In the present study, sediment samples were collected from different locations and diverse environments around Chennai city to evaluate the environmental conditions and the health of the water bodies. The grain size analysis of the sediment samples reveals that sand is the dominant fraction deposited in highenergy coastal environments followed by silty sand, sandy silt, while as the sediment samples of Cooum River and fresh water lakes and Buckingham canal show the dominance of silty clay and clayey silt respectively. The C/N ratio of the sediment samples indicates in situ source of algal organic matter, except Cooum River, while the confluence of the Cooum River to the sea and the Buckingham canal exhibits dominant terrestrial source of organic matter. Significant positive correlation of clay with TOC, C/N ratio signifies strong binding of these elements with finer clay particles. Predominant occurrences of diatom species such as Cyclotella striata, Navicula and Nitzchia linearis in the water bodies of Chennai shows high organic pollution caused by anthropogenic influences.
The present investigation was carried out at the established plantations and laboratory of the Department of Silviculture and Agroforestry, Dr. Y.S. Parmar University of Horticulture and Forestry, Nauni, Solan (H.P.) during the year 2008-2009. The experimental site lies in the mid hill zone of Himachal Pradesh with an elevation of 1250 m above mean sea level. It is located at 30o 51' N latitude and 76o 11' E longitude. The study revealed higher nutrient contents at surface layer D1 (0-15cm) which decreased with increase in soil depths. Among different tree species Alnus nitida registered significantly higher amount of available nitrogen at different soil depths. Phosphorus and potassium varied significantly under different tree species and found highest again under Alnus nitida. Phosphorus was noticed maximum (41.92 kg/ha) at 0-15cm which decreased to 40.40 kg/ha at 30-45cm soil depths. Similar trend observed for potassium where it decreased to about 32.50% at D3 (30-45cm) than at D1 (0-15cm). Irrespective of soil depths, the magnesium content was found highest (330.40kg/ha) under Melia azedarach. Magnesium decreased from 329.70 kg/ha at D1 to 281.40 kg/ha at D3 registering about 15% reduction. Calcium behaved in similar manner which irrespective of depths was registered highest under Alnus nitida plantation. A slight decrease in soil pH was observed as the soil depth increased. It lowered to 6.4 at D3 (30-45cm) from 6.55 at D1 (0-15cm). Organic carbon decreased to about 50% at D3 as compared to its value to D1 depth. Similarly, the soil microbial biomass decreased to more than 50% at D3 than that of D1 depth. Irrespective of soil depths the highest (2.15?g/g) microbial biomass was observed under Alnus nitida.
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