Plants indicators

United States, Canada, Mexico, western Europe, and Japan, producer lists indicating plant location, size, product concentration, and data on nitric acid use. Table 4. U.S. Production of Nitric Acid/ 10 t/yr, 100% Basis... 

Indicator plants generally have an offensive odor, which varies with the selenium concentration. Other vegetable matter grown on seleniferous soils may have a sufficiently high selenium content to be toxic when ingested by animals or humans. Apart from appearance in these seleniferous plants, selenium has been considered as a variable contaminant. Selenium is a necessary micronutrient in living organisms, needed by humans as well as animals (see Mineral NUTHiENTs). 

Jacobson, J. S.. and W. A. Feder. A Regional Network for Environmental Monitoring Atmospheric Oxidant Concentrations and Foliar Injury to Tobacco Indicator Plants in the Eastern United States. Massachusetts Agricultural Experiment Statioo Bulletin No. 604. Amherst University of Massachusetts, College of Food and Natural Resources, 1974. 31 pp. 

Nakamura, H.. and S. Maisunaka. Indicator plants for air pollutants. 1. Suscep-... 

Drug Chemical type Indication Plant producer... 

Heavy metal toxicity in plants is infrequent (143). In many cases, metal concentrations in plant parts show poor correlation with soil concentrations of the element (147). Plants tend to exclude certain elements and readily accept or concentrate others. Lisk (148) reported natural plant soil concentration ratios of 0.05 or less for As, Be, Cr, Ga, Hg, Ni, and V. Cadmium appears to be actively concentrated and selenium appears to be easily exchangeable. Indicator plants are capable of markedly concentrating specific elements, e.g., Astragalus spp. for selenium (138) and Hybanthus floribundus for nickel (149). Plants growing on mine wastes have been shown to evolve populations which exhibit metal-specific tolerances (150). 

The term indicator plant has been used somewhat differently. Qualitatively, indicator plants are diagnostic of certain environmental conditions, and these can fall into any of Baker s three categories. To avoid confusion, it has been suggested (Farago and Mehra, 1992) that the term concentration indicator should be used to describe plants where the plant soil concentration ratios are near 1. These three types are represented in Fig. 8-2. Some plants endemic to metalliferous soils acccumulate very high concentrations in their aerial parts and these are known as hyperaccumulators (Baker and Brooks, 1989 Chapters 3 and 4). Such plants are able to accumulate metals not only from soils with high metal concentrations, but also from soils with concentrations only marginally above normal. 

Fine plant fibrils will not be present unless plant fibers are present. Look for presence of plant fibers as an indicator. Plant fibers will usually be easy to identify by their morphology and internal structure. If plant fibers are present, fibrils small enough to have no reaction with polarized light will still be rare. 

Figure. 1. Map of Ohio River Valley showing ORV sites and coal-fired power plants, with sizes of circles indicating plant capacities. West, Center and East sampling sites indicated as W, C and E, respectively.

Plate 7. Sensitive tobacco plants (Nicotina tabacum L.. strain Bel W 3) with necrotic spots on leaves caused by ambient ozone, light brown spots having been induced by ozone injury 24 to 48 hrs ago. After longer time of exposure, dead tissue will be bleached. Phytotoxic concentrations of ozone in W. Germany have been demonstrated for the first time by the use of tobacco as indicator plant (Knabe et al.. 1973). Kettwig, W. Germany. l%7. 

Measurements should also be made on indicator plants and animals, which are not edible or directly involved in the human food chain. These indicators grow readily, concentrating radionuclides. Thus, these indicators near nuclear power facilities are very useful for monitoring changes in the level of environmental radioactivity. Table 9.6 shows biotic items suitable for sampling. Table 9.7 summarises the recommendations for collecting of samples. 

Milk and Livestock products Indicator plants Daily food... 

Indicator plants Select those species that can be collected regularly over a long period. Collect... 

In some of the most successful work of its kind described. Cannon (1964) used two botanical methods of prospecting in the Yellow Cat area of Utah. The first involved the analysis for uranium of juniper needles and leaves of shrubs, and the second the mapping of the distribution of indicator plants. Cannon found two selenium indicators Astralagus preussi and A. pattersoni to be excellent indicators of mineralized ground. 

Cannon, H.L., 1957. Description of indicator plants and methods of botanical prospecting on the Colorado Plateau. U.S. Geol. Surv. Bull., 1030-M 399—516. 

Selenium is an essential element but is toxic when excessive quantities are ingested. Exposure of horses is usually through consumption of seleniferous (accumulator or indicator) plants (e.g.. Astragalus spp.). Exposure to high quantities of selenium over a short time causes diarrhea (which is often foul smelling and contains air bubbles), neurological and cardiovascular effects, and respiratory difficulty. Death in these horses is due to respiratory failure. Chronic exposure to low levels of excessive selenium is characterized by hoof abnormalities at the coronary bands and by discoloration and loss of hair. The hoof deformities are painful and cause lameness. 

First, it is interesting to note that a deficiency or excess of one element does not directly induce a particular symptom in cultivated or wild plants. In this respect, it is necessary to examine the macro, trace and ultratrace element transfer from the different polluted and unpolluted soils into the plant. Indicator plants must be easy to identify, grown worldwide, and indicate the mineral transfer to the food chain. On cultivated soils in many parts of the world, these conditions are met by wheat Triticum sativum), rye Secale cereale), and red clover Trifolium pratense sativum) of the field and meadow varieties (TrifoUum pratense spontaneum). The green plants were harvested when the rye was in blossom, the wheat shooting, the field red clover in bud, and the meadow red clover in blossom. 

The certainly rate is stricter in comparison to the correlation coefficient r. The correlation of the calcium, potassium, phosphorus, and magnesium contents of the two species is very high, and shows the qualification of both species as indicator plants for these elements. The sodium content of both plant species is very low and demonstrates that their sodium concentration is not correlated under these conditions. 

Influence of Geological Origin of the Site on the Macro, Trace and Ultratrace Element Contents of Indicator Plants... 

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