scholarly journals On Landscape Patterns in Typical Mountainous Counties Middle Reaches of the Yangtze River in China

2021 ◽  
Vol 18 (8) ◽  
pp. 4000
Author(s):  
Yang Yi ◽  
Mingchang Shi ◽  
Chunjiang Liu ◽  
Hongzhang Kang ◽  
Bin Wang
Keyword(s):  
Land Use ◽  
Yangtze River ◽  
Patch Size ◽  
Natural Circulation ◽  
Landscape Patterns ◽  
The Yangtze River ◽  
Natural Forests ◽  
Human Disturbances ◽  
Zonal Distribution ◽  
Land Use Types

The landscape patterns of plantations (PT) are the results of human disturbances on local vegetation, and in turn, differ greatly from natural forests (NF), since the patterns strongly influence the natural circulation of material and energy. There is a need to understand the differences of landscape patterns between PT and NF, to establish a near natural afforestation strategy. This study chose three typical silvicultural counties in the middle reaches of the Yangtze River as the research areas and compared the landscape patterns of NF and PT, with other land use types (grassland, GL; cropland, CL; shrubland, SL; orchard, OR; built-up land, BUL; bare land, BL; and water bodies, WB). The results revealed that the areas of PT accounted for 7.67%, 12.05%, and 18.97% of three counties, bigger than GL, OC, BUL, BL, and WB, as one of main land use types. The landscape patterns of PT (mean patch size between 2.06 to 6.05 ha) were more fragmented than NF (mean patch size between 5.83 to 53.91 ha). NF areas increased along the relative altitude gradient, from 0 to 2500 m, while PT areas peaked from 100–1000 m. The higher the altitude, the more typical the zonal distribution of PT, the more aggregated the NF. NF had significant negative correlations with BL, BUL, CL, PT, GL, and OC, which suggest that human activities had seriously interfered with NF. Although PT as an ecological protection strategy was increasing, the landscape patterns of PT were obviously different from NF. This may affect the material energy flow in the ecological environment. The results in the present study have great implications in the other regions in China and the relevant parts of the world where natural forests were heavily disturbed.

scholarly journals Effects of Urbanization on Landscape Patterns in the Middle Reaches of the Yangtze River Region

Land ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1025
Author(s):  
Yang Yi ◽  
Chen Zhang ◽  
Guilian Zhang ◽  
Luqi Xing ◽  
Qicheng Zhong ◽  
...  
Keyword(s):  
Land Use ◽  
Landscape Pattern ◽  
Yangtze River ◽  
Diversity Index ◽  
Landscape Patterns ◽  
The Yangtze River ◽  
Landscape Pattern Metrics ◽  
Ecological Protection ◽  
River Region ◽  
Regional Sustainable Development

The middle reaches of the Yangtze River region (MRYRR) are China’s first trans-regional urban agglomeration, located in the center of the Yangtze River Economic Belt. The MRYRR is an important ecological reserve, and its land cover changes are affected by both socio-economic development and geographical environment. In this paper, Landsat ETM/TM/OLI remote sensing images were used to monitor land use and landscape patterns from 1990 to 2015. Through supervised classification, land use transfer matrix, landscape pattern metrics and correlation analysis, the spatial-temporal patterns of land use change and its relationship with socio-economic in the study area were revealed. The results showed that: (1) the main land use types in the study area were cropland (CL) and forestland (FL), accounting for more than three-quarters of the study area. During the study period, built-up land (BL) increased, CL decreased, FL increased first and then decreased; (2) the BL expanded mainly by occupying CL and FL, and regional landscape pattern was gradually fragmented, with complex patch shape and increasing diversity and heterogeneity. Among them, the BL is gradually gathered, and the FL and CL are gradually fragmented; (3) in the past 25 years, the urbanization process in this region has been obvious, and the Gross Domestic Product (GDP) has increased by 36 times. The socioeconomic variables were positively correlated with BL, orchard (OL) and Shannon diversity index (SHID), and negatively correlated with CL, Wasteland (WL), mean patch size (MPS) and contagion size (CONTAG). The results showed that the urbanization development has a great impact on the region, and the ecological protection task is still challenging. It is necessary to protect high-quality cropland and draw a red line for ecological protection. We should strengthen the construction of ecological corridors and ecological nodes to adapt to regional sustainable development.

scholarly journals The Evolution of the Interactive Relationship between Urbanization and Land-Use Transition: A Case Study of the Yangtze River Delta

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 804
Author(s):  
Bo Niu ◽  
Dazhuan Ge ◽  
Rui Yan ◽  
Yingyi Ma ◽  
Dongqi Sun ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
Socioeconomic Factor ◽  
The Yangtze River ◽  
Land Use Transition ◽  
The Yangtze River Delta ◽  
Interaction Relationship

In recent years, the impact of land-use systems on global climate change has become increasingly significant, and land-use change has become a hot issue of concern to academics, both within China and abroad. Urbanization, as an important socioeconomic factor, plays a vital role in promoting land-use transition, which also shows a significant spatial dependence on urbanization. This paper constructs a theoretical framework for the interaction relationship between urbanization and land-use transition, taking the Yangtze River Delta as an example, and measures the level of urbanization from the perspective of population urbanization, economic urbanization and social urbanization, while also evaluating the level of land-use morphologies from the perspective of dominant and recessive morphologies of land-use. We construct a PVAR model and coupled coordination model based on the calculated indexes for empirical analysis. The results show that the relationship between urbanization and land-use transition is not a simple linear relationship, but tends to be complex with the process of urbanization, and reasonable urbanization and land-use morphologies will promote further benign coupling in the system. By analyzing the interaction relationship between urbanization and land-use transition, this study enriches the study of land-use change and provides new pathways for thinking about how to promote high-quality urbanization.

scholarly journals Variation of soil nutrients and bacterial community diversity of different land utilization types in Yangtze River Basin, Chongqing Municipality

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9386
Author(s):  
Yanlin Li ◽  
Chunmei Zeng ◽  
Meijun Long
Keyword(s):  
Land Use ◽  
River Basin ◽  
Yangtze River ◽  
Yangtze River Basin ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Chongqing Municipality ◽  
Land Use Types ◽  
Physical And Chemical ◽  
And Chemical Properties

The diversity and community distribution of soil bacteria in different land use types in Yangtze River Basin, Chongqing Municipality were studied by using Illumina MiSeq analysis methods. Soil physical and chemical properties were determined, and correlation analyses were performed to identify the key factors affecting bacterial numbers and α-diversity in these soils. The results showed that the soil physical and chemical properties of different land use types decrease in the order: mixed forest (M2) > pure forest (P1) > grassland (G3) > bare land (B4). There were significant differences in bacterial diversity and communities of different land use types. The diversity of different land use types showed the same sequence with the soil physical and chemical properties. The abundance and diversity of bacterial in M2 and P1 soils was significantly higher than that in G3 and B4 soils. At phylum level, G3 and B4 soils were rich in only Proteobacteria and Actinobacteria, whereas M2 and P1 soils were rich in Proteobacteria, Actinobacteria and Firmicutes. At genus level, Faecalibacterium and Agathobacter were the most abundant populations in M2 soil and were not found in other soils. Pearson correlation analysis showed that soil moisture content, pH, AN, AP, AK and soil enzyme activity were significantly related to bacterial numbers, diversity and community distribution.

scholarly journals Examining the Relationship between Urban Land Expansion and Economic Linkage Using Coupling Analysis: A Case Study of the Yangtze River Economic Belt, China

2020 ◽  
Vol 12 (3) ◽  
pp. 1227 ◽  
Author(s):  
Bowen Chen ◽  
Changyan Wu ◽  
Xianjin Huang ◽  
Xuefeng Yang
Keyword(s):  
Land Use ◽  
Yangtze River ◽  
Spatial Relationship ◽  
Urban Land ◽  
Sustainable Land Use ◽  
Policy Implications ◽  
The Yangtze River ◽  
Negative Effects ◽  
Urban Land Expansion ◽  
The Relationship

Urban land expansion (ULE) has caused negative effects as a result of urbanization and industrialization in China in the past few decades. Strengthening economic linkage and the cooperation among regions has great implications for effectively controlling disorderly ULE and achieving sustainable and intensive land use. Previous research has rarely investigated the relationship between ULE and economic linkage. Therefore, this study analyzes the spatial patterns of ULE and economic linkage in the Yangtze River Economic Belt (YREB) of China via social network analysis and a gravity model. Moreover, the spatial relationship and coupling level between ULE and economic linkage are investigated by building a bivariate spatial autocorrelation model and a coupling coordination degree model, respectively. The results indicate that the YREB experienced rapid ULE, and the area increased from 4.24 × 104 km2 in 1990 to 7.89 × 104 km2 in 2015. The cities that experience rapid ULE have gradually transferred from the east to the west of the YREB. In addition, the economic linkage in eastern cities is evidently higher than that of western cities. Our bivariate spatial model further proves that there are strong negative spatial correlation characteristics between ULE and economic linkage. This indicates that the higher the economic linkage, the lower the speed of ULE. Moreover, the coupling coordination between ULE and economic linkage show that the overall coupling stage changed from an antagonistic stage to a running-in stage. However, the coupling coordination in the YREB presented significant spatial heterogeneity, and most cities in urban agglomeration had a relationship between ULE and economic linkage that was barely balanced, slightly unbalanced, or seriously unbalanced. By considering the limitations and obstacles of current initiatives, suggestions and policy implications for sustainable land use at large regional scales are suggested.

scholarly journals Effects of Land Use/Cover Change On Atmospheric Humidity in Three Urban Agglomerations in The Yangtze River Economic

2021 ◽  
Author(s):  
Baoni Li ◽  
Lihua Xiong ◽  
Quan Zhang ◽  
Shilei Chen ◽  
Han Yang ◽  
...  
Keyword(s):  
Land Use ◽  
Air Temperature ◽  
Land Surface ◽  
Yangtze River ◽  
Urban Expansion ◽  
Regional Climate ◽  
Urban Land ◽  
The Yangtze River ◽  
Atmospheric Humidity ◽  
Urban Agglomerations

Abstract Land use/cover change (LUCC) affects regional climate not only through its direct changes of land surface properties, but also through its further modifications of land-atmosphere interactions. Urban land expansion is a typical case of LUCC in highly populated areas, and has been widely discussed about its impacts on regional air temperature, notably known as urban heat island (UHI) effects. Besides air temperature, atmospheric humidity, as another key variable in hydrometeorology and climate, would be inevitably affected by LUCC as well. However, the impacts of LUCC on atmospheric humidity seem to have not been investigated as much as on temperature. We examined atmospheric humidity changes by trend analyses of humidity indicators in three representative urban agglomerations in the Yangtze River Economic Belt (YREB), China during 1965-2017, and found the evident urban dry island (UDI) effects which are characterized by significant humidity decrease and vapor pressure deficit increase. In different urban cores, the severity levels of UDI are different. Furthermore, strong positive correlations between humidity and evapotranspiration, and between evapotranspiration and leaf area were detected during 2001-2017 when cities entered the accelerated stage of land expansion, indicating that LUCC affects regional climate through an ecohydrological way. We speculated that the UDI effect will not appear until urban land expands to a certain scale. Besides, the UHI effect emerged in the early stage of urban expansion, about 5 years earlier than the UDI effect, and has not performed prominently in recent years. This implies that urbanization-induced LUCC may exert a larger influence on UDI than on UHI in the current later period of urban expansion.

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