Väetamise ja pestitsiidide kasutamise mõju mesilaselaadsetele (Apoidea) suvirapsil

Spring oilseed rape is an important oilseed crop, the area of which has increased significantly in northern Europe, including Estonia. Spring oilseed rape is predominantly autogamous but cross-pollination can have several positive effects, including higher seed yield and better quality. Hence, it is profitable to encourage high number of bees as the main pollinators in oilseed rape fields. On the other hand the expansion of oilseed rape growing area in Europe has increased the number of pests. This has resulted in the need to use more pesticides which have negative effects also on useful organisms, including pollinators. The aims of the current thesis were from one side to study the impact of oilseed rape (as crop which has high nutrient demand) foliar fertilization with different microfertilizers on the number of flower visiting bees (honey bees, bumble bees and solitary bees) and on the other hand the repellency of insecticide Fastac 50 EC on honey bees and the effect of sub-lethal doses of insecticide on respiratory pattern of bumble bees as it is a good indicator of their physiological state. The results of the study showed that to secure a higher number of pollinators for achieving higher seed yield and other benefits deriving from cross-pollination spring oilseed rape should receive proper complex fertilization. Applied microfertilizers turned out to be useless in terms of increasing the number of pollinators. In addition, the study tended to confirm that Fastac 50 EC does not show repellency for honey bees in field conditions. Flower density seemed to be the main signal for bees and might override the repellent effect. Even solutions with ten times lower concentrations of Fastac 50 EC than registered field rate in Estonia affected significantly the respiratory patterns of bumble bees and decreased the longevity. The study shows that as in field conditions additional factors may affect the choices of bees, laboratory and semi-field studies often do not reflect the situation in field conditions. The sub-lethal doses of pesticides bees encounter do affect the physiological state of the pollinators, being thus one possible reason for global pollination crisis. At the same time the application of pesticides is quite new phenomenon from the evolutionary perspective and pollinators have not learned to recognize the hazards. Pesticides should not be used routinely and prophylactically without regard to pest incidence but the need for the application should be previously monitored. The protection of pollinators against negative effects of pesticides should also be supported by the policies (e.g. through the environmental measures of the European Union common agricultural policy). In addition, further research on the ecotoxicity of pesticides is needed and more environmentally friendly growing technologies should be worked out (e.g. entomovector-technology and biopesticides).Suviraps on oluline õlikultuur, mille kasvupind on Põhja-Euroopas, k.a Eestis, oluliselt suurenenud. Raps on peamiselt isetolmlev, kuid risttolmlemisel on mitmeid eeliseid, sh tõstab seemente kvaliteeti ja kvantiteeti. Seetõttu on mesilaselaadseid kui rapsi peamisi tolmeldajaid igati kasulik soodustada. Teisest küljest on rapsi kasvupinna suurenemine toonud kaasa ka kahjurite arvukuse tõusu, mistõttu on vaja kasutada rohkem pestitsiide. Viimased avaldavad aga negatiivset mõju ka kasulikele organismidele, sh tolmeldajatele. Käesoleva doktoritöö eesmärgiks oli ühelt poolt uurida rapsi kui suure toitainetevajadusega kultuuri lehekaudse mikroväetistega väetamise mõju õisi külastavate mesilaselaadsete (meemesilaste, kimalaste ja erakmesilaste) arvukusele ning teiselt poolt repellentse insektitsiidi Fastac 50 EC eemalepeletavat toimet meemesilastele ja sub-letaalsete dooside mõju kimalaste hingamisrütmidele, mis on heaks füsioloogilise seisundi näitajaks. Uurimus näitas, et tolmeldajate arvukuse soodustamiseks on rapsi vaja kõrgema saagi ja teiste risttolmlemisest tulenevate eeliste tagamiseks kompleksväetisega väetada. Katses kasutatud lehekaudsed mikroväetised aga tolmeldajate arvukust enam täiendavalt ei suurendanud. Lisaks leiti, et põllu tingimustes ei avaldunud Fastac 50 EC väidetavalt repellentne toime meemesilastele – kõige olulisemaks signaaliks osutus õite tihedus, mis võis üle kaaluda insektitsiidi väidetavalt eemalepeletava toime. Katse põhjal selgus, et isegi kümme korda madalama kontsentratsiooniga Fastac 50 EC lahus kui on Eestis tegelik registreeritud põllul kasutatav doos, mõjutas oluliselt kimalaste hingamisrütme ja vähendas nende eluiga. Antud uurimustöö tulemused näitavad, et labori- ja väikeseskaalaliste põldkatsete tulemused ei peegelda tihti tegelikku olukorda põllu tingimustes. Sub-letaalsed pestitsiidi doosid mõjutavad tolmeldajate füsiloogilist seisundit ning võivad seega olla üheks globaalse tolmeldamiskriisi põhjuseks. Seejuures on pestitsiidide kasutamine evolutsioonilisest vaatepunktist küllaltki uus nähtus ja tolmeldajad ei ole veel õppinud riske ära tundma. Pestitsiide ei tohiks kasutada rutiinselt ja lihtsalt profülaktika mõttes, vaid vajadust selle järele tuleks põllul eelnevalt seirata. Tolmeldajate kaitsmist pestitsiidide negatiivsete mõjude eest tuleks toetada ka läbi erinevate poliitikate (sh läbi Euroopa Liidu ühise põllumajanduspoliitika keskkonnameetmete). Vajalikud on täiendavad uurimused pestitsiidide toksilisusest elusorganismidele ning välja tuleks töötada keskkonnasõbralikumaid kasvatustehnoloogiaid (nt entomovektor-tehnoloogia ja biopestitsiidid).Publication of this thesis is supported by the Estonian University of Life Sciences and by the Doctoral School of Earth Sciences and Ecology created under the auspices of European Social Fund

Puistu seisundi ja struktuuritunnuste kvantitatiivne hindamine hemiboreaalsetes metsaökosüsteemides

A Thesis for applying for the degree of Doctor of Philosophy in Forestry.Väitekiri filosoofiadoktori kraadi taotlemiseks metsanduse erialal.In recent years, the focus of Estonian forestry has been on the better integration of economical, ecological and social functions, and consideration of ecosystem services. Although forest conservation is an important step for maintaining biodiversity, it may insufficiently provide expected ecological value. Efforts should promote stand structural diversity also in commercial forests, as the variety of stand structural elements that form structural patterns will promote resources for different species and ecosystem services. Loss of structural diversity negatively affects forest resistance to different abiotic and biotic factors. The current thesis synthesizes several methods that could be used in forest management and planning to focus on ecosystem values. The main aims of the thesis are to quantify the structural heterogeneity and spatial patterns of stands with different management history, to quantify the proportion of visually healthy trees with internal decay indicating decreased vitality in intensively managed conifer forest stands and to distinguish the spatial location of trees with internal decay. The thesis is based on the data collected from the Estonian Network of Forest Research Plots and different structural indices were used to reach the set aims. The results showed that the variety of structural elements and patterns (multiple tree species and sizes, such as large old trees or regrowth, deadwood abundance, different spatial distribution of dead and alive trees) in forest stands with different management history showed significant differences but depended on the main tree species. Heterogeneous stand structures were generally significantly more abundant in unmanaged (natural, recovering or conservation) forests compared to other forest types. For example, unmanaged Norway spruce stands were significantly more heterogeneous in mingling of species and differences in tree dimensions when compared to managed stands, and the positioning of trees was more irregular. Living trees were significantly more often surrounded with dead trees in Scots pine stands belonging to natural forests than in recovering or managed forests, and dead trees more frequently clumped in natural forests. Despite the lack of visual symptoms of internal damage, conifers in intensively managed stands had well-developed decay at the root collar, especially in Norway spruce stands. Additionally, visually healthy trees with internal decay were relatively often clumped, especially in Norway spruce stands. Structural indices are effective tools that provide quantitative information about spatial forest structure, e.g., how trees of different species, dimensions or vitality status are mixed in space and how heterogeneous the structure of a forest stand is. The importance of such indices will increase in forest management as high-resolution remote sensing data providing tree-level information will be used on a large scale.Viimastel aastatel on Eestis esile tõusnud metsade majanduslike, ökoloogiliste ning sotsiaalsete funktsioonide parem omavaheline integreerimine ning ökosüsteemiteenustega arvestamine. Kuigi looduskaitsealadel on oluline roll metsade bioloogilise mitmekesisuse säilitamisel, tuleb bioloogilise mitmekesisuse hoidmise ja taastamisega tegeleda ka väljaspool kaitsealasid. Puistu struktuuri mitmekesisuse säilitamine ja edendamine majandusmetsades on oluline, sest struktuurielementide olemasolu ja rohkus võimaldavad sobivaid elupaiku erinevatele liikidele ning toetavad ökosüsteemiteenuste tagamist. Struktuuri mitmekesisuse vähenemine mõjutab negatiivselt metsa vastupanuvõimet abiootiliste ja biootiliste stressitegurite suhtes. Doktoritöö käsitleb erinevaid meetodeid metsamajanduses ja -korralduses varasemast enama tähelepanu suunamiseks metsaökosüsteemi väärtustele. Töö otsesteks eesmärkideks on analüüsida erineva majandamisrežiimiga metsades puistusisest heterogeensust ja puude ruumilise paiknemise mustreid ning hinnata visuaalselt hea seisundiga majandusmetsades puude juurekaelal mädaniku esinemist ja mädanikuga puude ruumilist paiknemist puistus. Väitekiri põhineb Eesti metsa kasvukäigu püsiproovitükkide võrgustiku puistute ja üksikpuude inventeerimisandmetel. Püstitatud eesmärkide saavutamiseks kasutati puistu ruumilist struktuuri kirjeldavaid indekseid. Selgus, et struktuurielementide ja -mustrite (erinevat liiki ja erinevate mõõtmetega puud, sh vanad ja jämedad puud või järelkasv, lamapuude rohkus, surnud ja elusate puude ruumiline paiknemine) mitmekesisus osutas olulistele erinevustele erineva majandamisrežiimiga puistutes, kuid erinevused sõltusid puistu peapuuliigist. Majandamata (sh kaitsealuste, looduslike ja taastuvate) metsade struktuur oli oluliselt heterogeensem võrreldes majandatud metsadega. Näiteks olid majandamata kuusikutes erinevad puuliigid ja erinevate mõõtmetega puud omavahel sagedamini segunenud ning puude paiknemise mustrid ebaregulaarsemad kui majandatud puistutes. Männikutes oli elusate puude naabruses seda tihedamini surnud puid, mida looduslikum oli puistu, ning surnud puud paiknesid viimases suhteliselt sageli grupiti. Vaatamata visuaalsete sümptomite puudumisele esines majandatud puistutes, eriti kuusikutes, puudel juurekaela kõrgusel mädanikku. Mädanikuga puud paiknesid suhteliselt sageli grupiti, eriti kuusikutes. Struktuuriindeksid on tõhusad vahendid, mille abil puistute struktuurile arvulisi hinnanguid anda, sh selle kohta, kuidas erinevat liiki, suuruse või seisundiga puud puistus segunevad ja kui heterogeenne on puistu struktuur. Selliste indeksite tähtsus suureneb metsanduses veelgi, kuna üksikpuu tasandil saadavad kaugseireandmed muutuvad laialdaselt kättesaadavaks ja kasutatavaks.Publication of this dissertation is supported by the Estonian University of Life Sciences

Organisatsiooniline kontroll ülikoolide juhtimises: mitmeparadigmaline lähenemine Tartu Ülikooli näitel

Tuginedes erinevate teadusfilosoofiliste paradigmade (modernistlik, sümbolistlik ja postmodernistlik) sünteesile on doktoritöö eesmärgiks välja töötada teoreetiline raamistik organisatsioonilise kontrolli mõistmiseks Tartu Ülikooli näitel. Antud eesmärgist kantuna, esimene ehk teoreetiline peatükk hõlmab organisatsioonilise kontrolli alaste käsitluste teadusfilosoofilist korrastamist paradigmade lõikes. Viimast silmas pidades tekib teoreetilises osas kontrollialase kirjanduse süstematiseerimine, mis annab lugejale ülevaatliku pildi sellest, kuidas vastavalt omaksvõetud teadusparadigmale on teadlased seni kontrolli olemust ja toimimist mõistnud. Teine ehk empiiriline peatükk rakendab kolme paradigmat Tartu Ülikooli juhtimisreformi uurimisel ning kolmas peatükk, sünteesides nii teoreetilist kui empiirilist peatükki kujundab metatasandil teoreetilise raamistiku organisatsioonilise kontrolli paremaks mõistmiseks. Doktoritöö tulemusena ilmnes, kuidas organisatsioonilise kontrolli loomus sõltub suuresti tekkinud dominantsetest diskursustest ülikoolis. Doktoritööst selgus, kuidas sisuliselt juhtimisreformi raames tekkinud diskursused keskendusid olemasolevate tähenduste hoidmisele (nt identiteediküsimused), samas põrkuvad otsese vajadusega harjunud tähendusi muuta (nt harjutamine valdkonnapõhise identiteedi vormis mõtlemisega). Kokkuvõttes tõi doktoritöö välja, kuidas olulised muutused ülikoolis ei ole mitte pelgalt komplekssed, vaid tulenevalt ülikoolide traditsioonilisest töökorraldusest sageli ka poliitilistel võimumängudel baseeruvad. Kuna suuremastaabilisi muudatusi juhitakse tsentraalselt tippjuhtkonna poolt, siis võib muudatuste taga peituv argumentatsioon tavatöötajast kaugele jääda. Seetõttu, kuigi muudatuste mõju on hilisemalt kõigile tuntav, ent vähese dialoogi tekkimise tõttu loob see viljaka pinnase ebakindlust ja ärevust sütitavate ning organisatsioonilist kontrolli haarata püüdvate dominantsete diskursuste tekkeks.The aim of the thesis is to offer a framework of organisational control that bases itself on the synthesis of multiple paradigms (modernism, symbolism and postmodernism) on the example of University of Tartu. That said, chapter one will tackle with complex nature of organisational control by mapping the fragmentation of existing control studies, then bringing out the essence of control via multiple paradigms in theory. Second chapter bases itself on multiparadigm research, which applies multiple paradigms witnessed in literature to study organisational control in university management. Finally, metaparadigm theory building chapter can be regarded as a conclusion and discussion that summarises both theoretical and empirical study in order to provide novel theoretical insights at the metalevel. Dissertation led to show how organisational control manifests in finding a strategic fit between sensegiving and sensemaking, a process, which is facilitated and negotiated by a paradox of sensekeeping and sensebreaking. By coupling sensekeeping with sensebreaking results in a paradox or a contradictory state of affairs where at one side there might be a need for a change, possibly with great reasons, yet from another side, these reasons or explanations are not strong enough to undermine the need to keep existing arrangements as they are. According to empirical phases of the thesis, strategic change processes tend to be not only highly complex and politically laden (since they have a great effect of large parts of the organisation), but due to the fact that as a rule they are driven by upper level managers, the communication over the argumentation for and about the essence of the change may stand too far from the organisational members (interpretive realities). Thus, as fundamental change in organisation has wide effects to many, yet the change process is usually managed by few there are lot of hidden possibilities of resistance and dominating discourses to emerge as an attempt to seek organisational control over the perceived uncertainties

Kehalisest kasvatusest vabastamiste analüüs aastate kaupa ühe kooli näitel

Uurimistöö analüüsib tervisetõendite sisu ja rolli kooliprogrammis ettenähtud kehalise kasvatuse eesmärkide täitmisel nelja õppeaasta jooksul ajavahemikul 01.09.2000–06.06.2005 Tabasalu Ühisgümnaasiumis. Tõendeid iseloomustavateks tunnusteks olid tõendi väljaandja, tõendi kestus ja tõendil märgitud vabastuse põhjus. Neid tunnuseid võrreldi erinevate vanuserühmade ning poiste ja tüdrukute vahel. Ilmnes, et suurimad kehalisest kasvatusest vabastajad on lapsevanemad, kes annavad ka valdava osa ühepäevastest tõenditest; haigusest taastumiseks ettenähtud tõendid täieliku vabastusena kehalisest kasvatusest annavad välja mitteprofessionaalid ning vabastuste hulk ohustab õppekava ülesannete saavutamist. Eesti Arst 2008; 87(11):853−85

The Poor and Embarrassing Cousin to the Gentrified Quantitative Academics: What Determines the Sample Size in Qualitative Interview-Based Organization Studies?

It is essential for scholars to reflect on their research practices and critically assess scientific rigor. In the current article, we aim to critically review the state of qualitative research in organization studies by focusing on trends in sample sizes. Organizational scholars presenting qualitative, interview-based manuscripts tend to face the ongoing challenge of how many interviews are enough. The research reported in this article, covering 11 years and investigating 855 interview-based studies, provides empirical evidence that, across the years, the number of interviews seems to be rather high. The total sample included studies with more than 100 interviews (8% of the sample), more than 50 interviews (34%) and studies with more than 30 interviews (62%). Furthermore, when studies start to increase in sample size, they often do so at the expense of homogeneity across respondents. We conclude by giving some possible explanations for why we are facing such a situation today.Für Forschende ist es essenziell wichtig, die eigenen Praktiken zu reflektieren und das Einhalten wissenschaftlicher Standards kritisch zu beurteilen. In diesem Beitrag unterziehen wir den Status qualitativer Forschung und genauer Trends mit Blick auf Stichprobengrößen in der Organisationswissenschaft einer kritischen Prüfung. Organisationsforscher/innen, die zu Studien veröffentlichen, in denen qualitative Interviews zum Einsatz kamen, sind kontinuierlich mit der Frage konfrontiert, welche Zahl an Interviews ausreichend ist. Um Trends hierzu einschätzen zu können, haben wir Veröffentlichungen zu 855 Interview-basierten Studien über elf Jahre gesichtet. Dabei wurde deutlich, dass die Zahl der geführten Interviews über die Jahre relativ hoch zu sein scheint: Insgesamt wurden in 8% unseres Samples über 100 Interviews, in 34% über 50 Interviews und in 62% über 30 Interviews geführt. Zugleich geht die Erhöhung der Zahl an Interviews mit einem Rückgang homogener Stichproben einher. In unserem Beitrag diskutieren wir mögliche Gründe für diese aktuelle Problemlage

Estonian bumblebees

Bumblebees – who are they and what do they look like? Bumblebees are insects with a burly, furry and colourful appearance. They are members of the bee genus Bombus in the family Apidae. People have given them different names and they can be met in forests, fields, meadows and gardens, both in the countryside and in towns. Bumblebees can be found throughout the world except for Australia and the Tropics. There are over 250 species of bumblebees in the world of which 68 species can be found in Europe. Bumblebees can be divided into true bumblebees and their nest parasites, known as cuckoo bumblebees. In Estonia 21 species of true bumblebees and 8 species of cuckoo bumblebees are found – 18 species of the true bumblebees belong to the species of the conservation category III of the Nature Conservation Act. This publication focuses mainly on true bumblebees (henceforth referred to a bumblebees)

Increasing Construction Quality of External Thermal Insulation Composite System (ETICS) by Revealing on-site Degradation Factors

The installation of External Thermal Insulation Composite System (ETICS) enables to protect building envelope from natural weather effects and increase energy efficiency. As the system can be installed externally with simple work methods the usage is growing in European countries. The quality of the outcomeisinfluencedby design, material selection, and on-site construction process. The on-site fixing process of ETICS is guided by numerous regulations and guidelines which have aninsignificant impact on the actual construction technology. A list of Degradation Factors (DF) is created to classify the relevant on-site activities. Categorised on-site Degradation Factors are basing onvarious studies, standards, and regulations set for products. The shortcomings are categorised in eight sets: substrate, mixtures, adhesive, insulation, anchors, reinforcement, finishing layer and auxiliary materials. Additionally, a field study has been conducted to test the occurrenceof on-site shortcomingsin Estonia. The collected measurements and observations did not reveal severe and systematic installation failures, but random deviations occurred in most layers which might lead to the degradation of ETICS. The paper categoriseson-site shortcomings which can lead to theloss of technical performance during the service life of the façade

Riski ja progressi kujutamine avalikus kommunikatsioonis e-valimiste näitel

The present thesis examined representation of risk and progress in public communication by the example of e-elections. Discourse analysis were used in the work to find out how critical- rational and constructive a debate was; what subjects and contexts were linked with discourses; if parties argued for their standpoints and how they did that, and whether something changed in social practice as a result of the debate or not. The framework of the research is the theory of risk society by Ulrich Beck according to which modern Western societies are in the middle of moving from the first stage of modernity or an industrial society towards the so-called second stage of modernity or a risk society. Unlike all former cultures and development stages of society, notwithstanding dangers they faced in many different ways, a modern society is confronted with itself in handling risks (Beck 2005: 236). According to Beck, the political system is also going through changes because of continuously increasing risks, and competent governmental control authorities and risk- sensitive public media begin increasingly take the floor and interfere in the system. Consensus existed previously regarding progress, according to which the technological progress was equalized to the social progress. In a risk society those mechanisms are changing and Beck considers involving citizens and discussing risks important. Progressive mentality has been prevailed in Estonia after the restoration of independence. The state has been introduced as a successful e-state; innovative technologies have been willingly adopted by people and came into use. Virtualization of elections or the concept of e-elections where people having the right to vote can make their choices via Internet was also proposed in connection with the increasing flow of e-services. Such an innovative step raised discussions both in media and the Parliament of Estonia during development of respective statutes. The present research examined opinion articles published in dailies, debates in the Parliament of Estonia and commentaries in Internet in 2005. A selection of texts based on the results of content analysis of seminar paper by Mari-Liis Jakobson and texts aggregated in the sample included risk and/or progress arguments. The sample included 14 texts from opinion articles of dailies and Internet commentaries to those articles. The longest debate on the 3rd of May and also debates on the 11th of May and 9th of June in the Parliament of Estonia were included in analysis. The work examined, on the basis of discourse analysis, risk and progress discourses that figured in different environments. Discourses divided into subdiscourses similarly in all environments. Three main fields differentiated in subdiscourses in case of both risk discourse and progress discourse: innovation versus counter-innovation, technological progress versus technological untrustworthiness, and progress of democracy as the third discourse. The analysis showed that discourses collided with each other and there were little intersection and constructive discussion. Manipulative tricks were often used and an argument of other party served as a basis in arguing: generally the argument was disproved by an opposite argument. Interests of an individual user (security, subjects of fraud, privacy) were mainly pointed out in the risk discourse. The analysis of social development and opportunities was represented to a lesser extent. Progress discourse depicted e-elections rather as a constructive force for society (increasing electoral activity, involvement of young people). Risk discourse gave more reasons in the context of conventionality and legality. Briefly we can say that risk discourse was more represented both in the Parliament of Estonia and opinion articles and commentaries but progress discourse prevailed nevertheless. In proof of the latter we can point out the fact that e-elections were enacted and also implemented without major changes that were requested by speakers of risk discourse. Against Beck’s risk society and on the basis of examined debate, we can say that risks are more often a subject in Estonia than before but the quality of the debate and the manner and form of dialogue in order to find results that would satisfy all parties was weak and striving to self-profit.http://tartu.ester.ee/record=b2115269~S1*es

Koolieelikute digivahendite kasutamise harjumused lapsevanemate hinnangul ja vanemate teadlikkus laste suunamisel

https://www.ester.ee/record=b5382354*es

Kohtulik järelevalve eestkostja tegevuse üle

http://www.ester.ee/record=b4377980~S1*es