The ecological role of ants in two Mexican agroecosystems.

abstract：:We studied the population structure of a high arctic breeding wader bird species, the White-rumped Sandpiper Calidris fuscicollis. Breeding adults, chicks and juveniles were sampled at seven localities throughout the species' breeding range in arctic Canada in 1999. The mitochondrial control region was analysed by DNA...

journal_title：Oecologia

authors： Wennerberg L,Klaassen M,Lindström Å

更新日期：2002-05-01 00:00:00

abstract：:Experimental plots covering a 120 years' observation period in unthinned, even-aged pure stands of common beech (Fagus sylvatica), Norway spruce (Picea abies), Scots pine (Pinus sylvestris), and common oak (Quercus Petraea) are used to scrutinize Reineke's (1933) empirically derived stand density rule [see text], N=tr...

journal_title：Oecologia

authors： Pretzsch H

更新日期：2006-01-01 00:00:00

abstract：:Mixed infections, where more than one parasite genotype is present in a single host, have been suggested to be an important factor in host-parasite interactions. As the host represents a limited resource, co-infecting parasite genotypes are expected to be under resource competition. Competition will not only modify th...

journal_title：Oecologia

authors： Vizoso DB,Ebert D

更新日期：2005-03-01 00:00:00

abstract：:The influence of ectoparasitic water mite larvae (Arrenurus) on the fluctuating asymmetry (FA) of forewing length and cell number in the foreweings of the damselfly Coenagrion puella has been investigated. We show a significant correlation between the FA of forewing length and the mite load. Most explanations for incr...

journal_title：Oecologia

authors： Bonn A,Gasse M,Rolff J,Martens A

更新日期：1996-12-01 00:00:00

abstract：:Soil amelioration by a wood-ant species and its consequences for the larval performance of autumnal moths feeding on mountain birch were studied at various distances from the nest mound. Soil nitrate and ammonium nitrogen did not show any clear relationship with distance. However, trees growing in the mound had over 2...

journal_title：Oecologia

authors： Karhu KJ,Neuvonen S

更新日期：1998-02-01 00:00:00

abstract：:Carbon allocation among bunchgrass tillers was examined with carbon-11 (11CO2) steady state labelling. Labelled carbon was continuously transported from parent tillers to anatomically attached daughter tillers at a time when morphological characteristics indicated that tiller maturation had occurred. Steady state leve...

journal_title：Oecologia

authors： Welker JM,Rykiel EJ Jr,Briske DD,Goeschl JD

更新日期：1985-09-01 00:00:00

abstract：:Cladoceran hatching frequency can easily be calculated from observed egg age distribution and estimated egg development time. The large timelag errors of models incorporating birth rates in the equation are avoided, and the population growth rate can be estimated directly. ...

journal_title：Oecologia

authors： Johnsen G

更新日期：1983-11-01 00:00:00

abstract：:Inoculation with arbuscular mycorrhizal (AM) fungi is known to increase the species diversity of plant communities. One mechanism that can increase the likelihood of species co-existence, and thus species diversity, is a trade-off between competitive ability and the magnitude of plant growth response to AM fungal inoc...

journal_title：Oecologia

authors： Stanescu S,Maherali H

更新日期：2017-02-01 00:00:00

abstract：:The period between oviposition and the start of hatching varied from about 17 weeks at 3°C to about 1 week at 22°C, and the length of the hatching period varied from about 34 days at 3°C to about 3 days at 22°C. Regression equations are provided to estimate the lengths of both periods at all temperatures between 3°C a...

journal_title：Oecologia

authors： Elliott JM

更新日期：1972-03-01 00:00:00

abstract：:Tests of density dependent regulation of population size depend on the concept of equilibrium population size. Such an equilibrium is a purely theoretical construct whose existence in the field is debatable and whose value cannot be measured. An equilibrium is supposed to fluctuate in time, but the extent of the fluct...

journal_title：Oecologia

authors： Wolda H

更新日期：1989-11-01 00:00:00

abstract：:Local adaptation and population differentiation of plants are well documented, but studies on interactions with natural enemies are rare. In particular, evidence for plant adaptation to the local biotic environment, such as herbivores remains poor. We used the black mustard Brassica nigra, an annual species of river v...

journal_title：Oecologia

authors： Bischoff A,Trémulot S

更新日期：2011-04-01 00:00:00

abstract：:Interrelationships between morphology, microhabitat, water relations, and photosynthesis of a xeric fern, Notholaena parryi D.C. Eat. (Pteridaceae), were examined in the western Colorado desert. In its typical microhabitat rock outcroppings protected N. parryi from direct sunlight and moderated the diurnal variations ...

journal_title：Oecologia

authors： Nobel PS

更新日期：1978-01-01 00:00:00

abstract：:Changing environments can have divergent effects on biodiversity-ecosystem function relationships at alternating trophic levels. Freshwater mussels fertilize stream foodwebs through nutrient excretion, and mussel species-specific excretion rates depend on environmental conditions. We asked how differences in mussel di...

journal_title：Oecologia

authors： Spooner DE,Vaughn CC,Galbraith HS

更新日期：2012-02-01 00:00:00

abstract：:Mature growth-phase internodes of Alaska paper birch (Betula resinifera) are preferred by the snowshoe hare (Lepus americanus) over juvenile growth-phase internodes due to the low food value of the latter. While the mature over juvenile preferencec cannot be explained by the levels of inorganic nutrients or gross chem...

journal_title：Oecologia

authors： Reichardt PB,Bryant JP,Clausen TP,Wieland GD

更新日期：1984-12-01 00:00:00

abstract：:Seed number per pod is negatively skewed in Leucaena leucocephala. Post-fertilisation abortion of pods does not completely explain the skewed distribution. It is shown that a pre-fertilisation regulation effectively restricts the formation of pods with less than a certain number of seeds. The regulation is rendered th...

journal_title：Oecologia

authors： Ganeshaiah KN,Uma Shaanker R,Shivashankar G

更新日期：1986-11-01 00:00:00

abstract：:This study examined the effects of elevated CO2 on secondary metabolites for saplings of tropical trees. In the first experiment, nine species of trees were grown in the ground in open-top chambers in central Panama at ambient and elevated CO2 (about twice ambient). On average, leaf phenolic contents were 48% higher u...

journal_title：Oecologia

authors： Coley P,Massa M,Lovelock C,Winter K

更新日期：2002-09-01 00:00:00

abstract：:This study quantified both the age- and sex-specific survival rates of juveniles and adults, and tested for interannual differences in age-specific survival rates of the southern elephant seal population at Marion Island. Pups were tagged on an annual basis from 1983 onwards at Marion Island, and a consistent recaptur...

journal_title：Oecologia

authors： Pistorius PA,Bester MN,Kirkman SP

更新日期：1999-11-01 00:00:00

abstract：:We demonstrate that an egg parasitoid, Anagrus delicatus (Mymaridae, Hymenoptera) and its host, Prokelesia marginata (Delphacidae, Homoptera) regularly disperse 1 km or more in a north Florida saltmarsh. Anagrus delicatus were caught on yellow sticky traps on offshore islets and oyster bars throughout the spring, summ...

journal_title：Oecologia

authors： Antolin MF,Strong DR

更新日期：1987-09-01 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：:Although an increase in competition is a common cost associated with intraspecific crowding, spatial aggregation across food-limited resource patches is a widespread phenomenon in many insect communities. Because intraspecific aggregation of competing insect larvae across, e.show $132#g. fruits, dung, mushrooms etc., ...

journal_title：Oecologia

authors： Rohlfs M,Hoffmeister TS

更新日期：2004-08-01 00:00:00

abstract：:Plant roots transfer water between soil layers of different water potential thereby significantly affecting the distribution and availability of water in the soil profile. We used a modification of the heat pulse method to measure sap flow in roots of Grevillea robusta and Eucalyptus camaldulensis and demonstrated a r...

journal_title：Oecologia

authors： Burgess SS,Adams MA,Turner NC,Ong CK

更新日期：1998-07-01 00:00:00

abstract：:Assembly rules provide a useful framework for predicting patterns of community assembly under defined environmental conditions. Habitat created by canopy-forming algae (such as kelps) provides a promising system for identifying assembly rules because canopies typically have a large and predictable influence on underst...

journal_title：Oecologia

authors： Irving AD,Connell SD

更新日期：2006-06-01 00:00:00

abstract：:A comparison of photosynthetic adaptations of desert ephemerals from sun and shade environments has shown differences in the magnitude and timing of maximum CO2 assimilation. Photosynthetic rates of species from the sun environment were significantly higher, and maximum observed levels occurred both earlier in the day...

journal_title：Oecologia

authors： Wallace CS,Szarek SR

更新日期：1981-10-01 00:00:00

abstract：:A reanalysis of data presented by Henneman (1983) to examine the relationship between intrinsic rate of increase and basal metabolism suggests there is no statistically significant correlation between the two variables when both are treated with comparable statistical techniques. In addition, I suggest there is no the...

journal_title：Oecologia

authors： Hayssen V

更新日期：1984-11-01 00:00:00

abstract：:Weight losses from sweet chestnut and beech leaves, attributable to biotic and abiotic breakdown processes, leaching and microbial decomposition have been studied using tethered leaves and litter bags. The experimental sites were two adjacent areas of deciduous woodland. In one area (the Castanea site) a mor-like mode...

journal_title：Oecologia

authors： Anderson JM

更新日期：1973-09-01 00:00:00

abstract：:Replacement of a native species by a nonnative can have strong effects on ecosystem function, such as altering nutrient cycling or disturbance frequency. Replacements may cause shifts in ecosystem function because nonnatives establish at different biomass, or because they differ from native species in traits like fora...

journal_title：Oecologia

authors： Benjamin JR,Fausch KD,Baxter CV

更新日期：2011-10-01 00:00:00

abstract：:1. The uptake of heavy metals via the alimentary tract can be an important factor for the metal budget of fish. 2. Concepts such as biomagnification, bioaccumulation, biotransference, or concentration factors, convey little information about the real threat originating from heavy metals in an aquatic food chain. 3. In...

journal_title：Oecologia

authors： Dallinger R,Prosi F,Segner H,Back H

更新日期：1987-08-01 00:00:00

abstract：:A widely cited benefit of predator diversity is greater suppression of insect herbivores, with corresponding increases in plant biomass. In the context of a vector-borne pathogen system, predator species richness may also influence plant disease risk via the direct effects of predators on the abundance and behavior of...

journal_title：Oecologia

authors： Long EY,Finke DL

更新日期：2015-04-01 00:00:00

abstract：:In a tropical environment near the equator in Nairobi, Kenya, flesh fly development is nearly continuous throughout the year with only a few individuals being channeled into pupal diapause during the coldest months. Two species reared in a field cage completed 7 generations/year. Generation time for nondiapause flies ...

journal_title：Oecologia

authors： Denlinger DL

更新日期：1978-01-01 00:00:00

abstract：:Seeds dispersed by tropical, arboreal mammals are usually deposited singly and without dung or in clumps of fecal material. After dispersal through defecation by mammals, most seeds are secondarily dispersed by dung beetles or consumed by rodents. These post-dispersal, plant-animal interactions are likely to interact ...

journal_title：Oecologia

authors： Andresen E,Levey DJ

更新日期：2004-03-01 00:00:00