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Dynamic features from remote sensing photos may be successfully extracted using deep learning and symmetric network structure, which can then be used to direct them to carry out accurate classification. The DBN model can more effectively extract features from photos since it uses unsupervised learning. It can be reduced to the many symmetric Restricted Boltmann Machines (RBM) training problem. In this paper, a soil rocky desertification (RD) assessment model based on a deep belief network (DBN) is created in light of the complicated influencing aspects of Karst RD risk assessment encompassing several geographical elements. The model builds upon the conventional RBM framework and incorporates the influence layer of related elements as an auxiliary requirement for retrieving Geographic Information System (GIS) score data. Then, in order to forecast the level of soil rocky desertification, it learns the features of many elements. The experimental results show that the proposed model proposed in this paper has better prediction performance and faster convergence speed, and its classification results for different degrees of RD are more consistent with the actual risk assessment results. [ABSTRACT FROM AUTHOR]

Landscape change is a dynamic feature of landscape structure and function over time which is usually affected by natural and human factors. The evolution of rocky desertification is a typical landscape change that directly affects ecological environment governance and sustainable development. Guizhou is one of the most typical subtropical karst landform areas in the world. Its special karst rocky desertification phenomenon is an important factor affecting the ecological environment and limiting sustainable development. In this paper, remote sensing imagery and machine learning methods are utilized to model and analyze the spatiotemporal variation of rocky desertification in Guizhou. Based on an improved CA-Markov model, rocky desertification scenarios in the next 30 years are predicted, providing data support for exploration of the evolution rule of rocky desertification in subtropical karst areas and for effective management. The specific results are as follows: (1) Based on the dynamic degree, transfer matrix, evolution intensity, and speed, the temporal and spatial evolution of rocky desertification in Guizhou from 2001 to 2020 was analyzed. It was found that the proportion of no rocky desertification (NRD) areas increased from 48.86% to 63.53% over this period. Potential rocky desertification (PRD), light rocky desertification (LRD), middle rocky desertification (MRD), and severe rocky desertification (SRD) continued to improve, with the improvement showing an accelerating trend after 2010. (2) An improved CA-Markov model was used to predict the future rocky desertification scenario; compared to the traditional CA-Markov model, the Lee–Sallee index increased from 0.681 to 0.723, and figure of merit (FOM) increased from 0.459 to 0.530. The conclusions of this paper are as follows: (1) From 2001 to 2020, the evolution speed of PRD was the fastest, while that of SRD was the slowest. Rocky desertification control should not only focus on areas with serious rocky desertification, but also prevent transformation from NRD to PRD. (2) Rocky desertification will continue to improve over the next 30 years. Possible deterioration areas are concentrated in high-altitude areas, such as the south of Bijie and the east of Liupanshui. [ABSTRACT FROM AUTHOR]

Rocky desertification (RD), a natural and human-induced process of land degradation in karst areas, has become the primary ecological disaster and one of the obstacles to sustainable ecological development in southwest China. Nevertheless, the variation of soil physical and chemical properties, bacterial and fungal communities, and their relationships in RD forests remains limited. Therefore, soil samples were collected from forests under four degrees of RD (NRD, non-RD; LRD, light RD; MRD, moderate RD; and SRD, severe RD) and subjected to high-throughput sequencing of 16S rRNA and ITS1 genes. The results showed a significant reduction in bacterial richness and diversity, while fungal richness and diversity decreased markedly and then showed a balanced trend with the increase in RD degree, indicating that bacteria and fungi did not present the same dynamics in response to the process of RD. The bacterial communities were dominated by Proteobacteria, Actinobacteria, Acidobacteria, and Chloroflexi, while the fungal communities were dominated by Basidiomycota, Ascomycota, and Mortierellomycota. The PCoA and NMDS demonstrated significant differences in microbial communities in study sites, among which the fungal communities in non-RD forest and LRD forest clustered together, suggesting that fungal communities were more stable than bacteria in RD forest. The db-RDA, Mantel test, and random forest model confirmed the important role of soil BD, pH, SOC, AN, and AP in driving microbial diversity and communities. The IndVal analysis suggested that Chloroflexi, Patescibacteria, Atheliales, and Cantharellales with high indicator values were identified as potential bio-indicators for RD forests. This study could not only improve our understanding of bacterial and fungal community dynamics across RD gradients, but also could provide useful information for the further use of microorganisms as indicators to reflect the environmental changes and ecosystem status during forest RD. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to reveal the landscape pattern evolution and driving factors of karst rocky desertification area, and provide a reference for optimizing the land landscape pattern, rocky desertification control and regional sustainable development in the demonstration area. [Method] Taking the typical Karst Plateau Bijie Salaxi demonstration area as the research object, the remote sensing images of three key time periods were selected, including ETM in 2005, 2010 and OLI in 2015. 3 S technology and landscape index analysis method were employed to study landscape pattern and the driving factors. [Result] The main landscape of the study area was cultivated land, followed by shrub forest. The changes of landscape transfer were mainly manifested in the transformation from cultivated land to forest, grassland and construction land, which accounted for 73. 31 % and 24. 75 % of the cultivated land transfer respectively in 2010; By 2015, they accounted for 79. 80 % and 19. 99 % respectively. At the landscape type level, the fragmentation degree of cultivated land, forestland and shrub land was increasing, and the fragmentation degree of grassland and construction land increased first and then decreased. Except for the unused land, the landscape patch shape tended to be complicated. In the overall level of the landscape, the landscape of demonstration area had developed in the direction of fragmentation, complexity, discretization and homogenization in the last 10 years. [Conclusion] The implementation of rocky desertification control project, urbanization construction and land abandonment were the main factors leading to the change of landscape pattern. [ABSTRACT FROM AUTHOR]

Karst in southwestern China forms a rocky desertification area with a particularly vulnerable ecological environment. Studying the potential of agricultural available biomass energy in this region is of great significance for the construction of the rural energy industry and ecological environment protection in karst mountains. This study investigated three regions with different degrees of rocky desertification in the karst mountains of southwestern China. The characteristics of rural energy consumption and their impact on the ecology of Karst region were analyzed. Moreover, the total available agricultural biomass energy resources in the study area were estimated via residue to product ratio, ecological returning coefficient, collection coefficient, conversion coefficient, and by-product coefficient. The research results indicate that the fragile karst ecological environment and the over-consumption of fuelwood resources are the most important reasons for the evolution of rocky desertification in this region, which exposes karst rocky desertification areas and increases the risk of rocky desertification. Given abundant agricultural biomass energy reserves in karst regions of southwestern China, promoting biomass energy as an alternative for fuelwood carries great significance for ecological protection of karst regions. This can serve as an important measure to promote ecological restoration in karst rocky desertification areas. [ABSTRACT FROM AUTHOR]