دانلود رایگان مقاله انگلیسی ترمیم خاک و مکان های احیا مجدد زندگی گیاهی در زمین های فسفریت کینگیسپ - اشپرینگر 2018

Abstract

Processes of initial soil formation were studied on long-term monitoring plots on dump rocks of quarry no. 3 of the Phosphorite production company in Kingisepp district of Leningrad oblast. Observations were performed in 1998, 2004, and 2014. It was shown that vegetation succession on the plots proceeds relatively quickly, and that the species composition of phytocenoses formed is typical of the areas with soddy-calcareous soils. Soil development proved to be correlated with the development of vegetation. Maximum changes in soil characteristics were observed with an increase in the density of forest vegetation and a decrease in the role of herbs. The molecular composition of humic acids in the studied soils remained stable; in particular, the ratio of aliphatic to alkyl aromatic fragments was virtually constant. This phenomenon could be due to the great amount of aliphatic components in the falloff of coniferous species subjected to humification.

CONCLUSIONS

Performed study attested to the dynamical restoration of phytocenoses and soils on calcareous loamy dump rocks from a quarry of the Phosphorite Production Company. Relatively intense development of vegetation resulted in the formation of forest communities that are most typical for taiga zone of European Russia. In general, we can note very favorable properties of substrate (pH and particle-size composition) for plant development, and this suggested relative efficiency of such method of reclamation. It was found that gradual mineralization of organic matter took place in the case, when substrate initially contained organic matter, and this resulted in the decrease of organic matter content in fine earth and increase of humus enrichment with nitrogen. Gradual increase of organic matter content was observed in the case of initially humusless substrates. It was determined that soil formation was connected with the initial characteristics of the plant cover, its further development, and its species composition. It was shown that maximal difference in morphogenetic characteristics of soil profiles was observed during the process of decrease of herbaceous vegetation participation and development of forest vegetation. Pedogenesis proceeded in a similar way under different forest phytocenoses. It has been proved that all studied plots had very low level of microbial community functioning. The results of qualitative and quantitative analyses of humic acids revealed low level of carbon skeleton changes in time and similarity of humic acids composition under different communities. It was determined that aliphatic groups contained in great amount in needles predominated appreciably over the aromatic ones, and this fact attested significant importance of forest falloff in soil humus formation.