Part Of Western Ghats Research Articles

Typification of Ardisia blatteri (Primulaceae)

Ardisia blatteri Gamble (1921: 121) is endemic to India and occurs in the southern part of Western Ghats (Dhanasekaran et al. 2016). This species has been considered as ‘Endangered’ in IUCN Red List of Threatened Species (IUCN 2016). The plants are rich in chemical constituents like alkaloids, tannins, saponins, anthraquinones, phenols, terpenoids and flavonoids, coumarins, steroids and phytosteroids and are used in traditional medicines (Dhanasekaran et al. 2016) for curing fever, cough, rheumatism, inflammation and many more ailments. The medicinal properties of this important plant require further research.

Influence of Change in Tree Density Under Selected Land use Land Cover System on Runoff Generation in Parts of Western Ghats, Karnataka

Influence of Change in Tree Density Under Selected Land use Land Cover System on Runoff Generation in Parts of Western Ghats, Karnataka

A new species of Striga section Polypleurae (Orobanchaceae) from southern Western Ghats of India

A new species of Striga from Tamil Nadu parts of Western Ghats of India is described and illustrated as Striga kamalii sp. nov. The new species shows similarity with S. densiflora in having a densely hispid stem, linear leaves, bracts longer than calyx, and oblong fruit shorter than calyx lobes, but differs in the 10-ribbed calyx, the glandular hairs on calyx and corolla tube, and the obovate-rounded petals. A detailed description, with data on distribution and parasitism together with relevant taxonomic notes and colour photographs are provided.

Changes in Ecological Landscape Pattern and Land Use from 1985 to 2014 in the Panshet Dam Catchment

The Sahyadri, the northern part of Western Ghats in the state of Maharashtra, India, are one of the most fragile ecosystems on Earth. There are major changes in the original ecosystem and land use in the Sahyadri over the past two centuries. A ground survey was conducted by Ecological Society, Pune in 1985 as well as in 2014 to assess current land use and status of biodiversity in the Panshet dam catchment situated in Sahyadri. This study probes to understand factors responsible for decline of biodiversity and changed land use. We highlight the extent and causes for change in land use. The study attempted to quantify this change by carrying out manual digitization of multispectral WV-2 satellite images by visual interpretation and ground truthing and compare with the study done by Ecological Society in 1985. The mapping of the catchment area shows that areas towards western escarpment i.e. away from the dam wall have retained better vegetation cover while degradation is evident in eastern parts of the catchment. Such studies will be useful for land use planning, understanding cost-benefits of nature conservation, assessing restoration potential, and developing conservation-restoration strategies on a regional scale. We recommend similar vegetation and land use class mappingfor all dam catchments in the Western Ghats.

Assessment of Juvenile Variability of Morphological and Biophysical Characters in Embelia ribes Burm.

Embelia ribes is a woody perennial forest climber that belongs to Rare Endangered and Threatened category. Because of its economic importance of its seeds and great demand in the market of ayurvedic and pharmaceutical medicines tremendous pressure is being imposed on its natural populations. The present study is an effort to analyze the variability of juvenile plants of Embelia ribes grown from the seeds collected from different geographical regions of the southern part of Western Ghats of India. Statistically significant variability between the accessions was shown only by internodal length and the other characters under study showed only insignificant variations. However, characters like number of tertiary branches, number of leaves per tertiary branches and epicuticular wax content showed some degree of variation. The present study reveals that the level of variability expressed in the case of juvenile plants of Embelia ribes when grown and compared under uniform nursery conditions is very low and this observation points to the alarming situation that the level of genetic variability among Embelia ribes plants distributed in the Western Ghats region of Kerala state of India is very low and measures to improve the extent of variability should be initiated with the objective of enriching in situ diversity and developing germplasm of the plant in which all the available genotypes across its natural habitats are conserved.

Population structure ofKnema attenuata(J.Hk.& Th.) - a red listed medicinal tree species in Northern Western Ghats of Karnataka, India

Among the several important tree species in Western Ghats of India, Knema attenuata is one of the important medicinal tree species being used in the traditional medicine and Ayurveda to cure many diseases and disorders. This species comes under IUCN (International Union for Conservation of Nature and Natural Resources) red list category. Hence, an assessment of population structure is the first step in conservation which provides the status of the species and its population in natural habitat. Present study was carried out in the Northern part of Western Ghats of Karnataka. The study was carried out by stratified random sampling method with sample plot size of 20 m × 20 m. The study revealed that the tree species was found to be distributed in both the districts and the population status varied between the locations. Density, basal area and regeneration of the species varied between locations. Distribution of stems in different girth classes varied and in many of the sites it was showing reverse ‘J'shape curve. Even though population of the species was moderately good in some of the areas studied, but in some areas regeneration and population of the species was not good and/or poor. In such sites appropriate measures are required to conserve the species.

Assessment of Juvenile Variability of Morphological and Biophysical Characters in Embelia Ribes Burm.

Embelia ribes is a woody perennial forest climber that belongs to Rare Endangered and Threatened category. Because of its economic importance of its seeds and great demand in the market of ayurvedic and pharmaceutical medicines tremendous pressure is being imposed on its natural populations. The present study is an effort to analyze the variability of juvenile plants of Embelia ribes grown from the seeds collected from different geographical regions of the southern part of Western Ghats of India. Statistically significant variability between the accessions was shown only by internodal length and the other characters under study showed only insignificant variations. However, characters like number of tertiary branches, number of leaves per tertiary branches and epicuticular wax content showed some degree of variation. The present study reveals that the level of variability expressed in the case of juvenile plants of Embelia ribes when grown and compared under uniform nursery conditions is very low and this observation points to the alarming situation that the level of genetic variability among Embelia ribes plants distributed in the Western Ghats region of Kerala state is very low and measures to improve the extent of variability should be initiated with the objective of enriching in situ diversity and developing germplasm of the plant in which all the available genotypes across its natural habitats are conserved.

Photogrammetric processing of hexagon stereo data for change detection studies

Abstract. Hexagon satellite data acquired as a part of USA Corona program has been declassified and is accessible to general public. This image data was acquired in high resolution much before the launch of civilian satellites. However the non availability of interior and exterior orientation parameters is the main bottle neck in photogrammetric processing of this data. In the present study, an attempt was made to orient and adjust Hexagon stereo pair through Rigorous Sensor Model (RSM) and Rational Function Models (RFM). The study area is part of Western Ghats in India. For rigorous sensor modelling an arbitrary camera file is generated based on the information available in the literature and few assumptions. A terrain dependent RFM was generated for the stereo data using Cartosat-1 reference data. The model accuracy achieved for both RSM and RFM was better than one pixel. DEM and orthoimage were generated with a spacing of 50 m and Ground Sampling Distance (GSD) of 6 m to carry out the change detection with a special emphasis on water bodies with reference to recent Cartosat-1 data. About 72 new water bodies covering an area of 2300 hectares (23 sq. km) were identified in Cartosat-1 orthoimage that were not present in Hexagon data. The image data from various Corona programs like Hexagon provide a rich source of information for temporal studies. However photogrammetric processing of the data is a bit tedious due to lack of information about internal sensor geometry.

SLOPE STABILITY ANALYSIS OF KALLAR-COONOOR HILL ROAD STRETCH OF THE NILGIRIS

The stability of slopes is always under severe thre ats in many parts of Western Ghats, especially in K allarCoonoor hill road stretch, causing disruption, loss of human life and economy. To minimize the instability of soil slope in between Kallar-Coonoor, a critical evaluation of roads is required. The stability of slopes depends on the soil shear strength parameters such as Cohesion, Angle of internal friction, Unit weigh t of soil and Slope geometry. The stability of a slope i s measured by its factor of safety using geometric and shear strength parameter based on infinite slopes. In this present study, investigation was carried ou t at 32 locations in the above said hill road stretch to es timate the factor of safety of the slope determined by MohrCoulomb theory based on shear strength parameter calculated from direct shear test which is a conventi onal procedure for this study. Back Propagation Artifici al Neural Network (BP-ANN) Model is used to predict the factor of safety. The input parameters for the (BP-ANN) are chosen as Cohesion, Angle of internal friction, Density and Slope angle and the factor of safety as output. Out of the parameters of 32 loca tions, the study of BP-ANN is trained with parameters of f irst 25 locations. Factor of safety was calculated for the remaining 7 locations. The results obtained in BP-A NN method were compared with that of conventional method and observed a good agreement between these two methods. The results obtained from these two methods were also compared with the details of actu al field Landslide occurred and indicates 71.4% of conventional method locations matching with the physical occurrences and 85.7% of BP-ANN predicted vulnerable locations match with the physically obse rved landslide locations.

A new Caccobius dung beetle (Scarabaeidae) from the Western Ghats of India

This study describes a new dung beetle Caccobiusdevagiriensissp. nov. belonging to the subgenus Caccophilus from the Kerala part of Western Ghats, India. A key to the species of the subgenus Caccophilus from Indian subcontinent is also provided. Caccobius ultor Sharp and Caccobius rufipennis Motschulsky are documented as new records.

A new species of the genusPremnaL. (Lamiaceae) from Western Ghats of India

A new species of Premna L., Premna rajendranii, is described from the Kerala and Tamil Nadu parts of Western Ghats. Detailed description, colour photographs, phenology, conservation status, distributional details and relevant taxonomic notes are provided along with a key to the Premna spp. distributed in Kerala.

Morphometric analysis of sub-watershed in parts of Western Ghats, South India using ASTER DEM

Morphometric analysis is a key to understand the hydrological process and hence is a prerequisite for the assessment of hydrological characteristics of surface water basin. Morphometric analysis to determine the drainage characteristics of Palar sub-watershed, a part of Shanmukha watershed in the Amaravati sub-catchment is done using Advanced Space-borne Thermal Emission and Reflection Global Digital Elevation Model (ASTER GDEM) data, and is supplemented with topographical maps in geographical information systems platform. This study uses ASTER GDEM data to extract morphometric features of a mountain stream at micro-watershed level. The sub-watershed is divided into six micro-watersheds. The sub-watershed includes a sixth-order stream. Lower stream orders, in particular first-order streams, dominate the sub-watershed. Development of stream segments is controlled by slope and local relief. Drainage pattern of the sub-watershed and micro-watersheds is dendritic in general. The mean bifurcation ratio of the sub-watershed is 3.69 but its variation between the various stream orders suggests structural control in the development of stream network. The shape factors reveal the elongation of the sub-watershed and micro-watersheds.The relief ratio reveals the high discharge capability of the sub-watershed and meagre groundwater potential. This study is a useful tool for planning strategies in control of soil erosion and soil conservation.

A paradigm quantitative approach for a regional risk assessment and management in a few landslide prone hamlets along the windward slope of Western Ghats, India

Landslide occurrences in Western Ghats are not rare but rather a brooding omnipresent reality with all its fury. The devastation caused by this cataclysmic phenomenon is unwittingly greater than one could imagine as the density of population in the state of Kerala is ~800perkm2. This study aims at providing a quantitative estimation of elements at risk to landslides in a stretch of landslide susceptible zones, demarcated using a heuristic approach and spreading over a few hamlets in parts of Western Ghats. The vulnerability results reveal that: 1,321,056 nos. of human population, 2656 cattle, livestock and poultry, and INR 2650 crore (~US$ 143 billion) worth of property are at risk. Management practices, on a regional scale, along transport corridors and major settlement areas are proposed. As this part of the world experiences a tropical climate, monsoon is the sole triggering mechanism of landslides. Hence an early warning system with reference to rainfall and a series of surface drainage network will help in minimizing the effects of the landslides.

Taiwanascus samuelsii sp. nov., an addition to Niessliaceae from the Western Ghats, Kerala, India

A new species of Taiwanascus, T. samuelsii, was collected from southern parts of Western Ghats on dead branches of Anacardium occidentale and is described. The new cleistothecial ascomycete is different from the type and only species in Taiwanascus, T. tetrasporus, in cleistothecial size, setae, and ascospore characteristics.

Geographic information system–based morphometric characterization of sub-watersheds of Meenachil river basin, Kottayam district, Kerala, India

The study areas Tikovil and Payppara sub-watersheds of Meenachil river cover 158.9 and 111.9 km2, respectively. These watersheds are parts of Western Ghats, which is an ecologically sensitive region. The drainage network of the sub-watersheds was delineated using SOI topographical maps on 1:50,000 scale using the Arc GIS software. The stream orders were calculated using the method proposed by Strahler's (1964). The drainage network shows that the terrain exhibits dendritic to sub-dendritic drainage pattern. Stream order ranges from the fifth to the sixth order. Drainage density varies between 1.69 and 2.62 km/km2. The drainage texture of the drainage basins are 2.3 km–1 and 6.98 km–1 and categorized as coarse to very fine texture. Stream frequency is low in the case of Payappara sub-watershed (1.78 km–2). Payappara sub-watershed has the highest constant of channel maintenance value of 0.59 indicating much fewer structural disturbances and fewer runoff conditions. The form factor value varies in between 0.42 and 0.55 suggesting elongated shape formed for Payappara sub-watershed and a rather more circular shape for Tikovil sub-watershed. The mean bifurcation ratio (3.5) indicates that both the sub-watersheds are within the natural stream system. Hence from the study it can be concluded that GIS techniques prove to be a competent tool in morphometric analysis.

GIS based morphometric evaluation of Chimmini and Mupily watersheds, parts of Western Ghats, Thrissur District, Kerala, India

GIS and Remote Sensing have proved to be an indispensible tool in morphometric analysis. The identification of morphometric properties based on a geographic information system (GIS) was carried out in two watersheds in the Thrissur district of Kerala, India. These watersheds are parts of Western Ghats, which is an ecologically sensitive area. Quantitative geomorphometric analysis was carried out for the Chimmini and Mupily watersheds independently by estimating their (a) linear aspects like stream number, stream order, stream length, mean stream length, stream length ratio, bifurcation ratio, length of overland flow, drainage pattern (b) aerial aspects like circulatory ratio, elongation ratio, drainage density and (c) relief aspects like basin relief, relief ratio, relative relief and ruggedness number. The drainage areas of Chimmini and Mupily watersheds are 140 and 122 km2 respectively and show patterns of dendritic to sub-dendritic drainage. The Chimmini watershed was classified as a sixth order drainage basin, whereas Mupily watershed was classified as a fifth order basin. The stream order of the basin was predominantly controlled by physiographic and structural conditions. The increase in the stream length ratio from lower to higher order suggests that the study area has reached a mature geomorphic stage. The development of stream segments is affected by rainfall and local lithology of the watersheds. The slope of both watersheds varied from 0° to 50° and 0° to 42° respectively and the slope variation is chiefly controlled by the local geology and erosion cycles. Moreover, these studies are useful for planning rain water harvesting and watershed management.

Weathering and landslide occurrences in parts of Western Ghats, Kerala

The climatic condition of Western Ghats has influenced the process of weathering and landslides in this mountainous tract along the southwest coast of India. During the monsoon period, landslides are a common in the Western Ghats, and its intensity depends upon the thickness of the loose unconsolidated soil formed by the process of weathering. Debris landslides with a combination of saprock, saprolite and soil, indicate the role of weathering in landslide occurrences. This paper reports on how the weathering in the windward slope of Western Ghats influences the occurrence of landslides and the factors which accelerate the weathering process. Rock and soil samples were collected from the weathering profile of hornblende gniess and granite gneiss. The chemical analysis and the calculated Chemical Index of Alteration (CIA) indicate the significant weathering and its possible influence on landslide occurrences in the study area. Mainly, the CIA value of lateritic soil and forest loam indicated the extent of high chemical weathering in this region. Rainfall is the dominant parameter influencing the chemical weathering process. In addition, deforestation, land use practices and soil erosion are some of the other important factors accelerating the weathering process and landslide occurrences in the region. The locations of the previous landslides superimposed on geology and soil show that most of the landslide occurrences are associated with the highly weathered zone, particularly lateritic soil and the 'severe' (rock outcrop) erodability zone.

Tick Infestation on Wild Snakes in Northern Part of Western Ghats of India

In total, 167 individuals of 30 species of snakes belonging to 22 genera and five families were examined for tick infestation from November 2008 to March 2010. Only two species of snakes, Ptyas mucosa (L., 1758) (Indian rat snake) and Naja naja (L., 1758) (spectacled cobra), were found infested by ticks. All ticks collected were identified to be Amblyomma gervaisi [previously Aponomma gervaisi (Lucas, 1847) 1. The average prevalence of these ticks on Indian rat snakes (n=48) was 29.16%, with abundance of 7.02 ticks per individual; on spectacled cobras (n=20), average prevalence was 30.00%, with abundance of 6.9 ticks per individual. The nymphs and males were predominant. All the ticks were found on the dorsal aspect of the body of the snake, and no ticks were recorded on the head, tail, or ventral body. The rate of tick infestation was highest in scrubland and was lowest in evergreen forests. Female Indian rat snakes showed higher tick infestation rates than male Indian rat snakes. Using Mann-Whitney U test, we found that longer snakes of both species had significantly higher rate of tick infestation in both the species of snakes.

Morphometric evaluation of Papanasam and Manimuthar watersheds, parts of Western Ghats, Tirunelveli district, Tamil Nadu, India: a GIS approach

A morphometric analysis was carried out to describe the topography and drainage characteristics of Papanasam and Manimuthar watersheds. These watersheds are part of Western Ghats, which is an ecologically sensitive region. The drainage areas of Papanasam and Manimuthar watersheds are 163 and 211 km2, respectively and they show patterns of dendritic to sub-dendritic drainage. The slope of both watersheds varied from 0° to 59° and 0° to 55°, respectively. Moreover, the slope variation is chiefly controlled by the local geology and erosion cycles. Each watershed was classified as a fifth-order drainage basin. The stream order of the basin was predominantly controlled by physiographic and structural conditions. The increase in stream length ratio from lower to higher order suggests that the study area has reached a mature geomorphic stage. The development of stream segments is affected by rainfall and local lithology of the watersheds.

Estimating potential landslide sites of an upland sub-watershed in Western Ghat’s of Kerala (India) through frequency ratio and GIS

The purpose of this study is to assess the susceptibility of landslides in parts of Western Ghats, Kerala, India, using a geographical information system (GIS). Landslide inventory of the area was made by detailed field surveys and the analysis of the topographical maps. The landslide triggering factors are considered to be slope angle, slope aspect, slope curvature, slope length, distance from drainage, distance from lineaments, lithology, land use and geomorphology. ArcGIS version 8.3 was used to manipulate and analyse all the collected data. Probabilistic-likelihood ratio was used to create a landslide susceptibility map for the study area. The result was validated using the Area under Curve (AUC) method and temporal data of landslide occurrences. The validation results showed satisfactory agreement between the susceptibility map and the existing data on landslide locations. As the result, the success rate of the model was (84.46%) and the prediction rate of the model was (82.38%) shows high prediction accuracy. In the reclassified final landslide susceptibility zone map, 5.68% of the total area is classified as critical in nature. The landslide susceptibility map thus produced can be used to reduce hazards associated with landslides and to land cover planning.