with soil exposure, and to identify plant species by: a) differential phenological and interannual patterns, b) spectral reflectance, and c) BRDF and the effect of solar angle.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26515033

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

    PubMed

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

    2015-10-30

    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 (13)C 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.

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

    NASA Astrophysics Data System (ADS)

    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. Alaska Volcano Observatory

    USGS Publications Warehouse

    Venezky, Dina Y.; Murray, Tom; Read, Cyrus

    2008-01-01

    Steam plume from the 2006 eruption of Augustine volcano in Cook Inlet, Alaska. Explosive ash-producing eruptions from Alaska's 40+ historically active volcanoes pose hazards to aviation, including commercial aircraft flying the busy North Pacific routes between North America and Asia. The Alaska Volcano Observatory (AVO) monitors these volcanoes to provide forecasts of eruptive activity. AVO is a joint program of the U.S. Geological Survey (USGS), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS). AVO is one of five USGS Volcano Hazards Program observatories that monitor U.S. volcanoes for science and public safety. Learn more about Augustine volcano and AVO at http://www.avo.alaska.edu.

  2. Factors determining parasite community richness and species composition in black snook Centropomus nigrescens (Centropomidae) from coastal lagoons in Guerrero, Mexico.

    PubMed

    Violante-González, Juan; Mendoza-Franco, Edgar F; Rojas-Herrera, Agustín; Gil Guerrero, Salvador

    2010-06-01

    Species richness and composition were determined for parasite communities in the black snook Centropomus nigrescens collected from five coastal lagoons in the Guerrero state, Mexico. A total of 354 fish were collected between December 2007 and November 2008. Twenty-four species of parasite were identified: 2 monogeneans, 12 digeneans, 4 acanthocephalans, 1 cestode, 4 nematodes, and 1 pentastomid. The communities consisted mainly of autogenic parasites, and all were dominated by the digenean Paracrytogonimus yamagutii. Community species composition was similar among lagoons, although the influence of local conditions prevented them from being identical. Host traits such as predator feeding habits, body size, and vagility contributed to parasite community structure and species composition. PMID:20336316

  3. Why does grassland productivity increase with species richness? Disentangling species richness and composition with tests for overyielding and superyielding in biodiversity experiments.

    PubMed

    Drake, John M

    2003-08-22

    The causal relationship between the biodiversity of natural and modified environments and their net primary production has been a topic of significant scientific controversy and scrutiny. Early theoretical and empirical results indicated that production was sometimes significantly correlated with species richness when species richness was directly manipulated in experimental systems. Possible mechanisms for this phenomenon include statistical sampling effects, complementary resource use and mutualistic interactions. However, the interpretation of experimental results has sometimes confounded species richness with species composition, and disentangling the effects of species diversity from species identity has proved a formidable challenge. Here, I present a statistical method that is based on simple probability models and does not rely on the species composition of individual plots to distinguish among three phenomena that occur in biodiversity-production experiments: underyielding, overyielding and (a new concept) superyielding. In some cases, distinguishing these phenomena will provide evidence for underlying mechanisms. As a proof-of-concept, I first applied this technique to a simulated dataset, indicating the strengths of the method with both clear and ambiguous cases. I then analysed data from the BIODEPTH experimental biodiversity manipulations. No evidence of either overyielding or superyielding was detected in the BIODEPTH experiment.

  4. CLIMATE CHANGE EFFECTS ON SPECIES COMPOSITION MEDIATES DECOMPOSITION IN AN OLD-FIELD ECOSYSTEM

    SciTech Connect

    Tyner, M.L.; Classen, A.T.

    2007-01-01

    Decomposition of leaf litter collected from an old-fi eld community grown under a combination of elevated atmospheric CO2 concentrations (+300ppm) and elevated surface temperature (+ 3.2°C) was examined in ambient conditions over 8 months in two separate experiments. In the fi rst experiment, we examined the main effects and interactions of CO2 and warming on litter quality and subsequent mass loss rates. Multi-species litter bags were constructed with litter collected from chambers with ambient CO2 and ambient temperatures (ACAT), elevated CO2 and elevated temperature (ECET), ambient CO2 and elevated temperature (ACET), and elevated CO2 and ambient temperature (ECAT). Litter collected from 6 species in each chamber was represented in decomposition bags in equal proportions. There were no differences in initial litter percent carbon (C) or nitrogen (N) among treatments. After 8 months, litter collected from ACET chambers lost over 20% more mass than litter collected from ECET or ACAT chambers, although biological differences were small. In the second experiment, we examined the indirect effect climate change may have on plant community composition, litter inputs, and subsequent mass loss rates. Litter bags were made from the same chambers mentioned above, but the amount of litter in the bag from each species was proportional to peak standing biomass of that species within the treatment. Initial litter in ECAT bags had up to 4% less C and 29% less N than ECET and ACET bags. Mass loss from ACET bags was 48% higher than mass loss from ECAT bags and 37% higher than mass loss from ACAT bags after 8 months of decomposition. These differences may have been driven by the higher proportion of litter from Lespedeza, a N-fi xer, in the natural ACET bags. Taken together, these data suggest that climate change will have a larger effect on decomposition by causing shifts in plant communities than it will by altering litter quality.

  5. Quantifying Phytogeographical Regions of Australia Using Geospatial Turnover in Species Composition

    PubMed Central

    González-Orozco, Carlos E.; Ebach, Malte C.; Laffan, Shawn; Thornhill, Andrew H.; Knerr, Nunzio J.; Schmidt-Lebuhn, Alexander N.; Cargill, Christine C.; Clements, Mark; Nagalingum, Nathalie S.; Mishler, Brent D.; Miller, Joseph T.

    2014-01-01

    The largest digitized dataset of land plant distributions in Australia assembled to date (750,741 georeferenced herbarium records; 6,043 species) was used to partition the Australian continent into phytogeographical regions. We used a set of six widely distributed vascular plant groups and three non-vascular plant groups which together occur in a variety of landscapes/habitats across Australia. Phytogeographical regions were identified using quantitative analyses of species turnover, the rate of change in species composition between sites, calculated as Simpson's beta. We propose six major phytogeographical regions for Australia: Northern, Northern Desert, Eremaean, Eastern Queensland, Euronotian and South-Western. Our new phytogeographical regions show a spatial agreement of 65% with respect to previously defined phytogeographical regions of Australia. We also confirm that these new regions are in general agreement with the biomes of Australia and other contemporary biogeographical classifications. To assess the meaningfulness of the proposed phytogeographical regions, we evaluated how they relate to broad scale environmental gradients. Physiographic factors such as geology do not have a strong correspondence with our proposed regions. Instead, we identified climate as the main environmental driver. The use of an unprecedentedly large dataset of multiple plant groups, coupled with an explicit quantitative analysis, makes this study novel and allows an improved historical bioregionalization scheme for Australian plants. Our analyses show that: (1) there is considerable overlap between our results and older biogeographic classifications; (2) phytogeographical regions based on species turnover can be a powerful tool to further partition the landscape into meaningful units; (3) further studies using phylogenetic turnover metrics are needed to test the taxonomic areas. PMID:24658356

  6. Coccolithophore responses to environmental variability in the South China Sea: species composition and calcite content

    NASA Astrophysics Data System (ADS)

    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).

  7. Alaska's renewable energy potential.

    SciTech Connect

    Not Available

    2009-02-01

    This paper delivers a brief survey of renewable energy technologies applicable to Alaska's climate, latitude, geography, and geology. We first identify Alaska's natural renewable energy resources and which renewable energy technologies would be most productive. e survey the current state of renewable energy technologies and research efforts within the U.S. and, where appropriate, internationally. We also present information on the current state of Alaska's renewable energy assets, incentives, and commercial enterprises. Finally, we escribe places where research efforts at Sandia National Laboratories could assist the state of Alaska with its renewable energy technology investment efforts.

  8. Soil disturbance as a grassland restoration measure-effects on plant species composition and plant functional traits.

    PubMed

    Schnoor, Tim; Bruun, Hans Henrik; Olsson, Pål Axel

    2015-01-01

    Soil disturbance is recognized as an important driver of biodiversity in dry grasslands, and can therefore be implemented as a restoration measure. However, because community re-assembly following disturbance includes stochastic processes, a focus only on species richness or establishment success of particular species will not inform on how plant communities respond ecologically to disturbance. We therefore evaluated vegetation development following disturbance by quantifying species richness, species composition and functional trait composition. Degraded calcareous sandy grassland was subjected to experimental disturbance treatments (ploughing or rotavation), and the vegetation was surveyed during four subsequent years of succession. Treated plots were compared with control plots representing untreated grassland, as well as nearby plots characterized by plant communities representing the restoration target. Species richness and functional diversity both increased in response to soil disturbance, and rotavation, but not ploughing, had a persistent positive effect on the occurrence of specialist species of calcareous sandy grassland. However, no type of soil disturbance caused the plant species composition to develop towards the target vegetation. The disturbance had an immediate and large impact on the vegetation, but the vegetation developed rapidly back towards the control sites. Plant functional composition analysis indicated that the treatments created habitats different both from control sites and target sites. Community-weighted mean Ellenberg indicator values suggested that the observed plant community response was at least partially due to an increase in nitrogen and water availability following disturbance. This study shows that a mild type of disturbance, such as rotavation, may be most successful in promoting specialist species in calcareous sandy grassland, but that further treatments are needed to reduce nutrient availability. We conclude that a

  9. Soil disturbance as a grassland restoration measure-effects on plant species composition and plant functional traits.

    PubMed

    Schnoor, Tim; Bruun, Hans Henrik; Olsson, Pål Axel

    2015-01-01

    Soil disturbance is recognized as an important driver of biodiversity in dry grasslands, and can therefore be implemented as a restoration measure. However, because community re-assembly following disturbance includes stochastic processes, a focus only on species richness or establishment success of particular species will not inform on how plant communities respond ecologically to disturbance. We therefore evaluated vegetation development following disturbance by quantifying species richness, species composition and functional trait composition. Degraded calcareous sandy grassland was subjected to experimental disturbance treatments (ploughing or rotavation), and the vegetation was surveyed during four subsequent years of succession. Treated plots were compared with control plots representing untreated grassland, as well as nearby plots characterized by plant communities representing the restoration target. Species richness and functional diversity both increased in response to soil disturbance, and rotavation, but not ploughing, had a persistent positive effect on the occurrence of specialist species of calcareous sandy grassland. However, no type of soil disturbance caused the plant species composition to develop towards the target vegetation. The disturbance had an immediate and large impact on the vegetation, but the vegetation developed rapidly back towards the control sites. Plant functional composition analysis indicated that the treatments created habitats different both from control sites and target sites. Community-weighted mean Ellenberg indicator values suggested that the observed plant community response was at least partially due to an increase in nitrogen and water availability following disturbance. This study shows that a mild type of disturbance, such as rotavation, may be most successful in promoting specialist species in calcareous sandy grassland, but that further treatments are needed to reduce nutrient availability. We conclude that a

  10. Soil Disturbance as a Grassland Restoration Measure—Effects on Plant Species Composition and Plant Functional Traits

    PubMed Central

    Schnoor, Tim; Bruun, Hans Henrik; Olsson, Pål Axel

    2015-01-01

    Soil disturbance is recognized as an important driver of biodiversity in dry grasslands, and can therefore be implemented as a restoration measure. However, because community re-assembly following disturbance includes stochastic processes, a focus only on species richness or establishment success of particular species will not inform on how plant communities respond ecologically to disturbance. We therefore evaluated vegetation development following disturbance by quantifying species richness, species composition and functional trait composition. Degraded calcareous sandy grassland was subjected to experimental disturbance treatments (ploughing or rotavation), and the vegetation was surveyed during four subsequent years of succession. Treated plots were compared with control plots representing untreated grassland, as well as nearby plots characterized by plant communities representing the restoration target. Species richness and functional diversity both increased in response to soil disturbance, and rotavation, but not ploughing, had a persistent positive effect on the occurrence of specialist species of calcareous sandy grassland. However, no type of soil disturbance caused the plant species composition to develop towards the target vegetation. The disturbance had an immediate and large impact on the vegetation, but the vegetation developed rapidly back towards the control sites. Plant functional composition analysis indicated that the treatments created habitats different both from control sites and target sites. Community-weighted mean Ellenberg indicator values suggested that the observed plant community response was at least partially due to an increase in nitrogen and water availability following disturbance. This study shows that a mild type of disturbance, such as rotavation, may be most successful in promoting specialist species in calcareous sandy grassland, but that further treatments are needed to reduce nutrient availability. We conclude that a

  11. Chemical composition and fuel wood characteristics of fast growing tree species in India

    NASA Astrophysics Data System (ADS)

    Chauhan, S. K.; Soni, R.

    2012-04-01

    India is one of the growing economy in the world and energy is a critical input to sustain the growth of development. Country aims at security and efficiency of energy. Though fossil fuel will continue to play a dominant role in energy scenario but country is committed to global environmental well being thus stressing on environment friendly technologies. Concerns of energy security in this changing climatic situation have led to increasing support for the development of new renewable source of energy. Government though is determined to facilitate bio-energy and many projects have been established but initial after-affects more specifically on the domestic fuelwood are evident. Even the biomass power generating units are facing biomass crisis and accordingly the prices are going up. The CDM projects are supporting the viability of these units resultantly the Indian basket has a large number of biomass projects (144 out of total 506 with 28 per cent CERs). The use for fuelwood as a primary source of energy for domestic purpose by the poor people (approx. 80 per cent) and establishment of bio-energy plants may lead to deforestation to a great extent and only solution to this dilemma is to shift the wood harvest from the natural forests to energy plantations. However, there is conspicuous lack of knowledge with regards to the fuelwood characteristics of fast growing tree species for their selection for energy plantations. The calorific value of the species is important criteria for selection for fuel but it is affected by the proportions of biochemical constituents present in them. The aim of the present work was to study the biomass production, calorific value and chemical composition of different short rotation tree species. The study was done from the perspective of using the fast growing tree species for energy production at short rotation and the study concluded that short rotation tree species like Gmelina arborea, Eucalyptus tereticornis, Pongamia pinnata

  12. Main sugar composition of floral nectar in three species groups of Scrophularia (Scrophulariaceae) with different principal pollinators.

    PubMed

    Rodríguez-Riaño, T; Ortega-Olivencia, A; López, J; Pérez-Bote, J L; Navarro-Pérez, M L

    2014-11-01

    In some angiosperm groups, a parallelism between nectar traits and pollination syndromes has been demonstrated, whereas in others there is not such relationship and it has been explained as due to phylogenetic constraints. However, nectar trait information remains scarce for many plant groups. This paper focuses on three groups of Scrophularia species, with different flower sizes and principal pollinators, to find out whether nectar sugar composition is determined by pollinator type or reflects taxonomic affinities. Since the species we examined have protogynous flowers, and gender bias in nectar sugar composition has been noted in few plant groups, we also investigated whether sexual phase influenced Scrophularia nectar composition. The sugar composition was found to be similar in all species, having high-sucrose nectar, except for the Macaronesian Scrophularia calliantha, which was the only species with balanced nectar; this last kind of nectar could be associated with the high interaction rates observed between S. calliantha and passerine birds. The nectar sugar composition (high in sucrose) was unrelated to the principal pollinator group, and could instead be considered a conservative taxonomic trait. No gender bias was observed between functionally female and male flowers for nectar volume or concentration. However, sexual phase significantly affected sucrose percentage in the largest-flowered species, where the female phase flowers had higher sucrose percentages than the male phase flowers.

  13. Chemical Composition, Nitrogen Fractions and Amino Acids Profile of Milk from Different Animal Species.

    PubMed

    Rafiq, Saima; Huma, Nuzhat; Pasha, Imran; Sameen, Aysha; Mukhtar, Omer; Khan, Muhammad Issa

    2016-07-01

    Milk composition is an imperative aspect which influences the quality of dairy products. The objective of study was to compare the chemical composition, nitrogen fractions and amino acids profile of milk from buffalo, cow, sheep, goat, and camel. Sheep milk was found to be highest in fat (6.82%±0.04%), solid-not-fat (11.24%±0.02%), total solids (18.05%±0.05%), protein (5.15%±0.06%) and casein (3.87%±0.04%) contents followed by buffalo milk. Maximum whey proteins were observed in camel milk (0.80%±0.03%), buffalo (0.68%±0.02%) and sheep (0.66%±0.02%) milk. The non-protein-nitrogen contents varied from 0.33% to 0.62% among different milk species. The highest r-values were recorded for correlations between crude protein and casein in buffalo (r = 0.82), cow (r = 0.88), sheep (r = 0.86) and goat milk (r = 0.98). The caseins and whey proteins were also positively correlated with true proteins in all milk species. A favorable balance of branched-chain amino acids; leucine, isoleucine, and valine were found both in casein and whey proteins. Leucine content was highest in cow (108±2.3 mg/g), camel (96±2.2 mg/g) and buffalo (90±2.4 mg/g) milk caseins. Maximum concentrations of isoleucine, phenylalanine, and histidine were noticed in goat milk caseins. Glutamic acid and proline were dominant among non-essential amino acids. Conclusively, current exploration is important for milk processors to design nutritious and consistent quality end products. PMID:26954163

  14. Chemical Composition, Nitrogen Fractions and Amino Acids Profile of Milk from Different Animal Species

    PubMed Central

    Rafiq, Saima; Huma, Nuzhat; Pasha, Imran; Sameen, Aysha; Mukhtar, Omer; Khan, Muhammad Issa

    2016-01-01

    Milk composition is an imperative aspect which influences the quality of dairy products. The objective of study was to compare the chemical composition, nitrogen fractions and amino acids profile of milk from buffalo, cow, sheep, goat, and camel. Sheep milk was found to be highest in fat (6.82%±0.04%), solid-not-fat (11.24%±0.02%), total solids (18.05%±0.05%), protein (5.15%±0.06%) and casein (3.87%±0.04%) contents followed by buffalo milk. Maximum whey proteins were observed in camel milk (0.80%±0.03%), buffalo (0.68%±0.02%) and sheep (0.66%±0.02%) milk. The non-protein-nitrogen contents varied from 0.33% to 0.62% among different milk species. The highest r-values were recorded for correlations between crude protein and casein in buffalo (r = 0.82), cow (r = 0.88), sheep (r = 0.86) and goat milk (r = 0.98). The caseins and whey proteins were also positively correlated with true proteins in all milk species. A favorable balance of branched-chain amino acids; leucine, isoleucine, and valine were found both in casein and whey proteins. Leucine content was highest in cow (108±2.3 mg/g), camel (96±2.2 mg/g) and buffalo (90±2.4 mg/g) milk caseins. Maximum concentrations of isoleucine, phenylalanine, and histidine were noticed in goat milk caseins. Glutamic acid and proline were dominant among non-essential amino acids. Conclusively, current exploration is important for milk processors to design nutritious and consistent quality end products. PMID:26954163

  15. Phenolic Acid Composition and Anti-Parasitic Effects of Four Peucedanum Species on Entamoeba histolytica Trophozoites

    PubMed Central

    DEGERLI, Serpil; TEPE, Bektas

    2015-01-01

    Background: The aim of this study was to determine phenolic acid composition and anti-parasitic effects of Peucedanum caucasicum, P. palimbioides, P. longibracteolatum and P. chryseum on Entamoeba histolytica. Methods: Methanol extracts of the plant species were prepared by soxhlet extraction. Phenolic acid compositions were determined by HPLC. Anti-proliferative effect of extracts on trophozoites was determined by using trypan blue dye exclusion test. For counting the cells, approximately a hundred of E. histolytica trophozoites were examined in each time. The data were presented as mean values with standard deviations and analyzed by repeated measures of ANOVA followed by Tukey test for post-hoc pairwise comparisons. The P-value was set at 0.05 for significance level. Results: All of the extracts showed a time and dose dependent amoebicidal action on trophozoites. Among the extracts tested, P. longibracteolatum showed the strongest amoebicidal effect on the trophozoites. As expected, this plant species also exhibited time and dose dependent activity on the trophozoites. At 4.0 mg/ml extract concentration, all of the trophozoites were killed by the extract in 72nd hour. Gallic (11.144 mg/g), P-hydroxybenzoic (17.646 mg/g), and o-coumaric acids (14.442 mg/g) were determined as the major phenolic acids of P. longibracteolatum. Gallic and P-hydroxybenzoic acids found in P. longibracteolatum could not be determined in other extracts. Therefore, high activity potential of this plant could probably be attributed to the presence of these phytochemicals. Conclusion: P. longibracteolatum can be further evaluated as potential therapeutic drugs for the treatment of Entamoeba infections. PMID:26622297

  16. Fatty acid composition of Juniperus species (Juniperus section) native to Turkey.

    PubMed

    Güvenç, Aysegül; Küçükboyaci, Nurgün; Gören, Ahmet Ceyhan

    2012-07-01

    Fatty acid compositions of seeds of five taxa of the Juniperus section of the genus Juniperus L. (Cupressaceae), i. e. J. drupacea Lab., J. communis L. var. communis, J. communis var. saxatilis Pall., J. oxycedrus L. subsp. oxycedrus, and J. oxycedrus subsp. macrocarpa (Sibth. & Sm.) Ball, were investigated. Methyl ester derivatized fatty acids of the lipophylic extracts of the five species were comparatively analyzed by capillary gas chromatography-mass spectrometry (GC-MS). Juniperus taxa showed uniform fatty acid patterns, among which linoleic (25.8 - 32.5%), pinolenic (11.9 - 24.1%) and oleic acids (12.4 - 17.2%) were determined to be the main fractions in the seed oils. Juniperonic acid was found to be remarkably high in J. communis var. saxatilis (11.4%), J. oxycedrus subsp. oxycedrus (10.4%), and J. communis var. communis (10.1%). To the best of our knowledge, the present work discloses the first report on the fatty acid compositions of seeds of this Juniperus section grown in Turkey.

  17. Acidification of the humic Lake Skjervatjern; effects on the volume and species composition of phytoplankton

    SciTech Connect

    Brettum, P. )

    1994-01-01

    This paper presents the effects of the experimental acidification on the volume and composition of phytoplankton from the investigations carried out in Lake Skjervatjern in connection with the HUMEX project. The results of the phytoplankton analysis are presented from Basin A, the acidified basin, and Basin B, the control, two years before the acidification started and two years during the acidification. In Basin B, the control basin, the succession of the main groups of phytoplankton throughout the growth season remained almost identical from year to year in the investigation period. The development of the phytoplankton was almost the same in the two basins before the acidification started. The results from the acidified Basin A in 1991 and 1992 show marked changes and an almost immediate response in the phytoplankton composition and percentage of the main algae groups, compared to the reference basin. The percentage of the green algae decreased, especially the species Oocystis submarina v. variabilis, while the dinoflagellate Peridinium inconspicuum and the cryptomonads increased in number and percentage of the total volume in the acidified basin. The total volume and the primary production measurements show an increase in Basin A compared to the control in the first year of acidification treatment (1991), but a decrease in the next year. 30 refs., 6 figs., 1 tab.

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

    PubMed

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

    2014-02-01

    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

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

    PubMed

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

    2014-02-01

    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.

  20. Species composition and assemblages of ichthyoplankton during summer in the East China Sea

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    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

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

    USGS Publications Warehouse

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

    1984-01-01

    An oligotrophic stream was continuously dosed for 1 yr at 2.5, 5 and 10 mu g l-1 CuT; c12, 25 and 50 ng l-1 Cu2+. 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 Lyngbya spp., a co-dominant during spring and summer. Population densities of Lyngbya spp. were markedly reduced at all Cu concentrations. Population densities of the principal Chlorophyta (Spirogyra spp., Cladophora spp.) and the diatom Amphipleura pellucida were reduced at 5 mu g l-1 CuT. Of the 22 most abundant taxa, 16 were reduced in abundance by continuous exposure to 10 mu g l-1 CuT. There was no commensurate reduction in standing crop. Achnanthes minutissima was the primary replacement species. Other taxa more abundant at 5 mu g l-1 CuT than in the control were Ceratoneis arcus, Cocconeis placentula, Navicula spp. and Synedra rumpens. Only A. minutissima and Calothrix spp. were more abundant at 10 mu g l-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 stream sections. The Canberra metric, an index sensitive to proportional rather than absolute differences, was the most informative. -from Authors

  3. Carotenoids in Rhodoplanes species: variation of compositions and substrate specificity of predicted carotenogenesis enzymes.

    PubMed

    Takaichi, Shinichi; Sasikala, Ch; Ramana, Ch V; Okamura, Keiko; Hiraishi, Akira

    2012-08-01

    Phototrophic bacteria necessarily contain carotenoids for photosynthesis, and accumulate unusual carotenoids in some cases. The carotenoids in all established species of Rhodoplanes (Rpl.), a representative of phototrophic genera, were identified using spectroscopic methods. The major carotenoid was spirilloxanthin in Rpl. roseus and Rpl. serenus, and rhodopin in "Rpl. cryptolactis". Rpl. elegans contained rhodopin, anhydrorhodovibrin, and spirilloxanthin. Rpl. pokkaliisoli contained not only rhodopin but also 1,1'-dihydroxylycopene and 3,4,3',4'-tetrahydrospirilloxanthin. These variations in carotenoid composition suggested that Rpl. roseus and Rpl. serenus had normal substrate specificity of the carotenogenesis enzymes of CrtC (acyclic carotene 1,2-hydratase), CrtD (acyclic carotenoid 3,4-desaturase), and CrtF (acyclic 1-hydroxycarotenoid methyltransferase). On the other hand, CrtC of Rpl. elegans, CrtD of "Rpl. cryptolactis", and CrtC, CrtD, and CrtF of Rpl. pokkaliisoli might have different characteristics from the usual activity of these normal enzymes in the normal spirilloxanthin pathway. These results suggest that the variation of carotenoids among the species of Rhodoplanes results from modified substrate specificity of the carotenogenesis enzymes involved.

  4. The Lake Huron pelagic fish community: persistent spatial pattern along biomass and species composition gradients

    USGS Publications Warehouse

    Warner, D.M.; Schaeffer, J.S.; O'Brien, T. P.

    2009-01-01

    Spatial patterns in the biomass of pelagic fish in Lake Huron have persisted over 10 years even though biomass decreased 86% and the fish community shifted from dominance by non-native species (rainbow smelt, Osmerus mordax) to dominance by native species (bloater, Coregonus hoyi). Based on multivariate analyses of acoustic biomass data and abiotic variables from the years 1997, 2004, 2005, and 2007, the strength of relationships between abiotic variables (primarily bottom depth) and fish community composition gradients decreased with fish biomass, suggesting that at high biomass, the influence of the measured abiotic variables is minimal. We observed consistently higher biomass in the North Channel and Georgian Bay than in the Main Basin, and as a result, we conclude that these smaller basins are likely important contributors to lakewide fish biomass, production, and dynamics. These results suggest that at current biomass levels, efforts to understand ecology, population dynamics, and lakewide abundance need to incorporate the effects of depth and geographic variation on fish distributions and ecology.

  5. The Ecuadorian Artisanal Fishery for Large Pelagics: Species Composition and Spatio-Temporal Dynamics.

    PubMed

    Martínez-Ortiz, Jimmy; Aires-da-Silva, Alexandre M; Lennert-Cody, Cleridy E; Maunder, Mark N

    2015-01-01

    The artisanal fisheries of Ecuador operate within one of the most dynamic and productive marine ecosystems of the world. This study investigates the catch composition of the Ecuadorian artisanal fishery for large pelagic fishes, including aspects of its spatio-temporal dynamics. The analyses of this study are based on the most extensive dataset available to date for this fishery: a total of 106,963 trip-landing inspection records collected at its five principal ports during 2008 ‒ 2012. Ecuadorian artisanal fisheries remove a substantial amount of biomass from the upper trophic-level predatory fish community of the eastern tropical Pacific Ocean. It is estimated that at least 135 thousand metric tons (mt) (about 15.5 million fish) were landed in the five principal ports during the study period. The great novelty of Ecuadorian artisanal fisheries is the "oceanic-artisanal" fleet component, which consists of mother-ship (nodriza) boats with their towed fiber-glass skiffs (fibras) operating with pelagic longlines. This fleet has fully expanded into oceanic waters as far offshore as 100°W, west of the Galapagos Archipelago. It is estimated that nodriza operations produce as much as 80% of the total catches of the artisanal fishery. The remainder is produced by independent fibras operating in inshore waters with pelagic longlines and/or surface gillnets. A multivariate regression tree analysis was used to investigate spatio-environmental effects on the nodriza fleet (n = 6,821 trips). The catch species composition of the nodriza fleet is strongly influenced by the northwesterly circulation of the Humboldt Current along the coast of Peru and its associated cold waters masses. The target species and longline gear-type used by nodrizas change seasonally with the incursion of cool waters (< 25°C) from the south and offshore. During this season, dolphinfish (Coryphaena hippurus) dominates the catches. However, in warmer waters, the fishery changes to tuna

  6. The Ecuadorian Artisanal Fishery for Large Pelagics: Species Composition and Spatio-Temporal Dynamics

    PubMed Central

    Martínez-Ortiz, Jimmy; Aires-da-Silva, Alexandre M.; Lennert-Cody, Cleridy E.; Maunder, Mark N.

    2015-01-01

    The artisanal fisheries of Ecuador operate within one of the most dynamic and productive marine ecosystems of the world. This study investigates the catch composition of the Ecuadorian artisanal fishery for large pelagic fishes, including aspects of its spatio-temporal dynamics. The analyses of this study are based on the most extensive dataset available to date for this fishery: a total of 106,963 trip-landing inspection records collected at its five principal ports during 2008 ‒ 2012. Ecuadorian artisanal fisheries remove a substantial amount of biomass from the upper trophic-level predatory fish community of the eastern tropical Pacific Ocean. It is estimated that at least 135 thousand metric tons (mt) (about 15.5 million fish) were landed in the five principal ports during the study period. The great novelty of Ecuadorian artisanal fisheries is the “oceanic-artisanal” fleet component, which consists of mother-ship (nodriza) boats with their towed fiber-glass skiffs (fibras) operating with pelagic longlines. This fleet has fully expanded into oceanic waters as far offshore as 100°W, west of the Galapagos Archipelago. It is estimated that nodriza operations produce as much as 80% of the total catches of the artisanal fishery. The remainder is produced by independent fibras operating in inshore waters with pelagic longlines and/or surface gillnets. A multivariate regression tree analysis was used to investigate spatio-environmental effects on the nodriza fleet (n = 6,821 trips). The catch species composition of the nodriza fleet is strongly influenced by the northwesterly circulation of the Humboldt Current along the coast of Peru and its associated cold waters masses. The target species and longline gear-type used by nodrizas change seasonally with the incursion of cool waters (< 25°C) from the south and offshore. During this season, dolphinfish (Coryphaena hippurus) dominates the catches. However, in warmer waters, the fishery changes to tuna

  7. The Ecuadorian Artisanal Fishery for Large Pelagics: Species Composition and Spatio-Temporal Dynamics.

    PubMed

    Martínez-Ortiz, Jimmy; Aires-da-Silva, Alexandre M; Lennert-Cody, Cleridy E; Maunder, Mark N

    2015-01-01

    The artisanal fisheries of Ecuador operate within one of the most dynamic and productive marine ecosystems of the world. This study investigates the catch composition of the Ecuadorian artisanal fishery for large pelagic fishes, including aspects of its spatio-temporal dynamics. The analyses of this study are based on the most extensive dataset available to date for this fishery: a total of 106,963 trip-landing inspection records collected at its five principal ports during 2008 ‒ 2012. Ecuadorian artisanal fisheries remove a substantial amount of biomass from the upper trophic-level predatory fish community of the eastern tropical Pacific Ocean. It is estimated that at least 135 thousand metric tons (mt) (about 15.5 million fish) were landed in the five principal ports during the study period. The great novelty of Ecuadorian artisanal fisheries is the "oceanic-artisanal" fleet component, which consists of mother-ship (nodriza) boats with their towed fiber-glass skiffs (fibras) operating with pelagic longlines. This fleet has fully expanded into oceanic waters as far offshore as 100°W, west of the Galapagos Archipelago. It is estimated that nodriza operations produce as much as 80% of the total catches of the artisanal fishery. The remainder is produced by independent fibras operating in inshore waters with pelagic longlines and/or surface gillnets. A multivariate regression tree analysis was used to investigate spatio-environmental effects on the nodriza fleet (n = 6,821 trips). The catch species composition of the nodriza fleet is strongly influenced by the northwesterly circulation of the Humboldt Current along the coast of Peru and its associated cold waters masses. The target species and longline gear-type used by nodrizas change seasonally with the incursion of cool waters (< 25°C) from the south and offshore. During this season, dolphinfish (Coryphaena hippurus) dominates the catches. However, in warmer waters, the fishery changes to tuna

  8. Fish composition and species richness in eastern South American coastal lagoons: additional support for the freshwater ecoregions of the world.

    PubMed

    Petry, A C; Guimarães, T F R; Vasconcellos, F M; Hartz, S M; Becker, F G; Rosa, R S; Goyenola, G; Caramaschi, E P; Díaz de Astarloa, J M; Sarmento-Soares, L M; Vieira, J P; Garcia, A M; Teixeira de Mello, F; de Melo, F A G; Meerhoff, M; Attayde, J L; Menezes, R F; Mazzeo, N; Di Dario, F

    2016-07-01

    The relationships between fish composition, connectivity and morphometry of 103 lagoons in nine freshwater ecoregions (FEOW) between 2·83° S and 37·64° S were evaluated in order to detect possible congruence between the gradient of species richness and similarities of assemblage composition. Most lagoons included in the study were <2 km(2) , with a maximum of 3975 km(2) in surface area. Combined surface area of all lagoons included in the study was 5411 km(2) . Number of species varied locally from one to 76. A multiple regression revealed that latitude, attributes of morphometry and connectivity, and sampling effort explained a large amount of variability in species richness. Lagoon area was a good predictor of species richness except in low latitude ecoregions, where lagoons are typically small-sized and not affected by marine immigrants, and where non-native fish species accounted for a significant portion of species richness. Relationships between species and area in small-sized lagoons (<2 km(2) ) is highly similar to the expected number in each ecoregion, with systems located between 18·27° S and 30·15° S attaining higher levels of species richness. Similarities in species composition within the primary, secondary and peripheral or marine divisions revealed strong continental biogeographic patterns only for species less tolerant or intolerant to salinity. Further support for the FEOW scheme in the eastern border of South America is therefore provided, and now includes ecotonal systems inhabited simultaneously by freshwater and marine species of fishes. PMID:27401481

  9. Fish composition and species richness in eastern South American coastal lagoons: additional support for the freshwater ecoregions of the world.

    PubMed

    Petry, A C; Guimarães, T F R; Vasconcellos, F M; Hartz, S M; Becker, F G; Rosa, R S; Goyenola, G; Caramaschi, E P; Díaz de Astarloa, J M; Sarmento-Soares, L M; Vieira, J P; Garcia, A M; Teixeira de Mello, F; de Melo, F A G; Meerhoff, M; Attayde, J L; Menezes, R F; Mazzeo, N; Di Dario, F

    2016-07-01

    The relationships between fish composition, connectivity and morphometry of 103 lagoons in nine freshwater ecoregions (FEOW) between 2·83° S and 37·64° S were evaluated in order to detect possible congruence between the gradient of species richness and similarities of assemblage composition. Most lagoons included in the study were <2 km(2) , with a maximum of 3975 km(2) in surface area. Combined surface area of all lagoons included in the study was 5411 km(2) . Number of species varied locally from one to 76. A multiple regression revealed that latitude, attributes of morphometry and connectivity, and sampling effort explained a large amount of variability in species richness. Lagoon area was a good predictor of species richness except in low latitude ecoregions, where lagoons are typically small-sized and not affected by marine immigrants, and where non-native fish species accounted for a significant portion of species richness. Relationships between species and area in small-sized lagoons (<2 km(2) ) is highly similar to the expected number in each ecoregion, with systems located between 18·27° S and 30·15° S attaining higher levels of species richness. Similarities in species composition within the primary, secondary and peripheral or marine divisions revealed strong continental biogeographic patterns only for species less tolerant or intolerant to salinity. Further support for the FEOW scheme in the eastern border of South America is therefore provided, and now includes ecotonal systems inhabited simultaneously by freshwater and marine species of fishes.

  10. Monitoring of Water Quality and Microalgae Species Composition of Penaeus monodon Ponds in Pulau Pinang, Malaysia

    PubMed Central

    Shaari, Asma Liyana; Surif, Misni; Latiff, Faazaz Abd.; Omar, Wan Maznah Wan; Ahmad, Mohd Noor

    2011-01-01

    Many reports have revealed that the abundance of microalgae in shrimp ponds vary with changes in environmental factors such as light, temperature, pH, salinity and nutrient level throughout a shrimp culture period. In this study, shrimp cultivation period was divided into three stages (initial = week 0–5, mid = week 6–10 and final = week 11–15). Physical and chemical parameters throughout the cultivation period were studied and species composition of microalgae was monitored. Physical parameters were found to fluctuate widely with light intensity ranging between 182.23–1278 μmol photon m−2s−1, temperature between 29.56°C −31.59°C, dissolved oxygen (DO) between 4.56–8.21 mg/l, pH between 7.65–8.49 and salinity between 20‰–30‰. Ammonium (NH4+-N), nitrite (NO2−-N), nitrate (NO3−-N), and orthophosphate (PO43−-P) concentrations in the pond at all cultivation stages ranged from 0.017 to 0.38 mg/l, 0.24 to 2.12 mg/l, 0.06 to 0.98 mg/l and 0.16 to 1.93 mg/l respectively. Statistical test (ANOVA) showed that there were no significant difference (p<0.05) in nutrients concentrations among the cultivation stages. All nutrients concentrations however were still in the tolerable level and safe for shrimp culture. The chlorophyll a contents were found to range from 5.03±2.17 to 32.61±0.35 μg/l throughout the cultivation period. A total of 19 microalgae species were found in the shrimp pond, with diatoms contributing up to 72% of the species followed by Chlorophyta (11%) and Cyanophyta (11%). However, weekly species abundance varied through the study period. At the initial stage, when there were no shrimps in the pond, Anabaena spp. and Oscillatoria spp. (Cyanophyta) were the dominant species, followed by Chlorella sp. and Dunaliella sp. (Chlorophyta). When shrimps were introduced into the pond, Amphora sp., Navicula sp. Gyrosigma sp. and Nitzschia sp. (diatoms) started to exist. At the middle and towards the final stage of the shrimp culture

  11. Alaska Library Directory, 1996.

    ERIC Educational Resources Information Center

    Jennings, Mary, Ed.

    This directory of Alaska's Libraries lists: members of the Alaska Library Association (AkLA) Executive Council and Committee Chairs; State Board of Education members; members of the Governor's Advisory Council on Libraries; school, academic and public libraries and their addresses, phone and fax numbers, and contact persons; personal,…

  12. Renewable Energy in Alaska

    SciTech Connect

    Not Available

    2013-03-01

    This report examines the opportunities, challenges, and costs associated with renewable energy implementation in Alaska and provides strategies that position Alaska's accumulating knowledge in renewable energy development for export to the rapidly growing energy/electric markets of the developing world.

  13. Alaska geothermal bibliography

    SciTech Connect

    Liss, S.A.; Motyka, R.J.; Nye, C.J.

    1987-05-01

    The Alaska geothermal bibliography lists all publications, through 1986, that discuss any facet of geothermal energy in Alaska. In addition, selected publications about geology, geophysics, hydrology, volcanology, etc., which discuss areas where geothermal resources are located are included, though the geothermal resource itself may not be mentioned. The bibliography contains 748 entries.

  14. Fatty acid composition of wild mushroom species of order Agaricales--examination by gas chromatography-mass spectrometry and chemometrics.

    PubMed

    Marekov, Ilko; Momchilova, Svetlana; Grung, Bjørn; Nikolova-Damyanova, Boryana

    2012-12-01

    Applying gas chromatography-mass spectrometry of 4,4-dimethyloxazoline fatty acid derivatives, the fatty acid composition of 15 mushroom species belonging to 9 genera and 5 families of order Agaricales growing in Bulgaria is determined. The structure of 31 fatty acids (not all present in each species) is unambiguously elucidated, with linoleic, oleic and palmitic acids being the main components (ranging between 70.9% (Marasmius oreades) and 91.2% (Endoptychum agaricoides)). A group of three hexadecenoic positionally isomeric fatty acids, 6-, 9- and 11-16:1, appeared to be characteristic components of the examined species. By applying chemometrics it was possible to show that the fatty acid composition closely reflects the classification of the species.

  15. 1964 Great Alaska Earthquake: a photographic tour of Anchorage, Alaska

    USGS Publications Warehouse

    Thoms, Evan E.; Haeussler, Peter J.; Anderson, Rebecca D.; McGimsey, Robert G.

    2014-01-01

    On March 27, 1964, at 5:36 p.m., a magnitude 9.2 earthquake, the largest recorded earthquake in U.S. history, struck southcentral Alaska (fig. 1). The Great Alaska Earthquake (also known as the Good Friday Earthquake) occurred at a pivotal time in the history of earth science, and helped lead to the acceptance of plate tectonic theory (Cox, 1973; Brocher and others, 2014). All large subduction zone earthquakes are understood through insights learned from the 1964 event, and observations and interpretations of the earthquake have influenced the design of infrastructure and seismic monitoring systems now in place. The earthquake caused extensive damage across the State, and triggered local tsunamis that devastated the Alaskan towns of Whittier, Valdez, and Seward. In Anchorage, the main cause of damage was ground shaking, which lasted approximately 4.5 minutes. Many buildings could not withstand this motion and were damaged or collapsed even though their foundations remained intact. More significantly, ground shaking triggered a number of landslides along coastal and drainage valley bluffs underlain by the Bootlegger Cove Formation, a composite of facies containing variably mixed gravel, sand, silt, and clay which were deposited over much of upper Cook Inlet during the Late Pleistocene (Ulery and others, 1983). Cyclic (or strain) softening of the more sensitive clay facies caused overlying blocks of soil to slide sideways along surfaces dipping by only a few degrees. This guide is the document version of an interactive web map that was created as part of the commemoration events for the 50th anniversary of the 1964 Great Alaska Earthquake. It is accessible at the U.S. Geological Survey (USGS) Alaska Science Center website: http://alaska.usgs.gov/announcements/news/1964Earthquake/. The website features a map display with suggested tour stops in Anchorage, historical photographs taken shortly after the earthquake, repeat photography of selected sites, scanned documents

  16. Effects of tree species richness and composition on moose winter browsing damage and foraging selectivity: an experimental study.

    PubMed

    Milligan, Harriet T; Koricheva, Julia

    2013-07-01

    The optimal foraging theory, the nutrient balance hypothesis, and the plant association theories predict that foraging decisions and resulting tree damage by large mammalian browsers may be influenced by the species richness and species composition of forest stands. This may lead to either associational susceptibility (increased damage on a focal plant in a mixed stand) or associational resistance (reduced damage in a mixed stand). Better understanding of the mechanisms and the relative importance of tree species richness and composition effects on foraging by mammalian browsers is needed to support sustainable management of forests and mammal populations. However, existing knowledge of forest diversity effects on foraging by large mammalian browsers comes largely from observational studies while experimental evidence is limited. We analysed winter browsing by moose (Alces alces L.) in a long-term, large-scale experiment in Finland, which represents a tree species richness gradient from monocultures to 2-, 3- and 5-species mixtures composed of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L.), Siberian larch (Larix sibirica Ledeb.), silver birch (Betula pendula Roth.) and black alder (Alnus glutinosa L.). The intensity of browsing per plot increased with tree species richness while browsing selectivity decreased with tree species being targeted more equally in species-rich mixtures. Tree species composition of a plot was also an important determinant of intensity of browsing. The greatest browsing occurred in plots containing preferred species (pine and birch) while intermediate preference species (larch and alder) experienced associational susceptibility when growing with pine and birch compared with their monocultures or mixtures without pine and birch. In contrast, we found no evidence of associational resistance; the presence of a least preferred species (spruce) in a mixture had no significant effect on moose browsing on other tree species. We

  17. Effects of tree species richness and composition on moose winter browsing damage and foraging selectivity: an experimental study.

    PubMed

    Milligan, Harriet T; Koricheva, Julia

    2013-07-01

    The optimal foraging theory, the nutrient balance hypothesis, and the plant association theories predict that foraging decisions and resulting tree damage by large mammalian browsers may be influenced by the species richness and species composition of forest stands. This may lead to either associational susceptibility (increased damage on a focal plant in a mixed stand) or associational resistance (reduced damage in a mixed stand). Better understanding of the mechanisms and the relative importance of tree species richness and composition effects on foraging by mammalian browsers is needed to support sustainable management of forests and mammal populations. However, existing knowledge of forest diversity effects on foraging by large mammalian browsers comes largely from observational studies while experimental evidence is limited. We analysed winter browsing by moose (Alces alces L.) in a long-term, large-scale experiment in Finland, which represents a tree species richness gradient from monocultures to 2-, 3- and 5-species mixtures composed of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L.), Siberian larch (Larix sibirica Ledeb.), silver birch (Betula pendula Roth.) and black alder (Alnus glutinosa L.). The intensity of browsing per plot increased with tree species richness while browsing selectivity decreased with tree species being targeted more equally in species-rich mixtures. Tree species composition of a plot was also an important determinant of intensity of browsing. The greatest browsing occurred in plots containing preferred species (pine and birch) while intermediate preference species (larch and alder) experienced associational susceptibility when growing with pine and birch compared with their monocultures or mixtures without pine and birch. In contrast, we found no evidence of associational resistance; the presence of a least preferred species (spruce) in a mixture had no significant effect on moose browsing on other tree species. We

  18. Extraction Pattern of Arsenic Species with Mineral Composition in Contaminated Soils in Korea

    NASA Astrophysics Data System (ADS)

    Park, M.; Shin, M.; Yoon, H.; Kim, Y.; Kim, K.; Ko, I.

    2006-12-01

    Specific determination of various arsenic species is gaining increasing attention because the toxicity of arsenic differs with chemical forms such as organic (MMA, DMA) or inorganic (arsenite, arsenate). Knowledge of extraction method for arsenic speciation in contaminated soils then notified and tested by many researchers. However, the analytical technique for separation of different arsenic species has been always challenging in different environmental samples. A achieving correct analytical results and resolving the lowest detection limit is also desirable. Extraction method for arsenic speciation have been studied by many researchers with the use of a variety of extractants such as H3PO4, HCl, Na2CO3, EDTA 'in soils and sediments including plenty of clay. We, in this study, reported a benign extraction method and presented the pattern of arsenic in contaminated soils of different mineral compositions. Soil samples were collected from tailings of 2 places (Kyungbuk, Jeonnam); both were from abandoned metal mines in Korea. Samples were air dried at room temperature and separated by mechanical sieving to three fractions (2mm_200 μm, 200_64μm, <64μm). Prepared samples were examined for total arsenic analysis used by KBSI method and modified Garcia-Manyes method for arsenic speciation. We extracted arsenic species from the soils by using a mixture of 1M phosphoric acid and 0.1% ascorbic acid. 0.2g of sample was placed in microwave digestion vessels along with 10ml extraction solution and treated for 15min at 60w microwave power. After the microwave stage, the contents were transferred to 30ml sample bottles and diluted to 16ml with deionized water, then centrifuged for 15min at 2500rpm. Total arsenic concentration of sample was analyzed by using ICP-AES (ICP-OES, Ultima2C, Jobin Yvon) and the arsenic species were analyzed by hyphenated system, SPE-HG-ICP-AES. To identify the mineral phases in bulk soil samples, we used XRD (Phillips X'Pert MPD) under 40kV/30m

  19. Phytochemical Composition, Antioxidant Activity and HPLC Fingerprinting Profiles of Three Pyrola Species from Different Regions

    PubMed Central

    Wang, Dongmei; He, Fengyuan; Lv, Zhenjiang; Li, Dengwu

    2014-01-01

    The present study was performed to investigate the variation of phytochemical composition, antioxidant activity and High Performance Liquid Chromatography (HPLC) fingerprinting profiles of three Pyrola species. Thirteen samples (eight P. decorata, three P. calliantha and two P. renifolia) were collected from different regions in China. The tannin, hyperoside and quercetin contents of all samples were determined by reverse-phase HPLC and varied within the range 9.77–34.75, 0.34–2.16 and 0.062–0.147 mg/g dry weigh, respectively. Total flavonoid content was evaluated and varied within the range 16.22–37.82 mg/g dry weight. Antioxidant activity was determined by DPPH assay, with IC50 ranging from 7.96 to 50.33 µg/ml, ABTS•+ and FRAP assay, within the range 612.66–1021.05 and 219.64–398.12 µmol equiv. Trolox/g, respectively. These results revealed that there were significant variations in phytochemical profiles and antioxidant activity among all samples. Due to the higher phytochemical content and significant antioxidant activity, P. calliantha was selected as the most valuable species, and the P. calliantha sample from Left banner of Alxa even possessed the strongest antioxidant activity among all the thirteen samples. Futhermore, Emei Mountain was proved to be the most suitable region for producing P. decorata. Moreover, in order to further evaluate the diversities and quality of Pyrola, HPLC fingerprint analysis coupled with hierarchical cluster and discrimination analyses were introduced to establish a simple, rapid and effective method for accurate identification, classification and quality assessment of Pyrola. Thirteen samples were divided into three groups consistent with their morphological classification. Two types of discriminant functions were generated and the ratio of discrimination was 100%. This method can identify different species of Pyrola and the same species from different regions of origin. Also, it can be used to compare and

  20. Geochemistry and flooding as determining factors of plant species composition in Dutch winter-flooded riverine grasslands.

    PubMed

    Beumer, Victor; van Wirdum, Geert; Beltman, Boudewijn; Griffioen, Jasper; Grootjans, Ab P; Verhoeven, Jos T A

    2008-08-25

    Dutch water policy aims for more frequent, controlled flooding of river valley floodplains to avoid unwanted flooding elsewhere; in anticipation of increased flooding risks resulting from climate changes. Controlled flooding usually takes place in winter in parts of the valleys which had not been subject to flooding in the last decades. It may thus affect existing nature with its conservation values. The goal of this study was to clarify the geochemical and hydrological factors determining plant species composition of winter-flooded river valley grasslands. A correlative study was carried out in 43 sites in 13 Dutch river valley floodplains, with measurements of flooding regime, vegetation composition, soil nutrients and soil pH status. With the use of canonical correspondence analysis (CCA) the plant species composition was investigated in relation to the geochemical variables and the winter winter-flooding regime. We found that the distributions of target species and non-target species were clearly correlated with geochemical characteristics and flooding regime. Clustering of sites within the CCA plots has led us to distinguish between four types of winter flooding in our areas: floodplains with (a) accumulating rain water, (b) low groundwater levels flooded with river water, (c) discharging groundwater and (d) high groundwater levels flooded with river water. Our major conclusions are (1) the winter groundwater level of winter-flooded grasslands was important for evaluating the effects of winter flooding on the geochemistry and plant species composition, and (2) winter winter-flooding effects were largely determined by the nature of the flooding. A high frequency of flooding particularly favoured a small set of common plant species. In areas with groundwater seepage, winter flooding may provide geochemical conditions suitable for diverse vegetation types with rare species. Rainwater flooded sites appeared less suitable for most target species.

  1. Geochemistry and flooding as determining factors of plant species composition in Dutch winter-flooded riverine grasslands.

    PubMed

    Beumer, Victor; van Wirdum, Geert; Beltman, Boudewijn; Griffioen, Jasper; Grootjans, Ab P; Verhoeven, Jos T A

    2008-08-25

    Dutch water policy aims for more frequent, controlled flooding of river valley floodplains to avoid unwanted flooding elsewhere; in anticipation of increased flooding risks resulting from climate changes. Controlled flooding usually takes place in winter in parts of the valleys which had not been subject to flooding in the last decades. It may thus affect existing nature with its conservation values. The goal of this study was to clarify the geochemical and hydrological factors determining plant species composition of winter-flooded river valley grasslands. A correlative study was carried out in 43 sites in 13 Dutch river valley floodplains, with measurements of flooding regime, vegetation composition, soil nutrients and soil pH status. With the use of canonical correspondence analysis (CCA) the plant species composition was investigated in relation to the geochemical variables and the winter winter-flooding regime. We found that the distributions of target species and non-target species were clearly correlated with geochemical characteristics and flooding regime. Clustering of sites within the CCA plots has led us to distinguish between four types of winter flooding in our areas: floodplains with (a) accumulating rain water, (b) low groundwater levels flooded with river water, (c) discharging groundwater and (d) high groundwater levels flooded with river water. Our major conclusions are (1) the winter groundwater level of winter-flooded grasslands was important for evaluating the effects of winter flooding on the geochemistry and plant species composition, and (2) winter winter-flooding effects were largely determined by the nature of the flooding. A high frequency of flooding particularly favoured a small set of common plant species. In areas with groundwater seepage, winter flooding may provide geochemical conditions suitable for diverse vegetation types with rare species. Rainwater flooded sites appeared less suitable for most target species. PMID:18514261

  2. Soil-occupancy effects of invasive and native grassland plant species on composition and diversity of mycorrhizal associations

    USGS Publications Warehouse

    Jordan, Nicholas R.; Aldrich-Wolfe, Laura; Huerd, Sheri C.; Larson, Diane L.; Muehlbauer, Gary

    2012-01-01

    Diversified grasslands that contain native plant species can produce biofuels, support sustainable grazing systems, and produce other ecosystem services. However, ecosystem service production can be disrupted by invasion of exotic perennial plants, and these plants can have soil-microbial “legacies” that may interfere with establishment and maintenance of diversified grasslands even after effective management of the invasive species. The nature of such legacies is not well understood, but may involve suppression of mutualisms between native species and soil microbes. In this study, we tested the hypotheses that legacy effects of invasive species change colonization rates, diversity, and composition of arbuscular-mycorrhizal fungi (AMF) associated with seedlings of co-occurring invasive and native grassland species. In a glasshouse, experimental soils were conditioned by cultivating three invasive grassland perennials, three native grassland perennials, and a native perennial mixture. Each was grown separately through three cycles of growth, after which we used T-RFLP analysis to characterize AMF associations of seedlings of six native perennial and six invasive perennial species grown in these soils. Legacy effects of soil conditioning by invasive species did not affect AMF richness in seedling roots, but did affect AMF colonization rates and the taxonomic composition of mycorrhizal associations in seedling roots. Moreover, native species were more heavily colonized by AMF and roots of native species had greater AMF richness (number of AMF operational taxonomic units per seedling) than did invasive species. The invasive species used to condition soil in this experiment have been shown to have legacy effects on biomass of native seedlings, reducing their growth in this and a previous similar experiment. Therefore, our results suggest that successful plant invaders can have legacies that affect soil-microbial associations of native plants and that these effects

  3. Composition of headspace volatiles and essential oils of three Thymus species.

    PubMed

    Stojanović, Gordana; Jovanović, Olga; Petrović, Goran; Mitić, Violeta; Jovanović, Vesna Stankov; Jovanović, Snežana

    2014-11-01

    Analysis of head space volatiles (HSV) and hydrodistilled essential oils (EO) of the above-ground parts of Thymus glabrescens Willd., T. praecox Opiz subsp. jankae (Celak.) Jalas (from two localities) and T. pulegoides L. was made by GC-FID and GC-MS. This is the first report on the headspace volatiles composition of T. glabrescens and T. pulegoides. The most abundant compound of T. glabrescens HSV was p-cymene (27.8%) followed by γ-terpinene (18.4%), while thymol (55.4%) and geraniol (10.5%) were the most abundant in the corresponding EO. T. praecox subsp. jankae EO from Serbia was characterized by (E)-caryophyllene (14.6%) and thymol (10.7%), which is substantially different from that of Bulgarian T. praecox subsp. jankae, which contained a-terpinyl acetate (20.1%) and linalool (17.7%) as its main components. The dominating components of the Serbian and Bulgarian T. praecox subsp. jankae HSV were α-pinene (29.4% and 18.6%, respectively), myrcene (12.1% and 23.2%, respectively), limonene (7.5% and 17.8%, respectively) and β-pinene (11.7% and 7.6%, respectively). Linalyl acetate predominated in T. pulegoides EO and HSV, representing 40.0% and 42.4% (respectively) of the total peak area. The chemical composition of the essential oils of the examined Thymus species could not be attributed to any particular recorded chemotype of T. glabrescens, T. praecox and T. pulegoides. PMID:25532293

  4. VIP Barcoding: composition vector-based software for rapid species identification based on DNA barcoding.

    PubMed

    Fan, Long; Hui, Jerome H L; Yu, Zu Guo; Chu, Ka Hou

    2014-07-01

    Species identification based on short sequences of DNA markers, that is, DNA barcoding, has emerged as an integral part of modern taxonomy. However, software for the analysis of large and multilocus barcoding data sets is scarce. The Basic Local Alignment Search Tool (BLAST) is currently the fastest tool capable of handling large databases (e.g. >5000 sequences), but its accuracy is a concern and has been criticized for its local optimization. However, current more accurate software requires sequence alignment or complex calculations, which are time-consuming when dealing with large data sets during data preprocessing or during the search stage. Therefore, it is imperative to develop a practical program for both accurate and scalable species identification for DNA barcoding. In this context, we present VIP Barcoding: a user-friendly software in graphical user interface for rapid DNA barcoding. It adopts a hybrid, two-stage algorithm. First, an alignment-free composition vector (CV) method is utilized to reduce searching space by screening a reference database. The alignment-based K2P distance nearest-neighbour method is then employed to analyse the smaller data set generated in the first stage. In comparison with other software, we demonstrate that VIP Barcoding has (i) higher accuracy than Blastn and several alignment-free methods and (ii) higher scalability than alignment-based distance methods and character-based methods. These results suggest that this platform is able to deal with both large-scale and multilocus barcoding data with accuracy and can contribute to DNA barcoding for modern taxonomy. VIP Barcoding is free and available at http://msl.sls.cuhk.edu.hk/vipbarcoding/.

  5. Chemical Composition and Biological Activity of Essential Oils from Different Species of Piper from Panama.

    PubMed

    Santana, Ana I; Vila, Roser; Cañigueral, Salvador; Gupta, Mahabir P

    2016-07-01

    The chemical composition of leaf essential oils from 11 species of Piper from Panama was analyzed by a combination GC-FID and GC-MS procedures. Six of them had sesquiterpene hydrocarbons as major constituents, three were characterized by monoterpene hydrocarbons, one by a diterpene, and one by a phenylpropanoid, dillapiole. The main components identified in each species were: cembratrienol (25.4 %) in Piper augustum; β-pinene (26.6 %) in Piper corrugatum; α-pinene (19.4 %) in Piper curtispicum; trans-β-farnesene (63.7 %) in Piper darienense; p-cymene (43.9 %) in Piper grande; dillapiole (57.7 %) in Piper hispidum; linalool (14.5 %), α-phellandrene (13.8 %), and limonene (12.2 %) in Piper jacquemontianum; β-caryophyllene (45.2 %) in Piper longispicum; linalool (16.5 %), α-phellandrene (11.8 %), limonene (11.4 %), and p-cymene (9.0 %) in Piper multiplinervium; β-selinene (19.0 %), β-elemene (16.1 %), and α-selinene (15.5 %) in Piper reticulatum; and germacrene D (19.7 %) in Piper trigonum. The essential oils of P. hispidum and P. longispicum at a concentration of 250 µg/mL showed larvicidal activity against Aedes aegypti, while the oils from P. curtispicum, P. multiplinervium, P. reticulatum, and P. trigonum were inactive (LC100 ≥ 500 µg/mL). The essential oils of P. grande, P. jacquemontianum, and P. multiplinervium showed no significant antifungal activity (MIC > 250 µg/mL) against several yeasts and filamentous fungal strains.

  6. Chemical Composition and Biological Activity of Essential Oils from Different Species of Piper from Panama.

    PubMed

    Santana, Ana I; Vila, Roser; Cañigueral, Salvador; Gupta, Mahabir P

    2016-07-01

    The chemical composition of leaf essential oils from 11 species of Piper from Panama was analyzed by a combination GC-FID and GC-MS procedures. Six of them had sesquiterpene hydrocarbons as major constituents, three were characterized by monoterpene hydrocarbons, one by a diterpene, and one by a phenylpropanoid, dillapiole. The main components identified in each species were: cembratrienol (25.4 %) in Piper augustum; β-pinene (26.6 %) in Piper corrugatum; α-pinene (19.4 %) in Piper curtispicum; trans-β-farnesene (63.7 %) in Piper darienense; p-cymene (43.9 %) in Piper grande; dillapiole (57.7 %) in Piper hispidum; linalool (14.5 %), α-phellandrene (13.8 %), and limonene (12.2 %) in Piper jacquemontianum; β-caryophyllene (45.2 %) in Piper longispicum; linalool (16.5 %), α-phellandrene (11.8 %), limonene (11.4 %), and p-cymene (9.0 %) in Piper multiplinervium; β-selinene (19.0 %), β-elemene (16.1 %), and α-selinene (15.5 %) in Piper reticulatum; and germacrene D (19.7 %) in Piper trigonum. The essential oils of P. hispidum and P. longispicum at a concentration of 250 µg/mL showed larvicidal activity against Aedes aegypti, while the oils from P. curtispicum, P. multiplinervium, P. reticulatum, and P. trigonum were inactive (LC100 ≥ 500 µg/mL). The essential oils of P. grande, P. jacquemontianum, and P. multiplinervium showed no significant antifungal activity (MIC > 250 µg/mL) against several yeasts and filamentous fungal strains. PMID:27286333

  7. Resilience of Alaska's Boreal Forest to Climatic Change

    NASA Technical Reports Server (NTRS)

    Chapin, F. S., III; McGuire, A. D.; Ruess, R. W.; Hollingsworth, T. N.; Mack, M. C.; Johnstone, J. F.; Kasischke, E. S.; Euskirchen, E. S.; Jones, J. B.; Jorgenson, M. T.; Kielland, K.; Kofinas, G. P.; Turetsky, M. R.; Yarie, J.; Lloyd, A. H.; Taylor, D. L.

    2010-01-01

    This paper assesses the resilience of Alaska s boreal forest system to rapid climatic change. Recent warming is associated with reduced growth of dominant tree species, plant disease and insect outbreaks, warming and thawing of permafrost, drying of lakes, increased wildfire extent, increased postfire recruitment of deciduous trees, and reduced safety of hunters traveling on river ice. These changes have modified key structural features, feedbacks, and interactions in the boreal forest, including reduced effects of upland permafrost on regional hydrology, expansion of boreal forest into tundra, and amplification of climate warming because of reduced albedo (shorter winter season) and carbon release from wildfires. Other temperature-sensitive processes for which no trends have been detected include composition of plant and microbial communities, long-term landscape-scale change in carbon stocks, stream discharge, mammalian population dynamics, and river access and subsistence opportunities for rural indigenous communities. Projections of continued warming suggest that Alaska s boreal forest will undergo significant functional and structural changes within the next few decades that are unprecedented in the last 6000 years. The impact of these social ecological changes will depend in part on the extent of landscape reorganization between uplands and lowlands and on policies regulating subsistence opportunities for rural communities.

  8. Malaspina Glacier, Alaska

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite covers an area of 55 by 40 kilometers (34 by 25 miles) over the southwest part of the Malaspina Glacier and Icy Bay in Alaska. The composite of infrared and visible bands results in the snow and ice appearing light blue, dense vegetation is yellow-orange and green, and less vegetated, gravelly areas are in orange. According to Dr. Dennis Trabant (U.S. Geological Survey, Fairbanks, Alaska), the Malaspina Glacier is thinning. Its terminal moraine protects it from contact with the open ocean; without the moraine, or if sea level rises sufficiently to reconnect the glacier with the ocean, the glacier would start calving and retreat significantly. ASTER data are being used to help monitor the size and movement of some 15,000 tidal and piedmont glaciers in Alaska. Evidence derived from ASTER and many other satellite and ground-based measurements suggests that only a few dozen Alaskan glaciers are advancing. The overwhelming majority of them are retreating.

    This ASTER image was acquired on June 8, 2001. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next six years to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18,1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. science team leader; Bjorn Eng of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The Terra mission is part of NASA's Earth Science Enterprise, along-term research and

  9. Nonlinear and threshold responses of grassland productivity and species composition to increased CO2 vary with soil type

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate change is likely to cause non-linear responses in ecosystem function and threshold changes in species composition. Here we report aboveground net primary productivity (ANPP) responses to a continuous CO2 concentration gradient (250 to 500 µL L-1) in experimental grassland communities on...

  10. Nitrogen addition and harvest frequency rather than initial plant species composition determine vertical structure and light interception in grasslands.

    PubMed

    Petersen, Ute; Isselstein, Johannes

    2015-01-01

    In biodiversity experiments based on seeded experimental communities, species richness and species composition exert a strong influence on canopy structure and can lead to an improved use of aboveground resources. In this study, we want to explore whether these findings are applicable to agriculturally managed permanent grassland. Vertical layered profiles of biomass, leaf area (LA) and light intensity were measured in a removal-type biodiversity experiment (GrassMan) to compare the canopy structure in grassland vegetation of different plant species composition (called sward types). Additionally, the altered sward types were subjected to four different management regimes by a combination of the factors fertilization (unfertilized, NPK fertilized) and cutting frequency (one late cut or three cuts). In spite of large compositional differences (ratio grasses : non-leguminous forbs : leguminous forbs ranging from 93 : 7 : 0 to 39 : 52 : 9), the vegetation of the same management regime hardly differed in its canopy structure, whereas the different management regimes led to distinct vertical profiles in the vegetation. However, the allocation of biomass in response to cutting and fertilization differed among the sward types. Vegetation dominated by grasses was denser and had more LA when fertilized compared with vegetation rich in dicots which merely grew taller. In functionally more diverse vegetation, light interception was not increased compared with vegetation consisting of more than 90 % of grasses in terms of biomass. Management had a much stronger influence on structure and light interception than plant species composition in this grassland experiment. PMID:26199402

  11. Composition and toxigenic potential of the Fusarium graminearum species complex from maize ears, stalks and stubble in Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Detailed knowledge of the composition and toxigenic potential of the Fusarium graminearum species complex affecting maize crops in Brazil is lacking. A multilocus genotype approach was used to identify 539 isolates from three sub-collections: 1) maize kernels (n= 110) from five states spanning sout...

  12. Essential oil composition and preliminary molecular study of four Hungarian Thymus species.

    PubMed

    Pluhár, Zsuzsanna; Kocsis, Marianna; Kuczmog, Anett; Csete, S; Simkó, Hella; Sárosi, Szilvia; Molnár, P; Horváth, Györgyi

    2012-03-01

    Chemical and genetic differences of twenty taxa belonging to four Thymus species were studied in order to determine whether molecular characters and essential oil components could be used as taxonomic markers and to examine the correlation between them. Plant samples, representing different taxa and geographic regions, were collected from experimentally grown populations. Essential oil samples were analysed by GC/MS and cluster analysis of volatile composition resulted in segregation of thymol chemotypes from sesquiterpenic ones. Thymol was characteristic for all the populations of Thymus glabrescens and T. pannonicus as well as for certain taxa belonging to T. praecox and T. pulegioides. Sesquiterpenes occurred in only two taxa of T. glabrescens, in each sample of T. praecox and in three taxa of T. pulegioides. Plant samples were analysed by random amplified polymorphic DNA (RAPD). The obtained dendrogram revealed high gene diversity. The 13 primers resulted 114 polymorphic RAPD bands, and the average percentage of polymorphism was 80.8%. The RAPD dendogram showed separation neither at interspecific nor at interpopulational levels. Therefore, further specific molecular studies involving more taxa are suggested. Partial correlation have been found between molecular and chemical assessments. PMID:22453802

  13. Chemical composition and antifungal activity of the essential oil of Origanum virens on Candida species.

    PubMed

    Salgueiro, L R; Cavaleiro, C; Pinto, E; Pina-Vaz, C; Rodrigues, A G; Palmeira, A; Tavares, C; Costa-de-Oliveira, S; Gonçalves, M J; Martinez-de-Oliveira, J

    2003-09-01

    The composition and the antifungal activity of the essential oil of Origanum virens on Candida species were studied. The essential oil was obtained from the aerial parts of the plant by hydrodistillation and analyzed by GC and GC-MS. The oil was characterized by its high content of carvacrol (68.1 %) and its biogenetic precursors, gamma-terpinene (9.9 %) and p-cymene (4.5 %). The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity against Candida strains (7 clinical isolates and 3 ATCC type strains). The inhibition of germ tube formation and flow cytometry, using the fluorescent probe propidium iodide (PI), were used to evaluate their mechanisms of action. MIC and MLC values were similar for most tested strains, ranging from 0.16 to 0.32 microL/mL. Concentrations lower than MIC values strongly prevent germ tube formation. The fungicidal effect is primarily due to an extensive lesion of the membrane. PMID:14598221

  14. Comparative study of the chemical composition of essential oils of five Tagetes species collected in Venezuela.

    PubMed

    Armas, Kaylin; Rojas, Janne; Rojas, Luis; Morales, Antonio

    2012-09-01

    The leaves and inflorescences of five species of Tagetes, family Asteraceae, were collected from different locations in Mérida state, Venezuela, and their essential oils analyzed by GC and GC/MS. Several differences were observed in the composition of these oils, mainly regarding the major components, which for T. caracasana were trans-ocimenone (64.3%) and cis-tagetone (13.7%), and for T. erecta, piperitone (35.9%) and terpinolene (22.2%). High amounts of trans-anethole (87.5%) and estragole (10.7%) were observed in T. filifolia, while T. subulata essential oil contained terpinolene (26.0%), piperitenone (13.1%) and limonene (10.8%). For T. patula, two different oil samples were analyzed, leaves (TPL) and inflorescences (TPI). The TPL oil showed terpinolene (20.9%) and piperitenone (14.0%) as main components, while the TPI sample was composed mainly of beta-caryophyllene (23.7%), terpinolene (15.6%) and cis-beta-ocimene (15.5%).

  15. Thermal stability and microstructure of catalytic alumina composite support with lanthanum species

    NASA Astrophysics Data System (ADS)

    Ozawa, Masakuni; Nishio, Yoshitoyo

    2016-09-01

    Lanthanum (La) modified γ-alumina composite was examined for application toward thermostable catalytic support at elevated temperature. La added alumina was prepared through an aqueous process using lanthanum (III) nitrate and then characterized by surface area measurement, X-ray powder diffraction (XRD), differential thermal analysis (DTA), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoemission spectroscopy (XPS) and surface desorption of CO2. It was found that the properties depended on the La content and heat treatment temperatures. The characterization of the surface, structural and chemical properties of La-Al2O3 showed the existence of a strong interaction between the La species and alumina via formation of new phase and modified surface in Al2O3 samples. LaAlO3 nanoparticle formed among alumina particles by the solid phase reaction of Al2O3 and La2O3. The increase of the surface basicity of La modified alumina was demonstrated using CO2 temperature programmed desorption experiments. The controlled surface interaction between La oxide and alumina provide the unique surface and structural properties of the resulting mixed oxides as catalysts and catalytic supports.

  16. Effects of Hypoxia on the Phylogenetic Composition and Species Distribution of Protists in a Subtropical Harbor.

    PubMed

    Rocke, Emma; Jing, Hongmei; Xia, Xiaomin; Liu, Hongbin

    2016-07-01

    Tolo Harbor, a subtropical semi-enclosed coastal water body, is surrounded by an expanding urban community, which contributes to large concentrations of nutrient runoff, leading to algal blooms and localized hypoxic episodes. Present knowledge of protist distributions in subtropical waters during hypoxic conditions is very limited. In this study, therefore, we combined parallel 454 pyrosequencing technology and denaturing gradient gel electrophoresis (DGGE) fingerprint analyses to reveal the protist community shifts before, during, and after a 2-week hypoxic episode during the summer of 2011. Hierarchical clustering for DGGE demonstrated similar grouping of hypoxic samples separately from oxic samples. Dissolved oxygen (DO) concentration and dissolved inorganic nitrogen:phosphate (DIN:PO4) concentrations significantly affected OTU distribution in 454 sequenced samples, and a shift toward a ciliate and marine alveolate clade II (MALV II) species composition occurred as waters shifted from oxic to hypoxic. These results suggest that protist community shifts toward heterotrophic and parasitic tendencies as well as decreased diversity and richness in response to hypoxic outbreaks. PMID:26979838

  17. Activity and species composition of aerobic methanotrophic communities in tundra soils.

    PubMed

    Vecherskaya, M S; Galchenko, V F; Sokolova, E N; Samarkin, V A

    1993-09-01

    The low-temperature, methane-oxidizing activities and species composition of methanotrophic communities in various tundra bog soils were investigated by radioisotopic and immunofluorescent methods. Methanotrophic bacteria carried out the methane oxidation process through all horizons of seasonally thawed layers down to permafrost. The highest activity of the process has been observed in the water surface layer of overmoistured soils and in water-logged moss covers. Up to 40% of(14)CH4 added was converted into(14)CO2, bacterial biomass, and organic exometabolites. By immunofluoresecent analysis it was demonstrated that the representatives of I+X (Methylomonas, Methylobacter, andMethylococcus) and II (Methylosinus, Methylocystis) methanotrophic groups occurred simultaneously in all samples at 61.6% and 38.4%, respectively. The number of methane-oxidizing bacteria in the ecosystems studied was 0.1-22.9×10(6) cells per gram of soil. Methanotrophic organisms ranged from 1% to 23% of the total bacterial number. PMID:23835752

  18. Effects of Hypoxia on the Phylogenetic Composition and Species Distribution of Protists in a Subtropical Harbor.

    PubMed

    Rocke, Emma; Jing, Hongmei; Xia, Xiaomin; Liu, Hongbin

    2016-07-01

    Tolo Harbor, a subtropical semi-enclosed coastal water body, is surrounded by an expanding urban community, which contributes to large concentrations of nutrient runoff, leading to algal blooms and localized hypoxic episodes. Present knowledge of protist distributions in subtropical waters during hypoxic conditions is very limited. In this study, therefore, we combined parallel 454 pyrosequencing technology and denaturing gradient gel electrophoresis (DGGE) fingerprint analyses to reveal the protist community shifts before, during, and after a 2-week hypoxic episode during the summer of 2011. Hierarchical clustering for DGGE demonstrated similar grouping of hypoxic samples separately from oxic samples. Dissolved oxygen (DO) concentration and dissolved inorganic nitrogen:phosphate (DIN:PO4) concentrations significantly affected OTU distribution in 454 sequenced samples, and a shift toward a ciliate and marine alveolate clade II (MALV II) species composition occurred as waters shifted from oxic to hypoxic. These results suggest that protist community shifts toward heterotrophic and parasitic tendencies as well as decreased diversity and richness in response to hypoxic outbreaks.

  19. Alaska marine ice atlas

    SciTech Connect

    LaBelle, J.C.; Wise, J.L.; Voelker, R.P.; Schulze, R.H.; Wohl, G.M.

    1982-01-01

    A comprehensive Atlas of Alaska marine ice is presented. It includes information on pack and landfast sea ice and calving tidewater glacier ice. It also gives information on ice and related environmental conditions collected over several years time and indicates the normal and extreme conditions that might be expected in Alaska coastal waters. Much of the information on ice conditions in Alaska coastal waters has emanated from research activities in outer continental shelf regions under assessment for oil and gas exploration and development potential. (DMC)

  20. Patterns in Species Composition of Fish and Selected Invertebrate Assemblages in Estuarine Subregions near Ponce de Leon Inlet, Florida

    NASA Astrophysics Data System (ADS)

    Paperno, R.; Mille, K. J.; Kadison, E.

    2001-01-01

    The Florida Fish and Wildlife Conservation Commission's Fisheries-Independent Monitoring program monitored the species composition and relative abundance of fishes and selected invertebrates in the estuarine waters near Ponce de Leon Inlet, Florida, from January 1993 through to December 1996. Sampling sites were located in three distinct physiographic and biotic estuarine subregions: Mosquito Lagoon (ML; 11 stations), Ponce de Leon Inlet (PI; 8 stations), and Tomoka Basin/River (TR; 8 stations). This series of subregions associated with Ponce de Leon Inlet is a species-rich estuarine system that is numerically dominated by a few taxa. A total of 1 080 477 animals representing 160 species and 56 families were recorded. Anchoa spp. (29·9%) and Menidia spp. (12·6%) were the numerically dominant taxa. Sciaenidae and Gobiidae were the most speciose families, with 12 species each (14·0% and 1·7% of the total animals collected, respectively), followed by the bothids 10 species (0·6% of total animals). Detrended correspondence analysis showed that the subregions could be discriminated by their respective species composition and relative abundance. Spatial differences in species composition were principally attributed to differences in the magnitude of seasonal recruitment events and to habitat characteristics associated with the presence of seagrass, inlet dynamics, or the influence of freshwater discharge. The presence of freshwater taxa (centrarchids) and the seasonal recruitment of juvenile Penaeidae, Micropogonias undulatus , Stellifer lanceolatus and Leiostomus xanthurus, characterize the TR area, whereas the presence of species associated with higher salinities ( Opisthonema oglinum and Harengula jaguana) characterize PI and with seagrass ( Lucania parva and Lagodon rhomboides) characterize ML.

  1. Libraries in Alaska: MedlinePlus

    MedlinePlus

    ... this page: https://medlineplus.gov/libraries/alaska.html Libraries in Alaska To use the sharing features on ... JavaScript. Anchorage University of Alaska Anchorage Alaska Medical Library 3211 Providence Drive Anchorage, AK 99508-8176 907- ...

  2. 75 FR 53331 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ... Interest to Hadohdleekaga, Incorporated, for the Native village of Hughes, Alaska, pursuant to the Alaska... Hughes, Alaska, and are located in: Kateel River Meridian, Alaska T. 9 N., R. 23 E., Sec. 5....

  3. Effects of environmental stresses on the species composition of phytoplankton populations. Final report, 1 March 1979-15 July 1980

    SciTech Connect

    Ryther, J. H.; Sanders, J. G.

    1980-07-01

    Studies concerned with the impact of anthropogenic stress associated with coastally located power plants on the species composition of marine phytoplankton assemblages have been underway under this Contract for 24 months. The impact of three pollutants associated with power plant cooling water systems has been studied: copper, chlorine, and thermal elevation. The primary goal has been to determine whether chronic addition of these pollutants at sublethal levels can affect the species composition and the succession of dominant species in natural phytoplankton assemblages. Stresses have been studied both singly and in combination. In conjunction with these primary objectives, a number of related problems imvolving phytoplankton response to pollutants and to zooplankton grazing have been studied. These experiments have been performed both in the large volume enclosures outdoors, and in laboratory cultures under constant conditions.

  4. SPECIES COMPOSITION, DISTRIBUTION, LIFE FORMS AND FOLK NOMENCLATURE OF FOREST AND COMMON LAND PLANTS OF WESTERN CHITWAN, NEPAL

    PubMed Central

    Dangol, D. R.

    2012-01-01

    This paper enumerates 349 plant species belonging to 77 families of vascular plants collected in the winter seasons of 1996 and 2000 by the flora teams of the Population and Ecology Research Laboratory, Nepal. Of the total species, 249 species belong to dicotyledons, 87 species to monocotyledons and 13 species to pteridophytes. Among the families, dicotyledons contributed the highest number of families (55 in number) followed by monocotyledons and pteridophytes. In the study areas, species composition varies with the type of habitats in the study plots. Some species are unique in distribution. The highest unique species are contributed by common lands (87 spp.), followed by the Chitwan National Park forest (36 spp.) and Tikauli forest (32 spp.). Ageratum houstonianum Mill., Cynodon dactylon (L.) Pers., Imperata cylindrica (L.) Beauv., Rungia parviflora (Retz.) Nees, Saccharum spontaneum L. and Thelypteris auriculata (J. Sm.) K. Iwats are the most common species across all the research blocks. Of the listed plants, many plants have local names either in Nepalese or other tribal languages. Plants are named in different ways on the basis of habit, habitat, smell, taste, and morphological characters of the plants, which are also the basis of nomenclature in plant taxonomy. PMID:22962539

  5. Alaska telemedicine: growth through collaboration.

    PubMed

    Patricoski, Chris

    2004-12-01

    The last thirty years have brought the introduction and expansion of telecommunications to rural and remote Alaska. The intellectual and financial investment of earlier projects, the more recent AFHCAN Project and the Universal Service Administrative Company Rural Health Care Division (RHCD) has sparked a new era in telemedicine and telecommunication across Alaska. This spark has been flamed by the dedication and collaboration of leaders at he highest levels of organizations such as: AFHCAN member organizations, AFHCAN Office, Alaska Clinical Engineering Services, Alaska Federal Health Care Partnership, Alaska Federal Health Care Partnership Office, Alaska Native health Board, Alaska Native Tribal health Consortium, Alaska Telehealth Advisory Council, AT&T Alascom, GCI Inc., Health care providers throughout the state of Alaska, Indian Health Service, U.S. Department of Health and Human Services, Office of U.S. Senator Ted Steens, State of Alaska, U.S. Department of Homeland Security--United States Coast Guard, United States Department of Agriculture, United States Department of Defense--Air Force and Army, United States Department of Veterans Affairs, University of Alaska, and University of Alaska Anchorage. Alaska now has one of the largest telemedicine programs in the world. As Alaska moves system now in place become self-sustaining, and 2) collaborating with all stakeholders in promoting the growth of an integrated, state-wide telemedicine network.

  6. Boreal Forest Ecosystems Along Canadian Transect in Central Canada:Multivariate Analysis of Species Composition, Detritus and Soil Carbon Data

    NASA Astrophysics Data System (ADS)

    Bhatti, J.; Yu, Z.; Apps, M. J.

    2001-05-01

    The species composition, detritus, and soil data from 97 boreal forest stands along a transect (BFTCS) in central Canada were analyzed using (detrended) (canonical) correspondence analysis to determine the dominant environmental/site variables that differentiate these forest stands. The forests include aspen, jack pine, black spruce and mixed wood stands. Black spruce stands are densely clustered together on understory DCA plot, suggesting that they have consistent understory species composition, such as feathermoss and ericades, whereas aspen stands have most diverse understory species composition (~30 species), mostly shrubs and herbs. Jack pine stands have several characteristic species of reindeer lichens (Cladina spp.), but have rare saplings and seedlings of jack pine. Although climatic variables show large variation along the transect, the CCA results indicate that site conditions are more important in determining species composition and differentiating the stand types. Characteristics of forest floor (duff layer, woody debris, and drainage) appear to be among the most important site variables. The black spruce stands have significantly higher average carbon (C) densities in duff layer (43,530 kg C/ha) than aspen (25,500 kg C/ha) and jack pine stands (19,400 kg C/ha). The thick duff layer in lowland black spruce stands plays an important role in regulating soil temperatures and moistures, and organic-matter decomposition, which in turn affect the ecosystem C dynamics. During forest succession after a stand-replacing disturbance (e.g., fires), tree biomass increases in all stand types as forests recover; however, detritus biomass first decreases and then increases after ~80 years. In all stand types, duff layer thickness increases with stand regrowth ages. Soil C densities show slight decrease with ages in aspen stands, but increase in other stand types. These results indicate the complex C transfer processes among different components (tree biomass, detritus

  7. Alaska: A frontier divided

    SciTech Connect

    O'Dell, R. )

    1986-09-01

    The superlatives surrounding Alaska are legion. Within the borders of the 49th US state are some of the world's greatest concentrations of waterfowl, bald eagles, fur seals, walrus, sea lions, otters, and the famous Kodiak brown bear. Alaska features the highest peak of North America, the 20,320-foot Mount McKinley, and the longest archipelago of small islands, the Aleutians. The state holds the greatest percentage of protected wilderness per capita in the world. The expanse of some Alaskan glaciers dwarfs entire countries. Like the periodic advance and retreat of its glaciers, Alaska appears with some regularity on the national US agenda. It last achieved prominence when President Jimmy Carter signed the Alaska National Interest Lands Conservation Act in 1980. Since then the conflict between environmental protection and economic development has been played out throughout the state, and Congress is expected to turn to Alaskan issues again in its next sessions.

  8. Post-fire salvage logging alters species composition and reduces cover, richness, and diversity in Mediterranean plant communities.

    PubMed

    Leverkus, Alexandro B; Lorite, Juan; Navarro, Francisco B; Sánchez-Cañete, Enrique P; Castro, Jorge

    2014-01-15

    An intense debate exists on the effects of post-fire salvage logging on plant community regeneration, but scant data are available derived from experimental studies. We analyzed the effects of salvage logging on plant community regeneration in terms of species richness, diversity, cover, and composition by experimentally managing a burnt forest on a Mediterranean mountain (Sierra Nevada, S Spain). In each of three plots located at different elevations, three replicates of three treatments were implemented seven months after the fire, differing in the degree of intervention: "Non-Intervention" (all trees left standing), "Partial Cut plus Lopping" (felling 90% of the trees, cutting the main branches, and leaving all the biomass in situ), and "Salvage Logging" (felling and piling the logs, and masticating the woody debris). Plant composition in each treatment was monitored two years after the fire in linear point transects. Post-fire salvage logging was associated with reduced species richness, Shannon diversity, and total plant cover. Moreover, salvaged sites hosted different species assemblages and 25% lower cover of seeder species (but equal cover of resprouters) compared to the other treatments. Cover of trees and shrubs was also lowest in Salvage Logging, which could suggest a potential slow-down of forest regeneration. Most of these results were consistent among the three plots despite plots hosting different plant communities. Concluding, our study suggests that salvage logging may reduce species richness and diversity, as well as the recruitment of woody species, which could delay the natural regeneration of the ecosystem.

  9. Post-fire salvage logging alters species composition and reduces cover, richness, and diversity in Mediterranean plant communities.

    PubMed

    Leverkus, Alexandro B; Lorite, Juan; Navarro, Francisco B; Sánchez-Cañete, Enrique P; Castro, Jorge

    2014-01-15

    An intense debate exists on the effects of post-fire salvage logging on plant community regeneration, but scant data are available derived from experimental studies. We analyzed the effects of salvage logging on plant community regeneration in terms of species richness, diversity, cover, and composition by experimentally managing a burnt forest on a Mediterranean mountain (Sierra Nevada, S Spain). In each of three plots located at different elevations, three replicates of three treatments were implemented seven months after the fire, differing in the degree of intervention: "Non-Intervention" (all trees left standing), "Partial Cut plus Lopping" (felling 90% of the trees, cutting the main branches, and leaving all the biomass in situ), and "Salvage Logging" (felling and piling the logs, and masticating the woody debris). Plant composition in each treatment was monitored two years after the fire in linear point transects. Post-fire salvage logging was associated with reduced species richness, Shannon diversity, and total plant cover. Moreover, salvaged sites hosted different species assemblages and 25% lower cover of seeder species (but equal cover of resprouters) compared to the other treatments. Cover of trees and shrubs was also lowest in Salvage Logging, which could suggest a potential slow-down of forest regeneration. Most of these results were consistent among the three plots despite plots hosting different plant communities. Concluding, our study suggests that salvage logging may reduce species richness and diversity, as well as the recruitment of woody species, which could delay the natural regeneration of the ecosystem. PMID:24412981

  10. Composition and hydrothermal pretreatment and enzymatic saccharification performance of grasses and legumes from a mixed-species prairie

    PubMed Central

    2011-01-01

    Background Mixtures of prairie species (mixed prairie species; MPS) have been proposed to offer important advantages as a feedstock for sustainable production of fuels and chemicals. Therefore, understanding the performance in hydrothermal pretreatment and enzymatic hydrolysis of select species harvested from a mixed prairie is valuable in selecting these components for such applications. This study examined composition and sugar release from the most abundant components of a plot of MPS: a C3 grass (Poa pratensis), a C4 grass (Schizachyrium scoparium), and a legume (Lupinus perennis). Results from this study provide a platform to evaluate differences between grass and leguminous species, and the factors controlling their recalcitrance to pretreatment and enzymatic hydrolysis. Results Significant differences were found between the grass and leguminous species, and between the individual anatomical components that influence the recalcitrance of MPS. We found that both grasses contained higher levels of sugars than did the legume, and also exhibited higher sugar yields as a percentage of the maximum possible from combined pretreatment and enzymatic hydrolysis. Furthermore, particle size, acid-insoluble residue (AcIR), and xylose removal were not found to have a direct significant effect on glucan digestibility for any of the species tested, whereas anatomical composition was a key factor in both grass and legume recalcitrance, with the stems consistently exhibiting higher recalcitrance than the other anatomical fractions. Conclusions The prairie species tested in this study responded well to hydrothermal pretreatment and enzymatic saccharification. Information from this study supports recommendations as to which plant types and species are more desirable for biological conversion in a mixture of prairie species, in addition to identifying fractions of the plants that would most benefit from genetic modification or targeted growth. PMID:22085451

  11. Effects of species and season on chemical composition and ruminal crude protein and organic matter degradability of some multi-purpose tree species by West African dwarf rams.

    PubMed

    Arigbede, O M; Anele, U Y; Südekum, K-H; Hummel, J; Oni, A O; Olanite, J A; Isah, A O

    2012-04-01

    Seasonal chemical composition and ruminal organic matter (OM) and crude protein (CP) degradabilities were determined in four tropical multi-purpose tree species (MPTS) namely; Pterocarpus santalinoides, Grewia pubescens, Enterolobium cyclocarpum and Leucaena leucocephala. Three West African dwarf (WAD) rams fitted with permanent rumen cannula were used for the degradability trials. Foliage samples were collected four times to represent seasonal variations as follows: January--mid dry; April--late dry; July--mid rainy and October--late rainy seasons. Leaf samples were randomly collected from the trees for estimation of dry matter (DM) and chemical composition. Ruminal in sacco OM and CP degradabilities were estimated from residues in nylon bags. All samples had high CP (161-259 g/kg DM) and moderate fibre concentrations [neutral detergent fibre (without residual ash], 300-501 g/kg DM; acid detergent fibre (without residual ash), 225-409 g/kg DM and acid detergent lignin, 87-179 g/kg DM across seasons. Interaction effects of species and season on chemical composition were highly significant (p = 0.001) except for trypsin inhibitor (p = 0.614). The MPTS recorded more than 60% OM and CP degradability at 24 h, which implied that they were all highly degradable in the rumen. Their incorporation into ruminant feeding systems as dry season forage supplements is therefore recommended.

  12. Divergent composition but similar function of soil food webs of individual plants: plant species and community effects.

    PubMed

    Bezemer, T M; Fountain, M T; Barea, J M; Christensen, S; Dekker, S C; Duyts, H; van Hal, R; Harvey, J A; Hedlund, K; Maraun, M; Mikola, J; Mladenov, A G; Robin, C; de Ruiter, P C; Scheu, S; Setälä, H; Smilauer, P; van der Putten, W H

    2010-10-01

    Soils are extremely rich in biodiversity, and soil organisms play pivotal roles in supporting terrestrial life, but the role that individual plants and plant communities play in influencing the diversity and functioning of soil food webs remains highly debated. Plants, as primary producers and providers of resources to the soil food web, are of vital importance for the composition, structure, and functioning of soil communities. However, whether natural soil food webs that are completely open to immigration and emigration differ underneath individual plants remains unknown. In a biodiversity restoration experiment we first compared the soil nematode communities of 228 individual plants belonging to eight herbaceous species. We included grass, leguminous, and non-leguminous species. Each individual plant grew intermingled with other species, but all plant species had a different nematode community. Moreover, nematode communities were more similar when plant individuals were growing in the same as compared to different plant communities, and these effects were most apparent for the groups of bacterivorous, carnivorous, and omnivorous nematodes. Subsequently, we analyzed the composition, structure, and functioning of the complete soil food webs of 58 individual plants, belonging to two of the plant species, Lotus corniculatus (Fabaceae) and Plantago lanceolata (Plantaginaceae). We isolated and identified more than 150 taxa/groups of soil organisms. The soil community composition and structure of the entire food webs were influenced both by the species identity of the plant individual and the surrounding plant community. Unexpectedly, plant identity had the strongest effects on decomposing soil organisms, widely believed to be generalist feeders. In contrast, quantitative food web modeling showed that the composition of the plant community influenced nitrogen mineralization under individual plants, but that plant species identity did not affect nitrogen or carbon

  13. Divergent composition but similar function of soil food webs of individual plants: plant species and community effects.

    PubMed

    Bezemer, T M; Fountain, M T; Barea, J M; Christensen, S; Dekker, S C; Duyts, H; van Hal, R; Harvey, J A; Hedlund, K; Maraun, M; Mikola, J; Mladenov, A G; Robin, C; de Ruiter, P C; Scheu, S; Setälä, H; Smilauer, P; van der Putten, W H

    2010-10-01

    Soils are extremely rich in biodiversity, and soil organisms play pivotal roles in supporting terrestrial life, but the role that individual plants and plant communities play in influencing the diversity and functioning of soil food webs remains highly debated. Plants, as primary producers and providers of resources to the soil food web, are of vital importance for the composition, structure, and functioning of soil communities. However, whether natural soil food webs that are completely open to immigration and emigration differ underneath individual plants remains unknown. In a biodiversity restoration experiment we first compared the soil nematode communities of 228 individual plants belonging to eight herbaceous species. We included grass, leguminous, and non-leguminous species. Each individual plant grew intermingled with other species, but all plant species had a different nematode community. Moreover, nematode communities were more similar when plant individuals were growing in the same as compared to different plant communities, and these effects were most apparent for the groups of bacterivorous, carnivorous, and omnivorous nematodes. Subsequently, we analyzed the composition, structure, and functioning of the complete soil food webs of 58 individual plants, belonging to two of the plant species, Lotus corniculatus (Fabaceae) and Plantago lanceolata (Plantaginaceae). We isolated and identified more than 150 taxa/groups of soil organisms. The soil community composition and structure of the entire food webs were influenced both by the species identity of the plant individual and the surrounding plant community. Unexpectedly, plant identity had the strongest effects on decomposing soil organisms, widely believed to be generalist feeders. In contrast, quantitative food web modeling showed that the composition of the plant community influenced nitrogen mineralization under individual plants, but that plant species identity did not affect nitrogen or carbon

  14. Alaska looks HOT!

    SciTech Connect

    Belcher, J.

    1997-07-01

    Production in Alaska has been sluggish in recent years, with activity in the Prudhoe Bay region in the North Slope on a steady decline. Alaska North Slope (ANS) production topped out in 1988 at 2.037 MMbo/d, with 1.6 MMbo/d from Prudhoe Bay. This year operators expect to produce 788 Mbo/d from Prudhoe Bay, falling to 739 Mbo/d next year. ANS production as a whole should reach 1.3 MMbo/d this year, sliding to 1.29 MMbo/d in 1998. These declining numbers had industry officials and politicians talking about the early death of the Trans-Alaskan Pipeline System-the vital link between ANS crude and markets. But enhanced drilling technology coupled with a vastly improved relationship between the state government and industry have made development in Alaska more economical and attractive. Alaska`s Democratic Gov. Tommy Knowles is fond of telling industry {open_quotes}we`re open for business.{close_quotes} New discoveries on the North Slope and in the Cook Inlet are bringing a renewed sense of optimism to the Alaska exploration and production industry. Attempts by Congress to lift a moratorium on exploration and production activity in the Arctic National Wildlife Refuge (ANWR) have been thwarted thus far, but momentum appears to be with proponents of ANWR drilling.

  15. Marsh Sediment and Species Composition in Hudson River Tidal Marshes: Change over the Last Millennium

    NASA Astrophysics Data System (ADS)

    Peteet, D. M.; Pederson, D. C.; Kurdyla, D.; Guilderson, T.; Kleinstein, D.; Higgiston, P.

    2004-05-01

    Understanding the signature of the Hudson River watershed to changes in the hydrological cycle is possible using marsh archives downriver. A suite of lower Hudson River tidal marshes is examined to identify changes in organic vs. inorganic content in the context of environmental change. Complex vegetational changes in the various marshes, identified by pollen and macrofossil studies, demonstrate the response to natural climate variability as well as human-induced changes of the last four centuries. While Piermont Marsh shows high inorganic content related to drought during the Medieval Warm Period, the subsequent Little Ice Age that followed shows a drop in this input. However, the nineteenth century of landscape disturbance reveals an increase again in upland watershed inorganics, followed by decline in the twentieth century. Jamaica Bay and Staten Island marshes to date show reduced inorganic input to these wetlands from the watershed up to the twentieth century. Jamaica Bay, NY marsh cores indicate increases in organic content in the twentieth century which may be related to dramatic land use changes in the surrounding New York area. An increase in the sand-sized fraction of organics may be attributed to the changes in local marsh plant production, but multiple hypotheses are being tested. Comparisons with adjacent Hackensack Meadowlands marshes demonstrate that local marsh plant production can dramatically alter the organic content and thus the carbon sequestration in the marshes. Species compositional changes in most of the marshes in the twentieth century resulted in a loss of biodiversity with the invasive increase of Typha (cattail) and Phragmites. This loss is linked to eutrophication of the estuary.

  16. Tree Species Composition and Harvest Intensity Affect Herbivore Density and Leaf Damage on Beech, Fagus sylvatica, in Different Landscape Contexts

    PubMed Central

    Mangels, Jule; Blüthgen, Nico; Frank, Kevin; Grassein, Fabrice; Hilpert, Andrea; Mody, Karsten

    2015-01-01

    Most forests are exposed to anthropogenic management activities that affect tree species composition and natural ecosystem processes. Changes in ecosystem processes such as herbivory depend on management intensity, and on regional environmental conditions and species pools. Whereas influences of specific forest management measures have already been addressed for different herbivore taxa on a local scale, studies considering effects of different aspects of forest management across different regions are rare. We assessed the influence of tree species composition and intensity of harvesting activities on arthropod herbivores and herbivore-related damage to beech trees, Fagus sylvatica, in 48 forest plots in three regions of Germany. We found that herbivore abundance and damage to beech trees differed between regions and that – despite the regional differences - density of tree-associated arthropod taxa and herbivore damage were consistently affected by tree species composition and harvest intensity. Specifically, overall herbivore damage to beech trees increased with increasing dominance of beech trees – suggesting the action of associational resistance processes – and decreased with harvest intensity. The density of leaf chewers and mines was positively related to leaf damage, and several arthropod groups responded to beech dominance and harvest intensity. The distribution of damage patterns was consistent with a vertical shift of herbivores to higher crown layers during the season and with higher beech dominance. By linking quantitative data on arthropod herbivore abundance and herbivory with tree species composition and harvesting activity in a wide variety of beech forests, our study helps to better understand the influence of forest management on interactions between a naturally dominant deciduous forest tree and arthropod herbivores. PMID:25938417

  17. Stimulation of soil nitrification and denitrification by grazing in grasslands: do changes in plant species composition matter?

    PubMed

    Le Roux, X; Bardy, M; Loiseau, P; Louault, F

    2003-11-01

    Stimulation of nitrification and denitrification by long term (from years to decades) grazing has commonly been reported in different grassland ecosystems. However, grazing generally induces important changes in plant species composition, and whether changes in nitrification and denitrification are primarily due to changes in vegetation composition has never been tested. We compared soil nitrification- and denitrification-enzyme activities (NEA and DEA, respectively) between semi-natural grassland sites experiencing intensive (IG) and light (LG) grazing/mowing regimes for 13 years. Mean NEA and DEA (i.e. observed from random soil sampling) were higher in IG than LG sites. The NEA/DEA ratio was higher in IG than LG sites, indicating a higher stimulation of nitrification. Marked changes in plant species composition were observed in response to the grazing/mowing regime. In particular, the specific phytomass volume of Elymus repens was lower in IG than LG sites, whereas the specific volume of Lolium perenne was higher in IG than LG sites. In contrast, the specific volume of Holcus lanatus, Poa trivialis and Arrhenatherum elatius were not significantly different between treatments. Soils sampled beneath grass tussocks of the last three species exhibited higher DEA, NEA and NEA/DEA ratio in IG than LG sites. For a given grazing regime, plant species did not affect significantly soil DEA, NEA and NEA/DEA ratio. The modification of plant species composition is thus not the primary factor driving changes in nitrification and denitrification in semi-natural grassland ecosystems experiencing long term intensive grazing. Factors such as trampling, N returned in animal excreta, and/or modification of N uptake and C exudation by frequently defoliated plants could be responsible for the enhanced microbial activities.

  18. Tree Species Composition and Harvest Intensity Affect Herbivore Density and Leaf Damage on Beech, Fagus sylvatica, in Different Landscape Contexts.

    PubMed

    Mangels, Jule; Blüthgen, Nico; Frank, Kevin; Grassein, Fabrice; Hilpert, Andrea; Mody, Karsten

    2015-01-01

    Most forests are exposed to anthropogenic management activities that affect tree species composition and natural ecosystem processes. Changes in ecosystem processes such as herbivory depend on management intensity, and on regional environmental conditions and species pools. Whereas influences of specific forest management measures have already been addressed for different herbivore taxa on a local scale, studies considering effects of different aspects of forest management across different regions are rare. We assessed the influence of tree species composition and intensity of harvesting activities on arthropod herbivores and herbivore-related damage to beech trees, Fagus sylvatica, in 48 forest plots in three regions of Germany. We found that herbivore abundance and damage to beech trees differed between regions and that - despite the regional differences - density of tree-associated arthropod taxa and herbivore damage were consistently affected by tree species composition and harvest intensity. Specifically, overall herbivore damage to beech trees increased with increasing dominance of beech trees - suggesting the action of associational resistance processes - and decreased with harvest intensity. The density of leaf chewers and mines was positively related to leaf damage, and several arthropod groups responded to beech dominance and harvest intensity. The distribution of damage patterns was consistent with a vertical shift of herbivores to higher crown layers during the season and with higher beech dominance. By linking quantitative data on arthropod herbivore abundance and herbivory with tree species composition and harvesting activity in a wide variety of beech forests, our study helps to better understand the influence of forest management on interactions between a naturally dominant deciduous forest tree and arthropod herbivores.

  19. Urban stress is associated with variation in microbial species composition-but not richness-in Manhattan.

    PubMed

    Reese, Aspen T; Savage, Amy; Youngsteadt, Elsa; McGuire, Krista L; Koling, Adam; Watkins, Olivia; Frank, Steven D; Dunn, Robert R

    2016-03-01

    The biological diversity and composition of microorganisms influences both human health outcomes and ecological processes; therefore, understanding the factors that influence microbial biodiversity is key to creating healthy, functional landscapes in which to live. In general, biological diversity is predicted to be limited by habitat size, which for green areas is often reduced in cities, and by chronic disturbance (stress). These hypotheses have not previously been tested in microbial systems in direct comparison to macroorganisms. Here we analyzed bacterial, fungal and ant communities in small road medians (average area 0.0008 km(2)) and larger parks (average area 0.64 km(2)) across Manhattan (NYC). Bacterial species richness was not significantly different between medians and parks, but community composition was significantly distinct. In contrast, ant communities differed both in composition and richness with fewer ant species in medians than parks. Fungi showed no significant variation in composition or richness but had few shared taxa between habitats or sites. The diversity and composition of microbes appears less sensitive to habitat patchiness or urban stress than those of macroorganisms. Microbes and their associated ecosystem services and functions may be more resilient to the negative effects of urbanization than has been previously appreciated.

  20. Distribution, diet, and energetic condition of age-0 walleye pollock (Gadus chalcogrammus) and pacific cod (Gadus macrocephalus) inhabiting the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Moss, Jamal H.; Zaleski, Marilyn F.; Heintz, Ron A.

    2016-10-01

    Walleye pollock (Gadus chalcogrammus) and Pacific cod (Gadus macrocephalus) are commercially and ecologically important species in Alaska waters. Little is known about their ecology after transitioning from larvae to free swimming fish until settlement to nursery habitats in the eastern Gulf of Alaska. Differences in the distribution, diet, body size, and energetic status between the eastern and central Gulf of Alaska were investigated during summer months to better understand regional and interspecific differences in life history and ecology. The composition of zooplankton prey in the diets of walleye pollock and Pacific cod inhabiting shelf waters was more varied relative to those inhabiting the slope and basin. Body condition and total energy content of Pacific cod was greater than walleye pollock, however total energy content increased with length at a similar rate for both species. Walleye pollock inhabiting continental slope waters had higher energy stores relative to those inhabiting the continental shelf and basin, indicating an energetic advantage for individuals remaining off the shelf during summer months or potentially the advection of fish with higher energy reserves off of the shelf. Previous studies have documented the importance of energy stores for surviving winter and future studies should focus on understanding the mechanisms influencing lipid storage and somatic growth for walleye pollock and Pacific cod inhabiting the eastern and central Gulf of Alaska.

  1. [Species composition and biodiversity of fish community in Dalian Lake, Shanghai].

    PubMed

    Yue, Feng; Luo, Zu-Kui; Wu, Di; Pei, En-Le; Wang, Tian-Hou

    2010-12-01

    A field fish survey of Dalian Lake, Shanghai was undertaken in Apr. 11-19, Apr. 27-May 8 and May 20-29, in total 24,061 fish individuals were collected, representing 22 species from 17 genera and 11 families. The dominant specie is Carassius auratus, accounting for 76.38% of the total. The eigenvalues of species diversity were showing below : Shannon-Wiener's index (H') being 1.0027, Simpson's index (lambda) being 0.5959, Pielous's index (J') being 0.3244, Margalef's index (D) being 2.0816 and relative rare species (R) being 90.91%. The fish community could be classified into 3 ecological types, which including river-sea migratory fish (3 species), river-lake migratory fish (1 species) and sedentary fish (18 species). Also they can be subcategoried into five types according to feeding habits, i.e., piscivorous fish (9 species), invertebrativorous fish (2 species), omnivores fish (7 species), planktotrophic fish (3 species), herbivorous fish (1 species). The results suggested that the biodiversity index and fish community stability are both at a low level. Compare to the lower reaches of Huangpu River, the proportion of piscivorous fish in Dalian Lake is higher, which suggested the water quality of Dalian Lake, located in the upper reaches of Huangpu River, is better than that in the downstream. It's required to intensify supervision and strengthen the environment protection of Dalian Lake to guarantee the sustainable development.

  2. [Composition and structure of the macrofauna associated with beds of two bivalve species in Cubagua Island, Venezuela].

    PubMed

    Hernández-Avila, Iván; Tagliafico, Alejandro; Rago, Nestor

    2013-06-01

    Bivalve aggregations constitute a microhabitat for a wide variety of organisms in intertidal, subtidal and deep-water marine benthic habitats. Increase in density of bivalve beds could offer more crevices and substratum for the associated fauna, affecting community composition. Beds of the Atlantic Pearl Oyster (Pinctada imbricata) and the Turkey Wing (Arca zebra) of contrasting population densities were evaluated to determine the composition and structure of the associated macrofauna of three taxa (Crustacea Decapoda, Mollusca and Echinodermata). We evaluated plots of three levels of bed density in both species, the associated fauna were identified and counted. Other species were collected by qualitative samples. Univariate and multivariate descriptors were tested comparing the associated fauna between the beds of two species at three levels of density. In these beds a total of 104 species belonging to 58 families were recorded. Mithraculus forceps (Majidae), Crucibulum auricula (Calyptraeidae) and Ophiotrix angulata (Ophiothrichidae) were the most common species found in these assemblages. The medium and high-density bivalve beds exhibited greater species number, abundance, Shannon diversity, evenness, taxonomic diversity, and taxonomic distinctness of associated fauna, than low-density bivalve beds. Moreover, multivariate analysis detected different assemblages of associated fauna between beds with different densities. Additionally, similarities were found in the communities of macrofauna in both beds of P imbricata and Area zebra. Our results suggest that bivalve aggregations at Cubagua Island provide additional habitat for macrofauna living in other shallow habitats such as Thalassia beds, corals and rocky environments. Bed density, associated with topographic complexity, represents an important factor for the composition and complexity of the associated fauna. PMID:23885582

  3. Digital Shaded-Relief Image of Alaska

    USGS Publications Warehouse

    Riehle, J.R.; Fleming, Michael D.; Molnia, B.F.; Dover, J.H.; Kelley, J.S.; Miller, M.L.; Nokleberg, W.J.; Plafker, George; Till, A.B.

    1997-01-01

    of Alaska at 1:2,500,000 scale (Alaska Department of Natural Resources, 1994), using the 1,000-m digital elevation data set referred to below. An important difference between our image and these previous ones is the method of reproduction: like the Thelin and Pike (1991) image, our image is a composite of halftone images that yields sharp resolution and preserves contrast. Indeed, the first impression of many viewers is that the Alaskan image and the Thelin and Pike image are composites of satellite-generated photographs rather than an artificial rendering of a digital elevation model. A shaded-relief image represents landforms in a natural fashion; that is, a viewer perceives the image as a rendering of reality. Thus a shaded-relief image is intrinsically appealing, especially in areas of spectacular relief. In addition, even subtle physiographic features that reflect geologic structures or the type of bedrock are visible. To our knowledge, some of these Alaskan features have not been depicted before and so the image should provide earth scientists with a new 'look' at fundamental geologic features of Alaska.

  4. Alaska Resource Data File: Chignik quadrangle, Alaska

    USGS Publications Warehouse

    Pilcher, Steven H.

    2000-01-01

    Descriptions of the mineral occurrences can be found in the report. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska. There is a website from which you can obtain the data for this report in text and Filemaker Pro formats

  5. Variation in fatty acid composition among nine forage species from a southeastern US estuarine and nearshore coastal ecosystem.

    PubMed

    Recks, Melissa A; Seaborn, Gloria T

    2008-09-01

    The fatty acid (FA) composition of nine potentially important forage species was determined (n = 330): red drum (Sciaenops ocellatus), spot (Leiostomus xanthurus), spotted seatrout (Cynoscion nebulosus), striped mullet (Mugil cephalus), pinfish (Lagodon rhomboides), Atlantic croaker (Micropogonias undulatus), star drum (Stellifer lanceolatus), striped anchovy (Anchoa hepsetus), and brief squid (Lolliguncula brevis). Samples were collected from estuarine and nearshore coastal waters around Charleston, South Carolina, USA, from March 2002-February 2003. Twenty-nine of 125 identified FAs were included in multivariate analyses of FA profiles. Despite existing intraspecific variation, the PRIMER routine analysis of similarity (ANOSIM) indicated each species was distinct, and discriminant function analysis correctly classified 99.5% of the training data set samples (n = 221) and 98.2% of the validation samples (n = 109). Most species could be characterized by distinctive levels of a suite of FAs. Our results indicated FA profiles can be used to reliably distinguish even closely related forage species in this southeastern US estuarine ecosystem. The information gained from this study not only provides insight into the biochemical composition of these important species but also provides fundamental information to support studies on the feeding ecology of local higher-level predators.

  6. A Composite Network Approach for Assessing Multi-Species Connectivity: An Application to Road Defragmentation Prioritisation

    PubMed Central

    Saura, Santiago; Rondinini, Carlo

    2016-01-01

    One of the biggest challenges in large-scale conservation is quantifying connectivity at broad geographic scales and for a large set of species. Because connectivity analyses can be computationally intensive, and the planning process quite complex when multiple taxa are involved, assessing connectivity at large spatial extents for many species turns to be often intractable. Such limitation results in that conducted assessments are often partial by focusing on a few key species only, or are generic by considering a range of dispersal distances and a fixed set of areas to connect that are not directly linked to the actual spatial distribution or mobility of particular species. By using a graph theory framework, here we propose an approach to reduce computational effort and effectively consider large assemblages of species in obtaining multi-species connectivity priorities. We demonstrate the potential of the approach by identifying defragmentation priorities in the Italian road network focusing on medium and large terrestrial mammals. We show that by combining probabilistic species graphs prior to conducting the network analysis (i) it is possible to analyse connectivity once for all species simultaneously, obtaining conservation or restoration priorities that apply for the entire species assemblage; and that (ii) those priorities are well aligned with the ones that would be obtained by aggregating the results of separate connectivity analysis for each of the individual species. This approach offers great opportunities to extend connectivity assessments to large assemblages of species and broad geographic scales. PMID:27768718

  7. Chemical Composition of the Fruit Oils of Five Fortunella Species Grown in the Same Pedoclimatic Conditions in Corsica (France).

    PubMed

    Sutour, Sylvain; Lurob, François; Bradesi, Pascale; Casanova, Joseph; Tomi, Félix

    2016-02-01

    Fruit oil from five species of kumquat (Fortunella japonica, F. margarita, F. crassifolia, F. obovata, and F. hindsii) grown in the same pedoclimatic conditions have been analyzed by a combination of chromatographic and spectroscopic techniques. The compositions of the five fruit oils were strongly dominated by limonene (84.2-96.3%). Other components present with appreciable contents were myrcene (1.3-12.9%) and germacrene D (0.3-2.4%). PMID:27032215

  8. Plankton studies in San Francisco Bay; VI, Zooplankton species composition and abundance in the North Bay, 1979-1980

    USGS Publications Warehouse

    Hutchinson, Anne

    1982-01-01

    Data are presented that summarize zooplankton species composition and abundance in North San Francisco Bay during 1979 and 1980. Sampling was conducted once monthly at six stations during 1979 and twice monthly at sixteen stations during 1980. Samples were collected by pump at three depths in the shipping channel and at one depth over the shoals. Subsamples were enumerated while alive. Total zooplankton biomass, as carbon, was calculated from estimated carbon quotas and abundances of each organism enumerated.

  9. Chemical Composition of the Fruit Oils of Five Fortunella Species Grown in the Same Pedoclimatic Conditions in Corsica (France).

    PubMed

    Sutour, Sylvain; Lurob, François; Bradesi, Pascale; Casanova, Joseph; Tomi, Félix

    2016-02-01

    Fruit oil from five species of kumquat (Fortunella japonica, F. margarita, F. crassifolia, F. obovata, and F. hindsii) grown in the same pedoclimatic conditions have been analyzed by a combination of chromatographic and spectroscopic techniques. The compositions of the five fruit oils were strongly dominated by limonene (84.2-96.3%). Other components present with appreciable contents were myrcene (1.3-12.9%) and germacrene D (0.3-2.4%).

  10. Sensitivity of density-dependent threshold to species composition in arthropod aggregates.

    PubMed

    Pierre, Broly; Quentin, Ectors; Geoffrey, Decuyper; Nicolis, Stamatios C; Jean-Louis, Deneubourg

    2016-01-01

    How mixed-species groups perform collective behaviours provides unique insights into the mechanisms that drive social interactions. Herein, we followed the aggregation process of two isopod species under monospecific and heterospecific conditions at three population densities. Our experimental results show that the formation of both the monospecific and heterospecific groups responds to a similar threshold function. Furthermore, the two species contribute equally to the mixed-species aggregate growth and are not spatiotemporally segregated. However, we show that the cohesion is weaker and the probability of forming aggregations is lower in heterospecific groups than in monospecific populations. Thus, our results show that amplification processes are shared between species, but that the weighting given to conspecific and heterospecific information differs. We develop a theoretical model to test this hypothesis. The model reproduces our experimental data and shows that a relatively low level of inter-attractions between species is able to generate mixed-species aggregates. Moreover the greater the total population, the lower this parameter value is needed to observe aggregation in both species. This highlights the importance to study not only qualitatively but also quantitatively the heterospecific interactions in mixed-species groups. Finally, the patterns observed could be biologically relevant in favouring the association between species. PMID:27576571

  11. Sensitivity of density-dependent threshold to species composition in arthropod aggregates

    PubMed Central

    Pierre, Broly; Quentin, Ectors; Geoffrey, Decuyper; Nicolis, Stamatios C.; Jean-Louis, Deneubourg

    2016-01-01

    How mixed-species groups perform collective behaviours provides unique insights into the mechanisms that drive social interactions. Herein, we followed the aggregation process of two isopod species under monospecific and heterospecific conditions at three population densities. Our experimental results show that the formation of both the monospecific and heterospecific groups responds to a similar threshold function. Furthermore, the two species contribute equally to the mixed-species aggregate growth and are not spatiotemporally segregated. However, we show that the cohesion is weaker and the probability of forming aggregations is lower in heterospecific groups than in monospecific populations. Thus, our results show that amplification processes are shared between species, but that the weighting given to conspecific and heterospecific information differs. We develop a theoretical model to test this hypothesis. The model reproduces our experimental data and shows that a relatively low level of inter-attractions between species is able to generate mixed-species aggregates. Moreover the greater the total population, the lower this parameter value is needed to observe aggregation in both species. This highlights the importance to study not only qualitatively but also quantitatively the heterospecific interactions in mixed-species groups. Finally, the patterns observed could be biologically relevant in favouring the association between species. PMID:27576571

  12. Sensitivity of density-dependent threshold to species composition in arthropod aggregates.

    PubMed

    Pierre, Broly; Quentin, Ectors; Geoffrey, Decuyper; Nicolis, Stamatios C; Jean-Louis, Deneubourg

    2016-08-31

    How mixed-species groups perform collective behaviours provides unique insights into the mechanisms that drive social interactions. Herein, we followed the aggregation process of two isopod species under monospecific and heterospecific conditions at three population densities. Our experimental results show that the formation of both the monospecific and heterospecific groups responds to a similar threshold function. Furthermore, the two species contribute equally to the mixed-species aggregate growth and are not spatiotemporally segregated. However, we show that the cohesion is weaker and the probability of forming aggregations is lower in heterospecific groups than in monospecific populations. Thus, our results show that amplification processes are shared between species, but that the weighting given to conspecific and heterospecific information differs. We develop a theoretical model to test this hypothesis. The model reproduces our experimental data and shows that a relatively low level of inter-attractions between species is able to generate mixed-species aggregates. Moreover the greater the total population, the lower this parameter value is needed to observe aggregation in both species. This highlights the importance to study not only qualitatively but also quantitatively the heterospecific interactions in mixed-species groups. Finally, the patterns observed could be biologically relevant in favouring the association between species.

  13. Essential oils from Schinus species of northwest Argentina: Composition and antifungal activity.

    PubMed

    Sampietro, Diego A; Belizana, Maria Melina E; Baptista, Zareath P Terán; Vattuone, Marta A; Catalán, Cesar A N

    2014-07-01

    The composition of the essential oils from leaves (Sal) and fruits of S. areira (Saf), and fruits of S. fasciculatus (Sff) and S. gracilipes (Sgf) were analyzed by GC/MS. The major compounds identified were sabinene (26.0 +/- 0.5%), bicyclogermacrene (14.5 +/- 0.4%), and E-citral (6.7+/- 0.2%) in Sal oil, limonene (27.7 +/- 0.7%), sabinene (16.0+/- 0.5%), beta-phellandrene (14.6 +/- 0.8%) and bicyclogermacrene (8.1 +/- 0.2%) in Saf oil, sabinene (22.7 +/- 0.6%), alpha-phellandrene (18.7 +/- 0.3%), beta-phellandrene (15.7 +/- 0.4%), and bicyclogermacrene (8.1 +/- 0.2%) in Sff oil and beta-pinene (25.4 +/- 0.8%), alpha-pinene (24.7 +/- 0.7%), and sabinene (13.6 +/- 0.4%) in Sgf oil.The antifungal activity of the four oils was evaluated on strains of Fusarium verticillioides and F. graminearum, and the results compared with the effect of epoxyconazole, pyraclostrobin and thyme oil. The Sff oil had the highest antifungal activity among the Schinus oils tested, with MIC100 (F. graminearum) = 6 per thousand and MIC100 (F. verticillioides) = 12 per thousand. A principal component analysis suggests that 9 constituents (alpha-thujene, alpha-terpinene, p-cymene, gamma-terpinene, terpinolene, 1-terpineol, alpha-calacorene, alpha-phellandrene, and terpinen-4-ol) explain the higher antifungal effect of Sff. The MIC100s of Schinus oils were on average 30-60 and 8.5-17 fold lower than those obtained for thyme oil on F. verticillioides and F. graminearum, respectively. In the case of commercial fungicides, their MIC100s were three orders of magnitude lower than those of Schinus oils. The last ones showed an additive interaction when assayed in mixtures with the commecial fungicides and thyme oil. The results suggest that the doses of fungicides required for control of the Fusarium species can be reduced when they are assayed in mixtures with the Schinus oils. PMID:25230518

  14. Serum chemistry reference ranges for Steller sea lion (Eumetopias jubatus) pups from Alaska: stock differentiation and comparisons within a North Pacific sentinel species.

    PubMed

    Lander, Michelle E; Fadely, Brian S; Gelatt, Thomas S; Rea, Lorrie D; Loughlin, Thomas R

    2013-12-01

    Blood chemistry and hematologic reference ranges are useful for population health assessment and establishing a baseline for future comparisons in the event of ecosystem changes due to natural or anthropogenic factors. The objectives of this study were to determine if there was any population spatial structure for blood variables of Steller sea lion (Eumetopias jubatus), an established sentinel species, and to report reference ranges for appropriate populations using standardized analyses. In addition to comparing reference ranges between populations with contrasting abundance trends, data were examined for evidence of disease or nutritional stress. From 1998 to 2011, blood samples were collected from 1,231 pups captured on 37 rookeries across their Alaskan range. Reference ranges are reported separately for the western and eastern distinct population segments (DPS) of Steller sea lion after cluster analysis and discriminant function analysis (DFA) supported underlying stock structure. Variables with greater loading scores for the DFA (creatinine, total protein, calcium, albumin, cholesterol, and alkaline phosphatase) also were greater for sea lions from the endangered western DPS, supporting previous studies that indicated pup condition in the west was not compromised during the first month postpartum. Differences between population segments were likely a result of ecological, physiological, or age related differences. PMID:24419664

  15. Flood frequency in Alaska

    USGS Publications Warehouse

    Childers, J.M.

    1970-01-01

    Records of peak discharge at 183 sites were used to study flood frequency in Alaska. The vast size of Alaska, its great ranges of physiography, and the lack of data for much of the State precluded a comprehensive analysis of all flood determinants. Peak stream discharges, where gaging-station records were available, were analyzed for 2-year, 5-year, 10-year, 25-year, and 50-year average-recurrence intervals. A regional analysis of the flood characteristics by multiple-regression methods gave a set of equations that can be used to estimate floods of selected recurrence intervals up to 50 years for any site on any stream in Alaska. The equations relate floods to drainage-basin characteristics. The study indicates that in Alaska the 50-year flood can be estimated from 10-year gaging- station records with a standard error of 22 percent whereas the 50-year flood can be estimated from the regression equation with a standard error of 53 percent. Also, maximum known floods at more than 500 gaging stations and miscellaneous sites in Alaska were related to drainage-area size. An envelope curve of 500 cubic feet per second per square mile covered all but 2 floods in the State.

  16. On the causes of rising gross ecosystem productivity in a regenerating clearcut environment: leaf area vs. species composition.

    PubMed

    Khomik, Myroslava; Williams, Christopher A; Vanderhoof, Melanie K; MacLean, Richard G; Dillen, Sophie Y

    2014-07-01

    Clearcutting a forest ecosystem can result in a drastic reduction of stand productivity. Despite the severity of this disturbance type, past studies have found that the productivity of young regenerating stands can quickly rebound, approaching that of mature undisturbed stands within a few years. One of the obvious reasons is increased leaf area (LA) with each year of recovery. However, a less obvious reason may be the variability in species composition and distribution during the natural regeneration process. The purpose of this study was to investigate to what extent the increase in gross ecosystem productivity (GEP), observed during the first 4 years of recovery in a naturally regenerating clearcut stand, was due to (i) an overall expansion of leaf area and (ii) an increase in the canopy's photosynthetic capacity stemming from either species compositional shifts or drift in physiological traits within species. We found that the multi-year rise in GEP following harvest was clearly attributed to the expansion of LA rather than a change in vegetation composition. Sizeable changes in the relative abundance of species were masked by remarkably similar leaf physiological attributes for a range of vegetation types present in this early-successional environment. Comparison of upscaled leaf-chamber estimates with eddy-covariance-based estimates of light-response curves revealed a broad consistency in both maximum photosynthetic capacity and quantum yield efficiency. The approaches presented here illustrate how chamber- and ecosystem-scale measurements of gas exchange can be blended with species-level LA data to draw conclusive inferences about changes in ecosystem processes over time in a highly dynamic environment.

  17. Repeated sampling reveals differential variability in measures of species richness and community composition in planktonic protists.

    PubMed

    Dolan, John R; Stoeck, Thorsten

    2011-12-01

    Diversity metrics and descriptors of protistan community structure were calculated from 12 samples of 10 l each collected from the Bay of Villefranche in the NW Mediterranean Sea. Variability of the sampling was on scales of minutes and meters. The individual samples were compared with each other and compared with a pooled data set from the total volume of 120 l, considered as the 'true' community. We focused on a single group of planktonic protists, tintinnids, a coherent functional and phylogenetic group in which morpho-species identifications by light microscopy are unambiguous. Tintinnid abundance in the samples ranged from 217 to 321 cells of 16-21 species with the number of rare species in a sample (< 1% of abundance) positively related to species richness of the sample. Rarefaction estimates of total species richness in the 12 samples ranged from 21 ± 3.5 to 37 ± 3.6 compared with the 34 species of the pooled data set. The measures of similarity reflected the differences between samples in both the numbers and identities of the least abundant or rare species. The species abundance distribution using pooled data was best fit by a log-series or geometric distribution; eight species accounted for about 90% of total cells and most species, the remaining 22 out of 34, were 'rare' (concentration < 1% of total cells). Among the samples, 5 were best fit by a geometric model, 1 by a log-series distribution, 2 by a log-normal or log-series model, and 4 could not be clearly assigned a particular distribution. Our results suggest that single sample estimates of species richness are relatively robust compared with measures of taxonomic similarity and species abundance distribution. When measuring differences among populations sample variability should be considered.

  18. Paleomagnetism of the Mesozoic Asik Mountain mafic complex in northern Alaska: implications for the tectonic history of the Arctic composite terrane

    USGS Publications Warehouse

    Lewchuk, Michael T.; Foucher, Jamie; Elmore, R.D.

    2004-01-01

    At least three mutually exclusive hypotheses exist for the origin of the Arctic composite terrane and its Mesozoic location relative to the stable craton of North America. The most widely accepted hypothesis calls for counterclockwise rotation of the Arctic composite terrane as it rifted from the Arctic Archipelago. A second hypothesis calls for no relative movement, and a third places the Arctic composite terrane on the Kula plate as a part of a separate ribbon-shaped microcontinent. All three hypotheses predict unique positions for the Arctic composite terrane with respect to rotation and translation since the middle of the Mesozoic. Paleomagnetic and susceptibility studies were conducted on rocks from 15 sites in the ~160 Ma (K-Ar cooling age) Asik Mountain mafic to ultramafic complex in the western part of the Arctic composite terrane. Coherent data from 11 sites yielded a direction of dec = 255.1°, inc = 82.1° κ = 19.3, α95 = 9.6°, α63 = 5.6°. Contact and fold tests were not possible but the direction differs distinctly from the modern magnetic direction. The anisotropy of magnetic susceptibility revealed a well-developed oblate fabric of variable orientation. The orientation of the fabric was not related to the regional stress regime, so we conclude that the rocks were not deformed and metamorphosed during thrusting, and thus the magnetic remanence direction obtained is most likely primary. The direction yields a pole position at long = 166.8°E, lat = 59.8°N, A95 = 18.4°, A63 = 10.7° that is discordant to the expected 160 Ma reference direction for North America. Counterclockwise rotation of the Arctic composite terrane would yield a perfect fit to the 160 Ma reference pole with an allowance for up to 5° of northward translation. This result, combined with previous paleomagnetic data, makes a convincing argument that the Arctic composite terrane has not remained fixed in its current orientation with respect to North America. However, the data are

  19. Summer spawning in the fourhorn sculpin, Myoxocephalus quadricornis, from Alaska

    USGS Publications Warehouse

    Goldberg, S.R.; Yasutake, W.T.; West, R.L.

    1987-01-01

    Histological ovarian analysis indicates summer spawning occurs in Myoxocephalus quadricornis (Fourhorn Sculpin) from Alaska. Previous studies have shown this species spawns during winter in the Baltic Sea; the data presented herein suggests that geographical variation may occur in the timing of spawning of this species.

  20. Chaetognatha in the Bahía Magdalena lagoon complex, Baja California Sur, México: species composition and assemblages.

    PubMed

    Cota Meza, M S

    2011-07-01

    The chaetognaths from 187 zooplankton samples collected from the Bahia Magdalena lagoon complex, Baja California Sur, Mexico during March, June, July, August, September, November, and December 1982 were studied. Twelve species belonging to two genera were identified. Sagitta euneritica and S. enflata were the most abundant and most frequent species with maximum abundance in July (40,000 org/100 m(3) and 6100 org/100 m(3) respectively). Sagitta pacifica, S. regularis and S. pseudoserratodentata were stenothermic (21 to 25 degrees C), whereas the rest of the species were eurythermic (15.5 to 29.5 degrees C). Sagitta euneritica contributed considerably to the zooplanktonic biomass, increasing the density in particular in BahíaAlmejas. The analysis of the species assemblages (Morisita index) showed that S. pacifica and S. regularis interact more frequently in August when there is a change of the water masses that converge in this zone during summer, when the California Countercurrent predominates. The composition of taxa during winter is characterized by the dominance of S. euneritica. Entering the warm period, an abrupt change occurs in taxa composition of the three zones studied: channels, Bahía Magdalena, and BahíaAlmejas. The amplitude and distribution of S. peruviana was influenced possibility by the oceanographic conditions of ENSO 1982. PMID:22315819

  1. Cuticle Fatty Acid Composition and Differential Susceptibility of Three Species of Cockroaches to the Entomopathogenic Fungi Metarhizium anisopliae (Ascomycota, Hypocreales).

    PubMed

    Gutierrez, Alejandra C; Gołębiowski, Marek; Pennisi, Mariana; Peterson, Graciela; García, Juan J; Manfrino, Romina G; López Lastra, Claudia C

    2015-04-01

    Differences in free fatty acids (FFAs) chemical composition of insects may be responsible for susceptibility or resistance to fungal infection. Determination of FFAs found in cuticular lipids can effectively contribute to the knowledge concerning insect defense mechanisms. In this study, we have evaluated the susceptibility of three species of cockroaches to the entomopathogenic fungi Metarhizium anisopliae (Metschnikoff) Sorokin by topical application. Mortality due to M. anisopliae was highly significant on adults and nymphs of Blattella germanica L. (Blattodea: Blattellidae). However, mortality was faster in adults than in nymphs. Adults of Blatta orientalis L. (Blattodea: Blattidae) were not susceptible to the fungus, and nymphs of Blaptica dubia Serville (Blattodea: Blaberidae) were more susceptible to the fungus than adults. The composition of cuticular FFAs in the three species of cockroaches was also studied. The analysis indicated that all of the fatty acids were mostly straight-chain, long-chain, saturated or unsaturated. Cuticular lipids of three species of cockroaches contained 19 FFAs, ranging from C14:0 to C24:0. The predominant fatty acids found in the three studied species of cockroaches were oleic, linoleic, palmitic, and stearic acid. Only in adults of Bl. orientalis, myristoleic acid, γ-linolenic acid, arachidic acid, dihomolinoleic acid, and behenic acid were identified. Lignoceric acid was detected only in nymphs of Bl. orientalis. Heneicosylic acid and docosahexaenoic acid were identified in adults of Ba. dubia. PMID:26470187

  2. Cuticle Fatty Acid Composition and Differential Susceptibility of Three Species of Cockroaches to the Entomopathogenic Fungi Metarhizium anisopliae (Ascomycota, Hypocreales).

    PubMed

    Gutierrez, Alejandra C; Gołębiowski, Marek; Pennisi, Mariana; Peterson, Graciela; García, Juan J; Manfrino, Romina G; López Lastra, Claudia C

    2015-04-01

    Differences in free fatty acids (FFAs) chemical composition of insects may be responsible for susceptibility or resistance to fungal infection. Determination of FFAs found in cuticular lipids can effectively contribute to the knowledge concerning insect defense mechanisms. In this study, we have evaluated the susceptibility of three species of cockroaches to the entomopathogenic fungi Metarhizium anisopliae (Metschnikoff) Sorokin by topical application. Mortality due to M. anisopliae was highly significant on adults and nymphs of Blattella germanica L. (Blattodea: Blattellidae). However, mortality was faster in adults than in nymphs. Adults of Blatta orientalis L. (Blattodea: Blattidae) were not susceptible to the fungus, and nymphs of Blaptica dubia Serville (Blattodea: Blaberidae) were more susceptible to the fungus than adults. The composition of cuticular FFAs in the three species of cockroaches was also studied. The analysis indicated that all of the fatty acids were mostly straight-chain, long-chain, saturated or unsaturated. Cuticular lipids of three species of cockroaches contained 19 FFAs, ranging from C14:0 to C24:0. The predominant fatty acids found in the three studied species of cockroaches were oleic, linoleic, palmitic, and stearic acid. Only in adults of Bl. orientalis, myristoleic acid, γ-linolenic acid, arachidic acid, dihomolinoleic acid, and behenic acid were identified. Lignoceric acid was detected only in nymphs of Bl. orientalis. Heneicosylic acid and docosahexaenoic acid were identified in adults of Ba. dubia.

  3. Species composition of coastal dune vegetation in Scotland has proved resistant to climate change over a third of a century.

    PubMed

    Pakeman, Robin J; Alexander, Jim; Beaton, Joan; Brooker, Rob; Cummins, Roger; Eastwood, Antonia; Fielding, Debbie; Fisher, Julia; Gore, Sarah; Hewison, Richard; Hooper, Russell; Lennon, Jack; Mitchell, Ruth; Moore, Emily; Nolan, Andrew; Orford, Katy; Pemberton, Clare; Riach, Dave; Sim, Dave; Stockan, Jenni; Trinder, Clare; Lewis, Rob

    2015-10-01

    Climate change is expected to have an impact on plant communities as increased temperatures are expected to drive individual species' distributions polewards. The results of a revisitation study after c. 34 years of 89 coastal sites in Scotland, UK, were examined to assess the degree of shifts in species composition that could be accounted for by climate change. There was little evidence for either species retreat northwards or for plots to become more dominated by species with a more southern distribution. At a few sites where significant change occurred, the changes were accounted for by the invasion, or in one instance the removal, of woody species. Also, the vegetation types that showed the most sensitivity to change were all early successional types and changes were primarily the result of succession rather than climate-driven changes. Dune vegetation appears resistant to climate change impacts on the vegetation, either as the vegetation is inherently resistant to change, management prevents increased dominance of more southerly species or because of dispersal limitation to geographically isolated sites. PMID:26059656

  4. Species composition of coastal dune vegetation in Scotland has proved resistant to climate change over a third of a century.

    PubMed

    Pakeman, Robin J; Alexander, Jim; Beaton, Joan; Brooker, Rob; Cummins, Roger; Eastwood, Antonia; Fielding, Debbie; Fisher, Julia; Gore, Sarah; Hewison, Richard; Hooper, Russell; Lennon, Jack; Mitchell, Ruth; Moore, Emily; Nolan, Andrew; Orford, Katy; Pemberton, Clare; Riach, Dave; Sim, Dave; Stockan, Jenni; Trinder, Clare; Lewis, Rob

    2015-10-01

    Climate change is expected to have an impact on plant communities as increased temperatures are expected to drive individual species' distributions polewards. The results of a revisitation study after c. 34 years of 89 coastal sites in Scotland, UK, were examined to assess the degree of shifts in species composition that could be accounted for by climate change. There was little evidence for either species retreat northwards or for plots to become more dominated by species with a more southern distribution. At a few sites where significant change occurred, the changes were accounted for by the invasion, or in one instance the removal, of woody species. Also, the vegetation types that showed the most sensitivity to change were all early successional types and changes were primarily the result of succession rather than climate-driven changes. Dune vegetation appears resistant to climate change impacts on the vegetation, either as the vegetation is inherently resistant to change, management prevents increased dominance of more southerly species or because of dispersal limitation to geographically isolated sites.

  5. Persistent Effects of Fire Severity on Early Successional Forests in Interior Alaska

    NASA Technical Reports Server (NTRS)

    Shenoy, Aditi; Johnstone, Jill F.; Kasischke, Eric S.; Kielland, Knut

    2011-01-01

    There has been a recent increase in the frequency and extent of wildfires in interior Alaska, and this trend is predicted to continue under a warming climate. Although less well documented, corresponding increases in fire severity are expected. Previous research from boreal forests in Alaska and western Canada indicate that severe fire promotes the recruitment of deciduous tree species and decreases the relative abundance of black spruce (Picea mariana) immediately after fire. Here we extend these observations by (1) examining changes in patterns of aspen and spruce density and biomass that occurred during the first two decades of post-fire succession, and (2) comparing patterns of tree composition in relation to variations in post-fire organic layer depth in four burned black spruce forests in interior Alaska after 10-20 years of succession.Wefound that initial effects of fire severity on recruitment and establishment of aspen and black spruce were maintained by subsequent effects of organic layer depth and initial plant biomass on plant growth during post-fire succession. The proportional contribution of aspen (Populus tremuloides) to total stand biomass remained above 90% during the first and second decades of succession in severely burned sites, while in lightly burned sites the proportional contribution of aspen was reduced due to a 40- fold increase in spruce biomass in these sites. Relationships between organic layer depth and stem density and biomass were consistently negative for aspen, and positive or neutral for black spruce in all four burns. Our results suggest that initial effects of post-fire organic layer depths on deciduous recruitment are likely to translate into a prolonged phase of deciduous dominance during post-fire succession in severely burned stands. This shift in vegetation distribution has important implications for climate-albedo feedbacks, future fire regime, wildlife habitat quality and natural resources for indigenous subsistence

  6. Influence of fluoride on the bacterial composition of a dual-species biofilm composed of Streptococcus mutans and Streptococcus oralis.

    PubMed

    Jung, Ji-Eun; Cai, Jian-Na; Cho, Sung-Dae; Song, Kwang-Yeob; Jeon, Jae-Gyu

    2016-10-01

    Despite the widespread use of fluoride for the prevention of dental caries, few studies have demonstrated the effects of fluoride on the bacterial composition of dental biofilms. This study investigated whether fluoride affects the proportion of Streptococcus mutans and S. oralis in mono- and dual-species biofilm models, via microbiological, biochemical, and confocal fluorescence microscope studies. Fluoride did not affect the bacterial count and bio-volume of S. mutans and S. oralis in mono-species biofilms, except for the 24-h-old S. mutans biofilms. However, fluoride reduced the proportion and bio-volume of S. mutans but did not decrease those of S. oralis during both S. oralis and S. mutans dual-species biofilm formation, which may be related to the decrease in extracellular polysaccharide formation by fluoride. These results suggest that fluoride may prevent the shift in the microbial proportion to cariogenic bacteria in dental biofilms, subsequently inhibiting the cariogenic bacteria dominant biofilm formation. PMID:27643392

  7. Effects of Re-vegetation on Herbaceous Species Composition and Biological Soil Crusts Development in a Coal Mine Dumping Site

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Zhang, Peng; Hu, Yigang; Huang, Lei

    2016-02-01

    Despite the critical roles of plant species' diversity and biological soil crusts (BSCs) in arid and semi-arid ecosystems, the restoration of the diversity of herbaceous species and BSCs are rarely discussed during the process of vegetation restoration of anthropogenically damaged areas in these regions. In this study, the herbaceous plant species composition, along with the BSCs coverage and thicknesses, was investigated at six different re-vegetation type sites, and the natural vegetation site of the Heidaigou open pit coal mine in China's Inner Mongolia Autonomous Region was used as a reference. The highest total species richness (16), as well as the species richness (4.4), occurred in the Tree and Herbaceous vegetation type site. The species composition similarities between the restored sites and the reference site were shown to be very low, and ranged from 0.09 to 0.42. Also, among the restored sites, the similarities of the species were fairly high and similar, and ranged from 0.45 to 0.93. The density and height of the re-vegetated woody plants were significantly correlated with the indexes of the diversity of the species. The Shrub vegetation type site showed the greatest total coverage (80 %) of BSCs and algae crust coverage (48 %). The Shrub and Herbaceous type had the greatest thicknesses of BSCs, with as much as 3.06 mm observed, which was followed by 2.64 mm for the Shrub type. There was a significant correlation observed between the coverage of the total BSCs, and the total vegetation and herbaceous vegetation coverage, as well as between the algae crust coverage and the herbaceous vegetation coverage. It has been suggested that the re-vegetated dwarf woody plant species (such as shrubs and semi-shrubs) should be chosen for the optimal methods of the restoration of herbaceous species diversity at dumping sites, and these should be planted with low density. Furthermore, the effects of vegetation coverage on the colonization and development the BSCs

  8. Effects of Re-vegetation on Herbaceous Species Composition and Biological Soil Crusts Development in a Coal Mine Dumping Site.

    PubMed

    Zhao, Yang; Zhang, Peng; Hu, Yigang; Huang, Lei

    2016-02-01

    Despite the critical roles of plant species' diversity and biological soil crusts (BSCs) in arid and semi-arid ecosystems, the restoration of the diversity of herbaceous species and BSCs are rarely discussed during the process of vegetation restoration of anthropogenically damaged areas in these regions. In this study, the herbaceous plant species composition, along with the BSCs coverage and thicknesses, was investigated at six different re-vegetation type sites, and the natural vegetation site of the Heidaigou open pit coal mine in China's Inner Mongolia Autonomous Region was used as a reference. The highest total species richness (16), as well as the species richness (4.4), occurred in the Tree and Herbaceous vegetation type site. The species composition similarities between the restored sites and the reference site were shown to be very low, and ranged from 0.09 to 0.42. Also, among the restored sites, the similarities of the species were fairly high and similar, and ranged from 0.45 to 0.93. The density and height of the re-vegetated woody plants were significantly correlated with the indexes of the diversity of the species. The Shrub vegetation type site showed the greatest total coverage (80%) of BSCs and algae crust coverage (48%). The Shrub and Herbaceous type had the greatest thicknesses of BSCs, with as much as 3.06 mm observed, which was followed by 2.64 mm for the Shrub type. There was a significant correlation observed between the coverage of the total BSCs, and the total vegetation and herbaceous vegetation coverage, as well as between the algae crust coverage and the herbaceous vegetation coverage. It has been suggested that the re-vegetated dwarf woody plant species (such as shrubs and semi-shrubs) should be chosen for the optimal methods of the restoration of herbaceous species diversity at dumping sites, and these should be planted with low density. Furthermore, the effects of vegetation coverage on the colonization and development the BSCs

  9. Effects of Re-vegetation on Herbaceous Species Composition and Biological Soil Crusts Development in a Coal Mine Dumping Site.

    PubMed

    Zhao, Yang; Zhang, Peng; Hu, Yigang; Huang, Lei

    2016-02-01

    Despite the critical roles of plant species' diversity and biological soil crusts (BSCs) in arid and semi-arid ecosystems, the restoration of the diversity of herbaceous species and BSCs are rarely discussed during the process of vegetation restoration of anthropogenically damaged areas in these regions. In this study, the herbaceous plant species composition, along with the BSCs coverage and thicknesses, was investigated at six different re-vegetation type sites, and the natural vegetation site of the Heidaigou open pit coal mine in China's Inner Mongolia Autonomous Region was used as a reference. The highest total species richness (16), as well as the species richness (4.4), occurred in the Tree and Herbaceous vegetation type site. The species composition similarities between the restored sites and the reference site were shown to be very low, and ranged from 0.09 to 0.42. Also, among the restored sites, the similarities of the species were fairly high and similar, and ranged from 0.45 to 0.93. The density and height of the re-vegetated woody plants were significantly correlated with the indexes of the diversity of the species. The Shrub vegetation type site showed the greatest total coverage (80%) of BSCs and algae crust coverage (48%). The Shrub and Herbaceous type had the greatest thicknesses of BSCs, with as much as 3.06 mm observed, which was followed by 2.64 mm for the Shrub type. There was a significant correlation observed between the coverage of the total BSCs, and the total vegetation and herbaceous vegetation coverage, as well as between the algae crust coverage and the herbaceous vegetation coverage. It has been suggested that the re-vegetated dwarf woody plant species (such as shrubs and semi-shrubs) should be chosen for the optimal methods of the restoration of herbaceous species diversity at dumping sites, and these should be planted with low density. Furthermore, the effects of vegetation coverage on the colonization and development the BSCs

  10. Accretion of southern Alaska

    USGS Publications Warehouse

    Hillhouse, J.W.

    1987-01-01

    Paleomagnetic data from southern Alaska indicate that the Wrangellia and Peninsular terranes collided with central Alaska probably by 65 Ma ago and certainly no later than 55 Ma ago. The accretion of these terranes to the mainland was followed by the arrival of the Ghost Rocks volcanic assemblage at the southern margin of Kodiak Island. Poleward movement of these terranes can be explained by rapid motion of the Kula oceanic plate, mainly from 85 to 43 Ma ago, according to recent reconstructions derived from the hot-spot reference frame. After accretion, much of southwestern Alaska underwent a counterclockwise rotation of about 50 ?? as indicated by paleomagnetic poles from volcanic rocks of Late Cretaceous and Early Tertiary age. Compression between North America and Asia during opening of the North Atlantic (68-44 Ma ago) may account for the rotation. ?? 1987.

  11. Plant compartment and biogeography affect microbiome composition in cultivated and native Agave species.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary goal of this research was to investigate the prokaryotic and fungal communities associated with the bulk soil, the rhizosphere, the phyllosphere, and the root and leaf endospheres, for three Agave species: the cultivated Agave tequilana and the native species, A. salmiana and A. deserti ...

  12. Notes to the species composition of the genus Paramacrobiotus Guidetti et al., 2009 (Tardigrada, Eutardigrada, Macrobiotidae).

    PubMed

    Degma, Peter

    2013-01-01

    For this paper I analyzed the descriptions of all seventy seven currently known Macrobiotus species with three macroplacoids, with or without a microplacoid, to ascertain if they fit to the morphological diagnosis of the genus Paramacrobiotus Guidetti et al., 2009. Most (sixty three species) differed from the genus Paramacrobiotus characters as they were either members of the Macrobiotus harmsworthi and furciger species groups or did not possess the combination of two unique genus characters (elongated macroplacoids and microplacoid considerably distant from the third macroplacoid, if present). Insufficient descriptions for a further ten species means their taxonomic positions remain unclear. Four Macrobiotus species are transferred to the genus Paramacrobiotus and their new taxonomic position is Paramacrobiotus danielisae (Pilato, Binda & Lisi, 2006) comb. nov., Paramacrobiotus hapukuensis (Pilato, Binda & Lisi, 2006) comb. nov., Paramacrobiotus priviterae (Binda, Pilato, Moncada & Napolitano, 2001) comb. nov. and Paramacrobiotus sklodowskae (Michalczyk, Kaczmarek & Weglarska, 2006) comb. nov.

  13. Notes to the species composition of the genus Paramacrobiotus Guidetti et al., 2009 (Tardigrada, Eutardigrada, Macrobiotidae).

    PubMed

    Degma, Peter

    2013-01-01

    For this paper I analyzed the descriptions of all seventy seven currently known Macrobiotus species with three macroplacoids, with or without a microplacoid, to ascertain if they fit to the morphological diagnosis of the genus Paramacrobiotus Guidetti et al., 2009. Most (sixty three species) differed from the genus Paramacrobiotus characters as they were either members of the Macrobiotus harmsworthi and furciger species groups or did not possess the combination of two unique genus characters (elongated macroplacoids and microplacoid considerably distant from the third macroplacoid, if present). Insufficient descriptions for a further ten species means their taxonomic positions remain unclear. Four Macrobiotus species are transferred to the genus Paramacrobiotus and their new taxonomic position is Paramacrobiotus danielisae (Pilato, Binda & Lisi, 2006) comb. nov., Paramacrobiotus hapukuensis (Pilato, Binda & Lisi, 2006) comb. nov., Paramacrobiotus priviterae (Binda, Pilato, Moncada & Napolitano, 2001) comb. nov. and Paramacrobiotus sklodowskae (Michalczyk, Kaczmarek & Weglarska, 2006) comb. nov. PMID:25232590

  14. Enterococcus species composition determined by capillary electrophoresis of the groESL gene spacer region DNA.

    PubMed

    Yasuda, M; Paar, J; Doolittle, M; Brochi, J; Pancorbo, O C; Tang, R J; Stoner, R E; Shiaris, M P

    2010-07-01

    Marine recreational beaches are monitored for fecal contamination by Enterococcus spp. (ENT) counts. Although different ENT species in the environment tend to thrive in and originate from distinct hosts, the current monitoring method does not differentiate among species. Time-consuming isolation-based species identification precludes routine analysis of environmental ENT communities. Therefore, an isolation-independent DNA fingerprinting method was developed to characterize environmental ENT communities using DNA length polymorphism of the spacer region between the groES and groEL genes common to most ENT species. Capillary electrophoresis resulted in distinct peak sizes of PCR products that carried polymorphic groESL spacers (300-335 bp in length) among 8 different ENT species (Enterococcus avium, Enterococcus gallinarum, Enterococcus casseliflavus, Enterococcus mundtii, Enterococcus hirae, Enterococcus faecium, Enterococcus durans, and Enterococcus faecalis). Distortions in true species ratios observed in electropherograms were caused by PCR biases arising in a mixed ENT community DNA template. E. faecalis was overestimated and E. avium and E. faecium were underestimated compared to the original species ratios in the mixed community. The PCR product bias was constant between species, so good approximation of the species ratio in ENT communities is possible. In environmental samples, a high percentage of E. faecalis (96%) together with high total ENT counts were observed in samples collected from a sewer line and from several sites in a storm drain system where sewage leaks were suspected. In contrast, samples with <400 CFU 100 ml-1 ENT were either dominated by E. mundtii or had 4 or more ENT species. The latter ENT community profiles are considered to be signatures of enterococci rarely associated with animals with low or of non-fecal origin.

  15. Chemical composition and bioethanol potential of different plant species found in Pacific Northwest conservation buffers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lands producing mixed lignocellulosic ethanol feedstocks may be able to produce more biomass with fewer resources than conventional monoculture crops, but lignocellulosic ethanol production processes and efficiencies can be highly dependent on feedstock composition. In this study, plants were collec...

  16. USGS Alaska State Mosaic

    USGS Publications Warehouse

    ,

    2008-01-01

    The Alaska State Mosaic consists of portions of scenes from the Multi-Resolution Land Characteristics 2001 (MRLC 2001) collection. The 172 selected scenes have been geometrically and radiometrically aligned to produce a seamless, relatively cloud-free image of the State. The scenes were acquired between July 1999 and September 2002, resampled to 120-meter pixels, and cropped to the State boundary. They were reprojected into a standard Alaska Albers projection with the U.S. National Elevation Dataset (NED) used to correct for relief.

  17. Species Richness Responses to Structural or Compositional Habitat Diversity between and within Grassland Patches: A Multi-Taxon Approach

    PubMed Central

    Lengyel, Szabolcs; Déri, Eszter; Magura, Tibor

    2016-01-01

    Habitat diversity (spatial heterogeneity within and between habitat patches in a landscape, HD) is often invoked as a driver of species diversity at small spatial scales. However, the effect of HD on species richness (SR) of multiple taxa is not well understood. We quantified HD and SR in a wet-dry gradient of open grassland habitats in Hortobágy National Park (E-Hungary) and tested the effect of compositional and structural factors of HD on SR of flowering plants, orthopterans, true bugs, spiders, ground beetles and birds. Our dataset on 434 grassland species (170 plants, 264 animals) showed that the wet-dry gradient (compositional HD at the between-patch scale) was primarily related to SR in orthopterans, ground-dwelling arthropods, and all animals combined. The patchiness, or plant association richness, of the vegetation (compositional HD at the within-patch scale) was related to SR of vegetation-dwelling arthropods, whereas vegetation height (structural HD at the within-patch scale) was related to SR of ground-dwelling arthropods and birds. Patch area was related to SR only in birds, whereas management (grazing, mowing, none) was related to SR of plants and true bugs. All relationships between HD and SR were positive, indicating increasing SR with increasing HD. However, total SR was not related to HD because different taxa showed similar positive responses to different HD variables. Our findings, therefore, show that even though HD positively influences SR in a wide range of grassland taxa, each taxon responds to different compositional or structural measures of HD, resulting in the lack of a consistent relationship between HD and SR when taxon responses are pooled. The idiosyncratic responses shown here exemplify the difficulties in detecting general HD-SR relationships over multiple taxa. Our results also suggest that management and restoration aimed specifically to sustain or increase the diversity of habitats are required to conserve biodiversity in

  18. Species Richness Responses to Structural or Compositional Habitat Diversity between and within Grassland Patches: A Multi-Taxon Approach.

    PubMed

    Lengyel, Szabolcs; Déri, Eszter; Magura, Tibor

    2016-01-01

    Habitat diversity (spatial heterogeneity within and between habitat patches in a landscape, HD) is often invoked as a driver of species diversity at small spatial scales. However, the effect of HD on species richness (SR) of multiple taxa is not well understood. We quantified HD and SR in a wet-dry gradient of open grassland habitats in Hortobágy National Park (E-Hungary) and tested the effect of compositional and structural factors of HD on SR of flowering plants, orthopterans, true bugs, spiders, ground beetles and birds. Our dataset on 434 grassland species (170 plants, 264 animals) showed that the wet-dry gradient (compositional HD at the between-patch scale) was primarily related to SR in orthopterans, ground-dwelling arthropods, and all animals combined. The patchiness, or plant association richness, of the vegetation (compositional HD at the within-patch scale) was related to SR of vegetation-dwelling arthropods, whereas vegetation height (structural HD at the within-patch scale) was related to SR of ground-dwelling arthropods and birds. Patch area was related to SR only in birds, whereas management (grazing, mowing, none) was related to SR of plants and true bugs. All relationships between HD and SR were positive, indicating increasing SR with increasing HD. However, total SR was not related to HD because different taxa showed similar positive responses to different HD variables. Our findings, therefore, show that even though HD positively influences SR in a wide range of grassland taxa, each taxon responds to different compositional or structural measures of HD, resulting in the lack of a consistent relationship between HD and SR when taxon responses are pooled. The idiosyncratic responses shown here exemplify the difficulties in detecting general HD-SR relationships over multiple taxa. Our results also suggest that management and restoration aimed specifically to sustain or increase the diversity of habitats are required to conserve biodiversity in

  19. Species Richness Responses to Structural or Compositional Habitat Diversity between and within Grassland Patches: A Multi-Taxon Approach.

    PubMed

    Lengyel, Szabolcs; Déri, Eszter; Magura, Tibor

    2016-01-01

    Habitat diversity (spatial heterogeneity within and between habitat patches in a landscape, HD) is often invoked as a driver of species diversity at small spatial scales. However, the effect of HD on species richness (SR) of multiple taxa is not well understood. We quantified HD and SR in a wet-dry gradient of open grassland habitats in Hortobágy National Park (E-Hungary) and tested the effect of compositional and structural factors of HD on SR of flowering plants, orthopterans, true bugs, spiders, ground beetles and birds. Our dataset on 434 grassland species (170 plants, 264 animals) showed that the wet-dry gradient (compositional HD at the between-patch scale) was primarily related to SR in orthopterans, ground-dwelling arthropods, and all animals combined. The patchiness, or plant association richness, of the vegetation (compositional HD at the within-patch scale) was related to SR of vegetation-dwelling arthropods, whereas vegetation height (structural HD at the within-patch scale) was related to SR of ground-dwelling arthropods and birds. Patch area was related to SR only in birds, whereas management (grazing, mowing, none) was related to SR of plants and true bugs. All relationships between HD and SR were positive, indicating increasing SR with increasing HD. However, total SR was not related to HD because different taxa showed similar positive responses to different HD variables. Our findings, therefore, show that even though HD positively influences SR in a wide range of grassland taxa, each taxon responds to different compositional or structural measures of HD, resulting in the lack of a consistent relationship between HD and SR when taxon responses are pooled. The idiosyncratic responses shown here exemplify the difficulties in detecting general HD-SR relationships over multiple taxa. Our results also suggest that management and restoration aimed specifically to sustain or increase the diversity of habitats are required to conserve biodiversity in

  20. Species Composition and Seasonal Distribution of Mosquito Larvae (Diptera: Culicidae) in Southern New Jersey, Burlington County.

    PubMed

    Verna, Thomas N

    2015-09-01

    A total of 36,495 larvae consisting of 45 species from 11 genera were collected from 7,189 sites from southern New Jersey, Burlington County between the months of March and October, 2001-2014. Density and seasonal distribution were determined among natural and artificial habitat. The most dominant species collected from natural habitat was Aedes vexans (Meigen) followed by Ochlerotatus canadensis canadensis (Theobald), Culex restuans Theobald, Culex pipiens L., and Culex territans Walker. The most dominant species collected from artificial habitat was Aedes albopictus (Skuse) followed by Ochlerotatus japonicus japonicus (Theobald), Cx. restuans, Cx. pipiens, and Ochlerotatus triseriatus (Say). Cx. restuans and Cx. pipiens were the only species categorized as dominant among both natural and artificial habitat and comprised greater than half the total density. Sympatry was common among dominant species from artificial habitat where a significant percentage of the total collection contained multiple species. The most common types of natural habitats were forested depressions and stream flood plains whereas rimless vehicle tires and various plastic containers were the most common artificial habitats. The pitcher plant Sarracenia purpurea L. was the only habitat exclusive to one species.

  1. Interspecies and interregional comparisons of the chemistry of PAHs and trace elements in mosses Hylocomium splendens (Hedw.) B.S.G. and Pleurozium schreberi (Brid.) Mitt. from Poland and Alaska

    USGS Publications Warehouse

    Migaszewski, Z.M.; Galuszka, A.; Crock, J.G.; Lamothe, P.J.; Dolegowska, S.

    2009-01-01

    Comparative biogeochemical studies performed on the same plant species in remote areas enable pinpointing interspecies and interregional differences of chemical composition. This report presents baseline concentrations of PAHs and trace elements in moss species Hylocomium splendens and Pleurozium schreberi from the Holy Cross Mountains (south-central Poland) (HCM) and Wrangell-Saint Elias National Park and Preserve (Alaska) and Denali National Park and Preserve (Alaska). Total PAH concentrations in the mosses of HCM were in the range of 473-2970 ??g kg-1 (dry weight basis; DW), whereas those in the same species of Alaska were 80-3390 ??g kg-1 DW. Nearly all the moss samples displayed the similar ring sequence: 3 > 4 > 5 > 6 for the PAHs. The 3 + 4 ring/total PAH ratios show statistically significant differences between HCM (0.73) and Alaska (0.91). The elevated concentrations of PAHs observed in some sampling locations of the Alaskan parks were linked to local combustion of wood, with a component of vehicle particle- and vapor-phase emissions. In HCM, the principal source of PAH emissions has been linked to residential and industrial combustion of coal and vehicle traffic. In contrast to HCM, the Alaskan mosses were distinctly elevated in most of the trace elements, bearing a signature of??the underlying geology. H.??splendens and P. schreberi showed diverse bioaccumulative capabilities of PAHs in all three study areas. ?? 2008 Elsevier Ltd.

  2. Decoupled connection between soil microbial community and organic geochemical composition: a case study in the Arctic tundra, North Slope of Alaska

    NASA Astrophysics Data System (ADS)

    Liang, C.; Steffens, M.; Jastrow, J. D.; Zhang, X.; Antonopoulos, D. A.; Kogel-Knabner, I.

    2013-12-01

    Two-way feedback interactions persist between the soil microbiology and the carbon (C) geochemistry through C substrate-uptake preference and microbial utilization/transformation. Therefore, an understanding of how those continuously iterative processes influence soil microbial community and geochemical composition of soil organic matter is essential. However, finding direct correlations between the both has remained a challenge and been little explored. Here we show an unequivocal evidence that the forces structuring the soil microbial community and the organic geochemical composition of tundra soils differ. We determined soil microbial community and soil organic C (SOC) composition by four molecular-level techniques, i.e. DNA pyrosequencing and phospholipids fatty acid (PLFA) biomarkers for microbial analysis and solid-state 13C NMR spectroscopy and neutral sugars for SOC characterization for active-layer and permafrost. By independently summarizing explanatory structures of the relative abundance of microbial groups and soil C forms (using ordination and cluster analysis), we found that microbial community and the SOC chemistry were each consistently characterized by the two distinct measurement approaches. These methods identified distinct pattern differences between soil horizons (permafrost layer versus active organic layer) in both microbial community and the SOC. We used correlations to build the hypothesis about 'decoupled connection between microbiology and SOC geochemistry', particularly of their non-linearity in tundra soils, and then to assess how the C decomposition rate constants (at 4°C) relate to those structural patterns. We demonstrate that the controls on soil microbial community structure are fundamentally different from those on substrate C composition within tundra soils, thus enriching our understanding of C biogeochemical cycling and associated microbial behaviors.

  3. Consideration of species community composition in statistical analyses of coral disease risk

    EPA Science Inventory

    Diseases are increasing in marine ecosystems, and these increases have been attributed to a number of environmental factors including climate change, pollution, and overfishing. However, many studies pool disease prevalence into taxonomic groups, disregarding host species compos...

  4. Impact of resource availability on species composition and diversity in freshwater nematodes.

    PubMed

    Michiels, Iris C; Traunspurger, Walter

    2005-01-01

    This study investigates the long-term effects of resource availability in a freshwater nematode community. We carried out a mesocosm experiment where natural nematode communities were exposed to nutrient addition/depletion over 2 years. Compared to the nutrient-addition treatment, species richness and diversity were strongly reduced upon nutrient depletion. The functional group of bacterial feeders particularly suffered severely from nutrient depletion. The decrease in diversity of bacterial feeders was linked to reduced species richness and diversity of large omnivorous species, as predicted by trophic-dynamic models. Tilman's (1976) statement, that under low nutrient levels the best competitor dominates the system, was applicable in our system. Upon nutrient depletion, resource depletion led to a monoculture of 1 small bacterial feeder, but even after 2 years of resource depletion, up to 16 species still coexisted. Our results provide strong evidence that freshwater nematode systems can be regulated by nutrient competition. PMID:15365809

  5. Abundance and species composition of Tintinnina (ciliophora) in Bahía Blanca estuary, Argentina

    NASA Astrophysics Data System (ADS)

    Barría de Cao, M. S.

    1992-03-01

    Numerical abundance and seasonal cycle of tintinnines species were studied in the inner part of the Bahía Blanca estuary. Sampling was carried out at two fixed stations at approximately weekly intervals over the period March 1986-February 1987. Nineteen species representing five genera were recorded. Most species belonged to the genus Tintinnopsis. Maximal abundances of tintinnines, 10·1 × 10 3 1 -1 and 11·3 × 10 3 1 -1 at each station respectively, were found in summer. Minimal abundances, 0·5 × 10 3 1 -1 and 0·7 × 10 3 1 -1 at each station respectively, were found in winter. Tintinnidium balechi, Tintinnopsis parva and Tintinnopsis glans were present throughout the year. Tintinnopsis gracilis, Tintinnopsis baltica and Tintinnopsis beroidea exhibited seasonal occurrence, the remaining species did not show a clear pattern of distribution. The presence of Favella taraikaensis demonstrated occasional intrusions of typical fauna of the outer estuary.

  6. Impact of competitor species composition on predicting diameter growth and survival rates of Douglas-fir trees in southwestern Oregon

    USGS Publications Warehouse

    Bravo, Felipe; Hann, D.W.; Maguire, Douglas A.

    2001-01-01

    Mixed conifer and hardwood stands in southwestern Oregon were studied to explore the hypothesis that competition effects on individual-tree growth and survival will differ according to the species comprising the competition measure. Likewise, it was hypothesized that competition measures should extrapolate best if crown-based surrogates are given preference over diameter-based (basal area based) surrogates. Diameter growth and probability of survival were modeled for individual Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees growing in pure stands. Alternative models expressing one-sided and two-sided competition as a function of either basal area or crown structure were then applied to other plots in which Douglas-fir was mixed with other conifers and (or) hardwood species. Crown-based variables outperformed basal area based variables as surrogates for one-sided competition in both diameter growth and survival probability, regardless of species composition. In contrast, two-sided competition was best represented by total basal area of competing trees. Surrogates reflecting differences in crown morphology among species relate more closely to the mechanics of competition for light and, hence, facilitate extrapolation to species combinations for which no observations are available.

  7. Species composition and natural infectivity of anthropophilic Anopheles (Diptera: Culicidae) in Córdoba and Antioquia states in northwestern Colombia

    PubMed Central

    Gutiérrez, Lina A; González, John J; Gómez, Giovan F; Castro, Martha I; Rosero, Doris A; Luckhart, Shirley; Conn, Jan E; Correa, Margarita M

    2011-01-01

    Malaria is a serious health problem in Córdoba and Antioquia states in northwestern Colombia, where 64.4% of the total Colombian cases were reported in 2007. Because little entomological information is available in this region, the aim of this work was to identify the Anopheles species composition and natural infectivity of mosquitoes distributed in seven localities with the highest malaria transmission. A total of 1,768 Anopheles mosquitoes were collected using human landing catches from March 2007 to July 2008. Ten species were identified; overall, An. nuneztovari s.l. was the most widespread (62%) and showed the highest average human biting rates. There were six other species of the Nyssorhynchus subgenus: An. albimanus (11.6%), An. darlingi (9.8%), An. braziliensis (6.6%), An. triannulatus s.l. (3.5%), An. albitarsis s.l. and An. oswaldoi s.l. at <1%; and three of the Anopheles subgenus: An. punctimacula, An. pseudopunctipennis s.l. and An. neomaculipalpus at <1% each. Two species from Córdoba, An. nuneztovari and An. darlingi, were detected naturally infected by Plasmodium vivax VK247 using ELISA and confirmed by nested PCR. All species were active indoors and outdoors. These results provide basic information for targeted vector control strategies in these localities. PMID:20140372

  8. Use of an airborne lidar system to model plant species composition and diversity of Mediterranean oak forests.

    PubMed

    Simonson, William D; Allen, Harriet D; Coomes, David A

    2012-10-01

    Airborne lidar is a remote-sensing tool of increasing importance in ecological and conservation research due to its ability to characterize three-dimensional vegetation structure. If different aspects of plant species diversity and composition can be related to vegetation structure, landscape-level assessments of plant communities may be possible. We examined this possibility for Mediterranean oak forests in southern Portugal, which are rich in biological diversity but also threatened. We compared data from a discrete, first-and-last return lidar data set collected for 31 plots of cork oak (Quercus suber) and Algerian oak (Quercus canariensis) forest with field data to test whether lidar can be used to predict the vertical structure of vegetation, diversity of plant species, and community type. Lidar- and field-measured structural data were significantly correlated (up to r= 0.85). Diversity of forest species was significantly associated with lidar-measured vegetation height (R(2) = 0.50, p < 0.001). Clustering and ordination of the species data pointed to the presence of 2 main forest classes that could be discriminated with an accuracy of 89% on the basis of lidar data. Lidar can be applied widely for mapping of habitat and assessments of habitat condition (e.g., in support of the European Species and Habitats Directive [92/43/EEC]). However, particular attention needs to be paid to issues of survey design: density of lidar points and geospatial accuracy of ground-truthing and its timing relative to acquisition of lidar data.

  9. Comparison of the chemical composition of three species of smartweed (genus Persicaria) with a focus on drimane sesquiterpenoids.

    PubMed

    Prota, N; Mumm, R; Bouwmeester, H J; Jongsma, M A

    2014-12-01

    The genus Persicaria is known to include species accumulating drimane sesquiterpenoids, but a comparative analysis highlighting the compositional differences has not been done. In this study, the secondary metabolites of both flowers and leaves of Persicariahydropiper, Persicariamaculosa and Persicariaminor, three species which occur in the same habitat, were compared. Using gas chromatography-mass spectrometry (GC-MS) analysis of extracts, overall 21/29 identified compounds in extracts were sesquiterpenoids and 5/29 were drimanes. Polygodial was detected in all species, though not in every sample of P. maculosa. On average, P. hydropiper flowers contained about 6.2 mg g FW(-1) of polygodial, but P. minor flowers had 200-fold, and P. maculosa 100,000 fold lower concentrations. Comparatively, also other sesquiterpenes were much lower in those species, suggesting the fitness benefit to depend on either investing a lot or not at all in terpenoid-based secondary defences. For P. hydropiper, effects of flower and leaf development and headspace volatiles were analysed as well. The flower stage immediately after fertilisation was the one with the highest content of drimane sesquiterpenoids and leaves contained about 10-fold less of these compounds compared to flowers. The headspace of P. hydropiper contained 8 compounds: one monoterpene, one alkyl aldehyde and six sesquiterpenes, but none were drimanes. The potential ecological significance of the presence or absence of drimane sesquiterpenoids and other metabolites for these plant species are discussed.

  10. Understanding species composition from NEON high resolution hyperspectral-LIDAR data across a heterogeneous landscape: Effects of land use, fire regime and topography

    NASA Astrophysics Data System (ADS)

    Bohlman, S.; Graves, S.; Shahriari Nia, M.; Paul, G.; Leila, K.; Wang, D. Z.

    2015-12-01

    The 2014 NEON hyperspectral LIDAR data allows landscape scale analysis of how abiotic factors and management history affect ecosystem composition and function. At the Ordway Swisher Biological Station (OSBS) in Florida, the core terrestrial NEON site in the Southeast U.S., we are developing a framework applicable to all NEON sites for mapping and analyzing species composition. In this region, small changes in topography (elevation varies by only 20 m at OSBS) along with fire history are the dominant controls on tree species composition. To discriminate species, we use compare support vector machines (SVMs) with possibilistic classifiers (POCs), which may classify species as unknown and represent ambiguity among spectrally similar species better than common classifiers than (SVM). Species classification was most accurate (90%) using POC in the dominant upland longleaf pine forest type (where most trees belonged to just two species: Pinus palustris and Quercus laevis). It was lower (<60%) using SVM and in the hardwood hammocks (where > 10 hardwood species commonly co-occur, including multiple Quercus). For co-occurring hardwood species that were difficult to separate spectrally, we combined the NEON hyperspectral data with additional data sets (global and regional plant trait databases, state-level maps of ecosystem type, and U.S. Forest Service inventory data) in a possibilistic framework to increase the separability of species identity. We then generate a landscape-scale map of species composition at OSBS. Combining this species map with a LIDAR-derived topography, we show that species associations vary with topography. For example, some Quercus species tend to co-occur with each other in uplands, but not in mesic hammocks. We examine potential factors causing changes in community composition, including topography, water table depth, soil type, current fire management regime, and historical land use. By combining the NEON hyperspectral and LIDAR data with detailed

  11. Leaf litter decomposition of four different deciduous tree species - resource stoichiometry, nutrient release and microbial community composition

    NASA Astrophysics Data System (ADS)

    Leitner, S.; Keiblinger, K. M.; Zechmeister-Boltenstern, S.

    2012-04-01

    Recently, there has been increasing interest in the role of microbial communities for ecosystem processes like litter decomposition and nutrient cycling. For example, fungi are thought to be key players during litter decomposition in terrestrial ecosystems because they are able to degrade recalcitrant compounds like lignin and also dominate the decomposition of cellulose and hemicellulose, whereas bacteria seem to play an important role for lignin decomposition especially under anaerobic conditions. However, our knowledge about the contribu