浙江大盘山香果树群落各层优势种叶片热值研究

Leaf Caloric Values of the Dominant Species from Emmenopterys henryi Community in Dapanshan National Nature Reserve

对浙江大盘山国家级自然保护区香果树群落各层优势植物不同季节叶的灰分含量和热值进行了比较，结果表明：（1）不同种类植物叶的灰分含量变化较大，介于3．60％～17．55％之间;不同季节植物叶的灰分含量不同，夏秋两季较高，春季较低，经检验，春季植物叶片灰分含量与夏秋两季相比，其差异达到了显著水平（P〈0．05）．群落各层植物叶的平均灰分含量由高到低依次为：草本层（10．42±3．24）%、藤本层（8．56±2．22）％、乔木层（8．80±2．69）％和灌木层（6．16±1．78）％，经检验，仅草本层和灌木层差异显著（P〈0．05）．（2）不同季节之间植物叶片干重热值和去灰分热值均以秋季为最高；各层植物叶的于重热值和去灰分热值由高到低均依次为灌木层（32．15±1．61）kJ／g、乔木层（30．92±1．15）kJ／g、藤本层（30．24±2．33）kJ／g和草本层（30．59±1．63）kJ／g，但各层次之间差异均未达到显著水平（P〉0．05）．（3）为了探讨生境片断化的影响，对保护较为完好的生境（H1）和破坏较严重的生境（H2）下共有的6种植物叶的热值和灰分含量进行了比较研究，结果显示，植物叶的热值为H2〉H1，而灰分含量为H1〉H2．

Emmenopterys henryi Oliv. , an endemic species in China, is one of the national second-class protected wild-plants. This paper focuses on the caloric values, ash contents and dynamics of the mature leaves from the dominant species in the various layers in E. henryi eommunity. The sampling site was located in Dapanshan National Nature Reserve and the calorie values were measured with GR3500-type oxygen bomb calorimeter. The ash contents （AC） of the species ranged from 3.60% to 17. 55% and varied with plant species and sampling seasons. The AC in autumn and summer were higher than those in spring. The ranking order of the average AC in the leaves was the following： herbaceous layer （10. 42%± 3. 24%） 〉 liana layer （8. 56±4.2.22%） 〉 tree layer （8.80%±4.2.69%） 〉shrub layer （6. 16±1.78%）, and the differences among herbaceous and shrub layers were found to be significant （P〈0. 05）. Gross caloric values （GCV） and ash-free caloric values （AFCV） of the species were highest in autumn. The ranking order of average GCV and GCV was the following： shrub layer （32.15±1.61 kJ/g） 〉 tree layer （30. 92±1.15 kJ/g） liana layer （30. 24± 2.33 kJ/g） 〉 herbaeeous layer （30. 59±1.63 kJ/g）, and the differences among these layers were found of little significance （P〉0. 05）. To explore the effects of fragmentation, caloric values of the six species in different habitats were compared. Their gross and ash-free caloric values in fragmentation habitats were all high, thus indicating that fragmentation has a remarkable influence on caloric values.