松嫩草原拂子茅种群热值、生物量和能量动态的研究

拂子茅（Calamagrostis epigejos)全株的叶的热值和季节变化规律相似，呈双峰曲线，2个峰值分别出现在6月中旬和8月初，茎热值的变化呈单峰曲线，峰值出现在8月初，穗笔立枯体的热值变化呈波动型，穗的最大值出现在9月初，立枯估出现在6月中旬，地上部能量现状量的季节变化与生物量变化同步，呈单峰曲线，不同季节能量在各器官中分配比率为：6月中旬为叶＞茎＞穗，7月初为叶＞茎＞立枯体＞穗，7月中旬为叶＞茎＞穗＞立枯体，8月至9月为叶＞茎＞立枯体＞穗，能量的垂直分配，地上部为从地表至20cm高度逐渐增加，最大值在１０－２０cm层占地上部总能量的２６．９１％，然后逐渐下降，地下部能量垂直分布规律是随着深度增加而逐渐减少，能量集中分布在地下0－10cm层在占地下部总能量69．01％。

Study on Dynamics of Calorific Value, Biomass and Energy in Calamagrostis epigejos Population in Songnen Grassland

There were two peaks of seasonal changes of the calorific value in shoot and leaves of Calamagrostis epigejos in middle June and in the early August respectively. The calorific value in stem presented a single peak curve which appeared in the early August. The calorific values in inflorescence and dead standing showed a fluctuation and the peak value of inflorescence was in the early September and that of dead standing was in middle June. The seasonal changes of energy standing crop on the above_ground part synchronized with that of the biomass, which presented a single peak curve. The energy allocated to each organ in different seasons was in the order as leaves >stem >inflorescence in middle June, leaves >stem >dead standing >inflorescence in early July, leaves >stem >inflorescence >dead standing in middle July, and leaves >stem >dead standing >inflorescence from August to September. The vertical allocation of energy in the parts of above_ground was that the energy value gradually increased from the surface to the 20 cm high level and the maximum value at the 10-20 cm high level which made up 26.91% of energy on the above_ground partion, and then it was decreased. In the under_ground portion, the energy value progressively decreased with depth and the maximum value was at 0-10 cm depth layer which made up 69.01% of energy of the under_ground portion.