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The Primula sibirica group is a set of approximately a dozen Arctic, taxonomically unrelated plant species that share a similar disjunct distribution on the shores of the Arctic Ocean and the northernmost part of the Baltic Sea. The origin of this phylogeographic pattern is not known. It has been suggested, first, that the species arrived after the last glaciation from the White Sea, second, that they are relicts of once larger populations or, third, that they arrived via jump dispersal. One of the species is the polyploid Creeping alkali grass, Puccinellia phryganodes, which is critically endangered in Finland. Here we used microsatellite markers to study seven extant and three extinct populations from coasts of the Bothnian Bay and the Arctic Sea (N = 297). We estimated the genetic diversity in the study populations and applied principal component analysis and Bayesian and coalescence methods to examine their population genetic structure and evolutionary history. We found that the endangered Bothnian Bay population still harbors a reasonably high amount of genetic diversity and is differentiated from the geographically closest populations. We show that Puccinellia phryganodes is more likely a climatic relict in the Bothnian Bay than a long-distance disperser and that the endangered southern population should be considered as an evolutionary significant unit rather than a mere representative of the main population. [ABSTRACT FROM AUTHOR]

The proportion of beef cattle in relation to the total number of cattle has increased in Europe, which has led to a higher contribution of beef cattle in the management of semi-natural grasslands. Changes in vegetation caused by this change in grazers are virtually unexplored so far. In the present study, the impacts of beef and dairy cattle on vegetation structure and composition were compared on Bothnian Bay coastal meadows. Vegetation parameters were measured in seven beef cattle, six dairy heifer pastures, and in six unmanaged meadows. Compared to unmanaged meadows, vegetation in grazed meadows was significantly lower in height and more frequently colonized by low-growth species. As expected, vegetation grazed by beef cattle was more open than that on dairy heifer pastures where litter cover and proportion of bare ground were in the same level as in the unmanaged meadows. However, the observed differences may have in part arisen from the higher cattle densities in coastal meadows grazed by beef cattle than by dairy heifers. The frequencies of different species groups and the species richness values of vegetation did not differ between the coastal meadows grazed by the two cattle types. One reason for this may be the relatively short management history of the studied pastures. The potential differences in grazing impacts of the two cattle types on vegetation structure can be utilized in the management of coastal meadows for species with divergent habitat requirements. [ABSTRACT FROM AUTHOR]

We identify four issues in the decision framework for species conservation management under climate change proposed by Shoo et al. () Clim Chan 119:239-246 and suggest ways to address them. First, binary-decision flow charts require Yes/No answers, which are not appropriate in most conservation decisions. A quantitative framework is preferable and action-guidance should be obtained even when the realistic answer to some questions remains 'we simply do not know'. Second, the proposed flow chart imposes an a priori order of precedence and does not explicitly allow simultaneous actions. A workable framework should enable optimal allocation between multiple kinds of conservation efforts and permit complementary actions. Third, the probability of success, co-benefit to non-target species, and cost are unlikely to have a simple, consistent relationship across taxa. These variables need to be assessed case-by-case for each conservation measure and species. Finally, the decision framework disregards the legal, social, and ethical aspects pertaining to decision-making. [ABSTRACT FROM AUTHOR]

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Host use by herbivores is largely determined by host properties such as nutrient content and chemical defence against foragers. The impacts of these attributes on a herbivore may largely depend on its life cycle stage. Lichen species are known to differ in nutritional quality and level of chemical defence and, consequently, vary as fodder for herbivores. The aim of this study was to explore the impact of several lichen species and the presence of their secondary metabolites on their use as hosts by a specialist lichen-feeder, Cleorodes lichenaria. This study also addressed, for the first time, how a specialist lichen-feeder deals with different lichen secondary metabolites. In the beginning of their development, larvae grew better on Xanthoria parietina than on the other host lichens, whereas older larvae grew best on Ramalina fraxinea. Lichen secondary chemicals in R. fraxinea and Parmelia sulcata hindered larval growth in the beginning but after 75 days lichen secondary chemicals had no impact on the mass of larvae. Physodic acids in Hypogymnia physodes were lethal to larvae. In general, larvae metabolized 70–95% of ingested lichen secondary chemicals and the rest of these were excreted in frass. Lichen secondary metabolites in P. sulcata restrict and in H. physodes prevent their use as a host for C. lichenaria larvae. Our main finding, the ability of larvae to metabolize several lichen secondary metabolites, indicates digestive adaptation to these chemicals. No signs of sequestration of these chemicals were found. [ABSTRACT FROM AUTHOR]

Responses of concentrations of usnic (UA) and perlatolic (PA) acids and the relative growth rate (RGR) of a mat-forming lichen, Cladina stellaris, to enhanced N and P input were studied in a fertilisation experiment. It was predicted on the basis of carbon-nutrient balance (CNB) hypothesis that the concentrations of these phenolics would decline and the growth rate increase in response to increased nutrient uptake. The concentration of UA showed a convex response pattern to increased N input whereas the concentration of PA was non-responsive. An ecologically realistic, "moderate", N treatment clearly lowered the level of UA both with and without the P application. Applying P alone caused a significant increase in the level of UA. The RGR of C. stellaris did not respond to nutrient addition. The results indicate that even though the CNB hypothesis may be applicable in explaining concentrations of lichen secondary metabolites, it may be applied under a relatively narrow set of conditions. Especially inherited constraints in the growth of lichen fungi may seriously limit the responsiveness of lichens to short-time changes in the availability of resources. These limitations may also apply to other perennials adapted to nutrient-poor conditions. [ABSTRACT FROM AUTHOR]