Numer and type of seeds introduced by footwear of travelers to Svalbard and germination success in 2008

Expanding visitation to Polar regions combined with climate warming increases the potential for alien species introduction and establishment. We quantified vascular plant propagule pressure associated with different groups of travelers to the high-Arctic archipelago of Svalbard, and evaluated the potential of introduced seeds to germinate under the most favorable average Svalbard soil temperature (10°C). We sampled the footwear of 259 travelers arriving by air to Svalbard during the summer of 2008, recording 1,019 seeds: a mean of 3.9 (±0.8) seeds per traveler. Assuming the seed influx is representative for the whole year, we estimate a yearly seed load of around 270,000 by this vector alone. Seeds of 53 species were identified from 17 families, with Poaceae having both highest diversity and number of seeds. Eight of the families identified are among those most invasive worldwide, while the majority of the species identified were non-native to Svalbard. The number of seeds was highest on footwear that had been used in forested and alpine areas in the 3 months prior to traveling to Svalbard, and increased with the amount of soil affixed to footwear. In total, 26% of the collected seeds germinated under simulated Svalbard conditions. Our results demonstrate high propagule transport through aviation to highly visited cold-climate regions and isolated islands is occurring. Alien species establishment is expected to increase with climate change, particularly in high latitude regions, making the need for regional management considerations a priority.

Flower and seed biomass, and germination rate of arctic tundra plants in response to long term experimental warming

We provide new information on changes in tundra plant sexual reproduction in response to long-term (12 years) experimental warming in the High Arctic. Open-top chambers (OTCs) were used to increase growing season temperatures by 1-2 °C across a range of vascular plant communities. The warming enhanced reproductive effort and success in most species; shrubs and graminoids appeared to be more responsive than forbs. We found that the measured effects of warming on sexual reproduction were more consistently positive and to a greater degree in polar oasis compared with polar semidesert vascular plant communities. Our findings support predictions that long-term warming in the High Arctic will likely enhance sexual reproduction in tundra plants, which could lead to an increase in plant cover. Greater abundance of vegetation has implications for primary consumers - via increased forage availability, and the global carbon budget - as a function of changes in permafrost and vegetation acting as a carbon sink. Enhanced sexual reproduction in Arctic vascular plants may lead to increased genetic variability of offspring, and consequently improved chances of survival in a changing environment. Our findings also indicate that with future warming, polar oases may play an important role as a seed source to the surrounding polar desert landscape.

Equivalent dose, dose rate and age determination of cobble surfaces in the Antarctic

Most current methods of reconstructing past sea levels within Antarctica rely on radiocarbon dating. However, radiocarbon dating is limited by the availability of material for dating and problems inherent with radiocarbon reservoirs in Antarctic marine systems. Here we report on the success of a new approach to dating raised beach deposits in Antarctica for the purpose of reconstructing past sea levels. This new approach is the use of optically stimulated luminescence (OSL) on quartz-grains obtained from the underside of cobbles within raised beaches and boulder pavements. We obtained eight OSL dates from three sites along the shores of Maxwell Bay in the South Shetland Islands of the Antarctic Peninsula. These dates are internally consistent and fit well with previously published radiocarbon ages obtained from the same deposits. In addition, when the technique was applied to a modern beach, it resulted in an age of zero. Our results suggest that this method will provide a valuable tool in the reconstruction of past sea levels in Antarctica and other coarse-grained beach deposits across the globe.

Parental exposure to elevated pCO2 influences the reproductive success of copepods

Substantial variations are reported for egg production and hatching rates of copepods exposed to elevated carbon dioxide concentrations (pCO2). One possible explanation, as found in other marine taxa, is that prior parental exposure to elevated pCO2 (and/or decreased pH) affects reproductive performance. Previous studies have adopted two distinct approaches, either (1) expose male and female copepoda to the test pCO2/pH scenarios, or (2) solely expose egg-laying females to the tests. Although the former approach is more realistic, the majority of studies have used the latter approach. Here, we investigated the variation in egg production and hatching success of Acartia tonsa between these two experimental designs, across five different pCO2 concentrations (385-6000 µatm pCO2). In addition, to determine the effect of pCO2 on the hatching success with no prior parental exposure, eggs produced and fertilized under ambient conditions were also exposed to these pCO2 scenarios. Significant variations were found between experimental designs, with approach (1) resulting in higher impacts; here >20% difference was seen in hatching success between experiments at 1000 µatm pCO2 scenarios (2100 year scenario), and >85% at 6000 µatm pCO2. This study highlights the potential to misrepresent the reproductive response of a species to elevated pCO2 dependent on parental exposure.

Seawater carbonate chemistry, mortality and hatching rate, size and mass of Clupea harengus during experiments, 2011

Due to atmospheric accumulation of anthropogenic CO2 the partial pressure of carbon dioxide (pCO2) in surface seawater increases and the pH decreases. This process known as ocean acidification might have severe effects on marine organisms and ecosystems. The present study addresses the effect of ocean acidification on early developmental stages, the most sensitive stages in life history, of the Atlantic herring (Clupea harengus L.). Eggs of the Atlantic herring were fertilized and incubated in artificially acidified seawater (pCO2 1260, 1859, 2626, 2903, 4635 µatm) and a control treatment (pCO2 480 µatm) until the main hatch of herring larvae occurred. The development of the embryos was monitored daily and newly hatched larvae were sampled to analyze their morphometrics, and their condition by measuring the RNA/DNA ratios. Elevated pCO2 neither affected the embryogenesis nor the hatch rate. Furthermore the results showed no linear relationship betweenpCO2 and total length, dry weight, yolk sac area and otolith area of the newly hatched larvae. For pCO2 and RNA/DNA ratio, however, a significant negative linear relationship was found. The RNA concentration at hatching was reduced at higher pCO2 levels, which could lead to a decreased protein biosynthesis. The results indicate that an increased pCO2 can affect the metabolism of herring embryos negatively. Accordingly, further somatic growth of the larvae could be reduced. This can have consequences for the larval fish, since smaller and slow growing individuals have a lower survival potential due to lower feeding success and increased predation mortality. The regulatory mechanisms necessary to compensate for effects of hypercapnia could therefore lead to lower larval survival. Since the recruitment of fish seems to be determined during the early life stages, future research on the factors influencing these stages are of great importance in fisheries science.

Seawater carbonate chemistry and hatching rate, malformation rate, metamorphosis rate and shell growth of the Pacific abalone in a laboratory experiment

The hatching process of the Pacific abalone Haliotis discus hannai was prolonged at a pH of 7.6 and pH 7.3, and the embryonic developmental success was reduced. The hatching rate at pH 7.3 was significantly (10.8%) lower than that of the control (pH 8.2). The malformation rates at pH 7.9 and pH 8.2 were less than 20% but were 53.8% and 77.3% at pH 7.6 and pH 7.3, respectively. When newly hatched larvae were incubated for 48 h at pH 7.3, only 2.7% of the larvae settled, while more than 70% of the larvae completed settlement in the other three pH treatments. However, most 24 h old larvae could complete metamorphosis in all four pH treatments. Overall, a 0.3-unit reduction in water pH will produce no negative effect on the early development of the Pacific abalone, but further reduction in pH to the values predicted for seawater by the end of this century will have strong detrimental effects.

Social status regulates growth rate: Consequences for life-history strategies

The life-history strategies of organisms are sculpted over evolutionary time by the relative prospects of present and future reproductive success. As a consequence, animals of many species show flexible behavioral responses to environmental and social change. Here we show that disruption of the habitat of a colony of African cichlid fish, Haplochromis burtoni (Günther) caused males to switch social status more frequently than animals kept in a stable environment. H. burtoni males can be either reproductively active, guarding a territory, or reproductively inactive (nonterritorial). Although on average 25–50% of the males are territorial in both the stable and unstable environments, during the 20-week study, nearly two-thirds of the animals became territorial for at least 1 week. Moreover, many fish changed social status several times. Surprisingly, the induced changes in social status caused changes in somatic growth. Nonterritorial males and animals ascending in social rank showed an increased growth rate whereas territorial males and animals descending in social rank slowed their growth rate or even shrank. Similar behavioral and physiological changes are caused by social change in animals kept in stable environmental conditions, although at a lower rate. This suggests that differential growth, in interaction with environmental conditions, is a central mechanism underlying the changes in social status. Such reversible phenotypic plasticity in a crucial life-history trait may have evolved to enable animals to shift resources from reproduction to growth or vice versa, depending on present and future reproductive prospects.

Potential impact of Wild boar (Sus scrofa) on Pheasant (Phasianus colchicus) nesting success

In recent decades wild boar have greatly increased in Europe due a combination of environmental and human factors. Because of a high reproduction rate, wild boar cause conflicts with human activities and in particularly agriculture. However, there are concerns also about environmental impact and in particular on ground nesting birds. Our study aim to evaluate the potential impact of wild boar on pheasants nests. Predation rates were compared between two areas with different wild boar abundance and between nests placed in fenced plots with no wild boar access (but accessible to other predators) and open plots in which the wild boar gains access. Predation rate by wild boar in the area with higher wild boar abundance was 61.5% whereas in the area with lower abundance was 16.0%. In plots with free access, wild boar predation was 34.2% whereas in exclusion plots we did not registered predation by wild boar. Moreover, wild boar resulted the main nest predator (total loss 22.8%). Our findings suggest that wild boar could have e strong impact on pheasant reproductive success.

Estonia in the eurozone - a strategic success. OSW Commentary No. 53, 2011-06-20

The adoption of the euro in January 2011 topped off Estonia’s integration policy. In the opinion of Estonian politicians, this country has never been so secure and stable in its history. Tallinn sees the introduction of the euro primarily in the political context as an entrenchment of the Estonian presence in Europe. The process of establishing increasingly close relations with Western European countries, which the country has consistently implemented since it restored independence in 1991, has been aimed at severing itself its Soviet past and at a gradual reduction of the gap existing between Estonia and the best-developed European economies. The Estonian government also prioritises the enhancement of co-operation as part of the EU and NATO as well as its principled fulfilment of the country’s undertakings. It sees these as important elements for building the country’s international prestige. The meeting of the Maastricht criteria at the time of an economic slump and the adoption of the euro during the eurozone crisis proved the determination and efficiency of the government in Tallinn. Its success has been based on strong support from the Estonian public for the pro-European (integrationist) policy of Estonia: according to public opinion polls, approximately 80% of the country’s residents declare their satisfaction with EU membership, while support for the euro ranges between 50% and 60%. Since Estonia joined the OECD in 2010 and adopted the euro at the beginning of 2011, it has become the leader of integration processes among the Baltic states. The introduction of the euro has reinforced Estonia’s international image and made it more attractive to foreign investors. The positive example of this country may be used as a strong argument by the governments in Lithuania and Latvia when they take action to meet the Maastricht criteria. Vilnius and Riga claim they want to adopt the euro in 2014. The improving economic situation in the Baltic states will contribute to the achievement of this goal, while an excessively high inflation rate, as in 2007, may be the main impediment1.

The effects of required/sequenced preparatory courses on academic success and retention at a community college

This dissertation had two purposes: first, to analyze how required sequenced college preparatory courses in mathematics, reading, and writing affect students' academic success and, second, to add to a theoretical model for predicting student retention at a community college. Grade point average, number of degree credits earned, and re-enrollment rate were measured as determinants of academic success. The treatment group had a significantly higher grade point average than the control group. There was no significant difference in the number of degree credits earned or re-enrollment rate for the groups. A series of logistic regressions used the independent variables E-ASSET scores in math, reading, and writing; number of college prep areas required; credits earned; grade point average; students' status; academic restrictions/required course sequencing; sex; race; and socio-economic status to determine the predictor variables for retention. The academic variable that showed the greatest potential as a predictor for retention was grade point average. Overall, receiving financial aid was the greatest predictor for re-enrollment. For a financial aid recipient the odds of re-enrollment were 2.70 times more likely than if no financial aid was received.

An evaluation of exchange rate policy and economic adjustment in Nicaragua, 1993--1995

Since the late 1970's, but particularly since the mid-1980s, the economy of Nicaragua has had persistent and large macroeconomic imbalances, while GDP per-capita has declined to 1950s' levels. By the second half of the 1990s, huge fiscal deficits and a reduction of foreign financing resulted in record hyperinflation. The Sandinista government's (1979–1990) harsh stabilization program in 1988–89 had only modest and short-lived success. It was doomed by their inability to lower the public sector deficit due to the war, plus diminishing financial support from abroad. Hyperinflation stopped only after their 1990 electoral defeat ended the war and massive aid began to flow in. Five years later, macroeconomic stability is still very fragile. A sluggish recovery of export agriculture plus import liberalization, have impeded a reduction of huge trade and current account deficits. Facing the prospects of diminished aid flows, the government's strategy has hinged on the achievement of a real devaluation through a crawling-peg adjustment of the nominal rate. However, at the end of 1995 the situation of the external accounts was still critical, and the modest progress achieved was attributable to cyclical terms-of-trade improvement and changes in the political outlook of agricultural producers. Using a Computable General Equilibrium Model and a Social Accounting Matrix constructed for this dissertation, the importance of structural rigidities in production and demand in explaining such outcome is shown. It is shown that under the plausible structural assumptions incorporated in the model, the role of devaluation in the adjustment process is restricted by structural rigidities. Moreover, contrary to the premise of the orthodox economic thinking behind the economic program, it is the contractionary effect of devaluation more than its expenditure-switching effects that provide the basis for is use in solving the external sector's problems. A fixed nominal exchange rate is found to lead to adverse results. The broader conclusion that emerges from the study is that a new social compact and a rapid increase in infrastructure spending plus fiscal support for the traditional agro-export activities is at the center of a successful adjustment towards external viability in Nicaragua. ^