Browsing by Author "J.S. Singh"

Now showing 1 - 20 of 169

A -> X BAND SYSTEM OF SrF
(Indian Academy of Sciences, 1980) N.P. Singh; J.S. Singh
[No abstract available]
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 in Wood: A Nutrient-conserving Strategy of Tropical Forests
(1985) S.P. Singh; R.K. Khanna; J.S. Singh
[No abstract available]
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.
Analysis of Forest Land-use and Vegetation in a Part of Central Himalaya, Using Aerial Photographs
(1987) A.K. Tiwari; J.S. Singh
[No abstract available]
Analysis of woody vegetation of Corbett National Park, India
(Kluwer Academic Publishers, 1995) Ashok Singh; V.S. Reddy; J.S. Singh
The paper presents a detailed analysis of woody forest vegetation of Corbett National Park, at the foothills of Garhwal and Kumaun Himalaya. Twenty nine stands of tropical forest vegetation were studied. The vegetation consists of nine community types. Tree density was higher in Shorea robusta dominated communities and lowest in the Anogeissus latifolia-Acacia catechu community. Total tree basal cover was maximum in Shorea robusta dominated communities. Sapling and seedling regeneration was poor in Shorea robusta communities. Mallotus philippensis, Syzygium cumini and Diospyros tomentosa showed good regeneration both in sapling and seedling layers across the communities. Sapling and seedling species diversities showed negative relation with total tree basal cover. Most of the dominant tree species exhibited significant positive relationship between tree height and circumference at breast height in all the communities. © 1995 Kluwer Academic Publishers.
Application of landscape ecology and remote sensing for assessment, monitoring and conservation of biodiversity
(2010) J.S. Singh; P.S. Roy; M.S.R. Murthy; C.S. Jha
Landscape ecology, inter alia, addresses the question as to how altered landscape patterns affect the distribution, persistence, and abundance of a species. Landscape ecology plays an important role in integrating the different scales of biodiversity from habitat patch to biome level. Satellite remote sensing technology with multi-sensor capabilities offers multi-scale information on landscape composition and configuration. Advances in geospatial analytical tools and spatial statistics have improved the capability to quantify spatial heterogeneity. Globally, landscape level characterization of biodiversity has become an important discipline of science. Considering the vast extent, heterogeneity, and ecological and economic importance of forest landscapes, significant efforts have been made in India during the past decade to strengthen landscape level biodiversity characterization. The generic frame work of studies comprises preparation of national databases providing information on composition and configuration of different landscapes using multi-scale remote sensing techniques, understanding the landscape patterns using geospatial models to elicit disturbance and diversity patterns and application of this information for bioprospecting and conservation purposes. Studies on hierarchical linkage of multi-scale information to study the processes of change, landscape function, dynamics of habitat fragmentation, invasion, development of network of conservation areas based on the understanding of multi-species responses to landscape mosaics, macro-ecological studies to understand environment and species richness, habitat and species transitions and losses, landscape level solutions to adaptation and mitigation strategies to climate change are a few of the future challenges. The paper presents the current experiences and, analyses in conjunction with international scenario and identifies future challenges of Indian landscape level biodiversity studies. © 2010 Indian Society of Remote Sensing.
Assessment of habitat features modulated carbon sequestration strategies for drought management in tropical dry forest fragments
(Elsevier B.V., 2024) R.K. Chaturvedi; Anshuman Tripathi; Rajiv Pandey; A.S. Raghubanshi; J.S. Singh
Habitat features, such as species diversity, functional diversity, tree size, disturbances and fragment sizes have differential impacts on carbon (C) storage and C-sequestration in forest ecosystems. Present study attempted to understand the tree strategies for modulating C-sequestration capacity across tropical dry forest fragments with variable edge distances. We evaluated the differences between drought strategies (i.e., drought avoiding and drought tolerant) for variations in stem density, relative growth rate (RGR), C-storage and C-sequestration, species diversity, functional diversity, tree size and disturbance indicators along edge distance gradient, besides analyzed the differences between drought strategies for responses of C-storage and C-sequestration to variations in species diversity, functional diversity, tree size and disturbance indicators. Various traits and functional indices were analyzed using standard statistical techniques. For total trees and for the two drought strategies, generalized linear modeling results showed a significant decline in stem density, RGR, C-stock, C-sequestration, species diversity, functional diversity and tree size indicators, while a considerable increase in disturbance indicators, along decreasing edge distance across the fragments. The drought strategies exhibited a high degree of variation in the slope of associations for above variables with edge distance across fragments. For predicting C-sequestration, structural equation modeling results showed highly significant influence of functional diversity indicators for drought avoiding strategy, while species diversity indicators were strongly significant for drought tolerant strategy. Moreover, fire index and drought index were critical predictors for C-sequestration for drought avoiding and drought tolerant strategies, respectively. This study provide inputs to understand the largely ignored processes of C-storage and C-sequestration in fragmented forests, which are currently prevalent due to heavy anthropogenic pressures. Our findings are useful for forest managers to understand vegetation responses to interactions of species diversity, functional diversity, tree size and disturbance indicators, for predicting the stability of larger fragments and for planning restoration of smaller fragments. © 2024 Elsevier B.V.
Asymptotic models of species-area curve for measuring diversity of dry tropical forest tree species
(2003) R. Sagar; A.S. Raghubanshi; J.S. Singh
In a dry tropical forest, we examine the fitness and predictability of two non-asymptotic models (log-linear and power) of species-area curve, and the effect of sample location and scale on their regression-derived coefficients (c, z) for measuring tree diversity. Results indicate that, the log-linear model relatively better fits the data set, and yields better prediction of number of species on a small scale (i.e. predicted number of species for 3 ha using an equation based on 1 ha data). On the other hand, predictions from power function model for a larger area (i.e. predicted number of species for 15 ha using 1 ha and 3 ha equations) were closer to the observed values. The suitability of the model to fit the data was strongly influenced by the site and the scale of the plot size. The equations for the two models derived from data of small area (1 ha plot size) yielded inconsistent results, but those derived from a larger plot size (3 ha) consistently underestimated the number of species for 15 ha. The underestimation by power function model was lower compared to that by log-normal model for predicting the number of tree species. The study also shows that the coefficient z is site- as well as scale-dependent. The coefficient c can be used to predict α-diversity, and the number of species per individual can adequately describe the coefficient z. The results support discrete community concept for the dry tropical forests along a disturbance gradient and indicate that higher the z, greater would be the impact of harvest of individuals on biodiversity.
Biomass estimation of dry tropical woody species at juvenile stage
(2012) R.K. Chaturvedi; A.S. Raghubanshi; J.S. Singh
Accurate characterization of biomass in different forest components is important to estimate their contribution to total carbon stock. Due to lack of allometric equations for biomass estimation of woody species at juvenile stage, the carbon stored in this forest component is ignored. We harvested 47 woody species at juvenile stage in a dry tropical forest and developed regression models for the estimation of above-ground biomass (AGB). The models including wood-specific gravity (ρ) exhibited higher R 2 than those without ρ. The model consisting of ρ, stem diameter (D), and height (H) not only exhibited the highest R 2 value but also had the lowest standard error of estimate. We suggest that ρ-based regression model is a viable option for nondestructive estimation of biomass of forest trees at juvenile stage. Copyright © 2011 R. K. Chaturvedi et al.
Biomass, net primary production and impact of bamboo plantation on soil redevelopment in a dry tropical region
(1999) Anand Narain Singh; J.S. Singh
Growth and impact of a bamboo (Dendrocalamus strictus (Roxb.) Nees) plantation on mine spoil in a dry tropical region were examined. Culm dynamics, biomass, net primary production, soil microbial biomass and N-mineralization were estimated at ages 3, 4, and 5 years. The recruitment of culm population varied between 18% and 36% and shoot mortality from 6-7% per year. Net accumulation of green culms during 3rd and 4th year was 3999 and between 4th and 5th year 10854 ha-1. Total biomass was 46.9 t ha-1 in the 3-year old to 74.7 t ha-1 in the 5-year old plantation with 35% occurring belowground. Total net primary production (NPP) ranged between 20.7 t ha-1 (3-year old) and 32.0 t ha-1 (5-year old), of which aboveground net production was 17.0 to 24.7 t ha-1 (between 3 to 4, and 4 to 5 years, respectively). Accounting for only 14% of the total biomass, foliage contributed 36% to NPP. Nutrient deposition through leaf litter was 45-79 kg N and 6-11 kg P ha-1. Litter bag experiment indicated 235 days for 50% and more than 1000 days for 95% decomposition. Amounts of N and P deposition and release increased with the age of the plantation. Rate of N-mineralization increased from 3.3 (3 years) to 6.9 μg g-1 month-1 (5 years). The proportion of mineralized-N converted into nitrate decreased with age. Soil microbial C increased from 127-319, microbial-N from 19-38 and microbial-P from 9-16 μg g-1 soil between 3 to 5 years. With increasing age of plantation, a greater proportion of soil C, N and P tended to be immobilized in soil microbial biomass. Net primary production and the soil redevelopment process exhibited a positive feed-back relationship.
Carbon and phosphorus in the soil biomass of some tropical soils of India
(1988) S.C. Srivastava; J.S. Singh
Microbial biomass C and P were measured for six tropical soils. Biomass C ranged from 149 to 667 μg g-1 soil and biomass P from 17 to 35 μg g-1 soil and the two were linearly related with the soil biomass having a mean P concentration of 3.5%. Soil biomass accounted for 2.5-5.6% of total soil organic C and 9.2-19.2% of the total soil organic P. The amount of biomass P was positively related with NaHCO3-extraclable soil inorganic P. P concentration in biomass on the other hand exhibited an inverse relationship with NaHCO3-extractable soil Pi. © 1988.
Carbon density and accumulation in woody species of tropical dry forest in India
(2011) R.K. Chaturvedi; A.S. Raghubanshi; J.S. Singh
We studied the carbon density and accumulation in trees at five sites in a tropical dry forest (TDF) to address the questions: how is the TDF structured in terms of tree and carbon density in different DBH (diameter at breast height) classes? What are the levels of carbon density and accumulation in the woody species of TDF? Is the vegetation carbon density evenly distributed across the forest? Does carbon stored in the soil reflect the pattern of aboveground vegetation carbon density? Which species in the forest have a high potential for carbon accumulation? The WSG among species ranged from 0.39 to 0.78gcm-3. Our study indicated that most of the carbon resides in the old-growth (high DBH) trees; 88-97% carbon occurred in individuals ≥19.1cm DBH, and therefore extra care is required to protect such trees in the dry forest. Acacia catechu, Buchanania lanzan, Hardwickia binata, Shorea robusta and Terminalia tomentosa accounted for more than 10tha-1 carbon density, warranting extra efforts for their protection. Species also differed in their capacity to accumulate carbon indicating variable suitability for afforestation. Annually, the forest accumulated 5.3t-Cha-1yr-1 on the most productive, wettest Hathinala site to 0.05t-Cha-1yr-1 on the least productive, driest Kotwa site. This study indicated a marked patchy distribution of carbon density (151t-Cha-1 on the Hathinala site to 15.6t-Cha-1 on the Kotwa site); the maximum value was more than nine times the minimum value. These findings suggest that there is a substantial scope to increase the carbon density and accumulation in this forest through management strategies focused on the protection, from deforestation and fire, of the high carbon density sites and the old-growth trees, and increasing the stocking density of the forest by planting species with high potential for carbon accumulation. © 2011 Elsevier B.V.
Carbon fluxes and species diversity in grazed and fenced typical steppe grassland of Inner Mongolia, China
(Oxford University Press, 2017) R. Sagar; G.Y. Li; J.S. Singh; Shiqiang Wan
Grasslands are dominant vegetation of China, support outstandingbiodiversity and sequester bulk amount of atmospheric CO2. Thesegrasslands are highly degraded and fragmented due to remarkableanthropogenic and grazing loads. Chinese Government has madegreat attempt to restore by grazing exclusion. The relations of carbonfluxes with species composition and diversity in the communitiessensitive to grazing by large herbivores are needed to be analysedunder the global climate change scenario. The objective of presentstudy was to comprehend the effects of grazing and fencing on theecosystem structure and function of the typical steppe grassland.MethodsTo meet the objectives, overgrazed and fenced (since year 2001) systemswere selected in typical steppe grassland at the DuolunRestoration Ecology Research Station, Inner Mogolia, China. Withineach system, three dominant communities with three replicateswere selected. In each replicate community, three 1 × 1 m plots,were randomly located. Each plot was divided into four 50 × 50 cmquadrats. A total of 216, 50 × 50 cm quadrats were sampled. Fromeach quadrat, number of individuals and above-ground herbaceousbiomass for each species, soil respiration (SR), ecosystem respiration(ER), net (NEE) as well as gross (GEE) ecosystem CO2 exchangeswere recorded in June 2015. Data were well analysed usingstatistical software. Canonical correspondence analysis showed differentialresponses of communities to the structure and function ofthe typical steppe grassland.Important FindingsAcross the communities, fencing reduced the soil temperatureby 12% and at the same time increased the soil moisture by44.30%, thus, increased the species richness by 28%, evenness by21%, above-ground biomass by 19% and plant carbon by 20%.Interestingly, fencing increased NEE by 128%, GEE by 77%, SR by65% and ER by 39%. Under fencing, species composition partiallygoverned the CO2 exchange processes.ConclusionsFencing reduces soil temperature and thereby improves speciesdiversity and more efficient CO2 sequestration and long-term andin-depth study is desirable for a better understanding of the relationshipbetween species diversity and ecosystem carbon uptake. © The Author(s) 2017. Published by Oxford University Press on behalf of the Institute of Botany, Chinese Academy of Sciences and the Botanical Society of China. All rights reserved.
Carbon Storage and Carbon Dioxide Sequestration by Urban Tree Cover: Case Study From Varanasi, India
(Springer, 2022) Ashutosh Kumar Singh; Vivek Kumar Nair; Hema Singh; Rohit Kumar Mishra; J.S. Singh
Increasing number of urban settlements is a major contributor to global climate change and has resulted into rising sea level, increasing the frequency of floods and droughts and ultimately decreasing human well-being. Urban areas are likely to account for 68 per cent of the world’s population by 2050, which will result in extensive environmental degradation and ecological destruction. They are considered the major source of carbon emissions because anthropogenic activities such as the heating of domestic spaces and vehicular emissions are concentrated in urban areas. Tree populations in urban areas have a tremendous potential to mitigate emissions through carbon sequestration. However, only a few studies on the quantification of carbon stock in urban vegetation are so far available. There is therefore an urgent need to quantify the amount of sequestered carbon in urban tree cover for better monitoring and management of regional carbon stock. In the present study, we explore the potential of carbon dioxide sequestration in trees at a few sites in the heavily populated city of Varanasi. Our study shows that the carbon stock in both above-ground and below-ground biomass in different sites averaged 1901 metric tonnes of carbon per hectare, with carbon dioxide sequestration of 6977 tonnes per hectare. This indicates that urban tree plantations have a significant potential to sequester anthropogenic carbon locally at source and to stock it in their biomass for long periods of time. Some key recommendations regarding the expansion of urban green cover and the planting of fast-growing native species are offered, in order to enhance carbon dioxide sequestration. © 2022, The National Academy of Sciences, India.
Changes in forest cover in a Central Himalayan catchment: Inadequacy of assessment based on forest area alone
(Academic Press, 1997) S.K.S. Rathore; S.P. Singh; J.S. Singh; A.K. Tiwari
The Central Himalayan region experiences severe ecological problems as a result of continuous deforestation, which threatens the subsistence population of the region. In the present study, changes in the forest cover of a catchment over a period of 16 years have been quantified. Baliya catchment (7783 ha) contains 2865.47 ha of different types of forest, i.e. sal (Shorea robusta), mixed sal, pine (Pinus roxburghii), pine-mixed broadleaf, mixed oak (Quercus spp.), cupressus (Cupressus torulosa). The process of fragmentation has been studied through changes in forest area and biomass. There has been a sharp decline in biomass, although only a marginal reduction in forest area (3.5%) has occurred. Decline in the stocking density has also been substantial. Forest area with higher crown cover (> 60%) declined from 736.32 ha to 292 ha during 1971-1989, indicating the intensity of human interference.
Changes in vegetation and soil during succession following landslide disturbance in the central Himalaya
(1993) V.S. Reddy; J.S. Singh
Recovery of soil properties, species sequence and changes in plant biomass following landslide damage were studied on 19 sites adjacent to oak (oak zone) and pine (pine zone) forests in the central Himalaya. Fine soil content, organic C and soil nutrients (N, P, Ca and K) increased with age in a non-linear manner. The changes in the soil properties were more rapid in early stages than in later stages. Annuals dominated the sites in early stages of succession. The herb species content and cover increased with age and were positively related with fine soil content and total soil nitrogen. In the oak zone sites, seedlings of pioneer tree species appeared from 6 years, while seedlings of climax oak species appeared after 15 years. On the other hand, seedlings of Pinus roxburghii appeared soon after disturbance in the pine zone, and the species persisted throughout the developmental stages. The process of succession corresponded to the tolerance model and the resource ratio hypothesis in the oak zone and to an inhibition model in the pine zone. Nomenclature follows Osmaston and Naithani). © 1993 Academic Press, Inc.
Changes with time in soil biomass C, N and P of mine spoils in a dry tropical environment
(1989) S.C. Srivastava; A.K. Jha; J.S. Singh
The data suggest that microbial biomass can be taken as a functional index of soil redevelopment. -from Authors
Comparative growth behaviour and leaf nutrient status of native trees planted on mine spoil with and without nutrient amendment
(Academic Press, 2001) Arvind Singh; J.S. Singh
The effect of nutrient amendment on growth of nine indigenous tree species planted on coal mine spoil was studied. Greater growth in fertilized plots was accompanied by greater foliar N and P concentrations in all species. The response to fertilization varied among Species and was greater in non-leguminous than in leguminous species. Furthermore, leguminous species exhibited higher growth rates compared to non-leguminous species. The log-transformed height-diameter relationships were significant for all tree species and treatments. Acacia catechu, Dalbergia sissoo, Gmelina arborea and Azadirachta indica fitted the elastic similarity model of tree growth; whereas Pongamia pinnata and Phyllanthus emblica followed the constant stress model. Tectona grandis was the only species which fitted the geometric similarity model. In Albizia lebbeck and Terminalia bellirica, the b-values (the gradients of the log-transformed height to diameter relationships) were considerably lower (<0.5), and these two species did not fit any model of tree growth. In several cases, the b-values were considerably influenced by nutrient amendment. The log-transformed crown mass and trunk mass relationships were Significant for all treatments and species. The slope of the crown mass:trunk mass relationship was near unity in A. indica, D. sissoo, G. arborea, P. emblica, P. pinnata, T. grandis, and T. bellirica. However, in A. catechu and A. lebbeck, this slope was well below unity suggesting a greater allocation to non-photosynthetic tissue. Fertilizer amendment resulted in a heavier crown relative to trunk in A. indica, T. grandis and T. bellirica. © 2001 Annals of Botany Company.
Comparative performance and restoration potential of two Albizia species planted on mine spoil in a dry tropical region, India
(2004) A.N. Singh; A.S. Raghubanshi; J.S. Singh
This study focussed on the comparative impact of young high density plantations of two Albizia species (Albizia lebbeck and Albizia procera) on the soil redevelopment process during early phase of mine spoil restoration in a dry tropical environment. Plant-hostile features such as high levels of pyrites, etc. were not present. We compared vegetational (biomass, net primary production (NPP), production efficiency, litter fall and its decomposition rate) and soil characters (soil nutrients, microbial biomass and N-mineralization rate) for these plantations. The A. lebbeck plantation accumulated greater biomass and exhibited higher net primary production than the A. procera plantation. The tree layer NPP of A. lebbeck plantation at 6 years age (25.4 t ha-1 years-1) was even higher than that of native dry deciduous forest. The short-lived components (foliage, fine roots) accounted for a greater proportion of ecosystem function (productivity) than the long-lived component (stem). The efficiency of foliage for NPP was greater in A. lebbeck than in A. procera. Decomposition of leaf litter of A. lebbeck was faster than that of A. procera. Ninety five percent mass loss of leaf litter would require 922 days in A. lebbeck and 1328 days in A. procera. Amounts of N and P deposition through leaf fall and release of these nutrients increased with the age of plantation in both species but were higher for A. lebbeck plantation. There was a significant improvement in soil properties due to plantation of both species, but the organic C and kjeldahl N levels were higher in A. lebbeck plantation as were the N-mineralization rates and soil microbial biomass. The proportional increase in soil biomass was much higher than that in soil organic C. The study indicated that the restoration efficiency of A. lebbeck was greater than that of A. procera. © 2004 Elsevier B.V. All rights reserved.