Rewetting does not return drained fen peatlands to their old selves

Peatlands have been drained for land use for a long time and on a large scale, turning them from carbon and nutrient sinks into respective sources, diminishing water regulation capacity, causing surface height loss and destroying biodiversity. Over the last decades, drained peatlands have been rewetted for biodiversity restoration and, as it strongly decreases greenhouse gas emissions, also for climate protection. We quantify restoration success by comparing 320 rewetted fen peatland sites to 243 near-natural peatland sites of similar origin across temperate Europe, all set into perspective by 10k additional European fen vegetation plots. Results imply that rewetting of drained fen peatlands induces the establishment of tall, graminoid wetland plants (helophytisation) and long-lasting differences to pre-drainage biodiversity (vegetation), ecosystem functioning (geochemistry, hydrology), and land cover characteristics (spectral temporal metrics). The Paris Agreement entails the rewetting of 500,000 km2 of drained peatlands worldwide until 2050-2070. A better understanding of the resulting locally novel ecosystems is required to improve planning and implementation of peatland rewetting and subsequent management.

Micro-Epidemiological Investigation of Echinococcus multilocularis in Wild Hosts from an Endemic Area of Southwestern Hungary

Echinococcus multilocularis is a tapeworm causing severe zoonotic disease in temperate Europe. Between 2018 and 2020, 68 golden jackals and 94 red foxes were investigated to determine the prevalence of E. multilocularis infection and its driving factors. The overall prevalence (golden jackal: 41.2%; red fox: 12.5%) significantly differed, whereas the mean intensities did not. The spatial scan statistics revealed three significant clusters of E. multilocularis infection. The binary logistic and ordinal regression results revealed that the golden jackal is more likely to become infected than the red fox, and the probability of infection level was also higher in jackals. Our findings highlight the golden jackal’s role, which could be as important as the red fox in the spread of this severe zoonotic agent. This micro-epidemiological approach can advance the knowledge on local drivers which facilitate the spread of E. multilocularis and could cause a relevant public health problem on the continent.

Hantavirus Research in Finland: Highlights and Perspectives

Finland has the highest incidence of hantavirus infections globally, with a significant impact on public health. The large coverage of boreal forests and the cyclic dynamics of the dominant forest rodent species, the bank vole Myodes glareolus, explain most of this. We review the relationships between Puumala hantavirus (PUUV), its host rodent, and the hantavirus disease, nephropathia epidemica (NE), in Finland. We describe the history of NE and its diagnostic research in Finland, the seasonal and multiannual cyclic dynamics of PUUV in bank voles impacting human epidemiology, and we compare our northern epidemiological patterns with those in temperate Europe. The long survival of PUUV outside the host and the life-long shedding of PUUV by the bank voles are highlighted. In humans, the infection has unique features in pathobiology but rarely long-term consequences. NE is affected by specific host genetics and risk behavior (smoking), and certain biomarkers can predict the outcome. Unlike many other hantaviruses, PUUV causes a relatively mild disease and is rarely fatal. Reinfections do not exist. Antiviral therapy is complicated by the fact that when symptoms appear, the patient already has a generalized infection. Blocking vascular leakage measures counteracting pathobiology, offer a real therapeutic approach.

Differences in temperature-sensitive expression of PcG-regulated genes among natural populations of Drosophila melanogaster

Asbstract Environmental temperature can affect chromatin-based gene regulation, in particular in ectotherms such as insects. Genes regulated by the Polycomb group (PcG) vary in their transcriptional output in response to changes in temperature. Expression of PcG-regulated genes typically increases with decreasing temperatures. Here we examined variations in temperature-sensitive expression of PcG target genes in natural populations from different climates of Drosophila melanogaster, and differences thereof across different fly stages and tissues. Temperature-induced expression plasticity was found to be stage- and sex-specific with differences in the specificity between the examined PcG target genes. Some tissues and stages, however, showed a higher number of PcG target genes with temperature-sensitive expression than others. Overall, we found higher levels of temperature-induced expression plasticity in African tropical flies from the ancestral species range than in flies from temperate Europe. We also observed differences between temperate flies, however, with more reduction of expression plasticity in warm-temperate than in cold-temperate populations. Although, in general, temperature sensitive expression appeared to be detrimental in temperate climates, there were also cases in which plasticity was increased in temperate flies, as well as no changes in expression plasticity between flies from different climates.

Rhagoletis pomonella (apple maggot).

R. pomonella is an important pest in apple production and its invasion of a new apple production area would have large economic and environmental impacts, both due to control efforts and likely export restrictions. R. pomonella is an important threat to apple production areas in temperate Europe, East Asia, and New Zealand that all lack apple-infesting tephritid pests. The only known invasion is the colonization of the West Coast of the USA with a recent spillover into parts of British Columbia. The means by which R. pomonella first arrived in the Pacific Northwest are speculative, but could range from natural spread via yet-undiscovered native populations to unintended human transport via larvae in infested fruit or pupae in soil. Its restricted host-use make the apple maggot an easier target for monitoring than extremely polyphagous species such as medfly [Ceratitis capitata], but its natural host, hawthorn [Crataegus monogyna] is widespread in all temperate environments both as a native and ornamental species and could provide a difficult-to-monitor reservoir.

First results of optically stimulated luminescence (OSL) analyses from loess-palaeosol sections along the Rhône Valley, France.

<p>Loess-palaeosol sequences are most important archives for reconstructing terrestrial palaeoenvironments. However, in the European Mediterranean, these archives are surprisingly scarcely investigated. In southern France, respective sediment-soil archives were last investigated in more detail in the middle of the last century, when major construction works in the region provided access to numerous loess exposures. However, this was before the breakthrough of luminescence-dating as a major chronometric method for the Later Pleistocene. Thus, the loess was poorly dated. Later, Mediterranean loess archives attracted fewer researchers than their central-European counterparts. Reasons for this may be that, compared to the loess belt of temperate Europe, Mediterranean loess deposits are often reworked and mixed with slope deposits. Moreover, palaeosols that developed during climate ameliorations of the last glacial period seem to reflect less pronounced temperature and humidity shifts than those in temperate regions. The most prominent palaeosol developed within the last-glacial loess in the Rhône Valley is a brown palaeosol with large carbonate concretions at its base. However, it is usually severely truncated.</p><p>We allocated joint research efforts from groups in Germany and France to track last-glacial sedimentation and climate shifts in loess-palaeosol sections along the Rhône Valley, south of the confluence of the River Saone at Lyon. Thereby, optically stimulated luminescence (OSL) dating serves as a vital tool for establishing chronometries for the loess-palaeosol sections in southern France, with first results from the Rhône Valley in Bosq et al. (2018, 2020). We summarize results from two sites that are regarded as key sections for palaeoenvironmental reconstruction along the Rhône Valley as evaluated from inspections during fieldwork, complemented by several smaller sections. Our presentation focusses on challenges met with OSL dating attempts of these Mediterranean archives and first achievements in backing the stratigraphies established by sediment-soil analyses in the field and laboratory by chronometric data.</p><p><strong>References</strong></p><p>Bosq, M., Bertran, P., Degeai, J.-P., Kreutzer, S., Queffelec, A., Moine, O., Morin, E., 2018. Last Glacial aeolian landforms and deposits in the Rhône Valley (SE France): Spatial distribution and grain-size characterization. Geomorphology 318, 1–20. doi:10.1016/j.geomorph.2018.06.010</p><p>Bosq, M., Kreutzer, S., Bertran, P., Degeai, J.-P., Dugas, P., Kadereit, A., Lanos, P., Moine, O., Pfaffner, N., Queffelec, A., Sauer, D., 2020. Chronostratigraphy of two Late Pleistocene loess-palaeosol sequences in the Rhône Valley (southeast France). Quaternary Science Reviews 245, 106473. doi:10.1016/j.quascirev.2020.106473</p>

Not back to their old selves – rewetted peatlands require functional understanding for sound management

<p><strong>Peatlands, in particular temperate, groundwater-fed fens, have widely been drained for agriculture. However, draining peatlands turns them into globally relevant carbon sources, diminishes water holding capacity and nutrient removal at landscape scales, and threatens their native biodiversity. Consequently, formerly drained peatlands are now being re-wetted in large numbers for mitigating climate change, combating eutrophication, managing water and preserving biodiversity. A comparison between >300 rewetted peatlands to > 260 close to natural peatlands across temperate Europe, however, indicates that rewetting drained peatlands induces a helophytization (a dominance of tall, graminoid wetland plants) with no trend back to their former biodiversity (vegetation) and function (geochemistry, hydrology) for at least several decades. An understanding of these locally novel ecosystems is required for sound and sustainable management of their ecosystem services.</strong></p>

The influence of fencing on seedling establishment during reforestation of oak stands: a comparison of artificial and natural regeneration techniques including costs

In temperate Europe, oak-dominated forests are widespread, supporting high biodiversity and providing important ecosystem services. Insufficient natural regeneration has, however, been a concern for over a century. The objective of this study was to gain insights into differences in regeneration success using artificial and natural regeneration techniques for reforestation of oak (Quercus robur L.) stands. We monitored seedlings following planting, direct seeding and natural regeneration over five years in a randomized block experiment in southern Sweden with fenced and non-fenced plots. Fencing had a strong positive effect on height growth, especially for planted seedlings that were taller than the other seedlings and more frequently browsed in non-fenced plots. In contrast, there was little effect of fencing on survival, establishment rate and recruitment rate of seedlings. Due to aboveground damage on seedlings from voles, protection of acorns did not improve establishment rate following direct seeding. Under current circumstances at the site with a sparse shelterwood of old oaks, we conclude that natural regeneration was the most cost-efficient regeneration method. It resulted in the most seedlings at the lowest cost. However, regeneration success was heavily influenced by interference from herbaceous vegetation. With a small additional investment in vegetation control, the results might have been improved for planting and direct seeding.