Soil organic carbon stocks increased across the tide-induced salinity transect in restored mangrove region.

Blue carbon in mangrove ecosystems contributes significantly to the global carbon cycle. However, large uncertainties maintain in the soil organic carbon (SOC) storage throughout the tide-induced salinity and alkalinity transect in the mangrove restoration region in Southern China. Total 125 soil samples were obtained to detect the SOC content and physicochemical properties. The mean SOC content of each layer ranged from 6.82 to 7.86 g kg-1, while the SOC density ranged from 2.99 to 11.41 kg m-2, increasing with soil depths. From different land covers in the study region, the SOC content varied from 4.63 to 9.71 g kg-1, increasing across the salinity and alkalinity transect, while the SOC density fluctuated from 3.01 kg m-2 in mudflats to 10.05 kg m-2 in mangrove forests. SOC concentration was favorably linked with total nitrogen (r = 0.95), and total phosphorus (r = 0.74), and negatively correlated with Cl- (r = - 0.95), electrical conductivity (r = - 0.24), and total dissolved solids (r = - 0.08). There were significant logarithmic relationships between SOC content and the concentrations of clay (r = 0.76), fine silt (r = 0.81), medium silt (r = - 0.82), and coarse silt (r = - 0.78). The spatial patterns of SOC concentration were notably affected by soil texture, physicochemical properties, and land-cover type, providing essential reference for future investigations of blue carbon budget in restored mangrove forests.

Adapting the Evidence Academy model for virtual stakeholder engagement in a national setting during the COVID-19 pandemic.

The COVID-19 pandemic raised the importance of adaptive capacity and preparedness when engaging historically marginalized populations in research and practice. The Rapid Acceleration of Diagnostics in Underserved Populations' COVID-19 Equity Evidence Academy Series (RADx-UP EA) is a virtual, national, interactive conference model designed to support and engage community-academic partnerships in a collaborative effort to improve practices that overcome disparities in SARS-CoV-2 testing and testing technologies. The RADx-UP EA promotes information sharing, critical reflection and discussion, and creation of translatable strategies for health equity. Staff and faculty from the RADx-UP Coordination and Data Collection Center developed three EA events with diverse geographic, racial, and ethnic representation of attendees from RADx-UP community-academic project teams: February 2021 (n = 319); November 2021 (n = 242); and September 2022 (n = 254). Each EA event included a data profile; 2-day, virtual event; event summary report; community dissemination product; and an evaluation strategy. Operational and translational delivery processes were iteratively adapted for each EA across one or more of five adaptive capacity domains: assets, knowledge and learning, social organization, flexibility, and innovation. The RADx-UP EA model can be generalized beyond RADx-UP and tailored by community and academic input to respond to local or national health emergencies.

Organic and inorganic carbon and their stable isotopes in surface sediments of the Yellow River Estuary.

Studying the carbon dynamics of estuarine sediment is crucial to understanding of carbon cycle in the coastal ocean. This study is to evaluate the mechanisms regulating the dynamics of organic (TOC) and inorganic carbon (TIC) in surface sediment of the Yellow River Estuary (YRE). Based on data of 15 surface sediment cores, we found that TIC (6.3-20.1 g kg-1) was much higher than TOC (0.2-4.4 g kg-1). Both TOC and TIC were generally higher to the north than to the south, primarily due to the differences in kinetic energy level (i.e., higher to the south). Our analysis suggested that TOC was mainly from marine sources in the YER, except in the southern shallow bay where approximately 75% of TOC was terrigenous. The overall low levels of TOC were due to profound resuspension that could cause enhanced decomposition. On the other hand, high levels of TIC resulted partly from higher rates of biological production, and partly from decomposition of TOC associated with sediment resuspension. The isotopic signiture in TIC seems to imply that the latter is dominant in forming more TIC in the YRE, and there may be transfer of OC to IC in the water column.

Spatial and temporal variations of particulate organic carbon in the Yellow-Bohai Sea over 2002-2016.

The Yellow-Bohai Sea (YBS) is a typical marginal sea in the Northwest Pacific Ocean; however, little is known about the dynamics of particulate organic carbon (POC) and underlying mechanisms. Here, we analyze the spatial and temporal variations of surface POC derived from MODIS-Aqua during 2002-2016. Overall, POC is higher in the Bohai Sea (315-588 mg m-3) than in the Yellow Sea (181-492 mg m-3), and higher in the nearshore than in the offshore. Surface POC is highest in spring in the YBS, and lowest in winter (summer) in the Bohai Sea (the Yellow Sea). The spatial and seasonal patterns of POC are due to combined influences of primary productivity, water exchange, sediment resuspension and terrestrial inputs. Surface POC shows an overall decreasing trend prior to 2012 followed by an upward trend until 2015 in the YBS, which is almost opposite to chlorophyll; the decrease (increase) may result from strengthened (weakened) water exchange with the East China Sea through the Yellow Sea Warm Current. Declined terrestrial runoff is also partly responsible for the decrease prior to 2012. Our study suggests that water exchange and sediment resuspension are dominant factors regulating the spatial and temporal variability of POC in the YBS.

A less or more dusty future in the Northern Qinghai-Tibetan Plateau?

Dust plays an important role in climate changes as it can alter atmospheric circulation, and global biogeochemical and hydrologic cycling. Many studies have investigated the relationship between dust and temperature in an attempt to predict whether global warming in coming decades to centuries can result in a less or more dusty future. However, dust and temperature changes have rarely been simultaneously reconstructed in the same record. Here we present a 1600-yr-long quantitative record of temperature and dust activity inferred simultaneously from varved Kusai Lake sediments in the northern Qinghai-Tibetan Plateau, NW China. At decadal time scale, our temperature reconstructions are generally in agreement with tree-ring records from Karakorum of Pakistan, and temperature reconstructions of China and North Hemisphere based on compilations of proxy records. A less or more dusty future depends on temperature variations in the Northern Qinghai-Tibetan Plateau, i.e. weak and strong dust activities at centennial time scales are well correlated with low and high June-July-August temperature (average JJA temperature), respectively. This correlation means that stronger summer and winter monsoon should occur at the same times in the northern Qinghai-Tibetan Plateau.