Buzzing in the pat : a new large-scale method for studying dung beetle functions

Lantakuoriaiset ovat tärkeitä maatalousekosysteemien toiminnan kannalta. Lantakuoriaisten keskuu-dessa useat erilaiset toiminnalliset ryhmät hajottavat laiduntavien eläinten lantaa ja kierrättävät lannan ravinteita takaisin maahan. Monet Suomen lantakuoriaiset ovat kuitenkin taantuneet elinympäristöjen vähenemisen ja muuttumisen myötä. Siksi on tärkeää selvittää, millaisia seurauksia eri lajien ja ryhmi-en taantumisella on ekosysteemien toiminnan kannalta. Monissa aihetta käsittelevissä tutkimuksissa tutkimusmenetelmät ovat kuitenkin perustuneet pienen mittakaavan kokeisiin, mikä saattaa vaikuttaa niissä havaittuihin tuloksiin. Tämän tutkielman tavoitteena on selvittää, voidaanko suurikokoisia aitauksia käyttää lantakuori-aisten toiminnan tutkimiseen Suomen olosuhteissa. Uuden menetelmän avulla halusin tutkia, miten eri lajeista kootut lantakuoriaisyhteisöt vaikuttavat lannan hajoamiseen ja laidunnurmen kasvuun. Lisäksi halusin selvittää laidunpaineen vaikutuksen lantakuoriaisten toimintaan. Kokeessa muodostin lantiais- ja sittiäislajeista erilaisia lantakuoriaisyhteisöjä, jotka sijoitin suu-riin, kahdesta vaihtoehtoisesta verkosta rakennettuihin aitauksiin. Pienempiverkkoisiin aitauksiin lisä-sin kaikki lantakuoriaiset ja suurempiverkkoisiin aitauksiin sittiäisiä pienikokoisemmat lantiaiset pääsi-vät itse verkon läpi. Testatakseni aitausten toimivuutta mittasin lantakuoriaisten määrää verkon ulko- ja sisäpuolella useaan otteeseen kokeen aikana. Aitauksien sisällä oli eri laidunpainetta nurmen pituudella kuvastavia ruutuja. Niillä seurasin lantaläjien hajoamista punnitsemalla läjiä kuudesti kokeen aikana. Lopuksi tutkin lantakuoriaisten vaikutusta laidunnurmen kasvuun punnitsemalla kasvibiomassaa läjien ympäriltä ja kasvattamalla rairuohoa läjien alta kaivetussa maassa. Suuret lantakuoriaishäkit näyttivät toimivan hyvin Suomen olosuhteissa. Eri lantakuoriaisyhtei-söjen vaikutuksesta lannan hajoamiseen sain vaihtelevia tuloksia eri aitaustyypeistä. Suurempiverkkoi-sissa aitauksissa sittiäiset osoittautuivat lantiaisia merkittävämmiksi lannan hajottajiksi, mutta pienem-piverkkoisissa aitauksissa eroja eri yhteisöjen toiminnallisesta tehokkuudesta ei löytynyt. Erot saattoi-vat johtua siitä, että toiseen aitaustyyppiin lisäsin lantakuoriaiset ja toiseen lantiaiset pääsivät itse ver-kon läpi. Tämä saattoi vaikuttaa lantakuoriaisten toimintaan. Laidunpaine vaikutti selvästi lannan hajoamisnopeuteen. Lantaläjät kevenivät huomattavasti nopeammin lyhyessä nurmessa kuin pitkässä. Lämpötilaerot erikorkuisten nurmien välillä saattoivat vaikuttaa lantakuoriaisten hakeutumiseen lyhyessä nurmessa olleisiin läjiin. Sen sijaan eri lanta-kuoriaisyhteisöillä ei ollut havaittavaa vaikutusta laidunnurmen kasvuun. Kaiken kaikkiaan tutkimuksestani selviää, että verkosta rakennettuja aitauksia voi käyttää tehok-kaasti lantakuoriaisten toiminnan tutkimiseen. Tutkimus vahvisti myös osittain aiempia havaintoja toiminnallisten ryhmien erilaisesta merkityksestä. Lisäksi laidunpaineen vaikutus lannan hajoamisno-peuteen osoitti, että laidunympäristöllä saattaa olla tärkeä merkitys lantakuoriaisten toimintaan.Dung beetles affect ecosystem functioning in agricultural landscapes. Among these beetles several functional groups decompose cattle dung and contribute to recycling its nutrients back to the soil. To-day many Finnish dung beetle species are threatened because of habitat change and fragmentation. Therefore, the impacts of changes in dung beetle community structure on ecosystem functioning needs to be addressed. However, many earlier studies of dung beetle functions have focussed only on small-scale manipulations with possible implications for interpretation of the results on larger scale. The aim of this study was to assess whether large-scale enclosures can be used to manipulate dung beetle communities in Finland. With this new method I wanted to examine how different dung beetle communities affected dung decomposition and nutrient cycling. I also wanted to examine wheth-er grazing pressure affected dung decomposition. I used two types of mesh enclosures to create different communities of Aphodius and Geotrupes species. In small mesh enclosures I added dung beetles manually, while in the large mesh enclosures the smaller Aphodius species could get through the mesh, and Geotrupes were then added manually to some of these enclosures. During the experiment I repeatedly measured the amount of dung beetles inside and outside of the mesh to assess the performance of the enclosures. Within enclosures I created plots that reflected different grazing pressure. In every plot I placed a dung pat which I then weighed six times during the summer. At the end of the experiment I studied the effect of dung beetles on nutri-ent cycling by weighing the biomass of grass. Overall, I found that the large enclosures are usable and work well in Finland. My results from the enclosures with the bigger mesh size showed that Geotrupes are more efficient decomposers of dung than are Aphodius. However, there were no significant differences between Aphodius and Geotrupes in enclosures made of smaller mesh. Thus, different enclosures may have affected the functioning of the dung beetles because I put the beetles to some enclosures and to some they could get through the mesh. Dung decomposition rates changed remarkably between the different grazing pressures. The end weight of pats was lighter in short grass compared to pats in long grass. It is possible that this reflects microhabitat selection by beetles choosing the warmer pats in the short grass. Dung beetle community structure did not affect rates of nutrient recycling, as measured by grass growth. In conclusion, the results of my study suggest that large-scale enclosures can be effectively used to study dung beetle functions in grassland habitats. This study also confirms earlier observations re-garding the significance of different functional groups of dung beetles, and shows that the grazing envi-ronment may have an important impact on the ecosystem functions provided by dung beetles

Hyvinvointitoimenpiteet osana koulutushanketta

Maaseutuyrittäjän työ on kuormittavaa niin henkisesti kuin fyysisesti. Maatilayrittäjä työskentelee usein yksin ja on itse vastuussa omasta jaksamisestaan. Siksi keinoja oman jaksamisen ja hyvinvoinnin edistämiseen on hyvä kartoittaa. Tutkimuksen tavoitteena oli tutkia Menestyvä keskisuomalainen nautakarjatila (MEKA) -hankkeen tarjoamien toimenpiteiden vaikuttavuutta maaseutuyrittäjän hyvinvointiin erityisesti itsenä johtamisen, palautumisen ja työturvallisuuden näkökulmista. Käytetty tutkimusote oli kvantitatiivinen ja se toteutettiin verkkokyselynä. Kyselyn kohdevastaajat olivat MEKA-hankkeeseen osallistuneet. Toimenpiteiden vaikuttavuuden lisäksi tutkimuksella selvitettiin käytännön esimerkkejä hankkeen kautta saaduista hyödyistä, sekä kehitysehdotuksia samantyyppisille hyvinvointihankkeille tulevaisuudessa. Tulokset osoittivat hankkeen toimenpiteiden olleen pääosin hyödyllisiä maaseutuyrittämisen johtamiskyvyn, palautumisen ja työturvallisuuden näkökulmista riippumatta tuotantosuunnasta. Itsensä johtamisen taito ja työturvallisuusnäkökulma osoittautuivat tilallisten oman näkemyksen mukaan aavistuksen tärkeämmäksi kuin palautuminen, mutta ero oli keskiarvollisesti marginaalinen. Maaseutuyrittäjät saivat hankkeen kautta peilattua omia toimintamallejaan ja siitä tuloksena oli muutokset maatilan arjessa ja työskentelytavoissa. Tutkimuksen perusteella hyvinvointihankkeella oli vaikutusta yrittäjien hyvinvointiin ja samankaltaisille hankkeille oli kysyntää edelleen

MESOCLOSURES - increasing realism in mesocosm studies of ecosystem functioning

Experimental studies linking community composition to functioning are typically confined to small and closed micro- or mesocosms. Such restricted conditions may affect both species’ biology and their environment. Yet, targeting simple features in the behaviour of species may circumvent these constraints. Focusing on ecological functions provided by dung beetles, we test whether large, open-top cages – MESOCLOSURES – will intercept the flight trajectories of beetles, thereby allowing manipulation of local community composition. MESOCLOSURES were built in both tropical forest (Brazil) and temperate grasslands (Finland), thus testing their general efficiency. Within the respective environments, we varied different aspects of MESOCLOSURE design: in the tropical forest, we examined the impact of MESOCLOSURE dimensions on exclusion efficiency, whereas in the temperate grassland, we assessed the potential for selectively excluding and including community members by different mesh sizes. In the temperate environment, we also went from method to application, using MESOCLOSURES to relate community composition to functioning under two simulated grazing regimes. MESOCLOSURES allowed efficient manipulation of dung beetle communities, maintaining dung beetle densities at intended levels in both temperate and tropical systems. In the tropics, the smallest cages (1 × 1 m) offered the highest contrast in beetle densities inside vs. outside of the fence, whereas the largest cages (9 × 9 m) offered the lowest. Nonetheless, densities inside cages never exceed one-fifth of those outside. At the temperate site, manipulations of community structure through mesh size yielded significant differences in functioning and suggested an interaction between small dung-dwelling species and large tunnelling species. Within cages, higher grazing was reflected in augmented dung removal. We conclude that MESOCLOSURES can be effectively used to study dung beetle functions across habitats and latitudes. As applied insights, the present study adds resolution to the significance of different functional groups of dung beetles and shows that grazing pressure may have an important impact on the ecosystem functions that they provide. Overall, this study suggests that targeted manipulation of dispersal may offer new solutions for linking fauna to ecosystem functions with minimal impact on the processes measured

Mesoclosures – increasing realism in mesocosm studies of ecosystem functioning

Experimental studies linking community composition to functioning are typically confined to small and closed micro‐ or mesocosms. Such restricted conditions may affect both species’ biology and their environment. Yet, targeting simple features in the behaviour of species may circumvent these constraints. Focusing on ecological functions provided by dung beetles, we test whether large, open‐top cages – MESOCLOSURES – will intercept the flight trajectories of beetles, thereby allowing manipulation of local community composition. MESOCLOSURES were built in both tropical forest (Brazil) and temperate grasslands (Finland), thus testing their general efficiency. Within the respective environments, we varied different aspects of MESOCLOSURE design: in the tropical forest, we examined the impact of MESOCLOSURE dimensions on exclusion efficiency, whereas in the temperate grassland, we assessed the potential for selectively excluding and including community members by different mesh sizes. In the temperate environment, we also went from method to application, using MESOCLOSURES to relate community composition to functioning under two simulated grazing regimes. MESOCLOSURES allowed efficient manipulation of dung beetle communities, maintaining dung beetle densities at intended levels in both temperate and tropical systems. In the tropics, the smallest cages (1 × 1 m) offered the highest contrast in beetle densities inside vs. outside of the fence, whereas the largest cages (9 × 9 m) offered the lowest. Nonetheless, densities inside cages never exceed one‐fifth of those outside. At the temperate site, manipulations of community structure through mesh size yielded significant differences in functioning and suggested an interaction between small dung‐dwelling species and large tunnelling species. Within cages, higher grazing was reflected in augmented dung removal. We conclude that MESOCLOSURES can be effectively used to study dung beetle functions across habitats and latitudes. As applied insights, the present study adds resolution to the significance of different functional groups of dung beetles and shows that grazing pressure may have an important impact on the ecosystem functions that they provide. Overall, this study suggests that targeted manipulation of dispersal may offer new solutions for linking fauna to ecosystem functions with minimal impact on the processes measured.68916924CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ400640/2012-0 || 558198/2009-

Data from: Mesoclosures – increasing realism in mesocosm studies of ecosystem functioning

1. Experimental studies linking community composition to functioning are typically confined to small and closed micro- or mesocosms. Such restricted conditions may affect both species’ biology and their environment. Yet, targeting simple features in the behaviour of species may circumvent these constraints. Focusing on ecological functions provided by dung beetles, we test whether large, open-top cages – MESOCLOSURES – will intercept the flight trajectories of beetles, thereby allowing manipulation of local community composition. 2. MESOCLOSURES were built in both tropical forest (Brazil) and temperate grasslands (Finland), thus testing their general efficiency. Within the respective environments, we varied different aspects of MESOCLOSURE design: in the tropical forest, we examined the impact of MESOCLOSURE dimensions on exclusion efficiency, whereas in the temperate grassland, we assessed the potential for selectively excluding and including community members by different mesh sizes. In the temperate environment, we also went from method to application, using MESOCLOSURES to relate community composition to functioning under two simulated grazing regimes. 3. MESOCLOSURES allowed efficient manipulation of dung beetle communities, maintaining dung beetle densities at intended levels in both temperate and tropical systems. In the tropics, the smallest cages (1 × 1 m) offered the highest contrast in beetle densities inside vs. outside of the fence, whereas the largest cages (9 × 9 m) offered the lowest. Nonetheless, densities inside cages never exceed one-fifth of those outside. At the temperate site, manipulations of community structure through mesh size yielded significant differences in functioning and suggested an interaction between small dung-dwelling species and large tunnelling species. Within cages, higher grazing was reflected in augmented dung removal. 4. We conclude that MESOCLOSURES can be effectively used to study dung beetle functions across habitats and latitudes. As applied insights, the present study adds resolution to the significance of different functional groups of dung beetles and shows that grazing pressure may have an important impact on the ecosystem functions that they provide. Overall, this study suggests that targeted manipulation of dispersal may offer new solutions for linking fauna to ecosystem functions with minimal impact on the processes measured

Soil temperatures

This file offers data on soil temperature, as recorded in each of four subplots on 27th July and reported verbally in the Results. The specific columns are the following: Replicate: the identity of the replicate MESOCLOSURE Enclosure type: treatment applied at the MESOCLOSURE level (for an in-depth description of treatment types, see main paper) Grass height: simulated grazing regime, with L identifying long grass and S identifying short grass Temperature: temperature recorded, in °C, with missing data indicated by an empty cel

Finnish_efficiency

This file offers the data behind Fig. 3B of Lähteenmäki et al., estimating the efficiency of the Finnish MESOCLOSURES in preventing the inflow of beetles as a function of species identity. Included are counts of beetles caught by bait pats in two settings: baits within the MESOCLOSURES, and baits outside the MESOCLOSURES. The specific columns are the following: Replicate: the identity of the replicate MESOCLOSURE Species: the identity of the species Total: the summed number of beetles caught inside and outside of the MESOCLOSURES Inside: the number of beetles caught inside of the MESOCLOSUR

Brazilian_efficiency

This file offers the data behind Fig. 3A of Lähteenmäki et al., estimating the efficiency of the Brazilian MESOCLOSURES in preventing the inflow of beetles as a function of MESOCLOSURE size. Included are counts of beetles caught by identical traps in two settings: traps within the MESOCLOSURES and traps outside the MESOCLOSURES. The specific columns are the following: Time: day of experiment (with individual trapping periods extending over 24 hours) Size: the dimension of the MESOCLOSURE (given as the length of MESOCLOSURE side, in metres) Replicate: the identity of the replicate cage Total: the summed number of beetles caught inside and outside of the MESOCLOSURE Inside: the number of beetles caught inside of the MESOCLOSUR

Dungweight

This file offers the data behind Fig. 4A-C of Lähteenmäki et al., estimating the effects of time, grazing regime (i.e. of grass length) and beetle taxa present on dung pat weight in the temperate experiment (for an in-depth description, see Appendix 1, section Experimental design, Finland). The specific columns are the following: BlockID: block identity CageID: cage identity Pat: dung pat replicate Grass height: simulated grazing regime, with L identifying long grass and S identifying short grass Geotrupes presence: design variable indicating whether Geotrupes was present or not Aphodius presence: design variable whether Aphodius was present or not Measurement: measurement day (treated as a categorical variable) Weight: dung weight, in gram