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- Author:
- Fry, Kenneth E.; Walker, Richard B.
- Source:
- Ecology 1967 v.48 no.1 pp. 155-157
- ISSN:
- 0012-9658
- Subject:
- Pseudotsuga menziesii; conifer needles; conifers; porosity; stomata; stomatal movement; transpiration
- Abstract:
- ... A method is presented for estimating large and small changes of stomatal aperture in conifer needles by means of partial infiltration of alcoholic fluids under pressure. Needles are placed in a small, widowed chamber and are observed while the pressure is increased. Minute reflections of light which emanate from the stomata indicate the specific pressure at which infiltration begins. In theory thi ...
- DOI:
- 10.2307/1933428
-
http://dx.doi.org/10.2307/1933428
- Author:
- Emlen, John T.
- Source:
- Ecology 1967 v.48 no.1 pp. 158-160
- ISSN:
- 0012-9658
- Subject:
- canopy; rapid methods; savannas; trees; woodlands
- Abstract:
- ... The per cent of a tract of savannah or woodland that is covered by tree canopy is measured by point quadrat sampling along a series of straight line transects using a vertical viewing tube. ...
- DOI:
- 10.2307/1933429
-
http://dx.doi.org/10.2307/1933429
- Author:
- Wimbush, D. J.; Barrow, M. D.; Costin, A. B.
- Source:
- Ecology 1967 v.48 no.1 pp. 150-152
- ISSN:
- 0012-9658
- Subject:
- cameras; color; glass; ground vegetation; legs; paper; photographs; photography; prisms; vegetation
- Abstract:
- ... The field equipment needed for a stereophographic method of measurement of vegetation consists of a camera mounted on a rectangular frame on four legs, from which a stereo pair of photographs of the ground or vegetation surface can be taekn. For color transparencies the stereo pair of images is projected upwards through two specially mounted projectors and prisms onto tracing paper on a glass tabl ...
- DOI:
- 10.2307/1933426
-
http://dx.doi.org/10.2307/1933426
- Author:
- Wigley, Roland L.
- Source:
- Ecology 1967 v.48 no.1 pp. 168-169
- ISSN:
- 0012-9658
- Subject:
- animals; benthic organisms; jaws; samplers; standard operating procedures
- Abstract:
- ... Two commonly used benthos samplers, van Veen and Smith—McIntyre, were tested to detect possible adverse characteristics for sampling epibenthic animals. A strong hydraulic disturbance (shock wave) was formed below the van Veen sampler as it descended through the water toward bottom. In this sampler the shock wave was sufficiently strong to force aside unattached benthic animals as long as 8 cm. Th ...
- DOI:
- 10.2307/1933432
-
http://dx.doi.org/10.2307/1933432
- Author:
- Ayala, Francisco Jose
- Source:
- Ecology 1967 v.48 no.1 pp. 67-75
- ISSN:
- 0012-9658
- Subject:
- Drosophila melanogaster; Drosophila pseudoobscura; biomass; carrying capacity; environmental factors; heterozygosity; homozygosity; longevity; population growth; population size; temperature
- Abstract:
- ... Four populations of Drosophila pseudoobscura and four of D. melanogaster were studied for the influence of certain environmental factors on the productivity and size of the populations. For each species a 2 x 2 factorial design was used, the variables being temperature (25°C and 19°C) and amount of food (2 and 3 food unites per week). A serial transfer technique was used to maintain the population ...
- DOI:
- 10.2307/1933418
-
http://dx.doi.org/10.2307/1933418
- Author:
- Tash, Jerry C.; Armitage, Kenneth B.
- Source:
- Ecology 1967 v.48 no.1 pp. 129-139
- ISSN:
- 0012-9658
- Subject:
- Cladocera; Copepoda; aquatic habitat; autumn; brackish water; community structure; eggs; energy; females; lakes; lipids; physicochemical properties; primary productivity; surveys; winter; zooplankton; Alaska
- Abstract:
- ... In a survey of the physicochemical characteristics, primary productivity and occurrence of zooplankton in fresh and brackish waters of Cape Thompson, Alaska, between June 28, 1960 and August 7, 1961, 14 species of Cladocera and 38 species of Copepoda (13 Calanoida, 11 Cyclopoida and 14 Harpacticoida) were distinguished in collections from 10 lakes, 8 lagoons and 111 pools. Seventy—three percent of ...
- DOI:
- 10.2307/1933424
-
http://dx.doi.org/10.2307/1933424
- Author:
- Saunier, R. E.; Wagle, R. F.
- Source:
- Ecology 1967 v.48 no.1 pp. 35-41
- ISSN:
- 0012-9658
- Subject:
- Quercus turbinella; chaparral; clay soils; diorite; drought; grasslands; quartz; reproduction; rooting; sediments; seedling production; shrubs; soil water; Arizona
- Abstract:
- ... The disjunct distribution, reproduction, and rooting habits of Quercus turbinella in the Arizona chaparral were studied on quartz diorite, sedimentary, and volcanic substrata. The oak was less dense on the sediments and volcanics that on quartz diorite. Lower densities on the bedded sediments resulted from restricted root penetration which prevented access to deep soil moisture; on the volcanic su ...
- DOI:
- 10.2307/1933415
-
http://dx.doi.org/10.2307/1933415
- Author:
- Janzen, Daniel H.
- Source:
- Ecology 1967 v.48 no.1 pp. 26-35
- ISSN:
- 0012-9658
- Subject:
- Acacia; Formicidae; ant colonies; evolution; fires; lowlands; shoots; stumps; vegetation; vegetation structure; Central America
- Abstract:
- ... The effect of fire on swollen—thorn acacias and their tenant obligate acacia—ants in the Central American dry lowlands is discussed. Fires may either consume the entire acacia shoot and ant colony, scorch and kill the acacia but not the ants, or kill neither acacia nor ant colony. Which alternative occurs depends on the structure of the immediately surrounding vegetation which in turn depends on h ...
- DOI:
- 10.2307/1933414
-
http://dx.doi.org/10.2307/1933414
- Author:
- King, Charles E.
- Source:
- Ecology 1967 v.48 no.1 pp. 111-128
- ISSN:
- 0012-9658
- Subject:
- Chlamydomonas reinhardtii; Euglena gracilis; Rotifera; algae; animals; clones; death; eggs; females; food intake; foods; oviposition; parents; parthenogenesis; population density; population growth; survival rate
- Abstract:
- ... Two clones of the rotifer Euchlanis dilatata were derived from a single parent by parthenogenesis so that in succeeding generations the individuals of one clone (the young orthoclone) were always derived from young parents and those of the other (the old orthoclone) from old parents. These clones were fed four different food concentrations (1.6, 4.9, 16.4, and 49.2 mg/ml) of three different algal ...
- DOI:
- 10.2307/1933423
-
http://dx.doi.org/10.2307/1933423
- Author:
- Morse, Douglass H.
- Source:
- Ecology 1967 v.48 no.1 pp. 94-103
- ISSN:
- 0012-9658
- Subject:
- Poecile carolinensis; Sitta; autumn; bark; branches; flocks; foraging; habitats; seeds; winter; Louisiana
- Abstract:
- ... Foraging behavior and interactions between Brown—headed Nuthatches (Sitta pusilla) and Pine Warblers (Dendroica pinus) were studied in longleaf pine lands of Louisiana during the fall and winter of 1963—64 and 1964—65. Both species frequently were members of flocks that formed around Carolina Chickadees (Parus carolinensis) and Tufted Titmice (P. bicolor). Most contact between the former two speci ...
- DOI:
- 10.2307/1933421
-
http://dx.doi.org/10.2307/1933421
- Author:
- Wiegert, Richard G.; Odum, Eugene P.; Schnell, Jay H.
- Source:
- Ecology 1967 v.48 no.1 pp. 75-83
- ISSN:
- 0012-9658
- Subject:
- Aphidoidea; Conyza canadensis; Dorymyrmex; Erigeron; Heterotheca subaxillaris; Oecanthus; fauna; field experimentation; food chain; grazing intensity; isotopes; phytophagous insects; predation; radionuclides; weeds; South Carolina
- Abstract:
- ... Phosphorous—32 tracer studies of plant—arthropod food chains showed a significant difference in both consumer diversity and grazing pressure between the two dominant plant species on a first—year weed field in South Carolina. Where Heterotheca subaxillaris was the labeled plant ³ ²P was transferred readily to a number of phytophagous insects and secondarily to the predator fauna. Where only Eriger ...
- DOI:
- 10.2307/1933419
-
http://dx.doi.org/10.2307/1933419
- Author:
- West, George C.
- Source:
- Ecology 1967 v.48 no.1 pp. 58-67
- ISSN:
- 0012-9658
- Subject:
- Passer montanus; Spizella; birds; combustion; diet; energy content; energy requirements; flocks; grasses; heat; seeds; stomach; traps; tree nutrition; winter; Illinois
- Abstract:
- ... Stomach analyses of 131 tree sparrows (Spizella arborea) were made from birds collected from November through March, 1954—1959, near Urbana in Champaign County, Illinois. Simultaneously, 119 collections of seeds from the ground and 452 collections of seeds falling into seed traps were taken and the dry weight in grams per hectare per winter and the relative proportion of different species of seeds ...
- DOI:
- 10.2307/1933417
-
http://dx.doi.org/10.2307/1933417
- Author:
- Sluss, R. R.
- Source:
- Ecology 1967 v.48 no.1 pp. 41-58
- ISSN:
- 0012-9658
- Subject:
- Chromaphis juglandicola; Coleoptera; carrying capacity; insects; irrigation; orchards; parasitism; population growth; predation; predators; spring; temperature; trees; vigor; walnuts; California
- Abstract:
- ... Populations of waln ut aphids and associated insects were observed over a four year period in several northern California walnut orchards. Temperature, leaflet age, amount of prior aphid feeding and coccinellid predation were found to be the most important factors influencing walnut aphid population changes. Sharp declines in aphid population levels were correlated with high temperatures, especial ...
- DOI:
- 10.2307/1933416
-
http://dx.doi.org/10.2307/1933416
- Author:
- Fitch, Henry S.; Fitch, Alice V.
- Source:
- Ecology 1967 v.48 no.1 pp. 160-165
- ISSN:
- 0012-9658
- Subject:
- Elaphe; absorption; developmental stages; eggs; humans; limestone; lizards; mortality; relative humidity; sand; snakes; temperature; water content; weight gain; wood; Great Plains region
- Abstract:
- ... In lizards and snakes the egg is a vulnerable stage in the life cycle with limitations that must often restrict geographic range or local occurrence of a species. Eggs of the rat snake, racer, ring—necked snake, Great Plains skink and five—linked skink were exposed in mixed groups to various controlled conditions of temperature and humidity to determine some of the differences between species in t ...
- DOI:
- 10.2307/1933430
-
http://dx.doi.org/10.2307/1933430
- Author:
- Waller, H. D.; Olson, J. S.
- Source:
- Ecology 1967 v.48 no.1 pp. 15-25
- ISSN:
- 0012-9658
- Subject:
- Liriodendron tulipifera; canopy; death; exudation; forest litter; forests; growing season; income; inventories; leaching; leaves; mineral soils; rain; roots; soil sampling; soil solution; stems; tree trunk; trees
- Abstract:
- ... An inventory of total Cs¹ ³ ⁷ distribution in a 500—m² tagged tulip poplar (Liriodendron tulipifera) forest at the Oak Ridge National Laboratory showed transfer from trees to soil during the first growing season. About one—third of the maximum amount of radiocesium found in the tree canopy during June was transferred to the forest floor and soil; the remainder moved back into woody tissue (stem an ...
- DOI:
- 10.2307/1933413
-
http://dx.doi.org/10.2307/1933413
- Author:
- Tinkle, Donald W.; Woodward, Donald W.
- Source:
- Ecology 1967 v.48 no.1 pp. 166-168
- ISSN:
- 0012-9658
- Subject:
- females; lizards; males; social behavior
- Abstract:
- ... The mean recapture radius has been shown to be an accurate measure of the degree of movements in populations of the lizard Uta stansburiana. It is relatively constant for differing numbers of captures, different numbers of individuals, different years in the same study area and for different periods of time. It is sensitive to density with which it varies inversely. Differences in the mean recaptu ...
- DOI:
- 10.2307/1933431
-
http://dx.doi.org/10.2307/1933431
- Author:
- Mninshall, G. Wayne
- Source:
- Ecology 1967 v.48 no.1 pp. 139-149
- ISSN:
- 0012-9658
- Subject:
- Bacillariophyceae; Gammarus; benthic organisms; carnivores; crops; diet; digestive system; fauna; foods; herbivores; invertebrates; leaves; omnivores; particulate organic matter; primary energy; stream channels; stream flow; woodlands; Kentucky
- Abstract:
- ... The community trophic structure of Morgan's Creek, Meade County, Kentucky was analyzed through regular measurement of standing crops of the chief potential sources of plant materials available to the animals (suspended particulate, attached particulate, and allochthonous leaf materials) and an examination of their gut contents. The most important food was allochthonous leaf materials, which occurr ...
- DOI:
- 10.2307/1933425
-
http://dx.doi.org/10.2307/1933425
- Author:
- McLaren, Ian A.
- Source:
- Ecology 1967 v.48 no.1 pp. 104-110
- ISSN:
- 0012-9658
- Subject:
- breeding sites; crushing; females; neonates; polygyny; seals; sexual selection
- Abstract:
- ... Seals have been shown to restrict recruitment in crowded populations because of gregarious and hierarchical behavior. Some authors have suggested that such behavior has evolved through group selection to prevent overutilization of resources. Published data are reviewed to show that more highly social seals have higher potential rates of increase. This is difficult to reconcile with group selection ...
- DOI:
- 10.2307/1933422
-
http://dx.doi.org/10.2307/1933422
- Author:
- Barbour, M. G.; Lange, R. T.
- Source:
- Ecology 1967 v.48 no.1 pp. 153-155
- ISSN:
- 0012-9658
- Subject:
- microscopy; organic matter; seeds; soil sampling; vegetation types
- Abstract:
- ... The numbers and types of seeds in topsoils of several South Australian vegetation types were tabulated by microscopic examination of soil samples. Isolation of organic matter by flotation on a dense solution followed by examination under 8x power gave excellent recovery of all seeds present, even of those as small as 1 mm. Relatively small sample volumes (50 cm³) appear sufficient to yield high fr ...
- DOI:
- 10.2307/1933427
-
http://dx.doi.org/10.2307/1933427
- Author:
- Neushul, M.
- Source:
- Ecology 1967 v.48 no.1 pp. 83-94
- ISSN:
- 0012-9658
- Subject:
- Agarum; Callophyllis; Laminaria; Rhodoptilum; algae; benthic plants; community structure; environmental factors; vegetation; Puget Sound; Washington (state)
- Abstract:
- ... Objectively defined, benthic plant associations in the Puget Sound region are compared with associations recorded by other workers, in this and other areas. A shallow Laminaria association, an Agarum dominated region at mid—depths and a red algal association of Rhodoptilum, Callophyllis, and hydroids near the lower (17 to 20 m) limits of plant distribution, are described. Variation in community co ...
- DOI:
- 10.2307/1933420
-
http://dx.doi.org/10.2307/1933420