Using modern portfolio theory to enhance ecosystem service delivery: A case study from China.

：Land management strategies often prioritize agricultural supply services at the expense of other ecosystem services. To achieve a high and steady supply of multiple ecosystem services, it is essential to optimize land management practices in areas suitable for agriculture. However, many studies on land management tend to focus on their benefits to ecosystem service delivery without adequately considering the potential risks to other services that might be involved. Here we use modern portfolio theory to quantitatively measure benefits and risks from land management strategies to enhance ecosystem services. We create seven land management scenarios that balance different kinds of ecosystem services in different ways in the agricultural production area of Maoming, Guangdong Province, China. The method yielded optimal portfolios of land management patterns that enhanced ecosystem services while reducing risk as much as possible. This includes a scenario delivering a 22% increase in agricultural production service, while simultaneously increasing the provision of nature-related ecosystem services by 2%. However, no optimization scenario was perfect, and there was always a trade-off between gaining certain ecosystem service benefits and creating a risk of losing others. Our portfolio theory approach reveals that it is essential to consider both the benefits and risks of land management strategies.

Implications of land sparing and sharing for maintaining regional ecosystem services: An empirical study from a suitable area for agricultural production in China.

The clarification of land use management in areas of potential land use conflict plays an important role in maintaining ecosystem services. However, the relationship between land use strategies and ecosystem services in potential conflict zones remains uncertain, lacking quantitative evidence. Therefore, to construct a healthy territorial space system, a spatial classification model for land use was built based on land sparing and sharing. In addition, the inherent characteristics of different modes in the landscape structure and functional heterogeneity were also resolved. Then, an empirical analysis was carried out with the coastal agricultural production area of Maoming City, Guangdong Province. Focusing on the potential area of land use conflicts in Maoming City, that is, the suitable area for agricultural production, this study determined the differences in ecosystem services under multiple land use patterns at the pixel level, explored the trade-offs of ecosystem services in the entire suitable area and a single model, and examined the gradient effect of ecosystem services with the intensity of cultivated land use. According to the results, ecosystem services significantly differed in land use patterns, and the comprehensive ecosystem service was the highest in the land sharing model. Ecosystem services exert a synergistic effect in the entire suitable area for agricultural production, whereas there exists no correlation within a single model. When the arable land area of intensive agriculture exceeds 84.84%, food supply and other ecosystem services will be reduced to varying degrees. The study bridges the gap in research on the relationship between land sparing and sharing and ecosystem services in Chinese regions, and proposes clear land remediation strategies in potential conflict zones, which can thus provide some guidance for achieving sustainable regional development.

Spatial identification and determinants of trade-offs among multiple land use functions in Jiangsu Province, China.

Understanding the relationships among multiple land use functions (LUFs) is crucial for land-based spatial planning that can guide targeted land use policy-making in complex socio-ecological systems. However, few studies concerned the interactions among various LUFs integrating the issues of economy, environment, and society at a fine scale. In this study, we quantified 12 LUFs using a geospatial model and statistical analysis at the grid scale in Jiangsu Province. Then, we identified the relationships among three primary LUFs-agricultural production function (APF), urban-rural living function (ULF), and ecological maintenance function (EMF)-and further explored the determinants of LUF trade-offs aimed to provide a reference for policy-makers to make decisions in future land use planning and management. The results revealed that the high trade-off areas for APF and ULF are mainly distributed in central and northern Jiangsu, and the trade-offs for both APF-EMF and ULF-EMF were higher in the area covered with water and forest. The determinants of LUF trade-offs mainly refers to land use/land cover, potential evapotranspiration, and vegetation coverage ratio. Moreover, landscape configuration metrics and distance to the nearest county and nearest road also have remarkable impacts on the trade-offs of APF-EMF and ULF-EMF. Finally, we proposed that the concepts of LUF trade-offs should be incorporated into the processes of delineating boundaries for urban growth, farmland, and natural areas. We also propose that land consolidation projects should be implemented in an orderly manner to alleviate LUF trade-offs.

A new framework of land use efficiency for the coordination among food, economy and ecology in regional development.

Great challenges regarding land use conflicts in rapid urbanization call for deeper research on land use efficiency (LUE) from the perspective of sustainable land use for the coordination among food security, economic development, and ecological protection. This study firstly develops a new framework of LUE based upon the expectations in land use and the coordination among three sub-categories in food production, economic development, and ecological protection, then, uses the coupling coordination degree model to quantify the spatial differentiation characteristics and coupling coordination relationships among three sub-categories, and finally uses the multivariable linear regression and geographical detectors to analyze the impact factors of sub-category efficiency. The framework is applied to Jiangsu Province in eastern China by using ten indicators (i.e., cultivated land quality, grain output, multiple cropping index, average GDP per km2, population density, proportion of industry and service industry, vegetation cover index, water conservation index, soil retention index, and carbon sequestration index) in terms of food production, economy, and ecology analysis at the county level. Compared with expectations, the LUE of Jiangsu in food production, economic development, and ecological protection is 54.15%, 85.56%, and 54.95%, respectively, indicating that Jiangsu has great potential for sustainable land use. The coupling coordination degree in land use generally synchronizes with the coupling degree, accounting for 65.34% of the province's area, of which 75.00% are in lower-coupling & lower-coordination, medium-coupling & medium-coordination. Among all the factors, proportion of industry and service industry, population density, multiple cropping index, average GDP per km2, and water conservation index have the most important roles in the coordinated development of land use sub-systems. Therefore, we suggest land use/urban management need to implement more integrated planning and differentiated strategies to stimulate land use potential and maintain efficient and sustainable land use.

Spatial identification and dynamic analysis of land use functions reveals distinct zones of multiple functions in eastern China.

Land use function (LUF) is a valuable concept that allows for more integrated assessments of land system change. Identifying the changes and relationships of multiple LUFs is pertinent to land use planning and management. Selection and quantification of LUF indicators are critical for LUFs assessment. However, past studies have mostly assessed LUFs using socioeconomic data, which are not suitable for spatial variable quantification. In this study, we proposed a new LUFs classification system based on spatial planning goals, and we applied the system to assess 12 LUFs across 63 counties in Jiangsu Province of eastern China based on multi-source data using geospatial modeling tools combined with statistical analysis of socioeconomic data. We also analyzed the change in LUFs between 2000 and 2015, as well as the interactions among multiple functions. Finally, we identified distinct function zones based on the LUFs assessment in 2000 and 2015 using k-means clustering. The result showed that 12 LUFs displayed significant changes and interactions between 2000 and 2015, which can be explained by differing topography and social-ecological characteristics among counties. Additionally, we found four distinct LUF zones that are spatially agglomerated in similar landscapes and characterize specific LUF relationships in each cluster. In the future, local LUFs and their changes over time should be taken into consideration for land use planning and management, which provide a reference for policy-makers to make decisions that better match local development realities.

Evaluating and predicting the effectiveness of farmland consolidation on improving agricultural productivity in China.

Food security has always been a focus issue in China. Farmland consolidation (FC) was regarded as a critical way to increase the quantity and improve the quality of farmland to ensure food security by Chinese government. FC projects have been nationwide launched, however few studies focused on evaluating the effectiveness of FC at a national scale. As such, an efficient way to evaluate the effectiveness of FC on improving agricultural productivity in China will be needed and it is critical for future national land consolidation planning. In this study, we selected 7505 FC projects completed between 2006 and 2013 with good quality Normalized Difference Vegetation Index (NDVI) as samples to evaluate the effectiveness of FC. We used time-series Moderate Resolution Imaging Spectroradiometer NDVI from 2001 to 2013, to extract four indicators to characterize agricultural productivity change of 4442 FC projects completed between 2006 and 2010, i.e., productivity level (PL), productivity variation (PV), productivity potential (PP), and multi-cropping index (MI). On this basis, we further predicted the same four characteristics for 3063 FC projects completed between 2011 and 2013, respectively, using Support Vector Machines (SVM). We found FC showed an overall effective status on improving agricultural productivity between 2006 and 2013 in China, especially on upgrading PL and improving PP. The positive effect was more prominent in the southeast and eastern China. It is noteworthy that 27.30% of all the 7505 projects were still ineffective on upgrading PL, the elementary improvement of agricultural productivity. Finally, we proposed that location-specific factors should be taken into consideration for launching FC projects and diverse financial sources are also needed for supporting FC. The results provide a reference for government to arrange FC projects reasonably and to formulate land consolidation planning in a proper way that better improve the effectiveness of FC.