Trade-Offs between Economic Benefits and Ecosystem Services Value under Three Cropland Protection Scenarios for Wuhan City in China

Over the past few decades urbanization and population growth have been the main trend all over the world, which brings the increase of economic benefits (EB) and the decrease of cropland. Cropland protection policies play an important role in the urbanization progress. In this study, we assess the trade-offs between EB and ecosystem services value (ESV) under three cropland protection policy scenarios using the LAND System Cellular Automata for Potential Effects (LANDSCAPE) model. The empirical results reveal that trade-offs between EB and ESV in urbanizing areas are dynamic, and that they considerably vary under different cropland protection policy scenarios. Especially, the results identify certain "turning points" for each policy scenario at which a small to moderate growth in EB would result in greater ESV losses. Among the three scenarios, we found that the cropland protection policy has the most adverse effect on trade-offs between EB and ESV and the results in the business as usual scenario have the least effect on the trade-offs. Furthermore, the results show that a strict balance between requisition and compensation of cropland is an inappropriate policy option in areas where built-up areas are increasing rapidly from the perspective of mitigating conflict between EB and ESV and the numbers of cropland protection that restrained by land use planning policy of Wuhan is a better choice

Projecting future impacts of cropland reclamation policies on carbon storage

Cropland reclamation policies result in carbon storage loss by the conversion of natural land. However, the future impacts of cropland reclamation policies (CRP) on carbon storage have seldom been explored. Taking Hubei, China as study area, this study assesses the impacts of cropland reclamation policies before and after optimization on carbon storage from 2010 to 2030. The LAND System Cellular Automata model for Potential Effects (LANDSCAPE) was used to simulate the land use patterns in 2030, while the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) Carbon Storage and Sequestration model was applied to calculate the changes in carbon storage. Results indicate that carbon storage loss due to cropland reclamation policies is expected to increase from 0.48 Tg·C to 4.34 Tg·C between 2010 and 2030 in Hubei. This increase is related to the loss of wetland and forest. Carbon storage loss can be reduced by 52%–73% by protecting carbon-rich lands. This study highlights the importance of considering the carbon storage loss when implementing cropland reclamation policies

Impact of cropland displacement on the potential crop production in China:a multi-scale analysis

Changes in the amount and location of cropland areas may affect the potential crop production at different spatial scales. However, most studies ignore the impacts of cropland displacement on potential crop production. In many countries, cropland protection policies mainly aim for no loss in cropland area, while there is no restriction on change of cropland location. Taking China as the study area, we analyze the impacts of cropland displacement on potential crop production at four administrative levels during the period 2000 and 2018. At the national level, we find a net decrease in cropland area of 0.81 Mha, while another 19.63 Mha was displaced. The former led to a decrease of 4.20 Mton in potential crop production, while the latter resulted in a decrease of 43.26 Mton as a result of lower quality of the newly cultivated lands. In other words, cropland displacement explains 91% of the total loss in potential crop production at the national scale. However, the contribution of cropland displacement to total change in potential crop production is increasingly smaller at provincial level, municipal level, and county levels. These findings highlight the importance of geographic location on crop production and suggest that cropland policies should consider geographic location in addition to cropland area

Urinary paraquat concentration and white blood cell count as prognostic factors in paraquat poisoning

Purpose: To investigate the effect of white blood cell (WBC) and urinary paraquat (PQ) levels on prognostic factors in patients exposed to PQ intoxication using multivariate logistic regression analysis.Methods: A total of 104 subjects intoxicated with PQ between December 2015 and July 2016 were used in this retrospective study. They comprised patients who survived (n = 78), and patients who died (n = 26). Clinical features and prognostic parameters were analyzed in both groups. Multivariate logistic regression analysis was used to establish a prognostic correlation model based on results from single factor variables.Results: Comparison of demographic and clinical attributes between the two groups, survivors (n = 78) and non-survivors (n = 26), revealed that those who survived were not as old (33.3 ± 9.9 years) as nonsurvivors (41.5 ± 12.9 years). In addition, on admission, it was found that the survivors ingested lower amounts of PQ (31.6 ± 13.8 ml) than non-survivors (67.88 ± 31.2 ml). There were significant differences between the two groups with respect to WBC, neutrophils, lymphocytes, lactate dehydrogenase (LDH), creatine kinase (CK), amylase, uric acid (UA), pH, partial pressure of oxygen (PaO2), base excess (BE), lactic acid, and D-dimer levels (p < 0.05).Conclusion: WBC and urine PQ concentration have strong correlation with prognostic factors in PQ poisoning.Keywords: Paraquat intoxication, Dithionite test, Multivariate logistic analysis, Prognosis, Predictor

Direct and indirect loss of natural habitat due to built-up area expansion:A model-based analysis for the city of Wuhan, China

Urbanization has been responsible for the loss of cropland worldwide, especially in China. To guarantee national food security, China has implemented a series of policies to protect cropland. One of these policies requires that one-hectare cropland should be reclaimed when urban expansion occupies one-hectare cropland. Since most cropland reclamation leads to a conversion of natural habitat, such as wetland and grassland, urban expansion may lead to (indirect) natural habitat loss in addition to direct loss from conversion of into urban area. While several studies assessed the direct habitat loss resulted from built-up area expansion, few studies investigated the indirect losses caused by cropland displacement. In this paper, a model-based approach is applied to explore both direct and indirect impacts of built-up area expansion on natural habitat loss for the city of Wuhan, China, between 2010 and 2020 using different scenarios. Our scenarios differ in the implementation of strict cropland protection policies and ecosystem conservation strategies. Results show that the indirect loss of natural habitat due to cropland displacement under strict cropland protection policies far outweighs the direct loss due to built-up area expansion alone. Moreover, we found that ecosystem conservation strategies mainly influence the type of natural habitat that is affected, while the total amount of natural habitat loss remains relatively constant

Determinants of Farmland Abandonment on the Urban–Rural Fringe

China’s urban explosion has resulted in a substantial loss of agricultural production on the fringes of many cities. Farmland is not only converted into urban uses but also taken out of production because it has lost its value for those who can farm it. This farmland abandonment process has received little research attention. This paper studies the abandonment of farmland around the rapidly urbanizing city of Wuhan and aims to identify its important determinants based on an extensive field survey among local farmers. Around 800 semi-structured field interviews were conducted to capture the parcel and location characteristics, farming practices, and household characteristics. Important parcel-related drivers of land abandonment are lack of family members to work the land and fragmentation of parcels. Spatial characteristics are less important, except for the presence of certain soil types that favour cultivation and designation under the farmland protection policy. The planted crop species and the option to transfer land to other farmers are important farming practices to continue cultivation. Moreover, farmers with a higher farming income and lower education levels are less likely to abandon their farmland. We suggest that land use policies can help in preventing further farmland abandonment by steering urban development away from the most suitable soils for farming and concentrating development to limit the fragmentation of parcels. Strengthening the land market and removing the remaining barriers for farmers to transfer land to colleagues can further help to keep farmland in production

Impact of Cropland Reclamation on Ecological Security in the Yangtze River Economic Belt, China

Ecological security is important both for maintaining the function of an ecosystem and for providing ecosystem services to the human wellbeing. The impact of land use change/cover on ecological security has attracted considerable attention, whereas the role of cropland reclamation remains unclear. The indirect loss of ecological land that occurs upon the request of cropland requisition-compensation policies offer further changes to ecological security. In order to ascertain the impact of cropland reclamation on ecological security, in this study three scenarios are established, addressing cropland returning to ecological lands without a slope limitation, with a slope <25°, and with a reclaimed cropland slope ≥25°. This study was conducted in the Yangtze River economic belt (YREB) due to its important contribution to ecological security in China. Land uses in different scenarios in 2030 are projected using the land use simulation model LANDSCAPE. Accordingly, ecological security in each scenario was evaluated using the contribution–vigour–organization–resilience framework, comprising the variables carbon storage, water purification, water yield, habitat quality, net primary productivity, mean patch area, Shannon’s diversity index, largest patch index and contagion, as well as the normalized difference vegetation index. The results indicate that about 62% of YREB land is projected to remain stable in terms of ecological security, while about 21% will deteriorate and 17% will improve between 2015–2030. Land where ecological security is projected to improve is concentrated in areas where broad and connected croplands are distributed. The fact that a higher proportion of areas will deteriorate than improve suggests that the negative impact of cropland change on ecological security should not be ignored. Comparing different scenarios, croplands returning to ecological lands pose a particularly significant impact on ecological security, particularly in the upper reaches of the YREB, where steep croplands are concentrated