不同退化程度高寒草甸主要植物的热值研究

对青海省果洛藏族自治州玛沁县不同退化程度高寒草甸中隶属10科的27种植物地上部分干质量热值进行测定，分析了高寒草甸退化过程中植物热值的变化规律。结果表明，1）高寒草甸常见植物地上部分平均热值为13.99～19.45 kJ·g-1，所测物种热值平均值为17.99 kJ·g-1，高于全球尺度上陆生植物平均热值；2）随着高寒草甸退化程度的增加，由于植物自身的生物学属性特征，不同科属植物热值的响应规律不一，其中禾本科、菊科和龙胆科随着草地退化程度的增加，植物的平均热值均呈先升高后降低的变化趋势，在轻度退化水平下达到最高，莎草科植物平均热值则随草地退化程度增加逐渐增加，不同植物种热值对草地退化的响应变化规律不完全一致；3）在群落水平上，随着草地退化程度的增加，群落热值变化趋势为先升高后降低，在轻度退化水平下达到最高，为18.16 kJ·g-1，重度退化水平下最低，为16.29 kJ·g-1，不同退化草地中群落热值的差异是由物种组成的变化产生的。

Study on caloril values of plants in alpine meadow with different degradation degrees

The caloric values of 27 species from 10 families in alpine meadow with different degraded degrees of Guoluo prefecture ware measured and the change law of caloric value among four degradation levels was analyzed. The results show that: 1) the average caloric value of aboveground parts for alpine meadow common plants varied from 13.99 kJ·g-1 to 19.45 kJ·g-1 and the average caloric value of all species was 17.99 kJ·g-1, which is higher than global scale terrestrial plants. 2) The caloric value changing trends were different due to characteristics of plants' own biological proprieties. With the increased degradation degree, the caloric values of Gramineae, Compositae and Gentianaceae were increased firstly and reached highest point in moderately degraded meadow, then decreased, and that of Cyperaceae showed gradually increasing trend. 3) Caloric value was increased firstly and then decreased with the increased of degradation degree at the level of community, which reached highest point 18.16 kJ·g-1 in lightly degraded meadow, and lowest 16.29 kJ·g-1 in heavy degraded degree. Changes in species composition lead to the variance of community caloric value among different degradation degrees.