27 research outputs found

    What are the important landscape components for habitat selection of the ortolan bunting Emberiza hortulana in northern limit of range?

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    Ortolan buntings Emberiza hotulana have undergone one of the most severe population declines of any European farmland bird over the last thirty years. The aim of this study was to find out which habitat features, including crop characteristics, ortolan bunting prefers in Estonia in breeding areas. This study compared currently occupied and unoccupied ortolan bunting territories. Occupied areas contained significantly more tall broadleaf trees, crop types, structural elements (trees, bushes, roads, overhead power lines and buildings) and spring wheat, but also had lower crop drilling densities. Ortolan bunting territories were best described by a logistic regression model containing six variables: amount of structural point elements, length of power lines, amount of tall broadleaf trees and number of different crops had a positive effect, whereas crop density and area of autumn-sown crops had a negative effect. Based on the findings of this study, the following conservation measures can be recommended: lower crop densities; spring rather than autumn-sown crops; small-field systems containing a variety of crops; scattered scrub preserved or planted; habitat patches of permanent grasslands, hedges and tall broadleaf trees retained within the agricultural landscape

    Landscape metrics and indices : an overview of their use in landscape research

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    The aim of this overview paper is to analyze the use of various landscape metrics and landscape indices for the characterization of landscape structure and various processes at both landscape and ecosystem level. We analyzed the appearance of the terms landscape metrics/indexes/indices in combination with seven main categories in the field of landscape ecology [1) use/selection and misuse of metrics, 2) biodiversity and habitat analysis; 3) water quality; 4) evaluation of the landscape pattern and its change; 5) urban landscape pattern, road network; 6) aesthetics of landscape; 7) management, planning and monitoring] in the titles, abstracts and/or key words of research papers published in international peer-reviewed scientific journals indexed by the Institute of Science Information (ISI) Web of Science (WoS) from 1994 to October 2008. Most of the landscape metrics and indices are used concerning biodiversity and habitat analysis, and also the evaluation of landscape pattern and its change (up to 25 articles per year). There are only a few articles on the relationships of landscape metrics/indices/indexes to social aspects and landscape perception

    Increasing landscape complexity enhances species richness of farmland arthropods, agri-environment schemes also abundance – A meta-analysis

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    Intensification of agricultural production and simplification of landscape structure have negatively affected arthropod communities, in particular since the end of Second World War. Agri-environment schemes may partly compensate for these losses and enhance arthropod populations, but their effectiveness is higher in simple landscapes rather than complex landscapes, characterized by a large proportion and diversity of semi-natural areas. As the landscape-scale species pool is known to drive local species richness, we tested our hypothesis that landscape complexity determines local arthropod species richness, whereas local management affects only arthropod abundance. Here we undertake a meta-analysis as part of a wider systematic review of the effects of land use heterogeneity on arthropod species richness. We searched for studies quantifying the effects of agri- environment schemes (e.g. wildflower strips/areas, grassy field margins, organic farming) and landscape complexity on arthropod richness and abundance. We additionally separated vegetation- vs. ground-dwelling taxa, because the effects were hypothesized to be greater in the more mobile vegetation-dwelling taxa. As expected, increasing landscape complexity enhanced arthropod richness, but not their abundance. Unexpectedly, agri-environment schemes did not only support the abundance of arthropods, but also their species richness. This pattern was driven by the vegetation-dwelling, not the ground-dwelling taxa, presumably because the higher mobility of vegetation-dwelling taxa allows faster responses to environmental changes. Our results show that agri-environment schemes in Europe benefit both arthropod abundance and species richness, whereas increasing landscape complexity primarily enhances species richness. This is why both local and landscape management need to be taken into account to halt current biodiversity losses in agricultural landscapes. Agri-environment schemes need to be implemented at a larger spatial and temporal scales to enhance landscape complexity, maintaining or restoring biodiversity sustainably

    Meritaimen- ja lohikantojen tila ja elvyttäminen kolmessa itäisen Suomenlahden jokivesistössä

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    Sout-East Finland - Russia ENPI CBC 2007-2012 Contact person: Nina PeuhkuriWe investigated by electrofishing the state of sea trout population and also the fish assemblage as a whole in two Finnish–Russian cross-border river systems, Mustajoki/Tchornaja/Soskuanjoki/Malinovka and Hounijoki/Buslovka/Rakkolanjoki/Seleznevka, draining into the Gulf of Finland. Based on the fish assemblage, we assessed the ecological status of the rivers. In the third of our target river systems, Gladyshevka/Rotshinka in the Karelian Isthmus, our interest was particularly focused on the Atlantic salmon population. In Mustajoki/Tchornaja/Soskuanjoki/Malinovka, trout dominated in density the upper reaches and small tributaries, their densities decreasing towards the river mouth. Restoration of rapids led to increased trout densities, but benign weather conditions may partly explain the trend. The trout population in this river system was found to be genetically unique and diverse. In Hounijoki/Buslovka/Rakkolanjoki/Seleznevka, only a few trout were found − from the Russian side. The absence of trout, especially from the upper reaches, is due to migration obstacles but also probably to poorer water quality compared to Mustajoki/Tchornaja/Soskuanjoki/Malinovka. This was also reflected in the poorer ecological status. In Gladyshevka/Rotshinka, both salmon and trout were caught from the River Gladyshevka, but neither of these from the River Rotshinka. The densities of salmon in the River Gladyshevka partly reflect the releases of hatchery fish. We established a broodstock of the Mustajoki/Tchornaja/Soskuanjoki/Malinovka trout to enhance restoration of this native sea trout population still found on both the Finnish and Russian sides of the cross-border riversdraining into the Gulf of Finland. We also transferred wild-caught trout to the River Soskuanjoki on the Finnish side and upper reaches of the River Malinovka on the Russian side to promote the existence of the population in the whole river system in the wild. Later observations of trout from the Finnish side suggested that trout accepted the area. We also analysed in which proportions trout from different native or hatchery populations around the Gulf of Finland are represented in the Finnish coastal sea trout catch. Genetic analyses indicated that at least 75% of the catch originated from Finnish hatchery releases, and at least 20% of the catch consisted of wild trout, mostly from Estonia. Trout from the cross-border rivers represented only about 1% of the total catch. Scale analysis of a sample of captured trout indicated that individuals were caught young and often undersized. The salmon releases into the River Gladyshevka started over a decade ago were continued during the project. Salmon were also released into the River Rakkolanjoki. A sample of released salmon was additionally tagged with T-bar anchor tags prior to release to gain information on their migration based on tag recoveries. Seven tags have so far been recovered.; Selvitimme sähkökoekalastuksin meritaimenkantojen tilaa sekä kalastoa kahdessa Suomen ja Venäjän rajajokivesistössä, Mustajoki/Tchornaja/Soskuanjoki/Malinovka ja Hounijoki/Buslovka/Rakkolanjoki/Seleznevka, jotka laskevat Viipurinlahteen itäisellä Suomenlahdella. Arvioimme kalastoon perustuen jokivesistöjen ekologisen tilan. Kolmas hankkeen kohdevesistö, jossa mielenkiintomme kohteena oli erityisesti merilohi, oli Karjalan kannaksella sijaitseva Gladyshevka/Rotshinka, joka on tärkeä merilohen palauttamiskohde itäisellä Suomenlahdella Venäjän puolella. Taimenen poikastiheydet ylittivät Mustajoki/Tchornaja/Soskuanjoki/Malinovka -jokivesistössä muiden kalalajien tiheydet erityisesti latvavesissä sekä sivu-uomissa. Taimentiheydet laskivat jokisuulle mentäessä. Taimenen poikastiheydet kasvoivat tutkimuksen aikana kunnostetuilla koskilla. Osittain kasvu voi selittyä taimenen lisääntymiselle ja poikasille suotuisilla sääolosuhteilla. Mustajoki/Tchornaja/Soskuanjoki/Malinovka -jokivesistön taimenkanta osoittautui perinnöllisesti ainutlaatuiseksi ja monimuotoiseksi. Hounijoki/Buslovka/Rakkolanjoki/Seleznevka -jokivesistöstä löytyi vai jokunen taimen Venäjän puolelta. Taimenen puuttuminen erityisesti jokivesistön yläosista selittyy nousuesteillä, mutta osittain myös veden Mustajoki/Tchornaja/Soskuanjoki/Malinovka -jokivesistöä heikommalla laadulla. Tätä heijasti myös havaittu huonompi ekologinen tila. Gladyshevka/Rotshinka -jokivesistöstä saatiin sekä lohta että taimenta Gladyshevka-joesta, mutta Rotshinka-joesta ei lajeista kumpaakaan. Glahyshevka-joessa havaitut lohitiheydet selittyvät osittain jokeen tehdyillä lohi-istutuksilla. Mustajoki/Tchornaja/Soskuanjoki/Malinovka -jokivesistön taimenesta perustettiin viljelyyn emokalasto tämän ainoan Suomen ja Venäjän puolelta Viipurinlahteen laskevista rajajoista tavatun alkuperäisen meritaimenkannan säilyttämiseksi ja suojelemiseksi. Villejä taimenia siirrettiin myös Soskuanjokeen ja Malinovka-joen yläosiin taimenkannan olemassaolon turvaamiseksi koko jokivesistön alueella. Soskuanjoesta myöhemmin tehtyjen havaintojen perusteella taimenet hyväksyivät siirtoalueen. Selvitimme myös, miten luonnontaimenkannat ja laitoskannat ovat edustettuina Suomen rannikon taimensaaliissa. Geneettiset analyysit osoittivat, että vähintään 75 % saaliista on peräisin laitoskannoista. Ainakin viidennes saaliista oli peräisin luonnonkannoista, enimmäkseen Viron puolelta. Rajajokiemme taimenten todettiin muodostavan taimenen kokonaissaaliista vain n. 1 %. Suomuanalyysit osoittivat taimenten jäävän saaliiksi nuorina ja usein alamittaisina. Yli vuosikymmen sitten aloitettua istutuksin toteutettua merilohen elvytysprojektia Gladyshevka-joella jatkettiin tässä hankkeessa. Merilohta istutettiin myös Rakkolanjokeen. Istukkaita myös merkittiin t-ankkurimerkein ennen vapautusta vaellustietojen kartuttamiseksi. Palautustiedot on saatu tähän mennessä seitsemästä merkistä.This project is co­funded by the European Union, the Russian Federation and the Republic of Finlan

    Applying trait-based community metrics of relevance to conservation for understanding community patterns of farmland birds in Northwest Russia

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    Use of community trait-based metrics has been increasingly implemented for achieving an integrated view of biodiversity in conservation planning. We examined the extent, to which the use of community metrics based on species traits reflecting plausible sensitivity to change would contribute to our understanding of landscape characteristics of importance to the conservation of farmland birds in a poorly studied region of Northwest Russia. We collected species data on farmland from 230 transects covering a total 215 km for each year of 2008, 2010 and 2011 and analysed them using generalised linear mixed modelling. We derived community indices from species traits of habitat specialisation, trophic position, relative brain size and body mass. By relating these indices to the numbers of all species regarded farmland and Species of European Conservation Concern (SPEC), and by analysing them against the type of field and occurrence in typical non-cropped landscape elements, we showed consistent, albeit weak, congruence among the taxonomic and trait-based community descriptors. All community descriptors had their lowest estimates in arable fields. Community specialisation was the highest in open abandoned fields, which confirms the importance of such fields as refuges for regionally specialised species. Pastures were characterised by the highest community biomass, which indicates a particularly good resource base. Presence of ditches, of all non-cropped elements, had the strongest positive relationship with the community descriptors. The SPEC number strongly correlated with the overall species richness of farmland birds. A relatively weak congruence between taxonomic and trait-based community descriptors highlights their cornplementarity in understanding the underlying mechanisms of community changes. However, similarity in patterns among field types means that, under the current level of production in the region, accounting for the species richness of farmland birds seems to be sufficient to rapidly assess community sensitivity to agricultural change.Peer reviewe

    Crop rotation and agri-environment schemes determine bumblebee communities via flower resources

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    <p>The biodiversity (flower cover and bumblebees) and environmental data used in the analyses.</p

    Bird migration in space and time: chain migration by Eurasian curlew Numenius arquata arquata along the East Atlantic Flyway

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    Migration patterns in birds vary in space and time. Spatial patterns include chain, leapfrog and telescopic migration. Temporal patterns such as migration duration, number, and duration of stopovers may vary according to breeding latitude, sex, and season. This study aimed to verify these patterns in a long-distance migrant, the Eurasian curlew Numenius arquata arquata, and to provide a synopsis of spatio-temporal migration patterns in this species of concern throughout the East Atlantic Flyway. We tagged 85 adults with GPS-data loggers in Germany, Poland, France and Estonia between 2013 and 2019. We computed the distance flown, linear loxodromic distance, duration, stopover number, total stopover duration, mean stopover duration, departure time and arrival time for 177 out of 187 tracks. On average (± standard deviation), spring migration occurred from 4 to 14 April (10.2 ± 8.4 days), curlews flew 3.623 ± 1.366 km, and had 5.8 ± 3.6 stopovers, with a duration of 29.4 ± 38.2 h per stopover, while autumn migration occurred from 18 to 29 June (10.9 ± 9.9 days), curlews flew 3.362 ± 1.351 km, and had 5.4 ± 4.0 stopovers, with 31.8 ± 32.3 h per stopover. Curlews displayed chain migration because wintering curlews maintained the latitudinal sequence to their breeding sites. Southern curlews had a longer nesting period due to their earlier arrivals. While spring arrival at breeding sites did not differ between the sexes, in autumn females departed earlier than males. Migration duration and distance, as well as stopover number and duration, showed a significant increase with breeding site latitude but did not differ between the sexes or between spring and autumn migrations, suggesting that curlews took a comparable amount of time migrating during both seasons. The high site faithfulness in curlews suggests that rapid autumn migration allows them to return to defend their winter foraging areas
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