金沙江干热河谷几种引进树种人工植被的生态学研究

采用标准木法和收获法，对金沙江元谋干热河谷几种引进树种的人工植被（即赤桉×新银合欢混交林、赤桉纯林、新银合欢纯林和印楝纯林）各层植被生物量与天然次生植被（坡柳-扭黄茅灌草丛）进行了比较研究，同时对各类植被的物种组成和物种多样性进行了比较分析。结果表明：（1）采用引进树种人工恢复的植被积累了大量生物质，总生物量大小依次为：赤桉×新银合欢混交林（4491 t/hm2）>新银合欢纯林（3991 t/hm2）>赤桉纯林（3857 t/ hm2）>印楝纯林（1306 t/hm2）>天然次生林（935 t/ hm2）。人工恢复植被生物量主要集中在乔木层，天然次生植被生物量主要集中在灌木、草本和凋落物层。（2）人工恢复植被的物种数均少于天然次生植被，而且不同植被的物种数和物种组成也存在差异。（3）各植被的Shannon wiener多样性指数和Margalef丰富度指数均表现为：印楝纯林>坡柳-扭黄茅灌草丛>赤桉纯林>赤桉×新银合欢混交林。在Alatato均匀度指数方面，各人工植被之间的差异不大，但人工植被与天然次生植被之间有显著差异。〖

ECOLOGICAL STUDY ON SEVERAL MAN-MADE FORESTS OF INTRODUCED SPECIES IN JINSHAJIANG DRY-HOT VALLEY

By means of the standard-timber and the harvesting methods,biomass of the vegetation in different layers of some man-made forests of introduced species including Ecucalyptus camaldulensis- Leucaena leucocephala mixed forest,Ecucalyptus camaldulensis pure forest,Leucaena leucocephala pure forest,Azadirachta indica pure forest and natural secondary forest in the dry-hot valley of Jinshajiang Riv- er,Yuanmou County,was comparatively studied.Species composition and plant diversity between man- made forests of introduced species and natural secondary forest have been compared too.The results showed that:(1)Man-made forests of introduced species in comparison with the natural secondary forest have larger biomass,and general biomass in different forests revealed Ecucalyptus camaldulensis-Leucaena leucocephala mixed forest(44.91 t/hm~2)>Leucaena leucocephala pure forest(39.91 t/hm~2)>Ecucalyptus camaldulensis pure forest(38.57 t/hm~2)>Azadirachta indica pure forest(13.06 t/hm~2)>natural second- ary forest(9.35 t/hm~2).Biomass in tree layers took up the most large parts of the man-made forests,and in natural secondary forest,shrub layer,herbaceous layer and litter layer were the main parts.(2)The number of species in man-made forest was fewer than in natural secondary forest,and it was different in the number of species and species composition in man-made forests.(3)The Shannon-wiener diversity indexes and Margalef evenness indexes in forests showed Azadirachta indica pure forest>natural secondary forest>Ecucalyptus camaldulensis pure forest>camaldulensis-Leucaena leucocephala mixed forest>Leucaena leucocephala pure forest.There was no significant difference in Alatato evenness indexes among man-made forests,but it was different between man-made forests and natural secondary forest.