Abstract | Teški metali kao što su olovo (Pb), kobalt (Co), cink (Zn), bakar (Cu) i mangan (Mn) su široko rasprostranjeni i prirodno prisutni elementi u okolišu. Za većinu organizama u niskim koncentracijama su bezopasni a neki od njih neophodni su za njihovo normalno funkcioniranje. Povećanje sadržaja metala u ekosustavima kao posljedica intenzivne poljoprivredne proizvodnje i drugih ljudskih aktivnosti utječu na smanjenje i/ili izumiranje organizama koji žive u takvim ekosustavima. Trčci su korisni kukci koji žive u tlu i hrane se brojnim vrstama štetnika u poljoprivredi. Vrlo su osjetljivi na promjene u okolišu te se često koriste kao bioindikatori kvalitete agroekosustava i onečišćenja okoliša. Cilj ovog diplomskog rada bio je: 1) utvrditi sadržaj teških metala u tlu i bioindikatorskoj vrsti trčka (Carabus coriaceus Linnaeus, 1758) prikupljenih na poljoprivrednoj i ne poljoprivrednoj površini te 2) izračunati bioakumulacijske faktore u vrsti C. coriaceus u svrhu procjene onečišćenja tla teškim metalima. Uzorci trčaka prikupljeni su tijekom 2022. godine u voćnjaku jabuke (Krapina) i šumi (NP Risnjak) pomoću “pitfall” lovki. Na svakoj pokusnoj površini postavljene su tri lovke. S obje lokacije izdvojeno je 20 primjeraka trčaka koji su pripremljeni za kemijske analize. Na obje lokacije uzorkovano je i tlo i to po jedan prosječan uzorak s dvije dubine (0-30 i 30-60 cm). Sadržaj metala (Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Pb) u trčcima i tlu utvrđen je primjenom pXRF metode. Rezultati istraživanja pokazuju da je jako humozno šumsko tlo na Risnjaku bilo onečišćeno niklom, dok je slabo humozno tlo voćnjaka u Krapini bilo onečišćeno kromom, arsenom, olovom i niklom. Značajno viši sadržaj kroma i cinka zabilježen je u trčcima iz voćnjaka, dok su trčci iz šumskog tla akumulirali značajno viši sadržaj mangana i bakra. Premda tla na promatranim lokacijama nisu bila onečišćena kobaltom, bakrom i cinkom rezultati utvrđenih bioakumulacijskih faktora (BAF >1) pokazuju da se vrsta trčka C. coriaceus može primijeniti za utvrđivanje onečišćenja tla jer pokazuje izrazitu tendenciju akumulacije kobalta, bakra i cinka. |
Abstract (english) | Heavy metals such as lead (Pb), cobalt (Co), zinc (Zn), copper (Cu) and manganese (Mn) are widespread and naturally occurring elements in the environment. In low concentrations they are harmless to most organisms and some of them are necessary for their normal functioning. The increase in metal levels in ecosystems as a result of intensive agricultural production and other human activities has an impact on the reduction and/or extinction of organisms living in such ecosystems. Ground beetles are beneficial insects that live in the soil and feed on many agricultural pests. They are very sensitive to changes in the environment and are often used as bioindicators of agroecosystem quality and pollution. The aim of this work was to 1) determine the levels of heavy metals in soil and ground beetle (Carabus coriaceus Linnaeus, 1758) bioindicator species collected from agricultural and non-agricultural plots, and 2) calculate bioaccumulation factors in the species C. coriaceus to assess soil pollution by heavy metals. In 2022, samples of ground beetles were collected in an apple orchard (Krapina) and in a forest (Risnjak National Park) using "pitfall" traps. Three traps were set in each experimental plot. At both sites, 20 specimens of ground beetles were prepared for chemical analysis, and at both sites the soil was also sampled, namely an average sample at two depths (0-30 and 30-60 cm). The content of metals (Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Pb) in the beetles and in the soil was determined using the pXRF method. The results show that the highly humic forest soil in Risnjak was contaminated with nickel, while the slightly humic soil of the orchard in Krapina was contaminated with chromium, arsenic, lead and nickel. Ground beetles from orchard were found to have significantly higher levels of chromium and zinc, while ground beetles from forest soil had significantly higher levels of manganese and copper. Although the soils at the observed sites were not contaminated with cobalt, copper and zinc, the results of the determined bioaccumulation factors (BAF > 1) indicate that the species C. coriaceus can be used to determine soil contamination, as it has a pronounced tendency to accumulate cobalt, copper and zinc. |