水保所知识产出(1956---)知识库

对黄土丘陵区微地形( 阳坡坡上、中、下部，坡顶，阴坡坡上、中、下部) 条件下草地植
物群落进行群落组成调查和地上、地下生物量测定，分析微地形对草地植物群落结构组成
和功能特征的影响． 结果表明: 研究区内草地植物群落主要由菊科、禾本科和豆科物种组
成．群落地上和地下生物量以及根系年生长量分别为164．12 g·m－2、1044．87 g·m－2、731．77
g·m－2·a－1 ．群落地上和地下生物量以及根系年生长量在不同坡向的大小均为: 阴坡＞阳坡＞
坡顶．在阴坡，群落生物量和根系年生长量的大小为: 坡下部＞坡中部＞坡上部＞坡顶部，阳坡群
落生物量在不同坡位的大小顺序与阴坡不同．根系生长主要集中在0 ～ 20 cm 土层，且从上到
下逐渐减小．根系周转率的平均值为0．75 a－1，在不同微地形条件下不同土层内大小不同．

In order to analyze the impact of micro-landform on grassland plant community structure
and function，species composition，aboveground and belowground biomass，and annual fine root
production at different slope aspects ( sunny slope and shady slope) and different slope positions
( top，upper，middle and lower) were investigated in the hilly Loess Plateau region． The results
showed that grassland communities were mainly composed of plants species belonging to Compositae，
Poaceae and Leguminosae． The aboveground and belowground biomass and annual fine root
production of community were 164．12 g·m－2，1044．87 g·m－2 and 731．77 g·m－2·a－1，respectively．
Aboveground biomass，belowground biomass and annual fine root production of community
were in the order of shady slope ＞ sunny slope ＞ top slope． In shady slope，the biomass of community
under different positions were in the order of lower ＞ middle ＞ upper ＞ top，but it exhibited different
orders in the sunny slope compared with shady slope． Fine root mainly concentrated in the 0－
20 cm top soil layer and decreased with soil depth． The average turnover time of root was 0．75 a－1
and changed with soil layers and micro-landform．