abstract：:Seasonal excavations of ramet systems in overlapping natural populations of Typha latifolia and T. angustifolia revealed intrapopulation variation in ramet size and reproduction. Reproductive "states" were recognized based on whether or not a ramet had flowered and the number of offspring ramets it possessed. As the g...

journal_title：Oecologia

authors： Grace JB,Wetzel RG

更新日期：1982-01-01 00:00:00

abstract：:Mortality estimates for the immature stages of two butterfly species, Danaus plexippus and D. chrysippus, were obtained by observing the survival of egg cohorts on different sized patches of food plants (Asclepias spp.), over a one-year period. Losses were variable (0-100%) but usually high (90% and over) throughout t...

journal_title：Oecologia

authors： Zalucki MP,Kitching RL

更新日期：1982-01-01 00:00:00

abstract：:Early models of hostplant exploitation by phytophagous insects suffer from unwarranted assumptions and may not be generally applicable. Wordmodels of the co-evolutionary approach may assume unwarranted evolutionary stability in 'strategic' explanations, whilst mathematical models derived from earlier optimal-diet stud...

journal_title：Oecologia

authors： Courtney SP

更新日期：1982-01-01 00:00:00

abstract：:Six early successional plant species with differing photosynthetic pathways (3 C3 species and 3 C4 species) were grown at either 300, 600, or 1,200 ppm CO2 and at either 0.0 or 0.25 ppm SO2. Total plant growth increased with CO2 concentration for the C3 species and varied only slightly with CO2 for the C4 species. Fum...

journal_title：Oecologia

authors： Carlson RW,Bazzaz FA

更新日期：1982-01-01 00:00:00

abstract：:The rarity of long-range seed dispersal (telechory) and commonness of antitelechory in desert plants are examined in light of contemporary mathematical theories of the evolution of dispersal and germination behaviors. Analysis of dispersal 3-habitat relationships in the flora of Israel supports the general trend towar...

journal_title：Oecologia

authors： Fllner S,Shmida A

更新日期：1981-10-01 00:00:00

abstract：:A comparison of photosynthetic adaptations of desert ephemerals from sun and shade environments has shown differences in the magnitude and timing of maximum CO2 assimilation. Photosynthetic rates of species from the sun environment were significantly higher, and maximum observed levels occurred both earlier in the day...

journal_title：Oecologia

authors： Wallace CS,Szarek SR

更新日期：1981-10-01 00:00:00

abstract：:In a North Carolina population of Diamorpha smallii, densities were artificially manipulated by thinning stands to predetermined densities. Individuals in areas of high density produce fewer seeds than individuals at low density in the same habitat. Three components of fecundity, the number of flowers per plant, the n...

journal_title：Oecologia

authors： Clay K,Shaw R

更新日期：1981-10-01 00:00:00

abstract：:1. In an attempt to evaluate the importance of individual daily habits to a freeliving animal, foraging behaviour of kestrels was observed continuously for days in sequence in open country. Data obtained in 2,942 observation hours were used. Flight-hunting was the prominent foraging technique yielding 76% of all prey ...

journal_title：Oecologia

authors： Rijnsdorp A,Daan S,Dijkstra C

更新日期：1981-09-01 00:00:00

abstract：:The foraging behavior of Mesocyclops edax in artificial patches of high and low prey density was examined. In low density patches Mesocyclops swam in an irregular curvilinear path with little or no looping behavior. In high density patches Mesocyclops exhibited extensive horizontal and vertical looping behavior. Horiz...

journal_title：Oecologia

authors： Williamson CE

更新日期：1981-09-01 00:00:00

abstract：:Desert annuals of Death Valley, California have higher average light-saturated photosynthetic capacities and leaf nitrogen contents than do early-successional annuals of Illinois. The leaves of annuals in the light-unlimited Death Valley environment change little in specific weight, nitrogen, or photosynthetic capacit...

journal_title：Oecologia

authors： Mooney HA,Field C,Gulmon SL,Bazzaz FA

更新日期：1981-08-01 00:00:00

abstract：:The survival time of small and isolated populations will often be relatively low, by which the survival of species living in such a way will depend on powers of dispersal sufficiently high to result in a rate of population foundings that about compensates the rate of population extinctions. The survival time of compos...

journal_title：Oecologia

authors： den Boer PJ

更新日期：1981-08-01 00:00:00

abstract：:Prosopis is a genus of phreatophytic trees inhabiting hot deserts and semiarid grasslands of the world. Although desert trees are exposed to unusual environmental temperature and water stress, few investigations have evaluated their water relations. This is particularly true for Prosopis species growing in areas where...

journal_title：Oecologia

authors： Nilsen ET,Rundel PW,Sharifi MR

更新日期：1981-08-01 00:00:00

abstract：:The climatic control of productivity for two populations of the lichen Cetraria cucullata (Bell.) Ach. growing in the arctic tundra of northern Alaska (70°28'N, 157°23'W) was examined. Respiratory losses of carbon vary with tissue temperature, tissue water content, and time since wetting. Potential net photosynthetic ...

journal_title：Oecologia

authors： Lechowicz MJ

更新日期：1981-08-01 00:00:00

abstract：:The objective of this study was to separate the effects of plant biomass and growth rate on vegetative reproduction in two species of cat-tail, Typha latifolia and T. angustifolia. Replicate clones of both species were grown under conditions of 100%, 42%, 24%, and 9% full sunlight with harvests at 41, 70, and 91 days ...

journal_title：Oecologia

authors： Grace JB,Wetzel RG

更新日期：1981-08-01 00:00:00

abstract：:The logistic equation has been used as the basis of two distinct models of population dynamics, a resource limited model and an equilibrium model. It is argued that although the two models are very different, the distinction between them has been obscured by the use of the same terminology for the parameters of both. ...

journal_title：Oecologia

authors： Pollard E

更新日期：1981-07-01 00:00:00

abstract：:Seasonal patterns of growth, 14CO2 uptake, and fluctuations in tissue titratable acidity were studied over the course of a year at a study site in the coastal plain of North Carolina.Elongation rates of Spanish moss strands were maximal in the summer and minimal in the winter. Summer maximal biomass addition rates wer...

journal_title：Oecologia

authors： Martin CE,Christensen NL,Strain BR

更新日期：1981-07-01 00:00:00

abstract：:It is illustrated theoretically that in a heterogeneous habitat the dispersal of individuals, even when it is random and density-independent, may have a pronounced effect of raising the average reproductive rate of the whole population, in addition to the effect of stabilization in the usual sense of reducing its vari...

journal_title：Oecologia

authors： Kuno E

更新日期：1981-05-01 00:00:00

abstract：:Daily energy metabolism and water flux were measured with doubly labeled water in the free-living insectivorous lizards Cnemidophorus tigris (mean body mass 15.7 g) and Callisaurus draconoides (8.6 g) in June 1979 in the Colorado Desert of California. C. tigris was an active forager; it spent 91% of its 5-h daily acti...

journal_title：Oecologia

authors： Anderson RA,Karasov WH

更新日期：1981-05-01 00:00:00

abstract：:In annual pastures utilized for grazing, the amount and quality of the standing dry matter in the dry season is of importance for the performance of the animals. Often both characteristics decline at the end of the green season. It is shown, that dispersal of the reproductive structures of the vegetation may be the ma...

journal_title：Oecologia

authors： de Ridder N,Seligman NG,van Keulen H

更新日期：1981-05-01 00:00:00

abstract：:Plants of Diplacus aurantiacus, a successional shrub common in California chaparral, were grown under controlled conditions in which either quantum flux density or nitrogen availability was varied. Photosynthesis and leaf nitrogen content were determined on a leaf area and a leaf weight basis, and whole plant growth w...

journal_title：Oecologia

authors： Gulmon SL,Chu CC

更新日期：1981-05-01 00:00:00

abstract：:This paper catalogues several different dichotomies that have all been termed r- and K-selection. The status of the concept of r- and K-selection is discussed and a more restricted usage of the terms is recommended. ...

journal_title：Oecologia

authors： Parry GD

更新日期：1981-03-01 00:00:00

abstract：:Coryphantha vivipara (Nutt.) Britton & Rose var. deserti (Engelm.) W.T. Marshall (Cactaceae) survived snow and tissue temperatures of-12°C in southern Nevada. However, the freezing point depression of the cell sap was only about 0.9°C. When the nocturnal air temperature in the laboratory was reduced from 10°C to-10°C ...

journal_title：Oecologia

authors： Nobel PS

更新日期：1981-03-01 00:00:00

abstract：:Intra-colony demography and life history characteristics of neotropical Africanized and temperate European honey bearaces were compared under simulated feral conditions. Major differences in colony demography were found which nevertheless resulted in some similar reproductive characteristics. European colonies were la...

journal_title：Oecologia

authors： Winston ML,Dropkin JA,Taylor OR

更新日期：1981-03-01 00:00:00

abstract：:Proteolytic activity in the gut contents of two cichlids and six cyprinids from an artificial basin in Sri Lanka was measured using a simple film strip method. This comparative study contributes to our general knowledge of digestion in herbivorous fish: 1) Specific proteolytic activity (per ml of gut content) is lower...

journal_title：Oecologia

authors： Hofer R,Schiemer F

更新日期：1981-03-01 00:00:00

abstract：:Estimates were made of the ecological fish production in two small lowland rivers uninhabited by salmonids. Eight sites were examined in the Utrata River drainage basin, and five in the Zalewka Brook. Nets were placed at the upper and lower limits of each site and fish were captured using electrofishing apparatus; at ...

journal_title：Oecologia

authors： Penczak T

更新日期：1981-02-01 00:00:00

abstract：:Birds searching for insects in the canopy of a northern hardwoods forest depart significantly from random in their use of tree species, even when these trees are generally similar in life form. All 10 foliage-dwelling bird species in the Hubbard Brook forest showed preferences for Yellow Birch, most had an aversion to...

journal_title：Oecologia

authors： Holmes RT,Robinson SK

更新日期：1981-02-01 00:00:00

abstract：:The diurnal changes in proline and water contents of Zygophyllum quatarense and Francoeuria crispa were investigated under desert conditions. In both plants, the proline content was low before sunrise amounting to 10.42 μmoles/g fresh weight in Zygophyllum and 6.3 μmoles/g fresh weight in Francoeuria. By the progress ...

journal_title：Oecologia

authors： Batanouny KH,Ebeid MM

更新日期：1981-01-01 00:00:00

abstract：:The food preferences of Octodon degus are examined in laboratory test. Results indicate that degus prefer new rather than mature leaves of Chilean matorral shrubs, and that degus do not discriminate between new leaves (equivalents of shrub seedlings) of different shrub species. The significance of degus preferences in...

journal_title：Oecologia

authors： Simonetti JA,Montenegro G

更新日期：1981-01-01 00:00:00

abstract：:The demographic and ecological characteristics of island populations of small mammals have received increasing attention in recent years, but few studies have compared the behavioral characteristics of island populations with those of mainland populations. Behavior is considered an important variable because it is bel...

journal_title：Oecologia

authors： Halpin ZT

更新日期：1981-01-01 00:00:00

abstract：:In previous papers we have described and verified a primary production model of the desert shrub Larrea tridentata. Here we address the validation phase of the evaluation of this model. Two versions of the model which differ in the priority scheme used for allocating carbon to reproductive or vegetative organs were co...

journal_title：Oecologia

authors： Reynolds JF,Cunningham GL

更新日期：1981-01-01 00:00:00

abstract：:The percent of species of the Cyperaceae possessing the C4 pathway was calculated for twenty-five regions of North America. A stepwise multiple regression analysis was used to determine which climatic variables were most highly correlated with the percent C4 species among the various regions. The square of the mean Ju...

journal_title：Oecologia

authors： Teeri JA,Livingstone DA

更新日期：1980-12-01 00:00:00

abstract：:Studies with Nasutitermes and Rhynchotermes (Isoptera, Nasutitermitinae) in a Costa Rican rainforest suggest that nitrogen fixation by gut symbionts may play a significant role in termite nutrition. Leaf-litter feeders ingest more and fix less nitrogen than do wood-litter feeders; both species feed preferentially on N...

journal_title：Oecologia

authors： Prestwich GD,Bentley BL,Carpenter EJ

更新日期：1980-09-01 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：:Food density, degree of hunger prior to foraging, and food processing difficulty were varied in order to determine their effects on the diet diversity of captive Peromyscus leucopus foraging for buried seeds. No relationship was found between diet diversity and food density. However, diet diversity exhibited a signifi...

journal_title：Oecologia

authors： Ebersole JP,Wilson JC

更新日期：1980-07-01 00:00:00

abstract：:I suggest that between-community variations in diversity patterns during succession in plant communities are due to the effects of selection on life history strategies under different disturbance regimes. Natural disturbances to plant communities are simultaneously a source of mortality for some individuals and a sour...

journal_title：Oecologia

authors： Denslow JS

更新日期：1980-07-01 00:00:00

abstract：:Data in the literature that in the Netherlands Carabus problematicus is an autumn breeder with overwintering larvae and adults have been confirmed. Pitfall catches show two peaks of adult beetles. The first small peak of activity is realized in May, the significance of which is not yet understood. The second higher pe...

journal_title：Oecologia

authors： Rijnsdorp AD

更新日期：1980-05-01 00:00:00

abstract：:The rates at which bumblebees of different proboscis lengths forage on flowers of a series of corolla tube lengths were determined. The results indicate significant correlations between proboscis length and time spent by bees on flowers. Bumblebees of long proboscis length can forage significantly faster than bees of ...

journal_title：Oecologia

authors： Inouye DW

更新日期：1980-05-01 00:00:00

abstract：:Net photosynthesis (10 klx light intensity, 150 μE m-2 s-1 PAR) and dark respiration of the lichen Ramalina maciformis at different temperatures are measured in relation to thallus water content. Both first increase with increasing hydration. Dark respiration then remains constant with increased water content until th...

journal_title：Oecologia

authors： Lange OL

更新日期：1980-04-01 00:00:00

abstract：:The relation between daily maximal rates of net photosynthesis and plant water status was studied during a dry season on irrigated and non-irrigated, naturally growing, perennial wild plants.Species were examined which differ in phenology, leaf anatomy and morphology: Hammada scoparia, Artemisia herba-alba, Zygophyllu...

journal_title：Oecologia

authors： Schulze E-,Hall AE,Lange OL,Evenari M,Kappen L,Buschbom U

更新日期：1980-04-01 00:00:00

abstract：:Clone mal9, a genotype ofSolanum dulcamara L. having photosynthetic characteristics similar to previously hypothesized shade ecotypes, is compared to five other genotypes having photosynthetic characteristics similar to previously hypothesized sun ecotypes. The primary differences are a 35% reduction in total leaf con...

journal_title：Oecologia

authors： Clough JM,Alberte RS,Teeri JA

更新日期：1980-01-01 00:00:00