Brodifacoum is effective against Norway Rats (Rattus norvegicus) in a tyrosine139cysteine focus of anticoagulant resistance, Westphalia, Germany

BACKGROUND: The single nucleotide polymorphism (SNP), and consequent amino acid exchange from tyrosine to cysteine at location 139 of the vkorc1 gene (i.e. tyrosine139cysteine or Y139C), is the most widespread anticoagulant resistance mutation in Norway rats (Rattus norvegicus Berk.) in Europe. Field trials were conducted to determine incidence of the Y139C SNP at two rat infested farms in Westphalia, Germany, and to estimate the practical efficacy against them of applications, using a pulsed baiting treatment regime, of a proprietary bait (KleratTM) containing 50 ppm brodifacoum. RESULTS: DNA analysis for the Y139C mutation showed that resistant rats were prevalent at the two farms, with an incidence of 80.0% and 78.6% respectively. Applications of brodifacoum bait achieved results of 99.2% and 100.0% control at the two farms, when measured by census baiting, although the treatment was somewhat prolonged at one site due to the abundance of attractive alternative food. CONCLUSION: The study showed that 50 ppm brodifacoum bait is fully effective against the Y139C SNP at the Münsterland focus and is likely to be so elsewhere in Europe where this mutation is found. The pulsed baiting regime reduced to relatively low levels the quantity of bait required to control these two substantial resistant Norway rat infestations. Previous studies had shown much larger quantities of bromadiolone and difenacoum baits used in ineffective treatments against Y139C resistant rats in the Münsterland. These results should be considered when making decisions about the use of anticoagulant against resistant Norway rats and their potential environmental impacts.

Moderate drought alters biomass and depth distribution of fine roots in Norway spruce

A rain shelter experiment was conducted in a 90-year-old Norway spruce stand, in the Kysucké Beskydy Mts (Slovakia). Three rain shelters were constructed in the stand to prevent the rainfall from reaching the soil and to reduce water availability in the rhizosphere. Fine root biomass and necromass were repeatedly measured throughout a growing season by soil coring. We established the quantities of fine root biomass (live) and necromass (dead) at soil depths of 0-5, 5-15, 15-25, and 25-35 cm. Significant differences in soil moisture contents between control and drought plots were found in the top 15 cm of soil after 20 weeks of rainfall manipulation (lasting from early June to late October). Our observations show that even relatively light drought decreased total fine root biomass from 272.0 to 242.8 g m-2 and increased the amount of necromass from 79.2 to 101.2 g m-2 in the top 35 cm of soil. Very fine roots, i.e. those with diameter up to 1 mm, were more affected than total fine roots defined as 0-2 mm. The effect of reduced water availability was depth-specific, as a result we observed a modification of vertical distribution of fine roots. More roots in drought treatment were produced in the wetter soil horizons at 25-35 cm depth than at the surface. We conclude that fine and very fine root systems of Norway spruce have the capacity to re-allocate resources to roots at different depths in response to environmental signals, resulting in changes in necromass to biomass ratio.

Protecting recognized Geneva Convention refugees outside their states of asylum

This article highlights the predicament of persons recognized as refugees according to the Convention Relating to the Status of Refugees (CSR1951 refugees) when they travel outside their state of asylum. Their status entails ipso facto that, if they are ill-treated abroad, they cannot turn to representatives of their state of nationality and request its diplomatic protection, nor can they expect to receive its consular assistance. It is submitted that a state of asylum ought to extend the scope of protection that it offers CSR1951 refugees residing in its territory, and provide them diplomatic protection and consular assistance when they travel abroad as if they were its nationals. Four claims are advanced in support of this contention: First: the advent of human rights treaties has not rendered obsolete the protection of nationals abroad nor has the practice fallen into disuse. On the contrary, protection abroad retains its pedigree and significance, as is illustrated by the recently adopted International Law Commission's Draft Articles on Diplomatic Protection and by frequent resort to consular assistance. Second: while states previously enjoyed unfettered discretion concerning whether and when to protect their nationals abroad, recent developments in domestic jurisdictions as well as in European Union (EU) treaties point to the potential emergence of a qualified duty to exercise state protection or to be willing to provide justifications for its refusal. These developments call particular attention to the vulnerability of CSR1951 refugees: the professed aim of the EU treaty regime is that EU citizens should enjoy effective state protection wherever they travel; by contrast, CSR1951 refugees are in need of state protection wherever they travel. Third: according to CSR1951, states of asylum are required to issue Convention Travel Documents (CTDs) to recognized refugees lawfully staying in their territory. While CTDs do not in of themselves authorize states of asylum to provide protection abroad to their CSR1951 refugees, they reflect partial recognition of the instrumental role of these states in facilitating safe refugee travel. Fourth: while the 'nationality of claims' requirement remains pivotal to the institution of diplomatic protection, and efforts to effectuate its general relaxation have thus far failed, the International Law Commission (ILC) has 'carved out' an exception authorizing states of asylum to provide protection abroad to their recognized refugees. The ILC's protection-enhancing agenda, reflecting progressive development of the law, is laudable, even though it has opted for a rather cautious approach.

Replacing Norway spruce with European beech: a comparison of biomass and Net Primary Production patterns in young stands

An alteration of species composition in temperate forests – both managed and natural - is one of the expected effects of environmental change. Present forest tree species ranges will be altered by changing environmental conditions. By a combination of continuous and destructive sampling, we compared biomass stocks and annual NPP in naturally regenerated stands of Norway spruce and European beech. We purposely selected a site where future environmental conditions are predicted to favour beech over presently dominant spruce. We found no difference in overall productivity, but biomass allocation differed significantly between the two species. Beech allocated more assimilates to stem and roots than spruce. There was no significant difference between the species in NPP of the fast turnover biomass pool comprising foliage and fine roots. Maximum height growth occurred about a month earlier than in spruce, potentially changing the timing of carbon (C) flow into the soil pools. We show that the replacement of spruce by beech will result in changes in forest biomass allocation and in alterations of belowground C cycle. Such changes will affect forest ecosystem function by modifying the magnitude and timing of certain C fluxes, but also by potentially changing the species composition of forest biota dependent on them.