Objective:To report a new species of sandfly,Sergentomyia(Neophlebotomus)ashwanii sp.nov.(Diptera:Psychodidae)from Western Ghats,India.Methods:A systematic sandfly survey was conducted in the Thrissur and Kollam distr...Objective:To report a new species of sandfly,Sergentomyia(Neophlebotomus)ashwanii sp.nov.(Diptera:Psychodidae)from Western Ghats,India.Methods:A systematic sandfly survey was conducted in the Thrissur and Kollam districts of Kerala,India using mechanical aspirators,light and sticky traps,both indoor and outdoor habitats,for a period of one year.Deoxyribonucleic acid barcoding of samples was performed targeting mitochondrial cytochrome oxidase I(COI)gene and sequence generated was subjected to phylogenetic analysis.Results:Sergentomyia(Neophlebotomus)ashwanii,a new sandfly species is recorded and described in this communication.A single row of 10-12 pointed teeth in the cibarium with 4-6 small denticles or fore-teeth are the key characteristics that is distinctive from other members of the subgenus Neophlebotomus.Mitochondrial COI barcode followed by phylogenetic analysis of the nucleotide sequence confirms that specimens of the species belong to the same taxonomic group while the genetic distance(14.2%)with the congeners established it to be a different species.Conclusions:The Western Ghats'being an important biodiversity hotspot and has dearth of systematic entomological surveys on sandflies.The current study tried to fill the void and also report a new sandfly species.展开更多
Revised Universal Soil Loss Equation(RUSLE) model coupled with transport limited sediment delivery(TLSD) function was used to predict the longtime average annual soil loss, and to identify the critical erosion-/deposi...Revised Universal Soil Loss Equation(RUSLE) model coupled with transport limited sediment delivery(TLSD) function was used to predict the longtime average annual soil loss, and to identify the critical erosion-/deposition-prone areas in a tropical mountain river basin, viz., Muthirapuzha River Basin(MRB; area=271.75 km^2), in the southern Western Ghats, India. Mean gross soil erosion in MRB is 14.36 t ha^(-1) yr^(-1), whereas mean net soil erosion(i.e., gross erosion-deposition) is only 3.60 t ha^(-1) yr^(-1)(i.e., roughly 25% of the gross erosion). Majority of the basin area(~86%) experiences only slight erosion(<5 t ha^(-1) yr^(-1)), and nearly 3% of the area functions as depositional environment for the eroded sediments(e.g., the terraces of stream reaches, the gentle plains as well as the foot slopes of the plateau scarps and the terrain with concordant summits). Although mean gross soil erosion rates in the natural vegetation belts are relatively higher, compared to agriculture, settlement/built-up areas and tea plantation, the sediment transport efficiency in agricultural areas and tea plantation is significantly high,reflecting the role of human activities on accelerated soil erosion. In MRB, on a mean basis, 0.42 t of soil organic carbon(SOC) content is being eroded per hectare annually, and SOC loss from the 4th order subbasins shows considerable differences, mainly due to the spatial variability in the gross soil erosion rates among the sub-basins. The quantitative results, on soil erosion and deposition, modelled using RUSLE and TLSD, are expected to be beneficial while formulating comprehensive land management strategies for reducing the extent of soil degradation in tropical mountain river basins.展开更多
The changes in species composition, abundance and forest stand structure were analyzed across altitudinal regimes in tropical forests of Eastern Ghats of northern Andhra Pradesh, India. Three 1-ha plots were establish...The changes in species composition, abundance and forest stand structure were analyzed across altitudinal regimes in tropical forests of Eastern Ghats of northern Andhra Pradesh, India. Three 1-ha plots were established with one each in low, medium and high altitudes. A total of 153 species, 2129 stems (709 stems .ha^-1) of ≥10 cm girth were enumerated. Species richness and diversity pattern varied along altitudinal gradient and increased with the altitude. Species richness varied from 52 to 110 species-ha^-1 and stand density from 639 to 836 stems.ha^-1 with average basal area of 34.39 m^2.ha^-1. Shannon-Wiener index (H') ranged from 4.55 to 5.17. Low altitude (i.e., Site 1) is dominated byXylia xylocarpa (59.22) and Lagerstroemia parviflora (23.90), medium altitude (i.e., Site 2) by Xylia xylocarpa (45;50) Bursera serrata (17.29), and high altitude (i.e., Site 3) has Schleichera oleosa (28.25) Pterocarpus marsupium (26.55) as predominant species. Taxonomically, Rubiaceae (12 species), Fabaceae (12), Euphorbiaceae (11), Rutaceae (7) and Lanraceae (7) were dominant families. Density-wise, Fabaceae, Combretaceae, Euphorbiaceae, Anacardiaceae and Myrtaceae were abundant. Thus, conservation assessment based on altitudinal regimes and the information on species structure and function can provide baseline information for monitoring and sustaining the biodiversity.展开更多
Nutrient composition of the manure of four pill millipedes (Arthrosphaera dalyi, ,4. davisoni, ,4. fumosa and,4, magna) inhabiting in semi-evergreen forests and plantations of the Western Ghats of Southwest India wa...Nutrient composition of the manure of four pill millipedes (Arthrosphaera dalyi, ,4. davisoni, ,4. fumosa and,4, magna) inhabiting in semi-evergreen forests and plantations of the Western Ghats of Southwest India was evaluated. The quantity and quality of fecal pellets differed between millipedes and their habitats (forest and plantation). Organic carbon content in manure was lower in plantations than in forests, while nitrogen content was elevated in plantations. The carbon to nitrogen (C/N) ratio of manure was lower in plantations compared to forests. The phosphorus content in manure was elevated in plantations in all except for A. dalyi. Calcium content of manure was increased in plantations than in forests. The contents of magnesium, potassium and phenolics in manure showed varied results. The mass of fecal pellets was correlated only with volume in forests (r=0.882; p 〈0.01) and pH in plantations (r=0.616; p 〈0.05), while the volume of fecal pellets was correlated with nitrogen content in forests (r=0.751; p 〈0.01) and cal- cium in plantations (=0.619; p 〈0.05). The conductivity was positively correlated with phosphorus and potassium, while magnesium was negatively correlated in forests as well as plantations. Potassium and magnesium were negatively correlated in forests (r=0.920; p〈0.001) and plantations (t=0.692; p 〈0.05). Overall, the physicochemical characteristics and nutrient composition of fecal pelets differed between millipedes as well as habitats. The low carbon to nitrogen ratio and the increased nitrogen, phosphorus and calcium content in the manure of millipedes inhabiting in plantations indicates possibilities for successfully employing them for in situ composting of forest or plantation residues.展开更多
Background: The effect of forest fire on soil is complex and relatively less understood than its above ground effect.Understanding the effect of fire on forest soils can allow improving management of valuable forest e...Background: The effect of forest fire on soil is complex and relatively less understood than its above ground effect.Understanding the effect of fire on forest soils can allow improving management of valuable forest ecosystems as adequate and proper information is very important for efficient management. We have studied the recovery of soil properties after fire, using a chronosequence approach(two, five and fifteen years after fire and control). Soil samples were collected from each plot of four fire patches(B0, B2, B5 & B15) from three different depths viz. 0–10(Top), 10–20(Middle), and 20–30 cm(Bottom).Results: Soil organic carbon was lower than unburned plots after the fire and could not recover to the level of unburned plot(B0) even in 15 years. Total N, available P, and extractable K were lower 2-years and 5-years after the fire but are higher than unburned plot after 15-years. Available nitrogen(NO_3^- and NH_4^+) remain unchanged or higher than B0 in burned patches. Soil pH, Bulk Density, Water Holding Capacity, and Electrical Conductivity was lower initially after the fire. Forest fires have affected soil properties considerably. The response of soil properties varied with years after fire and soil depth.Conclusion: Forest fires occur very frequently in the study area. Significant quantities of carbon and total nitrogen are lost to the atmosphere by burning of litter, duff, and soil OM. Because nitrogen is one of the most important soil nutrients, the recapture of N lost by volatilization during a fire must receive special attention. Long-term studies are required to better understand the recovery of soil nitrogen.展开更多
We investigated the distribution and resource values of liana species assessed in six hill complexes of southern Eastern Ghats, India. 143 liana species (DBH (diameter at breast height) ≥1.5 cm) and 32,033 liana ...We investigated the distribution and resource values of liana species assessed in six hill complexes of southern Eastern Ghats, India. 143 liana species (DBH (diameter at breast height) ≥1.5 cm) and 32,033 liana individuals were recorded from 110 transects (0.5 ha each covering 55 ha area) in the study sites. The resource values of lianas were broadly categorized into ecological and economic importance. About 90% (129) of liana species and 96% (30,564) of liana individuals were established ecological/economic values. Fruit rewards provided by 76 species and 20,325 individuals constituted the major resource of ecological importance. 82 species and 21,457 liana individuals are of economic importance as medicine, edible fruits, edible and medicinal values, and yet others are used for different domestic purposes including furniture, fuel wood, rope making etc.. Ecologically, the prevalence of succulent diaspores in lianas of Indian Eastern Ghats indicates the animal dependence of many liana species for dispersal and underlines the need for a holistic and whole-forest conservation approach in maintaining forest biodiversity.展开更多
We analyze the structure and composition of old-growth wet evergreen forest of Nelliampathy hills, the chain of hills lying immediately south of Palghat Gap, in the southern Western Ghats of India. We sampled 30 plots...We analyze the structure and composition of old-growth wet evergreen forest of Nelliampathy hills, the chain of hills lying immediately south of Palghat Gap, in the southern Western Ghats of India. We sampled 30 plots of 0.1 ha each (50 m × 20 m) at six locations enumerating all plants ? 10 cm girth at breast height. We pooled the data and computed various structural parameters. There were 152 species of 120 genera and 51 families of the study area. Of these, 118 (77%) were trees, 24 were climbers (16%) and 10 were shrubs (7%). Species richness varied from 58–99 per 0.5 ha sample and Shannon indices of diversity ranged from 4.4 to 5.2. Fifty-nine per cent (89 species) of the species were Indian Sub-continent elements and 34% (51 species) are endemic to the Western Ghats. Fifteen species are listed in various threat categories. Aglaia and Litsea were the most species-rich genera. Numbers of families ranged from 27–43 per 0.5 ha sample. Euphorbiaceae and Lauraceae were the most species-rich families. Stand density varied from 1714 to 2244 stems·ha?1 and basal area from 53.6 to 102.1 m2·ha?1. The vegetation was dominated by 3–6 species and six dominance patterns characterized the species composition within the hill complex. The old-growth evergreen forests of Nelliampathy exist as small fragments rich in biodiversity and can be used as benchmarks for comparison with disturbed forests.展开更多
Forest resource conservation has been widely accepted as a key to sustain the local and regional economic development. The forest edges are affected by anthropogenic activities including deforestation, forest fragment...Forest resource conservation has been widely accepted as a key to sustain the local and regional economic development. The forest edges are affected by anthropogenic activities including deforestation, forest fragmentation, selective logging, extraction of non-timber forest products, collection of medicinal plants, recreations, hydroelectric pro- jects and its associated developmental activities, which alter the biodiver- sity. The present study intends to evaluate the edge effect on vegetation structure and species compositions in the tropical forest ecosystems at Periyar Wildlife Sanctuary in the Western Ghats. High species richness (number of species) and Shannon's diversity indices were observed in the site IlI (completely undisturbed forest) compared to site I (adjacent to the village/edge of the forest, which is next to the teal( plantation, severely disturbed forest) and site II (in between the undisturbed forest and mod- erately disturbed forest) while density of tree species showed greater value in site II. Single species such as Tectona grandis (IVI of 80) and Terminaliapaniculata (IVI of 112) were the dominant tree species in site I and site II, respectively, whereas, in site III Terminalia bellirica, Bishofia javanica and Syzgium gardneri shared the dominance. Perturba- tion leads to alien plant invasion particularly Lantana camara, Eupato- rium odoratum and Ageratum conizoides. Site II is at forest transition level because the site is dominated by both natural species as well as plantation species such as Tectona grandis. This site seems to be a buffer zone on natural forest and plantations. Further studies are required to analyse the real patterns of regeneration and dynamic change due to human impact by long term monitoring with the establishment of perma- nent plots.展开更多
The paper evaluates sensitivity of various spaceborne digital elevation models (DEMs), viz., Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Shuttle Radar Topography Mapping Mission (SRTM...The paper evaluates sensitivity of various spaceborne digital elevation models (DEMs), viz., Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Shuttle Radar Topography Mapping Mission (SRTM) and Global Multi-resolution Terrain Elevation Data 2010 (GMTED), in comparison with the DEM (TOPO) derived from contour data of 20 m interval of Survey of India topographic sheets of 1 : 50,000 scale. Several topographic attributes, such as elevation (above mean sea level), relative relief, slope, aspect, curvature, slope-length and -steepness (LS) factor, terrain ruggedness index (TRI), topo- graphic wetness index (TWI), hypsometric integral (lhyp) and drainage network attributes (stream number and stream length) of two tropical mountain river basins, viz. Muthirapuzha River Basin and Pambar River Basin are compared to evaluate the variations. Though the basins are comparable in extent, they differ in respect of terrain characteristics and climate. The result.,; suggest that ASTER and SRTM provide equally reliable representation of topography portrayed by TOP() and the topographic attributes extracted from the spaceborne DEMs are in agreement with those derived from TOPO. Despite the coarser resolution, SRTM shows relatively higher vertical accuracy (RMSE -- 23 and 20 m respectively in MRB and PRB) compared to ASTER (RMSE - 33 and 24 m) and GMTED (RMSE - 59 and 48 m). Vertical accuracy of all the spaceborne DEMs is influenced by relief of the terrain as well as type of vegetation. Further, GMTED shows significant deviation for most of the attributes, indicating its inability for mountain-river-basin-scale studies.展开更多
We used standard isolation protocols to explore the endophytic fungal communities in three tissue types of two dominant orchids (Bulbophyllum neilgherrense and Vanda testacea) of the Kaiga forest of the Western Ghat...We used standard isolation protocols to explore the endophytic fungal communities in three tissue types of two dominant orchids (Bulbophyllum neilgherrense and Vanda testacea) of the Kaiga forest of the Western Ghats. We surface sterilized and assessed 90 segments of each orchid for the occurrence and diversity of endophytic fungal taxa. The 118 fungal isolates were obtained from root, bulb and leaves of B. neilgherrense, consisting of 17 anamorphic taxa (range, 10-15 taxa) with 1.3 fungal taxa per segment (range, 1.2-1.4 taxa). Four taxa (Aspergillus flavus, A. niger, Penicillium sp. and morpho sp. 1) belonged to the core group (11.1%--32.2%). The relative abundance of A. flavus and morpho sp. 1 was more than 10%. A total of 130 fungal isolates from roots, stems and leaves of V. testacea yielded 20 anamorphic taxa (range, 11-15 taxa) with 1.4 fungal taxa per segment (range, 1.4-1.5 taxa). Aspergillusflavus, A. niger, A. ochraceus, Gliocladium viride, Penicillium sp. and morpho sp. 1 belonged to the core group. Relative abundance exceeded 10% for A. flavus, A. niger, and morpho sp. 1. The Simpson and Shannon diversity indices were higher in leaf than root or bulb/stem of both orchids. Jaccard's similarity coefficient was higher between root and leaf in both orchids (56.3%-60%) than between other pairs. Our study revealed that the endophytic fungal assemblage and diversity orB. neilgherrense and E testacea of Kaiga forest of the Western Ghats were relatively similar between orchids and their tissues.展开更多
Forty-five species of wild edible fruits were identified and traditional local knowledge of their usage was recorded in 40 villages of Kodagu district in Central Western Ghats, India one of the eight top hotspots of b...Forty-five species of wild edible fruits were identified and traditional local knowledge of their usage was recorded in 40 villages of Kodagu district in Central Western Ghats, India one of the eight top hotspots of biodiversity in the world. We combined biodiversity inven-tory of trees with village interviews to record traditional ecological knowledge. Wild edible fruits were an opportunistic source of food for rural people. Wild edible fruits were rich in minerals, vitamins, carbohy-drates, proteins, fats and fiber. In recent years there has been a decline in numbers of wild fruit trees due to changes in land use from uncultivated private wooded area to cardamom and coffee cultivation. The availability of wild edible fruits that were once very common on private cultivated areas has declined and their distributions are now restricted more to jungles and wildlife sanctuaries. We propose methods for conservation and describe the need for sustainable utilization to provide supplemen-tary sources of nutritional and pharmaceutically useful edible wild fruits.展开更多
In the eastern part of the Indian shield, late Paleozoic-Mesozoic sedimentary rocks of the Talchir Basin lie precisely along a contact of Neoproterozoic age between granulites of the Eastern Ghats Mobile Belt (EGMB)...In the eastern part of the Indian shield, late Paleozoic-Mesozoic sedimentary rocks of the Talchir Basin lie precisely along a contact of Neoproterozoic age between granulites of the Eastern Ghats Mobile Belt (EGMB) and amphibolite facies rocks of the Rengali Province. At present, the northern part of the basin experiences periodic seismicity by reactivation of faults located both within the basin, and in the Rengali Province to the north. Detailed gravity data collected across the basin show that Bouguer anomalies decrease from the EGMB (~+15 mGal), through the basin (^-10 mGal), into the Rengali Province (^-15 mGal). The data are consistent with the reportedly uncompensated nature of the EGMB, and indicate that the crust below the Rengali Province has a cratonic gravity signature. The contact between the two domains with distinct sub-surface structure, inferred from gravity data, coincides with the North Orissa Boundary Fault (NOBF) that defines the northern boundary of the Talchir Basin. Post-Gondwana faults are also localized along the northern margin of the basin, and present-day seismic tremors also have epicenters close to the NOBF. This indicates that the NOBF was formed by reactivation of a Neo- proterozoic terrane boundary, and continues to be susceptible to seismic activity even at the present-day.展开更多
The purpose of this study was to quantify the changes in tree diversity and above-ground biomass associated with six land-use types in Kodagu district of India's Western Ghats. We collected data on species richnes...The purpose of this study was to quantify the changes in tree diversity and above-ground biomass associated with six land-use types in Kodagu district of India's Western Ghats. We collected data on species richness,composition and above-ground biomass(AGB) of trees,shrubs and herbs from 96 sample plots of 0.1 ha. Totals of83 species from 26 families were recorded across the landuses. Tree species richness, diversity and composition were significantly higher in evergreen forest(EGF) than in other land-uses. Similarly, stem density and basal area were greater in EGF compared to other land-uses. Detrended correspondence analysis(DCA) yielded three distinct groups along the land-use intensities and rainfall gradient on the first and second axes, respectively. The first DCA axis accounted for 45% and second axis for 35% of the total variation in species composition. Together the first two axes accounted for over 2/3 of the variation in species composition across land-use types. Across the land-uses,AGB ranged from 58.6 Mg ha-1 in rubber plantation to327.3 Mg ha-1 in evergreen forest. Our results showed that species diversity and AGB were negatively impacted bythe land-use changes. We found that coffee agroforests resembled natural forest and mixed species plantation in terms of tree diversity and biomass production, suggesting that traditional coffee farms can help to protect tree species, sustain smallholder production and offer opportunities for conservation of biodiversity and climate change mitigation.展开更多
The highly speciose gekkonid genus Cnemaspis Strauch,1887 is polyphyletic,with three distantly related and geographically isolated clades from Africa,South Asia(SA),and Southeast Asia.At present,there are 85 known spe...The highly speciose gekkonid genus Cnemaspis Strauch,1887 is polyphyletic,with three distantly related and geographically isolated clades from Africa,South Asia(SA),and Southeast Asia.At present,there are 85 known species within SA Cnemaspis,although the number continues to increase rapidly with focused surveys and rigorous taxonomic work.Recent studies have provided valuable insights into the diversity and evolutionary history of SA Cnemaspis;however,most of these studies lack sufficient sampling in the Western Ghats(WG),where the genus has its greatest diversity.We addressed this research gap by conducting extensive sampling across the WG and re-examining museum specimens,thus providing a systematic account of various extant Cnemaspis species along with their distribution and natural history.We described 12 new species and a southern WG endemic clade of SA Cnemaspis.Ten of the newly described species are endemic to the forests of the southern WG.We also identified 10 well-supported subclades that can be separated across morphological,geographic,and phylogenetic axes.A time-calibrated phylogeny and ancestral area reconstructions confirmed the Paleocene origin of SA Cnemaspis in the WG and provide insights into its evolutionary history and biogeography.The discovery of multiple endemic and deeply divergent lineages further highlights the evolutionary significance of the WG for lizards.展开更多
Abstract: We assessed soil fungal diversity in the dry deciduous forest ofa Bhadra Wildlife Sanctuary of the Western Ghats (210.31 m a.s.1.; N 13044' and E75°37′). Soil samples were collected by random mixed...Abstract: We assessed soil fungal diversity in the dry deciduous forest ofa Bhadra Wildlife Sanctuary of the Western Ghats (210.31 m a.s.1.; N 13044' and E75°37′). Soil samples were collected by random mixed sampling during winter (November, 2008), summer (March, 2009) and monsoon (August, 2009) seasons, and physico-chemical parameters were recorded. During winter, summer, and monsoon seasons, 49, 45 and 49 of fungal species belongs to 20, 18 and 19 of genera were isolated, respectively. Isolated soil fungi were mainly of the Mitosporic fungi, followed by Zygomycotina, Ascomycotina, Oomycotina and Coelomycetes. Indices of diversity, dominance and fisher alpha during winter, summer and monsoon seasons were 3.756, 3.638 and 3.738 (H), 0.9737, 0.9694 and 0.9726 (I-D) and 18.84, 29.83 and 19.46 (a), respectively. Spear- man's (r) correlation coefficient of fungal population with physicochemical parameters of soils showed significantly positive and negative correlations (p〈0.01) during winter, summer and monsoon seasons. Physico-chemical soil parameters played an important role in the occurrence, diversity, distribution, and relative abundance of fungal species in the tropical dry deciduous forest soil.展开更多
Biodiversity and ecosystem services play key roles in future economic strategies seeking to promote development and prosperity. This study assesses the status of biodiversity and flow of ecosystem services from select...Biodiversity and ecosystem services play key roles in future economic strategies seeking to promote development and prosperity. This study assesses the status of biodiversity and flow of ecosystem services from selected forest types in the Western Ghats. At the sampling sites, the number of tree species ranged from 16 to 79 per hectare depending on the forest type. The estimates for Shannon–Wiener index for trees in the evergreen, moist deciduous and dry deciduous forest plots were 3.02, 2.9 and 1.54, respectively. The total biomass carbon stocks in evergreen, moist deciduous and dry deciduous forests in the study area was 229, 221 and 189 t C/ha, respectively.Analysis of dependency patterns of local communities on forest resources indicated a high dependency on provisional services such as fuelwood, manure and fodder. The study records the highest dependency rates for fuelwood,ranging between 72 and 100% for the three forest types and indicates that forest ecosystems underpin the well-being of the population dependent directly and indirectly on them.展开更多
Plants diversity and phenological pattern of the trees were monitored in a montane wet temperate forest (shola) in the Kukkal Forest, Palni hills of the southern Western Ghats, India. Twelve random plots were select...Plants diversity and phenological pattern of the trees were monitored in a montane wet temperate forest (shola) in the Kukkal Forest, Palni hills of the southern Western Ghats, India. Twelve random plots were selected for sampling the vegetation. For phenological studies, twenty-three fleshy fruit trees were identified in the study area and 10 individuals of each species were selected to record the phenological events fortnightly between April 2002 and April 2004. The phenological events were divided into vegetative and reproductive phases. A total of 2279 individuals were inventoried which belong to 83 species, 68 genera and 40 families. About 30% of the species were endemic to the Western Ghats. The most dominant species (〉 1 cm dbh) was Psychotria nilgiriensis var. astephana (Rubiaceae), which accounted for 12% of the total sampled individuals. Lauraceae was the dominant family accounting for 20% of the individuals. Fruiting peak occurred in July 2003 and least in June 2002. During the peak period, fruits of 85 individuals of six species were observed. Syzygium tamilnadensis, Ilex wightiana and Beilschmiedia wightii fruited only once during the two years of study. The number of fruiting species showed no correlation with rainfall (r = 0.26, p = 0.2), while a correlation was found with fruit abundance (r = 0.40, p 〈 0.05). The results indicate that the montane wet temperate forest is unique in their diversity and a conspicuous display in phenology.展开更多
It is reasonably well established that the Earth has substantially cooled from the Archean to the pre-sent and hence the sites, rates and pro- cesses of crust formation must have changed through geo-logic time. Archea...It is reasonably well established that the Earth has substantially cooled from the Archean to the pre-sent and hence the sites, rates and pro- cesses of crust formation must have changed through geo-logic time. Archean and Proterozoic granitic rocks are the principal record of such changes. Massif-type charnockites in the Eastern Ghats granulite belt, India, of Archean and Proterozoic ages mirror the changing conditions and/or processes of continental crust for- mation. Though both can be explained by dehydration melting of mafic rocks, the conditions differ. Potasium and rubidium rich Proterozoic charnockites have significant negative Eu ano- maly indicating melting at shallow depths in the stability field of plagioclase. In contrast, sodium and strontium rich Archean charnockites with less LREE enrichment and less depletion in Eu indicate melting at greater depths in the stability field of garnet or amphibole.展开更多
Apatite grains in a stratabound manganese ore body from Eastern Ghats in Leliguma, Koraput district south Orissa, India were studied under optical and electron microscope. Apatite shows bimodal occurrence: one associa...Apatite grains in a stratabound manganese ore body from Eastern Ghats in Leliguma, Koraput district south Orissa, India were studied under optical and electron microscope. Apatite shows bimodal occurrence: one associated with granite/pegmatitic phase and other with manganese phase, and exhibits different microstructure and composition. Apatite in pegmatitic association (occurring as inclusion in quartz and feldspar) is small in size and occurs as subhedral grains having irregular boundaries and poor in manganese content (MnO: 0.16%). Apatite associated with manganese mineral phases (cryptomelane / romanechite) is mostly euhedral, relatively larger in size, contains higher manganese value, and exhibits some peculiar features like twinning, zoning, overgrowth, and occasionally contains inclusion of quartz and feldspar grains. Apatite grains occurring as inclusions within quartz and feldspar are of hydrothermal origin and formed along with pegmatitic minerals. Such apatite is almost devoid of manganese but relatively enriched in Sr, F and LREE content. The apatite in manganese mineral association formed during supergene process. The apatite of latter generation appears as idiomorphic crystals;contains up to 6.85% of MnO in solid solution and shows relatively higher HREE values. The higher HREE values may be due to its derivation from stratiform Mn-ore bodies and associated granitised rock during remobilization, solution and precipitation of Mn –rich fluid along structurally weak planes resulting in development of a stratabound ore body.展开更多
Shear zones in the boundary between Eastern Ghats Province (EGP) and the cratons of Singhbhum in the north and Bastar in the west provide an excellent opportunity to study the tectonics of shear zone development and i...Shear zones in the boundary between Eastern Ghats Province (EGP) and the cratons of Singhbhum in the north and Bastar in the west provide an excellent opportunity to study the tectonics of shear zone development and its timing in relation to the evolutionary history of the granulite suites. Detailed structural, microfabric and quartz C-axis patterns revealed a high temperature shear zone, at the western boundary between EGP and Bastar Craton (BC) around Paikmal. Petrological studies in this shear zone indicated decompression coeval with stretching in the sheared granulites. Geochronological constraints provided here indicate rapid exhumation of deep seated granulites in this boundary shear zone;the timing also is late in relation to the long-lived thermal (granulite formation) event in the EGP. Additionally, our geochronological data demonstrated the ~1600 Ma event in the Eastern Ghats Belt (EGB) involving sedimentation, magmatism, metamorphism and crustal anatexis, as a significant world event.展开更多
基金This study is supported by the Indian Council of Medical Research-Vector Control Research Centre intramural funding(project grant no.:IM-1905).
文摘Objective:To report a new species of sandfly,Sergentomyia(Neophlebotomus)ashwanii sp.nov.(Diptera:Psychodidae)from Western Ghats,India.Methods:A systematic sandfly survey was conducted in the Thrissur and Kollam districts of Kerala,India using mechanical aspirators,light and sticky traps,both indoor and outdoor habitats,for a period of one year.Deoxyribonucleic acid barcoding of samples was performed targeting mitochondrial cytochrome oxidase I(COI)gene and sequence generated was subjected to phylogenetic analysis.Results:Sergentomyia(Neophlebotomus)ashwanii,a new sandfly species is recorded and described in this communication.A single row of 10-12 pointed teeth in the cibarium with 4-6 small denticles or fore-teeth are the key characteristics that is distinctive from other members of the subgenus Neophlebotomus.Mitochondrial COI barcode followed by phylogenetic analysis of the nucleotide sequence confirms that specimens of the species belong to the same taxonomic group while the genetic distance(14.2%)with the congeners established it to be a different species.Conclusions:The Western Ghats'being an important biodiversity hotspot and has dearth of systematic entomological surveys on sandflies.The current study tried to fill the void and also report a new sandfly species.
基金Financial support from Kerala State Council for Science, Technology, and Environment (004/FSHP/05KSCSTE)
文摘Revised Universal Soil Loss Equation(RUSLE) model coupled with transport limited sediment delivery(TLSD) function was used to predict the longtime average annual soil loss, and to identify the critical erosion-/deposition-prone areas in a tropical mountain river basin, viz., Muthirapuzha River Basin(MRB; area=271.75 km^2), in the southern Western Ghats, India. Mean gross soil erosion in MRB is 14.36 t ha^(-1) yr^(-1), whereas mean net soil erosion(i.e., gross erosion-deposition) is only 3.60 t ha^(-1) yr^(-1)(i.e., roughly 25% of the gross erosion). Majority of the basin area(~86%) experiences only slight erosion(<5 t ha^(-1) yr^(-1)), and nearly 3% of the area functions as depositional environment for the eroded sediments(e.g., the terraces of stream reaches, the gentle plains as well as the foot slopes of the plateau scarps and the terrain with concordant summits). Although mean gross soil erosion rates in the natural vegetation belts are relatively higher, compared to agriculture, settlement/built-up areas and tea plantation, the sediment transport efficiency in agricultural areas and tea plantation is significantly high,reflecting the role of human activities on accelerated soil erosion. In MRB, on a mean basis, 0.42 t of soil organic carbon(SOC) content is being eroded per hectare annually, and SOC loss from the 4th order subbasins shows considerable differences, mainly due to the spatial variability in the gross soil erosion rates among the sub-basins. The quantitative results, on soil erosion and deposition, modelled using RUSLE and TLSD, are expected to be beneficial while formulating comprehensive land management strategies for reducing the extent of soil degradation in tropical mountain river basins.
文摘The changes in species composition, abundance and forest stand structure were analyzed across altitudinal regimes in tropical forests of Eastern Ghats of northern Andhra Pradesh, India. Three 1-ha plots were established with one each in low, medium and high altitudes. A total of 153 species, 2129 stems (709 stems .ha^-1) of ≥10 cm girth were enumerated. Species richness and diversity pattern varied along altitudinal gradient and increased with the altitude. Species richness varied from 52 to 110 species-ha^-1 and stand density from 639 to 836 stems.ha^-1 with average basal area of 34.39 m^2.ha^-1. Shannon-Wiener index (H') ranged from 4.55 to 5.17. Low altitude (i.e., Site 1) is dominated byXylia xylocarpa (59.22) and Lagerstroemia parviflora (23.90), medium altitude (i.e., Site 2) by Xylia xylocarpa (45;50) Bursera serrata (17.29), and high altitude (i.e., Site 3) has Schleichera oleosa (28.25) Pterocarpus marsupium (26.55) as predominant species. Taxonomically, Rubiaceae (12 species), Fabaceae (12), Euphorbiaceae (11), Rutaceae (7) and Lanraceae (7) were dominant families. Density-wise, Fabaceae, Combretaceae, Euphorbiaceae, Anacardiaceae and Myrtaceae were abundant. Thus, conservation assessment based on altitudinal regimes and the information on species structure and function can provide baseline information for monitoring and sustaining the biodiversity.
文摘Nutrient composition of the manure of four pill millipedes (Arthrosphaera dalyi, ,4. davisoni, ,4. fumosa and,4, magna) inhabiting in semi-evergreen forests and plantations of the Western Ghats of Southwest India was evaluated. The quantity and quality of fecal pellets differed between millipedes and their habitats (forest and plantation). Organic carbon content in manure was lower in plantations than in forests, while nitrogen content was elevated in plantations. The carbon to nitrogen (C/N) ratio of manure was lower in plantations compared to forests. The phosphorus content in manure was elevated in plantations in all except for A. dalyi. Calcium content of manure was increased in plantations than in forests. The contents of magnesium, potassium and phenolics in manure showed varied results. The mass of fecal pellets was correlated only with volume in forests (r=0.882; p 〈0.01) and pH in plantations (r=0.616; p 〈0.05), while the volume of fecal pellets was correlated with nitrogen content in forests (r=0.751; p 〈0.01) and cal- cium in plantations (=0.619; p 〈0.05). The conductivity was positively correlated with phosphorus and potassium, while magnesium was negatively correlated in forests as well as plantations. Potassium and magnesium were negatively correlated in forests (r=0.920; p〈0.001) and plantations (t=0.692; p 〈0.05). Overall, the physicochemical characteristics and nutrient composition of fecal pelets differed between millipedes as well as habitats. The low carbon to nitrogen ratio and the increased nitrogen, phosphorus and calcium content in the manure of millipedes inhabiting in plantations indicates possibilities for successfully employing them for in situ composting of forest or plantation residues.
基金the University Grants Commission, New Delhi for providing the financial support for the Ph.D. research through Junior Research Fellowship (UGC letter No. F. 17-115/98 (SA-I) dated-11 June 2013)
文摘Background: The effect of forest fire on soil is complex and relatively less understood than its above ground effect.Understanding the effect of fire on forest soils can allow improving management of valuable forest ecosystems as adequate and proper information is very important for efficient management. We have studied the recovery of soil properties after fire, using a chronosequence approach(two, five and fifteen years after fire and control). Soil samples were collected from each plot of four fire patches(B0, B2, B5 & B15) from three different depths viz. 0–10(Top), 10–20(Middle), and 20–30 cm(Bottom).Results: Soil organic carbon was lower than unburned plots after the fire and could not recover to the level of unburned plot(B0) even in 15 years. Total N, available P, and extractable K were lower 2-years and 5-years after the fire but are higher than unburned plot after 15-years. Available nitrogen(NO_3^- and NH_4^+) remain unchanged or higher than B0 in burned patches. Soil pH, Bulk Density, Water Holding Capacity, and Electrical Conductivity was lower initially after the fire. Forest fires have affected soil properties considerably. The response of soil properties varied with years after fire and soil depth.Conclusion: Forest fires occur very frequently in the study area. Significant quantities of carbon and total nitrogen are lost to the atmosphere by burning of litter, duff, and soil OM. Because nitrogen is one of the most important soil nutrients, the recapture of N lost by volatilization during a fire must receive special attention. Long-term studies are required to better understand the recovery of soil nitrogen.
基金the Department of Biotechnology (DBT),New Delhi for funding this study through a project (BT/6603/NDB/51/089/2005-2009) and to all officers and staff of Tamil Nadu forest department for permission to conduct research in forests of southern Eastern Ghats
文摘We investigated the distribution and resource values of liana species assessed in six hill complexes of southern Eastern Ghats, India. 143 liana species (DBH (diameter at breast height) ≥1.5 cm) and 32,033 liana individuals were recorded from 110 transects (0.5 ha each covering 55 ha area) in the study sites. The resource values of lianas were broadly categorized into ecological and economic importance. About 90% (129) of liana species and 96% (30,564) of liana individuals were established ecological/economic values. Fruit rewards provided by 76 species and 20,325 individuals constituted the major resource of ecological importance. 82 species and 21,457 liana individuals are of economic importance as medicine, edible fruits, edible and medicinal values, and yet others are used for different domestic purposes including furniture, fuel wood, rope making etc.. Ecologically, the prevalence of succulent diaspores in lianas of Indian Eastern Ghats indicates the animal dependence of many liana species for dispersal and underlines the need for a holistic and whole-forest conservation approach in maintaining forest biodiversity.
基金support from the Ministry of Environment and Forests, Government of India
文摘We analyze the structure and composition of old-growth wet evergreen forest of Nelliampathy hills, the chain of hills lying immediately south of Palghat Gap, in the southern Western Ghats of India. We sampled 30 plots of 0.1 ha each (50 m × 20 m) at six locations enumerating all plants ? 10 cm girth at breast height. We pooled the data and computed various structural parameters. There were 152 species of 120 genera and 51 families of the study area. Of these, 118 (77%) were trees, 24 were climbers (16%) and 10 were shrubs (7%). Species richness varied from 58–99 per 0.5 ha sample and Shannon indices of diversity ranged from 4.4 to 5.2. Fifty-nine per cent (89 species) of the species were Indian Sub-continent elements and 34% (51 species) are endemic to the Western Ghats. Fifteen species are listed in various threat categories. Aglaia and Litsea were the most species-rich genera. Numbers of families ranged from 27–43 per 0.5 ha sample. Euphorbiaceae and Lauraceae were the most species-rich families. Stand density varied from 1714 to 2244 stems·ha?1 and basal area from 53.6 to 102.1 m2·ha?1. The vegetation was dominated by 3–6 species and six dominance patterns characterized the species composition within the hill complex. The old-growth evergreen forests of Nelliampathy exist as small fragments rich in biodiversity and can be used as benchmarks for comparison with disturbed forests.
文摘Forest resource conservation has been widely accepted as a key to sustain the local and regional economic development. The forest edges are affected by anthropogenic activities including deforestation, forest fragmentation, selective logging, extraction of non-timber forest products, collection of medicinal plants, recreations, hydroelectric pro- jects and its associated developmental activities, which alter the biodiver- sity. The present study intends to evaluate the edge effect on vegetation structure and species compositions in the tropical forest ecosystems at Periyar Wildlife Sanctuary in the Western Ghats. High species richness (number of species) and Shannon's diversity indices were observed in the site IlI (completely undisturbed forest) compared to site I (adjacent to the village/edge of the forest, which is next to the teal( plantation, severely disturbed forest) and site II (in between the undisturbed forest and mod- erately disturbed forest) while density of tree species showed greater value in site II. Single species such as Tectona grandis (IVI of 80) and Terminaliapaniculata (IVI of 112) were the dominant tree species in site I and site II, respectively, whereas, in site III Terminalia bellirica, Bishofia javanica and Syzgium gardneri shared the dominance. Perturba- tion leads to alien plant invasion particularly Lantana camara, Eupato- rium odoratum and Ageratum conizoides. Site II is at forest transition level because the site is dominated by both natural species as well as plantation species such as Tectona grandis. This site seems to be a buffer zone on natural forest and plantations. Further studies are required to analyse the real patterns of regeneration and dynamic change due to human impact by long term monitoring with the establishment of perma- nent plots.
基金Financial support from Kerala State Council for Science,Technology,and Environment,Thiruvananthapuram and permission for the field studies in the protected areas by Kerala Forest Department
文摘The paper evaluates sensitivity of various spaceborne digital elevation models (DEMs), viz., Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Shuttle Radar Topography Mapping Mission (SRTM) and Global Multi-resolution Terrain Elevation Data 2010 (GMTED), in comparison with the DEM (TOPO) derived from contour data of 20 m interval of Survey of India topographic sheets of 1 : 50,000 scale. Several topographic attributes, such as elevation (above mean sea level), relative relief, slope, aspect, curvature, slope-length and -steepness (LS) factor, terrain ruggedness index (TRI), topo- graphic wetness index (TWI), hypsometric integral (lhyp) and drainage network attributes (stream number and stream length) of two tropical mountain river basins, viz. Muthirapuzha River Basin and Pambar River Basin are compared to evaluate the variations. Though the basins are comparable in extent, they differ in respect of terrain characteristics and climate. The result.,; suggest that ASTER and SRTM provide equally reliable representation of topography portrayed by TOP() and the topographic attributes extracted from the spaceborne DEMs are in agreement with those derived from TOPO. Despite the coarser resolution, SRTM shows relatively higher vertical accuracy (RMSE -- 23 and 20 m respectively in MRB and PRB) compared to ASTER (RMSE - 33 and 24 m) and GMTED (RMSE - 59 and 48 m). Vertical accuracy of all the spaceborne DEMs is influenced by relief of the terrain as well as type of vegetation. Further, GMTED shows significant deviation for most of the attributes, indicating its inability for mountain-river-basin-scale studies.
文摘We used standard isolation protocols to explore the endophytic fungal communities in three tissue types of two dominant orchids (Bulbophyllum neilgherrense and Vanda testacea) of the Kaiga forest of the Western Ghats. We surface sterilized and assessed 90 segments of each orchid for the occurrence and diversity of endophytic fungal taxa. The 118 fungal isolates were obtained from root, bulb and leaves of B. neilgherrense, consisting of 17 anamorphic taxa (range, 10-15 taxa) with 1.3 fungal taxa per segment (range, 1.2-1.4 taxa). Four taxa (Aspergillus flavus, A. niger, Penicillium sp. and morpho sp. 1) belonged to the core group (11.1%--32.2%). The relative abundance of A. flavus and morpho sp. 1 was more than 10%. A total of 130 fungal isolates from roots, stems and leaves of V. testacea yielded 20 anamorphic taxa (range, 11-15 taxa) with 1.4 fungal taxa per segment (range, 1.4-1.5 taxa). Aspergillusflavus, A. niger, A. ochraceus, Gliocladium viride, Penicillium sp. and morpho sp. 1 belonged to the core group. Relative abundance exceeded 10% for A. flavus, A. niger, and morpho sp. 1. The Simpson and Shannon diversity indices were higher in leaf than root or bulb/stem of both orchids. Jaccard's similarity coefficient was higher between root and leaf in both orchids (56.3%-60%) than between other pairs. Our study revealed that the endophytic fungal assemblage and diversity orB. neilgherrense and E testacea of Kaiga forest of the Western Ghats were relatively similar between orchids and their tissues.
文摘Forty-five species of wild edible fruits were identified and traditional local knowledge of their usage was recorded in 40 villages of Kodagu district in Central Western Ghats, India one of the eight top hotspots of biodiversity in the world. We combined biodiversity inven-tory of trees with village interviews to record traditional ecological knowledge. Wild edible fruits were an opportunistic source of food for rural people. Wild edible fruits were rich in minerals, vitamins, carbohy-drates, proteins, fats and fiber. In recent years there has been a decline in numbers of wild fruit trees due to changes in land use from uncultivated private wooded area to cardamom and coffee cultivation. The availability of wild edible fruits that were once very common on private cultivated areas has declined and their distributions are now restricted more to jungles and wildlife sanctuaries. We propose methods for conservation and describe the need for sustainable utilization to provide supplemen-tary sources of nutritional and pharmaceutically useful edible wild fruits.
文摘In the eastern part of the Indian shield, late Paleozoic-Mesozoic sedimentary rocks of the Talchir Basin lie precisely along a contact of Neoproterozoic age between granulites of the Eastern Ghats Mobile Belt (EGMB) and amphibolite facies rocks of the Rengali Province. At present, the northern part of the basin experiences periodic seismicity by reactivation of faults located both within the basin, and in the Rengali Province to the north. Detailed gravity data collected across the basin show that Bouguer anomalies decrease from the EGMB (~+15 mGal), through the basin (^-10 mGal), into the Rengali Province (^-15 mGal). The data are consistent with the reportedly uncompensated nature of the EGMB, and indicate that the crust below the Rengali Province has a cratonic gravity signature. The contact between the two domains with distinct sub-surface structure, inferred from gravity data, coincides with the North Orissa Boundary Fault (NOBF) that defines the northern boundary of the Talchir Basin. Post-Gondwana faults are also localized along the northern margin of the basin, and present-day seismic tremors also have epicenters close to the NOBF. This indicates that the NOBF was formed by reactivation of a Neo- proterozoic terrane boundary, and continues to be susceptible to seismic activity even at the present-day.
基金funded by the Indian Institute of Remote Sensing,Dehradun,India under IIRS-VCP project entitled“National Carbon Pool Assessment”(Project Number:(UAS(B)/DR/GOI/246/2011-12)。
文摘The purpose of this study was to quantify the changes in tree diversity and above-ground biomass associated with six land-use types in Kodagu district of India's Western Ghats. We collected data on species richness,composition and above-ground biomass(AGB) of trees,shrubs and herbs from 96 sample plots of 0.1 ha. Totals of83 species from 26 families were recorded across the landuses. Tree species richness, diversity and composition were significantly higher in evergreen forest(EGF) than in other land-uses. Similarly, stem density and basal area were greater in EGF compared to other land-uses. Detrended correspondence analysis(DCA) yielded three distinct groups along the land-use intensities and rainfall gradient on the first and second axes, respectively. The first DCA axis accounted for 45% and second axis for 35% of the total variation in species composition. Together the first two axes accounted for over 2/3 of the variation in species composition across land-use types. Across the land-uses,AGB ranged from 58.6 Mg ha-1 in rubber plantation to327.3 Mg ha-1 in evergreen forest. Our results showed that species diversity and AGB were negatively impacted bythe land-use changes. We found that coffee agroforests resembled natural forest and mixed species plantation in terms of tree diversity and biomass production, suggesting that traditional coffee farms can help to protect tree species, sustain smallholder production and offer opportunities for conservation of biodiversity and climate change mitigation.
基金This study was supported by the Critical Ecosystem Partnership Fund(Western Ghats)DBT-IISc Partnership Programme and Ministry of Environment,Forests,and Climate Change(MoEFCC)Singinawa Conservation Foundation,and Rufford Small Grant。
文摘The highly speciose gekkonid genus Cnemaspis Strauch,1887 is polyphyletic,with three distantly related and geographically isolated clades from Africa,South Asia(SA),and Southeast Asia.At present,there are 85 known species within SA Cnemaspis,although the number continues to increase rapidly with focused surveys and rigorous taxonomic work.Recent studies have provided valuable insights into the diversity and evolutionary history of SA Cnemaspis;however,most of these studies lack sufficient sampling in the Western Ghats(WG),where the genus has its greatest diversity.We addressed this research gap by conducting extensive sampling across the WG and re-examining museum specimens,thus providing a systematic account of various extant Cnemaspis species along with their distribution and natural history.We described 12 new species and a southern WG endemic clade of SA Cnemaspis.Ten of the newly described species are endemic to the forests of the southern WG.We also identified 10 well-supported subclades that can be separated across morphological,geographic,and phylogenetic axes.A time-calibrated phylogeny and ancestral area reconstructions confirmed the Paleocene origin of SA Cnemaspis in the WG and provide insights into its evolutionary history and biogeography.The discovery of multiple endemic and deeply divergent lineages further highlights the evolutionary significance of the WG for lizards.
文摘Abstract: We assessed soil fungal diversity in the dry deciduous forest ofa Bhadra Wildlife Sanctuary of the Western Ghats (210.31 m a.s.1.; N 13044' and E75°37′). Soil samples were collected by random mixed sampling during winter (November, 2008), summer (March, 2009) and monsoon (August, 2009) seasons, and physico-chemical parameters were recorded. During winter, summer, and monsoon seasons, 49, 45 and 49 of fungal species belongs to 20, 18 and 19 of genera were isolated, respectively. Isolated soil fungi were mainly of the Mitosporic fungi, followed by Zygomycotina, Ascomycotina, Oomycotina and Coelomycetes. Indices of diversity, dominance and fisher alpha during winter, summer and monsoon seasons were 3.756, 3.638 and 3.738 (H), 0.9737, 0.9694 and 0.9726 (I-D) and 18.84, 29.83 and 19.46 (a), respectively. Spear- man's (r) correlation coefficient of fungal population with physicochemical parameters of soils showed significantly positive and negative correlations (p〈0.01) during winter, summer and monsoon seasons. Physico-chemical soil parameters played an important role in the occurrence, diversity, distribution, and relative abundance of fungal species in the tropical dry deciduous forest soil.
基金supported by The TEEB India initiative of MoEFCC
文摘Biodiversity and ecosystem services play key roles in future economic strategies seeking to promote development and prosperity. This study assesses the status of biodiversity and flow of ecosystem services from selected forest types in the Western Ghats. At the sampling sites, the number of tree species ranged from 16 to 79 per hectare depending on the forest type. The estimates for Shannon–Wiener index for trees in the evergreen, moist deciduous and dry deciduous forest plots were 3.02, 2.9 and 1.54, respectively. The total biomass carbon stocks in evergreen, moist deciduous and dry deciduous forests in the study area was 229, 221 and 189 t C/ha, respectively.Analysis of dependency patterns of local communities on forest resources indicated a high dependency on provisional services such as fuelwood, manure and fodder. The study records the highest dependency rates for fuelwood,ranging between 72 and 100% for the three forest types and indicates that forest ecosystems underpin the well-being of the population dependent directly and indirectly on them.
基金conducted as a part of the project on the endemic birds in the Western Ghats funded by the Ministry of Environment and Forest, Government of India (23-1/2001-RE)
文摘Plants diversity and phenological pattern of the trees were monitored in a montane wet temperate forest (shola) in the Kukkal Forest, Palni hills of the southern Western Ghats, India. Twelve random plots were selected for sampling the vegetation. For phenological studies, twenty-three fleshy fruit trees were identified in the study area and 10 individuals of each species were selected to record the phenological events fortnightly between April 2002 and April 2004. The phenological events were divided into vegetative and reproductive phases. A total of 2279 individuals were inventoried which belong to 83 species, 68 genera and 40 families. About 30% of the species were endemic to the Western Ghats. The most dominant species (〉 1 cm dbh) was Psychotria nilgiriensis var. astephana (Rubiaceae), which accounted for 12% of the total sampled individuals. Lauraceae was the dominant family accounting for 20% of the individuals. Fruiting peak occurred in July 2003 and least in June 2002. During the peak period, fruits of 85 individuals of six species were observed. Syzygium tamilnadensis, Ilex wightiana and Beilschmiedia wightii fruited only once during the two years of study. The number of fruiting species showed no correlation with rainfall (r = 0.26, p = 0.2), while a correlation was found with fruit abundance (r = 0.40, p 〈 0.05). The results indicate that the montane wet temperate forest is unique in their diversity and a conspicuous display in phenology.
文摘It is reasonably well established that the Earth has substantially cooled from the Archean to the pre-sent and hence the sites, rates and pro- cesses of crust formation must have changed through geo-logic time. Archean and Proterozoic granitic rocks are the principal record of such changes. Massif-type charnockites in the Eastern Ghats granulite belt, India, of Archean and Proterozoic ages mirror the changing conditions and/or processes of continental crust for- mation. Though both can be explained by dehydration melting of mafic rocks, the conditions differ. Potasium and rubidium rich Proterozoic charnockites have significant negative Eu ano- maly indicating melting at shallow depths in the stability field of plagioclase. In contrast, sodium and strontium rich Archean charnockites with less LREE enrichment and less depletion in Eu indicate melting at greater depths in the stability field of garnet or amphibole.
文摘Apatite grains in a stratabound manganese ore body from Eastern Ghats in Leliguma, Koraput district south Orissa, India were studied under optical and electron microscope. Apatite shows bimodal occurrence: one associated with granite/pegmatitic phase and other with manganese phase, and exhibits different microstructure and composition. Apatite in pegmatitic association (occurring as inclusion in quartz and feldspar) is small in size and occurs as subhedral grains having irregular boundaries and poor in manganese content (MnO: 0.16%). Apatite associated with manganese mineral phases (cryptomelane / romanechite) is mostly euhedral, relatively larger in size, contains higher manganese value, and exhibits some peculiar features like twinning, zoning, overgrowth, and occasionally contains inclusion of quartz and feldspar grains. Apatite grains occurring as inclusions within quartz and feldspar are of hydrothermal origin and formed along with pegmatitic minerals. Such apatite is almost devoid of manganese but relatively enriched in Sr, F and LREE content. The apatite in manganese mineral association formed during supergene process. The apatite of latter generation appears as idiomorphic crystals;contains up to 6.85% of MnO in solid solution and shows relatively higher HREE values. The higher HREE values may be due to its derivation from stratiform Mn-ore bodies and associated granitised rock during remobilization, solution and precipitation of Mn –rich fluid along structurally weak planes resulting in development of a stratabound ore body.
文摘Shear zones in the boundary between Eastern Ghats Province (EGP) and the cratons of Singhbhum in the north and Bastar in the west provide an excellent opportunity to study the tectonics of shear zone development and its timing in relation to the evolutionary history of the granulite suites. Detailed structural, microfabric and quartz C-axis patterns revealed a high temperature shear zone, at the western boundary between EGP and Bastar Craton (BC) around Paikmal. Petrological studies in this shear zone indicated decompression coeval with stretching in the sheared granulites. Geochronological constraints provided here indicate rapid exhumation of deep seated granulites in this boundary shear zone;the timing also is late in relation to the long-lived thermal (granulite formation) event in the EGP. Additionally, our geochronological data demonstrated the ~1600 Ma event in the Eastern Ghats Belt (EGB) involving sedimentation, magmatism, metamorphism and crustal anatexis, as a significant world event.