Frontiers of Earth Science

ISSN 2095-0195

ISSN 2095-0209(Online)

CN 11-5982/P

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, Volume 5 Issue 2

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RESEARCH ARTICLE
Federated or cached searches: Providing expected performance from multiple invasive species databases
Jim GRAHAM, Catherine S. JARNEVICH, Annie SIMPSON, Gregory J. NEWMAN, Thomas J. STOHLGREN
Front Earth Sci. 2011, 5 (2): 111-119.  
https://doi.org/10.1007/s11707-011-0152-7

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Invasive species are a universal global problem, but the information to identify them, manage them, and prevent invasions is stored around the globe in a variety of formats. The Global Invasive Species Information Network is a consortium of organizations working toward providing seamless access to these disparate databases via the Internet. A distributed network of databases can be created using the Internet and a standard web service protocol. There are two options to provide this integration. First, federated searches are being proposed to allow users to search “deep” web documents such as databases for invasive species. A second method is to create a cache of data from the databases for searching. We compare these two methods, and show that federated searches will not provide the performance and flexibility required from users and a central cache of the datum are required to improve performance.

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A habitat overlap analysis derived from Maxent for Tamarisk and the South-western Willow Flycatcher
Patricia YORK, Paul EVANGELISTA, Sunil KUMAR, James GRAHAM, Curtis FLATHER, Thomas STOHLGREN
Front Earth Sci. 2011, 5 (2): 120-129.  
https://doi.org/10.1007/s11707-011-0154-5

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Biologic control of the introduced and invasive, woody plant tamarisk (Tamarix spp, saltcedar) in south-western states is controversial because it affects habitat of the federally endangered South-western Willow Flycatcher (Empidonax traillii extimus). These songbirds sometimes nest in tamarisk where floodplain-level invasion replaces native habitats. Biologic control, with the saltcedar leaf beetle (Diorhabda elongate), began along the Virgin River, Utah, in 2006, enhancing the need for comprehensive understanding of the tamarisk-flycatcher relationship. We used maximum entropy (Maxent) modeling to separately quantify the current extent of dense tamarisk habitat (>50% cover) and the potential extent of habitat available for E. traillii extimus within the studied watersheds. We used transformations of 2008 Landsat Thematic Mapper images and a digital elevation model as environmental input variables. Maxent models performed well for the flycatcher and tamarisk with Area Under the ROC Curve (AUC) values of 0.960 and 0.982, respectively. Classification of thresholds and comparison of the two Maxent outputs indicated moderate spatial overlap between predicted suitable habitat for E. traillii extimus and predicted locations with dense tamarisk stands, where flycatcher habitat will potentially change flycatcher habitats. Dense tamarisk habitat comprised 500 km2 within the study area, of which 11.4% was also modeled as potential habitat for E. traillii extimus. Potential habitat modeled for the flycatcher constituted 190 km2, of which 30.7% also contained dense tamarisk habitat. Results showed that both native vegetation and dense tamarisk habitats exist in the study area and that most tamarisk infestations do not contain characteristics that satisfy the habitat requirements of E. traillii extimus. Based on this study, effective biologic control of Tamarix spp. may, in the short term, reduce suitable habitat available to E. traillii extimus, but also has the potential in the long term to increase suitable habitat if appropriate mixes of native woody vegetation replace tamarisk in biocontrol areas.

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Subpixel measurement of mangrove canopy closure via spectral mixture analysis
Minhe JI, Jing FENG
Front Earth Sci. 2011, 5 (2): 130-137.  
https://doi.org/10.1007/s11707-011-0156-3

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Canopy closure can vary spatially within a remotely sensed image pixel, but Boolean logic inherent in traditional classification methods only works at the whole-pixel level. This study attempted to decompose mangrove closure information from spectrally-mixed pixels through spectral mixture analysis (SMA) for coastal wetland management. Endmembers of different surface categories were established through signature selection and training, and memberships of a pixel with respect to the surface categories were determined via a spectral mixture model. A case study involving DigitalGlobe’s Quickbird high-resolution multispectral imagery of Beilun Estuary, China was used to demonstrate this approach. Mangrove canopy closure was first quantified as percent coverage through the model and then further grouped into eight ordinal categories. The model results were verified using Quickbird panchromatic data from the same acquisition. An overall accuracy of 84.4% (Kappa = 0.825) was achieved, indicating good application potential of the approach in coastal resource inventory and ecosystem management.

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Understanding the transportational and depositional setting of Panchet Formation, Purulia and Bankura districts of West Bengal, India---- Evidence from grain size analysis
Bapi GOSWAMI, Dipsikha GHOSH
Front Earth Sci. 2011, 5 (2): 138-149.  
https://doi.org/10.1007/s11707-011-0169-y

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The rocks of Triassic Panchet Formation (TPF) of West Bengal, India, predominantly include sandstones of medium to fine grain-size, with subordinate shale and pebble horizons. Textural parameter like mean, standard deviation, skewness and kurtosis are calculated using standard methods to understand the transportation and the depositional environment of the sediments in a part of Panchet Formation. Granulometric analyses indicate the presence of fluvial environment interrupted with aeolian, beach and tidal environments prevailed during the time of deposition of the sediments in this part of Gondwanaland during the Triassic time.

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Assessment of soil erosion under woodlands using USLE in China
Changshun ZHANG, Gaodi XIE, Chunlan LIU, Chunxia LU
Front Earth Sci. 2011, 5 (2): 150-161.  
https://doi.org/10.1007/s11707-011-0158-1

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Universal Soil Loss Equation (USLE), originally developed by the USDA for agricultural lands and then used throughout the world, was applied in mountainous forest terrain in China. The woodland area was divide into 100 m × 100 m grid cells. The ArcInfo 9.2 GIS software provided spatial input data was used to predict the spatial distribution of the average annual soil loss on grid basis. The average rainfall erositivity factor (R) for national woodlands was found to be 21–1798 MJ·mm·ha-1·h-1·a-1. The soil erodibility factor (K) with a magnitude of 0.043 t·ha·h· ha-1·MJ-1·mm-1 is the highest for Chinese woodland. Most of the slope length factors (LS) were less than 5 for the national woodland. The highest and lowest values of cover and management factor (C) were found out to be 0.0068 and 0.2550 respectively for coniferous woodland and orchard woodland. The value of conservation factor (P) was assigned to be 1 for Chinese woodlands because of scarcity of conversation practice data at the national scale. The average annual soil loss of the national woodland areas was 3.82 t·km-2·a-1. About 99.89% of Chinese woodland area was found out to be under slight erosion class, whereas it only resulted in about 41.97% of soil loss under woodland area, and 58.03% of soil loss occurred under high erosion potential zone, namely more than 5 t·ha-1·a-1. Therefore, those zones need immediate attention from soil conservation point of view. The results here are consistent with many domestic and oversea previous researches under mountainous forests or hilly catchments, thus we showed that the USLE can be applied to estimations of soil erosion for Chinese woodlands at the national scale.

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Influence of natural pozzolana and lime additives on the temporal variation of soil compaction and shear strength
Khelifa HARICHANE, Mohamed GHRICI, Hanifi MISSOUM
Front Earth Sci. 2011, 5 (2): 162-169.  
https://doi.org/10.1007/s11707-011-0166-1

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Soil stabilization has been practiced for quite some time by adding mixtures, such as cement, lime and fly ash. The additives of lime (L), natural pozzolana (NP) or a combination of both were investigated here on the impact on the temporal variation of geotechnical characteristics of two cohesive soils. Lime and natural pozzolana were added at the content of 0–8% and 0–20%, respectively. The soil specimens were cured for 1, 7, 28 and 90 days and then tested for shear strength. Our data show that a combination of lime with natural pozzolana causes the increase in the maximum dry density but the decrease in the optimum moisture content in the gray soil, and vice verse in the red soil. The shear stress of both cohesive soils stabilized with lime or with the combination of lime and natural pozzolana was found to increase with time. The cohesion and the internal friction angle in lime-added samples were demonstrated to increase with time. The combination of lime with natural pozzolana exhibits a significant effect on the enhancement of the cohesion and the internal friction angle at later stages. The lime-natural pozzolana combination appears to produce higher shear parameters than lime or natural pozzolana used alone.

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Ecological effect caused by hydraulic engineering construction
Jie LIU, Fan CHEN, Qing CUI, Yun JIANG
Front Earth Sci. 2011, 5 (2): 170-177.  
https://doi.org/10.1007/s11707-011-0155-4

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This paper summarized the main ecological impact of hydraulic engineering to the hydrology and the sediment of the river, built up the index system assessing the ecological effect of the hydraulic engineering, and structured the integrative assessment model. This model was applied using the case project to verify the feasibility of integrative assessment system.

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Geochemical constraints on the depositional environment of Upper Devonian radiolarian cherts from Loei, north-eastern Thailand
Mongkol UDCHACHON, Hathaithip THASSANAPAK, Qinglai FENG, Chongpan CHONGLAKMANI
Front Earth Sci. 2011, 5 (2): 178-190.  
https://doi.org/10.1007/s11707-011-0153-6

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Late Devonian radiolarian chert sequences in the Indochina block of north-eastern Thailand are exposed in a narrow belt located to the east of Loei province. The analyzed radiolarian cherts were collected from Chiang Klom, Sumnoi and Pha Samyod localities. They are characterized by high silica content (>90 wt.%), high aluminum content and low iron content (Al2O3/(Al2O3 + Fe2O3): geomeans 0.91, 0.88 and 0.92). The Al/(Al+ Fe+ Mn) values are high in both cherts and interbedded shales (geomean 0.89). High Si/(Si+ Al+ Fe) ratios are observed in cherts (geomean 0.97) and slightly low in shales (geomean 0.69), whereas Fe2O3/TiO2 values are low (geomean 5.91). For rare earth element (REE) analysis, the cherts exhibit low La abundances (geomean 4.31, 3.59 and 4.22), slightly negative Ce anomalies (Ce/Ce*: geomean 0.81, 0.76 and 0.93), intermediate ratios of North American Shale Composite (NASC) normalized Lan/Cen (geomean 1.33, 1.37 and 1.12) and intermediate Lan/Ybn values (0.79, 0.94 and 1.22). In the interbedded shales, REE characteristics are more or less equal to the cherts. The results indicate that these late Devonian radiolarian cherts were deposited in a continental margin environment. High Si/(Si+ Al+ Fe) values indicate a biogenic origin of the cherts, however, additional silica content in the cherts could be the result of diagenetic alteration. Intermediate positive Eu anomalies (Eu/Eu*: geomean 1.32, 1.25 and 1.44) are interpreted as the result of detrital feldspar contribution corresponding to the distinctive low content of Fe. Geological evidences from the field support volcanic activities during the Late Devonian–Early Carboniferous. Weathered materials and fragments of basalts and andesites would possibly be supplied to the basin during chert sedimentation. These geochemical constraints indicate that, in western portion of Indochina, deep marine basin was closed before Late Devonian which was followed by the incursion of Early Carboniferous orogeny.

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Special bedrock buried hill and the reservoiring process in Qijia–Yitong basin in northeastern China
Zhenlin CHEN, Hongfu YIN, Hongbo MIAO, Yuchao QIU, Yu ZOU
Front Earth Sci. 2011, 5 (2): 191-196.  
https://doi.org/10.1007/s11707-011-0167-0

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The bedrock buried hill is a mountainous peak formed by the arching up of the basement rocks in a sedimentary basin. The mountainous peak could be the ancient buried hill, known as buried-hill drape structure, present before the formation of sedimentary cover. In contrast, the late-formed buried hill comes into being after the deposition of the sedimentary cover due to the fold, fracture, volcanic eruption and other tectonic events in later stages. No matter what type of buried-hills, the reservoiring is comparable, with the dissolved pores formed by weathering and leaching of bedrocks as the reservoir, and the overlying sedimentary rocks as the source rocks and cover rocks. These are known as ancient reservoir but newborn sources. We present here, however, a different situation of the buried hill in Yitong basin in northeastern China. The bedrock in Yitong basin is the Yanshanian granite, which occurs as a sill underlain by Paleozoic marine strata of low electric resistivity. A right-lateral strike-slip extrusion of Yitong basin in Himalayan period leads to the diapiric ascent of the Lower Paleozoic argillite, which in turn causes the arching up of the granite bedrock to form the buried hill. It is concluded, on the basis of drill No. Chang 37, that the natural gas is sourced from Carboniferous-Permian argillite, and reservoirs in the cracks developed beneath 300m of the granite sill, with the upper part of granite as the cover.

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Significance of pCO2 values in determining carbonate chemistry in groundwater of Pondicherry region, India
S Chidambaram, M.V Prasanna, U Karmegam, C Singaraja, S Pethaperumal, R Manivannan, P Anandhan, K Tirumalesh
Front Earth Sci. 2011, 5 (2): 197-206.  
https://doi.org/10.1007/s11707-011-0170-5

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The partial pressure of Carbon-Di-oxide plays a significant role in the water chemistry. It reflects the geochemical process and relates to the saturation index (SI) of the Carbonate minerals. A total number of 98 samples were collected from layered sequential aquifers like Alluvium, Upper Cuddalore sandstone, Lower Cuddalore Sandstone and Cretaceous formations, during Pre-Monsoon and Post-Monsoon seasons. Chemical parameters of groundwater such as pH, EC, TDS, Na+, K+, Ca2+, Mg2+, Cl-, HCO3-, SO42-,PO43- and H4SiO4 were determined. The study shows that an increase in the log pCO2 values during water-rock interaction which influences the process of mineral dissolution. Saturation index of the carbonate minerals like Calcite, Aragonite, Dolomite and Magnesite were derived and compared with the log pCO2 values. In both the seasons the decreasing log pCO2 increases the saturation index of most of the carbonate minerals studied. The saturation index of almost all carbonate minerals during both the seasons showed negative correlation irrespective of the formation. Log pCO2 also develops a negative correlation with pH in groundwater of the study area.

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Sediment yield assessment by EPM and PSIAC models using GIS data in semi-arid region
Ali Bagherzadeh, Mohammad Reza Mansouri Daneshvar
Front Earth Sci. 2011, 5 (2): 207-216.  
https://doi.org/10.1007/s11707-011-0168-z

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Among land degradation processes, soil erosion is the most serious threat to soil and water conservation in semi-arid regions. At the present study, the sedimentation hazard and the erosion zonation were investigated at Kardeh watershed, north-east of Iran by Erosion Potential Method (EPM) and Pacific Sonth-west Inter Agency Committee (PSIAC) models, in combination with the geographical information system (GIS) data, satellite data and field observations. According to our investigation the study area can be categorized into heavy, moderate and slight erosion zones with the total sediment yield of 147859 and 148078 m3/a estimated by EPM and PSIAC models, respectively. The sub-basins located at the middle and south parts of the watershed are highly eroded due to the geology formation and soil erodibility conditions, while the sub-basins at the north parts are moderately eroded because of the intensive land cover. The amounts of the sediment yield in most areas are found to be consistent between the EPM and PSIAC models (R2 = 0.95). Our data suggest the applicability of both empirical models in evaluating the sediment yield in arid and semi-arid watersheds.

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Habitat suitability of patch types: A case study of the Yosemite toad
Christina T. LIANG, Thomas J. STOHLGREN
Front Earth Sci. 2011, 5 (2): 217-228.  
https://doi.org/10.1007/s11707-011-0157-2

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Understanding patch variability is crucial in understanding the spatial population structure of wildlife species, especially for rare or threatened species. We used a well-tested maximum entropy species distribution model (Maxent) to map the Yosemite toad (Anaxyrus (= Bufo) canorus) in the Sierra Nevada mountains of California. Twenty-six environmental variables were included in the model representing climate, topography, land cover type, and disturbance factors (e.g., distances to agricultural lands, fire perimeters, and timber harvest areas) throughout the historic range of the toad. We then took a novel approach to the study of spatially structured populations by applying the species-environmental matching model separately for 49 consistently occupied sites of the Yosemite toad compared to 27 intermittently occupied sites. We found that the distribution of the entire population was highly predictable (AUC= 0.95±0.03 SD), and associated with low slopes, specific vegetation types (wet meadow, alpine-dwarf shrub, montane chaparral, red fir, and subalpine conifer), and warm temperatures. The consistently occupied sites were also associated with these same factors, and they were also highly predictable (AUC= 0.95±0.05 SD). However, the intermittently occupied sites were associated with distance to fire perimeter, a slightly different response to vegetation types, distance to timber harvests, and a much broader set of aspect classes (AUC= 0.90±0.11 SD). We conclude that many studies of species distributions may benefit by modeling spatially structured populations separately. Modeling and monitoring consistently-occupied sites may provide a realistic snapshot of current species-environment relationships, important climatic and topographic patterns associated with species persistence patterns, and an understanding of the plasticity of the species to respond to varying climate regimes across its range. Meanwhile, modeling and monitoring of widely dispersing individuals and intermittently occupied sites may uncover environmental thresholds and human-related threats to population persistence.

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12 articles