https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42906 Wed 07 Sep 2022 15:50:47 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45646 i.e., low (N1), middle (N2), and high (N3) N additions (10, 30, and 90 kg N hm^-2 a^-1, respectively) and an unfertilized control (CK; 0 kg N hm^-2 a^-1), were conducted in the desert grassland of Karamay, Xinjiang, in northwest China. Then, the amounts of 16 priority USEPA PAHs, the total amount of PAHs (∑PAHs), and three biotic-abiotic factors, including soil environmental factors, enzyme activities, and microbial functional diversity, were investigated to demonstrate the effects of N fertilization on PAHs degradation in the desert grassland. The results showed that, the amounts of ∑PAHs and 14 priority USEPA PAHs significantly decreased along the gradient of N addition (N2 ≤ N3 < N1 < CK)(P < 0.01), except for undetected acenaphthylene and acenaphthene, in all N additions treatments. This suggested N fertilization was advantageous to the decrease of soil PAHs in arid desert grassland. Low molecular weight PAHs/heavy molecular weight PAHs > 1.00, whereas 0.40 < fluoranthene/(fluoranthene+pyrene) < 0.50 in CK plots in both April and September, suggesting that PAHs mainly originated from a petroleum pollutant. ∑PAHs in the desert grassland soil equaled to (28.91±2.32) mg/kg in September in Karamay, indicating that the local soil had a heavy pollution level of PAHs. In most situations, the amounts of ∑PAHs and 14 priority USEPA PAHs had a significant regression relationship with soil organic matter, ammonium nitrogen, nitrate nitrogen, total nitrogen, available phosphorus, and urease activity in the generalized linear mixed models (GLMMs) (P < 0.05). The regression function of PAHs to biotic-abiotic factors varied among PAH types. Overall, our results showed that PAH degradation was a complex process in desert grassland soil, which was interactively determined by their own characteristics, plant roots, and microorganisms. N deposition might improve nutritional availability, with positive interactions with plant roots, microorganisms, and PAHs degradation, and the subsequent decrease in PAHs concentration along an N addition gradient.]]> Wed 02 Nov 2022 15:24:16 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42002 Tue 16 Aug 2022 16:44:24 AEST ]]>