Distribucija i dinamika populacija najznačajnijih grupa polinatora u agroekosistemima Vojvodine

Abstract

U radu je prikazana distribucija, dinamika i diverzitet insekata oprašivača iz reda Hymenoptera - Apiformes (Anthophila) i Diptera Syrphidae) na stepskim fragmentima i na suncokretu u agroekosistema Vojvodine. U cilju uvida u strukturu predela injenog uticaja na sastav i brojnost polinatora, kartirani su tipovistaništa oko svakog stepskog fragmenta. Na osnovu podataka dobijenih kartiranjem, odabrano je sedam stepskih fragmenata kojiu svom okruženju imaju visok udeo suncokreta kao masovnocvetajuće kulture i sedam stepskih fragmenata koji su bez ili saniskim udelom suncokreta. Iz reda Hymenoptera – Apoideazabeleženo je šest familija: Andrenidae, Apidae, Colletidae,Halictidae, Melittidae i Megachilidae, 114 vrsta, a iz reda Diptera(Syrphidae), registrovano je ukupno 11 vrsta. Predstavnici familija Andrenidae, Apidae i Halictidae su distribuirani na svim lokalitetima,predstavnici familije Megachilidae su distribuirani na 15 od 16lokaliteta, a najmanje su zastupljene jedinke familija Colletidae i Melittidae, distribuirane na pet lokaliteta. Polinatori reda Diptera familije Syrphidae su distribuirani na svim lokalitetima. Rezultati Kruskal-Volisovog H testa ukuzuju da je tokom sve tri sezone (2011.,2012., 2013.) na stepskim fragmentima najviše bilo zastupljeno vrsta solitarnih pčela, zatim vrsta osolikih muva, a najmanje vrsta bumbara. Istim testom je dobijano da je tokom sve tri sezone na stepskim fragmentima, registrovano najviše jedinki osolikih muva, zatim medonosne pčele, solitarne pčele, a najmanje jedinki bumbara. Fridmanovim testom su utvrđene razlike u brojnosti (dinamici) polinatora kroz sezone, uočen je porast broja jedinki medonosne pčele i opadanje broja jedinki solitarnih pčela.Rezultati dobijeni Man-Vitnijevim U-testom pokazuju da je na stepskim fragmentima koji imaju niži udeo suncokreta u predelu zastupljeno više jedinki i vrsta bumbara. Istim testom je dobijen rezultat da je na stepskim fragmentima sa visokim udelom suncokreta ima više jedinki medonosne pčele. Vilkoksonovim testom sume rangova je pokazano da su jedinke i vrste bumbara zastupljenije na stepskim fragmentima nakon cvetanja suncokreta, za vreme cvetanja suncokreta na stepskim fragmentima je registrovano više jedinki Apis mellifera, osolikih muva i solitarnih pčela. Modeli regresionih analiza linearnih mešovitih modela su pokazali da se sa porastom udela suncokreta u predelu smanjuje broj jedinki divljih pčela i jedinki i vrsta bumbara. Sa porastom udela polu-prirodnih staništa u predelu i većom cvetnom pokrovnosti, povećava se udeo jedinki i vrsta osolikih muva.

This paper shows distribution, dynamic and pollinator diversity Hymenoptera - Apiformes (Anthophila) and Diptera (Syrphidae) in semi-natural habitats and in sunflower crops in Vojvodina agroecosystems. Around each of 16 selected steppe fragments, habitat types were mapped to test how do landscape structure affects pollinator diversity and abundance in semi natural habitats and in sunflower crops. Based on the results obtained by mapping, seven study sites with high % of sunflower like mass flowering crops, and eight study sites with no or low % of mass flowering crops are selected. In total, there were 114 species from 6 families from order Hymenoptera-Apiformes: Andrenidae, Apidae, Colletidae, Halictidae, Melittidae and Megachilidae, and 11 species from order Diptera (Syrphidae). Insects from families: Andrenidae, Apidae, Colletidae and Halictidae were distributed on all study sites, while insects from family Megachilidae were distributed almost on all study sites (15 sites). At least only on five study sites were distributed insects from family: Colletidae and Melittidae. Hoverflies were distributed on all study sites. Kruskal-Wallis H test shows that an all three seasons (2011., 2012., 2013.) in semi natural habitats wild bees species were most abundant, followed by hoverfly species, and bumblebee species at the end. Same test shows that in all three seasons in semi natural habitats individuals of hoverflies were more abundant than individuals of honey bees, wild bees and individuals of bumblebees, which were least abundant. Friedman test shows differences in densities of pollinator through the seasons, and these results shows increasing in Apis mellifera densities and decline of wild bees densities through seasons. Man-Whitney U-test shows that there were more species and individuals of bumble bees in semi-natural habitats which landscapes are without or low % of sunflower. Same test shows that there were more individuals of honey bees in semi-natural habitats which landscapes have high % of sunflower. Wilcoxon signed-rank test shows that in semi-natural habitats species and individuals of bumblebees were more abundant after blooming sunflower, while species and individuals of wild bees as well as individuals of hoverflies and Apis mellifera were more abundant during blooming sunflower. Linear mixed-effect model shows that with increase of % of sunflower in landscape number of individuals of wild bees and species and individuals of bumblebees decreasing, and individuals of hoverflies increasing. With an increase of % of semi natural habitats and increase of flower cover, abundance and species of hoverflies increases.