ID: 54232
Title: High fluoride incidence in groundwater and its potential health effects in parts of Raigarh District, Chhattisgarh, India
Author: M K Beg, S K Srivastav, E J M Carranza and J B de Smeth
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 5, 10 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Fluoride, groundwater, health-risk, preventive measures
Abstract: High concentrations of fluoride (F-) in drinking water are harmful to human health. Knowledge of spatio-temporal distribution of F- content in groundwater is thus a prerequistic for taking preventive measures. This communication reports F- incidence in ground water and its relation with the prevalence of fluorosis in Tamnar area, Raigarh District, Chhattisgarh, India. Nearly 18% of the sampled wells had F- concentrations above the desirable limit (>1.0 mg/l), the highest value being 8.8 mg/l. High F- concentrations primarily occurred in coal-bearing Barakar Formation of the Gondwana Supergroup. Prevalence of dental fluorosis was observed in five villages, viz. Dholnara, Kunjhemura, Muragaon, Pata and Saraitola; whereas skeletal fluorosis was found to occur only in Muragaon. The spatial distribution of F- in groundwater, as indicated by hydrogeochemical analyses, corroborated well with the prevalence of dental and skeletal fluorosis. It is envisaged that, in addition to the people already affected, a large fraction of the population in the area is at potential risk, especially considering that the region falls in the coal mining and industrial belt. The health -risk map prepared using a Geographic Information System provides baseline information in taking mitiagation measures.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54231
Title: Biomass production and carbon stock of poplar agroforestry systems in Yamunanagar and Saharanpur districts of northwestern India
Author: R H Rizvi, S K Dhyani, R S Yadav and Ramesh Singh
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 5, 10 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Agroforestry, biomass, carbon stock, carbon dioxide assimilation, poplar
Abstract: Poplar (Populus deltoides) has gained considerable importance in agroforestry plantations of western Uttar Pradesh, Uttarakhand, Haryana, Punjab, and Jammu and Kashmir due to its deciduous nature, fast growth, short rotation and high industrial requirement. Poplar-based agroforestry systems are prevalent among farmers of Sharanpur (UP) and Yamunanagar (Haryana) districts of northwestern India. These systems are not only remunerative to the farmers, but also play an important role in the assimilation of atmospheric carbon dioxide in the form of biomass carbon stocks. An assessment of carbon storage vis-a-vis CO2 assimilation by poplar plantations in agroforestry has been made for these two districts. Contribution of poplar plantations to carbon storage was found to be 27-32 t ha-1 in boundary system, whereas it was 66-83 t ha-1 in agrisilviculture system at a rotation period of 7 years in the two districts. Thus, poplar plantations make important contributions towards atmospheric CO2 assimilation and hence play a significant role in the mitigation of atmospheric accumulation of greenhouse gas.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54230
Title: Patterns of diversity and conservation status of freshwater fishes in the tributaries of River Ramganga in the Shiwaliks of the Western Himalaya
Author: V M Atkore, K Sivakumar and A J T Johnsingh
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 5, 10 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Conservation, fish diversity, river ecology, species richness
Abstract: A short study was undertaken from December 2004 to April 2005, to assess the species diversity and composition of freshwater fishes in three tributaries of Ramganga river in the foothills of Western Himalaya. One tributary was within a protected area (PA; Corbett National Park); the other two were outside the PA (Lansdowne Forest Division). Cast nets were used for fish sampling, which was done from 9.00 a m to 5.00 p m.
In total, 43 species belonging to eight families and five orders were recorded which included 29 species belonging to the threatened category. Family Cyprinidae was represented by the maximum number of species. Species richness and diversity was high in the PA. Similarity in fish composition varied from 60% to 70% across the tributaries. Dynamiting, poisoning and diverting water flows to collect fish are the major threats. Creating awareness, controlling illegal fishing and protecting the breeding grounds of fishes are some of the measures recommended to counter these threats.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54229
Title: Trends in global solar photovoltaic research: silicon versus non-silicon materials
Author: Bikramjit Sinha
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 5, 10 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Amorphous silicon, cadmium telluride, crystalline silicon, dye-sensitized solar cells, gallium arsenide
Abstract: This article reports a comparative analysis of the thrust in solar photovoltaic (PV) research during 1981-1988 and 2001-2008. Global solar PV literature in the latter period recorded a 4.5-fold increase over those in 1981-1988. The USA leads all the countries in terms of absolute number of publications as is the case in other areas of basic sciences. But its relative activity in solar PV research in terms of transformative activity index (TAI) values has decreased from 1.8 in 1981-1988 to 0.9 in 2001-2008. The performance of National Renewable Energy Laboratory of USA, the top institute is similar to its national trend, i.e. increase in absolute number and decrease in TAI. Presence of 3 German institutes in the top 10 institutes is an indication of Germany ' s emphasis as well as the leadership in global solar PV research. The Share of silicon-based papers as percentage of total solar PV publication has decreased from around 36% in 1981- 1988 to 34% in 2001-2008. The share of non-silicon-based publication has increased from 9% in 1981-1988 to 17% in 2001-2008. Within silicon, the emphasis is still on crystalline silicon while among non-silicon materials, the growth of dye-sensitized solar cells output is outstanding. The developments especially in the areas of non-silicon solar PV cells, thus, raise hopes of the possibility of developing cost-effective and more efficient solar cells.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54228
Title: Space and time in language as a pattern in general fictivity
Author: Samir Karmakar and Rajesh Kasturirangan
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 5, 10 March 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Spatial expression, temporal expressions
Abstract: Systematic parallelism between spatial and temporal expressions in a language is conceived here as a pattern in general fictivity arising from an underlying cognitive manifold. Under this situation, we try to articulate some of the questions pertinent to the spatial and temporal cognition from the viewpoint of patterns in general fictivity.
Location: 241
Literature cited 1: None
Literature cited 2: None
ID: 54227
Title: An assessment of sample-based estimators of tree species richness in two wet tropical forest compartments in Panama and India
Author: S Magnussen, R Pelissier, F. He and B R Ramesh
Editor: Pierre Couteron
Year: 2007
Publisher: French Institute of Pondicherry, April 2007
Source: Centre for Ecological Sciences
Reference: None
Subject: Forest stand dynamics in the wet evergreen natural forests of the Western Ghats of India-Compilation of publications of the French Institute of Pondicherry
Keywords: Probability of occurrence, variance estimator, sample coverage, sample size, plot size, mixed-models
Abstract: We assessed the performance of ten incidence-based estimators of tree species richness in simulated simple random sampling with fixed-area plots. Stem diameter-limited tree species and location data came from two species-rich wet tropical forest compartments in Panama and India. Lower limits of stem diameter were 1 cm and 30 cm, respectively. Estimators varied widely in their estimates of richness and their rankings changed frequently across sites and sample designs. A gamma-Poisson estimator was overall best according to a performance score of the three accuracy statistics and sample size. However, until corroborated by further studies, Chao ' s 1981 non-parametric estimator is recommended for forest inventories with fixed -area plots.
Location: Kumta
Literature cited 1: None
Literature cited 2: None
ID: 54226
Title: Sampling strategies for the assessment of tree species diversity
Author: Gimaret-Carpentier, Clementine, Pelissier, Raphael, Pascal, Jean-Pierre & Houllier, Francois
Editor: Pierre Couteron
Year: 2007
Publisher: French Institute of Pondicherry, April 2007
Source: Centre for Ecological Sciences
Reference: None
Subject: Forest stand dynamics in the wet evergreen natural forests of the Western Ghats of India-Compilation of publications of the French Institute of Pondicherry
Keywords: Alpha-diversity, Beta-diversity, Non -parametric estimator, rare species, Simpson ' s index, topography, tropical forest
Abstract: This paper aims at proposing efficient vegetation sampling strategies. It describes how the estimation of species richness and diversity of moist evergreen forest is affected by (1) sampling design (simple random sampling, random cluster sampling, systematic cluster sampling, stratified cluster sampling); (2) choice of species richness estimators (number of observed species vs.non-parametric estimators) and (3) choice of diversity index (Simpson vs Shannon). Two sites are studied:a 28 ha area situated in the Western Ghats of India and a 25 ha area located at Pasoh in Peninsular Malaysia. The results show that: (1) whatever the sampling strategy, estimates the species richness depend on sample size in these very diverse forest ecosystems which contain many rare species. (2) Simpson ' s diversity index reaches a stable value at low sample sized while Shannon ' s index is affected more by the addition of rare species with increasing sample size; (3) cluster sampling strategies provide a good compromise between cost and statistical efficiency: (4) 300-400 sample trees grouped in small clusters (10-50 individuals) are enough to obtain unbiased and precise estimates of Simpson ' s index; (5) the local topography of the Western Ghats has a major influence on forest composition, the steep slopes being richer and more diverse than the ridges and gentle slopes; (6) stratified cluster sampling is thus an interesting alternative to systematic cluster sampling.
Location: Kumta
Literature cited 1: None
Literature cited 2: None
ID: 54225
Title: Topographic variation and stand heterogeneity in a wet evergreen forest of India
Author: Audrey Robert and Marie-Agnes Moravie
Editor: Pierre Couteron
Year: 2007
Publisher: French Institute of Pondicherry, April 2007
Source: Centre for Ecological Sciences
Reference: None
Subject: Forest stand dynamics in the wet evergreen natural forests of the Western Ghats of India-Compilation of publications of the French Institute of Pondicherry
Keywords: Diameter distributions, diameter growth, spatial patterns, topography, tree height
Abstract: We investigated the links between slope variation and heterogeneity in tree growth and stand structure. The study was conducted in an undisturbed wet evergreen forest in India. We selected three plots situated on gently slopes and three plots situated on steep slopes. Tree growth was considered as mean annual diameter increment. Stand structure was considered in relation to several characteristics: trunk diameter distributions, tree heights, and spatial distributions of stems and crowns. Except for the spatial structure, analyses were performed on samples including either all the species or only the dominant species (Vateria indica L). Diameter growth varied according to slope intensity and to tree size: growth of large trees was clearly higher on steep slopes whereas growth of small trees proved lower or similar. Diameter distributions were different among the six plots, but the difference cannot be related to slope intensity. On the contrary, tree heights differed according to slope intensity: for a given diameter, trees were taller on gently slopes than on steep slopes. Finally, stem spatial distribution showed strong regularity on gentle slopes whereas they were random on steep slopes. The observed changes between gentle and steep slopes suggest differences at tree level through a modification of its shape, but also differences in the major processes responsible for stand dynamics: competition, establishment and survival.
Location: Kumta
Literature cited 1: None
Literature cited 2: None
ID: 54224
Title: Simulation of the effect of topography and tree falls on stand dynamics and stand structure of tropical forests
Author: Audrey Robert
Editor: Pierre Couteron
Year: 2007
Publisher: French Institute of Pondicherry, April 2007
Source: Centre for Ecological Sciences
Reference: None
Subject: Forest stand dynamics in the wet evergreen natural forests of the Western Ghats of India-Compilation of publications of the French Institute of Pondicherry
Keywords: Individual-based model, slope, tree falls, crown asymmetry, spatial structure, tree growth
Abstract: Canopy gaps induced by tree falls have an important ecological role in forest communities since they act on forest sylvigenesis, dynamics and specific composition, mainly through modifications of the light context they involve. Some factors responsible for tree fall occurrences become more influent on sloping areas, particularly crown asymmetry. We have already shown in previous work (Robert, 2001) that slope also acts on the dynamics and structure of forests through the anisotropy of light it induces. In this paper we aim at investigating the consequences of tree falls of asymmetrical trees, and of canopy openness they create, combined with the increase of slope on tropical forest stands. We were particularly interested in the effects of slope and tree falls on tree growth, stand basal area, stand density and spatial structure of trees.
This study was achieved by means of an individual-based and distance-dependent model, taking into account competition for light and morphological constraints between trees. Inter-tree competitive relationships occurred at crown level and were illustrated by a synthetical index that partially depends on their elevation. Recruitment, growth and mortality of trees of the virtual stand were computed on the basis of yearly time. The mortality process consists of standing death and tree falls caused by the asymmetry of crowns.
The model shows that the effect of tree falls and of canopy gaps is more important than the effect of light anisotropy induced by slope. The presence of tree falls diminishes, and even inhibits, the positive effect of slope on competition for light. Furthermore, it totally prevents any slope effect on spatial structure of trees by maintaining it very regular. Finally, the occurrence of tree falls inverts slope effect on stand density and results in an impoverishment of trees on steep slopes.
Simulation results allow us to understand how the presence of canopy gaps on sloping areas participates in maintaining the phytosanitary quality of tropical stands. They also permit us to put forward the role of the presence of asymmetrical trees as a key parameter that conditions the effects of light anisotropy on forests on slopes.
Location: Kumta
Literature cited 1: None
Literature cited 2: None
ID: 54223
Title: A model to assess relationships between forest dynamics and spatial structure
Author: Moravie, Marie-Agnes & Robert, Audrey
Editor: Pierre Couteron
Year: 2007
Publisher: French Institute of Pondicherry, April 2007
Source: Centre for Ecological Sciences
Reference: None
Subject: Forest stand dynamics in the wet evergreen natural forests of the Western Ghats of India-Compilation of publications of the French Institute of Pondicherry
Keywords: Evergreen forest, India, Individual-based model, One-sided competition, Second density neighbourhood spatial analysis, Two-sided competition, wet forest
Abstract: A spatially explicit model was developed to study the relationships between the dynamics and spatial structure of forest stands. The objective was to test whether tree spatial structure can be used as an indicator of stand dynamics. The model simulates the growth, mortality and recruitment of trees in a multi-specific and uneven-aged stand. It includes deterministic and stochastic processes so that repeated simulations do not lead to the same stand but provide several possible results for a given dynamic (defined by a set of parameters). Second-order neighbourhood analyses were used to characterize the resulting spatial structures. They showed a high variability for a given set of parameters. Only the main trends in the spatial structure can be interpreted. Sensitivity analyses, concerning the influence of competition on spatial structure, showed that in heterogeneous stands confounding effects can hinder the interpretation of the spatial structure if all the trees are considered. The spatial structure of the canopy trees alone proved easier to interpret as it is directly linked to post recruitment competition. Inference on the dominant modality of competition (one-sided or two-sided) based on the spatial structure proved difficult.
Location: Kumta
Literature cited 1: None
Literature cited 2: None
ID: 54222
Title: A practical approach to the study of spatial structure in simple cases of heterogeneous vegetation
Author: Pelissier, Raphael & Goreaud, Francois
Editor: Pierre Couteron
Year: 2007
Publisher: French Institute of Pondicherry, April 2007
Source: Centre for Ecological Sciences
Reference: None
Subject: Forest stand dynamics in the wet evergreen natural forests of the Western Ghats of India-Compilation of publications of the French Institute of Pondicherry
Keywords: Local density function, Point pattern, Ripley ' s K-function, Second-order local neighbour density function
Abstract: Spatial heterogeneity is a characteristic of most natural ecosystem which is difficult to handle analytically, particularly in the absence of knowledge about the exogenous factors responsible for this heterogeneity. While classical methods for analysis of spatial point patterns usually require the hypothesis of homogeneity, we present a practical approach for partitioning heterogeneous vegetation plots into homogeneous subplots in simple cases of heterogeneity without drastically reducing the data. It is based on the detection of endogenous variations of the pattern using local density and second-order local neighbour density functions that allow delineation of irregularly shaped subplots that could be considered as internally homogeneous. Spatial statistics, such as Ripley ' s K-function adapted to analyse plots of irregular shape, can then be computed for each of the homogeneous subplots, Two applications to forest ecological field data demonstrate that the method, addressed to ecologies, can avoid misinterpretations of the spatial structure of heterogeneous vegetation stands.
Location: Kumta
Literature cited 1: None
Literature cited 2: None
ID: 54221
Title: Two-year tree growth patterns investigated from monthly girth records using dendrometer bands in a wet evergreen forest in India
Author: Raphael Pelissier and Jean-Pierre Pascal
Editor: Pierre Couteron
Year: 2007
Publisher: French Institute of Pondicherry, April 2007
Source: Centre for Ecological Sciences
Reference: None
Subject: Forest stand dynamics in the wet evergreen natural forests of the Western Ghats of India-Compilation of publications of the French Institute of Pondicherry
Keywords: Dendrometer bands, detrended growth profiles, seasonal growth variations, smoothed growth profiles, tropical wet evergreen forest, 2 yr growth trend, Western Ghats of India
Abstract: With the aim of characterizing tree growth patterns, this paper re-examines the growth data of 100 selected trees belonging to 24 species that were recorded monthly in a 0.2 ha plot of a wet evergreen forest in the Western Ghats of India during the period 1980-82 using dendrometer bands. The mean growth profile, combining all of the selected trees, showed; (a) a significantly lower annual growth rate during the second year of survey which seemed to be negatively related to monsoon precipitation; (b) significant intra-annual growth variation clearly related to the regular alternation between a period of heavy rain and a quite long dry season of the monsoon climatic regime. Analysis of the variability of the individual smoothed growth profiles representing the 2 yr trend of the growth data showed that : (a) the mean growth rate depended on a combination of an intrinsic endogenous variable (the structural class grouping species according to their maximum size), a tree size variable (tree diameter at breast height, dbh) and a neighbourhood variable (the number of taller neighbours in a 10-m radius); (b) the sudden change in growth rate from one year to the other was not predictable using these variables. The amplitude of the seasonal variations, investigated from the detrended growth profiles, appeared to be dependent on a combination of tree dbh and the number of taller neighbours in a 10 m radius. A co-inertia analysis of the smoothed and the detrended growth profiles indicated that the trees with fast growth also exhibited high seasonal variation. It is suggested that fast growing trees are those with favourable crown positions, which are consequently subject to high transpiration rates due to radiation and wind exposure.
Location: Kumta
Literature cited 1: None
Literature cited 2: None
ID: 54220
Title: Ecological meaning and predictive ability of social status, vigour and competition indices in a tropical rain forest (India)
Author: M A Moravie, M Durand, F Houllier
Editor: Pierre Couteron
Year: 2007
Publisher: French Institute of Pondicherry, April 2007
Source: Centre for Ecological Sciences
Reference: None
Subject: Forest stand dynamics in the wet evergreen natural forests of the Western Ghats of India-Compilation of publications of the French Institute of Pondicherry
Keywords: Competition indices, Dawkins code, Social status, Vateria indica, Tropical rain forest, India
Abstract: The aim of this paper is to assess and compare the ecological meaning and predictive ability of several competition indices, which belong to several types- tree vigour indices, tree social status indices, local density indices and spatial competition indices-and come from different disciplines-ecology, silviculture, growth and yield modeling. We consider the case of an upper canopy and light-demanding dipterocarp species, Vateria indica L. , which is frequent and endemic in the low to medium elevation moist evergreen forests of the Western Ghats in South India. Multivariate analyses showed that most indices are closely correlated with each other, as well as with tree size itself because they share common information on tree social status. Some indices bore additional information on local stand density that is independent from tree social status. The index that most accurately predicted diameter at breast height (dbh) increment in a modified version of the Dawkins code. This index can be assessed in the field without any complicated measurements but it requires preliminary training and regular cross-checking in order to ensure reproducibility across time and among observers. These results are consistent with those obtained on other light sensitive evergreen species in French Guiana. There is a need to generalize such studies to other species and forests and to better assess the meaning and predictive ability of competition indices in relation to the ecological behavior of the species.
Location: Kumta
Literature cited 1: None
Literature cited 2: None
ID: 54219
Title: Impact of selective logging on the dynamics of a low elevation dense moist evergreen forest in the Western Ghats (South India)
Author: Raphael Pelissier, Jean-Pierre Pascal, Francois Houllier, Henri Laborde
Editor: Pierre Couteron
Year: 2007
Publisher: French Institute of Pondicherry, April 2007
Source: Centre for Ecological Sciences
Reference: None
Subject: Forest stand dynamics in the wet evergreen natural forests of the Western Ghats of India-Compilation of publications of the French Institute of Pondicherry
Keywords: Dense moist evergreen forest, Growth, Mortality, Recruitment, Forest dynamics, Selective logging
Abstract: Within the framework of a programme on the functioning of dense moist evergreen forests of the Western Ghats, the French Institute of Pondicherry, in collaboration with the Karnataka Forest Department, installed permanent plots to monitor the dynamics of a low elevation forest. The preliminary results of the comparison of the demographic processes in two compartments are presented: one compartment had never been harvested, while the other was selectively felled in 1979-1980. They are compared in terms of species composition, recruitment, moratality and individual growth, in order to describe the natural forest dynamics and evaluate the impact of selective felling. In both compartments, the mortality rate, around 0.9% yr-1, is lower than in other tropical moist evergreen forests, while the average diameter increment, at 2.1(unlogged stand) and 2.9 mm yr-1 (logged stand), is higher. The impact of selective felling, 10 to 15 years after the harvest, is mainly noticeable: (i) on mortality of trees with dbh > 40 cm belonging to lower canopy and intermediate stratum species which died about four times more in the logged compartment; and (ii) on diameter increment of emergent and upper canopy tree species whose growth is still stimulated by about 50%. Despite the general trend of a reduction in the difference bewteen the density and the basal area of the two compartments, medium-term modification of the demographic processes among the various structural ensembles in the logged compartment, indicates that selective felling may not be sustainable in the long-term without consequences on the forest structure and composition.
Location: Kumta
Literature cited 1: None
Literature cited 2: None
ID: 54218
Title: Tree spatial patterns in three contrasting plots of a Southern Indian tropical moist evergreen forest
Author: Raphael Pelissier
Editor: Pierre Couteron
Year: 2007
Publisher: French Institute of Pondicherry, April 2007
Source: Centre for Ecological Sciences
Reference: None
Subject: Forest stand dynamics in the wet evergreen natural forests of the Western Ghats of India-Compilation of publications of the French Institute of Pondicherry
Keywords: Forest dynamics, forest mosaic, India, rainforests, spatial point patterns, spatial point processes, Western Ghats
Abstract: In a primary dense moist evergreen forest of southern India, spatial patterns of trees > 30 cm gbh were investigated from three contrasting 0.4 - ha plots that differed in topography and amount of disturbance due ot treefall. Exploratory data analysis is based on second-order neighbourhood and pair-correlation statistics used to describe the degree of clustering/regularity in patterns of all trees, and the degree of attraction/ repulsion between young trees and adults. Stochastic simulations from the Markov point process models are then used to fit spatial interaction models. The results show that spatial patterns can be related to particular dynamic proceses which depend on both exogenous and endogenous factors: on steep slopes disturbed by many treefalls, spatial pattern displays large clusters which can be interpreted as within-gap regeneration stages of various ages, while in areas undisturbed over a long period, interactions between young trees and adults give rise to spatial patterns consistent with substitution dynamic processes implying standing mortality rather than treefalls. Characterizing forest dynamics through spatial patterns of trees opens up the possibility of mapping structural units that might be considered as elementary functional patches of the forest mosaic.
Location: Kumta
Literature cited 1: None
Literature cited 2: None