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- Author:
- Burnison, B. Kent; Perez, Kenneth T.
- Source:
- Ecology 1974 v.55 no.4 pp. 899-902
- ISSN:
- 0012-9658
- Subject:
- carbon; chloroform; combustion; insect larvae; radionuclides
- Abstract:
- ... Current methods for the determination of radioactive carbon in samples of biological material are either expensive, elaborate, dangerous, time consuming, or subject to contamination. A simple and inexpensive method is described here which eliminates these disadvantages and allows for the determination of 14C—activity in simple (14C—glucose) or complex (chloroform extract of ground 14C—labeled wax ...
- DOI:
- 10.2307/1934429
-
http://dx.doi.org/10.2307/1934429
- Author:
- Sperling, Jon A.; Grunewald, Ralph; Dovala, Donald
- Source:
- Ecology 1974 v.55 no.4 pp. 895-898
- ISSN:
- 0012-9658
- Subject:
- Mastigocladus laminosus; air; algae; carbon dioxide; culture media; isotopes; pH; sodium hydroxide; trichomes
- Abstract:
- ... An inexpensive solid state pH control circuit was built for external use with existing pH meters that can use either a gas or a liquid solution for pH control of culture media. Mastigocladus laminosus showed a 49% reduction in the rate of radiophosphate (P—32) uptake between gas—controlled (30% CO₂ in air) pH intervals of 8.7 (optimal uptake) and 5.7. Isotope uptake rates at higher pH values (achi ...
- DOI:
- 10.2307/1934428
-
http://dx.doi.org/10.2307/1934428
- Author:
- Svendsen, Gerald E.
- Source:
- Ecology 1974 v.55 no.4 pp. 760-771
- ISSN:
- 0012-9658
- Subject:
- Marmota; burrows; environmental factors; females; habitats; population distribution; population dynamics; reproductive fitness; satellites; social behavior; social structure; Colorado
- Abstract:
- ... Behavioral and environmental factors in the spatial distribution and population dynamics of a yellow—bellied marmot (Marmota flaviventris) population were studied in 1971 and 1972 in Gunnison Co., Colorado. Yellow—bellied marmots are generally considered to be colonial; however, this is not their only option, depending upon the marmots' behavioral profile and the size and composition of the habita ...
- DOI:
- 10.2307/1934412
-
http://dx.doi.org/10.2307/1934412
- Author:
- de la Cruz, Armando A.; Gabriel, Benjamin C.
- Source:
- Ecology 1974 v.55 no.4 pp. 882-886
- ISSN:
- 0012-9658
- Subject:
- Juncus roemerianus; carbon; containers; crude fiber; energy content; leaves; lipids; nitrogen; oxygen; phosphorus; plant tissues; protoplasm; respiratory rate
- Abstract:
- ... In situ decomposition rate of Juncus roemerianus (Juncaceae) leaves determined by litterbag method was 40% per year. Caloric, elemental, and proximate nutritive analyses of leaves at various stages of life and decay–classified as young, mature, standing dead, partially decayed, decomposed fragments, and particulate detritus–showed the following: (a) an increase in caloric content (4630—4911 g cal/ ...
- DOI:
- 10.2307/1934425
-
http://dx.doi.org/10.2307/1934425
- Author:
- Schoener, Amy
- Source:
- Ecology 1974 v.55 no.4 pp. 818-827
- ISSN:
- 0012-9658
- Subject:
- fouling; islands; models; seasonal variation; temperature
- Abstract:
- ... Marine fouling and successional studies, documenting species changes on flat, isolated objects, provide some additional data on island colonization. Plotting numbers of species on these planar islands over time allows construction of several colonization curves. Contrary to the MacArthur—Wilson equilibrium model, in many cases these curves do not convincingly approach an equilibrium number of spec ...
- DOI:
- 10.2307/1934417
-
http://dx.doi.org/10.2307/1934417
- Author:
- Niering, William A.; Goodwin, Richard H.
- Source:
- Ecology 1974 v.55 no.4 pp. 784-795
- ISSN:
- 0012-9658
- Subject:
- Gaylussacia baccata; Smilax; Vaccinium; arboreta; botanical composition; clones; forests; graminoids; habitat conservation; hardwood; herbicides; landscaping; pastures; rights of way; shrublands; shrubs; tree growth; trees; wildlife habitats; Connecticut
- Abstract:
- ... Two decades of selective—use herbicide management on a demonstration right—of—way within the Connecticut Arboretum has resulted in a mosaic of relatively stable shrub communities and less stable herblands within the central hardwoods forest region. Areas of continuous dense shrub cover have resisted tree invasion for at least 15 yr. On abandoned pastureland shrub clones of Gaylussacia baccata, Smi ...
- DOI:
- 10.2307/1934414
-
http://dx.doi.org/10.2307/1934414
- Author:
- McNaughton, S. J.
- Source:
- Ecology 1974 v.55 no.4 pp. 864-869
- ISSN:
- 0012-9658
- Subject:
- Typha latifolia; acclimation; biomass production; carbon; climate; dry matter accumulation; ecotypes; environmental factors; leaves; net assimilation rate
- Abstract:
- ... Population samples of broad—leaved cattail (Typha latifolia L.) from a variety of climates were studied to determine the extent to which net productivity, as dry matter production rate, was determined by (a) net assimilation rate per unit left tissue and (b) rate of production of leaf tissue. Assimilation rates of the eight populations studied were identical. Similarly, acclimation responses stabi ...
- DOI:
- 10.2307/1934422
-
http://dx.doi.org/10.2307/1934422
- Author:
- Haller, William T.; Sutton, D. L.; Barlowe, W. C.
- Source:
- Ecology 1974 v.55 no.4 pp. 891-894
- ISSN:
- 0012-9658
- Subject:
- Azolla caroliniana; Eichhornia crassipes; Hydrilla verticillata; Lemna minor; Myriophyllum aquaticum; Myriophyllum spicatum; Najas; Pistia stratiotes; Salvinia auriculata; Vallisneria americana; greenhouse production; macrophytes; plant response; root growth; salinity; sodium chloride; toxicity; transpiration
- Abstract:
- ... Growth rates of 10 aquatic macrophytes in various salinities under greenhouse conditions varied widely. Salt concentrations of 1.66% and 2.5% were toxic to Pistia stratiotes L. and Eichornia crassipes (Mart.) Solms, respectively. Salinities of 16.65% or higher were toxic to Lemna minor L., but growth of Lemna was increased by salt concentrations of 0.83%, 1.66%, 2.50%, and 3.33% as compared to oth ...
- DOI:
- 10.2307/1934427
-
http://dx.doi.org/10.2307/1934427
- Author:
- Hoss, Donald E.
- Source:
- Ecology 1974 v.55 no.4 pp. 848-855
- ISSN:
- 0012-9658
- Subject:
- Lagodon rhomboides; adults; biomass; energy; energy requirements; estuaries; fish; juveniles; larvae; metabolism; primary productivity; rivers; trophic relationships; North Carolina
- Abstract:
- ... Biomass and rates of metabolism were estimated for a population of pinfish in the Newport River estuary, North Carolina. This information was used to estimate the routine energy requirements of the pinfish population and to relate these energy requirements to primary productivity in the estuary. Population estimations of larval, juvenile, and adult pinfish were made over a 2—yr period. Peak biomas ...
- DOI:
- 10.2307/1934420
-
http://dx.doi.org/10.2307/1934420
- Author:
- Wiens, John A.; Innis, George S.
- Source:
- Ecology 1974 v.55 no.4 pp. 730-746
- ISSN:
- 0012-9658
- Subject:
- adults; age structure; ambient temperature; biomass; birds; body weight; breeding; breeding season; clutch size; digestion; egg production; energy costs; energy flow; energy metabolism; energy requirements; fledglings; juveniles; migratory behavior; molting; mortality; phenology; population density; simulation models
- Abstract:
- ... We describe a simulation model that estimates population density flux, biomass changes, and bioenergetic demands of bird populations, especially with reference to the breeding season. changes in the population density of adults of each species considered were calculated from breeding census values and information on migratory movements. Using field or literature values for clutch size, mortality r ...
- DOI:
- 10.2307/1934410
-
http://dx.doi.org/10.2307/1934410
- Author:
- Ritchie, Jerry C.; McHenry, J. Roger; Gill, Angela C.
- Source:
- Ecology 1974 v.55 no.4 pp. 887-890
- ISSN:
- 0012-9658
- Subject:
- cropland; crops; eroded soils; forests; grasses; sediments; watersheds; Mississippi
- Abstract:
- ... A budget for the distribution of fallout ¹ ³ ⁷Cs was calculated for three small watersheds in northern Mississippi. The cover in one contributing watershed is predominantly forest, in the second it is predominantly grass, and in the third predominantly grass and crops. Of the total ¹ ³ ⁷Cs input, 97%, 88%, and 85%, respectively, remained in the forest, the grass, and the grass—crop watersheds. The ...
- DOI:
- 10.2307/1934426
-
http://dx.doi.org/10.2307/1934426
- Author:
- Kunz, Thomas H.
- Source:
- Ecology 1974 v.55 no.4 pp. 693-711
- ISSN:
- 0012-9658
- Subject:
- Coleoptera; Lepidoptera; Myotis; adults; autumn; body weight; diet; eating habits; eclosion; energy; flight; food availability; food consumption; foraging; insectivores; intraspecific competition; juveniles; lactating females; lactation; males; milk; molting; moths; pregnancy; seasonal variation; spermatogenesis; spring; stomach; summer; Kansas
- Abstract:
- ... The feeding behavior and ecology of the cave bat, Myotis velifer, in south—central Kansas are investigated. Emergence behavior and foraging patterns varied according to sex, age, reproductive condition, season, and colony size. Females had one synchronous period of departure in late states of pregnancy. Two feeding periods usually were evident in summer with a major period of activity soon after s ...
- DOI:
- 10.2307/1934408
-
http://dx.doi.org/10.2307/1934408
- Author:
- Myers, Judith H.
- Source:
- Ecology 1974 v.55 no.4 pp. 747-759
- ISSN:
- 0012-9658
- Subject:
- Mus musculus; environmental factors; esterases; farm buildings; females; feral animals; gene frequency; genotype; grasslands; hemoglobin; loci; mice; reproduction; sexual maturity; social structure; trapping; California
- Abstract:
- ... Two populations of house mice living in open grassland in northern California were tested for demic structure, which has been reported for populations living in farm buildings. Mice captured in each of two 0.8—ha trapping areas were typed for two blood proteins (hemoglobin and an esterase). Nonrandom distributions of genotypes within the populations occasionally occurred, but were not temporally s ...
- DOI:
- 10.2307/1934411
-
http://dx.doi.org/10.2307/1934411
- Author:
- Hawk, James A.; Colaianne, J. J.; Bell, A. E.
- Source:
- Ecology 1974 v.55 no.4 pp. 910-912
- ISSN:
- 0012-9658
- Subject:
- Tribolium castaneum; eggs; fecundity; genotype; genotype-environment interaction; lighting; temperature
- Abstract:
- ... Fecundity of two unrelated populations of Tribolium castaneum as measured by eggs laid and hatchability was studied in a factorial design involving two levels of temperature (28°C vs. 33°C) and of lighting (light vs. dark). Significant differences between genotype, temperatures, and lighting regimes were observed for egg numbers, whereas temperature represented the only significant influence on ha ...
- DOI:
- 10.2307/1934432
-
http://dx.doi.org/10.2307/1934432
- Author:
- Vickery, Robert K., Jr.
- Source:
- Ecology 1974 v.55 no.4 pp. 796-807
- ISSN:
- 0012-9658
- Subject:
- Mimulus; climate; genotype; habitats; hybridization; lighting; photoperiod; temperature
- Abstract:
- ... Minulus guttatus and its related species have adaptable genotypes that enabled each plant to grow in a wide range of climates. The growth of the clone members of the plants differed significantly from group to partially—overlapping group of climates. The group of optimal climates had moderate day temperatures with cool nights, high illumination, and long day photoperiods of 16 hr. Overall the plan ...
- DOI:
- 10.2307/1934415
-
http://dx.doi.org/10.2307/1934415
- Author:
- Fretwell, Stephen D.; Bowen, Daniel E.; Hespenheide, Henry A.
- Source:
- Ecology 1974 v.55 no.4 pp. 907-909
- ISSN:
- 0012-9658
- Subject:
- Passeriformes; clutch size; mortality; nests
- Abstract:
- ... This note clarifies and amplifies Ricklefs' (1968) demonstration that the growth period for passerines laying a small clutch has a wider range than for those laying larger clutches. We show that his argument does not distinguish between food— and predator—limited clutch size theories, and that the theoretical variances predicted by Ricklefs do not follow from his assumptions. We extend the theory ...
- DOI:
- 10.2307/1934431
-
http://dx.doi.org/10.2307/1934431
- Author:
- Grigg, Richard W.
- Source:
- Ecology 1974 v.55 no.4 pp. 876-881
- ISSN:
- 0012-9658
- Subject:
- age determination; corals; equations; growth rings; periodicity
- Abstract:
- ... Comparison of the number of growth rings present in the skeletons of colonies of two gorgonian corals, Muricea californica and M. fruticosa, with estimates of their age based on observed growth rates indicates that the periodicity of ring formation is annual. Data from two other methods used to determine periodicity support this conclusion. The results indicate that the observed growth of these go ...
- DOI:
- 10.2307/1934424
-
http://dx.doi.org/10.2307/1934424
- Author:
- Anderson, Stanley H.; Shugart, Herman H., Jr.
- Source:
- Ecology 1974 v.55 no.4 pp. 828-837
- ISSN:
- 0012-9658
- Subject:
- Paridae; Parulidae; Picidae; Thraupidae; analysis of variance; breeding; deciduous forests; discriminant analysis; habitat destruction; habitat preferences; habitats; prediction; saplings; watersheds; woodpeckers; Tennessee
- Abstract:
- ... Bird populations were sampled between May 30 and July 20, 1972, on twenty—four 0.08—ha plots on Walker Branch Watershed, a primarily deciduous forest located in Anderson County, Tennessee. Univariate analysis of variance was used to test for differences in abundance categories of each bird species with respect to 28 habitat variables. Differences in habitat preferences within major bird families ( ...
- DOI:
- 10.2307/1934418
-
http://dx.doi.org/10.2307/1934418
- Author:
- Dagg, Michael J.
- Source:
- Ecology 1974 v.55 no.4 pp. 903-906
- ISSN:
- 0012-9658
- Subject:
- Amphipoda; gravimetry; ingestion; mastication
- Abstract:
- ... During the feeding process of the grasping and chewing amphipod Calliopius laeviusculus, a significant portion of the prey body contents is lost to the surrounding water. The amount of material lost decreases as the size of the predator increases. If this loss is ignored in ingestion studies, the result is a substantial overestimation of assimilation and assimilation efficiency, as determined by t ...
- DOI:
- 10.2307/1934430
-
http://dx.doi.org/10.2307/1934430
- Author:
- Beatley, Janice C.
- Source:
- Ecology 1974 v.55 no.4 pp. 856-863
- ISSN:
- 0012-9658
- Subject:
- annuals; autumn; ecosystems; growing season; perennials; rain; reproduction; shrubs; spring; trophic relationships; winter; Mojave Desert; Nevada
- Abstract:
- ... Phenological events in Mojave desert systems are triggered by heavy rains (>25 mm [1 in]). The most predictable and consequential of these is a regional rain between late September and early December. This rainfall event is usually the precursor of successful vegetative and reproductive growth of shrubs the next spring, and is usually necessary for all growth phenomena of herbaceous perennials and ...
- DOI:
- 10.2307/1934421
-
http://dx.doi.org/10.2307/1934421