Investment In Defence Research Articles

Lesser leaf herbivore damage and structural defense and greater nutrient concentrations for invasive alien plants: Evidence from 47 pairs of invasive and non-invasive plants

Empirical evidence of enemy release is still inconsistent for invasive alien plant species, although enemy release is the key assumption for both the enemy release hypothesis (ERH) and the evolution of increased competitive ability hypothesis (EICA). In addition, little effort has been made to test this assumption in terms of defense investment using a multi-species comparative approach. Using a phylogenetically controlled within-study meta-analytical approach, we compared leaf herbivore damage, structural defenses and nutrients between 47 pairs of invasive versus native and/or non-invasive alien plants in China. The invasive relative to the co-occurring native or non-invasive (native and non-invasive alien) plants incurred lesser leaf herbivore damage, had lesser leaf concentrations of cellulose, hemicellulose, lignin and carbon, lesser leaf density and carbon or lignin to nitrogen ratio but greater nutrients, which may facilitate success of the invasive plants. The lesser structural investment did not result in lesser leaf construction costs for the invaders, which may be associated with their greater leaf nitrogen concentration. However, the invasive plants were not significantly different from the non-invasive alien plants in any trait. Our results provide strong evidence for ERH, also are consistent with EICA, and indicate that enemy release may be an important factor in alien plant invasions.

Environment, not phylogeny, drives herbivory and leaf attributes in trees from two contrasting forest formations of the Brazilian Atlantic Forest

ABSTRACT Background The degree of herbivory in plants can be related to leaf traits, which are, in turn, determined by phylogeny and environment. Aims The objective of our study was to determine the level of trait conservation (determined by phylogeny) vs. trait convergence (owing to overbearing effect of environmental factors) in leaf attributes and its relationship with rates of herbivory in two contrasting neotropical habitats. Methods We quantified herbivory and 12 leaf traits in 10 congeneric, co-occurring pairs of tree species of an Atlantic Rain Forest (ARF) and a coastal forest (Restinga - REST). Results Higher values of N, N:P, leaf area and water content were found for the ARF species, while REST species were characterised by higher total phenol, Ca, C:N and leaf mass per area. There was a great degree of trait convergence in leaf attributes by habitat, and a near lack of trait conservation. Rates of herbivory were related to leaf attributes and were significantly larger in ARF species compared to those in REST. Conclusions These findings indicate that leaf attributes are relatively convergent and closely related to habitat. The results also support theory in confirming greater investment in leaf defence in REST species in a more resource-poor environment than in ARF.

The SOCIMIs in Spain. An investment opportunity in the real estate sector

The purpose of the present work is to analyze the SOCIMIs (Real estate listed investment trusts in Spain), its performance and its potential as a diversification asset between June 2014 and December 2017. The tax advantages they offer, the main incentive for the creation of these types of companies, are bringing about an increase in development of real estate investment in Spain, which is behind other developed markets where they are generally called REITs (Real Estate Investment Trusts). First, the characteristics, operation, evolution in the market, portfolios and shareholders’ composition are studied. Next, the analysis shows high performance levels measured by the modified Sharpe Ratio and the Jensen’s Alpha for the main SOCIMIs on the market as well as a high portfolio diversification potential demonstrated by the Markowitz Efficient Frontier Model. SOCIMIs are characterized by being less risky investments than the market in general. Compared to traditional Real estate listed companies on the continuous market, SOCIMIs show better performance and lower levels of risk and, in general, all the companies studied –SOCIMIs and traditional Real estate listed companies- can be defined as defensive investments, less risky than the market.

Were the floods in the UK 2007 and Germany 2013 game-changers?

This paper examines recovery after major floods in the UK and Germany. It focuses on two areas that were badly hit by flooding: Catcliffe, near Sheffield in the UK, and Passau in Bavaria, Germany. It reports on surveys of residents and businesses in each place and on surveys of national flood experts in both countries. The two events were comparable in terms of impacts, levels of preparedness and government response and show similar patterns of speed and quality of recovery. In Germany, it took about 18 months for 90% or more of residents to get back to normal, while in the UK it took a year longer. This difference may be related to funding; in the UK, over 90% of funding came from household insurance while in Germany over 60% came from federal aid, which may have been quicker. In both countries, the economy had recovered to near normal within 12-18 months. The majority of people surveyed in both countries (74% in Germany and 67% in the UK) believe that their homes and businesses are as just as vulnerable now as they were before the respective floods. However, in the UK, half of the respondents thought their neighbourhood was safer and better prepared compared to only 11% in Germany. This may be because substantial progress has been made in improving protection in the UK in areas flooded in 2007. Both floods were considered to be 'game-changers' and resulted in a heightened awareness of flood risk, increased investment in flood defences and an increasing emphasis on citizens taking more responsibility for flood preparedness. However, the Environment Agency in the UK lacks powers to prevent development in flood-prone areas, in Germany there are issues of coordination across large catchments that cross state boundaries and the insurance sector could play a bigger role in 'building back better'. Many homes and businesses continue to be at risk from major floods and more progress needs to be made in making them more resilient. This article is part of the theme issue 'Urban flood resilience'.

To compete or defend: linking functional trait variation with life-history tradeoffs in a foundation tree species.

Although chemical deterrents to herbivory often exact costs in terms of plant growth, the manner in which those costs arise, and their physiological relationship to other functional traits, remain unclear. In the absence of appreciable herbivory, we examined interrelationships among chemical defense levels and other foliar functional traits (e.g., light-saturated photosynthesis, specific leaf area, nitrogen concentration) as co-determinants of tree growth and, by extension, competitive ability in high-density populations comprising 16 genotypes of Populus tremuloides. Across genotypes, concentrations of chemical defenses were not significantly related to other leaf functional traits, but levels of the salicinoid phenolic glycosides (SPGs) salicin, salicortin and tremulacin were each negatively correlated with relative mass growth (RMG) of aboveground woody tissue (P ≤ 0.001). RMG, in turn, underpinned 77% of the genotypic variation in relative height growth (our index of competitive ability). RMG was also positively related to light-saturated photosynthesis (P ≤ 0.001), which, together with the three SPGs, explained 86% of genotypic RMG variation (P ≤ 0.001). Moreover, results of a carbon balance simulation indicated that costs of resource allocation to SPGs, reaching nearly a third of annual crown photosynthesis, were likely mediated by substantial metabolic turnover, particularly for salicin. The lack of discernible links between foliar defense allocation and other (measured) functional traits, and the illustrated potential of metabolic turnover to reconcile influences of SPG allocation on RMG, shed additional light on fundamental physiological mechanisms underlying evolutionary tradeoffs between chemical defense investment and competitive ability in a foundation tree species.

Belgium: the reliable free rider

Belgium traditionally presents itself as a strong supporter of multilateral security cooperation and aims to be a reliable partner in the EU and NATO. Nevertheless, the uninterrupted decline of Belgium’s defence budget paints a different picture, that of a country that rides cheap on the defence efforts of its partners. Belgium does make equitable contributions to multinational military operations, but the lack of defence investments threatens to undercut its ability to continue to make substantial contributions to multilateral operations. This article builds on the literature on small states and military burden sharing to explain Belgium’s post-Cold War defence policy. More specifically, it argues that Belgium’s behaviour is anything but irrational, given that it allows to gain a high degree of security and influence at relatively low political and financial costs.

Target-oriented utility for interdiction of transportation networks

Optimal resource allocation in security has been a significant challenge for critical infrastructure protection. We study an optimal resource-allocation model for more cost-effective protection of critical targets on a transportation network. We apply target-oriented utility theory and use mixed-integer programming to determine the optimal level of investment needed to interdict an attacker on a transportation network. We assume that the attacker will choose one target among multiple targets to attack based on factors such as the attractiveness of targets to the attacker and the attack success probabilities, and will be deterred for sufficiently low attack success probabilities. Sensitivity analyses are conducted to illustrate how the optimal defensive strategy depends on parameters such as attacker success probabilities, attacker deterrence, target values, number of targets, and effectiveness of defensive investment.

Parasitism by an invasive nest fly reduces future reproduction in Galápagos mockingbirds.

Organisms allocate limited resources to competing activities such as reproduction, growth, and defense against parasites and predators. The introduction of a novel parasite may create new life history trade-offs. As hosts increase their investment in self-maintenance or defense, the cost of parasitism may carry over to other aspects of host biology. Here, in an experimental field study, we document delayed effects of an introduced nest parasite, Philornis downsi, on reproduction of Galápagos mockingbirds (Mimus parvulus). Parasitism of first nests reduced both the number and size of chicks that parents hatched when they re-nested several weeks later. The delayed effect of P. downsi on future reproduction may have been mediated by behavioral shifts by the parents to avoid or resist parasitism. Our results demonstrate that effects of parasitism can persist even after immediate exposure ends. We draw attention to the potential implications that introduced parasites have for host reproductive strategies.

НАТО versus PESCO: экономические аспекты

The article is devoted to economic consequences of the demands of the U. S. President Donald Trump to European NATO allies to increase defense spendings in the context of intensified European defense cooperation (in particular, the implementation of the PESCO initiative). Within NATO, a line of tension “West-East” or “old-new members” has been identified, due to both economic (the size and level of the economies’ development) and political (attitude to the USA as a guarantor of security) reasons. European states have committed to increase spendings both within NATO (defense investment pledge) and within PESCO. On the one hand, the development of the European defense identity and the growth of defense spendings will in any case serve to strengthen the overall NATO capabilities. On the other hand, in the medium and long term these measures are unlikely to lead to real strategic autonomy of Europe, although they are aimed at strengthening support for the military-industrial complex of the largest European states. The U.S. considers such policy as a challenge, given that American defense contractors have traditionally been involved in the distribution of defense orders in Europe (while the U.S. market is nearly closed for European companies). Under conditions of growing uncertainty and the crisis of globalization, support for defense industry enterprises can create additional impetus for internationalization of this economy sector, without which European products are unlikely to remain competitive in the global arms export market. The analysis shows that France as a country with one of the most technologically advanced military-industrial complexes will be the main “motor” and, most likely, the beneficiary of strengthening defense cooperation in Europe. Moreover, an additional factor of French ambitions may be a significant share of state participation in the defense sector of the economy and, in general, the strongest (in comparison with Germany and the UK) “national link” of the industry.

Case study of the cascading effects on critical infrastructure in Torbay coastal/pluvial flooding with climate change and 3D visualisation

Abstract Critical infrastructures (CIs) are commonly designed, built and maintained based on rigorous standards in order to withstand the climate and weather-related pressures. However, shifts in climate characteristics may result in increases of the magnitude and frequency of potential risks, or expose specific CI to new or increased risks not previously considered. As vital components of the normal functioning of modern societies, their resilience encompasses the operational elements, their structural integrity and the capacity to maximise business output under climate stressors. In this work, we apply an integrated and participatory methodological approach to assess the risk and enhance the resilience of interconnected CIs to urban flooding under climate change. The proposed methodology has been applied to an extended case study in Torbay to extend previous works, which seeks to protect coastal communities from future events through using the proposed methodology to justify future investment in coastal defences, as a part of the validation of EU-CIRCLE projects developed methodologies.

Exploring evolutionary theories of plant defence investment using field populations of the deadly carrot.

There are a number of disparate models predicting variation in plant chemical defences between species, and within a single species over space and time. These can give conflicting predictions. Here we review a number of these theories, before assessing their power to predict the spatial-temporal variation of thapsigargins between and within populations of the deadly carrot (Thapsia garganica). By utilizing multiple models simultaneously (optimum defence theory, growth rate hypothesis, growth-differentiation balance hypothesis, intra-specific framework and resource exchange model of plant defence), we will highlight gaps in their predictions and evaluate the performance of each. Thapsigargins are potent anti-herbivore compounds that occur in limited richness across the different plant tissues of T. garganica, and therefore represent an ideal system for exploring these models. Thapsia garganica plants were collected from six locations on the island of Ibiza, Spain, and the thapsigargins quantified within reproductive, vegetative and below-ground tissues. The effects of sampling time, location, mammalian herbivory, soil nutrition and changing root-associated fungal communities on the concentrations of thapsigargins within these in situ observations were analysed, and the results were compared with our model predictions. The models performed well in predicting the general defence strategy of T. garganica and the above-ground distribution of thapsigargins, but failed to predict the considerable proportion of defences found below ground. Models predicting variation over environmental gradients gave conflicting and less specific predictions, with intraspecific variation remaining less understood. Here we found that multiple models predicting the general defence strategy of plant species could likely be integrated into a single model, while also finding a clear need to better incorporate below-ground defences into models of plant chemical defences. We found that constitutive and induced thapsigargins differed in their regulation, and suggest that models predicting intraspecific defences should consider them separately. Finally, we suggest that in situ studies be supplemented with experiments in controlled environments to identify specific environmental parameters that regulate variation in defences within species.

Relationships between key functional traits of the waterlily Nuphar lutea and wetland nutrient content.

Little attention has been paid to how aquatic habitat characteristics affect the traits of plant species. Nuphar lutea (L.) Sm. is a keystone species distributed across temperate regions of Europe, northwest Africa and western Asia. Its apparently low phenotypic variability compared to other aquatic plants led us to test whether the species exhibited significant phenotypic variability and whether trait values correlated to environmental parameters. The hypotheses were that (1) the environmental variation within our set of wetlands (both water and sediment characteristics) led to significant variation among four sets of traits related respectively to growth, reproduction, defence and storage and (2) that nutrient limitation (nitrogen and especially phosphorus) should affect plant traits towards a higher investment in storage and defence and a lower investment in growth and reproduction, thereby negatively affecting the success of N. lutea. To test these hypotheses, 11 populations of N. lutea were sampled in wetlands differing in physicochemical characteristics and spread along three rivers. A total of 15 traits, grouped into four sets (growth, reproduction, storage and defence), were measured during the growing season. Most N. lutea traits were related to the environmental characteristics of wetlands. The growth and reproduction traits were mostly positively related to habitat resource conditions, whereas the defence traits were positively correlated with both ammonium concentration and temperature, outlining possible anoxic stress (habitat adversity). Nitrogen or phosphorus limitation led to the variation of only a few traits: the rhizome starch content was higher in phosphorus-limited wetlands, while the rhizome length and volume, and the number of flowers were higher in nitrogen-limited wetlands.

Adaptation and Adverse Selection in Markets for Natural Disaster Insurance

This paper studies social welfare in markets for natural disaster insurance. I quantify frictions in uptake, test for adverse selection, and estimate the welfare effects of proposed policy reforms by developing a model of natural disaster insurance markets and compiling new data. The paper has three main findings. First, willingness to pay for natural disaster insurance is remarkably low. In the high-risk flood zones throughout all U.S. Atlantic and Gulf Coast states, fewer than 60% of homeowners purchase flood insurance even though subsidized premia are only two-thirds of their own expected payouts. Second, homeowners select into insurance based on observable differences in houses' defensive investments against natural disasters (i.e., adaptation), but not on private information about risk. Exploiting house-level variation in flood insurance prices and construction codes reveals that requirements to elevate newly constructed homes reduce insurer costs by 31% and insurance demand by 25%. Asymmetric information between homeowners and insurers, however, does not affect average payouts. Third, ignoring how frictions, such as risk misperception, distort demand understates the welfare cost of currently proposed price increases and changes the sign of the predicted welfare effect. In the presence of such frictions, enforcing a natural disaster insurance mandate increases social welfare.

Psychological constraints on aggressive predation in economic contests.

When humans compete, they invest energy and effort to injure others and to protect against injury and exploitation. The psychology behind exploiting others and protecting against exploitation is still poorly understood and is addressed here in an incentivized economic contest game in which individuals invested in predatory attack and prey defense. Consistent with standard economic theory on production and predation, we find that individuals compete less intensely when they attack rather than defend and that attacks disproportionally often fail. We find, furthermore, 2 psychological mechanisms that restrain attack more than defense. First, individuals with stronger concern for others' welfare (Experiment 1a) and with stronger empathy (Experiment 1b) less frequently attack and when they attack, they do so less forcefully. Second, shorter decision times (Experiment 2a and Experiment 2b), along with cognitive taxation (Experiment 2b) associate with more forceful, but not with more frequent attack. Finally, investments in defense were neither predicted by other-concern and empathy, nor by decision time and cognitive taxation. Thus, individuals with stronger prosocial preferences and more deliberated decisions spent less energy on injuring others, and less often defeated their antagonists but ended-up personally wealthier. The waste of conflict can be reduced by strengthening prosocial preferences and cognitive resources available for deliberate decision-making. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Пріоритети нової ідеології військово-технічного співробітництва України з іноземними державами

The article examines issues of the development of military-technical cooperation of Ukraine with foreign countries under the modern conditions, which determine the necessity of significant changes in the system of military-technical cooperation towards liberalization of the foreign economic activity that includes goods and services of military and dual use and concerns the entities of all forms of ownership. This will facilitate the creation of the necessary conditions for expanding Ukraine’s presence on the international arms markets and on the Ukrainian market of foreign defence companies attracting the latest defence technologies and investments to the defence industry. The article provides the rationale for the directions of military-technical cooperation development, the main priorities of which are: satisfaction of the needs of Ukrainian military formations by import, preservation of traditional arms markets and development of new ones, the use of military-technical cooperation to form allies from Western partners and eliminate Russia as a competitor. It is proposed to consolidate these priorities in a separate document, the Strategy of military-technical cooperation of Ukraine with foreign countries, which will be considered as a long-term, consistent, constructive and rational plan. The development of Ukraine’s military-technical cooperation with foreign countries will help to provide the Armed Forces of Ukraine with modern weapons, strengthen Ukraine’s position on new arms markets and increase foreign currency income.

Strong but opposing effects of associational resistance and susceptibility on defense phenotype in an African savanna plant

The susceptibility of plants to herbivores can be strongly influenced by the identity, morphology and palatability of neighboring plants. While the defensive traits of neighbors often determine the mechanism and strength of associational resistance and susceptibility, the effect of neighbors on plant defense phenotype remains poorly understood. We used field surveys and a prickle‐removal experiment in a semi‐arid Kenyan savanna to evaluate the efficacy of physical defenses against large mammalian herbivores in a common understory plant, Solanum campylacanthum. We then quantified the respective effects of spinescent Acacia trees and short‐statured grasses on browsing damage and prickle density in S. campylacanthum. We paired measurements of prickle density beneath and outside tree canopies with long‐term herbivore‐exclusion experiments to evaluate whether associational resistance reduced defense investment by decreasing browsing damage. Likewise, we compared defense phenotype within and outside pre‐existing and experimentally created clearings to determine whether grass neighbors increased defense investment via associational susceptibility. Removing prickles increased the frequency of browsing by ~25%, and surveys of herbivory damage on defended leaves suggested that herbivores tended to avoid prickles. As predicted, associational resistance and susceptibility had opposing effects on plant phenotype: individuals growing beneath Acacia canopies (or, analogously, within large‐herbivore exclosures) had a significantly lower proportion of their leaves browsed and produced ~ 70–80% fewer prickles than those outside refuges, whereas plants in grass‐dominated clearings were more heavily browsed and produced nearly twice as many prickles as plants outside clearings. Our results demonstrate that associational resistance and susceptibility have strong, but opposing, effects on plant defense phenotype, and that variable herbivore damage is a major source of intraspecific variation in defense phenotype in this system.

Invasive species differ in key functional traits from native and non‐invasive alien plant species

AbstractQuestionsInvasive species establish either by possessing traits, or trait trade‐offs similar to native species, suggesting pre‐adaptation to local conditions; or by having a different suite of traits and trait trade‐offs, which allow them to occupy unfilled niches. The trait differences between invasives and non‐invasives can inform on which traits confer invasibility. Here, we ask: (a) are invasive species functionally different or similar to native species? (b) which traits of invasives differ from traits of non‐invasive aliens and thus confer invasibility? and (c) do results from the sub‐Antarctic region, where this study was conducted, differ from findings from other regions?LocationSub‐Antarctic Marion Island.MethodsWe measured 13 traits of all terrestrial native, invasive and non‐invasive alien plant species. Using principal components analysis and phylogenetic generalized least‐squares models, we tested for differences in traits between invasive (widespread alien species) and native species. Bivariate trait relationships between invasive and native species were compared using standardized major axis regressions to test for differences in trait trade‐offs between the two groups. Second, using the same methods, we compared the traits of invasive species to non‐invasive aliens (alien species that have not spread).ResultsBetween invasive and native species, most traits differed, suggesting that the success of invasive species is mediated by being functionally different to native species. Additionally, most bivariate trait relationships differed either in terms of theiry‐intercept or their position on the axes, highlighting that plants are positioned differently along a spectrum of shared trait trade‐offs. Compared to non‐invasive aliens, invasive species had lower plant height, smaller leaf area, lower frost tolerance, and higher specific leaf area, suggesting that these traits are associated with invasiveness. The findings for the sub‐Antarctic corresponded to those of other regions, except lower plant height which provides a competitive advantage to invaders in the windy sub‐Antarctic context.ConclusionOur findings support the expectation that trait complexes of invasive species are predominantly different to those of coexisting native species, and that high resource acquisition and low defence investment are characteristic of invasive plant species.

Russia’s Arms Sales Policy After the Ukraine Sanctions

Russia sells arms primarily to enhance its influence abroad in key regions, e.g., the Middle East, East, and South Asia. Since the government is the primary customer for this sector’s goods, this sector does not risk collapse even if arms sales decline though arms sales bring vital foreign currency. But, the intervening motive between seeking enhanced global influence and maintaining the defense sector is the acquisition of elite rents since the arms trade offers multiple opportunities for corruption. We then focus on the impact of arms production and sales on international security. First that means looking at how Russia’s militarization and its increasing conversion into a mobilization state is affected by the ever growing importance of defense investment and production to the government and the economy. We then investigate the impact of arms sales on international security in Latin America, the Middle East, and East Asia.

Phenolics lie at the centre of functional versatility in the responses of two phytochemically diverse tropical trees to canopy thinning.

Saplings in the shade of the tropical understorey face the challenge of acquiring sufficient carbon for growth as well as defence against intense pest pressure. A minor increase in light availability via canopy thinning may allow for increased investment in chemical defence against pests, but it may also necessitate additional biochemical investment to prevent light-induced oxidative stress. The shifts in secondary metabolite composition that increased sun exposure may precipitate in such tree species present an ideal milieu for evaluating the potential of a single suite of phenolic secondary metabolites to be used in mitigating both abiotic and biotic stressors. To conduct such an evaluation, we exposed saplings of two unrelated species to a range of light environments and compared changes in their foliar secondary metabolome alongside corresponding changes in the abiotic and biotic activity of their secondary metabolite suites. Among the numerous classes of secondary metabolites found in both species, phenolics accounted for the majority of increases in antioxidant and UV-absorbing properties as well as activity against an invertebrate herbivore and a fungal pathogen. Our results support the hypothesis that phenolics contribute to the capacity of plants to resist co-occurring abiotic and biotic stressors in resource-limited conditions.

Temporal variation in behavioral responses to dietary cues from a gape‐limited predator in tadpole prey: A test of the phylogenetic relatedness hypothesis

AbstractThe ability of prey to recognize and adequately respond to predators determines their survival. Predator‐borne, post‐digestion dietary cues represent essential information for prey about the identity and the level of risk posed by predators. The phylogenetic relatedness hypothesis posits that prey should respond strongly to dietary cues from closely related heterospecifics but respond weakly to such cues from distantly related prey, following a hierarchical pattern. While such responses have mostly been observed in prey at their first encounter with predators, whether prey maintain such hierarchical levels of investment through time remains unclear. We investigated this question by exposing Rhacophorus arboreus tadpoles to the non‐consumptive effect of gape‐limited newt predators Cynops pyrrhogaster that were fed one of five prey diets across a gradient of phylogenetic relatedness: frog tadpoles (Rhacophorus arboreus, Rhacophorus schlegelii, Pelophylax nigromaculatus, and Hyla japonica) and medaka fish (Oryzias latipes). Predators’ diet, time, and their interaction significantly influenced tadpole activity level. We found support for the phylogenetic relatedness hypothesis: Investments in defense were stronger to cues from tadpole diets than to cues from fish diet. However, such a hierarchical response was recorded only in the first four days following predator exposure, then gradually disappear by day 8 on which the tadpoles exhibited similar activity level across all predator treatments. The findings suggest that, at least under the threat of gape‐limited predators, prey use phylogenetic information to evaluate risk and appropriately invest in defense during early encounters with predators; however, energy requirements may prevent prey from maintaining a high level of defense over long exposure to predation risk.