Mahajäetud alade mõju röövtoiduliste lülijalgsete arvukusele tootmispõldudel
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Kuupäev
2024
Kättesaadav alates
30.08.2024
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Inimpopulatsiooni kiire kasvu ja sellega kaasneva suureneva nõudlusega muutub põllumajandus järjest intensiivsemaks, tuues kaasa pestitsiidide suurema kasutamise vajaduse. Kuigi pestitsiidid on taimekasvatuse seisukohalt olulised, aidates tõrjuda kahjureid ja tagada saagikust, siis nende kasutamine saastab mulda, vett ja õhku, vähendab elurikkust, põhjustab kahjurite resistentsust ja on kahjulikud ka inimese tervisele. Röövtoiduliste lülijalgsed pakuvad olulist loodusliku kahjuritõrje teenust ehk loodusehüve. Nende esinemine agroökosüsteemides võiks vähendada insektisiidide kasutamise vajadust. Röövtoiduliste putukate poolt pakutava kahjuritõrjehüve suurendamiseks on vaja pakkuda neile sobivaid elu-, toitumis-, varjumis- ja talvitumispaiku.
Käesoleva uurimustöö eesmärk oli välja selgitada, kas ja kuidas mõjutavad mahajäetud alad põllumajandusmaastikul röövtoiduliste lülijalgsete arvukust tootmispõldudel.
Uurimustöös kasutati putukate arvukuse määramiseks pinnasepüüniste- ja loodusliku kahjuritõrje potentsiaali hindamiseks peibutussööda katset. Katse viidi läbi Tartumaal ja koosnes 6 mahajäetud alast, 6 fookuspõllust ja 6 kontrollpõllust. Kõigile uuritavatele aladele paigutati 4 pinnasepüünist ja 4 peibutussööda alust 2, 10, 20 ja 30 m kaugusele uuritava ala servast, liikudes keskosa suunas. Pinnasepüünised asetati uuritavatele aladele 26.06.23, 27.07.23 ja 22.08.23 ning tühjendati 48 tunni möödudes. Peibutussööda alused asetati uuritavatele aladele 21.06.23, 28.07.23 ja 23.08.23 ning 6 tunni möödudes märgiti üles söödud, kadunud ja elusad vastsed. Kokku paigutati katsealadele putukate püüdmiseks 216 pinnasepüünist ja kahjuritõrje potentsiaali hindamiseks 216 peibutussööda alust.
Katse tulemusel selgus, et mahajäetud aladel sattus röövtoidulisi lülijalgseid pinnasepüünistesse oluliselt vähem kui tootmispõldudel. Selline tulemus võis olla mõjutatud valitud kogumismeetodi eripäradest ja taimestiku tihedusest. Tihedam taimestik võib piirata nii putukate liikumist mullapinnal aga ka maapinna soojenemist ja seeläbi mõjutada lülijalgsete aktiivsust. Pinnasepüüniste kasutamisel tuleb arvestada, et püügitulemus võib olla mõjutatud putukate aktiivsusest, vähem aktiivsemad liigid ei pruukinud püünistesse sattuda. Samas võib jooksiklaste ja lühitiiblaste suuremat arvukust tootmispõldudel põhjendada ka sellega, et tootmispõldudel võis olla suurem toidubaas sinna koondunud kahjurite tõttu. Mahajäetud aladel saadi aga oluliselt suurem kahjuritõrje potentsiaal, kui tootmispõldudel. Sellise tulemuse põhjuseks võis olla see, et mahajäetud alade tihedam taimestik on koduks paljudele erinevatele liikidele, sh liikidele keda pinnasepüünistega ei suudetud püüda. Kuna fookus- ja kontrollpõldude vahel ei esinenud olulist statistilist erinevust, ei saa järeldada, et mahajäetud aladelt levisid röövtoidulised lülijalgsed tootmispõldudele ja panustasid seal kahjuritõrjesse. Kuigi antud uurimustöös ei suudetud tõestada, et mahajäetud alad soodustavad röövtoiduliste lülijalgsete levikut tootmispõldudele, saadi siiski kinnitus, et maastiku mitmekesisus soodustab kisklust. Seega on vaja rohkem uurida, kuidas maastikukorraldust saab kasutada taimekahjurite kontrollimiseks röövtoiduliste lülijalgsete abil.
With the rapid increase in human population and the associated high demand for food, agriculture is becoming increasingly intensive, leading to the need for increased use of pesticides. While pesticides are important for crop production, helping to control pests and ensure yields, their use pollutes soil, water, and air, reduces biodiversity, causes pest resistance, and is also harmful to human health. Invertebrate arthropods provide an important natural pest control service or natural benefit. Their presence in agro-ecosystems could reduce the need for insecticides. To increase the pest control benefits provided by insect predators, it is necessary to provide suitable habitats for them to live, feed, shelter, and overwinter. This study aimed to find out whether and how abandoned areas in agricultural landscapes affect the abundance of arthropod predators in production fields. The study used pitfall traps to determine the abundance of insects and a sentinel pray experiment to assess the potential for natural pest control. The experiment was carried out in Tartu County and consisted of 6 abandoned areas, 6 focus fields and 6 control fields. For each study area, 4 pitfall traps and 4 sentinel prays were placed at 2, 10, 20 and 30 m from the edge of the study area, moving towards the centre. The pitfall traps were placed in the study areas on 26.06.23, 27.07.23, and 22.08.23 and emptied after 48 hours. Sentinel prays were placed in the study areas on 21.06.23, 28.07.23, and 23.08.23 and after 6 hours, eaten, missing, and live larvae were recorded. A total of 216 pitfall traps were placed in the test areas to capture insects and 216 sentinel prays were placed to assess the pest control potential. The results of the experiment showed that the number of arthropod predators in the pitfall traps was significantly lower in abandoned areas than in focal fields. This result may have been influenced by the particularities of the collection method chosen and the density of the vegetation. Dense vegetation can limit the movement of insects on the soil surface as well as the warming of the ground, thereby affecting arthropod activity. When using pitfall traps, it should be considered that the catch results may be influenced by insect activity; less active species might not be captured. The higher abundance of ground beetles and rove beetles in production fields can be explained by a larger food base due to the concen-tration of pests in these fields. The potential for pest control was higher in the abandoned fields than in the focal fields. The reason for such result could be that the denser vegetation in abandoned areas serves as a home to many different species, including those that could not be captured with pitfall traps. Since there was no significant statistical difference be-tween the focus and control fields, it cannot be concluded that predatory arthropods spread from abandoned areas to production fields and contributed to pest control there. Although this study did not provide confirmation that arthropod predators spread from the aban-doned areas to the production fields and contributed to pest control there, it did confirm that landscape diversity promotes predation. Hence, further research is needed to explore how landscape management can be utilized for controlling plant pests through predatory arthropods.
With the rapid increase in human population and the associated high demand for food, agriculture is becoming increasingly intensive, leading to the need for increased use of pesticides. While pesticides are important for crop production, helping to control pests and ensure yields, their use pollutes soil, water, and air, reduces biodiversity, causes pest resistance, and is also harmful to human health. Invertebrate arthropods provide an important natural pest control service or natural benefit. Their presence in agro-ecosystems could reduce the need for insecticides. To increase the pest control benefits provided by insect predators, it is necessary to provide suitable habitats for them to live, feed, shelter, and overwinter. This study aimed to find out whether and how abandoned areas in agricultural landscapes affect the abundance of arthropod predators in production fields. The study used pitfall traps to determine the abundance of insects and a sentinel pray experiment to assess the potential for natural pest control. The experiment was carried out in Tartu County and consisted of 6 abandoned areas, 6 focus fields and 6 control fields. For each study area, 4 pitfall traps and 4 sentinel prays were placed at 2, 10, 20 and 30 m from the edge of the study area, moving towards the centre. The pitfall traps were placed in the study areas on 26.06.23, 27.07.23, and 22.08.23 and emptied after 48 hours. Sentinel prays were placed in the study areas on 21.06.23, 28.07.23, and 23.08.23 and after 6 hours, eaten, missing, and live larvae were recorded. A total of 216 pitfall traps were placed in the test areas to capture insects and 216 sentinel prays were placed to assess the pest control potential. The results of the experiment showed that the number of arthropod predators in the pitfall traps was significantly lower in abandoned areas than in focal fields. This result may have been influenced by the particularities of the collection method chosen and the density of the vegetation. Dense vegetation can limit the movement of insects on the soil surface as well as the warming of the ground, thereby affecting arthropod activity. When using pitfall traps, it should be considered that the catch results may be influenced by insect activity; less active species might not be captured. The higher abundance of ground beetles and rove beetles in production fields can be explained by a larger food base due to the concen-tration of pests in these fields. The potential for pest control was higher in the abandoned fields than in the focal fields. The reason for such result could be that the denser vegetation in abandoned areas serves as a home to many different species, including those that could not be captured with pitfall traps. Since there was no significant statistical difference be-tween the focus and control fields, it cannot be concluded that predatory arthropods spread from abandoned areas to production fields and contributed to pest control there. Although this study did not provide confirmation that arthropod predators spread from the aban-doned areas to the production fields and contributed to pest control there, it did confirm that landscape diversity promotes predation. Hence, further research is needed to explore how landscape management can be utilized for controlling plant pests through predatory arthropods.
Kirjeldus
Bakalaureusetöö
Põllumajandussaaduste tootmise ja turustamise õppekaval
Märksõnad
bakalaureusetööd, põllumajandusmaastik, bioloogiline kahjuritõrje jooksiklased, lühitiiblased, Roheline Ülikool (töö toetab EMÜ Rohelise Ülikooli põhimõtteid), elurikkus, pärandkooslused, pärandmaastikud, maastikukaitse