对川中丘陵区 1 1年生人工桤柏混交林生态系统能量特征的研究表明 ,植物热值含量随植物种类、器官、分布层次以及季节等的变化而变化 ;生态系统的能量现存量为2 37.53× 1 0 1 0 J·hm- 2 ,每年以凋落物形式归还的能量为 7.55× 1 0 1 0 J·hm- 2 ·a- 1 ,其中凋落叶是系统能量归还的主要形式 ,其能量归还量占能量归还总量的 70 .2 9% ;生态系统能量净固定量为 2 6.73× 1 0 1 0 J·hm- 2 ·a- 1 ,能量转化效率为 2 .34% ,可见人工桤柏混交林具有较高的能量固定能力和太阳能转化效率 . The results showed that the plant caloric value varied with plant species, organs, distribution levels and seasons. The energy stock of ecosystems was 2 37.53 × 1 0 1 0 J · hm-2, and the annual energy returned as litter was 7.55 × 10 1 J · hm -2 · a -1. The litter was the main form of system energy return and the energy return Accounting for 70.29% of the total energy return; the net fixed energy of ecosystem is 2 6.73 × 10 01 J · hm -2 · a -1, and the energy conversion efficiency is 2.34% Forest has high energy fixation and solar energy conversion efficiency.