Zinc tolerance, based on root growth in zinc-containing solutions, was examined in samples of 30 Agrostis capillaris L. individuals collected from populations beneath five electricity pylons in North Wales. The populations were found to vary in zinc tolerance. Three of them contained individuals whose tolerance ranged from low to high, one population consisted of individuals with low to moderate tolerance, whilst the fifth population (ZK-180) contained no tolerant individuals. Differences in zinc tolerance were also found between seedlings raised from five seed populations collected from plants growing in the uncontaminated pasture areas adjacent to four of those pylons, and one further pylon in the same area. The population adjacent to pylon ZK-1 80 consistently showed little sign of tolerant individuals. Samples of seeds collected from the populations in the uncontaminated areas surrounding each pylon, and likely to have been the origin of the pylon populations were grown at a concentration of 15 ,ug Zn cm and root lengths of 105 randomly chosen seedlings from each were measured. The means and variance of tolerances of four of the five did not differ, but all were significantly higher than that adjacent to pylon ZK-1 80. Two cycles of selection and breeding for increased zinc tolerance were carried out using seed samples collected from four of the five populations of adults collected beneath pylons examined previously, and including population ZK-180. Marked increases in tolerance were effected in three of the four populations; no corresponding increase in tolerance was achieved for population ZK-180. It is concluded from these findings that the lack of zinc tolerance beneath pylon ZK-180 is due to the absence of appropriate variation in zinc tolerance within that population, and in potential colonizing material adjacent to it, a situation which contrasts with that for the other three pylons.

summary Most electricity pylons are zinc coated. It might be possible for this to cause zinc contamination of soil beneath the pylons sufficient to impose selective forces by which zinc‐tolerant populations would develop in a replicated manner. An investigation of Agrostis capilluris L. populations sampled under a series of pylons in North Wales shows that:  Zinc concentrations are considerably greater in soils beneath pylons, particularly adjacent to pylon legs.  Soils sampled under different pylons had mean zinc concentrations varying from 1250 ± 200 to 6500 ± 4000 μg−1 as total, and from 570 + 188 to 3000 ± 2000 μg g−1 as acetic acid extractable. In control soils, comparable values were from 170 ± 35 to 320 ± 90 μg g−1 total zinc, and 70±10 to 140 ± 30 μg g−1 acetic acid‐extraetable zinc.  Zinc toxieity is found in such soils causing significant reduction in plant dry weight and tiller production of normal material of A. capillaris.  The pattern of root growth response to increasing zinc concentration in solution culture of samples of adult plants collected from beneath pylons differed significantly.  Some individuals had zinc tolerance equivalent to that of zinc mine plants; others had low but measurable tolerance; others differed little from plants from uncontaminated control sites. These results clearly show that evolution of zinc tolerance has occurred rapidly, since the pylons sampled were all less than 30 years old, but the outcome is different under different pylons, almost certainly because of differing genetic constitutions of different founding populations.

SUMMARY Samples of 8-35 individuals of Agrostis capillaris, A. stolonifera, Anthoxanthutn odoratum, Deschampsia cespitosaand Eestuca ovina were collected from zinc-contaminated soils beneath electricity pylons erected in North Wales and Lancashire between 1956 and 1970. Their zinc tolerance was assessed, as was that of two individuals of the same species collected from adjacent uncontaminated soils. Five soil samples from beneath each pylon were collected for evaluating total and extractable soil zinc, soil pH, and soil organic matter.Some degree of zinc tolerance was detected in all five species, suggesting that evolution of tolerance has taken place relatively rapidly, particularly in A. capillaris, D. cespitosa, and Anthoxanthum odoratum. However, tolerant individuals of all species were not found beneath all pylons even when the species was present in the surrounding vegetation, l^his confirms and extends to other species previous findings in A. capillaris, that the gene or genes necessary for the evolution of tolerance are not universally present within species.

Much attention has been made towards adsorbent materials to be used in heavy metal removal from polluted water and various techniques are applied such as chemical, physical and biological techniques. This study was designed for using less expensive and much frequently available materials (orange & lemon peels) to remove copper and lead from industrial waste-water. Three forms of these peels (fresh dried small pieces and powder) were used. Also other factors such as pH and temperature were examined for probable effects on biosorption. Current data show that both orange and lemon peels are capable of removing copper and lead ions at significant capacity. Furthermore, lemon peels had higher capability than orange peels and the form of peel powder of both orange and lemon showed higher capacity than fresh and dried pieces where lemon powder has shown biosorption capacity of 72.5% and 71.3% for lead and copper respectively while orange powder had bioremoval percentage of 56.7% of lead and 34.5% for copper. In case of fresh lemon peels, these figures were 70.9% for lead and 62.2% for copper but fresh orange peels gave much less percentage (48.7of lead and 29.6% of copper). Regarding dried peels which showed the lowest values, but again, lemon peels were significantly better than those of orange. These values of lemon were 58.0% for lead and 57.1% for copper but for orange peels, the biosorption percentages reached 37.2% and 23.7% for lead and copper respectively. However, biosorption capacity of both fruit peels at different forms were significantly affected by various levels of both pH and temperature. The optimum pH and temperature values for better bioremoval capacity for all treatment within this study were 5 and 40 C° for pH and temperature respectively. Based on above, current data found that lemon peels are more efficient than the orange peels as biosorbents materials.

Phytoplankton assemblage in relation to physical and chemical characteristics of water in Al-Auda marsh of Maysan province southern Iraq was assessed from November 2012 to July 2013. Six sampling sites were chosen to examine all phytoplankton species in the study area. A total of 246 species and seventy-five genera have been recognized belonging to twelve phytoplankton classes as follows: Bacillariophyceae (106 taxa), Chlorophyceae (34 taxa), Euglenophyceae (29 taxa), Cyanophyceae (29 taxa), Conjugatophyceae (19 taxa), Mediophyceae (10 taxa), Cryptophyceas (5 taxa), Coscinodiscophyceae (4 taxa), Chrysophyceae (4 taxa), Dinophyceae (3 taxa), Trebouxiophyceae (2 taxa) whereas Compsopogonophyceae recorded only (one taxon).The finding showed class Bacillariophyceae dominated with (43.09%), followed by Chlorophyceae of (13.82%), then (11.79%) for each of Cyanophycean and Euglenophyceae. Mean ± standard deviation for water temperature was ranged between (14.3±1.6°C) during winter to (35.6±1.81°C) during summer, electrical Conductivity (2020±186μ.s/cm) during autumn to (6390±875μ.s/cm) during summer, total Phosphate 0.01±0.0 µg/l during winter to 0.3±0.08 µg/l during spring, and total nitrogen varied from 1.8±0.8 µg/l during winter to 6.9±0.5 µg/l during autumn. Seasonal distribution indicated that phytoplankton flourished predominantly during the summer and spring. The diversity index (H) recorded the highest value in spring and lowest value in autumn, Richness (D) and Evenness (E) indices achieved the highest values in spring, the lowest values in autumn. The Jaccard index (Ss%) recorded the highest similarity between autumn and winter, the lowest similarity was between autumn and spring. The results revealed Al-Auda marsh is mesotrophic according to phytoplankton composition.