Biomass

The Bala-fort forest is located in the Sariska Tiger reserve in Alwar, Rajasthan (27o4’ to 28o4’ N and 76o7’ to 77o13’ E). It is a tropical dry deciduous forest with dense ground vegetation. The influence of spatial heterogeneity and soil nutrients was evaluated on the distribution and growth of selected common herb and shrubs on the west facing hill slope in this forest. The density of herb Achyranthes aspera was highest among the four selected species (3320 stems 100m-2) in the valley and lowest (1970 stems100m-2) in the middle part of the slope. Among the shrubs Justicia adhatoda exhibited highest density (42 stems 100m-2) in the valley, Grewia flavescens 34 stems 100m-2 at the base and Capparis sepiaria 17 stems 100m-2 in the valley. According to frequency, Capparis sepiaria exhibited clumped dispersion whereas the other three selected species showed uniform dispersion on the west facing hill slope in this forest. Achyranthes aspera exhibited lowest biomass (0.17 kg 100m-2) whereas Justicia adhatoda, Grewia flavescens and Capparis sepiaria showed 6.4, 6.6 and 2.5 kg 100m-2 total biomass respectively, in the study site. The growth of Achyranthes aspera and Justicia adhatoda in different micro-environments did not respond to four selected elements (Sodium, Potassium, Calcium and Phosphorus) whereas Grewia flavescens exhibited higher growth at low percentage of four elements. Capparis sepiaria showed higher growth at higher percentage than at lower percentage of selected elements. The results obtained indicate that distribution and growth of selected plant species was regulated by the elevation of slope, density of tree species and soil nutrients in this forest.

The Bala-fort tropical dry deciduous forest in the Aravalli ranges is located in Alwar district of Rajasthan (27o4’ to 28o4’ N and 76o7’ to 77o13’ E). It supports a dense layer of herbs and shrubs because of its open forest canopy. Hence, the role of dominant herb and shrubs in the litter dynamics has been evaluated in this forest. The total annual litter of the forest floor was 328 g m-2 out of which more than 32 % was contributed by the selected shrubs of the ground vegetation. The shrub Grewia flavescens contributed from September to March, Capparis sepiaria from March to June whereas Justicia adhatoda throughout the year. It seems from the study that Justicia adhatoda plays greater role whereas the common herb Achyranthes aspera played the lowest role in the litter dynamics of this forest.

Effect of different concentrations of nitrogen (N) source (NaNO3) of BG-11 medium on growth of freshwater microalgae Chlorella vulgaris is studied. Different nitrogen step down concentrations of NaNO3 in per litre of medium were used like 17.6 mM (control), 8.8 mM and 4.4 mM. Optimum lipid was obtained with treatment of 8.8 mM NaNO3 concentration that showed 29.30 µg lipid per 100 µg of biomass. However, biomass in term of protein was higher (602.64±0.97 µg/ml) at 17.6 mM of NaNO3 concentration. Treatment of 4.4 mM NaNO3 concentration resulted in 20.03 µg of lipid per 100 µg biomass, which was higher than control, but with poor yield of biomass. Result indicates that changing the N concentration in BG-11 medium result in enhanced lipid production in Chlorella vulgaris.