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Smita Bisht , Mridula Negi , J. D. S. Negi

Abstract

Monthly foliage and leaf litter nutrient content (N, P, K, Ca and Mg) were studied along with leaf fall pattern to understand the nutrient conservation in natural and plantation ecosystems of Dalbergia sissoo. It was observed that elevated concentration of Nitrogen in foliage and leaf litter along with sandy soils and high percentage of nutrient withdrawal indicated suitability of site for D. sissoo. Manmade or natural disturbances may alter soil physico-chemical properties, especially enrichment of soil with clay, to create situations favourable for secondary successional species eliminating D. sissoo.

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J. D. S. Negi , P. S. Chauhan , Mridula Negi

Abstract

Available data on meteorological observation , phytosociological studies , population dynamics and biomass in moist Sal (Shorea robusta Gaertn. f.) forest of Doon Valley and adjacent dry deciduous forest are utilized to understand the structure and functioning of ecosystem. Seventy years mean maximum and mean minimum daily temperature and rainfall were analyzed for each five-year interval (1931-2000). It was observed that there is an increase of O.5°C in mean maximum temperature and decline of 1.1°C in mean minimum temperature. However total rain (monsoon , June to October + local rains , November to May) has declined by 17% during seventy year of period , whereas the local rains has increased by 27% since 1981 onward. Fluctuations in temperature and rainfall have pronounced effect on the distribution of evergreen and deciduous tree species. Further , change in climatic pattern and microclimatic conditions as a result of deforestation have noticeable impact on forest decline. Atmospheric CO₂. enrichment has put a positive response in enhancing productivity of these ecosystems.

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Omkar Singh , Mridula Negi

Abstract

No abstract

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M. C. Pande , V. N. Tandon , Mridula Negi

Abstract

The biomass production of 3, 6, 11, 16 and 21 years old plantations of Ailanthus excelsa has been discussed. Regression equations were worked out, it was observed that log models of type Log y = a + b log × are well suited for the prediction purposes. The peak values of biomass 41.8 t/ha and 40.3 t/ha were obtained at the age of 6 and 11 years respectively. The decreasing biomass of leaf and twig component with increasing age has also been discussed. Study on return of nutrients in these plantations has been suggested.

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M. C. Pande , V. N. Tandon , Mridula Negi

Abstract

The distribution of biomass in various tree component and productivity in an age series of plantations of Eucalyptus and Auriculaeformis have been discussed. For comparable ages the utilizable biomass recorded for Eucalyptus was higher than Acacia auriculaeformis. The maximum biomass produced at the age of 5 years in Eucalyptus has also been discussed. The present study suggests to raise Eucalyptus and Acacia auriculaeformis alternately in the same site, to maintain the fertility status of the soil to same extent.

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