武功山草甸不同海拔对土壤和植物凋落物磷含量的影响

以江西省武功山海拔1 600~1 900m的山地草甸为对象,对不同海拔下,凋落物全磷、土壤全磷、土壤有效磷的空间分布特征以及相互之间的相关性进行分析。结果表明,不同海拔梯度下凋落物全磷、土壤全磷、土壤有效磷分别是0.50~3.53、0.28~1.29、0.19~17.47mg·kg~(-1)。土壤全磷的含量随着海拔的逐渐增加,呈现出"U"型的分布规律,在海拔1 700~1 800m处含量较低。不同物种之间的全磷含量具有明显差异,芒(Miscanthus sinensis)、中华苔草(Carex chinensis)、毛秆野古草(Arundinella hirta)和武功山飘拂草(Fimbristylis wukungshanensis)含量分别是4.21、1.34、1.03、1.28g·kg~(-1),芒的全磷含量显著高于中华苔草、毛秆野古草和武功山飘拂草(P0.05)。相关性分析表明,海拔梯度与土壤全磷之间存在极显著相关性(P0.01),凋落物全磷与土壤有效磷显著正相关,凋落物全磷随着土壤有效磷的增加而增加;凋落物全磷与土壤全磷相关性不显著(P0.05)。说明土壤供磷能力的指标通过土壤有效磷反映,其含量高低主要由凋落物全磷之间的转化方向及分布状况决定,一般认为,凋落物全磷与土壤有效磷的相关性越显著,凋落物全磷的相对有效性就越高。本研究结果有助于进一步了解武功山山地草甸不同海拔梯度对土壤与凋落物磷含量的影响,同时也为山地草甸的植被恢复及可持续经营提供理论依据。

Effect of altitude on the phosphorus contents of soil and plant litter deposits in a Wugong Mountain meadow

Phosphorus is an essential element for plant growth and development.Along with nitrogen and potas-sium,it is one of the three main elements of plant nutrition.In this study,the correlations between the spatial distribution characteristics of litter total phosphorus,soil available phosphorus,and soil total phosphorus at different altitudes were investigated in a mountainous meadow at 1600 ~1900 m above sea level on Wugong Mountain,Jiangxi Province.The results showed that the change ranges of total phosphorus and soil available phosphorus in the litter were 0.50~3.53,0.28~1.29,and 0.19~17.47 mg·kg-1 ,respectively.The soil total phosphorus content in the soil increased with an increase in altitude gradient,showing a "U"type distribution pattern,and the soil total phosphorus content in the soil was low at 1700 ~ 1800 m.There were significant differences in the total phosphorus content between the different species;the phosphorus contents of Miscant-hus sinensis ,Carex chinensis ,Arundinella hirta ,and Fimbristylis wukungshanensis were 4.21,1.34,1.03, and 1.28 g·kg-1 ,respectively.Additionally,the total phosphorus content was significantly different between the different species.The total phosphorus content of M .sinensis was significantly higher than that of C .chinensis ,A .hirta ,and F .wukungshanensis .The correlation analysis showed that there was a significant correlation between the altitudinal gradient and soil total P (P <0.01).There was a significant positive correla-tion between total phosphorus and soil available phosphorus (P <0.05 ).The correlation between total phos-phorus and soil total phosphorus was not significant (P >0.05).It is generally believed that the correlation be-tween total phosphorus and available phosphorus in litter is more and more obvious,and the correlation be-tween soil phosphorus and phosphorus is mainly due to the change in direction and distribution of phosphorus in litter.The relative effectiveness of total phosphorus is higher.The results of this study have helped to gain a better understanding of the effects of different altitudes on the phosphorus content of soil and litter in a meadow on Wugong Mountain,and also provide the theoretical basis for vegetation restoration and sustainable manage-ment of mountain meadows.