The Last Trees Standing: Climate modulates tree survival factors during a prolonged bark beetle outbreak in Europe

Plant traits are an expression of strategic tradeoffs in plant performance that determine variation in allocation of finite resources to alternate physiological functions. Climate factors interact with plant traits to mediate tree survival. This study investigated survival dynamics in Norway spruce (Picea abies) in relation to tree-level morphological traits during a prolonged multi-year outbreak of the bark beetle, Ips typographus, in Central Europe. We acquired datasets describing the trait attributes of individual spruce using remote sensing and field surveys. We used nonlinear regression in a hypothesis-driven framework to quantify survival probability as a function of tree size, crown morphology, intraspecific competition and a growing season water balance. Extant spruce trees that persisted through the outbreak were spatially clustered, suggesting that survival was a nonrandom process. Larger diameter trees were more susceptible to bark beetles, reflecting either life history tradeoffs or a dynamic interaction between defense capacity and insect aggregation behavior. Competition had a strong negative effect on survival, presumably through resource limitation. Trees with more extensive crowns were buffered against bark beetles, ostensibly by a more robust photosynthetic capability and greater carbon reserves. The outbreak spanned a warming trend and conditions of anomalous aridity. Sustained water limitation during this period amplified the consequences of other factors, rendering even smaller trees vulnerable to colonization by insects. Our results are in agreement with prior research indicating that climate change has the potential to intensify bark beetle activity. However, forest outcomes will depend on complex cross-scale interactions between global climate trends and tree-level trait factors, as well as feedback effects associated with landscape patterns of stand structural diversity

Electro Mobility and Possible Scenarios for Slovakia

Arbeit an der Bibliothek noch nicht eingelangt - Daten nicht geprueftThis master thesis set out several questions aimed at the situation at electromobility in Slovakia in the scope of mid-term horizon. Will be the country among leaders or followers regarding use of electromobiles? Following questions have been asked and there was put effort for trying to find relevant answers. Questions and ansvers: When will it be favourable for the average Slovak consumer to own an electric car? Several types of calculations have been done to compare kind of total costs of ownership of vehicles with combustion engine and electromobiles during the life cycle of ten years. Acquisition cost of the electromobile and changing of battery during that time created advantage for clasic car ovnership. Comparation of the price of electromobile with average income in Slovakia have indicated, that aveage Slovak customer would have to work three to four years to be able to buy vehicle with electric engine. Electromobile can be more attractive in the case vhen its price decreases to the one of the clasic car in the same cathegory. Can Slovakias energy system cope with increased electricity consumption when the share of electric cars in the total number of passenger cars increases? Can the grid cope with peak loads caused by charging electric vehicles? Slovakia has actually 9% underproduction of electric energy, however should have 9% of overproduction in 2022. If there would be 30% of electromobiles in 2030 (assumption of IEA), they consume 6% of the production. Electric power would be sufficient. The grid can cope with peak loads having 40 -50% reserve in immediate power production. Will Slovakia have sufficient infrastructure to allow the development of electro-mobility and who will carry the largest share of costs in its creation? Ansver to this question depends on activities of private sector, which will bear majority of the costs representing over 160 mil. Euro according to strategy paper issued by Ministry of Economy. How will the state deal with the resulting decrease in excise duty on mineral oils - fuels? Having 30% of electric vehicles the fallout in state buget income would be 2,5% - arroung 35 mil. Eur. It is very realistic, that state would like to ballance this ammount either through increasing excise tax on mineral oils, or increasing of the price of eletricity. Most probable is, that it can be applied on both.8

Nest Sanitation as the Evolutionary Background for Egg Ejection Behaviour and the Role of Motivation for Object Removal

Higher interclutch colour variation can evolve under the pressure of brood parasitism to increase the detection of parasitic eggs. Nest sanitation could be a prerequisite for the evolution of anti-parasite defence in terms of egg ejection. In this respect, we used nest sanitation behaviour as a tool to identify: i) motivation and its underlying function and, ii) which features provoke ejection behaviour. Therefore, we experimentally tested whether size, colour or shape may influence ejection behaviour using artificial flat objects. We found a high interclutch variation in egg colouration and egg size in our tree sparrow (Passer montanus) population. Using colour and size we were in fact able to predict clutch affiliation for each egg. Our experiments further revealed the existence of direct anti-parasite behaviours and birds are able to recognise conspecific eggs, since only experimentally-deposited eggs have been removed. Moreover, experiments with different objects revealed that the motivation of tree sparrows to remove experimental objects from their nests was highest during egg laying for objects of varying size, most likely because of parasitism risk at this breeding stage. In contrary, motivation to remove white objects and objects with edges was higher during incubation stage as behavioural patterns connected to hatching started to emerge. The fact that rejection rate of our flat objects was higher than real egg ejection, suggests that egg ejection in tree sparrows and probably more general in small passerines, to be limited by elevated costs to eject eggs with their beaks. The presence of anti-parasite behaviour supports our suggestion that brood parasitism causes variation in egg features, as we have found that tree sparrows can recognise and reject conspecific eggs in their clutch. In conclusion, in tree sparrows it seems that nest sanitation plays a key role in the evolution of the removal of parasitic eggs