Authors: Shokoufeh Salimi; Suhad A.A.A.N. Almuktar; Miklas Scholz;
Climate change is identified as a major threat to wetlands. Altered hydrology and rising temperature can change the biogeochemistry and function of a wetland to the degree that some important services might be turned into disservices. This means that they will, for example, no longer provide a water purification service and adversely they may start to decompose and release nutrients to the surface water. Moreover, a higher rate of decomposition than primary production (photosynthesis) may lead to a shift of their function from being a sink of carbon to a source. This review paper assesses the potential response of natural wetlands (peatlands) and constructed wetlands to climate change in terms of gas emission and nutrients release. In addition, the impact of key climatic factors such as temperature and water availability on wetlands has been reviewed.
Impact of future climate scenarios on peatland and constructed wetland water quality: A mesocosm experiment within climate chambers
Response of the Peatland Carbon Dioxide Sink Function to Future Climate Change Scenarios and Water Level Management
Authors: Salimi S; Berggren M; Scholz M;
Stress factors such as climate change and drought may switch the role of temperate peatlands from carbon dioxide (CO2) sinks to sources, leading to positive feedback to global climate change. Water level management has been regarded as an important climate change mitigation strategy as it can sustain the natural net CO2 sink function of a peatland. Little is known about how resilient peatlands are in the face of future climate change scenarios, as well as how effectively water level management can sustain the CO2 sink function to mitigate global warming. The authors assess the effect of climate change on CO2 exchange of south Swedish temperate peatlands, which were either unmanaged or subject to water level regulation. Climate chamber simulations were conducted using experimental peatland mesocosms exposed to current and future representative concentration pathway (RCP) climate scenarios (RCP 2.6, 4.5 and 8.5). The results showed that all managed and unmanaged systems under future climate scenarios could serve as CO2 sinks throughout the experimental period. However, the 2018 extreme drought caused the unmanaged mesocosms under the RCP 4.5 and RCP 8.5 switch from a net CO2 sink to a source during summer. Surprisingly, the unmanaged mesocosms under RCP 2.6 benefited from the warmer climate, and served as the best sink among the other unmanaged systems. Water level management had the greatest effect on the CO2 sink function under RCP 8.5 and RCP 4.5, which improved their CO2 sink capability up to six and two times, respectively. Under the current climate scenario, water level management had a negative effect on the CO2 sink function, and it had almost no effect under RCP 2.6. Therefore, the researchers conclude that water level management is necessary for RCP 8.5, beneficial for RCP 4.5 and unimportant for RCP 2.6 and the current climate.
Diffuse Water Pollution from Agriculture: A Review of Nature-Based Solutions for Nitrogen Removal and Recovery
Authors: Giuseppe Mancuso; Grazia Federica Bencresciuto; Stevo Lavrnić; Attilio Toscano
The implementation of nature-based solutions (NBSs) can be a suitable and sustainable approach to coping with environmental issues related to diffuse water pollution from agriculture. NBSs exploit natural mitigation processes that can promote the removal of different contaminants from agricultural wastewater, and they can also enable the recovery of otherwise lost resources (i.e., nutrients). Among these, nitrogen impacts different ecosystems, resulting in serious environmental and human health issues. Recent research activities have investigated the capability of NBS to remove nitrogen from polluted water. However, the regulating mechanisms for nitrogen removal can be complex, since a wide range of decontamination pathways, such as plant uptake, microbial degradation, substrate adsorption and filtration, precipitation, sedimentation, and volatilization, can be involved. Investigating these processes is beneficial for the enhancement of the performance of NBSs. The present study provides a comprehensive review of factors that can influence nitrogen removal in different types of NBSs, and the possible strategies for nitrogen recovery that have been reported in the literature.
51. Real-time spectral information to measure crop water stress for variable rate irrigation scheduling
Authors: A. Nagy; A. Szabó; B. Gálya Farkasné; J. Tamás.
In recent years, the point measurements of water management properties have become widespread and the spatial heterogeneity of a field is important. Spectral analysis provides an opportunity to measure the water load of plants in real time under field conditions. Thus, NDVI data was recorded using different remote sensing methods and then compared the pigment and dry matter content of the plants with different statistical methods. NDVI values were higher in the irrigated area in all cases. The highest NDVI value was reached on 23 July in irrigated areas. Based on the descriptive statistics of the examined values, with the exception of the dry matter content, the standard deviation of the examined factors exceeded 20% in all cases, which indicates a greater heterogeneity of the variables.
Assessment of Capsicum annuum L. Grown in Controlled and Semi-Controlled Environments Irrigated with Greywater Treated by Floating Wetland Systems
Accumulation of trace elements, including heavy metals, were evaluated in soil and fruits of chilli plants (Capsicum annuum L.) grown under both laboratory-controlled and semi-controlled greenhouse location conditions. Chilli plant biomass growth in different development stages and fruit productivity were evaluated and compared with each other for the impact of growth boundary conditions and water quality effects. Treated synthetic greywaters by different operational design set-ups of floating treatment wetland systems were recycled for watering chillies in both locations. Effluents of each individual group of treatment set-up systems were labelled to feed sets of three replicates of chilli plants in both locations. Results revealed that the treated synthetic greywater (SGW) complied with thresholds for irrigation water, except for high concentrations (HC) of phosphates, total suspended soils, and some trace elements, such as cadmium. Chilli plants grew in both locations with different growth patterns in each development stage. First blooming and high counts of flowers were observed in the laboratory. Higher fruit production was noted for greenhouse plants: 2266 chilli fruits with a total weight of 16.824 kg with an expected market value of GBP 176.22 compared to 858 chilli fruits from the laboratory with a weight of 3.869 kg and an estimated price of GBP 17.61. However, trace element concentrations were detected in chilli fruits with the ranking order of occurrence as: Mg > Ca > Na > Fe > Zn > Al > Mn > Cu > Cd > Cr > Ni > B. The highest concentrations of accumulated Cd (3.82 mg/kg), Cu (0.56 mg/kg), and Na (0.56 mg/kg) were recorded in chilli fruits from the laboratory, while greater accumulations of Ca, Cd, Cu, Mn, and Ni with concentrations of 4.73, 1.30, 0.20, 0.21, and 0.24 mg/kg, respectively, were linked to fruits from the greenhouse. Trace elements in chilli plant soils followed the trend: Mg > Fe > Al > Cr > Mn > Cd > Cu > B. The accumulated concentrations in either chilli fruits or the soil were above the maximum permissible thresholds, indicating the need for water quality improvements.