Alien predators are known to potentially strongly affect their prey populations. We studied the impact of raccoon dogs (Nyctereutes procyonoides) on waterbird breeding success in eight semi-urban wetlands in Finland. We manipulated raccoon dog density in two wetlands by removing individuals (2002 protection year, 2003 and 2004 removal years). We additionally performed nest predation experiments. We monitored raccoon dog density, estimated hunting bag size and observed waterbird breeding success. Our hypothesis predicts that the omnivorous raccoon dog plays a role in waterbird breeding success by depredating nests. Our experiments shown that the raccoon dog hunting bag in eutrophic wetlands may be large, as we removed 8.6–20.0 animals per km2. Both our nest predation experiment and field data indicated that raccoon dogs affect the breeding success of waterbirds. We found a significant relationship between raccoon dog density index and predation rate of the artificial nests, but not between red fox (Vulpes vulpes) density and predation on artificial nests. We did not find an association between raccoon dog abundance and the breeding success of mallards (Anas platyrhynchos) and great crested grebes (Podiceps cristatus). However, our study shows that birds species with different breeding strategies – e.g. great crested grebe, mute swan (Cygnus olor), mallard, Eurasian wigeon (Mareca penelope), coot (Fulica atra), lapwing (Vanellus vanellus) and marsh harrier (Circus aeruginosus) – when considered together showed higher breeding success both in 2003 and 2004 when compared to breeding success before removal. There was, however, variation in how strongly the species responded to raccoon dog removal. Our results indicate that the removal of alien raccoon dogs can be an important tool in wetland management.

Species invasions often occur on coasts and estuaries where abiotic conditions vary, e.g. salinity, temperature, runoff etc. Successful establishment and dispersal of non-indigenous species in many such systems are poorly understood, partially since the species tend to show genetic and ecological plasticity at population level towards many abiotic conditions, including salinity tolerance. Plasticity may be driven by shifting expression of heat shock proteins such as Hsp70, which is widely recognized as indicator of physical stress. In this study, we developed a qPCR assay for expression of the hsp70 gene in the invasive round goby (Neogobius melanostomus) and tested the expression response of fish collected from a brackish environment in the western Baltic Sea to three different salinities, 0, 10 and 30. hsp70 expression was highest in fresh water, indicating higher stress, and lower at brackish (ambient condition for the sampled population) and oceanic salinities, suggestive of low stress response to salinities above the population’s current distribution. The highest stress in fresh water was surprising since populations in fresh water exist, e.g. large European rivers and Laurentian Great Lakes. The results have implications to predictions for the species’ plasticity potential and possible range expansion of the species into other salinity regimes.

Sosnowsky's hogweed (Heracleum sosnowskyi Manden.), an important invasive species in Eastern Europe, is a monocarpic perennial plant that propagates exclusively by seeds. Hence, interfering with seed viability could help control its spread. In the present study, we investigated the effect of exogenous GA(3) (25, 100 and 150 mg/L) sprayed twice onto flowering H. sosnowskyi plants on the development of fruits (mericarps) and their ability to germinate under field conditions over the growing seasons of 2018 and 2019. Mericarps from plants sprayed with GA(3) failed to develop normally. The width/length ratio of mericarps decreased by 23% to 25% after 150 mg/L GA(3) application and their average weight decreased between 7% and 39% under all GA(3) treatments. X-ray radiographs revealed that the internal structure was malformed, with many of the mericarps lacking well-developed seeds. Proportionally fewer well-developed mericarps were produced by GA(3)-treated plants than water-sprayed control plants in 2018. Seed germination assessed outdoors in seeds buried in the ground was also severely reduced (from 58% to 99% after 150 mg/L GA(3) application). This indicates that exogenous GA(3) sprays result in incomplete seed development and a consequent decrease in viability and germination. As the highest GA(3) dose used resulted in significantly reduced propagation of Sosnowsky's hogweed through seeds in the field, GA(3) provides a promising approach to the control of the spread of this invasive weed species.

The Baltic Sea is undergoing changes due to climate change, including an increase in its temperature. This may in turn lead to changes in the traits of the species that inhabit it, including non-endemic, invasive species. Palaemon elegans is a species native to the Atlantic Ocean that has been present in the Baltic Sea since the beginning of this century. Abilities such as high thermal tolerance make it successful in colonising new ecosystems like the brackish waters of this sea. However, less is known about the behavioural traits’ adaptions to these changes. This study aims then to find out how climate change may affect the behaviour of this species. To do so, five behaviours expressed by this species were observed and analysed to see how temperature change, seabed composition and body size influence their expression. The behaviours analysed were aggressiveness, movement frequency, reaction to food stimulus, number of feeding interactions and shelter-seeking. Analyses were conducted using ten-minute videos with ten specimens of P. elegans placed in water tanks and interacting in ecosystems representations with elements typical of the seabed where this species lives, both vegetation and rocks. Student's t-tests in R were then performed to test the significance of possible differences between the behaviours studied and the three parameters that may influence their expression. The results obtained show that the increase in water temperature might indeed lead to an increase in the frequency of the five behaviours studied except in aggressiveness. On the other hand, it was found that the composition of the ecosystem does not have a significant influence overall, while body size has a major influence on feeding related behaviours. Therefore,knowing more about changes in the behavior of species susceptible to climate change can be helpful to understand how biodiversity and its distribution will vary in the not so distant and changing future and what consequences it may generate at the ecosystem level.

During winter insects face energetic stress driven by lack of food, and thermal stress due to sub-optimal and even lethal temperatures. To survive, most insects living in seasonal environments such as high latitudes, enter diapause, a deep resting stage characterized by a cessation of development, metabolic suppression and increased stress tolerance. The current study explores physiological adaptations related to diapause in three beetle species at high latitudes in Europe. From an ecological perspective, the comparison is interesting since one species (Leptinotarsa decemlineata) is an invasive pest that has recently expanded its range into northern Europe, where a retardation in range expansion is seen. By comparing its physiological toolkit to that of two closely related native beetles (Agelastica alniandChrysolina polita) with similar overwintering ecology and collected from similar latitude, we can study if harsh winters might be constraining further expansion. Our results suggest all species suppress metabolism during diapause and build large lipid stores before diapause, which then are used sparingly. In all species diapause is associated with temporal shifts in storage and membrane lipid profiles, mostly in accordance with the homeoviscous adaptation hypothesis, stating that low temperatures necessitate acclimation responses that increase fluidity of storage lipids, allowing their enzymatic hydrolysis, and ensure integral protein functions. Overall, the two native species had similar lipidomic profiles when compared to the invasive species, but all species showed specific shifts in their lipid profiles after entering diapause. Taken together, all three species show adaptations that improve energy saving and storage and membrane lipid fluidity during overwintering diapause. While the three species differed in the specific strategies used to increase lipid viscosity, the two native beetle species showed a more canalized lipidomic response, than the recent invader. Since close relatives with similar winter ecology can have different winter ecophysiology, extrapolations among species should be done with care. Still, range expansion of the recent invader into high latitude habitats might indeed be retarded by lack of physiological tools to manage especially thermal stress during winter, but conversely species adapted to long cold winters may face these stressors as a consequence of ongoing climate warming.

Kirjallisuustieteellinen tutkielma erittelee puutarhan käsitettä ja sen monimerkityksellistä suhdetta luonnon ja kulttuurin väliseen dikotomiaan. Puutarha voidaan nähdä luonnon ja kulttuurin välisenä kohtaamispaikkana ja yhteensovittajana, sekä metaforisella tasolla että käytännössä. Tutkielman lähtökohtana ja pääaineistona on laguna pueblo intiaanikirjailija Leslie Marmon Silkon teos Gardens in the Dunes (1999), jossa puutarhat ovat keskeisessä roolissa myös luonto/kulttuuri-dikotomian neuvottelemisessa. Romaanin päähenkilöiden suhteet omiin puutarhoihinsa kuvastavat sekä heidän luontosuhdettaan että ajatusmaailmaansa laajemmallakin tasolla. Nämä puolestaan näkyvät siinä, minkälaisin keinoin henkilöhahmot viljelevät ja hoitavat maata, sekä puutarhojen erilaisissa sosiaalisissa ja kasvatuksellisissa merkityksissä. Silkon teos sijoittuu pitkälti 1890-luvun Yhdysvaltojen läntisille alueille, muun muassa Sonoran aavikolle Kalifornian ja Arizonan osavaltioiden rajalla. Tämä on kulttuurihistoriallisesti ja maantieteellisesti kriittinen ajanjakso myös alkuperäiskansojen näkökulmasta, sillä virallisesti katsottiin "rajaseudun" (engl. Frontier) pysähtyneen vuoteen 1890 - samalla intiaaniheimot pakotettiin reservaatteihin, sisäoppilaitoksiin, tai pakkotöihin, ja yleisesti miellettiin intiaanien ns. perinteisen kulttuurihistorian myös käytännössä "pysähtyneen" tähän ajanjaksoon. Teoksessaan Silko kuitenkin kulkee rajaseudun jälkiä taaksepäin, vieden kirjan päähenkilöitä pitkälle matkalle kohti Yhdysvaltain itärannikkoa, aina Englantiin ja Italiaan asti. Kulttuurinen ja poliittinen ajankuva näkyy vahvasti myös matkan aikana kohdatuissa puutarhoissa. Tutkielma nostaa esille myös muutamia ekokritisismissä vakiintuneita käsitteitä kuten erämaa, pastoraali ja "ekologinen Intiaani" (engl. wilderness, pastoral ja "ecological Indian"). Nämä käsitteet ovat saaneet paljon huomiota niin kirjallisuus- kuin kulttuuritutkimuksessa yleensäkin, ja ne sisältävät vaikutusvaltaisia metaforia ja mielikuvia, jotka puolestaan näkyvät eri kulttuurien luontokäsitysten muodostamisessa. Tutkielma vertaa puutarhan käsitettä myös erämaan ja pastoraalin keskisiin piirteisiin, sekä puutarhan mahdollisuuksia paljastaa uusia, merkityksellisiä näkemyksiä ihmisen ja (ei-inhimillisen) luonnon väliseen suhteeseen. Tutkielman teoreettiinen aineisto koostuu useasta eri ekokriittisestä lähteestä. Kirjallisuusteorian osalta keskeiseen aineistoon kuuluvut muun muassa Laura Coltellin (toim.) Reading Leslie Marmon Silko: Critical Perspectives Through Gardens in the Dunes (2007); Mary Ellen Snodgrassin Leslie Marmon Silko: A Literary Companion (2011) Cheryl Glotfelteyin ja Harold Frommin (toim.) The Ecocriticism Reader: Landmarks in Literary Ecology (1996); Laurence Buellin The Environmental Imagination: Thoreau, Nature Writing and the Formation of American Culture (1995); Greg Garrardin Ecocriticism (2004); sekä Nancy Easterlinin A Biocultural Approach to Literary Theory and Interpretation (2012). Kirjallisuustieteen ulkopuolelta tulevaa aineistoa ovat muun muassa Mara Millerin taidefilosifinen tutkielma The Garden as an Art (1993), ja Ken Thompsonin Where Do Camels Belong? The Story and Science of Invasive Species (2015).