Browsing by Author "O.P. Chaturvedi"

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A quantitative study of the forest floor biomass, litter fall and nutrient return in a Pinus roxburghii forest in Kumaun Himalaya
(Kluwer Academic Publishers, 1987) O.P. Chaturvedi; J.S. Singh
The present paper reports on the forest floor biomass, litter fall, nutrient return and turnover of organic matter in a Pinus roxburghii forest in Kumaun Himalaya. Peak values of fresh leaf litter, partially decomposed litter and wood litter on the forest floor occurred in April, May and September, respectively. The relative contribution of partially decomposed material to total forest floor biomass remained greatest throughout the annual cycle. The biomass of herbaceous vegetation was maximal in September with a total annual net production of 151 g m-2. The total annual litter fall was 895 g m-2, of which tree, shrub and herb litters accounted for 82.4%, 0.6%, and 16.8%, respectively. Annual nutrient return in kg ha-1 through litter fall amounted to 278.6 ash, 73.9 N, 5.5 P, 79.7 Ca, 15.1Mg, 20.7 K and 3.6Na. The turnover rate for tree litter was 48% and that for various nutrients on the forest floor ranged between 40-79%. © 1987 Dr W. Junk Publishers.
Accumulation, transfers and dissipation of energy in chir pine forests
(1991) O.P. Chaturvedi; J.S. Singh
Energy stored and net energy fixed at four sites of natural chir pine forest were assessed. Of the total energy stored by the vegetation (3836.6 GJ ha-1) 98.7% was in trees, 0.4% in shrubs and 0.9% in the herb layer. Net energy fixed by the vegetation was 318.5 GJ ha-1 yr-1 of which the shares of tree, shrub and herb layers were 84.7% 0.9% and 14.4%, respectively. The energy capture efficiency (photosynthetic radiation) of the vegetation was 1.07% (0.91% in trees, 0.01% in shrubs and 0.15% in herbs). Of the total transfer of energy to the forest floor through litter fall (142.7 GJ ha-1 yr-1 leaf litter and woody litter accounted for 68.4% and 31.6%, respectively. Energy stored in the above-ground biomass of the trees from 2877 ha or in the net annual above-ground production from 39,903 ha is sufficient to operate a 50 MW generating station for one year. Total biomass and net production from 1 ha of natural chir pine forest is sufficient to meet the energy need of an average household of western Himalaya for 61.1 and 4.4 years, respectively. © 1992.
The structure and function of pine forest in central himalaya. I. dry matter dynamics
(Oxford University Press, 1987) O.P. Chaturvedi; J.S. Singh
The present study deals with structure and function of four areas of Himalayan chir pine forest. Tree layer was monospecific on all sites with varied density and basal cover in the range of 540-1630 individuals per ha and 25·0-47·2 m2ha-1, respectively. Shrubs having low density were sparsely distributed. All allometric equations relating to biomass of different components, to circumference at breast height (cbh) were significant, with the exception of that for cone biomass. Total vegetation biomass (115-236 t ha-1) was distributed as 113-283 t ha-1 in trees. 0·56-0·82 t ha-1 in shrubs and 1·63-2·57 t ha-1 in herbs. Total forest floor biomass including herbaceous litter ranged between 9·6 and 13·6 t ha-1. Of the total annual litter fall (4·26-7·38 t ha-1), 60·3-75·1 per cent was distributed in leaf litter and 24·9-39·7 per cent in wood litter. Turnover rate of tree litter varied from 0·45 to 0·53, whereas rates for shrubs and herbs were assumed to 1. Net primary production of total vegetation ranged between 9·91 and 21·2 t ha-1 year-1, of which the contribution of trees, shrubs and herbs was 76·5- 88·1 per cent 0·6-1·8 per cent and 11·3-21·5 per cent, respectively. A compartment model of dry matter on the basis of mean data across sites was developed to show dry matter storage and flow of dry matter within the ecosystem. © 1987 Annals of Botany Company.
The structure and function of pine forest in central himalaya. II nutrient dynamics
(Oxford University Press, 1987) O.P. Chaturvedi; J.S. Singh
This paper elucidates nutrient dynamics in a pine forest, previously investigated for dry matter dynamics. The nutrient concentrations in different life forms were of the order: herb > shrub > tree whereas the standing state of nutrients were of the order: tree > shrub > herb. Soil, litter and vegetation respectively accounted for 38·1-82·2, 2·4-3·7 and 15·4-58·2 per cent of the total nutrients in the system. Considerable reductions (52-69 per cent) in concentrations of nutrient in needles occurred during senescence. The uptake of nutrients by vegetation, and also by different components with and without adjustment for internal recycling, has been calculated separately. Annual transfer of litter to the soil by vegetation was 76·21 N, 6·25 P, 57·24 Ca, 14·22 Mg, 19·92 K and 1·92 kg ha-1 Na. Turnover rate and turnover time for different nutrients ranged between 0·40-0·64 and 1·56-2·50 year, respectively. Compartment models for nutrient dynamics have been developed to represent the distribution of nutrient contents and net annual fluxes within the system. © 1987 Annals of Botany Company.