Effect of ration levels on food utilisation in the grasshopper Poecilocerus pictus.

abstract：:The random-mixing assumptions of many parasite-transmission models are challenged if healthy individuals can alter their behaviour to reduce their risk of infection. Some pathogens reduce the attractiveness of their hosts' excretions, for example, potentially altering contact rates and thus the predicted force of infe...

journal_title：Oecologia

authors： Hughes NK,Helsen S,Tersago K,Leirs H

更新日期：2014-12-01 00:00:00

abstract：:Many ecological studies rely heavily on chemical analysis of plant and animal tissues. Often, there is limited time and money to perform all the required analyses and this can result in less than ideal sampling schemes and poor levels of replication. Near infrared reflectance spectroscopy (NIRS) can relieve these cons...

journal_title：Oecologia

authors： Foley WJ,McIlwee A,Lawler I,Aragones L,Woolnough AP,Berding N

更新日期：1998-09-01 00:00:00

abstract：:Characterizing the causes of spatial and temporal variation in parasite-induced mortality under natural conditions is crucial to better understanding the factors driving host population dynamics. Our goal was to quantify this variation in the amphipod Paracalliope novizealandiae, a second intermediate host of the trem...

journal_title：Oecologia

authors： Bates AE,Poulin R,Lamare MD

更新日期：2010-07-01 00:00:00

abstract：:Increased nitrogen (N) deposition, resulting from the combustion of fossil fuels, production of synthetic fertilizers, growth of N(2)-fixing crops and high-intensity agriculture, is one of the anthropogenic factors most likely to cause global biodiversity changes over the next century. This influence may be especially...

journal_title：Oecologia

authors： Skogen KA,Holsinger KE,Cardon ZG

更新日期：2011-01-01 00:00:00

abstract：:The ostracod Cyprideis torosa Jones, 1850 is a dominant species in the meiofauna of brackish water habitats. Its production in the field over a five-year period has been calculated using two production models. The first model uses the age-distribution of shells preserved in the sediment to assess the stage-specific mo...

journal_title：Oecologia

authors： Herman PM,Heip C,Vranken G

更新日期：1983-06-01 00:00:00

abstract：:Effects of habitat fragmentation on species diversity and herbivore-parasitoid interactions were analyzed using the insect community of seed feeders and their parasitoids in the pods of the bush vetch (Vicia sepium L.). Field studies were carried out on 18 old meadows differing in area and isolation. The area of these...

journal_title：Oecologia

authors： Kruess A,Tscharntke T

更新日期：2000-01-01 00:00:00

abstract：:The study illustrates the ecological determinants and evolutionary consequences of dispersal in the pond-living water beetle Dineutus assimilis (Coleoptera: Gyrinidae). Over 2 years, local populatiopn dynamics were studied in 51 ponds within a 60-km2 study area. In most of the 31 occupied ponds, and even in large popu...

journal_title：Oecologia

authors： Nürnberger B

更新日期：1996-05-01 00:00:00

abstract：:Lizards may experience population declines and extinctions on a similar scale to that experienced by amphibians, and climate warming is one hypothesis proposed to explain these declines and extinctions. Within lizards, viviparous species are hypothesized to be more vulnerable to climate warming, because they have evol...

journal_title：Oecologia

authors： Wang Z,Ma L,Shao M,Ji X

更新日期：2017-12-01 00:00:00

abstract：:Herbivores and pathogens with acute host specificity may promote high tree diversity in tropical forests by causing distance- and density-dependent mortality of seedlings, but evidence is scarce. Although Lepidoptera larvae are the most abundant and host-specific guild of herbivores in these forests, their impact upon...

journal_title：Oecologia

authors： Norghauer JM,Grogan J,Malcolm JR,Felfili JM

更新日期：2010-02-01 00:00:00

abstract：:Developing eggs of Metrioptera roeseli HGB. have an obligate "embryonic" diapause in stage 23 and a facultative "initial" diapause in stage 4. Initial diapause is lacking when the ovipositing females are kept at long day photoperiod (LD 16/8), but is induced at LD 14/10 and LD 8/16. When natural light conditions are g...

journal_title：Oecologia

authors： Ingrisch S

更新日期：1984-02-01 00:00:00

abstract：:The photosynthetic incorporation of H14CO3- by the alga Platymonas subcordiformis decreased with increasing concentrations of NaCl in the medium. There was no correlation between the response of P. subcordiformis to salinity in high or low NaCl-concentrations in the growing solution. When other osmotic substances were...

journal_title：Oecologia

authors： Kirst GO

更新日期：1975-09-01 00:00:00

abstract：:A water flux model with daily resolution is described which permits one to assess how changes in the rooting volume, amount of sapwood, leaf area and conductance properties interact to affect water uptake, internal storage, and transpiration.A root zone water compartment is defined for a particular tree on the basis o...

journal_title：Oecologia

authors： Running SW,Waring RH,Rydell RA

更新日期：1975-03-01 00:00:00

abstract：:In this study, we investigated whether free-living insectivorous water pipits (Anthus spinoletta) choose prey according to biochemical quality as measured by protein, lipid, carbohydrate, energy and water contents and/or according to profitability as measured by density, size and catchability. Food preference - expres...

journal_title：Oecologia

authors： Brodmann PA,Reyer HU

更新日期：1999-09-01 00:00:00

abstract：:Stand thinning across different soil drainage types was used to test the ecophysiological basis for the control of foliar monoterpenes in current-year foliage of balsam trees [Abies balsamea (L.) P. Mill.] the year following treatment. Photosynthetic capacity (A max) was greater on mesic sites than on sub-hygric and h...

journal_title：Oecologia

authors： Lamontagne M,Bauce É,Margolis H

更新日期：2002-01-01 00:00:00

abstract：:In flowering plants, many dioecious species display a certain degree of sexual dimorphism in non-reproductive traits, but this dimorphism tends to be much less striking than that found in animals. Sexual size dimorphism in plants may be limited because competition for light in crowded environments so strongly penalise...

journal_title：Oecologia

authors： Labouche AM,Pannell JR

更新日期：2016-07-01 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：:Although it is well-documented from theoretical studies that pathogens have the capacity to generate cycles, the occurrence and role of pathogens and disease have been poorly empirically studied in cyclic voles and lemmings. In screening for the occurrence of disease in cyclic vole and lemming populations, we found th...

journal_title：Oecologia

authors： Niklasson B,Nyholm E,Feinstein RE,Samsioe A,Hörnfeldt B

更新日期：2006-11-01 00:00:00

abstract：:To investigate the physiological, behavioral, and genetic contributions to growth rate, we studied the thermal sensitivity of growth rate in hatchlings of the iguanid lizards Sceloporus occidentalis and S. graciosus in the laboratory. We used a cycling thermal regime patterned after thermal environments found in natur...

journal_title：Oecologia

authors： Sinervo B,Adolph SC

更新日期：1989-03-01 00:00:00

abstract：:Among species, photosynthetic capacity (Amax) is usually related to leaf nitrogen content (N), but variation in the species-specific relationship is not well understood. To address this issue, we studied Amax-N relationships in 23 species in adjacent Amazonian communities differentially limited by nitrogen (N), phosph...

journal_title：Oecologia

authors： Reich PB,Walters MB,Ellsworth DS,Uhl C

更新日期：1994-02-01 00:00:00

abstract：:Climate change is driving species range shifts worldwide. However, physiological responses related to distributional changes are not fully understood. Oceanographers have reported an increase in ocean temperature in the northwest Iberian Peninsula that is potentially related to the decline in some cold-temperate inter...

journal_title：Oecologia

authors： Martínez B,Arenas F,Rubal M,Burgués S,Esteban R,García-Plazaola I,Figueroa FL,Pereira R,Saldaña L,Sousa-Pinto I,Trilla A,Viejo RM

更新日期：2012-10-01 00:00:00

abstract：:While trying to achieve their nutritional requirements, foraging herbivores face the costs of plant defenses, such as toxins. Teasing apart the costs and benefits of various chemical constituents in plants is difficult because their chemical defenses and nutrient concentrations often co-vary. We used an approach deriv...

journal_title：Oecologia

authors： Bedoya-Pérez MA,Issa DD,Banks PB,McArthur C

更新日期：2014-08-01 00:00:00

abstract：:Dolman (1995) measured the intake rates of snow buntings feeding on seed patches at difference bird densities, for each of two different seed densities. Interference occurred in the low food density treatment, with intake rate declining at high bird densities, but did not occur in the high food density treatment. Dolm...

journal_title：Oecologia

authors： Moody AL,Ruxton GD

更新日期：1996-11-01 00:00:00

abstract：:Fine root extractions from soil cores of a south facing slope in the Southern Californian chaparral were used to study the dynamics of feeder root growth in a summer-dry area. The studies were concentrated on the root systems of Adenostoma fasciculatum, Arctostaphylos glauca, Ceanothus greggii, and Rhus ovata. The tot...

journal_title：Oecologia

authors： Kummerow J,Krause D,Jow W

更新日期：1978-01-01 00:00:00

abstract：:The spatial distributions of selected soil properties in two adjacent sites in southwest Michigan were examined to evaluate the potential effects of chronic disturbance on resource heterogeneity. One site was a cultivated field that had been cleared, plowed, and cropped annually for decades prior to sampling while the...

journal_title：Oecologia

authors： Robertson GP,Crum JR,Ellis BG

更新日期：1993-12-01 00:00:00

abstract：:Competition and facilitation are both considered major factors affecting the structure of plant assemblages, yet few studies have quantified positive, negative, and net effects simultaneously. In this study, we investigated the positive, negative, and net effects of tree saplings on the encroachment of two tree specie...

journal_title：Oecologia

authors： Kennedy PG,Sousa WP

更新日期：2006-06-01 00:00:00

abstract：:Spatial and temporal niche differentiation are potential mechanisms of plant species' coexistence in many communities, including many grasslands. In a 6-year field experiment, a dominant prairie bunchgrass, Schizachyrium scoparium, excluded species sharing similar phenology and rooting depth, but coexisted with specie...

journal_title：Oecologia

authors： Fargione J,Tilman D

更新日期：2005-05-01 00:00:00

abstract：:Long-term studies were carried out in central Finland between 1985 and 2003 to examine the temporal and spatial variation in the density of otter populations. Snow tracking was used to estimate the total population and the number of litters in the study area. In total 52 otters, including 16 cubs in 11 litters, lived ...

journal_title：Oecologia

authors： Sulkava RT,Sulkava PO,Sulkava PE

更新日期：2007-09-01 00:00:00

abstract：:It has commonly been assumed that pollinator energy intake increases with flowering plant density, and visitation to flowers should therefore be higher in denser stands. I therefore investigated the relationship between flight distance and flight time for bumblebees and butterflies foraging on Senecio integerrimus and...

journal_title：Oecologia

authors： Schmitt J

更新日期：1983-10-01 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：:Snail hosts of different ages constitute different resource environments for larval trematodes because each individual has a particular energy budget and energy allocation pattern at the time of infection. Effects of monomiracidial trematode infections on shell growth, body dry weight and reproductive effort of the sn...

journal_title：Oecologia

authors： Gérard C,Théron A

更新日期：1997-11-01 00:00:00