Iron reduction and gley formation by nitrogen-fixing clostridia.

abstract：:Predation pressure and resource availability often interact in structuring herbivore communities, with their relative influence varying in space and time. The operation of multiple ecological pressures and guild-specific herbivore responses may combine to override simple predictions of how the roles of plant quality a...

journal_title：Oecologia

authors： Zehnder CB,Stodola KW,Cooper RJ,Hunter MD

更新日期：2010-12-01 00:00:00

abstract：:Understanding how habitat selection changes with population density is a key concept in population regulation, community composition and managing impacts on biodiversity and ecosystem services. At low density, it is expected that individuals select habitats in terms of their preference, but as population density incre...

journal_title：Oecologia

authors： Pérez-Barbería FJ,Hooper RJ,Gordon IJ

更新日期：2013-11-01 00:00:00

abstract：:Leaf-chewing herbivores select food with a protein/carbohydrate ratio of 0.8-1.5, whereas phloem sap, which aphids feed on, has a ratio of approximately 0.1. Enhanced N fertilization increases the amino acid concentration in phloem sap and elevates the N/C ratio. The study examines: (1) whether aphids select between p...

journal_title：Oecologia

authors： Nowak H,Komor E

更新日期：2010-08-01 00:00:00

abstract：:The diurnal course of the xylem water flow in a solitary Salix fragilis L. tree in a wet grassland was measured using the tissue heat-balance method. There was considerable variation due to meteorological factors. Maximum flow rate was 0.4 kg h-1 m-2 of crown projection area, or 5.9 kg h-1 kg-1 leaf dry weight. The da...

journal_title：Oecologia

authors： Čermák J,Jeník J,Kučera J,Žídek V

更新日期：1984-10-01 00:00:00

abstract：:We describe differences in senescence among populations of grasshoppers that occur along an altitudinal gradient in the Sierra Nevada, California. Experimental males from five populations of the Melanoplus sanguinipes/devastator sibling species complex were reared in each of two thermal culture conditions from eggs of...

journal_title：Oecologia

authors： Tatar M,Gray DW,Carey JR

更新日期：1997-07-01 00:00:00

abstract：:During five consecutive growing seasons (winters) ca. 110 plants of the desert geophyte Bellevalia desertorum were marked individually in a 25 m2 plot on a south-facing slope in the central Negev Desert of Israel. The number of rosette leaves of each plant was recorded, as well as whether it flowered and produced seed...

journal_title：Oecologia

authors： Boeken B

更新日期：1989-08-01 00:00:00

abstract：:Desert populations of the evergreen dioecious shrub Simmondsia chinensis exhibit sex-related leaf and canopy dimorphisms not present in populations from more mesic coastal environments. Leaves on female shrubs have characteristically larger sizes, greater specific weights, and greater water-holding capacity than male ...

journal_title：Oecologia

authors： Wallace CS,Rundel PW

更新日期：1979-12-01 00:00:00

abstract：:The tadpoles of two anuran species, Rana sylvatica and Xenopus laevis, were fed various concentrations of two algae, Anabaena sphaerica (large filaments) and Chlorella pyrenoidosa (small unicells). Filtering rates were measured indirectly with a Coulter Counter system; buccal pumping rates were observed directly.Exper...

journal_title：Oecologia

authors： Seale DB,Wassersug RJ

更新日期：1979-01-01 00:00:00

abstract：:Ecological stoichiometry has advanced food web ecology by emphasising the importance of food quality over food quantity for herbivores. Here, we focus on the effects of abiotic factors such as nutrients and light (known to influence food quality) on grazer growth rates. As model organism we used the mudsnail Potamopyr...

journal_title：Oecologia

authors： Liess A,Lange K

更新日期：2011-09-01 00:00:00

abstract：:We tested (1) how the presence of a diverse soil faunal community affects ecosystem carbon balance and (2) whether habitat patchiness modifies the influence of soil fauna on plant growth and carbon dynamics. We constructed cylindrical microcosms that contained coniferous forest humus and different litter materials eit...

journal_title：Oecologia

authors： Sulkava P,Huhta V,Laakso J,Gylén ER

更新日期：2001-09-01 00:00:00

abstract：:Laboratory feeding experiments were conducted with Dipodomys ordii and Perognathus flavus in an attempt to discover a mechanism which might result in seed size selection. There was no marked difference in the proportions of four seed types collected whether the rodents foraged in the presence or absence of one another...

journal_title：Oecologia

authors： Hutto RL

更新日期：1978-01-01 00:00:00

abstract：:Host use by herbivores is largely determined by host properties such as nutrient content and chemical defence against foragers. The impacts of these attributes on a herbivore may largely depend on its life cycle stage. Lichen species are known to differ in nutritional quality and level of chemical defence and, consequ...

journal_title：Oecologia

authors： Pöykkö H,Backor M,Bencúrová E,Molcanová V,Backorová M,Hyvärinen M

更新日期：2010-10-01 00:00:00

abstract：:The structure and seasonal dynamics of phytoplankton communities in the littoral zone were compared between oligotrophic and eutrophic lakes in the southeastern United States. Differences in diversity and species composition between lakes could be ascribed to long-term variation in nutrients corresponding to trophic s...

journal_title：Oecologia

authors： Lemly AD,Dimmick JF

更新日期：1982-09-01 00:00:00

abstract：:Aspects of the demography of Monhystera disjuncta were investigated at different temperatures (in agnotobiotic cultures) and in different feeding conditions (monoxenic cultures with different bacterial strains, and different densities in the feeding suspension with one strain). Embryonic development time, minimum gene...

journal_title：Oecologia

authors： Vranken G,Herman PM,Heip C

更新日期：1988-11-01 00:00:00

abstract：CONCLUSION:For the abovementioned reasons, and with all due respect to the scholarship of Mansson and McGlade, who display a deep knowledge of thermodynamics and ecology, I cannot agree that Odum's use of energy concepts is "wholly discredited". Refinements from microscopic thermodynamics may not have been faithfully c...

journal_title：Oecologia

authors： Patten BC

更新日期：1993-04-01 00:00:00

abstract：:A series of field and laboratory experiments were conducted to examine whether natural levels of insect herbivory affect the arbuscular mycorrhizal (AM) colonization of two plant species. The plant species were the highly mycorrhizal (mycotrophic) Plantago lanceolata, which suffers small amounts of insect damage conti...

journal_title：Oecologia

authors： Gange AC,Bower E,Brown VK

更新日期：2002-03-01 00:00:00

abstract：:Genets of Trifolium repens (white clover) were collected from three patches of old permanent pasture dominated by Agrostis capillaris, Holcus lanatus or Lolium perenne. Plants derived from the genets were grown with plants of one grass species present on one side of each T. repens, and a different grass species on the...

journal_title：Oecologia

authors： Turkington R,Hamilton RS,Gliddon C

更新日期：1991-04-01 00:00:00

abstract：:Hybridisation is common in plants and can affect the genetic diversity and ecology of sympatric parental populations. Hybrids may resemble the parental species in their ecology, leading to competition and/or gene introgression; alternatively, they may diverge from the parental phenotypes, possibly leading to the colon...

journal_title：Oecologia

authors： Chartier M,Liagre S,Weiss-Schneeweiss H,Kolano B,Bessière JM,Schönenberger J,Gibernau M

更新日期：2016-02-01 00:00:00

abstract：:The sensitivity of carbon (C) assimilation to within-canopy nitrogen (N) allocation and of stomatal conductance (g s) to environmental variables were investigated along a vertical canopy gradient in a fertile Norway spruce [Picea abies (L.) Karst.] stand. Maximum rates of ribulose bisphosphate-saturated carboxylation ...

journal_title：Oecologia

authors： Tarvainen L,Wallin G,Uddling J

更新日期：2013-12-01 00:00:00

abstract：:This study examines the effect of different densities and the removal of all neighbours at different stages of development on all components of reproduction in the inbreeding annual Thlaspi arvense L. A 64-fold increase in density significantly reduced all repooductive components. The number of flower buds per plant w...

journal_title：Oecologia

authors： Matthies D

更新日期：1990-05-01 00:00:00

abstract：:The reproductive behaviour of the toad Bufo calamita was studied in a large population in the northern Rhineland, Germany. Toads bred at four spatially separated but neighbouring areas including 34 breeding ponds. Three methods were applied to monitor quantitatively the intensity of breeding and migratory activity: ca...

journal_title：Oecologia

authors： Sinsch U

更新日期：1988-08-01 00:00:00

abstract：:We investigated seasonality of gender differences in the patterns of flea infestation in nine rodent species to test if sex-biased parasitism in terms of mean abundance, species richness, prevalence and the level of aggregation (a) varies among hosts and between seasons, and (b) is linked to sexual size dimorphism. Se...

journal_title：Oecologia

authors： Krasnov BR,Morand S,Hawlena H,Khokhlova IS,Shenbrot GI

更新日期：2005-12-01 00:00:00

abstract：:Mortality estimates for the immature stages of two butterfly species, Danaus plexippus and D. chrysippus, were obtained by observing the survival of egg cohorts on different sized patches of food plants (Asclepias spp.), over a one-year period. Losses were variable (0-100%) but usually high (90% and over) throughout t...

journal_title：Oecologia

authors： Zalucki MP,Kitching RL

更新日期：1982-01-01 00:00:00

abstract：:Parents are expected to overproduce the less costly sex under poor food conditions. The previously regular 3-year cycle in the abundance of voles, the main prey of the Ural owl, Strix uralensis, temporarily disappeared in 1999-2001. We studied Ural owls' parental feeding investment and sex allocation during these poor...

journal_title：Oecologia

authors： Brommer JE,Karell P,Pihlaja T,Painter JN,Primmer CR,Pietiäinen H

更新日期：2003-09-01 00:00:00

abstract：:In two nearctic ants, Leptothorax canadensis and Leptothorax sp. A, young queens may either found their own nest solitarily after mating or seek adoption into an established colony. Whether a queen disperses or not is associated with genetically determined queen morphology in Leptothorax sp. A. Whereas a majority of w...

journal_title：Oecologia

authors： Heinze J

更新日期：1993-10-01 00:00:00

abstract：:In long-lived colonial birds, age at recruitment is an important life-history character. Variation in this parameter may reflect differences in several factors, including competitive ability and breeding strategies. Further, these differences may be due to timing of hatching (for instance through differences in compet...

journal_title：Oecologia

authors： Prévot-Julliard AC,Pradel R,Julliard R,Grosbois V,Lebreton JD

更新日期：2001-03-01 00:00:00

abstract：:Studies relating reproduction to food availability are usually restricted to food quantity, but ignore food quality and the effects of habitat structure on obtaining the food. This is particularly true for insectivorous birds. In this study we relate measures of reproductive success, time of reproduction and nestling ...

journal_title：Oecologia

authors： Brodmann PA,Reyer HU,Bollmann K,Schläpfer AR,Rauter C

更新日期：1997-01-01 00:00:00

abstract：:This is the first in a series of papers on the growth, photosynthetic rate, water and nutrient relations, root distribution and mycorrhizal frequency of two Norway spruce forests at different stages of decline. One of the stands was composed of green trees only while the other included trees ranging in appearance from...

journal_title：Oecologia

authors： Oren R,Schulze E-,Werk KS,Meyer J,Schneider BU,Heilmeier H

更新日期：1988-02-01 00:00:00

abstract：:Humans are rapidly altering thermal landscapes, so a central challenge to organismal ecologists is to better understand the thermal niches of ectotherms. However, there is much disagreement over how we should go about this. Some ecologists assume that a statistical model of abundance as a function of habitat temperatu...

journal_title：Oecologia

authors： Stoffels RJ,Richardson AJ,Vogel MT,Coates SP,Müller WJ

更新日期：2016-01-01 00:00:00

abstract：: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 exper...

journal_title：Oecologia

authors： Wedlich KV,Rintoul N,Peacock S,Cape JN,Coyle M,Toet S,Barnes J,Ashmore M

更新日期：2012-04-01 00:00:00