Green beach vegetation dynamics explained by embryo dune development

Sandy coastlines are dynamic environments with potential for biodiverse habitats, such as green beaches. Green beach vegetation can develop on nutrient-poor beaches landward from embryo dunes. It is characterised by low-dynamic coastal wetland habitat such as salt marshes and dune slacks. It has been hypothesised that the establishment of green beach vegetation is facilitated by the shelter provided by embryo dunes, however evidence is lacking. We explored the importance of geomorphology and soil conditions on the species richness and turnover of green beach vegetation over a time period of 10 years. We recorded 107 plots along 11 transects over a gradient from beach to dune on the island of Schiermonnikoog, the Netherlands. We characterised transect geomorphology at transect level and soil conditions and vegetation at plot level in 2006 and 2016. We found that the green beach vegetation was highly dynamic, total plant cover increased by 62% within 10 years. In 2006 beach width was an important factor in explaining species richness, with the highest number of species occurring on narrow beaches with a large volume of embryo dunes. In 2016, species richness was positively associated with the build-up of organic matter. Overall species richness declined relative to 2006 and was accompanied by an increase in elevation due to sand burial and the expansion of embryo dune volume. Our data suggests that geomorphology influenced the vegetation indirectly by affecting sand burial rate. Plant species richness declined less at sheltered conditions where sand burial was limited, allowing the build-up of organic matter. This indicates a time-dependent relationship between the development of embryo dunes and plant species richness: embryo dunes can be a source of shelter, thus increasing species richness, but can compete for space over time, lowering species richness again. Our results are relevant for engineering and management of biodiverse sandy shores

Феномен самодостатності містико-естетичного досвіду: місце в розумінні подібності християнства, даосизму, релігії давніх українців і сучасного містицизму

Correlative light and electron microscopy is an increasingly popular technique to study complex biological systems at various levels of resolution. Fluorescence microscopy can be employed to scan large areas to localize regions of interest which are then analyzed by electron microscopy to obtain morphological and structural information from a selected field of view at nm-scale resolution. Previously, an integrated approach to room temperature correlative microscopy was described. Combined use of light and electron microscopy within one instrument greatly simplifies sample handling, avoids cumbersome experimental overheads, simplifies navigation between the two modalities, and improves the success rate of image correlation. Here, an integrated approach for correlative microscopy under cryogenic conditions is presented. Its advantages over the room temperature approach include safeguarding the native hydrated state of the biological specimen, preservation of the fluorescence signal without risk of quenching due to heavy atom stains, and reduced photo bleaching. The potential of cryo integrated light and electron microscopy is demonstrated for the detection of viable bacteria, the study of in vitro polymerized microtubules, the localization of mitochondria in mouse embryonic fibroblasts, and for a search into virus-induced intracellular membrane modifications within mammalian cells

Long-term cardiometabolic disease risk in women with PCOS:a systematic review and meta-analysis

BACKGROUND: Polycystic ovary syndrome (PCOS) is associated with cardiometabolic disease, but recent systematic reviews and meta-analyses of longitudinal studies that quantify these associations are lacking. OBJECTIVE AND RATIONALE: Is PCOS a risk factor for cardiometabolic disease? SEARCH METHODS: We searched from inception to September 2019 in MEDLINE and EMBASE using controlled terms (e.g. MESH) and text words for PCOS and cardiometabolic outcomes, including cardiovascular disease (CVD), stroke, myocardial infarction, hypertension (HT), type 2 diabetes (T2D), metabolic syndrome and dyslipidaemia. Cohort studies and case-control studies comparing the prevalence of T2D, HT, fatal or non-fatal CVD and/or lipid concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TGs) between women with and without PCOS of ≥18 years of age were eligible for this systematic review and meta-analysis. Studies were eligible regardless of the degree to which they adjusted for confounders including obesity. Articles had to be written in English, German or Dutch. Intervention studies, animal studies, conference abstracts, studies with a follow-up duration less than 3 years and studies with less than 10 PCOS cases were excluded. Study selection, quality assessment (Newcastle-Ottawa Scale) and data extraction were performed by two independent researchers. OUTCOMES: Of the 5971 identified records, 23 cohort studies were included in the current systematic review. Women with PCOS had increased risks of HT (risk ratio (RR): 1.75, 95% CI 1.42 to 2.15), T2D (RR: 3.00, 95% CI 2.56 to 3.51), a higher serum concentration of TC (mean difference (MD): 7.14 95% CI 1.58 to 12.70 mg/dl), a lower serum concentration of HDL-C (MD: -2.45 95% CI -4.51 to -0.38 mg/dl) and increased risks of non-fatal cerebrovascular disease events (RR: 1.41, 95% CI 1.02 to 1.94) compared to women without PCOS. No differences were found for LDL-C (MD: 3.32 95% CI -4.11 to 10.75 mg/dl), TG (MD 18.53 95% CI -0.58 to 37.64 mg/dl) or coronary disease events (RR: 1.78, 95% CI 0.99 to 3.23). No meta-analyses could be performed for fatal CVD events due to the paucity of mortality data. WIDER IMPLICATIONS: Women with PCOS are at increased risk of cardiometabolic disease. This review quantifies this risk, which is important for clinicians to inform patients and to take into account in the cardiovascular risk assessment of women with PCOS. Future clinical trials are needed to assess the ability of cardiometabolic screening and management in women with PCOS to reduce future CVD morbidity

How Does Tree Density Affect Water Loss of Peatlands? A Mesocosm Experiment

Raised bogs have accumulated more atmospheric carbon than any other terrestrial ecosystem on Earth. Climate-induced expansion of trees and shrubs may turn these ecosystems from net carbon sinks into sources when associated with reduced water tables. Increasing water loss through tree evapotranspiration could potentially deepen water tables, thus stimulating peat decomposition and carbon release. Bridging the gap between modelling and field studies, we conducted a three-year mesocosm experiment subjecting natural bog vegetation to three birch tree densities, and studied the changes in subsurface temperature, water balance components, leaf area index and vegetation composition. We found the deepest water table in mesocosms with low tree density. Mesocosms with high tree density remained wettest (i.e. highest water tables) whereas the control treatment without trees had intermediate water tables. These differences are attributed mostly to differences in evapotranspiration. Although our mesocosm results cannot be directly scaled up to ecosystem level, the systematic effect of tree density suggests that as bogs become colonized by trees, the effect of trees on ecosystem water loss changes with time, with tree transpiration effects of drying becoming increasingly offset by shading effects during the later phases of tree encroachment. These density-dependent effects of trees on water loss have important implications for the structure and functioning of peatbogs

Managing hedgerows for nocturnal wildlife:Do bats and their insect prey benefit from targeted agri-environment schemes?

1. Mitigating the detrimental impacts of intensive farming on biodiversity requires the implementation of cost-effective conservation actions. Targeted agri-environment-schemes (AESs) to enhance populations of threatened species inhabiting farmland have been proposed for this purpose, yet their effectiveness for nocturnal wildlife remains unknown. 2. We assessed whether hedgerow management prescribed by targeted AESs to improve habitat conditions for the greater horseshoe bat (Rhinolophus ferrumequinum) in England may positively influence the species, the entire bat assemblage and the insect prey of bats. We specifically investigated the responses of bats (occurrence, activity, and species richness) and insects (biomass, abundance, and diversity) to time since last trimming (from 1 up to 10 years). We explored the mechanisms underlying the effects of AES via changes in trimming regime on bats. Moreover, we investigated the effects of landscape context on bats as we expected that highly mobile species would benefit further from landscape-scale management. 3. Bat species richness significantly increased with time since last trimming. Three bat taxa of major conservation concern in Western Europe substantially benefited from the targeted prescription, namely R. ferrumequinum, R. hipposideros and Plecotus spp. Insect-family richness and dipteran abundance were also significantly greater at hedgerows that were untrimmed for at least three years. The activity of more common bat species (i.e. pipistrelle bats) was not influenced by time since last trimming. 4. Changes in trimming regime strongly affected hedgerow height which directly and indirectly (by increasing prey abundance) influenced bat occurrence, activity and species richness along hedgerows. 5. The activity of highly mobile bat species was mainly associated with a range of landscape attributes. The amount of semi-natural grassland within 0.5 km of the sampling sites positively influenced R. ferrumequinum while the presence of urban areas negatively affected light-sensitive bat species. 6. Synthesis and applications. The implementation of targeted agri-environment-schemes can include effective measures to enhance bats and their insect prey in farmland. Although we highlight the success of current prescriptions on hedgerow management, we suggest that their effectiveness can easily be optimized by encouraging farmers to keep hedgerows untrimmed for longer periods (>3 up to 10 years). We also highlight that a multi-scale management approach is required to successfully promote bats in farmland

Do Bat Gantries and Underpasses Help Bats Cross Roads Safely?

Major roads can reduce bat abundance and diversity over considerable distances. To mitigate against these effects and comply with environmental law, many European countries install bridges, gantries or underpasses to make roads permeable and safer to cross. However, through lack of appropriate monitoring, there is little evidence to support their effectiveness. Three underpasses and four bat gantries were investigated in northern England. Echolocation call recordings and observations were used to determine the number of bats using underpasses in preference to crossing the road above, and the height at which bats crossed. At gantries, proximity to the gantry and height of crossing bats were measured. Data were compared to those from adjacent, severed commuting routes that had no crossing structure. At one underpass 96% of bats flew through it in preference to crossing the road. This underpass was located on a pre-construction commuting route that allowed bats to pass without changing flight height or direction. At two underpasses attempts to divert bats from their original commuting routes were unsuccessful and bats crossed the road at the height of passing vehicles. Underpasses have the potential to allow bats to cross roads safely if built on pre-construction commuting routes. Bat gantries were ineffective and used by a very small proportion of bats, even up to nine years after construction. Most bats near gantries crossed roads along severed, pre-construction commuting routes at heights that put them in the path of vehicles. Crossing height was strongly correlated with verge height, suggesting that elevated verges may have some value in mitigation, but increased flight height may be at the cost of reduced permeability. Green bridges should be explored as an alternative form of mitigation. Robust monitoring is essential to assess objectively the case for mitigation and to ensure effective mitigation

The effect of temperature on growth and competition between Sphagnum species

Peat bogs play a large role in the global sequestration of C, and are often dominated by different Sphagnum species. Therefore, it is crucial to understand how Sphagnum vegetation in peat bogs will respond to global warming. We performed a greenhouse experiment to study the effect of four temperature treatments (11.2, 14.7, 18.0 and 21.4°C) on the growth of four Sphagnum species: S. fuscum and S. balticum from a site in northern Sweden and S. magellanicum and S. cuspidatum from a site in southern Sweden. In addition, three combinations of these species were made to study the effect of temperature on competition. We found that all species increased their height increment and biomass production with an increase in temperature, while bulk densities were lower at higher temperatures. The hollow species S. cuspidatum was the least responsive species, whereas the hummock species S. fuscum increased biomass production 13-fold from the lowest to the highest temperature treatment in monocultures. Nutrient concentrations were higher at higher temperatures, especially N concentrations of S. fuscum and S. balticum increased compared to field values. Competition between S. cuspidatum and S. magellanicum was not influenced by temperature. The mixtures of S. balticum with S. fuscum and S. balticum with S. magellanicum showed that S. balticum was the stronger competitor, but it lost competitive advantage in the highest temperature treatment. These findings suggest that species abundances will shift in response to global warming, particularly at northern sites where hollow species will lose competitive strength relative to hummock species and southern species

Overcoming establishment thresholds for peat mosses in human-made bog pools

Globally, peatlands have been affected by drainage and peat extraction, with adverse effects on their functioning and services. To restore peat‐forming vegetation, drained bogs are being rewetted on a large scale. Although this practice results in higher groundwater levels, unfortunately it often creates deep lakes in parts where peat was extracted to greater depths than the surroundings. Revegetation of these deeper waters by peat mosses appears to be challenging due to strong abiotic feedbacks that keep these systems in an undesired bare state. In this study, we theoretically explore if a floating peat mat and an open human‐made bog lake can be considered two alternative stable states using a simple model, and experimentally test in the field whether stable states are present, and whether a state shift can be accomplished using floating biodegradable structures that mimic buoyant peat. We transplanted two peat moss species into these structures (pioneer sp. Sphagnum cuspidatum and later‐successional sp. S. palustre) with and without additional organic substrate. Our model suggests that these open human‐made bog lakes and floating peat mats can indeed be regarded as alternative stable states. Natural recovery by spontaneous peat moss growth, i.e., a state shift from open water to floating mats, is only possible when the water table is sufficiently shallow to avoid light limitation (<0.29 m at our site). Our experiment revealed that alternative stable states are present and that the floating structures facilitated the growth of pioneer S. cuspidatum and vascular plants. Organic substrate addition particularly facilitated vascular plant growth, which correlated to higher moss height. The structures remained too wet for the late‐successional species S. palustre. We conclude that open water and floating peat mats in human‐made bog lakes can be considered two alternative stable states, and that temporary floating establishment structures can induce a state shift from the open water state to peat‐forming vegetation state. These findings imply that for successful restoration, there is a clear water depth threshold to enable peat moss growth and there is no need for addition of large amounts of donor‐peat substrate. Correct species selection for restoration is crucial for success