水保所知识产出(1956---)知识库

以黄土高原延河流域森林、森林草原和草原3 个植被区的4 种典型草本植物达乌里
胡枝子、长芒草、铁杆蒿、茭蒿的叶片和枯落物为对象，测定叶片和枯落物中碳( C) 、氮( N) 、磷
( P) 、钾( K) 含量及其比值，分析草本植物在该区域的养分限制及再吸收规律．结果表明: 4 种
植物叶片N/P 均小于14，生长主要受氮元素含量限制; 除达乌里胡枝子外，其他3 种植物N、
P、K 的养分再吸收效率平均值分别为48．7%、32．5%、79．9%．茭蒿和铁杆蒿较高的N、P、K 养
分再吸收效率和叶片K 含量有助于其在水分竞争中占据优势．铁杆蒿枯落物的C /N 显著低于
长芒草和茭蒿的枯落物，因而更易分解和进行养分循环．这可能是铁杆蒿在3 个植被区分布广
泛的原因之一．

This study was conducted in the forest，forest-steppe and steppe vegetation zones along
the Yanhe Ｒiver Basin，where the leaf and litter samples from four dominant herbaceous plants including
Lespedeza davurica，Stipa bungeana，Artemisia sacrorum，Artemisia giraldii were taken． By
measuring the concentrations of carbon ( C) ，nitrogen ( N) ，phosphorus ( P) and potassium ( K) ，
we measured the concentrations and their ratios to explore the limit and resorption of nutrient in the
herbaceous plants． The results showed that the leaf N/P of four herbaceous plants was all lower than
14，suggesting their growth was mainly limited by N content． Except for L． davurica，the mean nutrient
resorption efficiency of K，N and P in the other three plants was 79．9%，48．7% and 32．5%，
respectively． The higher nutrient resorption efficiency and K concentration in the leaf were beneficial
for soil water competition of A． sacrorum and A． giraldii． The litter C /N in A． sacrorum was significantly
lower than that in S． bungeana and A． giraldii，which was easy to decompose to benefit the
nutrient recycling． This resulted in the wide distribution of A． sacrorum in the three vegetation areas．