abstract：:Environmentally controlled experiments on damping-off disease of garden cress (Lepidium sativum) caused by Pythium irregulare were used to study the effect of clumped planting patterns upon epidemic rates. In clumped stands of seedlings the rate of multiplication of disease was, in general, slower than in unclumped, e...

journal_title：Oecologia

authors： Burdon JJ,Chilvers GA

更新日期：1976-03-01 00:00:00

abstract：:Monk parakeets have been introduced into North America within the past 15 years and are apparently becoming established in several geographical regions. Several physiological responses of monk parakeets related to climatic tolerance were examined, and it is concluded that the species is equipped physiologically to occ...

journal_title：Oecologia

authors： Weathers WW,Caccamise DF

更新日期：1975-12-01 00:00:00

abstract：:The paper considers a model of competition, based upon the Lotka-Volterra equations, which explicitly considers the effect of density independent mortality upon the outcome of competition. The model's possible application to wild Drosophila species in Europe are considered. ...

journal_title：Oecologia

authors： Shorrocks B,Begon M

更新日期：1975-12-01 00:00:00

abstract：:In order to determine the influence of the hydrogen-ion concentration on the damage exerted to lichens by sulfur dioxide gas, thalli of the species Hypogymnia physodes and Xanthoria parietina were submerged in buffer solutions of pH 2 to pH 8 and subsequently exposed to SO2 gas. Net photosynthesis was employed as a cr...

journal_title：Oecologia

authors： Türk R,Wirth V

更新日期：1975-12-01 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 model is presented that simulates nitrogen uptake and response to nitrogen deficiency by a growing annual plant canopy. It is a descriptive model as it is not based on a detailed definition of the biochemical processes involved. It does incorporate a considerable amount of experimental knowledge about these processe...

journal_title：Oecologia

authors： Seligman NG,van Keulen H,Goudriaan J

更新日期：1975-09-01 00:00:00

abstract：:Two atlantic voyages were made by the FS Meteor during which pollen and spores were collected from the air. In the course of 32 days the average pollen content was 29/100 m3 air, the average spore content came to 5x104/100 m3 air. Both voyages occurred in late autumn. On the trip from Hamburg to the Azores the spore c...

journal_title：Oecologia

authors： Stix E

更新日期：1975-09-01 00:00:00

abstract：:The model of Meats (1974a) is tested against Laughlin's (1967a) data on growth in the field. A good measure of agreement is found. The model is then used to investigate the consequences of the univoltine T. paludosa starting its life cycle (flight season) at various dates in the range quoted by Coulson (1962)-i.e. fro...

journal_title：Oecologia

authors： Meats A

更新日期：1975-06-01 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：:The theory that early successional plants and annual plants will be less well defended against generalist herbivores than later successional plants and perennial plants, because they avoid herbivores by escaping in space and time, is evaluated. The theory is not supported in the ecosystem examined. The correlation bet...

journal_title：Oecologia

authors： Otte D

更新日期：1975-06-01 00:00:00

abstract：:Gas exchange measurements of two arctic tundra plants, Dupontia fischeri and Carex aquatilis, and two alpine tundra species, Deschampsia caespitosa and Geum rossii, were conducted under a range of atmospheric and soil moisture stress conditions to determine if photosynthetic adaptations to water stress may play a role...

journal_title：Oecologia

authors： Johnson DA,Caldwell MM

更新日期：1975-06-01 00:00:00

abstract：:The ecological overlap of three species of Hawaiian Drosophila: D. mimica D. kambysellisi, and D. imparisetae, has been investigated by analysis of the community matrix. The basic model is a Lotka-Volterra formulation, suitably expanded to include sexual dimorphism. We have also investigated equilibrium population siz...

journal_title：Oecologia

authors： Richardson RH,Smouse PE

更新日期：1975-03-01 00:00:00

abstract：:Two physiological races of the carabid beetle, Pterostichus nigrita, are compared. The larvae from the northern Scandinavian population (polar circle) develop faster in all temperature regimens, have a reduced mortality in lower temperatures and an increased growth rate in high temperatures compared with the central E...

journal_title：Oecologia

authors： Ferenz HJ

更新日期：1975-03-01 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：:Pre-hatching developmental times for prosobranch gastropods are greatly influenced by temperature and taxonomic affinity. If the data used here (including all available data from the Muricacea) are a representative sample, then reasonably accurate estimates of developmental time can be obtained for most prosobranchs k...

journal_title：Oecologia

authors： Spight TM

更新日期：1975-03-01 00:00:00

abstract：:Four colonies of the desert leaf-cutter ant Acromyrmex versicolor versicolor (Pergande) located 30 miles N.E. of Tempe, Arizona were observed over a 7 month period. The ants utilized trails in foraging, a characteristic of higher attines, as well as foraging singly, a typical pattern among the more primitive gardeners...

journal_title：Oecologia

authors： Gamboa GJ

更新日期：1975-03-01 00:00:00

abstract：:The duration times of the eggs, nauplii and copepodites of Cyclops vicinus and Eudiaptomus gracilis were obtained, by experiment, at 5, 10, 15 and 20°C. In contrast with previously published work on copepod development, the ovigerous females, used in the cultures at these temperatures, were removed from a water storag...

journal_title：Oecologia

authors： Munro IG

更新日期：1974-12-01 00:00:00

abstract：:Male dragonflies of the species Aeschna cyanea pay several visits per day to a suitable pond in search of mates. The influence of the population density upon the daily duration of presence of single dragonfly males was investigated by means of multiple regression analysis. Several environmental factors were also consi...

journal_title：Oecologia

authors： Kaiser H

更新日期：1974-12-01 00:00:00

abstract：:Carbon dioxide exchange patterns of prickly-pear cactus (Opuntia phaeacantha var. discata) were studied throughout the year to determine temperature influences on and seasonal responses of the process. Cacti exhibit CAM which permits nighttime carboxylation of CO2 to malate and daytime decarboxylation of malate to CO2...

journal_title：Oecologia

authors： Nisbet RA,Patten DT

更新日期：1974-12-01 00:00:00

abstract：:A simulation program on the germination of winter annuals is written in such a way that the influence of changing environmental conditions on germination characteristics such as the time of germination, the percentage of germination and the distribution function of germination is described as well as possible in accor...

journal_title：Oecologia

authors： Janssen JG

更新日期：1974-09-01 00:00:00

abstract：:Reduced rations of Calotropis gigantea produced a number of negative effects on the grasshopper Poecilocerus pictus such as heavy mortality (42% at 25% ration as aginst 11% at 100% ration), extension of hopper period (from 75 days about 113 days) and increase in the number of instars (from 6-7). At the tested 100, 50 ...

journal_title：Oecologia

authors： Muthukrishnan J,Delvi MR

更新日期：1974-09-01 00:00:00

abstract：:The hypothesis that dispersal in a heterogeneous environment can be an important factor in population stability is examined. It is shown that dispersal may increase the persistence time of a population by several orders of magnitude. ...

journal_title：Oecologia

authors： Roff DA

更新日期：1974-09-01 00:00:00

abstract：:Seven North American moss species responded differentially to fumigations with sulfur dioxide ranging from 0.5 to 4.0 ppm. Leucobryum glaucum and Dicranum scoparium were the most sensitive species; Dicranella heterophylla, Polytrichum ohioense and Pottia truncata, the most resistant. The results of fumigations with 0....

journal_title：Oecologia

authors： Nash TH 3rd,Nash EH

更新日期：1974-09-01 00:00:00

abstract：:A new technique based upon the dilution of C 14 /C 12 ratios in structural carbon of root systems during the course of the growing season was used to evaluate belowground turnover or productivity of two cool desert communities in northern Utah, USA. This technique provides a measure of turnover of the root system of e...

journal_title：Oecologia

authors： Caldwell MM,Camp LB

更新日期：1974-06-01 00:00:00

abstract：:Animals were acclimitized to a daily cycle of 15-25°C and a photoperiod of LD 12:12. Parietalectomized animals in an experimental thermal gradient (15°C-40°C, LD 12:12) selected significantly higher temperatures than controls at all hours of the day except from 0800-1200. These results suggest that the lizard parapine...

journal_title：Oecologia

authors： Hutchison VH,Kosh RJ

更新日期：1974-06-01 00:00:00

abstract：:The number of tracheal gills in the larval Limnephilini varies according to oxygen conditions of the surrounding waters. High proportions of oxygen cause a significant decrease in the number of gills, whereas low oxygen concentrations retult in a significant increase in the number of gills. These morphological adapati...

journal_title：Oecologia

authors： Wichard W

更新日期：1974-06-01 00:00:00

abstract：:1. There is a well-defined time sequence in the oxygen consumption of Porcellio scaber. A maximal rate (the 'active rate') is obtained in woodlice subjected to the maximal disturbance of food presentation, handling and light. After initial exploratory activity has ceased, the oxygen consumption declines through a seri...

journal_title：Oecologia

authors： Newell RC,Wieser W,Pye VI

更新日期：1974-03-01 00:00:00

abstract：:The effects of pollination, predispersal seed predation, and plant density upon seed production of Astragalus canadensis L. in a tall-grass prairie were studied by experimental manipulation of plant density. Seed production was greater at high than low plant densities; this was inferred to result from differences in p...

journal_title：Oecologia

authors： Platt WJ,Hill GR,Clark S

更新日期：1974-03-01 00:00:00

abstract：:As an extension of earlier investigations, the mating calls ofHyla arborea kretensis, Hyla a. molleri, andHyla a. sarda were studied, and variations in the calls with air temperature were determined. The mating calls of these species exhibit the typical structure, made up of short pulses of varying amplitude. The call...

journal_title：Oecologia

authors： Schneider H

更新日期：1974-03-01 00:00:00

abstract：:The energy turnover of weevil populations ofPhyllobius argentatus L.,Polydrosus undatus F., andStrophosomus sp. was investigated in a 123 years old (1970) beech forest in special consideration of their soil-living rhizophagous larvae (results of the energy turnover ofStrophosomus sp. imagines, see Grimm, 1973). I. Lif...

journal_title：Oecologia

authors： Schauermann J

更新日期：1973-12-01 00:00:00

abstract：:The regularly inundated region of the middle Amazon river together with its marginal lakes is characterized by special hydrographic, hydrochemical and biological conditions [1-4]. It is called "Várzea". Regular investigations of such Várzea lakes revealed several correlations between changes in water level, thermic an...

journal_title：Oecologia

authors： de Menezes Santos U

更新日期：1973-09-01 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：:1. The defecation behavior of the parasitoid larvae of Aleochara curtula in the Calliphora puparium was described. After occupation of the puparium the first-instar larva begins to defecate. With these excrements the larva closes the entry hole. Afterwards the first-instar larva as well as later the second-instar larv...

journal_title：Oecologia

authors： Fuldner D,Pfenning R

更新日期：1973-06-01 00:00:00

abstract：:The daily course of net photosynthesis and transpiration was measured with temperature and humidity controlled cuvettes at the end of the dry summer season in the Negev Desert. Species studied included: dominant species of the natural vegetation, cultivated plants in the run-off farm Avdat and permanently irrigated pl...

journal_title：Oecologia

authors： Schulze ED,Lange OL,Koch W

更新日期：1972-12-01 00:00:00

abstract：:The infestation of small alpine mammals with fleas during the year and at different altitudes was investigated. The data are based on an investigation carried out between 1966 and 1969 in Tirol (Austria) in different altitudinal zones of the alps, 1136 fleas having been collected from 625 insectivores and rodents. By ...

journal_title：Oecologia

authors： Mahnert V

更新日期：1972-12-01 00:00:00

abstract：:The potential production of estuarine interstitial microalgae from two tidal flats differing in sediment texture was determined manometrically. Sediment cores from the Southbeach tidal flat showed a maximum amount of productivity in the lower intertidal zone whereas sediment cores from Sally's Bend showed no productio...

journal_title：Oecologia

authors： Riznyk RZ,Phinney HK

更新日期：1972-09-01 00:00:00

abstract：:Long-termed fumigation of pea seedlings with SO2 caused typical alterations of the concentration of free glutamate and glutamine as well as fluctuations of the activity of glutamate dehydrogenase and glutamine synthetase. Shortly after the beginning of the fumigation with low concentrations of SO2 (up to 0,3 ppm) the ...

journal_title：Oecologia

authors： Jäger HJ,Pahlich E

更新日期：1972-06-01 00:00:00

abstract：:Experiments are described which demonstrate that the seeds of the desert species Blepharis persica are capable of germinating within 50 min of being exposed to moisture. Their radicles reach a length of about 49 mm within the first 24 h from wetting. The seeds can germinate in light and dark at temperatures ranging fr...

journal_title：Oecologia

authors： Gutterman Y

更新日期：1972-06-01 00:00:00

abstract：:Ovipositing females of the cynipid waspPseudeucoila bochei discriminate between parasitized and unparasitized hosts, which results in a far more uniform distribution of eggs over the hosts than would be obtained if oviposition were random (Fig. 1,a 0-f 0).For the description of the distributions a few models were work...

journal_title：Oecologia

authors： Bakker K,Eijsackers HJ,van Lenteren JC,Meelis E

更新日期：1972-03-01 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