[Effects of Photovoltaic Power Station Construction on Terrestrial Environment： Retrospect and Prospect].

With the rapid growth of global energy consumption, the environment will further deteriorate, and the competition among countries to reduce emissions will become more intense. Photovoltaic power generation using solar energy as a clean energy source is of strategic importance for achieving a carbon-neutral planet. Therein, centralized photovoltaic power stations in terrestrial ecosystems cover the earth's surface, which leads to changes in land use and has a significant effect on the surface energy balance and precipitation regimes, altering soil nutrient cycling and plant productivity, and ultimately significantly affects ecosystem functions and services. By synthesizing relevant studies on this topic over the past 20 years, we summarized the effects of photovoltaic power station construction on microclimate, soil, flora and fauna, and potential changes in terrestrial ecosystem functions. Overall, the photovoltaic power stations improved the quality of the soil condition, especially in harsh environments, and increased the vegetation coverage. In addition, photovoltaic power stations could affect ecosystem functions including plant productivity, soil erosion resistance, and soil carbon sequestration by regulating microclimatic factors such as solar radiation intensity, air temperature and humidity, wind speed, and wind direction. Although numerous studies have anticipated the potential effect of photovoltaic power stations on ecosystem structure and functions, empirical evidence remains scarce. Therefore, more studies focusing on the regional variability of the ecological impacts of photovoltaic power stations and the potential pathways of photovoltaic power stations affecting ecosystem functions are needed in the future. Improving the understanding of the ecological effects of photovoltaic power stations may help to provide a basis for ecological protection and restoration.

Effect of permafrost degradation on carbon sequestration of alpine ecosystems.

Permafrost degradation profoundly affects carbon storage in alpine ecosystems, and the response characteristics of carbon sequestration are likely to differ at the different stages of permafrost degradation. Furthermore, the sensitivity of different stages of permafrost degradation to climate change is likely to vary. However, related research is lacking so far on the Qinghai-Tibetan Plateau (QTP). To investigate these issues, the Shule River headwaters on the northeastern margin of the QTP was selected. We applied InVEST and Noah-MP land surface models in combination with remote sensing and field survey data to reveal the dynamics of different carbon (vegetation carbon, soil organic carbon (SOC), and ecosystem carbon) pools from 2001 to 2020. A space-for-time analysis was used to explore the response characteristics of carbon sequestration along a gradient of permafrost degradation, ranging from lightly degraded permafrost (H-SP) to severely degraded permafrost (U-EUP), and to analyze the sensitivity of the permafrost degradation gradient to climate change. Our results showed that: (1) the sensitivity of mean annual ground temperature (MAGT) to climatic variables in the U-EUP was stronger than that in the H-SP and S-TP, respectively; (2) rising MAGT led to permafrost degradation, but increasing annual precipitation promoted permafrost conservation; (3) vegetation carbon, SOC, and ecosystem carbon had similar spatial distribution patterns, with their storage decreasing from the mountain area to the valley; (4) alpine ecosystems acted as carbon sinks with the rate of 0.34 Mg‧ha-1‧a-1 during 2001-2020, of which vegetation carbon and SOC accumulations accounted for 10.65 % and 89.35 %, respectively; and (5) the effects of permafrost degradation from H-SP to U-EUP on carbon density changed from promotion to inhibition.

Soil microbial distribution and assembly are related to vegetation biomass in the alpine permafrost regions of the Qinghai-Tibet Plateau.

It is generally believed that there is a vegetation succession sequence from alpine marsh meadow to desert in the alpine ecosystem of the Qinghai-Tibet Plateau. However, we still have a limited understanding about distribution patterns and community assemblies of microorganisms' response to such vegetation changes. Hence, across a gradient represented by three types of alpine vegetation from swamp meadow to meadow to steppe, the soil bacterial, fungal and archaeal diversity was evaluated and then associated with their assembly processes, and glacier foreland vegetation was also surveyed as a case out of this gradient. Vegetation biomass was found to decrease significantly along the vegetation gradient. In contrast to irregular shifts in alpha diversity, bacterial and fungal beta diversities that were dominated by species replacement components (71.07-79.08%) significantly increased with the decreasing gradient in vegetation biomass (P < 0.05). These trends of increase were also found in the extent of stochastic bacterial and fungal assembly. Moreover, an increase in microbial beta diversity but a decrease in beta nearest taxon index were observed along with increased discrepancy in vegetation biomass (P < 0.001). Stepwise regression analyses and structural equation models suggested that vegetation biomass was the major variable that was related to microbial distribution and community assembly, and there might be associations between the dominance of species replacements and stochastic assembly. These findings enhanced our recognition of the relationship between vegetation and soil microorganisms and would facilitate the development of vegetation-microbe feedback models in alpine ecosystems.

Reduced microbial stability in the active layer is associated with carbon loss under alpine permafrost degradation.

Permafrost degradation may induce soil carbon (C) loss, critical for global C cycling, and be mediated by microbes. Despite larger C stored within the active layer of permafrost regions, which are more affected by warming, and the critical roles of Qinghai-Tibet Plateau in C cycling, most previous studies focused on the permafrost layer and in high-latitude areas. We demonstrate in situ that permafrost degradation alters the diversity and potentially decreases the stability of active layer microbial communities. These changes are associated with soil C loss and potentially a positive C feedback. This study provides insights into microbial-mediated mechanisms responsible for C loss within the active layer in degraded permafrost, aiding in the modeling of C emission under future scenarios.

Association between Metabolic Syndrome and Carotid Atherosclerosis: A Cross-sectional Study in Northern China.

OBJECTIVE: Increased carotid artery intima-media thickness (CIMT) and carotid plaque as manifestations of carotid atherosclerosis have been used as markers of cardiovascular disease (CVD). The components of metabolic syndrome (MetS) are linked to CVD, but the association between MetS and CVD is controversial. METHODS: A total of 8,933 Chinese adults aged 40 years or older from 2010 to 2014 were selected from the Jidong and Kailuan communities. MetS was defined by the International Diabetes Federation criteria. CIMT and carotid plaque were measured using color Doppler ultrasound. Logistic regression models were used to assess the association of MetS with carotid plaque and CIMT. RESULTS: MetS was found among 3,461 (3,461/8,933) participants. The odds ratio and 95% confidence internal (CI) for carotid plaques in participants with MetS was 1.16 (1.03-1.30). The risk of carotid plaques increased with the number of MetS components. The average CIMT was higher in participants with MetS (ß = 0.020, 95% CI, 0.014-0.027) and in participants with more MetS components. CONCLUSION: Individuals with MetS are at an increased risk for carotid atherosclerosis compared to those without MetS.

Effect of in-hospital medical complications on case fatality post-acute ischemic stroke: data from the China National Stroke Registry.

BACKGROUND: In-hospital medical complications are associated with poorer clinical outcomes for stroke patients after disease onset. However, few studies from China have reported the effect of these complications on the mortality of patients with acute ischemic stroke. In this prospective work, the China National Stroke Registry Study, we investigated the effect of medical complications on the case fatality of patients with acute ischemic stroke. METHODS: From September 2007 to August 2008, we prospectively obtained the data of patients with acute stroke from 132 clinical centers in China. Medical complications, case fatality and other information recorded at baseline, during hospitalisation, and at 3, 6, and 12 months after stroke onset. Multivariable Logistic regression was performed to analyze the effect of medical complications on the case fatality of patients with acute ischemic stroke. RESULTS: There were 39 741 patients screened, 14 526 patients with acute ischemic stroke recruited, and 11 560 ischemic stroke patients without missing data identified during the 12-month follow-up. Of the 11 560 ischemic patients, 15.8% (1826) had in-hospital medical complications. The most common complication was pneumonia (1373; 11.9% of patients), followed by urinary tract infection and gastrointestinal bleeding. In comparison with patients without complications, stroke patients with complications had a significantly higher risk of death during their hospitalization, and at 3, 6 and 12 months post-stroke. Having any one in-hospital medical complication was an independent risk factor for death in patients with acute ischemic stroke during hospital period (adjusted OR = 6.946; 95%CI 5.181 to 9.314), at 3 months (adjusted OR = 3.843; 95%CI 3.221 to 4.584), 6 months (adjusted OR = 3.492; 95%CI 2.970 to 4.106), and 12 months (adjusted OR = 3.511; 95%CI 3.021 to 4.080). Having multiple complications strongly increased the death risk of patients. CONCLUSION: Short-term and long-term outcomes of acute stroke patients are affected by in-hospital medical complications.