Maastikuelemendi mõju röövtoiduliste lülijalgsete arvukusele talirapsi põllul
Laen...
Kuupäev
2016
Kättesaadav alates
alates 30.05.2021
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Rapsi kasvatatakse üha suuremal kasvupinnal, Eestis on aastatega kasvupind tõusnud ligi
kolm korda, ulatudes 2015. aastal 70,8 tuhande hektarini. Enamlevinud kahjur rapsil on
naeri-hiilamardikas, kelle tõrjeks kasutatakse sünteetilisi taimekaitsevahendeid. Põllumajanduse
intensiivistumine toob kaasa põllumajandusmaastiku homogeniseerumise ja bioloogilise
mitmekesisuse vähenemise. Pool-looduslikud ja looduslikud alad pakuvad elu-,
varje- ja talvitumispaiku kasulikele organismidele põllul, sh. röövtoidulistele lülijalgsetele.
Käesoleva uurimustöö eesmärgiks oli kindlaks teha, kas ja kuidas erinevad rapsipõlluga
piirnevad maastikuelemendid mõjutavad põllul esinevate röövtoiduliste lülijalgsete arvukust
ja liigilist mitmekesisust ning kas röövtoiduliste lülijalgsete arvukus muutub naerihiilamardika
vastsete taimedelt mulda laskumise perioodil, mil nad on maapinnal toituvate
röövtoiduliste lülijalgsete potentsiaalseks toiduobjektiks.
Katse viidi läbi 2014.aastal Tartumaal 18nel vaatlusalal, mille keskmes oli talirapsi põld.
Katsealade valikul lähtuti looduslike ja pool-looduslike maastikuelementide osatähtsusest
vaatlusaladel ja rapsipõlluga piirnevast maastikuelemendi tüübist.
Töö tulemustest selgub, et katse käigus leitud röövtoiduliste lülijalgsete arvukus oli kõrge.
Enim leiti jooksiklasi, neile järgnesid lühitiiblased ja kõige vähem leiti ämblikulaadseid.
Peamiselt mõjutas röövtoiduliste lülijalgsete arvukust talirapsi põldudel maastikuelemendi
tüüp ja püüniste tühjendamise aeg ning röövtoidulisi lülijalgseid leiti talirapsi
tootmispõldudelt kõige rohkem perioodil, mil naeri-hiilamardika vastsed laskusid mulda
nukkuma. Röövtoidulised lülijalgsed eelistavad kõrreliste taimedega kooslusi. Kasulikud
röövtoidulised lülijalgsed võivad hoida naeri-hiilamardikate arvukuse talirapsil tõrjekriteeriumist
allpool, mistõttu nad toovad otsest majanduslikku kasu põllumajandustootjatele.
The area of oilseed rape has increased by nearly three times over the years, reaching 70.8 thousand hectares in 2015. The most common pest of oilseed rape is the pollen beetle, which is controlled by the use of synthetic pesticides. The intensification of agriculture leads to the homogenisation of the agricultural landscape and biological diversity decline. Semi-natural and natural areas offer a suitable habitat, protection from the elements and hibernation site for beneficial organisms in the field, including predatory arthropods. The aim of this study was to determine whether and how 1) different bordering landscape elements affect predatory arthropod abundance in winter oilseed rape fields and 2) predatory arthropod abundance changes while pollen beetle larvae drop to the soil to pupate, when they are easily accessible for ground dwelling predatory arthropods. The study was conducted in 2014 in Tartu County in 18 landscape sectors; each with an oilseed rape field in its centre. The study areas were selected on the basis of natural and semi-natural landscape element abundance and landscape element types adjacent to the oilseed rape field. Predatory arthropod abundance was high during the study. Ground beetles (Carabidae) were the most numerous family followed by staphylinids (Staphylinidae) and arachnids (Arachnida). Predatory arthropod abundance in oilseed rape fields was mainly influenced by landscape element type and sampling time; predatory arthropods were the most abundant when pollen beetle larvae were dropping to the ground to pupate in the soil. We can conclude that predatory arthropods prefer herbaceous vegetations. Beneficial predatory arthropods may keep the pollen beetle abundance in winter oilseed rape field below the economic threshold, which is why they bring direct economic benefits to farmers.
The area of oilseed rape has increased by nearly three times over the years, reaching 70.8 thousand hectares in 2015. The most common pest of oilseed rape is the pollen beetle, which is controlled by the use of synthetic pesticides. The intensification of agriculture leads to the homogenisation of the agricultural landscape and biological diversity decline. Semi-natural and natural areas offer a suitable habitat, protection from the elements and hibernation site for beneficial organisms in the field, including predatory arthropods. The aim of this study was to determine whether and how 1) different bordering landscape elements affect predatory arthropod abundance in winter oilseed rape fields and 2) predatory arthropod abundance changes while pollen beetle larvae drop to the soil to pupate, when they are easily accessible for ground dwelling predatory arthropods. The study was conducted in 2014 in Tartu County in 18 landscape sectors; each with an oilseed rape field in its centre. The study areas were selected on the basis of natural and semi-natural landscape element abundance and landscape element types adjacent to the oilseed rape field. Predatory arthropod abundance was high during the study. Ground beetles (Carabidae) were the most numerous family followed by staphylinids (Staphylinidae) and arachnids (Arachnida). Predatory arthropod abundance in oilseed rape fields was mainly influenced by landscape element type and sampling time; predatory arthropods were the most abundant when pollen beetle larvae were dropping to the ground to pupate in the soil. We can conclude that predatory arthropods prefer herbaceous vegetations. Beneficial predatory arthropods may keep the pollen beetle abundance in winter oilseed rape field below the economic threshold, which is why they bring direct economic benefits to farmers.
Kirjeldus
Märksõnad
maastikud, põllumajandusmaa, raps, kahjurid, lülijalgsed, ämblikulaadsed, jooksiklased, lühitiiblased, arvukus, magistritööd