Long-term monitoring CO2 concentrations and fluxes from two German reservoirs

The dataset contains eight-year data of biweekly CO2 concentrations and underlying potential drivers from two adjacent reservoirs with contrasting trophic states in Germany. The parameters include biweekly concentrations and fluxes of CO2 and CH4, discharge of inflow and outflow, water residence time (WRT), water temperature, DO, pH, DOC, wind speed, alkalinity, TP, NO3, DIC, air temperature, rainfall.</p

Gas Pressure Dynamics in Small and Mid-Size Lakes

Dissolved gases produce a gas pressure. This gas pressure is the appropriate physical quantity for judging the possibility of bubble formation and hence it is central for understanding exchange of climate-relevant gases between (limnic) water and the atmosphere. The contribution of ebullition has widely been neglected in numerical simulations. We present measurements from six lacustrine waterbodies in Central Germany: including a natural lake, a drinking water reservoir, a mine pit lake, a sand excavation lake, a flooded quarry, and a small flooded lignite opencast, which has been heavily polluted. Seasonal changes of oxygen and temperature are complemented by numerical simulations of nitrogen and calculations of vapor pressure to quantify the contributions and their dynamics in lacustrine waters. In addition, accumulation of gases in monimolimnetic waters is demonstrated. We sum the partial pressures of the gases to yield a quantitative value for total gas pressure to reason which processes can force ebullition at which locations. In conclusion, only a small number of gases contribute decisively to gas pressure and hence can be crucial for bubble formation

Differential Influence of No-Tillage and Precipitation Pulses on Soil Heterotrophic and Autotrophic Respiration of Summer Maize in the North China Plain

It is important to strengthen the studies on the response of soil respiration components to tillage practices and natural precipitation in cropland. Therefore, soil heterotrophic respiration (RH) and autotrophic (RA) respiration were monitored by a root exclusion method in the North China Plain (NCP). The tillage practices included no-tillage (NT) and conventional tillage (CT), and the study periods were the summer maize growth stages in 2018 and 2019. RH, RA, soil water content and temperature were measured continuously for 113 days by an automatic sampling and analysis system. The soil RH values on bright days and rain-affected days were higher under NT in 2018 (14.22 and 15.06 g CO2 m&minus;2 d&minus;1, respectively) than in 2019 (8.25 and 13.30 g CO2 m&minus;2 d&minus;1, respectively). However, the RA values on bright days and rain-affected days were lower under NT in 2018 (4.74 and 4.97 g CO2 m&minus;2 d&minus;1, respectively) than in 2019 (5.67 and 6.93 g CO2 m&minus;2 d&minus;1, respectively). Moreover, NT decreased RH but increased RA compared to CT in 2019. Compared to bright days, the largest increase in both RH and RA after rain pulses was under CT in 2019 (6.75 and 1.80 g CO2 m&minus;2 d&minus;1, respectively). Soil water content and soil temperature were higher in 2018 than in 2019. Moreover, NT increased soil water content and decreased soil temperature on bright days compared to CT in 2019. Furthermore, soil temperature accounted for more variations in RH on bright days and rain-affected days, but soil water content had a greater influence on RA on bright days. However, after precipitation, higher soil water content decreased RA under NT in 2018, while soil water content was positively related to RA under CT in 2019. This study determined the differential response of RH and RA to tillage practices and natural precipitation pulses, and we confirmed that excessively dry soil increases soil carbon loss after rain events in the NCP

Insights on Water and Climate Change in the Greater Horn of Africa: Connecting Virtual Water and Water-Energy-Food-Biodiversity-Health Nexus

Water is the key limiting factor in socioeconomic and ecological development, but it is adversely affected by climate change. The novel virtual water (VW) concept and water, energy, food, biodiversity, and human health (WEFBH) nexus approach are powerful tools to assess the sustainability of a region through the lens of climate change. Climate change-related challenges and water are complex and intertwined. This paper analyzed the significant WEFBH sectors using the multicriteria decision-making (MCDM) and analytic hierarchy process (AHP) model. The AHP model demonstrated quantitative relationships among WEFBH nexus sustainability indicators in the Greater Horn of Africa countries. Besides, the net VW imports and water footprints of major staple crops were assessed. The composite WEFBH nexus indices varied from 0.10 to 0.14. The water footprint of crops is increasing period by period. The results also revealed that most countries in the study area are facing WEFBH domains unsustainability due to weak planning or improper management strategies. The strong policy constancy among the WEFBH sector is vital for dissociating the high-water consumption from crop production, energy, environmental, and human health system. Thus, this study enhances insights into the interdependencies, interconnectedness, and interactions of sectors thereby strengthening the coordination, complementarities, and synergies among them. To attain sustainable development, we urgently call all public and private entities to value the amount of VW used in their daily activities and design better policies on the complex WEFBH nexus and future climate change