Scale dependence of forest fragmentation and its climate sensitivity in a semi-arid mountain:Comparing Landsat,Sentinel and Google Earth data

Landscape fragmentation is generally viewed as an indicator of environmental stresses or risks,but the fragmentation intensity assessment also depends on the scale of data and the definition of spatial unit.This study aimed to explore the scale-dependence of forest fragmentation intensity along a moisture gradient in Yinshan Mountain of North China,and to estimate environmental sensitivity of forest fragmentation in this semi-arid landscape.We developed an automatic classification algorithm using simple linear iterative clustering(SLIC)and Gaussian mixture model(GMM),and extracted tree canopy patches from Google Earth images(GEI),with an accuracy of 89.2%in the study area.Then we convert the tree canopy patches to forest category according to definition of forest that tree density greater than 10%,and compared it with forest categories from global land use datasets,FROM-GLC10 and GlobeLand30,with spatial resolutions of 10 m and 30 m,respectively.We found that the FROM-GLC10 and GlobeLand30 datasets underestimated the forest area in Yinshan Mountain by 16.88%and 21.06%,respectively;and the ratio of open forest(OF,10%<tree coverage<40%)to closed forest(CF,tree coverage>40%)areas in the underestimated part was 2:1.The underestimations concentrated in warmer and drier areas occupied mostly by large coverage of OFs with severely fragmented canopies.Fragmentation intensity of canopies positively correlated with spring temperature while negatively correlated with summer precipitation and terrain slope.When summer precipitation was less than 300 mm or spring temperature higher than 4℃,canopy fragmentation intensity rose drastically,while the forest area percentage kept stable.Our study suggested that the spatial configuration,e.g.,sparseness,is more sensitive to drought stress than area percentage.This highlights the importance of data resolution and proper fragmentation measurements for forest patterns and environmental interpretation,which is the base of reliable ecosystem predictions with regard to the future climate scenarios.

Impact of Conjugated Shear Joint of“X”Type on Macroscopic Karstification on the Basis of the Analysis of Google Earth Images

As viewed from space remote-sensing images （e.g. Google Earth images） of South Guizhou and North Guangxi, the authors found that macroscopic karst landscape on the Earth＇s surface is strongly controlled by the Conjugated shear joint of ＂X＂ type. Joints of this kind constitute a huge infiltration network and act as channel-ways for the permeation of meteoric waters from the surface, thus, leading to the dissolution of carbonate rocks nearby. As a result, the karst landscape is formed, which is dominated by linear karst valleys. An ＂X＂ karst valley network structure appears in the area where horizontal strata are distributed, and a feather-like network structure appears in the area where vertical strata are distributed, respectively. When the water permeates downwards to the underground-water level, it will flow horizontally along the strike of ＂X＂ joints toward the local base level of erosion to form an ＂X＂ network system of underground conduits in the area where horizontal strata are distributed, but it is relatively complex, because of the joining of other joints. This is the first time we have made use of Google Earth images to study the karst environment. Therefore, it has been successful in research on the Earth＇s geomorphology, which could only rely on aerial photos and satellite photos in the past. Google Earth images provide low-cost and applicable imaging materials for the study of Earth＇s geomorphology and karst rocky desertification and its control.

Mapping the Dyke Swarms Emplaced within the Different Archean Cratons of the Indian Shield Using Google^(TM) Earth Images and Arc GIS^(TM) Techniques

The Indian shield comprises a number of Archean–Paleoproterozoic cratonic blocks and predominantly Meso–Neoproterozoic mobile belts with Archean protoliths.All these ancient cratons were thought to be integral parts of

Does Geochronology of Few Dykes of a Swarm are True Representative of All Dykes of the Same Magmatic Event?: Constraints from the Geochemistry and Google^(TM) Earth Image–ArcG IS^(TM) Studies of the Paleoproterozoic Mafic Dyke Swarms of the Eastern Dharwa

A precise dating of a mafic dyke of a swarm in shield areas has great advantage to identify Large Igneous Provinces(LIPs;short-lived,mantle-generated magmatic event)(Bryan and Ernst,2008;Ernst et al.,2010).Such

Identifying ephemeral gullies from high-resolution images and DEMs using flow-directional detection

Ephemeral gullies,which are widely developed worldwide and threaten farmlands,have aroused a growing concern.Identifying and mapping gullies are generally considered prerequisites of gully erosion assessment.However,ephemeral gully mapping remains a challenge.In this study,we proposed a flow-directional detection for identifying ephemeral gullies from high-resolution images and digital elevation models(DEMs).Ephemeral gullies exhibit clear linear features in high-resolution images.An edge detection operator was initially used to identify linear features from high-resolution images.Then,according to gully erosion mechanism,the flow-directional detection was designed.Edge images obtained from edge detection and flow directions obtained from DEMs were used to implement the flow-directional detection that detects ephemeral gullies along the flow direction.Results from ten study areas in the Loess Plateau of China showed that ranges of precision,recall,and Fmeasure are 6 o.66%-90.47%,65.74%-94.98%,and63.10%-91.93%,respectively.The proposed method is flexible and can be used with various images and DEMs.However,analysis of the effect of DEM resolution and accuracy showed that DEM resolution only demonstrates a minor effect on the detection results.Conversely,DEM accuracy influences the detection result and is more important than the DEM resolution.The worse the vertical accuracy of DEM,the lower the performance of the flow-directional detection will be.This work is beneficial to research related to monitoring gully erosion and assessing soil loss.

Synthesis,characterization and cell imaging properties of rare earth compounds based on hydroxamate ligand

Six binuclear rare earth compounds were synthesized through the ligand of 4-Bromo-N-hydroxy-Nmethyl-benzamide（sH_2 bha）. Compounds 1-3 are isomorphous, and compound 1 is crystallized in the monoclinic system with the P2_1/c space group. Compounds 4 and 5 are isomorphous, and compound 4 is crystallized in the triclinic system with the P-1 space group. Compound 6 is crystallized in the triclinic system with the P-1 space group. The compounds were characterized by thermogravimetric analysis（TGA） and IR spectroscopy. The fluorescence spectrum in the visible area shows characteristic peaks of Eu, Tb, and Dy compounds. The efficiency of Eu compound on the viability of PC3 cells was assessed using CCK8 assays. From the CCK8 results, ionic concentration may have a great effect on PC3 cells＇ proliferation. Eu compound shows red fluorescence in the cytoplasm of PC3 cell. As for Eu compound, it might have potential application in cell imaging technology.

Comparison of TMI and AMSR-E sea surface temperatures with Argo near-surface temperatures over the global oceans

Satellite-derived sea surface temperatures（SSTs） from the tropical rainfall measuring mission（TRMM）microwave imager（TMI） and the advanced microwave scanning radiometer for the earth observing system（AMSR-E） were compared with non-pumped near-surface temperatures（NSTs） obtained from Argo profiling floats over the global oceans. Factors that might cause temperature differences were examined, including wind speed, columnar water vapor, liquid cloud water, and geographic location. The results show that both TMI and AMSR-E SSTs are highly correlated with the Argo NSTs; however, at low wind speeds, they are on average warmer than the Argo NSTs. The TMI performs slightly better than the AMSR-E at low wind speeds, whereas the TMI SST retrievals might be poorly calibrated at high wind speeds. The temperature differences indicate a warm bias of the TMI/AMSR-E when columnar water vapor is low, which can indicate that neither TMI nor AMSR-E SSTs are well calibrated at high latitudes. The SST in the Kuroshio Extension region has higher variability than in the Kuroshio region. The variability of the temperature difference between the satellite-retrieved SSTs and the Argo NSTs is lower in the Kuroshio Extension during spring. At low wind speeds, neither TMI nor AMSR-E SSTs are well calibrated, although the TMI performs better than the AMSR-E.

Upconversion NaGdF4 nanoparticles for monitoring heat treatment and acid corrosion processes of hair

Lanthanide-based upconversion core-shell NaGdF4 nanocrystals with strong upconversion luminescence and biocompatibility were synthesized by the solvothermal method.The multicolor upconversion emission of these NaGdF4 nanoparticles could be easily obtained by controlling the core-shell compositions.These multicolor core-shell NaGdF4 upconversion nanocrystals could be employed as fluorescent probes for imaging the mouse hair,by which the porous and scalelike structure of the mouse hair were presented clearly.Meanwhile,it was directly shown by fluorescent signals that the mouse hair could resist the corrosion of the strong acid even when the concentration of hydrochloric acid was increased to 36.5%,but could not avoid the carbonization at high temperature of 400 oC.This procedure based on upconversion fluorescent nanoprobes opens a novel route for investigating the basic physical structure and chemical properties of biological tissue and organism.