Search Results (130)

The proper functioning of peatlands depends on maintaining an adequate groundwater table, which is essential for ecosystem services beyond water retention. Most degraded peatlands have been drained for agriculture or forestry primarily through ditch construction. Rewetting through ditch blocking is the most common initial step in peatland restoration. This study analyzed the hydrological response to ditch blocking in three drained raised bogs in Norway (Aurstadmåsan, Midtfjellmåsan and Kaldvassmyra) using a Before–After–Control–Impact (BACI) design. Following rewetting, all sites demonstrated an average increase in groundwater levels of 6 cm across all piezometers affected by ditch blocking. The spatial influence of ditch blocking extended 12.7–24.8 m from the ditch with an average of 17.2 m. Additionally, rewetting increased the duration of favorable groundwater levels for peatland functioning by 27.7%. These findings highlight the effectiveness of ditch blocking in restoring hydrological conditions, although its impact is spatially limited. Future assessments should also address vegetation recovery and greenhouse gas emission reductions to ensure comprehensive restoration success. Full article

Climate change has led to an increasing frequency of droughts, potentially undermining soil stability. In such a changing environment, the shallow reinforcement effect of plant roots often fails to meet expectations. This study aims to explore whether this is associated with the alteration of plant traits as a response to environmental change. Focusing on Amorpha fruticosa, a species known for its robust root system that plays a crucial role in soil consolidation and slope stabilization, thereby reducing soil and water erosion, we simulated a drought-rewetting event to assess the legacy effects of drought on the soil shear strength and the mechanical and hydrological traits associated with the reinforcement provided by A. fruticosa. The results show that the legacy effect of drought significantly diminishes the soil shear strength. Pretreated with drought, plant roots undergo morphological alterations such as deeper growth, yet the underground root biomass and diameter decline, thereby influencing mechanical reinforcement. Chemical composition analysis indicates that the plant’s adaptation to drought modifies the intrinsic properties of the roots, with varying impacts on different root types and overall reinforcement. Concurrently, the stomatal conductance and transpiration rate of leaves decrease, weakening the capacity to augment soil matric suction through transpiration and potentially reducing hydrological reinforcement. Although rewetting treatments aid in recovery, drought legacy effects persist and impact plant functional attributes. This study emphasizes that, beyond soil matric suction, plant adaptive mechanisms in response to environmental changes may also contribute significantly to reduced soil shear strength. Consequently, ecological restoration strategies should consider plant trait adaptations to drought, enhancing root systems for soil conservation and climate resilience. Full article

Rewetting of drained wetlands is practiced as a method to enhance biodiversity, improve water and nutrient retention, and counteract climate change. While rewetting efforts are most commonly directed toward various types of wetlands, there are relatively few reports on the restoration of lakes drained in the past. The Olsztyn Lake District is a region where extensive, organized drainage works were carried out in the 19th century, leading to the disappearance of numerous lakes. This paper examines the changes that have occurred since the early 19th century in a group of 143 lakes identified as the complete set of fully drained lakes in the region. An analysis of cartographic materials revealed that the total area of these lakes, originally about 3000 hectares, was reduced to nearly zero by the early 20th century. However, a gradual restoration of the former lakes is now being observed, primarily as a result of spontaneous processes but also through planned interventions. The study of water quality and trophic status in 25 fully restored lakes revealed that such water bodies typically exhibit unfavorable conditions, primarily due to excessive phosphorus levels. A similar state was observed in 14 examined wetlands, which were partially rewetted. In the absence of organized restoration programs in the study region, the slow trend of passive rewetting of such water bodies is expected to continue. However, this process may be hindered by adverse hydroclimatic changes associated with ongoing climate warming. Full article

Oxidation of methane by soil microorganisms is an important mechanism controlling the content of this potent greenhouse gas in the atmosphere. Agricultural soils operate under stressful conditions, and ammonium (N-fertilization) and drying (global warming) may have a significant impact on methane oxidation. In order to investigate how soil methanotrophs respond to drying–rewetting (DW), ammonium addition (100 mg/g) (A), and their combined action (MS), agricultural soil microcosms were incubated over the three months and methane oxidation was measured before and after perturbations, while community composition was monitoring using 16S rRNA gene sequencing. A significant decline in the methane-oxidation activity after perturbations was found, with subsequent restoration, and the combined treatment was more effective than the sum of individual treatments, indicating a synergistic effect. After rewetting, the structure of the bacterial community returned to pre-dry-down levels, but the application of ammonia and combined action lead to irreversible changes in the structure of soil methanotrophic communities. Methanotroph Methylomicrobium were significantly reduced under disturbances, while there was a significant increase in the representation of Methylobacter accompanied by the facultative methylotroph Methylovorus. We concluded that methanotrophic communities in agricultural soil demonstrated flexibility, and even when the abundance of dominant populations drops, ecosystem functions can recover. Full article

The nucleation and growth of bubbles on homogeneous wetting surfaces have been extensively studied, but the intricate dynamics on hybrid wetting surfaces remain under-explored. This research aims to elucidate the impact of hybrid wettability on pool boiling heat transfer efficiency, specifically under downward-facing heating conditions. To this end, a series of hybrid wettability surfaces with varying hydrophilic and hydrophobic configurations are meticulously fabricated and analyzed. The study reveals distinctive interfacial phenomena occurring at the boundary between hydrophilic and hydrophobic regions during the boiling process. Experimental results indicate that surfaces with a higher proportion of hydrophilic to hydrophobic interfaces exhibit reduced superheat requirements and enhanced boiling heat transfer coefficients for equivalent heat flux densities. Furthermore, the rewetting characteristics of hybrid wettability surfaces are identified as pivotal factors in determining their critical heat flux (CHF). This investigation underscores the potential of hybrid wettability surfaces to optimize pool boiling heat transfer, offering valuable insights for the design and en-hancement of heat exchangers and other thermal management systems. Full article

Gravel mulching is a widely employed strategy for water conservation in arid agricultural regions, with potential implications for soil carbon (C) sequestration and greenhouse gas emissions. However, soil respiration and CO₂-C emissions remain uncertain owing to less consideration of the influence of precipitation patterns and planting age. In this study, we investigated the soil respiration rate (R_soil) and cumulative CO₂-C emission (C_cum), both measured over a period of 72 h, along with soil properties and enzyme activities under different precipitation conditions based on gravel mulching with different planting ages. We analyzed the effects of planting ages on R_soil and C_cum and revealed the underlying mechanisms driving changes in environmental factors on R_soil and C_cum. The results demonstrated that the R_soil reached the maximum value at about 1 h, 0.5 h, and 0.25 h after rewetting in 1, 10, and 20 years of gravel mulching under the condition with 1 mm, 5 mm, and 10 mm of precipitation, respectively, whereas the R_soil exhibited its maximum at about 8 h after soil rewetting under precipitation of 30 mm. The C_cum induced by precipitation pulses tends to decrease with increasing years of gravel mulching. The C_cum was 0.0061 t ha⁻¹ in the 20-year gravel-mulched soil, representing a 53.79% reduction compared to the 1-year gravel-mulched soil. Soil organic matter (SOM), planting ages, and alkaline phosphatase (ALP) were the primary factors influencing the R_soil and C_cum in 0–20 cm, while SOM, planting ages, and soil porosity (AirP) were the key factors affecting the R_soil and C_cum in 20–40 cm. The R_soil and C_cum in the 0–20 cm soil were regulated by soil enzyme activities, while those of 20–40 cm soil were controlled by soil properties. This indicates that the decrease in R_soil and C_cum is caused by soil degradation, characterized by a decrease in SOM and ALP. This study offers a novel insight into the long-term environmental impact of gravel mulching measures in arid areas, which is helpful in providing a theoretical basis for dryland agricultural management. It is imperative to consider the duration of gravel mulching when predicting the potential for C sequestration in arid agricultural areas. Full article

Drying and rewetting of soil stimulates soil carbon emission. The Birch effect, driven by these cycles, leads to CO₂ efflux, which can be monitored using real-time mass spectrometry (RTMS). Although soil fungi retain water during droughts, their contribution to CO₂ release during drying–rewetting cycles remains unclear. In this study, we present the first demonstration of integrating micromodels with RTMS to monitor the Birch effect by simulating drought and rewetting. Micromodels were inoculated with axenic fungal culture and dried to assess moisture retention. After drying, RTMS quantified CO₂ release upon rewetting with H₂¹⁸O mixtures. Our results showed that soil fungi released CO₂ upon rehydration and immediately utilized the external water source at the pore scale by generating subsequent ⁴⁶CO₂. This work is the first to integrate RTMS with microsystems to investigate pore-scale biogeochemistry and the involvement of fungi in the Birch effect. Full article

Studies of the impact of nitrification inhibitors (NIs), specifically DMPP and DMPSA, on N₂O emissions during “hot moments” have produced conflicting results regarding their effectiveness after rewetting. This study aimed to clarify the effectiveness of NIs in reducing N₂O emissions by assessing residual DMP concentration and its influence on ammonia-oxidizing bacteria (AOB) in two pot experiments using calcareous (Soil C, Calcic Haploxerept) and acidic soils (Soil A, Dystric Xerochrepts). Fertilizer treatments included urea (U), DMPP, and DMPSA. The experiments were divided into Phase I (water application to dry period, 44 days) and Phase II (rewetting from days 101 to 121). In both phases for Soil C, total N₂O emissions were reduced by 88% and 90% for DMPP and DMPSA, respectively, compared with U alone. While in Phase I, the efficacy of NIs was linked to the regulation of AOB populations, in Phase II this group was not affected by NIs, suggesting that nitrification may not be the predominant process after rewetting. In Soil A, higher concentrations of DMP from DMPP were maintained compared to Soil C at the end of each phase. Despite this, NIs had no significant effect due to low nitrification rates and limited amoA gene abundance, indicating unfavorable conditions for nitrifiers. The study highlights the need to optimize NIs to reduce N₂O emissions and improve nitrogen efficiency, while understanding their interactions with the soil. This knowledge is necessary in order to design fertilization strategies that improve the sustainability of agriculture under climate change. Full article

The summer drought in the United Kingdom (UK) in 2022 produced significant speculation concerning how its termination may impact and interact with the soil resource. Whilst knowledge regarding soils and droughts exists in the scientific literature, a coherent understanding of the wider range of impacts on soil properties and functions has not been compiled for temperate soils. Here, we draw together knowledge from studies in the UK and other temperate countries to understand how soils respond to drought, and importantly what and where our knowledge gaps are. First, we define the different types of droughts and their frequency in the UK and provide a brief overview on the likely societal impacts that droughts place on the soil and related ecosystems. Our focus is on ‘agricultural and ecosystem drought’, as this is when soils experience dry periods affecting crops and ecosystem function, followed by rewetting. The behaviour of moisture in soils and the key processes that contribute to its storage and transport are examined. The principal changes in the physical, chemical, and biological properties of soils resulting from drought, and rewetting (i.e., drought termination) are discussed and their extensive interactions are demonstrated. Processes that are involved in the rewetting of soils are explored for soil and catchment-scale soil responses. Lastly, soils’ recovery after drought is considered, knowledge gaps are identified, and areas to improve understanding are highlighted. Full article

The prevalence of plant parasitic nematodes (PPN) in the Irish peatlands was investigated in five different peatland habitats—raised bog, cutover scrub/woodlands, fens and peat grasslands, which were further sub-categorised into fourteen different sub-habitats. Within the raised bog habitat were healthy bog hummock (HBH), healthy bog lawn (HBL), degraded bog hummock (DBH) and degraded bog lawn (DBL) and the fen habitats were fen peat (FP) and rich fen peat (R-FP). Cutover scrub or woodland habitat included cutover scrub rewetted (C-RW), cutover scrub non-rewetted (C-NRW), woodlands rewetted (W-RW) and woodlands non-rewetted (W-NRW). Grassland included wasted peat (WP), rough grazing (RG-I) and improved fen peat grassland (IFPG-RW and IFPG-NRW). Soil samples from peatlands were all collected between July and December 2023 when the temperature ranged from 12 to 20 °C. One half of each sample was used for molecular nematode analysis and the other half for morphological identification of nematodes. For the morphological identification, a specific nematode extraction protocol was optimised for peatland soils, and the extracted nematodes were fixed onto slides to be studied under a high-power light microscope. Subsequently, the other part of the soil was processed to isolate total DNA, from which the 18S rRNA gene was sequenced for the identification of nematode taxa. The extracted DNA was also used for randomly amplified polymorphic DNA (RAPD) fingerprinting analysis to determine banding patterns that could classify different bog habitats based on PPN random primers. Compared to that in the climax habitats (HBH, HBL, DBH, DBL, FP, R-FP), PPN prevalence was recorded as being higher in grasslands (WP, RG-I, IFPG-RW and IFPG-NRW) and scrub/woodland ecosystems (C-RW, C-NRW, W-RW, W-NRW). The results indicate that nematode populations are different across the various bog habitats. Emerging and current quarantine PPN belonging to the families Pratylenchidae, Meloidogynidae, Anguinidae and Heteroderidae were noted to be above the threshold limits mentioned under EPPO guidelines, in grassland and wooded peatland habitats. Future actions for PPN management may need to be considered, along with the likelihood that these PPN might impact future paludiculture and other crops and trees growing in nearby agricultural lands. Full article

The rapid, effective restoration of degraded peatlands is urgently needed to reduce their current high levels of carbon loss. The re-introduction of Sphagnum moss, along with re-wetting, is key to returning carbon sequestration and retention capabilities to northern degraded bogs. Micropropagated Sphagnum has already been applied in large quantities, and more is planned, for restoration projects in Britain and parts of Europe. A comparison with wild-sourced Sphagnum material is therefore pertinent to demonstrate its safety and suitability for wide-scale application. Six Sphagnum species of both micropropagated and wild-sourced origin were assessed for photosynthetic capacity, nutrient content, form parity, chlorocyst size, and chloroplast numbers. Micropropagated Sphagnum had significantly higher light-saturated photosynthesis (P_max) rates, little color expression, an open growth habit, greater chloroplast numbers, and more numerous, smaller shoot apices than wild-sourced Sphagnum. Higher P_max rates were associated with a lower bulk density and higher tissue nutrient concentrations. Potentially, greater chloroplast numbers in micropropagated Sphagnum facilitate higher photosynthesis rates, driving rapid growth in early-stage plants, particularly in optimum moisture conditions. Micropropagated Sphagnum can be used confidently, propagated in large quantities, and will likely establish well on application to sites where re-wetting has already occurred, therefore making it highly beneficial for the restoration of degraded bogs. Full article

Reducing emissions from energy production and enhancing the capacity of land use systems to store carbon are both important pathways towards greenhouse gas neutrality. Expanding photovoltaics (PV) contributes to the former, while the rewetting of drained peatlands preserves the peat soil as long-term carbon store, thus contributing to the latter. However, both options are usually considered separately. This study analyses Peatland PV, defined as the combination of open-space PV with the rewetting of peatlands on the same site, and has an explorative and field-defining character. Due to a lack of empirical data, we used expert interviews to identify the strengths and weaknesses, opportunities, and threats of Peatland PV in the sparsely populated and peatland-rich state of Mecklenburg-Western Pomerania in North-East Germany. The material was analysed using a qualitative content analysis and compiled into SWOT and TOWS matrices. Besides the ecological and technological dimensions, this study focuses on the economic and legal framework in Germany. We found that Peatland PV may mitigate land use conflicts by contributing to climate and restoration targets, energy self-sufficiency, and security. Continued value creation can incentivize landowners to agree to peatland rewetting. Technical feasibility has, however, a significant influence on the profitability and thus the prospects of Peatland PV. Although Peatland PV has recently been included in the Renewable Energy Sources Act (EEG), several specialised legal regulations still need to be adapted to ensure legal certainty for all stakeholders. Pilot implementation projects are required to study effects on vegetation cover, soil, peatland ecosystem services, biodiversity, hydrology, and water management, as well as to analyse the feasibility and profitability of Peatland PV. Full article

Cocksfoot (Dactylis glomerata L.) is becoming increasingly important for grassland farming due to climate change, which alters precipitation and increases droughts. Although it is generally considered to be drought-tolerant, little is known about the differences between cultivars. This study aimed to investigate the effects of four different field capacity (FC) levels (80%, 60%, 40%, and rewetting to 80% after a period of 40% FC) on the yield, crude protein content, water consumption, water use efficiency (WUE), and drought susceptibility index of five European cocksfoot cultivars (cv). A pot experiment was conducted in a greenhouse subjected to the specified irrigation treatments over three growth periods. The results revealed significant differences in the cultivars’ responses to the irrigation treatments. Dry matter yield decreased under simulated drought conditions, while crude protein content and WUE increased. Prolana cv achieved the highest yield under drought conditions, Tandem cv had the highest WUE, and Laban cv exhibited the highest crude protein content. Rewetting to 80% FC in the last growth period resulted in similar dry matter and crude protein yields for all cultivars compared to full irrigation. These findings highlight the importance of selecting and breeding drought-tolerant cocksfoot cultivars to maintain high yields and quality in perennial grassland farming under future climate conditions. Full article

A total of 281 coleopteran species from 41 families were recorded from different sites of an abandoned cut-over peatland designated as the Carbon Measurement Supersite in Kaliningrad Oblast. This beetle assemblage is considered a baseline (pre-impact) faunal assemblage for further investigations during the ‘before–after’ (BA) or ‘before–after control-impact’ (BACI) study on a peatland that is planned to be rewetted. The spontaneously revegetated peatland has a less specialised beetle assemblage than at an intact raised bog. Tyrphobiontic species are completely absent from the peatland, while some tyrphophiles (5.3% of the total beetle fauna) are still found as remnants of the former raised bog communities. The predominant coenotic coleopteran group is tyrphoneutral generalists from various non-bog habitats (72.9%). The species composition is associated with the vegetation structure of the disturbed peatland (fragmentary Sphagnum cover, lack of open habitats, and widespread birch coppice or tree stand), which does not correspond to that of a typical European raised bog. The sampled coleopteran assemblage is divided into several relative ecological groups, whose composition and peculiarities are discussed separately. Possible responses to the rewetting measurements in different coleopteran groups are predicted and briefly discussed. A complex assemblage of stenotopic peatland-specialised tyrphophiles (15 spp.) and the most abundant tyrphoneutral generalists (31 spp.) were assigned as indicators for the environmental monitoring of peatland development. Full article

The most common pattern types for anode structuring, in particular the line, grid, and hexagonal-arranged hole pattern were evaluated in a comparable setup in full-cells and symmetrical cells. The cells with structured electrodes were compared to reference cells with unstructured anodes of similar areal capacity (4.3 mAh cm⁻²) and the onset of lithium plating during fast-charging was determined in situ by differential voltage analysis of the voltage relaxation and ex situ by post-mortem analysis. Furthermore, electrochemical impedance spectroscopy measurements on symmetrical cells were used to determine the ionic resistance of structured and unstructured electrodes of similar areal capacity. All cells with structured electrodes showed lower ionic resistances and an onset of lithium plating shifted to higher C-rates compared to cells with unstructured electrodes. The structure patterns with capillary structures, i.e., lines and grids, showed significant reduced lithium plating during fast-charging and a higher rate capability compared to reference cells with unstructured electrodes and cells with hole structured electrodes. The continuous rewetting of the electrode with liquid electrolyte by capillary forces and the reduced ionic resistance of the 3D electrode are identified as key factors in improving overall battery performance. The data of the studied cells were used to calculate the resulting energy and power densities of prospective commercial pouch cells and potential pitfalls in the comparison to cells with unstructured electrodes were identified. Full article