Kiletiivaliste parasitoidide (Apocrita: Parasitica) arvukus ja taksonoomiline mitmekesisus talirapsi põllul ja sellega piirneval maastikuelemendil
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Kuupäev
2017
Kättesaadav alates
alates 31.08.2022
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Magistritöö teema on seotud europrojektiga QuESSA (i.k. Quantification of Ecosystem
Services for Sustainable Agriculture; e.k. Ökosüsteemi teenuste roll jätkusuutlikus
põllumajanduses). Töö eesmärgiks oli välja selgitada kui palju ja milliseid potentsiaalselt
kasulikke parasitoide esineb talirapsi põllul ja sellega piirneval maastikuelemendil ning
uurida, kas rapsipõlluga piirnev põllumajandusmaastiku element mõjutab kiletiivaliste
parasitoidide arvukust ja mitmekesisust talirapsi põllul. Selleks viidi 2014. aastal Tartumaa
talirapsi põldudel ja nendega piirnevatel maastikuelementidel läbi välitööd. Käesoleva töö
käigus uuriti kasutades vesipüüniste meetodit, millised kiletiivaliste parasitoidide
sugukonnad esinevad rapsipõldudel ja nendega piirnevatel maastikuelementidel. Uuritavad
maastikuelemendid, mis piirnesid vaatlusala keskel asuva rapsipõlluga olid kitsas rohtne
põlluserv, kitsas puudega põlluserv ehk puiskoridor ja teine kultuurpõld ehk kontroll-ala.
Kokku leiti vesipüünistest 1344 isendit 18 erinevast sugukonnast. Kõige enam leiti
vesipüünistest Ichneumonoidea, Chalcidoidea ja Platygastroidea ülemsugukondadesse
kuuluvaid isendeid. Tulemused näitasid, et maastikuelemendi tüüp mõjutas oluliselt
parasitoidide arvukust ja mitmekesisust. Rohtse põlluservaga piirnenud rapsipõllult püüti
keskmiselt oluliselt rohkem parasitoide kui teise kultuurpõlluga piirnenud rapsipõldudelt.
Nii rohtsel põlluserval kui ka puiskoridoril endal paiknenud püünistest leiti oluliselt
rohkem parasitoide võrreldes teisel kultuurpõllul paiknenud püünistega. Parasitoidide
mitmekesisus oli kõige suurem puiskoridoridega piirnevatel rapsipõldudel. Ka kaugus
rapsipõllu servast mõjutas oluliselt parasitoidide keskmist arvukust põllul, arvukus vähenes
põllu keskosa suunas.
Töö tulemustest võib järeldada, et nii rohuriba kui ka puiskoridor põlluservas suurendasid
kasulike parasitoidide arvukust ja mitmekesisust. Seega suurendades maastikuelementide
osatähtsust põllumajandusmaastikul jõuavad parasitoidide poolt pakutavad reguleerivad
ökosüsteemi teenused suuremal määral ka kultuurpõllule.
This Master´s thesis is a part of the project QuESSA (Quantification of Ecosystem Services for Sustainable Agriculture). The research aims were to determine how many and what kind of potentially useful parasitoids are abundant in winter oilseed rape fields and in their adjacent landscape elements, and to find out whether landscape elements affect the abundance and diversity of parasitic Hymenoptera in winter oilseed rape fields. The experiment was carried out using water traps in winter oilseed rape fields and adjacent landscape elements in Tartu County, in the summer of 2014. The study area of each focal field was directly bordered by either a linear herbaceous element (a grass strip), a linear woody element (a line of shrub, hedge or trees) or with another field with a different crop (control area). Altogether 1344 individuals belonging to 18 different families were collected. Throughout the study the most abundant superfamilies were Ichneumonoidea, Chalcidoidea and Platygastroidea. The results showed that the type of landscape element had a significant effect on the abundance and diversity of parasitoids. On average, the abundance of parasitoids was higher in grass strips and woody linear elements, than in another crop field. Within the oilseed rape crop, the distance from the crop margin also influenced the average abundance of parasitoids significantly. The abundance decreased towards the centre of the field. It can be concluded from the results of the current study, that herbaceous linear and woody linear field bordering elements had a positive effect on the abundance of hymenopteran parasitoids. Therefore, by increasing the proportion of landscape elements in the agricultural lands the regulating ecosystem services offered by parasitoids can reach the fields, which could lead to reduced pest densities.
This Master´s thesis is a part of the project QuESSA (Quantification of Ecosystem Services for Sustainable Agriculture). The research aims were to determine how many and what kind of potentially useful parasitoids are abundant in winter oilseed rape fields and in their adjacent landscape elements, and to find out whether landscape elements affect the abundance and diversity of parasitic Hymenoptera in winter oilseed rape fields. The experiment was carried out using water traps in winter oilseed rape fields and adjacent landscape elements in Tartu County, in the summer of 2014. The study area of each focal field was directly bordered by either a linear herbaceous element (a grass strip), a linear woody element (a line of shrub, hedge or trees) or with another field with a different crop (control area). Altogether 1344 individuals belonging to 18 different families were collected. Throughout the study the most abundant superfamilies were Ichneumonoidea, Chalcidoidea and Platygastroidea. The results showed that the type of landscape element had a significant effect on the abundance and diversity of parasitoids. On average, the abundance of parasitoids was higher in grass strips and woody linear elements, than in another crop field. Within the oilseed rape crop, the distance from the crop margin also influenced the average abundance of parasitoids significantly. The abundance decreased towards the centre of the field. It can be concluded from the results of the current study, that herbaceous linear and woody linear field bordering elements had a positive effect on the abundance of hymenopteran parasitoids. Therefore, by increasing the proportion of landscape elements in the agricultural lands the regulating ecosystem services offered by parasitoids can reach the fields, which could lead to reduced pest densities.
Kirjeldus
Magistritöö
Maastikukaitse ja -hoolduse õppekaval
Märksõnad
magistritööd, agroökosüsteemid, kasulikud lülijalgsed, vesipüünised