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Natural selection on floral scent composition is a key element of the hypothesis that pollinators and other floral visitors drive scent evolution. The measure of such selection is complicated by the high-dimensional nature of floral scent data and uncertainty about the cognitive processes involved in scent-mediated communication. We use dimension reduction through reduced-rank regression to jointly estimate a scent composite trait under selection and the strength of selection acting on this trait. To assess and compare variation in selection on scent across species, time and space, we reanalyse 22 datasets on six species from four previous studies. The results agreed qualitatively with previous analyses in terms of identifying populations and scent compounds subject to stronger selection but also allowed us to evaluate and compare the strength of selection on scent across studies. Doing so revealed that selection on floral scent was highly variable, and overall about as common and as strong as selection on other phenotypic traits involved in pollinator attraction or pollen transfer. These results are consistent with an important role of floral scent in pollinator attraction. Our approach should be useful for further studies of plant-animal communication and for studies of selection on other high-dimensional phenotypes. In particular, our approach will be useful for studies of pollinator-mediated selection on complex scent blends comprising many volatiles, and when no prior information on the physiological responses of pollinators to scent compounds is available.

Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change., Measurement(s) earthworm communities • Abundance • organic material • Diversity • environmental properties Technology Type(s) digital curation Factor Type(s) location Sample Characteristic - Organism Lumbricina Sample Characteristic - Environment soil Sample Characteristic - Location global Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.13399118

International audience; Climate-smart forestry (CSF) is an emerging branch of sustainable adaptive forest management aimed at enhancing the potential of forests to adapt to and mitigate climate change. It relies on much higher data requirements than traditional forestry. These data requirements can be met by new devices that support continuous, in situ monitoring of forest conditions in real time. We propose a comprehensive network of sensors, i.e., a wireless sensor network (WSN), that can be part of a worldwide network of interconnected uniquely addressable objects, an Internet of Things (IoT), which can make data available in near real time to multiple stakeholders, including scientists, foresters, and forest managers, and may partially motivate citizens to participate in big data collection. The use of in situ sources of monitoring data as ground-truthed training data for remotely sensed data can boost forest monitoring by increasing the spatial and temporal scales of the monitoring, leading to a better understanding of forest processes and potential threats. Here, some of the key developments and applications of these sensors are outlined, together with guidelines for data management. Examples are given of their deployment to detect early warning signals (EWS) of ecosystem regime shifts in terms of forest productivity, health, and biodiversity. Analysis of the strategic use of these tools highlights the opportunities for engaging citizens and forest managers in this new generation of forest monitoring.

International audience; Although sunlight is essential for plant growth and development, the relative importance of each spectral region in shaping functional traits is poorly understood, particularly in dynamic light environments such as forest ecosystems.We examined responses of 25 functional traits from groups of 11 shade-intolerant and 12 understorey shade-tolerant forb species grown outdoors under five filter treatments differing in spectral transmittance: (a) transmitting c. 95% of solar radiation (280-800 nm); (b) attenuating ultraviolet-B (UV-B); (c) attenuating all UV; (d) attenuating all UV and blue light; (e) attenuating all UV, blue and green light.Our results show that UV-B radiation mainly affected the biochemical traits but blue light mainly affected the physiological traits irrespective of functional strategy, whereas green light affected both sets of traits. This would suggest that differentiation among suites of functional trait responses proceeds according to light quality. Biomass accumulation was significantly increased by UV-A radiation (contrasting treatment [b] vs. [c]) among shade-intolerant but decreased by blue light among shade-tolerant species; green and red light affected whole-plant morphological development differently according to functional groups. Shade-tolerant species were more plastic than shade-intolerant species in response to each spectral region that we examined except for UV-B radiation.Synthesis. Our results show that differences in the spectral composition of sunlight can drive functional trait expression irrespective of total irradiance received. The different responses of functional traits between functional groups imply that shade-tolerant and intolerant species have adapted to utilize spectral cues differently in their respective light environments.

Context: Place-based transdisciplinary research involves multiple academic disciplines and non-academic actors. Long-Term Socio-Ecological Research (LTSER) platform is one concept with ~ 80 initiatives globally. Objectives: As an exercise in learning through evaluation we audited (1) the siting, construction and maintenance of individual LTSER platforms, and (2) them as a distributed infrastructure for place-based transdisciplinary research with focus on the European continent. Methods: First, we defined a normative model for ideal performance at both platform and network levels. Second, four surveys were sent out to the 67 self-reported LTSER platforms officially listed at the end of 2016. Third, with a focus on the network level, we analyzed the spatial distribution of both long-term ecological monitoring sites within LTSER platforms, and LTSER platforms across the European continent. Fourth, narrative biographies of 18 platforms in different stages of development were analyzed. Results: While the siting ofLTSER platforms represented biogeographical regions well, variations in land use history and democratic governance were not well represented. Platform construction was based on 2.1 ecological monitoring sites, with 72% ecosystem and 28% social system research. Maintenance of a platform required three to five staff members, focused mostly on ecosystem research, was based mainly on national funding, and had 1–2 years of future funding secured. Networking with other landscape approach concepts was common. Conclusions: Individually, and as a network, LTSER platforms have good potential for transdisciplinary knowledge production and learning about sustainability challenges. To improve the range of variation of Pan-European social–ecological systems we encourage interfacing with other landscape approach concepts.

Publisher Copyright: © 2023 The Authors River lampreys (Lampetra fluviatilis) were caught in the fall 2014 on entering the River Perhonjoki for spawning and kept at a hatchery until spawning in late spring 2015 to produce larvae for compensatory stockings. Since the lampreys died massively from early February onwards, they were investigated in March and May to clarify the cause of the deaths. The symptoms in lampreys resembled those of lipid-related thiamine (vitamin B1) deficiency of salmonines, called the M74 syndrome in the Baltic Sea area. Because the lipid content of lampreys was known to be high, thiamine concentrations were analyzed in the liver and ovulated unfertilized eggs, and the mass, length, and whole-body lipid content were also measured. The hepatic total thiamine (TotTh) concentration was significantly negatively correlated with the body lipid content and fatness index (mass to length ratio) in both females and males. In females, the hepatic TotTh concentration was less than half that in males, and the most moribund lampreys were the largest and fattiest females. Females that survived until artificial stripping of the eggs were smaller, and their hepatic thiamine concentration was higher, and the fatness index lower, than in females in March. The concentration of free thiamine in the eggs had a stronger positive correlation with the hepatic TotTh concentration than the phosphorylated thiamine derivatives and was also significantly and negatively correlated with the fatness index and mass. It was concluded that increased lipid peroxidation due to the mobilization of polyunsaturated fatty acids from lipids in exogenous vitellogenesis consumed thiamine as an antioxidant during pre-spawning fasting—especially in the fattiest females—and thus caused their death. It is suggested that to ensure compensatory stockings, the largest lampreys could be thiamine-injected at the hatchery to improve their survival until stripping of the eggs and to improve the eggs’ thiamine status.

Warning This article contains terms, descriptions, and opinions used for historical context that may be culturally sensitive for some readers. Background Understanding drivers of boreal forest dynamics supports adaptation strategies in the context of climate change. Aims We aimed to understand how burn rates varied since the early 1700s in North American boreal forests. Methods We used 16 fire-history study sites distributed across such forests and investigated variation in burn rates for the historical period spanning 1700–1990. These were benchmarked against recent burn rates estimated for the modern period spanning 1980–2020 using various data sources. Key results Burn rates during the historical period for most sites showed a declining trend, particularly during the early to mid 1900s. Compared to the historical period, the modern period showed less variable and lower burn rates across sites. Mean burn rates during the modern period presented divergent trends among eastern versus northwestern sites, with increasing trends in mean burn rates in most northwestern North American sites. Conclusions The synchronicity of trends suggests that large spatial patterns of atmospheric conditions drove burn rates in addition to regional changes in land use like fire exclusion and suppression. Implications Low burn rates in eastern Canadian boreal forests may continue unless climate change overrides the capacity to suppress fire.

With rising temperatures and altered seasonality during climate change, most birds in the temperate zone advance their breeding and migration phenology, while simultaneously shifting their breeding ranges. Range shifts may have the potential to affect populations through various spatiotemporal responses, but could also affect gene flow among populations and indirectly affect or bias temporal responses, if not accounted for. These two aspects are central for assessing whether the observed responses compensate for the changes in the environment, or whether they lag behind. In the case of the latter, more extreme responses might be beneficial, such as facultative changes in life history by omitting autumn migration and staying at their breeding grounds, which in birds is often seen in the form of partial migration. Yet, the potential patterns for this remain unclear, and the underlying ecological drivers for such behavioural changes remain debated. If individuals are, for some reason, unable to obtain timely breeding onset, there might be other potential ways to save time, e.g., though reduced breeding preparations, however, associated with complex trade-offs. In chapter (I) I studied how breeding range shifts can bias our interpretation of migration dates on passage, a common response variable thought to approximate arrival at breeding latitudes. However, passage dates across a fixed point enroute on migration does not record where the birds are going. If the passing pool of birds successively head increasingly further north, where the onset of spring occur later, this might cause a temporal trend of delayed average passage dates. I found that passage dates trends were positively related to species-specific range shifts among short-distance migrants. In chapter (II) I explored how dispersal-mediated range shifts could affect wing lengths in a bird community of 45 bird species through dispersal of geographically varying phenotypes along an environmental gradient of 1100 km in Finland. The underlying thought is that unchanged phenotypes are displaced to new areas, where they affect the local average phenotype. I found that range shifts had a substantial average effect on the long-term local changes in wing lengths over half a century. A species' wings became more similar to southern conspecific populations. Hence, the direction of the change (i.e., wings becoming longer or shorter) is derived from the observed phenotype cline. The average level of this change varied with migration strategy and occurred at rates that correlated with range shift velocities. This mechanism could potentially affect a plethora of other heritable traits with geographic variation. I suggest it has the potential to comprise a third influential mechanism to how a population phenotypes may change with climate change, in addition to classic evolutionary and plastic processes, without ruling them out. In chapter (III), I studied the spatiotemporal migratory responses to annual temperature and long-term climate change in a partial migrant – the Eurasian sparrowhawk (Accipiter nisus) – focussing on the proportion of migrants and residents on the population level. I also tested and compared hypotheses on condition-dependent traits of resident individuals. Sparrowhawks became more migratory across the study period, opposite of the expectations with rising temperatures. Males were overrepresented among residents. As males of this species are roughly half the size of females, I suggest early arrival for territory is a key benefit from residency, as opposed to residency due to thermal superiority and dominance. Also, there were significant latitudinal patterns in the distribution of wintering individuals throughout a typical winter, suggesting smaller-scale migration patterns of residents to avoid the harshest conditions at higher latitudes. Last, in chapter (VI) I explored how reuse of nests might advance breeding onset and improve breeding success, by reducing the time and energy needed pre-breeding, potentially on the expense of increased predation risk. Studying the Eurasian Sparrowhawk, I found that reuse of nest increased the predation risk, but while nest reuse inevitably saves time, pairs reusing nests did not advance their laying beyond pairs building new nests . Breeding productivity and success declined with later laying, and this explained all confounding effect of nest reuse in non-predated nests, as reuse strategy entailed an overall delayed breeding schedule. Thus, nest reuse seems to be a “best of a bad job” opportunity for pairs who are delayed for any reason and may allow catching up lost time by reducing the pre-breeding preparations. My thesis illustrates two cases where range shifts may affect our interpretation of how fast species respond to climate change – a central topic in contemporary ecology. It provides an example of how a partial temporal trend of a true response may be confounded by co-occuring spatial responses. More substantially, I got support for the hypothesis that dispersal-mediated range shifts may be an influential mechanism for local phenotype change, which may complement or even question the relative role of adaptive mechanisms in shaping phenotypes during climate change. As such, this result may have wider implications for heritable traits with geographic variation, and I recommend a wider validation of this concept into contemporary ecology and evolution. My thesis also illustrates how extreme behavioural switches, such as skipping migration in partial migrants, may provide large shifts in the average life history of a population, where residency may be partly competition-driven. However, it remains unclear why the proportion of migrants may increase. This can potentially be explained by spatial responses currently unaccounted for. While early breeding directly affect productivity, pairs that are late, for whatever reason, may try to catch up lost time by reusing nests, but this also entailed a high increase in nest predation risk. Pairs reusing nests (non-predated attempts) showed a delayed laying which was related with lower success and output, putting a further emphasis on the importance of early breeding onset for this partial migrant . Lämpötilojen noustessa ilmastonmuutoksen myötä useimmat lauhkean vyöhykkeen linnut aikaistavat pesinnän- ja muuton ajoittumista samalla kun niiden levinneisyysalueet siirtyvät. Levinneisyysmuutokset saattavat vaikuttaa populaatioihin erilaisten spatiotemporaalisten vasteiden kautta, mutta se voi myös vaikuttaa vasteisiin geenivirran kautta tai vääristää havaittuja vasteita, ellei levinneisyysmuutoksia erikseen huomioida. Nämä kaksi näkökohtaa ovat keskeisiä arvioitaessa lintujen vasteiden riittävyyttä suhteessa ympäristön muutoksiin. Jos esimerkiksi fenologiset muutokset ovat liian hitaita, äärimmäisemmät vasteet elinkierrossa voivat olla hyödyllisiä, kuten osittaismuutto, jossa osa yksilöistä saattavat jäädä jää pesimäalueille talvehtimaan. Näiden käyttäytymismuutosten soveltuvuutta eri tilanteissa ja niiden taustalla olevista ekologisista syistä on kuitenkin edelleen paljon epäselvyyksiä. Jos yksilöt eivät pääse ajoissa aloittamaan pesintää voi olla muita tapoja säästää aikaa, esimerkiksi pesinnän valmisteluissa, mutta siitä voi olla myös haittaa. Luvussa (I) tarkastelin, kuinka levinneisyysalueiden muutokset voivat vääristää tulkintaamme lintujen muuton ajankohdasta ohimuuttavien lintujen tapauksessa. Ohimuttopäivä on yleinen vaste, kun tarkastellaan pesimäaikaista saapumista. Muuttoreitin varrella olevan kiinteän pisteen ohimuuton ajankohta ei kuitenkaan huomioi, minne linnut ovat menossa. Jos ohi muuttava lintujoukko suuntautuu yhä kauemmas pohjoiseen, missä kevät alkavat myöhemmin, tämä saattaa asteittain viivästyttää keskimääräisiä ohimuuttopäiviä. Havaitsin, että ohimuuton ajankohdan trendeillä oli positiivinen yhteys lajikohtaisiin levinneisyysmuutoksiin lyhyen matkan muuttajien keskuudessa. Luvussa (II) tutkin, kuinka levinneisyysalueiden muutokset, ja niihin liittyvä levittäytyminen, voivat vaikuttaa siipien pituuksiin 45 lajin lintuyhteisössä Suomessa, aineistossa, joka kattaa 1100 km maantieteellisen gradientin. Taustalla oleva ajatus on, että muuttumattomia fenotyyppejä omaavat yksilöt siirtyvät uusille alueille, joissa ne vaikuttavat paikalliseen fenotyypin keskiarvoon. Havaitsin, että levinneisyysmuutoksilla oli huomattava vaikutus lintujen siivenpituuden puolen vuosisadan ajallisiin trendeihin. Lajien siivet muuttuivat paikallisesti yhä samankaltaisimmaksi kuin kyseisen lajin eteläiset populaatiot. Muutoksen suunta (eli siipien pidentyminen tai lyhentyminen) riippui siis siitä, kummin päin havaittu maantieteellinen gradientti meni. Näiden lajikohtaisten muutosten keskimääräinen nopeus vaihteli muuttostrategian myötä ja korreloivat myös levinneisyysalueiden siirtymisnopeuksien kanssa. Kuvaamani prosessi voi mahdollisesti vaikuttaa lukuisiin muihin perinnöllisiin piirteisiin, joilla on maantieteellistä vaihtelua. Siinä tapauksessa, se muodostaa kolmannen mekanismin siihen, kuinka populaatioiden fenotyypit voivat muuttua ilmastonmuutoksen myötä, klassisten evoluution ja fenotyyppisen plastisuuden lisäksi, sulkematta niitä pois. Luvussa (III) tutkin osittaismuuttavan lajin – varpushaukan (Accipiter nisus) – spatiotemporaalisia vasteita vuotuiseen lämpötilaan ja pitkäaikaiseen ilmastonmuutokseen, keskittyen muuttajien ja paikallisten yksilöiden osuuteen populaatiotasolla. Testasin ja vertasin hypoteeseja siitä, miten yksilöiden tila vaikuttaa talvehtimiseen. Varpushaukoilla muuttavien osuus kasvoi tutkimusjakson myötä, toisin kuin mitä lämpötilan nousun perusteella odottaisi. Talvehtijoilla koiraat olivat yliedustettuina. Koska koiraat ovat suunnilleen puolet naaraiden koosta tällä lajilla, ehdotan, että reviirin varaaminen mahdollisimman varhain on keskeinen syy koiraan talvehtimiselle, toisin kuin kylmänkestävyys tai yksilöiden dominanssi. Myös talvehtivan osapopulaation jakaumassa leveysasteiden suhteen oli merkittäviä vaihteluja tyypillisen talven mittaan, mikä viittaa pienpiirteiseen muuttoliikehdintään myös talven aikana, välttääkseen ankarimpia olosuhteita korkeammilla leveysasteilla. Lopuksi luvussa (VI) tarkastelin, kuinka pesien uudelleenkäyttö voi aikaista pesinnän aloitusajankohtaa, ja parantaa pesimämenestystä vähentämällä pesinnän valmisteluihin kuluvaa aikaa ja energiaa. Havaitsin, että vaikka pesän uudelleenkäyttö väkisinkin säästää aikaa, pesiä uudelleen käyttävät parit eivät munineet uusia pesiä rakentavia pareja aikaisemmin. Pesinnän menestys heikkeni muninnan myöhemmän ajankohdan myötä, mikä selitti kaikki pesän uudelleenkäytön näennäiset vaikutukset saalistamattomissa pesissä, kun pesien uudelleenkäyttö yleisesti johti viivästyneeseen pesintään. Siten pesän uudelleenkäyttö näyttää olevan hätäratkaisu pareille, jotka ovat syystä tai toisesta myöhässä pesinnässä, ja mahdollistaa menetetyn ajan säästämisen pesinnän valmisteluista tinkimällä. Väitöskirjani havainnollistaa kahta tilannetta, joissa levinneisyysalueiden siirtymiset voivat vaikuttaa tulkintoihimme siitä, kuinka nopeasti lajit voivat reagoida ilmastonmuutokseen. Tämä on keskeinen aihe nykyekologiassa. Esitän esimerkin siitä, kuinka todellisen vasteen ajalliseen vaikutukseen voi vaikuttaa samanaikaisesti esiintyvät spatiaalinen vaste. Toisaalta sain myös tukea hypoteesille, että levinneisyysalueiden muutokset ja niihin liittyvä yksilötason liikehdintä, voivat vaikuttaa paikallisesti fenotyyppiseen muutokseen. Tämä voi täydentää tai jopa kyseenalaistaa adaptiivisten prosessien suhteellista roolia, kun tutkitaan ilmaston aiheuttamia muutoksia perinnöllisissä piirteissä, joilla on maantieteellinen gradientti. Suosittelen, tämän mekanismin laajempaa validointia ekologiassa ja evoluutiossa. Lisäksi opinnäytetyöni havainnollistaa, kuinka äärimmäiset käyttäytymismuutokset, kuten muuton jättäminen välistä osittaismuuttajilla, voivat aiheuttaa suuria muutoksia populaation keskimääräisessä vuosikierrossa, jossa talvehtiminen voi olla osittain lajin sisäisen kilpailun aiheuttama. On kuitenkin epäselvää, miksi muuttajien osuus saattaa kasvaa. Se saattaisi johtua huomiotta olevista alueellisista vasteista. Vaikka varhainen pesintä suoraan vaikuttaa pesimämenestykseen, pesinnässä viivästyneet parit saattavat pyrkiä kuromaan menetettyä aikaa kiinni käyttämällä vanhoja pesiä uudelleen, mutta tämä lisää myös riskiä, että pesä tulee saalistettua. Parit, jotka käyttivät pesiä uudelleen (ei-saalistetut pesintäyritykset), osoittivat muninnassa myöhäisemmän ajankohdan, mikä vuorossaan liittyi heikompaan pesimämenestykseen. Tämä korostaa entisestään tämän osittaismuuttajan varhaisen pesimisen alkamisen merkitystä.

In the Anthropocene, it is difficult to find natural systems that are not directly or indirectly affected by the actions of humans. Species with which we share our planet have to adapt to the changes humans introduce to survive. Human actions not only change abiotic components of the environment but also biotic components, such as the introduction or removal of species from habitats, resulting in altered ecosystem functioning. Even though we now understand the changes needed to curb the ill effects of human actions on natural environments, we are still progressively crossing thresholds set to protect the environment from anthropogenic effects. To prevent loss of biodiversity and maintain healthy ecosystems in the future, we need to do research where most of these disturbances are introduced acutely. In this thesis, I use birds as a study taxon to investigate how biodiversity is reacting to anthropogenic changes introduced on local and global scales. I consider two mechanisms of change operating at different scales, anthropogenic climate change and urbanisation. In chapters I and II, I investigate the effects of decreasing snow depth, due to anthropogenic climate change, on the abundances and range shifts of overwintering birds, respectively. I especially focus on the role of interactions between habitats and changing environmental variables in explaining the shuffling of overwintering bird communities. While shifts in the distributions of organisms and their abundances are well studied, in chapters III and IV, I focus on biotic interactions of organisms in the face of urbanisation and climate change, which are less explored. In particular, I consider ecosystems at a city level and explore the interactions of birds with native and alien plants in two very different cities facing similar problems: Helsinki, Finland and Bengaluru, India. Like many other cities of the world, Helsinki and Bangalore host several alien plant species, including, but not limited to, invasive species. Helsinki, at 60° N, faces the brunt of the consequences of a warming climate and the associated changes in weather. Here, frugivorous birds can act as vectors for alien plants to spread into novel habitats, amplified by change in phenologies brought on by warmer autumns. In Bengaluru, with rapid urbanization, avian pollinators in the city are quickly losing habitat and food resources. Here, alien plants could replace the native species that were historically present, allowing biodiversity to be maintained in the city. I show here how decreased snow depth due to the warming climate has resulted in an increase in the abundance of overwintering birds in Finland and how this also results in birds moving further poleward. More importantly, however, in chapters I and II, I find that birds are responding to climatic factors differently in different habitats, with the largest changes and shifts taking place on farmlands. Additionally, while a majority of the literature on the effects of warming climates focuses on the effects of temperature, here I show that snow cover could be playing an equally, if not more, important role in shaping winter bird communities. In chapter III, in Helsinki, I found that more birds are feeding on native fruit, which are more abundant in streetscapes despite there being more species of alien plants in the same habitats. However, there is no difference between native and alien species in the number of seeds dispersed. Finally, in chapter IV, I show that the alien trees in Bengaluru are an important resource for fauna in the city and they are unlikely to spread outside the city due to pollination by birds, as avian pollinators were more likely to engage in nectar theft from alien trees. The results of chapter III and IV show that alien species can provide resources to urban fauna with varying levels concerning the risk of dispersal. However, the species that have been seen to escape in small numbers need special attention from future research. The results of my thesis highlight the importance of studying the interactive effect of land use and climate change on global and local scales to aid in finding solutions that ensure we maintain healthy ecosystems in the future. Antroposeenikaudella ihmistoiminnan vaikutukset ulottuvat lähes kaikkiin ekosysteemeihin, ja lajien täytyy sopeutua ihmisten aiheuttamiin muutoksiin selviytyäkseen. Torjuaksemme nopeasti etenevää luonnon monimuotoisuuden katoamista ja ylläpitääksemme terveitä ekosysteemejä, tutkimusta on kohdistettava osa-alueisiin, joihin toimintamme seuraukset kohdistuvat akuuteimmin. Väitöskirjassani tutkin kuinka biodiversiteetti reagoi ihmisen aiheuttamiin muutoksiin globaalilla ja paikallisella tasolla käyttäen lintuja tutkimuskohteena. Keskityn kahteen mekanismiin, jotka toimivat eri tasoilla: ihmisen aiheuttamaan ilmastonmuutokseen ja urbanisaatioon. Kappaleissa I ja II tutkin ihmisen aiheuttaman ilmastonmuutoksen myötä vähenevän lumensyvyyden vaikutuksia talvehtivien lintujen runsauteen ja levinneisyyden muutoksiin. Keskityn habitaattien ja muuttuvien ympäristötekijöiden vuorovaikutuksiin talvehtivien lintuyhteisöjen muutoksia selittävänä tekijänä. Kappaleissa III ja IV paneudun harvemmin tutkittuihin elollisten organismien välisiin vuorovaikutuksiin urbanisaation ja ilmastonmuutoksen aiheuttamien paineiden alaisuudessa. Keskityn erityisesti kaupunkeihin ekosysteemeinä ja tutkin lintujen vuorovaikutuksia paikallisten ja vierasperäisten kasvilajien välillä Helsingissä (Suomi) ja Bengalurussa (Intia). Molemmissa kaupungeissa kasvaa useita vierasperäisiä kasvilajeja, joista osa on haitallisia vieraslajeja. 60° N sijaitseva Helsinki kohtaa lämpenevän ilmaston aiheuttamia muutoksia; kaupungissa hedelmiä syövät linnut voivat auttaa vieraslajeja leviämään uusiin elinympäristöihin lämpenevien syksyjen tehostamina. Bengalurussa vauhdikas urbanisaatio puolestaan vähentää pölyttävien lintujen elinympäristöjä ja ruokaresursseja; täällä vieraslajit saattavat korvata paikalliset lajit mahdollistaen monimuotoisuuden säilymisen kaupungissa. Osoitan väitöskirjassani, kuinka ilmastonmuutoksen myötä vähentynyt lumensyvyys on kasvattanut talvehtivien lintujen määrää Suomessa ja lisännyt lintujen pohjoisempaa levinneisyyttä. Ennen kaikkea osoitan kappaleissa I ja II muuttuvien ilmastotekijöiden vaikutuksen lintuihin olevan elinympäristöstä riippuvaa: suurimmat muutokset runsaudessa ja levinneisyydessä tapahtuvat viljelysmailla. Löydän myös todisteita lumipeitteen merkittävästä vaikutuksesta talvehtivien lintujen yhteisöihin lämpötilan vaikutusten ohella. Kappaleessa III esitän useampien lintujen käyttävän paikallisten lajien hedelmiä ravintonaan suhteessa vieraslajien hedelmiin Helsingissä. Kaupunkialueella esiintyy paikallisia hedelmiä enemmän, mutta vieraslajien lajirikkaus on runsaampaa. Huolimatta eroista ruokailussa, levitettyjen siementen määrissä ei näy eroja paikallisten lajien ja vieraslajien välillä. Kappaleessa IV esitän vierasperäisten puulajien toimivan tärkeänä resurssina paikallisille lajeilla Bengalurussa. Lajien riski levitä lintujen pölytyksen myötä kaupungin ulkopuolelle on pieni, sillä pölyttävät linnut varastavat mettä todennäköisemmin vierasperäisten lajien kukista. Yhdessä kappaleiden III ja IV tulokset osoittavat vieraslajien voivan tarjota resursseja eläinlajeille urbaaneissa ympäristöissä lajien levinneisyyden uhan vaihdellessa. Pienissäkin määrin leviämään onnistuneisiin vieraslajeihin on syytä perehtyä tulevissa tutkimuksissa. Väitöskirjani tulokset korostavat maankäytön ja ilmastonmuutoksen vuorovaikutusten tutkimuksen tärkeyttä eri mittakaavoissa, jotta voimme löytää ratkaisuja terveiden ekosysteemien säilyttämiseen tulevaisuudessa.

1. Climate change is expected to increase wildfire activity in boreal ecosystems, thus threatening the carbon stocks of these forests, which are currently the largest terrestrial carbon sink in the world. Describing the ecological processes involved in fire regimes in terms of frequency, size, type (surface vs. crown) and severity (biomass burned) would allow better anticipation of the impact of climate change on these forests. In Fennoscandia, this objective is currently difficult to achieve due to the lack of knowledge of long-term (centuries to millennia) relationships between climate, fire and vegetation.2. We investigated the causes and consequences of changes in fire regimes during the Holocene (last similar to 11,000 years) on vegetation trajectories in the boreal forest of northern Finland. We reconstructed fire histories from sedimentary charcoal at three sites, as well as vegetation dynamics from pollen, moisture changes from Sphagnum spore abundance at two sites, and complemented these analyses with published regional chironomid-inferred July temperature reconstructions.3. Low-frequency, large fires were recorded during the warm and dry mid-Holocene period (8500-4500 cal. year BP), whereas high-frequency, small fires were more characteristic of the cool and wet Neoglacial period (4500 cal. year BP onward). A higher proportion of charcoal particles with a woody aspect-characterizing crown fires-was recorded at one of the two sites at times of significant climatic and vegetational changes, when the abundance of Picea abies was higher.4. Synthesis. Our results show both a direct and an indirect effect of climate on fire regimes in northern Fennoscandia. Warm and dry periods are conducive to large surface fires, whereas cool and moist periods are associated with small fires, either crown or surface. Climate-induced shifts in forest composition also affect fire regimes. Climatic instability can alter vegetation composition and structure and lead to fuel accumulation favouring stand-replacing crown fires. Considering the ongoing climate warming and the projected increase in extreme climatic events, Fennoscandian forests could experience a return to a regime of large surface fires, but stand-replacing crown fires will likely remain a key ecosystem process in areas affected by climatic and/or vegetational instability.

While the science supporting fisheriesmanagement has generally been dominated by the natural sciences, there has been a growing recognition that managing fisheries essentially means managing economic systems. Indeed, over the past seven decades, economic ideas and insights have increasingly come to play a role in fisheries management and policy. As an illustration of this, the International Council for the Exploration of the Sea (ICES) has been actively seeking to expand the scope of its scientific expertise beyond natural sciences [another inter-governmental marine science organization which has done this over the same period is the North Pacific Marine Science organization (PICES)]. In particular, the recently created ICES Working Group on Economics set out to review current work and key future needs relating to economic research and management advice on marine capture fisheries. This article presents the results of this review and addresses how economic research can be incorporated into the science of ICES to provide integrated perspectives on fisheries systems that can contribute to the provision of advice in support of policy development and management decision-making for sustainable uses of living marine resources., We would like to thank the ICES secretariat for its support in organizing face-to-face and online meetings of the ECON working group and in developing the online survey of fisheries economists.We also express our gratitude to the three reviewers for their thoughtful suggestions, which helped us improve the manuscript.

AimThe Saimaa ringed seal (Pusa hispida saimensis) is endemic to Lake Saimaa in Finland. The subspecies is thought to have originated when parts of the ringed seal population of the Baltic region were trapped in lakes emerging due to post-glacial bedrock rebound around 9,000 years ago. During the 20th century, the population experienced a drastic human-induced bottleneck. Today encompassing a little over 400 seals with extremely low genetic diversity, it is classified as endangered. Our main aim was to evaluate the role of the 20th century bottleneck in the erosion of genetic diversity in the Saimaa seal population. We also evaluated connections with other ringed seals from the Baltic Sea, Lake Ladoga, North America, Svalbard and the White Sea.LocationLake Saimaa, Finland, together with the Baltic Sea and the Arctic Ocean.MethodsWe sequenced sections of the mitochondrial control region from 60 up to 125 years old museum specimens of the Saimaa ringed seal. The generated dataset was combined with publicly available sequences. We studied how genetic variation has changed through time in this subspecies, and how it is phylogenetically related to other ringed seal populations.ResultsWe observed temporal fluctuations in haplotype frequencies and loss of haplotypes accompanied by a recent reduction in female effective population size. In apparent contrast with the traditionally held view of the Baltic origin of the population, the Saimaa ringed seal mtDNA variation shows also affinities to North American ringed seals.Main conclusionsOur results suggest that the Saimaa ringed seal has experienced recent genetic drift associated with small population size. The results further suggest that extant Baltic ringed seals do not represent well the ancestral population of the Saimaa ringed seal, which calls for re-evaluation of the deep history of this subspecies.

Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) Fundacao de Apoio a Pesquisa do Distrito Federal (FAPDF), Fundacao de Amparo a Pesquisa do Estado do Amazonas (FAPEAM), BIODIVERSA/FAPEAM, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ), Bundesministerium fuer Bildung und Forschung, Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), FAPEAM-Program POSGRAD, Fundacao de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG), INPA/MCTI 465540/2014-7, Leibniz Competition 0621187/2017, Leibniz-Gemeinschaft R20F0002, Instituto Nacional de Pesquisas da Amazpnia, unidade de~pesquisa Ministerio da Ciencia, Tecnologia e Inovacoes (INPA/MCTI) 403758/2021-1, Programa Peixe Vivo of the Companhia Energetica de Minas Gerais 033W034A, Royal Society of New Zealand, Tertiary Education Commission, Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Foundation for Science and Technology, Associate LaboratoryARNET J45/2018, CEEC

1. Understanding species habitat use and factors affecting changes in their distribu-tions are necessary to promote the conservation of any biological community. We evaluated the changes in wetland use of the non- breeding waterbird community. Based on long-term citizen-science data (1988–2020), we tested the hypotheses that wetland use is associated with species diet and potential range-shift drivers (the tendency to occupy the same sites in consecutive years—site affinity—and the species' average temperature across its wintering range—species temperature index).2. We analysed species-specific wetland use of 25 species of waterbirds wintering in Czechia over a period of 33 years. The analyses explained variability in trends in numbers of the studied waterbird species across four inland wetland types: reser-voirs; fishponds; industrial waters created by flooding of former mining sites; and running waters.3. Trends in waterbird abundance positively correlated with species’ diet on fish-ponds, industrial and running waters. Among the diet groups, invertivores showed the largest increase in abundances on industrial waters, closely followed by her-bivores. Herbivores showed the largest increase in abundances in fishponds, and piscivores did so in running waters. Regarding range-shift drivers, species with higher site affinity showed higher abundances on running waters, while species with low species temperature index (i.e. wintering on average in sites with lower temperature) were more abundant on reservoirs. The abundance of both warm- dwelling and species with low site affinity increased on fishponds and industrial waters.4. Our findings suggest that the increased importance of the wetland types consid-ered here for wintering waterbirds is likely to be linked to diet related changes in habitat use and changes in species distributions; and highlight that wintering waterbirds are expected to select sites with higher availability of food, higher en-ergy content, and lower foraging cost.5. Recent and rapid changes in species distributions may lead to a decrease in the effectiveness of national and international conservation efforts. When planning conservation measures, it should be kept in mind that climate change does not only imply large-scale north/north- eastwards shifts of entire waterbird distribu-tions, but can also modify the use of the habitats by waterbird species inside their traditional wintering range. artificial wetlands, long-term monitoring, range-shift drivers, waterbirds, wetland type

Publisher Copyright: © 2023 Elsevier GmbH The Neotropical region is undergoing high levels of urban expansion and harbors the greatest diversity of vascular epiphytes globally. In cities, it could be expected that the density of woody vegetation positively predicts epiphyte communities by providing substrate, resources for pollinators, and buffering microclimatic conditions. However, there is a dearth of knowledge regarding how urbanization intensity affects the diversity of vascular epiphytes. In this study, we assessed the relationship between a woody cover gradient and bromeliad species richness and community composition across a streetscape of the Neotropical city of Xalapa (Mexico). We recorded bromeliads in nine street segments and one peri-urban green space. These sites represent a gradient of woody cover ranging from 10.5% to ∼87% in a 100 m buffer, and 100% in the peri-urban green space. We recorded 824 individuals of 14 species (all from the Tillandsioideae subfamily). The most abundant species was Tillandsia recurvata and the most frequent ones were T. juncea and T. schiedeana. Results show that bromeliad species richness was positively related to the woody cover, as expected. Interestingly, community composition did not associate with the percentage of woody cover. These results suggest that additional factors such as microclimatic conditions and seed availability and/or dispersal may be key modulators on the establishment of bromeliad species. Nevertheless, wooded streets do show potential for harboring diverse bromeliad communities.

Changing environmental conditions are influencing the seasonal timing in life history events of organisms. Such shifts in phenology are often linked to increasing temperatures that stimulate faster developments or earlier arrivals. This phenomenon has been demonstrated in terrestrial and aquatic realms, but data and knowledge are limited on how early life stages of fish are affected over long-term and broad environmental scales. Here, we analyze 2 decades (1974-1996) of size class-specific Baltic herring Clupea harengus membras L. larval data along the whole coast of Finland to expose shifts in phenology linked to changes in environmental covariates. We use a novel Bayesian hierarchical spatio-temporal hurdle model that describes larval occurrence and abundance with separate processes. Abundances are modeled with the Ricker population growth model that enables us to predict size-specific larvae groups in relation to the environment while accounting for population density dependence. We quantify shifts in phenology at multiple life stages, based on first appearances of smallest larvae (15 mm) appearing earlier than they have done historically. Our results show a strong signal in shifting phenology of the larvae toward an earlier development of 7.7 d per decade. Increasing temperature had a positive effect on the earlier development of larger larvae. Additionally, we highlight that the survival of larvae becomes more density dependent as their size increases. Our modeling framework can reveal phenological shifts of early life stages in relation to environmental change for survey data that do not necessarily cover the onset of reproduction.

Publisher Copyright: © 2021 Shanghai Ocean University A value chain analysis is a detailed description of all the activities and services needed to turn a raw product into a marketable good for delivery to final consumers. The mud crab business is considered by most marketing operators to be a profitable and viable business due to the high demand in the international market. Despite the importance of mud crab fishery, there is no structured marketing facilities in Bangladesh. This research aim to analyze the socioeconomic condition of actors, the profitability of farming, mapping the institutional and non-institutional barriers, and provide a better understanding of the possibility of technological interventions in the value chain. Qualitative and quantitative data were collected through participatory rural appraisal tools that include 200 individual interviews, 16 focus group discussions, and 24 key informant interviews conducted in south-west Bangladesh from July to December of 2019. The mud crab value chain analysis revealed that the chain started with crab collection (cultivated and wild harvest), before sale to local vendors, and ended with exporters through several intermediaries. Results noted that most (±95%) exportable crab came from natural sources, with rest (±5%) from aquaculture sector. The average price (USD/kg) ranged from $10.59−14.12 and $12.94−19.42 for male crabs (grade: XXL), followed by $10.00−11.77 and $11.77−17.06 for female (grade: FF1) in domestic and international markets, respectively. Despite the high profitability of these sectors, the livelihood of these stakeholders has remained relatively hard. Multi-pronged approaches, like a nursery or increasing farming and backyard seed production, and possible value addition at the farm level may help farmers.

Barking deer is found in dense tropical and subtropical forests of Asia. It is listed as “least concerned” by the International Union of Conservation of Nature and as “vulnerable” in Nepal, where it is also protected. Due to the habitat loss and fragmentation by human activities, barking deer abundance is decreasing, which may even ultimately lead to its extinction. This in turn might negatively affect local ecosystem such as the abundance of the endangered common leopard, for which barking deer is the main prey species in the mid-hills of Nepal. We therefore need to know factors affecting barking deer abundance and its habitat preferences. To determine these factors, we recorded barking deer either by direct sighting or by any evidence of its indirect presence observed through transect surveys in January and February, 2019. To analyze habitat preference, the presence of barking deer was set to 1 if the barking deer or any sign of its presence were observed “used plots,” or to 0 if the barking deer or any sign of its presence were not observed (“habitat availability plot”). We measured main four ecological drivers such as forest management regime, microclimate, disturbance and food resources, which include 11 habitat characteristics in spots where barking deer was present, and in randomly selected spots. We found that elevation, slope, distance from settlement, presence of tree species, depth of leaf litter and percentage cover of leaf litter were most significantly affecting its presence. These results can serve as guidelines for local authorities to prevent decline in abundance of barking deer.

International audience; The tree seed mycobiome has received little attention despite its potential role in forest regeneration and health. The aim of the present study was to analyze the processes shaping the composition of seed fungal communities in natural forests as seeds transition from the mother plant to the ground for establishment.We used metabarcoding approaches and confocal microscopy to analyze the fungal communities of seeds collected in the canopy and on the ground in four natural populations of sessile oak (Quercus petraea). Ecological processes shaping the seed mycobiome were inferred using joint species distribution models.Fungi were present in seed internal tissues, including the embryo. The seed mycobiome differed among oak populations and trees within the same population. Its composition was largely influenced by the mother, with weak significant environmental influences. The models also revealed several probable interactions among fungal pathogens and mycoparasites.Our results demonstrate that maternal effects, environmental filtering and biotic interactions all shape the seed mycobiome of sessile oak. They provide a starting point for future research aimed at understanding how maternal genes and environments interact to control the vertical transmission of fungal species that could then influence seed dispersal and germination, and seedling recruitment.

Conservation translocation is a common method for species recovery, for which one increasingly frequent objective is restoring lost ecological functions to promote ecosystem recovery. However, few conservation translocation programs explicitly state or monitor function as an objective, limiting the ability to test assumptions, learn from past efforts, and improve management. We evaluated whether translocations of hihi (Notiomystis cincta), a threatened New Zealand passerine, achieved their implicit objective of restoring lost pollination function. Through a pollinator-exclusion experiment, we quantified, with log response ratios (lnR), the effects of birds on fruit set and seed quality in hangehange (Geniostoma ligustrifolium), a native flowering shrub. We isolated the contributions of hihi by making comparisons across sites with and without hihi. Birds improved fruit set more at sites without hihi (lnR = 1.27) than sites with hihi (lnR = 0.50), suggesting other avian pollinators compensated for and even exceeded hihi contributions to fruit set. Although birds improved seed germination only at hihi sites (lnR = 0.22-0.41), plants at sites without hihi had germination rates similar to hihi sites because they produced 26% more filled seeds, regardless of pollination condition. Therefore, although our results showed hihi improved seed quality, they also highlighted the complexity of ecological functions. When an important species is lost, ecosystems may be able to achieve similar function through different means. Our results underscore the importance of stating and monitoring the ecological benefits of conservation translocations when functional restoration is a motivation to ensure these programs are achieving their objectives.Evaluación del Éxito de la Restauración Funcional Posterior a la Reintroducción de un Ave Polinizadora Desaparecida Resumen La reubicación para la conservación es un método común para la recuperación de especies en el cual un objetivo cada vez más frecuente es la restauración de las funciones ecológicas que se perdieron para promover la recuperación del ecosistema. Sin embargo, pocos programas de reubicación para la conservación establecen o monitorean explícitamente a la función como un objetivo, lo que limita la posibilidad de comprobar suposiciones, aprender de esfuerzos anteriores y mejorar la gestión. Analizamos si las reubicaciones de hihi (Notiomystis cincta), un ave paseriforme amenazada de Nueva Zelanda, lograron el objetivo implícito de restaurar la desaparecida función de polinización. Mediante un experimento de exclusión del polinizador, cuantificamos con relaciones de respuesta logarítmica (lnR) los efectos de las aves sobre el conjunto de frutos y la calidad de la semilla del arbusto floral nativo Geniostoma ligustrifolium. Aislamos las contribuciones del hihi cuando comparamos entre sitios con y sin su presencia. Las aves favorecieron más al conjunto de frutos en sitios sin hihi (lnR = 1.27) que en los sitios con hihi (lnR = 0.50), lo que sugiere que otras aves polinizadoras compensaron y excedieron las contribuciones del hihi al conjunto de frutos. Aunque las aves aumentaron la germinación de semillas sólo en sitios con hihi (lnR = 0.22-0.41), las plantas en los sitios sin hihi tuvieron tasas de germinación similares a los sitios con hihi porque produjeron 26% más de semillas completas sin importar la condición de la polinización. Por lo tanto, aunque nuestros resultados mostraron mejoras en la calidad de la semilla a causa del hihi, también resaltaron la complejidad de las funciones ecológicas. Cuando desaparece una especie importante, puede que los ecosistemas logren una función similar por medio de diferentes métodos. Nuestros resultados hacen hincapié en la importancia que tiene establecer y monitorear los beneficios ecológicos de las reubicaciones para la conservación cuando la restauración es motivo para asegurar que estos programas están logrando sus objetivos.

1. Many populations need to adapt to changing environmental conditions, such as warming climate. Changing conditions generate directional selection for traits critical for fitness. For evolutionary responses to occur, these traits need to be heritable. However, changes in environmental conditions can alter the amount of heritable variation a population expresses, making predictions about expected responses difficult. 2. The aim of this study was to evaluate the effects of ambient temperatures on evolutionary potential and strength of natural selection on the timing of reproduction in two passerine birds breeding in boreal forests. 3. Long‐term data on individually marked Willow Tits Poecile montanus (1975–2018) and Great Tits Parus major (1969–2018) were analysed with random regression animal models to assess if spring temperatures affect the expressed amount of additive genetic variation (VA) and heritability (h²) in the timing of breeding. We assessed if ambient temperatures of different seasons influenced the direction and strength of selection on breeding time. We also evaluated if the strength of selection covaried with evolutionary potential. 4. Levels of VA or h² expressed in laying date were unaffected by spring temperatures in both study species. Selection for earlier breeding was found in the Willow Tit, but not in the Great Tit. In the Willow Tit, selection for earlier breeding was more intense when the temperatures of following autumns and winters were low. Different measures of evolutionary potential did not covary strongly with the strength of selection in either species. 5. We conclude that there is no or little evidence that climate warming would either constrain or promote evolutionary potential in timing of breeding through changes in amount of genetic variance expressed in boreal Willow and Great Tits. However, selection on the timing of breeding, a life‐history event taking place in springtime, is regulated by temperatures of autumns and winters. Rapid warming of these periods have thus potential to reduce the rate of expected evolutionary response in reproductive timing.

Climate warming is rapidly reshaping the Arctic cryosphere and ocean conditions, with consequences for sea ice and pelagic productivity patterns affecting the entire marine food web. To predict how ongoing changes will impact Arctic marine ecosystems, concerted effort from various disciplines is required. Here, we contribute multi‐decadal reconstructions of changes in diatom production and sea‐ice conditions in relation to Holocene climate and ocean conditions off northwest Greenland. Our multiproxy study includes diatoms, sea‐ice biomarkers (IP25 and HBI III) and geochemical tracers (TOC [total organic carbon], TOC:TN [total nitrogen], δ13C, δ15N) from a sediment core record spanning the last c. 9,000 years. Our results suggest that the balance between the outflow of polar water from the Arctic, and input of Atlantic water from the Irminger Current into the West Greenland Current is a key factor in controlling sea‐ice conditions, and both diatom phenology and production in northeastern Baffin Bay. Our proxy record notably shows that changes in sea‐surface conditions initially forced by Neoglacial cooling were dynamically amplified by the shift in the dominant phase of the Arctic Oscillation (AO) mode that occurred at c. 3,000 yr BP, and caused drastic changes in community composition and a decline in diatom production at the study site. In the future, with projected dominant‐positive AO conditions favored by Arctic warming, increased water column stratification may counteract the positive effect of a longer open‐water growth season and negatively impact diatom production., We present the first continuous and high‐resolution diatom record from northeastern Baffin Bay spanning the last c. 9,000 years. Our data show that the variability in sea ice and primary production on the northwest Greenland shelf is linked to modulations in millennial‐scale Arctic Oscillation. The phenology and diatom community structure is largely controlled by water‐column stratification and sea‐ice conditions.

Intensive forest management has drastically reduced the amount and diversity of dead wood resulting in population decline of saproxylic species. Forestry practices can also disrupt spatiotemporal continuity of dead wood habitats. We studied the effects of stand- and landscape-level densities of host trees on the incidence (proportion of occupied trees) of saproxylic beetles inhabiting recently dead standing Scots pines, a common host-tree type both in natural and managed boreal forests. We compared the occurrence patterns of eight rare specialist and eight common generalist species. Saproxylic beetles were collected from a total of 315 trees in 67 forest stands, including both managed and natural forests, located in three regions which form a gradient in forest-use intensity. Species richness of the entire community at tree and stand level did not respond to the stand- and landscape-level host-tree density. The incidence of six common generalist species did not depend on the stand-level host-tree density, whereas the incidences of four rare specialist species increased with increasing host-tree density. Five out of eight rare specialist species were either significantly less common or absent from the region with the lowest landscape-level density of host trees. We conclude that rare specialist species living in recently dead pines are susceptible to changes in spatiotemporal dynamics of their host trees. To conserve rare early-successional species, it is necessary to ensure continuous input of dying trees by prolonging rotation times in mature forests, regenerating stands using seed-tree cutting and leaving as many permanent retention trees as possible.

Bats utilize forests as roosting sites and feeding areas. However, it has not been documented how bats utilize these habitats in the boreal zone with methods afforded by recent technological advances. Forest structure and management practices can create a variety of three‐dimensional habitats for organisms capable of flight, such as bats. Here, we study the presence of boreal bats in a forest forming a mosaic of different age classes, dominant tree species, canopy cover, soil fertility, and other environmental variables, throughout their active season in the summer using passive ultrasound detectors. Our results indicate a preference for mature forest by Eptesicus nilssonii and a pooled set of Myotis bats. Both groups of bats also showed temporal changes in their habitat use regarding forest age. In June and July, both groups occurred more often in mature than young forests, but from August onwards, the difference in occurrence became less evident in Myotis and disappeared completely in E. nilssonii. In addition, E. nilssonii was more often present in forests with low canopy cover, and its occurrence shifted from coniferous forests to deciduous forests during the season. The results reflect the within‐season dynamics of bat communities and their ability to utilize different types of forest as environmental conditions change. Yet, the results most importantly emphasize the importance of mature forests to bat diversity and the need to conserve such environments in the boreal zone., Forests provide bats with food and shelter. Here, we investigate habitat selection in boreal bat species in forests. Although different bat species show variability in habitat selection, all bats appear to favor older forests.

The impacts of climate change on biodiversity can be modulated by other changing environmental conditions (e.g. induced by land‐use change). The potential interactive effects of climate change and land use have rarely been studied for soil organisms. To test the effects of changing climatic conditions and land use on soil invertebrates, we examined earthworm communities across different seasons in different grassland‐use types (intensively managed grassland, extensively managed meadow and extensively managed sheep pasture). We predicted that the strength of climate change effects would vary with season and land use. Overall, extracted earthworm populations showed the strongest variations in response to the season, indicating major differences in activity patterns and extraction efficiency, whereas climate change and different grassland‐use types had fewer and weaker effects. Future climate, characterized by slightly higher precipitation in spring and autumn but a strong reduction during the summer, had positive effects on the abundance of extracted adult earthworms in spring but then reduced the abundance of active earthworms across the remaining seasons. In contrast, the total biomass of juveniles tended to be consistently lower under future climate conditions. Earthworm species responded differently to the climate change and different grassland management types, and these species‐specific responses further varied strongly across seasons. Intensive grassland management had negative effects, due to plant community composition, whereas sheep grazing favoured earthworm populations, due to dung deposition. There were only limited interactive effects between climate and land use, which thus did not support our main hypothesis. Nevertheless, these results highlight the complex and context‐dependent responses of earthworm communities and activity patterns to climate change, with potential consequences for long‐term population dynamics and crucial ecosystem functions. HIGHLIGHTS: We explored earthworm communities in response to climate change, different grassland‐use types and seasons Climate had species‐specific effects on active earthworms, but few interactions with land‐use type Intensive grassland management decreased, but sheep grazing favoured, active earthworm populations Strong seasonal variations in earthworm activity periods will be modulated by climate change

AIM: To characterize the functional diversity and selected ecological functions of marine epibenthic invertebrate communities at the ecosystem scale and to evaluate the relative contributions of environmental filtering, including bottom‐contact fishing, and competitive interactions to benthic community assembly. LOCATION: Flemish Cap, an ecosystem production unit and fishing bank in the high seas of the north‐west Atlantic Ocean. METHODS: Through the use of Hierarchical Modelling of Species Communities (HMSC), we have explored seven community response traits to the environment applied to 105 epibenthic species and evaluated the influence of such traits on the community assembly processes. Assumed bioturbation, nutrient cycling and habitat provision functions, linked to individual or a combination of biological traits, were mapped using random forest modelling. RESULTS: Functional richness within benthic communities reached an asymptote for trawl sets with roughly more than 30 species. Assemblages on top of the Flemish Cap (

Estimates of regional and global freshwater N2O emissions have remained inaccurate due to scarce data and complexity of the multiple processes driving N2O fluxes the focus predominantly being on summer time measurements from emission hot spots, agricultural streams. Here, we present four‐season data of N2O concentrations in the water columns of randomly selected boreal lakes covering a large variation in latitude, lake type, area, depth, water chemistry, and land use cover. Nitrate was the key driver for N2O dynamics, explaining as much as 78% of the variation of the seasonal mean N2O concentrations across all lakes. Nitrate concentrations varied among seasons being highest in winter and lowest in summer. Of the surface water samples, 71% were oversaturated with N2O relative to the atmosphere. Largest oversaturation was measured in winter and lowest in summer stressing the importance to include full year N2O measurements in annual emission estimates. Including winter data resulted in fourfold annual N2O emission estimates compared to summer only measurements. Nutrient‐rich calcareous and large humic lakes had the highest annual N2O emissions. Our emission estimates for Finnish and boreal lakes are 0.6 and 29 Gg N2O‐N/year, respectively. The global warming potential of N2O from lakes cannot be neglected in the boreal landscape, being 35% of that of diffusive CH4 emission in Finnish lakes., Up‐scaling of freshwater N2O emissions at regional to global scales has remained challenging due to sparse data based on summer measurements. We collected seasonal data on N2O concentrations from 112 randomly selected boreal lakes in Finland and determined a representative set of possible drivers. Our data underline the key role of nitrate in regulating seasonal and spatial N2O concentrations. Nitrate explained 78% of the variation in N2O across all lakes. The Global Warming Potential of N2O in our data was 35% of that of diffusive CH4 emission underlining the importance to include N2O in landscape GHG evasion estimates.

Publisher Copyright: © 2022 The Author(s). Published by Oxford University Press. Information on how urban areas affect bird communities during winter in the boreal region is still scarce. With the aim of assessing such role of the urban habitats on over-wintering boreal birds, I focused on a city-wide approach in the city of Lahti (southern Finland) and two nearby forests (as controls). Point count surveys were conducted in 157 sites within the city and 30 in the control forests. In order to achieve comparable sets of data to contrast with the reference forests, I randomly selected five 30 point count sub-samples from the Lahti city-wide survey. Species richness was, in general, higher in the sub-samples from the city of Lahti. Such pattern did not show relationship with the built cover of the studied sites. Bird abundances were 3.3-5.9 times higher in the urban sub-samples when contrasted with the forest ones. Although results of this study are limited to a single city and consider one wintering season, they clearly illustrate the important role of urban systems as habitat for wintering birds in boreal systems.

The world is rapidly urbanizing, thereby transforming natural landscapes and changing the abundance and distribution of organisms. However, insights into the effects of urbanization on species interactions, and plant–pathogen interactions in particular, are lacking. We investigated the effects of urbanization on powdery mildew infection on Quercus robur at continental and within-city scales. At the continental scale, we compared infection levels between urban and rural areas of different-sized cities in Europe, and investigated whether plant traits, climatic variables and CO emissions mediated the effect of urbanization on infection levels. Within one large city (Stockholm, Sweden), we further explored whether local habitat features and spatial connectivity influenced infection levels during multiple years. At the continental scale, infection severity was consistently higher on trees in urban than rural areas, with some indication that temperature mediated this effect. Within Stockholm city, temperature had no effect, while local accumulation of leaf litter negatively affected powdery mildew incidence in one out of three years, and more connected trees had lower infection levels. This study is the first to describe the effects of urbanization on plant–pathogen interactions both within and among cities, and to uncover the potential mechanisms behind the observed patterns at each scale., This research was supported by a grant from the Swedish Research Council Vetenskapsrådet (2015-03993 to AJMT)

Non-bee insects have been identified as important crop pollinators globally. However, strategies to protect pollinators and enhance crop pollination usually focus on supporting bees. This study examined the effects of landscape structure, location within field, and floral resources on pollinators’ visits on mass-flowering caraway (Carum carvi L.) in boreal farmland, and the effects of the visits on caraway yield. Pollinator visits on caraway flowers were monitored and caraway yield measured in 30 fields at landscapes ranging from field-dominated to forest-dominated landscapes. Hoverflies were the most abundant flower-visitors of caraway, followed by honeybees. Hoverflies and other flies made more flower visits on caraway than all bee species combined. Pollinator groups differed in their responses to landscape and local factors. Flies were most abundant near field edges and in landscapes with high forest cover. Non-syrphid flies and solitary bees responded positively to the cover of flowering herbs in the adjacent field margins. Flower visits by honeybees, instead, were positively related to the flowering crop cover in the study fields. Caraway seed yield increased with increasing number of flower visits by honeybees, hoverflies and all pollinators together. Pollinator exclusion reduced caraway fruit set (i.e. the number of fruits per flower) by 13% and seed yield by 40%. Our study is the first to report the high importance of flies to crop pollination in boreal farmland, where caraway is an important export crop. The results highlight the need of taking flies and their habitat requirements into account when developing strategies to enhance crop pollination. Highlights • Hoverflies were the most frequent flower-visitors on caraway, followed by honeybees. • Flies made more flower visits than all bee species combined. • Flies were abundant near field edges and in landscapes with high forest cover. • Honeybees responded positively to the flowering crop cover. • Flower visits by both honeybees and hoverflies increased caraway yield.

Sustainability science has increasingly adopted more action-oriented approaches in an attempt to mobilise and implement a broad knowledge base to sustain human wellbeing and promote sustainable development. There is an increasing recognition of the importance of knowledge exchange (KE) between scientists and end users of research for enhancing social, environmental and economic impacts of research. Here, we explore the process of KE through close observation of two cases of KE between external PhD researchers and local actors in small-scale fisheries at the community level in Zanzibar, Tanzania. First, we address context by examining perceptions of research held by actors at community level and patterns of interactions and flows of benefits between external researchers and local actors including fisheries managers, local research institute as well as fishers and traders. Second, we unpack experiences of actors engaged in the cases of KE. The study draws attention to KE processes in the Global South and actors outside decision-making processes in fisheries management. The study concludes that as KE is a complex and dynamic process and that (i) history and relationships between actors shape the outcomes of KE, (ii) KE includes more than knowledge-based processes and outcomes because multiple incentives of different actors shape KE and how it is experiences and (iii) knowledge-based outcomes of KE are complex and unpredictable as different actors create their own meaning from shared information. The results exemplify the inevitably complex and unpredictable nature of KE processes and their outcomes, and provide insight into how KE can contribute to science–society relationships.

Sustainability science is an emerging, free-standing scientific discipline. It has introduced a new approach to both sustainability research and educational programmes, while evoking novel perspectives to stronger societal contextualization. Among several other areas of sustainability research, competencies for sustainability have become a focal topic of sustainability education research. This research explores the educational programmes and the representation of the theory-based key competencies for sustainability. Through a qualitative content study of 45 master programmes associated with sustainability science, we aim to understand what kind of sustainability competencies can be found in sustainability science master’s programmes and how they reflect the current discussions of the discipline of sustainability science and possibly drive the future education in the field. The study reveals that commonly suggested competencies including systems thinking, anticipatory, strategic, interpersonal, and normative competencies were frequently mentioned as content and learning outcomes in the curricula and are firmly present and widely employed in sustainability education. Additionally, this study identified three other clusters of competencies: diverse modes of thinking, methodological plurality, and competencies for autonomy. In addition to the contribution to education in the field by suggesting three emerged competencies for sustainability science specifically, we aim to contribute to the ongoing discussion about the discipline by suggesting a process-oriented framing of sustainability science.

A total of 102 bacterial strains isolated from nodules of three Bambara groundnut and one soybean cultivars grown in nineteen soil samples collected from northern Ghana were characterized using multilocus gene sequence analysis. Based on a concatenated sequence analysis (glnII-rpoB-recA-gyrB-atpD-dnaK), 54 representative strains were distributed in 12 distinct lineages, many of which were placed mainly in the Bradyrhizobium japonicum and Bradyrhizobium elkanii supergroups. Twenty-four of the 54 representative strains belonged to seven putative novel species, while 30 were conspecific with four recognized Bradyrhizobium species. The nodA phylogeny placed all the representative strains in the cosmopolitan nodA clade III. The strains were further separated in seven nodA subclusters with reference strains mainly of African origin. The nifH phylogeny was somewhat congruent with the nodA phylogeny, but both symbiotic genes were mostly incongruent with the core housekeeping gene phylogeny indicating that the strains acquired their symbiotic genes horizontally from distantly related Bradyrhizobium species. Using redundancy analysis, the distribution of genospecies was found to be influenced by the edaphic factors of the respective sampling sites. In general, these results mainly underscore the high genetic diversity of Bambara groundnut-nodulating bradyrhizobia in Ghanaian soils and suggest a possible vast resource of adapted inoculant strains. In the northern savanna zones of Ghana, Bambara groundnut-nodulating Bradyrhizobium species are taxonomically diverse.

BAHD enzymes play a critical role in regulating plant metabolites and affecting cell stability. In the present study, BAHD gene family members were recognized in the genome of Theobroma cacao and characterized using available bioinformatics tools. We found 27 nonredundant putative tcBAHD genes in cacao for the first time. Our findings indicate that tcBAHD genes are diverse based on sequence structure, physiochemical properties, and function. In addition, tcBAHDs and their orthologous in G. raimnodii, and C. capsularis were clustered into five groups. According to phylogenetic analysis, BAHD family genes were probably evolve drastically after divergence. The divergence time of duplication events with purifying selection pressure was predicted to range from 1.82 MYA to 15.50 MYA. Pocket analysis revealed that SER amino acids play a key role in regulating the activity of tcBAHDs. Furthermore, cis-acting elements related to responsiveness of stress and hormone, especially ABA and MeJA, were observed in the promoter region of tcBAHD genes. RNA-seq analysis revealed that tcBAHD13 and tcBAHD26 are more involved in response to P. megakarya fungi. In conclusion, it seems that evolutionary processes, such as duplication events, caused a high diversity in the structure and function of tcBAHD genes.

Aquatic ecosystems are globally significant sources of greenhouse gases (GHG) to the atmosphere, offsetting the terrestrial sinks. A one-year field study was carried out in a shallow eutrophic Lake Wuliangsuhai, Inner Mongolia (draining waters from one of the largest irrigation areas in China), to estimate diffusive GHG fluxes and their relative importance in global warming potential (GWP). Our results showed high spatiotemporal variation in dissolved CO2, CH4 and N2O concentrations, while they did not differ significantly between the bottom and surface layers of the shallow waterbody. In general, GHG concentrations and diffusive fluxes were higher in the north part of the lake than in the south. GHG concentrations in the water under the ice were significantly higher than those during the open-water period. Spatial variability of GHG concentrations varied with the bathymetry of the lake. The location of study sites relative to the main inflow and abundance of submerged macrophytes were the main controlling factors of GHG concentrations, as indicated by the consistency of GHG concentrations at the sampling sites, particularly for N2O. The total diffusive GHG emission from Lake Wuliangsuhai was 76.9 ± 5.4 Gg CO2 equivalents yr−1, with CO2, CH4 and N2O contributing 16 %, 83 %, and 1 %, respectively. Overall, the results suggest that shallow lakes in mid-latitude arid areas with cold winters can be potentially important GHG sources. However, those lakes are insufficiently represented in the scientific literature, and therefore they deserve more research attention. Highlights • Greenhouse gases emissions from a shallow lake in semi-arid area were estimated. • Considerable spatiotemporal variation in dissolved CO2, CH4, and N2O concentrations. • Spatial variability of GHG was associated with lake bathymetry and abundance of macrophytes. • CH4 contributed 83% to the total emissions as CO2-equivalents. • Lakes are an important source of carbon to the atmosphere.

Due to the perceived low biodiversity of arid environments, species inhabiting these regions have received less research compared to tropical areas and biodiversity hotspots. However, arid conditions are predicted to characterise a larger number of regions globally and there is a greater need to identify strategies that allow species to survive in these harsh environments. Bats occupy a wide variety of habitats, including some of the most arid habitats on Earth, thanks also to their nocturnal habits, ability of powered flight and species-specific physiological adaptations. However, knowledge of the mechanisms in place to face the variety of stressors linked with aridity is still relatively scarce, particularly concerning behaviour and in the light of the diversity characterising bats as a group. In this thesis, I investigate further the responses and strategies that bats employ to cope with aridity, with a particular focus on the role of functional traits and movement. First, I model functional trait variation of bat assemblages to identify trends along the gradient of aridity globally. Bat assemblages inhabiting conditions of higher aridity display morphological and echolocation features more suitable to move in open habitats thanks to the greater speed and cost efficiency of flight. Additionally, larger body sizes appear to be favoured at these conditions, potentially as an advantage to reduce the exposure to cutaneous evaporative water loss by retaining a lower surface-to-volume ratio. Despite these general trends, bat communities in arid environments still retain functional diversity, with manoeuvrable species taking benefit from their ability to hunt in the vicinity of the vegetation. Therefore, I then investigate how a low-mobility species, Lavia frons, copes with seasonal changes in aridity and the associated reduction in resources by following its movement using miniaturised GPS devices across a rainy and a dry season. Despite the overall low mobility observed, L. frons appears to respond to seasonal increases in aridity by moving over larger areas and for extended periods of time, supporting the role of movement as a strategy to offset for low prey densities during harsh periods. Finally, due to the lack of synthesis on the topic of bat responses to aridity, I propose a narrative review integrating current available knowledge and thus providing an overview to facilitate future research. In my literature review, I cover both physiological and behavioural mechanism, pinpointing gaps in knowledge and the need of more direct studies on behaviour. Additionally, I discuss potential trade-offs among responses, focusing on the role of movement and roosting conditions in mediating the impact of environmental stressors. This thesis brings advances in the study of bat responses to aridity, targeting some of the knowledge gaps present in the literature and setting the ground for further research. My results also highlight the importance of taking into account the interactions between physiological and behavioural mechanisms, as well as environmental conditions, when approaching the study of bat responses to aridity. TIIVISTELMÄ Kuivien ympäristöjen lajeja on tutkittu vähemmän kuin trooppisten alueiden lajeja. Kuivia elinympäristöjä esiintyy maapallolla kuitenkin laajalti ja siksi on tärkeää tietää miten eliöt säilyvät näillä karuilla alueilla hengissä. Lepakot elävät monenlaisissa elinympäristöissä. Osa niistä on maapallon kuivimpia, mutta niissäkin lepakot selviytyvät yöaktiivisuutensa, hyvän lentotaitonsa ja fysiologisten sopeutumiensa ansiosta. Mekanismit, etenkin käyttäytymiseen liittyvät, joiden turvin lepakot noilla alueilla selviävät tunnetaan kuitenkin melko puutteellisesti. Tässä väitöskirjassa tutkin millaisia vasteita ja strategioita lepakoilla on kuivuuteen liittyen. Erityisenä kiinnostuksen kohteena on selvittää, mikä on toiminnallisten piirteiden ja liikkumisen merkitys. Ensin mallinnan lepakkoyhteisöjen toiminnallisten piirteiden vaihtelua selvittääkseni kuivuuden merkitystä laajassa mittakaavassa. Kuivien alueiden lepakkoyhteisöillä on sellaisia rakenteellisia ja kaikuluotaukseen liittyviä piirteitä, jotka sopivat avoimilla alueilla liikkumiseen ja saalistukseen. Näiden ansiosta niiden lento on nopeaa ja kustannustehokasta. Kuivissa oloissa valinta näyttää suosivan myös isompaa ruumiin kokoa, luultavasti siksi että se vähentää veden haihtumista. Näistä yleisistä suuntauksista huolimatta kuivien alueiden lepakkoyhteisöjen toiminnallinen monimuotoisuus säilyy, ja kyvykkäimmät lajit hyötyvät kyvystään saalistaa kasvillisuuden lähellä. Tutkin pienien satelliittipaikantimien avulla miten vähän liikkuva Lavia frons-laji selviytyy kun käytettävissä olevien resurssien määrä vaihtelee kuivien ja sadekausien välillä. Heikosta liikkumiskyvystään huolimatta L. frons liikkui laajemmalla alueella ja pidempiä aikoja kuivina aikoina kuin sadekausina. Tällä tavalla eläimet kykenivät tavallaan kompensoimaan kuivien kausien alhaiset saalistiheydet. Lepakoiden vasteista kuivuuteen ei tätä ennen ole tehty synteesiä. Kirjallisuuskatsauksessani käsittelen fysiologiaan ja käyttäytymiseen liittyviä mekanismeja ja tunnistan ne käyttäytymiseen liittyvät aiheet, joista tarvitaan vielä lisätutkimuksia. Lisäksi käyn läpi potentiaalisia kanssakäyntejä, keskittyen erityisesti siihen, että mikä rooli liikkumiseen ja lepopaikkoihin liittyvillä olosuhteilla on ympäristöstä johtuvien stressitekijöiden hallinnassa. Tämä väitöskirja on edistysaskel sen selvittämisessä, että miten lepakot reagoivat kuivuuteen. Tässä tutkimuksessa on paneuduttu nykytiedoissa olleisiin aukkoihin ja samalla luotu pohjaa uusille tutkimuksille. Tulokseni korostavat, että kuivuuden vaikutuksia tutkittaessa on tärkeää huomioida fysiologisten ja käyttäytymiseen liittyvien mekanismien vuorovaikutukset ympäristötekijöitä unohtamatta.

A popular idea in ecology is that trait variation among individuals from the same species may promote the coexistence of competing species. However, theoretical and empirical tests of this idea have yielded inconsistent findings. We manipulated intraspecific trait diversity in a ciliate competing with a nematode for bacterial prey in experimental microcosms. We found that intraspecific trait variation inverted the original competitive hierarchy to favor the consumer with variable traits, ultimately resulting in competitive exclusion. This competitive outcome was driven by foraging traits (size, speed, and directionality) that increased the ciliate’s fitness ratio and niche overlap with the nematode. The interplay between consumer trait variation and competition resulted in non-additive cascading effects - mediated through prey defense traits - on prey community assembly. Our results suggest that predicting consumer competitive population dynamics and the assembly of prey communities will require understanding the complexities of trait variation within consumer species.

Scientists have warned decision-makers about the severe consequences of the global environmental crisis since the 1970s. Yet ecological degradation continues and little has been done to address climate change. We investigated early-career conservation researchers' (ECR) perspectives on, and prioritization of, actions furthering sustainability. We conducted a survey (n=67) and an interactive workshop (n=35) for ECR attendees of the 5th European Congress of Conservation Biology (2018). Building on these data and discussions, we identified ongoing and forthcoming advances in conservation science. These include increased transdisciplinarity, science communication, advocacy in conservation, and adoption of a transformation-oriented social–ecological systems approach to research. The respondents and participants had diverse perspectives on how to achieve sustainability. Reformist actions were emphasized as paving the way for more radical changes in the economic system and societal values linked to the environment and inequality. Our findings suggest that achieving sustainability requires a strategy that (1) incorporates the multiplicity of people's views, (2) places a greater value on nature, and (3) encourages systemic transformation across political, social, educational, and economic realms on multiple levels. We introduce a framework for ECRs to inspire their research and practice within conservation science to achieve real change in protecting biological diversity.

Species can adapt to climate change by adjusting in situ or by dispersing to new areas, and these strategies may complement or enhance each other. Here, we investigate temporal shifts in phenology and spatial shifts in northern range boundaries for 289 Lepidoptera species by using long-term data sampled over two decades. While 40% of the species neither advanced phenology nor moved northward, nearly half (47%) -used one of the two strategies. The strongest positive population trends was observed for the minority of species (13%) that both advanced flight phenology and shifted their northern range boundaries northward. We show that, for Boreal Lepidoptera, a combination of phenology and range shifts is the most viable strategy under a changing climate. Effectively, this may divide species into winners and losers based on their propensity to capitalize on this combination, with potentially large consequences on future community composition.

High Arctic ecosystems and Indigenous livelihoods are tightly linked and exposed to climate change, yet assessing their sensitivity requires a long-term perspective. Here, we assess the vulnerability of the North Water polynya, a unique seaice ecosystem that sustains the world’s northernmost Inuit communities and several keystone Arctic species. We reconstruct mid-to-late Holocene changes in sea ice, marine primary production, and little auk colony dynamics through multi-proxy analysis of marine and lake sediment cores. Our results suggest a productive ecosystem by 4400–4200 cal yrs b2k coincident with the arrival of the first humans in Greenland. Climate forcing during the late Holocene, leading to periods of polynya instability and marine productivity decline, is strikingly coeval with the human abandonment of Greenland from c. 2200–1200 cal yrs b2k. Our long-term perspective highlights the future decline of the North Water ecosystem, due to climate warming and changing sea-ice conditions, as an important climate change risk., The North Water polynya is a unique but vulnerable ecosystem, home to Indigenous people and Arctic keystone species. New palaeoecological records from Greenland suggest human abandonment c. 2200–1200 cal yrs BP occurred during climate-forced polynya instability, foreshadowing future ecosystem declines.

International audience; Declines of large predatory fish due to overexploitation are restructuring food webs across the globe. It is now becoming evident that restoring these altered food webs requires addressing not only ecological processes, but evolutionary ones as well, because human-induced rapid evolution may in turn affect ecological dynamics. We studied the potential for niche differentiation between different plate armor phenotypes in a rapidly expanding population of a small prey fish, the three-spined stickleback (Gasterosteus aculeatus). In the central Baltic Sea, three-spined stickleback abundance has increased dramatically during the past decades. The increase in this typical mesopredator has restructured near-shore food webs, increased filamentous algal blooms, and threatens coastal biodiversity. Time-series data covering 22 years show that the increase coincides with a decline in the number of juvenile perch (Perca fluviatilis), the most abundant predator of stickleback along the coast. We investigated the distribution of different stickleback plate armor phenotypes depending on latitude, environmental conditions, predator and prey abundances, nutrients, and benthic production; and described the stomach content of the stickleback phenotypes using metabarcoding. We found two distinct lateral armor plate phenotypes of stickleback, incompletely and completely plated. The proportion of incompletely plated individuals increased with increasing benthic production and decreasing abundances of adult perch. Metabarcoding showed that the stomach content of the completely plated individuals more often contained invertebrate herbivores (amphipods) than the incompletely plated ones. Since armor plates are defense structures favored by natural selection in the presence of fish predators, the phenotype distribution suggests that a novel low-predation regime favors stickleback with less armor. Our results suggest that morphological differentiation of the three-spined stickleback has the potential to affect food web dynamics and influence the persistence and resilience of the stickleback take-over in the Baltic Sea.