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The quantitative identification of the coal texture is of great importance as a crucial parameter for coalbed methane (CBM) reservoir evaluation. This study combined drilling core data, electrical imaging logging data, and four conventional logging data, namely, compensation density (DEN), natural γ (GR), deep lateral resistivity (RD), and acoustic time difference (AC), to achieve accurate inversion of coal texture in the Shouyang Block. Meanwhile, wavelet analysis and Fisher discriminant analysis were introduced to the inversion process to further improve the accuracy. Through the utilization of software packages, such as Matlab and SPSS, the establishment of the coal texture logging interpretation chart of the No. 15 coal seam in the Shouyang block was successfully realized. The outcome of this comprehensive study reveals that the coal texture logging interpretation chart is an effective tool for the identification and classification of each coal texture and gangue. Moreover, the validity and reliability of this method were tested and confirmed using wells CS-8 and CS-9 in the region, achieving an accuracy of 97.1 and 93.2%, respectively. This innovative method has significant prospects for predicting and evaluating the coal texture in the Shouyang Block, which can be further applied to other regions.

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AimsDesert steppe is an important ecological barrier in northern China. Stipa breviflora and Cleistogenes songorica are the dominant species in the desert steppe. Both plant populations undergo plant cluster fragmentation to varying degrees when subject to grazing interference. However, when both plant populations are present in the same plant community, changes in their inter-specific relationship under grazing is important for regulation of the plant community and its functions. MethodsThis study investigated S. breviflora and C. songorica in a desert steppe, and used variance analysis, the Jaccard index and simple linear regression model analysis methods to study differences in the density of both species under four grazing intensities (i.e., control (CK) 0 sheep·hm-2·half year-1, light grazing (LG) 0.93 sheep·hm-2·half year-1, moderate grazing (MG) 1.82 sheep·hm-2·half year-1 and heavy grazing (HG) 2.71 sheep·hm-2·half year-1) at six scales (i.e., 5 cm×5 cm, 10 cm×10 cm, 20 cm×20 cm, 25 cm×25 cm, 50 cm×50 cm and 100 cm×100 cm). The study explored the competitive relationships between the plant populations. ResultsResults showed that grazing changes the relationship between dominant species. As grazing intensity increases, the competitive abilities of S. breviflora and C. songorica first increased and then decreased. Under heavy grazing conditions, the dominant populations of clustered grasses in the desert steppe resisted interference from high-intensity grazing by reducing inter-specific competition. ConclusionsAs grazing intensity increased, the densities of S. breviflora and C. songorica increased, and the increase became more obvious as the scale of analysis increased.