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Hydrological processes in lowland polders, especially those for paddy rice planting, are affected by complicated factors. The improved Wageningen Lowland Runoff Simulator (WALRUS) model incorporates an irrigation and drainage scheme, and a new stage–discharge relationship to account for hydrological processes in multi-land-use polder with paddy fields and pumping stations. Here, this model was applied to assess how climate and land use changes affected the runoff of a Chinese polder in Poyang Lake basin in the past two decades. Simulated results showed that the runoff in the autumn–winter transition and midsummer months increased significantly, whereas those in the other months decreased slightly during the period of 1996–2005, primarily affected by climate change. For the period of 2006–2014, the runoff in the autumn–winter transition and midsummer increased, while that in the other months declined, affected by both climate and land use/cover changes. The land use/cover change resulting from the conversion of rice–wheat rotation to dominantly double-rice cropping and the expansion of residential area, increased the runoff during this period by demanding more irrigation water from the outside basin.

After the Paris Climate Conference (COP21), countries worldwide are making progress toward carbon neutrality targets. However, despite flourishing economically, emerging countries fail to ensure environmental sustainability. Hence, it is crucial for these countries to identify the macroeconomic factor that could address the ecological concerns. Therefore, this paper examines the linkage between environmental innovations, energy productivity, economic globalization, and economic growth on environmental degradation in emerging countries. Based on the data from 1990 to 2017, the study applies the advanced panel data estimation tool cross-sectional autoregressive distributed lags (CS-ARDL) for the long-run and short-run empirical estimation that allows cross-sectional dependence and heterogeneity in slope parameters. The empirical results unveil that environmental innovations and energy productivity significantly improve environmental quality by reducing the ecological footprint. Moreover, the results unfold that economic globalization worsens the environmental quality by exacerbating the ecological footprint, while an inverted U-shaped relationship between environmental degradation and economic growth confirms the validity of the environment Kuznets curve in emerging countries. Results suggest that the government should develop such strategies that encourage environmental innovations and energy productivity to balance the speed of economic globalization and economic growth.

The construction of green infrastructure (GI) plays an important role in improving the rural ecological functions and building a green livable environment. In this paper, the methods of morpho spatial pattern analysis (MSPA) and space syntax analysis are used to study the GI network construction in Suining County, Jiangsu Province. The results show that: (1) In 2018, the area of ecological patches increased by 110% compared with 1998, and the utilization rate of the GI network was significantly improved. (2) A total of 66 ecological corridors were analyzed in the county, and the main corridors were distributed in the central and western regions. The correlation analysis of core ecological patches in 1998, 2008, and 2018 proved that location factors had the greatest impact on the results of function and connectivity. (3) According to the optimization results, ecological benefits can be improved through engineering measures to realize the revitalization and development of regional rural areas.

General greening in vegetation, especially in southwest China, has been observed globally in recent decade. However, temporal-spatial variation patterns and potential causes of vegetation greening are not well understood in southwest China. Here, we used data of the normalized difference vegetation index (NDVI) and climate, land use and land cover, geology, ecological afforestation and karst rocky desertification to analyze the temporal-spatial variation patterns in vegetation coverage and its response to climate change and human-induced factors in southwest China between 2000 and 2016. A general greening trend in vegetation, with significant differences in temporal-spatial variation patterns, was observed in southwest China from 2000 to 2016, and the area of significant vegetation greening from 2006 to 2016 increased by 4.68% relative to the level from 2000 to 2005. The increased proportion of significant vegetation greening was higher in the karst regions (6.95%), especially in the limestone region (8.00%), than in the nonkarst region (3.82%). Of all the vegetation greening trends, 65% was associated with human-induced factors, and 35% was resulted from climate change from 2000 to 2005. After the implementation of karst ecological restoration engineering, the contribution of human-induced factors to vegetation greening increased to 77% from 2006 to 2016, although southwest China experienced a serve drought during that time. These results highlight that karst ecological engineering projects can reduce the risks of desertification and karst ecosystem sensitivity to climate perturbations.

Several studies have identified threats that originate in areas surrounding protected areas (PAs). While there have been various efforts to integrate PAs with their surroundings, considerable challenges remain. Here we summarize these efforts to date, discuss their effectiveness, and provide recommendations for future research. Based on a broad literature review of theoretical and applied approaches, we have outlined 68 models for balancing conservation and sustainable development in PAs. We comprehensively analyzed 23 of these models for integrating PAs with their surroundings. They were divided into two categories: area-oriented and process-oriented approaches. This review reveals the absolute necessity of combining these two approaches for future conservation and sustainable development of PAs.

AbstractForests play an important role in global carbon cycles. However, the lack of available information on carbon stocks in dead organic matter, including woody debris and litter, reduces the reliability of assessing the carbon cycles in entire forest ecosystems. Here we estimate that the national DOM carbon stock in the period of 2004–2008 is 925 ± 54 Tg, with an average density of 5.95 ± 0.35 Mg C ha−1. Over the past two decades from periods of 1984−1988 to 2004−2008, the national dead organic matter carbon stock has increased by 6.7 ± 2.2 Tg carbon per year, primarily due to increasing forest area. Temperature and precipitation increase the carbon density of woody debris, but decrease that of litter. Additionally, the woody debris increases significantly with above ground biomass and forest age. Our results can improve estimates of the carbon budget in China's forests and for better understanding of effects of climate and stand characteristics on dead organic matter distribution.

Traditional green transportation research pays more attention to the optimization of transportation technology and structure in terms of traffic environment consumption constrains. The results cannot achieve on the feedback between transportation and land-use. The paper proposed urban land structure planning model, considering the interaction between land-use and transportation. It uses the index of land use structure as variables to set up bi-level programming model, from the perspective of the origin of traffic production. In this regard, GASA was used to solve the model in which the upper objective function minimized traffic environment consumption, and the lower objective function maximized transportation efficiency. Taking the case of Zhenjiang for example, the paper described the application of the bi-level programming planning model, and resulted for the feedback suggestion that land mixed extent and road area ratio should be improved properly.

The need to produce crops with higher yields is critical due to a growing global population, depletion of agricultural land, and severe climate change. Compared with the “source” and “sink” transport systems that have been studied a lot, the development and utilization of vascular bundles (conducting vessels in plants) are increasingly important. Due to the complexity of the vascular system, its structure, and its delicate and deep position in the plant body, the current research on model plants remains basic knowledge and has not been repeated for crops and applied to field production. In this review, we aim to summarize the current knowledge regarding biomolecular strategies of vascular bundles in transport systems (source-flow-sink), allocation, helping crop architecture establishment, and influence of the external environment. It is expected to help understand how to use sophisticated and advancing genetic engineering technology to improve the vascular system of crops to increase yield.

Salt-alkali is the main threat to global crop production. The functioning of phosphorus (P) in alleviating damage to crops from saline-alkaline stress may be dependent on the variety of crop but there is little published research on the topic. This pot experiment was conducted to study if P has any effect on rice (Oryza sativa L.) yield, dry matter and P accumulation and translocation in salt-alkaline soils. Plant dry weight and P content at heading and harvest stages of two contrasting saline-alkaline tolerant (Dongdao-4) and sensitive (Tongyu-315) rice varieties were examined under two saline-alkaline (light versus severe) soils and five P supplements (P0, P50, P100, P150 and P200 kg ha−1). The results were: in light saline-alkaline soil, the optimal P levels were found for P150 for Dongdao-4 and for P100 for Tongyu-315 with the greatest grain dry weight and P content. Two rice varieties obtained relatively higher dry weight and P accumulation and translocation in P0. In severe saline-alkaline soil, however, dry weight and P accumulation and translocation, 1000-grain weight, seed-setting rate and grain yield significantly decreased, but effectively increased with P application for Dongdao-4. Tongyu-315 showed lower sensitivity to P nutrition. Thus, a more tolerant variety could have a stronger capacity to absorb and translocate P for grain filling, especially in severe salt-alkaline soils. This should be helpful for consideration in rice breeding and deciding a reasonable P application in saline-alkaline soil.

Organic soil is an important transient reservoir of mercury (Hg) in terrestrial ecosystems, but the fate of deposited Hg in organic forest soil is poorly understood. To understand the dynamic changes of deposited Hg on forest floor, the composition of stable Hg and carbon (C) isotopes in decomposing litters and organic soil layer was measured to construct the 500 year history of postdepositional Hg transformation in a subtropical evergreen broad-leaf forest in Southwest China. Using the observational data and a multiprocess isotope model, the contributions of microbial reduction, photoreduction, and dark reduction mediated by organic matter to the isotopic transition were estimated. Microbial reduction and photoreduction play a dominant role in the initial litter decomposition during first 2 years. Dark redox reactions mediated by organic matter become the predominant process in the subsequent 420 years. After that, the values of Hg mass dependent fractionation (MDF), mass independent fractionation (MIF), and Δ199Hg/Δ201Hg ratio do not change significantly, indicating sequestration and immobilization of Hg in soil. The linear correlations between the isotopic signatures of Hg and C suggest that postdepositional transformation of Hg is closely linked to the fate of natural organic matter (NOM). Our findings are consistent with the abiotic dark reduction driven by nuclear volume effect reported in boreal and tropical forests. We recommend that the dark reduction process be incorporated in future model assessment of the global Hg biogeochemical cycle.