Hedging against biodiversity loss : forest herbs’ performance in hedgerows across temperate Europe

Questions: How do contrasting environmental conditions among forests and hedgerows affect the vegetative and reproductive performance of understorey forest herbs in both habitats? Can hedgerows support reproductive source populations of forest herbs, thus potentially allowing progressive dispersal of successive generations along these linear habitats? Location: Hedgerows and deciduous forest patches in agricultural landscapes across the European temperate biome. Methods: First, we assessed differences in environmental conditions among forests and hedgerows. Next, we quantified plant performance based on a set of functional life‐history traits for four forest herbs (Anemone nemorosa, Ficaria verna, Geum urbanum, Poa nemoralis) with contrasting flowering phenology and colonisation capacity in paired combinations of forests and hedgerows, and compared these traits among both habitats. Finally, we assessed relationships between plant performance and environmental conditions in both habitats. Results: All study species showed a higher above‐ground biomass in hedgerows than in forests. For Poa nemoralis and Geum urbanum, we also found a higher reproductive output in hedgerows, which was mainly correlated to the higher sub‐canopy temperatures therein. The “ancient forest herb” Anemone nemorosa, however, appeared to have a lower reproductive output in hedgerows than in forests, while for Ficaria verna no reproductive differences were found between the two habitats. Conclusions: This is the first study on such a broad geographical scale to provide evidence of reproductive source populations of forest herbs in hedgerows. Our findings provide key information on strategies by which forest plants grow, reproduce and disperse in hedgerow environments, which is imperative to better understand the dispersal corridor function of these wooded linear structures. Finally, we highlight the urgent need to develop guidelines for preserving, managing and establishing hedgerows in intensive agricultural landscapes, given their potential to contribute to the long‐term conservation and migration of forest herbs in the face of global environmental change

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Shifting dietary habits linked with contrasting population trends of two sympatric mustelids (Martes foina and Mustela putorius) over 16 years

Despite widespread concern about biodiversity declines, few empirical studies exist on long-term population trends of mammal carnivores. In the context of global change, it is essential to understand the population trends and resource use of mammal carnivores. Mammal carnivores fulfil an important ecosystem function in terrestrial ecosystems as their top-down role directly and indirectly influences prey populations which affects the entire food web. The objective of this study was to evaluate whether and how the population trends of two sympatric mustelid species, stone marten and polecat, have changed between 1998 and 2013 in Flanders, Belgium. In addition, we explored temporal changes in their dietary habits. From 1998-2013, in collaboration with a citizen science network, we collected road-killed animals over the entire area of Flanders (13,682 km(2)). Based on the number of collected road-killed animals we detected a decrease in the polecat population during 1998-2013 whereas the stone marten population has increased. By subsequent identification of the stomach contents of the specimens, we detected fluctuations throughout the year of the consumption of certain food types. In addition, the consumption of certain food items decreased (stone marten: fruits, grains and nuts and lagomorphs; polecat: birds, rodents and other mammals) or increased (stone marten: edible waste and polecat: amphibians) throughout this period of opposite population trends. An increase of the degree of specialization of the diet throughout the sampling period was also detected for both mustelid species. In summary, our study concludes contrasting population trends coupled with clear changes in feeding habits of two sympatric carnivore species. Understanding these long-term relationships between species population trends and their dietary ecology is vital for biodiversity conservation and nature management

Consumption of game and pest species by small- and medium-sized carnivores

Ecosystem services are the contributions that natural ecosystems make to people. Mammalian carnivores can provide both positive and negative ecosystem services by consuming pest or game species, respectively. In this study, we determined the consumption of certain game and pest species for a guild of sympatric small- and medium-sized carnivores (European badger, red fox, European polecat, stone marten, stoat and least weasel). We found that game and pest species comprise a notable proportion of the diet, ranging from 0.0% to 12.6% and from 2.7% to 46.3%, respectively. Furthermore, for all carnivores we found that the proportion of pest species such as rats and voles (i.e., positive ecosystem service) was higher than the proportion of game species such as pheasants, partridges and hares, i.e., negative ecosystem service). Moreover, stoat and weasel did not consume any game species. This study gives a first overview of the potential ecosystem services through consumption of pest and game species provided by small- and medium-sized carnivores

Molecular detection of tick-borne pathogens Borrelia afzelii, Borrelia miyamotoi and Anaplasma phagocytophilum in Eurasian red squirrels (Sciurus vulgaris)

Eurasian red squirrels (Sciurus vulgaris) are common hosts of ixodid ticks and could thus carry tick-borne disease agents. The relative contribution of the red squirrel, a medium-sized rodent species, to the transmission dynamics of tick-borne pathogens in Europe yet remains unclear. We analysed spleen and liver samples from 45 dead squirrels collected in Flanders, Belgium, during tick activity season and detected the presence of Borrelia burgdorferi s.l. in the spleen of two squirrels (4.4%). One of the sequences could be identified as Borrelia afzelii. Borrelia miyamotoi was detected in the spleen of three squirrels (6.7%) and Anaplasma phagocytophilum in four spleen samples (8.9%). Both A. phagocytophilum ecotype I and II were found. We could not detect the presence of "Candidatus Neoehrlichia mikurensis" or tick-borne encephalitis virus in any of the squirrels. Our results suggest that Eurasian red squirrels can host B. afzelii, as already proposed by previous studies, but we could not confirm the previous established association between squirrels and B. burgdorferi sensu stricto. Our results demonstrate the epidemiological importance of the red squirrel, particularly in (sub) urban areas, since they can harbour a similar community of tick-borne pathogens as do mice and voles and can act as hosts for A. phagocytophilum ecotype I, which has important implications for human health risk

Fruit orchards and woody semi-natural habitat provide complementary resources for pollinators in agricultural landscapes

Context To safeguard insect pollinators and their pollination services, we need to understand how landscape structure regulates the distribution of resources that sustain pollinator populations. However, evidence of how pollinator communities benefit from the variety of resources distributed across different habitat types is scarce. Objectives To explore complementary resource provision, we conducted a field study to examine the resources available to pollinators in fruit orchards and woody semi-natural habitat. Methods We studied 13 landscapes containing both habitat types in Flanders, Belgium. In every habitat element, we surveyed nesting resources, floral resources and wild pollinators (i.e. wild bees and hover flies) during three consecutive time periods in the season (once before- and twice after mass-flowering of the fruit orchards). Results We concluded that the composition of nesting resources for wild bees was clearly different between both habitat types. Woody semi-natural habitat also provided more diverse- and a higher cover of floral resources compared to fruit orchards. In addition, the composition of these floral resources became more and more distinct between the two habitat types as the season progressed. Based on the plant - pollinator network we identified key plant species for inclusion in management schemes to support pollinators. Conclusions Our study highlights that fruit orchards and woody semi-natural habitat provide a set of different, complementary resources during the flight season, for pollinating insects. Due to the higher diversity and abundance of resources in woody semi-natural habitat, conservation of woody semi-natural habitat is essential for the support of pollinators in agricultural landscapes

Soil carbon of hedgerows and ‘ghost’ hedgerows

Agroforestry can contribute significantly to carbon sequestration in agricultural lands, as carbon accumulates both in tree biomass and the soil. One of the oldest, yet declining, forms of agroforestry in Europe are hedgerow-bordered fields. An analysis of historical maps of our study area in Belgium shows that 70% of the hedgerow network was cleared since 1960, creating a large number of 'ghost' hedgerows. We selected arable fields next to hedgerows, 'ghost' hedgerows and grass strips to study how hedgerow trees influence SOC stocks and how much of these are still present after hedgerow clearing. SOC stocks to a depth of 23 cm reached up to 81.7 +/- 28.8 Mg C ha(-1) in hedgerows, storing a considerably larger amount of soil carbon compared to grass strips (56.6 +/- 14.5 Mg C ha(-1)). These built-up stocks were completely gone in 'ghost' hedgerows (57.9 +/- 14.1 Mg C ha(-1)). In the fields adjacent to hedgerows, SOC stocks were only slightly (and insignificantly) increased compared to stocks in fields with grass strips (56.4 +/- 6.3 vs 55.6 +/- 5.0 Mg C ha(-1)) with an exponential decay up to 30 m from the margin. This trend was still limitedly detectable in 'ghost' hedgerowbordered fields, however stocks were not elevated anymore (53.9 +/- 6.1 Mg C ha(-1)). Since 1960, 4 957 +/- 1 664 Mg C from the soil alone were released back into the atmosphere due to hedgerow removal in the study area. The implementation of a strict hedgerow conservation policy would thus be a highly effective climate change mitigation measure in agricultural landscapes