ISSN:0038-075X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

We analyzed leaf samples ofLarrea tridentata(Sesse & Moc. ex DC.) Cov. (n= 230) and ofPlantago insularisEastw. var.fastigiata(n= 179) for mineral elements by emission spectroscopy. The study was part of a program to evaluate baseline conditions near a geothermal area being developed for generation of electricity. Analyses varied between species, among locations, and within locations. As a general average, about a fifth of the variability was due to analytical error, which is largely the result of nonhomogenous samples. Cluster analysis grouped the so-called dust elements iron, silicon, aluminum, titanium, and sometimes vanadium. Correlations of interest were Ca versus Sr(+), K versus Na and Li(-), and P versus K(+). Frequency distribution histograms, skewness, and kurtosis calculations indicated some normal curves and possibly some log normal curves. Three- to fivefold ranges in concentrations of different elements were observed, even in populations defined as uniform by Duncan's multiple range test.

ISSN:0038-075X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

We made baseline measurements of mineral composition of alfalfa (Medicago sativaL.) and sugar beets (Beta vulgarisL.) from one field each in the Imperial Valley of California. The fields are in a geothermal area being developed for energy production, and the purpose of the investigation was to ascertain variability within a relatively large number of samples from a common area, so that subsequent samplings could be made to satisfactorily detect whether there were changes resulting from the geothermal activity. Means, standard deviations, frequency distribution, correlations, cluster trees, and other statistics were examined for over 20 elements at each site. Most elements were normally distributed, but there was three- to fourfold range in the concentration for each.

ISSN:0038-075X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Extensive sampling shows high variability in nitrate concentration within profiles of Mojave Desert soils. This high variability greatly complicates studies of desert soil N and its ecological role. Patterns in nitrate distribution suggest effects of litter decomposition under shrubs, surface leaching in bare areas, and plant uptake in the root zone. Two mechanisms proposed to explain high concentrations found at seemingly random depths are concentration at drying fronts and distribution along water potential gradients.

ISSN:0038-075X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

We collected separately leaves ofLycium andersoniiA. Gray from 20 different shrubs from the northern Mojave Desert. Half of each sample was washed in 1/10NHCl followed with deionized water before analysis in triplicate by optical emission spectrometry, and the other half was analyzed unwashed. Washed samples contained 12, 35, 33, 40, 55, 47, 57, 8, 8, 9, and 20 percent, respectively, less calcium, zinc, copper, iron, aluminum, silicon, titanium, strontium, barium, lithium, and lead than did unwashed leaves. The losses probably exceed contamination for some elements, because the results differed in some respects from those obtained for citrus. Statistically significant differences were not obtained for other elements analyzed. Even though 40 to 57 percent of the iron, aluminum, silicon, and titanium was washed from the leaves, cluster analyses grouped the four elements into a common cluster whether or not the leaves had been washed. Washing resulted in a lower coefficient of variation for some of the elements compared with unwashed leaves.

ISSN:0038-075X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Using optical emission spectrometry, we analyzed, in triplicate, 56 leaf samples, representing nine plant species from a Savannah River Plant flood plain (partially swampy), for 19 mineral elements. Each sample for trees represented a single tree. Unless the concentration of an element was very low, most of the variation for a given plant species was between samples. The analytical coefficient of variation (CV) was less than 10 percent for the mean of all elements for some species, and the analytical CV differences from species to species were statistically significant. The total CV also varied from element to element within species and was independent of analytical CV. Collection of each sample from a different plant (the trees) resulted in a higher CV. Barium concentrations in leaves were consistently higher than those of strontium in contrast to samples from western plants. All samples were high (500 to 3000 ±g/g) in manganese, typical for podzol soils under acidic and reducing conditions. Species differences were noted for nearly every element. A somewhat elevated concentration of cobalt was found in the leaves of one species. Molybdenum was above the detection limit for only one plant species.

ISSN:0038-075X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Analysis of a native fern (Pteridium aquilinumL.) growing in large tracts of soil at about 1200 meters mean sea level in Greece indicated that it tolerated low levels of copper. Corn plants (Zea maysL.) grown in potted soild from the area did respond slightly to Cu added to the soil.

ISSN:0038-075X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Using optical emission spectrography, we analyzed leaves of five native plant species (Adenostoma fasciculatum, Arctostaphylos viscida, Cupressus macnabiana, Cupressus sargentii, andQuercus durata) for mineral elements. There were 112 plants in all. In these plants, which are reasonably adapted to serpentine soil conditions, the calcium: magnesium ratios were normal in contrast to plants not adapted to such soil conditions. The nickel concentrations in the leaves were low for serpentine soil conditions, and there was no tendency for accumulation of chromium or cobalt. Strontium varied, as did calcium.

ISSN:0038-075X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Leaves with zinc-deficiency symptoms had a lower Zn concentration than corresponding leaves without symptoms and of the same age from the same orange (Citrus senensisL.) tree on sour orange (C. aurantiumL.) rootstock grown in Rhodes, Greece. There was considerable overlap, however, with the frequency distribution of each group approximating a normal curve. But both kinds of leaves combined showed a more normal distribution. Some leaves with symptoms had higher zinc concentrations than some without symptoms. There was a threefold range in Zn concentration for each group of leaves. Zinc-deficient leaves had less phosphorus, calcium, and manganese and more iron, aluminum, silicon, and titanium (the so-called dust elements) than did leaves with no deficiency symptoms. Some of these elements gave normal curves for both Zn-deficient and non-Zn-deficient leaves.

ISSN:0038-075X    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Galenia pubescens(Eckl. and Zeyh) Druce was grown in solution culture under a variety of conditions to test its cation-anion relationships. It is a plant in which mineral cations exceed mineral anions. It then has from fewer than 100 to 400 or more milliequivalents per 100 grams of organic acid anions to balance cations minus anions. Mineral cations exceeded mineral anions in leaves, stems, and roots whether sodium chloride was added in abundance or whether the nitrogen source was nitrate, ammonia, or urea. When sodium or chlorine was added, both ions tended to accumulate in leaves rather than in roots; sodium was more pronounced in this respect than was chlorine.Galenia pubescensgrew as well in a solution or in soil containing 400 meq/liter NaCl as in one without NaCl. The 400 meq/liter Na2SO4was excessive.Galenia pubescensis a subtropical nonfacultative halophyte that can grow in nonsaline conditions and also in seawater. It has a very high rate of photosynthesis and capacity to synthesize large quantities of protein. It has possibilities as a biomass crop.

ISSN:0038-075X    

出版商:OVID    

年代:1982

数据来源: OVID