小针茅草原植被地下与地上生物量季节动态及根冠比变化规律

Study on Seasonal Variation of Aboveground and Underground Biomasses of Vegetation in the Stipa klemenzii Steppe and Their Ratio

利用内蒙古苏尼特右旗小针茅荒漠草原生长季地上、地下生物量数据,分析小针茅草原植被地上、地下生物量以及根冠比的季节动态,并建立根冠比季节动态模型。研究结果表明:①小针茅草原植被地上生物量季节变化呈单峰型曲线,地上生物量的峰值出现在6月下旬,为46.14 g.m-2,地下生物量季节动态表现为"N"型变化规律,最高值出现在7月下旬,最低值出现在8月下旬,分别为1 275.46 g.m-2和365.1 g.m-2。②2011年小针茅草原植被根冠比季节波动较大,最小根冠比为16.8,出现在8月下旬,最大根冠比为51.05,出现在7月下旬。③小针茅草原植被地上生物量与根冠比具有较明显的相关关系,8月的相关关系最好,相关系数达到0.626,可以用8月的地上生物量模拟根冠比的变化。

In this paper,the aboveground and belowground biomasses and root-shoot ratio of vegetation in the Stipa klemenzii steppe in Sonid Right Banner,Inner Mongolia were analyzed based on the data of aboveground and underground biomasses of vegetation in the steppe in growing season,and seasonal dynamic variation models of root-shoot ratio of vegetation were developed.The results are as follows：（1） The curve of aboveground biomass of vegetation in the S.klemenzii steppe in 2011 was remarkably unimodal,the peak value was 46.14 g·m-2 and occurred in late June.The curve of seasonal dynamic change of underground biomass was N-shaped,the peak and lowest values occurred in late July and late August,and their values were 1 275.46 g·m-2 and 365.1 g·m-2,respectively.The peak value of underground biomass occurred one month later than that of aboveground biomass;（2） The root-shoot ratio of vegetation in the S.klemenzii steppe in 2011 was fluctuated seasonally,the lowest value（16.8） and the highest value（51.05） occurred in late August and late July respectively;（3） There was a significant correlation between the aboveground biomass and the root-shoot ratio in 2011,in which the correlation in August was the highest,and the correlation coefficient was as high as 0.626,so the aboveground biomass in August could be used to simulate the variation of root-shoot ratio of vegetation in the S.klemenzii steppe.