abstract：:Intraspecific and intrasexual variation in home range size, body mass and ecological productivity is examined in three selected species of Carnivora (Felis rufus: Canis latrans; Ursus americanus), reflecting different diets. We then compare the intraspecific results with prior cross-species studies. Home range size an...

journal_title：Oecologia

authors： Gompper ME,Gittleman JL

更新日期：1991-09-01 00:00:00

abstract：:The physiological activity and C and N allocation of beech seedlings planted in two different beech forest soils (acid brown earth, rendzina) were studied over 80 days. One adult earthworm Octolasion lacteum (Örley) was placed in half of the containers. Transpiration, CO2, assimilation, chlorophyll synthesis and N inc...

journal_title：Oecologia

authors： Wolters V,Stickan W

更新日期：1991-09-01 00:00:00

abstract：:I followed the within-generation distribution of a chewing specialist herbivore, the water-lily beetle, on individually marked leaves of the yellow water-lily. Yellow water-lilies produced new leaves steadily throughout the growth season. Average leaf longevity was 3-4 weeks, much shorter than the developmental time o...

journal_title：Oecologia

authors： Kouki J

更新日期：1991-09-01 00:00:00

abstract：:This study investigated direct and indirect interactions between the ant, Pheidole megacephala (Fabr.), the green scale, Coccus viridis (Green), and the scale's host plant, Pluchea indica (L.). To examine the influence of ants on scales and host plants, scale population densities, scale mortality rates, and plant perf...

journal_title：Oecologia

authors： Bach CE

更新日期：1991-07-01 00:00:00

abstract：:Seedlings of six subtropical rainforest tree species representing early (Omalanthus populifolius, Solanum aviculare), middle (Duboisia myoporoides, Euodia micrococca) and late (Acmena ingens, Argyrodendron actinophyllum) successional stages in forest development were grown in a glasshouse, under four levels of neutral...

journal_title：Oecologia

authors： Turnbull MH

更新日期：1991-06-01 00:00:00

abstract：:We examined the demographic costs of Chaoborus-induced defensive spine structures in Daphnia pulex. Our aim was to assess the role of resource limitation and the interaction effects of limiting food level and antipredator structures on fitness of D. pulex and to pinpoint those life stages that are most sensitive to ch...

journal_title：Oecologia

authors： Walls M,Caswell H,Ketola M

更新日期：1991-06-01 00:00:00

abstract：:The degree of CAM-cycling was examined in plants from 23 populations representing five morphologically similar species of Talinum to determine how CAM-cycling correlates with site aridity and drought stress. In the field, CAM-cycling, as indicated by the amount of malic acid accumulated in plant tissues overnight, and...

journal_title：Oecologia

authors： Harris FS,Martin CE

更新日期：1991-05-01 00:00:00

abstract：:The intensity of resource exploitation by phytophagous insects is usually considered to reflect population size. For populations of two flowerhead-attacking tephritid flies, however, the resources utilised were not related to the numbers of searching adults. Tephritis bardanae Schrank attacked 11-13% of the total flow...

journal_title：Oecologia

authors： Straw NA

更新日期：1991-05-01 00:00:00

abstract：:Models incorporating the energetics of individual daphnids (Cladocera) have been developed to predict the effect of environmental variables, particularly food availability, on population dynamics. One of them, that of Kooijman (1986), assumes that all assimilated energy enters a storage compartment prior to use in pro...

journal_title：Oecologia

authors： Bradley MC,Perrin N,Calow P

更新日期：1991-05-01 00:00:00

abstract：:The species composition of vesicular-arbuscular mycorrhizal (VAM) fungal communities changed during secondary succession of abandoned fields based on a field to forest chronosequence. Twenty-five VAM fungal species were identified. Seven species were clearly early successional and five species were clearly late succes...

journal_title：Oecologia

authors： Johnson NC,Zak DR,Tilman D,Pfleger FL

更新日期：1991-05-01 00:00:00

abstract：:The costs and benefits of resource integration in Hydrocotyle bonariensis were examined by comparing severed and intact clones grown across multiple resource gradients. Basipetal movement of water, nitrogen and photosynthates was demonstrated to occur between two rhizome branch systems interconnecting hundreds of rame...

journal_title：Oecologia

authors： Evans JP

更新日期：1991-04-01 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：:We report evidence from controlled experiments that long straight thorns deter herbivory by browsers. Cut branches of three woody species that had their thorns removed suffered significantly greater herbivory by a tethered goat than did paired intact branches. Branches on living Acacia seyal plants that had their thor...

journal_title：Oecologia

authors： Milewski AV,Young TP,Madden D

更新日期：1991-03-01 00:00:00

abstract：:The hypothesis that carnivorous plants are less responsive to prey at high soil nutrient levels than at lower levels (Givnish et al. 1984) is tested on four plant species (Drosera rotundifolia, Pinguicula alpina, P. villosa and P. vulgaris) from a subarctic environment. The response, measured in terms of seven charact...

journal_title：Oecologia

authors： Karlsson PS,Nordell KO,Carlsson BÅ,Svensson BM

更新日期：1991-03-01 00:00:00

abstract：:We used a complete block design to experimentally study direct and indirect interactions in a three trophic-level freshwater system consisting of a top predator, the green sunfish, Lepomis cyanellus, an intermediate predator, small-mouthed salamander larvae, Ambystoma barbouri, and prey, hatchling isopods, Lirceus fon...

journal_title：Oecologia

authors： Huang C,Sih A

更新日期：1991-02-01 00:00:00

abstract：:Resprouting is the main regeneration mechanism after fire in Mediterranean-type ecosystems. Herbivores play an important role in controlling postfire seedling establishment, but their influence on regeneration by resprouting is less well known. To study the effects of fire intensity on resprouting of Adenostoma fascic...

journal_title：Oecologia

authors： Moreno JM,Oechel WC

更新日期：1991-01-01 00:00:00

abstract：:Resource partitioning of diet and habitat use was studied in the entire Amazonian ungulate community of Northeastern Peru, which comprises the red brocket deer (Mazama americana), grey brocket deer (M. gouazoubira), collared peccary (Tayassu tajacu), white-lipped peccary (T. pecari), and lowland tapir (Tapirus terrest...

journal_title：Oecologia

authors： Bodmer RE

更新日期：1991-01-01 00:00:00

abstract：:Home range data were collected concurrently from four syntopic browsing ruminant species in a conserved savanna ecosystem. Mean home range areas were: giraffe (Giraffa camelopardalis) 282 km2; kudu (Tragelaphus strepsiceros) 21.9 km2; impala (Aepyceros melampus) 5.82 km2; steenbok (Raphicerus campestris) 0.62 km2. Hom...

journal_title：Oecologia

authors： du Toit JT

更新日期：1990-12-01 00:00:00

abstract：:Selection of sites for oviposition when the risk of predation by green frogs was variable studied in tandems of the damselfly Pyrrhosoma nymphula. In the absence of predators the number of tandems landing increased with the size of the oviposition site and with the number of pairs already present. Pairs approaching an...

journal_title：Oecologia

authors： Rehfeldt GE

更新日期：1990-12-01 00:00:00

abstract：:We present evidence of genetic variation in and covariation between leaf-level gas exchange properties and leaf size among family lines of Polygonum arenastrum. This self-fertilizing annual had previously been shown to vary genetically in developmental phenology and in morphology (size of leaves, internodes, flowers a...

journal_title：Oecologia

authors： Geber MA,Dawson TE

更新日期：1990-12-01 00:00:00

abstract：:We examined patterns of density and species diversity for leaf-mining Lepidopterans and gall-forming Hymenopterans in two oak (Quercus spp.) hybrid zones: Quercus depressipes x Q. rugosa and Q. emoryi x Q. coccolobifolia. In both species complexes, hybrid hosts typically supported significantly lower densities and spe...

journal_title：Oecologia

authors： Boecklen WJ,Spellenberg R

更新日期：1990-11-01 00:00:00

abstract：:Marion Island (47°S, 38°E) has one of the most oceanic climates on earth, with consistently low air temperatures, high precipitation, constantly high humidity, and low incident radiation. Since 1968 mean surface air temperature has increased significantly, by 0.025° C year-1. This was strongly associated with correspo...

journal_title：Oecologia

authors： Smith VR,Steenkamp M

更新日期：1990-11-01 00:00:00

abstract：:Life history theory predicts that migratory fishes should delay reproduction, be larger at first reproduction, and have higher fecundities than nonmigrants. We tested this hypothesis by comparing life histories of anadromous ("estuary") and resident freshwater ("upstream") threespine sticklebacks (Gasterosteus aculeat...

journal_title：Oecologia

authors： Snyder RJ,Dingle H

更新日期：1990-10-01 00:00:00

abstract：:Vallisneria americana was grown for six weeks in a greenhouse on relatively fertile sediment to test for factors other than nutrient limitation which may slow growth of this submersed macrophyte at pH 5. On the basis of dry mass accumulated, (1) low pH significantly depressed Vallisneria growth at constant free CO2 le...

journal_title：Oecologia

authors： Titus JE,Feldman RS,Grisé D

更新日期：1990-10-01 00:00:00

abstract：:The effect of tree canopy, understory, herbivores, and litter depth on seedling establishment, survival, and reproduction of the alien grass, Bromus tectorum (cheatgrass), was examined in a series of experiments in four forest habitat types in western North America. Higher recruitment, survival, and reproduction on cl...

journal_title：Oecologia

authors： Pierson EA,Mack RN

更新日期：1990-10-01 00:00:00

abstract：:Ant metapleural glands secrete surface antibiotics that affect pollen as well as bacteria and fungi. This may be one reason why ant pollination is rare. It is predicted that pollination by ants is possible only in the presence of certain ant and/or plant traits. Two traits are investigated; first, absence of the metap...

journal_title：Oecologia

authors： Peakall R,Angus CJ,Beattie AJ

更新日期：1990-10-01 00:00:00

abstract：:Carbon isotope ratios, photosynthesis, and transpiration were measured on a xylem-tapping mistletoe (Phoradendron juniperinum) and its host (Juniperus osteosperma) in southern Utah, USA. For host tissues, the carbon isotope ratios agreed with theoretical values predicted from gas exchange observations. However, for mi...

journal_title：Oecologia

authors： Marshall JD,Ehleringer JR

更新日期：1990-09-01 00:00:00

abstract：:We report the recovery of root nodules from P. glandulosa var. glandulosa in the eastern portion of its range, where the species reaches its greatest vegetational development. Single cores 4.7 cm in diameter and up to 250 cm deep yielded from 0 to over 250 nodules. Nodules were found at all depths below 10 cm, with th...

journal_title：Oecologia

authors： Johnson HB,Mayeux HS Jr

更新日期：1990-09-01 00:00:00

abstract：:Leaf surface conductance and apparent photosynthesis were measured during late summer and autumn on saplings and sprouts of pin cherry (Prunus pensylvanica), yellow birch (Betula alleghaniensis), American beech (Fagus grandifolia), and sugar maple (Acer saccharum) naturally revegetating a site in the northern hardwood...

journal_title：Oecologia

authors： Amthor JS,Gill DS,Bormann FH

更新日期：1990-08-01 00:00:00

abstract：:Models of the evolution of seed dormancy reveal that dormancy is favoured either when opportunities for establishment vary over time and when there is wide variation in the probability of success, or when the probability of success is limited by frequency dependence. Empirical evidence supporting the temporal heteroge...

journal_title：Oecologia

authors： Zammit C,Zedler PH

更新日期：1990-08-01 00:00:00

abstract：:Belowground processes in light gap openings are poorly understood, particularly in tropical forests. Fine roots in three zones of light gap openings and adjacent intact forest were regularly measured in buried bags and surface litter envelopes for 2 years. Fine root biomass does not vary significantly within gaps for ...

journal_title：Oecologia

authors： Sanford RL Jr

更新日期：1990-07-01 00:00:00

abstract：:Pea aphids have several alternative responses to the detection of alarm pheromone produced by conspecifics. One of these, dropping from the feeding site to the ground, is potentially costly owing to the risk of desiccation-induced mortality on the ground before another host plant can be reached. Both dropping and walk...

journal_title：Oecologia

authors： Dill LM,Fraser AH,Roitberg BD

更新日期：1990-07-01 00:00:00

abstract：:Pollen movement is often restricted in natural populations, and insufficient pollination is a potential constraint on sexual reproduction in outcrossing species. Seed-set should decrease with increased distance from the pollen source in outcrossing plants. This prediction was tested using females of the clonal, gynodi...

journal_title：Oecologia

authors： Widén B,Widén M

更新日期：1990-06-01 00:00:00

abstract：:Studies of predation by roach (Rutilus rutilus) on zebra mussel (Dreissena polymorpha) in a large, eutrophic lake showed that there was a clearly marked size threshold (∼ 160 mm SL) above which roach began to feed on mussels. Roach preying on various sizes of mussels selected them in proportions different from their a...

journal_title：Oecologia

authors： Prejs A,Lewandowski K,Stańczykowska-Piotrowska A

更新日期：1990-06-01 00:00:00

abstract：:The seasonal and long-term population dynamics of helminths parasitizing voles suggested that density-dependent factors might be important in the population dynamics of common species, whereas density-independent factors predominate in the regulation of the rare species. To test this, we used single and multiple regre...

journal_title：Oecologia

authors： Haukisalmi V,Henttonen H

更新日期：1990-06-01 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：:When testing census data of insect populations for regulation, and/or for overall density dependence in the course of numbers over years, certain conditions, which follow from the testing models, should be fulfilled. Even if the series of densities may be considered a piece of first-order Markov chain (a necessary con...

journal_title：Oecologia

authors： Den Boer PJ

更新日期：1990-05-01 00:00:00

abstract：:Demographic characteristics associated with the maintenance and growth of populations, such as seed dynamics, seedling emergence, survival, and tiller dynamics were examined for two tussock grasses, the native Agropyron spicatum and the introduced Agropyron desertorum in a 30-month field study. The introduced grass wa...

journal_title：Oecologia

authors： Pyke DA

更新日期：1990-04-01 00:00:00

abstract：:We examined the relationship between size variability and the distribution of functional gender in stands of the monoecious, wind-pollinated annual Ambrosia artemisiifolia. Populations of 60 individuals were grown in the greenhouse at a density of 372 m-2 and at two nutrient levels. Among the surviving plants, after s...

journal_title：Oecologia

authors： Ackerly DD,Jasieński M

更新日期：1990-04-01 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