塔里木河地区胡杨—柽柳混交林的结构与功能

在调查塔里木河地区不同混交模式林分生产力、生物量及其分配状况、林分土壤养分分配状况、混交距离对胡杨生长的影响与不同林分土壤水源涵养能力的基础上,研究不同混交模式的结构与功能关系.结果表明,胡杨—柽柳块状混交林的生产力、生物量及其分配状况均好于胡杨—柽柳带状混交林与胡杨纯林.胡杨—柽柳块状混交林林下枯落物分解速度较快,积累量明显少于胡杨—柽柳带状混交林与胡杨纯林,说明胡杨—柽柳块状混交林具有较好的改良土壤作用,胡杨—柽柳块状混交林的土壤物理、化学性质及其涵养水源功能好于胡杨—柽柳混交林与胡杨纯林.此外,25 a胡杨—柽柳混交林混交距离应大于900 cm;混交方式采用块状混交能起到较好的效果.

The Structure and Function of Populus Euphratica-Tamarix Chinensis Mixed Forests in Tarim River Area

The relationship between structure and function for different types of Populus euphratica and Tamarix chinensis mixed forests in Tarim river area was studied in terms of productivity, biomass, soil nutrients, effects of different mixed distances on the growth of Populus euphratiea trees as well as water conservation capacity of different stands. Results show that the productivity, biomass and its distribution status of mixed forest with block - shaped structure are better than those of mixed forest with strip - shaped structure. The decomposing speed of litters under block - shaped mixed forest is quicker and the accumulated quantity is obviously lower compared with strip - shaped mixed forest and pure forest. It is indicated that Populus euphratica and Tamarix chinensis mixed forests have good use for improving soil. Soil physical and chemical properties as well as water conservation capacity of block - shaped mixed forest are also higher than those of strip - shaped mixed forest and pure forest. Moreover, the mixed distance between Populus euphratica and Tamarix chinensis should be longer than 900 em in 25 - year - old forest and the better mixed mode is block - shaped.