不同退耕还林林草复合经营模式生物量和营养元素循环研究

Study on Biomass and Nutrient Content Cycle of Different Forest and Grass System in Converting Farm Lands to Forest and Grass

以四川盆周山地退耕还林中杉木与黑麦草、三倍体毛白杨与黑麦草、杂交竹与牛鞭草三种不同林草模式为研究对象,对其生物量及其分配、营养元素循环进行研究为林草混交提供理论支撑。结果表明:1林木与草生物量各组分所占比例地上部分>地下部分;树干>树枝、树叶。乔木层中,杉木现存量>毛白杨>杂交竹。各模式林木现存量分配规律均以树干材最大,杂交竹竿材>杉木>毛白杨;树皮现存量占乔木层的10%以上;毛白杨根系占23%,杉木占比例最小;树干与树冠之比,杂交竹最大。毛白杨树冠较大,树干与树冠之比较小;枝与叶现存量之比仍以杂交竹最大,杉木最小;光合系统与非光合系统比值杂交竹最大,充分说明这一模式的重要意义。

Forest and grass ecosystem plays a very important role in converting agricultural lands to forest.This paper makes a preliminary study was made on biomass and its distribution and neighborhood interference between forest and grassland about three different forest-grassland patterns(ⅠCunninghamia lanceolatta with Lolium multiflorum.ⅡTtiploid tomentosa with Lolium multiflorum.Ⅲ Bambusa pervariabilis×Dendrocal amopsis validus with Hemarthria) around the Sichuan basin.The result shows that:proportion of forest and grass biomass on the ground > under ground;trunk > twig and leaf.Pattern Ⅲ belongs to artificially management precisely,and Hemarthria yield attains to 7.28 t/km^2.In the other patterns grass biomass is very low,and especially in the patternⅡ.The grass biomass is the lowest.Cunninghamia lanceolatta remained content is by the most in the high forest.The second is Ttiploid tomentosa.The third is Bambusa pervariabilis×Dendrocal amopsis validus.The distribution of trunk remained content is higher in every pattern.The rate of the bark remained content is above 10% in the high forest.The rate of Ttiploid tomentosa root is 23%.And the rate of Cunninghamia Lanceolatta is the lowest;To Bambusa pervariabilis×Denarocal amopsis validus,the ration between trunk and crown is the biggest.This is relating to bamboo's grown features.Ttiploid tomentosa crown is the biggest but the ratio is the lowest .About the ratio of branch and leaf,Bambusa pervariabilis×Dendrocal amopsis validus is the highest but Cunninghamia lanceolatta is the lowest.The ration of trunk and leaf is Bambusa pervariabilis×Dendrocal amopsis validus > Ttiploid tomentosa> Cunninghamia lanceolatta.The biggest ration of photosynthetic system and non-photosynthetic system is Bambusa pervariabilis×Dendrocal amopsis validus.In the pattern Ⅲ everything is the biggest,pattern Ⅲ is a very important model.