Demographic vulnerability of the clonal and endangered meadow thistle

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Вклад региональных и глобальных факторов в межгодовую изменчивость гидрометеорологических условий прибрежной зоны Черного моря

Выполнен факторный анализ рядов среднегодовых и среднепятилетних значений метеорологических и гидрологических параметров по данным измерений на береговых гидрометстанциях. Получены количественные оценки вклада глобальных и региональных факторов в межгодовую и декадную изменчивость показателей гидрометеорологического режима черноморской прибрежной зоны Украины.Виконано факторний аналіз рядів середньорічних і середньоп’ятирічних значень метеорологічних і гідрологічних величин за даними вимірювань на берегових гідрометстанціях. Отримані кількісні оцінки внеску глобальних і регіональних факторів у міжрічну та декадну мінливість показників гідрометеорологічного режиму чорноморської прибережної смуги України.Factor analysis of the time-series of annual and five-year averaged meteorological and hydrological values measured on shore hydrometeorological stations was performed. Quantitative estimations were obtained for the global and regional factors input to the interannual and decadal variability of the Ukrainian Black Sea coastal zone hydrometeorological regimen indices

Combining agro-ecological functions in grass-clover mixtures

Grass-clover mixtures show many benefits for sustainable agriculture. In the Netherlands, organic farmers often work together in a so-called partner farm concept, with the aim to close nutrient cycles on a regional level. In this system, arable farms grow one-year grass-clover leys, as fodder for a livestock farm, in exchange for, e.g., manure. This practice could also be used in the transition of conventional farms towards a more circular regenerative and nature inclusive agriculture. In the current experiment we assessed the effect of a range of grass (Lolium perenne: Lp, Lolium multiflorum: Lm) and clover (Trifolium pratense: Tp and Trifolium repens: Tr) monocultures and mixtures on both below- and aboveground parameters in light of benefits for livestock and arable farms, and biodiversity. The grass monocultures showed good weed suppression, high root density, and especially Lp had a positive effect on soil structure. Clover, on the other hand, showed high herbage dry matter yield (particularly Tp) and Nitrogen (N) yield, and Tr showed high digestibility. Moreover, clover had a positive effect on the soil mineral N, and earthworm abundance tended to be higher in the clover monocultures. When (some of) the four species were combined in grass-clover mixtures, they combined the positive effects of the species and often even outperformed the (best) monocultures. We concluded that grass-clover mixtures increased agro-ecological functions

Incidence of gynaecological cancer during the COVID-19 pandemic:A population-based study in the Netherlands

Objective: To study the impact of the COVID-19 pandemic and consequent lockdown on the number of diagnoses of gynaecological malignancies in the Netherlands. Methods: We performed a retrospective cohort study using data from the Netherlands Cancer Registry (NCR) on women of 18 years and older diagnosed with invasive endometrial, ovarian, cervical or vulvar cancer in the period 2017–2021. Analyses were stratified for age, socioeconomical status (SES) and region. Results: The incidence rate of gynaecological cancer was 67/100.000 (n = 4832) before (2017–2019) and 68/100.000 (n = 4833) during (2020) the COVID-19 pandemic. Comparing the number of diagnoses of the two periods for the four types of cancer separately showed no significant difference. During the first wave of COVID-19 (March-June 2020), a clear decrease in number of gynaecological cancer diagnoses was visible (20–34 %). Subsequently, large increases in number of diagnoses were visible (11–29 %). No significant differences in incidence were found between different age groups, SES and regions. In 2021 an increase of 5.9 % in number of diagnoses was seen. Conclusion: In the Netherlands, a clear drop in number of diagnoses was visible for all four types of gynaecological cancers during the first wave, with a subsequent increase in number of diagnoses in the second part of 2020 and in 2021. No differences between SES groups were found. This illustrates good organisation of and access to health care in the Netherlands.</p

A Host–parasite Model Explains Variation in Liana Infestation Among Co‐occurring Tree Species

Lianas are structural parasites of trees that reduce the growth, survival and reproduction of their hosts. Given that co‐occurring tree species differ strongly in the proportion of individuals that are infested by lianas (liana prevalence), lianas could differentially impact tree species and thereby influence tree community composition. Surprisingly, little is known about what governs variation in liana prevalence. Here, we apply an approach inspired by disease ecology to investigate the dynamics of liana prevalence over 11 years on Barro Colorado Island, Panama. We followed the fate of 1,938 individual trees from 21 tree species, recording deaths and change in liana infestation status. With these data, we fit species‐specific Markov chain models to estimate four rates: colonization by lianas (analogous to disease transmission), shedding or loss of lianas (analogous to host recovery), baseline mortality of uninfested trees (baseline mortality) and additional mortality of infested trees (parasite lethality). Models explained 58% of variation in liana prevalence among tree species, and revealed that host shedding of lianas and parasite lethality were the most important contributors to interspecific variation in liana prevalence at our site. These rates were also strongly related to shade tolerance, with light‐demanding species having greater rates of shedding and lethality, and lower rates of liana prevalence. An indirect path analysis with a structural equation model revealed that both greater rates of liana shedding and liana‐induced lethality contribute to the observed lower rates of liana prevalence for light‐demanding tree species. Synthesis. Our approach revealed that the prevalence of liana infestation among tree species is driven via indirect pathways operating on the rates of shedding and lethality, which relate to the ability (or inability) of trees to shed and/or tolerate lianas. Shade‐tolerant trees have greater proportions of trees infested by lianas because they are both less able to shed lianas and more able to tolerate infestation

The demographic causes of population change vary across four decades in a long-lived shorebird

Understanding which factors cause populations to decline begins with identifying which parts of the life cycle, and which vital rates, have changed over time. However, in a world where humans are altering the environment both rapidly and in different ways, the demographic causes of decline likely vary over time. Identifying temporal variation in demographic causes of decline is crucial to assure that conservation actions target current and not past threats. However, this has rarely been studied as it requires long time series. Here we investigate how the demography of a long-lived shorebird (the Eurasian Oystercatcher Haematopus ostralegus) has changed in the past four decades, resulting in a shift from stable dynamics to strong declines (−9% per year), and recently back to a modest decline. Since individuals of this species are likely to respond differently to environmental change, we captured individual heterogeneity through three state variables: age, breeding status, and lay date (using integral projection models). Timing of egg-laying explained significant levels of variation in reproduction, with a parabolic relationship of maximal productivity near the average lay date. Reproduction explained most variation in population growth rates, largely due to poor nest success and hatchling survival. However, the demographic causes of decline have also been in flux over the last three decades: hatchling survival was low in the 2000s but improved in the 2010s, while adult survival declined in the 2000s and remains low today. Overall, the joint action of several key demographic variables explain the decline of the oystercatcher, and improvements in a single vital rate cannot halt the decline. Conservations actions will thus need to address threats occurring at different stages of the oystercatcher's life cycle. The dynamic nature of the threat landscape is further supported by the finding that the average individual no longer has the highest performance in the population, and emphasizes how individual heterogeneity in vital rates can play an important role in modulating population growth rates. Our results indicate that understanding population decline in the current era requires disentangling demographic mechanisms, individual variability, and their changes over time

State-dependent environmental sensitivity of reproductive success and survival in a shorebird

To understand the consequences of anthropogenic and environmental changes for wildlife populations, it is important to study how individuals differ in their sensitivity to environmental change, and whether this depends on individual characteristics. An individual’s reproductive performance may provide an integrative, unidimensional proxy of an individual’s characteristics. In this study, we define an individual’s characteristics by three such reproductive states, namely successful-, failed-, and non-breeders in the previous year. We used a 16-year dataset of individually marked breeding Eurasian Oystercatchers Haematopus ostralegus to examine the inter-annual fluctuations in reproductive success and survival among breeding states, and their state-dependent sensitivity to environmental conditions. Environmental conditions included available biomass of the main prey species of breeding Oystercatchers (Ragworm, Baltic Tellin and Lugworm), tidal height which reflects one of the main causes of nest loss (flooding) and conditions that may impact the energetic requirements during incubation, such as temperature. We also included environmental variables measured in winter, including available biomass of the main winter prey species (Blue Mussel and Common Cockle) along with factors that may affect food availability and energetic requirements for homeostasis, namely bivalve weight loss, windchill, winter severity, and precipitation. Breeding birds that were successful the previous year had higher survival, and were more likely to remain successful, than failed- and non-breeders. The effects of environmental conditions acted in the same direction on reproductive success but had opposite effects on survival among the three breeding states, especially for windchill and Blue Mussel biomass. The contrasting state-dependent effects of the environment on survival thus averaged out when examining consequences for lifetime reproductive nest success (LRnS); instead LRnS was largely influenced by environmental conditions acting upon reproduction. Our study indicates that an individual’s previous breeding state provides an integrative measure of heterogeneity in individuals’ sensitivity of reproduction and survival to environmental change. Incorporating previous breeding state as a source of individual heterogeneity in population modelling may improve predictions of future population dynamics in a rapidly changing world

Effectiveness and cost-effectiveness of a nurse-delivered intervention to improve adherence to treatment for HIV : a pragmatic, multicentre, open-label, randomised clinical trial

This trial was funded from public money by the Netherlands Organisation for Health Research and Development (ZonMW; grant number 171002208). Aardex provided support on the development of the study website. We thank all the HIV nurses and physicians from the seven HIV clinics involved in the AIMS study for their input and collaboration (Academic Medical Centre, Slotervaart hospital, and St. Lucas-Andreas hospital, all in Amsterdam; the Leiden University Medical Centre, Leiden; HAGA hospital, The Hague; Erasmus Medical Centre, Rotterdam; and Isala clinic, Zwolle), the study participants, and the Stichting HIV Monitoring (SHM) for their support in accessing the SHM database for identifying patient inclusion criteria and developing the Markov model. Finally, we thank and remember Herman Schaalma (deceased) for his contribution to the study design and grant application.Peer reviewedPostprin

Conceptualizing and quantifying body condition using structural equation modelling:A user guide

Body condition is an important concept in behaviour, evolution and conservation, commonly used as a proxy of an individual's performance, for example in the assessment of environmental impacts. Although body condition potentially encompasses a wide range of health state dimensions (nutritional, immune or hormonal status), in practice most studies operationalize body condition using a single (univariate) measure, such as fat storage. One reason for excluding additional axes of variation may be that multivariate descriptors of body condition impose statistical and analytical challenges. Structural equation modelling (SEM) is used in many fields to study questions relating multidimensional concepts, and we here explain how SEM is a useful analytical tool to describe the multivariate nature of body condition. In this ‘Research Methods Guide’ paper, we show how SEM can be used to resolve different challenges in analysing the multivariate nature of body condition, such as (a) variable reduction and conceptualization, (b) specifying the relationship of condition to performance metrics, (c) comparing competing causal hypothesis and (d) including many pathways in a single model to avoid stepwise modelling approaches. We illustrated the use of SEM on a real-world case study and provided R-code of worked examples as a learning tool. We compared the predictive power of SEM with conventional statistical approaches that integrate multiple variables into one condition variable: multiple regression and principal component analyses. We show that model performance on our dataset is higher when using SEM and led to more accurate and precise estimates compared to conventional approaches. We encourage researchers to consider SEM as a flexible framework to describe the multivariate nature of body condition and thus understand how it affects biological processes, thereby improving the value of body condition proxies for predicting organismal performance. Finally, we highlight that it can be useful for other multidimensional ecological concepts as well, such as immunocompetence, oxidative stress and environmental conditions

Love thy neighbour?-Spatial variation in density dependence of nest survival in relation to predator community

Aim: In many species, density-dependent effects on reproduction are an important driver of population dynamics. However, it is rarely considered that the direction of density dependence is expected to vary over space and time depending on anti-predator behaviour and predator community. Aggregation may allow for effective group mobbing against avian nest predators while aggregation may also attract mammalian predators, causing negative density dependence. We aim to quantify spatial variation in the effect of conspecific breeding density on nest survival in a mobbing bird species (Eurasian oystercatcher; Haematopus ostralegus) and identify whether this variation in density dependence can be explained by the predator community. Location: Country-wide (The Netherlands). Methods: We integrated reproductive data with breeding territory maps of Eurasian oystercatchers and occupancy maps of avian and mammalian predator species across the Netherlands for a 10-year period. Results: Spatial variation in the composition of the predator community explained the effects of neighbour density, showing decreasing nest survival when both conspecific density and mammalian dominance increased. Also, heterospecific density (from breeding godwits and lapwing) has an additional effect on the oystercatcher nest survival. Strikingly, this pattern did not extend to mammal-free island populations. Main conclusions: Our study provides evidence that both the strength and sign of density dependence can vary spatially within species, implying that it is dangerous to generalize results from a single local population to large-scale management implications and modelling exercises. The study also suggests that conservation actions that aim to attract breeding birds should be prioritized in areas with fewer mammalian predators, but this idea requires further testing on island populations