宁夏荒漠草原优势植物叶片C、N、P生态化学计量特征及群落稳定性研究

Study on Leaf Carbon,Nitrogen and Phosphorus Eco-stoichiometric Characteristics and Community Stability of Dominant Plants in Ningxia Desert Steppe

以宁夏盐池县荒漠草原8个典型植物群落为研究对象,研究不同群落优势植物叶片C、N、P生态化学计量特征、群落稳定性及相互关系,结果表明:(1)不同群落优势植物叶片C、N、P含量差异显著(P<0.05),油蒿叶片C含量和P含量最高,白刺叶片N含量最高。短花针茅叶片C∶N和C∶P均显著高于其他优势植物,苦豆子叶片N∶P显著高于其他优势植物。宁夏盐池县荒漠草原植物生长受N和P共同限制。(2)宁夏荒漠草原时间稳定性为45.78~111.55,以甘草群落时间稳定性最高;抵抗力稳定性为-0.51~0.38,以牛枝子群落最高;恢复力稳定性为4.60~5.05,以甘草群落最高、短花针茅群落最低。豆科植物为优势种的群落稳定性高于非豆科植物为优势种的群落。(3)优势植物叶片C含量、N含量、P含量和N∶P与群落稳定性正相关,C∶N、C∶P与群落稳定性负相关。优势植物叶片N含量和抵抗力稳定性(RS)、恢复力稳定性(RL)具有显著的正相关性(P<0.05)。因此,宁夏盐池县荒漠草原优势植物叶片C、N、P生态化学计量特征与群落稳定性具有相关性,特别是优势植物叶片N含量对群落RS和RL有显著影响。

This study explored leaf carbon(C),nitrogen(N)and phosphorus(P)eco-stoichiometric characteristics and community stability of eight distinct plant communities in the Ningxia desert steppe.The results showed that:(1)The leaf contents of C,N and P of dominant plants were significantly different in different communities(P<0.05).The contents of C and P of Artemisia ordosica were the highest,and the N content of Nitraria tangutorum was the highest.The C∶N and C∶P ratios of Stipa breviflora were significantly higher than the other dominant plants;The N∶P ratio of Sophora alopecuroides was significantly higher than other dominant plants.The growth of the Ningxia desert steppe plants was restricted by both N and P contents.(2)The temporal stability(Glycyrrhiza uralensis community as the highest),resistance stability(RS)(Lespedeza potaninii community as the highest),and resilience stability(RL)(Glycyrrhiza uralensis community as the highest and Stipa breviflora community as the lowest)of the Ningxia desert steppe ranged from 45.78 to 111.55,-0.51 to 0.38,and 4.60 to 5.05,respectively.The community with legumes as dominant species was more stable than that of other forages as dominant species.(3)The C,N,P contents and N∶P ratio in leaves of dominant plants had positive correlations with the stability of the community.The C∶N and C∶P ratios negatively correlated with community stability.There was a significant positive correlation between leaf N content and RS and RL values in dominant plants(P<0.05).In conclusion,the eco-stoichiometric characteristics of leaf C,N,and P of dominant plants were correlated with community stability in the Ningxia desert steppe.Especially the leaf N content in dominant plants had a significant influence on community resistance and resilience stability.