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Wetlands belong to the most endangered habitats in the world, and animals and plants occurring there are subjects of nature conservation efforts worldwide. Several species of bees and wasps have been comprehensively studied in recent years, but the biology and ecology of wetland-associated species remain largely enigmatic. The results showed that some of these species can be good bioindicators, useful in nature conservation. Hylaeus pectoralis is a small wetland-associated bee that is dependent on the presence of its nesting resource, cigar galls formed by the frit fly Lipara lucens on stems of common reed. We studied the presence of this bee species between 2011 and 2023, both in near-natural and anthropogenic habitats. This bee requires the presence of terrestrial reed with reed galls and occurs nearly exclusively in long-lasting localities of near-natural character with wet meadows rich in flowering plants. Our results showed that H. pectoralis requires mosaic sites with reed beds combined with wet meadows. The proportion of wet meadows in the H. pectoralis localities is more prominent than in localities where H. pectoralis was absent. The bee is polylectic, and we enlarged the number of pollen sources to plants of 22 families—the collected pollen was from plants of many habitats, including plants of wet meadows and aquatic plants. Though recording of H. pectoralis in the locality is simple using the rearing from collected reed galls, this ecologically sensitive species can be used as an essential bioindicator for the quality of wetland habitats and the studies of the continuity of the habitats. Implications for insect conservation: The presence of the mosaic of wet meadows with flowering plants, small reed beds, reed margins, and small water reservoirs is necessary not only for Hylaeus pectoralis but also for other biota of wetlands. Mowing of reed margins should be implemented to only a part of the habitat. This mosaic management allows the preservation of old Lipara-induced galls needed for nesting of ecologically sensitive bees and wasps. [ABSTRACT FROM AUTHOR]

Abstract Background Wet meadows, a type of wetland, are impacted by significant climate fluctuation and human activity, impacting soil microorganisms that play an essential role in ecosystem processes. Understanding the underlying ecological mechanisms and processes of wet meadows depends on the fungal communities associated with the plant roots. We used Illumina MiSeq profiling for amplicon sequencing to determine how environmental factors and elevation affect the fungal communities of the rhizosphere and rhizoplane related to three plant species, Cremanthodium ellisii, Cremanthodium lineare, and Caltha scaposa, in alpine wet meadows. Results The phyla Ascomycota and Basidiomycota dominated the rhizosphere (54.5% and 20.9%) and rhizoplane (51.6% and 36.4%), while the predominant fungal genera in the rhizosphere and rhizoplane were Unclassified fungi, Unclassified Ascomycota, Pseudeurotium, Tetracladium, Vishniacozyma, Rhodotorula, Cadophora, and Penicillium. Mantel test and network analysis revealed that the soil water content (SWC), soil organic carbon (SOC), and total nitrogen (TN) were the primary drivers of fungal communities. However, the influence of microbial biomass C (MBC), pH, microbial biomass N (MBN), and elevation varied. Stochastic assembly processes were dominant in both rhizosphere and rhizoplane fungal communities. FUNGuild functional prediction revealed site-specific variation in the trophic level and guild of plant-root-associated fungal communities. The rhizosphere contained 58.5% saprotrophs, 11.7% pathotrophs, and 12.6% symbiotrophs. In addition, 60.4% of the observed OTUs were arbuscular mycorrhizae, 13.2% were endophytes, 20.9% were ectomycorrhizae, and 1.09% were orchid mycorrhizae. The rhizoplane comprised 51.3% of OTUs linked with saprotrophs, 13.9% with pathotrophs, and 7.92% with symbiotrophs. Moreover, 36.1% of OTUs represented arbuscular mycorrhizae, 25.0% were endophytes, 30.6% were ectomycorrhizae, and 2.77% were ascribed to orchid mycorrhizae in the rhizoplane. The abundance of saprotrophs and pathotrophs in the rhizosphere was highest in C. ellisii at SI and SIII, while symbiotrophs were highest in C. lineare at SIII. Similar variations among the plant species and sites were observed in the fungal functional groups (guilds). Conclusions It was concluded that although root compartments significantly influenced the fungal communities in the rhizosphere and rhizoplane, environmental factors and plant types exhibited distinct effects. This study explains how physicochemical properties, plant species, and sites can alter the overall structure and functional repertoire of fungal communities in alpine wet meadows. Graphical Abstract

Background: Wet meadows, a type of wetland, are impacted by significant climate fluctuation and human activity, impacting soil microorganisms that play an essential role in ecosystem processes. Understanding the underlying ecological mechanisms and processes of wet meadows depends on the fungal communities associated with the plant roots. We used Illumina MiSeq profiling for amplicon sequencing to determine how environmental factors and elevation affect the fungal communities of the rhizosphere and rhizoplane related to three plant species, Cremanthodium ellisii, Cremanthodium lineare, and Caltha scaposa, in alpine wet meadows. Results: The phyla Ascomycota and Basidiomycota dominated the rhizosphere (54.5% and 20.9%) and rhizoplane (51.6% and 36.4%), while the predominant fungal genera in the rhizosphere and rhizoplane were Unclassified fungi, Unclassified Ascomycota, Pseudeurotium, Tetracladium, Vishniacozyma, Rhodotorula, Cadophora, and Penicillium. Mantel test and network analysis revealed that the soil water content (SWC), soil organic carbon (SOC), and total nitrogen (TN) were the primary drivers of fungal communities. However, the influence of microbial biomass C (MBC), pH, microbial biomass N (MBN), and elevation varied. Stochastic assembly processes were dominant in both rhizosphere and rhizoplane fungal communities. FUNGuild functional prediction revealed site-specific variation in the trophic level and guild of plant-root-associated fungal communities. The rhizosphere contained 58.5% saprotrophs, 11.7% pathotrophs, and 12.6% symbiotrophs. In addition, 60.4% of the observed OTUs were arbuscular mycorrhizae, 13.2% were endophytes, 20.9% were ectomycorrhizae, and 1.09% were orchid mycorrhizae. The rhizoplane comprised 51.3% of OTUs linked with saprotrophs, 13.9% with pathotrophs, and 7.92% with symbiotrophs. Moreover, 36.1% of OTUs represented arbuscular mycorrhizae, 25.0% were endophytes, 30.6% were ectomycorrhizae, and 2.77% were ascribed to orchid mycorrhizae in the rhizoplane. The abundance of saprotrophs and pathotrophs in the rhizosphere was highest in C. ellisii at SI and SIII, while symbiotrophs were highest in C. lineare at SIII. Similar variations among the plant species and sites were observed in the fungal functional groups (guilds). Conclusions: It was concluded that although root compartments significantly influenced the fungal communities in the rhizosphere and rhizoplane, environmental factors and plant types exhibited distinct effects. This study explains how physicochemical properties, plant species, and sites can alter the overall structure and functional repertoire of fungal communities in alpine wet meadows. [ABSTRACT FROM AUTHOR]

Soil enzymes play a vital role in the functioning of wetland ecosystems, driving energy flow and material cycling processes. Gahai wet meadow, one of the important components of alpine wetlands on the Qinghai-Tibet Plateau, has suffered serious degradation in the last 30 years due to climate change and human activities. We studied the spatial and temporal heterogeneity of soil nitrogen content and nitrogen (N)-cycle enzyme activities (i.e., urease, protease, nitrate reductase and nitrite reductase) in four degraded wet meadows in the Gahai wetlands. Our results suggested that with increasing wet meadow degradation, there was a significant decrease in soil water content, total nitrogen, ammonium nitrogen, microbial biomass nitrogen content, protease activities, and nitrite reductase activities; Conversely, soil temperature, nitrate nitrogen content, urease activities, and nitrate reductase activities increased significantly. Soil urease, protease, and nitrite reductase activities significantly decreased with increasing soil depth;The highest activity levels of the three N-cycle enzymes were observed in July and August. The linear mixed modeling results indicated that there were significant effects of degradation level and soil depth and their interactions on soil nitrate reductase and nitrite reductase activities (p < 0.01), while soil depth had significant effects only on soil urease and protease activities (p < 0.01). Redundancy analyses showed that soil ammonium and nitrate nitrogen were the main drivers of changes in soil N-cycle enzyme activity during the degradation of wet meadows. In summary, our study sheds light on the processes of soil enzyme activity in an alpine wetland ecosystem and provides valuable information for understanding the N cycling in these complex systems.

Aim: Typha latifolia causes serious problems in wet meadows by overgrowing and suppressing other native plants. To determine suitable management for T. latifolia control, we addressed the following question: What are the effects of long‐term cutting at different frequencies (once or twice per year and no management) and biomass removal on cover and other characteristics of T. latifolia, and on sward productivity and plant species composition? Location: Malá Strana nature reserve, Jizerské hory Mountains, Czechia. Methods: A long‐term experiment arranged in a randomised block design with three blocks was established in 2005. Data were collected from five treatments: unmanaged control; cutting once a year in June without biomass removal and with biomass removal; cutting twice per year in June and August without biomass removal and with biomass removal. Percentage cover of T. latifolia and other vascular plant species was visually estimated and T. latifolia characteristics (tiller density, height, dry‐matter biomass [DMB] yield and litter), sward height and DMB yield were measured during 2005–2018 at the end of June. Results and Discussion: Regular cutting once or twice per year regardless of cut biomass removal led to reductions in tiller density, height, litter and DMB yield of T. latifolia. Biomass removal had only a slight tendency to affect T. latifolia characteristics. The higher frequency of cutting significantly decreased the mean T. latifolia cover, litter and DMB yield. Cutting once or twice per year regardless of biomass removal led to successive changes in plant species composition but had no effect on the species richness and evenness. Conclusions: Cutting at least once per year without biomass removal seems to be sufficient to achieve a decrease in DMB yield and litter of T. latifolia plants, and thereby maintain the wet‐meadow vegetation without loss of species richness and also preventing the overgrowth of shrubs and trees. [ABSTRACT FROM AUTHOR]

Question: Interspecific competition and seed dispersal are key mechanisms that may influence plant community assembly, but their relative importance remains difficult to disentangle as they can be affected by abiotic conditions (environmental filtering). We experimentally studied the balance between these processes in a Molinia wet meadow plant community in which abiotic constraints are mostly represented by flooding, while agricultural practices such as mowing prevent the dominance of a few competitive species. We hypothesized that (H1) mowing, by decreasing competitive exclusion and (H2) seed addition, by increasing immigration, both enhance plant species diversity, and that (H3) small variations in flooding intensity become secondary to these processes in determining species assembly. Location: French National Nature Reserve "Etang de Cousseau", Nouvelle Aquitaine, France. Methods: In a three‐year experiment, we added seeds of 17 species characteristic of Molinia wet meadows and managed above‐ground competition through mowing. We measured spatial variations in soil moisture as an indicator of the flooding regime. We recorded species relative cover, species richness and evenness annually, and measured light availability, linked with canopy openness, twice. Results: From the beginning of the experiment, small‐scale variations in soil moisture mainly affected species richness, composition and evenness, and canopy openness. Mowing significantly increased light availability and evenness, and affected the relative cover of several species, but not species richness. The addition of seeds did not influence any of the variables monitored during the experiment. Conclusion: Our study helps to disentangle processes underlying community assembly in wet meadows. It demonstrates significant and rapid effects of mowing on canopy opening and on community assembly, while seed addition had only a slight effect, possibly explained by an insufficient decrease in competitive interactions through mowing or unmeasured processes. It also shows that abiotic heterogeneity remains a primary driver of community assembly, even on a small scale. Finally, our results suggest that the respective weight of the different filters (dispersion, environment, competition) is subject to interannual variability or environmental stochasticity. [ABSTRACT FROM AUTHOR]

The frequent occurrence of extreme rainfall events may greatly affect soil organic carbon (SOC) fractions and carbon (C) pool of wet meadow in the Qinghai-Tibet Plateau (QTP). However, it remains unclear how SOC fractions will change under different extreme rainfall frequency. Therefore, we set five extreme rainfall frequency treatments in the QTP wet meadow: CK (control plots), DF1 (once a week), DF2 (once every-two weeks), DF3 (once every-three weeks), DF4 (once every-four weeks), all treatments received ambient rainfall. We found that soil particulate organic carbon (POC) content increased with the increasing of extreme rainfall frequency in 0–40 cm layer. Extreme rainfall frequency significantly decreased dissolved organic carbon (DOC) content in 0–10 cm layer. DF2, DF3 and DF4 significantly decreased the soil easily oxidizable carbon (EOC) content, DF2 significantly increased and DF4 significantly decreased SOC content in 0–10 cm layer. Soil organic carbon storage (SOCS) decreased with the increase of extreme rainfall frequency, the lowest value in DF1 treatment (85.61 mg·hm−2) and the highest value in DF4 treatment (139.92 mg·hm−2). The EOC/SOC and DOC/SOC values at 20–40 cm were greater than those at 0–10 cm under each treatment, and the proportion of SOC fractions in the surface layer (0–10 cm) was more sensitive to the extreme rainfall frequency, while in the deep soil layer (10–20, 20–40 cm) was relatively stable. Redundancy analysis (RDA) showed that soil bulk density (BD) (Explanation = 31.8 %), total phosphorus (TP) (Explanation = 12.8 %), NH4+-N (Explanation = 8.8 %) were important environmental factors affecting the SOC fractions content under extreme rainfall frequency. Our study suggests that the increase of extreme rainfall frequency in the future will lead to significant differences in the content of SOC fractions and will reduce the SOCS by affecting soil physicochemical properties, and this may have a serious impact on the C sequestration function and C pool stability of QTP wet meadow soil.

Wetland ecosystems are important habitats for the growth and survival of numerous terrestrial orchids in Europe. This study reviews the current knowledge on the orchids of wetland vegetation in the Central Balkans. The orchid flora was analyzed from taxonomic, phytogeographical, ecological and conservation aspects. The most important taxa include the two Balkan endemics (Dactylorhiza cordigera subsp. bosniaca and D. kalopissi subsp. macedonica) and the three subendemics of the Balkans and the Carpathians (Dactylorhiza cordigera subsp. cordigera, D. maculata subsp. transsilvanica and Gymnadenia frivaldii), as well as a considerable number of Central European, Eurasian and boreal orchid representatives. Several orchid taxa occurring in the wet meadows and fens of the Central Balkans have a southern limit of their distribution in this part of Europe, suggesting that wetlands are important refuges for them. In total, 33 orchid taxa were recorded in plant communities from five classes, 10 orders and 17 alliances. Most orchid taxa grow in the following wetland vegetation types: wet meadows (class Molinio-Arrhenatheretea, order Molinietalia caeruleae, alliances Molinion caeruleae, Deschampsion cespitosae and Calthion palustris); fens (class Scheuchzerio palustris-Caricetea fuscae, order Caricetalia fuscae, alliance Caricion fuscae); tall-herb vegetation along mountain streams and springs (class Mulgedio-Aconitetea); marshes and herb-land vegetation of freshwater or brackish water bodies (class Phragmito-Magnocaricetea). This study highlights the importance of serpentine and silicate wetland vegetation types as important habitats for the survival of terrestrial orchids. In addition, detailed taxonomic, ecological and chorological studies of the wetland orchids of the Central Balkans need to be carried out in order to establish a successful plan for their conservation. [ABSTRACT FROM AUTHOR]

Brownfield technosol restoration represents a real opportunity to minimize land consumption, but it often requires intensive intervention and reconstruction, leading to soil donor site destruction and potential pollution. Using a former oil refinery brownfield site, this research compares the short-term (one year) impact of localized restoration methods, including soil surface scarification, organic matter addition, earthworm inoculation (locally and commercially sourced), on the soil fauna and vegetation properties. Vegetation rapidly covered the bare soil, but few significant impacts were observed in terms of the soil or vegetation structure. The initial positive impact of soil scarification on surface compaction quickly faded and earthworm inoculations did not seem to impact soil characteristics. Natural soil colonization by vegetation or fauna was the major driver in soil modification. The analysis of an intermediate reference showed a delay of multiple decades between vegetation, fauna density, and soil structure improvement, as well as the achievement of a soil of "good biological quality". We conclude that the use of engineer species on brownfield soil in its actual form is not an early restoration step but should be tested in later steps (e.g., when organic matter content is sufficient). However, additional research is needed in engineer species selection and multi-compartment approaches. A better understanding of the impacts of natural colonization in the early stages of technosol restoration is also essential for restoration techniques' improvement. [ABSTRACT FROM AUTHOR]

In Europe, 50%–70% of former natural grassland area has been destroyed during the past 30 years due to land use changes, losses are expected to increase in the future. Restoration is thought to reverse this situation by creating suitable abiotic conditions. In this paper, we investigate the effects of sod translocation with specific vegetation to facilitate the restoration of a former intensive agricultural field into a wet meadow. First, starting conditions were optimized including modification of the local hydrology, removal of the fertilized topsoil, application of liming, and translocation of fresh clippings as a seed source. The second part aimed at restoring the habitat for the butterfly species Phengaris (Maculinea) teleius, one of the species that was especially affected by the loss of wet meadows. This species engages in a complex myrmecophilous relationship with one host plant, Sanguisorba officinalis, and one obligate host ant, Myrmica scabrinodis. We used sod translocation to create islands of habitat to promote host plant and host ant colonization. After 4 years following the restoration, we observed that plants spread from the transplanted sods to the surroundings. The vegetation composition and structure of the transplanted sods attracted colonization of Myrmica ants into the restored areas. Following the increase in vegetation cover and height, Myrmica ant colonies further spread into the restored areas. Therefore, sod translocations can be considered an effective restoration method following topsoil removal in the process of restoring wet meadows to provide a starting point for ant colonization and plant dispersion. With these findings, this paper contributes to the evidence‐based restoration of wet meadows on former agricultural fields, including complex interactions between invertebrates and their required ecological relationships. [ABSTRACT FROM AUTHOR]

Effective management of wildlife populations threatened by disease requires accurate predictions about the consequences of intervention. However, generating such predictions is challenging, especially for organisms with complex life histories that are also threatened by climate change, such as montane amphibians. Cascades frogs (Rana cascadae) in northern California have experienced dramatic declines associated with the fungal pathogen Batrachochytrium dendrobatidis (Bd), and remnant populations are also threatened by changing climate conditions. We evaluated the population‐level impacts of treating Cascades frog metamorphs with the antifungal chemical itraconazole using a field experiment and population simulations. We explored the influence of larval habitat on these treatment effects by including metamorphs from different larval habitat types. We found that frogs treated with itraconazole were more than four times more likely to survive their first winter than untreated controls and had reduced Bd infection intensity compared to other surviving frogs from the same cohort in the following year. We also found an effect of larval habitat type on Bd infection in recently metamorphosed frogs, with the lowest levels of infection occurring in frogs emerging from larval habitats that tend to be intermediate in temperature and drying rate. Applying the differential apparent overwinter survival of treated and untreated metamorphs to population projections suggests that intermittent antifungal treatment of metamorphs has the potential to restore population viability. Our results indicate that in situ treatment of individual hosts may be a useful component of a comprehensive management strategy to reduce the risk of pathogen‐mediated population declines and extirpations. [ABSTRACT FROM AUTHOR]

The availability of high-quality food resources is a critical determinant of wildlife fitness. Over the past two decades, phenological mismatch - the temporal misalignment between animals' peak nutrient demand and optimal resource availability - has emerged as a significant conservation challenge. This issue is particularly worrisome for migratory birds, which must accumulate energy reserves to meet the elevated metabolic demands of migration between breeding and wintering grounds. In Poyang Lake, a crucial wintering ground along the East Asian-Australasian flyway, increasing asynchrony between vegetation growth and the migration of herbivorous waterbirds significantly impedes conservation efforts and presents a major management challenge for this Ramsar wetland. This study evaluates the efficacy of mowing, a grassland management measure, in regulating plant growth processes and restoring food resources for geese. In-situ mowing experiments were conducted with varying timings in Carex wet meadows, the primary foraging habitats of geese. Optimal mowing times were identified, and the maximum goose carrying capacity was assessed by comparing Carex growth and nutritional dynamics with goose dietary requirements. The results reveal that mowing effectively slows down the aging process of Carex, and protein content is identified as a critical limiting factor for geese foraging. Different mowing timings extend the suitable foraging period by 11-25 days. Estimates suggest varying carrying capacities with different mowing timings, supporting goose populations ranging from 133 to 2,046 in Changhuchi Lake during wintering. The optimal mowing window is early October, avoiding dates before late September and after late November. Moreover, multiple-stage mowing is recommended to accommodate different wintering stages. The study highlights mowing as a potential habitat restoration approach for goose conservation, effectively mitigating the challenges imposed by phenological mismatch directly and indirectly caused by anthropogenic activities., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Abstract Effective management of wildlife populations threatened by disease requires accurate predictions about the consequences of intervention. However, generating such predictions is challenging, especially for organisms with complex life histories that are also threatened by climate change, such as montane amphibians. Cascades frogs (Rana cascadae) in northern California have experienced dramatic declines associated with the fungal pathogen Batrachochytrium dendrobatidis (Bd), and remnant populations are also threatened by changing climate conditions. We evaluated the population‐level impacts of treating Cascades frog metamorphs with the antifungal chemical itraconazole using a field experiment and population simulations. We explored the influence of larval habitat on these treatment effects by including metamorphs from different larval habitat types. We found that frogs treated with itraconazole were more than four times more likely to survive their first winter than untreated controls and had reduced Bd infection intensity compared to other surviving frogs from the same cohort in the following year. We also found an effect of larval habitat type on Bd infection in recently metamorphosed frogs, with the lowest levels of infection occurring in frogs emerging from larval habitats that tend to be intermediate in temperature and drying rate. Applying the differential apparent overwinter survival of treated and untreated metamorphs to population projections suggests that intermittent antifungal treatment of metamorphs has the potential to restore population viability. Our results indicate that in situ treatment of individual hosts may be a useful component of a comprehensive management strategy to reduce the risk of pathogen‐mediated population declines and extirpations.

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Purpose: Global climate change scenarios forecast the increasing frequency of extreme precipitation events in the Qinghai-Tibet Plateau (QTP), events that likely will result in increased annual rainfall. The effects of varying rainfall frequency on terrestrial ecosystems, especially in QTP regions impacted by global warming, have become a major research topic. However, the responses of soil labile organic carbon fractions to different rainfall frequencies in the QTP remain unknown. Methods: In this study, we set five rainfall frequencies in the wet meadows of the QTP (control plots, CK; once a week, DF1; once every 2 weeks, DF2; once every 3 weeks, DF3; and once every 4 weeks, DF4). Rainfall frequency treatments received monthly ambient rainfall plus 25 mm of additional rainfall for each irrigation event, and the number of irrigation events was varied. The soil organic carbon fractions (soil organic carbon, SOC; microbial biomass carbon, MBC; and dissolved organic carbon, DOC) in the 0–10, 10–20, and 20–40 cm soil layers were determined. Results: We identified significant relationships of soil carbon fractions. With increased rainfall frequency, SOC content increased significantly and DOC content decreased significantly (P < 0.05). The MBC contents of DF3 were 25.1% (0–10 cm) and 32.14% (10–20 cm) higher than that of CK. During the plant growth season, soil carbon components had different patterns over time. The maximum SOC content was recorded in August, and the maximum soil DOC content was recorded in June or July. The minimum content of MBC was observed in July. Conclusion: Our results show that the low frequency of extreme rainfall events increased microbial activity and promoted the decomposition of SOC, which was not conducive to the accumulation of soil carbon. [ABSTRACT FROM AUTHOR]

The display of lekking Great Snipe males is an energetically demanding activity and therefore, access to the rich feeding sites in the proximity of their leks is essential. During the breeding season, Great Snipes mostly prey on earthworms, whose availability is affected by moisture and penetrability of the soil. In this study, we investigated the relation between the body condition of displaying Great Snipe males and the water level of the river flowing through their breeding grounds, which can affect soil characteristics. We found that the body condition of males decreased over the course of the lekking period in May, showing the great energetic expenditure of their advertising display in courtship. The high water level in the river resulted in the increase in body condition of birds, probably due to improved prey availability, as earthworms moved closer to the ground surface in search of optimal conditions. Further rise in the water level caused flooding of the meadow and a decrease in the body condition of lekking Great Snipes, possibly because of the deterioration of feeding condition, as earthworms tend to leave flooded areas. Moreover, as the flooded area enlarged, the floodplain became inaccessible for foraging Great Snipes, due to their relatively short legs restricting them from wading in deep water. Our results show that for the lowland leks of the Great Snipe to be preserved it is advisable to allow for the natural water level fluctuations in the river shaping the hydrological conditions of the floodplains. [ABSTRACT FROM AUTHOR]

Wet meadows are a declining and increasingly degraded ecosystem type. They contribute numerous ecosystem services, including nutrient cycling, water storage, and filtration, and provision of wildlife habitat, particularly for wetland‐dependent species such as the Whooping Crane (Grus americana). Conservation and restoration of wet meadows rely on understanding their hydrology but characterization of wet meadow hydroregimes is difficult given their hydrologic complexity, high variability, and distinct regional differences. To address this challenge, we used ground‐based time‐lapse imagery to assess inundation dynamics of an archetypal wet meadow over a six‐year period in the Central Platte River Valley, Nebraska, USA. We analyzed over 6500 images from March 2011 to May 2017 in the open‐source java‐based image processing software ImageJ. We also obtained data on groundwater, streamflow, precipitation, and evapotranspiration. We assessed the relationship between wet meadow inundation and hydrologic variables using wavelet coherence to look at fluctuations across a time–frequency spectrum and used random forest to identify seasonally specific variables of importance. We found hydroperiod, the duration surface water ponded within the wet meadow, had a mean of 141 d, on average lasting from 10 December to 1 May, but varied annually. Inundation generally peaked in the early spring, on average 10 March, but demonstrated a bimodal distribution, peaking again in late spring during wetter years. While inundation responded rapidly to precipitation events, it was highly related to streamflow, while an elevated groundwater table was necessary for sustained inundation. Overall, our study provided a comprehensive hydrological characterization of a reference wet meadow and demonstrated the utility of time‐lapse cameras for high‐resolution monitoring and assessment of highly variable wetland systems. Considering the uncertainties surrounding land‐ and water‐use changes, climate change, and the increasing demand for freshwater resources by growing human communities, understanding functional wet meadow hydroregimes and interrelated drivers is essential to inform wet meadow restoration, conservation, and management efforts. [ABSTRACT FROM AUTHOR]

Wetland ecosystems are important habitats for the growth and survival of numerous terrestrial orchids in Europe. This study reviews the current knowledge on the orchids of wetland vegetation in the Central Balkans. The orchid flora was analyzed from taxonomic, phytogeographical, ecological and conservation aspects. The most important taxa include the two Balkan endemics (Dactylorhiza cordigera subsp. bosniaca and D. kalopissi subsp. macedonica) and the three subendemics of the Balkans and the Carpathians (Dactylorhiza cordigera subsp. cordigera, D. maculata subsp. transsilvanica and Gymnadenia frivaldii), as well as a considerable number of Central European, Eurasian and boreal orchid representatives. Several orchid taxa occurring in the wet meadows and fens of the Central Balkans have a southern limit of their distribution in this part of Europe, suggesting that wetlands are important refuges for them. In total, 33 orchid taxa were recorded in plant communities from five classes, 10 orders and 17 alliances. Most orchid taxa grow in the following wetland vegetation types: wet meadows (class Molinio-Arrhenatheretea, order Molinietalia caeruleae, alliances Molinion caeruleae, Deschampsion cespitosae and Calthion palustris); fens (class Scheuchzerio palustris-Caricetea fuscae, order Caricetalia fuscae, alliance Caricion fuscae); tall-herb vegetation along mountain streams and springs (class Mulgedio-Aconitetea); marshes and herb-land vegetation of freshwater or brackish water bodies (class Phragmito-Magnocaricetea). This study highlights the importance of serpentine and silicate wetland vegetation types as important habitats for the survival of terrestrial orchids. In addition, detailed taxonomic, ecological and chorological studies of the wetland orchids of the Central Balkans need to be carried out in order to establish a successful plan for their conservation.

Brownfield technosol restoration represents a real opportunity to minimize land consumption, but it often requires intensive intervention and reconstruction, leading to soil donor site destruction and potential pollution. Using a former oil refinery brownfield site, this research compares the short-term (one year) impact of localized restoration methods, including soil surface scarification, organic matter addition, earthworm inoculation (locally and commercially sourced), on the soil fauna and vegetation properties. Vegetation rapidly covered the bare soil, but few significant impacts were observed in terms of the soil or vegetation structure. The initial positive impact of soil scarification on surface compaction quickly faded and earthworm inoculations did not seem to impact soil characteristics. Natural soil colonization by vegetation or fauna was the major driver in soil modification. The analysis of an intermediate reference showed a delay of multiple decades between vegetation, fauna density, and soil structure improvement, as well as the achievement of a soil of “good biological quality”. We conclude that the use of engineer species on brownfield soil in its actual form is not an early restoration step but should be tested in later steps (e.g., when organic matter content is sufficient). However, additional research is needed in engineer species selection and multi-compartment approaches. A better understanding of the impacts of natural colonization in the early stages of technosol restoration is also essential for restoration techniques’ improvement.

Aims: Reveal the soil organic carbon (SOC) stock change in the Qinghai-Tibetan Plateau (QTP) alpine wetlands in the past fifty years. The Qinghai-Tibetan Plateau (QTP) has a large area of alpine marshland and wet meadows. Artificial drainage, overgrazing and climate change have caused severe degradation of the alpine wetlands. However, little is known about the effects of wetland degradation on SOC stock, and studies only focused on the Zoige marshland, the biggest marshland of China. Direct SOC observations from the extensively distributed wet meadows remain scarce. Methods: SOC in the soil surface layer (0–50 cm) were investigated at four wetland sites where degradation has continued for decades. One site is in marshland, and three are in wet meadows of the QTP. Using datasets from the literature and the field measurements of the present study, we estimated the loss of alpine wetland SOC. Results and conclusions: Initially, marshland degradation to wet meadows prompted the accumulation of SOC; however, grazing in wet meadows reduced SOC accumulation. Wetland degradation to dried meadows led to a much greater SOC loss than that in the initial degradation stage, and grazing exacerbated the loss of SOC. An exponential decay rate of SOC was found in the grazed dried meadows. The wetlands of the QTP, have lost 141 ± 25 Tg in 1966–2016, representing 15% of the SOC stock. [ABSTRACT FROM AUTHOR]

Springbox capped springs divert water for livestock and threaten spring conservation in the Great Basin. Springbox restoration is used to increase water availability at riparian zones and wet meadows. The purpose of our study was to compare six restoration methods used to increase soil moisture. We used a BACI design to compare percent soil moisture before and after restoration at 24 spring sites in Northwestern Nevada, U.S.A. Percent soil moisture was measured at 5-, 15-, 30-, and 45-cm depths during spring and summer months. Year 2017 was wetter than 2016 causing an increase in percent soil moisture in all restoration treatments. Empty springbox cases, cases filled with sand, and caseless gravel-filled springs produced the greatest increase in percent soil moisture at all depths. We recommend sand-filled casings because these funnel water to the surface while sand prevents casing collapse. We recommend sand over gravel because sand is easier to displace as water flows to the surface. The ratio of δ18O/d16O suggests that springs are fed by shallow groundwater derived from recent precipitation. Inter-annual reductions in precipitation driven by climate change may be the ultimate force determining the preservation of Great Basin spring ecosystems. • Springbox restoration can recover ecohydrologic processes and riparian communities. • We compared five methods for recovering modified springs. • Sand filled or empty containers lead to higher soil moisture at all depths. • Results assist in improving spring management during a changing climate. [ABSTRACT FROM AUTHOR]

• Rainfall frequency significantly affected SOC fractions in 0–10 cm layer. • POC was more sensitive than other SOC fractions under different rainfall frequency. • SOCS decreased with the increase of rainfall frequency. • BD, TP, NH 4 + -N was closely related with the content of soil carbon fractions. The frequent occurrence of extreme rainfall events may greatly affect soil organic carbon (SOC) fractions and carbon (C) pool of wet meadow in the Qinghai-Tibet Plateau (QTP). However, it remains unclear how SOC fractions will change under different extreme rainfall frequency. Therefore, we set five extreme rainfall frequency treatments in the QTP wet meadow: CK (control plots), DF1 (once a week), DF2 (once every-two weeks), DF3 (once every-three weeks), DF4 (once every-four weeks), all treatments received ambient rainfall. We found that soil particulate organic carbon (POC) content increased with the increasing of extreme rainfall frequency in 0–40 cm layer. Extreme rainfall frequency significantly decreased dissolved organic carbon (DOC) content in 0–10 cm layer. DF2, DF3 and DF4 significantly decreased the soil easily oxidizable carbon (EOC) content, DF2 significantly increased and DF4 significantly decreased SOC content in 0–10 cm layer. Soil organic carbon storage (SOCS) decreased with the increase of extreme rainfall frequency, the lowest value in DF1 treatment (85.61 mg·hm−2) and the highest value in DF4 treatment (139.92 mg·hm−2). The EOC/SOC and DOC/SOC values at 20–40 cm were greater than those at 0–10 cm under each treatment, and the proportion of SOC fractions in the surface layer (0–10 cm) was more sensitive to the extreme rainfall frequency, while in the deep soil layer (10–20, 20–40 cm) was relatively stable. Redundancy analysis (RDA) showed that soil bulk density (BD) (Explanation = 31.8 %), total phosphorus (TP) (Explanation = 12.8 %), NH 4 +-N (Explanation = 8.8 %) were important environmental factors affecting the SOC fractions content under extreme rainfall frequency. Our study suggests that the increase of extreme rainfall frequency in the future will lead to significant differences in the content of SOC fractions and will reduce the SOCS by affecting soil physicochemical properties, and this may have a serious impact on the C sequestration function and C pool stability of QTP wet meadow soil. [ABSTRACT FROM AUTHOR]

• High-frequency extreme rainfall promotes the carbon sink function of wet meadows. • Increase in extreme rainfall frequency affects soil properties and promotes CO 2 absorption. • The increase in extreme rainfall frequency increases aboveground net primary productivity. • The increase in extreme rainfall frequency decreases soil bulk density. • The CO 2 flux was affected by soil carbon components under different extreme rainfall frequency. Extreme rainfall amount and frequency can alter carbon dioxide (CO 2) exchange between the soil and vegetation in wetlands. Seasonal redistribution of extreme rainfall events is one component of a hydrological regime that affects soil water content (SWC), but its impacts on ecosystem CO 2 exchange in the Qinghai-Tibet Plateau (QTP) wetlands remain unclear. Here, we conducted field simulation experiments to understand the effects of extreme rainfall with high to low frequency once every-one, two, three, and four weeks on CO 2 exchange of wet meadow ecosystem in QTP. The ecosystem absorbed more CO 2 with high-frequency extreme rainfall (−1468.52 mg C m-2h−1) than with current natural amounts and frequency of rainfall (−1162.51 mg C m-2h−1) throughout local vegetation growing seasons. However, under low-frequency extreme rainfall (−916.72 mg C m-2h−1) the wetland absorbed less CO 2 than under natural rainfall frequency. This difference comes from the changes in net ecosystem productivity (NEP) and ecosystem respiration (ER) in wet meadows due to soil temperature (ST) and soil nutrient content. In the rapid growth stage of plants, ER and NEP exhibited single-peak curves due to increases in ST and SWC, and they reached their maximum values in August. Our results indicate that the distribution pattern of extreme rainfall events plays a critical role in regulating ecosystem CO 2 exchange in the wet meadows of the QTP. More research on the related changes between contents of soil nutrient contents and extreme rainfall events could improve the accuracy of C budget estimation in wet meadows. The predicted regional impacts of future climate extremes of rainfall will rely on changes in their frequency and timing. [ABSTRACT FROM AUTHOR]

The rainfall amount and the frequency of extreme rainfall events have been predicted to increase in the Qinghai-Tibetan Plateau during the growing season. These changes will likely affect ecosystem processes, including those that control nitrogen (N) cycling and storage; however, the direction of the changes remains unclear. In this study, we experimentally altered the amount and frequency of precipitation events during the growing season (May through October) at an alpine wetland in the Qinghai-Tibetan Plateau. The treatments included ambient rain (CK) plus 25 mm of extra water for each irrigation event but with different irrigation frequency, i.e., weekly (DF1), biweekly (DF2), every three weeks (DF3) and every four weeks (DF4). During the growing season, the N 2 O flux showed a large seasonal variation. Compared with the treatment of natural rainfall events, the increase in the rainfall amount promoted the N 2 O emission flux. As the frequency of rainfall events increased, the aboveground biomass increased significantly from 85.82 g·m−2 to 245.79 g·m−2, and the accumulated N 2 O emissions first increased and then decreased; we observed the peak of the N 2 O flux at the DF2 rainfall frequency. We also found the significant linear relationships between soil N 2 O flux, nitrate nitrogen, and microbial biomass nitrogen content. Furthermore, among the soil microbial factors, higher rainfall frequency (DF1) significantly reduced the relative abundance of the original dominant species (Alphaproteobacteria) in the studied wetland soil. Our results indicate that alpine wetlands are highly sensitive to increased precipitation variability and high frequencies of extreme rainfall events could significantly reduce N 2 O emission. Future precipitation patterns could weaken the contribution rate of wetland N 2 O emission to the global warming. • The increase in rainfall amount promotes the flux of N2O. • N2O flux presents a unimodal response to rainfall frequency. • The increase in rainfall frequency increases vegetation biomass. • The increase in rainfall frequency reduces the abundance of dominant microorganisms. • The maximum N2O flux appears in the early stage of plant. [ABSTRACT FROM AUTHOR]

• Seed longevities for 3 wetland species were observed to be 17 years or greater. For all 3 species, inundation promoted or supported greater seed persistence • Drained wetlands are unlikely to have significant remnant seed banks of Carex species. • C. hystericina had greater seed persistence than C. Stricta, phalaris arundinacea. Limiting reinvasion of Phalaris arundinacea from wetland seed banks requires >10 yrs Seed persistence and longevity is poorly documented for wetland plants, despite the value of this knowledge for restoration. Seed persistence is particularly important information for sedge meadows (i.e., seasonally ponded freshwater wetlands dominated by Carex spp.), which often fail to recolonize without planting and are rapidly invaded by reed canary grass (Phalaris arundinacea L.). We conducted a 17-year seed burial study along a hydrological gradient in a Minnesota wetland to assess seed persistence of P. arundinacea and two common species of sedge meadows, bottlebrush sedge (Carex hystericina Muhl. ex Willd.) and upright sedge (Carex stricta Lam.). Seed samples were placed in capsules designed to prevent seed loss while allowing for environmental influences. Six boxes, each containing 126 seed capsules (3 species x 14 exhumation years x 3 replicates), were buried in wetland soils under three hydrological conditions (regularly, seasonally, or never inundated) along two transects. Seeds were exhumed 1-, 5-, 6-, 9-, and 17-years post-burial and tested for germinability and viability. For C. stricta and P. arundinacea, seed persistence (50% survival, P 50) was < 1 year under all hydrologic conditions, while for C. hystericina P 50 was 6 yrs where never inundated and > 17 years when seasonally or regularly inundated. Seed longevity was < 17 yrs for C. stricta and P. arundinacea in locations never inundated; for other hydrological conditions and for C. hystericina , seed longevity exceeded the duration of the burial experiment. If seed persistence is typically reduced where inundation is brief, sedge meadow wetlands drained and cultivated for many decades are unlikely to have long-buried seed banks to serve as propagule sources for revegetation. [ABSTRACT FROM AUTHOR]