内蒙古草原不同植物种群土壤化学元素特征

Properties of Soil Chemical Elements from Different Plant Population in Inner Mongolia Steppe

对内蒙古温带典型草原冷蒿(Artemisia frigida)、星毛委陵菜(Potentilla acaulis)、羊草(Leymus chinensis)、木地肤(Kochia prostrata)和小叶锦鸡儿(Caragana microphylla)种群土壤无机氮、微生物量氮、全氮、有机碳、净氮矿化速率和pH等特性进行了系统研究。结果表明,不同植物种群土壤pH值和全N含量3个取样期均以羊草最高,其次为星毛委陵菜,小叶锦鸡儿种群最低。除冷蒿与木地肤种群间外,其他种群间土壤pH值和全N含量均达到显著性差异(P<0.05)。羊草种群土壤无机N含量最高,其次依次为冷蒿种群、小叶锦鸡儿种群、木地肤种群和星毛委陵菜种群。各植物种群间土壤无机N含量均达到了显著性差异(P<0.05)。不同植物种群土壤微生物量氮(MBN)3个取样期均以小叶锦鸡儿最高,其次依次为羊草种群、冷蒿种群、木地肤种群和星毛委陵菜种群,各种群间差异显著(P<0.05)。3个培养期均以羊草种群土壤净氮矿化速率最高,其次依次为冷蒿、星毛委陵菜、木地肤和小叶锦鸡儿,各种群间均达到了显著差异(P<0.05)。土壤净氮矿化速率与植物种群土壤pH、温度和C∶N分别存在显著的正相关和负相关关系(P<0.05)。3个取样期土壤有机碳含量均以小叶锦鸡儿种群最高,其次为羊草种群,星毛委陵菜种群最低。除冷蒿种群与木地肤种群间土壤有机碳含量差异不显著(P>0.05)外,其他各植物种群间土壤有机碳含量均达到了显著性差异(P<0.05)。这些变化特征说明,随着草地退化和灌丛化,土壤养分呈降低趋势,尤其是有效养分变化更加明显。

In Inner Mongolia steppe, the paper studied the properties of soil chemical elements from several main plant populations, the results indicated that soil pH and total nitrogen content of Leymus chinensis population is the highest among different plant populations, and then Potentilla acaulis population, Caragana microphylla population is the lowest. Except between Artemisia frigida and Kochia prostrata populations, there are significant differences （ P〈0.05 ） between other plant populations. Soil inorganic nitrogen content of Leymus chinensis population is the highest, and then Artemisia frigida, Caragana microphylla, Kochia prostrata and Potentilla acaulis populations respectively. Soll inorganic nitrogen content has significant differences（P 〈 0.05）between all the different plant population populations. Soil microbial biomass nitrogen of Caragana microphylla population is the highest, and then Leymus chinensis, Artemisiafrigida, Kochia prostrate1 and Potentilla acaulis populations respectively. Soil microbial biomass nitrogen has significant differences （P 〈 0.05） between all the different plant populations. Soil net N mineralization rate of Leymus chinensis population is the highest of different plant populations,and then artemisia frigida, Potentilla acaulis, Kochia prostrata and Caragana microphylla populations respectively, and there are significant differences（ P 〈 0.05）between all the different plant populations. There are significant（P〈0.05）positive correlativity between soil net N mineralization rate and soil pH and temperature,and significant （P〈0.05） negative correlativity between soil net N mineralization rate and soil C ： N. Soil organic carbon content of Caragana microphylla population is the highest, and then Leymus chinensis population, and Potentilla acaulis population is the lowest. Except between Artemisia frigida and Kochia prostrata populations, there are significant differences（ P〈0.05） between other plant populations.