Species composition

In this way, the near-linear chlorophyll-phosphorus relationship in lakes depends upon the outcome of a large number of interactive processes occurring in each one of the component systems in the model. One of the most intriguing aspects of those components is that the chlorophyll models do not need to take account of the species composition of the phytoplankton in which chlorophyll is a constituent. The development of blooms of potentially toxic cyanobacteria is associated with eutrophication and phosphorus concentration, yet it is not apparent that the yield of cyanobacterial biomass requires any more mass-specific contribution from phosphorus. The explanation for this paradox is not well understood, but it is extremely important to understand that it is a matter of dynamics. The bloom-forming cyanobacteria are among the slowest-growing and most light-sensitive members of the phytoplankton. ... 

Ruby, E. G., and Nealson, K. H. (1978). Seasonal changes in the species composition of luminous bacteria in nearshore seawater. Limnolo. Oceanogr. 23 530-533. 

Numerous studies have shown that increased levels of UV affect photosynthetic activity (10-23), growth rate (24), nitrogen metabolism (25), and locomotion (26) of phytoplankton. Additionally, increases in UV-B are likely to alter community diversity as well as phytoplankton species composition. Thus, by weakening the base of the food web and altering trophodynamic relationships, UV-induced changes could potentially have far-reaching effects on the entire ecosystem. 

The results of two successful iron-fertilization experiments in the eastern equatorial Pacific have clearly shown that phytoplankton growth rate is limited by iron at that location (Martin et al., 1994 Coale et al., 1996). The species composition and size distributions of the ecosystem are influenced by iron availability (Landry et al., 1997). In particular, large diatoms do not grow at optimum rates in the absence of sufficient iron. Loukos et al. (1997) used a simple... 

Records of past environmental change are preserved in a broad range of Earth materials. Past environments are inferred from "proxy" records, meaning measurements of physical and chemical parameters of marine and terrestrial sediment, polar ice, and other materials that were in some way influenced by their environment during accumulation. Examples of proxy records are the distribution of glacial deposits, the isotopic composition of terrestrial and marine sediments and ice, the abundance and species composition of plant and animal fossils, and the width of tree rings. 

Measured end points are photosynthesis as the incorporation of radiolabelled H C03 ( C) and bacterial activity as the incorporation of radiolabelled thymidine (thym) fluorometric measurements basal fluorescence (Fo) and photon yield (Y) chlorophyll-a concentration (chl-a) species composition (spp) and the biovolume of algae obtained after algal counting (biovolume)... 

The first case is based on a hypothetical stream receiving a metal-poUuted source (for instance the outlet of a metal factory). In this case, metal concentration is expected to be driven by dilution, being higher under low-flow than under base-flow conditions and minimum during floods. Metal accumulation is expected to be maximum under low-flow conditions and proportional to the duration of this water scarcity situation. Chronic exposure will lead to community adaptation, which is often related to changes in species composition. Metals will therefore be bioaccumulated in fluvial biofihns and transferred to higher trophic levels in the fluvial food web. 

Guasch H, Leira M, Montuelle B, Geiszinger A, Roulier JL, Tomes E, Serra A (2009) Use of multivariate analyses to investigate the contribution of metal pollution to diatom species composition search for the most appropriate cases and explanatory variables. Hydrobiologia 627 143... 

The other boundary conditions are relatively simple. The temperature and species composition far from the disk (the reactor inlet) are specified. The radial and circumferential velocities are zero far from the disk a boundary condition is not required for the axial velocity at large x. The radial velocity on the disk is zero, the circumferential velocity is determined from the spinning rate W = Q, and the disk temperature is specified. 

Benthic invertebrate communities are taxonomically and trophically complex, and their abundance and species composition in a water body often vary seasonally and among years. Sediment-dwelling invertebrates can be readily sampled but considerable effort is often required to remove benthic organisms from grab samples of sediment, to determine their taxonomic composition, and to obtain sufficient sample mass of a target taxon for analysis. Sampling would not substantially affect target populations. 

Periphyton are microscopic and macroscopic algae that attach to and grow on solid surfaces, such as lake bottoms, rooted aquatic vegetation, and submerged woody debris. Periphyton form part of the base of littoral food webs in lakes. Periphyton communities are taxonomically diverse and the attached communities contain other organisms, such as bacteria and zooplankton, as well as detrital material. Periphyton vary seasonally and annually in both abundance and species composition. 

Several studies have indicated that the species diversity of indigenous soil communities will influence the species composition of ectorhizosphere populations (176). On mature roots, seasonal successions may be observed as the soil microbial activity varies with temperature, water content, nutrition, and root exudation. Acero et al. (177) found that the composition of alder (Almis) rhizosphere populations alternated between one dominated by Bacillus spp. in autumn and winter and one dominated by Pseudomonas spp. in spring and summer. 

T. Bongers, The maturity index an ecological measure of environmental di.stur-bance ba.sed on nematode species composition. Oecologia 70 14 (1990). 

In a similar spirit, Inoue et al. [120] and Hashimoto et al. [121] generalized MPC dynamics so that the collision operator reflects the species compositions in the neighborhood of a chosen cell. More specifically, consider a binary mixture of particles with different colors. The color of particle i is denoted by c,-. The color flux of particles with color c in cell E, is defined as... 

Schneiter, R. Brugger, B. Sandhoff, R. Zellnig, G. Leber, A. Lampl, M. Athenstaedt, K. Hrastnik, C. Eder, S. Daum, G. Paltauf, F. Wieland, F. T. Kohlwein, S. D. Electrospray ionization tandem mass spectrometry (ESI-MS/MS) analysis of the lipid molecular species composition of yeast subcellular membranes reveals acyl chain-based sorting/remodeling of distinct molecular species en route to the plasma membrane. J. Cell Biol. 1999,146,741-754. 

The Pedemontana Jungle sectors that have been left isolated are subject to edge effect, with changes clearly visible in microclimatic variables. The AGB in fragments is notably reduced for the main five tree species studied, but the species composition has also changed. 

Not surprisingly, Zeleznik and Gordon (1960,1968) and Brinkley (1960) proved that the two methods were computationally and conceptually equivalent. The balanced reactions of the equilibrium constant method are counterparts to the species compositions required by the minimization technique in fact, given the same choice of components, the reactions and expressions of species compositions take the same form. 

To balance a reaction, we first choose a species to appear on the reaction s left side, and express that species composition in terms of a basis B. The basis might be a list of the elements in the species stoichiometry, or an arbitrary list of species that combine to form the left-side species. Then we form a second basis B composed of species that we want to appear on the reaction s right side. To balance the reaction, we calculate the transformation matrix relating basis B to B, following the procedures in Chapter 5. The transformation matrix, in turn, gives the balanced reaction and its equilibrium constant. 

Tietjen, J.H. 1980. Population structure and species composition of the free-living nematodes inhabiting sands of the New York Bight Apex. Estuar. Coast. Mar. Sci. 10 61-73. 

Sanders, J.G., G.R. Abbe, and G.F. Riedel. 1990. Silver uptake and subsequent effects on growth and species composition in an estuarine community. Sci. Total Environ. 97/98 761-769. 

Biovolume of benthic algal communities was reduced at both dose levels when compared to controls (Carder and Hoagland 1998) Altered species composition (DeNoyelles and Kettle 1985)... 

Algal densities and biomass reduced, diversity decreased, and species composition altered. Within 16 days after removal of atrazine stress, net productivity was indistinguishable from controls, but community structure remained altered at day 21 (Hamala and Kollig 1985)... 

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