The Study On The Relationship Between Mowing Succession And The Rule Of Energy Fixation And Distribution

Leymus chinensis steppe is a distinctive formation in the east of Eurasia steppe region, and has a extensive distribution in the steppe region of China. This steppe is one of types with high utilization value. L. chinensis steppe is the important mowing and grazing rangeland for Inner Mongolia husbandry. But due to excess and irrational utilize, L. chinensis steppe occur degradation with different degree. As one of major utilization manner, mowing takes away a portion of material and energy from the system. Successive and intensity mowing must lead the lost and unbalance of substance and energy, and lead up to degradation succession of the grassland. Based on dynamic monitoring data and plant sampling for 18 years on the field treated with different frequency and different season mowing, we studied the rule of energy fixing and distribution on different biological levels including community, population, individual and tissue in L. chinensis steppe, and tend to reveal the energetic succession mechanism of L. chinensis steppe, and analyze and conclude the rule of mowing succession at a long time scale. The research can perfect and enrich the ecological succession theory, and provide theoretical basis for establishing rational mowing system and utilizing manner.The major results are as follows:1. The study about the caloric value of major plant population shows: the caloric value is different for plant species, part of plant, sampling seasons and climate condition. The caloric values of major plant populations vary from 15703 to 18141j/g. The shrub (Caragana microphylla) has the highest value. Most of grasses have higher calorie value, but the values of most of herbs are low. The calorie values of underground parts for major populations vary from 15051-16410j/g. Among them, the value of underground part of rhizome grasses is higher. The difference of underground caloric value of different species isn?ˉt...