青藏高原典型植被土壤溶解性氮与植物量相关性分析

摘要

研究区域位于中国生态网络海北高寒草甸生态系统定位研究站,选取青藏高原典型植被禾草-矮嵩草草甸、小嵩草草甸和金露梅灌丛草甸,对其土壤速效无机氮(IN)/溶解性有机氮(DON)储量与植物量相关性进行分析,发现三种草地土壤IN储量同地上植物量具有正相关性,其中灌丛相关系数高于草甸；地带性植被(禾草-矮嵩草草甸)土壤IN储量同地上植物量之间的相关性高于其偏途演替阶段(小嵩草草甸)；土壤溶解性有机氮的消耗同地上植物量的形成具有一定程度的正相关性,其中小嵩草草甸和金露梅灌丛草甸达到中度相关水平,禾草-矮嵩草草甸为低度相关水平；地下根系现存量同IN/DON之间均没有明显的相关关系.说明土壤IN/DON对地上植物量的形成可能具有一定程度的贡献,如果这一论断成立,那么研究其对植物量形成的贡献形式及过程将成为亟待解决的问题.%Using chemical analysis to study the relationship between dissolved inorganic nitrogen/dissolved organic nitrogen and biomass in three typical plateau vegetations, which are Gramineae - Kobresia humilis meadow, Potentil-la fruticosa Shrub meadow and Kobresia pygmae meadow. The results showed that: there was a positive relationship between dissolved inorganic nitrogen formation and plant biomass aboveground, Shrub meadow had higher correlation coefficient than other ones, and the health grassland had stronger interaction than sub-health grassland. There was positive relationship between dissolved organic nitrogen consumption and plant biomass aboveground, and they were medium correlation coefficient in P. Fruticosa Shrub meadow and K. Pygmae meadow, while it was weaker correlation coefficient in G. K. Humilis meadow. There was no relationship between plant biomass below ground and dissolved inorganic or dissolved organic nitrogen. To sum up,dissolved organic nitrogen and inorganic nitrogen maybe have different contribution to plant biomass aboveground in different plant vegetations. But we don' t know what kinds of forms and processes of dissolved nitrogen playing in different meadows.