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Highest Biomass (highest + biomass)
Selected AbstractsSEAWEED ABUNDANCE AND DIVERSITY IN HIGH ENERGY AND LOW ENERGY AREAS AT PORT ARANSAS, TEXAS JETTIESJOURNAL OF PHYCOLOGY, Issue 3 2001Article first published online: 24 SEP 200 Agan, J. C. & Lehman, R. L. Department of Physical and Life Sciences, Texas A&M University-Corpus Christi 6300 Ocean Dr., Corpus Christi, TX 78412 USA Benthic algal sampling from high and low energy zones at a selected site on the south jetty at Port Aransas, Texas was completed between April 1999 and February 2000. Species composition and seasonal periodicity in relation to temperature and salinity fluctuations were determined. Dominant plants throughout the year included Bryocladia cuspidata, Bryocladia thyrsigera, Gelidium pusillum, Centroceras clavulatum, Ulva fasciata, and Padina gymnospora. The Rhodophyta dominated species coverage, along with biomass accumulation, although Chlorophyta species accrued the greatest biomass on the high energy side in April and June sampling. Chlorophyta are important to benthic coverage and biomass in the shallowest of waters, despite being fewer in species richness. Phaeophyta species including Petalonia fascia, Hincksia mitchelliae, and Ectocarpus siliculosus were found only during the cooler months. Padina gymnospora was the one exception as it was collected year-round. Results indicate that a greater Rhodophyta abundance was found on the channel side (low energy), where as, the surf side (high energy) contained a greater Chlorophyta abundance. Phaeophyta abundance for both high and low energy sites were comparable possibly due to the greater depth of water in which they are located. Little variance occurred in average biomass accumulation throughout the year. Highest biomass was in August (216.613g dry weight) with lowest occurring in April (107.4205g dry weight). [source] SEAWEED ABUNDANCE AND DIVERSITY IN HIGH ENERGY AND LOW ENERGY AREAS AT PORT ARANSAS, TEXAS JETTIESJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 9 OCT 200 Agan, J. C. & Lehman, R. L. Department of Physical and Life Sciences, Texas A&M University-Corpus Christi 6300 Ocean Dr., Corpus Christi, TX 78412 USA Benthic algal sampling from high and low energy zones at a selected site on the south jetty at Port Aransas, Texas was completed between April 1999 and February 2000. Species composition and seasonal periodicity in relation to temperature and salinity fluctuations were determined. Dominant plants throughout the year included Bryocladia cuspidata, Bryocladia thyrsigera, Gelidium pusillum, Centroceras clavulatum, Ulva fasciata, and Padina gymnospora. The Rhodophyta dominated species coverage, along with biomass accumulation, although Chlorophyta species accrued the greatest biomass on the high energy side in April and June sampling. Chlorophyta are important to benthic coverage and biomass in the shallowest of waters, despite being fewer in species richness. Phaeophyta species including Petalonia fascia, Hincksia mitchelliae, and Ectocarpus siliculosus were found only during the cooler months. Padina gymnospora was the one exception as it was collected year-round. Results indicate that a greater Rhodophyta abundance was found on the channel side (low energy), where as, the surf side (high energy) contained a greater Chlorophyta abundance. Phaeophyta abundance for both high and low energy sites were comparable possibly due to the greater depth of water in which they are located. Little variance occurred in average biomass accumulation throughout the year. Highest biomass was in August (216.613g dry weight) with lowest occurring in April (107.4205g dry weight). [source] Hepatotoxic cyanobacterial blooms in the lakes of northern PolandENVIRONMENTAL TOXICOLOGY, Issue 5 2005Joanna Mankiewicz Abstract The lakes of northern Poland are among the recreational sites most valued by Polish and German holiday makers. Given the socioeconomic importance of these lakes, water quality should be maintained at high levels for such intensive recreational purposes. In 2002 studies of species composition, biomass, and toxin production by phytoplankton and the attendant physicochemical variables were performed in order to assess the risk of cyanobacterial blooms in selected northern lakes: Lakes Jeziorak, Jagodne, Szymoneckie, Szymon, Taltowisko, Siecino, and Trzesiecko. The research showed that total phosphorus (0.1 mg P/L) and total nitrogen (1.5 mg N/L) in the studied lakes almost exceeded the permissible limits for eutrophication of water bodies. Most phytoplankton samples were taken in late summer, when cyanobacteria were expected to reach their highest biomass. At the time of sampling most of the lakes were dominated by oscillatorialean and nostocalean species. Average chlorophyll-a concentration was higher than 10 ,g/L in almost all the lakes studied, which corresponded with an average microcystin concentration in the range of 4,5 ,g/L. The main microcystins in the analyzed samples were dmMC-RR, MC-RR, MC-YR, and MC-LR. The results demonstrated a potential for intensive cyanobacterial blooms to appear during the summer in northern Polish lakes. The levels of cyanobacteria found in the lakes investigated indicated that toxicity had reached the first-alert level according to World Health Organization recommendations. If microcystin-producing cyanobacteria dominate, with a microcystin concentration of 2,4 ,g/L, symptoms of toxicity can appear in the swimmers most sensitive to exposure. Analysis of cyanobacterial assemblages in northern Polish lakes also indicated a significant presence of Aphanizomenon species including a Scandinavian species, A. skujae (Skuja) Kom.-Legn. & Cronb. Future investigations of Polish lakes also should assess neurotoxins and study the biology of their producers. This study was the first attempt to evaluate the potential danger of toxic cyanobacterial blooms in the lakes of northern Poland. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 499,506, 2005. [source] Comparison of the abilities of redtop (Agrostis alba L.) and zoysiagrass (Zoysia japonica Steud.) to purify liquid animal wasteGRASSLAND SCIENCE, Issue 1 2006Naoko Takada-Oikawa Abstract The animal waste treatment facility of Azabu University utilizes cultivation beds where liquid animal waste is purified by filtration through soil and vegetation. The beds are presently covered with zoysiagrass (Zoysia japonica Steud.), which thrives in warm weather. However, the purification activities of this grass decrease during winter dormancy. To improve purification activity between autumn and early spring, we introduced redtop (Agrostis alba L.), which thrives in cool conditions, into an experimental bed and compared the purification efficiency with that of zoysiagrass. Drainage purified through the bed of redtop showed significantly lower values of turbidity, chemical oxygen demand, total phosphorus and ammonium-nitrogen concentrations, and significantly higher nitrate-nitrogen concentrations than that through zoysiagrass during the late vegetative stage when redtop had the highest biomass. This suggested vigorous nitrification activity of rhizosphere under aerobic conditions afforded by redtop. The high purification efficiency of redtop appeared to be associated with better essential salts absorption and improved physicochemical properties of soil supporting its growth. The results showed that the purification efficiency of redtop is higher than that of zoysiagrass under seasonal low temperatures. [source] Effects of resource competition and herbivory on plant performance along a natural productivity gradientJOURNAL OF ECOLOGY, Issue 2 2000René Van Der Wal Summary 1,The effects of resource competition and herbivory on a target species, Triglochin maritima, were studied along a productivity gradient of vegetation biomass in a temperate salt marsh. 2,Transplants were used to measure the impact of grazing, competition and soil fertility over two growing seasons. Three parts of the marsh were selected to represent different successional stages; Triglochin reached local dominance at intermediate biomass of salt-marsh vegetation. At each stage, three competition treatments (full plant competition, root competition only, and no competition) and three grazing treatments (full grazing, no grazing on Triglochin, and no grazing on Triglochin or neighbours) were applied to both seedlings and mature plants. 3,Competition and herbivory reduced biomass and flowering of Triglochin. The impact of grazing was strongest at the stage with the lowest biomass, while both herbivory and competition had a significant impact at the stage with the highest biomass. When plants were protected from direct herbivory, competition operated at all three successional stages. 4,Grazing reduced light competition when vegetation biomass was low or intermediate, but at high biomass there was competition for light even when grazing occurred. Herbivore exclusion increased the effects of plant competition. Except at low biomass, the negative impact of plant competition on Triglochin performance was greater than the positive effect of not being grazed. 5,Grazing played a minor role in seedling survival and establishment which were largely controlled by competitive and facilitative effects. 6,Once established, the persistence of Triglochin will be determined largely by grazing. Intense grazing in the younger marsh and increasing competition for light in the older marsh will restrict the distribution to sites with intermediate biomass. [source] Microbial biomass and activity in composts of different composition and ageJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 5 2004Andreas Gattinger Abstract The aim of this study was to perform a comparison of microbial activity and biomass in biowaste (BWC), yard waste (YWC), and cattle-manure composts (CMC) of different age. Two different methods for either biomass (microbial C following fumigation-extraction and microbial lipid phosphate) or activity measurements (CO2 -production rate and fluorescein diacetate hydrolysis) provided comparable information, as judged from their strong correlation. Microbial biomass and activity declined with time in all composts. Microbial biomass C was strongly correlated with microbial activity but was even stronger correlated with pH. CMC proved to be very distinct from the two other compost types by having the highest biomass and the lowest specific activity (i.e., activity per unit biomass). The microbiological properties analyzed allow us to discriminate among different compost types, helping to assign their potential applications. Mikrobielle Biomasse und Aktivität in Komposten unterschiedlicher Zusammensetzung und unterschiedlichen Alters Ziel dieser Studie war es, Bioabfall-, Grünabfall- und Rindermistkomposte unterschiedlicher Altersgruppen hinsichtlich ihrer mikrobiellen Aktivität und Biomasse zu vergleichen. Die zwei unterschiedlichen Methoden für die Bestimmung der mikrobiellen Biomasse (Cmik mittels Fumigation-Extraktion und Lipidphosphat) und Aktivität (CO2 -Produktion und Hydrolyse von Fluoresceindiacetat) lieferten jeweils vergleichbare Aussagen, die Parameter waren eng miteinander korreliert. Mikrobielle Biomasse und Aktivität nahmen mit zunehmendem Alter in den einzelnen Komposten ab. Mikrobieller C war eng mit der mikrobiellen Aktivität korreliert, jedoch war die Korrelation zwischen dem pH-Wert und Cmik stärker ausgeprägt. Die größte mikrobielle Biomasse und die niedrigste spezifische Aktivität (Aktivität pro Biomasseeinheit) wurden im CMC festgestellt, wodurch sich dieser Kompost deutlich von den beiden anderen Komposten unterschied. Die in dieser Untersuchung beschriebenen mikrobiellen Eigenschaften ermöglichen es, zwischen Komposten unterschiedlicher Zusammensetzung zu unterscheiden und daraus mögliche Anwendungsbereiche für Komposte abzuleiten. [source] Relationships between macro-epibenthic communities and fish on the shelf grounds of the western MediterraneanAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 4 2009Francesc Ordines Abstract 1.The present study characterizes the macro-epibenthic assemblages, and the relationships between demersal species and benthic habitats on the shelf trawl fishing grounds off the Balearic Islands (western Mediterranean). 2.The data used were collected during experimental bottom trawl surveys from 2002 to 2005. A total of 157 samples from 38,255 m depth were analysed. 3.Three macro-epibenthic assemblages were identified in both the shallow (at 38,91 m) and deep shelf (90,255 m). Macroalgae bathymetric distribution was identified as the main factor explaining the segregation between shallow and deep shelf assemblages. 4.Two especially sensitive habitats were identified: maërl and crinoid beds; a third habitat was identified as Peyssonnelia beds, which represented the highest biomass on the whole shelf, with a similar species richness to the maërl beds. On the deep shelf, crinoid beds represented the highest biomass. 5.Habitat type had a significant effect on the distribution of demersal commercial species, most of them being more abundant in the two sensitive habitats mentioned and in the Peyssonnelia beds. Some species showed size-specific habitat preferences. 6.Fisheries management in the area should take into account the resilience of these benthic habitats, and their importance from both ecological and sustainable fisheries management perspectives. Copyright © 2008 John Wiley & Sons, Ltd. [source] Effects of carbon sources on fungal morphology and lovastatin biosynthesis by submerged cultivation of Aspergillus terreusASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009Zhihua Jia Abstract The influences of various carbon sources on fungal morphological changes and lovastatin production were investigated in submerged cultivation of a mutant of Aspergillus terreus. Lactose produced the least biomass (2.3 ± 0.15 gDCW l,1); however, the highest maximal specific lovastatin productivity (,max) was obtained. Glycerol achieved the highest lovastatin titer (937.5 ± 12.5 mg l,1), while soluble starch resulted in the highest biomass (12.05 ± 0.05 gDCW l,1) and the second highest lovastatin titer (501.3 ± 23.4 mg l,1). With the carbon source turning to be more easily metabolized, the values of ,max dropped gradually while the corresponding Dp and mean filament ratio rose tardily. The value of ,max (19.8 mg gDCW,1 d,1) was obtained in the presence of lactose while glucose resulted in the least ,max (3.0 mg gDCW,1 d,1). This led to a 6.6-fold decrease. The corresponding Dp and mean filament ratios appeared to reverse the effects, thus producing 1.9 and 3.3-fold increases, respectively. The slowly utilizable carbon sources regulated the lovastatin production through both the inducement of fungal morphology differentiation and the control of metabolic regulation. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Allochthonous and autochthonous particulate organic matter in floodplains of the River Danube: the importance of hydrological connectivityFRESHWATER BIOLOGY, Issue 2 2003Thomas Hein SUMMARY 1.,The elemental composition, the proportion of living organic carbon and the carbon stable isotope signatures of particulate organic matter (POM) were determined in a large river floodplain system in order to elucidate the major carbon sources in relation to the hydrological conditions over a 13-month period. 2.,Two floodplain segments and the main channel of the River Danube downstream of Vienna (Austria), were compared on the basis of discharge and water age estimations. The more dynamic floodplain was connected to the main channel for 46% of the study period and drained up to 12% of total discharge at high water. 3.,The mean C : N ratio and ,13C signature of the POM increased from the floodplain site that was more isolated from the river (6.6; ,33,) to the main channel (8.4; ,25,). At the dynamic floodplain site, the C : N ratio and the ,13C signature of the POM increased with hydrological connectivity (expressed as water age). 4.,Only during flood events (4% frequency of occurrence), a considerable input of riverine POM was observed. This input was indicated by a C : N ratio of the POM pool of more than 10, the amount of detrital carbon (>80% of the total POM pool) and a ,13C signature of POM of more than ,25, in the dynamic floodplain. 5.,Plankton derived carbon, indicated by C : N ratios less than eight and ,13C values lower than ,25,, dominated the particulate organic carbon (POC) pool at both floodplain sites, emphasising the importance of local (autochthonous) production. Phytoplankton was the major plankton compartment at the dynamic site, with highest biomasses at medium water ages. 6.,At the dynamic floodplain site, the Danube Restoration Project has enhanced the duration of upstream surface connection with the main channel from 4 to 46% frequency of occurrence. Therefore, the export of living POC to the main channel is now established during phases of maximum phytoplankton production and doubled the estimated total export of non-refractory POM compared with prerestoration conditions. [source] | |||||||||||||