Sari Repka

LEAF VALUE: EFFECTS OF DAMAGE TO INDIVIDUAL LEAVES ON GROWTH AND REPRODUCTION OF MOUNTAIN BIRCH SHOOTS

Most damage caused by invertebrate herbivores is local and limited in extent and may therefore seem inconsequential. However, in addition to providing photosynthates to the whole plant, individual leaves may preferentially feed local sinks, including pri- mordial meristems that develop later. For leaf damage, this may have local consequences and, in the case of preformed meristems, may result in time lags. To investigate such consequences and to determine the degree of independence among shoot modules, we studied shoot traits after damage to individual leaves in long shoots and vegetative and generative short shoots of field-growing mountain birch, Betula pubescens subsp. czere- panovii (Orlova) Hamet-Ahti. For short shoots, the results suggest that, due to the catkin, generative shoots have a higher priority in resource use than vegetative shoots. The overwinter survival of vegetative short shoots was decreased after their young leaves had been damaged early in the previous season. Otherwise, there were no significant effects of leaf damage on vegetative shoots. In generative shoots, leaf damage affected size and reproduction instead of survival. Because leaf damage significantly decreased leaf size-in the generative shoots in the posttreatment year, leaves presumably competed with the catkin for resources within the shoot. Damage also reduced the catkin mass and the mean seed mass in the treatment year. In the post- treatment year, catkin mass and total seed mass were reduced by the treatments, but dif- ferences in the number of seeds and mean seed mass did not quite reach significance. The treatments had no effects on leaf mass of neighbors of vegetative or generative shoots in the treatment year or in the posttreatment year. In the treatment year, removal of long shoot leaves from a growing long shoot did not affect growth of the long shoot, indicating that such growth was supported by resources external to the shoot. However, local effects were evident in the posttreatment year: leaf mass decreased in shoots that developed from axillary buds in long shoots whose supporting leaves had been clipped in the previous year. Consequently, removal of individual leaves may have local effects on shoot survivorship, reproduction, and growth. Timing of damage and shoot type modified the consequences of local leaf damage, and there were no consistent responses for all situations. Due to the limited extent of damage, the effects were not likely to result from nutrient loss due to damage. Instead, consequences of local leaf damage could be explained largely by effects on local sinks and meristem primordia.

Specificity of predator-induced neck spine and alteration in life history traits in Daphnia pulex

It has been proposed that the predator-induced defensive neck spine in Daphnia pulex has a demographic cost. Our results show that this cost is not merely an allocation cost related to the formation and maintenance of the neck spine. In a life table experiment, we tested whether spine induction and life history traits in D. pulex are affected by different invertebrate predators: first and third instar Chaoborus, fourth instar Mochlonyx and two size classes of Notonecta and Dytiscus larvae. D. pulex showed sensitivity to the different predators. Predator-exposure affected one or more of the following life history traits of D. pulex: the timing of first reproduction, clutch size, and growth. In some cases, exposure to predators altered life history traits when neck spine induction did not occur. These shifts in life history traits occurring in the absence of spine induction may be caused by behavioral or physiological changes triggered by the predators.

Maritime traffic externalities in the Gulf of Finland until 2030

Abstract Maritime traffic in the Gulf of Finland has grown remarkably during the 2000s. This increase has an impact on the environment and exposes it to risks. These problems should be controlled to guarantee sustainable development and the welfare of inhabitants in the area. A method for estimating the impact of ship-originated air emissions on the environment is to calculate their environmental externalities which are a part of the total marginal social costs of shipping. The internalization of externalities as a control method of transport would comply with the polluter pays principle and act as a fair traffic control method between transport modes. In this paper, we present the results of CO2, NOx, SOx and PM emissions originating from ships and their externalities in the Gulf of Finland up to 2015. The calculation algorithm developed for this study produces emission estimates per annum and converts them into externalities. We focus on passenger, tanker, general cargo, Ro-Ro, container and bulk vessel...

Post-fledging movements of white-tailed eagles: Conservation implications for wind-energy development

The presence of poorly sited wind farms raises concerns for wildlife, including birds of prey. Therefore, there is a need to extend the knowledge of the potential human–wildlife conflicts associated with wind energy. Here, we report on the movements and habitat use of post-fledging satellite-tagged white-tailed eagles in Finland, where wind-energy development is expected to increase in the near future. In particular, we examine the probability of a fledgling approaching a hypothetical turbine that is placed at different distances from the nest. We found that this probability is high at short distances but considerably decreases with increasing distances to the nest. A utilisation–availability analysis showed that the coast was the preferred habitat. We argue that avoiding construction between active nests and the shoreline, as well as adopting the currently 2-km buffer zone for turbine deployment, can avoid or minimise potential impacts on post-fledging white-tailed eagles.

Estimating Costs and Benefits of Sulphur Content Limits in Ship Fuel

Sulphur oxides and particulate matter have detrimental effects on human health and the environment. It has been decided to limit the sulphur content of ship fuel to 0.1w% in the SECA area. Here, we estimated the costs for Finland and the achievable health and environmental benefits. Results show that the additional costs were 375–751 million euros per year in Finland. Benefits were estimated to range from 223 to 652 million euros. Even though in wide scale the benefits are more significant than the costs, there may be differences between countries due to geography, business structure, and population density.

Clay- and algae-induced effects on biomass, cell size and toxin concentration of a brackish-water cyanobacterium

We studied if biomass, cell dimensions and microcystin concentration of the cyanobacterium Anabaena sp. (strain BIR 257; recently also referred to as Dolichospermum) change in the presence of turbidity caused by clay and a eukaryotic green algal species. Anabaena sp. was incubated in experimental lab bioassays, with added clay and the chlorophyte Brachiomonas submarina. A control was established containing a single species of Anabaena sp. Biomass of Anabaena, given as carbon concentration increased in response to clay addition, suggesting that Anabaena was stimulated by lower light conditions whereas B. submarina was not. Cell lengths increased most likely as a response to lower light conditions. Dissolved toxin concentration decreased in treatments containing clay. Increased clay turbidity may favour the cyanobacterium Anabaena sp. over its eukaryotic competitors in the future Baltic Sea, especially in low-salinity estuaries.

Maritime Transport in the Gulf of Bothnia 2030

Scenarios for shipping traffic in the Gulf of Bothnia (GoB) by 2030 are described in order to identify the main factors that should be taken into account when preparing a Maritime Spatial Plan (MSP) for the area. The application of future research methodology to planning of marine areas was also assessed. The methods include applying existing large scale quantitative scenarios for maritime traffic in the GoB and using real-time Delphi in which an expert group discussed different factors contributing to future maritime traffic in the GoB to find out the probability and significance of the factors having an impact on maritime traffic. MSP was tested on transnational scale in the Bothnian Sea area as a pilot project.

Reviewing the History of Natural Sciences Research on the Bothnian Sea, 1975–2008

The Bothnian Sea is a shallow body of brackish water andpart of the northern-most limb of the Baltic (Fig. 1). Withsalinity averaging 5–6 per mille, a ragged coastline, andslow sedimentation rates (Voipio 1981; Grano¨ et al. 1999),it forms its own unique environment. The A˚ land Islandsand the shape of the seabed prevent the nutrient-richbottom water from Baltic proper from flowing into theBothnian Sea. This constitutes the main reason whyeutrophication has not yet become a major problem here.However, the situation is now beginning to change as aresult of nutrient-rich water draining into the Bothnian Seafrom the many Swedish and Finnish rivers (Lundberg et al.2009). While the Bothnian Sea is an economically impor-tant region with the majority of herring in the Baltic beingcaught here (Parmanne 1998), it has generally not been thefocus of much scientific effort and the reason for this couldbe its rather good condition. The same is true for moni-toring as there are fewer sites, temporally and spatially, inthe Bothnian Sea than in the smaller Archipelago Sea(HELCOM 2009). Consequently it is difficult to conductspatially representative surveys with an insufficient spatialdistribution of sites (Erkkila¨ and Kalliola 2007). Throughreviewing the past 33 years of research on the BothnianSea (1975–2008) (Saikku et al. 2009), we have identifiedgaps in the current knowledge allowing us to providerecommendations for future research focus.The website ISI Web of Knowledge and the ScienceCitation Index Expanded database was searched for articlesrelating to the Bothnian Sea (defined by the latitudes of60.5 N and 63.5 N, and the coasts of Finland and Sweden,Fig. 1). Research work with a focus outside of this region,with no research carried out within the designated BothnianSea area, has not been taken into consideration. The focusof the review is on research into the natural environmentand the human impact on this environment published inEnglish peer-reviewed international and ISI-recognizedscientific journals. This may, therefore, exclude articlespublished particularly in the 1970s and 1980s. A keywordsearch was also performed with ‘‘Gulf of Bothnia’’ as acheck for articles which, while mainly dealing with theGulf, included research carried out in the Bothnian Searegion as well. All articles which came up in the searcheswere manually checked. A final dataset of 132 articlesreferring to the Bothnian Sea were reviewed and summa-rized and these articles were divided under 7 main thematicresearch topics (Fig. 2; Table 1). These research topicswere chosen to describe the natural sciences research donein the Bothnian Sea area, and an article was categorizedinto a research topic based on its major research theme alsogiving potential information on past and future directionsof research.RESEARCH VOLUME AND QUANTITYBothnian Sea research was carried out in small groups ofscientists with the publications most commonly authoredby 1–3 people. A total of 327 different scientists carried outresearch over the past 33 years, but 80% of them publishedonly one article on the Bothnian Sea during this time.Many scientists are, therefore, not continuously researchingor at least not continuously publishing research relating tothe Bothnian Sea. This would mean that the Bothnian Searegion was not a constant and career-spanning topic ofresearch. However, instead of suggesting a lack of interest,