新疆荒漠草地地上和地下生物量分配格局

Distribution patterns of aboveground and underground biomass in desert grasslands in Xinjiang

草地生态系统中生物量的分配格局对研究生态系统碳储量和碳循环有着重要意义,为了探究新疆荒漠草地地上和地下生物量分配格局,分析了新疆荒漠草地分配特征,对荒漠草地地上、地下生物量进行评估。结果表明:(1)荒漠草地地上和地下生物量分别为15.16~164.67和1109.50~3284.00 g·m^(−2),根冠比介于16.09~98.42,地下生物量均大于地上生物量。(2)荒漠草地地上生物量与地下生物量呈幂函数关系y=535.35x^(0.2916)(R^(2)=0.51,P<0.01),对数方程拟合斜率为0.45,与1存在显著性差异(P<0.05),说明地上和地下生物量呈异速生长关系。(3)土壤深度为0-50 cm时,荒漠草地地下生物量占总地下生物量的76.05%,说明绝大部分根系集中在0-50 cm土层,荒漠草地地下生物量分布曲线符合幂函数。研究荒漠草地生物量分配格局对准确评估荒漠草地碳储量、深刻理解干旱区草地碳循环有重要意义。

The allocation of biomass in grassland ecosystems is essential for research on carbon storage and cycling in ecosystems.To explore the distribution patterns of aboveground and underground biomass of desert grasslands in Xinjiang,its distribution characteristics were analysed and evaluated.The results showed that:(1)Aboveground and underground biomass of desert grasslands ranged from 15.16 to 164.67 and 1109.50 to 3284.00 g·m^(−2),respectively.The root-shoot ratios ranged from 16.09 to 98.42.Therefore,the belowground biomass was greater than the aboveground biomass.(2)The power function relationship between aboveround and underground biomass in the desert grasslands was y=535.35x^(0.2916)(R^(2)=0.51,P<0.01),and the slope of the fit(using logarithmic equation)was 0.45,which was significantly different from 1.Thus,an allometric growth relationship between the aboveground and underground biomass was established.(3)Approximately 76.05%of the total underground biomass of the desert grasslands is distributed at a soil depth of 0-50 cm,showing that most roots cluster in this upper layer of soil.Moreover,the distribution curve of underground biomass of the desert grasslands conforms to the power function.The study of biomass distribution patterns in desert grasslands is necessary to accurately assess desert grassland carbon stocks and develop a deeper understanding of the carbon cycle in dryland grasslands.