Effects of Biocrusts on Soil Nitrogen Mineralization in the Rocky Desertification Area of Guizhou
To explore the impact of biological soil crust on soil nitrogen mineralization in rocky desertification areas of Guizhou,the Guanling-Zhenfeng Huajiang Rocky Desertification Comprehensive Control Demonstration Area in Guizhou Province was selected as the study area.The seasonal dynamic characteristics of soil inorganic nitrogen pool and nitrogen mineralization rate of three different types of biocrusts in Zanthoxylum bungeanum forest,including moss crust,algae-moss mixed crust,and bare soil(without crust),were studied through field in situ buried tube cultivation experiments.The results showed that the ammonium nitrogen content of the three types of soils showed a trend of summer>spring>autumn>winter,and the ammonium nitrogen content of moss crust was significantly higher than that of mixed crust and bare soil in autumn,spring,and summer,which were 1.64,1.69,and 1.94 times higher than mixed crust and 3.36,3.43,and 4.83 times higher than bare soil,respectively;The highest values of nitrate nitrogen content in mixed crust and moss crust both occurred in summer,and the nitrate nitrogen content in moss crust was significantly higher than that in bare soil in winter,spring,and summer,which were 3.57,4.04,and 4.81 times higher than that in bare soil,respectively;The variation trend of inorganic nitrogen content in different types of soils in the same season and in different seasons of the same type of soil was similar to that of nitrate nitrogen content.The net ammonification rate,net nitrification rate,and net nitrogen mineralization rate of the three types of soils were all the lowest in winter.The net ammonification rate of moss crust in summer was significantly higher than the other two types of soils,which were 1.90 and 6.08 times higher than those of mixed crust and bare soil,respectively;The net nitrification rate in spring and summer was significantly higher than that in bare soil,which were 4.09 and 3.18 times higher than in bare soil,respectively;The net nitrogen mineralization rate was significantly higher in spring and summer than that in mixed crust and bare soil.Soil temperature was the main influence factor of soil nitrogen mineralization in autumn and winter,and soil moisture was the main influence factor of soil nitrogen mineralization in spring and summer.In summary,the formation and development of biological crust in karst rocky desertification areas can effectively promote the process of nitrogen mineralization,which is one of the important biological factors affecting nitrogen cycling in this region.
Biological soil crustNitrogen mineralizationRate of nitrogen mineralizationVariation along with seasonal changeSoil temperature and moistureRocky desertification area
万方数据
维普
