Effects of indiscriminate foraging by tropical hummingbirds on pollination and plant reproductive success: experiments with two tropical treelets (Rubiaceae).

abstract：:During the inventory of ant heaps of the group Formica rufa, performed in the years 1972-73 in the Wielkopolski National Park near Poznań, it was found that the vegetal cover composition, determining to a large extent phytosociologic associations, is likely not so important to ants as the dominant stand. First of all,...

journal_title：Oecologia

authors： Wiśniewski J

更新日期：1976-06-01 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：:Seasonal net nitrogen (N) and phosphorus (P) mineralization was investigated at Abisko, Swedish Lapland in soils of a subarctic heath and in soils of a colder (by about 4° C), high altitude fellfield by (a) using in situ soil incubation in soils which had been shaded or subjected to two levels of increased temperature...

journal_title：Oecologia

authors： Jonasson S,Havström M,Jensen M,Callaghan TV

更新日期：1993-08-01 00:00:00

abstract：:Proteolytic activity in the gut contents of two cichlids and six cyprinids from an artificial basin in Sri Lanka was measured using a simple film strip method. This comparative study contributes to our general knowledge of digestion in herbivorous fish: 1) Specific proteolytic activity (per ml of gut content) is lower...

journal_title：Oecologia

authors： Hofer R,Schiemer F

更新日期：1981-03-01 00:00:00

abstract：:Leptopterna dolobrata (L.) (Holarctis) and Calocoris roseomaculatus (De Geer) (Palaearctis) are single-brooded in the whole range of their distribution and hibernate in the egg stage. Both species are active only for 21/2 months, while the egg stage lasts over 9 months.The main food plants of Leptopterna are Dactylis ...

journal_title：Oecologia

authors： Braune HJ

更新日期：1971-09-01 00:00:00

abstract：:The presence of litter has the potential to alter the population dynamics of plants. In this paper, we explore the effects of litter on population dynamics using a simple experimental laboratory system with populations of the annual crucifer, Cardamine pensylvanica. Using a factorial experiment with four densities and...

journal_title：Oecologia

authors： Molofsky J,Lanza J,Crone EE

更新日期：2000-09-01 00:00:00

abstract：:Twospotted spider mites, Tetranychus urticae Koch are arrhenotokous. As a result of this genetic structure, primary and secondary sex ratios diverge from the 1:1 female:male ratio commonly found in diploid systems. Ratios vary, but 3:1 is the most common. The influence of life history parameters on spider mite sex rat...

journal_title：Oecologia

authors： Krainacker DA,Carey JR

更新日期：1990-03-01 00:00:00

abstract：:Current theory predicts that in low-density, seed-limited plant populations, seed predation will be more important than competition in determining the number of individuals that reach maturity. However, when plant density is high, competition for microsites suitable for establishment and growth is expected to have a r...

journal_title：Oecologia

authors： Sousa WP,Quek SP,Mitchell BJ

更新日期：2003-11-01 00:00:00

abstract：:Intraspecific variation in behavior and diet can have important consequences for population and ecosystem dynamics. Here, we examine how differences in reproductive investment and spatial ecology influence individual diet specialization in male and female southern sea otters (Enhydra lutris nereis). We hypothesize tha...

journal_title：Oecologia

authors： Smith EA,Newsome SD,Estes JA,Tinker MT

更新日期：2015-05-01 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：:In arctic tundra soil, oxygen depletion associated with soil flooding may control plant growth either directly through anoxia or indirectly through effects on nutrient availability. This study was designed to evaluate whether plant growth and physiology of two arctic sedge species are more strongly controlled by the d...

journal_title：Oecologia

authors： Gebauer RL,Reynolds JF,Tenhunen JD

更新日期：1995-11-01 00:00:00

abstract：:No definitive explanation for the form of the relationship between species diversity and ecosystem productivity exists nor is there agreement on the mechanisms linking diversity and productivity across scales. Here, we examine changes in the form of the diversity-productivity relationship within and across the plant c...

journal_title：Oecologia

authors： Jennings MD,Williams JW,Stromberg MR

更新日期：2005-05-01 00:00:00

abstract：:In white pine (Pinus strobus) seedlings grown in five forest soils from New York State, net photosynthetic capacity (Amax) plant-1 was correlated with total foliar N plant-1 (r 2=0.57), but was more highly correlated with total foliar P plant-1 (r 2=0.82). There was no relationship (r 2<0.01) between Amax [g leaf]-1 a...

journal_title：Oecologia

authors： Reich PB,Schoettle AW

更新日期：1988-10-01 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：:Increases in woody vegetation and declines in grasses in arid and semi-arid ecosystems have occurred globally since the 1800s, but the mechanisms driving this major land-cover change remain uncertain and controversial. Working in a shrub-encroached grassland in the northern Chihuahuan Desert where grasses and shrubs t...

journal_title：Oecologia

authors： Throop HL,Reichmann LG,Sala OE,Archer SR

更新日期：2012-06-01 00:00:00

abstract：:1. In an attempt to evaluate the importance of individual daily habits to a freeliving animal, foraging behaviour of kestrels was observed continuously for days in sequence in open country. Data obtained in 2,942 observation hours were used. Flight-hunting was the prominent foraging technique yielding 76% of all prey ...

journal_title：Oecologia

authors： Rijnsdorp A,Daan S,Dijkstra C

更新日期：1981-09-01 00:00:00

abstract：:General circulation models project more intense and frequent droughts over the next century, but many questions remain about how terrestrial ecosystems will respond. Of particular importance, is to understand how drought will alter the species composition of regenerating temperate forests wherein symbiotic dinitrogen ...

journal_title：Oecologia

authors： Wurzburger N,Miniat CF

更新日期：2014-04-01 00:00:00

abstract：:As humans continue to alter tropical landscapes across the world, it is important to understand what environmental factors help determine the persistence of biodiversity in modified ecosystems. Studies on well-known taxonomic groups can offer critical insights as to the fate of biodiversity in these modified systems. ...

journal_title：Oecologia

authors： Moura NG,Lees AC,Aleixo A,Barlow J,Berenguer E,Ferreira J,Mac Nally R,Thomson JR,Gardner TA

更新日期：2016-03-01 00:00:00

abstract：:Recent work suggests that soil nutrient heterogeneity may modulate plant responses to drivers of global change, but interactions between N heterogeneity and changes in rainfall regime remain poorly understood. We used a model grassland system to investigate the interactive effects of N application pattern (homogeneous...

journal_title：Oecologia

authors： Xi N,Carrère P,Bloor JM

更新日期：2015-06-01 00:00:00

abstract：:Mark-release-recapture techniques were adapted for studying the territorial black swallowtail butterfly, Papitio polyxenes. Population sizes were similar from year to year and somewhat higher in second broods. The overall sex ratio was a male-biased 4.0:1. Of 340 marked males, 45.3% were recaptured an average of 5.7 t...

journal_title：Oecologia

authors： Lederhouse RC

更新日期：1983-09-01 00:00:00

abstract：:In the non-reproductive period, six species of brood parasites (4 cuckoos, 2 viduines) observed in Rhodesia and in the Kalahari were found to inhabit other areas than their hosts, being either nomadic or migratory in habit. They are hence exposed to different environmental conditions.Histological examination of the go...

journal_title：Oecologia

authors： Immelmann K

更新日期：1969-09-01 00:00:00

abstract：:Plants of Diplacus aurantiacus, a successional shrub common in California chaparral, were grown under controlled conditions in which either quantum flux density or nitrogen availability was varied. Photosynthesis and leaf nitrogen content were determined on a leaf area and a leaf weight basis, and whole plant growth w...

journal_title：Oecologia

authors： Gulmon SL,Chu CC

更新日期：1981-05-01 00:00:00

abstract：:The time at which plants emerge from the soil is shown to be correlated with both survival and growth in each of four years in a plant community emerging after yearly plowing. For all seven species investigated, earlier emerging individuals generally had both a higher biomass and probability of survival. There were di...

journal_title：Oecologia

authors： Miller TE

更新日期：1987-05-01 00:00:00

abstract：:Exposure to enhanced levels of ambient ultraviolet (UV) radiation (UVR) can have adverse effects on aquatic organisms including damage at the cellular and molecular level and impairment of development, fecundity and survival. Much research has been conducted on the role of the harmful UVB radiation. However, due to it...

journal_title：Oecologia

authors： Rick IP,Mehlis M,Eßer E,Bakker TC

更新日期：2014-02-01 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：:Clone mal9, a genotype ofSolanum dulcamara L. having photosynthetic characteristics similar to previously hypothesized shade ecotypes, is compared to five other genotypes having photosynthetic characteristics similar to previously hypothesized sun ecotypes. The primary differences are a 35% reduction in total leaf con...

journal_title：Oecologia

authors： Clough JM,Alberte RS,Teeri JA

更新日期：1980-01-01 00:00:00

abstract：:Climate change due to greenhouse gas emissions is predicted to raise the mean global temperature by 1.0-3.5°C in the next 50-100 years. The direct and indirect effects of this potential increase in temperature on terrestrial ecosystems and ecosystem processes are likely to be complex and highly varied in time and spac...

journal_title：Oecologia

authors： Rustad L,Campbell J,Marion G,Norby R,Mitchell M,Hartley A,Cornelissen J,Gurevitch J,GCTE-NEWS.

更新日期：2001-02-01 00:00:00

abstract：:Olfactory responses of parasitoids can be variable. This was shown by olfactometer experiments with females of two sibling Asobara species, larval endoparasitoids of Drosophilidae. Oviposition experiences of adult female parasitoids significantly altered their behavioural responses in microhabitat and host location. F...

journal_title：Oecologia

authors： Vet LE,van Opzeeland K

更新日期：1984-08-01 00:00:00

abstract：:Algal polyunsaturated fatty acids (PUFA), essential for somatic growth and reproduction of aquatic animals, are influenced by ambient environmental conditions, including light and nutrients. Few studies have addressed the extent to which changes in algal PUFA can influence stream herbivore PUFA profiles and the implic...

journal_title：Oecologia

authors： Guo F,Kainz MJ,Sheldon F,Bunn SE

更新日期：2016-06-01 00:00:00

abstract：:Generalist parasites may disproportionately use certain hosts because of different benefits associated with each host species. I measured the growth rate of the marine snail Trichotropis cancellata, a facultative kleptoparasite that can suspension feed and steal food, on different hosts to determine the relative nutri...

journal_title：Oecologia

authors： Iyengar EV

更新日期：2004-03-01 00:00:00