花椒杂草系统地下生物量的空间分配格局  

Spatial Distribution Patterns of Underground Biomass in the Chinese Pricklyash and Weeds System

作　　者：骆宗诗[1] 侯永兴 章路[3] 谢大军[1] 罗晓华[1] 向成华[1] 

机构地区：[1]四川省林业科学研究院,四川成都610081 [2]阆中市二龙林业工作站,四川阆中637400 [3]四川省林业调查规划院,四川成都610081

出　　处：《四川林业科技》2009年第5期22-27,15,共7页Journal of Sichuan Forestry Science and Technology

基　　金：国家"十一五"科技支撑项目--四川盆地低山丘陵区农林复合系统可持续经营技术研究(2006BAD03A054)

摘　　要：农林复合系统中，地下生物量的分配格局是目的物种和间作作物竞争的结果，因而可以看作是模式物种选择及系统设计的依据。在花椒杂草系统模式更新改造中，为了达到间作作物选择和行间配置的合理性，采用壕沟法研究了系统地下生物量的空间分配现状。结果表明：（1）花椒杂草系统地下生物量总量248．57g·m^-2，杂草生物量占82％，花椒仅占18％；（2）该系统地下生物量总量和杂草生物量在水平空间上呈均匀分配，而在垂直空间上随土层加深呈负指数分配，其表达式分别是Y=1024．6exp^-0.5254x（R^2=0．9688，x为土层深度，cm）和Y=1187．2exp^-0.6889（R^2=0．9989，x为土层深度，cm）；花椒根量均匀分配于垂直空间，而在水平空间上呈负指数式分配，其表达式为Y=118．3exp^-0.3817x（R^2=0．8215，x为距树干距离）；（3）花椒吸水根生物量均匀分配于地下空间，杂草吸水根生物量的分配呈现出明显的分层现象，其吸水根总量的81．11％分配于0～15cm土层，而15cm以下土层仅占18．89％；（4）所研究的256个500cm^3的取样单元中，花椒和杂草吸水根的重合率50．4％，非重合率49．6％；然而在127个吸水根非重合单元中，花椒吸水根仅占29．1％，杂草吸水根却占了70．9％。文中根据花椒和杂草地下空间生物量的分配现状，讨论了四川盆地丘陵区退耕还林地花椒模式更新中间作物选择、行间配置和水肥管理应注意的问题．The distribution pattern of underground biomass can be seen as a result of interspecific competition between specific species and intercrops in an agroforestry system, so it can be a determinant of species selection and system design. To achieve the rationality of intercrops selection and accessible breadth planting in a row in the model shifting of the Chinese prieklyash （Zanthoxylum bungenum）-weeds, the underground biomass distribution of this system throughout the soil profile was measured by a method of entrenchment. The main results showed＇that （i） the total underground biomass in the Chinese pricklyash and weeds system was 248.57g ·m^ -2, the amount of weeds and Chinese pricklyash occupied respectively 82% and 18% of the total underground biomass. （ii） The underground biomass of system and weeds presented an even distribution in horizontal sample space, but they were negative-exponentially distributed with the deepening of soil profile in vertical sample space, and exponential expressions of system and weeds were y = 1 024.6exp^ -0. 5254x （ R^2 = 0. 9688） and y = 1 187.2exp ^-0.6889x （ R^2 = 0. 9989 ）, respectively. The amount of Chinese pricklyash root biomass was even in the vertical distribution, however, negativeexponential in the horizontal distribution, and its formula was y = 118. 3exp^ -0.3871x （ R^2 = 0. 8215）. （iii） Fine root （ diameter 〈 = 1 mm） biomass of Chinese pricklyash was an even distribution in forest land, and the distribution of the fine root biomass of weeds presented clearly strata in vertical soil space. And 81.11% of total fine roots of weeds was distributed in 0 - 15 cm soil layer,and 18.89% of these was only gained in 15 cm -30 cm soil layer. （iv） The ratio of overlap of fine roots between Chinese prieklyash and weeds was 50. 4% , and the ratio of no-overlap of these was 49.6% in the 256 sampled plots, whose size was 500 cm^3. Furthermore, the number of the 127 no-overlap plots occupied alone by Chinese pricklyash fine roots was only 29.1%

关 键 词：农林复合系统 吸水根 生物量 分配格局 模式更新 

分 类 号：S451[农业科学—植物保护]