Tele-connecting local consumption to cultivated land use and hidden drivers in China.

China faces significant pressure on cultivated land resources due to the accelerated pace of urbanization in recent years. The study of embodied cultivated land offers a new perspective on alleviating pressure on cultivated land between different regions. However, the temporal dynamics characteristic and the intersectoral linkages of embodied cultivated land have rarely been systematically described. Therefore, we applied an environmental extended multi-regional input-output approach to analyze the spatial patterns and flow relationships of virtual cultivated land (VCL) between regional, provincial and sectoral scale in China from 2007 to 2017, considering both temporal and spatial dimensions. Then, we explored the hidden drivers of VCL change using structural decomposition analysis (SDA). Our results showed that trade embodied cultivated land increase by 8.5 % from 2007 to 2017. The flow trend is primarily flowed out from the less developed northwest China but with abundant cultivated land to the more developed regions of the southeast coast. Especially, in 2015, the net outflow of VCL from the northwest region reached 15.82 Mha, which was the maximum value during the study period. In addition, agricultural and construction sector were the major land consumption sector. VCL consumed by the agricultural sector declined 12.51 %, while the VCL consumed by construction sector had a significant growth in 2007-2017. Furthermore, the results of SDA revealed that cultivated land use intensity and per capita final demand were the main factors causing changes in embodied cultivated land. The results can help clarify the responsible parties for land consumption and provide a guarantee for alleviating the pressure on regional cultivated land resources.

Research on the Optimal Allocation of Ecological Land from the Perspective of Human Needs-Taking Hechi City, Guangxi as an Example.

The configuration of ecological land directly affects the structure and function of an ecosystem and, ultimately, its ability to meet human needs. From the perspective of human needs, this paper classified human needs into material needs, security needs and spiritual needs. Using Hechi City, Guangxi as the study area, we combined the Multi-objective planning (MOP) and PLUS models to study the quantity and spatial optimization of ecological land under different human needs scenarios, and the optimal allocation of ecological land within the ecological red line was also discussed. We conclude that: (1) Hechi City currently has less arable land, which cannot fully guarantee the material needs of human beings; there is more forest land than the amount needed to meet human needs, which reduces the efficiency of ecological land use. (2) In terms of quantity optimization, and considering the goals of different human needs, the area of grass to forest should be extended to satisfy security needs; the area of arable land should be significantly increased in line with material needs; the area of grass and water, with the goal of accommodating spiritual needs, is the largest compared with the rest of the goals. Under the comprehensive needs goal, the forest land area is greatly reduced, and the rest of the land area is increased; the goals of human material, spiritual and security needs are basically met. (3) In terms of spatial layout optimization, in order to meet the security needs target, grass to forest conversion should be carried out in the northern area to enhance the aggregation of forest land; to meet the material needs target, the southwestern gentle slope area should be concentrated toward continuous farming to guarantee the aggregation of arable land while increasing the area of arable land; to meet the spiritual needs target, the area of water in the northwestern area should be increased, and the rest of the changes are similar to the security needs target; to meet the comprehensive needs target, the overall land use connectivity becomes stronger, the fragmented land types become less and the concentrated continuous area of forest land, arable land and grass increases. (4) The results of the ecological land adjustment within the ecological red line indicate that the current ecological red line delineation is good, and a small amount of adjustment can meet human needs. Based on human demand, combined with the MOP-PLUS model for ecological land optimization, it can accurately portray the spatial and temporal evolution pattern of land use and reveal the optimization path of ecological land, which has important theoretical and practical values.

Scenario-Based Analysis of Land Use Competition and Sustainable Land Development in Zhangye of the Heihe River Basin, China.

Rapid economic growth has a significant impact on land use change, which would threaten the natural ecology. Zhangye city of the Heihe River Basin, China is an ecologically vulnerable region where land use changes significantly due to socioeconomic development and population increases. The study employed a computable general equilibrium of land use change (CGELUC) model to simulate land use change and then used a dynamic land system (DLS) model to spatialize land use change during 2015-2030 under three development scenarios in Zhangye city. The three development scenarios are the baseline scenario (BAU), the resource consumption scenario (RCS) and the green development scenario (GDS). We found that economic growth would lead to land demand increases in high value-added industries and decreases in low value-added industries. The cultivated land would decrease while the built-up area would increase. By 2030, the cultivated land will decrease by 8.16%, 10.89% and 4.16%, respectively, under BAU, RCS and GDS, while the built-up area will increase by 8.61%, 10.39% and 4.75%, respectively. The expansion of built-up area under RCS presents spatial characteristics of centralized distribution, while spatial characteristics of uniform discrete distributions are presented under GDS. The expansion of ecological land under GDS would be considerable, especially in the north of Sunan County and Gaotai County, and around the natural reserve of Ganzhou County. This paper provides a scientific reference for coordinating economic development and ecological protection in the rapidly developing urbanized areas in western China.

Can the establishment of ecological security patterns improve ecological protection? An example of Nanchang, China.

Establishing ecological security patterns provides new ideas for maintaining regional ecological security. Methods for establishing these patterns have been extensively investigated in several studies, but the ecological protection effects of these patterns need further examination. Nanchang is the capital city of Jiangxi province and a typical representative of rapidly developing cities. With the proposal of an ecological environment protection plan for Nanchang metropolitan area, the coordinated development of ecology, economy and society has become the local development goal. This study used Nanchang City as an example for the establishment of an ecological security pattern through the circuit theory. The ecological sources of a 1068.56 km2 location and 20 ecological corridors with a total area of 957.39 km2 were identified. Three development scenarios in 2015-2040 were set up, namely, unrestricted development (UD), core area protection (CP) and ecological security pattern restriction (ESPR) scenarios. The UD scenario followed the land expansion rate from 2010 to 2015. The CP scenario used a nature reserve as a forbidden conversion area. Under the ESPR scenario, ecological security pattern was regarded as a prohibited conversion area. The CLUMondo model was used in simulating land use and evaluating the ecological protection effects of the scenarios. Through comparison, we determined that the ecological security indices under UD, CP and ESPR were 0.230, 0.242 and 0.249, respectively, from the perspective of the overall ecological security of the region. In the evaluation of the landscape characteristics of EL, under ESPR, the landscape connectivity was the best. The detailed analysis results showed that the ecological security pattern not only could protect the regional ecological security on the regional scale but also had an outstanding protection effect on the local scale. In summary, compared with the UD and CP scenarios, ecological security patterns had a better effect on regional ecological protection.

Research on recognition and protection of ecological security patterns based on circuit theory: a case study of Jinan City.

Accelerated urbanization and population growth have resulted in the loss of ecological land and biodiversity, accompanied by the degradation of ecosystem services. Identifying and improving existing ecological security patterns are of great significance for maintaining the sustainable development of cities. In this study, Jinan, the capital of China's Shandong Province, was used as a case study area. Based on three ecosystem services, namely, soil conservation, water conservation and carbon fixation, ecological sources were determined. Furthermore, a resistance surface was constructed based on biodiversity. On these bases, the circuit theory concept of random walks was applied to simulate ecosystem processes in a heterogeneous landscape and identify ecological corridors, pinch points and barriers. A total of 25 ecological sources, 48 ecological corridors and 19 pinch points were identified, and restoration areas were delimited to three levels. These elements together constituted the ecological security patterns. Specifically, the ecological sources were mainly distributed in southern Jinan and were covered mostly with forest land. The ecological corridors were located mainly in the eastern and southwestern plains below the southern mountainous areas and were covered mostly with cropland. Furthermore, the eastern corridors were much longer than the southwestern corridors. Pinch points were distributed mostly along rivers or around large-scale construction land. Barriers were distributed mainly in Zhangqiu District and northern Licheng District. Based on these findings, hierarchical restoration areas were delimited. Differentiated development contradictions in restoration areas were discussed, and corresponding ecological protection measures were proposed. An ecological security optimization pattern of "one center, two wings, and two belts" was finally proposed to provide planning strategies for decision-makers.

Evaluation of ecological sustainability based on a revised three-dimensional ecological footprint model in Shandong Province, China.

This study used the revised three-dimensional ecological footprint model (3DEF), to calculate the status of sustainable ecological development in Shandong Province in 2010-2015, analyze dynamic changes in sustainability characteristics, and explore factors affecting sustainable development. The results showed the following (Wackernagel & Rees, 1996). Seventeen prefecture-level cities featured varying degrees of ecological deficits, and ecological development was unsustainable in all cities (Wackernagel et al., 2004). Footprint sizes differed between the cities, but changed little over time. Cropland was the main contributor to footprint size, as it was the main capital flow utilization component (Daly, 1994). For all cities, footprint depth exceeded the original length of 1; lack of capital flow caused capital stock depletion. There was a significant positive linear correlation between changes in energy footprint and footprint depth (Zhou et al., 2015). The 17 prefecture-level cities were divided into four natural capital utilization categories using clustering: zone I (2 cities), in which capital stock consumption greatly exceeded capital flow occupancy, contain the most severe ecological stress; zone II (9 cities), wherein the level of stock capital consumption was significantly higher than capital flow consumption, the regional development pressure was greater, and the ecological sustainability was lower; zone III (4 cities), which featured mild natural capital utilization and a relatively high capacity for sustainable development; zone IV(2 cities), which featured lagging stock capital utilization, relatively, and the highest capacity for sustainable development. These results would help coordinate resource utilization and economic development in Shandong Province.

Did the ecological engineering have a great impact on the land use change?

Overuse of land resources has increasingly contributed to environmental crises in China. To mitigate widespread land degradation, actions have been taken to maintain and restore the ecological environment through efforts such as ecological engineering. By analyzing trends in land use, the impact and effectiveness of ecological engineering can be determined. In this study, such changes in Huanjiang County in China were considered. In the early 1990s, an eco-immigration policy and "returning farmland to forest program" were implemented in the county, drastically impacting land use. Land use/land cover changes were detected and analyzed using remote sensing data recorded over 4 years (1995, 2000, 2005, and 2010). Land transfer flow and the rate of land use change elucidated the extent of changes, while nuclear density analysis indicated spatial agglomeration. The results indicate that, over a period of 15 years, farmland area increased, while forest area decreased initially before subsequently increasing. From 1995 to 2000, the highest transfer flow was observed in the grassland to farmland conversion (79.34%). From 2000 to 2005, the transfer flow of conversions was the highest for forest to farmland (56.79%). Land use changes were not prominent from 2005 to 2010. Direct drivers of land use change exert obvious impacts on land use, and indirect drivers impact direct drivers that are then channeled through direct anthropogenic drivers (e.g., land use policies). We found that ecological engineering has a very significant impact on land use change, and that impact varies from region to region.

Assessing temporal-spatial land use simulation effects with CLUE-S and Markov-CA models in Beijing.

In order to solve the problem of extensive land use in rural residential areas and promote the construction of a new socialist countryside and farmland protection, it is important to graspe the temporal and spatial evolution of rural settlements. In this study, with Beijing as an example, the efficiencies of CLUE-S and Markov-CA models in simulating spatial temporal evolution of rural residential areas are analyzed. With 14 driving factors chosen, the land uses in Beijing in 2000 and 2005 are simulated and predicted using the two models. Grid size of 220 m × 220 m is used. The accuracies and Kappa coefficients of the simulation and prediction results are analyzed and the following conclusions are made. The core part of CLUE-S model is logistic regression, which grants it obvious advantage in capturing the trends of land use changes with more discrete distributions. Meanwhile, Markov-CA model takes neighborhood into consideration, making it relatively more advantageous in simulating and predicting changes of land uses with the character of nearest-neighbor diffusion. However, among various land uses, only urban land use has this character, the correct prediction rates of the CLUE-S model in 2000 and 2005 were 60.99% and 81.35%, respectively, while the accuracy of the Markov-CA model prediction was 51.33% and 73.68%, and it is the main reason that CLUE-S model returns better simulation and prediction results of rural residential areas for both 2000 and 2005 than Markov-CA model.

The land Gini coefficient and its application for land use structure analysis in China.

We introduce the Gini coefficient to assess the rationality of land use structure. The rapid transformation of land use in China provides a typical case for land use structure analysis. In this study, a land Gini coefficient (LGC) analysis tool was developed. The land use structure rationality was analyzed and evaluated based on statistical data for China between 1996 and 2008. The results show: (1)The LGC of three major land use types-farmland, built-up land and unused land-was smaller when the four economic districts were considered as assessment units instead of the provinces. Therefore, the LGC is spatially dependent; if the calculation unit expands, then the LGC decreases, and this relationship does not change with time. Additionally, land use activities in different provinces of a single district differed greatly. (2) At the national level, the LGC of the three main land use types indicated that during the 13 years analyzed, the farmland and unused land were evenly distributed across China. However, the built-up land distribution was relatively or absolutely unequal and highlights the rapid urbanization in China. (3) Trends in the distribution of the three major land use types are very different. At the national level, when using a district as the calculation unit, the LGC of the three main land use types increased, and their distribution became increasingly concentrated. However, when a province was used as the calculation unit, the LGC of the farmland increased, while the LGC of the built-up and unused land decreased. These findings indicate that the distribution of the farmland became increasingly concentrated, while the built-up land and unused land became increasingly uniform. (4) The LGC analysis method of land use structure based on geographic information systems (GIS) is flexible and convenient.