abstract：:The responses to drought of the solar tracking winter annualLupinus arizonicus (Wats.) were examined under field and laboratory growth regimes. Under drought conditions tracking movements were maintained until the plant reached the wilting point. The leaves and leaflets were observed to cup in response to decreases in...

journal_title：Oecologia

authors： Forseth I,Ehleringer JR

更新日期：1980-01-01 00:00:00

abstract：:At least once a year the mountain pine beetle searches for lodgepole pines that provide a suitable habitat for a new brood. After attacking females feed, they produce an attractant pheromone that causes beetles to aggregate and, during outbreaks, to usually mass attack the "focus" tree. Near the completion of mass att...

journal_title：Oecologia

authors： Geiszler DR,Gallucci VF,Gara RI

更新日期：1980-01-01 00:00:00

abstract：:(i) The growth of ca. 100 individuals of a small deciduous tree Euphorbia pyrifolia, of different ages and edaphic regimes, and with different levels of infestation by the coccid Icerya seychellarum, has been studied on Aldabra Atoll over two years (1976-1978). Infestation on leaves ranged between 0 and 1.3 mg dry wei...

journal_title：Oecologia

authors： Newbery DM

更新日期：1980-01-01 00:00:00

abstract：:If the natural enemy component of biological control is functional in small mammals, then the introduciton of weasels should effectively reduce populations of deer mice and Oregon voles. Seven weasels introduced to an area of forest habitat in coastal British Columbia did not appreciably lower the abundance of mice or...

journal_title：Oecologia

authors： Sullivan TP,Sullivan DS

更新日期：1980-01-01 00:00:00

abstract：:The activity behaviour of the common vole, Microtus arvalis was studied in an enclosure during a one-year cycle. The number of voles varied between 2 and 25 specimens. Emergence from burrows, running through pathways and visits at a feeding site were automatically recorded by passage counters which we developed for us...

journal_title：Oecologia

authors： Lehmann U,Sommersberg CW

更新日期：1980-01-01 00:00:00

abstract：:Seasonal changes in the Crassulacean Acid Metabolism (CAM) activity and growth characteristics of Opuntia humifusa Raf. were examined under midwest climatic conditions. Twenty-four hour studies were done at monthly intervals for two years, with diurnal changes in transpiration, gas exchange, and titratable acidity mon...

journal_title：Oecologia

authors： Koch KE,Kennedy RA

更新日期：1980-01-01 00:00:00

abstract：:Species of the 'bana' vegetation in the Amazonas region of equatorial South America have scleromorphic leaves. This leaf type, which characterizes the vegetation of Mediterranean climates, among others, has apparently evolved in this community in response to the oligotrophic soils and widely fluctuating water table.An...

journal_title：Oecologia

authors： Sobrado MA,Medina E

更新日期：1980-01-01 00:00:00

abstract：:It has been suggested that soil nitrification is inhibited as a succession develops. This hypothesis was examined in a sub tropical rain forest succession containing five successional stages. Soil mineral nitrogen was measured at the time of collection and after 20 days incubation in the laboratory or field. Sampling ...

journal_title：Oecologia

authors： Lamb D

更新日期：1980-01-01 00:00:00

abstract：:Water stress and temperature effects on growth, translocation and reallocation of 14C assimilated by blue grama (Bouteloua gracilis (H.B.K.) Lag. ex Steud.) were studied for sods extracted from shortgrass prairie. The sods were kept at either 24°/16° or 34°/16°C (day/nigh) temperatures and were labeled at two phenolog...

journal_title：Oecologia

authors： Chung HH,Trlica MJ

更新日期：1980-01-01 00:00:00

abstract：:Measurements of carbon isotope ratios of nine taxa of arid zone mosses from North America and 24 taxa of European bryophytes show consistent values indicative of C3 metabolism. Other morphological, physiological and biochemical characteristics provide the mechanism of adaptation to environmental stresses of heat and e...

journal_title：Oecologia

authors： Rundel PW,Stichler W,Zander RH,Ziegler H

更新日期：1979-12-01 00:00:00

abstract：:Desert populations of the evergreen dioecious shrub Simmondsia chinensis exhibit sex-related leaf and canopy dimorphisms not present in populations from more mesic coastal environments. Leaves on female shrubs have characteristically larger sizes, greater specific weights, and greater water-holding capacity than male ...

journal_title：Oecologia

authors： Wallace CS,Rundel PW

更新日期：1979-12-01 00:00:00

abstract：:Gene frequencies at nine polymorphic enzyme loci were followed in 22 cage populations of D. melanogaster all founded from the same stock but subsequently maintained in different environments. The three factors distinguishing the different environments were temperature and the alcohol and yeast in the medium and for ea...

journal_title：Oecologia

authors： Oakeshott JG

更新日期：1979-12-01 00:00:00

abstract：:In the laboratory the consumption (C), egestion (F), assimilation (A) and assimilation efficiency (A/C) of dry matter and of the bioelements C, N, P, K, Ca, Mg, S and Na were studied weekly during the whole feeding stage. The larvae were reared in clusters of 10 individuals (on average 3.5 ♂♂ and 6.5 ♀♀), fed one-year...

journal_title：Oecologia

authors： Larsson S,Tenow O

更新日期：1979-11-01 00:00:00

abstract：:The thermoregulatory significance of a striped-melanic colour polymorphism in the common garter snake, Thamnophis sirtalis, was assessed through a combination of labortory experimentation and field study. In experiments with living snakes the melanic morph maintained a higher body temperature than the striped morph, w...

journal_title：Oecologia

authors： Ralph Gibson A,Bruce Falls J

更新日期：1979-10-01 00:00:00

abstract：:The insect fauna of 80 day-old plots of corn and sweet potato monocultures and dicultures in Costa Rica were compared using sweep sampling. Six hundred sweeps were taken in each of the three habitats. There were 15% more total species in the diculture than either monoculture but approximately the same total number of ...

journal_title：Oecologia

authors： Risch SJ

更新日期：1979-09-01 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：:Growth and respiration were measured in a species of Anonchus (Nematoda: Plectidae) at 5°C, 10°C, 15°C, 20°C and 25°C. At 5°C no growth was measurable but the organisms remained active. Maximum production occurred at 15°C, but the highest rate of growth occurred at 20°C. Thus, adult size attained is dependent on the t...

journal_title：Oecologia

authors： Laybourn J

更新日期：1979-08-01 00:00:00

abstract：:At constant cladode temperature the stomatal resistance of O. inermis increased when the cladode-air vapor pressure difference was increased and stomatal resistance decreased when the cladode-air vapor pressure difference was lowered. Net CO2 fixation in the dark was very responsive to these humidity dependent changes...

journal_title：Oecologia

authors： Osmond CB,Ludlow MM,Davis R,Cowan IR,Powles SB,Winter K

更新日期：1979-07-01 00:00:00

abstract：:European data from 15 long-term censuses of breeding land bird communities were analysed in order to measure community stability. Stability was here operationally defined as year-to-year persistence of community structure (total density, number of species, diversity, evenness of the species-abundance distribution, spe...

journal_title：Oecologia

authors： Järvinen O

更新日期：1979-01-01 00:00:00

abstract：:Dusky-footed woodrats (Neotoma fuscipes) and desert woodrats (N. lepida) experience pronounced seasonal variations in the aridity of their habitats. The effects of seasonal aridity upon the water conserving abilities of these species were assessed through measurements of water conserving abilities and kidney structure...

journal_title：Oecologia

authors： Stallone JN

更新日期：1979-01-01 00:00:00

abstract：:The foraging strategies of four naturally co-existing heteromyid rodent species were investigated: Dipodomys deserti (≈100 g), D. merriami (≈38 g), Microdipodops pallidus (≈13 g), and Perognathus longimembris (≈7 g). In 208 over-night laboratory foraging trials animals were provided with millet seed distributed in clu...

journal_title：Oecologia

authors： Trombulak SC,Kenagy GJ

更新日期：1979-01-01 00:00:00

abstract：:The population metabolism of N. muscorum at a beechwood site in southern England was determined for two separate year periods by two methods; a detailed computer analysis and a 'best estimate'. These methods, which are based on data of biomass, population dynamics, field temperatures, and respiration rates of all life...

journal_title：Oecologia

authors： Goddard SJ

更新日期：1979-01-01 00:00:00

abstract：:Leaf diffusion resistance (r 1) of the upper and lower leaf surfaces of several Populus clones was related to leaf water potential (ψ1), light intensity, vapor pressure deficit (VPD), and temperature by intrinsicallylinear, logarithmic multiple regression analyses. Regression equations accounted for up to 80% of varia...

journal_title：Oecologia

authors： Pallardy SG,Kozlowski TT

更新日期：1979-01-01 00:00:00

abstract：:Nitrogen mineralization and net nitrification rates were 3-7 times greater in soil incubations from a girdled Liriodendron tulipifera (L.) stand than in a control stand. Neither litter nor root extracts had an inhibitory effect on nitrogen mineralization or nitrification rate. A lack of nitrification inhibitors also w...

journal_title：Oecologia

authors： Johnson DW,Edwards NT

更新日期：1979-01-01 00:00:00

abstract：:Effects of herbicides (Garlone 3A, MCPA, 2,4-D and Krenite) and nitrogen fertilizer (NH4NO3), commonly used in Swedish forestry, on nitrogen fixation (C2H2-reduction) by Peltigera praetextata (Sommerf.) Zopf. (field and laboratory) and its phycobiont Nostoc sp. (laboratory) were studied. The alga was affected by the h...

journal_title：Oecologia

authors： Hällbom L,Bergman B

更新日期：1979-01-01 00:00:00

abstract：:Factors influencing the consumption of algae and the rate of feeding by the larvae of Heterotrissocladius changi Saether and Polypedilum nebeculosum (Meigen) (Chironomidae: Diptera) were determined from collections made between July 1975 and May 1977 in Yellowknife Bay, situated in the Canadian subarctic. Although bot...

journal_title：Oecologia

authors： Moore JW

更新日期：1979-01-01 00:00:00

abstract：:Data from the US/IBP Desert Biome validation studies indicate that above-ground production and biomass allocated to reproduction in Larrea tridentata vary from one year to another depending upon the timing and extent of soil-moisture availability. In an attempt to verify these observations and determine to what extent...

journal_title：Oecologia

authors： Cunningham GL,Syvertsen JP,Reynolds JF,Willson JM

更新日期：1979-01-01 00:00:00

abstract：:Evidence was given that the freezing tolerance of Halimione portulacoides, a wintergreen halophyte, can be explained by protection of sensitive cellular membranes in vivo. Experiments were done with cloned cuttings of a plant from the German North Sea coast. One series received no NaCl (O-plants) the other 3% NaCl (Na...

journal_title：Oecologia

authors： Maier M,Kappen L

更新日期：1979-01-01 00:00:00

abstract：:Direct and interactive effects of daylength and temperature preconditioning of above- and below-ground parts of Chrysanthemum morifolium Ramat. 'Astrid' are examined in relation to net photosynthesis. Most previous work on thermal preconditioning has concentrated on the effects of a given thermal regime on entire plan...

journal_title：Oecologia

authors： Adams MS,Fayyaz MM

更新日期：1979-01-01 00:00:00

abstract：:The legume foodplants of Colias butterflies possess specific chemical components which stimulate oviposition in females of the genus. Different legumes provide different degrees of stimulation, as demonstrated by close correlation between field observations and laboratory experiments with a new behavioral assay. Sever...

journal_title：Oecologia

authors： Stanton ML

更新日期：1979-01-01 00:00:00

abstract：:More than 500 species of the Poaceae are found in Kenya, East Africa. Eighteen of twenty-seven tribes are exclusively (except the Paniceae and Danthonieae) of the C3 photosynthetic type. A floristic analysis of low altitude grasslands suggests that nearly all species at these low altitudes are of the C4 photosynthetic...

journal_title：Oecologia

authors： Tieszen LL,Senyimba MM,Imbamba SK,Troughton JH

更新日期：1979-01-01 00:00:00

abstract：:The tadpoles of two anuran species, Rana sylvatica and Xenopus laevis, were fed various concentrations of two algae, Anabaena sphaerica (large filaments) and Chlorella pyrenoidosa (small unicells). Filtering rates were measured indirectly with a Coulter Counter system; buccal pumping rates were observed directly.Exper...

journal_title：Oecologia

authors： Seale DB,Wassersug RJ

更新日期：1979-01-01 00:00:00

abstract：:Computer simulations of a pollinator foraging in a mixture of two species were used to explore how plant reproduction can be influenced by interspecific pollination movements. Interspecific pollen transfer led to strong competitive effects when availabilities of pollen, receptive stigma surfaces, or pollinator movemen...

journal_title：Oecologia

authors： Waser NM

更新日期：1978-01-01 00:00:00

abstract：:A technique is presented in which desiccation as a source of error in fresh weight determinations of soft-bodied microfauna is avoided by weighing the animal in a drop of silica fluid. ...

journal_title：Oecologia

authors： Lundkvist H

更新日期：1978-01-01 00:00:00

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：:Mechanical aspects of predation by the shore crab, Carcinus maenas, on the edible mussel, Mytilus edulis, were examined. The shore crabs from the population studied utilized five distinct, largely size-related, mussel-opening techniques. Crushing the mussel umbone appeared the most successful opening method for medium...

journal_title：Oecologia

authors： Elner RW

更新日期：1978-01-01 00:00:00

abstract：:The influence of irrigation and nitrogen fertilization in early summer on root and shoot growth of Atriplex confertifolia, a C4 shrub species, was examined in a cold-winter desert community in northern Utah. Soil water and xylem pressure potentials were monitored during the summer period.At the time of watering the su...

journal_title：Oecologia

authors： Hodgkinson KC,Johnson PS,Norton BE

更新日期：1978-01-01 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：: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：:Leslie matrices are used to compare theoretical populations of gregarious and solitarious Desert Locusts, Schistocerca gregaria (Forsk.). Despite their lower fecundity, the synchrony and faster maturation of gregarious populations permit them to have much faster rates of increase than solitarious populations. When rea...

journal_title：Oecologia

authors： Cheke RA

更新日期：1978-01-01 00:00:00