Dynamics of Carbon and Nitrogen Storages in Plant-Soil System During Desertification Process in Horqin Sandy Land
沙漠化过程中科尔沁沙地植物-土壤系统碳氮储量动态

Organic carbon and nitrogen storages in plant-soil system were measured at different desertification stages(potential,light,moderate,severe,and most-severe) in Horqin sandy land.From potential desertification to light,moderate,severe,and most-severe desertification,total biomass(aboveground and belowground) carbon storages decrease by 26.4%,51.0%,79.0%,and 91.0%,respectively,while total biomass nitrogen storages decrease by 33.6%,66.9%,87.4%,and 93.2%,soil organic carbon storages by 52.2%,75.9%,87.0%,and 90.1%,and soil nitrogen storages by 43.5%,71.0%,81.3%,and 82.7%,respectively.The carbon and nitrogen storages in plant-soil system are in the order: potential(C:(5 266) g·m-2 and N: 534 g·m-2)>light(C:(2 619) g·m-2 and N: 303 g·m-2)>moderate(C:(1 368) g·m-2 and N: 156 g·m-2)>severe(C: 715 g·m-2 and N: 99 g·m-2)>most severe(C: 517 g·m-2 and N: 91 g·m-2).The biomass carbon and nitrogen storages decline more rapidly at later desertification stage(from severe to most-severe) than initial stage(from potential to light),while soil carbon and nitrogen decline more rapidly at initial stage.There is a greater proportional decline in soil carbon than in nitrogen during desertification process.The biomass nitrogen storages decline more rapidly than carbon at initial stage,however,the case is reverse at later stage.