内蒙古锡林河流域羊草草原主要建群植物热值及灰分动态变化

草地植物作为生物燃料供给料已经被人们所提及,而植物的热值和灰分含量作为评价生物燃料质量的重要指标,却很少被人们研究。本文通过对内蒙古锡林河流域羊草草原5种多年生禾本科植物(羊草、冰草、大针茅、羽茅和隐子草)的热值和灰分进行测定,探讨了植物热值和灰分的月变化及二者之间相关性。结果表明:5种植物干重热值及去灰分热值月变化均为单峰形变化曲线,干重热值的最大值出现在8月(19.2MJ·kg-1),去灰分热值最大值出现的月份因植物种类不同而表现一定的差异;灰分含量的月变化趋势表现为先降低后升高;冰草、大针茅和隐子草干重热值与灰分含量之间表现为极显著线性负相关(P<0.01),羽茅干重热值与灰分之间表现为显著线性负相关(P<0.05),而羊草干重热值与灰分含量之间的相关性不显著。

Dynamic variations of caloric value and ash content of five dominant grass species in a Leymus chinensis steppe in Xilin River Basin of Inner Mongolia

Grassland plants have been recognized as the feedstocks for biofuel production, but their caloric value and ash content, as the important indicators for assessing the quality of biofuels, are rarely documented. This paper measured the caloric value and ash content of five dominant grass species (Leymus chinensis, Agropyron cristatum, Stipa baicalensis, Achnatherum sibiricum, and Cleistogenes squarrosa) in a Leymus chinensis steppe in Xilin River Basin of Inner Mongolia over a growth season, and approached the monthly variations of and the correlation between the caloric value and ash content. The dynamic variations of dry mass caloric value and ash-free caloric value of the five species followed a single peak pattern. The highest dry mass caloric value (19.2 MJ·kg-1) was observed in August, but the months the maximum ash-free caloric value was observed varied with the plant species. The monthly variations of the ash content of the plant species all showed a trend of decreasing in early growth season and increasing later. There was a significant negative linear correlation (P<0.05) between the dry mass caloric value and ash content of the five plant species except L. chinensis.