In response to ecosystem degradation from rapid economic development, China began investing heavily in protecting and restoring natural capital starting in 2000. We report on China's first national ecosystem assessment (2000-2010), designed to quantify and help manage change in ecosystem services, including food production, carbon sequestration, soil retention, sandstorm prevention, water retention, flood mitigation, and provision of habitat for biodiversity. Overall, ecosystem services improved from 2000 to 2010, apart from habitat provision. China's national conservation policies contributed significantly to the increases in those ecosystem services.
The long-term stressful utilization of forests and grasslands has led to ecosystem degradation and C loss. Since the late 1970s China has launched six key national ecological restoration projects to protect its environment and restore degraded ecosystems. Here, we conducted a large-scale field investigation and a literature survey of biomass and soil C in China's forest, shrubland, and grassland ecosystems across the regions where the six projects were implemented (∼16% of the country's land area). We investigated the changes in the C stocks of these ecosystems to evaluate the contributions of the projects to the country's C sink between 2001 and 2010. Over this decade, we estimated that the total annual C sink in the project region was 132 Tg C per y (1 Tg = 10 g), over half of which (74 Tg C per y, 56%) was attributed to the implementation of the projects. Our results demonstrate that these restoration projects have substantially contributed to CO mitigation in China.
Recent expansion of the scale of human activities poses severe threats to Earth’s life-support systems. Increasingly, protected areas (PAs) are expected to serve dual goals: protect biodiversity and secure ecosystem services. We report a nationwide assessment for China, quantifying the provision of threatened species habitat and four key regulating services—water retention, soil retention, sandstorm prevention, and carbon sequestration—in nature reserves (the primary category of PAs in China). We find that China’s nature reserves serve moderately well for mammals and birds, but not for other major taxa, nor for these key regulating ecosystem services. China’s nature reserves encompass 15.1% of the country’s land surface. They capture 17.9% and 16.4% of the entire habitat area for threatened mammals and birds, but only 13.1% for plants, 10.0% for amphibians, and 8.5% for reptiles. Nature reserves encompass only 10.2–12.5% of the source areas for the four key regulating services. They are concentrated in western China, whereas much threatened species’ habitat and regulating service source areas occur in eastern provinces. Our analysis illuminates a strategy for greatly strengthening PAs, through creating the first comprehensive national park system of China. This would encompass both nature reserves, in which human activities are highly restricted, and a new category of PAs for ecosystem services, in which human activities not impacting key services are permitted. This could close the gap in a politically feasible way. We also propose a new category of PAs globally, for sustaining the provision of ecosystems services and achieving sustainable development goals.
Soil as the largest global carbon pool has played a great role in sequestering the atmospheric carbon dioxide (CO 2 ). Although global carbon sequestration potentials have been assessed since the 1980s, few investigations have been made on soil carbon sequestration (SCS) in China's cropland. China is a developing country and has a long history of agricultural activities. Estimation of SCS potentials in China's cropland is very important for assessing the potential measures to prevent the atmospheric carbon rise and predicting the atmospheric CO 2 concentration in future. After review of the available results of the field experiments in China, relationships between SCS and nitrogen fertilizer application, straw return and no-tillage (NT) practices were established for each of the four agricultural regions. According to the current agricultural practices and their future development, estimations were made on SCS by nitrogen fertilizer application, straw return and NT in China's cropland. In the current situation, nitrogen fertilizer application, straw return and zero tillage can sequester 5.96, 9.76 and 0.800 Tg C each year. Carbon sequestration potential will increase to 12.1 Tg C yr À1 if nitrogen is fertilized on experts' recommendations. The carbon sequestration potentials of straw return and NT can reach 34.4 and 4.60 Tg C yr À1 when these two techniques are further popularized. In these measures, straw return is the most promising one. Full popularization of straw return can reduce 5.3% of the CO 2 emission from fossil fuel combustion in China in 1990, which meets the global mean CO 2 reduction requested by the Kyoto Protocol (5.2%). In general, if more incentive policies can be elaborated and implemented, the SCS in China's cropland will be increased by about two times. So, popularization of the abovementioned agricultural measures for carbon sequestration can be considered as an effective tool to prevent the rapid rise of the atmospheric CO 2 in China.
Due to advances in telemedicine, mobile medical care, wearable health monitoring, and electronic skin, great efforts have been directed to non-invasive monitoring and treatment of disease. These processes generally involve disease detection from interstitial fluid (ISF) instead of blood, and transdermal drug delivery. However, the quantitative extraction of ISF and the level of drug absorption are greatly affected by the individual’s skin permeability, which is closely related to the properties of the stratum corneum (SC). Therefore, measurement of SC impedance has been proposed as an appropriate way for assessing individual skin differences. In order to figure out the current status and research direction of human SC impedance detection, investigations regarding skin impedance measurement have been reviewed in this paper. Future directions are concluded after a review of impedance models, electrodes, measurement methods and systems, and their applications in treatment. It is believed that a well-matched skin impedance model and measurement method will be established for clinical and point-of care applications in the near future.
Straw incorporation (SI) is a common practice in China and has important implications for agricultural sustainability. This study aimed to quantitatively summarise the response of top soil (0-20 cm) carbon (C) to SI under different agricultural management regimes. Results indicated that compared with straw removal (SR), SI significantly increased soil C storage by 12 %. Moreover, incorporation of chopped straw with tillage treatment (ploughing and rotary tillage) increased C storage compared to unchopped straw without tillage treatment. SI implementation with upland cropping, in the northwest and northeast resulted in higher C storage compared with rice cropping, and in the northern and southern regions. Changes in soil C were observed based on SI variables, including tillage and straw amounts in fine-textured soils, however straw amount rather than tillage treatment exhibited a greater influence on soil C in coarse-textured soils. We concluded SI implementation with increased amounts of chopped straw for a longer duration was favourable to soil C sequestration in Chinese croplands. Furthermore, we estimated if SI was popularised across all of China's agricultural regions, soil C sequestration potential would reach 48.25 6.2 Tg C year −1. SI practices should therefore be encouraged.
Abstract. Forest biomass and its allocation have long been considered important in forest ecosystem structure and function. However, discrete forest biomass data and its allocation to various forest components must be standardized to explore many ecological questions, e.g., plant allometric scaling laws, biomass allocation theory, and terrestrial carbon cycling. Currently, available data sets focus either on regions other than China, or studies in China are spatially and/or temporally limited, e.g., specific habitats and/or time periods. Therefore, the applicability of conclusions to world or China forests might be problematic. Consequently, in the present study, published studies (during the 1978-2008 period) on biomass and its allocations in China's forests (excluding Hong Kong, Macao, and Taiwan) were collected and critically reviewed, and a comprehensive forest biomass data set of China was developed. The data set included the following biomass data: tree overstory components (stems, branches, leaves, and roots, among all other plant material), the understory vegetation (saplings, shrubs, herbs, and mosses), woody liana vegetation, and the necromass components of dead organic matter (litterfall, suspended branches, and dead trees). Moreover, associated information was also included, i.e., geographical location, climate, soil fertility, stand description, sampling regime (the dimension and sample size of plots), and biomass measurement methods. The data set included 1607 entries for 348 study sites, which exhibited a broad spatial distribution, and covered broad climatic gradients (À5.18C to 23.88C in mean annual temperature and 223-2515 mm in mean annual precipitation). Our data set can be used to verify the accuracy of models used to budget China's forest carbon dynamics, and also provides an opportunity to further elucidate and confirm general principles and patterns in ecology. Finally, the data set is freely available for noncommercial scientific applications.
Few investigations have been made on the impact of elevated ozone (O 3 ) concentration on methane (CH 4 ) emission from rice paddies. Using open-top chambers in situ with different O 3 treatments, CH 4 emissions were measured in a rice paddy in Yangtze River Delta, China in 2007 and 2008. There were four treatments applied: charcoal-filtered air (CF), nonfiltered air (NF), and charcoal-filtered air with different O 3 additions (O 3 -1 and O 3 -2). The mean O 3 concentrations during the O 3 fumigation were 19.7, 22.6, 69.6 and 118.6 ppb in 2007 and 7.0, 17.4, 82.2 and 138.3 ppb in 2008 for treatments CF, NF, O 3 -1 and O 3 -2, respectively. The rice yields, as compared with CF, were reduced by 32.8% and 37.1%, 58.3% and 52.1% in treatments O 3 -1 and O 3 -2 in 2007 and 2008, respectively. The diurnal patterns of CH 4 emission varied temporally with treatments and there was inconsistence in diurnal variations in CH 4 emissions from the paddy field. The daily mean CH 4 emissions were significantly lower in treatments O 3 -1 and O 3 -2 than those in treatments CF and NF. Compared with CF treatment, CH 4 emissions from the paddy field were decreased to 46.5% and 38.3%, 50.6% and 46.8% under treatments O 3 -1 and O 3 -2 in the whole growing seasons of 2007 and 2008, respectively. The seasonal mean CH 4 emissions were negatively related with AOT40 (accumulative O 3 concentration above 40 ppb; Po0.01 in both years), but positively related to the relative rice yield (reference to CF; Po0.01 in 2007 and Po0.001 in 2008), aboveground biomass (Po0.01 in both years) and underground biomass (Po0.01 in 2007 and Po0.05 in 2008). The decreased CH 4 emission from the rice paddy due to an increased O 3 exposure might partially mitigate the global warming potential induced by soil carbon loss under elevated O 3 concentrations.
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