Impact assessment of a hydroelectric project on the flora in the Western Himalayan region based on vegetation analysis and socio-economic studies

This study provides an overview of the impacts of a proposed hydroelectric power project in the Western Himalayan region in India, using a primary database on floristic diversity and vegetation analysis. The remote sensing data revealed that in the submergence zone only mixed deciduous forest that occupies 807.5 ha area and has a wood biomass volume of 4,027,503 m³ is likely to be lost due to impoundment. A total of 165 plant species found in the submergence zone also occur in the influence and free draining catchment area of the project. In the influence zone of the project area only one tree species (Acer oblongum) is found under conservation threat category, which is also present in the free draining catchment of the project. The project affected population (6716 people) residing in the submergence and influence zone depend upon the surrounding forests for fuel wood, fodder, wild edibles etc., and most likely they will settle in the nearby areas, thus mounting more pressure on residual forests of the influence zone for various forest products. Further, from the vegetation analysis it is evident that several tree species (e.g. Lannea coromandelica, Terminalia alata, T. bellerica etc.), may face more pressure from exploitation as they provide a number of useful products and are represented in lower numbers in the forests of the project area. To compensate for the loss of various goods and services provided by the forests falling in the submergence zone and to offset the increased pressure of the project affected families on the forests of influence zone, a biodiversity management plan is suggested incorporating socio-economic considerations.     

Seasonal evaluation and spatial variability of suspended particulate matter in the vicinity of a large coal-fired power station in India—A case study

Coal combustion in the power sector gives rise to the emission of primary and secondary particulate pollutants. Since the emission of pollutants depends on coal quality and combustion technology, and given that transport, transformation and deposition of contaminants depend on regional climatic conditions, specific studies for the power stations is needed to evaluate their environmental impacts. Monitoring of ambient respirable suspended particulate matter (RSPM) and suspended particulate matter (SPM) levels around a large coal-fired power station in India was carried out. The specific objectives were the determination of spatial and seasonal variability in RSPM and SPM levels, and their relationship with meteorological parameters such as wind velocity and relative humidity. The results have shown a marked seasonal trend and spatial variability in RSPM and SPM levels in the study area. Higher concentrations of ambient RSPM and SPM were found in downwind monitoring stations compared to upwind direction. Ratios of RSPM to SPM and correlation coefficient values between RSPM and SPM along with meteorological parameters were also worked out. Relative humidity and wind velocity have shown an inverse relation with particulate deposition pattern.     

Thiram: degradation, applications and analytical methods

In this review a brief introduction to thiram (tetramethylthiuram disulfide; TMTD) pesticide has been given along with other applications. All the important methods available are systematically arranged and are listed under various techniques. Some of these methods have been applied for the determination of thiram in commercial formulations, synthetic mixtures in grains, vegetables and fruits. A comparison of different methods is the salient feature of this review.     

Reactive solute transport in macroscopically homogeneous porous media: analytical solutions for the temporal moments

In this work, we investigate one-dimensional solute transport affected by rate-limited sorption, first-order mass transfer, and first-order transformation. Analytical expressions are obtained for the temporal moments of the solute in the solution phase. The effect of various rate coefficients on the temporal moments is examined. It was found that, in the presence of transformation reactions, the mean arrival time, and the spread and skewness of the breakthrough curves, are not monotonic functions of the rate coefficients. These solutions will be useful as a preliminary analysis tool for ascertaining the relative importance of various processes under given conditions. They may also be used to analyze the accuracy of various numerical techniques used for simulation of reactive transport.     

Precision of a Mammalian Circadian Clock

 This paper reports study of day-to-day instability in the locomotor activity rhythm of the nocturnal field mouse Mus booduga. The free-running period (τ) of this rhythm was estimated in constant darkness in n=347 adult male mice. The "onset" and "offset" of locomotor activity rhythm were used as phase markers of the circadian clock. The precision of the onset of locomotor activity was observed to be a non-linear function of τ, with maximal precision at τ close to 24 h. The precision of the offset of locomotor activity was found to increase with increasing τ. These results suggest that the homeostasis of τ is tighter when τ is close to 24 h. Received: 5 May 1998 / Accepted: 11 February 1999     

Interference of three weed extracts on uptake of nutrient in three different varieties of paddy through radio tracer techniques

Interference of three dominant weed extracts viz., Ageratum conyzoides L., Melilotus indica All. and Parthenium hysterophorus L. were examined on seed germination, seedling growth, and nutrient uptake (32P and 65Zn) in three different varieties (PD-10, PD-12 and PB) of paddy (Oryza sativa L.). Among the three different varieties irrespective of weed extracts, PD-10 and PD-12 were resistant and PB was susceptible in terms of seed germination, radicle length and plumule dry weight; and PD-12 and PB were resistant and susceptible, respectively, in terms of plumule length and total seedling dry weight. A. conyzoides caused maximum reduction in seed germination and M. indica in seedling growth in different varieties of paddy. The weed extracts interfered in uptake of both 32P and 65Zn and there was a gradual decrease in uptake of both nutrients with increasing concentration of extracts in both root and shoot. The uptake of 32P and 65Zn was more inhibitory with the extracts of A. conyzoides and M. indica, respectively in different varieties. The inhibition in seed germination, seedling growth and nutrient uptake may be due to the presence of phenolics and other secondary metabolities. The phenolics such as gallic, vanillic, protocatechuic and p-hydroxybenzoic acids were identified from these weed extracts.     

Heavy metal toxicity on dehydrogenase activity on rhizospheric soil of ectomycorrhizal pine seedlings in field condition

The present investigation was carried out to study the toxicity of heavy metals (Zn, Cd, Cu, Ni, Pb and Al) on the dehydrogenase activity of ectomycorrhizal (Suillus leutus, Scleroderma aurantium, Cenococcum graniforme and Boletus spp.) and non-mycorrhizal rhizospheric soil of pine seedlings. The treatment of heavy metals adversely affected the dehydrogenase activity. Inoculation of mixed ectomycorrhizal fungi harbored increased activity of dehydrogenase. It was observed that in absence of ectomycorrhizae, heavy metals drastically reduced the enzyme activity at higher concentration of metals.