Spatial variability of soil chemical properties in Maksimir Park

Cilj ovog diplomskog rada bio je utvrditi prostornu varijabilnost kemijskih značajki tla (pH vrijednost, sadržaj humusa, ukupnog dušika i sumpora, kroma, bakra, olova i cinka) na području Parka Maksimir. Uzorkovanje je provedeno u kolovozu 2022. godine na 12 lokacija unutar parka na dubini od 0-30 cm. Ciljane kemijske značajke tla utvrđene su standardnim laboratorijskim metodama, a za prikaz prostorne varijabilnosti značajki tla i izradu kartografskih prikaza korištena je deterministička prostorna interpolacijska tehnika Inverse Distance Weighting (IDW). Rezultati ukazuju da je tlo Parka Maksimir jako kisele do alkalne reakcije. Kiselo tlo prevladava u sjevernom šumskom dijelu parka, dok je alkalno tla smješteno u južnom dijelu parka u blizini prometnica. Sadržaj humusa ukazuje da je tlo u Parku dosta (3,9 %) do vrlo jako humozno (13,7 %) te dobro (0,168 %) do vrlo bogato (0,562 %) opskrbljeno ukupnim dušikom. Količina ukupnog sumpora na području Parka varirala je od 0,074 % do 0,119 % s prosječnom vrijednošću od 0,094 % i koeficijentom varijacije od 11,9 %. Sadržaj akumuliranih metala u prosjeku je iznosio 48,3 mg Pb/kg, 97,8 mg Zn/kg, 32,1 mg Cu/kg, 97,9 mg Cr/kg. Na svim promatranim lokacijama u Parku sadržaj olova i bakra bio je ispod prepisanih MDK vrijednosti, dok je u sjevernim dijelovima parka s kiselom reakcijom tla sadržaj cinka i kroma premašio propisane MDK vrijednosti (60 mg Zn/kg i 40 mg Cr/kg) u rasponu od 63,0-114,0 mg Zn/kg i 88,0-99,5 mg Cr/kg.The aim of this thesis was to determine the spatial variability of soil chemical characteristics (pH value, organic matter content, total nitrogen and sulphur, chromium, copper, lead and zinc contetnt) in the Maksimir park located in Zagreb. Soil sampling was carried out in August 2022 at 12 locations at a depth of 0-30 cm. The selected soil chemical properties were determined by standard laboratory methods, and the deterministic spatial interpolation technique Inverse Distance Weighting (IDW) was used to display the spatial variability of the soil properties. The results indicate that the soil of Maksimir Park is highly acidic to alkaline. Acidic soil predominates in the northern forest part of the park, while alkaline soil is located in the southern part of the park near roads. The organic matter content indicates that the soil in the Park is quite (3.9%) to very highly supplied (13.7%) by organic matter, as well as good (0.168%) to very rich (0.562 %) supplied with total nitrogen. The amount of total sulfur in the Park varied from 0.074% to 0.119% with an average value of 0.094% and a coefficient of variation of 11.9%. The average content of accumulated metals was 48.3 mg Pb/kg, 97.8 mg Zn/kg, 32.1 mg Cu/kg, 97.9 mg Cr/kg. In all observed locations in the Park, the content of lead and copper was below the prescribed threshold values, while in the northern parts of the park with an acidic soil reaction, the zinc and chromium content exceeded the prescribed threshold values (60 mg Zn/kg and 40 mg Cr/kg) in the range from 63.0-114.0 mg Zn/kg and 88.0-99.5 mg Cr/kg