EVALUATIOM OF PHYSICAL AND MECHANICAL PROPERTIES OF PARTICLEBOARD PRODUCED FROM WOOD OF Cupressus torulosa IN MIXTURE WITH Pinus taeda

The objective of this work was to evaluate the quality of particleboard produced with 100% of wood of Cupressus torulosa and in different mixing proportions with Pinus taeda. The experimental panels were produced with wood particles of Cupressus torulosa/Pinus taeda, in proportions of 100/0%, 80/20%, 60/40%, 40/60%, 20/80% and 0/100%, totaling six treatments. The panels were produced with nominal density of 0.75g/cm³, 8% urea-formaldehyde resin and 1% paraffin emulsion. The quality of the panels was evaluated by water absorption and swelling thickness 2 and 24 hours, static bending (MOE and MOR), perpendicular tension (internal bonding) and screw withdrawal. The comparative evaluations of the results of this research, with the Pinus taeda, others species referenced in the literature, and normative requirements of EN 312-2003 for commercial panels, indicated great potential of the wood of Cupressus torulosa for the particleboard production.

Assessment of Health of Reclaimed Limestone Mine Spoil using Microbial Biomass Carbon as Biological Indicator

The mining and quarrying in hill ranges of Mussoorie and Dehradun was the glaring example of deforestation and damages of forest resources at 70s and 80s. Mussoorie, the queen of hill station and Doon valley had been stripped off its green cover during this period. This reckless and unscientific exploitation of limestone deposits occurred without any thought for consequential environmental effects. The ecological restoration of these mined areas started almost more than two decades (around 80s) earlier by different agencies through applying mechanical, physical and biological measures. The microbial biomass consists mostly of bacteria and fungi which decompose plant, animal residues and soil organic matter to release carbon dioxide and plant available nutrients such as nitrogen (N), into the soil that are available for plant uptake. It is also an early indicator of changes in total Soil Organic Carbon (SOC). Unlike Total Organic Carbon (TOC), Microbial Biomass Carbon (MBC) responds quickly to soil changes. About half of the microbial biomass is located in the surface 10 cm of a soil profile. It is commonly affected by factors such as water, carbon content of soil, soil types, climate and management practices. The study was under taken to assess the role of rehabilitation/restoration of limestone mined area of Mussoorie hill on improving the health of soil using Microbial Biomass Carbon (MBC) as biological indicator. The study demonstrated the soil health status of reclaimed lime stone mine site which was dominated by Cupressus torulosa. Besides that Microbial Biomass Carbon (MBC) was also estimated under the natural forest of Quercus leucotrichophora as a control. It was estimated by Chloroform Fumigation method. It has been observed that the MBC of soil under reclaimed mined soil dominated by Cupressus torulosa ranges from 200 µg/gm to 600 µg/gm and in natural forest of Quercus leucotrichophora (Banj Oak) it ranges from 600 – 800 µg/gm which is higher than the reclaimed site. Though the MBC in reclaimed site is lower than the natural forest, however it indicating the improvement of soil quality of reclaimed mined spoil due to rehabilitation efforts carried out in these mined areas. The substratum of soil and nutrient limitation for microbial communities can affect the central role in the soil nutrient cycling which facilitate the microbial biomass. It can be concluded that reclaimed limestone mine site improving with time and it may take some more time to improve the spoil to reach the nutrient level up to natural forest.