不同海拔梯度高寒草地地下生物量与环境因子的关系

Relationships between belowground biomass of alpine grassland and environmental factors along an altitude gradient

以新疆天山南坡的巴音布鲁克高寒草地为对象,研究了不同海拔梯度高寒草地地下生物量的变化及其与环境因子的关系.结果表明:随着海拔的升高,高寒草原、高寒草原化草甸和高寒草甸的地下生物量逐渐增大,二者呈极显著正相关(P<0.01).地下生物量从表层至底层逐渐递减,呈"T"形分布.高寒草原、高寒草原化草甸和高寒草甸0～10cm土层的地下生物量分别占总地下生物量的68.1%、84.1%和86.7%.地下生物量与大气温度呈极显著负相关,与相对湿度和土壤含水量呈极显著正相关(P<0.01),而与有机质、速效氮和pH等无显著相关.

Taking Bayanbulak alpine grassland on the southern slope of Tianshan Mountain, Xin- jiang as test object, the relationships between belowground biomass and environmental factors along an altitude gradient were analyzed. The results showed that with increasing altitude, the belowground biomass of alpine steppe dominated by Stipa purpurea and Festuca ovina, alpine steppe meadow dominated by Kobresia capillifolia and S. purpurea, and alpine meadow dominated by Carex stenocarpa, Alchemilla tianschanica, and K. capillifolia all increased gradually. There was a significant positive correlation between altitude and belowground biomass （ P 〈 0.01 ）. The belowground biomass decreased with soil deep and with a ‘T’ shape distribution. In alpine steppe, alpine steppe meadow, and alpine meadow, the belowground biomass in 0-10 cm soil layer occupied 68.1%, 84. 1% and 86. 7% of the total, respectively. The belowground biomass of the alpine grassland was negatively correlated with air temperature and positively correlated with relative humidity and soil water content （P 〈0. 01 ）, but had no significant correlation with soil organic matter, available nitrogen, and pH value.