Sphagnum paludiculture farms, where Drosera species grow spontaneously under semi-natural conditions, may provide fresh Drosera raw material for the pharmaceutical industry as a sustainable ...alternative to collecting Drosera from natural peatlands. We collected and measured the fresh mass of all plants of Drosera rotundifolia and Drosera intermedia growing in 1 m2 plots located in fields of cultivated Sphagnum palustre and Sphagnum papillosum, and thus calculated plant density, total biomass and harvestable yield (flowering plants only). We found significantly higher total biomass (433 ± 368 kg ha-1) and yield (292 ± 227 kg ha-1 yr 1) for D. rotundifolia compared to D. intermedia (68 ± 67 kg ha-1 and 56 ± 55 kg ha-1 yr-1) in July/August. The highest recorded total biomass for D. rotundifolia growing on S. palustre was 590 ± 342 kg ha-1. Total biomass and yield for D. rotundifolia were, respectively, 5–54 times and 3–29 times literature values reported for natural habitats in central and northern Europe. The effect of Sphagnum species was significant for D. rotundifolia, which achieved higher total biomass and yield in the S. palustre field than in the S. papillosum field. D. intermedia grew only in the S. papillosum field because the S. palustre field lacked suitable microhabitats. Highly productive populations of D. rotundifolia developed in both Sphagnum paludiculture fields two years after their establishment, but there was only a small population of D. intermedia at that stage. For commercial farming and sustainable production of D. rotundifolia we recommend its cultivation on S. palustre lawns, harvesting in July/August, and harvesting only plants that are more than 12 months old.
Round-leaved sundew (Drosera rotundifolia L.) is a rare bog species that is commonly collected for the European herbal market in the wild, leading to the destruction of its natural populations. The ...aim of this study is to compare sundew cultivation methods on Sphagnum lawn that meet the requirements of the pharmaceutical industry and could promote a sustainable commercial cultivation. Seed germination and seedling survival of D. rotundifolia were studied in biodegradable cellulose pots, paper mesh bags or directly sown (cultivation methods) in a natural, a semi-natural Sphagnum farming and a greenhouse environment (cultivation conditions); using different seed densities. Drosera was cultivated on Sphagnum palustre or S. papillosum lawn and with or without co-occurring vascular plants. Best seed germination for all cultivation methods was recorded in the greenhouse, most successful were cellulose pots (≤ 26 %). Cellulose pots were also most successful under semi-natural (≤ 15 %) and natural (≤ 7 %) conditions. Lowest seed germination rates (< 1 %) were found for direct sowing under semi-natural and natural conditions, indicating that large-scale cultivation by direct sowing requires large quantities of seeds. High survival rates were observed for all cultivation methods in the second year of growth (mean 70 %). The removal of co-occurring vascular plants showed a positive correlation with the number of Drosera seedlings in the first year and led to a higher number of surviving Drosera plants in the second year. Cultivation of D. rotundifolia in biodegradable cellulose pots and direct seed sowing on Sphagnum lawns meet the cultivation requirements of the pharmaceutical industry and have many ecological benefits compared to collection in the wild.
Phragmites australis, Typha latifolia, T. angustifolia and Arundo donax are tall wetland graminoids with the potential to replace fossil fuels under sustainable cultivation conditions. We ...investigated the biomethane (CH4) production of these four species, including four different genotypes of P. australis, which represent the high intraspecific diversity of European reed. All plants were grown under three different macronutrient supplies (no nutrients added, an equivalent of 75 kg N ha−1 year−1 added and an equivalent of 500 kg N ha−1 year−1 added). Biomethane production was measured in four independent batch digestion tests. Across all experiments, fertilization regime had little effect on CH4 yield, which was on average 222 ± 31 L kg−1 volatile solids (VS). The lowest yield was produced by T. angustifolia (140 L kgVS−1) receiving no nutrients, while the highest yield was produced by A. donax (305 L kgVS−1) in the highest nutrient treatment. The intraspecific diversity of P. australis did not affect biomethane production. All P. australis genotypes produced on average 226 ± 19 L CH4 kgVS−1, which, although high, was still lower than conventional biogas species. The biomass production of P. australis was less increased by fertilization than that of Typha sp. and A. donax, but all species had similar biomass without fertilization.
Wetland buffer zones (WBZs) are riparian areas that form a transition between terrestrial and aquatic environments and are well-known to remove agricultural water pollutants such as nitrogen (N) and ...phosphorus (P). This review attempts to merge and compare data on the nutrient load, nutrient loss and nutrient removal and/or retention from multiple studies of various WBZs termed as riparian mineral soil wetlands, groundwater-charged peatlands (i.e. fens) and floodplains. Two different soil types (‘organic’ and ‘mineral’), four different main water sources (‘groundwater’, ‘precipitation’, ‘surface runoff/drain discharge’, and ‘river inundation’) and three different vegetation classes (‘arboraceous’, ‘herbaceous’ and ‘aerenchymous’) were considered separately for data analysis. The studied WBZs are situated within the temperate and continental climatic regions that are commonly found in northern-central Europe, northern USA and Canada. Surprisingly, only weak differences for the nutrient removal/retention capability were found if the three WBZ types were directly compared. The results of our study reveal that for example the nitrate retention efficiency of organic soils (53 ± 28%; mean ± sd) is only slightly higher than that of mineral soils (50 ± 32%). Variance in load had a stronger influence than soil type on the N retention in WBZs. However, organic soils in fens tend to be sources of dissolved organic N and soluble reactive P, particularly when the fens have become degraded due to drainage and past agricultural usage. The detailed consideration of water sources indicated that average nitrate removal efficiencies were highest for ground water (76 ± 25%) and lowest for river water (35 ± 24%). No significant pattern for P retention emerged; however, the highest absolute removal appeared if the P source was river water. The harvesting of vegetation will minimise potential P loss from rewetted WBZs and plant biomass yield may promote circular economy value chains and provide compensation to land owners for restored land now unsuitable for conventional farming.
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•The efficiency of wetland buffer zones for nutrient retention was reviewed.•Organic and mineral soils as nutrient filters or sources were compared.•Processes driving phosphorus and nitrogen fluxes were described.•The indirect and direct impact of vegetation were unraveled.•Implications for wetland restoration and open research questions were specified.
Paludiculture, sustainable and climate-smart land use of formerly drained, rewetted organic soils, can produce significant biomass in peatlands whilst potentially restoring several additional wetland ...services. However, the site conditions that allow maximum biomass production and nutrient removal by paludiculture crops have rarely been studied.
We studied the relationship between soil characteristics, including plant-available nutrients, peak biomass, stand age, harvest period, and nutrient removal potential for two important paludiculture species, Typha latifolia and Phragmites australis, on rewetted peat and mineral soils in a large-scale European survey.
T. latifolia and P. australis were able to produce an aboveground peak biomass of 10–30 t dry matter ha−1 y−1 and absorbed significant amounts of carbon, nitrogen, phosphorus, and potassium in stands older than 3 years. They were able to grow in a wide range of abiotic soil conditions. Low N:P ratios (5–9) and low N content (< 2%) in T. latifolia tissue suggest N limitation, but P uptake was still surprisingly high. P. australis had higher N:P ratios (8–25) and was less responsive to nutrients, suggesting a higher nutrient use efficiency. However, both species could still produce significant biomass at lower nutrient loads and in winter, when water content was low and nutrient removal still reasonable.
Based on this European wetland survey, paludiculture holds a great potential to combine peat preservation, water purification, nutrient removal, and a high biomass production. Paludicrops take up substantial amounts of nutrients, and both summer and winter harvests provide an effective way to sequester carbon in a range of high-valued biomass products and to control nutrient effluxes from rewetted sites at the landscape scale.
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•T. latifolia and P. australis have great potential for nutrient removal in wetlands.•Both species produce high biomass in a wide range of abiotic soil conditions.•Substantial carbon sequestration in biomass despite nutrient limitation•Tissue nutrient ratios are species-specific and T. latifolia removes more P and K.•Winter harvesting produces useful biomass and is more sustainable in the long term.
A paludicultural experiment was conducted in the Massaciuccoli Lake Basin (Tuscany, IT) to test this restoration strategy to reduce water eutrophication and subsidence phenomena of peat soils. The ...species tested were three perennial rhizomatous grasses (PRGs), Arundo donax, Miscanthus x giganteus, Phragmites australis, and two woody crops managed as short-rotation coppice (SRC), Populus x canadensis ‘Oudemberg’ and Salix alba ‘Dimitrios’, each of these species promising high productivity under wet conditions. The study aimed to test the combustibility of their harvested biomass as a function of crop age and harvest date. Parameters important for combustion and exhaust gas emissions were analyzed: ash content, concentration of chlorine (Cl), sulfur (S), nitrogen (N), phosphorus (P), carbon (C), hydrogen (H), calcium (Ca), magnesium (Mg), potassium (K) and sodium (Na). Results indicated that the SRC crops appeared the most suitable for combustion. A general improvement in biomass quality with crop age was found for all crops tested, showing a significantly lower concentration of critical elements (Cl, N, S) and ash content in the 3rd year after planting. The biomass quality of PRGs was not significantly improved by a delayed harvest in February, as successfully practiced in northern Europe. In general, although concentrations of the most important critical elements were higher than expected for all crops, the calculated higher heating values were promising. Combustibility performances could be improved by finding an optimal mixture of SRC and PRG biomass.
In einem Steppenökosystem der westlichen Mongolei wurden an stark beweideten Standorten entlang von Beweidungsgradienten Daten zur Vegetationsdichte, der oberirdischen Biomasse und Individualgewichte ...sowie zur Anzahl blühender Individuen des Kurzstrauches Artemisia xerophytica erfasst. Bodenkundliche Daten wurden verwendet um zwischen dem Beweidungseinfluss und edaphischen Einflussfaktoren unterscheiden zu können. Die für Artemisia xerophytica erfassten Daten spiegeln den angenommenen Beweidungseinfluss bis zu einer Entfernung von 800 m vom Beweidungsschwerpunkt wider. Bei abnehmendem Beweidungsdruck nehmen die Vegetationsbedeckung und die absolute Biomasse pro Einheit zu. Die durchschnittliche Wuchshöhe der Sträucher als Indikator für die Vitalität der Pflanzen, zeigt einen Zusammenhang sowohl zur Entfernung vom Beweidungsschwerpunkt als auch zur Bestandesdichte. Letzteres kann durch einen zusätzlichen intraspezifischen Wettbewerb bei höherer Bestandesdichte erklärt werden. Mit zunehmender Distanz vom Beweidungsschwerpunkt werden diese Merkmale jedoch von den den Bodenwasserhaushalt beeinflussenden pedologischen Eigenschaften überprägt, woraus relativ ähnliche Degradationsformen resultieren. Diese Ergebnisse stehen im Widerspruch zu anderen auf dem Skalenniveau von Pflanzengemeinschaften durchgeführten Studien, die keine signifikanten Veränderungen entlang von Beweidungsgradienten nachweisen konnten. Eine mögliche Erklärung dafür sind die unterschiedlichen Skalenebenen der Untersuchungen. Die vorliegende Untersuchung erfolgte innerhalb einer einzelnen Pflanzengemeinschaft mit dem Vergleich verschiedener Populationen einer Art., Data on stand density, above-ground biomass, individual plant weight and the proportion of flowering plants of the dwarf semi-shrub Artemisia xerophytica were collected along a grazing gradient defined by increasing distance (0 to 2000 m) from grazing hot spots in a desert steppe ecosystem in western Mongolia. Soil data were used to distinguish between grazing and edaphic influences. All parameters recorded for Artemisia xerophytica reflect the assumed gradient of grazing intensity up to 800 m distance from the grazing hot spot. As grazing pressure decreases, plant density and total biomass per plot increase. The average shrub weight, an indicator of plant vitality, is related to both: distance from the grazing hot spot and stand density; which may be explained by additional intraspecific competition at higher densities. At a longer distance these effects are masked by variations in soil parameters determining water availability, leading to quite similar degradation forms. These results are in contrast to other studies carried out at the scale of plant communities, which did not detect significant changes along a grazing gradient. One explanation is the different map scale; our study took place only within a single plant community comparing different populations of one species.
Variants of the SARS-CoV-2 virus carry differential risks to public health. The Omicron (B.1.1.529) variant, first identified in Botswana on November 11, 2021, has spread globally faster than any ...previous variant of concern. Understanding the transmissibility of Omicron is vital in the development of public health policy.
The aim of this study is to compare SARS-CoV-2 outbreaks driven by Omicron to those driven by prior variants of concern in terms of both the speed and magnitude of an outbreak.
We analyzed trends in outbreaks by variant of concern with validated surveillance metrics in several southern African countries. The region offers an ideal setting for a natural experiment given that most outbreaks thus far have been driven primarily by a single variant at a time. With a daily longitudinal data set of new infections, total vaccinations, and cumulative infections in countries in sub-Saharan Africa, we estimated how the emergence of Omicron has altered the trajectory of SARS-CoV-2 outbreaks. We used the Arellano-Bond method to estimate regression coefficients from a dynamic panel model, in which new infections are a function of infections yesterday and last week. We controlled for vaccinations and prior infections in the population. To test whether Omicron has changed the average trajectory of a SARS-CoV-2 outbreak, we included an interaction between an indicator variable for the emergence of Omicron and lagged infections.
The observed Omicron outbreaks in this study reach the outbreak threshold within 5-10 days after first detection, whereas other variants of concern have taken at least 14 days and up to as many as 35 days. The Omicron outbreaks also reach peak rates of new cases that are roughly 1.5-2 times those of prior variants of concern. Dynamic panel regression estimates confirm Omicron has created a statistically significant shift in viral spread.
The transmissibility of Omicron is markedly higher than prior variants of concern. At the population level, the Omicron outbreaks occurred more quickly and with larger magnitude, despite substantial increases in vaccinations and prior infections, which should have otherwise reduced susceptibility to new infections. Unless public health policies are substantially altered, Omicron outbreaks in other countries are likely to occur with little warning.
The Omicron variant of SARS-CoV-2 is more transmissible than prior variants of concern (VOCs). It has caused the largest outbreaks in the pandemic, with increases in mortality and hospitalizations. ...Early data on the spread of Omicron were captured in countries with relatively low case counts, so it was unclear how the arrival of Omicron would impact the trajectory of the pandemic in countries already experiencing high levels of community transmission of Delta.
The objective of this study is to quantify and explain the impact of Omicron on pandemic trajectories and how they differ between countries that were or were not in a Delta outbreak at the time Omicron occurred.
We used SARS-CoV-2 surveillance and genetic sequence data to classify countries into 2 groups: those that were in a Delta outbreak (defined by at least 10 novel daily transmissions per 100,000 population) when Omicron was first sequenced in the country and those that were not. We used trend analysis, survival curves, and dynamic panel regression models to compare outbreaks in the 2 groups over the period from November 1, 2021, to February 11, 2022. We summarized the outbreaks in terms of their peak rate of SARS-CoV-2 infections and the duration of time the outbreaks took to reach the peak rate.
Countries that were already in an outbreak with predominantly Delta lineages when Omicron arrived took longer to reach their peak rate and saw greater than a twofold increase (2.04) in the average apex of the Omicron outbreak compared to countries that were not yet in an outbreak.
These results suggest that high community transmission of Delta at the time of the first detection of Omicron was not protective, but rather preluded larger outbreaks in those countries. Outbreak status may reflect a generally susceptible population, due to overlapping factors, including climate, policy, and individual behavior. In the absence of strong mitigation measures, arrival of a new, more transmissible variant in these countries is therefore more likely to lead to larger outbreaks. Alternately, countries with enhanced surveillance programs and incentives may be more likely to both exist in an outbreak status and detect more cases during an outbreak, resulting in a spurious relationship. Either way, these data argue against herd immunity mitigating future outbreaks with variants that have undergone significant antigenic shifts.
Endometriosis is a common, chronic condition in women of reproductive age that is characterized by the presence of functional endometriotic lesions outside the uterus. The Endometriosis Symptom Diary ...(ESD) is an electronic patient-reported outcome (ePRO) instrument that assesses women's experience of endometriosis symptoms, with pain scored using a 0-10 numeric rating scale. This study investigated patterns of data missing from the ESD in the VALEPRO study.
Post hoc analyses of missing data were conducted.
Of 272 participants using the ESD, 26.5% had no missing diary entries, 46.7% had > 0-5% of entries missing, 13.2% had > 5-10% of entries missing and 13.6% had > 10% of entries missing over the entire study period. The duration of missing episodes (defined as ≥1 consecutive days with missing diary entries) was generally short; most (81.4%) were 1 day. The difference in mean worst pain scores between missing and complete episodes per participant was - 0.1, suggesting that missing episodes were not related to severity of pain. Entries were significantly more likely to be missing on Fridays (18.5%) and Saturdays (22.9%) compared with other days of the week (p < 0.0001). Participants in the USA had significantly more long missing episodes than those in Germany (proportions of missing episodes longer than 1 day, 22.6 and 10.5%, respectively; p < 0.0001). The proportions of women with ≥1 missing entry were 50.0, 70.2 and 79.8% for women with elementary education, secondary education, and a college or university education, respectively. The proportions of women with ≥1 missing entry were similar for those with and without children (72.2 and 74.3%, respectively).
Most participants were highly compliant with entering data in the ESD and the amount of missing data was low. Entries were significantly more likely to be missing on Fridays and Saturdays compared with other days of the week, and participants in the USA had significantly more long missing episodes than participants in Germany.
Clinicaltrials.gov, NCT01643122 , registered 4 July 2012.
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