Kisklusrisk ja elupaiga ajalugu päevaliblikate koosluste mõjutajatena

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Ökoloogia üks keskseid ülesandeid on kirjeldada ja seletada liigirikkuse varieeruvuse mustreid. Käesolevas doktoritöös uuriti kahe, sageli raskesti hinnatava elupaigaparameetri – kiskluse ning elupaikade hävimise määra – mõju päevaliblikate populatsioonidele ja kooslustele. Vaatamata sellele, et nende faktorite mõju peetakse liigirikkuse mustrite kujunemisel oluliseks, on vähemasti putukate kohta empiirilist infot looduslikes kooslustes minimaalselt. Töös keskenduti päevaliblikate kooslustele Lääne-Eesti loopealsetel. Konkreetsemalt küsiti, kuivõrd mõjutavad kiilid kui kiskjad päevaliblikate liigirikkuse mustreid ning kuivõrd päevaliblikate liigirikkuse tänapäevased mustrid on mõjutatud elupaiga ajaloolisest karakteristikutest. Tulemused näitavad, et nii kisklusrisk kui ka elupaiga ajaloolised parameetrid seletavad olulise osa päevaliblikate koosluste liigirikkuse varieerumisest. Kiilide ruumiliselt ja sesoonselt varieeruv kisklussurve on piisav, et mõjutada mitte ainult päevaliblikate arvukust, vaid ka liigirikkust ning liigilist koosseisu. Nimelt puudusid kõrgema kiilide arvukusega loopealsetelt suurema tõenäosusega need päevaliblikaliigid, kelle lennuaeg kattub kiilide arvukuse tippajaga ning liigirikkus kiilirohketel aladel oli madalam. Seega on kisklus oluline faktor, mida arvestada ka praktilises looduskaitses. Nii ajalooline kui tänapäeva elupaiga pindala seletas olulise osa kitsaste elupaigaspetsialistide liigirikkuse varieerumisest. Samal ajal ei sõltunud generalistde liigirikkus ei tänapäeva ega ajaloolise elupaiga pindalast, mis viitab nende kahe rühma erinevale tundlikkusele elupaiga pindala muutumise suhtes. Käesoleva töö tulemused näitavad, et ainult tänapäevase elupaiga parameetrite teadmisest ei pruugi piisata, hindamaks liigi seisundit dünaamilises tugeva inimmõjuga maastikus.Revealing major biotic and abiotic gradients along which species are spatially distributed is one of the major goals in ecology. In this thesis butterfly community structure along the gradients of dragonfly predation risk and habitat history was examined. In spite of the growing awareness of the importance of predation risk and habitat past characteristics in different ecosystems, community-level responses along these gradients have rarely been addressed in empirical studies focusing on insects. Current thesis focused on these issues in butterfly communities in seminatural calcareous grasslands (alvars) in Western Estonia. The results show that the variation in predation risk and past habitat characteristics can explain a significant amount of variation in butterfly species composition and richness. Butterfly communities at predator rich sites were biased towards a greater proportion of species flying during off peak dragonfly abundance, and butterfly species richness in dragonfly-rich habitat patches was lower than in dragonfly-poor patches. The gradient of predation risk could thus be an important factor to consider in practical conservation work as well. Both historical and current habitat area explained a significant amount of variation in strict habitat specialist butterflies, whereas species richness of other grassland butterflies was associated neither with past nor current habitat area. These patterns imply differential sensitivity of these two groups to habitat changes. The results of the thesis show that relying on just current habitat characteristics may not be sufficient to assess the status of species diversity in dynamic, human-affected landscapes

The European Butterfly Indicator for grassland species: 1990-2013

This report presents the fifth version of the European Grassland Butterfly Indicator, one of the EU biodiversity indicators of the European Environment Agency

The European Butterfly Indicator for Grassland species: 1990-2015

This report presents the sixth version of the European Grassland Butterfly Indicator, one of the EU biodiversity indicators of the European Environment Agency.The indicator is based on more than 9200 transects in national Butterfly Monitoring Schemes covering 22 countries across Europe, most of them active in the European Union. In 2015, counts were made in more than 4500 transects.Butterflies represent the largest animal group (insects), highly included in food webs, having a high impact on ecosystem services and stability. This report does not represent only the patrimonial conservation of some species, but indicates the changes in biodiversity on grasslands and discusses underlying causes.Fluctuations in numbers between years are typical features of butterfly populations. The assessment of change istherefore made on an analysis of the underlying trend.Indicators were produced on EU, European (EU plus Norway and Switzerland) and pan-European level (including Ukraine, Russia and Armenia).The underlying analysis of the indicator shows that since 1990, grassland butterfly abundance has declined by 30%.The rate of loss has slowed in the last 5-10 years. Part of this slowing down might be caused by climate warming, as this favours cold-blooded animals like butterflies, thus masking the effects of intensification. In parts of Western Europe butterfly numbers outside nature reserves have come to an absolute minimum, meaning it is unlikely for the indicator to further drop.The priority now is to halt further losses and support recovery. This can only come about with greater protection and more sustainable management of semi-natural grassland

Integrating national Red Lists for prioritising conservation actions for European butterflies

Red Lists are very valuable tools in nature conservation at global, continental and (sub-) national scales. In an attempt to prioritise conservation actions for European butterflies, we compiled a database with species lists and Red Lists of all European countries, including the Macaronesian archipelagos (Azores, Madeira and Canary Islands). In total, we compiled national species lists for 42 countries and national Red Lists for 34 of these. The most species-rich countries in Europe are Italy, Russia and France with more than 250 species each. Endemic species are mainly found on the Macaronesian archipelagos and on the Mediterranean islands. By attributing numerical values proportionate to the threat statuses in the different national Red List categories, we calculated a mean Red List value for every country (cRLV) and a weighted Red List value for every species (wsRLV) using the square root of the country's area as a weighting factor. Countries with the highest cRLV were industrialised (NW) European countries such as the Netherlands, Belgium, the Czech Republic and Denmark, whereas large Mediterranean countries such as Spain and Italy had the lowest cRLV. Species for which a Red List assessment was available in at least two European countries and with a relatively high wsRLV (50) are Colias myrmidone, Pseudochazara orestes, Tomares nogelii, Colias chrysotheme and Coenonympha oedippus. We compared these wsRLVs with the species statuses on the European Red List to identify possible mismatches. We discuss how this complementary method can help to prioritise butterfly conservation on the continental and/or the (sub-)national scale

The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity