祁连山北麓荒漠草原5种优势植物生物量与土壤养分特征OA北大核心CSTPCD

To clarify the relationship between plant biomass and soil nutrients of dominant plants in desert grass-lands,this study selected five dominant plant species:Peganum harmala,Setaria viridis,Festuca sinensis,Pucci-nellia distans,and Agropyron cristatum.We measured their biomass and root-zone soil nutrients to explore bio-mass allocation and its relationship with soil nutrients.The results are as follows:(1)There were significant dif-ferences in total biomass and root-shoot ratio among the five dominant plant species(P<0.05),with Peganum har-mala having the highest total biomass and Puccinellia distans having the lowest.The perennial plants Peganum harmala,Puccinellia distans,Festuca sinensis,and Agropyron cristatum had most of their biomass allocated be-low ground,whereas the annual plant Setaria viridis had most of its biomass above ground.The order of root-shoot ratio among the five plants was as follows:Puccinellia distans>Agropyron cristatum>Festuca sinensis>Peganum harmala>Setaria viridis.(2)There were significant differences(P<0.05)in root-zone soil organic car-bon,available nitrogen,available potassium,total nitrogen,total phosphorus,total potassium,and their stoichio-metric characteristics among the five plant species.The order of soil C:N ratio among the five plants was as fol-lows:Puccinellia distans>Setaria viridis>Agropyron cristatum>Peganum harmala>Festuca sinensis.(3)Varia-tions in plant biomass,root-shoot ratio,and soil nutrients varied among the plants.The root-zone soil total potassi-um of Peganum harmala,Setaria viridis,and Festuca sinensis and the root-zone soil moisture of Puccinellia dis-tans and Agropyron cristatum exhibited weak variation,whereas the other plant characteristics,soil nutrients,and stoichiometric characteristics exhibited moderate variation.The biomass of the five dominant plant species exhib-ited a positive correlation with the root-zone soil available nitrogen and total potassium(P<0.05).The allocation of plant biomass and soil nutrient composition significantly vary among different species and life histories in the desert grassland ecosystem.In the future,it will be necessary to restore degraded desert ecosystems by applying appropriate fertilization based on the nutrient requirements of different dominant plant species.