Reproductive ecology of a parasitic plant differs by host species: vector interactions and the maintenance of host races.

abstract：:Ten populations of the perennial herb, Liatris acidota Engelm. & Gray (Compositae), growing on the Texas Gulf Coast (USA) were analyzed for age structure, frequency of predation, and frequency of asexual reproduction. Nine of the ten populations exhibited non-stable age distributions due to a deficiency of young non-s...

journal_title：Oecologia

authors： Schaal BA

更新日期：1978-01-01 00:00:00

abstract：: Fluorogenic substrate analogues (MUF substrates) are very sensitive in detecting hydrolytic enzymes. This method was adapted for the quantitative analysis of extracellular enzymes in snails and other animals. It was then used to determine cellobiase, chitobiase, protease, esterase, phosphatase and lipase in the diges...

journal_title：Oecologia

authors： Brendelberger H

更新日期：1996-12-01 00:00:00

abstract：:Frugivorous birds disperse the seeds of many fruit-bearing plants, but the fate of seeds after defecation or regurgitation is often unknown. Some rodents gather and scatter hoard seeds, and some of these may be overlooked, germinate, and establish plants. We show that these two disparate modes of seed dispersal are li...

journal_title：Oecologia

authors： Vander Wall SB,Kuhn KM,Gworek JR

更新日期：2005-09-01 00:00:00

abstract：:Ecological traits that reflect movement potential are often used as proxies for measured dispersal distances. Whether such traits reflect actual dispersal is often untested. Such tests are important because maximum dispersal distances may not be achieved and many dispersal events may be unsuccessful (without reproduct...

journal_title：Oecologia

authors： Lancaster J,Downes BJ

更新日期：2017-05-01 00:00:00

abstract：:In resource-limited savannas, the distribution and abundance of fine roots play an important role in acquiring essential resources and structuring vegetation patterns and dynamics. However, little is known regarding the three-dimensional distribution of fine roots in savanna ecosystems at the landscape scale. We quant...

journal_title：Oecologia

authors： Zhou Y,Boutton TW,Wu XB,Wright CL,Dion AL

更新日期：2018-04-01 00:00:00

abstract：:Invasive generalist ectoparasites provide a tool to study factors affecting expansion rates. An increase in the number of host species may facilitate geographic range expansion by increasing the number of suitable habitats and by affecting local extinction and colonization rates. A geographic perspective on parasite h...

journal_title：Oecologia

authors： Välimäki P,Kaitala A,Madslien K,Härkönen L,Várkonyi G,Heikkilä J,Jaakola M,Ylönen H,Kortet R,Ytrehus B

更新日期：2011-08-01 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：:The aim of this study was to test if females of the aphid hyperparasitoid Dendrocerus carpenteri (Curtis produce patch marks. We tested if these marks inform a foraging female of the identity of the producer of the mark (the female herself or a conspecific female) and on the producer's success or failure in finding ho...

journal_title：Oecologia

authors： Höller C,Hörmann R

更新日期：1993-05-01 00:00:00

abstract：:Debate on the control of population dynamics in reef fishes has centred on whether patterns in abundance are determined by the supply of planktonic recruits, or by post-recruitment processes. Recruitment limitation implies little or no regulation of the reef-associated population, and is supported by several experimen...

journal_title：Oecologia

authors： Forrester GE

更新日期：1995-08-01 00:00:00

abstract：:Environmental effects on parents can strongly affect the phenotype of their offspring, which alters the heritability of traits and the offspring's responses to the environment. We examined whether P limitation of the aquatic invertebrate, Daphnia magna, alters the responses of its offspring to inadequate P nutrition. ...

journal_title：Oecologia

authors： Frost PC,Ebert D,Larson JH,Marcus MA,Wagner ND,Zalewski A

更新日期：2010-04-01 00:00:00

abstract：:Leaf water relationships were studied in four widespread forest tree species (Ilex opaca Ait., Cornus florida L., Acer rubrum L., and Liriodendron tulipifera L.). The individuals studied all occurred on the same site and were selected to represent a range of growth forms and water relationships in some of the principa...

journal_title：Oecologia

authors： Roberts SW,Strain BR,Knoerr KR

更新日期：1980-09-01 00:00:00

abstract：: Quantifying pathways of energy transfer between plants, pests, and beneficial insects is a necessary step toward maintaining pest stable agroecosystems in the absence of chemical subsidies. A diet switching experiment utilizing a predatory ladybird beetle, Hippodamia variegata (Goeze), evaluated the use of naturally ...

journal_title：Oecologia

authors： Ostrom PH,Colunga-Garcia M,Gage SH

更新日期：1996-12-01 00:00:00

abstract：:Fungal feeding soil invertebrates feed on a wide spectrum of fungal species suggesting that mixed diets increase fitness. We investigated relationships between food preferences for seven saprophytic fungal species/forms and fitness parameters (mortality, growth, time to reproduction, reproduction, egg size) in two Col...

journal_title：Oecologia

authors： Scheu S,Simmerling F

更新日期：2004-05-01 00:00:00

abstract：:Prey intake and selection were related to within-shoal position for Atlantic cod (Gadus morhua) engaged in annual migration across the Newfoundland shelf in the northwest Atlantic. Comparisons made among fish occupying five regions from the front to rear of a large (>10 km across) migrating shoal indicated that leadin...

journal_title：Oecologia

authors： DeBlois EM,Rose GA

更新日期：1996-10-01 00:00:00

abstract：:Optimal diet theory often fails to predict a forager's diet choice when prey are mobile. Because they escape or defend themselves, mobile prey are likely to increase the forager's handling time, thereby decreasing its fitness gain rate. Many animals have been shown to select their prey so as to maximize either their f...

journal_title：Oecologia

authors： Barrette M,Wu GM,Brodeur J,Giraldeau LA,Boivin G

更新日期：2009-01-01 00:00:00

abstract：:Hydrologic regime is an important control of primary production in wetland ecosystems. I investigated the coupling of flooding, soil salinity and plant production in northern prairie marshes that experience shallow spring flooding. Field experiments compared whitetop (Scolochloa festucacea) marsh that was: (1) nonfloo...

journal_title：Oecologia

authors： Neill C

更新日期：1993-10-01 00:00:00

abstract：:1.) The daily ration required to maintain a population growth rate, r m, of zero (threshold ration) increased with increasing Asplanchna body mass. This relationship is described by the equation T=0.342 W0.797 where T=threshold ration (μg day-1 dry mass) and W=Asplanchna body mass (μg adult-1 dry mass). 2.) The thresh...

journal_title：Oecologia

authors： Stemberger RS,Gilbert JJ

更新日期：1984-11-01 00:00:00

abstract：:The life history of Yucca glauca in the Great Plains was the subject of a four year field study. Data were incorporated in a stage transition model (based on rosette size) to explain how populations are maintained in spite of large regional and temporal variation in sexual reproductive success. Rosette size was found ...

journal_title：Oecologia

authors： Kingsolver RW

更新日期：1986-06-01 00:00:00

abstract：:Three-to-five-year population oscillations of northern small rodents are usually synchronous over hundreds of square kilometers. This regional synchrony could be due to similarity in climatic factors, or due to nomadic predators reducing the patches of high prey density close to the average density of a larger area. W...

journal_title：Oecologia

authors： Norrdahl K,Korpimäki E

更新日期：1996-09-01 00:00:00

abstract：:Anthropogenic disturbance can have important indirect effects on ecosystems by disrupting species interactions. Here we examine the effects of anthropogenic disturbance on distance dispersal by ants for the diaspores of myrmecochorous Euphorbiaceae in Brazilian Caatinga. Rates of diaspore removal and distances removed...

journal_title：Oecologia

authors： Leal LC,Andersen AN,Leal IR

更新日期：2014-01-01 00:00:00

abstract：:Ideal free distribution (IFD) models predict that animals distribute themselves such that no individual can increase its fitness by moving to another patch. Many empirical tests assume that the interference among animals is independent of density and do not quantify the effects of density on fitness traits. Using two ...

journal_title：Oecologia

authors： van der Hammen T,Montserrat M,Sabelis MW,de Roos AM,Janssen A

更新日期：2012-05-01 00:00:00

abstract：:The effect of feeding of the mirid bug Capsodes infuscatus on fruit production of the geophyte Asphodelus ramosus was studied in a desert area in Israel. Plant and bug densities and percent loss of fruit production were measured in a relatively dry lower colluvial slope, an intermediate upper colluvial slope, and a re...

journal_title：Oecologia

authors： Ayal Y,Izhaki I

更新日期：1993-04-01 00:00:00

abstract：:Energy metabolism (oxygen consumption) in acclimated juvenile yellow banded and unbanded Cepaea hortensis Müll. was measured at 5°, 10°, 15°, 20°, and 25°C with Englemann respirometers. Metabolic rates were also measured after abrupt temperature changes from 5° to 20° and from 25° to 10°C.Energy metabolism in the two ...

journal_title：Oecologia

authors： Steigen AL

更新日期：1979-08-01 00:00:00

abstract：:We obtined data on body mass and growth rates for the immature members of two groups of wild baboons in Amboseli National Park, Kenya. Data were collected without feeding, trapping, or handling. The data were separated into cross-sectional and longitudinal components, allowing both the examination of body mass-age rel...

journal_title：Oecologia

authors： Altmann J,Alberts S

更新日期：1987-04-01 00:00:00

abstract：:Tropical ferns are characterized by a high diversity of plant life forms, yet there have been few large-scale studies on the functional ecology of these different forms. We examined epiphytic, hemiepiphytic, and terrestrial ferns, and asked whether there are differences in the mineral nutrition and water relations acr...

journal_title：Oecologia

authors： Watkins JE Jr,Rundel PW,Cardelús CL

更新日期：2007-08-01 00:00:00

abstract：:The purpose of this research was to investigate the influence of nitrogen availability on growth and the patterns of dry matter and nitrogen allocation of the dune grasses Ammophila arenaria and Elymus mollis. Plants were grown from rhizome segments under near-ambient coastal conditions and received either high or low...

journal_title：Oecologia

authors： Pavlik BM

更新日期：1983-03-01 00:00:00

abstract：:The evolution of longevity requires a low risk of mortality from extrinsic factors, relative to intrinsic factors, so that individuals that differentially invest in physiological self-maintenance and minimize their annual reproductive costs will maximize lifetime fitness through a prolonged reproductive lifespan. The ...

journal_title：Oecologia

authors： Apanius V,Nisbet IC

更新日期：2006-02-01 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：:It has long been argued that seed dispersal enhances recruitment in tropical trees by allowing offspring to `escape' strong density/distance-dependent attack by insects, pathogens and rodents. Here we examined the effects of canopy openness and parent-offspring distance upon the frequency and timing of Chlorocardium r...

journal_title：Oecologia

authors： Hammond DS,Brown VK,Zagt R

更新日期：1999-05-01 00:00:00

abstract：:Enhanced ultraviolet-B (UV-B) radiation may have multiple effects on both plants and animals and affect plant-herbivore interactions directly and indirectly by inducing changes in host plant quality. In this study, we examined combined effects of UV-B and herbivory on the defence of the mountain birch (Betula pubescen...

journal_title：Oecologia

authors： Anttila U,Julkunen-Tiitto R,Rousi M,Yang S,Rantala MJ,Ruuhola T

更新日期：2010-09-01 00:00:00