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Full-Text Articles in Life Sciences

Can Microhabitat Selection Or Differences In 'Catchability' Explain Male-Biased Sex Ratios In Overwintering Populations Of Monarch Butterflies?, Dennis F. Frey, Kingston L.H. Leong May 1993

Can Microhabitat Selection Or Differences In 'Catchability' Explain Male-Biased Sex Ratios In Overwintering Populations Of Monarch Butterflies?, Dennis F. Frey, Kingston L.H. Leong

Biological Sciences

No abstract provided.


Temporal Variation In Potassium Chloride Extractable Aluminum, Sodium, And Soil Ph, And The Effects On Interpretation Of Subsoil Aluminum Toxicity In Yellow Earths, S. J. Carr, G. S.P. Ritchie Mar 1993

Temporal Variation In Potassium Chloride Extractable Aluminum, Sodium, And Soil Ph, And The Effects On Interpretation Of Subsoil Aluminum Toxicity In Yellow Earths, S. J. Carr, G. S.P. Ritchie

Food Science and Nutrition

Temporal variation in two soil tests ([Al] and the ratio [Al]:[Na] in 1:5 0.005M KCl extract) and pH were evaluated on six occasions during a twelve month study of eleven yellow earths in the Merredin region (31°5, 118°E) of Western Australia. The [Al] and ratio [Al]:[Na] in 1:5 0.005M KCl extracts are useful soil tests capable of distinguishing between productive and non-productive (Al toxic) yellow earths in Western Australia. The aim of the study was to determine the most appropriate time to sample yellow earths, in order to predict accurately which soils ...


Zinc Adsorption By Sterilized And Non-Sterilized Soil In The Presence Of Citrate And Catechol, P. Chairidchai, G. S.P. Ritchie Feb 1993

Zinc Adsorption By Sterilized And Non-Sterilized Soil In The Presence Of Citrate And Catechol, P. Chairidchai, G. S.P. Ritchie

Food Science and Nutrition

The effect of organic ligands on zinc (Zn) adsorption in the rhizosphere may be influenced by microbial activity depleting the concentration of the ligand over time. Zinc adsorption by sterile and non-sterile lateritic soil was measured by shaking the soils with Zn solutions at a soil-liquid ratio of 1: 5 for five periods of time ranging from 17-480 h. The concentrations of Zn and the ligands were determined after the selected times. The speciation of Zn was then estimated. Changes in Zn adsorption with time in the presence of organic ligands were due to changes in pH and Zn complexation ...


Life History And Description Of Immature Stages Of Aciurina Thoracica (Diptera: Tephritidae) On Baccharis Sarothroides In Southern California, David H. Headrick, Richard D. Goeden Jan 1993

Life History And Description Of Immature Stages Of Aciurina Thoracica (Diptera: Tephritidae) On Baccharis Sarothroides In Southern California, David H. Headrick, Richard D. Goeden

Horticulture and Crop Science

Aciurina thoracica Curran forms galls on branches of at least three species of Baccharis in southern California. The egg, second and third instars, and puparium obtained from B. sarothroides Gray are described and illustrated. Aciurina thoracica's median oral lobe is described and illustrated. The egg is inserted singly into branch tips of B. sarothroides in early spring. Gall and larval growth continue through summer and fall, and pupariation occurs in early winter. Adults emerge in late winter or early spring, mate, and oviposit into newly forming branch tips. Adult behavior including courtship and copulation is described and compared with ...


Life History And Description Of Immature Stages Of Procecidochares Stonei Blanc & Foote On Viguiera Spp. In Southern California (Diptera: Tephritidae), John F. Green, David H. Headrick, Richard D. Goeden Jan 1993

Life History And Description Of Immature Stages Of Procecidochares Stonei Blanc & Foote On Viguiera Spp. In Southern California (Diptera: Tephritidae), John F. Green, David H. Headrick, Richard D. Goeden

Horticulture and Crop Science

Procecidochares stonei Blanc & Foote is a facultatively multivoltine, stenophagous, gall-forming fruit fly on Viguiera laciniata Gray and V. deltoidea Gray var. parishii (Greene) Vasey and Rose (Asteraceae) in southern California. The latter host record is new; other published host records are questioned. Eggs, first through third instar larvae, and puparia are described for the first time. Galls formed on both host plants are described. The severe drought in southern California during the last 5 years has reduced the densities of P. stonei on V. d. var. parishii. Fly reproduction was restricted to one generation per year on the few host plant individuals that thrived in favored sites where they received supplemental water (i.e., along drip lines of boulders and margins of paved roads). Adult behaviors described include grooming, feeding, wing displays, courtship ...


The Influence Of Ph On The Forms Of Cadmium In Four West Australian Soils, S. S. Mann, G. S.P. Ritchie Jan 1993

The Influence Of Ph On The Forms Of Cadmium In Four West Australian Soils, S. S. Mann, G. S.P. Ritchie

Food Science and Nutrition

The forms of cadmium in soils affect its uptake by plants and hence its potential toxicity to animals and humans. We studied the effect of pH on the forms of native and added Cd in four West Australian soils which differed in their clay, hydrous oxide and organic matter content. The forms of Cd were extracted sequentially by KCl, BaCl2, NaOCl, ammonium oxalate and concentrated acids.
The majority of Cd applied to a sandy soil was found in the soluble (KCl) and the exchangeable (BaCl2) forms at all pH values. In the siliceous sand, the proportion of the ...


H+/Oh- Excretion And Nutrient Uptake In Upper And Lower Parts Of Lupin (Lupinus Angustifolius L.) Root Systems, S. P. Loss, A. D. Robson, G. S.P. Ritchie Jan 1993

H+/Oh- Excretion And Nutrient Uptake In Upper And Lower Parts Of Lupin (Lupinus Angustifolius L.) Root Systems, S. P. Loss, A. D. Robson, G. S.P. Ritchie

Food Science and Nutrition

The cultivation of narrow-leafed lupins (Lupinus angustifolius L.) increase rates of subsoil acidification, and this is thought to be partly related to their pattern of nutrient uptake and H+/OH- excretion. The main hypothesis of this study was that H+ and OH- excretion is not distributed evenly over the entire length of the root system but is limited to zones where excess cation or anion uptake occur. Seedlings of nodulated lupins were grown in solution culture using vertically split pots that allowed the upper and lower zones of the root system to be supplied with varying concentrations of K+ and ...


Phosphorus Retention And Release From Sandy Soils Of The Peel-Harvey Catchment, G. S.P. Ritchie, D. M. Weaver Jan 1993

Phosphorus Retention And Release From Sandy Soils Of The Peel-Harvey Catchment, G. S.P. Ritchie, D. M. Weaver

Food Science and Nutrition

In order to manage phosphorus (P) losses from soils to waterbodies, knowledge of the mechanisms through which P is retained or released from the soil is essential. Sandy soils of the Peel-Harvey catchment (Western Australia) were subjected to a range of environmental and management factors in the laboratory and field in order to gain an understanding of the mechanisms that affect the magnitude of P losses. Sandy soils accumulated P, despite having little sorption capacity, and this accumulation could be monitored by measuring an acid-extractable fraction. The potential, short-term P loss could be estimated by determination of water-soluble soil solution ...


Al Toxicity Of Wheat Grown In Acidic Subsoils In Relation To Soil Solution Properties And Exchangeable Cations, S. J. Carr, G. S.P. Ritchie Jan 1993

Al Toxicity Of Wheat Grown In Acidic Subsoils In Relation To Soil Solution Properties And Exchangeable Cations, S. J. Carr, G. S.P. Ritchie

Food Science and Nutrition

Toxic concentrations of soluble A1 in the subsoil decrease the yield of wheat grown on many yellow earths in the eastern wheatbelt of Western Australia. In our previous research (Carr et al. 1991), we observed variable plant response to high concentrations of soluble Al in subsoils of yellow earths in different regions of the wheatbelt. Environmental conditions (e.g. water supply) and/or an unidentified soil mitigating factor may have contributed to the variable plant response to soluble Al in some of the regions studied.
We collected ten soils from four regions of the eastern wheatbelt of Western Australia. In ...


The Long-Term Fate Of Copper Fertilizer Applied To A Lateritic Sandy Soil In Western Australia, R. G. Mclaren, G. S.P. Ritchie Jan 1993

The Long-Term Fate Of Copper Fertilizer Applied To A Lateritic Sandy Soil In Western Australia, R. G. Mclaren, G. S.P. Ritchie

Food Science and Nutrition

A soil copper fractionation was carried out on soils sampled from plots in a long-term copper fertilizer trial on a lateritic sandy soil in Western Australia. At copper application rates up to 8.25 kg copper sulphate ha-1, a high proportion of the applied copper was initially associated with the soil organic matter. During the course of the trial (20 years), a substantial proportion of this copper became redistributed to a residual soil fraction, i.e. the residue remaining after extractions to remove organic matter and iron oxides. However, significant redistribution of copper with time was not detected in ...


Effect Of Lupins And Pasture On Soil Acidification And Fertility In Western Australia, S. P. Loss, G. S.P. Ritchie, A. D. Robson Jan 1993

Effect Of Lupins And Pasture On Soil Acidification And Fertility In Western Australia, S. P. Loss, G. S.P. Ritchie, A. D. Robson

Food Science and Nutrition

An 'across the fence' comparison of farmer paddocks with nearby virgin bush sites was made at 3 locations, to measure the effects of lupins and subterranean clover based pastures on the chemical properties of the soil. Estimated rates of acidification in the 0-60 cm depth were 0.29-0.55 kmol H+/ha.year for wheat-lupin paddocks and 0.16-0.2 1 kmol H+/ha .year for pasture paddocks. A significant proportion of this acidification occurred below 20 cm, particularly in the lupin paddocks (up to 70% of the total). Severe water repellency had developed at 1 location that had produced ...


The Effect Of Citrate And Ph On Zinc Uptake By Wheat, P. Chairidchai, G. S. P. Ritchie Jan 1993

The Effect Of Citrate And Ph On Zinc Uptake By Wheat, P. Chairidchai, G. S. P. Ritchie

Food Science and Nutrition

Zinc uptake by plants may be influenced by its reaction with organic ligands in the rhizosphere. Therefore, four experiments were conducted to examine the effects of an organic ligand (citrate) and pH on the uptake of Zn by wheat (Triticum aestivum L. emend. Thell). Plants were grown for 21 to 28 d in a nutrient solution (containing 0-0.05 µmol L-1 Zn) in a temperature controlled tank, either in the absence or presence of citrate and at constant or variable pH (3.7-7.1). Dry matter weights of plant parts and Zn content in the shoots were determined. The ...


Effect Of Gypsum And Lime On Wheat Growth In Pots Containing An Acidic Subsoil, C. D.A. Mclay, G. S. P. Ritchie Jan 1993

Effect Of Gypsum And Lime On Wheat Growth In Pots Containing An Acidic Subsoil, C. D.A. Mclay, G. S. P. Ritchie

Food Science and Nutrition

A pot experiment was conducted to establish whether gypsum or lime could increase wheat growth in an acid subsoil. Wheat (Triticum aestivum c. v. Gutha) was grown in 3 kg of soil which had been mixed with basal nutrients and different rates of gypsum and lime. Wheat in the treatment which received no gypsum or lime showed the most severe nutrient deficiency symptoms and had the lowest shoot and root dry weights. Lime treatments increased shoot and root growth 2 to 3 fold and decreased the concentration of total Al and the calculated activities of all Al species. Gypsum increased ...