植物热值的测定

植物热值是草原生态系统中能流研究的重要指标。热值测定采用氧弹法，其原理是将定量试样在充氧的弹筒中燃烧，由燃烧后水温的升高计算试样发热量。为了获得准确测定结果，应注意读温准确、试样均匀、选择最佳氧气压力，以及尽量减少对样品的污染。测定结果表明，草原植物的热值随不同植物种，以及同一种植物不同部位和生长发育的阶段而变化。

The Measurement of Calorific Values to Plant Material

The calorific values of plants is an important index in the research of energy flow of the grassland ecosystem. The measurement of calorific values uses bomb calorimeter. The principle is to burnout quantitative sample in a bomb with oxygen and the calorific values of plant material is calculated according to raised temperature value. The exact data would be obtained by paying attention to keep temperature values accuratly, mix sample evenly, select the optimum pressure of oxygen and reducing sample pollution as much as possible. The results have shown that calorific values of grassland plants varies along with different species of plants and different parts of plant in the same species and different growing stages of plant.