东北草原优势植物羊草热值和能量特征

羊草植株和茎热值的季节变化不规则 ,植株最大值出现在 7月中旬 ,为 2 0 .74 4kJ/g ,茎最大值出现在 5月初 ,为 2 1.94 5kJ/g。叶的热值变化从 5月初至 7月中旬基本上呈上升趋势 ,最大值为 2 1.873kJ/g ,然后保持相对平稳。穗的热值变化从 6月初至 7月中旬呈逐渐上升 ,最大值为2 4 .653kJ/g ,然后下降。立枯体热值较低 ,随着植株热值的变化发生一些小的波动。羊草种群地上部能量现存量的季节变化呈单峰曲线 ,峰值出现在 8月中旬 ,为 8518.2 4kJ/m2 。能量现存量的垂直结构 ,地上部为从地表至 30cm高度逐渐增加 ,最大值在 2 0～ 30cm层 ,为 2 154.87kJ/m2 ,然后逐渐下降。地下部变化规律为随着深度增加能值逐渐减少 ,最大值在 0～ 10cm层 ,为 17971.90kJ/m2 。能量在各器官的分配 ,5月份为叶 >茎 ;6月初至 7月初为叶 >茎 >穗 >立枯体 ;7月初至9月初为叶 >茎 >立枯体 >穗 ;9月中旬为叶 >立枯体 >茎 >穗

Calorific value and energy character of dominant Leymus chinensis in Northeast grassland

The calorific value changes of shoot and stem of Leymus chinensis were irregular in growth season.The greatest value of shoot was 20.744 kJ/g in the middle July and that of stem was 21. 945 kJ/g in early May. The calorific value changes of leaf basically trended towards going up from early May to middle July and the greatest value was 21.873 kJ/g, and then kept relatively stable. The calorific value of inflorecence progressively increased from early June to middle July and the greatest value was 24.653 kJ/g, and after that decreasing. The calorific value of dead standing was relatively low, which fluctuated small with the value changes of shoot. The seasonal changes of energy standing crop presented single peak curve on the parts of above ground in L. chinensis population and the peak value was 8 548.24 kJ/m 2 in the middle August. The inverse structure of energy in the parts of above ground was that the energy value gradually increased from surface to 30cm high and the greatest value was 2 154.87 kJ/m 2 in 20~30 cm layer, and after that decreasing. In the parts under ground, the change law of energy value progressively decreased with degree of depth and the greatest value was 17 971.90 kJ/m 2 in 0~10 cm layer. The distribution ratios of energy were leaf>stem in early May; leaf>stem>inflorecence>dead standing from early June to early July; leaf>stem>dead standing>inforecence from early July to early September; leaf>dead standing>stem>inforecence in middle September.