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ID: 54195
Title: Effect of Himalayan topography on two-dimensional interpretation of magnetotelluric data
Author: G. Pavan Kumar and A Manglik
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 3, 10 February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Magnetotelluric data, mountainous regions, resistivity curves, topographic variations
Abstract: Magnetotelluric method is a powerful tool for deep crustal studies of tectonically active mountainous regions such as the Himalaya, where logistic constraints severely limit the use of other artificial source electrical and electromagnetic methods. Topographic variations in mountains regions distort apparent resistivity curves and thus lead to artefacts in interpreted models. In the present work, we have analysed a simplified two-dimensional (2D) model of the subsurface electrical resistivity structure along a profile in the Garhwal Himalaya for the effect of topography. The topography varies significantly along the profile between the foothills and the higher Himalaya. We first computed TE and TM-mode apparent resistivity and phase curves at various stations along the profile for a model with topography and then inverted these datasets for two cases. In the first case the surface of the earth was assumed to be flat, whereas in the second case the actual topography was included in the model. The results suggest that the interpreted model assuming flat earth is similar to the one obtained by including topography in the model. Inclusion of 10% Gaussian noise to the synthetic data does not change these results. Thus, we infer that the effect of 2D topography is not prominent in the 2D interpretation of the selected Garhwal Himalaya profile.
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54194
Title: Seasonal prediction of the Indian monsoon
Author: Sulochana Gadgil and J Srinivasan
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 3, 10 February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Atmospheric models, Indian summer monsoon, seasonal prediction, simulation
Abstract: Under the project ' Seasonal Prediction of the Indian Monsoon ' (SPIM), the prediction of Indian summer monsoon rainfall by five atmospheric general circulation models (AGCMs) during 1985-2004 was assessed. The project was a collaborative effort of the coordinators and scientists from the different modelling groups across the country. All the runs were made at the Centre for Development of Advanced Computing (CDAC) at Bangalore on the PARAM Padma supercomputing system. Two sets of simulations were made for this purpose. In the first set, the AGCMs were forced by the observed sea surface temperature (SST) for May-September during 1985-2004. In the second set, runs were made for 1987, 1988, 1994, 1997 and 2002 forced by SST which was obtained by assuming that the April anomalies persist during May-September. The results of the first set of runs show, as expected from earlier studies, that none of the models were able to simulate the correct sign of the anomaly of the Indian summer monsoon rainfall for all the years. However, among the five models, one simulated the correct sign in the largest number of years and the second model showed maximum skill in the simulation of the extremes (i.e. droughts or excess rainfall years). The first set of runs showed some common bias which could arise from an excessive sensitivity of the models to El Nino Southern Oscillation (ENSO) or an inability of the models to simulate the link of the Indian monsoon rainfall to Equatorial Indian Ocean Oscillation (EQUINOO), or both. Analysis of the second set of runs showed that with a weaker ENSO forcing, some models could simulate the link with EQUINOO, suggesting that the errors in the monsoon simulations with observed SST by these models could be attributed to unrealistically high sensitivity to ENSO.
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54193
Title: Leaf traits and herbivory as indicators of ecosystem function
Author: Prajjwal Dubey, Gyan P Sharma, A S Raghubanshi and J S Singh
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 3, 10 February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Grazing, litter decomposition, nutrient dynamics, plant functional types
Abstract: Plant functional types bridge the gap between plant physiology and ecosystem processes. In the present article, we review the plant functional traits and their response to grazing, and discuss how this affects the nutrient dynamics of the system under the pressure of herbivory. The results also strengthen the management of ecosystems being grazed by herbivores.
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54192
Title: Role of cyclones and other factors in the decline of the ports of northern Orissa
Author: Sila Tripati and A S Unnikrishnan
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 3, 10 February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Cyclones, east coast of India, Orissa, ports, siltation, storm surges, tidal range
Abstract: The maritime trade of Orissa with transoceanic countries is evident from the early historical period onwards. It has been observed that new ports were set up after the decline of old ports in the nearby vicinity; however, information on the decline of ancient ports is very sparse. The archival and historical records of the 16th and 19th centuries and the writings of contemporary scholars mention the ports of northern Orissa, viz., Balasore, Dhamra, Pipli, Chandbali, Laichanpur, Churamani and False Point, and their decline because of the shifting of the power centre, heavy taxation, bribes and sometimes due to natural forces such as siltation, formation of sandbars and cyclones. The devastating cyclones which occurred along the Orissa coast between 1823 and 1900 caused enormous loss of human lives and property and destroyed the ports and port structures. The role of cyclones in the decline of these ports is scarcely mentioned in contemporary literature. Occurrences of storm surges durign cyclonic events combined with the relatively large tidal ranges present along the Orissa coast caused tremendous destruction in the coastal area. In this article, an attempt has been made to study the decline of the ports of northern Orissa between Paradip and Sagar and to understand the various causative factors such as cyclones, storm surges and siltation, besides anthropogenic factors.
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54191
Title: Dumortierite from Susunia Hill, Bankura District, West Bengal, India
Author: Samiran Mahapatra and Aniket Chakrabarty
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 3, 10 February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54190
Title: Biodiversity access and benefit-sharing: weaving a rope of sand
Author: K D Prathapan and Priyadarsanan Dharma Rajan
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 3, 10 February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54189
Title: Mutualism of spider crab, Doclia ovis (Herbst, 1790) in Indian waters
Author: Prasanna Yennawar and Prasad Tudu
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 3, 10 February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54188
Title: Conflict between development and the environment
Author: K Kesava Rao
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 3, 10 February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54187
Title: Collaborative studies on the fauna of the Western Ghats-Sri Lanka biodiversity hotspot
Author: Suresh P Benjamin
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 3, 10 February 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: None
Abstract: None
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54186
Title: A decision tree analysis for predicting the occurrence of the pest, Helicoverparmigera and its natural enemies on cotton based on economic threshold level
Author: M Pratheepa, K Meena, K R Subramaniam, R. Venugopalan and H Bheemanna
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 2, 25 January 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Chrysoperla carnea, cotton, decision tree, economic threshold level, Helicoverpa armigera
Abstract: The cotton bollworm, Helicoverpa armigera (Hubner) is one of the most important pests affecting crop production globally. The data-mining technique, for predicting pest incidence using biotic and abiotic factors has been developed so far. To identify the biotic and abiotic factors that play a role in the occurrence of the pest, the decision tree analysis in conjunction with Shannon information measure was explored. The developed classification model has the ability to successfull treat ' categorical ' variables as well as ' continuous ' variables in the database. The information - theoretic classification method used in the present study was aimed at finding a minimal set of database attributes involved in the induced model and was successfull in predicting pest incidence. It was found that there was 8.82% misclassified testing data. The confusion matrix for the testing set revealed that the classification was done more accurately using the training set. The developed prediction or classification model will be helpful in forewarning about pest incidence and also to identify the factors influencing the pest population density. Using this model, agricultural farmers can apply pest control strategies on time to reduce crop loss.
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54185
Title: Using MASW to map depth to bedrock underneath Dehradun fan deposits in NW Himalaya
Author: A K Mahajan and Nitesh rai
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 2, 25 January 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Bedrock, fan deposits, multichannel analysis, shear wave velocity, surface waves
Abstract: Dun Valley is an intermontane valley located within the Siwalik foreland basin in Garhwal Himalayan. With the evolution of Dun Valley, Dun gravels and post-Siwalik formations were deposited in this valley in the form of fan deposits. Earlier information on the thickness of Dun gravels in the Dehradun fan and bedrock depth level was based on stratigraphy studies and estimated to be 600 m. Later, based on tube-well boring and field observations, the thickness of the Dun gravels has been revised to 100-300 m. In the present communication, shear wave velocity (Vs) field has been calculated using multichannel analysis of surface waves (MASW), surveyed using 4.5 Hz frequency geophones with Elastometer-aided weight drop hammer as a source. This enabled us to map the thickness of the Dun gravels and the depth to bedrock underneath the Dehradun fan deposits as 35 m in the northern flank of the syncline, 140 m in the centre of the broad syncline and 90 m in the southern flank of the syncline below the ground surface. The Middle Siwalik sandstone and Upper Siwalik conglomerates bedrock have been assigned a shear wave velocity of ~750-800 m/s and ~950-1000 m/s respectively, after running a seismic profile directly on the respective bedrock exposed along the river sections. Based on 1D and 2D Vs profiles from north to south, a model of cross-section showing depth of bedrock/thickness of the Dun gravels has been presented. Different litho units of the Dehradun fan defined by earlier researchers have been validated with Vs. Each unit, i.e. units A-C, has been assigned Vs as 700-850, 500-700 and <500 m/s respectively.
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54184
Title: Carbon storage and sequestration in bamboo-based smallholder homegardens of Barak Valley, Assam
Author: Arun Jyoti Nath and Ashesh Kumar Das
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 2, 25 January 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Bamboo farming, carbon assimilation ratio, smallholder, homegarden
Abstract: Smallholder farming systems throughout the world are believed to be potential sinks to remove atmospheric CO2. Smallholder bamboo farming system in Barak Valley, Assam, which forms a part of the traditional homegarden system, holds promise in this respect. Occurrence of bamboo in all homesteads coupled with progressive increase in culm density over the years reflects its potential for carbon (C) storage. Hundred homegardens were selected from the study site and the total number of culms from all the different age classes per clump of Bambusa cacharensis, Bambusa vulgaris and Bambusa balcooa were recorded with their diameter at breast height. Harvest method was employed to estimate the aboveground biomass and from biomass values C stock was determined. C estimate in aboveground vegetation in bamboo farming system ranged from 6.51 (2004) to 8.95 (2007) Mg ha-1 with 87%, 9% and 4% of the total C stored in culm, branch and leaf respectively. The rate of C sequestration was 1.20-1.46 Mg ha-1 yr-1, with a mean of 1.32 Mg ha-1yr-1. In bamboo farming system under selective felling regime, although the C stock and sequestration was low compared to other agroforestry systems across the world, it represented a permanent stock. Harvesting of mature culms was balanced by C gain from new culms produced in the clump. Carbon assimilation ratio, an index to evaluate C sequestration potential per unit of C stock, exhibited bamboo farming as an efficient C sequester than other pure plantations or natural forests. Promotion of smallholder bamboo farming systems to reduce atmospheric greenhouse gas levels to receive certified emission reduction is recommended.
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54183
Title: Silver quantum dots for selective detection of mercuric ions
Author: Govindhan Maduraiveeran, Vairaperumal Tamilmani and Ramasamy Ramaraj
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 2, 25 January 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Environmental toxicity, mercuric ion, optical sensor, silicate sol-gel, quantum dot
Abstract: In this article, we demonstrate a highly sensitive and selective optical sensor for mercuric ions based on silver quantum dot (AgQD) dispersed in functionalized silicate sol-gel matrix in aqueous solution with a detection limit of 5 pM, which is highly sensitive compared to other reported methods. The present optical sensor is simple to prepare, and a cost-effective, and time-savings procedure without any external assemblies attached on the surface of AgQD. The AgQD sensor shows very high sensitivity and selectivity with simple instrumentation technique. We expect that the AgQD-based optical sensor is a promising candidate for the detection of environmentally toxic mercury in aqueous medium.
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54182
Title: A breeder ' s perspective on the tiller dynamics in sugarcane
Author: Raman Kapur, S K Duttamajumder and K Krishna Rao
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 2, 25 January 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Intra-row competition, precision farming, sugarcane, tiller dynamics and mortality
Abstract: Sugarcane is a vegetatively propagated crop grown for sugar. A sugarcane ' clump ' comprises of several cane stalks arising from subsurface sprouting of the underground buds in the form of tillers which develop into millable canes, providing the sink for sucrose accumulation. Thus, the number of millable stalks and the individual stalk weight constitute the yield in sugarcane. The conventional sugarcane agriculture, wherein two or three-budded stalk pieces called ' setts ' are used for planting, does not exercise strict control on the intra-row spacing and this often leads to sub-or supra-optimal tiller population. If it is suboptimal, it leads to poor yield. When in excess, it leads to competition and results in poor tiller survival. Although tillering ability is a genetically governed trait, a breeder tends to select the types which produce a near-optimal number of millable canes. What is overlooked in the process is the substantial tiller mortality. In our opinion, both these practices (breeding and agronomy) do not do justice to the very nature of the sugarcane plant and are rather wasteful. With this perspective, sugarcane planting and breeding are revisited to drive home the point that better selection of sugarcane variability and efficient planting system be adopted for reducing the cost of seed and increasing the profitability. Fortunately, it is being demonstrated at a few places in the country that better sugarcane agronomy is the route to enhanced productivity and juice quality. Further, the gains extend to ratoon crops as well, resulting in an overall win-win situation for the farmer and the factory.
Location: 241
Literature cited 1: None
Literature cited 2: None

ID: 54181
Title: Mapping ecologically sensitive, significant and salient areas of Western Ghats: proposed protocols and methodology
Author: Madhav Gadgil , R J Ranjit Daniels, K. N. Ganeshaiah, S Narendra Prasad, M S R Murthy, C S Jha, B R Ramesh and K A Subramanian
Editor: P Balaram
Year: 2011
Publisher: Current Science Association, Vol 100, No 2, 25 January 2011
Source: Centre for Ecological Sciences
Reference: None
Subject: Current Science
Keywords: Ecologically sensitive areas, mapping, methodology, protocols
Abstract: The Western Ghats Ecology Expert Panel (WGEEP) of the Ministry of Environment and Forests, Government of India (GOI) has been asked to identify ecologically sensitive areas (ESAs) along the Western Ghats, and to suggest how to manage them. The concept of ESAs has been extensively discussed in the literature. Several ESAs have been set up in India over the last 22 years under the Environment Protection Act, 1986, and a GOI committee under the chairmanship of Pranob Sen has proposed certain criteria for identification of ESAs. However, WGEEP noted that we still lack a global consensus either on the criteria to define ESAs or on a workable methodology to identify them. Furthermore, there are no clear guidelines on the management regime that should prevail in ESAs, and the Pranob Sen Committee has not addressed this issue at all. Hence, WGEEP decided to undertake an excercise of defining ESAs and developing a workable methodology to assign levels of ecological significance/sensitivity as a first step towards putting ESAs on the map of the Western Ghats. This article provides a report on the outcome of a series of discussions and consultations held by WGEEP to build a consensus on defining and mapping ESAs. It hopes to provoke discussion and feedback from a wider section of experts, with the aim of finalizing a generic methodology for mapping ESAs in other ecologically significant, biodiversity-rich areas within and outside the country. We hope to shortly prepare a companion paper that will address the equally vital management issues.
Location: 241
Literature cited 1: None
Literature cited 2: None