Grassland Resistance and Resilience after Drought Depends on Management Intensity and Species Richness

The degree to which biodiversity may promote the stability of grasslands in the light of climatic variability, such as prolonged summer drought, has attracted considerable interest. Studies so far yielded inconsistent results and in addition, the effect of different grassland management practices on their response to drought remains an open question. We experimentally combined the manipulation of prolonged summer drought (sheltered vs. unsheltered sites), plant species loss (6 levels of 60 down to 1 species) and management intensity (4 levels varying in mowing frequency and amount of fertilizer application). Stability was measured as resistance and resilience of aboveground biomass production in grasslands against decreased summer precipitation, where resistance is the difference between drought treatments directly after drought induction and resilience is the difference between drought treatments in spring of the following year. We hypothesized that (i) management intensification amplifies biomass decrease under drought, (ii) resistance decreases with increasing species richness and with management intensification and (iii) resilience increases with increasing species richness and with management intensification

Resilience isn't the same for all: comparing subjective and objective approaches to resilience measurement

Robust resilience measurement can improve our understanding of how people and societies respond to climate risk. It also allows for the effectiveness of resilience‐building interventions to be tracked over time. To date, the majority of measurement tools use objective methods of evaluation. Broadly speaking, these relate to approaches that solicit little, if any, judgment on behalf of the subject in question. More recently, subjective methods of evaluation have been proposed. These take a contrasting epistemological view, relying on people's self‐assessments of their own capacity to deal with climate risk. Subjective methods offer some promise in complementing objective methods, including: factoring in people's own knowledge of resilience and what contributes to it; more nuanced contextualization; and the potential to reduce survey length and fatigue. Yet, considerable confusion exists in understanding subjectivity and objectivity. Little is also known about the merits and limitations of different approaches to measurement. Here, I clarify the conceptual and practical relationships between objective and subjective forms of measuring resilience, aiming to provide practical guidance in distinguishing between them. In reviewing existing toolkits, I propose a subjectivity–objectivity continuum that groups measurement approaches according to two core tenets: (a) how resilience is defined and (b) how resilience is evaluated. I then use the continuum to explore the strengths and weaknesses of different types of toolkits, allowing comparison across each. I also emphasize that there is no one‐size fits all approach to resilience measurement. As such, evaluators should carefully consider: their epistemology of resilience; core objectives for measurement; as well as resource and data constraints, before choosing which methods to adopt

Climate Impacts, Political Institutions, and Leader Survival: Effects of Drought and Flooding Precipitation.

We explore how the political survival of leaders in different political regimes is affected by drought and flooding precipitation, which are the two major anticipated impacts of anthropogenic climate change. Using georeferenced climate data for the entire world and the Archigos dataset for the period of 1950-2010, we find that irregular political exits, such as coups or revolutions, are not significantly affected by climate impacts. Similarly, drought has a positive but insignificant effect on all types of political exits. On the other hand, we find that floods increase political turnover through the regular means such as elections or term limits. Democracies are better able to withstand the pressures arising from the economic and social disruptions associated with high precipitation than other institutional arrangements. Our results further suggest that, in the context of floods, political institutions play a more important role than economic development for the leaders’ political survival

Intra- and extracranial circulatory changes in cigarette smokers assessed by ultrasound: transcranial Doppler (TCD) and duplex scanning investigation

The group of 98 "healthy smokers" was analyzed in order to evaluate potential influence of cigarette smoking on intracranial blood flow disturbances and extracranial carotid intimal changes, performing transcranial Doppler (TCD) and Duplex scanning of the carotid arteries. Almost 70% of smokers analyzed in our study had some intracranial circulatory changes, predominantly in the vertebral arteries (35%). Half of smokers analyzed had some pathological intimal changes in the carotid arteries. The most frequent finding was wall thickening (23%) and then calcified (13%) and soft plaques (10%). Dose response relationship between smoking and atherosclerosis is also introduced. More than 30 cigarettes smoked per day can significantly influence plaque development and already 20 cigarettes smoked per day can cause significant intracranial blood flow disturbances. The majority of our investigated smokers were in high risk category for development of cerebrovascular disease and 5% were in a very high risk category. Cessation of cigarette smoking will eliminate it as a risk factor. A low dose-response relation and the development of tolerance produced by exposure to nicotine were also introduced

Preimineervlieg vraagt een veelzijdige aanpak

In de afgelopen vier jaar onderzochten de Vlaamse proefcentra PCG, Inagro en PSKW samen met het ILVO hoe we de preimineervlieg kunnen beheersen. We zochten o.a. uit welke afdekmaterialen geschikt zijn voor de beheersing, welke middelen de vliegen en/of maden kunnen bestrijden en welke impact bepaalde factoren hebben op de overleving van de poppen. In dit artikel geven we een overzicht van de resultaten met focus op de biologische teelt