Direct and indirect effects of plant and frugivore diversity on structural and functional components of fruit removal by birds.

abstract：:Increases in terrestrial primary productivity across the Arctic and northern alpine ecosystems are leading to altered vegetation composition and stature. Changes in vegetation stature may affect predator-prey interactions via changes in the prey's ability to detect predators, changes in predation pressure, predator id...

journal_title：Oecologia

authors： Wheeler HC,Chipperfield JD,Roland C,Svenning JC

更新日期：2015-07-01 00:00:00

abstract：:Habitat fragmentation poses an inherent problem for metacommunity dynamics, as dispersal among communities is hindered by increasing isolation and the loss of patches. Wetlands are one such system that have undergone excessive destruction and fragmentation in recent years. Zooplankton within these communities have his...

journal_title：Oecologia

authors： Allen MR

更新日期：2007-08-01 00:00:00

abstract：:In fasting Pisidium amnicum and Sphaerium corneum, regular periods of behavioural and metabolic quiescence were shown to occur in the normoxic, constant environment of the flow-through chamber of a heat-flow microcalorimeter. The metabolic rate was suppressed to 7.5% of normal at 10° C and to 8.5-9.7% at 20° C for per...

journal_title：Oecologia

authors： Holopainen IJ,Penttinen OP

更新日期：1993-03-01 00:00:00

abstract：:When heterospecific seabirds are part of a nesting colony, there may be less opportunity for conspecifics to come in direct contact with each other, resulting in lower intraspecific aggressiveness. To determine if individuals spend less time in aggressive behavior when nesting in conspecific rather than heterospecific...

journal_title：Oecologia

authors： Pius SM,Leberg PL

更新日期：1997-06-01 00:00:00

abstract：:Seasonal and nutritionally induced changes of whole body protein metabolism have been studied in 45 to 57 mm shell-length Mytilus edulis from Whitsand Bay, southwest England. The subtraction of measured net protein balances from coincident rates of protein synthesis, determined in vivo by supplying 15N-labelled alga a...

journal_title：Oecologia

authors： Hawkins AJ

更新日期：1985-04-01 00:00:00

abstract：:In this review I offer a solution to the problem why endotherm populations appear to be so inefficient in converting food energy into body substance despite the fact that individual endotherms are just as 'efficient' in this respect as individual ectotherms. Calculated for individuals of half the adult mass both ectot...

journal_title：Oecologia

authors： Wieser W

更新日期：1985-07-01 00:00:00

abstract：:Many native communities contain exotic plants that pose a major threat to indigenous vegetation and ecosystem functioning. Therefore the enemy release hypothesis (ERH) and biotic resistance hypothesis (BRH) were examined in relation to the invasiveness of the introduced dune grass Ammophila arenaria in South Africa. T...

journal_title：Oecologia

authors： Knevel IC,Lans T,Menting FB,Hertling UM,van der Putten WH

更新日期：2004-11-01 00:00:00

abstract：:Interspecific relationships such as mutualism and parasitism are major drivers of biodiversity. Because such interactions often comprise more than two species, ecological studies increasingly focus on complex multispecies systems. However, the spatial heterogeneity of multi-species interactions is often poorly underst...

journal_title：Oecologia

authors： Schöner CR,Schöner MG,Kerth G,Grafe TU

更新日期：2013-09-01 00:00:00

abstract：:To evaluate the general extent to which sex-related differences in palatability occur in boreal dioecious woody plants, males and females of five dioecious woody plant species were presented to free-ranging mountain hares (Lepus timidus) during winter. Hares strongly preferred branches from male plants when feeding on...

journal_title：Oecologia

authors： Hjältén J

更新日期：1992-02-01 00:00:00

abstract：:Eggs of the elm leaf beetle Xanthogaleruca luteola are often heavily attacked by the chalcidoid wasp Oomyzus gallerucae. We studied the chemical signals mediating interactions between the egg parasitoid, its host, and the plant Ulmus campestris. Olfactometer bioassays with O. gallerucae showed that volatiles of the ho...

journal_title：Oecologia

authors： Meiners T,Hilker M

更新日期：1997-09-01 00:00:00

abstract：:Larvae of the sessile marine invertebrate Bugula neritina (Bryozoa) are protected by an effective chemical defense. From the larvae, we isolated three bryostatin-class macrocyclic polyketides, including the novel bryostatin 20, that deterred feeding by a common planktivorous fish that co-occurs with B. neritina. A uni...

journal_title：Oecologia

authors： Lopanik N,Lindquist N,Targett N

更新日期：2004-03-01 00:00:00

abstract：:We examined under laboratory conditions the thermopreference of the migratory locust, Locusta migratoria migratorioides, following infection by the entomopathogenic fungus Metarhizium anisopliae var. acridum and its influence on mycosis. Infected locusts raised their body temperature more frequently than healthy consp...

journal_title：Oecologia

authors： Ouedraogo RM,Goettel MS,Brodeur J

更新日期：2004-01-01 00:00:00

abstract：:In plagiotropic plants, axillary buds on the stolon can be exposed to low red:far-red (R:FR) ratios, while the leaves may be positioned in the uppermost layer of the sward where they are exposed to a high R:FR ratio. We tested whether the light environment of unfolded leaves influences outgrowth of the axillary buds a...

journal_title：Oecologia

authors： Lötscher M,Nösberger J

更新日期：1997-08-01 00:00:00

abstract：:Predator-generated variation in prey energy intake remains the dominant explanation of adaptive response to predation risk in prey life history, morphology and physiology across a wide range of taxa. This "behavioural hypothesis" suggest that chemical or visual signals of predation risk reduce prey energy intake leadi...

journal_title：Oecologia

authors： Beckerman AP,Wieski K,Baird DJ

更新日期：2007-05-01 00:00:00

abstract：:The host specificity of insect parasitoids and herbivores is thought to be shaped by a suite of traits that mediate host acceptance and host suitability. We conducted laboratory experiments to identify mechanisms shaping the host specificity of the aphid parasitoid Binodoxys communis. Twenty species of aphids were exp...

journal_title：Oecologia

authors： Desneux N,Barta RJ,Hoelmer KA,Hopper KR,Heimpel GE

更新日期：2009-05-01 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 examined cellular immunity of adult tree swallows feeding nestlings under variable weather conditions. Birds received an injection of phytohaemagglutinin (PHA), which causes a local swelling, reflecting the strength of T-cell-mediated immunocompetence. There was a negative relationship between the immune response a...

journal_title：Oecologia

authors： Lifjeld JT,Dunn PO,Whittingham LA

更新日期：2002-01-01 00:00:00

abstract：:The decision how to allocate marginal resources to reproduction and growth can have important effects on associated life-history parameters as well as on population dynamics. In addition to showing variation among individuals in a population, such allocation rules may be either condition-dependent or fixed in differen...

journal_title：Oecologia

authors： Lardner B,Loman J

更新日期：2003-12-01 00:00:00

abstract：:The impact of predation by the robber fly Proctacanthus milbertii Macquart on populations of adult grasshoppers from grasslands of the Nebraska sandhills was estimated. Densities of P. milbertii were estimated at 437 individuals per hectare (2 se=122). Overall densities of 23 species of grasshoppers were estimated to ...

journal_title：Oecologia

authors： Joern A,Rudd NT

更新日期：1982-10-01 00:00:00

abstract：:The operative temperature of the environment was estimated for starlings using hollow, unheated taxidermic mounts. On average, adults foraging in full sun were characterized by shorter foraging bouts than those adults foraging in full shade. Simultaneous observations of air temperature, operative temperature, and the ...

journal_title：Oecologia

authors： Clark L

更新日期：1987-01-01 00:00:00

abstract：:The foraging behavior of Mesocyclops edax in artificial patches of high and low prey density was examined. In low density patches Mesocyclops swam in an irregular curvilinear path with little or no looping behavior. In high density patches Mesocyclops exhibited extensive horizontal and vertical looping behavior. Horiz...

journal_title：Oecologia

authors： Williamson CE

更新日期：1981-09-01 00:00:00

abstract：:1. It was clarified, by means of breeding experiments conducted within a temperature range of 14-34°C, if the growth of Pieris influenced by diurnally fluctuating temperatures depends on a simple additive influence of day-and-night-temperatures or if its growth is accelerated or retarded under these conditions by spec...

journal_title：Oecologia

authors： Neumann D,Heimbach F

更新日期：1975-06-01 00:00:00

abstract：:Coryphantha vivipara (Nutt.) Britton & Rose var. deserti (Engelm.) W.T. Marshall (Cactaceae) survived snow and tissue temperatures of-12°C in southern Nevada. However, the freezing point depression of the cell sap was only about 0.9°C. When the nocturnal air temperature in the laboratory was reduced from 10°C to-10°C ...

journal_title：Oecologia

authors： Nobel PS

更新日期：1981-03-01 00:00:00

abstract：:Induction of plant defence against herbivores may include the attraction by volatile infochemicals of natural enemies of the herbivore. The emitted volatiles that mediate this attraction may also affect the behaviour of the herbivore itself. In this paper we investigate the response of the herbivorous spider miteTetra...

journal_title：Oecologia

authors： Dicke M,Dijkman H

更新日期：1992-10-01 00:00:00

abstract：:This study uses short-term assays and long-term transplant experiments to document the potential importance of fish predation and herbivory to the distribution and abundance of reef-building corals in a Caribbean back-reef system. Experimental manipulations of fish access reveal that the zonal patterns of the two reef...

journal_title：Oecologia

authors： Littler MM,Taylor PR,Littler DS

更新日期：1989-08-01 00:00:00

abstract：:Ecosystem water-use efficiency (eWUE; the ratio of net ecosystem productivity to evapotranspiration rate) is a complex landscape-scale parameter controlled by both physical and biological processes occurring in soil and plants. Leaf WUE (lWUE; the ratio of leaf CO(2) assimilation rate to transpiration rate) is control...

journal_title：Oecologia

authors： Monson RK,Prater MR,Hu J,Burns SP,Sparks JP,Sparks KL,Scott-Denton LE

更新日期：2010-02-01 00:00:00

abstract：:Occurrence and diet of ten carnivorous predators (four falconiforms, four owls, and two foxes), and population levels of their mammalian prey, were monitored over 45 months at a semi-arid site in north-central Chile. Early in this period, small mammals irrupted and then declined markedly to a density 7% of that at pea...

journal_title：Oecologia

authors： Jaksié FM,Jiménez JE,Castro SA,Feinsinger P

更新日期：1992-01-01 00:00:00

abstract：:In this study we assessed the effectiveness of rodents as dispersers of Quercus ilex in a patchy landscape in southeastern Spain. We experimentally followed the fates of 3,200 marked and weighed acorns from dispersal through the time of seedling emergence over three years. Rodents handled about 99% of acorns, and disp...

journal_title：Oecologia

authors： Gómez JM,Puerta-Piñero C,Schupp EW

更新日期：2008-03-01 00:00:00

abstract：:The effects of irradiance during growth on biomass allocation, growth rates, leaf chlorophyll and protein contents, and on gas exchange responses to irradiance and CO2 partial pressures of the evergreen, sclerophyllous, chaparral shrub, Ceanothus megacarpus were determined. Plants were grown at 4 irradiances for the g...

journal_title：Oecologia

authors： Mahall BE,Schlesinger WH

更新日期：1982-09-01 00:00:00

abstract：:Plant population and community dynamics may be altered by increasing atmospheric CO(2) concentrations [[CO(2)]] through intraspecific variation in the responses of vegetative and reproductive growth. Although these responses may be regulated by age at flowering, little is known about the direct effects of age at flowe...

journal_title：Oecologia

authors： Lewis JD,Wang X,Griffin KL,Tissue DT

更新日期：2003-04-01 00:00:00