Nitrogen cycle of a typical Suaeda salsa marsh ecosystem in the Yellow River estuary  

作　　者：Xiaojie Mou Zhigao Sun Lingling Wang Chuanyuan Wang 

机构地区：[1]Key laboratory of Coastal Environment Processes, CAS, Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China [2]Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012, China [3]Graduate University of Chinese Academy of Sciences, Beijing 100039, China

出　　处：《Journal of Environmental Sciences》2011年第6期958-967,共10页环境科学学报（英文版）

基　　金：supported by the Innovation Program of the Chinese Academy of Sciences(No.KZCX2YW-223);the National Natural Science Foundation of China(No.40803023,40806048);the Key Program of Natural Science Foundation of Shandong Province(No. ZR2010DZ001);the Talents Foundation of the Chinese Academy of Sciences(No.AJ0809BX-036);the Open Research Foundation of Key Laboratory of China Oceanic Administration for Coast Ecology and Environment(No. 200906)

摘　　要：The nitrogen（N） biological cycle of the Suaeda salsa marsh ecosystem in the Yellow River estuary was studied during 2008 to 2009.Results showed that soil N had significant seasonal fluctuations and vertical distribution.The N/P ratio（15.73±1.77） of S.salsa was less than 16,indicating that plant growth was limited by both N and P.The N absorption coefficient of S.salsa was very low（0.007）,while the N utilization and cycle coefficients were high（0.824 and 0.331,respectively）.The N turnover among compartments of S.salsa marsh showed that N uptake from aboveground parts and roots were 2.539 and 0.622 g/m2,respectively.The N translocation from aboveground parts to roots and from roots to soil were 2.042 and 0.076 g/m2,respectively.The N translocation from aboveground living bodies to litter was 0.497 g/m2,the annual N return from litter to soil was far less than 0.368 g/m2,and the net N mineralization in topsoil during the growing season was 0.033 g/m2.N was an important limiting factor in S.salsa marsh,and the ecosystem was classified as unstable and vulnerable.S.salsa was seemingly well adapted to the low-nutrient status and vulnerable habitat,and the nutrient enrichment due to N import from the Yellow River estuary would be a potential threat to the S.salsa marsh.Excessive nutrient loading might favor invasive species and induce severe long-term degradation of the ecosystem if human intervention measures were not taken.The N quantitative relationships determined in our study might provide a scientific basis for the establishment of effective measures.The nitrogen（N） biological cycle of the Suaeda salsa marsh ecosystem in the Yellow River estuary was studied during 2008 to 2009.Results showed that soil N had significant seasonal fluctuations and vertical distribution.The N/P ratio（15.73±1.77） of S.salsa was less than 16,indicating that plant growth was limited by both N and P.The N absorption coefficient of S.salsa was very low（0.007）,while the N utilization and cycle coefficients were high（0.824 and 0.331,respectively）.The N turnover among compartments of S.salsa marsh showed that N uptake from aboveground parts and roots were 2.539 and 0.622 g/m2,respectively.The N translocation from aboveground parts to roots and from roots to soil were 2.042 and 0.076 g/m2,respectively.The N translocation from aboveground living bodies to litter was 0.497 g/m2,the annual N return from litter to soil was far less than 0.368 g/m2,and the net N mineralization in topsoil during the growing season was 0.033 g/m2.N was an important limiting factor in S.salsa marsh,and the ecosystem was classified as unstable and vulnerable.S.salsa was seemingly well adapted to the low-nutrient status and vulnerable habitat,and the nutrient enrichment due to N import from the Yellow River estuary would be a potential threat to the S.salsa marsh.Excessive nutrient loading might favor invasive species and induce severe long-term degradation of the ecosystem if human intervention measures were not taken.The N quantitative relationships determined in our study might provide a scientific basis for the establishment of effective measures.

关 键 词：compartment model nitrogen biological cycle Suaeda salsa Yellow River estuary 

分 类 号：X144[环境科学与工程—环境科学] P931.7[天文地球—自然地理学]